1,983 results on '"Fibres"'
Search Results
2. The use and disappearance of vegetal fibres in clay–sand mixtures in furnace walls in pre-seventeenth-century iron smelting sites in the Chūgoku region (Japan)
- Author
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Michel-Tanaka, Xavier
- Published
- 2023
- Full Text
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3. Assessing feasibility of peanut shell powder/linear low-density polyethylene for rotational moulding process.
- Author
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Khanna, Prashant and Ramkumar, P L
- Abstract
A polymer processing method called rotational moulding is utilised to make hollow things without tension. Despite being the resin matrix of choice for rotational moulding, linear low-density polyethylene (LLDPE) performs only moderately in areas where sturdiness is required. In order to maintain the necessary strength, fibres might fill the gap. A variety of testing methods, including FTIR, particle size distribution, bulk density, MFI, DSC, and TGA, were used to support the requirement of processability for rotational moulding in the current study. Peanut shell powder (PSP) was combined with the LLDPE at amounts varying from 2 to 20%. The importance of both materials’ peaks can be seen in FTIR results, which suggested a range of 8% to 18% PSP in LLDPE. Particle size distribution and Bulk density measurement indicated that blends above 14% PSP are not recommended for rotational moulding. Based on MFI data, it was determined that PSP blends of 14% and above have values lower than 3 g/10min which is not suitable in terms of sufficient flow ability in rotational moulding. The inclusion of PSP was found to increase the blend’s crystallinity by 6.6% for 12% PSP blend. As per DSC and TGA data, adding peanut shell powder to LLDPE does not significantly alter the processing temperature range as compared to neat LLDPE, making rotational moulding appropriate for blends containing 8% to 12% PSP. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Hardwoods: Anatomy and Functionality of Their Elements—A Short Review.
- Author
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Esteban, Luis G., de Palacios, Paloma, Gasson, Peter, García-Iruela, Alberto, García-Fernández, Francisco, and García-Esteban, Lydia
- Subjects
COMPARATIVE anatomy ,WOOD ,HARDWOODS ,RESEARCH personnel ,ANATOMY - Abstract
Hardwoods are complex heterogeneous and orthotropic structures that have evolved to the present day, adapting to successive climate episodes to prosper on Earth. Attributing a specific functionality to individual hardwood elements is difficult because of their interconnection in this heterogeneous three-dimensional network. However, tree physiology research is helping to enhance knowledge in this field. This work is a short review of the possible functionalities of hardwood elements, in some cases supported by experimentation and in others by comparative anatomy. It is intended for students or researchers starting out in the world of hardwood anatomy to aid their understanding of the functionality of hardwood elements. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
5. Hybrid fibre-reinforced cementitious composites with short polyethylene and continue carbon fibres: Influence of roving impregnation on tensile and cracking behaviour
- Author
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Cesare Signorini, Ameer H. Ahmed, Marco Liebscher, Jitong Zhao, Thomas Köberle, and Viktor Mechtcherine
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Mineral-bonded composites ,Mineral impregnation ,Fibres ,Carbon textile ,LC3 ,Bond behaviour ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Hybrid externally-bonded reinforcements are considered a viable technique for strengthening existing concrete structures. They combine high-performance impregnated textiles with matrices containing dispersed microfibres to foster the ductility and toughness of the composite system. In this paper, the mechanical performance of textile-reinforced strain-hardening cement-based composites (TR-SHCC) is investigated in detail. A novel high-performance inorganic binder based on limestone calcined clay cement (LC3) is reinforced with both polyethylene (PE) dispersed microfibres and carbon fibre (CF) textiles as continuous biaxial reinforcement. The CF yarns are impregnated by an automated process to improve the monolithic response under uniaxial tensile loading and to ensure high production consistency. Fully inorganic suspensions, i.e., geopolymer and cement-based, are being investigated, as they can provide superior thermal stability compared to traditional polymeric impregnating agents. Interphase adhesion is investigated by single-yarn pull-out tests, microscopy and µCT at various micro scales. On the one hand, the improved adhesion promoted by cement impregnation resulted in the finest and most diffuse crack pattern. Conversely, the strength of the overall composite is mainly governed by the tensile failure of the yarns, irrespective of the bond, and dispersed fibres consistently improve the post-cracking stage and the strength of the hybrid composites.
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- 2024
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6. Evaluating physico-mechanical properties of NaOH-treated natural fibres: Effects of polyolefin
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Md Zillur Rahman, Md Abdul Hannan, Mohammad Zahirul Islam Mollah, Mohammad Bellal Hoque, Khulud Saad Al-mugren, and Mohammad Rashed Iqbal Faruque
- Subjects
Polypropylene ,Fibres ,Physicomechanical properties ,Degradation ,Water uptake ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
The bottle gourd plant fibres (BGPF) and okra fibres were processed and refined (w/w 6 % NaOH) before being incorporated with polyolefin (polypropylene) for composite fabrication using a blending technique. The polyolefin matrix is used to develop composites with 5 % okra fibres and varying percentages (25, 30, 35 and 40 %) of BGPF. The results indicated that the ''35 % BGPF +5 % okra +60 % polypropylene'' composition achieved remarkable mechanical properties with tensile strength (26.95 MPa), tensile modulus (3.16 GPa), decreased elongation at break (1.71 %), bending strength (52.53 MPa), bending modulus (3.45 GPa), impact strength (14.25 kJ/m2), and hardness (69 D-shore). Moreover, these composites absorbed minimal water when a specific portion was submerged. The scanning electron microscopy (SEM) test on the composites revealed good fibre adhesion and adherence content between BGPF and okra fibres. Additionally, the thermo-gravimetric analysis and differential scanning calorimetry exhibited weight loss of composites during maximum cellulose degradation (80 %) at 483 °C. In the composites of the fibre-PP matrix, two distinct physical changes were observed indicating glass transition and degradation. However, the mechanical properties decreased after soil degradation. Thus, remarkable properties were achieved for the fibres-fibres and fibres-polyolefin (polypropylene) interfacial interactions.
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- 2024
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7. Recent Advances in Hygrothermal Aging of Plant Fiber Reinforced Composites
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Cai, Ming, Guo, Yaowei, Wang, Lamei, Ma, Qihua, Sun, Baozhong, and Waterhouse, Geoffrey I.N.
- Published
- 2024
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8. An INNOVative Approach for Mechanical Characterization of Coatings on Fibres
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Benzarti, M. and Henry, P.
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- 2024
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9. Experimental investigation of toughening carbon fibre/epoxy composites with graphene/phenoxy fibres
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Lin, Han, Sampson, William, and Potluri, Venkata
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Composites ,Toughening ,Fibres ,Polymer Nanocomposites ,Graphene - Abstract
This thesis reports a toughening concept for carbon fibre reinforced polymer composites using continuous thermoplastic nanocomposite fibres in which dissolvable phenoxy was used as a toughener for the epoxy matrix and at the same time as a carrier to deliver graphite nanoplatelets (GNP) into desired positions of composites. Nanocomposites containing different GNP contents were prepared via masterbatch dilution method, and these were melt spun and drawn into fibres at varying take-up speeds. Structural characterisation revealed that the dispersion of GNP worsened with both increasing GNP content and take-up speed, especially in the fibre core region. Moreover, due to the strong shear stress exerted by the spinneret wall, GNP in the outer layer of the fibre showed a tangential orientation, which was absent in the fibre centre. As a consequence, the Young's modulus, which is a low-strain property, increased with both GNP content and take-up speed, while the tensile strength remained relatively unchanged because it was more sensitive to the GNP agglomeration. Theoretical analysis with simple rule of mixtures and shear-lag theory suggested the enhanced Young's modulus originated from the increased orientation degree (η₀) of GNP at high take-up speeds, which was not attainable from SEM/TEM characterisation. Moreover, the η₀ was found to be in good agreement with the normalised areal ratio (ratio of the area of the imaginary fibre sheath layer to the whole cross-sectional area) of fibres at each take-up speed, which could indicate the variation in the reinforcing efficiency of GNP in the fibre core and sheath layer due to the different dispersion qualities of GNP in these two regions. The electrical percolation threshold was 8.0 wt% for compression moulded plates, which was relatively lower than the rheological one (8.8 wt%) due to the fact that less GNP was required to form a conductive network that can be detected by the static electrical measurements. Conversely, fibres with the same GNP content were not conductive because of the orientation, separation and aggregation of GNP upon drawing. The dissolution behaviour of pure phenoxy and GNP/phenoxy fibres was studied in model systems using optical microscopy. Results showed that GNP/phenoxy nanocomposite fibres took longer than pure phenoxy fibres to completely dissolve, probably because the tangentially oriented GNP in the outer layer of the fibre hindered the interdiffusion of phenoxy chains and RTM6-2 precursors. The dissolution study also suggested that too high a dissolution temperature could lead to a premature gelation of the epoxy resin and that thinner fibres were preferred for use in composites. As a proof of concept, GNP/phenoxy fibres were 3D braided with carbon fibre (CF) to produce hybrid strands, followed by resin infusion to prepare composite laminates. Both phenoxy and GNP improved the Mode I interlaminar fracture toughness (GIc) of composites although phenoxy exhibited a more pronounced toughening effect. This was attributed mainly to the significantly intensified CF breakage and pullout in regions where pure phenoxy or GNP/phenoxy fibres initially located, as evidenced by the SEM observation on the fracture surfaces of composites. Crack deflection induced by the phase-inverted RTM6-2 nodules in the presence of relatively high local concentration of phenoxy, crack pinning caused by GNP and GNP pullout/separation were also proposed as the toughening mechanisms.
- Published
- 2023
10. Effectiveness of the Concrete Equivalent Mortar Method for the Prediction of Fresh and Hardened Properties of Concrete.
- Author
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Ibrahim, Haruna, Wardeh, George, Fares, Hanaa, and Ghorbel, Elhem
- Subjects
MORTAR ,DIGITAL image correlation ,NON-monogamous relationships ,CONCRETE ,CONCRETE mixing ,FLY ash - Abstract
Modern concrete mix design is a complex process involving superplasticisers, fine powders, and fibres, requiring time and energy due to the high number of trial tests needed to achieve rheological properties in the fresh state. Concrete batching involves the extensive use of materials, time, and the testing of chemical admixtures, with various methodologies proposed. Therefore, in some instances, the required design properties (physical and mechanical) are not achieved, leading to the loss of resources. The concrete equivalent mortar (CEM) method was introduced to anticipate concrete behaviour at fresh and hardened states. Moreover, the CEM method saves time and costs by replacing coarse aggregates with an equivalent sand mass, resulting in an equivalent specific surface area at the mortar scale. This study aims to evaluate the performance of fibre in CEM and concrete and determine the relationships between the CEM and the concrete in fresh and hardened states. Steel and polypropylene fibres were used to design three series of mixtures (CEM and concrete): normal-strength concrete (NSC), high-strength concrete (HSC), high-strength concrete with fly ash (HSCFA), and equivalent normal-strength mortar (NSM), high-strength mortar (HSM), and high-strength mortar with fly ash (HSMFA). This study used three-point bending tests and digital image correlation to evaluate load and crack mouth opening displacement (CMOD) curves. An analytical mode I crack propagation model was developed using a tri-linear stress–crack opening relationship. Post-cracking parameters were optimised using inverse analysis and compared to actual MC2010 characteristic values. The concrete slump is approximately half of the CEM flow; its compressive strength ranges between 78% and 82% of CEM strength, while its flexural strength is 60% of CEM strength. The post-cracking behaviour showed a significant difference attributed to the presence of aggregates in concrete. The fracture energy of concrete is 28.6% of the CEM fracture energy, while the critical crack opening of the concrete is 60% of that of the CEM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. A 6-week randomized-controlled field study: effect of isokinetic eccentric resistance training on strength, flexibility and muscle structure of the shoulder external rotators in male junior handball players.
- Author
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Vetter, Sebastian, Witt, Maren, Hepp, Pierre, Schleichardt, Axel, Schleifenbaum, Stefan, Roth, Christian, Denecke, Timm, Henkelmann, Jeanette, and Köhler, Hans-Peter
- Subjects
SHOULDER exercises ,ISOKINETIC exercise ,SHOULDER ,KNEE muscles ,RESISTANCE training ,STRENGTH training ,HANDBALL players ,INDUCTIVE effect ,DIFFUSION tensor imaging - Abstract
Background: Team handball involves a tremendous amount of shoulder motion with high forces during repeated extended external range of motion. This causes shoulder complaints and overuse injuries. While eccentric training for the lower extremity shows preventive effects by improving strength, range of motion and fascicle length, there is a research gap for the shoulder joint and for advanced tissue characterization using diffusion tensor imaging. Objectives: To investigate the effects of 6-week eccentric isokinetic resistance training on strength, flexibility, and fiber architecture characteristics of the external rotators compared to an active control group in junior male handball players. Methods: 15 subjects were randomly assigned to the eccentric training group and 14 subjects to the active control group (conventional preventive training). Primary outcome measures were eccentric and concentric isokinetic strength of the external rotators, range of motion, and muscle fascicle length and fascicle volume. Results: The intervention group, showed significant changes in eccentric strength (+15%). The supraspinatus and infraspinatus muscles showed significant increases in fascicle length (+13% and +8%), and in fractional anisotropy (+9% and +6%), which were significantly different from the control group. Conclusion: Eccentric isokinetic training has a significant effect on the function and macroscopic structure of the shoulder external rotators in male junior handball players. While strength parameters and muscle structure improved, range of motion did not change. This research helps understanding the physiology of muscle and the role of eccentric training on shoulder function and muscle structure. Furthermore, DTI was found to be a promising tool for advanced tissue characterization, and the in vivo derived data can also serve as model input variables and as a possibility to extend existing ex-vivo muscle models. Future research is needed for functional and structural changes following convenient eccentric field exercises. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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12. CELL-FUNCTION TRADE-OFFS IN STEMS AND ROOTS OF ENTANDROPHRAGMA ANGOLENSE (WELW.) C. DC AND ENTANDROPHRAGMA CYLINDRICUM (SPRAGUE).
- Author
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ADENIYI, Ifedayo Michael, AJAYI, Babatunde, and OLANIRAN, S. Oluyinka
- Subjects
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ACETIC acid , *WOOD , *MICROSCOPES , *HYDROGEN peroxide , *STATISTICAL software - Abstract
Anatomical features that underlie tree functions in E. angolense and E. cylindricum were investigated in this study. Mechanical, hydraulic and storage functions, including their presumed dominance in either stem and root region were also stated. This study was carried out at Forestry Research Institute of Nigeria (FRIN), Jericho hills, Ibadan. Stem and root wood cores were obtained by non-destructive sampling from tree stem at breast height of 1.35m, while root samples were obtained from the lateral root of each mature tree at a radius of about 100cm to the trunk. Sectioning of sample materials was performed using a Reichert microtome sliding machine. Maceration was done by preparing wood samples into slivers in equal volume of glacial acetic acid (ethanoic acid) and hydrogen peroxide (1:1) in two hours (2hrs) at a temperature of 100°C. Microscopic investigations and measurements of wood cells were performed using a Zeis light microscope (Standard 25), and all data analyses were completed using R statistical software (R Core Team 2016). Results showed average values of vessel parameters, fibre parameters were higher at the stem region than at the root region in both wood species, while ray dimensions were higher at the root regions than at the stem regions of the two species. This suggested that the two wood species would rather trade off mechanical and hydraulic functions for storage function at the root region in order to be efficient in water conduction as large vessels will bring about embolism. Therefore, vessels were wider in the stem regions than in the root regions of the two wood species; rays were also wider in the root than in the stem, hence, this study revealed that storage functions could be dominance in the root region rather than the stem region of both E. angolense and E. cylindricum. [ABSTRACT FROM AUTHOR]
- Published
- 2024
13. Local and Systemic Effects of Bioactive Food Ingredients: Is There a Role for Functional Foods to Prime the Gut for Resilience?
- Author
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Jacquier, Emma F., van de Wouw, Marcel, Nekrasov, Elena, Contractor, Nikhat, Kassis, Amira, and Marcu, Diana
- Subjects
PREBIOTICS ,GUT microbiome ,FUNCTIONAL foods ,WELL-being ,BIOACTIVE compounds ,HORMESIS ,PROBIOTICS - Abstract
Scientific advancements in understanding the impact of bioactive components in foods on the gut microbiota and wider physiology create opportunities for designing targeted functional foods. The selection of bioactive ingredients with potential local or systemic effects holds promise for influencing overall well-being. An abundance of studies demonstrate that gut microbiota show compositional changes that correlate age and disease. However, navigating this field, especially for non-experts, remains challenging, given the abundance of bioactive ingredients with varying levels of scientific substantiation. This narrative review addresses the current knowledge on the potential impact of the gut microbiota on host health, emphasizing gut microbiota resilience. It explores evidence related to the extensive gut health benefits of popular dietary components and bioactive ingredients, such as phytochemicals, fermented greens, fibres, prebiotics, probiotics, and postbiotics. Importantly, this review distinguishes between the potential local and systemic effects of both popular and emerging ingredients. Additionally, it highlights how dietary hormesis promotes gut microbiota resilience, fostering better adaptation to stress—a hallmark of health. By integrating examples of bioactives, this review provides insights to guide the design of evidence-based functional foods aimed at priming the gut for resilience. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. Nutritionally Valuable Components and Heat-Induced Contaminants in Extruded Snack Products Enriched with Defatted Press Cakes.
- Author
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Jozinović, Antun, Panak Balentić, Jelena, Ačkar, Đurđica, Benšić, Mirta, Babić, Jurislav, Barišić, Veronika, Lončarić, Ante, Miličević, Borislav, and Šubarić, Drago
- Subjects
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CAKE , *POLLUTANTS , *MICROWAVE ovens , *SNACK foods , *PRODUCT improvement , *OILSEEDS - Abstract
This research studies the influence of the addition of defatted press cakes (from the production of hazelnut, camelina, pumpkin, and hemp seed oil) on nutritionally important components: fibre, resistant starch, polyphenols, hydroxymethylfurfural (HMF), and acrylamide in directly and indirectly expanded snacks. The amounts of press cakes added to corn grits were 3, 6, and 9%. Extrusion was carried out in a laboratory single-screw extruder. For indirectly expanded products (SCFX), supercritical CO2 was injected during extrusion, and secondary expansion was completed in the microwave oven. The type and content of press cake, as well as the type of product, significantly influenced total polyphenol content and antioxidant activity. Press cakes increased the contents of both soluble and insoluble fibre (from 1.94% d. m. and 1.28% d. m. for extrudates without press cakes up to 3.17% d. m. and 6.94% d. m. for SCFX extrudates with press cakes, respectively), and resistant starch was not markedly influenced by their addition. The influence of the content of press cake on HMF was not significant, whereas the type of cake and the type of extrusion influenced HMF significantly. In a raw mixture of corn grits with 3% of pumpkin press cake, HMF was below the limit of detection, and the highest content was found in the classically extruded sample with the addition of 9% of camelina press cake (580 ppb). In all samples, the acrylamide content was below the limit of detection, indicating that safe products were obtained. This research shows potential for the implementation of supercritical CO2 extrusion in the production of safe, nutritionally improved snack products. Future research might bring about the design of cost-effective processes applicable in the industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Nutritional impact of no-added sugar fruit puree consumption at different eating occasions: a modelling study on French children.
- Author
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Poinsot, Romane, Richonnet, Céline, and Vieux, Florent
- Subjects
- *
FRENCH people , *VITAMIN A , *NUTRITIONAL requirements , *AGE groups , *NUTRITIONAL status - Abstract
Objective: The recommended level of five fruits and vegetables per day is reached by a minority of French children. No-added sugars fruit puree (NASFP) can be consumed as a complement of fresh fruit to meet the recommendation for fruits and vegetables. The objective was to simulate the nutritional impact of an increase in consumption of NASFP among French children, together with a reduction in sweetened foods. Design: The study was conducted on French children aged 1–17 years. The simulation consisted in introducing NASFP on four different eating occasions (breakfast, lunch, snack and dinner) to reach one serving and removing the same serving of sweetened foods. Intakes in nutrients to favour, nutrients to limit and prevalence of adequacy to nutritional requirements were compared between observed and simulated diets in the whole sample and in five different age groups. Setting: France. Participants: Children from 1 to 17 years of age in the last available French representative dietary survey (INCA3). Results: Simulated diets were more nutrient-dense thanks to increases in nutrients to favour from NASFP (especially fibres, iodine, Se, and vitamin A and C) associated with reductions in energy and nutrients to limit (especially free sugars) coming from sweetened foods. Prevalence of adequacy increased from 2 to 14·5 points for fibres and from 4·5 to 12 points for free sugars according to age group and eating occasion. Conclusion: Promoting NASFP in replacement of sweetened products is a promising strategy to improve the nutritional quality of French children's diet through a better adherence to national guidelines. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Fibrous microstructure and biomechanics of healthy and diseased aortic tissues
- Author
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Luo, Tao and Sutcliffe, Michael
- Subjects
Aorta ,Cardiovascular diseases ,Collagen ,Elastin ,Fibres ,Mechanical property - Abstract
Typical cardiovascular diseases are mostly asymptomatic until fatal consequences are caused. Patient-specific simulations have the potential to guide clinical diagnosis but are impeded by the missing patient-specific material properties. To close this gap, this dissertation explored the role of the two most significant loading components, collagen and elastin, in defining mechanical responses of artery walls. These associations are crucial for understanding the mechanical remodelling of diseased tissues and the potential failure mechanisms implicated. These aims are achieved through experiments and numerical approaches. Firstly, collagen and elastin fibre parameters of human aortic dissection flaps were extracted from histology slides. Their material properties and relationships with fibrous parameters were also studied. Secondly, a computational framework based on the unsupervised deep learning UNet model was proposed to characterise the heterogeneity of vessels. Lastly, a simulation framework was developed and used for parameter studies to estimate artery material performances according to a few critical collagen fibre parameters. The results demonstrated that fibre dispersion and waviness in the aortic dissection flap changed with patient age and clinical presentations, and these changes can be captured by the material constants in the strain energy density function. Additionally, high material heterogeneity was characterised by the localised strain maps and simulations. Strain maps of axial strips demonstrated a zebra pattern with vertical high strain concentrations due to fibre configurations when subjected to uniaxial tensile tests. Furthermore, based on the fibrous parameters obtained in the preceding study, the proposed simulation method predicted strain-stress curves that fit well with experiments. Parameter studies using this methodology proved that the fibre recruitment efficiency dictates tissue mechanical performances and largely depends on the primary fibre orientation regarding the loading direction. In addition, collagen fibre waviness determines the starting point of nonlinearity in the strain-stress responses of arteries. In summary, the remodelling of collagen and elastin fibres within artery walls can explain the clinical observations and is mechanically significant in predicting the adjustments of material performances.
- Published
- 2022
- Full Text
- View/download PDF
17. Forecasting residual mechanical properties of hybrid fibre-reinforced self-compacting concrete (HFR-SCC) exposed to elevated temperatures
- Author
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Waleed Bin Inqiad, Elena Valentina Dumitrascu, and Robert Alexandru Dobre
- Subjects
Residual compressive strength ,Flexural strength ,Fibres ,Gene expression programming ,Fly ash ,Slag ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
The use of hybrid fibre-reinforced Self-compacting concrete (HFR-SCC) has escalated recently due to its significant advantages in contrast to normal concrete such as increased ductility, crack resistance, and eliminating the need for compaction etc. The process of determining residual strength properties of HFR-SCC after a fire event requires rigorous experimental work and extensive resources. Thus, this study presents a novel approach to develop equations for reliable prediction of compressive strength (cs) and flexural strength (fs) of HFR-SCC using gene expression programming (GEP) algorithm. The models were developed using data obtained from internationally published literature having eight inputs including water-cement ratio, temperature, fibre content etc. and two output parameters i.e., cs and fs. Also, different statistical error metrices like mean absolute error (MAE), coefficient of determination (R2) and objective function (OF) etc. were employed to assess the accuracy of developed equations. The error evaluation and external validation both approved the suitability of developed models to predict residual strengths. Also, sensitivity analysis was performed on the equations which revealed that temperature, water-cement ratio, and superplasticizer are some of the main contributors to predict residual compressive and flexural strength.
- Published
- 2024
- Full Text
- View/download PDF
18. Transfert de masse non-stationnaire depuis des particules sous écoulement
- Author
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Bielinski, Clément and Kaoui, Badr
- Subjects
transfert de masse ,écoulement ,convection forcée ,capsules ,fibres ,membranes ,perméabilité ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Mass transfer from particles is encountered in many biomedical applications. In operating conditions, particles are subjected to flows whose effect on solute transport is still not well understood. In this article we consider mass transfer from core-shell capsules and fibers subjected to various flow conditions. The combined effects of the flow and the shell permeability on the mass transfer efficiency are analyzed and quantified by correlations for the Sherwood number (the dimensionless mass transfer coefficient). The permeability is found to significantly affect the mass transfer efficiency, but it is a hardly measurable quantity. A new characterization method is proposed and validated using experimental data. All the obtained results can be applied to heat transfer from or to particles subjected to flow.
- Published
- 2023
- Full Text
- View/download PDF
19. Changes in the production materials of Burmese textiles in the nineteenth century—dyes, mordants and fibres of Karen garments from the British Museum’s collection
- Author
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Diego Tamburini, Joanne Dyer, Caroline Cartwright, and Alexandra Green
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Karen ,Myanmar ,Burmese textiles ,Dyes ,Fibres ,Mordants ,Fine Arts ,Analytical chemistry ,QD71-142 - Abstract
Abstract The materials of six Karen textiles from the British Museum’s collection were investigated with the main aim of studying the production changes over the course of the nineteenth century and how these changes related to local and colonial trade networks. The textiles span chronologically from the 1830s to the early 1900s according to their attribution dates, and include traditional garments such as tunics and skirts, in addition to representing a broad colour palette and different dyeing and weaving techniques. The investigation was conducted non-invasively by using digital microscopy, broadband multispectral imaging (MSI) and fibre optic reflectance spectroscopy (FORS). The results guided a sampling campaign during which samples were taken and investigated by optical microscopy (OM), scanning electron microscopy energy dispersive X-ray spectrometry (SEM–EDX) and high-performance liquid chromatography coupled to diode array detector and tandem mass spectrometry (HPLC–DAD-MS/MS). Local natural dyes, such as red and yellow from Morinda citrifolia, lac dye (Kerria lacca), gamboge (Garcinia sp.), turmeric (Curcuma longa), indigo and tannins were found in the older textiles, supporting a possible early production, whereas mixtures of natural and synthetic dyes, including synthetic alizarin (CI 58000), rhodamine B (CI 45170), orange I (CI 14600), diamond green B (CI 42000), diamond green G (CI 42040), auramine O (CI 41000), naphthol yellow S (CI 10316), chrysamine G (CI 22250), crystal violet (CI 42555) and Pigment Red 53:1 (CI 15585:1) were identified in the later textiles. Observations on mordants revealed the use of aluminium, tin and chrome, whereas fibre characterisation highlighted the use not only of cotton (Gossypium sp.) but also of felted wool imported from Europe and Chinese silk dyed with the Chinese cork tree (Phellodendron chinense) yellow dye. The results draw an interesting picture of the introduction of new dyeing materials and techniques in Myanmar over the nineteenth century, and how these impacted the production of traditional Karen textiles.
- Published
- 2023
- Full Text
- View/download PDF
20. Designing out microplastic pollution released from textiles and apparel during laundering
- Author
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Elisabeth Allen, Claudia E. Henninger, Jane Wood, Arthur Garforth, and Edidiong Asuquo
- Subjects
microplastics ,fibres ,synthetic textiles ,laundry ,pollution ,design ,textile production ,Environmental sciences ,GE1-350 ,Environmental technology. Sanitary engineering ,TD1-1066 - Abstract
The washing of synthetic materials has been named as the largest contributor of microplastic pollution to our oceans. With the consumption of petrochemical-based synthetic materials expected to grow, due to an increased demand, the release of microplastic fibres to our environments is expected to also accelerate. To combat microplastic fibre release, this study explores source-directed interventions within the design and manufacturing process of textiles to reduce the amount of pollution released from the surface and the edges of the fabric structure. Using standardised wash tests and polyester fabric swatches that were created in-house with systematic structural adjustments, single jersey knit fabrics were shown to release over three times more microplastic pollution than twill woven fabric. This illustrates that increasing the tightness of a fabric could be implemented within the design of fabrics for environmental benefits. Additionally, the laser cutting technique reduced microplastic fibres released by over a third compared to scissor cutting and overlock serging, showing that the edge of the fabric is a significant source of microplastic pollution released during laundering. This research highlights the adaptable and innovative eco-design approaches to clothing production which is necessary to help the sector reach international sustainability targets and regulations.
- Published
- 2024
- Full Text
- View/download PDF
21. Nutritional impact of no-added sugar fruit puree consumption at different eating occasions: a modelling study on French children
- Author
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Romane Poinsot, Céline Richonnet, and Florent Vieux
- Subjects
Fruit puree ,Children ,INCA3 ,Substitution ,Fibres ,Free sugars ,Public aspects of medicine ,RA1-1270 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Abstract Objective: The recommended level of five fruits and vegetables per day is reached by a minority of French children. No-added sugars fruit puree (NASFP) can be consumed as a complement of fresh fruit to meet the recommendation for fruits and vegetables. The objective was to simulate the nutritional impact of an increase in consumption of NASFP among French children, together with a reduction in sweetened foods. Design: The study was conducted on French children aged 1–17 years. The simulation consisted in introducing NASFP on four different eating occasions (breakfast, lunch, snack and dinner) to reach one serving and removing the same serving of sweetened foods. Intakes in nutrients to favour, nutrients to limit and prevalence of adequacy to nutritional requirements were compared between observed and simulated diets in the whole sample and in five different age groups. Setting: France. Participants: Children from 1 to 17 years of age in the last available French representative dietary survey (INCA3). Results: Simulated diets were more nutrient-dense thanks to increases in nutrients to favour from NASFP (especially fibres, iodine, Se, and vitamin A and C) associated with reductions in energy and nutrients to limit (especially free sugars) coming from sweetened foods. Prevalence of adequacy increased from 2 to 14·5 points for fibres and from 4·5 to 12 points for free sugars according to age group and eating occasion. Conclusion: Promoting NASFP in replacement of sweetened products is a promising strategy to improve the nutritional quality of French children’s diet through a better adherence to national guidelines.
- Published
- 2024
- Full Text
- View/download PDF
22. Blossoming Beauty: Enhancing Natural Fibres with Calendula Officinalis L. Flower Dye and Assessing Color Fastness with Microbial Properties.
- Author
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Mariselvam, R., Ranjitsingh, A.J.A., Mideen, Ponani Kaja, Manoharadas, Salim, Krishnamoorthy, Rajapandiyan, and Alshuniaber, Mohammad A
- Subjects
CALENDULA officinalis ,NATURAL fibers ,PINEAPPLE ,BANANAS ,FLOWERS ,FLOWERING of plants ,NATURAL dyes & dyeing - Abstract
Mordants are materials used to fix long periods of colour on selected fabrics or fibres. The current research aimed to dye natural fibres like palm leaf (Borassus flabellifer L.), korai grass (Cyperus pangorei L.), banana fibre (Musa accuminata L.), screw fine fibre (Pandanus), sisal fibre (Agave sisalana Perrine), and pineapple fibres (Ananas comosus L.) with Calendula officinalis plant flower dye. The dye was fixed to the selected fibre material with the help of different mordants. The Calendula officinalis flower dye produced different colours, like black, brown, orange, sandal, yellow, etc., on the dyed materials. The different colour formations on the dyed materials are based on the mordents used to fix the dye. The mordants tonify the different colours in the same dyestuff of Calendula officinalis flower dye. Mordant-based dyed natural fibres have good fastness properties against light and water. Calendula officinalis dyes have potential activity against the skin infection-causing organism Pseudomonas aeruginosa. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. Preparation of Bioactive Polyamide Fibres Modified with Acetanilide and Copper Sulphate.
- Author
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Biniaś, Dorota, Biniaś, Włodzimierz, Ślusarczyk, Czesław, and Machnicka, Alicja
- Subjects
- *
COPPER sulfate , *ACETANILIDE , *ACETANILIDES , *POLYAMIDES , *FOURIER transform infrared spectroscopy , *FIBERS - Abstract
This paper presents a simple method of obtaining polyamide 6 fibres modified with acetanilide and copper ions. During the spinning of the fibres with the additives applied, a partial reduction of CuSO4 to Cu2+ and Cu+ ions occurs, which is observed as a change in the blue colour of the prepared polyamide granulate to the grey–brown colour of the formed fibres. CuMPs obtained as a result of the salt reduction should give the obtained fibres bioactive properties. Three types of microorganisms were selected to assess the microbiological activity of the obtained fibres, i.e., Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Escherichia coli. The fibres have antibacterial activity against Gram-positive and Gram-negative bacteria. The largest inhibition zones were obtained for the Gram-positive bacteria Staphylococcus aureus, ranging from 1.5 to 4.5 mm, depending on the concentration of CuMPs. The morphology of the fibres' surfaces was examined by means of scanning electron microscopy (SEM) and optical microscopy (OM). The changes in the polymer structure chemistry are studied by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray structure studies (WAXS and SAXS) and an energy-dispersive spectroscopy (EDS) analysis. The newly obtained bioactive polyamide fibres can be used in many areas, including medicine, clothing and environmental protection for the production of filters. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Fibre interface molecular engineering for textile-based wearable electronics
- Author
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Zhu, Chuang, Liu, Xuqing, and Li, Yi
- Subjects
Sensors ,Electroless deposition ,Molecular engineering ,Fibres ,Wearable electronics - Abstract
Textile-based wearable electronics, as the next generation of wearable devices, have attracted considerable interest. Conductive fibres are the building blocks for developing these flexible and wearable devices. Electroless deposition (ELD) is a traditional method to deposit metal nanoparticles on different materials by autocatalytic chemical reduction of metal cations in a liquid bath. However, there are no catalytic sites on the fibre surface to initiate the ELD. To solve this problem, this research aims to coat polyphenols including dopamine, tannic acid and curcumin on the fibre surface via pi-pi stacking and then served as the platform to capture catalysts via cation-pi interaction for depositing metal nanoparticles on fibres. By introducing the polyphenols-assisted ELD, conductive yarns and fabrics were obtained and the resistance of Ni-coated cotton yarns reached 0. 05 ohm/cm. The fibre interface molecular engineering provided strong adhesion forces between the metal layer and the fibre surface, resulting in durable metal-coated yarns and fabrics. On the other hand, the surface morphology of metal deposits on fibres was controlled in nanoscale by adjusting the ELD time to yield the metal coatings with multilayers shape on fibre surface in which unfilled gaps between metal nanoparticles prevented the metal films from cracking under bending. In addition, the Kelvin structure model was proposed to illustrate the relationship between the conductivity and flexibility of metal-plated fabrics. As a result, the normalised resistance of Ni-deposited fabrics (20 min ELD) was only 1.6 after 1000 mechanical bending cycles (bending radius = 0.1 mm). To construct these metallised substrates into wearable sensors, the fibrous structure was utilised. Based on the change of fibre-to-fibre contacts in metal-coated yarns and 3D fibrous sponges under mechanical deformations, fibre-shaped wearable electronics including finger bending sensors, arm bending sensors, pressure sensors, touch sensors and human-machine interfaces for monitoring human motions were obtained by collecting different resistance values. The research indicated that polyphenols-assisted ELD can metallise other flexible substrates and extend the applications of conductive and flexible samples.
- Published
- 2021
25. Opportunities and Limitations in Recycling Fossil Polymers from Textiles
- Author
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Sabrina Bianchi, Flavia Bartoli, Cosimo Bruni, Cristina Fernandez-Avila, Laura Rodriguez-Turienzo, Jorge Mellado-Carretero, Daniele Spinelli, and Maria-Beatrice Coltelli
- Subjects
textile ,sorting ,mechanical recycling ,polyester ,acrylics ,fibres ,Chemical technology ,TP1-1185 ,Biochemistry ,QD415-436 - Abstract
The recovery and recycling of textile waste is becoming urgent since textiles are generating more and more waste. In one year, about 92 million tons of textile waste are produced and the fashion industry accounts for 58 million tons of plastic waste per year. Several different synthetic fibres are used in textiles, thanks to their excellent processability and mechanical properties, but on the other hand, the difficulties linked to their end of life and the release of microplastics from them during washing is currently a cause of great concern. In this context, policy actions have been aimed at promoting recycling of waste and replacing fossil-based fibres with biobased fibres. The current review, considering both scientific papers published on international journals and web sources, considers the sorting of textiles and the possible recycling of polyesters, polyamides and acrylics. Nevertheless, the contamination and presence of mixed fibres in fabrics is another issue to face for recycling. Methodologies to solve the issue linked to the presence of elastane, present in the stretch fabrics, as well as the possibility of recycling textiles in the non-woven and composite sector are investigated. Moreover, chemical recycling and enzymatic recycling of fossil polymers are also considered. Thanks to the comprehensive scheme of this review, it is possible to deduce that, while the use of biobased materials should rapidly increase in textile applications, the perspective of recycling materials obtained from waste textile into durable and/or high-performance products seems the most promising.
- Published
- 2023
- Full Text
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26. Effectiveness of the Concrete Equivalent Mortar Method for the Prediction of Fresh and Hardened Properties of Concrete
- Author
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Haruna Ibrahim, George Wardeh, Hanaa Fares, and Elhem Ghorbel
- Subjects
concrete ,concrete equivalent mortar ,fibres ,fracture properties ,digital image correlation ,fly ash ,Building construction ,TH1-9745 - Abstract
Modern concrete mix design is a complex process involving superplasticisers, fine powders, and fibres, requiring time and energy due to the high number of trial tests needed to achieve rheological properties in the fresh state. Concrete batching involves the extensive use of materials, time, and the testing of chemical admixtures, with various methodologies proposed. Therefore, in some instances, the required design properties (physical and mechanical) are not achieved, leading to the loss of resources. The concrete equivalent mortar (CEM) method was introduced to anticipate concrete behaviour at fresh and hardened states. Moreover, the CEM method saves time and costs by replacing coarse aggregates with an equivalent sand mass, resulting in an equivalent specific surface area at the mortar scale. This study aims to evaluate the performance of fibre in CEM and concrete and determine the relationships between the CEM and the concrete in fresh and hardened states. Steel and polypropylene fibres were used to design three series of mixtures (CEM and concrete): normal-strength concrete (NSC), high-strength concrete (HSC), high-strength concrete with fly ash (HSCFA), and equivalent normal-strength mortar (NSM), high-strength mortar (HSM), and high-strength mortar with fly ash (HSMFA). This study used three-point bending tests and digital image correlation to evaluate load and crack mouth opening displacement (CMOD) curves. An analytical mode I crack propagation model was developed using a tri-linear stress–crack opening relationship. Post-cracking parameters were optimised using inverse analysis and compared to actual MC2010 characteristic values. The concrete slump is approximately half of the CEM flow; its compressive strength ranges between 78% and 82% of CEM strength, while its flexural strength is 60% of CEM strength. The post-cracking behaviour showed a significant difference attributed to the presence of aggregates in concrete. The fracture energy of concrete is 28.6% of the CEM fracture energy, while the critical crack opening of the concrete is 60% of that of the CEM.
- Published
- 2024
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27. Influence of Fire Exposition of Fibre-Cement Boards on Their Microstructure.
- Author
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Schabowicz, Krzysztof, Gorzelańczyk, Tomasz, Zawiślak, Łukasz, and Chyliński, Filip
- Subjects
- *
FIRE exposure , *ENERGY dispersive X-ray spectroscopy , *SCANNING electron microscopes , *MICROSTRUCTURE , *CEMENT composites - Abstract
The diagnostics of materials, elements and structures after fire exposure are very complicated. Researchers carrying out such diagnostics encounter difficulties at the very beginning, e.g., how to map fire conditions. In this publication, the authors focused on the analysis of the fibre-cement composite used as facade cladding. The fibre-cement boards are construction products used in civil engineering. The fibre-cement boards are characterised by two phases: the matrix phase and the dispersed phase. The analysis of fibre-cement composite was performed using non-destructive methods. The use of non-destructive methods in the future will allow for the analysis of facades after fires without the need to obtain large elements, which will significantly reduce costs while increasing safety. The aim of the work was to determine internal changes in the microstructure of fibre-cement boards after exposure to fire. The degraded samples were compared with reference samples in the evaluation of the microstructure. An analysis was performed using a scanning electron microscope, images of backscattered electrons (BSE) and maps obtained using Energy Dispersive X-ray Spectroscopy (EDX), which allowed conclusions to be drawn. The observed changes were presented in the form of photos showing changes in the composition of the plates, and they were commented on. It should be noted that fire temperatures act destructively, and a number of changes can be observed in the microstructure. The results of the work indicate that, in the future, the use of non-destructive methods will make it possible to assess the degree of degradation of the façade after a fire. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Microplastics in Lampanyctus crocodilus (Risso 1810, Myctophidae), a Common Lanternfish Species from the Ibiza Channel (Western Mediterranean).
- Author
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Novillo-Sanjuan, Olga, Gallén, Sergio, Raga, Juan Antonio, and Tomás, Jesús
- Subjects
- *
PLASTIC marine debris , *MICROPLASTICS , *GASTROINTESTINAL system , *FOOD chains , *ANTHROPOGENIC effects on nature , *SPECIES - Abstract
Microplastics' presence in the pelagic environment is still largely unknown due to the difficulty of sampling in this part of the ocean. In this study, we quantify microplastics' exposure in a pelagic lanternfish species from the western Mediterranean, Lampanyctus crocodilus (Risso 1810), which occupies an intermediate position in the marine food web. L. crocodilus were captured in the Ibiza Channel by a trawling vessel and microplastics were extracted by digestion of their gastrointestinal systems. Almost half of the analysed lanternfish contained microplastics, mostly blue and black fibres (40.9% and 34.66%, respectively). In fishes with at least one microplastic, the median was 3 MPs/fish (CI 95% = 3.46–6.8), similar to other studies performed in other fish species in the area. Biometric parameters of fish, such as total length and body condition, were not correlated with the number of microplastics. Data presented here contribute to quantifying the severity of microplastic pollution in the pelagic environment and in a wild, non-commercial species. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Mechanical and Environmental Assessment of Lathe Waste as an Addiction to Concrete Compared to the Use of Commercial Fibres.
- Author
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Los Santos-Ortega, Jorge, Fraile-García, Esteban, Ferreiro-Cabello, Javier, and González-González, Carlos
- Subjects
- *
CONCRETE waste , *MILD steel , *GLASS fibers , *FIBERS , *LATHES , *WASTE products - Abstract
The use of fibres applied to concrete in order to improve its properties is widely known. Nowadays, research is not only focused on improving mechanical properties but also on the environmental implications. The aim of this research was a mechanical and environmental comparison between different types of fibres. For this purpose, commercial fibres of three materials were used: low carbon steel, modified polyolefins, and glass fibre. In order to improve the sustainability of the sector, we also analysed and compared the performance of using a waste product, such as fibres from machining operations on lathes. For the evaluation of the mechanical properties, compression and flexural tests were carried out. The results show that the use of low carbon steel fibres increases the flexural strength by 4.8%. At the environmental level, and in particular for impact categories such as the Global Warming Potential (GWP), lathe waste fibres prove to be the most suitable. For instance, compared to glass fibres, CO2 emissions are reduced by 14.39%. This is equivalent to a total of 38 kg CO2 emissions per m3 of reinforced concrete. In addition to avoiding the consumption of 482 MJ/m3 of fossil fuels, the results of the research indicate the feasibility of using waste fibres as a substitute for commercial fibres, contributing to an improved environmental balance without losing mechanical performance. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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30. Changes in the production materials of Burmese textiles in the nineteenth century—dyes, mordants and fibres of Karen garments from the British Museum's collection.
- Author
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Tamburini, Diego, Dyer, Joanne, Cartwright, Caroline, and Green, Alexandra
- Subjects
- *
MORDANTS , *NINETEENTH century , *COINCIDENCE , *TANDEM mass spectrometry , *MALACHITE green , *CHEMOTAXONOMY , *HIGH performance liquid chromatography , *FOOD aroma - Abstract
The materials of six Karen textiles from the British Museum's collection were investigated with the main aim of studying the production changes over the course of the nineteenth century and how these changes related to local and colonial trade networks. The textiles span chronologically from the 1830s to the early 1900s according to their attribution dates, and include traditional garments such as tunics and skirts, in addition to representing a broad colour palette and different dyeing and weaving techniques. The investigation was conducted non-invasively by using digital microscopy, broadband multispectral imaging (MSI) and fibre optic reflectance spectroscopy (FORS). The results guided a sampling campaign during which samples were taken and investigated by optical microscopy (OM), scanning electron microscopy energy dispersive X-ray spectrometry (SEM–EDX) and high-performance liquid chromatography coupled to diode array detector and tandem mass spectrometry (HPLC–DAD-MS/MS). Local natural dyes, such as red and yellow from Morinda citrifolia, lac dye (Kerria lacca), gamboge (Garcinia sp.), turmeric (Curcuma longa), indigo and tannins were found in the older textiles, supporting a possible early production, whereas mixtures of natural and synthetic dyes, including synthetic alizarin (CI 58000), rhodamine B (CI 45170), orange I (CI 14600), diamond green B (CI 42000), diamond green G (CI 42040), auramine O (CI 41000), naphthol yellow S (CI 10316), chrysamine G (CI 22250), crystal violet (CI 42555) and Pigment Red 53:1 (CI 15585:1) were identified in the later textiles. Observations on mordants revealed the use of aluminium, tin and chrome, whereas fibre characterisation highlighted the use not only of cotton (Gossypium sp.) but also of felted wool imported from Europe and Chinese silk dyed with the Chinese cork tree (Phellodendron chinense) yellow dye. The results draw an interesting picture of the introduction of new dyeing materials and techniques in Myanmar over the nineteenth century, and how these impacted the production of traditional Karen textiles. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Micro fading test for textile single yarns: a new methodology applied to the Reformation Tapestry to assess its sensitivity to light
- Author
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Giulia Vannucci, Salwa Joram, Anna Beselin, and Stefan Röhrs
- Subjects
MFT ,Micro-fading test ,Textiles ,Fibres ,Yarns ,Tapestry ,Fine Arts ,Analytical chemistry ,QD71-142 - Abstract
Abstract Tapestries and especially pile carpets can be challenging objects for assessing their photosensitivity by microfading: they are often made of relatively thick yarns resulting in a non-flat airy surface. For this reason, focusing the light on the object’s surface is difficult and the precision of the colour change measurement is hampered. In this study, an improved test methodology was developed to overcome the difficulties by analysing single yarns. The methodology consists in flattening the yarn between glass microscope slides tightly held together by means of 4 strong paired neodymium magnets. The results show that the newly-developed sample preparation together with the required instrumental adjustment allow to significantly reduce the standard deviation and variation coefficient which often characterize microfading measurements of textiles. The methodology for sample preparation is evaluated and had been applied to samples from the Reformation Tapestry dating to 1667 from the collection of the Museum Europäischer Kulturen (Museum of European Cultures) in Berlin.
- Published
- 2023
- Full Text
- View/download PDF
32. Decision-making Algorithm for Waste Recovery Options. Review on Textile Waste Derived Products
- Author
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Zandberga Anda, Kalnins Silvija Nora, and Gusca Julija
- Subjects
ahp ,circular economy ,clothing waste ,fibres ,multi-criteria analysis ,sustainability ,topsis ,waste recovered product ,Renewable energy sources ,TJ807-830 - Abstract
As the volume of textile waste steadily increases, mechanical, chemical and biological technologies for textile waste recovery are evolving. Also, the legal framework of the European Union has stated the commitments for promoting the recycling of textile waste in the Member States. So far, however, no decision-making algorithms have been developed for the selection of products recovered from textile waste. Within the present study, a hybrid multi-criteria decision-making algorithm for evaluating textile waste recovered products has been developed applying seven circular economic criteria – ‘Circular economy approach of the technology’, ‘Added-value potential of final product’, ‘Share of textile waste in total waste feedstock’, ‘Diversity of textile mix suitable for specific technology’, ‘Pre-treatment of waste feedstock’, ‘Recovery potential’ and ‘Maturity of a recovery technology’. The weighting of the criteria was determined by eight waste management experts. The results of the expert-based criteria evaluation show that the most important criteria are ‘Added-value potential of final product’ and ‘Circular economy approach of the technology’. The developed decision-making methodology has been adapted to nine textile waste recovered products – compost, refuse-derived fuel, ethanol, glucose, building insulation material from cement and textile waste mix, building insulation material from denim textile waste, terephthalic acid, recovered cotton and recovered polyester. The multi-criteria, decision-making ranking of the products textile shows that the highest potential for products recovered from textile waste is for glucose and terephthalic acid, while the lowest – for ethanol, compost and refuse-derived fuel.
- Published
- 2023
- Full Text
- View/download PDF
33. Trends on Reinforced Polymer Composites – A Review
- Author
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Tamara APARECI (GÎRNEȚ), Irina DĂNĂILĂ (ȚÎCĂU), Iulian PĂDURARU, Adrian CÎRCIUMARU, and Mihaela-Claudia GOROVEI
- Subjects
polymer ,fibres ,composites ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In recent years, the interest in using fiber reinforced composites (FRC) has increased due to their potential to replace traditional materials in various applications. The advantages of polymer composites from natural fibres are: biodegradability, high performance, market availability and low price. This article is based on a review that discusses both polymer composite materials and typical applications by other authors on fiber reinforced composites (FRCs).
- Published
- 2022
- Full Text
- View/download PDF
34. Bleaching cotton in textile conservation: a closer look using atomic force microscopy
- Author
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Rana T. A. Salem, Karen Thompson, and Mahesh Uttamlal
- Subjects
Textiles ,Conservation ,Cellulose ,Atomic force microscopy ,Nanoscience ,Fibres ,Fine Arts ,Analytical chemistry ,QD71-142 - Abstract
Abstract Aqueous bleaching may be used in textile conservation to improve the appearance of historic and culturally significant textiles. It is generally accepted amongst conservators that bleaching imparts damage. The aim of this research is to characterise the condition of cotton fibre's surface pre- and post-bleaching using atomic force microscopy (AFM). Unprocessed cotton calico (‘raw’ cotton), scoured cotton, and a historic cotton dress shirt (circa. 1920) were bleached using three separate methods: NaBH4 for 15 min; H2O2/NaBO3 for 1 h; and H2O2/NaBO3 buffered to pH 8.4 for 1 h. AFM was used in tapping-mode to obtain height, amplitude, and phase images. AFM imaging was able to distinguish between the cuticle, primary walls, and secondary walls of the cotton fibres. The data shows that bleaching has the effect of softening and removing individual layers of the cotton structure. Unprocessed cotton calico and scoured cotton fared better against the impact of bleaching. This was in stark contrast to the historic shirt where the already damaged surface of cotton fibres underwent further degradation using both oxidative and reductive bleaching. In general, reductive bleaching was more aggressive on the fibre surface compared to oxidative bleaching. The use of AFM provides further evidence of the physical effects of bleaching on historic textiles, and cotton textiles more broadly, and it has the potential to influence the conservator’s decision-making.
- Published
- 2022
- Full Text
- View/download PDF
35. Novel analytical techniques for the assessment of molecular and structural changes of human hair due to chemical modifications
- Author
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Abduljawad, Tahani and Wortmann, Franz
- Subjects
610.28 ,PhastSystem ,differential scanning calorimetry ,proteins ,DSC ,SEM ,cysteic acid ,keratin intermediate filament-associated proteins (KAPs) ,ATR-FTIR ,SDS-PAGE ,Alpha-keratinous fibres ,bio material ,chemical damage ,Human hair ,animal hair ,forensic applications ,industry ,fibres ,Natural polymers ,cosmetic - Abstract
Human hair, like other Alpha-keratinous fibres, is a highly complex biomaterial. The application of analytical methods to human hair is used in the assessment of chemical damage, constituting the first step to prevent hair deterioration and to develop new products; making hair analysis a very important method for the cosmetic industry and hair researchers. Very little systematic research on the protein patterns of the keratin structures of human hair and how they relate to chemical damage have been reported. This study set out to develop advance techniques which are only rarely used on keratin fibres, where it focuses on gel electrophoresis. The study aims to standardise the data acquisition process, also refining the data analysis methodology for extracting more in-depth information at the molecular level. The techniques included two different types of electrophoresis (SDS-PAGE and the PhastSystem), differential scanning calorimetry (DSC), attenuated fourier transmission spectroscopy (ATR-FTIR) and transmission-FTIR. By suggesting the extraction, staining and destaining times allows to minimise the measurement variability in the protein patterns, thus allowing for more repeatable protein pattern analysis with less sample-to-sample variation. Methods for both the standardisation length of the protein patterns and using the normalisation of the intensity variations have been proposed and this approach has not been attempted before. In human hair the clustering method, demonstrates high correlation between populations of human hair samples. The content of the amino acids, cysteine and cysteic acid, show in the case of darker hair colour a systematic increase, confirmed by use of transmission-FTIR along with ATR-FTIR. A significant increase in extractability is accompanied with an increase in cysteic acid content in cuticle, as presented by dark shade sample with high extractability. For animal hair, the chemical damage in the keratin intermediate filament proteins (KIFs) or keratin intermediate filament-associated proteins (KAPs) levels was analysed and cluster analysis was proposed as a way to classify animal hair fibres by sub species. The application and optimisation of the electrophoresis analytical methods to human and animal hair in the assessment of chemical damage is novel and very useful for the cosmetic industry, hair researchers and related forensic applications. A further investigation using transmission FTIR could be used in the analysis of the amount of cysteic acid in the cortex could be carried out similar to that which was carried out for the cuticle.
- Published
- 2019
36. Novel diesel particulate filters containing fine ceramic fibres
- Author
-
Houston, Alastair James and Clyne, Bill
- Subjects
DPF ,Diesel Particulate Filter ,Ceramic fibres ,Filtration ,Fluid flow ,Thermal Shock Resistance ,Composite ,Fibres - Abstract
Ongoing concerns about the adverse health effects of carbon particulates in diesel engine exhausts continue to drive the quest for improved performance from Diesel Particulate Filter (DPF) systems. Two of the main areas in which improvements are being sought are in enhanced filtration efficiency of very fine particles (< 50 nm), particularly immediately after regeneration (the periodic removal of accumulated particulate via combustion), and in improved thermal shock resistance. To contribute to these aims, this work focuses on creating novel composite materials through the introduction of fine ceramic fibres. Filtration efficiency is considered by experimental measurement of porosity and permeability. Porosity of the material is shown to increase with fibre content, providing a larger volume for soot collection. The permeability is shown to slightly decrease due to the fine nature of the fibres. However, these small fibre diameters, in comparison to the larger particles, offer an increased surface area and scope for an improved soot trapping capability. A simulation, modelling the particles and fibres as simplified spheres and cylinders, allows an understanding into the effect of porosity, fibre proportion, and the sizes of the particles and fibres on the permeability. An empirical equation linking these factors is suggested. A model of this type, on a hybrid particle-fibre-void composite material, has not been studied in the literature, and so offers a novel insight into the complex behaviour of such materials, practicable not only to DPFs, but to any other applications of such composites systems. The model is shown to have good agreement with the experimentally derived data. Finally, the effect of fibres on the thermal shock resistance is investigated. The fibres show improved fracture toughness, and variability in the stiffness which suggests, via a derived figure of merit, that thermal shock resistance improves with increased fibre proportion. Thermal shock is induced experimentally using a vacuum plasma sprayer, and the experimental results, measured as a decrease in stiffness as a consequence of micro-cracking, are comparable to those of the merit index. The study concludes that there appears to be a significant benefit to adding fine ceramic fibres into current DPF materials. The increased porosity, whilst also significantly increasing the specific surface area, suggests the filter could offer a higher soot loading capacity, thus lengthening the time between regenerations. The inclusion of small diameter fibres predicts that the period of initially low filtration efficiency of a clean filter could be shortened, with little impact on the permeability. Fibres also offer significant advantages for the thermal shock resistance. Fibres are well-known for their toughening ability and this remains true for these hybrid particle and fibre composites.
- Published
- 2019
- Full Text
- View/download PDF
37. Novel concrete reinforcement for wave energy converters
- Author
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Li, Xiaoteng, Jones, Martyn, and Newlands, Moray
- Subjects
624 ,FRP ,Fibres ,Wave Energy ,Concrete - Abstract
The experimental work programme developed in this study investigates the behaviour of novel concrete reinforcement for the wave energy converters. The reinforcement included fibre-reinforced polymer (FRP), synthetic fibres, steel fibres and ultra-high-molecular-weight polyethylene (UHMWPE). 24 cube specimens were tested using a pull-out test where no splitting was allowed to develop to examine the bond between FRP (glass and carbon) bars and concrete. 45 beam specimens were subjected to three-point or four-point bending tests where the beams were bent until their failure in order to study the structural behaviour of flexural concrete elements reinforced with internal FRPs, external FRPs as well as fibrous reinforcement. A large-scale WEC prototype was produced, and design of reinforcing this prototype with novel reinforcement was proposed. The bond behaviour between FRP bars and concrete as well as influence of seawater ions were investigated. The shear strength contribution of FRP-reinforced concrete beams was analysed. Also, the structural behaviour of beams reinforced or strengthened with FRPs was presented and compared with estimations using existing methods. A concept of Crack Resistance Indices (CRIs) was introduced to reflect the cracking behaviour of the beams. Appropriate methods for evaluating the flexural strength of beams externally bonded with CFRPs using epoxy resin was developed. Influence of the water and seawater exposures on the CFRP strengthening capacity was also discussed. Addition of macro-synthetic fibres to the concrete at a dosage of 20 kg/m3 significantly improved the toughness of FRP-strengthened beams. Longitudinally aligning macro-steel fibres into concrete beams could provide the latter with competitive flexural and shear strengths. The relation between the aligned fibre dosages and the beam's flexural strength was formulised. Influence on the flexural strength from factors of the concrete strength, addition of cementitious materials and the alignment effectiveness was also studied. A circular Vierendeel-truss-type WEC prototype was designed and produced from precast concrete elements. Assembly of the prototype was accomplished whilst reinforcing with UHMWPE ropes remained at the proposal stage. A 3D printed concrete beam reinforced with UHMWPE ropes was also trialled.
- Published
- 2019
38. Bioactive scaffold-based tissue engineering strategies for orthopaedic applications
- Author
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Maksimcuka, Jekaterina, Kimber, Susan, Withers, Philip, and Tsigkou, Olga
- Subjects
616.7 ,fibres ,Bioactive glass ,osteogenesis ,electrospinning ,vascularisation - Abstract
Bone transplantation is one of the most frequent procedures performed worldwide. Common grafts include autologous, allogeneic, xenograft or synthetic grafts. The availability of autologous grafts is limited, and leads to donor site morbidities, while allografts and xenografts are associated with the risk of disease transmission, immune rejection and have poorer osteointegration than autografts. Bioglassà is a commonly used synthetic graft that upon implantation, bonds to hard tissues through hydroxyapatite layer formation however, it comes in block or particle form. Alternatively, fibrous scaffolds are easier to handle, and they resemble the fibrillar structure of bone extracellular matrix. Cotton-wool like bioactive glass fibres can be easily packed into the defect site, however, their effect on bone formation and angiogenesis has not been evaluated. In this thesis it is hypothesised that 70S30C cotton-wool like bioactive glass fibres have osteo-stimulatory properties and are able to enhance tube like network formation which ultimately could be exploited for non-load bearing bone regeneration applications. Cotton- wool like bioactive glass fibres, were created through the electrospinning process. Several electrospinning parameters were optimised to produce bead free fibres with homogeneous diameters. Human bone marrow mesenchymal stem cells (MSCs) were used to assess in vitro effect of the fibres on cell attachment and proliferation, however the data was inconclusive. The 7osteo-stimulatory effect of bioactive glass has been credited to the ion release, hence conditioned media was obtained from the dissolution of the fibres in cell culture medium and it was shown not to inhibit cell proliferation. Furthermore, it was revealed that the conditioned media combined with the commonly used osteogenic supplements resulted in earlier and stronger osteogenic differentiation of MSCs than commercially available osteogenic media alone. Furthermore, the osteo-stimulatory ability of fibre conditioned media surpassed that of BioglassÃ. MSCs grown in the presence of fibre conditioned media produced higher levels of calcium, collagen and osteocalcin. Gene expression analysis revealed that MSCs undergo faster osteogenic differentiation in the presence of conditioned-osteogenic media than in osteogenic media alone. However, the fibre conditioned media failed to enhance tube-like network formation when human umbilical vein endothelial cells and MSCs were co-cultured in collagen gel. This thesis demonstrates, for the first time, ability of the 70S30C bioactive glass conditioned media to induce osteogenic differentiation of MSCs, which could have a broad range of applications, from bone fracture healing to osteoporosis treatments, osteosarcoma lesion healing and periodontal disease management.
- Published
- 2019
39. Opportunities and Limitations in Recycling Fossil Polymers from Textiles.
- Author
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Bianchi, Sabrina, Bartoli, Flavia, Bruni, Cosimo, Fernandez-Avila, Cristina, Rodriguez-Turienzo, Laura, Mellado-Carretero, Jorge, Spinelli, Daniele, and Coltelli, Maria-Beatrice
- Subjects
SYNTHETIC fibers ,TEXTILE recycling ,CHEMICAL recycling ,PLASTIC marine debris ,NONWOVEN textiles ,TEXTILE waste ,WASTE recycling ,BIODEGRADABLE plastics - Abstract
The recovery and recycling of textile waste is becoming urgent since textiles are generating more and more waste. In one year, about 92 million tons of textile waste are produced and the fashion industry accounts for 58 million tons of plastic waste per year. Several different synthetic fibres are used in textiles, thanks to their excellent processability and mechanical properties, but on the other hand, the difficulties linked to their end of life and the release of microplastics from them during washing is currently a cause of great concern. In this context, policy actions have been aimed at promoting recycling of waste and replacing fossil-based fibres with biobased fibres. The current review, considering both scientific papers published on international journals and web sources, considers the sorting of textiles and the possible recycling of polyesters, polyamides and acrylics. Nevertheless, the contamination and presence of mixed fibres in fabrics is another issue to face for recycling. Methodologies to solve the issue linked to the presence of elastane, present in the stretch fabrics, as well as the possibility of recycling textiles in the non-woven and composite sector are investigated. Moreover, chemical recycling and enzymatic recycling of fossil polymers are also considered. Thanks to the comprehensive scheme of this review, it is possible to deduce that, while the use of biobased materials should rapidly increase in textile applications, the perspective of recycling materials obtained from waste textile into durable and/or high-performance products seems the most promising. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. The effect of soil fabric on shrinkage behaviour and microstructure evolution of soft soils upon drying.
- Author
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Zhao, Hongfen
- Subjects
SOIL drying ,MICROSTRUCTURE ,SOILS ,X-ray computed microtomography ,SCANNING electron microscopy - Abstract
Soft soils often contain important fractions of fines and organic matter which are characterized by high shrinkage potential. Investigating the shrinkage behaviour of soft soils is of primary importance to assess the durability of infrastructures exposed to climatic stresses. This paper investigates the influence of soil fabric on the shrinkage properties and the change in the microporosity structures over drying. Soil shrinkage tests were performed on Shenzhen soft clay (SZ soft clay) and fibrous peat. The effect of the initial fabric was investigated by comparing the samples at natural and reconstituted states, and the reconstituted peat samples with different fibre contents. To assist in the interpretation of the results, microstructural changes in the soil fabric were investigated by mercury intrusion porosimetry, scanning electron microscopy, and micro-CT scan. As the water gradually drains from the multilevel pores, different drying stages were identified. Pore refinements occurred during the drying process, accompanied by a progressive reduction in the peak pore entrance. Contrary to SZ soft clay, intensive shrinkage occurred in the last stage of fibrous peats, due to the collapse of interpores and cracks created during drying. The results showed that the magnitude of the intensive shrinkage increased with the fibre content. It suggests that fibres act as an unstable element in peat upon drying. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Effect of the number of filaments on the tensile properties of polyacrylonitrile- and pitch-based carbon fiber epoxy-impregnated bundle composites
- Author
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Kimiyoshi Naito
- Subjects
Composites ,Fibres ,Mechanical properties ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
This study investigated the effect of the number of filaments on the tensile properties of high tensile strength polyacrylonitrile-based (T1000GB) and high modulus pitch-based (K13D) carbon fiber epoxy-impregnated bundle composites. In addition, the Weibull statistical distributions of the tensile strength were evaluated. The results clearly demonstrate that the tensile strength of the bundle composites increased with the increasing number of filaments in the case of a smaller number of filaments, ultimately reaching a maximum value. In contrast, for a larger number of filaments, the tensile strength decreased with the increasing number of filaments. In addition, for a smaller number of filaments, the Weibull modulus of the bundle composites increased with an increase in the number of filaments, whereas it remained constant in the case of a larger number of filaments.
- Published
- 2023
- Full Text
- View/download PDF
42. Local and Systemic Effects of Bioactive Food Ingredients: Is There a Role for Functional Foods to Prime the Gut for Resilience?
- Author
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Emma F. Jacquier, Marcel van de Wouw, Elena Nekrasov, Nikhat Contractor, Amira Kassis, and Diana Marcu
- Subjects
microbiota ,resilience ,functional foods ,gut health ,hormesis ,fibres ,Chemical technology ,TP1-1185 - Abstract
Scientific advancements in understanding the impact of bioactive components in foods on the gut microbiota and wider physiology create opportunities for designing targeted functional foods. The selection of bioactive ingredients with potential local or systemic effects holds promise for influencing overall well-being. An abundance of studies demonstrate that gut microbiota show compositional changes that correlate age and disease. However, navigating this field, especially for non-experts, remains challenging, given the abundance of bioactive ingredients with varying levels of scientific substantiation. This narrative review addresses the current knowledge on the potential impact of the gut microbiota on host health, emphasizing gut microbiota resilience. It explores evidence related to the extensive gut health benefits of popular dietary components and bioactive ingredients, such as phytochemicals, fermented greens, fibres, prebiotics, probiotics, and postbiotics. Importantly, this review distinguishes between the potential local and systemic effects of both popular and emerging ingredients. Additionally, it highlights how dietary hormesis promotes gut microbiota resilience, fostering better adaptation to stress—a hallmark of health. By integrating examples of bioactives, this review provides insights to guide the design of evidence-based functional foods aimed at priming the gut for resilience.
- Published
- 2024
- Full Text
- View/download PDF
43. Nutritionally Valuable Components and Heat-Induced Contaminants in Extruded Snack Products Enriched with Defatted Press Cakes
- Author
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Antun Jozinović, Jelena Panak Balentić, Đurđica Ačkar, Mirta Benšić, Jurislav Babić, Veronika Barišić, Ante Lončarić, Borislav Miličević, and Drago Šubarić
- Subjects
snacks ,oil press cakes ,fibres ,polyphenols ,hydroxymethylfurfural ,acrylamide ,Organic chemistry ,QD241-441 - Abstract
This research studies the influence of the addition of defatted press cakes (from the production of hazelnut, camelina, pumpkin, and hemp seed oil) on nutritionally important components: fibre, resistant starch, polyphenols, hydroxymethylfurfural (HMF), and acrylamide in directly and indirectly expanded snacks. The amounts of press cakes added to corn grits were 3, 6, and 9%. Extrusion was carried out in a laboratory single-screw extruder. For indirectly expanded products (SCFX), supercritical CO2 was injected during extrusion, and secondary expansion was completed in the microwave oven. The type and content of press cake, as well as the type of product, significantly influenced total polyphenol content and antioxidant activity. Press cakes increased the contents of both soluble and insoluble fibre (from 1.94% d. m. and 1.28% d. m. for extrudates without press cakes up to 3.17% d. m. and 6.94% d. m. for SCFX extrudates with press cakes, respectively), and resistant starch was not markedly influenced by their addition. The influence of the content of press cake on HMF was not significant, whereas the type of cake and the type of extrusion influenced HMF significantly. In a raw mixture of corn grits with 3% of pumpkin press cake, HMF was below the limit of detection, and the highest content was found in the classically extruded sample with the addition of 9% of camelina press cake (580 ppb). In all samples, the acrylamide content was below the limit of detection, indicating that safe products were obtained. This research shows potential for the implementation of supercritical CO2 extrusion in the production of safe, nutritionally improved snack products. Future research might bring about the design of cost-effective processes applicable in the industry.
- Published
- 2024
- Full Text
- View/download PDF
44. Identification of inorganic fibres in workplace air by SEM-EDS
- Author
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Mattenklott Markus, Kaiser Dennis, and Gasse Bianca
- Subjects
fibres ,workplace air ,sem/eds ,identification ,Microbiology ,QR1-502 ,Physiology ,QP1-981 ,Zoology ,QL1-991 - Published
- 2024
- Full Text
- View/download PDF
45. Single cell multi-omics characterise discrete human tendon cells populations that persist in vitro and on fibrous scaffolds
- Author
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A Gomez-Collignon, R Brown, A Carr, S Dakin, A Lach, C Loizou, M Rogers, R Sharp, and A Kendal
- Subjects
tenocyte ,tendon fibroblast ,human tendon ,single-cell rna sequencing ,cite-seq ,transcriptomic ,tendinopathy ,in vitro ,culture ,polydioxanone ,scaffolds ,fibres ,Diseases of the musculoskeletal system ,RC925-935 ,Orthopedic surgery ,RD701-811 - Abstract
Chronic tendinopathy represents a growing healthcare burden in the ageing global population. Curative therapies remain elusive as the mechanisms that underlie chronic inflammation in tendon disease remain unclear. Identifying and isolating key pathogenic and reparative cells is essential in developing precision therapies and implantable materials for improved tendon healing. Multiple discrete human tendon cell populations have been previously described ex vivo. To determine if these populations persist in vitro, healthy human hamstring tenocytes were cultured for 8 d on either tissue culture plastic or aligned electrospun fibres of absorbable polydioxanone. Novel single-cell surface proteomics combined with unbiased single-cell transcriptomics (CITE-Seq) was used to identify discrete tenocyte populations. 6 cell populations were found, 4 of which shared key gene expression determinants with ex vivo human cell clusters: PTX3_PAPPA, POSTN_SCX, DCN_LUM and ITGA7_NES. Surface proteomics found that PTX3_PAPPA cells were CD10+CD26+CD54+. ITGA7_NES cells were CD146+ and POSTN_SCX cells were CD90+CD95+CD10+. Culture on the aligned electrospun fibres favoured 3 cell subtypes (DCN_LUM, POSTN_SCX and PTX3_ PAPPA), promoting high expression of tendon-matrix-associated genes and upregulating gene sets enriched for TNF-a and IL-6/STAT3 signalling. Discrete human tendon cell subpopulations persisted in in vitro culture and could be recognised by specific gene and surface-protein signatures. Aligned polydioxanone fibres promoted the survival of 3 clusters, including pro-inflammatory PTX3-expressing CD10+CD26+CD54+ cells found in chronic tendon disease. These results improved the understanding of preferred culture conditions for different tenocyte subpopulations and informed the development of in vitro models of tendon disease.
- Published
- 2022
- Full Text
- View/download PDF
46. A Review on Fresh, Hardened, and Microstructural Properties of Fibre-Reinforced Geopolymer Concrete.
- Author
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Baskar, Prabu, Annadurai, Shalini, Sekar, Kaviya, and Prabakaran, Mayakrishnan
- Subjects
- *
THERMOMECHANICAL properties of metals , *LIGHTWEIGHT concrete , *PORTLAND cement , *FLY ash , *COMPOSITE materials , *SOLUBLE glass , *FIBERS , *CONSTRUCTION materials - Abstract
Alternative eco-friendly and sustainable construction methods are being developed to address growing infrastructure demands, which is a promising field of study. The development of substitute concrete binders is required to alleviate the environmental consequences of Portland cement. Geopolymers are very promising low-carbon, cement-free composite materials with superior mechanical and serviceability properties, compared to Ordinary Portland Cement (OPC) based construction materials. These quasi-brittle inorganic composites, which employ an "alkali activating solution" as a binder agent and industrial waste with greater alumina and silica content as its base material, can have their ductility enhanced by utilising the proper reinforcing elements, ideally "fibres". By analysing prior investigations, this paper explains and shows that Fibre Reinforced Geopolymer Concrete (FRGPC) possesses excellent thermal stability, low weight, and decreased shrinking properties. Thus, it is strongly predicted that fibre-reinforced geopolymers will innovate quickly. This research also discusses the history of FRGPC and its fresh and hardened properties. Lightweight Geopolymer Concrete (GPC) absorption of moisture content and thermomechanical properties formed from Fly ash (FA), Sodium Hydroxide (NaOH), and Sodium Silicate (Na2SiO3) solutions, as well as fibres, are evaluated experimentally and discussed. Additionally, extending fibre measures become advantageous by enhancing the instance's long-term shrinking performance. Compared to non-fibrous composites, adding more fibre to the composite often strengthens its mechanical properties. The outcome of this review study demonstrates the mechanical features of FRGPC, including density, compressive strength, split tensile strength, and flexural strength, as well as its microstructural properties. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Micro fading test for textile single yarns: a new methodology applied to the Reformation Tapestry to assess its sensitivity to light.
- Author
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Vannucci, Giulia, Joram, Salwa, Beselin, Anna, and Röhrs, Stefan
- Subjects
- *
YARN , *TAPESTRY , *CARPETS , *REFORMATION , *MAGNETS , *STANDARD deviations - Abstract
Tapestries and especially pile carpets can be challenging objects for assessing their photosensitivity by microfading: they are often made of relatively thick yarns resulting in a non-flat airy surface. For this reason, focusing the light on the object's surface is difficult and the precision of the colour change measurement is hampered. In this study, an improved test methodology was developed to overcome the difficulties by analysing single yarns. The methodology consists in flattening the yarn between glass microscope slides tightly held together by means of 4 strong paired neodymium magnets. The results show that the newly-developed sample preparation together with the required instrumental adjustment allow to significantly reduce the standard deviation and variation coefficient which often characterize microfading measurements of textiles. The methodology for sample preparation is evaluated and had been applied to samples from the Reformation Tapestry dating to 1667 from the collection of the Museum Europäischer Kulturen (Museum of European Cultures) in Berlin. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. Physical Properties of Substrates as a Driver for Hermetia illucens (L.) (Diptera: Stratiomyidae) Larvae Growth.
- Author
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Yakti, Wael, Müller, Marcus, Klost, Martina, Mewis, Inga, Dannehl, Dennis, and Ulrichs, Christian
- Subjects
- *
HERMETIA illucens , *LARVAE , *DIPTERA - Abstract
Simple Summary: This study aimed to investigate how the growth and nutrient composition of black soldier fly larvae could differ based on the physical structure of the feed given to the larvae. The results show that manipulating only the physical properties of the substrate can change larval growth, survival rate, and body composition. These results can help optimise the substrate by modifying its physical properties. The growth and nutritional profile of the black soldier fly larvae (BSFL) is usually investigated and compared when the larvae feed on substrates that differ in the chemical composition as well as physical properties. This study compares BSFL growth on substrates that differ primarily in physical properties. This was achieved by using various fibres in the substrates. In the first experiment, two substrates with 20% or 14% chicken feed were mixed with three fibres (cellulose, lignocellulose, or straw). In the second experiment, the growth of BSFL was compared with a 17% chicken feed substrate that additionally contained straw with different particle sizes. We show that the substrate texture properties values did not influence the BSFL growth, but the bulk density of the fibre component did. The substrate mixed with cellulose led to higher larvae growth over time in comparison to substrates with higher bulk density fibres. BSFL grown on the substrate mixed with cellulose reached their maximum weight in 6 days instead of 7. Neither the fibres nor the nutrient level changed the crude protein content of BSFL and the values ranged between 33.5% and 38.3%, but an interaction between the fibre and nutrient level was observed. The size of straw particles in the substrates influenced the BSFL growth and led to a 26.78% difference in Ca concentration, a 12.04% difference in Mg concentration, and a 35.34% difference in P concentration. Our findings indicate that the BSFL-rearing substrates can be optimised by changing the fibre component or its particle size. This can improve the survival rate, reduce the cultivation time needed to reach the maximum weight, and alter the chemical composition of BSFL. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. Polystyrene Microplastics of Varying Sizes and Shapes Induce Distinct Redox and Mitochondrial Stress Responses in a Caco-2 Monolayer.
- Author
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Saenen, Nelly D., Witters, Margo S., Hantoro, Inneke, Tejeda, Inés, Ethirajan, Anitha, Van Belleghem, Frank, and Smeets, Karen
- Subjects
MICROPLASTICS ,MITOCHONDRIA ,POLYSTYRENE ,OXIDATION-reduction reaction ,MONOMOLECULAR films ,KNOWLEDGE gap theory ,MITOCHONDRIAL DNA - Abstract
Currently, we lack crucial knowledge on how the physicochemical properties of particles affect cellular health, resulting in an important gap in our understanding of the human toxicity of microplastics (MPs). Our aim was to evaluate the impact of the size and the shape of MPs on uptake and the intracellular effects in a human epithelial colorectal adenocarcinoma (Caco-2) cell line. Spherical (200 nm and 2 µm) and fibre-/fragment-shaped (8.9 ± 10.1 µm by 1.14 ± 0.97 µm) polystyrene microplastics (PS-MPs) were used to study their uptake and the potential to induce redox and mitochondrial stress responses after 24 h of exposure. We demonstrated the cellular uptake of both spherical and fibre-/fragment-shaped MPs in a size-dependent manner. In response to 2 µm spheres, we observed differential expressions of redox-related genes, including HMOX1, CAT, and GPX1. All PS-MPs decreased the intracellular H
2 O2 levels, which can be attributed to mitochondrial stress responses, such as increased mitochondrial DNA content, footprint, and morphology. Altogether, we demonstrated uptakes and changes in redox and mitochondrial parameters for all PS-MPs, with the 200 nm spheres showing the most profound effects. This suggests that the induction of defensive responses in Caco-2 cells mainly correlates with the number of particles taken up. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
50. Assessment of transverse thermal conductivity of coir fibre using experimental, analytical, and numerical methods.
- Author
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Chamath, L. G., Srimal, L. K. T., and Sewvandi, G. A.
- Subjects
THERMAL conductivity ,COIR ,FIBERS ,THERMOPHYSICAL properties ,NATURAL fibers ,RAYLEIGH model ,INSULATING materials - Abstract
Researchers aim to produce sustainable insulation materials using lignocellulose fibres (natural plant fibres). Lignocellulose fibres are readily available, biodegradable, and low-cost materials for insulation. However, these materials are formulated as composites and not as fibres alone. Thus, the thermal properties of these composites depend on the volume fraction of each phase. The evaluation of thermal conductivity can be followed by experimental, analytical, and numerical methods. Numerical and analytical methods are convenient investigational methods; they are more cost-effective, have a higher degree of flexibility in design enhancement, and are faster methods of analysing results than the experimental method. The thermal conductivity value of each phase should be used to analyse the thermal properties of composite materials. However, there is no specific method to determine the thermal conductivity of natural fibres. Therefore, this work suggests a new method to find the thermal conductivity of coir fibres. The method follows the inverse calculation of the analytical methods to find the thermal conductivity of coir fibres, and the substitution values for the equations will be determined by an experimental method. The two-phase composite was fabricated by coir fibres and epoxy with different volume fractions. Next, the thermal conductivity was measured for the fabricated composite and epoxy using the hot disk method. Finally, the transverse thermal conductivity of the fibre was calculated using available analytical models namely, the Rule of mixture, Maxwell's model, Rayleigh's model, and the Lewis-Nielsen model. The thermal conductivity value determined was 0.3058 W/mK. The results were validated through numerical modelling. The thermal conductivity of fibres was determined using a binderless compacted fibre disk, and the obtained value was 0.2797 W/mK. This value was correlated with the results obtained with the analytical and numerical methods. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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