17 research outputs found

    Optimization of Photovoltaic Panel Array Configurations to Reduce Lift Force Using Genetic Algorithm and CFD

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    Aerodynamic lift force acting on the solar structure is important while designing the counterweight for rooftop-mounted solar systems. Due to their unique configuration, the load estimated for solar structures using international building codes can be either higher or lower than the actual. Computational Fluid Dynamics(CFD) simulations haveproven to be an efficient tool for estimating wind loads on solar panels for design purposes and identifying critical design cases. Computational Fluid Dynamics (CFD) simulations usually require high computation power, and slight changes in geometry to find optimum configuration can be time-consuming. An optimization method to minimize lift force effects on solar photovoltaic (PV) arrays installed on rooftops usesthe Computational Fluid Dynamics (CFD)and genetic algorithms proposed in this paper. The tilt angle and pitch between two rows of solar panels were parameterized, and a genetic algorithm was used to search for aconfiguration resulting in minimum wind lift force acting on the solar photovoltaic plant. Only combinations with a performance ratio >80% were considered. Three different rooftopphotovoltaic (PV) plant layout configurations were analyzed in this research. Two rows of photovoltaic (PV) panel arrays wereconsidered for optimization in the 2D domain using ANSYS Fluent. Results showed that the difference in wind-liftforce between optimized configurations against that with maximum lift force configuration for all three cases above was fifty percent

    Flow boiling heat transfer characteristics of R600a and R290 in vertical mini-channels

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    High heat dissipation from compact modern electronic devices demands smart cooling solutions to ensure proper functionality. Two phase heat transfer has the capability to cope with high heating/cooling demands with better temperature uniformity along the chip. Refrigerant related environmental concerns (ozone depletion, global warming etc.) instigated recent surge for new alternatives. Natural refrigerants are regaining their fame, however reliable experimental studies under wide operating conditions are required for designing novel practical devices. Keeping in view the current demands, this study is focused on the thermal performance of two natural hydrocarbon refrigerants (Isobutane R600a, and Propane R290) in uniformly heated small vertical stainless steel tubes. The heat transfer performance of natural refrigerants is also compared with R134a under similar experimental conditions.  The experiments are carried out under wide operating conditions and continued till completion of dryout. The effects of operating parameters (heat flux, mass flux, vapor quality, saturation temperature etc.) along with assessment of macro and micro-scale correlations are the very subjects of this study

    A Comparative Study of the Effect of Non-Antibiotic Feed Additives on Experimental Colonization of Salmonella Enterica Serovar Enteridis and Intestinal Pathomorphology in Broiler Chickens

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    ABSTRACT The objective of this study was to evaluate the effect of eubiotics on the intestinal morphology of broilers. For this purpose, 125 birds were divided into six groups with two replicates each (10 birds in each replicate). Group A was given a Basal diet. All groups except group A were challenged with Salmonella enterica serovar Enteritidis. Group B was provided the basal diet, group C was fed a Probiotic-added diet; group D was fed a Prebiotics-based diet; group E was given essential oils plus the basal diet; and group F was provided with organic acids plus the basal diet. Two separate experiments were carried out for Salmonella recovery, checking the cecal tonsils and conducting an intestinal pathomorphic evaluation. Villus length, villus width, villus surface area, and crypt depth were measured by micrometry. There was an overall improvement (p<0.05) in intestinal morphometric parameters for all the treatment groups except for the negative control group, which showed the lowest villus height and villus depth values. Maximum villus height (p<0.05) of the duodenum was achieved by group E, which was fed a diet containing essential oils, whereas a maximum villus surface area index (p<0.05) was recorded for the birds of Group D, which were fed a diet containing prebiotics. Maximum villus height (p<0.05) and surface area index in ileum mucosa was recorded (p<0.05) in the birds of group D (treated with prebiotics). It is concluded that there is an overall increase in the gut histology of broilers fed non-antibiotic based feed

    Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children

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    We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2

    Development of a localized production model for the automotive industry, built into the concept of industry 4.0 in the kingdom of Saudi Arabia

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    Saudi Arabia vision-2030 is mainly focused on industrialization to reduce reliance on oil revenue. Localized Manufacturing (LM) concept, which has gained its importance worldwide in this fast-changing technological world to meet customers’ unique needs of 21st century. Now-a-days, manufacturing industry is shifting from standard product development to customized product development keeping in view the growing unique customer-’s needs. The research objective of this research was to maximize LM Application in the Kingdom of Saudi Arabia to meet unique customers’ needs. Automobile industry was selected to apply Industry 4.0 technologies i.e., 3D Printing/Additive manufacturing. The specifications, fulfilling the customer’s unique needs have been incorporated to manufacture the desired part by 3D printing/additive manufacturing. Data was collected from Saudi automobiles customers regarding their unique needs on a particular automobile part. Using the Product Design and Development methodology by Ulrich et al data was collected, analysed and as a result of data analysis, a model for maximization of localized manufacturing was developed for implementation of LM technique. Results shows that using Industry 4.0 concept, customers’ unique needs can be satisfied and fulfilled in less time and it will be more economical as compared to standard/conventional manufacturing/production methods. Based on the results of this research a model for maximization of localized manufacturing is developed utilizing Industry 4.0 techniqu

    Surgery for Tetralogy of Fallot in Adults: Early Outcomes

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    Abstract Objective: To study the in-hospital outcome of adult patients who had undergone surgical repair for Tetralogy of Fallot. Methods: A retrospective descriptive study was conducted at the Punjab Institute of Cardiology searching the hospital records. All those adult patients who had undergone repair for Tetralogy of Fallot from January 2012 to December 2014 were included in the study. All the patients were operated by the same surgical team. Patients who underwent primary repair as well as those with previous palliative procedures were included in the study. Thirty days outcome was studied by recording variables from the database. Data was analysed using Statistical Package for Social Sciences version 16. Results: A total of 80 patients was included in the study, in which there were 48 (60%) male patients and 32 (40%) female patients. Mean age was 21±0.21 years. Those with previous palliation were 15 (18.75%). The associated problems observed were: atrial septal defect 27 (33.75%), right aortic arch 30 (37.5%), patent ductus arteriosus 6 (7.5%) and double outlet right ventricle 3 (3.75%). In-hospital mortality recorded was 7 (8%). Postoperative complications encountered were low cardiac output syndrome 9 (11.25%), pleural effusion requiring tapping 3 (3.75%), reoperation for bleeding 3 (3.8%), pulmonary regurgitation (moderate to severe) 20 (25%) which occurred in the transannular patch group only and atrial arrhythmia 4 (5%). Conclusion: A large number of adult patients are still operated for tetralogy of Fallot in Pakistan. With increasing experience in the technique the mortality and morbidity is comparable to international literature

    The IFN-λ genetic polymorphism association with the viral clearance induced by hepatitis c virus treatment in Pakistani patients

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    BACKGROUND: Polymorphisms in the interferon λ (INF λ) genes on chromosome 19 have been associated with clearance of hepatitis C virus (HCV) induced by interferon and ribavirin therapy however there is no such data available for Pakistani patients with HCV infection. OBJECTIVES: In this study, the effects of single nucleotide polymorphisms (SNPs) have been investigated in response to treatment with interferon-α and ribavirin in a cohort of 75 HCV genotype 3a patients. PATIENTS AND METHODS: A total number of 50 SNPs from the Interferon λ region on chromosome 19 were genotyped to investigate allelic associations with the treatment response in HCV type 3a patients. Thirteen SNPs were associated with HCV clearance, with the most significant alleles being RS8109886 (Fisher’s P = 0.0001), RS8113007 (Fisher’s P = 0.0001) and RS12979860 (Fisher’s P = 0.0002). RESULTS: These SNPs were found to be the most suitable SNPs for predicting treatment response in the present study. These findings support those reported previously. This could be used to improve HCV treatment strategies and suggest that Pakistani patients should be genotyped for the relevant SNPs to identify the patients who are more likely to respond to interferon and ribavirin therapy. CONCLUSIONS: This therapy is costly and can be accompanied by several adverse side-effects, hence pre-treatment prediction of patients who are most likely to benefit would have both economic and patient benefits in the long term

    Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children

    No full text
    We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2
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