NOPR Collection:

Hydrodynamic studies of gas-solid fluidization in hexagonal bed for non-spherical particles

2009-11-06T16:30:34Z

Title: Hydrodynamic studies of gas-solid fluidization in hexagonal bed for non-spherical particles Authors: Padhi, Saroj K; Singh, R K Abstract: This paper presents hydrodynamic properties (minimum fluidization velocity, pressure drop at minimum fluidization, minimum bubbling velocity, minimum slugging velocity, particulate fluidization, bubbling fluidization, expansion ratio, fluctuation ratio etc.) of gas solid fluidization in hexagonal bed. Experimental values of these properties in hexagonal bed have been compared with corresponding values in cylindrical bed. Page(s): 951-954

Voltammetric behaviour of an antibiotic drug and its enhancement determination in presence of cetyltrimethylammonium bromide

2009-10-30T16:30:32Z

Title: Voltammetric behaviour of an antibiotic drug and its enhancement determination in presence of cetyltrimethylammonium bromide Authors: Jain, Rajeev; Mishra, Ritesh; Dwivedi, Ashish Abstract: Electrochemical behaviour of cefpodoxime proxetil (CP) at a dropping mercury electrode (DME) in presence of surfactants [cetyltrimethylammonium bromide (CTAB), sodium lauryl sulphate (SDS), Tween-20, Triton X-100] was studied by using different voltammetric techniques. Compared with DME without CTAB, reduction peak potential of CP shifts negatively and peak current is increased significantly, due to enhanced accumulation of CP with CTAB at hydrophobic electrode surface. Two well defined, cathodic and diffusion controlled waves were observed for CP in presence of CTAB in entire pH range. In electrochemical determination of CP using differential pulse polarography, presence of CTAB in absence of surfactant enhanced detection limit from 0.71 x 10^-5 mol l^-1 to 1.6 x 10^-7 mol l^-1. Analysis of CP in pharmaceutical formulations exhibited mean recoveries of 99% and 98% for both reduction peaks. Page(s): 945-950

Facile spectrophotometric determination of cerium using malachite green –iodide system in geological and environmental samples

2009-10-30T16:30:34Z

Title: Facile spectrophotometric determination of cerium using malachite green –iodide system in geological and environmental samples Authors: Janghel, Etesh K; Pervez, Y Abstract: A simple and highly sensitive method is proposed for determination of trace amount of cerium. New method involves bleaching of greenish colour dye-malachite green, by the action of iodine, which is released by reaction between potassium iodide and cerium (IV) in acidic medium. Beer’s law is obeyed over concentration range of 0.6 to 4.6 μg cerium (IV) in final volume of 25 ml (0.024-0.184 ppm). Molar absorptivity and Sandell’s sensitivity were found to be 1.36 x 10⁵ l mol^-1 cm^-1 and 0.002 μg cm^-2, respectively. New method has been successf ully applied for determination of cerium in silicate rocks, high purity rare earth oxides, soil, plant tissue and natural water samples. Page(s): 940-944

Centralized monitoring and control of air conditioning units

2009-11-02T16:30:26Z

Title: Centralized monitoring and control of air conditioning units Authors: Sanikommu, Nirmala; Joshi, A S Abstract: A virtual instrument has been developed using LabVIEW graphical programming language to monitor current drawn by air conditioning units (ACUs) at a central location. Program is flexible and permits operator to control, override and limit operational time of individual units so that wasteful expenditure is avoided. Concurrently, in the event of a power outage, load on back up DG sets can be programmed and restricted only to areas of emergency. Minimal hardware changes are required for implementation of new design system in existing ACU installations. Substantial reduction in cabling cost is achieved by designing additional hardware to reduce number of cables, connecting data acquisition card to AC systems. Page(s): 934-939