Effect of Sand Mining on Economic Performance of Groundwater Irrigation in Cuddalore District of Tamil Nadu

The effect of sand mining on the economic performance of groundwater irrigation has been studied in the Panruti taluk of Cuddalore district in Tamil Nadu. A comparison of water productivity for different farms-size categories has been done in sand mining and non-sand mining blocks. The cropping sequence, cropping intensity, irrigation particulars, investment pattern on tubewells, use of different HP-motors, etc. have been studied in sand mining and non-sand mining blocks. The study has revealed that due to sand mining externality, the watertable has gone down and to offset this effect, the farmers have been increasing the horse-power of their motors. Thus, investment has been increasing in the sand mining block in all farm-size categories. Its repercussions have been reflected in the economic performance of sand mining block in terms of higher annual cost and unit cost of irrigation. The study has suggested to take necessary steps to augment the groundwater recharge on one hand and imposing restrictions on indiscriminate sand mining on the other hand. The regulation of sand quarrying has also been suggested to streamline the flow of river Malattar.Resource /Energy Economics and Policy,

A comparative study on the production of ethanol from lignocellulosic biomass by chemical and biological method

Ethanol derived from non-edible biomass is renewable and a clean source of energy. It is independent of the food industry and it is economically feasible. The first generation biofuel or bioethanol is still not a very convenient source of energy as it prominently depends on the availability of grains. The main objective of this work is to develop an industrious efficient process to produce ethanol from lignocellulosic biomasses like wood and leaf in a lab scale. Two processes were compared. The first process involved an alkaline pre-treatment of the powdered biomass followed by dilute acid hydrolysis. The second process involved an alkaline treatment followed by direct hydrolysis of the biomass by use of a fungal species obtained from rotting wood. Following hydrolysis, fermentation was performed using _Saccharomyces cerevisiae_ and ethanol produced was measured. The process methodologies performed here are liable to be scaled up easily. The final study determines factors such as temperature, strength of the reagents and retention time to maximize ethanol production

Gunn Effect in Silicon Nanowires: Charge Transport under High Electric Field

Gunn (or Gunn-Hilsum) Effect and its associated negative differential resistivity (NDR) emanates from transfer of electrons between two different energy bands in a semiconductor. If applying a voltage (electric field) transfers electrons from an energy sub band of a low effective mass to a second one with higher effective mass, then the current drops. This manifests itself as a negative slope or NDR in the I-V characteristics of the device which is in essence due to the reduction of electron mobility. Recalling that mobility is inversely proportional to electron effective mass or curvature of the energy sub band. This effect was observed in semiconductors like GaAs which has direct bandgap of very low effective mass and its second indirect sub band is about 300 meV above the former. More importantly a self-repeating oscillation of spatially accumulated charge carriers along the transport direction occurs which is the artifact of NDR, a process which is called Gunn oscillation and was observed by J. B. Gunn. In sharp contrast to GaAs, bulk silicon has a very high energy spacing (~1 eV) which renders the initiation of transfer-induced NDR unobservable. Using Density Functional Theory (DFT), semi-empirical 10 orbital ($sp^{3}d^{5}s^{*}$) Tight Binding (TB) method and Ensemble Monte Carlo (EMC) simulations we show for the first time that (a) Gunn Effect can be induced in narrow silicon nanowires with diameters of 3.1 nm under 3 % tensile strain and an electric field of 5000 V/cm, (b) the onset of NDR in I-V characteristics is reversibly adjustable by strain and (c) strain can modulate the value of resistivity by a factor 2.3 for SiNWs of normal I-V characteristics i.e. those without NDR. These observations are promising for applications of SiNWs in electromechanical sensors and adjustable microwave oscillators.Comment: 18 pages, 6 figures, 63 reference

Cerebrospinal fluid lysozyme in the diagnosis of tuberculous meningitis

Pretreatment lysozyme levels in cerebrospinal fluid (CSF) were estimated in 37 patients with tuberculous meningitis (TBM), 16 with non-tuberculous meningitis (non-TBM) and 13 with non-inflammatory conditions of the central nervous system (controls) in an attempt to assess the role of CSF lysozyme in the diagnosis of TBM. Lysozyme content in the CSF was found to be elevated in all patients with bacteriologically confirmed TBM and in a large proportion of patients in whom the disease was clinically diagnosed but bacteriologically not confirmed. The enzyme was not detected in all but one of the control subjects and in most (69%) of the non-TBM patients

Single strand conformation polymorphism profiles with biotinylated PCR products to detect mutations in rpoB gene of Mycobacterium tuberculosis

A fragment of the rpoB gene, including the region shown to be involved in rifampicin resistance, was amplified from 15 rifampicin-resistant and 6 rifampicin- sensitive clinical isolates of Mycobacterium tuberculosis by the polymerase chain reaction (PCR). One of the primers, employed in PCR, was biotinylated. The biotinylated strand of the PCR product was separated from the unbiotinylated strand using streptavidin magnetic beads. Both the strands were subjected to single strand conformation polymorphism in polyacrylamide gel electrophoresis. The DNA bands were silver stained to study their migration pattern. A shift in the migration of either of the strands of the test strain compared to the strands from a control rifampicin-sensitive strain was considered as indicative of resistance. This strategy was found to ease the visualization of shift in the migration of the strands in 17 of 21 samples and thereby detection of mutations

Use of streptavidin magnetic beads in single strand conformation polymorphism profiles to detect mutations in rpoB gene of M.tuberculosis

Single strand conformation polymorphism (SSCP) is one of the promising techniques to identify mutations in short pieces of DNA (Orita et al. 1989). In this technique, DNA of interest is often amplified by the polymerase chain reaction (PCR) and then denatured by heat or alkali treatment before electrophoresis on a non denaturing polyacrylamide gel. Differences in mobility of either of the single strands compared to the control DNA indicate mutations which affect the secondary structure and alter the mobility of the DNA. We applied PCR-SSCP for the detection of mutations in the rifampicin resistance determining region (RRDR) of the rpoB gene of M. tuberculosis (Telenti et al. 1993a; 1993b). A nested PCR was used to amplify the RRDR. In the first PCR, 293-bp product was amplified and in the second PCR a 103- bp of the first PCR product was amplified. However, in our experience using denaturation by alkali or heating, the denatured PCR product most often reannealed to form a large proportion of double stranded DNA during the electrophoresis (Selvakumar et al. 1997a). After visualisation by staining with ethidium bromide or silver staining, most of the DNA was in the double stranded form, with very little or no single stranded DNA. The single strands that could be observed often ran close together, making analysis of any difference in mobility difficult. Therefore an attempt was made to generate biotinylated PCR product using a biotinylated forward primer and later the biotinylated strand was separated using sterptavidin magnetic beads. The separated strands eliminated the problem of strand reannealing during SSCP and were silver stained to detect the shift in the mobility. Since the nested PCR requires more time and is more expensive. a biotinylated PCR product was generated in a single PCR using a biotinylated forward primer and an unbiotinylated reverse primer. This simplified protocol was applied to clinical isolates in an attempt to detect rifampicin resistance

A novel method of staining acid-fast bacilli in sputum containers

Background & objectives: Making centrifuged deposit smears from sputum to detect acid-fast bacilli (AFB) is considered hazardous. We carried out this study to stain the centrifuged deposits with carbol-fuchsin in sputum containers and to decolourize and counterstain their smears made on glass slides. Methods: The centrifuged deposits of 180 sputum samples from pulmonary tuberculosis patients were used for making smears (initial deposit smears) and staining by Ziehl-Neelsen (ZN) method for the detection of AFB. Each of the sputum deposit was then treated with one ml of 1 per cent carbol-fuchsin and a smear made between 2 to 3 h was then decolourized and counterstained by the same procedures followed in ZN method (2 h stained deposit smear). The coded initial deposit smears and the corresponding 2 h stained deposit smears were read by the same readers and the results compared. Results: One hundred and fifty (70 positive and 80 negative) 2 h stained deposit smears were compared with initial deposit smears and the difference was not statistically significant. Interpretation & conclusion: Centrifuged deposits of sputum in sputum containers can be stained by carbol-fuchsin within 2-3 h and their smears made subsequently on glass slides can then be decolourized and counterstained by the procedures followed in ZN method for detection of AFB by light microscopy

In vitro susceptibility of Mycobacterium tuberculosis to trifluoperazine

The reference strain, Mycobacterium tuberculosis H37Rv, 19 drug-sensitive and 15 drug resistant clinical isolates of M. tuberculosis were tested for their in vitro susceptibility to trifluoperazine (TFP), an antipsychotic drug, by broth dilution method. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of TFP against M. tuberculosis H37Rv were 8 and 32 mg/l, respectively. The distribution of the sensitive and resistant isolates, with respect to the MIC of TFP, was similar. The distribution of the sensitive and resistant isolates, with respect to the MBC of TFP, was different and the difference was statistically significant. The findings suggest that TFP is more bactericidal to drug-resistant isolates than to the sensitive isolates

Welding

Friction welding method is one of the most simple, economical and highly productive methods in joining similar and dissimilar metals. It is widely used in the automotive, aircraft and aerospace industrial applications. For many applications it is often necessary to join aluminium (6061) to make finished part. In this project the main aim is to weld the small thickness of aluminum (6061) plates for that friction welding machine used is of higher cost. Here the aim is reduce the cost of friction welding machine with simple parts like three phase A.C induction motor, bush, frame stand, friction tool, universal vice, vertical moving bed, horizontal moving bed, etc. The result expected would be of same strength as that of old friction welding machine. It is very easy and at same time production time is very much reduced. This machine is best suitable for mass production