Enzymic analysis of soya beans lacking lipoxygenases

The homozygous inheritance of recessive alleles for lipoxygenase, -L₁, -L₂ and -L₃ incorporated into a commercial soya bean seed line, IAC 8, was evaluated. The activity of each isozyme, determined by spectrophotometry demonstrated a very low activity for the mutant -L₁ and respective progeny and a low activity for -L₂, -L₃ and their progenies. The methodology employed was shown to be a reliable and rapid method when evaluating lipoxygenase from crops.     

Kinetics of Urea Decomposition in the Presence of Transition Metal Ions: Ni2+

The literature on kinetics of the urea decomposition reaction was reviewed for the 333–373 K range of temperature. Possible reactions in the pH range of 5–9 were identified. Kinetic simulations indicated significant accumulation of the cyanate intermediate in the pH-time–temperature range that was studied. The effects of Ni²⁺ hydrolysis and complexation with the urea decomposition products were incorporated into the simulations. The kinetic simulation of the rate of Ni²⁺ removal from the solutions was compared against the experimental data. The experimental results indicated an agglomerative growth mechanism for the precipitation process. Chemical analyses showed that the composition of the precipitate varies with digestion time, in agreement with the predictions of the kinetic simulation.     

Lipid composition and de novo lipid biosynthesis of human palmar fat in Dupuytren's disease

Seventy-two surgically obtained Dupuytren's disease palmar-fat (DDPF) specimens and 18 location-matched specimens from patients not suffering from this disease (controls) were studied for their total lipid composition and de novo lipogenic activity. Incubation of "DDPF" with 1-[14C]acetate in oxygen produced [14C]palmitate and [14C]stearate in approximately equal yields as those obtained from "controls." No [14C]octanate was formed in any of the palmar-fat preparations. The lipids and fatty acid analysis revealed differences: (a) DDPF specimens were richer in free fatty acids, methyl esters of fatty acids and free-cholesterol than specimens of controls. (b) DDPF specimens contained less phospholipids. (c) DDPF specimens showed a significantly higher content of octanoate and other short-chain fatty acids than specimens of controls. The above findings are not incompatible with the results expected if some mild hypoxia occurred in DDPF; this has been suggested in the statistical correlations observed for this disease and alcoholism with liver involvement.     

The influence of annealing on the crystallization and tribological behavior of MWNT/PEEK nanocomposites

In this study, annealing influence on crystallization and scratch behavior of neat and multi‐wall carbon nanotube (MWNT) reinforced poly(ether ether ketone) (PEEK) nanocomposites have been investigated. Crystallization behavior of normal and annealed samples was investigated by using differential scanning calorimeter (DSC). Scratch behavior of normal and annealed samples was investigated by using micro scratch tester. In DSC analysis, it was detected that, melting enthalpy of annealed neat PEEK was increased sharply when compared to neat PEEK. Melting enthalpies of annealed PEEK nanocomposites prepared with addition of up to 1 wt% MWNT were increased with a decreased trend. However, nanocomposites with higher contents of MWNTs (>1 wt%) were dramatically affected by annealing process and melting enthalpy decreased sharply. Friction coefficient values of “annealed MWNT reinforced PEEK composites” were found to be lower than “normal PEEK composites.” Annealing process affects scratch hardness of both annealed and MWNT reinforced PEEK. Annealed nanocomposites with various MWNT concentrations showed higher scratch hardness values than normal PEEK nanocomposites. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

An investigation of ballistic response of reinforced and sandwich concrete panels using computational techniques

Structural performance of nuclear containment structures and power plant facilities is of critical importance for public safety. The performance of concrete in a high-speed hard projectile impact is a complex problem due to a combination of multiple failure modes including brittle tensile fracture, crushing, and spalling. In this study, reinforced concrete (RC) and steel-concrete-steel sandwich (SCSS) panels are investigated under high-speed hard projectile impact. Two modeling techniques, smoothed particle hydrodynamics (SPH) and conventional finite element (FE) analysis with element erosion are used. Penetration depth and global deformation are compared between doubly RC and SCSS panels in order to identify the advantages of the presence of steel plates over the reinforcement layers. A parametric analysis of the front and rear plate thicknesses of the SCSS configuration showed that the SCSS panel with a thick front plate has the best performance in controlling the hard projectile. While a thick rear plate is effective in the case of a large and soft projectile as the plate reduces the rear deformation. The effects of the impact angle and impact velocity are also considered. It was observed that the impact angle for the flat nose missile is critical and the front steel plate is effective in minimizing penetration depth.     

Design and fabrication of novel interconnectors for solid oxide fuel cells via rubber pad forming

Rubber pad forming is studied numerically and experimentally to fabricate interconnectors for solid oxide fuel cells (SOFCs) from thin Crofer sheets instead of classical thick ones with machined flow channels. In the theoretical program, the effects of the rib angle, rib width and channel depth on the formability are numerically investigated and optimized as 120°, 0.5 mm and 0.5 mm, respectively. In addition, flow simulations are performed to analyze the flow uniformity in the flow-field for the final geometry and homogenous reactant distributions are observed. In the experimental program, the interconnector with numerically optimized geometry is successfully manufactured by rubber pad forming, trimming, piercing and spot welding processes. This interconnector is used to build a two-cell stack. A similar stack is also constructed with a conventional interconnector for comparison. The performances of these stacks are measured at different operating temperatures. According to the simulation and experimental results, rubber pad forming is found to be a highly effective manufacturing route to fabricate SOFC interconnectors from thin Crofer sheets, providing higher specific and volumetric power density values for SOFC stacks compared to those of conventional stacks with interconnectors having machined flow channels.     

Object manipulation with a variable-stiffness robotic mechanism using deep neural networks for visual semantics and load estimation

Neural Computing and Applications - In recent years, the computer vision applications in the robotics have been improved to approach human-like visual perception and scene/context understanding....     

Dark fermentative biohydrogen production by Acinetobacter junii-AH4 utilizing various industry wastewaters

Hydrogen (H₂) is one of the most promising renewable energy sources, anaerobic bacterial H₂ fermentation is considered as one of the most environmentally sustainable alternatives to meet the potential fossil fuel demand. Bio-H₂ is the cleanest and most effective source of energy provided by the dark fermentation utilizing organic substrates and different wastewaters. In this study, the bio-H₂ production was achieved by using the bacteria Acinetobacter junii-AH4. Further, optimization was carried out at different pH (5.0–8.0) in the presence of wastewaters as substrates (Rice mill wastewater (RMWW), Food wastewater (FWW) and Sugar wastewater (SWW). In this way, the optimized experiments excelled with the maximum cumulative H₂ production of 566.44 ± 3.5 mL/L (100% FWW at pH 7.5) in the presence of Acinetobacter junii-AH4. To achieve this, a bioreactor (3 L) was employed for the effective production of H₂ and Acinetobacter junii-AH4 has shown the highest cumulative H₂ of 613.2 ± 3.0 mL/L, HPR of 8.5 ± 0.4 mL/L/h, HY of 1.8 ± 0.09 mol H₂/mol glucose. Altogether, the present study showed a COD removal efficiency of 79.9 ± 3.5% by utilizing 100% food wastewater at pH 7.5. The modeled data established a batch fermentation system for sustainable H₂ production. This study has aided to achieve an ecofriendly approach using specific wastewaters for the production of bio-H₂.     

On the improvement of a scalable sparse direct solver for unsymmetrical linear equations

This paper focuses on the application level improvements in a sparse direct solver specifically used for large-scale unsymmetrical linear equations resulting from unstructured mesh discretization of coupled elliptic/hyperbolic PDEs. Existing sparse direct solvers are designed for distributed server systems taking advantage of both distributed memory and processing units. We conducted extensive numerical experiments with three state-of-the-art direct linear solvers that can work on distributed-memory parallel architectures; namely, MUMPS (MUMPS solver website, http://graal.ens-lyon.fr/MUMPS), WSMP (Technical Report TR RC-21886, IBM, Watson Research Center, Yorktown Heights, 2000), and SUPERLU_DIST (ACM Trans Math Softw 29(2):110–140, 2003). The performance of these solvers was analyzed in detail, using advanced analysis tools such as Tuning and Analysis Utilities (TAU) and Performance Application Programming Interface (PAPI). The performance is evaluated with respect to robustness, speed, scalability, and efficiency in CPU and memory usage. We have determined application level issues that we believe they can improve the performance of a distributed-shared memory hybrid variant of this solver, which is proposed as an alternative solver [SuperLU_MCDT (Many-Core Distributed)] in this paper. The new solver utilizing the MPI/OpenMP hybrid programming is specifically tuned to handle large unsymmetrical systems arising in reservoir simulations so that higher performance and better scalability can be achieved for a large distributed computing system with many nodes of multicore processors. Two main tasks are accomplished during this study: (i) comparisons of public domain solver algorithms; existing state-of-the-art direct sparse linear system solvers are investigated and their performance and weaknesses based on test cases are analyzed, (ii) improvement of direct sparse solver algorithm (SuperLU_MCDT) for many-core distributed systems is achieved. We provided results of numerical tests that were run on up to 16,384 cores, and used many sets of test matrices for reservoir simulations with unstructured meshes. The numerical results showed that SuperLU_MCDT can outperform SuperLU_DIST 3.3 in terms of both speed and robustness.