Recovery of Economic Minerals from Graphite Float of Rajpura Dariba mines

A 3000 tpd lead-zinc ore beneficiation plant was commissioned in 1983 to produce lead and zinc concentrates suitable for Indian smelters. The problems encountered in the production of individual concentrates are mainly high graphite and lower lead grade in lead concentrate and high silica in zinc concentrate. Due to variable nature of ore quality, Graphite mica - schist, the incidence of high graphite and lower grade of lead in lead concentrates can be explained and taken care by use of pre flotation of graphite and by gravity techniques. It has been observed during extensive laboratory scale testing by in-house R&D of HZL and by the National Laboratories in India and plant operations for over a decade that incidence of graphite mica -schist in the ore affects zinc flotation only to a limited extent whereas lead metallurgy is adversely affected. Hence one of the methods tried was pre-flotation of graphite ahead of lead-zinc selective flotation. In this paper, efforts made towards recovery of lead and zinc minerals present in the pre-graphite float are discussed. The studies include lead and zinc depressionduring reverse flotation, graphite depression and lead flotation and use of gravity techniques. The results indicate that gravity techniques are effective in removing most of the liberated graphite,thereby ensuring enrichment of lead and zinc minerals present in the higher specific gravity fractions, which can be recirculated and recovered in the plant

Effects of the surgical excision of the sinus gland and eyestalk ablation on osmotic regulation

Sinus gland is a neurohaemal organ wherein hormones from different neurosecretory centres are stored. The sinus gland of Scylla serrata is well developed and macroscopically visible owing to its well known characteristic opacity and slightly bluishhue. It is located at the dorsal aspect of the junction between the medulla interna and the medulla terminalis in the eyestalk. Since it is a compact structure it is possible to remove the sinus gland from the eyestalk. There are two surgical procedures for the removal of the sinus gland. The first procedure involves the removal of the retinal portion of the eye cap and the other involves surgical excision without disturbing the eye cap and thereby the vision of the crab (Kleinholz, 1947)

Carbohydrate nature of lyophilized leaf powder of Azadirachta indica induced inhibition of the activities of accessory reproductive ducts in male rats

Reports have been shown that the chemical nature of leaf powder/extract was carbohydrate-rich in nature. The purpose investigation is designed to investigate the dose dependent effect of carbohydrate nature of lyophilized A.indica leaf powder on some of the androgen dependent biochemical parameters in the reproductive organs which include epididymis (divided in to caput, corpus and cauda), vas deferens, seminal vesicle and ventral prostate of treated rats given 25, 50 and 75 mg in suspension of 1 mL Propylene Glycol, respectively/kg body weight, once daily, orally, for 24 days. Results indicated no significant difference in the body weight of all treated animals. However, there was decreased (P ≤ 0.05) in the weight of accessory reproductive organs. The biochemical analysis showed a dose dependent decrease (P ≤ 0.05) in the total protein content and the activity of acid phosphatase (ACP)  and an increase (P ≤ 0.05) in the total free sugar, glycogen, cholesterol contents and the activities of alkaline phosphatase (ALP)  and lactate dehydrogenase (LDH) in the reproductive organs of treated rats. Blood serum levels of testosterone, LH and FSH in treated groups were significantly (P ≤ 0.05) reduced respectively when compared to controls. In the present study, the changes in biochemical composition of androgen dependent reproductive organs suggest a deficiency in the level of circulating androgen and decrease in the serum hormone levels in the lyophilized A.indica leaf powder treated animals clearly indicates the action of carbohydrate-rich leaf powder on the secretion of pituitary gonadotropins and inturn in the testosterone biosynthesis in the testis and reproductive organs

Dose response effects of carbohydrate nature of lyophilized leaf powder of Azadirachta indica on testis of albino rats

The purpose investigation is designed to investigate the effect of carbohydrate nature of lyophilized Azadirachta indica leaf powder on the histology of testis, since experimental studies shown that the chemical nature of leaf powder was studied and observed that the leaf powder was carbohydrate-rich in nature. In the present study of histomorphometric and histopathological dose dependent assessments of carbohydrate nature of lyophilized A.indica leaf powder on the testis of male wistar rats given 25, 50 and 75 mg in suspension of 1 mL Propylene Glycol, respectively/kg body weight, once daily, orally, for 24 days showed varying degrees of desquamation of seminiferous epithelial cells, degeneration of seminiferous tubules and presence of large-sized multinucleated cells as well as the spermatogenesis was arrested either at the primary spermatocytes or the spermatogonial stages. Damaged seminiferous tubules contained the abundance of vacuoles with varying size Total count, cell and nuclear diameter of spermatogonia, spermatocytes, spermatids and Leydig cells were reduced in a dose dependent manner (P ≤ 0.05). From the results obtained, it can be observed such effects on the testis are possibly due to curtailing of androgen supply within the testis or it may be a direct effect of this carbohydrate-rich nature of lyophilized A. indica leaf powder on the tissue probably due to direct or indirect gonadotrophic hormone deficiency

Design of probe for NQR/NMR detection

Nuclear Magnetic Resonance (NMR) is a RF technique that is able to detect any compound by sensing the excited resonance signals from atomic nuclei having non-zero spin. NQR is similar to NMR but the only difference is NMR needs a DC magnetic field and due to this its application in the field is limited. A FPGA based NQR spectrometer is designed using a single FPGA chip to perform the digital tasks required for NQR spectrometer. Design of Probe for NMR/NQR spectrometer is researched. Parallel tuned and series tuned Probes are discussed and simulated.14N NQR from NaNO2 is observed from spectrometer designed with parallel tuned probe

The Building of Pulsed NQR/NMR Spectrometer

NQR spectrometer designed is composed of four modules; Transmitter, Probe, Receiver and computer controlled (FPGA & Software) module containing frequency synthesizer, synchronous demodulator, pulse programmer and display. The function of the Transmitter module is to amplify the RF pulse sequence to about 200 W power level into the probe (50 Ohm) which is a parallel resonance circuit with a tapped capacitor. The probe excites the nucleus and picks-up the signal emitted from the nuclei. The nuclear signal at the same frequency as the excitation, which is typically in the range of a few microvolts is amplified, demodulated and filtered (1 kHz to 100 kHz) by receiver module. 14N NQR, 1H and 2H NMR signals are observed from the spectrometer.As the SNR of NQR signal is very low, NQR signal processing based on Adaptive Line Enhancement is presented