High efficiency multi-junction solar cell design

Energy from the sun is the best option for electricity generation as it is abundantly available everywhere and sustainable source. Advance of Photovoltaic (PV) technology in recent years has made solar energy one of the practical alternative energy sources available in the energy market. In order to make the PV energy more affordable and cost effective, major focus of the research community and industry is improvement on power efficiency of PV systems. Early stage of solar panel manufacturing known as process technology plays a crucial role in achieving above limits. This paper presents a novel process technology for solar panel with 6 junctions

Resource variation in colorectal surgery; a national centre-level analysis.

BACKGROUND: Delivery of quality colorectal surgery requires adequate resources. We set out to assess the relationship between resources and outcomes in English colorectal units. METHODS: Data was extracted from the ACPGBI resource questionnaire to profile resources. This was correlated with Hospital Episode Statistics (HES) outcome data including 90-day mortality and readmissions. Patient satisfaction measures were extracted from the Cancer Experience Patient Survey (CEPS) and compared at unit level. Centres were divided by workload into low, middle, and top tertile. RESULTS: Completed questionnaires were received from 75 centres in England. Service resources were similar between low and top tertiles in access to CEPOD theatre, level 2 or 3 beds per 250,000 population or likelihood of having a dedicated colorectal ward. There was no difference in staffing levels per 250,000 unit of population. Each 10% increase in the proportion of cases attempted laparoscopically, was associated with reduced 90-day unplanned readmission (RR 0.94, 95% CI 0.91 to 0.97, p<0.001). The presence of a dedicated colorectal ward (RR 0.85, 95% CI 0.73 to 0.99, p =0.040) was also associated with a significant reduction in unplanned readmissions. There was no association between staffing or service factors and patient satisfaction. DISCUSSION AND CONCLUSIONS: Resource levels do not vary based on unit of population. There is benefit associated with increased use of laparoscopy and a dedicated surgical ward. Alternative measures to assess the relationship between resources and outcome, such as failure to rescue, should be explored in UK practice. This article is protected by copyright. All rights reserved

Development of microcontroller based over-current relay controls

This Project is about designing the controls of an Overcurrent relay using microcontroller. Relay is an electrical switch. Generally it operates on electromagnetic principle for switching action. Over current (OC) relay is a type of relay which performs its switching action based on an input current to it. When the input current exceeds a particular pick up value the relay operates. Microcontroller based relays are gaining popularity as these have no mechanical contacts. These can operate at very high speeds. Any kind of characteristics can be obtained by using these. In a typical microcontroller based relay there is a current transducer, a controller, current transformer and a circuit breaker. Microcontroller reads load current via CT, transducer and ADC. When current is above pickup it gives a signal to circuit breaker to trip. Microcontroller can be programmed to obtain IDMT characteristic

Vulnerability of European wheat to extreme heat and drought around flowering under future climate

Identifying the future threats to crop yields from climate change is vital to underpin the continuous production increases needed for global food security. In the present study, the vulnerability of European wheat yield to heat and drought stresses around flowering under climate change was assessed by estimating the 95-percentiles of two indices at flowering under rain-fed conditions: the heat stress index (HSI95) and the drought stress index (DSI95). These two indices represent the relative yield losses due heat stress or drought stress around flowering that could be expected to occur once every 20 years on average. The Sirius wheat model was run under the predicted 2050-climate at 13 selected sites, representing the major wheat-growing regions in Europe. A total of 19 global climate models (GCMs) from the CMIP5 ensemble were used to construct local-scale climate scenarios for 2050 (RCP8.5) by downscaling GCMs climate projections with the LARS-WG weather generator. The mean DSI95 due to extreme drought around flowering under the baseline climate (1981–2010) was large over Europe (DSI95 ∼ 0.28), with wide site variation (DSI95 ∼ 0.0–0.51). A reduction of 12% in the DSI95 was predicted under the 2050-climate; however, vulnerability due to extreme drought around flowering would remain a major constraint to wheat yield (DSI95 ∼ 0–0.57). In contrast, HSI95 under the baseline climate was very small over Europe (HSI95 ∼ 0.0–0.11), but was predicted to increase by 79% (HSI95 ∼ 0.0–0.23) under the 2050-climate, categorising extreme heat stress around flowering as an emergent threat to European wheat production. The development of wheat varieties that are tolerant to drought and heat stresses around flowering, is required, if climate change is not to result in a reduction of wheat yield potential under the future climate in Europe

Neutrino mass and charged lepton flavor violation in an extended left-right symmetric model

We consider an $U(1)_{L_\mu -L_\tau}$ extended left-right symmetric gauge theory where the neutrino masses are generated through inverse seesaw mechanism. In this model the muon $(g-2)$ anomaly is accounted for by the mediation of $Z_{\mu\tau}$, the gauge boson of $U(1)_{L_\mu - L_\tau}$ symmetry. The symmetries of the model require the light neutrino mass matrix to have a particular two-zero texture, which leads to non-trivial constraints in the minimum neutrino mass. In addition, the model predicts observable charged lepton flavor violation in $\mu-\tau$ sector.Comment: 21 pages, 2 figures, 2 tables, Version accepted in Nucl. Phys.

Local impacts of climate change on winter wheat in Great Britain

Under future CMIP5 climate change scenarios for 2050, an increase in wheat yield of about 10% is predicted in Great Britain (GB) as a result of the combined effect of CO2 fertilization and a shift in phenology. Compared to the present day, crops escape increases in the climate impacts of drought and heat stresses on grain yield by developing before these stresses can occur. In the future, yield losses from water stress over a growing season will remain about the same across Great Britain with losses reaching around 20% of potential yield, while losses from drought around flowering will decrease and account for about 9% of water limited yield. Yield losses from heat stress around flowering will remain negligible in the future. These conclusions are drawn from a modelling study based on the response of the Sirius wheat simulation model to local-scale 2050-climate scenarios derived from 19 Global Climate Models from the CMIP5 ensemble at 25 locations representing current or potential wheat-growing areas in GB. However, depending on susceptibility to water stress, substantial interannual yield variation between locations is predicted, in some cases suggesting low wheat yield stability. For this reason, local-scale studies should be performed to evaluate uncertainties in yield prediction related to future weather patterns

Formulation and in vitro Evaluation of Eudragit® Microspheres of Stavudine

Purpose: The aim of this study was to formulate and evaluate microencapsulated controlled release preparations of a highly water-soluble drug, stavudine, using Copolymers synthesized from acrylic and methacrylic acid esters (Eudragit RS 100 and RL 100) as the retardant material. . Methods: Microspheres were prepared by solvent evaporation method using an acetone / liquid paraffin system. Magnesium stearate was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeritic properties and drug loading, as well by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry, x-ray powder diffractometry and scanning electron microscopy. The in vitro release studies were performed in pH 6.8, phosphate buffer. Results: The prepared microspheres were white, free flowing and spherical in shape. The drug-loaded microspheres showed 67-91% of entrapment and release was extended upto 6 to 8 h. The infrared spectra and differential scanning calorimetry thermographs showed stable character of stavudine in the drug-loaded microspheres and revealed the absence of drug-polymer interactions. X-ray diffraction patterns showed that there was decrease in crystallinity of the drug. Scanning electron microscopy study revealed that the microspheres were spherical and porous in nature. Conclusion: The best-fit release kinetics was achieved with Higuchi plot followed by zero order and First order. The release of stavudine was influenced by the drug to polymer ratio and particle size & was found to be diffusion controlled. Keywords: Stavudine, Eudragit, microspheres, controlled release, polymethacrylate > Tropical Journal of Pharmaceutical Research Vol. 4 (1) 2005: pp. 369-37