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In this study, an application algorithm has been introduced to explore structural optimisation for gear pump housing. In the study, experimental and theoretical (analytical and numerical) methods are utilised. A commercial external spur gear pump which has 17.1 Lmin − 1 volumetric flow rate with maximum pressure capacity of 250 bar has been considered for an application case study. In the experimental section of the study, four pressure sensors (emitters) were placed with angle intervals of 45°, 90°, 135°, and 180° on the pump's housing to measure operating pressure values at specific pressure regions of the housing from inlet to outlet. According to experimental results of the pressure measurements, a response surface analysis (RSA) was carried out and then an estimation model (empirical equation), which could be used to calculate pressure values at any specific region of the housing, was obtained. According to the RSA results gained, it appears that the estimation model has 99.9 % R value which can be used for adequately predicting accurate pressures at any region of the housing. Subsequently, this estimation model has been adapted for commercial finite elementmethod (FEM)-based engineering software and from which stress distributions on the housing were simulated three dimensionally. FEM-based simulation outputs showed that there were no failure signatures on the pump housing. As the main conclusion of the study, it is seen that an estimation model gives an adequate approach to predict pressure values at any specific pressure region of the pump housing and, especially, stress distribution results has highlighted that a structural optimisation study may be suitable for the pump housing. [ABSTRACT FROM AUTHOR]

In this study, a novel failure diagnostic system for timing belts was developed in order to prevent a catastrophic belt failure. These failures may occur before running out the nominal belt life and lead to an extensive engine damage, thereby resulting costly repairs. Timing belt failures are generally resulted from three reasons, that is, lack of a tooth, fiber separation on belt sides, and teeth splitting. Three optical sensors with laser beam whose diameter is 0.6 mm was located on suitable positions and it is used to produce error signal resulted from disturbance of laser beam flows due to failure. The error signal is processed by the processor, which is independent from the electronic control unit (ECU) to alert the driver or ECU, directly. Experimental apparatus which consists of two camshaft pulleys and an idler pulley with belt tensioner has been set up to simulate real engine conditions. Experimental results show that the optical monitoring technique is reliable to determine timing belt failure types simultaneously in the range of 500-7000 rpm engine speed and it is also easier, low cost and more applicable than other methods such as vibration monitoring. [ABSTRACT FROM AUTHOR]

In this study, a novel 'crash pendulum' test system which enables the observation of energy absorption capabilities of the materials/structures was developed. The system works with two simple pendulum principles and allows free mass collision axially. On the system, each mass block fixed to pendulum arm has an energy capacity of 4 kJ and moves at a velocity of 8 m/s. The data for the velocity of the mass block versus time were derived from the data for the angular displacement versus time. Kinetic energy was calculated by processing the velocity-time data with momentum equations. Restitution coefficient ( e) of materials/structures on the contact region and mean impulsive force can also be calculated. In this study, steel and foam materials, whose restitution coefficient had already been known, were tested to validate the system. Finally, characteristics of a cylindrical aluminum tube were measured and then compared with the values which are available in the literature. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine new, different and low-cost substrates that can be used for enzyme production from the white rot fungus Trametes versicolor (ATCC 11235) by taking advantage of the broad substrate specificity of pyranose 2-oxidase. In this report, we investigated the production of pyranose 2-oxidase from T. versicolor (ATCC 11235) using ten different agricultural residues such as clover straw, almond shells, hazelnut cobs, grass and others. Pyranose 2-oxidase activity was determined as 2.332 U/g at the 9th day in a submerged culture containing clover straw and tap water shaken at 150 rpm and 26°C, and the optimum clover straw concentration was determined to be 12 g/l. The effects of different glucose, nitrogen and phosphate sources on the production of pyranose 2-oxidase were studied in the clover straw medium. Analyses of biomass, protein, reduced sugar and nitrogen concentrations were also monitored in a clover straw medium that did not contain carbon or nitrogen and phosphate sources under the parameters determined. The produced pyranose 2-oxidase was used for improving the properties of cotton fabrics. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the composition of both main and extractive components of Turkish black pine cones. It explores the carbohydrate composition, the resin acid composition as well as the fungi-toxic activities of cone extractives. It also analyzes the solubilities and lignin content of the cones. Moreover, the chemical constituents of the cones from species Pinus annandii and Pinus sylvestris are studied.

The main constituents and cyclohexane extractives of wood obtained from planted and native oriental spruce, P. orientalis, were comparatively investigated. The plantation stand in Belgrad Forest near the city Istanbul is about 1000 km west to the original provenance in northeast Turkey with somewhat different environmental factors. The distribution of the main components and the total extractive contents in the woods were affected insignificantly. Only few differences were notable in the amount of sugar monomers of the main polyoses, mannan and xylan, when the native and planted woods were subject to total hydrolyses. The yield of lipophilic extractives in native and planted woods was almost the same. The composition of lipophilic extractives of the woods, determined after proper derivatization by GC-MS, were also not different qualitatively, but some constituents exhibited quantitative changes. Although the planted wood contained significantly more resin acids, sterols, and alcohols, the natural samples had more unsaturated fatty acids. [ABSTRACT FROM AUTHOR]

Objective. The aim of this study was to examine the effect of carbamazepine on the pharmacokinetics of orally administered simvastatin in healthy volunteers. Methods. In a randomised, two-phase crossover study and a wash out of 2 weeks, 12 healthy volunteers took carbamazepine for 14 days (600 mg daily except 200 mg daily for the first 2 days) or no drug. On day 15, each subject ingested 80 mg simvastatin. Serum concentrations of simvastatin and its active metabolite simvastatin acid were measured up to 24 h. Results. Carbamazepine decreased the mean total area under the serum concentration–time curve of simvastatin and simvastatin acid by 75% (P<0.001) and 82% (P<0.001), respectively. The mean peak concentrations of both simvastatin and simvastatin acid were reduced by 68% (P<0.01), and half-life of simvastatin acid was shortened from 5.9±0.3 h to 3.7±0.5 h (P<0.01) by carbamazepine. Conclusion. Carbamazepine greatly reduces the serum concentrations of simvastatin and simvastatin acid, probably by inducing their metabolism. Concomitant administration of carbamazepine and simvastatin should be avoided or the dose of simvastatin should be considerably increased. [ABSTRACT FROM AUTHOR]

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors specifically inhibit HMG-CoA reductase in the liver, thereby inhibiting the biosynthesis of cholesterol. These drugs significantly reduce plasma cholesterol level and long term treatment reduces morbidity and mortality associated with coronary heart disease. The tolerability of these drugs during long term administration is an important issue. Adverse reactions involving skeletal muscle are not uncommon, and sometimes serious adverse reactions involving skeletal muscle such as myopathy and rhabdomyolysis may occur, requiring discontinuation of the drug. Occasionally, arthralgia, alone or in association with myalgia, has been reported. In this article we review scientific data provided via Medline, adverse drug reaction case reports from the Swedish Drug Information System (SWEDIS) and the World Health Organization’s International Drug Information System (INTDIS) database, focusing on HMG-CoA reductase inhibitor-related musculoskeletal system events. Cytochrome P450 (CYP) 3A4 is the main isoenzyme involved in the metabolic transformation of HMG-CoA reductase inhibitors. Individuals with both low hepatic and low gastrointestinal tract levels of CYP3A4 expression may be at in increased risk of myotoxicity due to potentially higher HMG-CoA reductase inhibitor plasma concentrations. The reported incidence of myotoxic reactions in patients treated with this drug class varies from 1 to 7% and varies between different agents. The risk of these serious adverse reactions is dose-dependent and may increase when HMG-CoA reductase inhibitors are prescribed concomitantly with drugs that inhibit their metabolism, such as itraconazole, cyclosporin, erythromycin and nefazodone. Electrolyte disturbances, infections, major trauma, hypoxia as well as drugs of abuse may increase the risk of myotoxicity. It is important that the potentially serious adverse reactions are recognised and correctly diagnosed so that the HMG-CoA reductase inhibitor may at once be withdrawn to prevent further muscular damage. [ABSTRACT FROM AUTHOR]

In this study, an application algorithm has been introduced to explore structural optimisation for gear pump housing. In the study, experimental and theoretical (analytical and numerical) methods are utilised. A commercial external spur gear pump which has 17.1 L min−1 volumetric flow rate with maximum pressure capacity of 250 bar has been considered for an application case study. In the experimental section of the study, four pressure sensors (emitters) were placed with angle intervals of 45°, 90°, 135°, and 180° on the pump's housing to measure operating pressure values at specific pressure regions of the housing from inlet to outlet. According to experimental results of the pressure measurements, a response surface analysis (RSA) was carried out and then an estimation model (empirical equation), which could be used to calculate pressure values at any specific region of the housing, was obtained. According to the RSA results gained, it appears that the estimation model has 99.9% R2 value which can be used for adequately predicting accurate pressures at any region of the housing. Subsequently, this estimation model has been adapted for commercial finite element method (FEM)‐based engineering software and from which stress distributions on the housing were simulated three dimensionally. FEM‐based simulation outputs showed that there were no failure signatures on the pump housing. As the main conclusion of the study, it is seen that an estimation model gives an adequate approach to predict pressure values at any specific pressure region of the pump housing and, especially, stress distribution results has highlighted that a structural optimisation study may be suitable for the pump housing. [ABSTRACT FROM AUTHOR]