Stability of Standard Electrolytic Conductivity Solutions in Glass Containers

The stability of solutions having an electrolytic conductivity, κ, of 5 μS/cm to 100 000 μS/cm packaged in glass screw-cap bottles, glass serum bottles, and glass ampoules was monitored for 1 year to 2 years. The conductivity was determined by measuring the ac resistance of the solution. Mass loss was also monitored for solutions packaged in bottles. The solutions were prepared using KCl in water (κ ≥100 μS/cm) or KCl in 30 % (by mass) n-propanol 70 % (by mass) water (κ ≤ 15 μS/cm). The conductivity changes were compared by packaging type and by nominal κ. The main causes of the κ changes are evaporation (screw-cap bottles) and leaching (screw-cap bottles, serum bottles, and ampoules). Evaporation is determined from mass loss data; leaching occurs from the glass container with no change in mass. The choice of optimal packaging, which depends on the conductivity level, is the packaging in which κ changes the least with time. Ampoules are the most suitable packaging for standards having nominal κ values of 500 μS/cm to 100 000 μS/cm. Screw-cap bottles are most suitable for standards having a nominal κ of 5 μS/cm to 100 μS/cm.     

Quantitative Physiological Assessment of Stress Via Altered Immune Functioning Following Interaction With Differing Automotive Interface Technologies

Technology can enhance or diminish a user's psycho-physiological stress level; the ability to quantify these responses can help evaluate and refine design. The capability of drivers to accomplish basic tasks utilizing differing sensory modalities while maintaining lane discipline within a computer-simulated environment was assessed. Fifteen healthy subjects provided capillary blood samples before and after using three human–machine interface designs—touch-screen, voice control, and multimodal. Using a chemiluminescent technique termed Leukocyte Coping Capacity, the ability of leukocytes to produce reactive oxygen species in vitro was assessed. Significant poststressor changes in leukocyte activity of varying magnitude were observed following the use of all interfaces; with the multimodal interface provoking the most pronounced response and voice control the least. Although still requiring further research, the results support the proposition for using immune responsiveness as a means for quantifying psychological stress during assessment of ergonomic design and psycho-physiological and social interaction.     

Indium and tellurium doping of CdS crystals in cadmium vapor and their luminescent properties

A technique is devised for vapor-phase doping of CdS in the quaternary system Cd-In-Te-S. CdS crystals are doped with In and Te via four-zone annealing in Cd and InTe vapors. The luminescence spectra of the CdSIn,Te[Cd] crystals (where [Cd] indicates annealing in cadmium vapor) are found to contain orange and red emission bands, in contrast to those of CdS[Cd] crystals, which are dominated by green emission. The CdSIn,Te[Cd] crystals are shown to be photosensitive. Sphalerite (metastable) CdS crystals doped with In and Te are prepared under far-from-equilibrium conditions. The bands in their luminescence spectra are shifted to longer wavelengths as compared to stable CdSIn,Te[Cd] crystals.Translated from Neorganicheskie Materialy, Vol. 40, No. 12, 2004, pp. 1415–1417.Original Russian Text Copyright © 2004 by Odin, Chukichev, Rubina     

Luminescent Properties of CdS Crystals Doped with Gallium and Tellurium in Cadmium Vapor

A technique is devised for vapor-phase doping CdS in the quaternary system Cd–Ga–Te–S. CdS crystals are doped with Ga and Te via four-zone annealing in a vapor phase containing Ga, Te, and Cd (the more volatile component of CdS). The luminescence spectra of the CdSGa,Te[Cd] crystals are found to contain orange and red emission bands, in contrast to those of CdS[Cd] crystals, which are dominated by green emission.     

Contrived approach to novel antibacterial poly(vinyl acetate-co-[2-(methacryloyloxy)ethyl]trimethylammonium chloride) and poly(vinyl acetate-co-[vinylbenzyl]trimethylammonium chloride) via RAFT polymerization with multi-characterization

Journal of Polymer Research - The complex and incompletely understood phenomenon of shear-induced crystallization of polymers may be nowadays analysed via the in situ POM-shear stage methodology....     

Two‐Phase Emulgels for Direct Ink Writing of Skin‐Bearing Architectures

Direct ink writing (DIW) provides programmable and customizable platforms to engineer hierarchically organized constructs. However, one‐step, facile synthesis of such architectures via DIW has been challenging. This study introduces inks based on two‐phase emulgels for direct printing and in situ formation of protecting layers enveloping multicomponent cores, mimicking skin‐bearing biological systems. The emulgel consists of a Pickering emulsion with an organic, internal phase containing poly(lactic acid) stabilized by chitin/cellulose nanofibers and a continuous, cross‐linkable hydrogel containing cellulose nanofibers and any of the given solid particles. The shear during ink extrusion through nozzles of low surface energy facilitates the generation of the enveloped structures via fast and spontaneous phase separation of the emulgel. The skin‐bearing architectures enable control of mass transport as a novel configuration for cargo release. As a demonstration, a hydrophilic molecule is loaded in the hydrogel, which is released through the core and skin, enabling regulation of diffusion and permeation phenomena. This 3D‐printed functional material allows independent control of strength owing to the hierarchical construction. The new method of fabrication is proposed as a simple way to achieve protection, regulation, and sensation, taking the example of the functions of skins and cuticles, which are ubiquitous in nature.     

Luminescent properties of CdSe single crystals doped with antimony or bismuth

CdSe single crystals were doped with Bi and Sb from Sb₂Se₃ and Bi₂Se₃ vapors. The introduction of Sb and Bi was found to produce new luminescence centers. Both bismuth and antimony generate deep levels in the band gap of CdSe. The maxima in the photoconductivity spectra of Sb and Bi-doped CdSe are redshifted. Both doped and undoped CdSe crystals are shown to be photosensitive     

Effects of iso-and heterovalent substitutions on the luminescent properties of CdS in the systems Zn, Cd ‖ S, Te and In(III), Cd ‖ S, Te

We have studied the luminescent properties of three CdS-based solid-solution series, resulting from isovalent anion substitution (CdS_1?x Te_x), isovalent cation and anion substitutions (Cd_1?x Zn_xS_1?x Te_x), and heterovalent cation substitution in combination with isovalent anion substitution (Cd_1?x In_2x/3S_1?x Te_x). The last two systems have been studied for the first time. The results demonstrate that red or near-IR lumiescence occurs in the three systems, but CdS crystals codoped with In and Te are more attractive because of the high impurity-related emission intensity at rather low In and Te concentrations.     

Synthesis of silicon and germanium containing heteroaromatic sulfides as cholesterol level lowering and vasodilating agents

Silicon and germanium containing heteroaromatic sulfides have been prepared using phase transfer catalytic (PTC) system thiol / Si or Ge containing alkyl halide / solid KOH / 18- crown-6 / toluene. The target sulfides were isolated in yields up to 92 %. It has been found that 2-{[dimethyl (beta-triethylgermylethyl)-silylmethyl]thio}-1-methylimidazole and 2-{[dimethyl(beta-triphenylsilylethyl) silyl-methyl]thio}benzothiazole are the most active cholesterol level lowering and vasodilating agents.