Infrared (8-12 um) Dome Materials: Current Status

The 8-12 um range of infrared radiation being very significant for various electrooptic applications, various materials present themselves as candidates for use as dome (window) materialsin this range. This paper discusses various thermal, mechanical and optical properties of thesematerials. Further, trends in the development of these materials are also presented

An Update of Rhinosinusitis

Rhinosinusitis is one of most common disease worldwide, affecting the quality of life of the person afflicted by it. Its causes and pathophysiology has been well delineated so far, but its treatment is changing fast due to change in organisms causing itand also emergence of resistance to antimicrobial agents, thus making the management challenging. This article highlights the changing microbial pattern, classification of the disease, its socio-economic burden, medical treatment and ever evolving surgicaltreatment, with its indications.

Efficient water management: Way forward to climate smart grain legumes production

This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

Nonlinear regression analysis and response surface modeling of Cr (VI) removal from synthetic wastewater by an agro-waste Cocos Nucifera: Box-Behnken Design(BBD)

In this study mixture of coconut shell and coir was used for Cr (VI) removal from synthetic wastewater and statistical tool Response Surface Modeling (RSM) was applied to optimize process parameters. The solution pH (2–6), reaction time (20–100 minutes) and adsorbent quantity (0.03–0.2 g) was optimized to find the maximum response of Cr (VI) removal using statistical Box-Behnken design (BBD) software. The equilibrium data obtained by the batch experiment were analyzed by ANOVA and found fitted in a second-order polynomial equation through multiple regression analysis. The optimum value of pH, adsorbent quantity and reaction time for 99% of Cr(VI) was found as 2, 0.1 g and 100 minutes, respectively. By using non-linear regression method it was found that Freundlich isotherm and Pseudo-second-order kinetic with high correlation coefficient (R2 ), low Chisquare (v2 ) and root mean squares errors (RMSE), best describe the adsorption of Cr (VI) on mixture of coconut shell and coir (MCSC) surface. Positive enthalpy (DH�) and negative Gibbs free energy (DGo ) values confirm the endothermic and spontaneous nature of adsorption process. Pre and post adsorption phenomenon was confirmed by characterization of adsorbent using AFM, FTIR, SEM, and EDX analysis. The adsorbent MCSC has regenerative property and can be reused 3–4 times after treating with alkaline medium (0.2 N NaOH) and offered more than 60% removal of Cr (VI) at the fourth cycle. It can be inferred based on this study that MCSC is an effective adsorbent for Cr (VI) removal and can be used on an industrial scale for social and environmental benefi

Effect of grain size on the transmission of zinc sulphide windows in the 8-12 μm range of infrared

18-21Zinc Sulphide is widely used in the fabrication of windows/domes transmitting in the far IR range (8-12 μm). Fabrication of zinc sulphide windows from ZnS powder prepared by a modified acid process has been described. IR transmission of these windows in 8-12 μm region has been found to be strongly dependent upon grain size of the windows

Preparation and Characteristics of IR Window Grade Zinc Sulphide Powder

Zinc sulphide (ZnS) is an important II-VI compound well-Known for the electrooptic applications. It is also one of the most suitable materials for the fabrication of IR transmitting domes and windows because of its transmission in the IR region of (2-12 micron) the spectrum as well as its excellent thermo - mechanical properties. The ZnS domes and windows are prepared by hot pressing or hot isostatic pressing (HIP) of optical quality grade ZnS powder. This paper describes the preparation of optical quality grade ZnS powder using a modified acid process maintaining a constant pH. The resulting ZnS powder is subjected to thermal treatment in different atmospheres and at different temperatures. The ZnS powder thus obtained has been characterised by chemical analysis partical size measurement IR spectrophotometry XR-D and XR-F analysis. The role of various experimental parameters involved, e.g., concentration of ZnSO/sub 4/ solution firing temperature and firing atmospheres is investigated. A transmission of 69 per cent was achieved after HIP of the ZnS powder prepared by this method

Two-step synthesis and hydrolysis of cyclic di-AMP in Mycobacterium tuberculosis.

Cyclic di-AMP is a recently discovered signaling molecule which regulates various aspects of bacterial physiology and virulence. Here we report the characterization of c-di-AMP synthesizing and hydrolyzing proteins from Mycobacterium tuberculosis. Recombinant Rv3586 (MtbDisA) can synthesize c-di-AMP from ATP through the diadenylate cyclase activity. Detailed biochemical characterization of the protein revealed that the diadenylate cyclase (DAC) activity is allosterically regulated by ATP. We have identified the intermediates of the DAC reaction and propose a two-step synthesis of c-di-AMP from ATP/ADP. MtbDisA also possesses ATPase activity which is suppressed in the presence of the DAC activity. Investigations by liquid chromatography -electrospray ionization mass spectrometry have detected multimeric forms of c-di-AMP which have implications for the regulation of c-di-AMP cellular concentration and various pathways regulated by the dinucleotide. We have identified Rv2837c (MtbPDE) to have c-di-AMP specific phosphodiesterase activity. It hydrolyzes c-di-AMP to 5'-AMP in two steps. First, it linearizes c-di-AMP into pApA which is further hydrolyzed to 5'-AMP. MtbPDE is novel compared to c-di-AMP specific phosphodiesterase, YybT (or GdpP) in being a soluble protein and hydrolyzing c-di-AMP to 5'-AMP. Our results suggest that the cellular concentration of c-di-AMP can be regulated by ATP concentration as well as the hydrolysis by MtbPDE

The effect of Mn on the structural and magnetic behaviour of Fe–6Si–8B alloy produced by high energy ball milling

The alloys of Fe–6Si–8B and Fe–6Si–8B–1Mn were prepared using high energy planetary ball mill. X-ray diffraction patterns of the milled samples confirmed the formation of the alloys by dissolution of Si in Fe after 30 and 24 h of milling for the Fe–6Si–8B and Fe–6Si–8B–1Mn samples respectively. The lattice parameter was found to increase continuously with milling time and the rise was steeper for the quaternary alloy. After 36 h of milling, the crystallite size for the two samples were reduced to 98 and 86 nm respectively. Mossbauer spectra suggested the formation of minor amount of α-Fe2O3. The value of saturation magnetization was 162 Am2/kg for Fe–6Si–8B alloy obtained after 18 h of milling. However, the value decreased with increased milling time as well as with Mn-addition. The remanance value showed similar tendency as that for saturation magnetization. In contrast, the coercivity value was found to be increasing with milling time and with Mn-addition

Indigenous Nutrient Supplying Capacity of Young Alluvial Calcareous Soils Favours the Sustainable Productivity of Hybrid Rice and Maize Crops

The crop productivity in calcareous soils is low due to their low organic matter content, high pH levels and improper nutrient management without considering the indigenous nutrient supplying capacity and crop yield potential; therefore, this study was conducted for a quantitative assessment of the nutrient supplying capacity of a calcareous soil on the productivity of hybrid and conventional rice and maize crops using an omission plot technique. The treatments included the ample application of Nitrogen (N), Phosphorus (P), Potassium (K), Sulphur (S) and Zinc (Zn), and an unfertilized check and omissions of N, P, K, S and Zn in rice and maize for six cropping seasons. The impact of the nutrient omission towards crop productivity was highest for nitrogen followed by phosphorous, potassium, zinc and sulphur. The total grain yield (3 yr average) in the hybrid rice–maize system was highest (16.32 t ha−1) for the optimum fertilized plot and lowest (6.34 t ha−1) for the unfertilized check. The sustainable yield index indicated that hybrid and conventional rice-maize cropping systems were more sustainable in the amply fertilized plot than in the nutrient-limited and unfertilized treatment plots. The average percent contributions of nitrogen, phosphorous, and potassium from the soil towards total nutrient removal were 36, 80 and 137 kg ha−1, in the hybrid system and 24, 54 and 104 kg ha−1 in the conventional system, respectively. The return on investment (ROI) of the N, P, K, S and Zn for the hybrid rice was 21.2, 7.1, 6.7, 4.1, and 0.3 USD, respectively, while for the maize it was 28.8, 7.6, 4.9, 6.5, and 0.7 USD, respectively. The results suggest that there is a direct link between the soil nutrient supplying capacity and the nutrient requirements by different types of crops in calcareous soil; therefore, the omission plot technique used for the assessment of the indigenous nutrient supplying capacity could be used in the larger domain for improved nutrient management, through synchronization with a targeted crop yield for improved productivity, soil fertility, nutrient use efficiency and farm income