Recovery of vanadium pentoxide from spent catalyst used in the manufacture of sulphuric acid

Vanadium has many industrial uses and its contribution to environmental contamination is increasing all the time. Recovery of vanadium pentoxide from spent sulphuric acid catalysts was performed using a three-step process involving acid leaching, oxidation and precipitation. Several different acids were used in the leaching process. Finally, sulphuric acid was used in various concentrations, solid to liquid ratios, stirring times and temperatures. A high solid/liquid ratio in the leaching stage was used to obtain high concentration of vanadium pentoxide and low acid consumption that allowed direct precipitation without the use of extraction by rather expensive organic solvents. Sodium carbonate solution of one mole/liter concentration was used in the precipitation stage. An industrial application including material balance and operating conditions with an overall vanadium pentoxide recovery efficiency of (70%) was proposed

Community knowledge, attitude and practice on rabies, incidence in humans and animals and risk factors to rabies in selected districts of Tigray Region, Ethiopia

Community awareness and assessing the trend of suspected rabies cases play a significant role in preventing its fatality. Therefore, a cross-sectional study design was employed (October 2016 - April 2017) to assess community knowledge, attitude and practice (KAP), and Incidence and risk factors to rabies (human and animal) in the study area. A semi-structured questionnaire was employed to collect required information from 1440 study participants. Retrospective data of five-year (2012-2016) from hospitals and health centers (human cases), and veterinary clinics (animal cases) was used. Majority of the study participants (64.3%) were rural residents, 95.2% have heard about rabies and 50.1% were found dog owners. Among the study participants, 72.2%, 66.0%, and 62.4% have a good level of knowledge, attitude, and practices about rabies, respectively. A strong association between knowledge, attitude and practice with sex; educational level; occupation, dog ownership and rural/urban dwellers (p<0.05) was recorded. Furthermore, a total dog bite cases of 398 domestic animals and 4617 humans were found registered on casebooks of both veterinary and human health service centers of the study districts during the five years study period among which the highest percentage (36.4%) was recorded from canines. The highest anti-rabies vaccine coverage recorded was 36.0% in the year 2016, and higher human dog bite cases recorded was 50.1% on individuals aged between 5-15 years (both male and female). Hence, the current findings suggest that there is a need for coordinated and integrated effort of government, professionals (medical and veterinarians), community and other stake holders towards rabies control and prevention.Keywords: Animal, Human, Tigray, Rabies, Statu

Alcohol drinking patterns among high school students in Ethiopia: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Alcohol use is an important risk factor for morbidity, mortality and social harm among adolescents. There is paucity of data on alcohol use among high school students in Ethiopia. This study aimed to determine the prevalence and factors associated with alcohol use among high school students in Ethiopia</p> <p>Methods</p> <p>A cross-sectional study was conducted to assess the prevalence of alcohol use and its predictors among high school students in eastern Ethiopia in April 2010. A sample of students was taken from all schools based on their enrollment size. Prevalence estimates and their 95% confidence intervals were calculated. Logistic regression was performed to adjust and examine associations.</p> <p>Results</p> <p>A total of 1721 students participated in the study. The mean age of the study population was 16.4 (SD 1.6) years. A total of 372 (22.2%; 95% CI 20.2 - 24.2%) students drink alcohol. Of these, 118 (31.7%) were females and 254 (68.3) males. Multivariate analysis indicated that males (OR 2.09; 95% CI 1.45-3.00), older age (OR 1.16; 95% CI 1.01-1.34), having friends who used alcohol (OR 10.09; 95% CI 6.84-14.89) and living with people who use alcohol (OR 2.77; 95% CI 1.89-4.07) increased the odds of drinking among students.</p> <p>Conclusion</p> <p>There is a high level of alcohol use among high school students in the study area. Involvement of parents, health workers and school authorities are necessary to avert the problem. Specifically, their involvement in awareness campaigns and peer education training are important to encourage students to avoid alcohol use.</p

COVID-19 Detection on Chest x-ray Images by Combining Histogram-oriented Gradient and Convolutional Neural Network Features

The COVID-19 coronavirus epidemic has spread rapidly worldwide after a person became infected with a severe health problem. The World Health Organization has declared the coronavirus a global threat (WHO). Early detection of COVID 19, particularly in cases with no apparent symptoms, may reduce the patients mortality rate. COVID 19 detection using machine learning techniques will aid healthcare systems around the world in recovering patients more rapidly. This disease is diagnosed using x-ray images of the chest; therefore, this study proposed a machine vision method for detecting COVID-19 in x-ray images of the chest. The histogram-oriented gradient (HOG) and convolutional neural network (CNN) features extracted from x-ray images were fused and classified using support vector machine (SVM) and softmax. The proposed feature fusion technique (99.36 percent) outperformed individual feature extraction methods such as HOG (87.34 percent) and CNN (93.64 percent)

Sexual and reproductive health communication and awareness of contraceptive methods among secondary school female students, northern Ethiopia: a cross-sectional study

Sexual and reproductive health communication and awareness of contraceptive methods among secondary school female students, northern Ethiopia: a cross-sectional study. Health, 14: 252 http://dx.doi. org/10.1186/1471-2458-14-252 Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. BMC Public Permanent link to this version: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-87988 R E S E A R C H A R T I C L E Open Access Sexual and reproductive health communication and awareness of contraceptive methods among secondary school female students, northern Ethiopia: a cross-sectional study Abstract Background: Adolescent girls continue to fall victim to unintended pregnancy and its consequences, with particular problems arising in low income countries. Awareness about methods of contraception is an important step towards gaining access and using suitable contraceptive methods. However, studies assessing the relationship between sexual and reproductive health communication and awareness of contraceptive methods among secondary school female students are lacking. Methods: A cross sectional study was conducted among 807 female students in six secondary schools in Mekelle town, Ethiopia. Study participants were selected with a stratified cluster sampling technique. Data collection was carried out using a structured, self-administered questionnaire, and data entry was done using EPI Info Version 3.3.2 software. The data were then cleaned and analyzed using SPSS version 20. Bivariate and multivariate logistic regressions were used to determine factors associated with awareness of female students on methods of contraception. Result: Of all the students, 127(15.8%) reported ever having had sex, of whom 109(85.8%) had ever used contraceptives. Twenty (16%) of the sexually active students reported having been pregnant, of whom 18(90%) terminated their pregnancies with induced abortion. Discussion on sexual and reproductive health matters with their parent/s and peer/s in the six months prior to the study was reported by 351(43.5%) and 493(61.1%) of the students respectively. 716(88%) students were aware of different methods of contraception. Discussing sexual and reproductive health issues with parents (AOR =2.56(95% CI: 1.45, 4.50)) and peers (AOR = 2.46(95% CI: 1.50, 4.03)) were found to be independent predictors for contraceptive awareness among students. Conclusions: Discussion on sexual and reproductive health issues with family and peers has a positive effect on contraceptive awareness of students. Therefore, strategies to improve open parent-child communication, and appropriate peer-to-peer communication in schools on sexual and reproductive health should be established and strengthened

Optimizing the Steering of Driverless Personal Mobility Pods with a Novel Differential Harris Hawks Optimization Algorithm (DHHO) and Encoder Modeling

This paper aims to improve the steering performance of the Ackermann personal mobility scooter based on a new meta-heuristic optimization algorithm named Differential Harris Hawks Optimization (DHHO) and the modeling of the steering encoder. The steering response in the Ackermann mechanism is crucial for automated driving systems (ADS), especially in localization and path-planning phases. Various methods in the literature are used to control the steering, and meta-heuristic optimization algorithms have achieved prominent results. Harris Hawks optimization (HHO) algorithm is a recent algorithm that outperforms state-of-the-art algorithms in various optimization applications. However, it has yet to be applied to the steering control application. The research in this paper has been conducted in three stages. First, practical experiments were performed on the steering encoder sensor that measures the steering angle of the Landlex mobility scooter, and supervised learning was applied to model the results obtained for the steering control. Second, the DHHO algorithm is proposed by introducing mutation between hawks in the exploration phase instead of the Hawks perch technique, improving population diversity and reducing premature convergence. The simulation results on CEC2021 benchmark functions showed that the DHHO algorithm outperforms the HHO, PSO, BAS, and CMAES algorithms. The mean error of the DHHO is improved with a confidence level of 99.8047% and 91.6016% in the 10-dimension and 20-dimension problems, respectively, compared with the original HHO. Third, DHHO is implemented for interactive real-time PID tuning to control the steering of the Ackermann scooter. The practical transient response results showed that the settling time is improved by 89.31% compared to the original response with no overshoot and steady-state error, proving the superior performance of the DHHO algorithm compared to the traditional control methods. The MATLAB source code and the result files for the proposed algorithm are available at https://github.com/MohamedRedaMu/DHHO

Probing the Environment with Galaxy Dynamics

I present various projects to study the halo dynamics of elliptical galaxies. This allows one to study the outer mass and orbital distributions of ellipticals in different environments, and the inner distributions of groups and clusters themselves.Comment: 5 pages, 2 figs, to appear in Proc. ESO Workshop, Groups of Galaxies in the Nearby Universe (5-9 Dec 2005), eds. I. Saviane, V. Ivanov & J. Borissova (Springer-Verlag

Representative transcript sets for evaluating a translational initiation sites predictor

<p>Abstract</p> <p>Background</p> <p>Translational initiation site (TIS) prediction is a very important and actively studied topic in bioinformatics. In order to complete a comparative analysis, it is desirable to have several benchmark data sets which can be used to test the effectiveness of different algorithms. An ideal benchmark data set should be reliable, representative and readily available. Preferably, proteins encoded by members of the data set should also be representative of the protein population actually expressed in cellular specimens.</p> <p>Results</p> <p>In this paper, we report a general algorithm for constructing a reliable sequence collection that only includes mRNA sequences whose corresponding protein products present an average profile of the general protein population of a given organism, with respect to three major structural parameters. Four representative transcript collections, each derived from a model organism, have been obtained following the algorithm we propose. Evaluation of these data sets shows that they are reasonable representations of the spectrum of proteins obtained from cellular proteomic studies. Six state-of-the-art predictors have been used to test the usefulness of the construction algorithm that we proposed. Comparative study which reports the predictors' performance on our data set as well as three other existing benchmark collections has demonstrated the actual merits of our data sets as benchmark testing collections.</p> <p>Conclusion</p> <p>The proposed data set construction algorithm has demonstrated its property of being a general and widely applicable scheme. Our comparison with published proteomic studies has shown that the expression of our data set of transcripts generates a polypeptide population that is representative of that obtained from evaluation of biological specimens. Our data set thus represents "real world" transcripts that will allow more accurate evaluation of algorithms dedicated to identification of TISs, as well as other translational regulatory motifs within mRNA sequences. The algorithm proposed by us aims at compiling a redundancy-free data set by removing redundant copies of homologous proteins. The existence of such data sets may be useful for conducting statistical analyses of protein sequence-structure relations. At the current stage, our approach's focus is to obtain an "average" protein data set for any particular organism without posing much selection bias. However, with the three major protein structural parameters deeply integrated into the scheme, it would be a trivial task to extend the current method for obtaining a more selective protein data set, which may facilitate the study of some particular protein structure.</p

Diagnostics to Support Elimination of Lymphatic Filariasis-Development of Two Target Product Profiles

As lymphatic filariasis (LF) programs move closer to established targets for validation elimination of LF as a public health problem, diagnostic tools capable of supporting the needs of the programs are critical for success. Known limitations of existing diagnostic tools make it challenging to have confidence that program endpoints have been achieved. In 2019, the World Health Organization (WHO) established a Diagnostic Technical Advisory Group (DTAG) for Neglected Tropical Diseases tasked with prioritizing diagnostic needs including defining use-cases and target product profiles (TPPs) for needed tools. Subsequently, disease-specific DTAG subgroups, including one focused on LF, were established to develop TPPs and use-case analyses to be used by product developers. Here, we describe the development of two priority TPPs for LF diagnostics needed for making decisions for stopping mass drug administration (MDA) of a triple drug regimen and surveillance. Utilizing the WHO core TPP development process as the framework, the LF subgroup convened to discuss and determine attributes required for each use case. TPPs considered the following parameters: Product use, design, performance, product configuration and cost, and access and equity. Version 1.0 TPPs for two use cases were published by WHO on 12 March 2021 within the WHO Global Observatory on Health Research and Development. A common TPP characteristic that emerged in both use cases was the need to identify new biomarkers that would allow for greater precision in program delivery. As LF diagnostic tests are rarely used for individual clinical diagnosis, it became apparent that reliance on population-based surveys for decision making requires consideration of test performance in the context of such surveys. In low prevalence settings, the number of false positive test results may lead to unnecessary continuation or resumption of MDA, thus wasting valuable resources and time. Therefore, highly specific diagnostic tools are paramount when used to measure low thresholds. The TPP process brought to the forefront the importance of linking use case, program platform and diagnostic performance characteristics when defining required criteria for diagnostic tools