155 research outputs found

    Data on structural and composition-related merits of gC3N4 nanofibres doped and undoped with Au/Pd at the atomic level for efficient catalytic CO oxidation

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    Precise design of graphitic carbon nitride (gC3N4) nanostructures is of grand importance in different catalytic applications. This article emphasizes additional data on the fabrication of metal-free gC3N4 nanofibres (gC3N4NFs) and its associated structural and composition analysis compared with Au/Pd co-doped gC3N4 nanofibres (Au/Pd/gC3N4NFs). The data is including the typical fabrication process of metal-free gC3N4 nanofibers and its SEM, TEM, and element mapping analysis beside Raman, and FTIR spectra relative to Au/Pd/gC3N4NFs. We also investigated the catalytic CO oxidation durability testes on Au/Pd/gC3N4NFs compared to Pd/gC3N4NFs and Au/gC3N4NFs. The presented data are associated with the research article entitled “Rational synthesis of one-dimensional carbon nitride-based nanofibers atomically doped with Au/Pd for efficient carbon monoxide oxidation.” [1].This publication was supported by Qatar University Internal Grant No. IRCC-179 . The findings achieved herein are solely the responsibility of the authors.Scopu

    Pattern of systemic lupus erythematosus in Egyptian patients: the impact of disease activity on the quality of life

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    INTRODUCTION: Systemic lupus erythematosus (SLE) afflicts young people disproportionately, often at a crucial time in their lives when they are trying to establish relationships, start families and launch careers. As a result, persons with SLE may experience a wide range of physical and psychosocial problems that are not always fully captured by descriptions of the disease’s physiological consequences alone. METHODS: In order to characterize the spectrum of the effects of SLE with regards to disease activity and its impact on the quality of life (QoL), a case control study involving 59 SLE Egyptian patients (mean age 28.6 years , 94.9% females) and 20 healthy controls was undertaken. Disease activity was measured by SLE Disease Activity Index (SLEDAI), and quality of life was measured by Short Form 36 health questionnaire (SF-36). RESULTS: Mucocutaneous and hematological manifestations were present in most of the patients and arthralgia in half of them. All domains of SF-36 including general health, physical functions, physical limitations, energy/fatigue, emotional well-being, pain, social functions, and health changes were significantly lower in SLE patients compared to controls. Except for emotional limitations, all domains were correlated with disease activity and low in class IV-V lupus nephritis. CONCLUSION: Physicians should focus on QoL and how to improve it; health education regarding the negative impact of disease activity on the patients should be given attention. The results of QoL studies help physicians to understand and provide better support to SLE patients beside rapid meticulous control of disease activit

    Clinical Assessment Of Arthroscopic Temporomandibular Joint Discopexy Using Wire Fixation Technique

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    Introduction Anterior disc displacement is one of the most frequent temporomandibular joint (TMJ) disorders, which often results in clicking, joint pain, a limited range of motion and masticatory difficulties.Methodology Four subjects (with a total number of six joints) who had significant pain and dysfunction that did not respond to non-surgical therapy, went into arthroscopic disc repositioning using wire fixation for 3 weeks then it was removed, and the patient continued on occlusal splints.Results After six months postoperatively, there was a significant increase in the MIO (Maximum incisal opening) and an insignificant decrease in the pain perception in the VAS (visual analogue scale) Conclusion The study concluded that arthroscopic temporomandibular joint disc repositioning is an effective minimally invasive procedure for the treatment of some temporomandibular joint internal derangements refractory to conventional conservative therapy in regards to clinical outcomes

    Pattern of irritable bowel syndrome and its impact on quality of life in primary health care center attendees, Suez governorate, Egypt

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    Introduction: Irritable bowel syndrome (IBS) is one of the most common disorders diagnosed by gastroenterologists and a common cause of general practice visits. Although this disease is not life threatening, patients with IBS seem to be seriously affected in their everyday life. The study was designed to explore the pattern of IBS in clinical practice and the impact on the quality of life. Methods: This is a case control descriptive study. 117 individuals were included in this study. Rome II criteria were used for the diagnosis of IBS. Impact of IBS on patient's quality of life was determined by irritable bowel syndrome quality of life (IBS-QOL) questionnaire. Results: Prevalence of IBS among the study sample was 34.2%. 10% were IBS-Diarrhea, 37.5% were IBS-Constipation and 52.5% were alternators. There is statistical insignificant relationship between IBS (+) and age while it was a significant relation regarding gender (more common among women 80%). There is statistical significance relationship between IBS (+) on one hand and marital status and occupational status on the other hand. Patients with IBS had statistically significant lower scores for all IBS- QOL domains compared with the control group. Conclusion: IBS is a prevalent disorder that affects females more than males and it has significant impacts on work, lifestyle and social well-being.Key words: Irritable bowel syndrome, quality of life, Roma I

    Atmospheric Corrosion Behavior of Al 6xxx Alloys in Qatar State

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    Al 6000 series [Al-Mg-Si-Cu] are widely used in oil field for frames, tanks, pipelines and machinery applications. They showed a relatively high corrosion resistant, thermal and electrical conductivity and low cost. Establishing a materials map (Corrosion Atlas) for different region in Qatar. Al 6063 and Al 6082 are part of this map. Studying the forms of corrosion for the two Al alloys at different sites. Studying the corrosion rate, pit aspect ratio and pit density of the Al alloys after different times of exposure at different atmospheric condition. Many authors have been studied the corrosion behavior of aluminum alloys indoor significantly than the outdoor studies. However, the indoor corrosion studies seem to be markedly ignored numbers of air pollutants practically sulfur and chloride contaminations. In addition, weather exposure designs (outdoor tests) of aluminum and its alloys have been performed in different atmosphere all over the world by many countries. The aim of this article is to investigate the atmospheric corrosion behavior of Aluminum alloy Al-6063 after 6 months of exposure at seven different sites in Qatar which are representing different environments (Desert, industrial, coastal and marine) by visual observation with low power optical analysis for counting the pit depth and pit density for each site. In addition, electrochemical techniques were applied on the collected specimens to show the effect of the formed oxide layer on the corrosion behavior. SEM was used to study the susceptibility of studied alloys to intergrainular corrosion and the influence of sulfur and chloride compounds in intergrainular corrosion. The results were put in comparison with indoor test in 3.5% NaCl + 1%HCl mixture using SEM and Accelerated electrochemical techniques.qscienc

    Enhancing the corrosion resistance of reinforcing steel under aggressive operational conditions using behentrimonium chloride

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    Aggressive operational conditions e.g. saline media and acidic gases, e.g., CO2 can increase the corrosion rate of reinforcing steel. Accordingly, the necessity to protect the steel under the above conditions without affecting the mechanical properties of the concrete is growing. Herein, the inhibition efficiency of a new corrosion inhibitor, behentrimonium chloride (BTC, C25H54ClN), is explored in a simulated-concrete pore solution (SCP) with 3.5 wt.% NaCl at different pH using electrochemical impedance spectroscopy (EIS) and polarization methods. Using only a 50 ?mol L?1 of BTC, we are able to measure an inhibition efficiency of 91, 79, and 71% in SCP solution with 3.5% NaCl at pH of 12.5, 10 and 7, respectively without showing any effect on the mechanical properties on the cured mortars. Temkin isotherm is used to describe the physisorption of BTC inhibitor on the steel surface. Also, the adsorption and influence of the inhibitor on the metal surface are characterized using the scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. In conclusion, this new inhibitor shows high corrosion inhibition efficiencies under different aggressive conditions and can be used in concrete to reduce the corrosion rate of reinforcing steel without decreasing the mechanical properties of the concrete. - 2019, The Author(s).The publication of this article was funded by the Qatar National Library.Scopu

    Novel enzyme-free multifunctional bentonite/polypyrrole/silver nanocomposite sensor for hydrogen peroxide detection over a wide pH range

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    Precise designs of low-cost and efficient catalysts for the detection of hydrogen peroxide (H2O2) over wide ranges of pH are important in various environmental applications. Herein, a versatile and ecofriendly approach is presented for the rational design of ternary bentonite-silylpropyl-polypyrrole/silver nanoarchitectures (denoted as BP-PS-PPy/Ag) via the in-situ photo polymerization of pyrrole with salinized bentonite (BP-PS) in the presence of silver nitrate. The Pyrrolyl-functionalized silane (PS) is used as a coupling agent for tailoring the formation of highly exfoliated BP-PS-PPy sheet-like nanostructures ornamented with monodispersed Ag nanoparticles (NPs). Taking advantage of the combination between the unique physicochemical properties of BP-PS-PPy and the outstanding catalytic merits of Ag nanoparticles (NPs), the as-synthesized BP-PS-PPy/Ag shows a superior electrocatalytic reduction and high-detection activity towards H2O2 under different pH conditions (from 3 to 10). Intriguingly, the UV-light irradiation significantly enhances the electroreduction activity of H2O2 substantially, compared with the dark conditions, due to the high photoelectric response properties of Ag NPs. Moreover, BP-PS-PPy/Ag achived a quick current response with a detection limit at 1 μM within only 1 s. Our present approach is green, facile, scalable and renewabl
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