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Hydroxyapatite (Hap) doped or embedded with silver has shown improved bactericidal properties, and its mechanical properties were greatly improved by doping or impregnating Hap with metals such as Magnesium or Zinc, or by impregnating Hap with metal oxides such as MgO, or ZnO. This work describes the preparation of Ag-ZnO-Hap nanocomposites with 4 different Ag-ZnO–Ca mole ratios. XRD, FTIR, SEM, and TEM analysis of all prepared materials identified Hap as the only crystalline phase present in all samples exhibiting a uniform rod-like morphology with particles in the 20–40 nm size range. Microwave Plasma-Atomic Emission Spectroscopy confirmed the presence of zinc and silver in all embedded Hap samples. The antibacterial activity was tested against two different strains; Escherichia coli (E. coli (MV10Nal), and Gram-negative Aggregatibacter actinomycetemcomitans (A.a). The mechanical testing consisted of evaluating breaking force, work of fracture, and brittleness/ductility of Hap and Ag/ZnO/Hap composites. Our study clearly shows that reinforcing Hap with silver and zinc oxide yields superior bactericidal and mechanical properties.

The structure-function relationships of plant-based proteins that give rise to desirable texture attributes in order to mimic meat products are generally unknown. In particular, it is not clear how to engineer viscoelasticity to impart cohesiveness and proper mouthfeel; however, it is known that intermolecular β-sheet structures have the potential to enhance the viscoelastic property. Here, we investigated the propensity of selected peptide segments within common corn α-zein variants to maintain stable aggregates and β-sheet structures. Simulations on dimer systems showed that stability was influenced by the initial orientation and the presence of contiguous small hydrophobic residues. Simulations using eight-peptide β-sheet oligomers revealed that peptide sequences without proline had higher levels of β-sheet structuring. Additionally, we identified that sequences with a dimer hydrogen-bonding density of >22% tended to have a larger percent β-sheet conformation. These results contribute to understanding how the viscoelasticity of zein can be increased for use in plant-based meat analogues.

Hydrogen production through hydrolysis of sodium borohydride (NaBH4) by using metal catalysts is promising for fuel cell applications. Nickel (Ni) and its alloys are favorable due to their high catalytic activity, relatively low cost and availability. In present study, the effects of temperature, pH, reduction rate and reducing agent concentration, which significantly affect the catalyst performance, were investigated using the response surface methodology (RSM). A mathematical model was derived according to results which were obtained from four-level orthogonal Taguchi L16 (44) experimental design used for the optimization of multiple parameters in the process. From the RSM analyses, that compatible with the predicted experimental results, maximum hydrogen generation rate (HGR) 49.81 L min(-1) gcat(-1) was obtained temperature of 278.12 K, pH of 5.52, reducing agent concentration of 85.96 NaBH4.water(-1) and reduction rate of 6.82 mL min(-1). Analysis of variance reveals that both pH and rate of reduction have significant effect than the temperature on the HGR. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Efficient hydrogen generation is a significant prerequisite of future hydrogen economy. Therefore, the development of efficient non-noble metal catalysts for hydrolysis reaction of sodium borohydride (NaBH4) under mild conditions has received extensive interest. Since the transition metal boride based materials are inexpensive and easy to prepare, it is feasible to use these catalysts in the construction of practical hydrogen generators. In this work, temperature, pH, reducing agent concentration, and reduction rate were selected as independent process parameters and their effects on dependent parameter, such as hydrogen generation rate, were investigated using response surface methodology (RSM). According to the obtained results of the RSM prediction, maximum hydrogen generation rate (53.69 L. min−1gcat-1) was obtained at temperature of 281.18 K, pH of 5.97, reducing agent concentration of 31.47 NaBH4/water and reduction rate of 7.16 ml min−1. Consequently, after validation studies it was observed that the RSM together with Taguchi methods are efficient experimental designs for parameter optimization.

Amide I and Amide III vibrational modes are frequently used to study protein secondary structure with Fourier transform infrared (FT-IR) spectroscopy. However, for protein mixtures, neither the sole Amide I nor Amide III region provides sufficient information for structural quantitation because of overlapping peaks, especially in the Amide I region. Here, an improved quantitative approach is proposed to estimate secondary structure of protein systems using resolution enhancement and curve-fitting data processing techniques on a gluten model system to investigate structure-function relationships. Twelve different scenarios were prepared to assign bands in the Amide I region. Frequency ranges of 1660–1640 cm−1 and 1665–1660 cm−1 were found to highly contribute to variability in secondary structure contents of samples. Utilization of the Amide III region as a conducive tool to assign bands in the Amide I region led to a better differentiation of some secondary structural motifs and a more accurate quantitation of protein secondary structure. The study presents an understanding of FT-IR data analysis for a quick technique to assess secondary structures of protein mixtures.

Viscoelasticity of corn zein is associated with the formation of β-sheet secondary structures; however, studies of the fundamentals of this conformational change are limited due to zein insolubility and poor analytical resolution. Here, changes in soluble zein conformation were evaluated as the protein self-assembles in increasingly hydrophilic solvents to the concentration just before aggregation and precipitation. Circular dichroism spectra of zein showed that α-helix structures decrease in favor of random coil and β-sheets with increases in water content in an ethanol-water system, similar to observations of zein when it becomes viscoelastic in dough systems. This was further supported by changes in Thioflavin T fluorescence emission spectra and intrinsic viscosity measurements. Two widely recognized molecular models for α-zein (hairpin and superhelical conformations) were tested at 75 and 45% ethanol concentration using molecular dynamics simulation for agreement with experimental results. Increase in solvent hydrophilicity increased β-sheets and reduced distance between backbone anomeric carbons only for hairpin model, suggesting it to be the more valid of the two. These findings emphasize the importance of transformation to β-sheets during zein self-assembly and provide further insight into the mechanisms by which the protein is functionalized into viscoelastic systems.

The aim of the study was to investigate whether retinal neurovascular structural impairment in children and adolescents with type 1 diabetes mellitus (T1D) without clinical signs of diabetic retinopathy (DR) could be detected early via optical coherence tomography (OCT) and OCT angiography (OCTA). In the current prospective, cross-sectional, observational clinical study children and adolescents with T1D without DR were evaluated between December 2018 and May 2019. Retinal neurovascular structures in the macular and optic disc regions were examined in detail and quantitatively assessed using OCT and OCTA. Data from subjects with T1D were compared with data from healthy controls. Whether retinal neurovascular structural changes were significantly associated with puberty stage, diabetes duration, and HbA1c level was also investigated. The T1D group included 110 eyes and the control group included 84 eyes. In the T1D group the mean inside disc vessel density (VD) was significantly lower than that of the control group (p

Olive mill wastewater (OMW) is produced in large quantities in the production of olive oil with the three-phase method. This waste, which is not biodegradable and characterized by a heavy organic load containing toxic components (such as phenols), is usually given to aqueous receptors or soil, either directly (untreated) or treated inadequately. Biologically active phenolic compounds that inhibit biodegradation of this waste are toxic at high concentrations, especially for microorganisms, but have positive effects with strong antioxidant properties on human health when properly isolated and properly concentrated. Hydroxytyrosol (HT) is one of the most interesting and abundant compounds among the biophenols present in OMW. According to this study, a newly synthesized nanomaterial, graphene oxide (GO), has been utilized for the separation of HT and total biophenolic substance from OMW. Graphene oxide from graphite oxidation was synthesized using a modified Hummer’s method. In order to understand how GO behaves during thermal degradation, thermogravimetric/differential scanning calorimetry analyses were performed. Two-parameter and three-parameter equilibrium isotherm models and kinetic models have been used to determine the mechanism of kinetic sorption and adsorption type. Thermodynamic data indicate that the adsorption process is exothermic, applicable and spontaneous.

With the discovery of graphene, the necessary synthesis studies have been carried out for the use of graphene oxide (GO) as an adsorbent to remove toxic materials. In this study, GO nanopowder was ...

In this study, a novel nanomaterial, graphene oxide (GO), which has never been used as an adsorbent in the separation of hydroxytyrosol (HT), has been utilized. GO nanosheets were synthesized by graphite oxidation naturally, which is known as modified Hummer's method. Then, the material obtained was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods. Adsorption of HT from aqueous media onto synthesized GO was found to be >85% under optimum conditions (with 0.01 mg GO in 10 mL of solution at 150 rpm for 1440 min, where pH is 9). On the other hand, equilibrium (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Redlich-Peterson) and kinetic (pseudo-first order, pseudo-second order, Elovich and intra-particle diffusion) models have been applied for analysis and representation of data. Thermodynamic findings point out that the related adsorption system is exothermic, applicable and spontaneous. © 2019 117M848 The authors thank The Scientific & Technological Research Council of Turkey (TÜBİTAK) for financial support for this research project (Grant number: 117M848 ).

Biohydrogen production from dairy wastewater with subsequent biogas purification by hollow fiber membrane module was investigated in this study. The purified and not purified (raw) biohydrogen were used as fuel in polymer electrolyte membrane (PEM) fuel cell. Furthermore, the effect of CO2 on the performance of PEM fuel cell was evaluated considering cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and polarization curves. The maximum H2 production rate was 0.015 mmol H2/mol glucose and the biohydrogen concentration in biogas was ranged 33%–60% (v/v). CO2/H2 selectivity decreased with increasing pressure and maximum selectivity was obtained as 4.4 at feed pressure of 1.5 bar. The electrochemical active surface (EASA) areas were decreased with increasing CO2 ratio. The maximum power densities were 0.2, 0.08 and 0.045 W cm−2 for 100%, 80% and 60% (v/v) H2, respectively. The results indicated that integrated PEM fuel cell/biogas purification system can be used as a potential clean energy sources during acidogenic biohydrogen production from dairy wastewater.

This study presents a potential application for adding value to corn gluten meal, which is often used as animal feed and underutilized in food industry. This study is aimed to improve water holding ability of zein-rich by product corn gluten and investigate possibility of using it as an emulsifier. The potential use of microfluidization (500–1250 bar and 25 °C) and pH shifting (to pH6, 8, and 10) as a modification process for corn gluten meal and their effects on emulsifying properties were investigated. The formulations used for CGM(g):corn oil (mL) mixtures were 5:15, 5:30, 5:50, 10:15, 10:30, 10:50, 15:15, 15:30, and 15:50. Microfluidization and pH modification decreased the particle size of emulsions, resulting in the formation of tissues and micropores, and a consequent increase in surface area and water-holding capacity. pH shifting in dispersions around neutrality (pH6 and pH8) provided improvements in emulsion properties; however, excessive shifting (pH10) caused protein denaturation. Herschel-Bulkley model was well-fitted to explain flow behaviors. Flow and viscoelastic measurements showed that all formulations exhibited shear thinning and elastic gel-like behavior. The sedimentation rate, measured using LUMiSizer, was decreased by microfluidization and pH modifications. This study showed that these treatments can be used to convert an underutilized material into a valuable one in food industry.

This study presents a Fenton digestion method for milk samples based on UV irradiation for cadmium determination using flame atomic absorption spectrometry. The method was developed as an alternative to microwave digesters, using very basic apparatus and easy to acquire chemicals. Fenton digestion process was performed by the help of citric acid coated magnetic nanoparticles. Optimum conditions of the digestion process were applied to milk samples to evaluate analytical performance of the method. Limit of detection and limit of quantification values calculated for cadmium in milk were 0.53 and 1.8 mg/L, respectively. The method was applied to three different milk samples to validate the method's suitability and accuracy. Percent recovery values calculated for the samples spiked at two different concentrations ranged between 86 and 111%. Due to differences in the content of the spiked and control/standard milk samples, exact matrix matching calibration strategy using the same brand of milk sample in the preparation of calibration standard was employed and the accuracy of cadmium quantification was greatly enhanced (≈100%).

OBJECTIVE: To evaluate vascular changes in the early period after coronavirus disease 2019 (COVID-19) infection and at 6-month follow-up. METHODS: This study included 50 eyes of 25 patients who had been hospitalized for polymerase chain reaction-positive COVID-19 infection and 50 eyes of 25 healthy individuals. All subjects underwent optical coherence tomography angiography using a 6 × 6 macular protocol in the early period after hospital discharge and 6 months later. Foveal vessel density (VD) and parafoveal VD values were measured from 4 quadrants (superior, inferior, nasal, and temporal) of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). The choriocapillaris (CC) flow area and the foveal avascular zone area also were measured. The OCTA measurements of the patient group were compared both between time points and with the control group at each time point. RESULTS: COVID-19 patients showed lower VD values than control subjects in all parafoveal quadrants of both the SCP (superior, p = 0.01; inferior, p = 0.048; nasal, p = 0.003; temporal, p = 0.048) and the DCP (superior, p = 0.001; inferior, p = 0.011; nasal, p = 0.012; temporal, p = 0.018) at the initial checkup and in all parafoveal quadrants of the SCP (superior, p = 0.0001; inferior, p = 0.007; nasal, p = 0.001; temporal, p = 0.017) and in 2 of the parafoveal quadrants of the DCP (superior, p = 0.003; inferior, p = 0.016) at 6-month follow-up. CC flow area values were significantly lower at the 6-month follow-up than at the initial examination (p = 0.044). CONCLUSION: It is important to perform appropriate follow-up for COVID-19 patients because retinal vascular flow changes may persist in the long term.

A series of thin Pt-Co films with different metal ratios were deposited by using the sequential cosputtering directly on a commercial hydrophobic carbon paper substrate at room temperature and in ultra-high vacuum (UHV) conditions. Their electrocatalytic properties toward the oxygen reduction reaction were investigated in 0.5 M $H_2 SO_4$ solution by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) on rotating disc electrode (RDE). The results showed that Pt particles, deposited by dc-magnetron gun, surround the large Co-clusters deposited by rf-magnetron gun. In addition, the increase of Co content led to an increase in the electrochemical active surface area $(EASA) from 23.75 m_2 /gPt to 47.54 m_2 /gPt for pure Pt and Pt:Co (1:3),$ respectively, which corresponded the improvement of the utilization of Pt by a factor of 1.91. This improvement indicated that the sequential magnetron cosputtering was one of the essential technique to deposit homogeneous metal clusters with desirable size on the gas diffusion layer by adjustment plasma parameters.

OBJECTIVE: To examine the changes in choriocapillaris and retina caused by coronavirus disease 2019 (COVID-19) by comparing optical coherence tomography angiography (OCTA) findings of COVID-19 patients and healthy controls. METHODS: The study and control groups consisted of 54 eyes of 27 participants, each. Patients and controls underwent OCTA examination. Foveal zone vessel density and parafoveal zone vessel density (for 4 quadrants: nasal, temporal, superior, inferior) were calculated for both superficial and deep capillary plexuses. Additionally, choriocapillaris flow and foveal avascular zone areas were calculated. RESULTS: For the parafoveal area in the study group, vessel density was significantly lower in the superior and nasal quadrants of the superficial capillary plexus and in all quadrants of the deep capillary plexus compared with controls (p < 0.05 for all). The study group had significantly higher choriocapillaris flow area values compared with controls (p = 0.042). CONCLUSION: Reduced vessel density of the retinal capillary plexus was detected in COVID-19 patients who may be at risk for retinal vascular complications.

Recent studies show that carbonaceous materials have gained interest because of their superior features over the alternative adsorbents. Therefore, it is of great value to synthesize novel carbonaceous adsorbents. In the present study, graphene oxide nanopowders (GON) were synthesized through a modified Hummer’s method. The material has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) methods. Naproxen has been selected as the model pharmaceutical to investigate the adsorption performance of GON. The highest adsorption removal was found to be 65.28% under the optimum conditions (0.03 g of GON for the adsorption of 10 mg/L naproxen solution at 100 rpm mixing the speed of shaking bath). The relevant adsorption system was an exothermic, spontaneous, and chemisorption process depending on the kinetic (pseudo-first order, pseudo-second order, intraparticular, and Elovich models), equilibrium (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Harkin-Jura, and Halsey isotherm equations), and thermodynamic parameters.

Corn gluten meal is an underutilized byproduct due to its hydrophobic nature although it contains high amount of protein. The primary objectives of this study were to enhance the water holding capacity of this protein-rich byproduct with microfluidization technique and use it in bread-making formulations instead of gluten with the addition of different supplements. The increase in stability, surface area, and consequently water holding capacity with microfluidization resulted in the formation of compatible and homogeneous dough structure for gluten-free bread formulations. The dough exhibited linear viscoelastic behavior at strains lower than 0.5%. Elastic moduli were higher than viscous moduli for all formulations, meaning solid-like behavior. The addition of xanthan and citrus fiber resulted in higher moduli values. The decrease in particle size and the emergence of new tissues resulted in revealing of carotenoids like lutein and zeaxanthin, responsible for the yellow color of corn gluten meal. The breads produced from microfluidized samples had 1.19–1.27 times higher specific volumes than untreated samples of the same formulation. Similar improvements (1.03–1.22) were obtained with the addition of xanthan and citrus fiber. Both microfluidization treatment and the addition of supplements led to lower hardness, and higher cohesiveness and springiness values.

There are two main obstacles preventing the commercialization of polymer electrolyte fuel cells (PEMFCs) such as low durability of support material and high cost of metal catalyst. It is necessary to use support materials to increase the distribution of the catalysts and to be accumulated more in the active area. Despite widespread usage of carbon as support material, carbon suffers from oxidation under fuel cell working conditions. In the past several years, researchers have given many efforts to develop new support materials, which have high surface area, and are electrically conducting and chemically stable. Among all support materials, graphene, thanks to two-dimensional graphite form, has unique physical and electrical properties; because of these superior features, graphene can be an ideal support material for nanoparticles. In this study, we updated the Hummers' method by addition of certain amount of potassium dichromate in addition to potassium permanganate as oxidant agent. After that, graphene oxide was uniformly coated with conductive polyaniline (PANI) polymers by the liquid-liquid interface polymerization method. Finally, PANI/GO composite was pyrolyzed at certain temperature and time to reduce graphene oxide to few layers of graphene. Electrochemical active surface area (EASA) of commercially obtained Pt/VulcanXC-72 was calculated as 29.5m(2)/gPt, while EASA of Pt/RGO catalysts was 63.7m(2)/gPt.

Background The availability and movement of water inside the food materials play essential roles for food stability by affecting their physical and chemical properties, and microbiological activity. Understanding the moisture sorption behavior is a necessary step to control food properties. Food processing unit operations like drying and cooking influence the behavior of starch since such systems trigger swelling or shrinkage as a result of moisture sorption or desorption mechanisms. Also, these processes alter many aspects of starch-containing foods such as acceptability, nutritional value, quality, and shelf-life. Scope and approach Therefore, understanding the water transport in starchy foods and the changes occurring in functional properties of starch has a great importance to describe and model their sorption and drying behavior. First, the primary mechanisms occurring during water transport such as moisture sorption, swelling, gelatinization, and glass transition are discussed using experimental results presented in the literature. Additionally, the hybrid mixture theory (HMT) and its potential for predicting transport mechanisms in starchy foods is discussed. Key findings and conclusions In addition to experimental considerations, the mathematical modeling provides complementary information to predict the heat and fluid transfer. The hybrid mixture theory based multiscale models are able to describe the physico-chemical changes and general transport mechanisms occurring within a porous food matrix. This theory can also be used to predict the quality changes in food products during processing.

This study presents the potential of microfluidization as a value adding process to corn gluten meal (CGM), which is often used as animal feed and is underutilized in food industry. In this study, we aimed to improve water holding ability of corn gluten and to investigate possibility of using this zein-rich byproduct as the main ingredient in gluten-free bread formulations. For this reason, microfluidization as a milling process for CGM, and its effects on rheological and textural properties of gluten-free bread formulations were investigated. In addition, the effects of pH modification and hydrocolloids were analyzed. Microfluidization led to a higher surface area by disintegrating the large CGM molecules, and the structure became compatible to be used in gluten-free bread formulations by overcoming hydrophobic nature. However, structural deformations were detected with pH modifications. The linear viscoelastic region of dough was observed at strains lower than 0.5%. For all formulations, elastic moduli (G') were higher than viscous moduli (G") indicating solid-like behavior. The addition of HPMC and guar resulted in higher moduli values. Microfluidization and pH modifications provided brighter color by revealing lutein and zeaxanthin due to decreased particle size. Texture profile showed that microfluidization and hydrocolloids decreased hardness, increased springiness and cohesiveness, which are desired characteristics for bread. Lastly, the addition of hydrocolloids led to an increase in specific volume by providing gas retention within the structure. HPMC provided 1.23-1.62 times bigger samples than control samples while it was only 1.02-1.12 times bigger for samples with guar according to specific volume analysis.

While increasing cases related to gluten intolerance have encouraged scientists to develop healthier and better-quality gluten-free products, a more ideal viscoelastic behavior is still needed. In this study, we systematically investigated a dough system composed of corn zein, starch, and additional protein (5% of total protein, termed "co-protein") to achieve similar rheological properties of wheat dough. Three types of starches (corn, wheat, and rice) and four types of co-proteins (casein, sodium caseinate, gliadin, and glutenin) were combined with zein at room temperature and at 35 °C, above zein's glass transition temperature. In small and large deformation tests, only rice starch was found to improve significantly the functionality of zein dough, resulting in formulations with similar rheological properties to wheat dough, i.e., low phase angle value, high complex modulus, and high extensional viscosity implying an elastic dough with high strength and resistance to deformation. Rice starch also significantly lowered glass transition temperature of zein dough, associated with improved performance even at room temperature. Combining zein with a proper starch type, and in cases co-proteins, substantially improved rheological properties of zein dough similar to that of wheat dough, with potential implications to the gluten-free and the plant-based protein market.

Complete starch extraction has been a problem in the corn wet-milling, and here enzymes affecting different structures were used to provide a thorough understanding of the contribution of those structures to starch and protein retention for a way to achieve higher extraction rates. The combination of Frontia Fiberwash® (mix of cellulases and xylanases) and Olexa® (protease) led to an increase in starch (4.5 %) and protein (3.0 %) extraction. Enzymes changed secondary structure composition of proteins due to change in concentration of protein sub-fractions. The protein matrix around starch granules, the key factor for starch retention, was weakened with reducing agents/acids or ultrasound, which better separated starch and protein bodies. Chemicals led to 3.3–5.4 % and 0.7–1.7 % increase in starch and protein extraction, respectively, whereas an ultrasound treatment resulted in 2.2 % and 0.6 % increase. Overall, the study showed starch granules and protein bodies can be freed from wet-milled fiber fraction leading to higher extraction rate when the protein matrix is loosened.

Complete starch extraction has long been an issue in the wet-milling industry, and here structures in the fine and coarse fiber fractions that retain starch were identified and quantified for potential treatments to increase starch and protein extraction rates. Six main structures were identified in the fiber fraction and three of them were directly related to the retention of starch granules. Elemental composition analysis to quantify the contribution of structures responsible for starch retention showed that the protein matrix contributed to 54 % of total starch retention. Confocal microscopy showed that starch granules in the peripheral region of vitreous endosperm were embedded in the protein matrix, whereas the ones in the central region were either stuck in the cell wall polysaccharides or almost free to be liberated. Secondary structural composition of proteins showed differences in fine and coarse fiber fractions. Protein disruption would lead to the largest increase in starch extraction.

In this study, graphene oxide (GO) nanosheets were evaluated for the recovery of biophenols from an agricultural biomass, olive leaf. Modified Hummer's method was used to synthesize GO by natural oxidation of graphite. The adsorbent was characterized by several novel analysis methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the other hand, optimization of the adsorption process was applied utilizing multivariate statistic technique such as Response Surface Methodology (RSM) in order to consider any possible interaction between variables with less number of experiments as well as to model a response affected by several variables. The outcome of the present study indicates that the optimum conditions for the adsorption of were 4.57/10 of pH together with 24.62/30 °C of temperature and 3 mg of GO to achieve the maximum yields of each dependent variable such as total biophenol content (TBC) and the most prevalent compound, oleuropein (OC). The verification of the calculated models was held by several error function analysis. © 2017 Elsevier B.V.

In the present work, new and efficient Cobalt–Titanium–Boride (Co–Ti–B) catalysts were developed for catalytic hydrolysis reaction of alkaline NaBH4 solution. Hydrogen generation rate was measured using the ternary Co–Ti–B catalyst as a function of different Ti concentration, solution temperature, NaBH4 concentration, and NaOH (a base-stabilizer) concentration. The performance of the system was analyzed from thermodynamic points of view and compared with the pristine Co–B catalyst. In addition to high catalytic efficiency, the catalyst must also comprise important features like high stability in severe conditions and should have high tolerance against deactivation. The highest hydrogen generation rate was obtained with 5% Ti/(Ti + Co) molar ratio, and for this catalyst the optimum fuel concentration was identified as 5 wt.% NaBH4 with 5 wt.% NaOH.

Nanocomposites stand out as promising materials in many fields due to their properties such as strength, hardness, thermal stability, and lightness. Introducing self-healing ability to polymer nanocomposites provides new guidelines for strong, sustainable, and durable materials. Microcapsule-based self-healing materials work independently of an external stimulus such as pH, heat, light and solvent. In this paper, we developed autonomously self-healing UV-cured polyurethane graphene oxide nanocomposite coatings by means of efficient and useful copper-catalyzed azide-alkyne (CuAAC) click chemistry. Low molecular weight tetra-arm azide was successfully capsulated within poly(vinyl formal) capsules. Alkyne functional graphene-oxide reinforced nanocomposites containing azide microcapsules were prepared through photo-polymerization. The self-healing ability and anti-corrosion properties of the nanocomposites were studied after the damage occurred. The self-healing experiments show that the microcapsules provided a self-healing efficiency of around 70% after 24 h. Chemical, morphologic, mechanical, and thermal properties of the films were investigated. Furthermore, the electrochemical analysis of films showed that the microcapsule containing films has a higher polarization resistance and a lower corrosion current.

Electrochemical properties of porous nickel (Ni) foam, electrodeposited zinc (Zn) on Ni foam (Ni–Zn) and electrodeposited reduced graphene oxide (rGO) on Ni–Zn foam electrodes (Ni–Zn-rGO) in 6 M KOH electrolyte were investigated. Cyclic voltammetry (CV) and galvanostatic charge–discharge cycling (GCD) techniques were used to carry out the redox interactions, and cycling capacitive properties of the electrodes in KOH solution. Platinum (Pt) and gold (Au) foil were used as a counter electrode and the current collector in the electrochemical measurements, respectively. The specific capacitances of the electrodes were found from the GCD measurements as 155, 722 and 1820 F/g for Ni, Ni–Zn and Ni–Zn/rGO electrodes at the current density of 1 A/g, respectively. Scanning electron microscope (SEM) images of the three electrodes were also taken into account to associate all the electrochemical measurements. These results clearly show that specific capacitance values highly increased after the deposition of Zn and rGO to Ni electrode.

WOS: 000423584300006, Phenol is considered to be a priority pollutant due to its toxicity and carcinogenic effect. Thus, innovative and effective methods have been developed to remove undesired phenol from wastewater. Membrane processes are one of the innovative and effective methods used for the removal of phenol from wastewater. In this study, we investigate the effect of carbon and graphene oxide (GO) coating on phenol removal efficiencies of microfiltration, ultrafiltration, and nanofiltration membranes. Obtained results show the removal efficiencies of all membranes increase with rising pressure. Among all membranes, the carbon-coated nanofiltration membrane (NF90) showed the highest performance with a removal efficiency of 99% under a pressure of 6 bars. The physico-chemical properties of the coated and uncoated membranes were investigated by using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction and contact angle techniques (WCA).

Performance of cathode materials in microbial fuel cell (MFC) from dairy wastewater has been investigated in laboratory tests. Both cyclic voltammogram experiments and MFC tests showed that Pt-Ni cathode much better than pure Pt cathode. MFC with platinum cathode had the maximum power density of 0.180 Wm(-2) while MFC with Pt: Ni (1:1) cathode produced the maximum power density of 0.637 Wm(-2), even if the mass mixing ratio of Pt is lower in the alloy were used. The highest chemical oxygen demand (COD) removal efficiency was around 82-86% in both systems. The cyclic voltammogram (CV) analyses show that Pt: Ni (1:1) offers higher specific surface area than Pt alone does. X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) results showed that entire Pt: Ni (1:1) alloys can reduce the oxygen easily than pure platinum, even though less precious metal amount. The main outcome of this study is that Pt-Ni, may serve as a alternative catalyst in MFC applications. (C) 2015 Elsevier Ltd. All rights reserved.

The corrosion inhibition characteristics of quaternized 1,(4)-tetrakis[(2-mercapto)pyridine]phthalocyanine (I) and 2,3-octakis[(2-mercapto)pyridine] phthalocyanine (II) on aluminum in 0.1 M HCl solution has been studied by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The maximum inhibition efficiency was obtained for compound I with two-electrochemical techniques applied. Langmuir isotherm fits well the experimental data. The inhibition efficiency increases with increase in the phthalocyanine concentration, but decreases with an increase in temperature. The phthalocyanines act predominately as cathodic inhibitor.

The aim of the present work is to investigate the kinetic properties of Co-B nanoparticles which are deposited on graphene sheets by simultaneous chemical reduction of Co+2 and graphite oxides using NaBH4 as the reducing agent. The reduced Co−B/graphene nanocomposites were characterized by X-ray diffraction, and the effects of the concentration of NaBH4, NaOH, and hydrolytic temperature were discussed in detail. The results show that the concentration of NaBH4 and NaOH indeed exerted a significant impact on the hydrogen generation rate of Co-B/graphene catalysts. Reaction rate of hydrolysis first rises up and then decreases subsequently with the rising of NaOH and NaBH4 concentration. The results show that the Co-B/graphene catalyst has the high catalytic activity with activation energy of 52.45 kJ·mol−1, and showed high resistance against deterioration and stability as a function of time. The present method is promising for the synthesis of effective supported catalysts for hydrolysis of NaBH4.