126 research outputs found
Simplified prediction equation for ultimate stress in beams prestressed with hybrid tendons
No full textThe use of unbonded tendons is getting more widespread in post-tensioning industry; especially in rehabilitation and strengthening of existing damaged concrete members. The prediction of the stress at ultimate in unbonded tendon is important in calculating the capacity of structural members. This thesis presents a simplified prediction equation for concrete beams prestressed with hybrid (a combination of bonded and unbonded) tendons. The proposed equation is based on the Generalized Incremental Analysis (GIA) which uses the trussed-beam model developed by Ozkul et al. (2008) and Nassif et al. (2003). The main objective of this research is to develop a simple, but accurate design equation for the prediction of the stress at ultimate in unbonded tendon. Most important parameters such as loading type, effective prestress of unbonded tendon, concrete strength, area of steel reinforcement and span-to-depth ratio are taken into consideration. The equation is applicable to beams prestressed with unbonded or hybrid, FRP or steel, external or internal tendons. For the validation of the proposed simplified equation, test results available in the literature (199 beams) are collected. The results show that the proposed simplified equation exhibited very good accuracy for the calculation of stress at ultimate in unbonded tendon. The simplified equation is easy to use, accurate and applicable to any material type and combination of tendons.M.S.Includes bibliographical referencesby Gonca Una
Occurrence of and Factors Associated With the Presence of Aflatoxin M1 in Breast Milk of Mothers in Fethiye, Turkey
No full textAflatoxins comprise a group of mycotoxins that are found in the environment. Exposure to aflatoxins has been reported to cause serious health problems in humans. Since aflatoxin M-1 (AFM(1)) is secreted in breast milk, the exposure of infants to this toxin is an important concern. The aim of this study was to determine the prevalence, levels of, and factors associated with the presence of AFM(1) in breast milk of mothers in Fethiye, Turkey. Breast milk samples were taken from 100 mothers who had given birth over the period of October-November 2017. The AFM(1) content of the samples was determined via enzyme-linked immunosorbent assay. The lowest limit for milk samples in the Ridascreen (R) AFM(1) commercial test kit is 5 ng/L. Because of this, AFM(1) levels below 5 ng/L in the breast milk samples were assessed as negative. Of the breast milk samples tested, 53 were positive. The average AFM(1) amount in the positive samples was 6.36 ng/L (ppt; range 5.10-8.31 ng/L). Mothers who were housewives, lived in damp, humid houses, or ate spices or dried fruits and vegetables had significantly greater prevalence of AFM(1) in their breast milk than those who were employed, did not report dampness or mold in the home, or did not eat spices or dried fruits and vegetables. AFM(1) in breast milk could be an important risk factor for infant health. Informing the public about food safety could reduce the amount of AFM(1) being transferred into breast milk via food channels.Mug. la Sitki Kocman University Research Projects Coordination Office [17/186]The author(s) disclosed receipt of the following financial support for the research and/or authorship of this article: Mug. la Sitki Kocman University Research Projects Coordination Office, project grant number 17/186
Correction to: Determination of growth and developmental stages in hand–wrist radiographs: Can fractal analysis in combination with artificial intelligence be used? (Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie, (2024), 10.1007/s00056-023-00510-1)
No full textFollowing the publication of the original article the authors reported that the “Author Contribution” section had been published incompletely by the publisher. Below is the complete section: M. Gonca: Conceptualization, methodology, acquisition of the data, data analysis, writing original draft preparation, reviewing, and editing; M.F. Sert: Data analysis, writing original draft preparation; D.N. Gunacar: Acquisition of the data, writing, reviewing, and editing; T.E. Kose: Acquisition of the data, supervision, writing, reviewing, and editing; B. Beser: Acquisition of the data, data collection, writing, reviewing, and editing. The original article has been corrected. We apologize for the error
1950’lere Doğru Çerkeş Sokağı ve Çevresi
No full textBu yazıda, 1950’ler Ankara’sının Çerkeş ve Gonca sokakları çevresinin belleğimizde kalan anılarından yola çıkılarak; tarihi, sosyal ve kültürel yapının nasıl değiştirildiği/değiştiği ve giderek Eski Ankara’yı nasıl yokolma noktasına getirdiği anlatılmak istenmiştir. Bu amaçla “anılar-duyumlar-gözlemler-tanıklıklar”dan hareket edilerek, bu bilgiler belgeler ve fotoğraflarla harmanlanmış, yetemediğimiz yerlerde de “inceleme-araştırma-görüşme”lerle doğrulanmaları yolu izlenmiştir. Sıralanan saptamalarımızın çoğu bu iki sokağın sınırlarını aşıp o günün Türkiye’sinin her yerinde görülebilecek türdendir. Zamanın acımasız tahripkarlığının bu hızlı gidişi karşısında, eski Ankara’yı belki de tümüyle yitirmemiz kaçınılmaz görünmektedir
Implant stability outcomes after immediate and delayed revascularized free fibula flaps: a preliminary comparative study
No full textCapar, Gonca Duygu (Trakya author)Purpose: This pilot study investigated the retrospective outcomes of implants placed immediately or with a delayed protocol in revascularized free fibula flaps (FFF). Materials and Methods: Patients undergoing FFF between 2014 and 2017 were included in the study. Implants were inserted either immediately or 23.63 +/- 10.61 months after reconstructive surgery. Resonance frequency analyses were recorded at the time of implant placement (first control) and 4 months postoperatively while uncovering and screwing the gingiva formers (second control). The statistical significance level was set at P .05). Conclusion: High stability scores similar to alveolar bone could be achieved by both immediate and delayed implant placement. Bicortical implantation results in better implant stability
Femoral vein wall thickness measurement: A new diagnostic tool for Behcet's disease
No full textObjectives. Diagnosing Behcet's disease (BD) is a challenge, especially in countries with a low prevalence. Recently, venous wall thickness (VWT) in lower extremities has been shown to be increased in BD patients. In this study, we aimed to investigate the diagnostic performance of common femoral vein (CFV) thickness measurement in BD and whether it can be used as a diagnostic tool. Methods.. Patients with BD (n=152), ankylosing spondylitis (n=27), systemic vasculitides (n=23), venous insufficiency (n=29), antiphospholipid syndrome (APS; n=43), deep vein thrombosis due to non-inflammatory causes (n=25) and healthy controls (n=51) were included in the study. Bilateral CFV thickness was measured with ultrasonography by a radiologist blinded to cases. Results. Bilateral CFV thickness was significantly increased in BD compared with all control groups (P < 0.001 for all). The area under the receiver operating characteristic curve for bilateral CFV thicknesses in all comparator groups was >0.95 for the cut-off value (0.5 mm). This cut-off value also performed well against all control groups with sensitivity rates >90%. The specificity rate was also >80% in all comparator groups except APS (positive predictive value: 79.2-76.5%, negative predictive value: 92-91.8% for right and left CFV, respectively). Conclusion. Increased CFV thickness is a distinctive feature of BD and is rarely present in healthy and diseased controls, except APS. Our results suggest that CFV thickness measurement with ultrasonography, a non-invasive radiological modality, can be a diagnostic tool for BD with sensitivity and the specificity rates higher than 80% for the cut-off value >= 0.5mm
Porphyry-Cu Deposits of Turkey
No full textTurkey, located within the western Tethyan-Eurasian Belt contains numerous porphyry copper deposits formed by the subduction, collision and post-collisional events during the closure of NeoTethys Ocean between the latest Cretaceous and late Miocene. These porphyry systems and associated epithermal and skarn deposits are associated with the subduction and post-subduction magmatic rocks emplaced along arc-parallel belts as in eastern Pontides and arc transverse extensional terranes as in the western Anatolian province (WAP) and Southeastern Anatolian Orogenic Belt (SEAOB). The porphyry deposits are formed in magmatic-arc (Pontides, Aegean and Bitlis-Zagros subduction), post-collisional settings (Pontides, WAP, SEAOB) after continental collision (Central Anatolian Crystalline Complex), and extensional arc setting (WAP). The porphyry Cu systems begin in the Late Cretaceous at the north, and generally young southward, where paired Late Cretaceous and Eocene metallogenic episodes are present in the eastern Pontides, WAP and SEAOB. The dominance of ages between ca. 83 and 70 Ma broadly coincides with the final stages of Late Cretaceous magmatism at the Pontides and SEAOB. The available ages are indicative of epidocity and a limited period of formation for porphyry Cu systems in these belts, and comparable to the metallogenic evolution of Turkey. The Eocene porphyry systems in discontinuous belts across Turkey reflect collisional to post-collisional processes. The number of known porphyry deposits in porphyry belts is related to the level of erosion. Therefore, the magmatic belts with fewer known porphyry may indicate too shallow or too deep crustal levels for their exposure. The estimates of numbers of undiscovered deposits combined with grade and tonnage models in Monte Carlo simulation revealed a lower density of known porphyry deposits in the Pontides, WAP and SEAOB relative to well-explored provinces around the world. This suggests that undiscovered deposits are likely present in Pontides, WAP and SEAOB. © Springer Nature Switzerland AG 2019.Barrick Gold Corporation YDAG-103Y098Acknowledgements The work is part of a collaborative research project generously sponsored by Barrick Gold Corp, Teck Cominco Ltd., and Eldorado Gold-Tüprag Metal-Mining Ltd. The finan - cial and logistical support from these companies are greatly appreciated. Part of the work is also supported by TÜB İTAK via a research project (Ç YDAG-103Y098) by the f st author. MDRU contribution no.256
Geochemical characterization of a Quaternary monogenetic volcano in Erciyes Volcanic Complex: Cora Maar (Central Anatolian Volcanic Province, Turkey)
No full textKuscu, Gonca Gencalioglu/0000-0001-9801-6542WOS: 000298652300011Central Anatolian Volcanic Province (CAVP) is a fine example of Neogene-Quaternary post-collisional volcanism in the Alpine-Mediterranean region. Volcanism in the Alpine-Mediterranean region comprises tholeiitic, transitional, calc-alkaline, and shoshonitic types with an "orogenic" fingerprint. Following the orogenic volcanism, subordinate, within-plate alkali basalts (sl) showing little or no orogenic signature are generally reported in the region. CAVP is mainly characterized by widespread calc-alkaline andesitic-dacitic volcanism with orogenic trace element signature, reflecting enrichment of their source regions by subduction-related fluids. Cora Maar (CM) located within the Erciyes pull-apart basin, is an example to numerous Quaternary monogenetic volcanoes of the CAVP, generally considered to be alkaline. Major and trace element geochemical and geochronological data for the CM are presented in comparison with other CAVP monogenetic volcanoes. CM scoria is basaltic andesitic, transitionalcalc-alkaline in nature, and characterized by negative Nb-Ta, Ba, P and Ti anomalies in mantle-normalized patterns. Unlike the "alkaline" basalts of the Mediterranean region, other late-stage basalts from the CAVP monogenetic volcanoes are classified as tholeiitic, transitional and mildly alkaline. They display the same negative anomalies and incompatible element ratios as CM samples. In this respect, CM is comparable to other CAVP monogenetic basalts (sl), but different from the Meditterranean intraplate alkali basalts. Several lines of evidence suggest derivation of CM and other CAVP monogenetic basalts from shallow depths within the lithospheric mantle, that is from a garnet-free source. In a wider regional context, CAVP basalts (sl) are comparable to Apuseni (Romania) and Big Pine (Western Great Basin, USA) volcanics, except the former have depleted Ba contents. This is a common feature for the CAVP volcanics and might be related to crustal contamination or source characteristics. Indeed, HFS and other incompatible element ratios suggest the role of crustal contamination in the genesis of the CAVP monogenetic basalts.Scientific and Technological Research Council of Turkey (TUBITAK-CAYDAG)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [102Y131]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The research was funded by the Scientific and Technological Research Council of Turkey (TUBITAK-CAYDAG), project number 102Y131. The author gratefully acknowledges partial support by TUBITAK towards presenting part of this study at the 2nd International Maar Conference in Hungary. Zoltan Pecskay of Institute of Nuclear Research (ATOMKI) of Hungarian Academy of Sciences is thanked for the K/Ar analyses. Christoph Breitkreuz, Gerhard Worner, and Karoly Nemeth provided constructive comments that helped to improve the manuscript
EFFECTS OF ATORVASTATIN, PIOGLITAZONE AND ERYTHROPOIETIN ON THE EXPRESSIONS OF IRON TRANSPORT MOLECULES IN PHLEBOTOMY-ENHANCED ANEMIA OF RATS WITH CHRONIC KIDNEY DISEASE
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