A Reduced Switch Asymmetric Multilevel Inverter Topology Using Unipolar Pulse Width Modulation Strategies for Photovoltaic Application

A new design of multilevel inverter configuration is proposed for reducing the component count and improving the quality of waveform in a photovoltaic system. The proposed configuration operates at the binary asymmetric condition for generating the large amount output voltage level with small amount harmonic distortion. Unipolar trapezoidal reference with triangular carriers is used for generating the desired switching pulses to generate the required output voltage level. The proposed configuration requires eight unipolar switches for generating the 31-level output voltage level with total harmonic distortion of 3.18% without using any filters. The value of %total harmonic distortion (THD) satisfies the IEEE 519 harmonic standard. Separate DC sources of proposed configuration are replaced by the array of photovoltaic panels for testing the configuration with the renewable energy source. The proposed configuration is tested with an experimental setup for proving the operation of it. Selected simulation and experimental results are shown for the verification of proposed configuration ability

Economic evaluation of shortened, bedaquiline-containing treatment regimens for rifampicin-resistant tuberculosis (STREAM stage 2) : a within-trial analysis of a randomised controlled trial

Background: The STREAM stage 2 trial assessed two bedaquiline-containing regimens for rifampicin-resistant tuberculosis: a 9-month all-oral regimen and a 6-month regimen containing an injectable drug for the first 2 months. We did a within-trial economic evaluation of these regimens. Methods: STREAM stage 2 was an international, phase 3, non-inferiority randomised trial in which participants with rifampicin-resistant tuberculosis were randomly assigned (1:2:2:2) to the 2011 WHO regimen (terminated early), a 9-month injectable-containing regimen (control regimen), a 9-month all-oral regimen with bedaquiline (oral regimen), or a 6-month regimen with bedaquiline and an injectable for the first 2 months (6-month regimen). We prospectively collected direct and indirect costs and health-related quality of life data from trial participants until week 76 of follow-up. Cost-effectiveness of the oral and 6-month regimens versus control was estimated in four countries (oral regimen) and two countries (6-month regimen), using health-related quality of life for cost-utility analysis and trial efficacy for cost-effectiveness analysis. This trial is registered with ISRCTN, ISRCTN18148631. Findings: 300 participants were included in the economic analyses (Ethiopia, 61; India, 142; Moldova, 51; Uganda, 46). In the cost-utility analysis, the oral regimen was not cost-effective in Ethiopia, India, Moldova, and Uganda from either a provider or societal perspective. In Moldova, the oral regimen was dominant from a societal perspective. In the cost-effectiveness analysis, the oral regimen was likely to be cost-effective from a provider perspective at willingness-to-pay thresholds per additional favourable outcome of more than US$4500 in Ethiopia,$1900 in India, $3950 in Moldova, and$7900 in Uganda, and from a societal perspective at thresholds of more than $15 900 in Ethiopia,$3150 in India, and $4350 in Uganda, while in Moldova the oral regimen was dominant. In Ethiopia and India, the 6-month regimen would cost tuberculosis programmes and participants less than the control regimen and was highly likely to be cost-effective in both cost-utility analysis and cost-effectiveness analysis. Reducing the bedaquiline price from$1·81 to $1·00 per tablet made the oral regimen cost-effective in the provider-perspective cost-utility analysis in India and Moldova and dominate over the control regimen in the provider-perspective cost-effectiveness analysis in India. Interpretation: At current costs, the oral bedaquiline-containing regimen for rifampicin-resistant tuberculosis is unlikely to be cost-effective in many low-income and middle-income countries. The 6-month regimen represents a cost-effective alternative if injectable use for 2 months is acceptable. Funding: USAID and Janssen Research & Development

Combustion and emission characteristics of diesel engine fuelled with rice bran oil methyl ester and its diesel blends

There has been a worldwide interest in searching for alternatives to petroleum-derived fuels due to their depletion as well as due to the concern for the environment. Vegetable oils have capability to solve this problem because they are renewable and lead to reduction in environmental pollution. The direct use of vegetable oils as a diesel engine fuel is possible but not preferable because of their extremely higher viscosity, strong tendency to polymerize and bad cold start properties. On the other hand, Biodiesels, which are derived from vegetable oils, have been recently recognized as a potential alternative to diesel oil. This study deals with the analysis of rice bran oil methyl ester (RBME) as a diesel fuel. RBME is derived through the transesterification process, in which the rice bran oil reacts with methanol in the presence of KOH. The properties of RBME thus obtained are comparable with ASTM biodiesel standards. Tests are conducted on a 4.4 kW, single-cylinder, naturally aspirated, direct-injection air-cooled stationary diesel engine to evaluate the feasibility of RBME and its diesel blends as alternate fuels. The ignition delay and peak heat release for RBME and its diesel blends are found to be lower than that of diesel and the ignition delay decreases with increase in RBME in the blend. Maximum heat release is found to occur earlier for RBME and its diesel blends than diesel. As the amount of RBME in the blend increases the HC, CO, and soot concentrations in the exhaust decreased when compared to mineral diesel. The NOx emissions of the RBME and its diesel blends are noted to be slightly higher than that of diesel