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Koleksiyon [5]
Tam Metin [2]
Yazar [20]
Yayın Türü [9]
Konu Başlıkları [20]
Dergi Adı [20]
Yayıncı [20]
Dil [2]
Yazar Departmanı [2]

Tuncer, I | Delilbasi, C | Deniz, E | Soluk-Tekkesin, M | Olgac, V | Sencift, K


Purpose: Bisphosphonates are commonly used drugs in pediatric patients in the treatment of osteoporotic diseases and various types of cancers. The purpose of this study was to evaluate the effects of pamidronate administration on mandibular growth and tooth eruption in new born rats. Materials and Methods: Forty Sprague Dawley rats were included in the study and divided into four groups as; 14th day pamidronate group, 30th day pamidronate group, 14th day control group and 30th day control group. Pamidronate groups were daily injected with 1.25 mu g/g pamidronate disodium subcutaneously whereas control groups were injected with steri . . .le saline. Eruption levels of lower incisor and molar teeth were assessed macroscopically. Mandibular growth was assessed by measuring reference points in cone beam tomography. Histological and histomorphometric examinations were performed under light microscope to evaluate tooth morphology and number of osteoclasts. Results: Retardation in mandibular growth, decrease in number of osteoclasts, delay in tooth eruption, degeneration in both tooth morphology and structure were observed in the pamidronate groups compared to control groups. Conclusion: Pamidronate administration during growth and development stage may adversely affect tooth eruption and mandibular growth in new born rats Daha fazlası Daha az


Degitz, IA | Yilmaz, MS | Piskin, S

Article | 2017 | CHEMICAL INDUSTRY & CHEMICAL ENGINEERING QUARTERLY23 ( 4 ) , pp.581 - 588

In this study, MCM-41 was prepared from the gold mine tailings slurry as an alternative silica source. The effects of the reaction time, temperature, and pH adjustments on the synthesis of MCM-41 were investigated. The optimum condition for the synthesis process of pure and highly ordered MCM-41 from tailings slurry was found to be at 30 degrees C for 60 min with a pH of 11. In addition, MCM-41 was synthesized from a pure silica source, in order to compare the structural properties of the obtained sample from that of the slurry produced at optimum conditions. The samples synthesized from tailings slurry had a high surface area of 98 . . .3 m(2)/g and a pore volume of 0.74 cm(3)/g. The structural properties of the samples produced from the slurry were closely related with those that were synthesized from a pure silica source. Results indicate that the tailings slurry has the potential to be used as a cheap, alternative silica source which can be used for the synthesis of a pure and ordered mesoporous silica MCM-41 Daha fazlası Daha az

Examining the Behavior of Credit Rating Agencies Post 2008 Economic Turmoil

Uslu, CL


The demand for sovereign ratings has increased throughout last decades. Until the 1990's, credit rating agencies (CRAs) did not rate most of the emerging markets and the focus was almost only on developed countries, however, during this decade the number of sovereigns rated increased dramatically due to addition of emerging markets to the portfolio. The global financial crisis in 2008 led to the loss of credibility of these major credit rating companies. None of these three agencies showed any signal of macroeconomic problems in countries where the financial crisis created devastating macroeconomic results. It is believed that this . . .failure has led credit rating agencies to behave more conservatively. This paper aims to determine whether CRAs tend to behave conservatively after the 2008 global financial crisis. If the downgrading is greater than the worsening of the economic situation in the given economies, then we can infer that CRAs tend to behave more conservatively. The good working model in estimating ratings assigned by CRAs before the crisis failed to estimate the ratings after 2008 crisis. This may have happened due to two reasons. First, as experienced in the aftermath of the former crisis, credit rating agencies may have added new macroeconomic variables in the process of assigning ratings or change the weight assigned to the already existing macroeconomic variables. Second, it is a known fact that ratings emerge from the combination of two distinct information; the quantitative part reflected by macroeconomic indicators and the qualitative judgements of the agency about the sovereign Daha fazlası Daha az

Young children’s number sense development: Age related complexity across cases of three children

Yilmaz, Z.

Article | 2017 | International Electronic Journal of Elementary Education9 ( 4 ) , pp.891 - 902

Children start to develop number sense even well before they start the school. Developing number sense serves as an intermediate tool for learning conventional mathematics taught in schools. This number sense has three key areas: number knowledge, counting and arithmetic operations. As a result, the aim of this study was to examine aged related complexity of number sense development of young children’s aged four, six and seven under two key areas: number knowledge and counting. Semi structured task based clinical interviews were employed to examine number sense development. Five different assessment tasks were employed with three ch . . .ildren. Children’s responses were analysed to identify their level of number sense understanding and difficulties with developing number sense. Findings were reported under two categories: first children’s ability to understand number concept and their ability to accomplish number word sequences and second counting. Findings of the study indicated a significant age related complexity and improvement in both two aspects of number sense. Older children with more experience developed better number sense than the younger children. © IEJEE Daha fazlası Daha az

Risk transmission and contagion in the equity markets: International evidence from the global financial crisis

Gencer, H.G. | Hurata, M.Y.

Article | 2017 | Romanian Journal of Economic Forecasting20 ( 3 ) , pp.110 - 129

This study examines the time-varying volatility spillover mechanisms between the US (S&P 500) and the world’s largest stock markets, including those of the G20 countries, along with some selected European equity exchanges between 1994 and 2014. In the context of the empirical study, we adopt a multivariate BEKK-GARCH model with its asymmetric generalization. Overall, our results suggest that there is a significant shock and volatility transmission from the S&P 500 to the other stock markets while the opposite (from the others to the US) is also observed for some market-pairs under investigation. Furthermore, we analyze whether marke . . .t volatilities and time-varying correlations significantly change during the different phases of the 2007-2009 global financial crisis or not. The linear regression analyses with the dummy indicators suggest heightened variances and correlations, which signifies the crisis spillover and contagion. © 2017, Institute for Economic Forecasting. All rights reserved Daha fazlası Daha az

The translucency effect of different colored resin cements used with zirconia core and titanium abutments

Capa, N. | Celebi, C. | Casur, A. | Tuncel, I. | Usumez, A.

Article | 2017 | Nigerian Journal of Clinical Practice20 ( 12 ) , pp.1517 - 1521

Purpose: The purpose of this study was to evaluate the effect of the different color of resin cements and zirconia cores on the translucency parameter (TP) of the restoration that simulates the implant-supported fixed prosthesis using titanium base on the bottom. Materials and Methods: Zirconia core plates (Zr-Zahn) were prepared in A2 shades (n = 11). Resin cement plates (3M ESPE) were prepared in A2, A1, translucent (TR) shades (n = 11). The initial color measurements and were measured on zirconia core plates, and resin cements plates using a spectrophotometer. Then, the resin cement plates were placed below the zirconia core plat . . .es, and the second measurements were done. The final measurements were done after placing the titanium discs in the bottom. The data were analyzed with two-way analysis of variance and Tukey honestly significant differences tests (? = 0.05). Results: The highest TP values were recorded for A1-colored resin specimens and the lowest for zirconia core plates in the first measurement (P < 0.05). The addition of zirconia core decreased the TP values in all tested resin cement groups (P < 0.05). The highest TP value was recorded for A1-colored resin cement with zirconia core plates and the lowest for A2 and TR with zirconia core plates after second measurements (P < 0.05). The addition of titanium decreased the TP of the zirconia core plate and resin cement combination (P < 0.05). Conclusions: The addition of a zirconia core under the resin cement dramatically reduced the TP values, and the presence of a titanium layer decreased the TP value and caused a darker appearance. © 2018 Nigerian Journal of Clinical Practice | Published by Wolters Kluwer - Medknow Daha fazlası Daha az

Zero valent zinc nanoparticles promote neuroglial cell proliferation: A biodegradable and conductive filler candidate for nerve regeneration

Aydemir Sezer, U. | Ozturk, K. | Aru, B. | Yanıkkaya Demirel, G. | Sezer, S. | Bozkurt, M.R.

Article | 2017 | Journal of Materials Science: Materials in Medicine28 ( 1 ) , pp.1517 - 1521

Regeneration of nerve, which has limited ability to undergo self-healing, is one of the most challenging areas in the field of tissue engineering. Regarding materials used in neuroregeneration, there is a recent trend toward electrically conductive materials. It has been emphasized that the capacity of conductive materials to regenerate such tissue having limited self-healing ability improves their clinical utility. However, there have been concerns about the safety of materials or fillers used for conductance due to their lack of degradability. Here, we attempt to use poly(?-caprolactone) (PCL) matrix consisting of varying proporti . . .ons of zero valent zinc nanoparticles (Zn NPs) via electrospinning. These conductive, biodegradable, and bioactive materials efficiently promoted neuroglial cell proliferation depending on the amount of Zn NPs present in the PCL matrix. Chemical characterizations indicated that the incorporated Zn NPs do not interact with the PCL matrix chemically and that the Zn NPs improved the tensile properties of the PCL matrix. All composites exhibited linear conductivity under in vitro conditions. In vitro cell culture studies were performed to determine the cytotoxicity and proliferative efficiency of materials containing different proportions of Zn NPs. The results were obtained to explore new conductive fillers that can promote tissue regeneration. © 2016, Springer Science+Business Media New York Daha fazlası Daha az

Challenges and Possible Consequences of Transatlantic Trade and Investment Partnership

Kurtul, H | Akkartal, E

Conference Object | 2017 | FINANCIAL ENVIRONMENT AND BUSINESS DEVELOPMENT4 , pp.189 - 197

In recent years, the European Union (EU) and the USA change their trade policy, and also they began negotiations for signing the most comprehensive free trade agreement. Its negotiations began in the second half of 2013 and is called Transatlantic Trade and Investment Partnership (TTIP), whose key points are transparency, coherence, and nondiscriminatory. With these types of qualifications, EU and US administration believes that this partnership will boost economic power, and not only the EU and the USA but also all countries in the world will benefit from the outputs of the agreement. On the other hand, although their intensions ar . . .e widely on the same direction, sometimes controversial platforms occur, because both parties do not want to change their implementations at some topics such as conformity assessments, genetically modified products, and hormone-treated meat. Accordingly, the objective of this paper is to identify mainly the key challenges of the TTIP with qualitative and quantitative data. Descriptive analysis of the data will be displayed. The agreement has two main bodies as horizontal side which means regulatory cooperation and sectorial side. In this paper, regulatory cooperation and its context are considered as essential subjects. Sectors have more details and it is hard to explain all situations in sectors. After focusing on the reasons of the existence of the TTIP, the need will be explained. Then the main elements, such as market access, regulatory coherence, and improved cooperation, are mentioned. As a conclusion, mostly recommendations and expectations take part because of the fact that negotiations are going on Daha fazlası Daha az

Turkey’s Unique Energy Corridor Role at the Center of Eurasia in the 21st Century

Kısacık, Sina | Kaya, Furkan

Article | 2017 | Marmara Üniversitesi Siyasal Bilimler Dergisi5 ( Özel sayı ) , pp.93 - 105

Bu makalenin amacı, Türkiye'nin 21. yüzyılda Avrasya'nın merkezindeki eşsiz enerji koridoru rolünün incelenmesidir. Petrolün ve doğalgazın, endüstrinin yanı sıra diğer alanlarda da kullanılmaya başlanmasıyla birlikte, bu kaynakların çıkartılması, işlenmesi ve taşınması, tedarikçiler ve bunları talep edenler arasında önemli bir konu haline gelmiştir. Avrasya'da, kıtanın doğusu petrol ve doğalgaz bakımından zengin olmasına rağmen, kıtanın batısında önemli miktarda hidrokarbon rezervleri bulunmamaktadır. Enerji güvenliği perspektifi bağlamında, hem tüketiciler hem de talep edenler, hidrokarbon kaynaklarının kesintisiz taşınmasını öncel . . .emektedirler. Bu durum, transit ülkelerin varlığını zorunlu kılmaktadır. Günümüzde yeni dünya düzeni, bölgesel istikrarsızlıklar temelinde şekillenmektedir. Buna ilaveten kıtanın çekim merkezi de değişmektedir. Türkiye bir enerji koridoru olarak bu gelişmelerin ve kıtanın merkezindedir. Nihayetinde, mevcut ve proje halindeki petrol ve doğalgaz boru hattı projeleri, hem Türkiye hem de enerji tedarikçisi ve talep eden ülkeler için faydalı olacaktır This paper aims to examine Turkey’s sui generis energy role at the center of Eurasia in the 21st century. With the start of using oil and natural gas in the industry and also elsewhere, drilling, processing and transporting these resources have become an important issue between demanders and suppliers. In Eurasia, although eastern part of the continent is rich in terms of oil and gas, western part of the continent lacks significant volume of hydrocarbons. In terms of energy security perspective, both producers and demanders prioritize the uninterrupted transportation of hydrocarbons. This situation necessitates the presence of transit countries. Nowadays, the new world order has been shaping in the perspective of regional instabilities. In addition, center of gravity of the continent has been changing. Turkey is at the center of these developments and continent as an energy corridor. Hence, the existing and projected oil and natural gas pipeline projects will be beneficial for either Turkey or energy supplier/demander countrie Daha fazlası Daha az

Experimental study for the hydraulic efficiency of an overtopping type wave energy converter with a circular runup ramp

Akgül, Mehmet Adil | Kabdaşlı, Mehmet Sedat

Article | 2017 | Balıkesir Üniversitesi Fen Bilimleri Enstitüsü Dergisi19 ( 1 ) , pp.118 - 131

Bu çalışmada, dairesel silindir formundaki bir tırmanma yüzeyi üzerinde düzenli dalgalar etkisinde meydana gelecek aşma debileri ölçülmüş ve aşan su kütlesinin enerji bütçesinden yola çıkılarak sistemin bir dalga enerjisi dönüştürücü olarak hidrolik verimi incelenmiştir. İki boyutlu fiziksel modelleme teknikleri uygulanarak gerçekleştirilen çalışmada aşma debilerinin dalga parametreleri ile değişimi incelenmiş ve debilerin tahmini için ampirik bir bağıntı önerilmiştir. Hidrolik verim, aşan su kütlesinin ortalama gücünün dalga enerji akısına oranı cinsinden elde edilmiştir. Çalışma, özellikle kısa periyodlu dalgalarda yapının %40'a y . . .akın bir hidrolik verim sağladığını göstermekte olup verimin artan dalga boyu ile azaldığını ortaya koymuştur In this study, overtopping rates on a circular cylindrical overtopping ramp under regular waves have been measured and hydraulic efficiency of the device as a wave energy converter has been assessed by analyzing the energy budget of the overtopped water mass. The study has been carried out by conducting two-dimensional physical model tests. The variation of overtopping rates with wave parameters has been studied and an empirical formula has been evaluated for the estimation of overtopping rates. The efficiency of the system has been calculated as the ratio of the mean power of the overtopped water mass to the wave energy flux. Results indicate that the hydraulic efficiency based on the kinetical komponent can reach 40% for the case of steep waves and the efficiency is reduced with increasing wavelengt Daha fazlası Daha az


Okbaz, A | Pinarbasi, A | Olcay, AB


In the present study, 3-D numerical simulations on heat and fluid flow characteristics of double-row multi-louvered fins heat exchanger are carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles in the range of 20 degrees

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