1,484 research outputs found

    Electroless Plating of Ni-B Composite Coating on AZ31 Mg alloy

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    A Ni–B coating was electroless-deposited directly on H3PO4/HF pickled AZ31. The thickness of the plating layer was estimated through weight gain measurements and was affected by temperature, time and bath composition. The highest thickness was obtained at 6 g/L of NaHB4 at 85oC.  An adherent compact layer of Ni-B was obtained. Electrochemical impedance spectroscopy measurements in 3.5 wt.% sodium chloride aqueous solution suggest that the plating can protect the magnesium alloy substrate from corrosion attack

    Effect of Pickling and Activation Treatments on the Performance of Electroless Plating of Ni-B Coating on AZ31 Mg Alloy

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    Pickling is particularly critical before Ni-B electroless plating to create a uniform and catalytically active surface.  In the present work, pickling treatment of AZ31 Mg alloy was performed in phosphoric acid followed by immersion in 40% HF.  The effect of concentration of both H3PO4 and HF as well as the effect of time were investigated.   The pickled samples were then electroless plated with a Ni-B composite.  The performance of the Ni-B composite coating was investigated under the SEM.Results show that the highest quality coating was obtained upon pickling AZ31 Mg alloy samples in 50% phosphoric acid for 1 min, followed by activation in 40% HF for 15 min. Higher concentration of H3PO4 results in a higher concentration of PO3−4, leading to a higher tendency to produce insoluble films (mainly Mg3(PO4)2 and AlPO4) on the substrate surface slowing down the rate of Mg alloy oxidization and dissolution.  Activation of pickled AZ31 Mg samples in HF results in the formation of corrosion resistant dense layer of magnesium fluoride. SEM investigation predicted the electroless deposition of an adherent compact layer of Ni–B composite coating on the H3PO4/HF pickled AZ31 samples. Key Words: AZ31 Mg alloy, pickling, activation, HF, electroless plating DOI: 10.7176/CMR/11-5-04 Publication date:May 31st 201

    Better Heat And Power Integration Of An Existing Gas-oil Plant In Egypt Through Revamping The Design And Organic Rankine Cycle

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    Objective: The current study aims mainly to Maximize Condensate Recovery (NGLs), focusing on a gas processing train of Gas-Oil Separation Plant (GOSP) located in Egypt with a capacity of 4,230 kmole/h. Methods: The research study accounts for the constraint of Reid Vapor Pressure (RVP) specification, which makes the storage in floating roof tanks is of a great risk. The study proposes the installation of the cryogenic train that recovers condensates (C4+). This train comprises of compression unit, expansion unit, three-phase separators and a re-boiled absorber. The problem of RVP will no longer exist because of the re-boiled absorber achieving RVP according to export specifications (RVP below 82.74 kPa). Heat integration is applied over the whole process to minimize the reliability of the external utilities. Further, an Organic Rankine cycle (ORC) is introduced to the existing unit for more heat integration to develop useful work from process waste heat. Furthermore, both environmental emissions of CO2 and economic implications are investigated. Results: Energy integration played a vital role in decreasing the compressing power by about 31%, the cooling load by about 81%, and eliminating the heating load leading to zero CO2 emissions. Conclusion: The new energy-integrated retrofit scenarios exceed the recommended revamping schemes by previous works and base case in all aspects of condensate recovery, energy-saving, environmental concerning and economics

    Effect of metformin on Sirtuin-1 disorders associated with diabetes in male rats

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    Background: Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance, hyperinsulinaemia and hyperglycaemia. Increased glucose production through abnormally elevated hepatic gluconeogenesis is central to the manifestation of hyperglycaemia in T2DM. Metformin corrects hyperglycaemia mainly through inhibition of gluconeogenesis. Sirtuin 1 (SIRT1) has been identified as regulator of gluconeogenic gene expression. The present study aimed to evaluate the effect of metformin on SIRT1 level and activity in liver and pancreas of diabetic rats. Further, the possible role of SIRT1 on metabolic disorders associated with diabetes mellitus, including serum levels of glucose, insulin, triglyceride (TG) and high density lipoprotiens (HDL), will be explored.Methods: Thirty-two male albino rats were divided into control group (GpI), diabetic (DM) group (GpII), (metformin + DM) group (GpIII) administered 120 mg/kg metformin daily for 1 month before induction of diabetes, (DM + metformin) group (GpIV) administered 250 mg/kg metformin daily for 1 month after induction of diabetes. At the end of the study, BMI%, serum levels of glucose, insulin, TG and HDL, HOMA, SIRT1 level and activity in liver and pancreas and pancreatic DNA ladder were assessed.Results: Our results showed significant decrease in serum glucose, insulin and TG levels and HOMA; significant increase in HDL level and SIRT1 level and activity in liver and pancreas beside the marked disappearance of pancreatic apoptosis in GpIII & IV relative to GpII. Regarding BMI%, it showed no significant changes in GpIV relative to GpII. No significant change was recorded between GpIII and GpIV regarding all studied parameters except on serum TG.Conclusion: Lowered SIRT1 in diabetes was improved by the administration of Metformin. Consequently, the pathophysiological disorders associated with T2DM were improved.Keywords: DM, Metformin, SIRT1, Pancreatic apoptosi

    Evaluation of Clinical and Biochemical Traits in Egyptian Barki Sheep with Different Growth Performances.

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    The Barki sheep industry is becoming increasingly important in Egypt because of the high quality of their meat and wool. This sheep breed is also commonly known for its resistance to arid and harsh environmental conditions. Such characteristics can be exploited in solving the problematic situation of inadequate animal protein for human consumption, particularly under climatic changes. However, very few studies have investigated aspects of breeding, nutrition, and susceptibility to infectious or non-infectious diseases in Barki sheep. Herein, we propose to unravel the differences in the clinical and biochemical profiles among Barki sheep of different growth rates. We measured clinical and biochemical parameters in stunted (n = 10; test group) and in good body condition (n = 9; control group) Barki sheep. Animals subjected to this experiment were of the same sex (female), age (12 months old), and housed in the same farm with similar conditions of feeding, management practice, and vaccination and deworming regimens. Regarding clinical examination, stunted/tested sheep showed a significantly higher pulse and respiratory rate compared to sheep with a good body condition/control group. The appetite, body temperature, and digestion processes were the same in both groups. In biochemical investigations, nutritional biomarkers were reduced markedly in stunted sheep compared with the control sheep, including total protein (p = 0.0445), albumin (p = 0.0087), cholesterol (p = 0.0007), and triglycerides (p = 0.0059). In addition, the Barki sheep test group suffered from higher levels of urea and blood urea nitrogen than the control group. Consistently, growth and thyroid hormone levels were lower in stunted sheep than the control sheep, although the differences were not statistically significant (p > 0.05). No significant differences were detected in both groups for serum levels of calcium, phosphorus, magnesium, iron, and zinc (p > 0.05). To detect the reasons for emaciation, certain debilitating infections were tested. All tested sheep showed negative coprological tests for gastrointestinal parasites, and had no obvious seropositivity to brucellosis, toxoplasmosis, neosporosis, or Q fever. This study demonstrates the useful biochemical markers for monitoring growth performance in Egyptian Barki sheep and unravels the usefulness of this breed in nationwide breeding and farming

    Effect of Al2O3 and WO3 Ceramic Additives on the Surface Morphology and Mechanical Properties of Electroless Nickel-Boron Composite Coatings Fabricated on AZ31 Magnesium Alloy

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    In the present study, synthesis and a comparison of properties (structural and mechanical)  of  Ni–B and Ni–B–Al2O3 and Ni-B-WO3 composite coatings have been presented  to  elucidate the beneficial role  of Al2O3 or WO3 addition in  binary Ni–B coatings. The  Ni–B– Al2O3 and Ni-B-WO3 coatings were synthesized by  adding Al2O3 or NaWO3 powdered particles into the  above  mentioned Ni–B  coating solution.  A significant improvement in mechanical properties has been observed by the addition of Al2O3 or WO3 additions.  This novel composite coating composition will be useful for wear and corrosion applications. DOI: 10.7176/CMR/11-8-05 Publication date:October 31st 201

    Water Conservation and Management Practices at the University of Sharjah to Achieve Sustainability Excellence

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    The University of Sharjah is a leading educational and research institution in the Gulf region. To stimulate the different aspects of sustainability in education and research as well as to ensure the implementation of sustainability concepts throughout the University campus operations, the concept of sustainability circles is implemented. The University being in hot-arid-zone and mostly surrounded by desert terrain relies on unconventional water conservation programs and initiatives such as the use of innovation & technology, reuse and recycling of water, and awareness campaigns. In line with such programs, the use of potable water is limited for hygiene purposes and wastewater generated within the University is reused after treatment to irrigate the vast green spaces through the most efficient irrigation water application systems. Examples of water conservation practices include use of efficient water devices, reuse of treated greywater for toilet flushing at a selected location, water quality monitoring, preservation to conserve water for its intended use, promoting waterless car wash on the campus grounds etc. On-campus water is also conserved through disseminating knowledge and awareness to the University community and beyond through various sustainability related programs and initiatives organized by Sustainability Office for water conservation and environmental protection

    KIRURŠKO LIJEČENJE STRES URINARNE INKONTINENCIJE, FEKALNE INKONTINENCIJE I VAGINALNOG PROLAPSA NOVOM OPERACIJOM »URETRO-ANO-VAGINOPLASTIKA«

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    We put forward a novel concept explaining the mechanism of micturition and the factors that control urinary continence. Also, we describe the mechanism of defecation and the factors that control stool continence and prevent fecal incontinence. A weak internal urethral sphincter (IUS) will not withstand sudden rise of intra-abdominal pressure and urine will leak. The weakness of the IUS is mostly due to traumatic rupture of its wall as a result of the huge vaginal distension that happens during prolonged, difficult and multiple frequent labors. So, surgical correction is by exposing that rupture and mending its walls. Also the marked vaginal distension which occurs in labor will cause lacerations in the internal anal sphincter (IAS) which is intimately related to the posterior vaginal wall. The torn weak IAS will cause fecal incontinence (FI). Exposing the torn IAS and mending the torn walls will restore the sphincter strength and fecal continence. Vaginal prolapse occurs as a result of vaginal wall weakness, redundancy and flabbiness subsequent to its marked stretching of its walls during vaginal deliveries. Overlapping the vaginal flaps both in the anterior and posterior vaginal wall, such repair will strengthen the vaginal walls, as if we put a collagenous mesh but instead this is an autologus collagenous mesh. We innovated an operation called »urethro-ano-vagino-plasty« to surgically treat urinary incontinence, fecal incontinence and and vaginal prolapse. Objectives. To describe this novel operation, and assess its results for a follow up period of 24 months. Methods. 134 patients with SUI and FI were assessed. Urethro-ano-vaginoplasty was done, and the results were assessed immediately and for 24 months follow up. Results. 121 (90.3%) gained urinary and fecal continence and remained continent in the follow up period. Conclusion. The internal anal sphincter (IAS) is a collageno-muscular tissue cylinder that surrounds the anal canal innervated by alpha-sympathetic nerve supply from the hypogastric nerves. It is surrounded in its lower part by the EAS which is a striated muscle innervated by the pudendal nerve. Its damage during childbirth causes fecal incontinence and mending the torn walls restores fecal continence.Predstavljena je nova koncepcija o mehanizmu mokrenja i čimbenicima koji reguliraju mokraćnu kontinenciju. Također, opisan je mehanizam defekacije te čimbenici koji kontroliraju kontinenciju stolice i sprječavaju fekalnu inkontinenciju. Slab unutarnji uretralni sfinkter (IUS) se ne može suprostaviti naglom porastu intraabdominalnog tlaka te će mokraća bježati. Slabost IUS-a je većinom posljedica ozljede njegove stijenke zbog silnog vaginalna širenja koje se zbiva tijekom produljenih, tešlih i učestalih rađanja. Kirurška korekcija se sastoji u nalaženju prsnuća i opskrbi njegove stijenke. Vaginalno širenje tijekom poroda uzrokuje prsnuće unutarnjeg analnog sfinktera (IAS), koji je intimno povezan sa stražnjom vaginalnom stijenkom. Oslabljeni i prsnuti IAS uzrokuje fekalnu inkontinenciju (FI). Prikaz prsnutog IAS-a i šivanje njegovih razderanih stijenki uspostavit će snagu sfinktera i fekalnu kontinenciju. Vaginalni prolaps nastaje kao posljedica slabosti i mlohavosti vaginalne stijenke te njene proširenosti, zbog istezanja tijekom vaginalnog rađanja. Preklapanjem vaginalnih režanja prednje i stražnje stijenke ojačava se stijenka, umjesto umjetne mrežice postavljamo vlastitu autolognu kolagenu mrežicu. Izumjeli smo za korekciju urinarne i fekalne inkontinencije te vaginalna prolapsa novu operaciju i nazcvali je »uretro-ano-vagino-plastika«. Cilj rada je opisati novu operaciju i prosuditi njen uspjeh nakon 24 mjeseca. Metoda. Operirane su 134 bolesnice sa stres urinarnom inkontinencijom i fekalnom inkontinencijom. Rezultati. 121 bolesnica (90,3%) je opet postigla mokraćnu i fekalnu kontinenciju i zadržala ih tijekom praćenja. Zaključak. Unutarnji analni sfinkter je kolegano-mišićni tkivni cilindar, inerviran alfa-simpatičnim živcima iz hipogastričkog pleksusa koji okružuje analni kanal. U donjem dijelu je okružen vanjskim sfinkterom koji je poprečno-prugaste mišićne građe i inerviran ograncima pudendalnog živca. Njegovo oštećenje tijekom rađanja uzrokuje fekalnu inkontinenciju, a šivanje prsnute stijenke uspostavlja fekalnu kontinenciju

    Neurological Alterations in Type 1 Diabetes Mellitus Among Adolescents

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    BACKGROUND: Diabetes mellitus (DM) is a group of chronic disorders of metabolism characterised by high blood glucose levels. There is an increased prevalence of Type 1 DM in children and adolescents with its adverse complications especially microvascular ones (retinopathy, nephropathy and neuropathy) that might cause multiple organ damage. AIM: To study the relation between DM and neurological affection. METHODS: Fifty-nine children with type I DM, divided randomly into 2 groups, aged 8-18 years old of both sexes were enrolled in this cross-sectional study. All children were subjected to full history taking, physical, neurological and systemic examination. RESULTS: There was an affection of motor power in both upper limbs as well as lower limbs. Also, we found that there was an affection of the superficial peripheral sensation affecting both upper and lower limbs. CONCLUSION: Neurological assessment of children with diabetes mellitus type I should be a routine to early discover these manifestations which can have a deteriorating effect on the child’s health

    ISOLATION AND MOLECULAR IDENTIFICATION OF INDIGENOUS BACTERIAL ISOLATES ABLE TO DEGRADE ORGANOPHOSPHATES

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    The wide and indiscriminate use of pesticides for pest control in agriculture has inflicted serious harm and problems to humans as well as to the biodiversity. Microbial degradation of pesticides in contaminated soils has been considered advantageous to decontaminate areas that have been polluted by pesticides. Chlorpyrifos and diazinon were the most persistent residues in Egyptian soils. Four bacterial isolates were isolated from organophosphorus insecticides contaminated soils and genetically identified based on DNA sequence of 16s rDNA gene, Cronobacter muytjensii GH10, Achromobacter xylosoxidans GH9OP, Pseudomonas aeruginosa GH2NO8 and Pseudomonas putida GH4SNO/P were able to degrade 92.59%, 97.75%, 91.82%, and 90.78% of diazinon (600mg/l) as compared with 16.99% in control and 93.43%, 78.51%, 93.18% and 95.36% of chlorpyrifos (480mg/l) as compared with 4.28%, in control, respectively after 20 days of incubation
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