Visualization of convection loops due to Rayleigh–Benard convection during solidification

This paper describes the techniques adopted for visualization of Rayleigh–Benard convection during solidification of eutectic, hypo- and hyper-eutectic salt solutions. Neutrally buoyant hollow glass spheres were inducted in the body of the solidifying salt solution. The convection currents were captured by scattering of a laser beam by these beads. The apparatus has two components, namely: (i) measurement of interface/mushy region movement and temperature distribution and (ii) flow visualization with laser beam scattered by hollow glass spheres. The distinct nature of convection cells in the eutectic and hypo eutectic region is brought out.     

Abundance of actinides in cosmic radiation

Ultra heavy (UH) cosmic rays of Z65 are produced either by s- or r-process of nucleosynthesis. Since these two processes occur under different astrophysical environments, the relative abundances of UH ions could be an important parameter in finding their source and origin. Data analysis is carried out on four detector stacks exposed in space by UH cosmic ray experiment on board LDEF. Scanning and analysis of 0.21 m² detector area resulted in finding of 72 UH ions (68Z96) including two actinides (88Z100). The ratio of actinides to that of sub-actinides is found to be 0.034±0.024, which is well within the observational limits of other experiments. Results suggest possible sources, which predominantly ejects r-process synthesized material.     

Working group report: High energy and collider physics

This is a summary of the projects undertaken by the working group I on high energy and collider physics.     

Necessary optimality conditions and saddle points for approximate optimization in banach spaces

In this article we study approximate optimality in the setting of a Banach space. We study various solution concepts existing in the literature and develop very general necessary optimality conditions in terms of limiting subdifferentials. We also study saddle point conditions and relate them to various solution concepts. Part of this research was carried out when the author was a post-doctoral fellow at UAB, Barcelona by the Grant No. SB99-B0771103B of the Spanish Ministry of Education and Culture. The hospitality and the facilities provided at CODE, UAB is gratefully acknowledged.     

Thermal cyclization of 3-arylamino-3-(2-nitrophenyl)-propenal Schiff base hydrochlorides followed by triethyl phosphite mediated deoxygenation: a facile synthesis of quindolines

A simple and useful method for the synthesis of various 2-substituted quindolines starting from 2-nitroacetophenone is described.     

Mild and efficient deprotection of allyl ethers of phenols and hydroxycoumarins using a palladium on charcoal catalyst and ammonium formate

An efficient procedure for the cleavage of allyl phenyl ethers and allyl coumarinyl ethers using a catalytic amount of 10% Pd/C in combination with ammonium formate is described. Allyl ethers of phenols are deprotected in preference to those of alcohols and this method is compatible with several reducible functional groups such as CHO, COCH₃, CO₂Et and NHCOCH₃.     

Non-invasive diagnosis of type 2 diabetes in Helicobacter pylori infected patients using isotope-specific infrared absorption measurements

Helicobacter pylori causes several gastrointestinal diseases and may also contribute to the development of type 2 diabetes (T2D). Several studies suggest that there might be a potential link between H. pylori infection and T2D, but it still remains the subject of debate. Here, we first report the cumulative effect of H. pylori infection and T2D by exploiting the excretion kinetics of ¹³C/¹²C and ¹⁸O/¹⁶O isotope ratios of exhaled breath CO₂ in response to an oral dose of ¹³C-enriched glucose in individuals with T2D and non-diabetic controls (NDC) harbouring the H. pylori infection. Using a high-resolution integrated cavity output spectroscopy (ICOS) technique in the infrared region, we observed that the isotopic fractionations of ¹³C and ¹⁸O in breath CO₂ are distinctly altered in H. pylori infected T2D patients as well as in H. pylori infected NDC. Several optimal diagnostic cut-off points of ¹³C and ¹⁸O isotopes of breath CO₂ were also determined which exhibited the diagnostic sensitivity and specificity of ～97?% and thus suggesting that breath ¹³C and ¹⁸O isotopes might be considered as potential biomarkers for the non-invasive assessment of the gastric pathogen prior to the onset of T2D. This may open a new diagnostic strategy for treating these common diseases in an alternative way.     

Injectable hydrogels

Hydrogels are promising for a variety of medical applications due to their high water content and mechanical similarity to natural tissues. When made injectable, hydrogels can reduce the invasiveness of application, which in turn reduces surgical and recovery costs. Key schemes used to make hydrogels injectable include in situ formation due to physical and/or chemical cross‐linking. Advances in polymer science have provided new injectable hydrogels for applications in drug delivery and tissue engineering. A number of these injectable hydrogel systems have reached the clinic and impact the health care of many patients. However, a significant remaining challenge is translating the ever‐growing family of injectable hydrogels developed in laboratories around the world to the clinic. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012