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11.
Ben Ammar Nour Elhouda Essid Rym Saied Taieb en Murat Elkahoui Salem Hamzaoui Ahmed Hichem 《Polymer Bulletin》2020,77(3):1343-1357
Polymer Bulletin - The aim of this study was to elaborate a suitable hydrogel to be used as drug carrier for antileishmanial treatment. Therefore, a PVP hydrogel was synthesized using gamma... 相似文献
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Abstract—This article proposes a new robust adaptive hybrid controller for three-phase pulse-width modulated rectifiers to improve control performance. This hybridization is implemented by combining the second-order sliding mode with the adaptive gain super-twisting control law in the DC bus voltage control loop and state feedback adaptive control in the d-q-axis current control loops. The control objectives are fourfold: (1) driving the DC bus voltage to a reference signal without using a priori knowledge of the plant parameters, (2) forcing the d-q-axis current errors to zero, (3) assuring a satisfactory power factor correction in relation to the AC source, and (4) eliminating the chattering effect. In the closed-loop control system, three-phase source currents and the DC bus voltage are supposed to be available for feedback. As a result, no a priori knowledge of the plant parameters is necessary in the design of the proposed controller. In addition, the proposed controller does not have the disadvantages of singularity, over-parameterization, and chattering phenomenon. Results of experimental studies prove that the proposed control system guarantees the tracking of reference signals with high performance despite all the parameter and external disturbance uncertainties. 相似文献
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Apaydın Ömer Faruk Yılmaz Murat 《Bulletin of Engineering Geology and the Environment》2021,80(6):4197-4205
Bulletin of Engineering Geology and the Environment - The most important methods that are used to estimate ballast fouling are the Los Angeles abrasion and MgSO4 tests. The effects of chemical and... 相似文献
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There has been a great interest in research towards elastomers and their composites with an attempt to obtain the desired biological and mechanical response to scaffold materials in bone tissue engineering. Composites made of ceramic-thermoplastic mixtures have been shown success to deliver the inorganic component while fail to provide replacement of an elastic protein, that is, collagen, of the target bone tissue. Thus, in order to match up with the inherent elasticity of the native tissue, it is proposed an alternative to well-known thermoplastic-containing matrices by using a poly(glycerol-sebacate) (PGS)–beta-tricalcium phosphate elastomeric composite to offer flexibility and mechanical integrity. This study reports for the first time a successful extrusion of PGS containing biodegradable composites with shape-memory feature. The resulting structures are physically and chemically characterized. In vitro cell culture performance of the obtained materials is investigated by using an MC3T3-E1 mouse preosteoblast cell line. The materials obtained in this study can be shaped into the desired size and various forms via temperature stimuli. Resulting materials have been proposed for craniofacial tissue engineering as a bone filler in which surgeons need to shape biomaterials during the surgical procedure due to the complex geometry of the bones. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48689. 相似文献
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Ömer Kesmez Esin Akarsu H. Erdem Çamurlu Emre Yavuz Murat Akarsu Ertuğrul Arpaç 《Ceramics International》2018,44(3):3183-3188
Single layer and multilayer films consisting of SnO2, Ta2O5, SiO2, TiO2, indium tin oxide (ITO) and antimony tin oxide (ATO) have been prepared by sol-gel dip coating technique. All of the multilayer films contained a SiO2 top layer, which was composed of SiO2 nanoparticles. The other films had polymeric character. Obtained films were characterized by ellipsometry, XRD, AFM and SEM. Light transmittance values of the films were compared. Films other than SiO2 and Ta2O5 were found to have crystalline structure. Thickness values of the films were in the range of 30–115 nm and roughness values were in 1.2–23 nm range. Single layer porous silica provided 95% light transmittance, whereas ITO-TiO2-SiO2 multilayer film provided a light transmittance of 97.2%. 相似文献
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This study was carried out on very steep and difficult terrain. Whole trees were logged uphill to the forest road by a Koller K300 cable crane. Investigations were carried out by time studies for which the repetition time measurement method was selected. Through time studies, the productivity and cost of the Koller cable system were evaluated. 相似文献
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Mustafa Yıldırım Murat Tonaroğlu Murat E. Selçuk Cem Akgüner 《Bulletin of Engineering Geology and the Environment》2013,72(3-4):413-420
For over 50 years, the Upper Oligocene–Upper Miocene sedimentary sequence in Istanbul has been considered to be formed of two distinct sequences separated by an unconformity. However, recent field observations and an analysis of numerous borehole data indicate the Gürp?nar, Çukurçe?me and Güngören Formations are in fact a single sequence of alternating clay–sand/sandstone beds/lenses, here named the Avc?lar Formation. The Bak?rköy Formation, which is typically composed of carbonate rocks, conformably overlies the Avc?lar Formation. The paper provides the geotechnical parameters of the units within the Avc?lar Formation which it is hoped will facilitate selecting suitable geotechnical and engineering geological parameters to represent the deposits and minimize errors in the interpretation/evaluation of in-situ conditions. 相似文献
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Carolin Braun Eduard Spuling Niklas B. Heine Murat Cakici Martin Nieger Stefan Brse 《Advanced Synthesis \u0026amp; Catalysis》2016,358(10):1664-1670
Pyridyl‐substituted [2.2]paracyclophanes build a multifunctional structural motif that is useful in material chemistry, catalysis and for luminescent structures. Nonetheless, there is still a lack of general methods for the synthesis of these structures tolerating easily accessible bromides as well as different isomeric pyridyl groups. Hence the coupling of functionalized [2.2]paracyclophanes with various substituted and functionalized pyridyl derivatives was achieved using Stille, Suzuki and Kumada coupling conditions. Hereby the Stille coupling of a [2.2]paracyclophane is presented as a versatile reaction for the formation of heteromeric [2.2]paracyclophane‐containing biaryl structures.