54 research outputs found

    Computational Fluid Dynamics Modeling of a Broiler House Microclimate in Summer and Winter

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    Appropriate microclimate conditions in broiler housing are critical for optimizing poultry production and ensuring the health and welfare of the birds. In this study, spatial variabilities of the microclimate in summer and winter seasons in a mechanically ventilated broiler house were modeled using the computational fluid dynamics (CFD) technique. Field measurements of temperature, relative humidity, and airspeeds were conducted in the house to compare the simulated results. The study identified two problems of high temperature in summer, which could result in bird heat stress and stagnant zones in winter, and simulated possible alternative solutions. In summer, if an evaporative cooling pad system was used, a decrease in temperature of approximately 3 °C could be achieved when the mean air temperature rose above 25 °C in the house. In winter, adding four 500-mm circulation fans of 20-m spacing inside the house could eliminate the accumulation of hot and humid air in the stagnant zones in the house. This study demonstrated that CFD is a valuable tool for adequate heating, ventilation, and air conditioning system design in poultry buildings

    Helicobacter pylori Diagnostic Tests Used in Europe : Results of over 34,000 Patients from the European Registry on Helicobacter pylori Management

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    Funding Information: This study was funded by Richen; however, clinical data were not accessible and the company was not involved in any stage of the Hp-EuReg study (design, data collection, statistical analysis, or manuscript writing). We want to thank Richen for their support. This project was promoted and funded by the European Helicobacter and Microbiota Study Group (EHMSG), the Spanish Association of Gastroenterology (AEG) and the Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd). The Hp-EuReg was co-funded by the European Union programme HORIZON (grant agreement number 101095359) and supported by the UK Research and Innovation (grant agreement number 10058099). The Hp-EuReg was co-funded by the European Union programme EU4Health (grant agreement number 101101252). Acknowledgments We want to especially thank Sylva-Astrik Torossian for her assistance in language editing. Natalia García Morales is the first author who is acting as the submission’s guarantor. All authors approved the final version of the manuscript.Peer reviewedPublisher PD

    Fate and Characteristics of Dissolved Organic Nitrogen through Wastewater Treatment Systems

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    Dissolved organic nitrogen (DON) represents a significant portion (25-80%) of total dissolved nitrogen in the final effluent of wastewater treatment plants (WWTPs). DON in treated wastewater, once degraded, causes oxygen depletion and/or eutrophication in receiving waters and should be reduced prior to discharge. Biodegradability, bioavailability, and photodegradability are important characteristics of wastewater derived DON and are subjects of research in this dissertation. Four research tasks were performed. In the first task, laboratory-scale chemostat experiments were conducted to examine whether solids retention time (SRT) could be used to control DON and biodegradable DON (BDON) in treated wastewater. Nine different SRTs from 0.3 to 13 were studied. There was no correlation between effluent DON and SRTs. However, BDONs at SRTs of 0.3 to 4 days were comparable and had a decreasing trend with SRTs after that. These results indicate the benefit of high SRTs in term of producing effluent with less BDON. The second task was a comprehensive year-round data collection to study the fate of DON and BDON through the treatment train of a trickling filter (TF) WWTP. The plant removed substantial amounts of DON (62%) and BDON (76%) mainly through the biological process. However, the discharged concentrations in the effluent were still high enough to be critical for a stringent total nitrogen discharge limit (below 5 mg-N/L). Evolution of bioavailable DON (ABDON) along the treatment trains of activated sludge (AS) and TF WWTPs and relationship between ABDON and BDON were examined in the third task. ABDON exerted from a combination of bacteria and algae inocula was higher than algae inoculated ABDON and bacteria inoculated BDON suggesting the use of algae as a treatment organism along with bacteria to minimize effluent DON. The TF and AS WWTPs removed 88% and 64% of ABDON, respectively. In the last task, photodegradable DON (PDON) in primary wastewater and final effluent from TF and AS WWTPs was studied. PDON and BDON fractions of DON data in the final effluent of TF and AS WWTP samples elucidate that photodegradation is as critically important as biodegradation when mineralization of effluent DON is a concern in receiving waters

    Mathematical modeling of wastewater-derived biodegradable dissolved organic nitrogen

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    <p>Wastewater-derived dissolved organic nitrogen (DON) typically constitutes the majority of total dissolved nitrogen (TDN) discharged to surface waters from advanced wastewater treatment plants (WWTPs). When considering the stringent regulations on nitrogen discharge limits in sensitive receiving waters, DON becomes problematic and needs to be reduced. Biodegradable DON (BDON) is a portion of DON that is biologically degradable by bacteria when the optimum environmental conditions are met. BDON in a two-stage trickling filter WWTP was estimated using artificial intelligence techniques, such as adaptive neuro-fuzzy inference systems, multilayer perceptron, radial basis neural networks (RBNN), and generalized regression neural networks. Nitrite, nitrate, ammonium, TDN, and DON data were used as input neurons. Wastewater samples were collected from four different locations in the plant. Model performances were evaluated using root mean square error, mean absolute error, mean bias error, and coefficient of determination statistics. Modeling results showed that the <i>R</i><sup>2</sup> values were higher than 0.85 in all four models for all wastewater samples, except only <i>R</i><sup>2</sup> in the final effluent sample for RBNN modeling was low (0.52). Overall, it was found that all four computing techniques could be employed successfully to predict BDON.</p

    The Economic and Environmental Impact of Greenhouse Heating Pipe Insulation

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    This study aimed to determine the effect of optimum pipe insulation thickness on energy savings and air pollution under greenhouse conditions. In this regard, an optimization model based on a Life Cycle Cost (LCC) analysis was carried out using the P1–P2 method. Three fuel types, coal, natural gas, and fuel oil, were tested with nominal pipe sizes ranging from 25 to 65 mm, and hot water was used in the system. Our findings showed that the highest insulation thickness (0.807 m), the greatest energy savings ($62.351/m), and the lowest payback period (0.502 years) were achieved with a 65 mm pipe size for fuel oil. Overall, the insulation minimizes heat loss through the heating pipelines, resulting in economic and environmental benefits. Fuel oil was determined as the best option for savings in this study. Hence, for fuel oil utilization, the emissions of CO2 varied from 2.762 to 3.798 kg/m and SO2 from 0.014 to 0.020 kg/m for pipe thicknesses ranging from 25 and 65 mm, respectively

    The Economic and Environmental Impact of Greenhouse Heating Pipe Insulation

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    This study aimed to determine the effect of optimum pipe insulation thickness on energy savings and air pollution under greenhouse conditions. In this regard, an optimization model based on a Life Cycle Cost (LCC) analysis was carried out using the P1&ndash;P2 method. Three fuel types, coal, natural gas, and fuel oil, were tested with nominal pipe sizes ranging from 25 to 65 mm, and hot water was used in the system. Our findings showed that the highest insulation thickness (0.807 m), the greatest energy savings ($62.351/m), and the lowest payback period (0.502 years) were achieved with a 65 mm pipe size for fuel oil. Overall, the insulation minimizes heat loss through the heating pipelines, resulting in economic and environmental benefits. Fuel oil was determined as the best option for savings in this study. Hence, for fuel oil utilization, the emissions of CO2 varied from 2.762 to 3.798 kg/m and SO2 from 0.014 to 0.020 kg/m for pipe thicknesses ranging from 25 and 65 mm, respectively

    Growth regime and environmental remediation of microalgae

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    Microalgal bioremediation of CO2, nutrients, endocrine disruptors, hydrocarbons, pesticides, and cyanide compounds have evaluated comprehensively. Microalgal mitigation of nutrients originated from municipal wastewaters, surface waters, and livestock wastewaters has shown great applicability. Algal utilization on secondary and tertiary treatment processes might provide unique and elegant solution on the removing of substances originated from various sources. Microalgae have displayed 3 growth regimes (autotrophic, heterotrophic, and mixotrophic) through which different organic and inorganic substances are being utilized for growth and production of different metabolites. There are still some technology challenges requiring innovative solutions. Strain selection investigation should be directed towards identification of algal that are extremophiles. Understanding and manipulation of metabolic pathways of algae will possible unfold solution to utilization of algae for mitigation of dissolve organic nitrogen in wastewaters

    A Cross-Sectional Study Investigating Association Of Liver Diseases In Moderate To Severe Psoriasis Patients

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    Background and Design: Non-alcoholic fatty liver disease (NAFLD), which is a systemic comorbidity of psoriasis, is the most common liver disease in population with risk of cirrhosis progression. The aim of this study was to investigate the frequency and risk factors of NAFLD in moderate:-severe psoriasis patients. Materials and Methods: Patients aged 18 years and older, who were followed up with a diagnosis of moderate to severe psoriasis at Hacettepe University Faculty of Medicine, Department of Dermatology and Venereology between 2015 and 2016, were included. Demographic and disease-related data (age, sex, age at psoriasis onset, alcohol use, family history of psoriasis, psoriatic arthritis history), and associating systemic diseases were reviewed. Liver function tests (LFT) were evaluated during routine examinations. Evaluation of gastroenterology consultations was reviewed with indications (positive hepatitis markers, elevated LFT, liver disease history). Abdominal, liver and biliary system ultrasonography results were assessed. Descriptive stastistics were evaluated by cross-table and chi-square test. The difference between the two means was evaluated by t-tests. P value less than 0.05 were accepted as statistically significant. Results: Two hundred and sixty-six patients with moderate-severe psoriasis were included. 12% of the patients (n=31) had elevated LFT. Abdominal ultrasonography was performed in 77% (n=24) of patients who were evaluated by gastroenterology department for LFT elevation. NAFLD was found in 65% (n=20) of patients with high LFT. The incidence of coronary artery disease, hypertension and hyperlipidemia was significantly higher in patients with high LFT compared to patients with normal LFT (p=0.003, p=0.011 and p=0.001, respectively). Examination and laboratory values were compared according to presence of elevation in LFT; uric acid levels were statistically higher in psoriatic patients with high LFT (p=0.002). The mean waist circumference in patient group with elevated LFT and in group with normal LFT was found to be 108.3 +/- 9.6 cm and 98.2 +/- 15.4 cm, respectively. The difference was statistically significant (p=0.005). Conclusion: NAFLD should be kept in mind as a frequent and important cause of elevated LFT observed in psoriasis patients. The presence of comorbidities such as cardiovascular diseases, hypertension and hyperlipidemia, which are frequently observed in psoriasis patients diagnosed with NAFLD, should be investigated. We recommend measurement of waist circumference and blood pressure and parameters including fasting blood glucose, lipid profile and uric acid in terms of metabolic syndrome.WoSScopu
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