Catalytic activity,stability and impedance behavior of PtRu/C,PtPd/C and PtSn/C bimetallic catalysts toward methanol and formic acid oxidation

PtRu, PtPd and PtSn with weight ratios of (2:1) on carbon black (Vulcan XC-72) supported bimetallic catalysts were prepared by using microwave method via chemically reduction of H₂PtCl₆·6H₂O, RuCl₃, PdCl₂ and SnCl₂·2H₂O precursors with ethylene glycol (EG). These prepared catalysts were systematically investigated and obtained results were compared with commercial Pt black, PtRu black catalysts and with each other. The catalysts were characterized with XRD, ICP-MS, EDS and TEM. The electrocatalytic activities, stability and impedance of the catalysts were investigated in sulfuric acid/methanol and sulfuric acid/formic acid mixtures using electrochemical measurements. The results showed that PtSn/C catalyst showed comparable activity and durability with commercial Pt/C catalyst toward methanol oxidation. The synthesized PtRu/C catalyst was found to completely oxidize methanol and it showed more catalytic activity than commercial PtRu catalyst. Bimetallic PtPd/C catalyst gave better activity than both commercial Pt black and synthesized Pt/C catalyst for oxidation of formic acid. Higher electrochemical active surface areas were obtained with supported bimetallic catalysts.     

Screening of the most consumed beverages and spices for their bioactive non-nutrient contents

The present research emphasizes on the bioactive non-nutrient components of the frequently consumed food products daily. The most popular beverages (instant, filter and Turkish coffee, green, black, sage, apple, rosehip, linden and fennel tea infusions) and herbal spices (cinnamon thyme, cumin, mint, sweet pepper, chili pepper, sumac, black pepper and clove) were investigated to evaluate the antioxidant capacities of the samples. Amount of total biophenols (TB) and total flavonoids (TF) were measured by Folin–Ciocalteu and Aluminum chloride colorimetric methods, respectively. CUPRAC (The cupric ion reducing antioxidant capacity) assay and DPPH (α, α-diphenyl-β-picrylhydrazyl) free radical scavenging method were applied to determine the antioxidant activity (AA) of the products. Antimicrobial analyses of the samples were also conducted based on in vitro study. Furthermore, the main biophenol of each sample was identified through high performance liquid chromatography (HPLC). The outcome of the present study will be a useful guidance for the researchers looking for the health benefits of these daily consumed food products.     

Model predictive force control in milling based on an ensemble Kalman filter

Journal of Intelligent Manufacturing - Process force determines productivity, quality, and safety in milling. Current approaches of process design often focus on a priori optimization. In...     

Comparative evaluation of granules made with different binders by a fluidized bed method

Granules were prepared using three different binders, pregelatinized starch (PGS), gelatin (GEL), and polyvinylpyrrolidone (K30) by a fluidized bed method. As a quantitative measurement of mechanical strength or abrasion resistance, granules were subjected to a friability test for certain periods of time, and friability indexes (FI) as a function of time were calculated. The data obtained were analyzed by applying standard mathematical models. According to the derived parameters of the logistic and Weibull models, which fit best to the data, mechanical strength of granules made with K30 was observed to be lower than that of the granules of PGS and GEL which have similar values of model parameters. Flow properties, consolidation, and compressibility behaviors of unfriabled (UFR) and friabled (FR) granules, which were selected based upon their Weibull time parameter, were investigated as comparative. The flow rate of granules decreased due to diminishing particle size depending on binder type and friability, but the values of angle of repose were within the acceptable limits. Regarding consolidation behavior, the change of relative density vs. the number of taps, i.e., packing rate for FR granules of GEL was slower than that of its UFR form, whereas FR granules of PGS and K30 showed faster change in relative density compared to their UFR forms. According to the parameters obtained from the Heckel equation, PGS and K30 were found to produce softer, more plastic and readily deformable granules than GEL, and the compressibility of their FR forms was not influenced negatively.     

Creating a high-quality wool-oriented Turkish merino herd and investigation of mechanical and dyeability properties of fabrics produced from Turkish merino in comparison with Australian merino

Today, the need for quality wool suitable for worsted fabric production in the world is mainly met by Australian merino wool. In Turkey, which has a significant sheep population, in addition to domestic breeds, approximately 10% of the total sheep population (around four million head) is composed of merino cross breeds. However, the fleece quality is far from meeting Australian merino wool standards. Therefore, the aim of this study is to ensure a merino herd with high-quality wool in Turkey. For this aim, by carrying out field studies in the Thrace region of Turkey where Turkish Merino sheep are widely bred, sheep with fleece that can meet the demands of the worsted industry were determined. As a result of field studies in which thousands of sheep were examined, it was determined that 43 female and 10 male sheep had fleece that would meet these standards. Then the breeders of the sheep, which had quality fleece, were persuaded and these sheep were purchased, and “Turkey's wool-oriented Turkish (Karacabey) Merino Herd” consisting of 30 sheep and three rams was formed in the farm of Tekirdağ Namık Kemal University. In the second part of this study, a 100% wool fabric produced by using Australian merino was taken as a reference and it was aimed to produce the same fabric from Turkish merino wool. For this aim, the wool-oriented Turkish Merino herd, which was bred at the university farm for 1 year, was shorn in May 2022. Then, Turkish and Australian merino wools were first converted into worsted yarn and then into woven fabric. The results of mechanical (tensile strength, pilling, abrasion resistance, felting shrinkage, Hofmann dimensional change, bending stiffness) and dyeability (dye-uptake, CIE L*a*b* and colour yield (K/S) values; washing, rubbing and light fastness values) properties of fabrics produced from Turkish and Australian merino wool is presented.     

Ab initio study of boron-rich amorphous boron carbides

Amorphous boron carbide compositions having high B contents (B_xC_1−x, 0.50 ≤ x ≤ 0.95) are systematically created by way of ab initio molecular dynamics calculations, and their structural, electrical, and mechanical characteristics are inclusively investigated. The coordination number of both B and C atoms increases progressively with increasing B/C ratio and more close-packed materials having pentagonal pyramid motifs form. An amorphous diamond-like local arrangement is found to be dominant up to 65% B content, and beyond this content, a mixed state of amorphous diamond– and B-like structures is perceived in the models because sp³ hybridization around C atoms is still leading one for all compositions. The pentagonal pyramid motifs around C atoms are anticipated to appear beyond 65% content. The intericosahedral linear C–B–C chains do not form in any model. All amorphous boron carbides are semiconducting materials. The mechanical properties gradually increase with increasing B concentration, and some amorphous compositions are proposed to be hard materials on the basis of their Vickers hardness estimation.     

Nitrate Ion Sensing Properties of Peripheral 3,4,5-Trimethoxyphenoxy and Chlorine Substituted Metallo and Metal-free Phthalocyanines

Journal of Inorganic and Organometallic Polymers and Materials - The purpose of this study is to investigate the capability of novel peripheral metal-free and metallo (2H, Fe, Co, Zn) mono nuclear...     

Optimization of nanofiber-caproate/laurate esters synthesis,their characterization,and usage as emulsifier in o/w emulsion

The aim of this study is to optimize the esterification of nanofibers with caproyl/lauroyl chlorides at different substitution degrees' (DS) and to investigate the usage of nanofiber derivatives in model emulsions. First, cellulosic material was obtained and milled into nanofibers using a micro-fluidizer. Then, these nanofibers were esterified with caproyl/lauroyl chlorides in a solvent of DMAc/LiCl with DMAP as an acid scavenger. The esterification of nanofibers with caproyl/lauroyl chlorides was optimized for fatty acid chloride mole and reaction time. Esterification reactions were carried out at 80°C with various molar ratios of acyl chlorides (3–15 moles) versus anhydroglucose unit of nanofibers and for various time durations (30–360 min). The hydrophobic derivatives with DS in the range of 0.34–2.77 were successfully obtained. Using the data obtained as a result of the optimization, nanofiber-fatty acid esters with different DS (0.50–2.75) were produced and characterized. Analyzes showed that the esterification process was successful and as the degree of esterification increased, the crystallinity index and thermal stability of the derivatives decreased. Then, the nanofiber-caproate/laurate esters with different DS were used as emulsifier (0.5 wt%) in an oil-in-water model emulsion containing 25 wt% oil and the emulsions were analyzed. The nanofiber caproate/laurate esters with a DS of 0.50–1.25 were suitable for o/w emulsions, while samples with a DS of 2.00 and above were not found suitable. Emulsions prepared by using nanofiber derivatives with 1.25 DS had higher G′ and G″ and viscosity values and lower droplet sizes than those of other group.     

Automated steel surface defect detection and classification using a new deep learning-based approach

Neural Computing and Applications - In this study, a new deep learning-based approach has been developed that detects and classifies surface defects that occur in the steel production process. The...