Seismic analysis and design of electrical cable trays and support systems

Most cable trays in nuclear power plants are classified as seismic category I components. Current safety requirements dictate that all such components be adequately designed in order to remain functional during and after the most severe possible earthquake, so that a safe and orderly plant shut-down can be ensured. The design aspects of electrical cable trays and support systems are discussed from the seismic and structural standpoint. The effects of the inherent flexibility of commonly used cable trays is considered. A procedure for the selection of trays and the design of their support structure is recommended. The dynamic characteristics of typical trays are determined analytically and also from test results. The advantages of a rigid support system are discussed. Two procedures are presented for the design of the support systems, namely, static loading and spectral analysis. The interaction between trays and supports is discussed.     

Structure-Activity-Relationship-Aided Design and Synthesis of xCT Antiporter Inhibitors

The xCT antiporter is a cell membrane protein involved in active counter-transportation of glutamate (outflux) with cystine (influx) over the human cell membrane. This feature makes the xCT antiporter a crucial element of the biosynthesis of the vital free radical scavenger glutathione. The prodrug sulfasalazine, a medication for the treatment of ulcerative colitis, was previously proven to inhibit the xCT antiporter. Starting from sulfasalazine, a molecular scaffold jumping followed by SAR-assisted design and synthesis provided a series of styryl hydroxy-benzoic acid analogues that were biologically tested in vitro for their ability to decrease intracellular glutathione levels using four different cancer cell lines: A172 (glioma), A375 (melanoma), U87 (glioma) and MCF7 (breast carcinoma). Depletion of glutathione levels varied among the compounds as well as among the cell lines. Flow cytometry using propidium iodide and the annexin V marker demonstrated minimal toxicity in normal human astrocytes for a promising candidate molecule (E)-5-(2-([1,1′-biphenyl]-4-yl)vinyl)-2-hydroxybenzoic acid.     

Multi-objective optimization of lithium-ion battery pack casing for electric vehicles: Key role of materials design and their influence

The battery box is the structure that comprises the battery cells and its casing. It is designed to fix and protect the battery module. During the actual driving, there exists stress and resonance on a battery pack and its outer casing due to external vibration and shock. The safety of an electric vehicle largely depends on the mechanical characteristics of its battery pack. Besides, a lighter weight electric vehicle has a longer driving range, which makes it much more popular in vehicle market. In this paper, a comprehensive design procedure based on multi-objective optimization and experiments is applied to compare the maximum equivalent stress and resonance frequency on a battery pack casing with different materials (DC01 steel, aluminum 6061, copper C22000, and carbon nanotube [CNT]) under bumpy road, sharp turns, and sudden braking conditions to obtain the best material. Moreover, CNT is proved to be the best material considering all the performance standards. Response surface optimization design method is adopted to get an optimal design of the battery pack casing. Optimization results conclude that the maximum equivalent stress can be reduced from 3.9243 to 3.2363 MPa, and the six-order resonance frequency can be increased from 722.65 to 788.71 Hz. Experiments are carried to validate the mechanical performance of the optimal design; the deviation between the simulation and experimental results is within the tolerance.     

Oil Families and Their Potential Sources in the Southern Gulf of Suez,Egypt

Abstract

Four oil families are identified in the southern Gulf of Suez, through high-resolution geochemical studies including gas chromatography, gas chromatography–mass spectrometry, and carbon isotope analyses. Biological features characterize oils in family 1a, suggesting tertiary carbonate source rocks for these oils, rich in type II organic matter and deposited under anoxic depositional environment. Family 1b oil shows minor variations in the source of organic matter and the depositional environment, as it was derived from carbonate source rock with more algal and bacterial contribution and minor input of terrestrial organic sources, deposited under less saline condition compared to family 1a oil. Family 2 oil, although genetically related to family 1a oil, has some distinctive features, such as diasterane to sterane and pristane to phytane ratios, which suggest clay-rich source rocks and a more oxic depositional environment. Also, the lack of oleanane indicates pre-tertiary source rocks for this oil. In contrast, family 3 oil is of mixed sources (marine and non-marine), generated from low sulfur and clay-rich source rock of tertiary and/or younger age. Family 4 oil seems to be mixed from family 1b and family 3 oils, sourced mainly from carbonate source rocks rich in clay minerals with algal and bacterial contributions. Family 4 oil is highly mature, family 1b oil lies within equilibrium values (peak oil generation stage), while the other families are more or less near equilibrium.     

An optics inspired optimization method for optimal design of truss structures

This paper presents optics inspired optimization (OIO) as a new optimization technique for optimum design of truss structures with continuous variables. In OIO, the physical laws that govern the image formation in spherical mirrors are artificially modeled to develop a new metaheuristic method. In OIO, the surface of the objective function to be minimized is considered as the reflecting wavy mirror consisting of peaks and valleys. In the reflecting surface, each peak is assumed to reflect as a convex mirror and each valley to reflect as a concave one. By assuming each solution candidate as an artificial object (or light point) that is artificially glittered ray is reflected back by the function surface, the artificial image (new solution) is formed based on the governing equations in physics of optics. Compared with the other existing optimization techniques, OIO seems to be a promising alternative approach for solving truss optimum design problems.     

Cloud point preconcentration and flame atomic absorption spectrometry: application to the determination of manganese in milk and water samples

Cloud point extraction has been used for preconcentration of trace amount of manganese. The analyte was complexed with 1-(2-pyridylazo)-2-naphtol (PAN) and Triton X-114 was added as surfactant. After phase separation, based on the cloud point of the mixture, and dilution of the surfactant-rich phase with methanol, the enriched analyte was determined by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, enhancement factor of 49.1 was obtained. The detection limit was 0.39 ng ml⁻¹ for manganese. The proposed method was applied to the determination of manganese in milk and water samples.