23 research outputs found

    Utilization of Used Vegetable Oil as a Biodiesel Fuel

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    In this study the reusing of vegetable oil as an alternative substitute for biodiesel was investigated. The used vegetable oil (UVO) was obtained from Baraka Factory – Potato chips line, Wad Madani, Sudan. The biodiesel is produced from used vegetable oil by alkali transesterification. The kinematic viscosity of biodiesel (at 40ÂșC), flash point, density (at 15ÂșC), and calorific value were 5.35cSt, 119ÂșC, 0.881gm/ml, and 41.9MJ/kg respectively. The results showed that the used vegetable oil is suitable for biodiesel productio

    Polyarteritis nodosa presenting as a bladder outlet obstruction

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    Polyarteritis nodosa (PAN) of the urinary tract is rare. An unusual case of systemic PAN involving the bladder neck is described. A 27-year-old man, with known diastolic hypertension diagnosed 2 years earlier, was admitted with chronic urinary obstruction complicated by hydronephrosis. He had symptoms of myalgia and weight loss, was afebrile but had an elevated erythrocyte sedimentation rate and acute-on-chronic renal impairment. All virological and serological tests including hepatitis B and anti-neutrophil cytoplasmic antibody were negative. A computed tomography scan of the brain revealed small-vessel disease. A bladder neck mass was visualised on cystoscopy. Histological examination of this demonstrated a medium-sized necrotising vasculitis with small-vessel fibrinoid necrosis suggestive of PAN. At least six of the American College of Rheumatology criteria for PAN were met. The patient was treated with pulses of intravenous cyclophosphamide and oral corticosteroids with a good clinical response

    Behavior of bonded and unbonded prestressed normal and high strength concrete beams

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    AbstractThe major disadvantage of using ordinary reinforced concrete (RC) elements is the corrosion of steel, which occurs due to effect of cracks in tension zones. The main advantage of the fully prestressed concrete system is the absence of cracks in the concrete at the nominal service load and therefore better durability will be achieved. Combining the PC system with the use of high strength concrete is a milestone, which will potentially result in a new design approach. The disadvantage of the use of this combination is referred to the reduced ductility of concrete members.This paper presents an experimental program conducted to study the behavior of bonded and unbounded prestressed normal strength (NSC) and high strength concrete (HSC) beams. The program consists of a total of nine beams; two specimens were reinforced with non-prestressed reinforcement, four specimens were reinforced with bonded tendons, and the remaining three specimens were reinforced with unbonded tendons. The overall dimensions of the beams are 160×340×4400-mm. The beams were tested under cyclic loading up to failure to examine its flexural behavior. The main variables in this experimental program are nominal concrete compressive strength (43, 72 and 97MPa), bonded and unbonded tendons and prestressing index (0%, 70% and 100%). Theoretical analysis using rational approach was also carried out to predict the flexural behavior of the specimens. Evaluation of the analytical work is introduced and compared to the results of the experimental work

    Antimicrobial modification of PLA scaffolds with ascorbic and fumaric acids via plasma treatment

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    An optimal medical scaffold should be biocompatible and biodegradable and should have adequate mechanical properties and scaffold architecture porosity, a precise three-dimensional shape, and a reasonable manufacturing method. Polylactic acid (PLA) is a natural biodegradable thermoplastic aliphatic polyester that can be fabricated into nanofiber structures through many techniques, and electrospinning is one of the most widely used methods. Medical fiber mat scaffolds have been associated with inflammation and infection and, in some cases, have resulted in tissue degradation. Therefore, surface modification with antimicrobial agents represents a suitable solution if the mechanical properties of the fiber mats are not affected. In this study, the surfaces of electrospun PLA fiber mats were modified with naturally occurring L-ascorbic acid (ASA) or fumaric acid (FA) via a plasma treatment method. It was found that 30 s of radio-frequency (RF) plasma treatment was effective enough for the wettability enhancement and hydroperoxide formation needed for subsequent grafting reactions with antimicrobial agents upon their decomposition. This modification led to changes in the surface properties of the PLA fiber mats, which were analyzed by various spectroscopic and microscopic techniques. FTIR-ATR confirmed the chemical composition changes after the modification process and the surface morphology/topography changes were proven by SEM and AFM. Moreover, nanomechanical changes of prepared PLA fiber mats were investigated by AFM using amplitude modulation-frequency modulation (AM-FM) technique. A significant enhancement in antimicrobial activity of such modified PLA fiber mats against gram-positive Staphylococcus aureus and gram-negative Escherichia coli are demonstrated herein. © 2020 The AuthorsQatar National Research Fund (a member of The Qatar Foundation) [22-076-1-011]; Qatar University Collaborative Grant [QUCG-CAM-20/21-3]; Czech Science FoundationGrant Agency of the Czech Republic [19-16861S

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    The tree clustering technique and the physical reality of galaxy groups

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    In this paper the tree clustering technique (the Euclidean separation distance coefficients) is suggested to test how the Hickson compact groups of galaxies (HCGs) are really physical groups. The method is applied on groups of 5 members only in Hickson’s catalog

    Thermal control of a small satellite in low earth orbit using phase change materials-based thermal energy storage panel

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    Thermal control of small satellites in low earth orbit (LEO) is not easy due to the intermittent heating conditions. The satellites in LEO are sometimes present in the illumination zone and other times in the eclipse zone, which imposes difficulties keeping their temperatures within the safe range. The present study investigates a thermal energy storage panel (TESP) integrated with phase change materials (PCM) to control the temperatures of satellite subsystems. The TESP was made of aluminium with outer dimensions of 100 mm long, 71 mm wide, and 25 mm high. The PCMs used were organic-based materials, which were RT 12, RT 22, and RT 31. The TESP was tested under two thermal powers of 11 W and 14 W. These powers are typical of satellite subsystems. The finite volume method was adopted for thermal analysis of the TESP. The significance of this study is that it provides a detailed computational analysis of the TESP for microsatellites' temperature management under typical LEO conditions. The research outcomes show a significant advancement in the thermal managing performance of PCM-based TESP. RT 22 could reduce the highest temperature by 4.7 % and raise the lowest by 9.5 %. It was observed from the analysis that the PCM with intermediary melting temperature provided better thermal control efficiency. RT 12 reported a lower extreme temperature difference (ETD) and could decrease it by 63.9 % relative to the case with no PCM. At the same time, RT 22 reported an ETD of 23 min and could reduce it by 63 % relative to the case with no PCM at 14 W. The present study concluded that PCMs show great potential as a viable approach for effectively thermally managing devices that experience cyclic thermal fluctuations, such as the subsystems of satellites operating in LEO
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