An efficacious “naked-eye” selective sensing of cyanide from aqueous solutions using a triarylmethane leuconitrile

A triarylmethane dye 1 detects CN^? from water and shows remarkable selectivity over other anions and dramatic color changes, in solution as well as when dyed. The pH stability of 1 in the range of 1.2–10.7 offers additional advantage in the sensing process under physiological conditions.     

Oxidation of polycyclic aromatic hydrocarbons with hydrogen peroxide catalyzed by Iron(III)porphyrins

A variety of iron-metallated functional porphyrins have been synthesized and their catalytic activity to oxidize polycyclic aromatic hydrocarbons, (PAHs) using hydrogen peroxide as oxidant was investigated. It was found that iron-metallated porphyrins bearing strong electronegative groups at β-pyrrolic positions show an exceptionally high catalytic efficiency.     

Thermal and Optical Properties of Zn<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Mn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Te Diluted Magnetic Semiconductor Studied by Photoacoustic Spectroscopic Method

Using photoacoustic spectroscopy, the composition-dependent absorption coefficient (α), thermal diffusivity (σ), and optical bandgap (E _g) of Zn_1−x Mn _x Te diluted magnetic semiconductor have been measured. For higher Mn compositions, the absorption spectrum of the Zn–Mn–Te system consists of three regions, viz., the high absorption region, the exponential region, and the weak absorption tail. The bandgap follows a nonlinear variation with composition, showing a downward bowing with a minimum around x = 0.31 as a consequence of the electro-negativity difference between the substituted atoms. The composition-dependent band-edge effective mass of the carriers does not show the bowing behavior indicating that the momentum matrix is not the same for all the Zn_1−x Mn _x Te alloys due to different lattice constants. The absorption spectra show that the transition is allowed and direct.     

Studies in the prediction of water inflows to longwall mine workings

The paper decribes results of mathematical investigations into the prediction of mine water inflows to longwall coal workings. Numerical calculations are reported on the basis of experimentally deduced hydraulic conductivities above longwall panels. The effect of longwall working on hydraulic conductivities is investigated by mathematical analyses of stress and failure. Numerical calculations of mine water inflows are reported on the basis of mathematically inferred hydraulic conductivities. Results are correlated with field data.     

Two unit repairable redundant standby system

The Laplace-Stieltjes (LS) transform for the distribution of time to first system failure (TFSF), transition probability, availability and mean time to system failure have been derived for two unit repairable redundant standby system with perfect as well as imperfect switchover condition. General expressions for computing various reliability performance indices have been obtained by using Markov Renewal techniques considering general distributions for time to failure and time to repair for the units.     

Oxidants, antioxidants and diseases--a brief review

Although oxygen (O2) is needed to the body, partially reduced forms of O2 and some of their derivatives collectively called reactive oxygen species (ROS), are highly toxic prooxidants to the body. To prevent ROS toxicity body's endogenous and exogenous antioxidants (AOS) act in concert. To maintain health a balance between pro and anti oxidants is very necessary.     

Treating health care [being interactive]

The numbers are staggering. In a chilling report, the U.S. Institute of Medicine (10M) estimates that somewhere between 44,000 and 98,000 Americans die each year from "avoidable medical errors" costing the nation about US$17 billion to US$29 billion annually. Errors include failing to make timely and accurate diagnosis, selecting improper treatment, and following a treatment plan incorrectly. For example, hospital staff might give the wrong drug or dosage, or a surgeon might operate on the wrong body part. Errors in surgery or emergency treatment can be especially serious. The root causes of these errors are inadequate training, poor processes, and information systems that don't expose patient information at relevant times - sometimes leading to confusion about the patient's identity or the intended procedures. Network technologies show great promise in solving some of the dangerous and tragic "avoidable medical errors" that currently plague the health care industry.     

Influence of polyethylene glycol template on microstructure and electrochromic properties of tungsten oxide

Electrochemical synthesis of tungsten oxide (WO₃) thin film nanostructures by potentiostatically controlling the surface aggregates formed at the electrode–electrolyte interface, in the presence of a polymeric template (polyethylene glycol 400, PEG) from a plating sol of peroxotungstic acid (PTA) is presented. The nanoparticulate morphology of the WO₃ film changes drastically upon varying PEG content in the precursor sol; from an amorphous structure with randomly distributed pores for a film derived from a PTA sol with PEG:ethanol in a 3:7 volume ratio, to a mesoporous, nanocrystalline material with hybrid structures encompassing spherical grains and nanorod-like shapes with a triclinic modification for a film formed in a sol with PEG:ethanol in a 1:1 volume ratio. This approach highlights the role of the PEG proportion in controlling crystal growth, assembly patterns and pore structure. The film derived from the sol with PEG:ethanol in a 1:1 volume ratio exhibits superior transmission modulation and coloration efficiency as compared to the film obtained from a sol with PEG:ethanol in a 3:7 volume ratio. While the latter film deteriorates rapidly within 35 color-bleach cycles, the former film sustains more than 3500 cycles, without significant degradation. This film also exhibits fast switching between the clear and blue states; these are repercussions of the mesopore structure and the interconnected nanocrystallite phase.