Synthesis of some new o-thioazo ligands and evaluation of their metallochromic properties

The synthesis of several new o-thioazo derivatives of p-cresol and 2-naphthol is reported, as well as their spectral properties, acid dissociation constants, and potential as metallochromic reagents. All the ligands form complexes with CU²⁺ and Ni²⁺. o-Mercaptoazo complexes of Fe³⁺ and Cu²⁺ with molar absorptivities of 3.83 × 10⁴ and 3.58 × 10⁴ l.mole⁻¹ cm⁻¹, respectively, are described.     

Improved Efficiency and Stability of Flexible Dye Sensitized Solar Cells on ITO/PEN Substrates Using an Ionic Liquid Electrolyte

Flexible dye‐sensitized solar cells (DSSCs) built on plastic substrates have attracted great interest as they are lightweight and can be roll‐to‐roll printed to accelerate production and reduce cost. However, plastic substrates such as PEN and PET are permeable to water, oxygen and volatile electrolyte solvents, which is detrimental to the cell stability. Therefore, to address this problem, in this work, an ionic liquid (IL) electrolyte is used to replace the volatile solvent electrolyte. The initial IL‐based devices only achieved around 50% of the photovoltaic conversion efficiency of the cells using the solvent electrolyte. Current‐voltage and electrochemical impedance spectroscopy (EIS) analysis of the cells in the dark indicated that this lower efficiency mainly originated from (i) a lack of blocking layer to reduce recombination, and (ii) a lower charge collection efficiency. To combat these problems, cells were developed using a 12 nm thick blocking layer, produced by atomic layer deposition, and 1 μm thick P25 TiO₂ film sensitized with the hydrophobic MK‐2 dye. These flexible DSSCs utilizing an IL electrolyte exhibit significantly improved efficiencies and a <10% drop in performance after 1000 h aging at 60°C under continuous light illumination.     

Transfer measurements for the Ti+Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2⁺ and 3⁻ states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for ^46,48Ti+⁶¹Ni systems. The present paper gives the results of these studies.     

Differential inhibition of postnatal brain,spinal cord and body growth by a growth hormone antagonist

Background  

Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH.     

Cooperative Lewis Pairs Based on Late Transition Metals: Activation of Small Molecules by Platinum(0) and B(C6F5)3

A Lewis basic platinum(0)–CO complex supported by a diphosphine ligand and B(C₆F₅)₃ act cooperatively, in a manner reminiscent of a frustrated Lewis pair, to activate small molecules such as hydrogen, CO₂, and ethene. This cooperative Lewis pair facilitates the coupling of CO and ethene in a new way.     

Anionic polymerization of styrene in ionic liquids

For the first time anionic polymerization of styrene has been successfully carried out at ambient temperatures in an ionic liquid, providing milder reaction conditions than classical methods. The addition of the zwitterion provides better dissociation of the metal cation based initiators and the IL based reaction allows the use of a much milder Lewis base initiator than is usually required. The present method also eliminates the traditional solvents and rigorous reaction conditions.     

Measurement of spontaneous polarization in ferroelectric smectic liquid crystals

This paper presents measurements of spontaneous polarization made on two ester-bridged materials (SCE1 and CE8). The two materials are chosen to be representative of long pitch (SCE1) and short pitch (CE8) materials. The measurements were made by two different methods, Diamant bridge and field reversal; these methods are compared and the results shown to be in good agreement. The variation in results between different samples of these materials is discussed and the results compared (where possible) with the work of other authors. Special attention is paid to the variation which occurs between the published spontaneous polarization measurements of different authors. The reasons for this variation are examined and variation in sample alignment and the determination of the transition temperature by different authors are shown to be major causes.     

Effects of molding temperatures on aqueous fatigue behavior of polycarbonate

Fatigue behavior of polycarbonate was investigated to evaluate its potenitial as a material for prosthetic heart valves. Smooth and notched small cantilever specimens were injection molded using various combinations of cylinder and mold temperates. Fatigue testing was conducted in a machine specifically designed to accommodate multipe specimens inliquid environments. Results presented herein are for water immersion. The fatigue lives fell on Weibull distributions with nonzero minimum-life parameters. S-N equations were fitted at constant probabilities of failure; most of these had nonzero fatigue-limit parameters. Polycarbonate fatigue strengths, of notched spcimens particularly, were greatly influenced by cylinder and mold temperatures. Notch sensitivities varied from very low to quite high. These effects were attributed to molecular orientation and residual stresses.     

Precipitation of zinc sulfide by hydrolysis of thioacetamide in the presence of hydrazine hydrochloride

Zinc sulfide can be precipitated quantitatively from solutions buffered at pH 2 using thioacetamidehydrazine hydrochloride mixtures as precipitants. Optimum results are obtained using equimolar quantities of thioacetamide and hydrazine hydrochloride. Coprecipitation of cobalt sulfide was studied using citrate-citric acid, and sulfate-bisulfate buffers. Optimum separations are achieved using a sulfate-bisulfate buffer containing ammonium thiocyanate.