Impact Fatigue Characteristics of Valve Leaves for Small Hermetic Reciprocating Compressors

This paper presents an investigation on the impact fatigue characteristics of valve leaves that are prevalently used in hermetic reciprocating compressors especially for the household type refrigerators. The investigation relates the impact fatigue lifetime of the valve leaves that is the heart of the compressor, with the working temperature, material type (carbon steel, stainless steel and improved stainless steel grade) and tumbling duration after the manufacturing process. The investigation provides a better understanding of the impact fatigue characteristics of valve leaves while designing a high performance compressor to decrease the energy consumption. \ud A unique automated impact fatigue test system was designed and produced, which enables to carry out impact fatigue tests of the compressor valve leaves under the desired impact velocities. In the test system, original valve plate and valve leaf couple was utilized through the experimentation in order to simulate the real behavior in the compressor. A fixture was designed to mount the valve plate. The main principle of the system is to create pulsating airflow through a high frequency solenoid valve. The impact fatigue life was determined for various impact velocities and at different operating temperatures

Underfilled blood tube containing EDTA: Is it an inappropriate sample for HbA1c assay?

IntroductionBlood samples having inappropriate volume are a substantial part of preanalytical errors. Inadequate sample volume for glycated haemoglobin (HbA1c) test may be a common problem of patients with diabetes mellitus having vascular changes. In this study, we compared HbA1c concentrations of underfilled and appropriately filled blood collection tubes. Materials and methodsTo compare HbA1c concentrations, blood samples were collected into 2 mL tubes containing K3-EDTA from 109 subjects. Two blood samples (underfilled and appropriately filled) were drawn from a patient by the same personnel and materials. HbA1c measurements were assayed on a Cobas 6000 analyser module c 501 (Roche Diagnostics, Mannheim, Germany). The HbA1c% results were compared by t-test and Wilcoxon’s signed-rank statistical methods (SPSS Inc., Chicago, USA). Bias analysis was performed using Microsoft Excel 4.0. ResultsUnderfilled samples were classified three groups (group 1, N = 44; group 2, N = 36; and group 3, N = 29) according to the filling ratio of the samples; 0.5 mL and below ( 50%), respectively. When we compared underfilled tubes with pairing filled tubes, there was a statistically significant difference only with tubes filled less than 25% (P = 0.030). Furthermore, we have done bias analysis between paired tubes according to the diagnostic cut-off value of 6.5%. The bias was more prominent in up to 50% underfilled blood tubes (1.1%), when HbA1c concentrations were below the diagnostic cut-off of 6.5%. ConclusionsWe suggest that the blood tubes with EDTA for HbA1c measurement should be filled with at least 50% to avoid clinical variations

Ab-initio study of iridium on silicon (001) surface

Ankara : The Department of Physics and the Graduate School of Engineering and Science of Bilkent Univ., 2013.Thesis (Master's) -- Bilkent University, 2013.Includes bibliographical references leaves 61-64.Self-assembled nanowire growth on semiconductor surface is based on deposing sub-monolayer material over the surface. Even though high resolution STM image gives plausible surface analysis, determination of the nanowire structure is the most di↵ucult part of these experiments. Due to the this reason, first-principles investigation is essential to understand the one dimensional nanowire structure grown over the surface as well as the STM images of these structures. Recently, iridium silicide nanowire on Si (001) surface is observed. In this thesis, we study formation of the nanowire after deposition of Ir on Si(001). Ab-initio plane wave pseudopotential calculations are performed for number of iridium silicide nanowires generated by increasing iridium coverage on Si(001) surface. For the iridium coverage as 0.125 ML, the possible nanowire formation is analyzed and its calculated STM images are compared with experimental STM image. As a result of our detailed analysis, we suggest that the STM image observed at experiment doesn’t consist of Ir atoms since Ir atom tends to be buried into the Si bulk. We model the possible nanowire formation which is consistent with pseudo-STM calculation. According to our model, iridium is placed at the troughs between the dimer rows on the surface and it creates a structure by breaking the Si dimer bonds. The coverage implied by the model, is consistent with experimental numbers.Oğuz, İsmail CanM.S

Presentation antineutrophil cytoplasmic autoantibody negative-associated granulomatosis with polyangiitis with pyuria

Pulmonary renal syndrome is a rare but serious complication of systemic vasculitis. The majority the cases are antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis. In this case, a 58 years old female case having aworsening clinical picture of probable urinary infection and acute renal failure was presented. By means of proteinuria, pyuria, hematuria and unexplained acute renal failure, we review the relevant literature on pulmonary renal syndrome associated with granulomatosis with polyangiitis (GPA) with negative serum ANCA serology. This report demonstrates the difficulty of diagnosing granulomatosis with polyangiitis (GPA) until renal biopsy was done while initial diagnostic serological negative ANCA testing

MEDICAL MALPRACTICE VERDICTS OF HIGH COURT IN TURKEY

Amaç: İnsan sağlığının korunmasında ve geliştirilmesinde çok önemli rolü olan tıp biliminin uygulayıcıları zaman zaman bu görevlerini tam olarak yerine getirmedikleri iddiasıyla karşılaşmaktadır. Yüksek Yargıya taşınan bu olumsuz durumların incelenmesiyle hem tıp mensuplarının karşılaştıkları iddialara açıklık kazandırmak hem de uygulamada bu aksaklıkların giderilmesine katkı sağlamak amaçlanmıştır. Yöntemler: Bu çalışmada Türkiye'de 1978-2006 yılları arasında Yargıtay'a intikal etmiş 30 olgunun dosyaları retrospektif olarak incelenerek elde edilen veriler ilgili literatür ışığında tartışılmıştır. Bulgular: Yüksek yargıya yansıyan olguların %93'ünün (28 olgu) tazminat davası konusu olduğu belirlendi. Olayın gerçekleştiği zaman ile yargıtay kararları arasında 10 olguda 5-10 yıl arası iken 4 olguda sürenin 10 yılı geçtiği gözlendi. Yargılamaya konu olan tıbbi girişimlerin ölümle veya sekelle sonuçlanıp sonuçlanmamasının, yüksek yargı kararı çıkana kadar geçen süre ile anlamlı ilişkisinin olmadığı belirlendi (χ²=1,272; p=0,529). Sağlık çalışanlarının yüksek yargı organının kararlarına göre belirlenen kusur nedenleri arasında ilk sırada 14 hastada yanlış tedavinin geldiği (%47) bunu sırasıyla 10 hastada özen ve dikkat göstermeme (%33), 4 hastada (%13) ihmal, 2 hastada (%7) ise tanı hatasının takip ettiği gözlendi. Uzmanlık alanlarına göre kusur dağılımı incelendiğinde istatistiksel olarak anlamlı fark bulunmamıştır (χ²=15,152; p=0,651). Sonuç: Sağlık çalışanlarının önde gelen kusurlu bulunma nedenlerine dikkat çekilmeye çalışıldı. Tıbbi uygulama hatalarına yönelik yasal mevzuatın içeriğinin düzenlenmesi gerekliliği konusu tartışıldı. Objectıve: Medical malpractice claims increases against health professional and this issue gain importance in the world. Judgment involving inquiry and prosecution procedures are still dilemma for health professional in the world. The judgment on the verdict also takes interest of lawyers, patients. In this study, we aimed to discuss the verdicts of the High Court on malpractice cases. Methods: We presented thirty cases which have sentenced by the High Court of Turkey on medical malpractice claims and judgment between the years of 1978-2006. The files of these cases were examined retrospectively.Results: Of the cases, 93% (n=28) of verdicts were related to compensation. The period between the time that incident (event resulted to malpractice claim) occurred and the time of High Court sentence were longer than 10 years in 4 cases, between 5-10 years in 10 cases. Significant difference was not found in the outcomes of medical interventions resulted to death or functional losses between the period of time spent in justice (χ²=1.272; p=0.529). Causes of liabilities according to judgment; incorrect treatment was found in 14 cases (47%), lack of care and attention, careless in 10 cases (33%), negligence in 4 cases (13%) and misdiagnosis in 2 cases (7%) were observed. Significant difference was not found in the cases found liable between the specialties (χ²=15.152; p=0.651). Conclusıon: Major causes of liabilities were reviewed. The necessity of a malpractice legislation was discussed by the help of the literature

Özerklik desteği ve çocukların okula bağlılığı: motivasyonun aracılık rolü

The present study examined the mediating role of motivation in the association between autonomy support and children's school attachment. The study participants consisted of 437 primary school students (232 girls and 205 boys) selected from six schools in a province located in Turkey's southeast region. A hypothesized model was developed and tested by structural equation modeling on cross-sectional data. The data were collected via The School Attachment Scale for Children and Adolescents, The Scale for Motivation in Education, and The Short Form of the Learning Climate Scale. The results indicated that autonomy support had an indirect effect on school attachment through internal motivation. Contrary to these findings, it has been determined that neither identified external motivation nor introjected external motivation affected attachment to the school's directly and indirectlyBu çalışmada, özerklik desteği ile çocukların okula bağlanması arasındaki ilişkide motivasyonun aracı rolü incelenmiştir. Araştırmanın katılımcılarını, Türkiye'nin Güneydoğu Anadolu bölgesinde yer alan bir ildeki altı okuldan seçilen 437 ilkokul öğrencisi (232 kız ve 205 erkek) oluşturmuştur. Kesitsel veriler üzerinde yapısal eşitlik modellemesi ile varsayımsal bir model geliştirilmiş ve test edilmiştir. Veriler Çocuklar ve Ergenler için Okula Bağlanma Ölçeği, Eğitimde Motivasyon Ölçeği ve Öğrenme İklimi Ölçeği Kısa Formu ile toplanmıştır. Sonuçlar, özerklik desteğinin içsel motivasyon yoluyla okula bağlanma üzerinde dolaylı bir etkisi olduğunu göstermiştir. Bu bulguların aksine, ne özdeşleşmiş dışsal motivasyonun ne de içselleştirilmiş dışsal motivasyonun okula bağlanmayı doğrudan ve dolaylı olarak etkilemediği belirlenmiştir

Autonomy Support and Children's School Attachment: Motivation as a Mediator [Özerklik Desteǧi ve Çocuklarin Okula Baǧliliǧi: Motivasyonun Aracilik Rolü]

The present study examined the mediating role of motivation in the association between autonomy support and children's school attachment. The study participants consisted of 437 primary school students (232 girls and 205 boys) selected from six schools in a province located in Turkey's southeast region. A hypothesized model was developed and tested by structural equation modeling on cross-sectional data. The data were collected via The School Attachment Scale for Children and Adolescents, The Scale for Motivation in Education, and The Short Form of the Learning Climate Scale. The results indicated that autonomy support had an indirect effect on school attachment through internal motivation. Contrary to these findings, it has been determined that neither identified external motivation nor introjected external motivation affected attachment to the school's directly and indirectly. © 2021 The authors. All right reserved

Diversity and novelty in information retrieval

This tutorial aims to provide a unifying account of current research on diversity and novelty in different IR domains, namely, in the context of search engines, recommender systems, and data streams

Diversity and novelty in web search, recommender systems and data streams

This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in Proceedings of the 7th ACM international conference on Web search and data mining, http://dx.doi.org/10.1145/2556195.2556199This tutorial aims to provide a unifying account of current research on diversity and novelty in the domains of web search, recommender systems, and data stream processing