Bendability of aluminiumand steel-clad chromium plates

The present paper describes how the cladding of chromium plate with dissimilar metals improves the plastic bendability of the chromium. Three-point bending tests at various temperatures were performed for three types of chromium specimens: a monolithic chromium plate, aluminium- and steel-clad chromium plate. The aluminium-clad chromium plate was bent at 343 K up to a bent angle of 90 degrees without failure, even when the chromium layer was located outside of the plate (tension side), while the monolithic chromium plate could be bent exclusively at temperatures above 403 K. When the chromium layer was located inside of the steel-clad chromium plate (compression side), the plate was successfully bent at 307 K. The FE stress analysis of bending proved that the cladding of chromium plates with proper metals of different kinds is effective to reduce the tensile stress in chromium induced during bending and also the residual stress existing after bending operation.     

Resolution of Epoxydienes by Reversed-Phase Chiral HPLC and its Application to Stereochemistry Assignment of Mulberry Looper Sex Pheromone

Resolution of insect pheromonal cis-epoxydiene racemates derived from (Z,Z,Z)-3,6,9-trienes was examined with a reversed-phase chiral HPLC column. The results showed that a Chiralcel OJ-R column was suitable for separating the enantiomers having a C₁₇–C₂₃ unsaturated straight chain except for 9,10-epoxydienes with a C₂₁–C₂₃ chain. To determine the absolute configuration of the separated enantiomers, each of the optically active epoxydienes was hydrogenated over Pd-BaSO₄ and its behavior was examined on this chiral column by cochromatography with the corresponding chiral epoxy compound having a saturated chain, which was prepared via a Sharpless epoxidation reaction. This analysis showed that the dextrorotatory C₁₇–C₂₃ 3,4- and 6,7-epoxydienes and C₁₇–C₂₀ 9,10-epoxydienes with shorter R _ts possess (3S,4R)-, (6S,7R)-, and (9R,10S) configurations, respectively, and the levorotatory enantiomers with longer R _ts possess the opposite configuration. An abdominal tip extract of the mulberry looper, Hemerophila artilineata Butler (Lepidoptera: Geometridae: Ennominae), included (9S,10R)-(Z,Z)-cis-9,10-epoxy-3,6-octadecadiene as a main sex pheromone component. The synthetic (9S,10R)-9,10-epoxydiene, rather than its antipode, elicited strong antennal and behavioral responses from the male moths in electrophysiological and field tests.     

Effect of satellite bubbles on dynamics of gas absorption from a CO2 bubble into a downward-flowing liquid

The dynamic process of gas absorption from a CO₂ bubble into a liquid is examined in the presence of satellite bubbles. The bubble under consideration is held stationary, except its jittering, by the liquid flowing downward. The mass transfer rate is determined by monitoring the rate of reduction in the equivalent bubble diameter during the initial absorption process. It is found that the interaction with the satellite bubbles generally hampers the dissolution of the primary bubble. The extent of reduction in the dissolution rate increases with the net contacting time during the interaction. When the secondary bubbles interact with the primary bubble mainly outside of its wake, however, the dissolution tends to be enhanced due to induced turbulence in the surrounding liquid flow. A simple theoretical model is developed to simulate the observed results as well as the basic features prevailing in a recently proposed scheme, called the GLAD system, for shallow injection of CO₂ gas into seawater.     

Effect of crosslinking structure on sorption of CO2 in photocrosslinked PVCA film

The sorption behavior of CO₂ gas in photocrosslinked poly(vinyl cinnamate) film was examined under atmospheric pressure. The sorption isotherm was well described by the Langmuir equation, suggesting that sorption of CO₂ is mainly governed by adsorption in the microvoids. The amount of sorbed CO₂ was significantly affected by the degree of crosslinking. The CO₂ sorption was enhanced at a lower degree of crosslinking but was decreased at a higher degree of crosslinking. The unexpected increase in the amount of adsorbed CO₂ correlated with the increase in the number of microvoids that occurred as a result of the crosslinking reaction. However, further crosslinking led to a decrease in the mean size of the microvoids. The smaller microvoids, in comparison to CO₂ molecules, did not act as adsorption sites, so that the amount of sorbed CO₂ decreased. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1744–1750, 2000     

Analysis of the current distortion factor of a three‐phase,three‐wire system

In a balanced three‐phase system, the three‐phase current distortion factor of three‐phase ac power sources has been expressed by applying the conventional single‐phase current distortion factor, which is defined for a single‐phase system. However, in an unbalanced three‐phase system, it is difficult to express the three‐phase current distortion factor for distorted three‐phase ac currents by means of the conventional single‐phase current distortion factor. For instance, the conventional current distortion factors for three‐phase ac currents are usually different from each other in the unbalanced three‐phase system. To solve the above problem, this paper proposes a novel definition of the three‐phase current distortion factor. The proposed three‐phase current distortion factor is quite effective for the unbalanced three‐phase system as well as the balanced three‐phase system. © 2000 Scripta Technica, Electr Eng Jpn, 131(4): 1–10, 2000     

A computer-aided design of EMC microstrip dipole arrays using nonlinear optimization techniques

This paper describes a method for designing electromagnetically coupled (EMC) printed dipole arrays. The advantages of EMC dipoles include greater bandwidth, higher efficiency, and an easier match to the feed lines, when compared to classically fed printed antennae. The excitation mechanism is provided by a strip transmission line embedded inside the substrate which couples energy parasitically to the microstrip antenna. Electromagnetically coupled microstrip dipoles have been investigated by empirical or approximate analysis techniques. As a result an approximate model has been derived for microstrip dipoles. The method is based on the method of moments solution to an integral equation derived from the approximate Green function for a grounded dielectric slab. The element lengths and offsets and the stub length of the EMC dipole array are determined by the direct search optimization method of Hooke and Jeeves. To show the feasibility of the proposed method, a mathematical formulation and numerical results are presented for Chebyshev arrays. © 1998 Scripta Technica, Electr Eng Jpn, 125(4): 60–66, 1998     

Investigation of partial discharge mechanism by simultaneous measurement of current waveform and light emission

We observed current pulse waveforms of partial discharge (PD) in SF₆ gas so as to investigate the PD mechanism. We also measured light intensity and light emission image of PD simultaneously under different conditions of applies voltage and SF₆ gas pressure. From these experiments, we found that the “double-peak current waveform” appeared at high pressure and high voltage conditions. We also analyzed the mutual correlation of waveforms between a single current and the light emission. Moreover, we obtained experimental evidence of filmentlike light image appearing at the PD tip under the same condition with double-peak current waveform. From the electric field analysis around the needle electrode tip, we believe that the filamentlike light image expands beyond the critical electric field of SF₆ gas. Thus, we concluded that these current waveforms with double peaks showed evidence of leader-type PD, leading to breakdown. Finally, we could point out that leader-type PD should be distinguished and measured for the diagnosis of GIS insulation performance. © 1999 Scripta Technica, Electr Eng Jpn, 129(4): 58–65, 1999     

Overview of Ferroptosis and Synthetic Lethality Strategies

Ferroptosis, a term first proposed in 2012, is iron-dependent, non-apoptotic regulatory cell death induced by erastin. Ferroptosis was originally discovered during synthetic lethal screening for drugs sensitive to RAS mutant cells, and is closely related to synthetic lethality. Ferroptosis sensitizes cancer stem cells and tumors that undergo epithelial−mesenchymal transition and are resistant to anticancer drugs or targeted therapy. Therefore, ferroptosis-inducing molecules are attractive new research targets. In contrast, synthetic lethal strategies approach mechanisms and genetic abnormalities that cannot be directly targeted by conventional therapeutic strategies, such as RAS mutations, hypoxia, and abnormalities in the metabolic environment. They also target the environment and conditions specific to malignant cells, have a low toxicity to normal cells, and can be used in combination with known drugs to produce new ones. However, the concept of synthetic lethality has not been widely adopted with ferroptosis. In this review, we surveyed the literature on ferroptosis-related factors and synthetic lethality to examine the potential therapeutic targets in ferroptosis-related molecules, focusing on factors related to synthetic lethality, discovery methods, clinical application stages, and issues in drug discovery.