NOPR Collection:

Calibration of reference hydrometers using solid density standards

1996-06-01T00:00:00Z

Title: Calibration of reference hydrometers using solid density standards Authors: Sharam, D C; Sinha, S Abstract: This note suggests the use of solid density standard to calibrate reference standard hydrometers instead of conventional method of a calibrated open scale hydrometer. This ensures better accuracy of measurement, ease of operation and traceability in density measurement. Page(s): 131-132

Development of a tungsten-carbide based hard facing consumable for surfacing of rock roller drill bits

1996-06-01T00:00:00Z

Title: Development of a tungsten-carbide based hard facing consumable for surfacing of rock roller drill bits Authors: Goel, R; Grewal, G Abstract: The wear resistance of tool components can be significantly enhanced by surfacing with composite rods comprising of tungsten-carbide based flux sheathed in a mild steel tube, Statistical factorial experiments indicate that the best performance of the rod is obtained with the de-oxidizer and slag former contents fixed at one mass percent, each, In addition, it is found that the presence of the binder in the flux leads to a marked degradation in the weldability and' the flow properties of the weld pool. Page(s): 127-130

A Newtonian heat-transfer model for selection of heater configuration for hard chrome plating baths

1996-06-01T00:00:00Z

Title: A Newtonian heat-transfer model for selection of heater configuration for hard chrome plating baths Authors: Grewal, G; Hundal, R Abstract: The present paper analyses the problem of heat transfer in electroplating baths during the period of initial heat-up prior to starting the plating operation. Specifically, a lumped mass heat transfer model is developed for predicting the initial heating-up time in industrial hard-chrome plating baths. This model offers a rigorous technique for the accurate selection of heater units of an optimal power rating, for applications in the electroplating industry. Page(s): 124-126

Fly ash-A potential heterogeneous catalyst in peroxidative degradation of aqueous dye solutions

1996-06-01T00:00:00Z

Title: Fly ash-A potential heterogeneous catalyst in peroxidative degradation of aqueous dye solutions Authors: Sur, B; Mandal, S; Chaudhuri, S K Abstract: The potentiality of fly ashes from coal-fired power plants has been investigated as heterogeneous catalyst in oxidative decolourization of aqueous solutions of several reactive, acid and chrome dyes, using H₂O₂ in the temperature range 300-323 K. It is observed that the catalytic activity of fly ashes depends on their physico-chemical characteristics and pH of the reaction medium. For an initial dye concentration of 100 mg/L and H₂O₂ of 5.2 x 10^-2 kmol/m³, complete decolourization is possible within I500, 900 and 600s of all reactive, acid and chrome dyes, respectively, at 313 K and pH 3.75±0.15 using 2% (w/v) fly ash loading. The extent of deactivation of catalytic effect of fly ash depends on total contact time, characteristics of fly ash surface and specific dye used. Page(s): 119-123