Non-Edible Plant Oils as New Sources for Biodiesel Production

Due to the concern on the availability of recoverable fossil fuel reserves and the environmental problems caused by the use those fossil fuels, considerable attention has been given to biodiesel production as an alternative to petrodiesel. However, as the biodiesel is produced from vegetable oils and animal fats, there are concerns that biodiesel feedstock may compete with food supply in the long-term. Hence, the recent focus is to find oil bearing plants that produce non-edible oils as the feedstock for biodiesel production. In this paper, two plant species, soapnut (Sapindus mukorossi) and jatropha (jatropha curcas, L.) are discussed as newer sources of oil for biodiesel production. Experimental analysis showed that both oils have great potential to be used as feedstock for biodiesel production. Fatty acid methyl ester (FAME) from cold pressed soapnut seed oil was envisaged as biodiesel source for the first time. Soapnut oil was found to have average of 9.1% free FA, 84.43% triglycerides, 4.88% sterol and 1.59% others. Jatropha oil contains approximately 14% free FA, approximately 5% higher than soapnut oil. Soapnut oil biodiesel contains approximately 85% unsaturated FA while jatropha oil biodiesel was found to have approximately 80% unsaturated FA. Oleic acid was found to be the dominant FA in both soapnut and jatropha biodiesel. Over 97% conversion to FAME was achieved for both soapnut and jatropha oil

Observation of γγ → ττ in proton-proton collisions and limits on the anomalous electromagnetic moments of the τ lepton

The production of a pair of τ leptons via photon–photon fusion, γγ → ττ, is observed for the f irst time in proton–proton collisions, with a significance of 5.3 standard deviations. This observation is based on a data set recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. Events with a pair of τ leptons produced via photon–photon fusion are selected by requiring them to be back-to-back in the azimuthal direction and to have a minimum number of charged hadrons associated with their production vertex. The τ leptons are reconstructed in their leptonic and hadronic decay modes. The measured fiducial cross section of γγ → ττ is σfid obs = 12.4+3.8 −3.1 fb. Constraints are set on the contributions to the anomalous magnetic moment (aτ) and electric dipole moments (dτ) of the τ lepton originating from potential effects of new physics on the γττ vertex: aτ = 0.0009+0.0032 −0.0031 and |dτ| < 2.9×10−17ecm (95% confidence level), consistent with the standard model

Comparison of effects of Bupivacaine and Ropivacaine in patients undergoing elective Caesarean section

Introduction: Spinal anesthesia is considered a reasonable choice for cesarean section. Bupivacaine and ropivacaine have been used as intrathecal drugs alone or in combination with various opioids. Ropivacaine is considered a valid and safe alternative to bupivacaine for spinal anesthesia.&#x0D; Objectives: To compare the efficacy and safety of hyperbaric ropivacaine with hyperbaric bupivacaine in spinal anesthesia for elective cesarean section.&#x0D; Methodology: Sixty pregnant women undergoing elective cesarean section were allocated into two groups. Group R received 3 ml of 0.5% hyperbaric ropivacaine (2 ml 0.75% plain ropivacaine mixed with 1 ml of 25 %dextrose) and Group B received 2.5 ml of 0.5% hyperbaric bupivacaine. Both the groups were compared in terms of onset of sensory and motor block, regression of sensory and motor block, duration of analgesia and side effects.&#x0D; Results: The onset of sensory block was comparable in both groups but was statistically insignificant. The onset of motor block in Bupivacaine(7.53 ± 1.72) min was faster when compared to Ropivacaine group(14.33 ± 6.19) min. Regression of sensory and motor block both were faster in Ropivacaine group. Duration of analgesia was longer in Bupivacaine group(131.17 ± 32.95)min than Ropivacaine group(125.33 ± 30.54)min.&#x0D; Conclusion: Ropivacaine can be used as an alternative to Bupivacaine for spinal anesthesia in cesarean section but has a shorter duration of sensory and motor block.</jats:p

Promoting Sustainability in the Energy Sector in Nepal-with a Focus on Biodiesel Fuel

This thesis is focused on sustainability analysis of alternative fuels in Nepal and presents the resullts of the tests on fuel and atomization characterisation of different biodiesel feedstocks including canola, jatropha, soapnut and waste cooking oil. A new model to evaluate sustainability of renewable alternatives energy resources has been developed and tested.This study analyzes the sustainability of various energy sources including micro hydro power and biodiesel in the context of Nepal. The main focus is on the development of biodiesel fuels from non-edible oil resources including waste cooking oil, jatropha and soapnut oil feedstocks grown on the marginal lands of Nepal. Biodiesel fuel samples were prepared by acid and/or base catalyst transesterification. Both single stage and dual stage transesterification processes were employed depending on the free fatty acid content of the oil feedstock. The oil to biodiesel conversion rate and total yield were monitored. The quality of the biodiesel fuels including viscosity etc was confirmed by an external laboratory and all fuels met the ASTM fuel quality requirements. Canola, jatropha and soapnut biodiesel fuels were tested to determine some atomization properties - density, surface tension and viscosity - at elevated temperatures and pressures. The density of three biodiesel fuels and diesel were determined up to 523 K and 7 MPa using a capacitance type densitometer. The results showed a linear relationship with temperature and pressure over the measured range. The experimental data were well within the range of canola and other biodiesel fuels found in the literature. Kay’s mixing rule was used to predict the density of some biodiesel blends and the results were found to be in agreement with less than 5% error with the measured data. The surface tension was measured using a pendant drop apparatus for all three biodiesel and diesel fuels for temperatures and pressures up to 473K and 7 MPa. Results showed a linear relationship with temperature as well as with pressure. Temperature has a higher effect on surface tension than pressure. The viscosity of all three biodiesel and diesel fuels were measured using a torsional vibration viscometer up to 523 K and 7 MPa. Results showed that the viscosity-temperature relationship of all three biodiesel fuels tested followed a modified Andrade equation which was also applicable when temperature and pressure were both applied simultaneously. The measured and regressed kinematic and dynamic viscosities obtained were comparable with values in the literature

Effective Power Electronics Understanding Using Circuit Simulation

&lt;p&gt;Learning power electronics circuits through simulation is one of the best ways for an Undergraduate and Postgraduate student to understand the subject effectively. This article aims to provide a panoramic view of different software tools used for simulating electrical circuits and enable students to have the best choice among various tools. A simple buck converter is considered for illustration and is realized using multiple approaches using MATLAB, Scilab, and LTspice software tools. As MATLAB and LTSpice software tools provide the open loop characteristics of any physical system, a detailed analysis of frequency response for constant voltage operation (Gvd) and average current operations (Gid) for the converter is carried out. Though Scilab is open-source software it provides the same accuracy as that of a licensed tool, such as MATLAB. However, slowness in simulation is observed while simulating complex systems. For a quick insight into the frequency response, the LTspice software tool provides a high-speed response compared to MATLAB.&lt;/p&gt;</jats:p

A Comparative Study of Dexmedetomidine and Esmolol on Hemodynamic Responses During Laparoscopic Cholecystectomy

Background: Laparoscopic surgery has various advantages like minimal invasiveness and quick recovery. However carbon dioxide used for pneumoperitoneum during laparoscopic surgery causes increase in heart rate, blood pressure and systemic vascular resistance. The present study compared the efficacy of Dexmedetomidine and Esmolol on hemodynamic responses during laparoscopic cholecystectomy.&#x0D; Material and Methods: A total of 100 patients scheduled for laparoscopic cholecystectomy were randomly allocated in two groups, 50 in each group. Esmolol group received bolus dose of 1 mg/kg intravenous Esmolol just before pneumoperitoneum followed by an infusion of 200 mcg/kg/minand Dexmeditomidine group  received bolus dose of 1 mcg/kg iv Dexmedetomidine over 10 minutes before pneumoperitoneum  followed by 0.6 mcg/kg/hr in infusion. Hemodynamic parameters like Heart rate, Mean arterial pressure, Systolic blood pressure, Diastolic blood pressure were recorded at different time intervals.&#x0D; Results: It was found that in Dexmeditomidine group  there was a statistically significant decrease in heart rate before pneumoperitoneum (84.24±9.17) and 10 minutes after pneumoperitoneum (79.40±7.41)compared to Esmolol Group  before pneumoperitoneum (91.40±5.98) and10 minutes after pneumoperitoneum (95.18±14.17).There was statistically significant decrease in Mean arterial pressure in Dexmeditomidine group  at  30 minutes (86.53±6.13), 50 minutes (77.95±4.85) , after release of pneumoperitoneum (92.42±3.91) and after extubation (99.50±11.81) compared  to Esmolol group  at 30 minutes (91.23±8.97), 50 minutes (94.34±12.64) after release of pneumoperitoneum (102.5±10.44) and after extubation (112.39±11.15).&#x0D; Conclusion: Dexmedetomidine was found to be more effective than Esmolol in attenuating the hemodynamic responses following pneumoperitoneum during laparoscopic cholecystectomy.</jats:p

Effective Power Electronics Understanding Using Circuit Simulation

&lt;p&gt;Learning power electronics circuits through simulation is one of the best ways for an Undergraduate and Postgraduate student to understand the subject effectively. This article aims to provide a panoramic view of different software tools used for simulating electrical circuits and enable students to have the best choice among various tools. A simple buck converter is considered for illustration and is realized using multiple approaches using MATLAB, Scilab, and LTspice software tools. As MATLAB and LTSpice software tools provide the open loop characteristics of any physical system, a detailed analysis of frequency response for constant voltage operation (Gvd) and average current operations (Gid) for the converter is carried out. Though Scilab is open-source software it provides the same accuracy as that of a licensed tool, such as MATLAB. However, slowness in simulation is observed while simulating complex systems. For a quick insight into the frequency response, the LTspice software tool provides a high-speed response compared to MATLAB.&lt;/p&gt;</jats:p