214 research outputs found
Shaking table study of masonry buildings with reinforced plaster
U radu je prikazano određivanje seizmičkog ponašanja zidanih građevina sa žbukom od armiranog morta, pri čemu je naglasak stavljen na promjenu odziva konstrukcije kada se umjesto obične žbuke koristi žbuka armirana polipropilenom i čelikom. Na vibracijskom stolu analizirana je otpornost na seizmičko opterećenje jednokatnih, jednorasponskih zidanih građevina. U toku ispitivanja, određeni su prirodni periodi, spektri ubrzanja odziva i spektar ovisnosti zidanih građevina. Za ispitane su građevine izrađeni i modeli metodom konačnih elemenata te su rezultati proračuna uspoređeni s rezultatima ispitivanja.The objective of this study is to determine seismic behaviour of masonry buildings with reinforced plaster mortar, with a particular focus on the modification of structural response due to application of the polypropylene and steel reinforced plaster, as compared to an ordinary type of plaster. The resistance of one-storey single-span masonry buildings subjected to seismic load on the shaking table is investigated in the study. Experimental results revealed natural periods, response acceleration spectrums, and spectrum interactions of masonry buildings. In addition, finite element models of test buildings were established, and their results were compared with those obtained during experimental stud
Seismic Assessment in a Historical Masonry Minaret by Linear and Non-linear Seismic Analyses
Operational Modal Analysis (OMA) method is frequently used in order to determine dynamical properties of historical masonry structures. In this study, damage pattern of historical Alaca minaret which is selected as application is investigated under different ground motions by updating finite element models (FEM) depending on operational modal analysis test. Initial Finite element model was prepared in ABAQUS V10 program and numerical dynamic characteristics of minaret were determined. In addition, experimental dynamic properties of minaret were provided by operational modal analysis. Initial numerical model of brick masonry structure was calibrated via OMA method. Then, linear and non-linear seismic analyses of calibrated FEM of historical minaret were performed by using different earthquakes acceleration records that occurred in Turkey. Concrete Damage Plasticity model was taken into account in non-linear seismic analyses. As a result of the analyses, it is concluded that the stresses obtained with linear analyses aren’t as realistic as the non-linear analyses results and the earthquakes can cause some damages in the minaret.
 
Eş Zamanlı Veri Transferi ile Lcr-Metre ve Doğru Akım Kaynaklarının Senkron Çalıştırılması Sağlanarak Yarıiletken Cihazların Karakterizasyonunda Yeni Yöntem Geliştirilmesi
Organik elektronik alanında üretilen yarıiletken aygıtlar yüksek elektrik alanlar altında tetiklenmektedir ve bu tür aygıtların dielektrik analizini 100-200 V'luk gerilim altında yapan cihazlar piyasada bulunmamaktadır. Bu problemi çözebilmek için yüksek gerilim altında dielektrik analiz yapabilen niteliklere sahip bir ölçüm sistemi geliştirilmiştir. Bunun için geniş bir frekans aralığında birkaç voltluk AC uygulayarak dielektrik spektroskopi analizi yapan cihaza, harici bir DC gerilim kaynağı uygun bir şekilde bağlandı. Bu iki cihazın eşzamanlı çalışması gerekmektedir fakat bu işlemin bağımsız iki cihaz için manuel olarak yapılması oldukça zordur. Bu çalışmada, geliştirdiğimiz eş zamanlı veri transfer programı kullanılarak DC gerilim kaynağı (yarıiletken malzemeler veya aygıtların Akım-Gerilim (I-V) özelliklerinin belirlenmesinde kullanılan) ve LCR Metre cihazının (Kapasitans-Gerilim (C-V), Kapasitans-Frekans (C-f), Kondüktans-Gerilim (G-V) ve Kondüktans-frekans (G-f) özelliklerinin belirlenmesinde kullanılan) eş zamanlı haberleşebilmesi için program geliştirilmiştir. Eş zamanlı veri transfer program ile elde edilen tüm veriler program arayüzünde oluşturulan Excel dosyasına aktarılarak dielektrik spektroskopik özelliklerine ait bilgiler kayıt edilmektedir. Geliştirilen programın literatürde dielektrik özellikleri daha önceden belirlenmiş malzemeler üzerine yapılan ön çalışmalarda tutarlı ve hassas veriler elde edilebildiği ve yüksek bir performansla çalıştığı gözlenmiştir
The effect of placental angiogenic and anti-angiogenic factors on pregnancy outcome in patients with early onset preeclampsia
Objective: The aim was to evaluate the possible effects of anti-angiogenic factors including soluble endoglin (sEng), placental growth factor (Pgf), and soluble fms-like tyrosine kinase 1 (sFlt-1) in both normotensive pregnant patients and preeclampsia (PE) patients. Material and Methods: The study was carried out at the Departments of Gynecology and Obstetrics and Biochemistry of Yozgat Bozok University Training and Research Hospital. Eighteen women with PE who were pregnant for at least 20 weeks comprised the study group. The control group consisted of 33 pregnant women with no complications and with similar demographic features. In the study, laboratory parameters, demographic characteristics, sEng, sFlt-1, and Pgf levels, delivery type, APGAR scores of the infants, and birthweight were determined and a comparison was made between the groups. Results: It was found that the sEng level was significantly lower in the PE group compared to the control group (p<0.05). In addition, the Pgf, birthweight, and 1st and 5th-minute APGAR scores were significantly lower in the PE group compared to the control group (p[removed
The relationship between oxidative stress and preeclampsia. The serum Ischemia-modified albumin levels and thiol/disulfide homeostasis
Objective: Preeclampsia (PE) is a dangerous complication of pregnancy and still a major cause of maternal-fetal morbidity and mortality. Its etiology remains largely unknown, but researchers have suggested oxidative stress-mediated inflammation for the same. The purpose of this study is to investigate the relationship between oxidative stress and PE as well as the usability of oxidative stress indicators such as serum ischemia-modified albumin (IMA) levels and thiol/disulfide balance in the prediction of PE. Materials and Methods: The study included 47 pregnant women with PE and 57 healthy pregnant women. We measured their serum IMA, native thiol, total thiol, and disulfide levels. Additionally, we determined the optimal cutoff values via the receiver operating characteristic curve analysis. Results: There were no differences between the two groups with respect to the maternal age, body mass index, gravida, and parity. The native and total thiol levels were found to be low when the disulfide and IMA levels were high in the patients with PE (p<0.05). When the IMA level was corrected by the albumin level (IMAR), the significant difference between the two groups disappeared. We also found that the native and total thiol concentrations were correlated with the systolic and diastolic blood pressures. The optimal cut-off values calculated for the prediction of PE were as follows: 178.45 µmol/L (with sensitivity of 72% and specificity of 83%) for native thiol, 232.55 µmol/L (with a sensitivity of 75% and specificity of 85%) for total thiol, and 29.05 µmol/L (with sensitivity of 65% and specificity of 72%) for disulfide. Conclusion: The balance of thiol/disulfide may play a role in the pathogenesis of PE and could be used as a biological marker for PE. © 2020 by Turkish Society of Obstetrics and Gynecology Turkish Journal of Obstetrics and Gynecology published by Galenos Publishing House
Mevcut binalar için güçlendirme yöntemleri geliştirilmesi
TÜBİTAK MAG01.05.2005Bugün ülkemizde ve diğer ülkelerde yaygın olarak uygulanan "sistem iyileştirmesi" yöntemi, dayanımı ve rijitliği yetersiz çerçevelerin bazı gözlerinin betonarme dolgu ile doldurularak yeni bir yatay yük taşıyıcı sistemi olmuşturulması olarak tanımlanabilir. Ülkemizde bugün karşılaşılan en önemli sorunlardan biri de hasar görmemiş ve kullanılmakta olan çok sayıda zayıf binanın depreme dayanıklı duruma getirilmesidir. Bu binaların güçlendirilmesinde, "sistem iyileştirmesi" yönteminin kullanılması elbette mümkündür. Ancak sözü edilen yöntemde dolgu duvarların oluşturulmasında beton kullanılacağından, binaların boşaltılması gerekmektedir. Çok sayıda binanın boşaltılması ve binada yaşayanların eşyaları ile birlikte başka bir konuta yerleştirilmesi pratik bir çözüm değildir. Bu proje kapsamında, depreme dayanıklı olmayan ve halen kullanılmakta olan binaların boşaltılmadan güçlendirilmesini sağlayacak yöntemler geliştirilmiş ve bunların gerekli dayanım ve rijitliği sağladığı deneysel ve analitik olarak kanıtlanmıştır.In the system behavior improvement technique, the general philosophy is to introduce a new lateral load resisting system, which will increase the lateral strength and the lateral stiffness of the existing system, which is generally a non-ductile frame with inadequate lateral stiffness. Various techniques based on this principle have been developed and applied in the past. Among them, the most widely used technique is the formation of new stiff walls through infilling some bays of the existing frame with reinforced concrete infills. Use of infilled frames as a method of seismic behavior improvement for existing structures is presently a very common application in Turkey. All these techniques are applicable at the cost of a certain discomfort to the occupants and, the application of these techniques in the rehabilitation of undamaged buildings may not very practical. With this project, the development of new strengthening techniques was achieved. Experimental and anaylical studies have been done to proove the effectiveness of newly developed strengthening techniques. In this study, rapid and yet reliable rehabilitation methodologies for Turkey have be developed
Molecular Genetic Analysis of the PLP1 Gene in 38 Families with PLP1-related disorders: Identification and Functional Characterization of 11 Novel PLP1 Mutations
<p>Abstract</p> <p>Background</p> <p>The breadth of the clinical spectrum underlying Pelizaeus-Merzbacher disease and spastic paraplegia type 2 is due to the extensive allelic heterogeneity in the X-linked <it>PLP1 </it>gene encoding myelin proteolipid protein (PLP). <it>PLP1 </it>mutations range from gene duplications of variable size found in 60-70% of patients to intragenic lesions present in 15-20% of patients.</p> <p>Methods</p> <p>Forty-eight male patients from 38 unrelated families with a PLP1-related disorder were studied. All DNA samples were screened for <it>PLP1 </it>gene duplications using real-time PCR. <it>PLP1 </it>gene sequencing analysis was performed on patients negative for the duplication. The mutational status of all 14 potential carrier mothers of the familial <it>PLP1 </it>gene mutation was determined as well as 15/24 potential carrier mothers of the <it>PLP1 </it>duplication.</p> <p>Results and Conclusions</p> <p><it>PLP1 </it>gene duplications were identified in 24 of the unrelated patients whereas a variety of intragenic <it>PLP1 </it>mutations were found in the remaining 14 patients. Of the 14 different intragenic lesions, 11 were novel; these included one nonsense and 7 missense mutations, a 657-bp deletion, a microdeletion and a microduplication. The functional significance of the novel <it>PLP1 </it>missense mutations, all occurring at evolutionarily conserved residues, was analysed by the <it>MutPred </it>tool whereas their potential effect on splicing was ascertained using the <it>Skippy </it>algorithm and a neural network. Although <it>MutPred </it>predicted that all 7 novel missense mutations would be likely to be deleterious, <it>in silico </it>analysis indicated that four of them (p.Leu146Val, p.Leu159Pro, p.Thr230Ile, p.Ala247Asp) might cause exon skipping by altering exonic splicing elements. These predictions were then investigated <it>in vitro </it>for both p.Leu146Val and p.Thr230Ile by means of RNA or minigene studies and were subsequently confirmed in the case of p.Leu146Val. Peripheral neuropathy was noted in four patients harbouring intragenic mutations that altered RNA processing, but was absent from all <it>PLP1</it>-duplication patients. Unprecedentedly, family studies revealed the <it>de novo </it>occurrence of the <it>PLP1 </it>duplication at a frequency of 20%.</p
Turner syndrome and associated problems in turkish children: A multicenter study
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology
Polybaric melting of a single mantle source during the Neogene Siverek phase of the Karacadağ Volcanic Complex, SE Turkey
Volume CXIV, Number 4, November 7, 1996
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa
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