903 research outputs found
In-situ TiB2 and Fe2Ti intermetallic assisted hard coatings by Fe-Ti-B based hardfacing electrodes
No full textThe aim of this study was to form Fe2Ti and TiB2 phases on the steel surface in-situ using ferroalloy starting materials and to investigate the changes in the surface properties such as microstructural, hardness, wear and corrosion behavior. To this end, Fe(18-X)TiXB2 (x = 3-5) based hardfacing electrodes were produced and coated on AISI 1010 steel substrate using electric arc welding method. The development of the substrate coating interface, solidification behavior and microstructural conditions of the samples were examined using a variety of characterization methods. In the coating microstructures, intermetallic phases such as TiB2 and Fe2Ti, alpha-Fe + Fe2Ti eutectic structure and trace amounts of non-equilibrium phases were detected. It has been understood that these phases formed in the microstructure have important effects on the hardness, wear and corrosion resistance of the coating. In the hardness test performed by nanoindentation method, very high hardnesses such as 3254 (+/- 26) HV in TiB2 phase and 1130.1 (+/- 13) HV in Fe2Ti phase were measured. As a result of the ball on disc reciprocal wear test performed against Al2O3 ball at different loads, it has been observed that titanium has an effect on the friction coefficient, and the wear resistance increases with the increasing amount of titanium in the electrode cover composition. In addition, according to the potentiodynamic polarization test results carried out in 3.5% NaCl solution, it has been determined that the corrosion potential increased with increasing titanium in the electrode cover composition, there was no linear change detected in the current density. (C) 2021 Elsevier B.V. All rights reserved.Authors are grateful to the financial support provided by TUBITAK (Turkey Scientific and Technological Research) with Project no. 219M192.TUBITAK (Turkey Scientific and Technological Research) [219M192
Wind quality designation concept and application
No full textGenerally, wind energy production is based on the average wind speed without any classification. This article proposes a classification system on the basis of wind speed durations greater than a given threshold value. For this purpose, the wind quality designation (WQD) concept is defined based on the wind potential duration, amount, and intensity on a threshold level. Its classifications are depicted on five risk percentage classes as excellent, very good, good, fair, and weak. Apart from the classification, the change of WQD with wind speed threshold provides qualitative and quantitative wind speed energy production assessment. The specific objective of the article is to present theoretical WQD explanations on the basis of the most frequently employed two-parameter Weibull probability distribution function (PDF). The application is provided for Adiyaman City, Kahta meteorology station wind speed records from the Southeastern province of Turkey. It is noticed that there is no Weak category at this station and the most effective quality class is Excellent from 14 m/s to almost 27 m/s wind speeds. The average wind speed corresponds to about 62% WQD. Finally, the wind speed potential durations PDF abides by the logarithmic-normal PDF, whereas amount and intensity accord with the Weibull PDFs
Detailed analysis on thermal, microstructural, mechanical, and morphological features of side chain liquid crystalline polymer/isotactic polypropylene graft copolymers: Effect of grafted and ungrafted polymer units
No full textSOYKAN, UGUR/0000-0002-9244-026X; OZTURK SEN, Behiye/0000-0001-6936-4388The main scope of this comprehensive study is to investigate the effects of poly(p-benzophenoneoxycarbonylphenyl acrylate), poly(BPOCPA), which presenting as only graft units or both graft and ungrafted units in the matrix, on the fundamental features of isotactic polypropylene (IPP). The graft copolymerization of BPOCPA onto IPP was performed with the aid of bulk melt polymerization at varying monomer content levels ranging from 5% to 40%. The thermal behavior, crystal quality, mechanical performance, and surface morphology of the samples were investigated by means of differential scanning calorimeter, X-ray diffractometer (XRD), universal mechanical test, and scanning electron microscope (SEM) techniques. Thermal analyses depicted that there existed the noteworthy enhancements in both crystalline melting temperatures and percent crystallinities of matrix polymers. Furthermore, according to XRD results, a and b parameters increased significantly at low percentages of the graft units, while the parameter c decreased in all products in consistence with the content. As for the mechanical characterization, the grafting led to remarkable improvements in modulus, tensile and impact strength of the products. SEM micrographs indicated that the samples were completely homogeneous without any phase separation and the products exhibited brittle nature with some ductility.Abant Izzet Baysal UniversitesiAbant Izzet Baysal University [BAP-2010.03.03.372]; Bolu Abant Izzet Baysal Universitesi [BAP-2010.03.03.372]Abant Izzet Baysal Universitesi, Grant/Award Number: BAP-2010.03.03.372; Bolu Abant Izzet Baysal Universitesi, Grant/Award Number: BAP-2010.03.03.37
Role of free volume in mechanical behaviors of side chain lcp grafted products of high density polyethylene
No full textThe monomer, p-benzophenoneoxycarbonylphenyl methacrylate (BPOCPMA) the polymer of which exhibit mesomorphic behavior as side chain LCP has been graft copolymerized onto high density polyethylene (HDPE) in order to improve its properties. The PALS analysis of the products displayed that the graft copolymerization, while led to relatively small increase in the free volume size at low percentages of poly(BPOCPMA), resulted in decreases in the size and fraction of the free volume with the increase of poly(BPOCPMA) content. The graft copolymerization gave rise to remarkable improvements in the mechanical properties, especially in tensile strength and modulus, and the improvements were accompanied by the decreases in the free volume fraction. SEM analysis of the fracture surfaces of the mechanical test samples displayed a gradual transition from ductile fracture at low graft contents to brittle nature dominated at high percentages of poly(BPOCPMA). The XRD analysis showed significant expansions in the lateral dimensions (a and b parameters) of the orthorhombic unit cell in the crystalline domains of HDPE matrix, in consistence with poly(BPOCPMA) content. The grafting also gave rise to noteworthy increases in the crystalline melting temperature of the HDPE
Five Indications for Hand Hygiene Compliance among Healthcare Providers in a University Hospital
No full textŞen, Sevim/0000-0003-3301-4153; Ugur, Esra/0000-0002-2119-6175Objective: Nowadays, one of the main reasons for the increase in healthcare costs is healthcare associated infections. It is a known fact that healthcare-associated infections are mostly transmitted by the hands of healthcare professionals. Hand hygiene compliance decreases hospital infection rates. In this study five indications for hand hygiene compliance among healthcare providers in a university hospital were investigated. Methods: Hand hygiene practices of the health professionals who work in inpatient clinics, outpatient clinics and emergency rooms were observed by clinical education nurses in a university hospital from December 2009 to January 2010. 112 Hand Hygiene Forms were filled out. Results: Total observation time was 17 805 minutes. The percentage of the filled out observation forms were 53% for nurses, 27% for medical doctors, 13% for unlicensed assistive personnel, and 7% for other healthcare professionals. Compliance with hand hygiene throughout the hospital was 75%. Hand hygiene was mostly applied after contact with the patient and his/her environment, and most common hand hygiene method was hand washing. Conclusions: Ensuring hand hygiene compliance of healthcare professionals is the first step in infection control programs to prevent nosocomial infections. As the study findings also point out, continuous education including hand hygiene indications and methods for all hospital staff, and evaluation of the success of the program is recommended
A detailed survey for determination of the grafted semifluorinated acrylic compound effect on thermal, microstructural, free volume, mechanical and morphological features of HDPE
No full textThis study mainly aims to investigate the role of grafted semifluorinated acrylic compound in the crucial characteristic properties of high density polyethylene (HDPE). Graft copolymerization of the semifluorinated acrylic compound, 3,3,4,4,5,5,6,6,7,7,8,8,8-dodecafluoro-5-methyloctyl-4-(acryloyloxy) benzoate (ABCF13) onto HDPE within the different content levels of ABCF13 (5, 10, 15, 20, 30 and 40 %) was performed by bulk-melt polymerization method. The changes in the thermal, microstructural and free volume characteristics of graft coproducts with extent of grafting were investigated in detail by means of DSC, powder X-ray diffraction and PALS techniques, respectively. The experimental findings showed that the melting temperature of crystalline domains and crystallinity ofHDPE reached the maxima at the 15 % and 40 % ABCF13 contents, respectively. The grafting of ABCF13 onto HDPE also gave rise to significant expansion and contraction in lateral dimensions of orthorhombic unit cell parameters in the crystalline domains of HDPE. Moreover, PALS analyses depicted that the size of the free volumes increased almost linearly with the grafting percentage. As for mechanical behaviours of the graft products, remarkable improvements were achieved in especially tensile strength (from 18.75 MPa to 43.75 MPa) and impact strength (from 19.30 Mpa to 38.72 MPa). The morphological properties of the fractured surfaces obtained from tensile and impact tests of products were also examined by SEM analysis. The samples possessed completely homogeneous structure without any phase separation. A gradual transition from ductile behaviour to brittle nature was observed as the grafting level increased in the products
LaFontaine Seçme Masallar [Cover: LaFontaine'den Massallar]
No full textAbout this Turkish book I will not be able to write much. Its dust jacket cover features a composite picture of animals involved in La Fontaine's fables. Inside, there is a life of La Fontaine, followed by fables without illustration on 7-124. At the end, before advertisements for the publisher's series of thirty classics and of one hundred fairytale books, there is an alphabetical index. My purchase of this book from Ugur has led us to several transactions, as he keeps finding me more Turkish fable books.This is a hardbound book (hard cover)This book has a dust jacket (book cover)Language note: TurkishOriginal language: freErenler Matbaas
Effects of Sperm from Different Bulls on Developmental Competence, Blastosist Quality and Cell Number of Bovine Embryos In Vitro
No full textWOS: 000354410400007The aim of this study was to investigate the effects of sperm from different bulls on the developmental competence, blastosist quality and cell number of bovine embryos in vitro. In vitro matured bovine oocytes were fertilized with frozen-thawed sperm from five different bulls of Austrian Simmental Fleckvieh and then cultured in Synthetic Oviduct Fluid (SOF) medium at 38.5 degrees C, 5% CO2, 5% O-2 and 90% N-2 atmosphere with high humidity for 8 days. In the present study, there was no significant effect of bull variations on cleavage, morula, morula/cleavage, blastocyst and blastocyst/cleavage rates of embryos. Additionally, ICM cell numbers and ICM/total cells ratio of blastocysts obtained from in vitro fertilized oocytes with five bull's sperm were similar. However trophectoderm and total cell numbers of blastocysts obtained from in vitro fertilized oocytes with bull 5 sperm were lower than other bulls (P<0.05). In the present study, blastocysts quality was affected by bull variations and the percentage of excellent or good quality blastosist (Grade I) were lower (P<0.05) in embryos from fertilized oocytes with bull 5 sperm than those of other bulls, but the percentage of low quality blastosist (Grade III) were higher (P<0.05). There was a positive correlation between quality and total cell numbers of blastocysts in experimental groups. Result of present study showed that developmental competence of embryos in vitro were not affected by bulls variations, but may be influence blastocyst quality and cell numbers of blastocyst
Learning Hierarchical Task Networks from Traces and Semantically Annotated Tasks
No full textiii iv Acknowledgements I wish to thank the following persons, without whom this work would not have been possible: • My wife Rachel, who lovingly and expertly brandished carrots and sticks to ensure progress over the last year. • My parents Jeffrey and Cynthia who supported me through both my childhood and eleven years of post-secondary education. • My advisor, Héctor Muñoz-Avila, who has been a source of funding, knowl-edge, inspiration, and friendship for the past five years. • My frequent co-author Ugur Kuter, whose ideas strongly influenced Chapters 4 and 5 in particular. • My other committee members, Brian Davison, Jeff Heflin, and Henry Baird, each of whom have been available and helpful throughout my time at Lehigh
A Comparison of the Inhibitory Effects of Anti-Cancer Drugs on Thioredoxin Reductase and Glutathione S-Transferase in Rat Liver
No full textWOS: 000458732100013PubMed: 30198440Background: While Thioredoxin Reductase (TrxR) plays an important role in regulation of the intracellular redox balance and various signalling pathways, Glutathione S-Transferase (GSTs) enzymes belong to the detoxification family that catalyse the conjugation of glutathione with various endogenous and xenobiotic electrophiles. Since TrxR and GSTs are overexpressed in many cancer cells, they have been identified as potential targets to develop chemotherapeutic strategies. Method: The mitochondrial TrxR (TrxR2) enzyme and the cytosolic CYST enzyme was purified from rat liver via affinity chromatography. After the purification, the in vitro inhibition effects of some anticancer drugs (cisplatin, calcium folinate, carboplatin, epirubicin hydrochloride, doxorubicin hydrochloride, paclitaxel, etoposide, fluorouracil, and methotrexate) were investigated on both enzymes. Since only methotrexate inhibits both enzymes among all the anticancer drugs, a molecular docking study was performed to determine the binding site and the binding affinity of methotrexate to the enzymes. Results: Firstly, TrxR2 and GST were found to have a specific activity of 0.436, 1765 EU/mg proteins with a yield of 39.20%, 31.28% and 207.6, 3516.6 of purification fold, respectively. While TrxR2 was strongly inhibited by all of the anticancer drugs, GST was not inhibited by any of the anticancer drugs except methotrexate. Conclusion: Both enzymes were inhibited by only methotrexate in rat liver, and methotrexate was well placed in the active sites of both proteins. Therefore, it may be argued that methotrexate may be a more effective anticancer drug than all other drugs used in this study against the multi drug resistance that will occur during chemotherapy.Ataturk University Scientific Research Projects Coordination Commission (ATAUNIBAP)Ataturk University [PRJ2015/97, PRJ2015/357]This work was financially supported by Ataturk University Scientific Research Projects Coordination Commission (ATAUNIBAP) with project number PRJ2015/97 and PRJ2015/357. The author(s) have no potential conflict of interest with respect to the research, authorship, and/or publication of this article. Conceived and designed the experiments: Harun Budak (group leader) and Ilknur Ozgencli. Performed the experiments: Harun Budak, Ilknur Ozgencli, Deryanur Kilic, Ugur Guller, Mehmet Ciftci, and Omer I. Kufrevioglu. Analysed the data: Harun Budak, Ilknur Ozgencli, Deryanur Kilic, and Ugur Guller. Contributed reagents/materials/analysis tools: Harun Budak. Wrote the paper: Harun Budak, Ilknur Ozgencli, Deryanur Kilic, and Ugur Guller. All authors read and approved the final manuscript
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