Yazar "Ersoy, Orkun" seçeneğine göre listele

Listeleniyor 1 - 20 / 21
  • Küçük Resim Yok
    Öğe
    An ultrasonic-assisted direct impregnation method for preparation of diatomite-based phase change material nanocomposites
    (Bulgarian Acad Science, 2016) Konuklu, Yeliz; Ersoy, Orkun
    Diatomite is an important natural raw material and the nanotube structures of diatomite are important in the preparation of composites. The nanotube structure of diatomite protects the phase change material from their environment. This work aims to develop leakage- free, thermally stable natural diatomite/phase change material nanocomposites (NanoCPCMs) by the ultrasonicassisted direct impregnation method for thermal energy storage applications. This work uses diatomite and paraffin as the supporting and phase change materials, respectively. The diatomite- based form- stable nanoCPCMs were analyzed via scanning electron microscopy and differential scanning calorimetry. Paraffin leakage of nanoCPCMs was determined at 95 C by water bath for 45 minutes. At the end of test, thermal stability at 95 C evaluated with DSC analysis. The results show that the leakage- free NCPCMs were synthesized successfully for thermal energy storage applications.
  • Küçük Resim Yok
    Öğe
    Association of amoxicillin use and molar incisor hypomineralization in piglets: Visual and mineral density evaluation
    (PERGAMON-ELSEVIER SCIENCE LTD, 2013) Kuscu, Ozgur Onder; Sandalli, Nuket; Dikmen, SerdaI; Ersoy, Orkun; Tatar, Ilkan; Turkmen, Ismet; Caglar, Esher
    Aim: The aim of the present study was to determine the prevalence of MIH both visually and quantitatively, and describes the range of mineral densities of enamel specimens from three groups of piglets where two groups were given different doses of amoxicillin in infancy. Methods: In this blind randomized clinical study, 20 piglets were randomly divided into three groups. Group A received a standard dose (50 mg/kg/day) and Group B received a high dose (90 mg/kg/day) of amoxicillin in selected days of the month (20 working days) they were born. Group K did not receive any medication and served as control. Thirteen right mandibular permanent first molars (PFMs) were randomly collected from 3 groups of piglets at age 10 months for evaluation under X-ray micro-tomography. Tomographic data were obtained using a Skyscan 1174 compact micro-CT in the Department of Anatomy. Results: Prevalence of MIH was 0% in all groups. MD values were quantified after enamel grey level (0-255) measurements on horizontal cross-sectional slices. After MD measurements, the effects of amoxicillin use on MIH are presented. Conclusions: While MIH is a multifactorial disturbance, the present study attempted to highlight the clinical findings of a possible relationship between amoxicillin use and MIH with the aid of X-ray micro-tomography. (C) 2013 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Correlation of ignimbrites in the central Anatolian volcanic province using zircon and plagioclase ages and zircon compositions
    (ELSEVIER SCIENCE BV, 2012) Aydar, Erkan; Schmitt, Axel K.; Cubukcu, H. Evren; Akin, Lutfiye; Ersoy, Orkun; Sen, Erdal; Atici, Gokhan
    Episodes of high eruptive fluxes (>10(-3) km(3)/year) in continental environments are associated with magmatism related to subduction, post-orogenic collapse, intra-plate hot spots, or rifting. During such episodes, voluminous ignimbrite deposits are produced which cover landscapes over 10(4)-10(5) km(2). In such sequences, brief eruptive recurrence and chemical similarity limit the applicability of geochronological and geochemical correlation methods. Here, we present complementary geochronological data (Ar-40/Ar-39 plagioclase eruption and Pb-206/U-238 zircon crystallization ages) for ignimbrites from the Miocene-Holocene Central Anatolian Volcanic Province (CAVP). In addition, we successfully employed zircon geochemistry (trace elements, oxygen isotopes) as an alteration-resistant indicator to correlate rhyodacitic to rhyolitic ignimbrites whose eruption age differences are too brief to be resolved by Ar-40/Ar-39 geochronology. By applying this method, we dismiss previous correlations between stratigraphic members (i.e., Sofular and Gordeles, Sofular and Sanmadentepe), but demonstrate close relationships for other CAVP ignimbrites (i.e., Kayak units 1 to 4; Cemilkoy ignimbrite and overlying fallout deposits). Our chronostratigraphy reveals two previously unrecognized eruptive pulses at -9-8 Ma and 7-5 Ma which are characterized by increasing magmatic temperatures (-75-100 degrees C within each cycle). Despite a long-term (10 Ma) eruptive productivity that is about one order of magnitude smaller than in other magmatically active continental plateaus, the CAVP achieved high eruptive fluxes during brief (1-2 Ma) intervals. (C) 2011 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Easy and industrially applicable impregnation process for preparation of diatomite-based phase change material nanocomposites for thermal energy storage
    (PERGAMON-ELSEVIER SCIENCE LTD, 2015) Konuklu, Yeliz; Ersoy, Orkun; Gokce, Ozgur
    The high porosity, high oil and water absorption capacity and low density of diatomite make it ideal for industrial applications. The porous structure of diatomite protects phase change materials (PCMs) from environmental factors as a supporting matrix and phase changes occur in nanopores of diatomite. Previous research on diatomite/PCMs composites aimed optimal composite preparation but many methods were feasible only in laboratory scale. In large scale industrial fabrication, easy, continuous and steady state methods are need to be performed. The main purpose of this study was to prepare leakagefree, thermally stable nanocomposite PCMs (nanoCPCMs) by an easy, continuous and steady state method for high temperature thermal energy storage applications. A series of nanoCPCMs with different paraffin:diatomite mass ratios were prepared. The properties of nanoCPCMs have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (MR). The leak (exudation) test was performed on prepared composites at higher temperatures (95 degrees C) in comparison with literature. As the optimum composite for thermal energy storage applications, thermal reliability of nanoCPCM was evaluated after 400 cycles of melting and freezing. NanoCPCM melted at 36.55 degrees C with latent heat of 53.1 J/g. (C) 2015 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Effect of engraving speeds of CO2 laser irradiation on in-ceram alumina roughness: a pilot study
    (INFORMA HEALTHCARE, 2015) Ersu, Bahadir; Ersoy, Orkun; Yuzugullu, Bulem; Canay, Senay
    Objectives. The aim of the study was to determine the effect of CO2 laser on surface roughness of In-Ceram-Alumina-ceramic. Materials and methods. Four aluminum-oxide ceramic disc specimens were prepared of In-Ceram Alumina. Discs received CO2 laser irradiation with different engraving speeds (100, 400, 600 and 800 mm/min) as a surface treatment. The roughness of the surfaces was measured on digital elevation models reconstructed from stereoscopic images acquired by scanning-electron-microscope. Surface roughness data were analyzed with One-Way-Analysis-of-Variance at a significance level of p < 0.05. Results. There was no significant difference between the roughness values (p = 0.82). Due to higher laser durations, partial melting signs were observed on the surfaces. Tearing, smearing and swelling occurred on melted surfaces. Swelling accompanying melting increased the surface roughness, while laser power was fixed and different laser engraving speeds were applied. Conclusion. Although different laser irradiation speeds did not affect the roughness of ceramic surfaces, swelling was observed which led to changes on surfaces.
  • Küçük Resim Yok
    Öğe
    Effect of pre-treatment methods on natural raw materials-based phase change material composites for building applications
    (Elsevier Sci Ltd, 2020) Konuklu, Yeliz; Ersoy, Orkun; Akar, Hasan Burak; Erzin, Fatma
    This study focuses on the effect of pre-treatment methods of natural raw materials to the properties of diatomite or sepiolite-based heptadecane composites for building applications. In order to see the effects of different pre-treatment methods, the composites were prepared using impregnation method without pre-treatment, with microwave treatment and calcination treatment of raw materials before compounding. Chemical (FTIR), morphological (SEM) and thermal (DSC) analysis results showed that shapestabilized diatomite- and sepiolite-based hexadecane composites were successfully prepared by impregnation method. It was observed that the pre-treatment performed in the diatomite with microwave for no more than 1 min increased the percentages of PCM and latent heats from 28,36% and 51.71 J/g to 35,78% and 65.24 J/g, respectively. The percentage of PCM and latent heat increased from 22,23% and 40.541/g to 32,38% and 59.54 J/g, respectively, after the microwave treatment of sepiolite for 3-6 min. The results showed that pre-treatment with calcination in raw material-based PCM composites did not have a positive effect as much as pre-treatment with microwave. The success of the microwave pretreatment against calcination has been attributed to the homogeneous microwave heating process. Leak tightness tests and thermal performance tests of composites in cement-based grouting mortar have also proven that composites store excess heat and can provide thermal regulation in building applications as leakage-free energy storage materials. (C) 2020 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Estrogen as a Novel Agent for Induction of Adipose-Derived Mesenchymal Stem Cells for Osteogenic Differentiation: In Vivo Bone Tissue-Engineering Study
    (LIPPINCOTT WILLIAMS & WILKINS, 2014) Calis, Mert; Demirtas, Tugrul Tolga; Atilla, Pergin; Tatar, Ilkan; Ersoy, Orkun; Irmak, Gulseren; Ozgur, Figen
    Background: This study investigated whether the in vivo osteogenic differentiation potential of adipose-derived mesenchymal stem cells is enhanced by 17-estradiol. Methods: Thirty Sprague-Dawley rats were randomized and divided into five experimental groups. For the surgical procedure, biparietal full-thickness bone defects (7 mm in diameter) were created. A chitosan-hydroxyapatite scaffold was used as the vehicle system for 17-estradiol-loaded nanoparticles and adipose-derived mesenchymal stem cells. The first group, the blank defect group, was the control group. The defects were filled with either scaffold, estradiol, and scaffold; scaffold and adipose-derived mesenchymal stem cells; or estradiol, scaffold, and adipose-derived mesenchymal stem cells as experimental groups. The rats were killed at the end of weeks 4 and 12, and their calvariae were harvested for histologic and microtomographic evaluation. Results: Micro-computed tomographic evaluation of estradiol, scaffold, and adipose-derived mesenchymal stem cells revealed the highest median value (82.59 17.17), and the difference was significant compared with the blank defect group (p = 0.004). Histologic samples demonstrated a significant difference between experimental groups for bone defect repair at the end of weeks 4 and 12 (p = 0.003 and p < 0.001). The estradiol, scaffold, and adipose-derived mesenchymal stem cell group had the highest median score (3.00 +/- 0.0) at week 12, which was significantly higher than scores for the scaffold and adipose-derived mesenchymal stem cell group and the blank defect group. Conclusion: 17-Estradiol appears to be a novel and promising agent for future cell-based bone tissue-engineering studies.
  • Küçük Resim Yok
    Öğe
    Estrogen as a novel agent for induction of adipose-derived mesenchymal stem cells for osteogenic differentiation: In vivo bone tissue-engineering study
    (Lippincott Williams and Wilkins, 2014) Calis, Mert; Demirtas, Tugrul Tolga; Atilla, Pergin; Tatar, Ilkan; Ersoy, Orkun; Irmak, Gulseren; Celik, Hakan Hamdi
    BACKGROUND: This study investigated whether the in vivo osteogenic differentiation potential of adipose-derived mesenchymal stem cells is enhanced by 17?-estradiol. METHODS: Thirty Sprague-Dawley rats were randomized and divided into five experimental groups. For the surgical procedure, biparietal full-thickness bone defects (7 mm in diameter) were created. A chitosan-hydroxyapatite scaffold was used as the vehicle system for 17?-estradiol-loaded nanoparticles and adipose-derived mesenchymal stem cells. The first group, the blank defect group, was the control group. The defects were filled with either scaffold, estradiol, and scaffold; scaffold and adipose-derived mesenchymal stem cells; or estradiol, scaffold, and adipose-derived mesenchymal stem cells as experimental groups. The rats were killed at the end of weeks 4 and 12, and their calvariae were harvested for histologic and microtomographic evaluation. RESULTS: Micro-computed tomographic evaluation of estradiol, scaffold, and adipose-derived mesenchymal stem cells revealed the highest median value (82.59 ± 17.17), and the difference was significant compared with the blank defect group (p = 0.004). Histologic samples demonstrated a significant difference between experimental groups for bone defect repair at the end of weeks 4 and 12 (p = 0.003 and p < 0.001). The estradiol, scaffold, and adipose-derived mesenchymal stem cell group had the highest median score (3.00 ± 0.0) at week 12, which was significantly higher than scores for the scaffold and adipose-derived mesenchymal stem cell group and the blank defect group. CONCLUSION: 17?-Estradiol appears to be a novel and promising agent for future cell-based bone tissue-engineering studies. Copyright © 2014 by the American Society of Plastic Surgeons.
  • Küçük Resim Yok
    Öğe
    Fabrication and characterization of form-stable phase change material/xonotlite microcomposites
    (Elsevier, 2017) Konuklu, Yeliz; Ersoy, Orkun
    In this research novel microcomposites composed of phase change materials (PCMs) and xonotlite were fabricated and characterized. Xonotlite mineral and its composites have wide application areas in building materials industry due to their thermo-insulating properties. Lauric acid, decanoic acid and paraffin were used as phase change materials. Xonotlite was prepared as composite matrix. In order to analyse the composite structure and thermal performance of microcomposites, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used. The experimental results demonstrate that paraffin/xonotlite composites were synthesized successfully and paraffin was the most suitable phase change material for preparation of phase change material/xonotlite composites. However, this study emphasized the correct choice of PCM that will be used in xonotlite including composites. Fatty acids have dissolution effect on xonotlite matrix. The melting and freezing temperatures were measured through differential scanning calorimetry analysis and found to be 35.05 and 40.42 degrees C, respectively. The melting and crystallization heats were determined to be 65.8 and -63.5 kJ/kg. We recommended that the fabricated nanocomposite-PCMs offer proper phase transition temperature range heat enthalpy values for thermal energy storage applications.
  • Küçük Resim Yok
    Öğe
    Histomorphometrical and radiological comparison of low-level laser therapy effects on distraction osteogenesis: experimental study
    (SPRINGER LONDON LTD, 2014) Kan, Bahadir; Tasar, Ferda; Korkusuz, Petek; Ersoy, Orkun; Cetinkaya, Alper; Gur, Cagla Z.; Meral, Gokce
    Distraction osteogenesis (DO) is the application of traction to the callus formed between bone segments and stimulation of bone formation by creating stress on the callus with this traction. Shorten the duration of DO and increasing the capacity of bone formation is important to prevent the possible complications of DO. For this reason, it was considered that low-level laser therapy (LLLT) may affect positively DO and it can decrease the complication range by shortening the period. Unilateral mandibular distractors were applied on 16 female white New Zealand rabbit to prove this hypothesis with micro CT, plain radiograph and histomorphometric analyses. Eight rabbits were applied LLLT with GaAlAs laser on the distraction area during the distraction period. On the post-distraction 28th day, four rabbits from study group and four rabbits from control groups were sacrificed. The rest of the rabbits were sacrificed on post-distraction 56th day. As a result of this study, significant positive effects of LLLT on post-distraction 28th day were revealed with all analyses. In histomorphometrical analyses, new bone formation was significantly higher in short-term laser applied group comparing to that of short-term control group (p = 0.029). In both microCT and plain radiograph, the highest radioopacity values were observed in short-term laser group when compared with that of the controls (p = 0.043 and p = 0.025, respectively). Even though LLLT increased the healing capacity on short-term, it was not sufficient on long-term (post-distraction 56th day) healing. LLLT application on distraction period, activate healing on bone so it may decrease DO period. The result of this study should be supported with clinical studies and the most effective laser source, dose and application time should be revealed with experimental and clinical studies.
  • Küçük Resim Yok
    Öğe
  • Küçük Resim Yok
    Öğe
    Insecticidal potential of native diatomaceous earth against sitophilus granarius (Coleoptera: Curculionidae)
    (ResearchersLinks Ltd, 2020) Salim, Muhammad; Gökçe, Ayhan; Naqqash, Muhammad Nadir; Ersoy, Orkun
    The granary weevil, Sitophilus granarius is one of the serious pests of cereal crops worldwide. To control this pest, diatomaceous earth (DE) formulation consisted of diatoms, obtained from Nigde Province, Turkey, was tested against adults of the granary weevil, Sitophilus granarius (L.) under laboratory conditions (25±1°C, 60±5% RH). Diatomaceous earth was applied to wheat grain at the rates of 100, 250, 300, 500, 750, 1000, 1500 and 2000 mg/Kg. Adult mortalities were assessed after 7, 14 and 21 days. Mortality rates rose with increases in dosage and length of exposure. Significantly higher mortality (89.75±3.66%) after one week occurred in grains treated with the highest concentration (2000 mg/Kg). At the highest concentration (2000 mg/Kg), the mortality reached as high as 100% after 2 weeks, while the lowest significant percent mortality (1.00±1.00%) was recorded in the control one week after exposure and only increased to 3.53±0.00% after 3 weeks. Percent weight loss in grain was also determined after 21 days. A significantly higher percent weight loss (7.29±0.11%) was found in the control, while no weight loss was observed in grains treated with the highest concentration (2000 mg/Kg). The grains were also observed for adult emergence for a period of 45 days. More than 90% reduction in adult emergence was recorded at concentrations of 1500 and 2000 mg/Kg. Conversely, the highest number of adults emerged at a dosage of 100 mg/Kg and in the control, i.e. 114.67±7.42 and 143.33±11.66 adults, respectively. The present study proposed that DE might potentially be effective in controlling S. granarius based on its ability to cause desiccation to the insects' protective cuticular wax layer. In order to develop environmentally sound control programs for in sito management of granary weevils, it will be necessary to expand the present study based on life table to get a comprehensive understanding and to determine the effect DE has on granary weevils and other grain pests when it is combined with plant extracts. © 2020 ResearchersLinks Ltd.
  • Küçük Resim Yok
    Öğe
    Life cycle assessment and shrinkage properties of high performance mortars incorporating synthetic wollastonite microfibers
    (Emerald Group Publishing Ltd, 2023) Oz, Hatice Oznur; Gunes, Muhammet; Yucel, Hasan Erhan; Ersoy, Orkun; Sever, Yunus; Demirel, Sevgi
    In this study, the use of an alternative material as supplementary cementitious material was researched for the design of high-performance mortars (HPMs). Synthetic wollastonite microfibres (SWMs) were produced from calcite and quartz sand. The SWMs were then replaced at ratios of 0, 3, 6, 9 and 12% by cement weight to investigate the fresh, mechanical and shrinkage properties of HPMs. Test results showed that the mechanical and shrinkage properties of HPMs improved up to 9% inclusion of SWMs. The compressive strength, flexural strength, modulus of elasticity, fracture toughness and fracture energy of HPM incorporating 9% SWM was higher than that of the control mixture by 8.8-9.1%, 7.5-9.9%, 4.7-6.7%, 8.9-4.6% and 13.2-2.5% at 28-90 days, respectively. Similarly, the ratios for maximum drying shrinkage and average crack width were determined as 10.5% and 58.3%, respectively, at the end of 60 days. These findings were also supported by microstructural analysis. Moreover, the potential environmental impacts resulting from the production of 1 kg SWM and HPM incorporating 9% SWM were evaluated using the life cycle analysis software (LCA) SimaPro 8.5.0.0. Based on the LCA results, SWMs can be used as an alternative material to develop sustainable concrete structures.
  • Küçük Resim Yok
    Öğe
    Marginal Fit of All-Ceramic Crowns Before and After Cementation: An In Vitro Study
    (QUINTESSENCE PUBLISHING CO INC, 2018) Halici, Saniye Eren; Hekimoglu, Canan; Ersoy, Orkun
    The marginal integrity of all-ceramic crowns for anterior and posterior teeth were evaluated. A total of 60 ceramic crowns (In-Ceram Alumina, IPS e.max Press, and Lava) were fabricated for the epoxy resin maxillary first central incisor and first molar and divided into three groups (n = 20). The crowns were measured at the facial, lingual, mesial, and distal finish lines (52 points) before and after cementation using scanning electron microscopy. The results were analyzed using one-way analysis of variance, paired samples t test, and independent t test. The mean values of marginal gaps were within acceptable clinical limits before and after cementation. The values of the anterior crowns at the buccal finish line were higher than those at the proximal finish line areas (P < .05). However, these were insignificant at four measurement areas for posterior crowns (P > .05). Marginal gaps of crowns at the anterior teeth were higher than at the posterior teeth for all groups.
  • Küçük Resim Yok
    Öğe
    Niğde Üniversitesi Ar-Ge Strateji Belgesi (Nanoteknoloji Araştırmaları)
    (2017) Konuklu, Yeliz; Zan, Recep; Soylu, Asım; Ersoy, Orkun
    Nanoteknoloji birçok alandaki uygulamalarından dolayı yüksek bir potansiyele sahip bir alandır. Uluslararası platformda Nanoteknolojik araştırma ve uygulamalar için yapılan yatırımlar günden güne artmaktadır. Dünyadaki bilimsel ve teknolojik gelişmeleri her alanda takip edebilmek ve uluslararası standartlara ulaşmak için Nanobilim ve Nanoteknoloji konusundaki çalışmaların ülkemizde de yoğunlaşması gerekmektedir. Hazırlanan strateji belgesinin temel amacı Ömer Halisdemir Üniversitesi'nin Nanoteknoloji Araştırmaları alanında mevcut araştırma - geliştirme potansiyelinin belirlenerek arttırılması, ayrıca üniversite-sanayi arasında işbirliğinin geliştirilmesi ve bu alanda ?Ar-Ge Strateji Belgesinin? hazırlanmasıdır. Hazırlanan Nanoteknoloji Araştırmaları Ar-Ge Strateji belgesi ile üniversite-sanayi işbirliği yapılarak katma değeri yüksek teknolojik ürünlerin ortaya çıkarılması ve geliştirilmesi hedeflenmektedir. Ömer Halisdemir Üniversitesi Nanoteknoloji Uygulama ve Araştırma Merkezimiz Nanoteknoloji alanında üç ana konu üzerinde yog?unlas?mıs?tır. Bunlar 1)fonksiyonel özellikli nanokompozit ve nanoenkapsülasyon çalışmaları 2) nanoyapıların üretimi ve optimizasyonu çalışmaları 3)karbon temelli nanomalzemelerin sentezi, karakterizasyonu ve farklı endüstrilerde kullanılabilirlikleri üzerine yapılan çalışmalardır. Ayrıca bazı araştırmacılarımız nano ölçekte manyetik özellik gösteren örneklerin üretimi ile ilgili çalışmalara başlamıştır. Ömer Halisdemir Üniversitesi, sahip olduğu insan kaynağı ve altyapı olanakları açısından Nanoteknoloji alanında ülkemizin ihtiyaç duyduğu Ar-Ge çalışmalarını yapacak ve bu alanda ilk beş üniversite arasına girebilecek potansiyele sahiptir. TÜBİTAK 1000 kodlu ?Üniversitelerde Ar-Ge Strateji Belgesi Hazırlatılması ve Uygulatılması? çağrısı kapsamında hazırlanan beş yıllık Ar-Ge Strateji Belgesi ile Ömer Halisdemir Üniversitesi?nin Nanoteknoloji Araştırmaları alanındaki mevcut potansiyelinin en iyi şekilde değerlendirilmesi ve ülkemizde ilk beş üniversite içerisine girmesi için gerekli yol haritası çizilmiştir. Ömer Halisdemir Üniversitesi Nanoteknoloji Araştırmaları alanında yapacağı çalışmalarla gelecek on yıl içerisinde sadece Türkiye?deki ilk beş üniversite arasına girmeyi değil aynı zamanda bu alanda dünyada da önemli bir eğitim ve Ar-Ge merkezi olmayı hedeflemektedir. Ömer Halisdemir Üniversitesi Nanoteknoloji Araştırmaları alanında Ar-Ge strateji Belgesi?nin hazırlanması esnasında üniversite-sanayi işbirliğinin desteklenmesi ve teşvik edilmesi konusunda üniversitenin Nanoteknoloji Araştırmaları Ar-Ge altyapısındaki eksiklikler tespit edilmiş ve bu eksikliklerin giderilmesine yönelik beş yıl içerisinde atılacak olan adımlar Üniversite üst yönetimi desteğiyle bes? adet is? paketi ile gerçekleştirilmiştir. Bunlar; 1.Nanoteknoloji Araştırmaları Mevcut Durum ve Sektörel ihtiyaç çalışmaları çalıs?tayının düzenlenmesi 2.Web Sayfası, Bros?ür, Posterlerin hazırlanması 3.I?s?birlig?i ve Tanıtım Toplantıları 4.Proje Hazırlama Eg?itimi: Nig?de Üniversitesinde Nanoteknoloji alanında çalıs?ma yapan ve bu alanda projeler yapmak isteyen üniversite personeline projeler hakkında bilgi verilecektir. 5.Nanoteknoloji Aras?tırmaları Ar-Ge Strateji Belgesinin Hazırlanması olarak özetlenebilir. Ömer Halisdemir Üniversitesi ?Nanoteknoloji Aras?tırmaları? alanındaki stratejik amaçları; 1. Nanoteknoloji alanında Ar-Ge faaliyetlerini artırmak, 2. Araştırma sonucunda ortaya çıkan bilginin geniş kitlelere ulaşmasını sağlamak, 3. Nanoteknoloji alanında işbirliğinin sağlanmasına yönelik akademik ve bilgilendirme toplantıları yapmak, 4. Nanoteknoloji alanında Ar-Ge altyapısının iyileştirilmesi ve geliştirilmesini sağlamak olarak belirlenmiştir.
  • Küçük Resim Yok
    Öğe
    Possible Use of Volcanic Ash as a Filler in Polyphenylene Sulfide Composites: Thermal, Mechanical, and Erosive Wear Properties
    (WILEY, 2014) Avcu, Egemen; Coban, Onur; Bora, Mustafa Ozgur; Fidan, Sinan; Sinmazcelik, Tamer; Ersoy, Orkun
    It is a common practice to use particle materials as fillers to improve engineering properties of polymer composites and to lower the cost of final products. There is an obvious cost advantage of compounding volcanic ash (VA) in polymers, either to replace traditional fillers. This study is concerned with thermal, mechanical, and erosive properties of VA-filled polyphenylene sulfide (PPS) composites. Composite samples containing VA particles at various concentrations (0, 2.5, 5, 10, 15, and 20 wt%) were manufactured by twin screw extruder and injection molding machine. Thermal properties were investigated by thermogravimetric and dynamic mechanical analysis methods. Erosive wear properties were investigated by performing solid particle erosion tests at 30 degrees and 90 degrees impingement angles. The mechanical properties such as flexural strength and modulus of uneroded samples and residual flexural strength and modulus of eroded composite samples were determined by three-point bending tests. Results show that thermal, mechanical, and residual mechanical properties of the PPS composite were significantly improved by adding VA, although erosion resistance was decreased markedly. It was concluded that VA can be used as a reinforcement in PPS composites to improve thermal and mechanical properties and to reduce the cost of the PPS composites. (C) 2014 Society of Plastics Engineers
  • Küçük Resim Yok
    Öğe
    Preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage
    (PERGAMON-ELSEVIER SCIENCE LTD, 2016) Konuklu, Yeliz; Ersoy, Orkun
    This paper is one of the first study about the preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage applications. Sepiolite is an important natural fibrous raw material. Nanoscale fibrous tubular structure of sepiolite becomes important in nanocomposite preparation. In this study, sepiolite/paraffin and sepiolite/decanoic acid nanocomposites were manufactured by the direct impregnation method. By the preparation of nanocomposites, PCM move in tubular channels of sepiolite, phase changing occurs in these tubes and surface area increases like as in microencapsulation. The structure and properties of nanocomposites PCMs (CPCM) have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The SEM results prove the successful preparation of phase change material/sepiolite nanocomposites and point out that the fibers of sepiolite is modified with phase change materials in the nanocomposite. The phase change enthalpies of melting and freezing were about 62.08 J/g and 62.05 J/g for sepiolite/paraffin nanocomposites and 35.69 J/g and -34.55 J/g for sepiolite/decanoic acid nanocomposites, respectively. The results show that PCM/sepiolite nanocomposites were prepared successfully and their properties are very suitable for thermal energy storage applications. (C) 2016 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Sentetik Vollastonitin Tasarlanmış Çimento Esaslı Kompozitlerde Lif Donatı Olarak Uygulaması
    (2020) Yücel, Hasan Erhan; Ersoy, Orkun; Öz, Hatice Öznur
    Bu çalısmada laboratuvar ortamında gelistirilen yüksek boy:çap oranlı (44:1) sentetik vollastonit (SV 16), tasarlanmıs çimento esaslı kompozitlerde (ECC), çimento, uçucu kül (UK) ve çimento+UK yerine farklı oranlarda kullanılmıstır. Bunun sonucunda ECC karısımlarının taze ve mekanik özellikleri belirlenmistir. ECC matrislerinin taze halde iken; yayılma çapı, akıs süresi, plastik viskozite ve esik kayma gerilmesi bulunmustur. Mekanik özellikler; basınç, elastisite modülü ve kırılma toklugu deneylerinin yanı sıra egilme performansının belirlenmesi için uygulanan dört noktalı egilmede çekme deneyi ile belirlenmistir. Ayrıca, karısımların çatlak dagılımları tespit edilmistir. Deney sonuçlarına göre, ECC?nin islenebilirligi SV oranı arttıkça, azaltmıstır. Mekanik deneyler sonucunda hem deformasyon kapasitesinin arttırılması hem de çatlak sonrası lif köprüleme yoluyla tasıma gücünü koruma parametreleri göz önüne alınarak, SV?nin çimento+UK yerine kullanılmasının en iyi sonuçları verdigi belirlenmistir. Bu nedenle, daha düsük boy:çap oranlı (30:1) SV 28 adlı vollastonitin ECC?ye olan etkisi de çimento+UK yerine kullanılarak test edilmistir. Daha yüksek boy:çap oranlı SV 16 vollastoniti, SV 28?e göre ECC?nin performans özelliklerini daha çok gelistirmistir. Bu nedenle, farklı agrega tane boyutunda (0-1000 ?m) ve M2.2 karısımında (UK/çimento=2,20) sentetik vollastonitin etkisi SV 16 kullanılarak tespit edilmistir. Deney sonuçları, deformasyon kapasitesi ve tasıma gücü parametreleri dikkate alınarak degerlendirildiginde, en iyi karısım grubunun UK/çimento=1.20, 0-400 ?m agrega tane boyutu ve çimento+UK yerine SV 16 vollastonitinin kullanılması sonucunda elde edildigi belirlenmistir. Bu nedenle, durabilite deneyleri olan hızlı klor geçirimliligi, kılcal su geçirimliligi ve donma-çözülme ile boyutsal stabilite deneyleri olan kuruma rötresi ve kısıtlanmıs rötre deneyleri bu karısım grubuna uygulanmıstır. Mekanik, durabilite ve boyutsal stabilite deneyleri göz önüne alındıgında en iyi performansı %6 SV 16 içeren ECC karısımının gösterdigi tespit edilmistir. Bu karısım grubu dikkate alınarak lif hacmi giderek azaltılmıs ve %1.6 lif içeriginde standart ECC karısımına benzer deformasyon kapasitesi, tasıma gücü ve çatlak dagılımı belirlenmistir. Böylece ECC tasarımında %6 SV 16 kullanımıyla %20 lif tasarrufu saglanmıstır.
  • Küçük Resim Yok
    Öğe
    Termal Enerji Depolama Özellikli Sepiyolit Katkılı Diyatomit/Faz Degistiren Madde Kompozitlerinin Üretilmesi Ve Karakterizasyonu
    (2018) Konuklu, Yeliz; Ersoy, Orkun; Çelik, Selahattin; Toraman, Öner Yusuf; Paksoy, Halime Ömür
    Bu proje kapsamında termal enerji depolama özelligi olan sepiyolit ve diyatomit esaslı FDM kompozitleri üretilmistir. Isıtma ve sog?utma uygulamalarının verimlilig?inin arttırılmasında faz deg?is?tiren maddelerde (FDM) termal enerji depolamadan yararlanılmaktadır. Sepiyolitin sahip oldug?u lifsi tu?bu?ler kanallı yapı, diyatomitin sahip oldug?u nano go?zenekler ic?eren tu?bu?ler yapı kompozit hazırlamada o?nem kazanmaktadır. Bu proje kapsamında organik FDM (alkanlar ve yag asitleri), diyatomit ve sepiyolit kullanarak sepiyolit/FDM, diyatomit/FDM, diyatomit+sepiyolit/FDM kompozitleri hazırlanmıstır. Kompozit üretimi sırasında; dogrudan emdirme, ultrasonik karıstırma destekli emdirme, vakumlu emdirme, inkübatör destekli emdirme, kalsinasyon destekli emdirme ve mikrodalga destekli emdirme metodları kullanılmıstır. Proseslerin optimizasyonu amacı ile; kalsinasyon destekli emdirme ve mikrodalga destekli emdirme yöntemleri sırasında farklı sıcaklık degerleri ve farklı süreler incelenmistir. Ayrıca kompozit materyallere farklı oranlarda FDM eklenmesi ve kullanılan FDM oranının ısıl özelliklere etkisi belirlenmistir. Kompozitlerin termal iletkenliklerini arttırma amacı ile Kompozit içerisine kütlece %0,5-5 alüminyum eklenmistir. Üretilen kompozitler morfolojik, kimyasal, termal yönden sırasıyla taramalı elektron mikroskobu (SEM), FTIR, termal gravimetrik analizi (TGA) ve diferansiyel taramalı kalorimetre (DSC) ile incelenmistir. Hazırlanan kompozitlerin yüksek sıcaklıklarda sızıntı yapıp yapmadıgını anlamak amacı ile su banyosu testinin yanısıra mikrotomografi ile yeni bir metod gelistirilmistir. Ayrıca sepiyolit katkılı FDM/diyatomit kompozitlerin termal performansları FDM/diyatomit kompozitleri ile kars?ılas?tırılarak sepiyolitin etkisi arastırılmıstır. Yapılan çalısmalar sonucunda; kullanılan mineral türünün ve kullanılan yöntemin kompozitin termal özelliklerini etkiledigi belirlenmistir. Mineral esaslı alkan ve parafin kompozitleri mineral esaslı yag asidi kompozitleri ile karsılastırıldıgında; proseslerinin konrol edilebilirliginin ve elde edilen kompozit verimlerinin daha yüksek oldugu dikkat çekmektedir. Hazırlanan mineral esaslı FDM kompozitleri bina yapı elemanlarına eklenerek bina elemanlarındaki termal performansları belirlenmistir. Proje kapsamında hazırlanan kompozitlerin uygulanan ısıtma prosesi karsısında referans bina malzemesinin sıcaklıgına göre 240 dk. geciktirebildigi anlasılmıstır. Diyatomitin ve sepiyolitin biyouyumlu olmaları, c?evre kirlilig?i ve c?evre sag?lıg?ı ac?ısından sorunsuz olmaları nedeniyle hazırlanan kompozitlerin bina uygulamalarında, gu?venli bir s?ekilde termal konfor sag?layıcı ve ısıl tampon olus?turucu madde olarak kullanılabilecekleri ve enerji tasarrufunda bu?yu?k katkılar sag?layacakları o?ngo?ru?lmektedir.
  • Küçük Resim Yok
    Öğe
    Vertical Anatolian mavoment project
    (2011) Çiner, Atilla; Rojay, Bora; Çubukçu, Evren; Ersoy, Orkun; Aydar, Erkan; Sayın, Erman; Kutluay, Alkor
    [Abstract Not Available]