[en] Large reserves of lignite at Neyveli in Tamil Nadu have made it possible to commission a pit-head thermal power station, a fertilizer plant, and a carbonization plant for producing coke. Mining is the basic activity at Neyveli. The above mentioned industrial units contribute to environmental pollution which is however well controlled. Large scale afforestation has been done in the mined out areas. (M.G.B.)

[en] Waterhammer in the main feedwater piping of PWR steam generators has been investigated in recent years by the Utilities, Architect Engineering (A/E) firms, Nuclear Steam Supply System (NSSS) Vendors, and Consultants. Combustion Engineering's (CE's) involvement in such studies and the modifications made to eliminate waterhammer in the feedring and piping of CE steam generators are discussed separately in another discussion titled, Waterhammer in Steam Generators and Other Related Systems. Waterhammer study in the economizer or preheater, to our knowledge, has been conducted only by NSSS vendors and certain consultants. This discussion mainly deals with waterhammer study in the CE System 80 steam generator economizer. The auxiliary feedwater sparger design pertinent to waterhammer is also discussed

[en] Modern gas avalanche detectors are instruments of choice for detecting single charges deposited in gas or emitted from thin solid radiation converters. We will discuss the main factors governing the operation of gas avalanche photomultipliers combining solid photocathodes with advanced micro-pattern gaseous multipliers. Also we will summarize the properties of UV photocathodes and film-protected photocathodes for the visible spectral range. We review recent progress and application of single charge counting detectors and discuss briefly their application to High Energy Physics experiments. (author)

[en] In the present work, the performance of a cesium iodide thin film photocathode is studied in detail. The optical absorbance of cesium iodide films has been analyzed in the spectral range from 190 nm to 900 nm. The optical band gap energy of 500 nm thick cesium iodide film is calculated from the absorbance data using a Tauc plot. The refractive index is estimated from the envelope plot of transmittance data using Swanepoel's method. The absolute quantum efficiency measurement has been carried out in the wavelength range from 150 nm to 200 nm. The crystallographic nature and surface morphology are investigated by X-ray diffraction and transmission electron microscopy techniques. In addition, the elemental composition result obtained by energy dispersive X-ray analysis is also reported in the present work

[en] In the present work, cesium iodide (CsI) thin films of different thicknesses have been prepared by thermal evaporation technique. The crystallite size and grain size of these films are compared by using X-ray diffraction (XRD) profile analysis as well as by transmission electron microscopy (TEM) counting, respectively. These two methods provide less deviation between crystallite size and grain size in the case of thin CsI films of 4 nm, but there is comparatively large difference in case of thicker CsI films (20 nm, 100 nm and 500 nm). It indicates that dislocations are arranged in a configuration which causes small orientational difference between two adjacent coherent regions. The crystallite size obtained from XRD corresponds to the size of the coherent scattering region, whereas in TEM micrograph, single grain may correspond to many such coherent scattering regions. Other physical parameters such as strain, stress and deformation energy density are also estimated precisely for the prominent XRD peaks of thicker CsI films in the range 2θ=20°−80° by using a modified Williamson–Hall (W–H) analysis assuming uniform deformation model (UDM), uniform deformation stress model (UDSM) and uniform deformation energy density model (UDEDM)

[en] We have investigated the influence of water molecule absorption on photoemissive and structural properties of potassium bromide (KBr) thin film photocathode under humid air exposure at relative humidity 62 ±3%. It is evident from photoemission measurement that the photoelectron yield of KBr photocathode is degraded exponentially with humid air exposed time. Structural studies of the “as-deposited” and “humid air aged” films reveal that there is no effect of relative humidity on film's crystalline face centered cubic structure. However, the crystallite size of “humid air aged” KBr film has been increased as compared to “as-deposited” one. In addition, topographical properties of KBr film are also examined by means of scanning electron microscope, transmission electron microscope and atomic force microscope and it is observed that granular characteristic of film has been altered, even for short exposure to humid atmosphere

[en] We have experimentally investigated the following aspects related to the quantum efficiency of CsI photocathodes: the type of substrate, the film thickness and the effect of a 'bulk treatment' during the film growth. We discovered that, using a high reflectivity aluminium substrate, the photoemission of very thin CsI film is enhanced. Our study also revealed that photocathodes become less sensitive to moisture when a negative bias voltage is applied to the substrate during the film deposition process

[en] Potentiometric studies on metal complexes of a La(III), Ce(III), Eu(III) and Gd(III) with 2, 6-pyridinediol has been carried out at different ionic strengths and in aqueous and in dioxane-water medium at 30 ± 0.1 degC. Bjerrum - Calvin titration technique as modified by Irving and Rossotti has been employed to determine proton-ligand and metal-ligand stability constants. The order of log K₁ value with respect to metal ions is La(III) < Ce(III) < Eu(III) < Gd(III). (author)

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