An Investigation On Model Predictive Controllers’ Applications Of A Chemical Engineering Process

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2006Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2006Bu çalışmada, Model Öngörülü Kontrol edicilerin kimya mühendisliğinin en öenmli uygulamalarından biri olan kimyasal reaktörlerde kullanımı ve performansı incelenmiştir. Propilen oksit ve su reaksiyonundan ortaya çıkan propilen glikolun konsantrasyonu ve reaktörün sıcaklığı, propilen oksit ve soğutma suyunun akış debisinin ayarlanması ile control edilmiş, soğutma suyu sıcaklığı ve propilen oksitin giriş konsantrasyonu bozucu etki olarak değerlendirilmiştir. Tasarlanan kontrol edici, ayar noktası değişimleri ve bozucu etkilere karşı cevabı yönünden incelenmiştir. Bu etkilere kontrol edicinin kısa sürede cevap verdiği gözlemlenmiştir. Ayrıca kontrol edicinin gürbüzlüğünü test etmek amacı ile sistem parametreleri değiştirilmiş ve kontrol edicinin yeni sistemde de o modele ait olmayan basamak cevabı ile reaktörü kontrol edebildiği gözlemlenmiştir.In this study, applications and performance of MPC on chemical reactors, one of the most important chemical engineering applications, are examined. Propylene glycol concentration, resulting from reaction of propylene oxide and water, is controlled with reactor temperature by manipulating propylene oxide and coolant flow rates. Temperature of cooling water and initial concentration of propylene oxide are evaluated as measured disturbances. The designed controller is examined in terms of set point tracking and disturbance rejection. It is seen that the controller tracks the set point and rejects the effect of disturbances in a reasonably short time. Also in order to test the robustness of the controller, the system parameters have been changed and it is observed that the controller performs finely with old step response data model.Yüksek LisansM.Sc

The Effect of Insulin Resistance and Obesity on Low−Density Lipoprotein Particle Size in Children

Objective: In adults, it was shown that obesity and insulin resistance affect low−density lipoprotein (LDL) particle size and small dense (sd) LDL is associated with cardiovascular diseases. In this study, we investigated the effect of obesity and insulin resistance on LDL particle size

Beyond the ‘East-West’ dichotomy: global variation in cultural models of selfhood

Markus and Kitayama’s (1991) theory of independent and interdependent self-construals had a major influence on social, personality, and developmental psychology by highlighting the role of culture in psychological processes. However, research has relied excessively on contrasts between North American and East Asian samples, and commonly used self-report measures of independence and interdependence frequently fail to show predicted cultural differences. We revisited the conceptualization and measurement of independent and interdependent self-construals in 2 large-scale multinational surveys, using improved methods for cross-cultural research. We developed (Study 1: N = 2924 students in 16 nations) and validated across cultures (Study 2: N = 7279 adults from 55 cultural groups in 33 nations) a new 7-dimensional model of self-reported ways of being independent or interdependent. Patterns of global variation support some of Markus and Kitayama’s predictions, but a simple contrast between independence and interdependence does not adequately capture the diverse models of selfhood that prevail in different world regions. Cultural groups emphasize different ways of being both independent and interdependent, depending on individualism-collectivism, national socioeconomic development, and religious heritage. Our 7-dimensional model will allow future researchers to test more accurately the implications of cultural models of selfhood for psychological processes in diverse ecocultural contexts

Antibiotic susceptibility of Klebsiella pneumoniae strains isolated from clinical samples

Antibiotic resistance in bacteria has become a worrying phenomenon in today's world. K. pneumoniae is a member of the Enterobacteriaceae family, which causes nosocomial infections as an opportunistic pathogen but inherently harboured as a part of the natural human microbiota. Carbapenem resistance of K. pneumoniae was a rare occurrence up to ten years ago, but in recent years many types of carbapenemase producing K. pneumoniae have become common. This retrospective study aims analysing susceptibility to various antibiotics, commonly used in treatment against K. pneumoniae strains isolated by using conventional methods from various infection sites. Antibiotic susceptibility tests were performed by using an automated system, the VITEK 2 Compact ®. In this study, 502 K. pneumoniae strains isolated from patients that treated at various services of a university hospital with 515-bed capacity were examined. When compared to the data available with studies of recent years in Turkey, especially in intensive care and inpatient services, the resistance of K. pneumoniae strains to antibiotics against most to carbapenems is rapidly increasing in the degree of high concern. Therefore, in all hospitals, antibiotic management policies should be implemented with a multidisciplinary approach

İlahiyat Fakültesi Öğrencilerinin Mizah Anlayış- larının Bazı Değişkenlere Göre İncelenmesi

Mizah anlayışı ve dindarlık birbirlerinden uzak kavramlar olarak algılan- maktadır. Bundan dolayı olsa gerek ülkemizde bu iki kavram arasındaki ilişkiyi araştıran çalışma sayısı oldukça azdır. Araştırmanın amacı yüksek din öğre- nimi gören öğrencilerin mizah anlayışlarını demografik değişkenler ve dindar- lık algısı bağlamında incelemektir. Araştırmanın örneklemi 2014-2015 eğitim- öğretim yılında Türkiye'nin 6 İlahiyat Fakültesinde öğrenim gören toplam 346 kişiden (186 kız, 160 erkek) oluşan ilahiyat lisans ve ilköğretim din kültürü ve ahlak bilgisi öğretmenliği öğrencileridir. Katılımcıların mizah anlayışları hak- kında bilgi toplamak için Aslan, Alparslan, Evlice, Aslan ve Cenkseven (1999) tarafından Türkçe'ye uyarlanmış Çok Boyutlu Mizah Duygusu Ölçeği (ÇBMDÖ) kullanılmıştır. Bu araştırma sonucunda, katılımcıların mizah anla- yışlarının, cinsiyete, yaşa, sosyoekonomik düzeye göre anlamlı şekilde farklı- laştığı ancak sınıf düzeyine ve ikamet edilen yere göre farklılaşmadığı tespit edilmiştir. Literatürdeki birçok araştırmanın aksine araştırma bulgularına ba- kıldığında öğrencilerin dindarlık algısı ve mizah anlayışları arasında olumlu bir ilişki olduğu görülmüştür

Retail location competition under carbon penalty

We study the retail location problem in a competitive linear market in which two retailers simultaneously choose their locations. Both retailers procure identical products from a common supplier and each consumer purchases from the closest retailer. Each retailer incurs transportation costs for inventory replenishment from the warehouse and consumer travels to the store. We consider two carbon tax schemes imposed on retailers: for supply-chain-related transportation and for consumer-related transportation. Our analysis indicates that intense competition between retailers leads to a "minimal differentiation" equilibrium, which substantially increases the total system emissions. According to our numerical experiments with realistic parameter values, carbon tax on supply-chain-related transportation does not affect retail location decisions. Carbon tax on consumer transportation, however, may effectively induce the retailers to approach the middle of their respective markets, reducing the total system emissions. Our analysis also indicates that a low carbon price, relative to market profitability, only reduces the total system profit without any effect on emissions. Our findings suggest that the central policymaker avoid a uniform carbon price across different sources of emission and sectors with different characteristics

Exhibition / Sergi: Gönül Tankut 10. Yıl Anma Sergisi / Gönül Tankut Commemoration Exhibition; Güner’ce Tasarımlar / Güner’s Designs

Publisher's Versio

Comparison of the CMV Antigenemia Test and CMV-DNA PCR Results in Solid Organ Transplant Recipients

Cytomegalovirus (CMV) infection is among the most common important viral infections in solid organ transplant (SOT) recipients. Diagnostic tests for detecting CMV replication are widely used for this group of patients, however there is no clear agreement on the cut-off levels for interpretation of clinical decisions especially when the low level of viral load is detected. In this study, CMV pp65 antigenemia test results were compared with plasma CMV-DNA levels detected by quantitative real-time polymerase chain reaction (qPCR) in samples of kidney and liver transplant recipients in the Central Laboratory of Dokuz Eylul University Hospital between 2011 and 2013, and the correlation between these two tests and viral load equivalent to antigenemia positivity were determined. In the study, pp65 antigenemia and CMV-DNA qPCR results were evaluated retrospectively. The samples from the same patients were included if the time between antigenemia and CMV-DNA qPCR tests were less than 48 hours. SPSS v15.0 was used for correlation, regression and ROC curve analysis. The results of the 217 samples collected from 100 patients (59 male, 41 female; age range: 16-71, mean age: 46 +/- 13 years), 36 liver and 64 kidney recipients were evaluated in the study. Of the patients 80% were CMV IgM negative, IgG positive; 1% was CMV IgG and IgM positive; 2% were CMV IgM and IgG negative, while for 17 patients serological results could not be reached. CMV pp65 antigenemia and CMV-DNA were both negative in 102 (47%) samples, while both were positive in 37 (17%) samples. The single sample from a case with CMV IgM and IgG positivity yielded negative results for both antigenemia and CMV-DNA tests. In 78 samples antigenemia were negative and CMV-DNA qPCR were positive, while there were no samples with antigenemia positive and qPCR negative. Mean values of antigenemia and qPCR tests were 23 positive cells/200.000 leukocytes (range: 1 to 230 positive cells) and 12.595 copies/ml (range: 180 to 106.311 copies/ml), respectively. There was a significant correlation between antigenemia and qPCR results among the samples that were positive by both assays (r=0.785). ROC curve analysis showed that CMV viral load of 205 copies/ml in plasma corresponds to >= 1 pp65 antigen positive cells per 200.000 leukocytes (sensitivity: 91.7%, specificity: 90.3%). Higher analytical sensitivity of qPCR test can be explained by the results of CMV-DNA PCR positive and antigenemia negative samples. Nonexistence of samples with antigen positive and PCR negative results supported this finding. ROC analysis showed that any sample with CMV-DNA qPCR result less than 205 copies/ml, could be accepted as pp65 antigenemia negative. This viral load value is valid only for the studied patient group and assays, therefore could be changed according to study population and tests