An equation of state for 1,1-difluroethane (HFC 152a)

An equation of state for 1,1-difluoroethane (HFC 152a, CH₃CHF₂) has been developed on the basis of reliable experimental data including PVT, liquid C_p, and saturated-liquid-density data measured by our group. It is a non-dimensionalized virial equation whose functional form is the same as that originally developed for 1,1,1,2-tetrafluoroethane (HFC 134a) in our group. The effective range is for pressures up to 15 MPa, temperatures from 230 to 450 K, and densities to 1000 kg m⁻³. The equation represents reliable PVT measurements within ± 1% in pressure for the superheated vapour and supercritical fluid, while within ±0.5% in density for the compressed liquid. In addition, it should be noted that the equation represents the other essential thermodynamic properties including vapour pressures, saturated-liquid/ vapour densities, isobaric/isochoric specific heats and sound velocity in both the liquid and gaseous phase of HFC 152a.     

Bias-stress-induced increase in parasitic resistance of InP-based InAlAs/InGaAs HEMTs

The reliability of InP-based HEMTs is studied, focussing on how it is affected by the doped layer material and gate recess structure. Bias-and-temperature stress tests reveal that fluorine-induced donor passivation in the recess region, formed adjacent to the gate electrode, causes the source resistance (R_s) to increase at large drain bias voltages. The increase in R_s can be prevented by using InP or InAlP as the carrier supply layer material instead of InAlAs. On the other hand, the increase in the drain resistance (R_d) does not depend on the material of the carrier supply layer, which suggests that a mechanism different from that in the case of R_s should be considered. It is also found that a deep gate recess suppresses the increase in R_d after long-term stressing.     

When West meets East: Contributions of Eastern traditions to the future of psychotherapy.

Discusses 2 interrelated traditions as they are reflected in contemporary and traditional approaches to psychotherapy in Japan. One uses various meditational and self-focusing instructional sets whose common goal is to facilitate the slowing down, deepening, and clearer focusing of sensory and interpersonal awareness. The 2nd tradition focuses on physical self-regulation and autonomic self-control through exercises that foster enhanced voluntary control over physical states and processes. Eastern psychology offers a set of practices that help the individual overcome the inherent selfishness of his/her isolated experience. The goals of such work include recognition of gratitude to important people in the client's life, rediscovery of the joy of meaningful work, and the experience of a unifying cosmic consciousness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robust tracking servo system considering force disturbance for the optical disk recording system

This paper proposes a new robust tracking servo system for the optical disk recording system with feedforward controller based on the prediction of the tracking error. In optical recording systems, the feedback servo system must suppress the influence of force disturbance and parameter variation. To overcome this problem, this paper designs the robust feedback control system by using coprime factorization and disturbance observer. The detecting signal of the optical disk recording system is only a tracking error. Hence, the feedforward controller of the proposed tracking control system is constructed based on both the "zero-phase-error tracking" control theory and the prediction of the tracking error. The experimental results point out that the proposed tracking servo system has a quick and precise tracking response and keeps the residual tracking error below its tolerance.     

Effects of supercritical carbon dioxide treatment on the morphology of poly(l‐lactide)

Synthetic l ‐lactide random copolymers can be employed as controlled release materials when prepared using supercritical carbon dioxide (scCO₂), since they are biodegradable via hydrolysis. To determine the effects of thermal properties on polymer performance following scCO₂ processing, three types of poly(l ‐lactide) having different properties were assessed. The T_m of one poly(l ‐lactide) sample (H‐100) was found to be approximately 170 °C over the processing pressure range from 8 to 18 MPa, while a second sample (H‐440) also showed a constant value of approximately 152 °C. In contrast, the poly(l ‐lactide) REVODE exhibited a T_m of 146 °C prior to processing but a higher value of 147 °C following treatment at 8 MPa. Unlike the H‐100 and H‐440, the T_m value of the REVODE tended to decrease with increasing pressure. The T_g values increased greatly under mild conditions of 8 MPa pressure and a temperature of 40 °C. In particular, the T_g values for the H‐440 and REVODE increased by 4 °C and 5 °C, respectively. All T_g values were lowest at 12 MPa and increased with increasing processing pressure, although the effect of processing temperature was minimal. The Χ_{c DSC} of the H‐100 was 18% initially but increased to 20% upon scCO₂ processing at 40 °C and 14 MPa, and showed further increases at higher processing temperatures. Although the relationship between processing temperature and Χ_{c DSC} values for the H‐440 showed the same trend as observed with the H‐100, a different trend was seen for the REVODE. The Χ_{c XRD} values obtained from the XRD analyses differed from the values generated by DSC analysis, and showed a maximum degree of crystallinity following processing at 80 °C both with and without scCO₂ treatment. ATR FT‐IR analyses identified peaks due to semicrystalline regions in poly(l ‐lactide) samples treated with scCO₂, even when applying low temperatures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44006.     

Rewired Cellular Metabolic Profiles in Response to Metformin under Different Oxygen and Nutrient Conditions

Metformin is a metabolic disruptor, and its efficacy and effects on metabolic profiles under different oxygen and nutrient conditions remain unclear. Therefore, the present study examined the effects of metformin on cell growth, the metabolic activities and consumption of glucose, glutamine, and pyruvate, and the intracellular ratio of nicotinamide adenine dinucleotide (NAD⁺) and reduced nicotinamide adenine dinucleotide (NADH) under normoxic (21% O₂) and hypoxic (1% O₂) conditions. The efficacy of metformin with nutrient removal from culture media was also investigated. The results obtained show that the efficacy of metformin was closely associated with cell types and environmental factors. Acute exposure to metformin had no effect on lactate production from glucose, glutamine, or pyruvate, whereas long-term exposure to metformin increased the consumption of glucose and pyruvate and the production of lactate in the culture media of HeLa and HaCaT cells as well as the metabolic activity of glucose. The NAD⁺/NADH ratio decreased during growth with metformin regardless of its efficacy. Furthermore, the inhibitory effects of metformin were enhanced in all cell lines following the removal of glucose or pyruvate from culture media. Collectively, the present results reveal that metformin efficacy may be regulated by oxygen conditions and nutrient availability, and indicate the potential of the metabolic switch induced by metformin as combinational therapy.     

Characterization of petroleum-degrading bacteria from oil-contaminated sites in Vietnam

Four petroleum-degrading bacterial strains, 2TN-NB, 6TBX-CL, MVK2-5, and XCK, were isolated from various oil-contaminated sites in Vietnam. Determination of the nucleotide sequence of the gene encoding 16S rRNA allowed 2TN-NB to be identified as Acinetobacter sp. and the other three stains as Pseudomonas sp. Among the four isolates, 2TN-NB was most effective in degrading crude oil: in 1 d, it degraded 95% of the crude oil in the culture medium (5%, v/v). The isolated strains could also degrade a sulfur-containing aromatic hydrocarbon, dibenzothiophene (DBT), with low efficiency. Except for MVK2-5, which degraded crude oil least efficiently, the isolates produced biosurfactants in amounts sufficient for structural analysis. FT-IR measurement suggested that strains 6TBX-CL and XCK produced glycolipid-type biosurfactants while that produced by 2TN-NB was of the polysaccharide type.     

The Development of Alkoxide-Directed Metallacycle-Mediated Annulative Cross-Coupling Chemistry

Alkoxide-directed metallacycle-mediated cross-coupling is a rapidly growing area of reaction methodology in organic chemistry. Over the last decade, developments have resulted in more than thirty new and highly selective intermolecular (or “convergent”) C−C bond-forming reactions that have established powerful retrosynthetic relationships in stereoselective synthesis. While early studies were focused on developing transformations that forge a single C−C bond by way of a functionalized and unsaturated metallacyclopentane intermediate, recent advances mark the ability to employ this organometallic intermediate in additional stereoselective transformations. Among these more advanced coupling processes, those that embrace the metallacycle in subsequent [4+2] chemistry have resulted in the realization of a number of highly selective annulative cross-coupling reactions that deliver densely functionalized and angularly substituted carbocycles. This review discusses the early development of this chemistry, recent advances in reaction methodology, and shares a glimpse of the power of these processes in natural product synthesis.