27 research outputs found

    Determination of Effectiveness of combined Biological and Physicochemical Treatment of Vinasse

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    Combined biological and Physicochemical treatment method was used to treat vinasse using microorganisms (Aspergillus niger (fungi) and Bacillus subtilis (bacteria)), coagulants (aluminium sulphate (Al2(SO4)3) and iron III chlorides (FeCl3)) and followed by filtration. Three factors; coagulant type, type of microorganism and coagulant concentration was analysed using full factorial design (2n) with replication, on their percentage removal of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS) and turbidity. Pareto chart and regression analysis with a 95% confidence interval (5% significant level) were used to analyse the results using MINITAB 22 (current version). Initially, the vinasse had (COD), (BOD), (TSS), and turbidity of 10240 mg/â„“, 5340 mg/â„“, 400 mg/â„“, and 1980 NTU, respectively, and a pH of 5.68. COD, BOD, TSS, and turbidity were reduced by 99.5%, 99.7%, 99.7%, and 93.7%, respectively, after the treatment, while pH was raised to 7.5, which is neutral. Using Bacillus subtilis and aluminium sulphate, the combined biological and physicochemical process produced good results for the treatment of vinasse

    Assessment of the Impacts of Climate Variability on Hydropower Generation

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    Climate change poses potential impacts on hydropower generation either positively by increasing or negatively by decreasing river flow. This study assessed the impacts of climate variability on hydropower with a focus on the New Pangani Falls in Tanzania. Rainfall and temperature time series data from 1980-2014 were analyzed in relation to river discharge and associated impacts to hydropower generation. The Man-Kendall test was used to detect trend in both annual and seasonal time series. The results showed a negative trend in annual rainfall with Z= -2.41 at α = 0.05 and the slope Q = -0.964. Seasonal trend analysis showed that the amount of rainfall received during both dry and wet seasons has been decreasing. Positive trend was observed in both average annual maximum and minimum temperature series at α = 0.1 with Z = 1.73 and α = 0.001 with Z= 4.04, respectively and a positive slope for both. Analysis of regime shift at a 5% significant level showed that, rainfall in the New Pangani falls from 1980 to 2014 experienced two decreasing shifts both occurring in the last 15 years of analysis with a percentage of change of more than 10%. This strongly confirms climate variability in the study area. The study shows that hydropower generation depends strongly on the river inflow to the dam (r = 0.98) while changes in temperature do not affect the functioning of the hydropower plant as depicted by the weak linear relationship between temperature, rainfall (r = 0.085) and power generation (r = -0.082). It can be concluded, therefore, that river discharge variability in catchment has an adverse impact on hydropower generation in hydropower plant.&nbsp

    Energy Recovery routes from Municipal Solid Waste, A case study of Arusha-Tanzania

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    A study of energy recovery from municipal solid waste was undertaken. The energy content of the solid waste is 12MJ/kg. The elemental composition shows that the municipal solid waste contains 50% and 5% of carbon and hydrogen respectively. The energy flow (exothermic and endothermic) and thermal degradation analysis were carried out using differential scanning calorimetry and thermo-gravimetric analyser respectively. Experiments were performed at heating rate of 10 K/min, 20 K/min, 30 K/min and 40 K/min in the nitrogen atmosphere at temperature between room temperature and 1273 K. The thermal degradation kinetic parameters values of activation energy (Ea) ranged from 205.9 to 260.6kJ/mol. It has been observed that municipal solid waste is less reactive to combustion as compared to coal and biomass, but its reactivity can be improved through pre-treating process so as to reduce noncombustible materials such as oxygen and ash content. Also pyrolysis and gasification can be used to convert MSW to liquid or gaseous fuel. Keywords: Municipal Solid Waste, Thermal behavior, Thermo gravimetric Analysis

    Perceived risk of infection and death from COVID-19 among community members of low- and middle-income countries: A cross-sectional study [version 1; peer review: awaiting peer review]

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    Background: Risk perceptions of coronavirus disease 2019 (COVID-19) are considered important as they impact community health behaviors. The aim of this study was to determine the perceived risk of infection and death due to COVID-19 and to assess the factors associated with such risk perceptions among community members in low- and middle-income countries (LMICs) in Africa, Asia, and South America. Methods: An online cross-sectional study was conducted in 10 LMICs in Africa, Asia, and South America from February to May 2021. A questionnaire was utilized to assess the perceived risk of infection and death from COVID-19 and its plausible determinants. A logistic regression model was used to identify the factors associated with such risk perceptions. Results: A total of 1,646 responses were included in the analysis of the perceived risk of becoming infected and dying from COVID-19. Our data suggested that 36.4% of participants had a high perceived risk of COVID-19 infection, while only 22.4% had a perceived risk of dying from COVID-19. Being a woman, working in healthcare-related sectors, contracting pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, as well as seeing or reading about individuals infected with COVID-19 on social media or TV were all associated with a higher perceived risk of becoming infected with COVID-19. In addition, being a woman, elderly, having heart disease and pulmonary disease, knowing people in the immediate social environment who are or have been infected with COVID-19, and seeing or reading about individuals infected with COVID-19 on social media or TV had a higher perceived risk of dying from COVID-19. Conclusions: The perceived risk of infection and death due to COVID-19 are relatively low among respondents; this suggests the need to conduct health campaigns to disseminate knowledge and information on the ongoing pandemic

    Ethnic comparison in takotsubo syndrome : novel insights from the International Takotsubo Registry

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    © The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Background: Ethnic disparities have been reported in cardiovascular disease. However, ethnic disparities in takotsubo syndrome (TTS) remain elusive. This study assessed differences in clinical characteristics between Japanese and European TTS patients and determined the impact of ethnicity on in-hospital outcomes. Methods: TTS patients in Japan were enrolled from 10 hospitals and TTS patients in Europe were enrolled from 32 hospitals participating in the International Takotsubo Registry. Clinical characteristics and in-hospital outcomes were compared between Japanese and European patients. Results: A total of 503 Japanese and 1670 European patients were included. Japanese patients were older (72.6 ± 11.4 years vs. 68.0 ± 12.0 years; p < 0.001) and more likely to be male (18.5 vs. 8.4%; p < 0.001) than European TTS patients. Physical triggering factors were more common (45.5 vs. 32.0%; p < 0.001), and emotional triggers less common (17.5 vs. 31.5%; p < 0.001), in Japanese patients than in European patients. Japanese patients were more likely to experience cardiogenic shock during the acute phase (15.5 vs. 9.0%; p < 0.001) and had a higher in-hospital mortality (8.2 vs. 3.2%; p < 0.001). However, ethnicity itself did not appear to have an impact on in-hospital mortality. Machine learning approach revealed that the presence of physical stressors was the most important prognostic factor in both Japanese and European TTS patients. Conclusion: Differences in clinical characteristics and in-hospital outcomes between Japanese and European TTS patients exist. Ethnicity does not impact the outcome in TTS patients. The worse in-hospital outcome in Japanese patients, is mainly driven by the higher prevalence of physical triggers.Open Access funding provided by Universität Zürich. CT has been supported by the H.H. Sheikh Khalifa bin Hamad Al-Thani Research Programme and the Swiss Heart Foundation. L.S.M. has been supported by EU HORIZON 2020 (SILICOFCM ID777204). J.R.G has received a grant “Filling the gap” from the University of Zurich. The InterTAK Registry is supported by The Biss Davies Charitable Trust.info:eu-repo/semantics/publishedVersio

    Ethnic comparison in takotsubo syndrome: novel insights from the International Takotsubo Registry

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    Background Ethnic disparities have been reported in cardiovascular disease. However, ethnic disparities in takotsubo syndrome (TTS) remain elusive. This study assessed differences in clinical characteristics between Japanese and European TTS patients and determined the impact of ethnicity on in-hospital outcomes.Methods TTS patients in Japan were enrolled from 10 hospitals and TTS patients in Europe were enrolled from 32 hospitals participating in the International Takotsubo Registry. Clinical characteristics and in-hospital outcomes were compared between Japanese and European patients.Results A total of 503 Japanese and 1670 European patients were included. Japanese patients were older (72.6 +/- 11.4 years vs. 68.0 +/- 12.0 years; p Conclusion Differences in clinical characteristics and in-hospital outcomes between Japanese and European TTS patients exist. Ethnicity does not impact the outcome in TTS patients. The worse in-hospital outcome in Japanese patients, is mainly driven by the higher prevalence of physical triggers.</p

    Thermal Characterization of Pine Sawdust as Energy Source Feedstock

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    Pine sawdust was analyzed for thermal chemical conversion such as combustion, torrefaction, pyrolysis and gasification. The methods used to analyze involved performing proximate analysis, ultimate analysis, heating value and thermal decomposition for determining the biomass characteristics. Based on elemental composition, the pine sawdust exhibited lower energy content of 15.01 MJ/kg than bituminous coal that has about 31.8 MJ /kg. The kinetic parameters of pine sawdust described the individual component decomposition; the easiest component to decompose is hemicelluloses followed by cellulose and lignin. The heat released during thermal degradation of pine sawdust was -4380 J/g under inert condition, this shows pine sawdust potential for production of energy during combustion. Keywords: Thermogravimentry, Kinetics, Pine Sawdust, Differential Scanning Calorimetr

    The Study of Kinetic Properties and Analytical Pyrolysis of Coconut Shells

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    The kinetic properties of coconut shells during pyrolysis were studied to determine its reactivity in ground form. The kinetic parameters were determined by using thermogravimetric analyser. The activation energy was 122.780 kJ/mol. The pyrolysis products were analyzed using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effects of pyrolysis temperature on the distribution of the pyrolytic products were assessed in a temperature range between 673 K and 1073 K. The set time for pyrolysis was 2 s. Several compounds were observed; they were grouped into alkanes, acids, ethers and alcohols, esters, aldehydes and ketones, furans and pyrans, aromatic compounds, and nitrogen containing compounds. The product compositions varied with temperature in that range. The highest gas proportion was observed at high temperature while the acid proportion was observed to be highest in coconut shells, thus lowering the quality of bio-oil. It has been concluded that higher pyrolysis temperature increases the amount of pyrolysis products to a maximum value. It has been recommended to use coconut shell for production of gas, instead of production of bio-oil due to its high proportion of acetic acid

    Ceruminous gland adenocarcinoma in a domestic Persian-mix cat (Felis catus)

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    A nine years old Persian-mix female cat has been suffering from recurrent bilateral ceruminous gland adenocarcinoma for many years. Masses were first noticed and resected five years ago, but reoccurred later on two more occasions. The animal has usually experienced distressful ear canal problems in association with these masses. The tumor cellular morphology was reviewed, described and discussed. This article is the first in documenting ceruminous gland adenocarcinoma in a Persian-mix cat in Libya
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