► Wind, solar/solar thermal based hybrid energy/storage systems have been proposed. ► GA-optimized controllers are installed to alleviate the mismatch between the generation and demand. ► Performance ...of each controller is examined from dynamic behaviour in time-domain simulations. ► GA-optimized controller is compared with conventional controller.
Wind, Solar photovoltaic and solar thermal power systems are emerging renewable energy technologies and can be developed as viable options for electricity generation in future. In this paper, autonomous hybrid generation systems consisting of wind turbine generators (WTGs), solar thermal power system (STPS), solar photovoltaic (PV), diesel engine generators (DEGs), fuel cells (FCs), battery energy storage system (BESS), flywheel (FW), ultra capacitors (UCs) and aqua electrolyzer (AE) have been considered for simulation studies. The power system frequency deviates for sudden changes in load or generation or the both. The comparative performance of the controllers installed to alleviate this frequency deviation for different hybrid systems, is carried out using time domain simulation. In practice, controllers (PI or PID) are tuned manually which is difficult and time consuming. The computational intelligence has opened paths to a new generation of advanced process control. Here, GA is used for optimization of controllers’ gains of the proposed hybrid systems. The simulation results demonstrate the effectiveness of the GA based controllers in terms of reduced settling time, overshoot and oscillations. The results are compared with conventional controllers.
Smokeless tobacco products have been linked to precancerous and cancers of oral cavity for long. Evidence was available on the association between smokeless tobacco (SLT) products and oral cancers at ...regional but not at global level. Present meta-analysis is aimed to evaluate the risk of oral cancer with the use of SLT products among "ever" versus "never" users.
Studies published for the period (1960-2016) are retrieved using Pubmed, Indmed, EMBASE, and Google Scholar search engines for the subject "ever" versus "never" users of SLT products and estimated the risk association with oral cancer. Summary odds ratios (relative risk) are estimated and meta-analysis was performed using random-effects model.
Thirty-seven studies from four of six WHO regions, Southeast Asia region (SEAR), the Eastern Mediterranean Region (EMR), Europe, and region of Americas (North and South) are included in the analysis. Significant risk with SLT products with oral cancer was found for SEAR (4.44, 95% CI = 3.51 to 5.61) and for EMR (1.28, 95% CI = 1.04 to 1.56). Significantly higher risk (p < .001) was found for females (5.83, 95% CI = 2.93 to 11.58). Product wise analysis for different SLT products revealed various levels of risk viz. gutkha (8.67, 95% CI = 3.59 to 20.93), pan tobacco / betel liquid (7.18, 95% CI = 5.48 to 9.41), oral snuff (4.18, 50% CI = 2.37 to 7.38), Mainpuri tobacco (3.32, 95% CI = 1.32 to 8.36), and snus (0.86, 95% CI = 0.58 to 1.29).
A significant positive association was observed between SLT use and the risk of oral cancer, in SEAR, EMRs, and among women users.
The present meta-analysis demonstrates SLT product use and the risk of oral cancer at global level. Moreover, the present analysis provided data on the risk associated with individual SLT product. The results fulfil the gap in the data on independent effect of individual SLT product use on the outcome of oral cancer at global level, conclusively. Chewing SLT products was associated with higher risk of oral cancer than other types of SLT. This can serve as a useful tool for policy makers in forming strict policies in controlling SLT menace. Hence, we propose that in addition to smoking, efforts should be directed towards SLT product cessation as well in reducing oral cancer incidence.
Acoustic Resonance Spectroscopy enables highly accurate measurement of the properties (geometry/material) of a structure based on the structure's natural vibrational resonances. In general, measuring ...a specific property in multibody structures presents a significant challenge due to the complex overlapping peaks within the resonance spectrum. We present a technique for extracting useful features from a complex spectrum by isolating resonance peaks that are sensitive to the measured property and insensitive to other properties (noise peaks). We isolate specific peaks by selecting frequency regions of interest and performing wavelet transformation, where the frequency regions and wavelet scales are tuned via a Genetic Algorithm. This contrasts greatly from traditional wavelet transformation/decomposition techniques, which use a large number of wavelets at different scales to represent the signal, including the noise peaks, and results in a large feature size, thus decreasing Machine Learning generalizability. We provide a detailed description of the technique and demonstrate the feature extraction technique for example regression and classification problems. We observe reductions of 95% and 40% in regression and classification errors, respectively, when using the Genetic algorithm/Wavelet Transform feature extraction, compared to using no feature extraction, or using Wavelet Decomposition, which is common in optical spectroscopy. The feature extraction has potential to significantly increase the accuracy of spectroscopy measurements based on a wide range of Machine Learning techniques. This would have significant implications for ARS, as well as other data-driven methods for other types of spectroscopy, e.g. optical.
Isotopic analysis of precipitation over the Andaman Island, Bay of Bengal was carried out for the year 2012 and 2013 in order to study the atmospheric controls on rainwater isotopic variations. The ...oxygen and hydrogen isotopic compositions are typical of the tropical marine sites but show significant variations depending on the ocean-atmosphere conditions; maximum depletion was observed during the tropical cyclones. The isotopic composition of rainwater seems to be controlled by the dynamical nature of the moisture rather than the individual rain events. Precipitation isotopes undergo systematic depletions in response to the organized convection occurring over a large area and are modulated by the integrated effect of convective activities. Precipitation isotopes appear to be linked with the monsoon intraseasonal variability in addition to synoptic scale fluctuations. During the early to mid monsoon the amount effect arose primarily due to rain re-evaporation but in the later phase it was driven by moisture convergence rather than evaporation. Amount effect had distinct characteristics in these two years, which appeared to be modulated by the intraseasonal variability of monsoon. It is shown that the variable nature of amount effect limits our ability to reconstruct the past-monsoon rainfall variability on annual to sub-annual time scale.
To systematically review and meta-analyse the studies investigating the association between smokeless tobacco (SLT) use and all-cause mortality and cause-specific mortality outcomes among adult users ...of SLT and estimate the number of attributable deaths worldwide.
Random-effects meta-analysis was used to estimate the pooled risk of death due to SLT use. Population attributable fractions were derived and used to calculate the number of attributable deaths. Observational studies published upto 2015 were identified through MEDLINE, IndMED, Google Scholar and other databases. Data on the prevalence of SLT use was obtained from latest reports or national surveys. Data on the disease burden were obtained from the Global Burden of Disease Study. Hospital-based or community-based case-control and cohort studies that adjusted for the smoking status were included.
16 studies that provided estimates for mortality due to all cause, all cancer, upper aerodigestive tract (UADT) cancer, stomach cancer, cervical cancer, ischaemic heart disease (IHD) and stroke were included. A significant association was found for mortality due to all cause (1.22; 1.11-1.34), all cancer (1.31; 1.16-1.47), UADT cancer (2.17; 1.47-3.22), stomach cancer (1.33; 1.12-1.59), cervical cancer (2.07; 1.64-2.61), IHD (1.10; 1.04-1.17) and stroke (1.37; 1.24-1.51). Subgroup analysis showed major regional differences. Globally, the number of attributable deaths from all-cause mortality was 652 494 (234 008-1 081 437), of which 88% was borne by the South-East Asian region.
SLT is responsible for a large number of deaths worldwide with the South-East Asian region bearing a substantial share of the burden.
The effectiveness of well-known electrolyte additives singly or in combination on LiCoO2/graphite pouch cells has been systematically investigated and compared using the ultra high precision charger ...(UHPC) at Dalhousie University and electrochemical impedance spectroscopy (EIS). UHPC studies are believed to identify the best electrolyte additives singly or in combination within a short time period (several weeks). Three parameters: 1) the coulombic efficiency (CE); 2) the charge endpoint capacity slippage (slippage) and 3) the charge transfer resistance (Rct), of LiCoO2/graphite pouch cells with different electrolyte additives singly or in combination were measured and the results for over 55 additive sets are compared. The experimental results suggest that a combination of electrolyte additives can be more effective than a single electrolyte additive. However, of all the additive sets tested, simply using 2 wt.% vinylene carbonate yielded cells very competitive in CE, slippage and Rct. It is hoped that this comprehensive report can be used as a guide and reference for the study of other electrolyte additives singly or in combination.
•Over 55 combinations of additives are studied in LiCoO2/graphite pouch cells.•High precision coulometry and impedance spectroscopy were used in these studies.•The studies identify which additives give cells with the smallest parasitic reactions and the lowest resistance surface films.•Electrolytes with 2% vinylene carbonate are a good baseline to compare advanced electrolytes against.•Additives including VC, FEC, VEC, LiBOB, LiTFSI and others are highlighted in this work.
Tobacco use has been identified as the single biggest cause of inequality in morbidity. The objective of this study is to examine the role of social determinants on current tobacco use in thirteen ...low-and-middle income countries.
We used nationally representative data from the Global Adult Tobacco Survey (GATS) conducted during 2008-2010 in 13 low-and-middle income countries: Bangladesh, China, Egypt, India, Mexico, Philippines, Poland, Russian Federation, Thailand, Turkey, Ukraine, Uruguay, and Viet Nam. These surveys provided information on 209,027 respondent's aged 15 years and above and the country datasets were analyzed individually for estimating current tobacco use across various socio-demographic factors (gender, age, place of residence, education, wealth index, and knowledge on harmful effects of smoking). Multiple logistic regression analysis was used to predict the impact of these determinants on current tobacco use status. Current tobacco use was defined as current smoking or use of smokeless tobacco, either daily or occasionally. Former smokers were excluded from the analysis. Adjusted odds ratios for current tobacco use after controlling other cofactors, was significantly higher for males across all countries and for urban areas in eight of the 13 countries. For educational level, the trend was significant in Bangladesh, Egypt, India, Philippines and Thailand demonstrating decreasing prevalence of tobacco use with increasing levels of education. For wealth index, the trend of decreasing prevalence of tobacco use with increasing wealth was significant for Bangladesh, India, Philippines, Thailand, Turkey, Ukraine, Uruguay and Viet Nam. The trend of decreasing prevalence with increasing levels of knowledge on harmful effects of smoking was significant in China, India, Philippines, Poland, Russian Federation, Thailand, Ukraine and Viet Nam.
These findings demonstrate a significant but varied role of social determinants on current tobacco use within and across countries.
Vitamin D in Ankle Fractures NK, Sinha; RK, Sinha
Malaysian orthopaedic journal,
7/2021, Letnik:
15, Številka:
2
Journal Article
Recenzirano
Odprti dostop
It is of critical importance to know multiple factors that can adversely impact operative outcome following ankle trauma and authors are to be commended for underlining various predicting factors. We ...believe that one more factor that may be considered in this context is the perioperative Vitamin D level in cases of ankle fracture fixation
PDF
