10,273 research outputs found

    Refined shell elements for the analysis of functionally graded structures

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    The present paper considers the static analysis of plates and shells made of Functionally Graded Material (FGM), subjected to mechanical loads. Refined models based on the Carrera's Unified Formulation (CUF) are employed to account for grading material variation in the thickness direction. The governing equations are derived from the Principle of Virtual Displacement (PVD) in order to apply the Finite Element Method (FEM). A nine-nodes shell element with exact cylindrical geometry is considered. The shell can degenerate in the plate element by imposing an infinite radius of curvature. The Mixed Interpolation of Tensorial Components (MITC) technique is extended to the CUF in order to contrast the membrane and shear locking phenomenon. Different thickness ratios and orders of expansion for the displacement field are analyzed. The FEM results are compared with both benchmark solutions from literature and the results obtained using the Navier method that provides the analytical solution for simply-supported structures subjected to sinusoidal pressure loads. The shell element based on refined theories of the CUF turns out to be very efficient and its use is mandatory with respect to the classical models in the study of FGM structures

    Pengaruh Kepuasan Kerja Terhadap Kinerja Karyawan Bagian Produksi Pada Pabrik PT. Sunan Rubber Palembang

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    The purpose of this research was to determine the effect of job satisfaction on production department employee performance in the factory of PT. Sunan Rubber Palembang. In this study, the population is taken employees in the factory of PT. Sunan Rubber Palembang. Samples taken are all production department employees, amounting to 130 employees. Analytical techniques used to process the data that are validity testing, reliability testing, classical assumption test, and simple linear regression analyzes that are done by using software special package for social sciences (SPSS) version 17.00. The conclusion of that job satisfaction significantly influence employee performance. Coefficients of the table in the column sig. generated significant value less than 0,05. Futhermore, based on the table, R Square value of 0,500, it can be concluded that the percentage of variables influence job satisfaction on performance of the production department employee variables in thr factory of PT. Sunan Rubber Palembang amounted to 50,0% and the remaining 50.0% were caused by other variables not tested in this study

    Degradation of lansoprazole and omeprazole in the aquatic environment

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    Lansoprazole and omeprazole degrade in water leading to sulfides, benzimidazolones and a red complex material. Degradation is accelerated in acid medium and by solar simulator irradiation. Benzimidazoles, dianilines and pyridines have also been identified

    Another Theory of Prostitution

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    This paper presents a model of prostitution as an economic activity characterised by stigma, whose supply is based on the availability of other earning opportunities. On the basis of available empirical evidence and findings from other studies, we put forward a rigorous economic analysis of the industry and its different markets making no restrictive assumptions regarding the gender, pay and nature of forgone earning opportunities of the prostitute, and applying the same behavioural hypotheses to prostitutes and clients.

    Unusual products of the aqueous chlorination of atenolol

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    The reaction of the drug atenolol with hypochlorite under conditions that simulate wastewater disinfection was investigated. The pharmaceutical reacted in 1 h yielding three products that were separated by chromatographic techniques and characterized by spectroscopic features. Two unusual products 2-(4-(3-(chloro(2-chloropropan- 2-yl)amino)-2-hydroxypropoxy) phenyl) acetamide and 2-(4- (3-formamido- 2-hydroxypropoxy) phenyl) acetamide were obtained along with 2-(4-hydroxyphenyl) acetamide. When the reaction was stopped at shorter times only 2-(4-(3-amino-2-hydroxypropoxy) phenyl) acetamide and the dichlorinated product were detected. Tests performed on the seeds of Lactuca sativa show that chlorinated products have phytotoxic activity

    Oncological, Vascular, and Spinal Uses of Contrast-Enhanced Ultrasound in Neurosurgery

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    Contrast-enhanced ultrasound (CEUS) is a real-time, feasible technique. Both intraoperatively and bedside, it satisfies the need for serial assessment and easy performability. Initially employed in neuro-oncology, it has recently overcome this first application. The chapter aims to give a comprehensive view of its use in oncological, vascular, and spinal neurosurgery. CEUS versatility across the aforementioned areas is analyzed, underlining its complementarity to other well-settled imaging techniques. Its major oncological (both cerebral and spinal) and vascular (including aneurysms, AVMs, dAVFs, carotid plaques, and stroke) application and state of the art are discussed. The chapter is focused on reporting CEUS advantages and disadvantages, giving an insight to future perspectives and applications

    Indole-3-butyric acid induces ectopic formation of metaxylem in the hypocotyl of Arabidopsis thaliana without conversion into indole-3-acetic acid and with a positive interaction with ethylene

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    The role of the auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) and of the auxin-interacting phytohormone ethylene, on the ectopic formation of primary xylem (xylogenesis in planta) is still little known. In particular, auxin/ethylene-target tissue(s), modality of the xylary process (trans-differentiation vs. de novo formation), and the kind of ectopic elements formed (metaxylem vs. protoxylem) are currently unknown. It is also unclear whether IBA may act on the process independently of conversion into IAA. To investigate these topics, histological analyses were carried out in the hypocotyls of Arabidopsis wild type seedlings and ech2ibr10 and ein3eil1 mutants, which are blocked in IBA-to-IAA conversion and ethylene signalling, respectively. The seedlings were grown under darkness with either IAA or IBA, combined or not with the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. Adventitious root formation was also investigated because this process may compete with xylogenesis. Our results show that ectopic formation of protoxylem and metaxylem occurred as an indirect process starting from the pericycle periclinal derivatives of the hypocotyl basal part. IAA favoured protoxylem formation, whereas IBA induced ectopic metaxylem with ethylene cooperation through the EIN3EIL1 network. Ectopic metaxylem differentiation occurred independently of IBA-to-IAA conversion as mediated by ECH2 and IBR10, and in the place of IBA-induced adventitious root formation
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