Ultrasonic pretreatment of sludge: A review Pilli, Sridhar; Bhunia, Puspendu; Yan, Song ...
Ultrasonics sonochemistry,
2011, 2011-Jan, 2011-01-00, 20110101, Letnik:
18, Številka:
1
Journal Article
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Ultrasonication is an emerging and very effective mechanical pretreatment method to enhance the biodegradability of the sludge, and it would be very useful to all wastewater treatment plants in ...treating and disposing sewage sludge. Ultrasonication enhances the sludge digestibility by disrupting the physical, chemical and biological properties of the sludge. The degree of disintegration depends on the sonication parameters and also on sludge characteristics, therefore the evaluation of the optimum parameters varies with the type of sonicater and sludge to be treated. The full-scale installations of ultrasonication have demonstrated that there is 50% increase in the biogas generation, and in addition evaluation of energy balance showed that the average ratio of the net energy gain to electric consumed by the ultrasound device is 2.5. This review article summarizes the benefits of ultrasonication of sludge, the effect of sonication parameters, impact of sludge characteristics on sludge disintegration, and thereby the increase in biogas production in anaerobic digester. Due to uncertainty in the unit representation by many researchers and nonavailability of the data, comparison of these results is complicated. Comparison of ultrasonication with other pretreatment options is necessary to evaluate the best economical and environmental pretreatment technology for sludge treatment and disposal. The optimum parameters for the ultrasonication vary with sludge characteristics.
The effect of estrogen on tendon and ligament metabolism and function Leblanc, D.R.; Schneider, M.; Angele, P. ...
Journal of steroid biochemistry and molecular biology/The Journal of steroid biochemistry and molecular biology,
September 2017, 2017-09-00, 20170901, Letnik:
172
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•The effect of estrogens on tendons and ligaments is poorly understood.•Research implies a positive effect of estrogens on tendon tissue biology and biomechanics.•However, results are ...in part conflicting, highlighting the need of for further in-depth research in the field.
Tendons and ligaments are crucial structures inside the musculoskeletal system. Still many issues in the treatment of tendon diseases and injuries have yet not been resolved sufficiently. In particular, the role of estrogen-like compound (ELC) in tendon biology has received until now little attention in modern research, despite ELC being a well-studied and important factor in the physiology of other parts of the musculoskeletal system. In this review we attempt to summarize the available information on this topic and to determine many open questions in this field.
Black and Latino men who have sex with men (MSM) have the highest risk of HIV of any group in the U.S. Prevalence could be even higher among Black and Latino MSM belonging to the House Ball Community ...(HBC), an understudied community comprised primarily of Black and Latino sexual and gender minorities, with HIV prevalence from non-probability samples ranging from 4% to 38%.
Basic Psychological Needs Theory will be utilized to understand how sexual health communication (SHC) influences sexual health behaviors of HBC-MSM. The proposed study will advance this goal by describing characteristics of SHC embedded within social and sexual networks, and identifying the effects of SHC on sexual health behaviors among a sample of Black and Latino HBC-MSM.
This study entails cross-sectional quantitative survey design with internet-based data collection to test a theory-driven model of the effects of autonomy supportive communication on sexual health behaviors. Respondent-driven sampling (RDS) and internet driven sampling (ID) will be used to recruit a sample of 200 HBC-MSM. We will utilize egocentric network analysis to describe (a) the HBC-specific social and/or sexual network members who provide SHC; (b) the degree of autonomy support provided by network members, and (c) the sexual health behaviors characterizing the sample of HBC-MSM. Structural equation modeling (SEM) will be performed to test associations between autonomy supportive sexual health communication (independent variable) and sexual health behaviors (outcome), with needs satisfaction and intrinsic motivation as intervening mediators.
Such knowledge is necessary to expand understanding of how SHC impacts sexual health behaviors for HBC-MSM. The study provides an critical perspective on sexual health behaviors and motivations as participants operate in HBC. Knowledge generated from this study will help improve current HIV prevention interventions, as well as inform the development of future interventions, tailored to HBC-MSM.
Leaf area index (LAI) is one of the surface parameters that has importance in climate, weather, and ecological studies, and has been routinely estimated from remote sensing measurements. Canada-wide ...LAI maps are now being produced using cloud-free Advanced Very High-Resolution Radiometer (AVHRR) imagery every 10 days at 1-km resolution. The archive of these products began in 1993. LAI maps at the same resolution are also being produced with images from the SPOT VEGETATION sensor. To improve the LAI algorithms and validate these products, a group of Canadian scientists acquired LAI measurements during the summer of 1998 in deciduous, conifer, and mixed forests, and in cropland. Common measurement standards using the commercial Tracing Radiation and Architecture of Canopies (TRAC) and LAI-2000 instruments were followed. Eight Landsat Thematic Mapper (TM) scenes at 30-m resolution were used to locate ground sites and to facilitate spatial scaling to 1-km pixels. In this paper, examples of Canada-wide LAI maps are presented after an assessment of their accuracy using ground measurements and the eight Landsat scenes. Methodologies for scaling from high- to coarse-resolution images that consider surface heterogeneity in terms of mixed cover types are evaluated and discussed. Using Landsat LAI images as the standard, it is shown that the accuracy of LAI values of individual AVHRR and VEGETATION pixels was in the range of 50–75%. Random and bias errors were both considerable. Bias was mostly caused by uncertainties in atmospheric correction of the Landsat images, but surface heterogeneity in terms of mixed cover types were also found to cause bias in AVHRR and SPOT VEGETATION LAI calculations. Random errors come from many sources, but pixels with mixed cover types are the main cause of random errors. As radiative signals from different vegetation types were quite different at the same LAI, accurate information about subpixel mixture of the various cover types is identified as the key to improving the accuracy of LAI estimates.
In Ghana, men who have sex with men (MSM) are disproportionately affected by HIV. Pre-exposure prophylaxis (PrEP) is a biomedical intervention that reduces the risk of HIV infection but is not ...currently available in Ghana. This paper explores knowledge and acceptability of HIV PrEP among Ghanaian MSM. Qualitative content analysis was conducted on 22 focus group discussions (N = 137) conducted between March and June 2012 in Accra, Kumasi, and Manya Krobo. Overall, participants reported low knowledge of PrEP. However, once information about PrEP was provided, there was high acceptability. The primary reason for acceptability was that PrEP provided an extra level of protection against HIV. Acceptability of PrEP was conditioned on it having minimal side effects, being affordable and efficient in preventing HIV infection. No acceptability of PrEP was attributed to limited knowledge of side effects and perceived lack of effectiveness. The reasons provided to utilize PrEP and condoms were that condoms protect against other STIs, and sexual partner factors. This is the first known study to explore PrEP knowledge and acceptability among Ghanaian MSM. It is important that key stakeholders preemptively address potential barriers to PrEP acceptability, uptake, and adherence, especially among MSM, once PrEP becomes available in Ghana.
This Letter presents nonlinear gyrokinetic simulations of microtearing mode turbulence. The simulations include collisional and electromagnetic effects and use experimental parameters from a high-β ...discharge in the National Spherical Torus Experiment. The predicted electron thermal transport is comparable to that given by experimental analysis, and it is dominated by the electromagnetic contribution of electrons free-streaming along the resulting stochastic magnetic field line trajectories. Experimental values of flow shear can significantly reduce the predicted transport.
Summary
The Women's Health Initiative (WHI) double-blind, placebo-controlled clinical trial randomly assigned 36,282 postmenopausal women in the U.S. to 1,000 mg elemental calcium carbonate plus ...400 IU of vitamin D
3
daily or placebo, with average intervention period of 7.0 years. The trial was designed to test whether calcium plus vitamin D supplementation in a population in which the use of these supplements was widespread would reduce hip fracture, and secondarily, total fracture and colorectal cancer.
Introduction
This study further examines the health benefits and risks of calcium and vitamin D supplementation using WHI data, with emphasis on fractures, cardiovascular disease, cancer, and total mortality.
Methods
WHI calcium and vitamin D randomized clinical trial (CT) data through the end of the intervention period were further analyzed with emphasis on treatment effects in relation to duration of supplementation, and these data were contrasted and combined with corresponding data from the WHI prospective observational study (OS).
Results
Among women not taking personal calcium or vitamin D supplements at baseline, the hazard ratio HR for hip fracture occurrence in the CT following 5 or more years of calcium and vitamin D supplementation versus placebo was 0.62 (95 % confidence interval (CI), 0.38–1.00). In combined analyses of CT and OS data, the corresponding HR was 0.65 (95 % CI, 0.44–0.98). Supplementation effects were not apparent on the risks of myocardial infarction, coronary heart disease, total heart disease, stroke, overall cardiovascular disease, colorectal cancer, or total mortality, while evidence for a reduction in breast cancer risk and total invasive cancer risk among calcium plus vitamin D users was only suggestive.
Conclusion
Though based primarily on a subset analysis, long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women. Other health benefits and risks of supplementation at doses considered, including an elevation in urinary tract stone formation, appear to be modest and approximately balanced.
Abstract Objective To determine whether participation in a farmers' market incentive pilot program had an impact on food security and fruit and vegetable (F&V) intake of participants. Methods ...Participants in the Supplemental Nutrition Assistance Program were eligible to receive a dollar-per-dollar match up to $10/wk in farmers' market incentives. The researchers used a pretest-posttest design to measure F&V intake and food security status of 54 adult participants before and after receiving farmers' market incentives. The 6-item Behavior Risk Factor Surveillance System questionnaire and US Household Food Security Survey Module were used to measure F&V intake and food security, respectively. Wilcoxon signed-rank test was used to compare scores of F&V intake. Results After receiving incentives, fewer individuals reported experiencing food insecurity–related behaviors. A significantly increased intake ( P < .05) was found among selected vegetables. Conclusion and Implications Participation in a farmers' market incentive program was positively related to greater food security and intake of select vegetables among participants in the Supplemental Nutrition Assistance Program.
Nazarov reactions mediated by BF3-etherate of a series of carbon-substituted allenyl vinyl ketones provided intermediates in which substituents on the termini of the allenes had rotated away from the ...vinyl moieties, and these intermediates were trapped by (4 + 3)-cyclizations. A computational examination of the torquoselectivity of these Nazarov reactions confirmed a kinetic preference for the observed isomers and pointed to steric interactions and the degree of allene deformation as significant factors in determining the torquoselectivity. The study also suggested that the high proportion of one geometrical isomer in the Nazarov products might also be due to some preferential trapping of the major Nazarov intermediate.
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