223 results
Search Results
2. A comprehensive comparison between synthetic and bio-based wet-strength additives for paper manufacturing.
- Author
-
Singh, Varsha, Bachala, Satish Kumar, Madan, Manisha, Ahuja, Arihant, and Rastogi, Vibhore Kumar
- Subjects
LITERATURE reviews ,ADDITIVES ,COMPARATIVE literature ,PAPER products ,ENVIRONMENTAL health - Abstract
Wet-strength additives are vital in maintaining the structural integrity of paper and paper-based products in wet conditions. Most wet-strength additives are synthetically produced and pose environmental and human health risks. Therefore, there is a growing interest in developing natural and environment-friendly wet-strength additives for paper. However, the unavoidable replacement of these harmful wet-strength additives with greener materials to achieve similar wet-strength without compromising product performance, with the added option of sustainability, is challenging. This review discusses up-to-date conventional synthetic, natural, and other wet-strength additives used in developing wet-strength in paper-based products. A detailed description of the additive's reaction mechanisms and working principles for achieving the required wet-strength is also analyzed. Moreover, a detailed comparative literature review of the physio-chemical properties of these wet-strength additives is also discussed. Finally, the paper also discusses the challenges associated with bio-based additives in improving the wet-strength of paper-based products, comparing the well-established synthetic wet-strength additives. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Enhancing Paper Packaging's Wet Strength Using the Synergy between Chitosan and Nanofibrillated Cellulose Additives.
- Author
-
Andze, Laura, Skute, Marite, Zoldners, Juris, Andzs, Martins, Sirmulis, Gatis, Irbe, Ilze, Milbreta, Ulla, Dabolina, Inga, and Filipova, Inese
- Subjects
- *
CELLULOSE , *PACKAGING materials , *ADDITIVES , *CHITOSAN , *RESEARCH personnel , *PACKAGING - Abstract
The demand for eco-friendly packaging materials has urged researchers to look for alternatives to petroleum-based polymers. In this regard, paper-based products have turned out to be a promising choice; however, their weak resistance to water has limited their application. The use of various additives to enhance paper's moisture resistance is a common practice. However, considering the growing global agenda for sustainable development, the search for new bio-based paper additives has become increasingly important. This study investigated the potential synergistic impact of the addition of nanofibrillated cellulose (NFC) and chitosan additives (CHIT) to different fiber combinations to improve paper's properties, in particular, their wet strength. The efficacy of the additive application order was examined and was found to be crucial in achieving the desired outcomes. The results showed that incorporating CHIT after NFC enhanced the paper's tensile and burst indicators, as well as the paper stretch in the dry state, by 35–70%, 35–55%, and 20–35%, respectively. In addition, the tensile index and stretch in the wet state improved 9–13 times and 2.5–5.5 times over, respectively. The air permeability decreased 2.5–12 times over. These findings demonstrate that the sequential addition of the NFC and CHIT additives yield a greater enhancement of paper's properties than using each additive separately. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Integration of Organic Waste for Soil Stabilization through MICP.
- Author
-
Golovkina, Darya A., Zhurishkina, Elena V., Filippova, Arina D., Baranchikov, Alexander E., Lapina, Irina M., and Kulminskaya, Anna A.
- Subjects
ORGANIC wastes ,SOIL stabilization ,TECHNOLOGICAL innovations ,MICROCOCCUS luteus ,WASTE paper ,CALCITE - Abstract
Microbial-induced calcite precipitation (MICP) is an innovative technology in civil engineering. However, the high cost of components and the fragility of the treated soil limit its wide use. One of the possible solutions is organic waste incorporation at different stages of the technology. In the present study, we consider the use of spent brewer's yeast (BSY) to produce bacterial inoculates and wastepaper, flax shives and sawdust as reinforcing additives into the soil. We showed that the replacement of expensive components of LB medium by BSY extract increased biomass growth characteristics of Bacillus subtilis K51, B. cereus 4b and Micrococcus luteus 6 strains by 1.4, 1.5 and 1.8 times, respectively, while for B. subtilis 168, they were comparable to LB medium. The urease activities of all strains were not reduced compared to the control. Among the three kinds of cellulose-containing waste, wastepaper incorporation into MICP-treated soil samples led to an increase in compressive strength by 2.1 times and precipitated calcite percentage by almost 1.5 times compared to a sample without additives. Thus, we showed the potential for soil stabilization through MICP using organic waste. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Some zero product preserving additive mappings of operator algebras.
- Author
-
Wenbo Huang, Jiankui Li, and Shaoze Pan
- Subjects
OPERATOR algebras ,JORDAN algebras ,ADDITIVES - Abstract
Let M be a von Neumann algebra without direct commutative summands, and let A be an arbitrary subalgebra of LS (M) containing M, where LS (M) is the ∗-algebra of all locally measurable operators with respect to M. Suppose δ is an additive mapping from A to LS (M) that satisfies the condition δ(A)B ∗ + Aδ(B) + δ(B)A ∗ + Bδ(A) = 0 whenever AB = BA = 0. In this paper, we prove that there exists an element Y in LS (M) such that δ(X) = XY - YX∗, for every X in A. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Step selection functions with non‐linear and random effects.
- Author
-
Klappstein, Natasha J., Michelot, Théo, Fieberg, John, Pedersen, Eric J., and Mills Flemming, Joanna
- Subjects
HOME range (Animal geography) ,SPLINES ,HABITATS ,REALISM ,ADDITIVES - Abstract
Step selection functions (SSFs) are used to jointly describe animal movement patterns and habitat preferences. Recent work has extended this framework to model inter‐individual differences, account for unexplained structure in animals' space use and capture temporally varying patterns of movement and habitat selection.In this paper, we formulate SSFs with penalised smooths (similar to generalised additive models) to unify new and existing extensions, and conveniently implement the models in the popular, open‐source mgcv R package.We explore non‐linear patterns of movement and habitat selection, and use the equivalence between penalised smoothing splines and random effects to implement individual‐level and spatial random effects. This framework can also be used to fit varying‐coefficient models to account for temporally or spatially heterogeneous patterns of selection (e.g. resulting from behavioural variation), or any other non‐linear interactions between drivers of the animal's movement decisions.We provide the necessary technical details to understand several key special cases of smooths and their implementation in mgcv, showcase the ecological relevance using two illustrative examples and provide R code to facilitate the adoption of these methods. This paper offers a broad overview of how smooth effects can be applied to increase the flexibility and biological realism of SSFs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Special issue: additive manufacturing applied to adhesive bonding.
- Author
-
Carbas, Ricardo J. C. and Marques, Eduardo A. S.
- Subjects
ADHESIVE manufacturing ,POLYMERIC composites ,ADDITIVES ,ADHESIVE joints ,ADHESIVES - Abstract
The Journal of Adhesion has published a special issue on the topic of "Additive Manufacturing Applied to Adhesive Bonding." This technology has already had a significant impact on various industries by allowing for the agile production of prototypes and equipment. The issue includes six papers that explore the combination of adhesion research with additive manufacturing processes. Topics covered include the use of complex lattice structures, the influence of process parameters on bonded joints, build plate adhesion, and the effect of moisture absorption on layer adhesion. The guest editors express their gratitude to the authors and reviewers for their contributions to the issue. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
8. A Comprehensive Review of Nanotechnology Applications in Oil and Gas Well Drilling Operations.
- Author
-
Alkalbani, Alhaitham M. and Chala, Girma T.
- Subjects
GAS well drilling ,OIL well drilling ,GUAR gum ,XANTHAN gum ,DRILLING fluids ,LUBRICATING oils ,NANOTECHNOLOGY ,LUBRICANT additives - Abstract
The field of nanotechnology has shown promise in addressing major problems and improving drilling effectiveness. An overview of the difficulties encountered during oil and gas well drilling operations and the demand for creative solutions opens the debate. This review explores how nanotechnology is transforming the oil industry and enhancing performance as a whole. The evaluation of the uses of nanotechnology for better oil recovery, real-time monitoring, innovative materials, drilling fluids, and reservoir characterization are extensively discussed in this review. The primary function of additives is to improve the fundamental characteristics of drilling fluids. The variety of fluid additives available is a reflection of the complex drilling–fluid systems that are currently being used to enable drilling in increasingly difficult subsurface conditions. Common additives used in water- and oil-based drilling fluids include lubrication, shale stability, filtration control, rheology control, viscosification, and pH regulation. Drilling fluids frequently contain filtration control additives such as starch, polyanionic cellulose (PAC), carboxymethyl cellulose (CMC), and nanoparticles (NP). Commonly used rheology-modifier additives are xanthan gum, carboxymethyl cellulose, guar gum powder, and, more recently, salt-responsive zwitterionic polymers that were used as viscosifiers to water-based drilling fluids. The three main additives that regulate pH are citric acid monohydrate, potassium hydroxide, and sodium hydroxide. Additives that stabilize shale, such as potassium and sodium salts and asphaltenes, are often used. A wide range of materials are included in the category of lubricating additives, including polymers, asphaltenes, glass beads, oils of various grades, and oil-surfactants. Various fibrous materials, including wood, cotton, fibrous minerals, shredded tires from vehicles, and paper pulp, are used as additives to control circulation. Furthermore, shredded cellophane, bits of plastic laminate, plate-like minerals like mica flakes, granulated inert materials such as nut shells, and nano-polymers are used in wellbores to reduce fluid loss. The incorporation of nanoparticles into drilling fluids has produced upgraded fluids with better features, including improved lubricity, thermal stability, and filtering capacities. These developments aid in lowering friction, enhancing wellbore stability, and enhancing drilling efficiency. This paper also emphasizes how nanotechnology has made enhanced drilling equipment and materials possible. Drilling equipment's longevity and performance are increased by nanocomposite materials that have been reinforced with nanoparticles due to their improved mechanical strength, wear resistance, and thermal stability. Advanced reservoir characterisation tools, including nanoparticle tracers and nanoscale imaging methods, can help locate the best drilling sites and increase production effectiveness. On the other hand, nanofluids and nanoemulsions can potentially increase oil recovery because they enhance fluid mobility, lower interfacial tension, and alter rock wettability. Although nanotechnology has many advantages, there are also issues that need to be resolved. For an implementation to be effective, factors including nanoparticle stability, dispersion, and potential environmental effects must be carefully taken into account. This review highlights the need for future research to create scalable manufacturing procedures, improve nanoparticle behaviour, and determine nanomaterials' long-term environmental effects. In conclusion, this in-depth analysis illustrates the use of nanotechnology in transforming the process of drilling oil and gas wells. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Influence of Blending High-Calcium Additive on Environmental Safety of B, F, and Se: A Case Study from Thermodynamic Calculation.
- Author
-
Sutopo, Ulung Muhammad, Desfitri, Erda Rahmilaila, Hayakawa, Yukio, and Kambara, Shinji
- Subjects
ENVIRONMENTAL security ,COAL-fired power plants ,CALCIUM compounds ,YTTERBIUM ,FOOD additives ,ADDITIVES - Abstract
Coal remains an important fuel for use in thermal power plants. However, coal-burning power plants produce large amounts of CFA, which contains TEs such as B, F, and Se, which are leached upon contact with water and act as potential polluters of aquifer systems and soil. To study the transformation of TEs, a thermodynamic calculation (FactSage 7.2) was used. Paper sludge ash was used as a calcium compound additive. The influence of blending a high-calcium additive on the environmental safety of TEs was investigated based on the effect of the mass addition ratio of PS ash. This study's results confirmed that the leaching processes of TEs, namely (CaO)
2 (Al2 O3 ), CaF2 , Ca10 (PO4 )F2 , and CaSeO4 (H2 O)2 , were caused by the formation of B, F, and Se compounds during the leaching process. Thus, it is clear that calcium has the greatest influence on the transformation of TEs due to their reaction, which, in turn, minimizes the effects of the TEs' release into the environment. The concentrations of TEs from the sample and addition of PS ash decreased slightly, indicating that the inhibition of TEs was enabled through the addition of PS ash. Although the PS ash YB had the highest calcium content, the PS ash YC gave the best results during the B and Se inhibition processes. The experimental observation was also evaluated for comparison. For the analysis of TEs' leaching ratios using the thermodynamic calculation and experiment, the experimental results were lower than those initially predicted. These results will help us to choose the best available control technology to minimize the effects of TEs released into the environment. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
10. On n-Jordan homoderivations in rings.
- Author
-
Belkadi, Said, Ali, Shakir, and Taoufiq, Lahcen
- Subjects
INTEGERS ,ADDITIVES ,JORDAN algebras - Abstract
Let R be a ring and let n ≥ 1 be a fixed integer. An additive mapping h of a ring R into itself is called an n-Jordan homoderivation if h (x n) = (h (x) + x) n - x n holds for all x ∈ R . In this paper, we initiate the study of n-Jordan homoderivations on rings. Precisely, we characterize n-Jordan homoderivations in terms of homoderivations and anti-homomorphisms under certain conditions. Finally, we conclude our paper with a direction for further research. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. The algebraic structure of additive codes over 28.
- Author
-
Cheng, Xiangdong
- Subjects
FINITE fields ,LINEAR operators ,ADDITIVES ,LINEAR codes - Abstract
In this paper, we investigate the algebraic structure of 2 r 8 s -additive codes, where r and s are nonnegative integers, 2 (respectively, 8 ) denotes the finite field of order 2 (respectively, 8). We first give the generator polynomials of additive cyclic codes over 8 and then the generator polynomials of additive cyclic codes over 2 8 is also given. In addition, we introduce a linear map W : 2 8 → 2 , and study its properties. What's more, the dual of additive cyclic codes over 2 8 are investigated as well. And we get that the duals of any additive cyclic codes over 2 8 are also additive cyclic codes. Finally, separable 2 8 -additive cyclic codes are investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Effect of Additives on Thermal Degradation and Crack Propagation Properties of Recycled Polyethylene Blends.
- Author
-
Kharmoudi, Hniya, Lamtai, Alae, Elkoun, Said, Robert, Mathieu, and Diez, Carl
- Subjects
CARBON-black ,CRACK propagation (Fracture mechanics) ,POLYETHYLENE ,LIGAMENTS ,ADDITIVES ,COMPATIBILIZERS - Abstract
Additives, such as antioxidants (AOs), carbon black (CB) and compatibilizers (COs), are used in recycled polymer blends for different reasons. AOs slow thermal degradation, CB gives blends a black color and protect them against ultraviolet (UV) light, and compatibilizers improve compatibility between the different phases of the mixture and consequently enhance the mechanical properties of the final blend. In this paper, the three additives were added to recycled polyethylene (PE) blends to study their effect on the final properties and to determine the best formulations that help improve the mechanical properties of recycled PE blends. Stress Crack Resistance (SCR) was accessed by performing Notched Crack Ligament Stress (NCLS) and Un-notched Crack Ligament Stress (UCLS). On the other hand, Oxidative Induction Time (OIT) was used to determine the oxidation time of the blends and the effect of each additive on this property. Based on the results of this study, it was proven that adding carbon black and antioxidants delay the thermal degradation of recycled PE blends and consequently improve the OIT. Otherwise, resistance to stress cracking is improved only by adding a compatibilizer to the reference blend. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. An Improvement of the Upper Bound for the Number of Halving Lines of Planar Sets.
- Author
-
Alonso, Estrella, López, Mariló, and Rodrigo, Javier
- Subjects
DISCRETE geometry ,POINT set theory ,ADDITIVES - Abstract
In this paper, we provide improvements in the additive constant of the current best asymptotic upper bound for the maximum number of halving lines for planar sets of n points, where n is an even number. We also improve this current best upper bound for small values of n, namely, 106 ≤ n ≤ 336 . To obtain this enhancements, we provide lower bounds for the sum of the squares of the degrees of the vertices of a graph related to the halving lines. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Spent coffee grounds enhanced compressive strength of cement mortar: an optimization study.
- Author
-
Yee, Jia Jun, Khong, Sheh Ching, Tee, Kong Fah, Jolius, Gimbun, and Chin, Siew Choo
- Abstract
This paper presents an optimization study of spent coffee grounds (SCG) as cement mortar additives to enhance mortar strength. In recent years, sustainable materials have begun finding their way into cement mortar, with SCG being one. There is limited optimization study on the SCG addition in mortars, hence this study was performed to optimize the curing time and SCG addition in cement mortar to achieve the highest compressive strength through response surface methodology. Scanning Electron Microscopy (SEM) characterization was carried out on the SCG particles to identify their physical properties. An Energy Dispersive X-ray (EDX) analysis was carried out to identify its chemical properties. Simultaneously, a workability test, the flow table test, is conducted to study the effect of SCG on the flowability of the cement mortar mixes. The synergistic effect between SCG content in cement mortar mixes and the curing period was statistically studied and analyzed. Both parameters were then optimized to obtain the best performance mix of SCG in cement mortar. It was found that 1.1% SCG and a curing day of 68 days produced the highest compressive strength (33.4MPa) of cement mortar. The Response Surface Methodology (RSM)-optimized cement mortar mix presented at least a 12.62% improvement in compressive strength from control cement mortar without SCG additives (28.77MPa). Experimental validation of the optimum condition showed a good agreement with a deviation of 3.12% in three replicates, thus indicating that the optimum model in this work can be used to model the compressive strength of the SCG-cement mortar mixture.Article Highlights: The addition of spent coffee grounds (SCG) in cement mortar enhanced its strength by 12.6%. The optimum SCG addition that corresponds to the highest mortar strength is 1.1%. The flowability of cement mortar mix decreases as the percentage of SCG addition increases. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Verifiable Additive Homomorphic Secret Sharing with Dynamic Aggregation Support.
- Author
-
Wang, Sinan, Peng, Changgen, Deng, Xinxin, Peng, Zongfeng, and Chen, Qihong
- Subjects
HOMOMORPHISMS ,SHARING ,GOVERNMENT property ,ADDITIVES ,PROBLEM solving ,INFORMATION sharing - Abstract
(n , m , t) -Homomorphic Secret Sharing (HSS) allows n clients to share data secretly to m servers, which compute a function f homomorphically on the received secretly shared data while restricting the input data acquired by a collection of t servers to private ones. In Verifiable Homomorphic Secret Sharing (VHSS), if there are partially colluding malicious servers submitting erroneous computation results to the client, such erroneous computation results will be rejected by the client. In traditional static homomorphic secret sharing schemes, once a secret share of raw data is assigned to a group of servers, then all servers in the group must participate in the computation, which means that the computation has to be restarted once some servers fail to perform the task. In order to solve the above problem, we propose the first dynamic homomorphic secret sharing scheme for additive computation in this paper. In our scheme, once some servers fail, there is no need to recalculate the secret sharing but only the need to reissue the index set of servers that perform the computation, Our structure assigns more computation to the servers, which is very useful in real scenarios. In addition, we propose dynamic verifiable homomorphic secret sharing schemes based on the above schemes, which have less computational overhead compared to the existing schemes, although we sacrifice the public verifiability property. Finally, we give a detailed correctness, security, and verifiability analysis of the two proposed schemes and provide the theoretical and experimental evaluation results of the computational overhead. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Characterization of the Solution Properties of Sodium Dodecylsulphate Containing Alkaline–Surfactant–Polymer Flooding Media.
- Author
-
Bús, Csaba, Kutus, Bence, Ágoston, Áron, Janovák, László, and Sipos, Pál
- Subjects
SODIUM dodecyl sulfate ,SURFACE active agents ,ENHANCED oil recovery ,INFRARED spectroscopy ,ADDITIVES - Abstract
Alkaline–surfactant–polymer (ASP) flooding by means of which alkali additives, surfactant and polymer are inserted as the same slug is one of the most favourable worldwide focuses of Chemical Enhanced Oil Recovery (cEOR) research and field trials, due to the individual synergy of the three chemical components. To develop efficient oil recovery chemicals, it is essential to fully understand the mechanism behind ASP flooding. Nonetheless, there are hardly any studies reporting a systematic characterization of the ASP process. Thus, the present paper focuses on modelling this process in a laboratory by the use of an anionic surfactant—sodium dodecyl sulphate (SDS) in alkaline–polymer media—which is composed of a commercial water-soluble polymer (Flopaam AN125SH
® , SNF Floerger, Andrézieux-Bouthéon, France) and alkali compounds (NaOH and Na2 CO3 ). The samples were characterized using rheometry, dynamic light scattering (DLS), infrared spectroscopy (IR) and measurement of inferfacial tension (IFT) between the samples and rapeseed oil. In accordance with the experimental results, surprisingly lower IFT values were recorded between the alkaline–polymer solutions and rapeseed oil than the samples which contained SDS. Increasing polymer and sodium chloride concentration caused a decrease (from 0.591 mN/m to 0.0486 mN/m) in IFT between the surfactant containing samples and rapeseed oil. The IR measurements confirmed that the surfactant was not detected in the oil phase in the absence of NaOH and Na2 CO3 . The effects of SDS on the viscosity of the mixtures were also investigated, as viscosity is a considerably important parameter in processes using polymers. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
17. Strong Comonotonic Additive Systemic Risk Measures.
- Author
-
Wang, Heyan, Gong, Shuo, and Hu, Yijun
- Subjects
SYSTEMIC risk (Finance) ,ADDITIVES ,AXIOMS - Abstract
In this paper, we propose a new class of systemic risk measures, which we refer to as strong comonotonic additive systemic risk measures. First, we introduce the notion of strong comonotonic additive systemic risk measures by proposing new axioms. Second, we establish a structural decomposition for strong comonotonic additive systemic risk measures. Third, when both the single-firm risk measure and the aggregation function in the structural decomposition are convex, we also provide a dual representation for it. Last, examples are given to illustrate the proposed systemic risk measures. Comparisons with existing systemic risk measures are also provided. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Additive manufacturing-driven simultaneous optimization of topology and print direction for thermoelastic structures considering strength failure.
- Author
-
Jiang, Hexin, He, Zhicheng, Li, Eric, and Jiang, Chao
- Subjects
LAGRANGE multiplier ,FINITE element method ,TOPOLOGY ,STRAINS & stresses (Mechanics) ,STRUCTURAL optimization ,ADDITIVES - Abstract
This paper presents a strength-based simultaneous optimization method for optimizing thermoelastic structural topology and print direction in the presence of anisotropy induced by additive manufacturing. The approach utilizes the bi-directional evolutionary structural optimization framework and defines design variables including element density and print-off angle. Firstly, an anisotropic thermoelastic constitutive model is established for finite element analysis. By introducing the Tsai–Hill failure criteria, the strength constraint to evaluate the stress level of additively manufactured anisotropic components is formulated. The P-norm aggregation function is employed to approximate the maximum strength failure coefficient. Then, the aggregated strength constraint is augmented to the optimization objective through a Lagrange multiplier. Sensitivity analysis of the new objective function with respect to the elemental design variables is performed, and an analytical approach is proposed to optimize the print-off angle. To improve the stability of the optimization procedure, a series of numerical algorithms and parameter updating strategies are developed. The effectiveness of our proposed method is demonstrated through typical numerical examples, highlighting a desirable match between the structural topology and the print direction can greatly improve the structural performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Reaction-induced nano-sized TiC in additive manufactured Ni-Co based superalloy.
- Author
-
Min, Shiling, Liu, Jing, Liu, Dongyan, Li, Xiangwei, Zhang, Shuyan, Wang, Li, Dong, Jiasheng, and Lou, Langhong
- Subjects
HEAT resistant alloys ,TITANIUM carbide ,HETEROGENOUS nucleation ,CARBON nanofibers ,NICKEL alloys ,NANOSTRUCTURED materials ,ADDITIVES - Abstract
Carbon nanofibers (CNFs) and graphene nanosheets (GNs) are introduced to obtain nano-sized TiC particles in a novel additive manufactured Ni-Co-based superalloy. The double strengthening effects of reaction-induced TiC and remaining CNFs/GNs are conceptualized in the present paper. The CNFs and GNs act as heterogeneous nucleation sites for the formation of uniformly distributed TiC nanoparticles, which inhibits the crack and homogenize the microstructure. Interestingly, the existence of remaining GNs/CNFs is revealed via 3D atom-by-atom tomographic reconstruction technology for the first time. This unique combination of nanoparticles and residual CNFs/GNs nanofillers has great potential to develop superalloys with excellent properties. The formation of nano-sized dispersion TiC particles is induced by the introduction of carbon nanofibers and graphene nanosheets in additive manufactured superalloy, which inhibits the crack and homogenizes the microstructure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Short-time implied volatility of additive normal tempered stable processes.
- Author
-
Azzone, Michele and Baviera, Roberto
- Subjects
MARKET volatility ,OPTIONS (Finance) ,SQUARE root ,ADDITIVES - Abstract
Empirical studies have emphasized that the equity implied volatility is characterized by a negative skew inversely proportional to the square root of the time-to-maturity. We examine the short-time-to-maturity behavior of the implied volatility smile for pure jump exponential additive processes. An excellent calibration of the equity volatility surfaces has been achieved by a class of these additive processes with power-law scaling. The two power-law scaling parameters are β , related to the variance of jumps, and δ , related to the smile asymmetry. It has been observed, in option market data, that β = 1 and δ = - 1 / 2 . In this paper, we prove that the implied volatility of these additive processes is consistent, in the short-time, with the equity market empirical characteristics if and only if β = 1 and δ = - 1 / 2 . [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. TILING EDGE-ORDERED GRAPHS WITH MONOTONE PATHS AND OTHER STRUCTURES.
- Author
-
ARAUJO, IGOR, PIGA, SIMÓN, TREGLOWN, ANDREW, and XIANG, ZIMU
- Subjects
TILING (Mathematics) ,ADDITIVES ,COLLECTIONS - Abstract
Given graphs F and G, a perfect F-tiling in G is a collection of vertex-disjoint copies of F in G that together cover all the vertices in G. The study of the minimum degree threshold forcing a perfect F-tiling in a graph G has a long history, culminating in the Kühn--Osthus theorem [D. Kühn and D. Osthus, Combinatorica, 29 (2009), pp. 65-107] which resolves this problem, up to an additive constant, for all graphs F. In this paper we initiate the study of the analogous question for edge-ordered graphs. In particular, we characterize for which edge-ordered graphs F this problem is well-defined. We also apply the absorbing method to asymptotically determine the minimum degree threshold for forcing a perfect P-tiling in an edge-ordered graph, where P is any fixed monotone path. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Application of Plant Oils as Functional Additives in Edible Films and Coatings for Food Packaging: A Review.
- Author
-
Moghadas, Hooman Chodar, Chauhan, Ruchi, and Smith, J. Scott
- Subjects
FOOD packaging ,EDIBLE coatings ,VEGETABLE oils ,PACKAGING materials ,FOOD preservation ,ADDITIVES - Abstract
Increasing environmental concerns over using petroleum-based packaging materials in the food industry have encouraged researchers to produce edible food packaging materials from renewable sources. Biopolymer-based edible films and coatings can be implemented as bio-based packaging materials for prolonging the shelf life of food products. However, poor mechanical characteristics and high permeability for water vapor limit their practical applications. In this regard, plant oils (POs) as natural additives have a high potential to overcome certain shortcomings related to the functionality of edible packaging materials. In this paper, a summary of the effects of Pos as natural additives on different properties of edible films and coatings is presented. Moreover, the application of edible films and coatings containing POs for the preservation of different food products is also discussed. It has been found that incorporation of POs could result in improvements in packaging's barrier, antioxidant, and antimicrobial properties. Furthermore, the incorporation of POs could significantly improve the performance of edible packaging materials in preserving the quality attributes of various food products. Overall, the current review highlights the potential of POs as natural additives for application in edible food packaging materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. THE USE OF CONCRETE SLURRY WASTE TO IMPROVE THE PROPERTIES OF THE STABILISED SOIL.
- Author
-
Davidová, Vendula, David, Tomáš, Mondschein, Petr, and Reiterman, Pavel
- Subjects
CONCRETE waste ,ADDITIVES ,CIVIL engineering ,ECOLOGICAL impact ,SLURRY ,COMPRESSIVE strength - Abstract
It is often necessary to use stabilising additives during construction to improve the resulting soil properties to ensure the good quality of civil engineering structures. These additives are often produced at high temperatures and with a high carbon footprint. This paper focuses on soil stabilization with waste concrete slurry, which is produced during the production of fresh concrete. The selected clay soil was stabilized with cement and CSW at 2, 4, and 6% by weight of soil. Compressive strength, the resistance to freezing and thawing, Initial bearing index (IBI), and California bearing capacity (CBR) were monitored. The research did not confirm better performance of CSW binder even at higher dosage compared to cement, which was due to the high water content of the mixtures. Positive results were achieved especially in Freez-Thaw resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Improvement of Biogas Production Utilizing a Complex Anaerobic Digestion Model and Gradient-Based Optimization.
- Author
-
Kegl, Tina, Kegl, Breda, and Kegl, Marko
- Subjects
ANAEROBIC digestion ,BIOGAS production ,ORGANIC wastes ,RENEWABLE energy sources ,BIOGAS - Abstract
Anaerobic digestion (AD) is a promising technology for renewable energy production from organic waste. In order to maximize the produced biogas quantity and quality, this paper deals with the optimization of the AD process in a CSTR bioreactor of a full-scale biogas plant. For this purpose, a novel approach was adopted coupling, a highly complex BioModel for AD simulation, and a gradient-based optimization method. In order to improve AD performance, the dosages of various types of biological additives, the dosages of inorganic additives, and the temperature in the bioreactor were optimized in three different scenarios. The best biogas quality was obtained using multi-objective optimization, where the objective function involves the following two conflicting objectives: the maximization of biogas production and minimization of the needed heating energy. The obtained results show that, potentially, the content of C H 4 can be increased by 11%, while the contents of H 2 , H 2 S , and N H 3 can be reduced by 30%, 20%, and 81% when comparing the simulation results with the experimental data. The obtained results confirm the usefulness of the proposed approach, which can easily be adapted or upgraded for other bioreactor types. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. On α−Centralizer Mappings in Semiprime Rings.
- Author
-
Sögütcü, E. Koç, Rehman, N., and Polat, S.
- Subjects
NILPOTENT Lie groups ,ADDITIVES ,AUTOMORPHISMS - Abstract
Let R be a 2−torsion free semiprime ring, α an automorphism and U a noncentral square-closed Lie ideal of R. An additive mapping T : R → R is called a left (resp. right) α−centralizer of R if T(xy) = T(x)α(y) (resp. T(xy) = α(x)T(y)) holds for all x, y ∈ R. In this paper, we proved the following result: i) If T (uvu) = α (u) T (v) α (u) for all u, v ∈ U, then T is a left α−centralizer, ii) If T(uvu) = T(u)α(vu) (resp. T(uvu) = α(uv)T(u)) for all u, v ∈ U, then T is a left (resp. right) α-centralizer on U. [ABSTRACT FROM AUTHOR]
- Published
- 2024
26. A Pexider system of additive functional equations in Banach algebras.
- Author
-
Dehghanian, Mehdi, Sayyari, Yamin, Donganont, Siriluk, and Park, Choonkil
- Subjects
BANACH algebras ,QUADRATIC equations ,FUNCTIONAL equations ,ADDITIVES - Abstract
In this paper, we solve the system of functional equations { f (x + y) + g (y − x) = 2 f (x) , g (x + y) − f (y − x) = 2 g (y) and we investigate the stability of g-derivations in Banach algebras. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Structure and Properties of WC-Fe-Ni-Co Nanopowder Composites for Use in Additive Manufacturing Technologies.
- Author
-
Krinitcyn, Maksim, Svarovskaya, Natalia V., Rodkevich, Nikolay, Ryumin, Egor, and Lerner, Marat
- Subjects
ELECTRIC wire ,BENDING strength ,ELECTRIC wiring ,ADDITIVES ,NANOSTRUCTURED materials ,POWDERS - Abstract
In this work, the samples of the WC-Fe-Ni-Co composition were obtained and studied. Alloy NiCo 29-18 is used as a binder (Fe-Ni-Co). In this paper, a comparative analysis of the samples obtained using commercial micron-sized WC powder and the samples obtained is carried out using nano-WC synthesized via the electric explosion of wire (EEW) method. The samples were subjected to vacuum sintering, then their structure, density, and porosity, as well as microhardness and oxidation resistance, were studied. Five different additives were used to stabilize sintering: VC, Cr
3 C2 , NbC, Y2 O3 , and Nd2 O3 . All these additives are described in the literature as additives that are used in the sintering of materials of the WC-Co system. Also, the samples from the WC-Fe-Ni-Co material were obtained using additive manufacturing technology with material extrusion. Bending strength and hardness of the additively fabricated samples were determined. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
28. Flame Retardant Additives Used for Polyurea-Based Elastomers—A Review.
- Author
-
Dukarski, W., Rykowska, I., Krzyżanowski, P., and Gonsior, M.
- Subjects
FIREPROOFING agents ,ELASTOMERS ,BIODEGRADABLE plastics ,SURFACE coatings ,POLYURETHANES ,POLYURETHANE elastomers ,ADDITIVES - Abstract
The growing interest in modern polymer materials has targeted research on complex plastic coatings and the possibilities of modifying their features and properties during manufacturing. Today's modern coatings, including polyurea and polyurethane, are among the most modern developed resins. Compared to other polymer coatings, they are distinguished by their versatility, strength, and durability. They undoubtedly represent the next step in the evolution of coatings. Advances in coating technology have also led to the development of spray, injection, and roto-cast application equipment, improving polyurea-based elastomers' performance. For many years, there has been much interest in increasing the flame resistance of polymers. This is dictated by safety considerations and the increasing requirements for the flammability of plastics, the area of application of which is growing every year. This text attempts to provide an overview of current research on flame retardant composites. Particular attention was paid to polyurea (PU) and polyurea-based hybrids and the application areas of polyurea coatings. The paper defines flame retardants, discusses how they work, and presents the types of flame retardants and the current trends of their usage in the production of plastics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Research process on silage and feeding effect of sugarcane tops.
- Author
-
GUO Fang-zhu, WANG Shu-yang, XU Fu-qiang, SUN Xi-si, LIU Guo-qiong, YING Xiong-mei, and WANG Zhi-neng
- Abstract
The sugarcane top is one of the main by-products of sugarcane, which is rich in resources and comprehensive in nutritional value, and is one of the sources of roughage for ruminants. Silage is an effective method to preserve and develop sugarcane top feed, but the high content of carbohydrate and yeast makes natural silage easy to deteriorate, and the high content of fiber will affect the digestibility and palatability of the feeding animals. At present, the research on sugarcane top silage mainly focuses on the use of various additives, mixed silage with other materials, the effect of sugarcane top silage on ruminants, and the influence of sugarcane harvest time, varieties and silage time on silage. In this paper, the effects of additives, mixed silage and other factors on the quality, nutritional value, aerobic stability and feeding effect of sugarcane top silage were summarized, which provided reference for promoting the utilization of sugarcane top and the preparation of high-quality silage. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Rejecting an Additive Solution to Regan's Lifeboat Case.
- Author
-
Kary, Daniel
- Subjects
- *
DOGS , *ADDITIVES - Abstract
This paper considers a solution to a scenario found in Tom Regan's Case for Animal Rights, offered by Daniel Kary. Regan considers a case where either one human or any number of dog's must be sacrificed. He chooses the human because they would be harmed more than any dog would be. This is initially puzzling since Regan claims that humans and dogs have equal inherent value (the objective value as an end that entities have). Kary's solution argues the human should be saved since their possible experiences have greater intrinsic value (the objective value as an end that experiences have) than those of any number of dogs'. The rationale is that dog experiences are too similar to be additive. The paper acknowledges that Kary's alternative solution is more plausible than Regan's, but it ultimately fails to be convincing. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. ANÁLISE DO PLANEJAMENTO DE PROCESSOS LICITATÓRIOS: UM ESTUDO DE CASO EM UMA SECRETARIA MUNICIPAL DE URBANISMO.
- Author
-
Bentes Kato, Ricardo and Morais Portal, Ghabriel
- Abstract
Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
32. Evaluation of a method for the additive tooling of injection mould inserts.
- Author
-
Schrock, Steffen, Junk, Stefan, and Albers, Albert
- Subjects
EVALUATION methodology ,NEW product development ,STUDENT projects ,ADDITIVES ,INJECTION molding - Abstract
Purpose: This study aims to investigate a systematic approach to the production and use of additively manufactured injection mould inserts in product development (PD) processes. For this purpose, an evaluation of the additive tooling design method (ATDM) is performed. Design/methodology/approach: The evaluation of the ATDM is conducted within student workshops, where students develop products and validate them using AT-prototypes. The evaluation process includes the analysis of work results as well as the use of questionnaires and participant observation. Findings: This study shows that the ATDM can be successfully used to assist in producing and using AT mould inserts to produce valid AT prototypes. As a reference for the implementation of AT in industrial PD, extracts from the work of the student project groups and suitable process parameters for prototype production are presented. Originality/value: This paper presents the application and evaluation of a method to support AT in PD that has not yet been scientifically evaluated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. The Sustainability of Using DuraCrete as Cement Additive to Estuarine Soft Soil Stabilization.
- Author
-
Al-Gemeel, Ali N., Al-Hayo, Noor, Ong, Dominic E. L., and Zhuge, Yan
- Abstract
Large areas of estuarine deposits exist on the coastal plains of the southeast Queensland coast with a countered depth of up to 30 m. These deposits are categorized as sediments that originated during the Holocene Age. The sediments have not been consolidated or subjected to considerable pressure since the end of the Ice Age. The structure of these deposits consists of large ratios of porosity, causing high soil compressibility, which lowers the bearing capacity of the soils. Therefore, the soils of the region cannot maintain sufficient support for construction loads, and consequent malfunctions could occur in short-term and long-term periods. The objective of this paper is to investigate the suitability of new soil stabilization additives in the southeast Queensland region and the optimum additive content of cementitious materials and an advanced mixing modifier branded as DuraCrete. A combination of Portland cement and DuraCrete was used as a soil additive. Three DuraCrete-to-cement ratios were used: 2%, 3%, and 4% by weight. Soil collected from the Port of Brisbane region was treated by adding the additives as a percentage of its weight; four percentages were considered: 10%, 20%, 25%, and 30% for each combination of additives. The performance of the treated soils was examined under unconfined compression after 28 days of curing. The results revealed that increases in the unconfined compressive strength were detected as DuraCrete was added to the mixtures. For 30% additives, increases of about 15%, 34%, and 17% were detected when DuraCrete was added as 2%, 3%, and 4%, respectively. The results also revealed that 3% DuraCrete content provided significant stabilization compared to 2% and 4% for 25% and 30% additive-treated soils; such behavior was also observed for the specimens of 25% content of additives. Additionally, DuraCrete can be considered a promising material that can be combined with cement to obtain the desired stabilization of soft soils. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Electrochemical Performance Study of Solar Cells Made of the Perovskite Material.
- Author
-
WEIPING LIU and FANGZHOU JIN
- Subjects
SOLAR cells ,PEROVSKITE ,FUMARATES ,PERFORMANCE theory ,SULFAMIC acid - Abstract
Perovskite solar cells (PSCs) have low cost and high photoelectric conversion efficiency (PCE), but their performance still needs to be improved. This paper analyzed the electrochemical performance of PSCs by additives. First, PSCs with sulfamic acid (SA) and fumaric acid (FMAC) as additives were prepared; then, the electrochemical properties to be measured were briefly introduced. It was found that the electrochemical properties of both SA-PSCs and FMAC-PSCs were effectively improved compared with the standard samples, their photovoltaic conversion efficiency (PCE) was 18.46% and 19.48%, respectively, and they showed better stability. After aging experiments, the PCE of SA-PSCs and FMAC-PSCs was 74.7% and 76.8% of that before the experiments; after light experiments, the PCE of SA-PSCs and FMAC-PSCs was 52.4% and 54.6% of the pre-experimental ones, which were superior to the standard PSC samples. The experimental results verify the optimization effect of additives on PSCs, which is beneficial to further improving PSCs performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
35. Research Progress of Additives to Improve Hydration Resistance of Magnesia-calcium Materials.
- Author
-
ZANG Weinan, LUAN Jian, WANG Chunyan, MIAO Zhenhua, LI Jia, and HAN Haopeng
- Subjects
ADDITIVES ,HYDRATION ,MAGNESIUM ,CALCIUM ,STEEL industry - Abstract
Magnesia-calcium materials have stable hot performance, good resistance to the erosion and corrosion of liquid steel and steel slag, and a special role in purifying liquid steel, so they are widely used in iron and steel industry. However, hydration of magnesia-calcium materials seriously restricts their use, so researches have been done to improve their hydration resistance, obtaining a series of achievements. In this paper, the improvements on the hydration resistance of magnesia-calcium materials by additives in recent 20 years were presented, and their mechanisms were summarized. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Electrochemistry of Tin Deposition from Methanesulfonic Acid.
- Author
-
Yang, Yuantao, Wang, Junli, Wang, Xuanbing, Wei, Jinlong, Tong, Xiaoning, Xu, Ruidong, and Yang, Linjing
- Subjects
CHRONOAMPEROMETRY ,SATURATION vapor pressure ,TIN ,ELECTROCHEMISTRY ,ELECTROLYTIC reduction ,SCANNING electron microscopy - Abstract
The electrolytic refining of crude tin is generally carried out in the fluorosilicic acid (H
2 SiF6 ) system with the assistance of bone glue and β-naphthol. However, the high saturated vapor pressure and low stability of H2 SiF6 present environmental concerns and do not align with sustainable development goals. In this paper, the electrochemical behavior of tin on a glassy carbon (GC) electrode was studied in a relatively green and environmentally friendly methanesulfonic acid (MSA) system. Bone glue, sodium lignosulfonate, and β-naphthol were used as additives to make the deposit morphology smooth and to ensure grain refinement. The electrochemical reduction process of Sn2+ in an MSA system is a quasi-reversible process controlled by diffusion. The apparent activation energy E a = 14.189 kJ/mol for the ion diffusion of Sn2+ was further calculated. The results of chronoamperometry showed that the electrocrystallization of Sn2+ on the GC electrode gradually tended to three-dimensional instantaneous nucleation with the increase in applied potential. The morphology and phase of the deposits were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the deposits were uniform and dense pure tin. This work elucidates the electrochemical behavior of tin in a methanesulfonic acid system. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
37. Strong commutativity preserving additive maps on rank k triangular matrices.
- Author
-
Chooi, Wai Leong, Tan, Li Yin, and Tan, Yean Nee
- Subjects
DIVISION rings ,MATRICES (Mathematics) ,ADDITIVES ,INTEGERS - Abstract
Let $ n\geqslant 2 $ n ⩾ 2 be an integer and let $ T_n({\mathbb {D}}) $ T n (D) be the ring of $ n\times n $ n × n upper triangular matrices over a division ring $ {\mathbb {D}} $ D with centre $ Z(T_n({\mathbb {D}})) $ Z (T n (D)). In this paper, we characterize additive maps $ \psi :T_n({\mathbb {D}})\rightarrow T_n({\mathbb {D}}) $ ψ : T n (D) → T n (D) satisfying $ [\psi (A),\psi (B)]-[A,B]\in Z(T_n({\mathbb {D}})) $ [ ψ (A) , ψ (B) ] − [ A , B ] ∈ Z (T n (D)) for all $ A,B\in T_n({\mathbb {D}}) $ A , B ∈ T n (D). We then deduce from this result a complete characterization of strong commutativity preserving additive maps $ \psi :T_n({\mathbb {D}})\rightarrow T_n({\mathbb {D}}) $ ψ : T n (D) → T n (D) on rank k upper triangular matrices, where $ 1\leqslant k\leqslant n $ 1 ⩽ k ⩽ n is a fixed integer such that $ k\neq n $ k ≠ n when $ |{\mathbb {D}}|=2 $ | D | = 2. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Antisolvent free deposition of lead–tin-based MAPbxSn1−x(I0.75Br0.25)3 perovskite with a wide range of bandgap variation
- Author
-
Howlader, C. Q., Geerts, W., and Chen, Y. M.
- Published
- 2024
- Full Text
- View/download PDF
39. Lowering hexacelsian sintering temperature with additives: solid or liquid phase mechanisms.
- Author
-
Saintonge, Arnaud, Braun, James, Danet, Julien, Allemand, Alexandre, Piquero, Thierry, Beaudet-Savignat, Sophie, and Lepetitcorps, Yann
- Subjects
- *
SINTERING , *STERIC hindrance , *TITANIUM dioxide , *CARBON dioxide , *ADDITIVES , *INTEGRITY - Abstract
The sintering temperature of an oxide/oxide composite, comprising a barium aluminosilicate (BaAl 2 Si 2 O 8 or BAS) matrix reinforced with alumina fibers, is constrained to avoid a decrease in the mechanical properties of the fibers. This paper highlights the potential of sintering additives in lowering the sintering temperature of the hexagonal BAS (hexacelsian), thereby safeguarding the integrity of the fibers. Consequently, the role of sintering additives, MgO, TiO 2 , and B 2 O 3 , is investigated to determine their impact on the BAS matrix sintering. The addition of 1 wt% of these additives successfully achieved this objective, as confirmed through thermal and microstructural analyses. MgO and TiO 2 facilitated sintering kinetics through a solid-phase mechanism. Concerning the addition of B 2 O 3 , its effect on BAS sintering accelerated densification through a transient liquid-phase mechanism. Another consequence of incorporating these sintering additives is the destabilization of the hexagonal BAS. To limit this phenomenon, the addition of 1 wt% Rb 2 CO 3 served as a stabilizer through steric hindrance, partially substituting the Ba element in the BAS matrix with Rb. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Research progress on the tribological properties of epoxy‐based solid‐lubricating composites.
- Author
-
Song, Luyang, Jiang, Tao, Yu, Hua, Zhou, Yayu, Cao, Xinna, Wang, Peng, Zhang, Bibo, Yu, Zhuoli, Pan, Kunming, and Wei, Shizhong
- Subjects
- *
EPOXY resins , *PROSPECTING , *ADDITIVES - Abstract
Highlights To modify the tribological properties of epoxy (EP), additive phases, such as inorganic/organic lubricating fillers, are often introduced to form EP‐based solid‐lubricating composites, which are extensively utilized in industrial sectors like aerospace, automotive, and electronics. The composite methods can be divided into single‐phase composite and multiphase composite. Single‐phase fillers can improve the tribological properties of the composite while the content and distribution of the fillers should be precise controlled. Multiphase fillers offer significant advantages in enhancing the comprehensive properties of EP, making them more suitable for practical harsh environments. This review investigates the progress in research on the tribological properties of EP‐based solid‐lubricating composites and provides an outlook on the future development of lubricating fillers. In this paper, the commonly used lubricating fillers in EP‐based solid‐lubricating composites and their composite methods, including inorganic and organic fillers, were reviewed. The various EP‐based solid‐lubricating composites, and their lubrication or wear mechanisms were introduced in detail, and the future development directions of the composites were prospected. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Estimates of the Kobayashi metric and Gromov hyperbolicity on convex domains of finite type.
- Author
-
Wang, Hongyu
- Subjects
- *
CONVEX domains , *PSEUDOCONVEX domains , *ADDITIVES - Abstract
In this paper, we give a local estimate for the Kobayashi distance on a bounded convex domain of finite type, which relates to a local pseudodistance near the boundary. The estimate is precise up to a bounded additive term. Also, we conclude that the domain equipped with the Kobayashi distance is Gromov hyperbolic that gives another proof of the result of Zimmer. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Complex dynamics induced by additive Allee effect in a Leslie-Gower predator-prey model.
- Author
-
Yang, Yue, Meng, Fanwei, Xu, Yancong, and Rong, Libin
- Subjects
ALLEE effect ,LOTKA-Volterra equations ,PREDATION ,HOPF bifurcations ,BIFURCATION diagrams ,LIMIT cycles ,ADDITIVES - Abstract
In this paper, we investigate the complex dynamics of a predator-prey model, specifically the Leslie-Gower model, with additive Allee effect and simplified Holling Ⅲ functional response. The model has been analyzed for various bifurcations, including the nilpotent cusp singularity of codimension 3, Bogdanov-Takens bifurcation of codimension 3, and Hopf bifurcation of codimension 2. Additionally, a codimension 2 cusp of limit cycles and the coexistent acute angle region of three limit cycles have been identified. Notably, the isola bifurcation of limit cycles, which indicates a new mechanism of sustained oscillation, has been observed for the first time in a Leslie-Gower predator-prey model with additive Allee effect. One-parameter and two-parameter bifurcation diagrams and corresponding phase portraits have been presented to verify the theoretical results. From a biological perspective, the additive Allee effect may result in system collapse, leading to the extinction of the predator population and survival of the prey. The finding of the isola bifurcation of limit cycles is of significant interest, highlighting a novel mechanism of sustained oscillation in this complex system. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Succinct data structures for bounded clique-width graphs.
- Author
-
Chakraborty, Sankardeep, Jo, Seungbum, Sadakane, Kunihiko, and Satti, Srinivasa Rao
- Subjects
- *
DATA structures , *ADDITIVES - Abstract
Clique-width is a well-studied graph parameter owing to its use in understanding algorithmic traceability, and in this paper, we study the class of bounded clique-width graphs through the lens of succinct data structures. A data structure is said to be succinct if the amount of space used by the data structure is information-theoretically optimal up to lower-order additive terms. More specifically, we design a succinct data structure for graphs on n vertices whose clique-width is at most k ≤ ϵ log n for some constant 0 < ϵ < 1 / 6 , that supports degree, adjacency, and neighborhood queries efficiently. This resolves an open problem of Kamali (Algorithmica-2018). As an application of our main technique, we also propose succinct data structures for distance-hereditary and Ptolemaic graphs, which are subclasses of the class of graphs with clique-width at most 3. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. On λ-k-skew Lie product involving commuting additive maps on prime ∗-algebras.
- Author
-
Khan, Abdul Nadim, Ali, Shakir, Raza, Mohd Arif, and Alhazmi, Husain
- Subjects
- *
ADDITIVES - Abstract
Let be an ∗-algebra and k ∈ ℤ + . For A , B ∈ , the product defined by ∗ [ A , δ A (B) λ ∗ ] k = ∗ [ A , ∗ [ A , δ A (B) λ ∗ ] k − 1 ] 1 , where ∗ [ A , δ A (B) λ ∗ ] 0 = δ A (B) λ ∗ and ∗ [ A , δ A (B) λ ∗ ] 1 = A δ A (B) λ ∗ − δ A (B) λ ∗ A ∗ , is called λ - k -skew Lie product of A and B , where δ A (B) λ ∗ = A B − λ B A ∗ . This paper discusses some useful characteristics of λ - k -skew Lie products on prime ∗-algebras. Moreover, we investigate the effects of an additive map ϕ on with a λ - k -skew Lie product. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Regression analysis of clustered panel count data with additive mean models.
- Author
-
Wang, Weiwei, Cui, Zhiyang, Chen, Ruijie, Wang, Yijun, and Zhao, Xiaobing
- Subjects
REGRESSION analysis ,ADDITIVES - Abstract
In biomedical studies, panel count data have been extensively investigated. Such data occur if study subjects are monitored or observed only at some discrete time points during observation periods. In addition, these data may be collected from multiple centers, and study subjects from the same center might be correlated. Limited literature exists for clustered panel count data. Ignoring such cluster effects could result in biased variance estimation. In this paper, two semiparametric additive mean models are proposed for clustered panel count data. The first model contains a common baseline function across all clusters, while the second model features cluster-specific baseline functions. Some estimation equations are derived to estimate the regression parameters of interest for the proposed two models. For the common baseline model, the baseline function is also estimated. Given some regularity conditions, the resulting estimators are shown to be consistent and asymptotically normal. Extensive simulation studies are carried out and indicate that the proposed approaches perform well in finite samples. An application of the China Health and Nutrition Study is also provided for illustration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. A comprehensive review of warm-mix asphalt mixtures: mix design, construction temperatures determination, performance and life-cycle assessment.
- Author
-
Liu, Ning, Liu, Liping, Li, Mingchen, and Sun, Lijun
- Subjects
ASPHALT ,CONSTRUCTION ,WATER damage ,ADDITIVES ,ROADS - Abstract
The paper provides a review of mix design, construction temperature determination, performance and life-cycle assessment (LCA) of WMA mixtures. The mix design of WMA mixtures using almost the same design protocols as the HMA mixtures. The techniques used for determining WMA mixtures' construction temperatures include the analogy, phase angle, compaction energy index (CEI) and traffic densification index (TDI), and 4% air void methods. The use of Sasobit is advisable for the road prone to rutting. For the road prone to water damage, the use of foaming technologyis not suitable and Rediset is recommended. For the road prone to fatigue failure, the use of Water-based processes is not recommended, while Evotherm and Rediset are advisable. From an environmental point of view, water-based processes are recommended for the production of WMA mixtures, followed by organic additives and chemical additives, whereas the use of water-bearing additives is not recommended. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. A New FE Modelling Approach to Simulate the Inter‐Layer Adherence in Hybrid Sandwich Structures Achievable by Additive Manufacturing.
- Author
-
Garofano, Antonio, Sellitto, Andrea, Acanfora, Valerio, Battaglia, Miriam, and Riccio, Aniello
- Subjects
- *
SANDWICH construction (Materials) , *COMPOSITE structures , *COREMAKING , *ADDITIVES , *FUSED deposition modeling , *DEBONDING - Abstract
Numerically predicting the mechanical behavior of additively manufactured sandwich structures, particularly those produced through filament extrusion, poses a significant challenge. Existing collapse mechanisms, including interlayer debonding, lack comprehensive numerical formulation. This paper presents an improved finite element (FE) modeling approach for filament‐based additive processes. Utilizing the cohesive zone model (CZM), it incorporates a cohesive‐type contact to simulate critical layer interactions, such as the core‐face sheet interface. Validation against a literature‐referenced composite sandwich structure with designed for additive manufacturing honeycomb core demonstrates good agreement between the proposed numerical approach and experimental test data in compression and bending. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Laser-based additive manufacturing of polypropylene-agarose composites: Processing properties and compressive mechanical properties.
- Author
-
Schlicht, Samuel and Drummer, Dietmar
- Subjects
- *
MANUFACTURING processes , *LASER peening , *BIOMEDICAL engineering , *POLYPROPYLENE , *GELATION , *THERMAL properties , *ADDITIVES - Abstract
Gelling polymers, used for the fabrication of hydrogels, are employed for various applications in medical engineering. The present paper explores a novel approach for the additive manufacturing of polypropylene-hydrogel composites by applying laser-based powder bed fusion of powder blends at ambient temperatures, hence allowing for the integration of additives sensitive to heat degradation. Based on applying superposed fractal exposure strategies for the temporally and spatially discretized melting of prepared powder blends, the processing of composites containing a proportion of up to 75% of agarose can be demonstrated. Prepared specimens depict a water absorption exceeding 100 wt-% while exhibiting non-linear, progressive mechanical properties under compressive stress and enhanced stress relaxation similar to human cartilage tissue. The results illustrate the suitability of fractal exposure strategies for the processing of materials sensitive to heat degradation with divergent thermal properties. Furthermore, the proposed approach provides a novel process route for the fabrication of functionalized polymer components, representing a foundation for the integration of hydrogels for medical applications, such as drug delivery applications and functionalized, load-bearing scaffolds. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. A retrofit solution for substituting a conventional primary distribution by using additive manufacturing in a spiral mandrel die assembly in blown film extrusion.
- Author
-
Ulbrich, Chris and Schiffers, Reinhard
- Subjects
- *
ARBORS & mandrels , *MANUFACTURING processes , *EXTRUSION process equipment , *RETROFITTING , *ADDITIVES , *EXTRUSION process - Abstract
In blown film extrusion, spiral mandrel dies are the most common die design. This type of die assembly consists of three main components dividing the course of the melt into a 90° deflection, an n-fold star division and the spiral mandrel itself. Conventional manufacturing processes are used to manufacture the components. Therefore, shaping inside the die is usually limited to straight-line flow paths particularly in the area of the melt deflection and distribution. Partially, this leads to inhomogeneous flow patterns as fillets can only be integrated sparsely due to the limitations of the manufacturing technologies. The use of additive manufacturing, on the other hand, offers the possibility of realising channels that are freely routed between the inlet and outlet, resulting in a gentler melt deflection. In a previous research project, a blown film die assembly consisting of a primary and a secondary distribution was additively manufactured. Many advantages were achieved by the additive primary distribution alone through the free design of the melt channels. This paper introduces a new die design concept containing a retrofit solution for conventional spiral mandrel dies which substitutes the conventional primary distribution with an additively manufactured one. For this, the die design developed in the preceding project is adapted to replace the conventional primary distribution and can be combined with an existing spiral mandrel manufactured conventionally. As spiral mandrels are well established in the industry and as they are expensive components, they are retained. In this way, the advantages of both concepts, such as the gentle melt deflection and the avoidance of weld lines, are combined. Additionally, it was possible to achieve improvements in terms of residence time and purgeability. Further work needs to be done to adjust the designing process to remedy the deterioration in mass flow distribution. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Lp-theory of linear canonical transforms and related uncertainty principles.
- Author
-
Xuan Chen, Pei Dang, and Weixiong Mai
- Subjects
- *
HEISENBERG uncertainty principle , *BANACH algebras , *ADDITIVES - Abstract
In this paper, we revisit some fundamental properties of linear canonical transform (abbreviated as LCT). In particular, we prove the additive property rigorously for LCT in the higher dimensional case (abbreviated as MLCT). We also consider the Lp-theory of MLCT with 1 ≤ p ≤ 2. Specifically, the inversion theorem of MLCT by the related Gauss and Abel means is studied, and the pointwise convergence of approximate identities with respect to convolution for MLCT is also obtained. As applications, we study the Lp-type Heisenberg-Pauli-Weyl uncertainty principles and the Lp-type Donoho-Stark uncertainty principles for MLCT. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.