A Two-Level Homogenization Approach for Polymer Nanocomposites with Coated Inclusions

In polymer nanocomposites, other than the matrix and inclusion, a third phase so-called interphase, is commonly observed. Inter-phase properties affect the overall macroscopic mechanical behavior. It is crucial to model the interphase and obtain the effective composite properties accordingly. Homogenization theory is very useful and powerful; however, many of the homogenization-based techniques have deficiencies. The goal of the study is to combine two very well-known homogenization techniques to model the polymer nanocomposites with coated inclusions. One of the goals of the study is to demonstrate the deficiency that originated from the interphase modeling and overcome this problem by the proposed two-level homogenization method. This method aims to model load transfer between the matrix and the reinforcement element through the interphase in a correctly. For this purpose, first, an effective inclusion is formed using finite element homogenization, then the effective inclusion and the matrix are homogenized using micromechanics-based Double Inclusion method. The proposed method provides a remarkable improvement compared to the micromechanics-based method for the soft interphase case

Positions of OECD Countries in the Context of Governance and Economic Performance

Son yıllarda başarılı yönetişimin ekonomik performansa etkisi tartışmaların odaknoktası haline gelmiştir. Yönetişimin ekonomik büyüme ve gelişme üzerindekirolünün önemli olduğu düşünülmektedir. Bu çalışmada OECD ülkelerinin,yönetişim değişkenleri ve bazı makroekonomik değişkenler açısındankümelenmeleri amaçlanmaktadır. Bu sayede söz konusu ülkelerin birbirlerinegöre konumlarının yanı sıra Türkiye ile olan konumları da belirlenmiştir. Otuzbeş OECD üyesi ülkenin ele alındığı araştırmada kümeleme analizi kullanılarakyedi değişkene ilişkin derlenen 2016 yılı verileri analiz edilmiştir. Analizsonuçlarına göre; bu ülkeler üç farklı kümede gruplanmış ve Türkiye’nin Meksikaile aynı küme altında toplandığı tespit edilmiştir.Good governance has been a key focus in economic performance policy discussions in recent years. The role of governance can be seen an important determinant of economic growth and development. In the present study, it was aimed to cluster based on selected governance and macroeconomic variables of Organisation for Economic Co-operation and Development (OECD) Contries and to determine the place of Turkey would occupy in this cluster. 2016 data for thirty-five OECD Countries and seven variables were analyzed. According to the analysis results; the countries were clustered in three groups and Turkey was in the same cluster with Mexico

Analysis of health indicators effectiveness in SAARC and OECD countries with ARAS and WASPAS

Sağlığa yönelik yatırımların ağırlığı ülkeden ülkeye değişmekle birlikte, bu yatırımların finansmanı kamu ve özel kesim tarafından sağlanır ve bu durum da toplumların refah seviyesi üzerinde etkili olur. Sağlık yatırımlarının nicelik olarak artırılmasının yanında niteliğinin de artırılması gerekmektedir ve sağlık göstergeleri performans analizlerinin yapılması faydalı olmaktadır. Bu bağlamda çalışmada Güney Asya Bölgesel İşbirliği Örgütü (SAARC) ülkeleri ile Ekonomik Kalkınma ve İşbirliği Örgütü (OECD) ülkeleri içinde toplam sağlık harcamaları en yüksek olan ülkelerin sağlık göstergeleri performansı ölçülmeye çalışılmıştır. Sağlık performansını etkileyen kriterler olarak toplam, kamu ve özel sağlık harcamaları, bebek ölüm oranı, kişi başına düşen GSYİH, doğuşta beklenen yaşam süresi ve ölüm oranı değişkenleri dikkate alınmıştır. ARAS ve WASPAS’ın uygulandığı araştırmada ulaşılan en güncel yıl olan 2019 verileri kullanılmıştır. Sonuçta ARAS ve WASPAS’ın benzer sonuçlar ürettiği gözlenmiştir. Elde edilen bulgulara göre sağlık performansı en yüksek olan ülkeler Norveç, İsviçre, İsveç ve İrlanda iken en düşük olanlar ise Butan, Pakistan, Hindistan, Nepal ve Bangladeş’tir.Investments in the health sector vary from country to country. However, financing of investments is provided by the public and private sectors; thus, it has an impact on the welfare of countries. Hence, increasing both the quality and quantity of health expenditures is essential. In this line, the research on performance analysis of health indicators is useful. This study analyzes the performance of health indicators of the countries in the South Asian Regional Cooperation Organization (SAARC) and the Organization for Economic Co-operation and Development (OECD), which have the highest level of health expenditures. To do so, we have utilized total, public, and private health expenditures, infant mortality rate, GDP per capita, life expectancy at birth, and mortality rate as the variables affecting health performance. Employing ARAS and WASPAS methods, we have used the most recent data, 2019. Our results yield similar findings of ARAS and WASPAS. Furthermore, we have documented that the countries with the highest health performance are Norway, Switzerland, Sweden, and Ireland. In contrast, Bhutan, Pakistan, India, Nepal, and Bangladesh are the countries with the lowest performance

The next step of the word problem over monoids

It is known that a group presentation P can be regarded as a 2-complex with a single 0-cell. Thus we can consider a 3-complex with a single 0-cell which is known as a 3-presentation. Similarly, we can also consider 3-presentations for monoids. In this paper, by using spher- ical monoid pictures, we show that there exists a finite 3-monoid-presentation which has unsolvable ‘‘generalized identity problem’’ that can be thought as the next step (or one- dimension higher) of the word problem for monoids. We note that the method used in this paper has chemical and physical applications

Lyme Arthritis in Primary Care; Case Report

Primary health care is the closest point to the patient. The person who is ill or suspicious of his / her health goes to the family physician, the family health center or the closest health institution. The correct diagnosis and treatment at Primary health care center is of great importance in terms of the cost effectiveness and public health improvement. Lyme arthritis is one of the diseases caused by Borrelio Burgdorferi, spirochete passing through the bite of the hard ticks of Ixodes. Infections may involve the skin, central nervous system, heart, eye and other organs, while in most cases joints are the main site of involvement. A very small percentage of children presenting with arthritis complaints have Lyme arthritis. In Europe, the most common form of arthritis following bacterial infection in children and adolescents is Lyme arthritis. Frequently, joint swelling is accompanied by pain. In this case report, we present a patient with Lyme arthritis who complained of pain, swelling, and inability to walk

Examination of the vertebral heart scale and anatomical structure of different dog breeds by computed tomography

This study aims to reveal the statistical difference by measuring the vertebral heart scale and anatomical structures of the heart in different dog breeds. The vertebral heart scale (VHS) has recently been described as a method for measuring the heart silhouettes of dogs and cats. Vertebral heart scale (VHS) may vary in dog and cat breeds due to age, weight, etc. Twenty-one dogs (10 males and 11 females) of different ages and weights were used. Among the dog breeds used are the French Bulldog, Russian Poodle, Rottweiler, Jack Russell, Golden Retriever, King Charles, Pekingese, Belgian Shepherd, Husky, Chihuahua, Cocker, Terrier, Bulldog, Bouvier and Flanders breeds. Multislice detectors were scanned at 80 kV, 200 MA, 639 mGY, and 0.625 mm slice thickness. The resulting images were saved in Digital Imaging and Communications in Medicine (DICOM) format. The obtained sections were measured in 3D-Slicer software. Thoracic height (TH) and cranial vena cava (CVC) measurement parameters were statistically significant with weight (P<0.05). Vertebral heart scale (VHS) was not statistically significant with any parameter in the correlation analysis (P>0.05). At the correlation table of animal weight with the measurements, it was seen that it had a very significant positive correlation with other measurement parameters except vertebral heart score (VHS) (P<0.01). Vertebral heart scale was determined as 9.09±1.37 vertebrae in females and 9.50±0.52 vertebrae in males. The study aims to contribute to veterinary anatomy, surgery and internal medicine

Eyelid tumors in dogs: 47 cases retrospective study (2006-2017)

Çalışmada 2006-2017 yılları arasında İstanbul Üniversitesi Veteriner Fakültesi Cerrahi Anabilim Dalı Kliniği’ne göz kapağında kitle şikayeti ile getirilen ve sağaltımları yapılan toplam 47 köpeğe ait göz kapağı tümörleri olguları retrospektif olarak değerlendirildi. Olguların ayrıntılı göz muayenesi yapıldı. Kitlelerin uzaklaştırılmasında V şeklinde eksizyon yeğlenerek, tümör tam katlı olarak bölgeden uzaklaştırıldı. Yapılan histopatolojik inceleme sonucu, meibomian bezlerden köken alan neoplazmaların çoğunlukta olduğu belirlendi. Çalışma sonunda elde edilen veriler ile göz kapağı tümörü oluşumunda ırk predispozisyonu, yaşın ve cinsiyetin etkisi ile en yaygın görülen göz kapağı tümörü belirlenip, kullanılan cerrahi yöntemin rekonstruktif blefaroplastiye gerek kalmadan, kitlelerin uzaklaştırılmasında yeterli olduğu görüldü.In this study, the eyelid tumors and the treatment results of 47 dogs referred to Istanbul University Faculty of Veterinary Medicine Department of Surgery with a complaint of eyelid masses were evaluated retrospectively. Cases underwent detailed ophtalmic examination. A V-shaped excision was performed and the tumor was removed in full-thickness. Histopathological examination revealed that most of the neoplasms originating from the meibomian glands were observed. The most common eyelid tumors and formation of the eyelid tumors with respect to the race predisposition, and effects of age and sex were defined. The surgical method used were sufficient for removal of the masses without the necessity of a reconstructive blepharoplasty

Kaplamalı takviyeye sahip polimer nanokompozitler için iki seviyeli bir homojenleştirme yöntemi

Polymer nanocomposites are materials which have polymer matrices and nano-scalereinforcement elements. Other than the matrix and the reinforcement element, an-other phase in nanocomposite systems has been observed and some of the propertyenhancement or deficiency has been attributed to this phase. The third phase inthe composite system is known as the interphase. The local properties of polymernanocomposites are not easy to distinguish since the length scale is very small andcharacterization at the nano-scale is not a simple procedure. Macroscopic behaviorof nanocomposites can be deducted by homogenization of a representative volumeelement in many different ways. The aim of the thesis is to propose a new homoge-nization approach to model the polymer nanocomposites with coated inclusions. Un-derstanding the structure of nanocomposites, formation of the interphase and differentcharacterization techniques for the interphase are important for this aim. Interphaseproperties affect the overall macroscopic mechanical behavior. So it is important tomodel the interphase and obtain the effective composite properties accordingly. Dif-ferent homogenization techniques and applications related to this problem are studiedand a new approach is proposed. This method aims to model load transfer betweenthe matrix and the reinforcement element through the interphase in a correct way.Furthermore, a computational gain is aimed with the proposed model in comparisonto a full three-phase finite element simulation. Another goal is to extend the proposedmethod to viscoelasticity. For this purpose two-dimensional and three-dimensional fi-nite element codes are developed for a viscoelastic homogenization framework. Theformulations regarding the viscoelastic homogenization are derived and presented.----M.S. - Master of ScienceBAP (Bilimsel Arastirma Projeleri