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In the present study, the effect of different ratios of GelMA concentration has been exhibited for wound dressing implementation by the electrospinning method using a new polymer combination of Gelatin methacrylate (GelMA)/Polycaprolactone (PCL)/Chitosan (CS). The nanofiber composites were fabricated due to their biocompatible, biodegradable, improved mechanical strength, low degradation rate, and hydrophilic nature to develop cell-mimicking, cell adhesion, proliferation, and differentiation. Different concentrations of GelMA were added to the PCL/CS solution as 5, 10, and 20 wt%, respectively, in the formic acid/acetic acid (7:3) solution. A photoinitiator was added to the solution for photo-crosslinking of GelMA. The influence of different solution concentrations (5, 10, and 20 wt%) on the structure’s nanofiber production and fiber morphology was examined. SEM micrographs revealed that varied GelMA concentrations resulted in suitable and stable nanofiber composites. The average diameter of nanofiber composites grows as the GelMA concentration rises. FTIR, DSC, tensile test, degradation, and swelling test were evaluated. The results demonstrated that high mechanical strength, hydrophilic properties, and a slow degradation rate were observed with the presence and increment of GelMA concentration within the nanofiber composites. The antibacterial potential of GelMA/PCL/CS nanofiber composites was evaluated against P. aeruginosa and S. aureus using a disc diffusion assay. In vitro cell culture research was conducted by seeding NIH 3T3 fibroblast cells on nanofiber composites, proving these cells’ high cell proliferation rate, viability, and adhesion. 10 wt% GelMA-based nanofiber composites were found to have great potential for wound dressing applications.

Cations with suitable sizes to occupy an interstitial site of perovskite crystals have been widely used to inhibit ion migration and promote the performance and stability of perovskite optoelectronics. However, such interstitial doping inevitably leads to lattice microstrain that impairs the long-range ordering and stability of the crystals, causing a sacrificial trade-off. Here, we unravel the evident influence of the valence states of the interstitial cations on their efficacy to suppress the ion migration. Incorporation of a trivalent neodymium cation (Nd3+) effectively mitigates the ion migration in the perovskite lattice with a reduced dosage (0.08%) compared to a widely used monovalent cation dopant (Na+, 0.45%). The photovoltaic performances and operational stability of the prototypical perovskite solar cells are enhanced with a trace amount of Nd3+ doping while minimizing the sacrificial trade-off.

Packaging must have a good commercial appearance and is generally obtained by ink transferred to its substrate. It is important that the ink used in packaging printing is produced from environmentally friendly and sustainable raw materials as well as being suitable for the printing system. The increasing demand in the field of printed packaging and the scarcity of resources to meet this demand have accelerated the search for new sources for inks. For this purpose, inks produced in the laboratory using a modified cellulose-based binder, a commercial acrylic resin and a commercial soybean protein were compared with a commercial ink. As a result of the study, it was determined that the printability properties of the ink obtained by using the modified cellulose-based binder were better than the ink obtained with commercial soybean protein. It was determined that it showed printability properties close to the ink produced with commercial acrylic binders. By using modified cellulose-based water-based flexographic ink instead of other commonly used binders, more environmentally friendly sustainable inks can be produced.

Injecting hydrogen into the natural gas network to reduce CO2 emissions in the EU residential sector is considered a critical element of the zero CO2 emissions target for 2050. Burning natural gas and hydrogen mixtures has potential risks, the main one being the flame flashback phenomenon that could occur in home appliances using premixed laminar burners. In the present study, two-dimensional transient computations of laminar CH4- + air and CH4 + H-2 + air flames are performed with the open-source CFD code OpenFOAM. A finite rate chemistry based solver is used to compute reaction rates and the laminar reacting flow. Starting from a flame stabilized at the rim of a cylindrical tube burner, the inlet bulk velocity of the premixture is gradually reduced to observe flashback. The results of the present work concern the effects of wall temperature and hydrogen addition on the flashback propensity of laminar premixed methane-hydrogen-air flames. Complete sequences of flame dynamics with gradual increases of premixture velocity are investigated. At the flame flashback velocities, strong oscillations at the flame leading edge emerge, causing broken flame symmetry and finally flame flashback. The numerical results reveal that flashback tendency increase with increasing wall temperature and hydrogen addition rate. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Less energy consumption and more efficient use of renewables are among the sustainable energy targets of modern societies. The essential activities to be achieved under these objectives are to increase distributed generation (DG) structures’ applicability. DG systems are small-scale versions of the traditional power grid; they are supported by micro turbines, photovoltaics (PV) modules, hydrogen fuel cells, wind turbines, combined heat and power systems, and energy storage units. The aim of this research is to detail the performance analysis of a proton-exchange membrane fuel cell (PEMFC)-based grid-connected distributed generation system with the help of empirical calculations. To this end, we aimed to establish the system and analyze the performance of the reliable operation of the system with experimental verifications. The findings demonstrate how much power can be generated annually, through real meteorological data, to dispatch to constantly variable loads. While 53.56% of the total energy demand is met by the utility grid, 46.44% of the demand is met by the produced energy i.e., from the DG. The PEMFC-based DG system analyzed in detail in this study was located at Marmara University. According to the results of the performance analysis, significant points of this study will be highlighted to assist the researchers working in this field. Our results are encouraging and can be certified by a larger sample size with neat weather conditions in terms of the percentage of procurement of energy.

The quest for sustainable monomers and \"green\" synthetic pathways for the design, fabrication, and modification of various polymers is of great importance and attracts a great deal of attention. Here, a highly versatile and novel bio-based platform was developed by reacting castor oil with propiolic acid for performing amino-yne click reactions. Owing to the electron-deficient nature of the propiolic acid esters, amino-yne click reactions were conducted with ease at room temperature, in the absence of any catalyst and solvent (as long as the amines were low-viscosity liquids at room temperature), and within 5 min. Several primary and secondary amines were shown to react readily with the developed platform. Furthermore, thermosets were prepared by using the propiolated castor oil and multifunctional amines. The prepared thermosets displayed improved thermal properties and elastomer-like mechanical properties.

Natural dyes have grown in popularity due to their eco-friendliness. They can be used as a substitute for synthetic dyes to minimize environmental pollution. This research investigates the natural colouring behaviour of haar singhar flower (HSF) extract in cotton dyeing. Colorant was extracted under various conditions utilizing various extraction mediums such as aqueous, basic, and acidic. On cotton, it was discovered that applying 55 mL of aqueous extract containing 1.5 g/100 mL sodium chloride for 40 minutes at 70 °C yielded the best colour output. A new hue with good colour fastness was developed utilizing chemical and bio-mordants. The existence of nyctanthin as a colouring agent in haar singhar flowers was discovered through FTIR analysis of the extract. The CIE Lab system revealed that using 2 g/100 mL of pistachio shell as a bio-mordant resulted in good quality reddish yellow hues. It was discovered that ultrasonic radiations have a high potential for isolating colourants and dyeing cotton fabric under decreased conditions of temperature, time and volume. The application of biomordants has made the procedure greener, more efficient, and safer.

This work aimed to comprehensively assess the influence of various surface modifications on the formation of apatite ability for EBM Ti-6Al-4V alloy. Sandblasting (S), acid-etching (E), sandblasting and acid-etching (SE), anodization (NA), micro-arc oxidations in 1M H2SO4solution (SM) and 1M H3PO4solution (PM) methods were applied to modify electron beam melted (EBM) Ti-6Al-4V surface. The α/α’-Ti structures and TiO2phases were detected by XRD. The surface roughness (Ra) values ranged from 0.25 μm and 2.86 μm. The wettability of samples was between around 25° and 104°. The SM sample possessed the lowest contact angle. In vitro tests were employed in the simulated body fluid (SBF) solution for 28 days. The samples with different surface textures demonstrated bioactive behaviors. In vitro test results showed that apatite layers formed on the surfaces. The SM sample exhibited good apatite formation ability when the Ca/P ratios were considered. The apatite formation for the SM sample might derive from high roughness, low contact angle value, the existence of Ti-OH groups, and anatase and rutile phases. The SM can be implemented to boost bioactivity on EBM Ti-6Al-4V alloys.

In this study, two novel silicon phthalocyanines (SiPc) having axial anchoring groups (3: SiPc carrying bis-dibutyl phenoxy acrylic acid and 5: SiPc carrying bis-dibutyl phenoxy carboxylic acid) are synthesized as the photosensitizers of dye sensitized solar cells (DSSCs). The obtained novel photosensitizers are elucidated by using 1H NMR, MALDI-TOF, FT-IR, UV-Vis spectroscopy, and elemental analysis. Moreover, the electrochemistry of SiPcs is investigated with voltametric and in-situ spectroelectrochemical analysis. Both SiPcs illustrate similar two reductions and one oxidation Pc based redox processes. In-situ spectroelectrochemical results support the Pc based characters of the voltametric responses. The chromaticity diagrams and optical responses of the anionic and cationic moieties are recorded with the in-situ spectroelectrochemistry to determine the viability of them for various photoelectrochemical usage. Finally, SiPcs are investigated as dyes in DSSCs in order to investigate the influence of bis-dibutyl phenoxy acrylic acid and bis-dibutyl phenoxy carboxylic acid anchoring groups to the photovoltaic performance of SiPcs. DSSCs sensitized with SiPc (3) and SiPc (5) illustrate good photovoltaic performance with 1.48 and 1.99 mA/cm2 short circuit current density, 0.751 and 0.657 V open circuit potential, 0.52 and 0.57 fill factor, and 0.57% and 0.75% power conversion efficiency respectively.

International audience; Nanofluids have emerged as powerful instruments in heat transfer applications due to their improved thermophysical properties. Additionally, many heat transfer equipments are started to be operated within the range of transitional flow regions in the advances in thermal management enhancement techniques. However, up to date, the friction factor and heat transfer coefficient features of nanofluids within the transitional flow regions and the effect of nanoparticle addition into the base fluid on the laminar-to-turbulent transition characteristics are still not understood clearly with contradictory published results. At this point, this paper comprehensively reviews the studies dealing with the nanofluid flow within the transitional flow regions for internal flow applications. After the presentation of applications of nanofluid flow in the transitional flow regions, the nanofluid properties such as nanoparticle type and concentration and base fluid type in the reviewed studies are given in detail. The pressure drop and heat transfer features of nanofluid flow within the transitional flow regions are distinctly identified and discussed for internal flows. The effect of the nanoparticle addition into the liquid on the transition onset is discussed with results from different research groups. A complete evaluation, challenges and further studies are proposed based on available results in the literature.

Researchers are focusing their efforts on renewable energy sources to avoid future global energy and environmental crises. One of the renewable energy sources, biomass, can be processed using a variety of techniques and thermodynamic cycles. Biomass gasification, for example, has several environmental and technical benefits. Biochar, on the other hand, is produced by the use of a thermal pretreatment technique to biomass, and it can be used to overcome the drawbacks of biomass in gasification operations. Despite the fact that biochar improves the quality and volume of syngas, there is a few research on this topic in the literature. Although researchers have used a variety of process simulators, the number of gasification systems developed in the Aspen HYSYS simulator is very limited, and no circulating fluidized bed (CFB) gasification model for biochar gasification has ever been reported to our knowledge. Based on the non-stoichiometric equilibrium technique, a unique CFB gasifier model was developed in this work. The impacts of various operating parameters on the syngas were evaluated. In addition, the gasification performance of 10 biochar samples with varying physicochemical features was compared to the physicochemical qualities of solid fuels in a steam and CO2 mixture. As a result, biochar samples with a high carbon content formed an H2-rich syngas with a high calorific value during steam gasification. According to parametric studies, the optimum gasification temperature is about 700 ◦C, the optimum gasification pressure is 1 bar, and the optimum ratios of steam/biochar and CO2/biochar are between 0.2–0.3 and 0.5–1.0, respectively.

The use of metal-free click reactions for the design and synthesis of novel flame retardant reactive monomers for thiol-ene photopolymerization is an intriguing area of research. In this study, we have prepared a new, 9,10-dihy-dro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-based, P-and N-containing reactive flame retardant via the metal-free azide-alkyne click reaction. For this purpose, first, azide-functionalized DOPO (DOPO-N-3) has been synthesized via Atherton-Todd reaction, and then this compound has been reacted with acetylene dicar-boxylic acid diallyl ester (ACDAE) to give the flame retardant monomer, namely DOPO-triazole diallyl ester (DTDAE). As prepared flame retardant monomer was characterized by nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) spectroscopies. Thermoset materials prepared by using DTDAE displayed over 90% gel content values. Polar triazole and phosphorous units rendered the surface of the ther-mosets hydrophilic. The thermal stability of the networks was enhanced, char yields increased and the glass transition temperatures (T(g)s) were increased. The limiting oxygen index (LOI) values of the crosslinked materials increased up to 27.8% as the DTDAE content was increased in the formulations. The synthetic method described in this study provides a practical approach for the synthesis of a P-and N-containing flame retardant through a metal-free azide-alkyne click reaction Also, the fact that DTDAE is in a liquid state makes this study valuable as it indicates that it can be easily dispersed. It is also believed this promising compound can be used in different polymer structures and formulations to develop new flame retardants in future studies to be applied in industrial applications.

In this study, 10 mg fluconazole (10 FCZ) and 10 mg gentamicin (10 GEN) loaded with 40% polymethylmethacrylate (40% PMMA) fibers were fabricated by electrospinning and the performance of the formulations (40% PMMA, 40% PMMA/10 FCZ, 40% PMMA/10 GEN, and 40% PMMA/10 FCZ/10 GEN) was tested. 10 mg Gentamicin-loaded 40% PMMA fiber mat showed a more significant zone of inhibition against the S. aureus compared to the zone of 40% PMMA/10 GEN/10 FCZ fiber. The biocompatibility test using a human adipose-derived mesenchymal stem cell (MSCs) as a cell model proved that the amount of loaded and released GEN has no toxic effects on the MSCs.

Tedious trial-and-error procedures are commonly practiced for surface modification of the perovskite solar cell (PSC) active layers. A guideline to rationally choose the passivating functional groups of the polymeric structure that is eminently effective in passivating the charged defects and elongating the device lifetime is hence in urgent demand. Herein, three prototypical polymers, poly(vinyl acetate) (PVA), polyethylene glycol (PEG), and poly(9-vinylcarbazole) (PVK), are selected to investigate the structural effect of the polymeric modification agents on the PSCs. We found that PVA possesses the Lewis base functional group with the minimized steric hindrance and the strongest electron-donating ability, enabling the most effective defect passivation on the perovskite film surface and the most enhanced carrier diffusion capacity. It demonstrates a power conversion efficiency (PCE) of 23.20% and noticeably enhanced operational stability. Our work provides important insights toward the selection of polymeric modification agents for high-performance and long-term stable PSCs.

In the present study, poly(lactic acid) (PLA) and poly(ethylene succinate) (PESu) or poly(ethylene glycol) (PEG) under the framework of quality by design, were blended to produce effective sustained-release matrices for Paclitaxel delivery. A complete physicochemical characterization including weight variation, thickness, water uptake, moisture absorption, moisture loss, and hydrolytic degradation under physiological conditions, was performed. Quality by design approach was applied to study the critical parameters. In vitro cancer toxicity was studied in human cancer cell lines including lung and breast adenocarcinoma. The developed Paclitaxel-loaded films can act as a promising alternative topical matrix as an implant for breast and lung cancer treatment. © 2022 Taylor & Francis Group, LLC. 2-s2.0-85130053009

With the development of the manufacturing industry, machining parameters and material processing efficiency are important due to cost, sustainability, and other parameters, which are determining factors for usage width, material choice, and production rate. Machinability and optimization are among the scientists\" and industry workers\" timely objectives, guiding the manufacturing industries. Thus, the study and analysis of parameters such as surface roughness, tool wear, and force application in superalloy machining would be beneficial in various fields of the manufacturing industry. In this work, RSM (surface response method) modelling and analysis of relationship Fx, Fy, Fz forces between surface roughness of Inconel-718 material, which is a very unique alloy in terms of corrosion resistance, high-temperature elevation, and fatigue values, is examined. From this work, it was found that an experimental design was prepared using the Taguchi method, and the required number of measurements and parameter values were determined with a small number of experiments. Then, the most ideal values were determined using the Response Surface Methodology and ANOVA method to determine the best parameter levels after the surface roughness and cutting forces measurements.

This study proposed a control method, a data-driven predictive control (DDPC), for the hand exoskeleton used for active, passive, and resistive rehabilitation. DDPC is a model-free approach based on past system data. One of the strengths of DDPC is that constraints of states can be added to the controller while performing the controller design. These features of the control algorithm eliminate an essential problem for rehabilitation robots in terms of easy customization and safe repetitive rehabilitation tasks that can be planned within certain constraints. Experiments were carried out with a designed hand rehabilitation system under repetitive and various therapy tasks. Real-time experiment results demonstrate the feasibility and efficiency of the proposed control approach to rehabilitation systems.

Cellulose aerogel (CA) isolated from tea stem wastes (TSW) is a good fire retardant and heat insulator, environmentally friendly, thermally stable and highly porous material with a network structure. These outstanding properties have attracted a huge interest in the materials world. In this study, firstly, following delignification and removing hemicellulose, pure raw cellulose was isolated using TSW, hydrogel form of cellulose was prepared by regeneration of cellulose solution, and then, the final product (CA) was produced via freeze-drying. The data results showed that the aerogel had a three dimensionally network structure. Moreover, it can be deduced that thermal durability of the studied CA could be effective because of its fire retardant and heat insulating property. In addition, the production process of CA is easily available at low cost and sustainable.

Peripherally tetra-4-carboxyethylphenoxy substituted oxotitanium (IV), cobalt(II), zinc(II) and metal free phthalocyanines were synthesized to research the sensitizing abilities of these dye molecules in standard dye sensitized solar cells (DSSCs). All the synthesized phthalocyanine complexes have been characterized by using elemental analyses, UV-Vis, FT-IR, H-1 NMR and MALDI-TOF MS spectroscopic techniques. Electrochemistry of metallo phthalocyanines (MPcs) were studied with electrochemical and in-situ spectroelectrochemical measurements. H2Pc (7) and ZnPc (5) illustrated similar Pc based electron transfer reactions. Differently, CoPc (6) and TiOPc (4) illustrated metal based redox reactions, which enhanced the redox functionality of these complexes. Metal based reductions for CoPc (6) and TiOPc (4) were recorded in addition to the Pc based one. In-situ spectroelectrochemical measurements supported the proposed voltametric mechanism. Moreover, the color and spectra of the electrogenerated species were determined with the in-situ spectroelectrochemical analyses to predict possible optoelectrochemical application of the complexes. Pronounced optical and color changes during the electrolysis of the complexes indicated electrooptical and possible solid state electrochemical functionality of the complexes. TiO2 semiconductor on the fluoride doped indium tin oxide coated glass electrode (FTO) was decorated with H2Pc (7) and TiOPc (4) bearing four carboxyl anchoring groups and they were first of all tested as possible dye for the DSSC. H2Pc (7), TiOPc (4), CoPc (6) and ZnPc (5) dyes used in DSSCs showed 2.9%, 3.3%, 1.02% and 2.2% of power conversion efficiencies respectively.

In this study, a new Donor-Acceptor-Donor (D-A-D) electroactive molecules (HCQM1 and HCQM2) containing 9H-carbazole and 9-phenyl-9H-carbazole as donor along with quinoxaline (HQ) as acceptor were synthesized and then coated on Indium Tin Oxide/Glass (ITO/Glass) surface by the electrochemical oxidation process. The HOMO-LUMO band gap values obtained by electrochemical oxidation and reduction onsets were calculated as 2.64 and 2.68 eV, respectively. On the other hand, UV-Vis absorption measurements showed that the charge transfer band of HCQM1 was detected at 500 nm with 50 nm red shift upon compared with the HCQM2. According to AFM results, it is seen that the roughness of the poly(HCQM2) film is higher than the poly(HCQM1) film. Finally, the polymer film of HCQM2 showed multi-electrochromic color change (yellow, green, and dark blue) upon the oxidation process. When the electrochromic performance of the HCQM1 and HCQM2 polymer films was compared, it was discovered that the HCQM2 with phenylene spacer unit has better stability and a higher percentage transmittance change (& UDelta;T%) between neutral and oxidized states.

This paper proposes a framework to extract knowledge-management elements from business systems in healthcare organizations. According to results of in-depth interviews with experts in the field, a framework is defined, and software was developed to generate log files. Following the application of the Bag of Words (BoW) method on log files of 455 days for feature extraction, the k-means algorithm was used to cluster the feature vectors. The framework was tested with queries for confirmation. The developed framework successfully clustered the generated reports at operational, tactical, and strategic levels to extract knowledge-management elements. This study provides evidence for the knowledge-management pyramid by finding that the generated reports are reviewed mostly at the operational level, then tactical, and then the least at the strategic level. Our framework has the potential to be used not only in the health sector, but also in banking, insurance, and other businesses using business intelligence, especially in accordance with the organization’s goals at operational, tactical, and strategic levels of the knowledge-management pyramid.

In this study, metal and metal-free novel phthalocyanines containing peripheral and non-peripheral tetra 2-ben-zylphenoxy groups were synthesized. The compounds were characterized by UV-Vis, FT-IR, H-1 NMR, and MALDI-TOF mass spectrometry as well as elemental analysis. These new phthalocyanines exhibited excellent solubility in most organic solvents, and their redox behavior was investigated in different solvents such as dimethyl sulfoxide (DMSO) and dichloromethane (DCM). The redox behavior of the peripheral and non-peripheral phthalocyanine compounds 1a -c and 2a -c was determined by cyclic voltammetry and in situ spec-troelectrochemistry. According to organic field-effect transistors (OFETs) measurements, the peripheral and non-peripheral phthalocyanine-cobalt complexes which have higher mobility than others were utilized top-gate bottom-contact OFETs fabrication. The output characteristics of the device show that its mobility is approximately 5 x 10(-2) cm(2)/Vs with p-type accumulation.