7 research outputs found

    Activity of varying compositions of CoeNieP catalysts for the methanolysis of ammonia borane

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    Various compositions of CoeNieP catalysts supported on a palladium-activated Al2O3 (Pd eAl2O3) substrate were synthesized, characterized and investigated for catalytic methanolysis of ammonia-borane (AB, H3NBH3). The CoeNieP/PdeAl2O3 catalysts were synthesized by polymer-stabilized Pd nanoparticle-catalyzation and activation of the Al2O3 substrate support and the electroless deposition of cobalt-nickel (CoeNi) metal particles on the surface of the Al2O3 support for a plating time of 30 min. The CoeNieP/PdeAl2O3 catalysts are stable enough to be isolated as solid materials and characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM). At 40 ± 0.5 �C, the isolable, re-dispersible and reusable catalysts were found active in the methanolytic dehydrogenation of ammonia-borane retaining up to 65% of its initial activity after five cycles. Rates of hydrogen evolution were used to determine the kinetics of methanolysis reaction. The ranges of examined catalyst particle amounts, AB concentrations and temperatures were 15.75e63 mg, 50e200 mM, and 30e55 �C, respectively. Hydrogen desorption was identified as the rate controlling step in the methanolysis reaction and using the data, the kinetic rate constant (€kH2 ), the hydrogen desorption equilibrium constant (KH2 ), and the overall equilibrium constant (K1) parameters in a LangmuireHinshelwood rate expression were determined to be 1.4 mol/g-cat. s, 1.5918 L/ mol and 1.5986 L/mol, respectively. Activation parameters such as enthalpy of activation (DH), entropy of activation (DS), and activation energy (Ea) that were obtained by Eyring and Arrhenius equations are reported for the various catalyst ratio

    Classification and characterization of bio-oil obtained from catalytic and non-catalytic pyrolysis of desludging sewage sample

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    Sewage sludge is a very harmful waste when improperly discharged into the environment because of its inherent abundant pathogens, organic pollutants, and heavy metal constituents. The pyrolysis of sewage sludge is viewed not only to reduce pollutants associated with it but also one of the viable alternative sources for renewable energy or biofuel production. In this study, the effect of catalyst and temperature on the yield and composition of bio-oil obtained from the catalytic and non-catalytic pyrolysis of desludging sewage samples (DSS) was investigated. Modified pyrolysis reactor was used to pyrolyze the DSS at temperature ranges of 300–400, 400–500, 500–600 and 600–700 ℃ with and without the use of zeolite-Y catalyst. The ‘heterogeneous’ catalysis reaction yielded 20.9 wt% bio-oil, while the reaction without catalyst yielded 18.2 wt% bio-oil. Pyrolysis of the DSS favored char yield of between 55.4 and 76.6 wt%. The X-ray Fluorescence (XRF) analysis showed high silica (46 and 56.1 wt%), calcium (20.9 and 15.50 wt%), and low organic matter (12 and 12.87 wt%) contents present in the desludging feedstock before and after pyrolysis respectively. The gas chromatography–mass spectrometry (GCMS) analysis indicated the presence of nitrogen-containing compounds (between 20 and 50 wt%), mono-aromatics (18 and 28 wt%) and oxygenated compounds, in the form of carboxylic acids, aliphatics, ketones, ethers, esters and aldehydes in the bio-oils. Pyrolysis process development is, therefore, essential to clean the environment of pollutants from sewage sludge, by its conversion to more useful chemicals. In contrast, sewage sludge with high silica content may be tailored to the production of building materials

    An unusual case of autoimmune pancreatitis presenting as pancreatic mass and obstructive jaundice: a case report and review of the literature

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    <p>Abstract</p> <p>Background</p> <p>Autoimmune pancreatitis is a rare chronic inflammatory pancreatic disease that is increasingly being diagnosed worldwide. As a result of overlap in clinical and radiological features, it is often misdiagnosed as pancreatic cancer. We report the case of a patient with autoimmune pancreatitis that was initially misdiagnosed as pancreatic cancer.</p> <p>Case presentation</p> <p>A 31-year-old Caucasian man presented to our hospital with epigastric pain, jaundice and weight loss. His CA 19-9 level was elevated, and computed tomography and endoscopic ultrasound revealed a pancreatic head mass abutting the portal vein. Endoscopic retrograde cholangiopancreaticography showed narrowing of the biliary duct and poor visualization of the pancreatic duct. Fine-needle aspiration biopsy revealed atypical ductal epithelial cells, which raised clinical suspicion of adenocarcinoma. Because of the patient's unusual age for the onset of pancreatic cancer and the acuity of his symptoms, he was referred to a tertiary care center for further evaluation. His immunoglobulin G4 antibody level was 365 mg/dL, and repeat computed tomography showed features typical of autoimmune pancreatitis. The patient's symptoms resolved with corticosteroid therapy.</p> <p>Conclusion</p> <p>Autoimmune pancreatitis is a rare disease with an excellent response to corticosteroid therapy. Its unique histological appearance and response to corticosteroid therapy can reduce unnecessary surgical procedures. A thorough evaluation by a multidisciplinary team is important in rendering the diagnosis of autoimmune pancreatitis.</p

    Rate and predictors of blood pressure control in a federal qualified health center in Michigan: a huge concern?

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    Hypertension (HTN) is particularly burdensome in low‐income groups. Federal‐qualified health centers (FQHCs) provide care for low‐income and medically underserved populations. To assess the rates and predictors of blood pressure (BP) control in an FQHC in Michigan, a retrospective analysis of all patients with HTN, coronary artery disease, and/or diabetes mellitus (DM) seen between January 2006 and December 2008 was conducted. Of 212 patients identified, 154 had a history of HTN and 122 had DM. BP control was achieved in 38.2% of the entire cohort and in 31.1% of patients with DM. The mean age was lower in patients with controlled BP in both the total population (P=.05) and the DM subgroup (P=.02). A logistic regression model found only female sex (odds ratio, 2.27; P=.02) to be associated with BP control and a trend towards an association of age with uncontrolled BP (odds ratio, 0.97; P=.06). BP control in nondiabetics was 47.8% vs 31.1% in diabetic patients (P=.02). We found that patients who attended the FQHC had a lower rate of BP control compared with the national average. Our study revealed a male sex disparity and significantly lower rate of BP control among DM patients

    A Brief Overview from the Physiological and Detrimental Roles of Zinc Homeostasis via Zinc Transporters in the Heart

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