Studies on coconut shell powder and crysnanoclay incorporated acrylonitrile-butadiene rubber/ styrene butadiene rubber (NBR/SBR) green nanocomposites

The development of commercially viable “green products” based on natural resources for both matrices and reinforcements for a wide range of applications is on the rise. This effort includes new pathways to produce natural polymers with better mechanical properties and thermal stability using nanotechnology and use of naturally occurring fillers such as lignocellulosic and hemicellulose to make biodegradable rubber composites. The blends of acrylonitrile butadiene rubber (NBR) and styrene butadiene rubber (SBR) with coconut shell powder (CSP) have been prepared by using a compounding technique in presence of different amounts of crysnanoclay (CN). The effect of CN loading on tensile properties, thermal properties, swelling behavior, and water uptake behavior were studied. Significant improvement of Young's modulus and tensile strength was observed as a result of addition of nanoclay to the rubber matrix especially at 10 wt% loading. Presence of CSP resulted in ahigher in water sorption but after incorporation of CN the water sorption tended to decrease. Thermal characteristics were performed using thermogravimetric analysis (TGA). TGA thermograms indicated that incorporation of CSP filler decreases the thermal stability of nanocomposites. The dispersion of CSP and CN in rubber matrix was analyzed from scanning electron microscopy. POLYM. COMPOS., 38:727–735, 2017. © 2015 Society of Plastics Engineer

In silico docking analysis of piperine with cyclooxygenases

The structure of 1-[5-(1,3-benzodioxol- 5-yl)-1-oxo-2,4- pentadienyl]piperidine (Piperine), C17H19O3N, a versatile bioactive molecule has been redetermined at 100(2) K by X-ray crystallography to explore their potential utilization in inhibition of prostaglandin release. The crystal structure is stabilized by weak nonclassical intermolecular C-H…O hydrogen bonds and also intermolecular C-H…π interactions. The crystallographic coordinates of the compound were extrapolated to docking studies to elucidate the action of piperine against the enzymes, cyclooxygenases (COX-1 and COX-2) involved in biosynthesis of prostaglandin release. Using AutoDock suite, piperine was docked at the binding site of COX-1 and COX-2 enzyme and a strong affinity (-9.06kcal/mol, Ki =227.73nM and -8.77kcal/mol, Ki = 375.62nM, respectively) was formed by Hydrogen bonds and hydrophobic interactions. These results suggest that piperine can be a promising lead for the development of COX family inhibitors

Equilibrium, Thermodynamic, and Kinetic Studies

Publisher Copyright: © 2022 Razia Sulthana et al.The economic viability of adsorbing crystal violet (CV) using pepper seed spent (PSS) as a biosorbent in an aqueous solution has been studied. A parametrical investigation was conducted considering parameters like initial concentration of dye, time of contact, pH value, and temperature variation. The analysis of experimental data obtained was carried out by evaluating with the isotherms of Freundlich, Sips, Tempkin, Jovanovic, Brouers-Sotolongo, Toth, Vieth-Sladek, Radke-Prausnitz, Langmuir, and Redlich-Peterson. The adsorption kinetics were studied by implementing the Dumwald-Wagner, Weber-Morris, pseudo-first-order, pseudo-second-order, film diffusion, and Avrami models. The experimental value of adsorption capacity (Qm=129.4 mg g-1) was observed to be quite close to the Jovanovic isotherm adsorption capacity (Qm=82.24 mg g-1) at (R2), coefficient of correlation of 0.945. The data validation was found to conform to that of pseudo-second-order and Avrami kinetic models. The adsorption process was specified as a spontaneous and endothermic process owing to the thermodynamic parametrical values of ΔG0, ΔH0, and ΔS0. The value of ΔH0 is an indicator of the process's physical nature. The adsorption of CV to the PSS was authenticated from infrared spectroscopy and scanning electron microscopy images. The interactions of the CV-PSS system have been discussed, and the observations noted suggest PSS as a feasible adsorbent to extract CV from an aqueous solution.publishersversionpublishe

Haemoglobin and Hematinic Status Before and After Bariatric Surgery over 4 years of Follow-Up

From Springer Nature via Jisc Publications RouterHistory: received 2020-03-02, rev-recd 2020-08-17, accepted 2020-08-18, registration 2020-08-19, pub-electronic 2020-09-01, online 2020-09-01, pub-print 2021-02Publication status: PublishedFunder: University of ManchesterAbstract: Purpose: Bariatric surgery is associated with deficiencies of vitamins and minerals, and patients are routinely advised supplements postoperatively. We studied prevalence of vitamin B12, folate and iron deficiencies and anaemia before and after bariatric surgery over 4 years of follow-up. Materials and Methods: We performed a retrospective cohort analysis of 353 people with obesity, including 257 (72.8%) women, who underwent gastric bypass (252, 71.4%) or sleeve gastrectomy (101, 28.6%) at our National Health Service bariatric centre in Northwest England. Results: At baseline, mean (standard error) age was 46.0 (0.6) years, body mass index 53.1 (0.4) kg/m2, serum vitamin B12 400.2 (16.4) pg/L, folate 7.7 (0.2) μg/L, iron 12.0 (0.3) μmol/L, ferritin 118.3 (8.4) μg/L and haemoglobin 137.9 (0.8) g/L. Frequency of low vitamin B12 levels reduced from 7.5% preoperatively to 2.3% at 48 months (P < 0.038). Mean folate levels increased from baseline to 48 months by 5.3 μg/L (P < 0.001) but frequency of low folate levels increased from 4.7% preoperatively to 10.3% (P < 0.048). Ferritin levels increased from baseline to 48 months by 51.3 μg/L (P < 0.009). Frequency of low ferritin levels was greater in women (39.1%) than in men (8.9%) at baseline (P < 0.001) and throughout the study period. Haemoglobin was low in 4.6% of all patients at baseline with no significant change over the study period. Conclusion: There were notable rates of haematinic insufficiencies in bariatric surgical candidates preoperatively. Our study lends further support to regular supplementation with vitamin B12, folic acid, and iron in people undergoing bariatric surgery

The role of glucocorticoid receptor polymorphisms and glucocorticoid sensitivity in human obesity and the metabolic syndrome

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Development of a new inexpensive green thermoplastic composite and evaluation of its physico-mechanical and wear properties

In the present study an attempt has been made to use turmeric spent (TS) as reinforcing filler to fabricate polypropylene (PP) green composite for load bearing and tribological applications. PP/TS composites were fabricated using varying amounts of TS viz, 10, 20, 30 and 40 (w/w) by twin screw extrusion method. The fabricated PP green composites were evaluated for physico-mechanical and tribological properties. Experimentally obtained tensile values were compared with theoretically predicted values using different theoretical models. Tensile modulus of composites increased from 1041 to 1771MPa with the increase in filler addition from 0 to 40wt.. Flexural strength and flexural modulus of composites were improved after incorporation of TS into PP matrix. The water absorption characteristics of composites were determined. The effect of abrading distances viz., 150, 300, 450, and 600m and different loads of 23.54 and 33.54N at 200rpm on the abrasive wear behaviour were studied using dry sand/rubber wheel abrasive test rig. The TS filler lowered the abrasion resistance of PP/TS composites. The wear volume loss and specific wear rate as a function of abrading distance and load were determined. The surface morphology of tensile fractured green composites and their worn surface features were examined under scanning electron microscope

Investigation on physicomechanical and wear properties of new green thermoplastic composites

This study was aimed at fabrication of green composites of polypropylene (PP) matrix 5, 10, 15, and 20 wt% of saw palmetto spent (SPS) (a spent of nutraceuticals) as filler material. Two wt% organically modified montmorillonite clay (MMT) was used as a co‐filler in all formulations and composites were fabricated by melt blending. The fabricated PP/SPS/MMT composites were characterized for physicomechanical and tribological properties. Improvement in tensile modulus of the composites was noticed with increase in SPS content. The tensile strength of composites was decreased by 14% with increase in filler content from 5 to 20 wt%. Flexural strength of the composites increased from 31.3 to 37.8 MPa (21% improvement) and also flexural modulus improved from 956 to 1383 MPa (45% improvement) with increased SPS content. Composites were subjected to three‐body abrasion with different loads and abrading distances. Scanning electron microscope (SEM) study revealed that the predominant wear mechanisms of composite material sliding against continuous flowing sand were microploughing and filler detachment from the polymer matrix. POLYM. COMPOS., 37:2306–2312, 2016. © 2015 Society of Plastics Engineer

Development of green thermoplastic composites from Centella spent and study of its physicomechanical, tribological, and morphological characteristics

To enhance biodegradability of plastics and to utilize Centella spent (CTS) gainfully, green composites were prepared using high-density polyethylene (HDPE) and CTS. The green composites were fabricated by extrusion, followed by injection molding. HDPE/CTS composites were fabricated with 10, 20, and 30 wt% of CTS using maleic anhydride-grafted-polyethylene (MA-g-PE) as compatibilizer. The fabricated composites were tested for physicomechanical and tribological properties, which included water absorption, density, tensile properties, and three-body abrasive wear test. Tensile modulus of composites increased from 579 MPa to 950 MPa (64% improvement) with increase in filler addition from 0% to 30%. The experimentally obtained tensile property values including tensile strength, tensile modulus, and tensile elongation at break were compared with theoretical model values. The effects of 150, 300, 450, and 600 m abrading distances and 23.5 and 33.5 N normal loads at 200 r/min on the abrasive wear characteristics were studied using dry sand/rubber wheel abrasive test rig. Incorporation of CTS filler lowered the abrasion resistance of HDPE/CTS composites. The surface morphology of tensile-fractured specimens and worn surface features of composite specimens were examined by scanning electron microscopy