Mechanical and phonon properties of the superhard LuB2, LuB4, and LuB12 compounds

We have studied structural, elastic, and lattice dynamical properties of the LuB_2, LuB_4, and LuB₁₂ compounds by using the plane-wave pseudopotential approach to the density-functional theory within the generalized gradient approximation. We have considered three different crystal structures of LuB_x: LuB₂ (P6/mmm), LuB₄ (P4/mbm), and LuB₁₂ (Fm-3m). The most stable structure is found to be tetragonal (P4/mbm) structure. The comparative results on the basic physical parameters such as lattice constants, bulk modulus, bond distances, elastic constants, shear modulus, Young's modulus, and Poison's ratio are reported. Also, we have predicted that LuB₄ and LuB₁₂ compounds are potential superhard materials. Furthermore, the phonon dispersion curves and corresponding phonon density of states (DOS) are computed for considered phases. Our structural and some other results are in agreement with the available experimental and other theoretical data.     

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.     

A New Approach for Analyzing Drawdown Data from a Partially Penetrating Well

Water Resources Management - A pumping test conducted in an aquifer of large thickness is typically performed with partially penetrating wells. In this study, a novel, practicable method is...     

Confectionery industry: a case study on treatability-based effluent characterization and treatment system performance

Source-based wastewater characterization and stream segregation provide effective management of industrial wastewaters. The characterization of wastewater sources from a confectionery factory was presented and performance of the wastewater treatment plant was evaluated in this study. All of the wastewater sources in the factory, except the vacuum water line, can be characterized by high concentrations of soluble pollutants and low pH. High organic content of the wastewater generated from the confectionery industry promoted the application of anaerobic technology as a pre-treatment before the conventional aerobic treatment. The average chemical oxygen demand (COD) removal and biogas production for expanded granular sludge bed reactor were 88% and 1,730 Nm(3)/day, respectively. The effluent from the investigated facility can be used for irrigation provided that conductivity values are within acceptable limits.     

Cataract extraction comparative study of ocular Beh?et's disease and idiopathic uveitis

A retrospective clinical trial was performed to review the management and discuss the outcome of cataract extraction in eyes with complicated cataract due to ocular Beh?et's disease (BD) (n = 55) and idiopathic uveitis (IU) (n = 43). The aim was to find the best method of treatment in each pathology. The surgical methods were intracapsular cataract extraction (ICCE), extracapsular cataract extraction (ECCE), ECCE + intraocular lens (ECCE + IOL), and ECCE + trabeculectomy (ECCE + T). The postoperative visual prognosis was found to be significantly worse in eyes with ocular BD, than in those with IU because of the severe posterior segment complications of ocular BD, particularly optic atrophy (p < 0.05). When the outcome was evaluated with regard to the individual surgical techniques, the prognosis was found to be significantly better in eyes with IU undergoing ECCE than in those with BD undergoing the same operation (p < 0.05). No significant differences were observed between the groups with regard to the other surgical treatment modalities (p < 0.05).     

Separation and adsorption properties of poly styrene‐graft‐ethyl methacrylate copolymer for zinc,copper, and cobalt ions in water samples

In this article, separation and adsorption properties of poly styrene‐graft‐ethyl methacrylate copolymer for zinc, copper, and cobalt ions in water samples were investigated. For this aim, some experimental and analytical parameters such as solution pH, sample flow rate, type of eluting agent, and sample solution volume were optimized. The adsorbed metal ions on polymeric resin were eluted with 5 ml of 2 mol l^?1 HNO₃ and they were determined by flame atomic absorption spectrometry. In optimized conditions, the adsorption capacities for Zn, Cu, and Co were obtained as 6.8, 5.2, and 7.5 mg g^?1, respectively. The detection limits were calculated as 0.82 μg l^?1 for Zn, 1.24 μg l^?1 for Cu, and 0.68 μg l^?1 for Co from standard deviation of the blank (50 ml, pH 5.8) measurements 10 replicates. The relative standard deviation of recoveries for seven replicate analyses of Zn, Cu, and Co ions (50 ml of 0.10 mg l^?1) were found as 2.4, 2.8, and 1.5%, respectively. The accuracy of method was checked with certified reference material (NIST SRM 1643e, trace elements in water) and the developed method was successfully applied to tap water, commercial drinking water, and mineral water samples. POLYM. ENG. SCI., 54:1555–1559, 2014. © 2013 Society of Plastics Engineers     

Designing with Light: Advanced 2D, 3D,and 4D Materials

Recent achievements and future opportunities for the design of 2D, 3D, and 4D materials using photochemical reactions are summarized. Light is an attractive stimulus for material design due to its outstanding spatiotemporal control, and its ability to mediate rapid polymerization under moderate reaction temperatures. These features have been significantly enhanced by major advances in light generation/manipulation with light-emitting diodes and optical fiber technologies which now allows for a broad range of cost-effective fabrication protocols. This combination is driving the preparation of sophisticated 2D, 3D, and 4D materials at the nano-, micro-, and macrosize scales. Looking ahead, future challenges and opportunities that will significantly impact the field and help shape the future of light as a versatile and tunable design tool are highlighted.     

On the Cooling Rate-Microstructure Relationship in Molten Metal Gas Atomization

Metallurgical and Materials Transactions A - Gas atomization is the most used powder production technique since it provides good control on particles shape, surface oxidation and dimension. It is a...     

Structural,elastic, and lattice dynamical properties of YB2 compound

In this work, density functional theory calculations on the structural, mechanical, lattice dynamical, and thermodynamical properties of YB₂ in AlB₂-type and monoclinic (C2/m) structures are reported. The local density approximation has been used for modeling exchange–correlation effects. We have predicted the lattice constants, bulk modulus, elastic constants, shear modulus, Young’s modulus, Poison’s ratio, Debye temperature, and sound velocities. Furthermore, the phonon dispersion curves, corresponding phonon density of states, some thermodynamical quantities such as internal energy, entropy, heat capacity, and their temperature-dependent behaviors are presented. Our structural and some other results are in agreement with the available experimental and theoretical data.