Homogeneous asymmetric hydrogenation ofo-chloroacetophenone to enantiomerically pureo-chloro-(1-phenyl)ethanol catalyzed by BINAP-Ru(II) complex

The BINAP-Ru(II) catalyst (2,2-bis(diphenylphosphino)-1,1-binaphthyl)chloro(p-cymene)rutheniun chloride is found to be highly active and enantioselective for homogeneous asymmetric hydrogenation of o-chloroacetophenone to optically pureo-chloro-(1-phenyl)ethanol. In contrast to results of Noyori and coworkers, no organic and inorganic bases are required to obtain high activities and enantioselectivities     

Reordering for improving global Arnoldi–Tikhonov method in image restoration problems

This paper discusses the solution of large-scale linear discrete ill-posed problems arising from image restoration problems. Since the scale of the problem is usually very large, the computations with the blurring matrix can be very expensive. In this regard, we consider problems in which the coefficient matrix is the sum of Kronecker products of matrices to benefit the computation. Here, we present an alternative approach based on reordering of the image approximations obtained with the global Arnoldi–Tikhonov method. The ordering of the intensities is such that it makes the image approximation monotonic and thus minimizes the finite differences norm. We present theoretical properties of the method and numerical experiments on image restoration.     

Glycation of soy protein isolate with two ketoses: d-Allulose and fructose

Modification of food proteins to have improved functional properties is of great importance. In this study, modification of soy protein isolate (SPI) was achieved through glycation. SPI was glycated in a spray dryer (SD) and an incubator followed by freeze drying (FD). d -Allulose, an important rare sugar, was used in SPI glycation as the carbohydrate source, and results were compared with fructose. In addition to the sugar type, two different SPI powder: sugar ratios (1:1 and 5:1) were investigated. For the glycated samples, emulsification activity, free amino groups, protein solubility, Fourier-transform infrared spectroscopy analysis, antioxidant activity experiments and time-domain NMR relaxometry measurements for hydration were conducted. According to the results, the solubility of SPI that is limited in native form has shown a significant improvement after glycation through both FD and SD methods. Besides, glycation through the FD method was found to be more favourable due to its milder conditions than the SD method. Considering the physicochemical properties, the best combination for the highest glycation degree was found to be the samples prepared at the 1:1 ratio with d -Allulose in the FD method. Overall, it was concluded that glycation of SPI enhanced its functional properties such as antioxidant and emulsification activities.     

Casting properties of ASTM A128 Gr. E1 steel modified with Mn-alloying and titanium ladle treatment

This work aims to produce a high manganese steel with more refined austenite grains and better wear resistance without sacrificing the toughness and tensile properties by Mn alloying and Ti ladle treatment in comparision to ASTM A128 Gr. E1 steel (1.0C-13Mn) that is mostly used in the mining industry. The 1.0C-17Mn-xTi alloys (x=0, 0.05 and 0.1, in wt.%) were prepared. A relationship was established between the microstructures and mechanical properties of the as-cast and solution annealed alloys. Increasing Ti content increases the stable Ti(CN) phase on and beside the grain boundaries and decreases up to 37% the austenite grain size of the as-cast alloy with 0.10wt.% Ti. Correspondingly, after solution annealed, optimized titanium content (0.05wt.%) results in significant improvements in wear resistance, hardness, elongation, yield and tensile strengths by 44%, 31%, 30%, 8% and 12%, respectively, except 9% decrease in impact toughness compared to ASTM A 128 Gr. E1 steel without modification. These results show that 1.0C-17Mn-0.05Ti alloy can be used for parts exposed to high load wear and applied in conditions where relatively high tensile properties with sufficent ductility is needed.

     

Dyeing of poly(lactic acid) fibres with synthesised novel heterocyclic disazo disperse dyes

Poly(lactic acid) (PLA) is the first melt‐processable, renewable, sustainable and biodegradable natural‐based synthetic fibre. It has a broad range of uses and combines ecological advantages with outstanding performance in textiles. PLA fibre, as an aliphatic polyester, can be dyed with disperse dyes. Apart from the limited number of commercial disperse dyes, disperse dye exhaustion on PLA is generally lower than that on  poly(ethylene terephthalate) (PET). In this study, new heterocyclic disazo disperse dyes, substituted with methyl, nitro and chloro groups at their ortho‐, meta‐ and para‐ positions, synthesised in our previous study, were applied to PLA and PET fibres to examine their dyeing performance, and colour fastness and dye exhaustion properties. Different shades of yellow, orange, reddish brown and brown were obtained. Most of the synthesised novel heterocyclic disazo disperse dyes exhibited good build‐up properties with high K/S levels on both fibres. Para‐ bonding substituent provided higher K/S values than meta‐ and ortho‐ positions for –NO₂ and –Cl substituents for both fibres. Overall, the most synthesised novel heterocyclic disazo disperse dyes in this study exhibited good build‐up properties with high K/S, exhaustion and wet fastness levels on both PLA and PET fibres.      

Usage of bioactivated PCL nanofiber as a fluoxetine capturing matrix in milk

ABSTRACT

In this study, for the first time, polycaprolactone (PCL) nanofiber matrix was bioactivated for the removal of fluoxetine from milk. Bioactivated nanofiber was prepared by immobilizing fluoxetine antibody on PCL nanofiber matrix. The fluoxetine removal efficiency of bioactivated nanofiber in milk was found to be approximately 93.6%. This removal did not significantly change the biochemical composition of milk. In conclusion, as a novel product, bioactivated nanofibrous PCL matrix can be used for the removal of drugs or unwanted chemicals from breast milk or from other fluids.     

Gas chromatographic-olfactometric characterization of aroma active compounds in sun-dried and vacuum-dried tarhana

The influence of drying methods on the aroma active volatiles of sun-dried tarhana (SDT) and vacuum-dried tarhana (VDT) were compared using headspace SPME, GC-O and GC-MS. Although vacuum drying reduced the total amount of volatiles as compared to SDT (total FID peak area), more aroma active material was retained with VDT (total olfactory peak area). Vacuum drying retained a greater number of aroma active components (41) whereas the sun-dried method retained only 23. Aldehydes were the largest single class of aroma compounds in both types of tarhana: 17 in VDT and 10 in SDT. Other differentiating aroma compounds include alcohols, terpenes, and phenols such as geraniol, terpinolene, and 4-vinylguaiacol among others. A total of 22 aroma active components were present in greater amounts in the VDT versus only four aroma compounds present in greater amounts in the SDT.     

Preparation of Lead Zirconate Titanate (Pb(Zr0.52Ti0.48)O3) by Homogeneous Precipitation and Calcination

Preparation of phase-pure PZT (Pb(Zr_0.52Ti_0.48)O₃) powders was achieved, in the presence of urea (CH₄N₂O), by homogeneous precipitation. Aqueous solutions of PbCl₂, ZrOCl₂·8H₂O, and TiCl₄ were used as the starting materials in the synthesis of phase-pure PZT powders. Phase evolution behavior of precursor powders was studied by powder X-ray diffraction (XRD) in air, over the temperature range of 90° to 750°C. The morphology of the formed powders was studied by scanning electron microscopy (SEM). Semiquantitative chemical analyses of the samples were performed by energy-dispersive X-ray spectroscopy (EDXS).     

Phase Relations in the System Al2O3─Ce2Si2O7 in the Temperature Range 900° to 1925°C in Inert Atmosphere

Equilibrium relationships in the system Al₂O₃-Ce₂Si₂O₇ in inert atmosphere have been investigated in the temperature range 900° to 1925°C. A simple eutectic reaction was found at 1375°C and 51 mol% Ce₂Si₂O₇. A high-low polymorphic transformation in Ce₂Si₂O₇ was observed at 1274°C. New XRD patterns are suggested for both polymorphs of cerium pyrosilicate. The melting point of Ce₂Si₂O₇ was found to be 1788°C. A value for ΔH°_m,Ce2Si2O7 of 36.81 kJ/mol was calculated from the initial slope of the experimentally determined liquidus in equilibrium with the pyrosilicate phase.     

Characterization of Fenugreek (<Emphasis Type="Italic">Trigonella foenum-graecum</Emphasis>) Seed Lipids

The composition and content of lipids, fatty acids, triacylglycerols, tocopherols and sterols in nine fenugreek genotypes were analyzed. Lipid content in fenugreek seeds ranged from 5.8 to 15.2%. Major fatty acids were: linoleic acid (45.1–47.5%), α-linolenic (18.3–22.8%), oleic (12.4–17.0%), palmitic (9.8–11.2%) and stearic (3.8–4.2%) acids. The ratios of n-6 to n-3 fatty acids were between 2.1 and 2.7. Similar fatty acid distribution was observed in all analyzed samples with some deviations. α-Tocopherol was the predominant component found in the fenugreek lipid antioxidants, and it constituted over 84% of the total amounts of tocopherols. It amounts ranged from 620 to 910 mg/kg lipids. β-Sitosterol was the major sterol in all samples, varying from 14,203 to 18,833 mg/kg of lipids. Campesterol and cycloartenol were other major sterols, and these compounds including β-sitosterol constituted 56–72% of all sterols. Fenugreek seed lipids consisted predominantly triunsaturated (56.9–66.5%) and diunsaturated (32.2–41.6%) triacylglycerides. Among these components trilinolein (LLL; 12.9–20.5%) dominated followed by PLL (14.0–20.4%), LnLnO (7.8–17.7%), PLO (5.7–11.6%), OLL (6.9–10.6%), LLLn (3.2–9.6%), and LnLnL (3.5–7.6%). Results of the study show that fenugreek seed lipids may be a source of a nutraceutical ingredient for food applications.