1,103 research outputs found

    System integration of hydrogen energy technologies using renewable energy resources

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    The objective of this work has two major tasks that investigation the use of CHHP system at the Missouri University of Science and Technology (Missouri S&T) campus and studying solid waste as renewable source of energy: current and future possibility in Libya. Task one has three major topics. In Topic I, Design of Combined Hydrogen, Heat and Power (CHHP) system for the campus using local resources and treated biogas can be used to generate CHHP using a Molten Carbonate Fuel Cell (MCFC). In Topic II, hydrogen recovery and cleaning system, Heat recovery and electric power usage, hydrogen compression, storage, and dispensing/distribution system, electricity use and economic benefits of the system in operation, and thermal use. In Topic III, utilization of hydrogen production, hydrogen end-uses, CHHP hydrogen output, and hydrogen application consider but not used in the design. In task 2, generation of solid waste in Libya, overview of Waste-to-energy (WTE) conversions, solid waste management, WTE benefits and challenges in Libya. Results for Tasks I and II have been presented. --Abstract, page iv

    Coral Growth and Skeletal Density Relationships in Some Branching Corals of the Red Sea, Egypt

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    The coral reefs at the exposed zones are exhibited to strong wave action, renewable water masses, clear seawater and small temperature variations, however, in the sheltered zones they exposed to high turbidity, high temperature variations and protected from the surge waves and currents. In situ measurements of seasonal and annual growth rates and the branch thicknesses using Varner Caliber and the laboratory measurements of skeletal densities using Archimedes’s Principle were done in four branching coral species growing in the exposed and sheltered zones of Hurghada and Hamrawin at the northern Red Sea. Acropora humilis recorded the highest seasonal and annual growth rates at all zones; 0.68±0.02, 0.76±0.03, 0.66±0.03 and 0.69±0.02mm/month and 7.25±0.20, 7.96±0.33, 7.10±0.11 and 7.34±0.14mm/yr respectively. Pocillopora damicornis recorded the highest averages of skeletal density at the different zones of Hurghada and Hamrawin; 2.04±0.35, 1.64±0.26, 2.64±0.66 and 1.96±0.18gm/cm3 respectively and the highest averages of the branch thicknesses at the exposed and sheltered zones of Hurghada (1.66±0.42cm2, 1.51±0.30cm2) while, A. humilis recorded the highest average of the branch thicknesses at the exposed and sheltered zones of Hamrawin (1.49±0.16cm2, 1.14±0.08cm2). A. humilis was the fastest growing species in the worm season at the exposing and sheltered zones of Hurghada and Hamrawin, while P. damicornis was the slowest growing species because of it tends to form thick and dense branches. The oceanographic and local conditions as; temperature variations, aragonite saturation, turbidity, effects of surge waves and light intensity are responsible about the differences in the skeletal parameters of the studied species. Keywords: Branching corals – Growth rates - Skeletal density – Branch thicknesses – exposed and sheltered zones

    Data-centric communication framework for multicast iec 61850 routable GOOSE messages over the WAN in modern power systems

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    In this paper, a data-centric communication framework is proposed for multicast routable generic object-oriented substation event (GOOSE) messages (MRGM) over the wide area network (WAN) for effective substation-to-substation (SS2SS) and substation to control center (SS2CC) communications. In this structure, the IEC 61850 GOOSE message is transmitted over the WAN using the data distribution service (DDS) as a fast, reliable, and secure data-centric communication middleware. The main feature of this framework is its multicast capability, where several authorized subscribers can receive a published message simultaneously. This can significantly improve the system monitoring and control of the protection systems in modern smart grids, where intelligent schemes can be applied. The effectiveness of the proposed platform, in terms of total end-to-end delay between participants, is evaluated through experimental results obtained from the actual hardware-based test setup developed at the Florida International University (FIU) smart grid testbed. The results demonstrate that the latency between sending and receiving a GOOSE message among participants is within its maximum time span defined by the IEC 61850-90-5 working group for communications over the WAN

    A Unique Solution of Stochastic Partial Differential Equations with Non-Local Initial condition

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    In this paper, we shall discuss the uniqueness ”pathwise uniqueness” of the solutions of stochastic partial differential equations (SPDEs) with non-local initial condition,We shall use the Yamada-Watanabe condition for ”pathwise uniqueness” of the solutions of the stochastic differential equation; this condition is weaker than the usual Lipschitz condition. The proof is based on Bihari’sinequality

    Existence and Uniqueness of Abstract Stochastic Fractional-Order Differential Equation

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    In this paper, the existence and uniqueness about the solution for a class of abstract stochastic fractional-order differential equations                                           where  in and  are given functions, are investigated, where the fractional derivative is described in Caputo sense. The fractional calculus, stochastic analysis techniques and the standard Picard′sPicard's iteration method are used to obtain the required

    The Differential Efficiency of Chlorella vulgaris and Oscillatoria sp. to Treat the Municipal Wastewater

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    The utilization of microalgae to treat wastewater becomes an alternative biological wastewater treatment technique worldwide because of its low cost and environmental clean. Chlorella vulgaris and Oscillatoria sp. were cultured in municipal wastewater under controlled laboratory conditions with continuous light illumination and aeration. Physical properties (pH, TDS and Salinity), and nutrient contents (ammonia, nitrite and total phosphorus)were measured in the raw wastewater. Growth rates of the cultured species in terms of optical densities and cell counts, nutrient salts removal efficiencies were measured during the experimental durations after; 24, 48, 72, 96 , 120 and 144hrs. Lipids, proteins and carbohydrates contents were also evaluated after 144hrs. The recorded optical density of Chlorella vulgaris was 0.188±0.01 at 680 nm and 0.17±0.01 at 750 nm after 24hrs then increased to 1.45±0.002 at 680nm and 1.43±0.01 at 750nm at the end of 120hrs, meanwhile the optical density of Oscillatoria sp. was increased from 0.132±0.01 at 680 nm and 0.102±0.01 at 750 nm after 24hrs to 1.054±0.004 at 680 nm and 0.99±0.002 at 750 nm at the end of 120hrs of the experiment. On the other hand, the cell count of Chlorella vulgaris was enriched from 6.8±2.2 cell/ml after 24hrs to 720±120 cell/ml at the end of 120h of the culturing. Overall, efficiencies of nutrients removal were 99.426%, 100% and 82.211% for ammonia, nitrite and total phosphorus respectively at the end of 120hrs of Chlorella vulgaris culturing, while Oscillatoria sp nutrient removal efficiencies recorded 98.125%, 100% and 84.718% for ammonia, Nitrite and total phosphorus respectively. Chlorella vulgaris biomass was estimated 26.66±7.5% lipid 35.1±1.6% protein and 29.34±3.25% carbohydrate, however Oscillatoria sp. biomass was estimated 11.76±0.79% lipids, 32.9±1.92% protein and 27.36±3.78% carbohydrates. Keywords: municipal Wastewater, Chlorella vulgaris, Oscillatoria sp., nutrient removal, biochemical parameters

    Insulin sensitizing agent improves clinical pregnancy rate and insulin resistant parameters in polycystic ovarian syndrome patients with acanthosis nigricans: a randomized controlled study

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    Objective: To investigate the effect of adding metformin to clomiphene citrate (CC) in polycystic ovarian syndrome (PCOS) patients with acanthosis nigricans (AN) who were previously not responding to CC. Material and Methods: A double blinded randomized controlled trial (NCT02562664) included 66 PCOS women with acanthosis nigricans who were CC resistant (at least 3 months). Day 3 follicle stimulating hormone (FSH) level, fasting insulin, fasting glucose and homeostatic model assessment were used to quantify insulin resistance. Participants were randomly assigned to either group I (CC with placebo tablets) or group II (CC with metformin) for three cycles. Insulin resistance parameters as well as clinical pregnancy rate had been evaluated in both groups. The statistical analysis was done using Chi- square and Fischer exact tests. Results: The demographic data was comparable in both groups, however; there was higher cumulative pregnancy rate after three cycles of stimulation in group II (18/33) (54.5%) in comparison with group I (7/33) (21.1%) (P=0.03). There was a significant improvement in the insulin resistance parameters after three months of combining clomiphene citrate with metformin as compared with CC alone. Conclusion: Adding metformin to CC in clomiphene citrate resistant PCOS patients who have acanthosis nigricans improves the pregnancy rate and insulin resistant parameters

    A Review of Artificial Intelligence in Breast Imaging

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    With the increasing dominance of artificial intelligence (AI) techniques, the important prospects for their application have extended to various medical fields, including domains such as in vitro diagnosis, intelligent rehabilitation, medical imaging, and prognosis. Breast cancer is a common malignancy that critically affects women’s physical and mental health. Early breast cancer screening—through mammography, ultrasound, or magnetic resonance imaging (MRI)—can substantially improve the prognosis for breast cancer patients. AI applications have shown excellent performance in various image recognition tasks, and their use in breast cancer screening has been explored in numerous studies. This paper introduces relevant AI techniques and their applications in the field of medical imaging of the breast (mammography and ultrasound), specifically in terms of identifying, segmenting, and classifying lesions; assessing breast cancer risk; and improving image quality. Focusing on medical imaging for breast cancer, this paper also reviews related challenges and prospects for AI

    Obstetric hemorrhage and shock management: using the low technology Non-pneumatic Anti-Shock Garment in Nigerian and Egyptian tertiary care facilities

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    Abstract Background Obstetric hemorrhage is the leading cause of maternal mortality globally. The Non-pneumatic Anti-Shock Garment (NASG) is a low-technology, first-aid compression device which, when added to standard hypovolemic shock protocols, may improve outcomes for women with hypovolemic shock secondary to obstetric hemorrhage in tertiary facilities in low-resource settings. Methods This study employed a pre-intervention/intervention design in four facilities in Nigeria and two in Egypt. Primary outcomes were measured mean and median blood loss, severe end-organ failure morbidity (renal failure, pulmonary failure, cardiac failure, or CNS dysfunctions), mortality, and emergency hysterectomy for 1442 women with ≥750 mL blood loss and at least one sign of hemodynamic instability. Comparisons of outcomes by study phase were assessed with rank sum tests, relative risks (RR), number needed to treat for benefit (NNTb), and multiple logistic regression. Results Women in the NASG phase (n = 835) were in worse condition on study entry, 38.5% with mean arterial pressure <60 mmHg vs. 29.9% in the pre-intervention phase (p = 0.001). Despite this, negative outcomes were significantly reduced in the NASG phase: mean measured blood loss decreased from 444 mL to 240 mL (p < 0.001), maternal mortality decreased from 6.3% to 3.5% (RR 0.56, 95% CI 0.35-0.89), severe morbidities from 3.7% to 0.7% (RR 0.20, 95% CI 0.08-0.50), and emergency hysterectomy from 8.9% to 4.0% (RR 0.44, 0.23-0.86). In multiple logistic regression, there was a 55% reduced odds of mortality during the NASG phase (aOR 0.45, 0.27-0.77). The NNTb to prevent either mortality or severe morbidity was 18 (12-36). Conclusion Adding the NASG to standard shock and hemorrhage management may significantly improve maternal outcomes from hypovolemic shock secondary to obstetric hemorrhage at tertiary care facilities in low-resource settings
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