199 research outputs found

    Experimental Investigation on a Slurry Pump at Different Operating Parameters

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    Study on slurry pump performance has attracted much interest in many engineering fields. When pumps are required to handle slurries. The pump head and efficiency are mainly affected by the solid size, solid concentration and solid density. Centrifugal slurry pumps are benign used extensively for pipeline transportation systems and phosphate extraction industry because of their capabilities to economically convey large size abrasive solids in bulk. There is a lack of information about the effect of slurry on the performance characteristics of conventional centrifugal pumps when working without and with cavitation. A test rig with a testing centrifugal pump was constructed. The suction pipe between the mixing tank and pump inlet was designed to avoid solid deposition in suction pipe and to keep the pressure loss between the sump and the pump as low as possible. The rig was designed so that the flow rates, suction pressure, rotational speed, and solid concentration could be varied independently. The results showed that the head generating capability and pump efficiency decrease, also the power consumption increases with increasing solid concentration, consequently the head and efficiency of the pump with NPSH decreases with increasing the solids concentration and particle size, and cavitation inception accelerates with increase the solid concentration

    Effect of Battery Charging Rates for Electric Hybrid Vehicle on Fuel consumption and emissions behaviors in different road conditions: a comparative Study with Conventional Car

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    The transportation sector is a major source of worldwide carbon emissions and represents a significant contributor to air quality issues, particularly in metropolitan areas. To address the enormous carburization issues, the transportation sector must embrace low-emission vehicle technology. The team is presently developing a passenger electric hybrid car with the goal of reducing the environmental pollution. Hybrid electric vehicles (HEVs), which have a record of success in lowering hydrocarbon usage, stand as an intermediary technique between fully electric cars and internal combustion engines. In the present work, the conventional gasoline car has been tested on road at different trips condition. The gasoline fuel consumption as well as the SI engine emissions have been tested. A complete Hybrid electric system has been impeded instead of conventional driving gasoline engines and tested at a different charging rate of the battery. A comparison between the tested systems shows increased fuel efficiency as a key advantage of using HEVs technology. However, there are still unresolved issues about the system\u27s energy reliability. HEVs emit up to 21.0, 5.8, 9.0-, and 23.3-times lower NOx, UHC, CO, and particle number emissions than comparable gasoline vehicles. The development of after-treatment systems, enhanced engine management methods and the use of renewable fuels are emerging as research strategic prioritie

    Synthesis and biological assessment of new benzothiazolopyridine and benzothiazolyl- triazole derivatives as antioxidant and antibacterial agents

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    ABSTRACT. A novel series of benzothiazolopyridine derivatives was synthesized via interaction of -2-(benzothiazol-2-yl)-3-(4-chlorophenyl)acrylonitrile (2) with a diverse of commercially available reagents (indandione, thiobarbituric acid, and malononitrile). Moreover, a novel group of benzothiazole linked substituted 1,2,3-triazole derivatives were synthesized by exploring the chemical behavior of 5-benzothiazolyl-2-(4-chlorophenyl)-triazol-4-amine through refluxing in glacial acetic acid, condensation with phthalic anhydride, and cyanoacetylation reactions. All newly synthetized compounds have been tested for their antioxidant and antibacterial activities compared with ascorbic acid and Ampicillin as reference drugs, respectively. The benzothiazolo- pyridopyrimidine compound 6 was found the most potent antioxidant agent with IC50 = 0.015 mg/mL compared to the results of ascorbic acid (IC50 = 0.022 mg/mL). The investigated compounds showed no antibacterial properties against Gram-negative bacterial species, Pseudomonas aeruginosa and Escherichia coli. Benzothiazolopyridine derivative 5 displayed the best growth inhibition against Gram-positive bacteria, Staphylococcus aureus and Bacillus cereus with inhibition zones 24 and 20 mm, respectively.   KEY WORDS: Benzothiazole, Pyridobenzothiazole, 1,2,3-Triazole, Naphtharidine, Antioxidant   Bull. Chem. Soc. Ethiop. 2022, 36(2), 451-463.                                                              DOI: https://dx.doi.org/10.4314/bcse.v36i2.17                                                     &nbsp

    The diagnostic role of MDCT enterography in small bowel lesions

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    AbstractPurposeTo evaluate the role of MDCT enterography in the diagnosis of small bowel diseases.Patient and methodsThirty nine patients suspected to have small bowel diseases were examined with 64 MDCT enterography.ResultMDCT enterography easily diagnosed small intestinal diseases which confirmed with histopathological results, operative data and follow up.ConclusionsMDCT can be used as a front-line imaging and one stop imaging modality for the detection of small bowel diseases. However, biopsy is still the confirmatory diagnostic method

    A Comparative Study on Developing the Hybrid-Electric Vehicle ‎Systems and its Future Expectation over the Conventional Engines Cars

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    The use of hybrid electric vehicles (HEVs) as an alternative to traditional petroleum-powered cars has risen due to climate change, air pollution, and fuel depletion. The transportation sector is the second largest energy-consuming sector that accounts for 30% of the world’s total delivered energy and about 60% of world oil demand. In 2008, the transportation sector accounted for about 22% of total world CO2 emissions. Within this sector, road vehicles dominate oil consumption and represent 81% of total transportation energy demand. This review discusses opportunities to reduce energy consumed and greenhouse gases in this sector and briefly discusses the Hybrid electric vehicles as a solution to improve fuel economy and reduce emissions. Also, the Classification of Hybrid Electric Vehicles, and the General architectures of hybrid electric vehicles and their subtypes have been discussed. Hybrid electric vehicle system components, system analysis, and fuel economy benefits are also explained. As the comparison results proved that the benefits of improved engine thermal efficiency outweigh the losses caused by longer energy transmission paths and showed that hybridization can improve fuel economy by about 24% in typical urban cycles. This study offers a thorough analysis of hybrid electric vehicles, including information on the designs, and energy management systems, created by different researchers. According to the thorough analysis, the current systems can execute HEVs rather effectively, but their dependability and autonomous systems remain not satisfactory. Several variables, difficulties, and issues related to the future generation of hybrid cars have been highlighted in this research

    Implementation of breast cancer continuum of care in low- and middle-income countries during the COVID-19 pandemic

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    Breast cancer is the most common malignancy among women worldwide. The current COVID-19 pandemic represents an unprecedented challenge leading to care disruption, which is more severe in low- and middle-income countries (LMIC) due to existing economic obstacles. This review presents the global perspective and preparedness plans for breast cancer continuum of care amid the COVID-19 outbreak and discusses challenges faced by LMIC in implementing these strategies. Prioritization and triage of breast cancer patients in a multidisciplinary team setting are of paramount importance. Deescalation of systemic and radiation therapy can be utilized safely in selected clinical scenarios. The presence of a framework and resource-adapted recommendations exploiting available evidence-based data with judicious personalized use of current resources is essential for breast cancer care in LMIC during the COVID-19 pandemic

    Effects of Electrohydraulic Therapy of Shock Waves on Pain and Lymphedema Measurement Post-Radical Mastectomy

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    Background: Lymphedema post-mastectomy remains a challenging problem. This study aimed to investigate the efficacy of shock wave electrohydraulic treatment (ESWT) for patients with pain and lymphedema. Methods: Thirty patients (30 women) with pain & lymphedema post-radical mastectomy were evaluated to participate in this Clinical trial. They were recruited from the Minia Cancer Institute- Minia University and Deraya University outpatient clinics. Their ages varied between the ages of 40 and 50 years. They were divided into two groups. Group (1) 'Group of studies': 15 patients seeking ESWT in addition to conventional medical care. Group (2) 'Control group': 15 people seeking conventional medical care only. Patients of the study group (1) were treated with a number of impulses, at least 500 shocks at E2 at 4Hz (equivalent to 0.11mJ/mm square energy). Treatment sessions were delivered twice weekly for six treatments (3 weeks). The assessment used a Visual analogue scale (VAS) for pain and arm circumference midway between the shoulder and elbow for lymphedema measurement. Results: showed that (ESWT) on pain and lymphedema measurement post-radical mastectomy effectively decreased pain as evidenced by the highly significant decreases in the visual analogue scale. These results revealed a substantial VAS reduction (P<0.0001). Effects of the ESWT on lymphedema measurement via the arm circumference measurement at the point where the shoulder and the elbow meet post-radical mastectomy were investigated. These results revealed a notable reduction in the mean value of the arm circumference measurement (ACM) (P<0.0001). Conclusion: The significant reductions in VAS and assessment of the ACM arm range show that the ESWT, in addition to conventional therapy, significantly impacted upper limb structural components following radical mastectomy

    A Validated UPLC-PDA Method for Simultaneous Determination of 3 Biologically Active Isoflavans in Trigonella stellata Extract

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    © The Author(s) 2020. In this study, an ultra-performance liquid chromatography (UPLC)/photodiode array method was developed for the simultaneous determination of trigonellan glucoside (1), isotrigonellan (2), and methoxy-isotrigonellan (3) in Trigonella stellata extract using an external standard method. The extract was prepared using a standardized method by maceration of the dried plant material in ethanol. The 3 isoflavans (1-3) were separated on an Acquity UPLC C18 column using gradient elution with a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and 0.1% (v/v) formic acid in acetonitrile, and ultraviolet detection. The method provides a linear correlation for all analytes over the investigated ranges with all correlation coefficients greater than 0.998. The validated lower limits of quantitation were 53, 127, and 5 μg/mL for isoflavans 1, 2, and 3, respectively. Intraday and interday precisions (percent relative SD [RSD%]) were less than 8.3% and accuracy (RE%) ranged from 90% to 100%. The method’s capability to remain unaffected by small, but deliberate variations in method parameters (method’s reliability during normal usage) described by the robustness showed RSD% less than 4.6% measured by varying 3 different parameters. The validated method was successfully applied to simultaneously determine the concentration of the 3 new isoflavans having anti-inflammatory and antidiabetic activities. The results revealed that the validated method can be used for quality control of herbal preparations containing these or similar isoflavans that are marketed for the prevention of inflammation and as antidiabetics

    Outdoor Residual Insecticide Spraying (ODRS), a new approach for the control of the exophilic vectors of human visceral Leishmaniasis : phlebotomus orientalis in East Africa

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    Background. Visceral Leishmaniasis (VL) due to Leishmania donovani is a neglected protozoan parasitic disease in humans, which is usually fatal if untreated. Phlebotomus orientalis, the predominant VL vector in East Africa, is a highly exophilic/exophagic species that poses a major challenge to current Integrated Vector Management (IVM). Here we report results of pilot studies conducted in rural villages in Gedarif state, Sudan, to evaluate outdoor residual spraying of 20mg active ingredient (a.i.) /m2 deltamethrin insecticide applied to the characteristic household compound boundary reed fence and to the outside of household buildings (Outdoor Residual Insecticide Spraying, ODRS), and as an alternative, spraying restricted to the boundary fence only (Restricted Outdoor Residual Insecticide Spraying, RODRS). Methods. Four to six clusters of 20 households were assigned to insecticide treatments or control in three experiments. Changes in sand fly numbers were monitored over 2,033 trap-nights over 43-76 days follow-up in four sentinel houses per cluster relative to unsprayed control clusters. Sand fly numbers were monitored by sticky traps placed on the ground on the inside (“outdoor”) and the outside (“peridomestic”) of the boundary fence, and by CDC light traps suspended outdoors in the household compound. The effects of ODRS on sand fly numbers inside sleeping huts were monitored by insecticide knockdown. Results. After a single application, ODRS reduced P. orientalis abundance by 83%-99% in outdoor and peridomestic trap locations. ODRS also reduced numbers of P. orientalis found resting inside sleeping huts. RODRS reduced outdoor and peridomestic P. orientalis by 60%- 88%. By direct comparison, RODRS was 58%-100% as effective as ODRS depending on the trapping method. These impacts were immediate on intervention and persisted during follow-up, representing a large fraction of the P. orientalis activity season. Relative costs of ODRS and RODRS delivery were 5.76and5.76 and 3.48 per household, respectively. Conclusions. The study demonstrates the feasibility and high entomological efficacy of ODRS and RODRS, and the expected low costs relative to current IVM practises. These methods represent novel sand fly vector control tools against predominantly exophilic/exophagic sand fly vectors, aimed to lower VL burdens in Sudan, with potential application in other endemic regions in East Africa

    Injection Drug Use Is a Risk Factor for HCV Infection in Urban Egypt

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    OBJECTIVE: To identify current risk factors for hepatitis C virus (HCV) transmission in Greater Cairo. DESIGN AND SETTING: A 1:1 matched case-control study was conducted comparing incident acute symptomatic hepatitis C patients in two "fever" hospitals of Greater Cairo with two control groups: household members of the cases and acute hepatitis A patients diagnosed at the same hospitals. Controls were matched on the same age and sex to cases and were all anti-HCV antibody negative. Iatrogenic, community and household exposures to HCV in the one to six months before symptoms onset for cases, and date of interview for controls, were exhaustively assessed. RESULTS: From 2002 to 2007, 94 definite acute symptomatic HCV cases and 188 controls were enrolled in the study. In multivariate analysis, intravenous injections (OR = 5.0; 95% CI = 1.2-20.2), medical stitches (OR = 4.2; 95% CI = 1.6-11.3), injection drug use (IDU) (OR = 7.9; 95% CI = 1.4-43.5), recent marriage (OR = 3.3; 95% CI = 1.1-9.9) and illiteracy (OR = 3.9; 95% CI = 1.8-8.5) were independently associated with an increased HCV risk. CONCLUSION: In urban Cairo, invasive health care procedures remain a source of HCV transmission and IDU is an emerging risk factor. Strict application of standard precautions during health care is a priority. Implementation of comprehensive infection prevention programs for IDU should be considered
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