DSpace Arşivi :: by Yazar "Çelik E." değerine göre listeleniyor

Yazar "Çelik E." seçeneğine göre listele

Listeleniyor 1 - 10 / 10

Antimicrobial activity of colloidal silver nanoparticles prepared by sol-gel method
(2011) Lkhagvajav N.; Yaşa I.; Çelik E.; Koizhaiganova M.; Sari O.
In this study, the antimicrobial activity of colloidal silver nanoparticles prepared by the sol-gel method was investigated, and the turbidity, viscosity and pH of the colloidal solutions were determined. The size of the silver nanoparticles was measured by Atomic Force Microscopy (AFM). The minimum inhibitory concentration (MIC) value of the colloidal solution resistance to test microorganisms Escherichia coli, Staphylococcus aureus, Candida albicans, Bacillus subtilis, Salmonella typhimurium, Pseudomonas aeruginosa and Klebsiella pneumoniae was carried out by the Broth Microdilution Method. It was found that the silver nanoparticles inhibited the growth and multiplication of the tested microorganisms, including the fungus C. albicans. The antimicrobial activity was observed against all tested microorganisms at a very low concentration of 2-4 µg/ml of nano silver.
Assessment of antimicrobial activity of nanosized Ag doped TiO2 colloids
(2012) Yaşa I.; Lkhagvajav N.; Koizhaiganova M.; Çelik E.; Sari Ö.
In the present research, the antimicrobial effects of nanosized silver (Ag) doped TiO2 colloidal solutions prepared using a sol-gel technique were investigated. In order to determine the solution characteristics, the turbidity, viscosity and pH of the colloidal solutions were measured. Differential thermal analysis-thermogravimetry equipment was used to determine the chemical structures and reaction types of the films formed from these solutions. The morphology of Ag doped TiO2 nanoparticles was evaluated by atomic force microscopy. The disc diffusion method was employed to explore antimicrobial activity, and the Broth Microdilution method was used to obtain MIC values of nanosized Ag doped TiO2 colloidal solutions against the test microorganisms Escherichia coli, Staphylococcus aureus,Candida albicans, Bacillus subtilis, and Salmonella typhimurium. It was found that the silver doped TiO2 nanoparticles inhibited the growth and multiplication of the test microorganisms, including the fungus C. albicans. Antimicrobial activity was observed against all tested microorganisms at a very low concentration of 1. 125-2. 81 µg/ml of nano silver in 1-25 % Ag-TiO2 solutions. © 2012 Springer Science+Business Media B.V.
Cerium-doped yttrium iron garnet thin films prepared by sol-gel process: Synthesis, characterization, and magnetic properties
(Springer Science and Business Media, LLC, 2009) Öztürk Y.; Avgın I.; Erol M.; Çelik E.
We studied here synthesis, characterization, and magnetic properties of YIG (yttrium-iron-garnet, Y3Fe5O12) and Ce-doped YIG (CexY3-xFe5O12) thin films prepared by using a sol–gel technique for magneto-optical applications. Pure YIG and Ce-doped YIG films were deposited on a glass and Si (100) substrates out of a solution prepared from Ce, Y, and Fe-based precursors, solvent, and chelating agent at low temperature using the sol–gel technique. Prior to coating process, solution characteristics that influence the intended thin film structure were determined using turbidimeter, pH meter, and rheometer machines. Film thickness was monitored with varying sol–gel solution’s properties and spin coating’s process parameters. Since we mainly want to improve the magnetic properties of our films, an optimum sol–gel solution containing cerium, yttrium, and iron precursors were found, and a garnet phase was formed after annealing at temperatures between 700 and 1,000? C for 2 h in air. The thermal, structural, and microstructural properties of the films were characterized using DTA/TG, XRD, and SEM-EDS. The magnetic properties of the films produced by doping with Ce with an optimal process conditions were investigated through VSM device. The films include micro and nanosize CeO2 regions because of using partially dissolved Ce precursor in the solution. Our preliminary study revealed that a significant improvement in magnetic properties of polycrystalline YIG thin films have been achieved through the substitution of Ce. © Springer-Verlag Berlin Heidelberg 2009.
Comparison of risk factors in surgically treated patients with coronary artery disease and obstructive peripheral arterial disease [Cerrahi yöntemle tedavi Edilen koroner arter ve tikayici periferik arter hastalarinda risk faktörlerinin karşilaştirilmasi]
(Duzce University Medical School, 2015) Çelik E.; Yürekli İ.; Yetkin U.; Çakir H.; Dönmez K.; Gümüş M.; Durusoy R.; Gürbüz A.
Aim: Due to increase in life expectancy, quality of life and alteration of life style; deaths by cardiovascular reasons are also increasing. In this era, cardiovascular diseases are the most important mortality and morbidity causes of especially aging population. Atherosclerosis is the major cause of cardiovascular diseases and its clinical reflections are diseases like coronary artery disease (CAD) and peripheral arterial disease (PAD). Choices in treatment of cardiovascular diseases are medical, peripheral vascular interventions and surgical interventions. There are many predisposing factors like age, hyperlipidemia, smoking, diabetes mellitus and hypertension for CAD and PAD. These risk factors also cause morbidity after surgical interventions and increase total length of hospital stay. Methods: In this study, we retrospectively investigated 868 CAD and 268 PAD patients who were treated with surgical intervention between January 2007 and December 2010 for development of acute renal injury after surgery and effects of risk factors over intensive care unit and total length of hospital stay. Results: Blood transfusion rates were higher in patients with acute renal injury at both CAD and PAD groups. This was consistent with literature. In addition, postoperative acute renal injury incidences were higher in patients with hypertension and preoperative low hematocrit levels. Intensive care unit stay was longer in CAD patients with chronic obstructive pulmonary disease. Blood transfusion rates were higher, length of intensive care unit and hospital stay was longer in smoking PAD patients. Significantly, length of hospital stay of CAD patients with high LDL levels was longer. Conclusion: We believe that, postoperative morbidity rates may be lowered and intensive care unit and hospital stay lengths may be shortened in CAD and PAD patients by a careful examination of preoperative risk factors and planning of perioperative medical treatment. © 2015 Düzce Medical Journal.
Concentration and path-length dependence on the faraday rotation of magnetic fluids based on highly water-soluble fe3o4/paa nanoparticles synthesized by a high-temperature hydrolysis method
(2013) Küçükdermenci S.; Kutluay D.; Çelik E.; Mermer O.; Avgyn Y.
In this study, highly water-soluble Fe3O4/PAA (polyacrylic acid) nanoparticles (NPs) were synthesized by a high-temperature hydrolysis method. We report the first demonstration of the concentration and path-length dependence on the Faraday rotation (FR) for a magnetic fluid (MF) synthesized by this novel method. Experiments were performed in the DC regime (0-6 × 10-2 T) at room temperature. Measurements were carried out with 5-3.33 mg/ml and 1.18 mg/ml samples in cells (2, 5, 7 and 10) mm. The maximum rotation was recorded as 0.96° cm-1 for the 3.33 mg/ml concentration in the cell 10 mm. It was found that the magnetic fluid behaves with a distinctive phenomenon in different sized cells although its concentration was the same. The role of the different parameters on the FR was discussed via spatial limitations imposed by the cells and a premature saturation term. This work provides a new insight for FR investigations of MFs including highly water-soluble magnetic NPs.
Management of chronic hepatitis in special hosts and special situations: A consensus report of the study group for viral hepatitis of the Turkish society of clinical microbiology and infectious diseases [Özel Konaklarda ve Özel Durumlarda Kronik Hepatit Yönetimi: Türk Klinik Mikrobiyoloji ve İnfeksiyon Hastalıkları Derneği Viral Hepatit Çalışma Grubu Uzlaşı Raporu]
(AVES Ibrahim Kara, 2014) Mıstık R.; Aydın M.; Aksoy S.; Altın N.; Altunal N.; Avşar K.; Bezirgan S.; Büke Ç.; Çelik A.K.; Çelik E.; Dikici N.; Hızel K.; İskender S.; Kaya A.; Korkmaz F.; Köse Ş.; Saçlıgil C.; Sırmatel F.; Tarakçı H.; Turgut H.; Tütüncü E.; Yuluğkural Z.
Study Group for Viral Hepatitis of the Turkish Society of Clinical Microbiology and Infectious Diseases convened a meeting to develop a consensus report on management of chronic hepatitis in special hosts and special situations. Relevant literature and international guidelines were reviewed, and recommendations agreed are presented at the end of each section such as therapy of chronic hepatitis B (CHB) in patients with compensated and decompensated cirrhosis, prevention and therapy of recurrent hepatitis B after liver transplantation, management of fulminant hepatitis B, therapy of CHB in hemodialysis patients, management of CHB in nonliver solid organ transplant recipients, management of CHB in immunosuppressed nontransplant patients, therapy of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) coinfection, management of HBV and hepatitis C virus (HCV) coinfection, management of CHB in alcoholic patients and injecting drug users, therapy of CHB in pregnancy and lactation period, extrahepatic manifestations in HBV infection, HBV, HCV and hepatitis D virus coinfection, therapy of chronic hepatitis C (CHC) in patients with compensated and decompensated cirrhosis, treatment of patients with recurrent HCV infection following liver transplantation, therapy of CHC in hemodialysis patients, management of CHC in nonliver solid organ transplant recipients, therapy of HCV, HBV and HIV coinfection, management of CHC in immunosuppressed nontransplant patients, HCV infection and biological agents, HCV infection and chemotherapy, management of CHC in alcoholic patients and injecting drug users, fatty liver and CHC, hemoglobinopathy and CHC, CHC in pregnancy and lactation period, extrahepatic manifestations in HCV infection. Klimik Dergisi © 2014, AVES Ibrahim Kara. All rights reserved.
Nanometric measurement of the pre nano scale TiO2 powders via flame spray pyrolysis: Synthesis, properties and photocatalytical decomposition of methylen blue
(2012) Erol M.; Yurddaskal M.; Yildirim S.; Mermer Ö.; Bas G.; Çakmakçi M.; Numan Durakbasa M.; Çelik E.
In this study, nanometric measurement of the TiO2 powders were analysed that were synthesized via flame spray pyrolysis for photocatalytic decomposition process. Continues increase of new metrological demands have enabled to fulfill the highest demand in measurement resolution. In order to obtain crystalline structure, the produced powders were post-annealed at 600°C after flame spray pyrolysis process. The phase structure was analyzed by x-ray diffractometer (XRD). Particle size of the powders was determined using particle size analyzer. The morphology and accurate size of the primary particles were further investigated by several devices in order to illuminate the particle size, phase structure, morphology and photocatalytic properties. Copyright © (2012) by the International Measurement Federation (IMEKO).
New gelatin-hydroxyapatite nanocomposite films containing nano silver: Synthesis, and, mechanical and antimicrobial properties
(2011) Koizhaiganova M.; Lkhagvajav N.; Ya¸sa I.; Çelik E.
A new gelatin-hydroxyapatite (GHA) nanocomposite with different amounts of nanosilver (nAg) has been obtained by a colloidal chemical route. The AFM results revealed that the particle size of nAg particles was less than 20 nm. The morphology of the prepared hydroxyapatite (HA) powder was investigated by X-ray diffraction (XRD). The nanocomposite films were characterized by FT-IR spectroscopy, showing the interaction of the GHA with nAg. Mechanical properties and antimicrobial effects against the test microorganisms, bacteria E.coli and S. aureus and fungi C. albicans, A. niger and T. viridae, were also studied. The results obtained showed that the antimicrobial effects of the nanocomposite films as well as their mechanical properties like tensile strength and elongation at break are improved by increasing the amount of nano Ag from 10 to 50 ppm. Therefore, this material is a promising biomaterial to use in food, pharmaceutical and medical applications, etc. Copyright © 2011 American Scientific Publishers.
A novel lubricant with Nano-silica additives and its uses for leather performance properties
(International Union of Leather Technologists and Chemists Societies (IULTCS), 2015) Erciyes A.; Yigit R.; Başaran B.; Ocak B.; Çelik E.
Leather has a fibrous network gives many favourable properties in line with consumer demands. Thanks to lubrication, both the individual fibers of the network become compliance, thereby, maintaining its mechanical behaviour and the structure would be improved regarding the homogeneity, unity, uniformity and appearance. Hence, the key function of lubricant is to enhance the physico-mechanical properties of leathers and to upgrade their qualities by adding aesthetic value. Those are achieved by use of lubricant emulsions of small particle size capable of deeply penetrating into the hierarchy of tridimensional woven structure. Nano-silica particles are of potential advantages for incorporation into fatliquoring formulations because of their lubricating efficiencies and there will take many interests in terms of attainable value added products with them.
Structural and magnetic properties of cerium-doped yttrium-iron garnet thin films prepared on different substrates using the sol-gel process
(2013) Öztürk Y.; Erol M.; Çelik E.; Mermer O.; Kahraman G.; Avgyn I.
The cerium-substituted yttrium-iron garnet (Ce-YIG) CexY3-xFe5O12 is considered as a promising material for applications in high-performance magnetic and magneto-optic devices. In this work cerium-substituted yttrium-iron garnet films were produced on fused silica and Si(100) substrates using the sol-gel technique from solutions with the yttrium/cerium molar ratio 2.8/0.2. A heat treatment was applied to those as-deposited garnet films at temperatures ranging from 800 °C to 1000 °C for 2 h in air. The as-deposited garnet films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to investigate their structural properties. A vibrating-sample magnetometer was used at room temperature to characterize the magnetic properties of the as-deposited garnet thin films.

Yazar "Çelik E." seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri