MEASUREMENT SYSTEM FOR INPUT BIAS –OFFSET CURRENTS OF AN OPERATIONAL AMPLIFIER
A very simple microprocessor (µP) -based dedicated instrument is designed here.' The Overall system design consists of both hardware and software designs. This set-up yields the exact values of input bias and input off-set currents on the µP display panel, one after the other, when the operational amplifier (OP- AMP) under test is connected across the test terminals.
Microprocessor Based Instrument for Resistance and Diode Testing
The component tester reported in this paper is a microprocessor based instrument. It is used for evaluating resistances in the range of 100–10M Ohms divided equally over five automatically selected ranges. It has also got the capability of testing silicon diodes for their usefulness. The diode can be connected in any particular fashion. The hardware circuit is IC based and includes resistance detector, relay drivers, buffer, constant current source, diode tester, analog to digital converter and Intel 8085 based programmable microprocessor kit.
Denitrification of PVA-immobilized denitrifying photosynthetic bacterium, Rhodobacter sphaeroides
Abstract A newly isolated denitrifying strain, Rhodobacter sphaeroides NII2 was immobilized in polyvinyl alcohol (PVA) gel, and the properties of the cells in the gel were examined. The immobilized cells had low or almost no denitrification activity, but the cells were activated by incubation in light with culture medium for denitrification containing 0.5% nitrate and no other nitrogen source. Cells grown in the dark were activated by incubation at an earlier stage and to a higher rate than the light-grown cells. The activation was markedly enhanced in the PVA gel with a low cell concentration. The immobilized cells consumed nitrate with a temporary accumulation of NO 2 and evolved nitrogen gas. The immobilized cells could use various organic compounds as electron donors for denitrification. Thus, the immobilized cells were applied to a continuous treatment of synthetic wastewater using an aparatus devised by this laboratory. The results showed an efficient removal of NO 3 -N from the test water.