Ultraslow Electron Spin Dynamics in GaAs Quantum Wells Probed by Optically Pumped NMR

Optically pumped nuclear magnetic resonance (OPNMR) measurements were performed in two different electron-doped multiple quantum well samples near the fractional quantum Hall effect ground state nu=1/3. Below 0.5K, the spectra provide evidence that spin-reversed charged excitations of the nu=1/3 ground state are localized over the NMR time scale of ~40 microseconds. Furthermore, by varying NMR pulse parameters, the electron spin temperature (as measured by the Knight shift) could be driven above the lattice temperature, which shows that the value of the electron spin-lattice relaxation time lies between 100 microseconds and 500 milliseconds at nu=1/3.Comment: 6 pages (REVTEX), 6 eps figures embedded in text; published version; minor changes to match published versio

X-ray production in low energy proton stopping

The X-ray yields of stopping protons in an iron-nickel-cobalt alloy are calculated for use in predicting radiation damage in encased electronic devices

Conservation of energy by utilisation of waste heat direct power reduction in ferro alloy industry

Ferro Alloy Industry is a power intensive industry. Ferro alloys, such as Ferro Manganese, Ferro Silicon, Silico Manganese are manufactured in electric smelting furnace. Due to thermodynamic considerations, production of these Ferro alloys consume large amount of power. With the development of steel industry, requirement of Ferro Alloys as well as power is increasing day-by-day. Hence due consideration can be given in minimising electric power. The object of this paper is to give various directions in which work can be done to achieve saving in power. The paper deals with various factors affecting power consumpt-ion & work areas for improving technology to reduce energy consumption

Utilisation of ore fines by agglomeration with special reference to sintering of manganese ore fines

Agglomeration is required to coagulate the ore fines to the desired size to make them suitable for metallurgical operations. The well known methods of agglomeration are briquetting, pelletisation and Sintering. About 20-30 % of fines are generated during mining operation, handling and screening of ores before they are sized for the smelting furnace. This paper deals with the various process parameters which are determined for the manufacture of Manganese Ore Sinter on a continuous sinter plant of 20 Tons per day capacity

Study of serum cobalamin level in vegetarian v/s nonvegetarian geriatric individuals

Background: Vegetarianism is found in all geographic areas, they may have lower B-12 levels than nonvegetarian; problem could be graver in elderly. This study intended to recognise geriatric individuals with B-12 deficiency so as to save them from anaemia, dementia & neuropsychiatric disturbances by timely recommendations for supplementation.Methods: Current study was conducted on 200 healthy attendants divided in to two groups- A comprised of 100 vegetarian and B of 100 nonvegetarian geriatric individuals (> 60yrs.), they had no previous chronic disease and an attempt was made to exclude diabetes mellitus, hypertension, chronic gastritis, hypoplastic & aplastic anaemia. Those with history of alcohol intake, PPI therapy & regular vitamin supplementation were excluded. Complete clinical examination and routine blood tests were done. Serum cobalamin level was determined by ACCU-BIND ELISA Microwells method.Results: Total of 58 vegetarians were found to be B-12 deficient compared to 42 normal (>350pg/ml) this was statistically significant. Out of 100 nonvegetarian 48 were deficient while 52 had normal levels this too was statistically significant. On comparing the vegetarians and non vegetarian groups significant result was obtained (p <0.01). When different age groups were statistically compared insignificant result was obtained, same was true for gender distribution. Statistically significant result was obtained on comparing vegetarian Vs nonvegetarian group.Conclusions: Irrespective of the dietary habit B-12 deficiency is prevalent in elderly, as 58% of vegetarian & 48% of nonvegetarian were found B-12 deficient, detailed dietary analysis revealed that majority of them consumed nonvegetarian food only occasionally. No significant effect of increasing age & gender was found on B-12 levels in either group. Every elderly vegetarian or non vegetarian irrespective of gender should get their B-12 levels checked & if found low should receive B-12 supplement.

A comparative study on the application of various artificial neural networks to simultaneous prediction of rock fragmentation and backbreak

AbstractIn blasting operation, the aim is to achieve proper fragmentation and to avoid undesirable events such as backbreak. Therefore, predicting rock fragmentation and backbreak is very important to arrive at a technically and economically successful outcome. Since many parameters affect the blasting results in a complicated mechanism, employment of robust methods such as artificial neural network may be very useful. In this regard, this paper attends to simultaneous prediction of rock fragmentation and backbreak in the blasting operation of Tehran Cement Company limestone mines in Iran. Back propagation neural network (BPNN) and radial basis function neural network (RBFNN) are adopted for the simulation. Also, regression analysis is performed between independent and dependent variables. For the BPNN modeling, a network with architecture 6-10-2 is found to be optimum whereas for the RBFNN, architecture 6-36-2 with spread factor of 0.79 provides maximum prediction aptitude. Performance comparison of the developed models is fulfilled using value account for (VAF), root mean square error (RMSE), determination coefficient (R2) and maximum relative error (MRE). As such, it is observed that the BPNN model is the most preferable model providing maximum accuracy and minimum error. Also, sensitivity analysis shows that inputs burden and stemming are the most effective parameters on the outputs fragmentation and backbreak, respectively. On the other hand, for both of the outputs, specific charge is the least effective parameter

TRANSDERMAL DELIVERY OF CALCIUM CHANNEL BLOCKER: DEVELOPMENT AND CHARACTERIZATION

  Objective: Felodipine, a BCS class II calcium channel blocker, is used in the management of hypertension and angina pectoris. Due to the poor solubility and low bioavailability of the drug, there is a necessity to design an alternative route to achieve a constant plasma concentration of felodipine for its maximum therapeutic utility and can be achieved by transdermal route.Methods: In this study, matrix type transdermal patches were prepared using different combinations of hydrophilic polymer, namely, polyvinylpyrrolidone (PVP) and hydrophobic polymer, namely, ethyl cellulose (EC) by solvent evaporation technique and were subjected for characterization.Results: The Fourier transform infrared studies confirmed the compatibility between drug and polymers. Hydrophilic nature of the polymers greatly influenced physical characteristics and dissolution rate. Equal percentage of PVP and EC yielded patches with good folding endurance. The concentration of plasticizer present in the patches gave them desired folding endurance, and it increased with the presence of hydrophilic polymer. The formulation with highest PVP concentration, F3, exhibited a maximum drug release of 96.23% for 24 hrs. While the formulation with highest EC concentration, F5, exhibited only 74.45% drug release for 24 hrs.Conclusion: From the data, formulation F2 (PVP/EC, 2:1) can be concluded as best formulation due to its desired physical characteristics, good initial drug release, sustained release behavior, and good in vitro permeation. This formulation can be further studied in a clinical scenario

Evaluation of granisetron as an antiemetic in patients undergoing abdominal hysterectomy under spinal anaesthesia

Background: PONV most common complications related to surgery and anaesthesia despite major advances in spinal, epidural and combined spinal-epidural anesthesia techniques IONV are still present in a significant number of patients. Ondansetron, used for controlling PONV induced by chemotherapy or radiation. Recently 5HT3 receptor antagonist granisetron has more potent, selective and longer acting activity than ondansetron. Granisetron is more active for control of PONV in cisplatin induced vomiting than ondansetron. It also reduces PONV in strabismus repair, tonsillectomy, and general surgeries, it has less side effects as compared to ondansetron. Objective of the study was to study efficacy and safety of granisetron and compare it with ondansetron for prevention of IONV and PONV.Methods: 80 ASA grade I and II women undergoing abdominal hysterectomy under spinal anaesthesia were studied. Patients in group A received injection granisetron 2 mg and group B injection ondansetron 4 mg,10 minutes prior to induction of spinal anaesthesia. Main outcome measures were occurrence of nausea, retching or vomiting in intraoperative and postoperative period at 6, 12, 18 and 24 hours’ post-surgery. The response of patient to therapy and side effects were evaluated in both groups. The results were analyzed by ‘z’ test (p<0.5) considered significant.Results: Demographic characteristics of both groups were comparable patients in granisetron (80%) had more complete response as compared to ondansetron (47.5%). Adverse effects were lower in granisetron group.Conclusions: Granisetron 2 Mg has better efficacy and safety profile than ondansetron 4 Mg

Treatment of Snake Bites at a Regional Burn Center: Report of a Case Series

Background. Although uncommon, snakebites can cause significant morbidity and mortality. The objective of this study was to review the characteristics, treatment, and outcome of patients with a suspected or known snakebite who were treated at a regional verified burn center. Methods. A retrospective chart review of all snakebite victims was conducted for the time frame between January 1991 and June 2009. Results. During the study period, 12 patients were identified. One of the twelve patients was excluded because he had been admitted as an outpatient for wound debridement after being initially treated at another facility. Ten of the remaining 11 patients were male (90.9%). Rattlesnakes were responsible for the majority of bites. One of the eleven patients needed a fasciotomy. The majority of patients received antivenin (ACP/fabAV). No anaphylactoid reactions to either antivenin were recorded. There were no deaths. Conclusion. With burn centers evolving into centers for the care of complex wounds, patients with snakebite injuries can be managed safely in a burn center