30 research outputs found

    Coupled Oxidation-Extraction Desulfurization : A Novel Evaluation for Diesel Fuel

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    This work was financially supported by the National Science Foundation of China (21176021, 21276020, 2187081257). We extend our appreciation to the Deanship of Scientific Research at King Saud University for funding the work, through Research Group Project No. RG-1436-026.Peer reviewedPostprin

    Robust Hāˆž control for a class of uncertain mechanical systems

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    In this article, the problem of H āˆž control is investigated for a class of mechanical systems with input delay and parameter uncertainties which appear in all the mass, damping and stiffness matrices. Two approaches, norm-bounded and linear fractional transformation (LFT) uncertainty formulations, are considered. By using a new Lyapunov-Krasovskii functional approach, combined with the advanced techniques for achieving delay dependence, improved robust Hāˆž state-feedback controller design methods are developed. The existence condition for admissible controllers is formulated in the form of linear matrix inequalities (LMIs), and the controller design is cast into a convex optimisation problem subject to LMI constraints. If the optimisation problem is solvable, a desired controller can be readily constructed. The result for the norm-bounded uncertainty case improves the existing ones in terms of design conservatism, and that for the LFT uncertainty case represents the first attempt in this direction. An illustrative example is provided to show the effectiveness and advantage of the proposed controller design methodologies.Xuebo Yang, Huijun Gao, Peng Shi and Guangren Dua

    Oxidative Desulfurization of Gasoline by Ionic Liquids Coupled with Extraction by Organic Solvents

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    In this work, desulfurization of real fluidized catalytic cracking (FCC) gasoline was investigated in dual steps; first in oxidative desulfurization (ODS) using imidazolium and pyrrolidonium based BrĆønsted acidic ionic liquids (ILs) as solvent and catalyst and hydrogen peroxide as oxidant. In second step, extractive desulfurization took place using organic solvents of furfural, furfural alcohol and ethylene glycol. Variety of factors such as temperature, time, mass ratio of oil/ILs and regeneration and recycling of ILs, multiple-step desulfurization of ILs and organic solvents and solvent/oil ratio were also investigated. The S-content was significantly decreased to ca. 18 ppm from initial S-content of 260 ppm with a total S-removal of ca. 95% in one-step ODS using pyrrolidonium based ILs coupled with five-step extraction desulfurization (EDS) using furfural alcohol as extractant. This work shows that oxidative desulfurization using ionic liquids coupled with extractive desulfurization using organic solvents is a potential method to produce clean gasoline

    In Vitro Comparison of the Efficacies of Natamycin and Silver Nitrate against Ocular Fungiā–æ

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    The in vitro activity of the silver nitrate was assessed in comparison with that of natamycin against 128 corneal Fusarium isolates and 90 corneal Aspergillus isolates. MIC90s of silver nitrate were 2 Ī¼g/ml for Fusarium spp. and 1 Ī¼g/ml for Aspergillus spp. MIC90s of natamycin were 8 Ī¼g/ml for Fusarium spp. and 32 Ī¼g/ml for Aspergillus spp. Silver nitrate exhibited potent antifungal activity against ocular fungi in vitro

    Schisandra Fruit Vinegar Lowers Lipid Profile in High-Fat Diet Rats

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    Hyperlipidemia and its associated obesity, hepatic steatosis, and NAFLD are worldwide problems. However, there is no ideal pharmacological treatment for these. Therefore, the complementary therapies that are both natural and safe have been focused. Healthy foods, such as fruit vinegar, may be one of the best choices. In this study, we made a special medicinal fruit vinegar, Schisandra fruit vinegar (SV), and examined its lipid-lowering effects and the underlying mechanisms in a high-fat diet rat model. The results showed that SV significantly reduced the body weight, liver weight, liver index, the serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), free fatty acid (FFA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and malondialdehyde (MDA), increased the content of high-density lipoprotein cholesterol (HDL-C) and the activity of superoxide dismutase (SOD), upregulated the expressions of peroxisome proliferative activated receptor (PPAR-Ī±), peroxisomal acyl-coenzyme A oxidase 1 (ACOX1), and carnitine palmitoyltransferase 1 (CPT1) proteins, increased the contents of key component of antioxidant defense NF-E2-related factor 2 (NRF2) and its downstream heme oxygenase-1 (HO-1) protein, and downregulated the expression of Kelch-like ECH-associated protein 1 (KEAP1). These results suggest that SV has weight loss and lipid-lowering effects in HFD rats, which may be related to its upregulation of the expressions of Ī²-oxidation -elated PPAR-Ī±, CPT1, and ACOX1 and the regulation of the expressions of antioxidant pathway-related KEAP1-NRF2-HO-1. Therefore, all these data provide an experimental basis for the development of SV as a functional beverage which is safe, effective, convenient, and inexpensive

    A clinical and neuropathological study of Chinese patients with diabetic peripheral neuropathy.

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    OBJECTIVE: To examine whether the neuropathological and metabolic changes of peripheral nerves are correlated to clinical features in diabetes mellitus type 2 patients with peripheral neuropathy. METHODS: 147 type 2 diabetic patients with signs/symptoms of diabetic peripheralneuropathy (DPN) aged 53.4 Ā± 12.3 years and 134 healthy volunteers aged 55.5 Ā± 11.7 years were investigated for fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), and red blood cell sorbitol (RBC sorbitol) in addition to nerve conduction velocity (NCV). Among the 147 diabetic patients, 10 patients underwent superficial peroneal nerve biopsy for light and electron microscopy. RESULTS: In the experimental group, the levels of HbA1c and RBC sorbitol showed significant increase compared with the controlled group, whereas motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) both showed decline and SNCV decreased at a greater extent. Morphologically, there were various degrees of nerve fiber loss, associated with axon degeneration and capillary luminal narrowing in 10 patients undergone nerve biopsy. CONCLUSION: The metabolic change of sorbitol, the consequently observed changes in NCV and histopathology of peripheral nerves are positively correlated with the duration of diabetes and overall level of blood glucose
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