Capacity Increase for Existing Steel Bridges Using Prestressed Cables

In the present study, a practical approach is proposed for geometric nonlinear analysis of existing steel bridges. The approach is defined by finite element displacement direct rigidity procedure, which is based on an iterative procedure. Tangent rigidity matrix is used for cable truss and/or framed steel structures formed by finite elements. Hence, effects of prestressed cables in system rigidity can be taken into account in the analyses. Moreover, stressing effects on cables are taken into account with equivalent temperature change. The research has three main parts. In the first part, prestressed cables are investigated for capacity increase for steel bridges. In the second part, an iterative procedure is proposed for existing steel bridges that can be used for geometric nonlinear analysis. In the third part, a representative bridge is modeled and analyzed. In the model, first, the representative model is analyzed as it is existing form and then, it is analyzed with prestressed cables in two different forms. So, three different results are investigated for their structural behaviors. In the analyses, geometric nonlinear behavior is investigated and results are evaluated. As a result of the study, capacity change by using stressed cables is defined for existing bridges

The application of Zirconium Base Coatings on Steel Surfaces by Using Electro-Spark Deposition (ESD) Method

Elektro-Kıvılcım Biriktirme (ESD) tekniği metal yüzeylerin mekanik özelliklerini ve korozyon direncini geliştirmek için kullanılmaktadır. Mevcut çalışmada, ESD tekniği kullanılarak zirkonyum elektrot malzeme ile kaplanmış çelik yüzeyler karakterize edilmiştir. Altlık ve elektrot malzemenin en uyumlu olduğu parametreler araştırılmıştır. Bu amaçla kaplama deneylerinde klasik ESD cihazlarından farklı olarak özel bir yazılım içeren bilgisayar kontrollü bir darbe jeneratörü sistemi kullanılmıştır.Akım şiddeti 300 A ve etki süresi 200 s olan elektrik darbelerin kullanımı ile 3 paso kaplama sonucu ortalama 20 m kalınlığında biriktirme işlemi gerçekleştirilmiştir. En verimli sonuçlara sahip olan numune üzerinde XRD, SEM, EDX, mikro sertlik ve tribometre cihazları ile araştırmalar gerçekleştirilmiştir. XRD sonuçları, kaplamada ZrN ve ZrO2 fazlarının mevcudiyetini ifade etmektedir. Kaplanmış çelik numunelerin mekanik özellikleri belirgin şekilde gelişmiştir.Electro-Spark Deposition (ESD) technique is used to improve mechanical properties and corrosion resistance of metal surfaces. In the present study, steel surfaces that were coated with zirconium electrode materials by using ESD technique have been characterized. Firstly, the electrical parameters of process were investigated to achieve a best coating layer for this substrate-electrode couple. With this purpose, a pulse generator system containing pc control with special software is used which is different from classical ESD equipment in the coating experiments. Using electrical pulses with current amplitude of 300 A and duration of 200 s, it has been possible to developed a deposit layer with average thickness of 20 m after three coating pass. Then the coated samples were characterized with XRD, SEM, EDX, micro-hardness tester and tribometer. The XRD results indicated that the coating consists of ZrN and ZrO2 phases. The mechanical properties of coated steel samples were significantly improved

Can coffee consumption be used to accelerate the recovery of bowel function after cesarean section? Randomized prospective trial

Objectives: To evaluate whether coffee consumption accelerates the recovery of bowel function after cesarean section or not.Material and methods: This study was designed as randomized controlled study. Patients were randomly assigned to oneof two groups: Ultimately, Group 1 (n = 51) was the study group and drank three cups of coffee after cesarean, whereasgroup 2 (n = 52) was not given any treatment. The primary outcome measure was the time to first defecation after surgery,the secondary outcomes were time to first bowel movement, passage of flatus, time to toleration of a solid diet, additionalantiemetic and analgesic requirement.Results: There were no significant differences in demographic variables between the groups. The mean time to passageof first flatus was significantly shorter in the study group than the control group (8.6 ± 3.3 h vs 11.3 ± 7.5 h, respectively;p = 0.022). First defecation was 20.7 ± 11.5 h for the study group and at 29.1 ± 14.3 h for the control group (p = 0.001). Inaddition, there was a significant difference in mean time to toleration of solid food between the study and control groups(8.78 ± 2.33 h vs 12.88 ± 4.2.60 h, respectively; p < 0.001).Conclusions: Coffee can be used in patients to enhance the recovery of gastrointestinal function after elective cesareansection

Effects of monochromatic light stimuli during embryogenesis on some performance traits, behavior, and fear responses in Japanese quails

Lighting is crucial in poultry rearing and the subjects with light intensity, source, and color having been addressed in numerous studies. Numerous studies with monochromatic light from light-emitting diode (LED) bulbs have been reported. In the current study, fertile Japanese quail eggs were exposed to a dark environment (Control) or monochromatic green (560 nm) and blue (480 nm) lighting throughout incubation. There were no significant differences in hatch weight, hatchability, total embryonic mortality, hatch time, growth performance, and slaughter-carcass traits in the study (P > 0.05). Furthermore, the lowest mean in terms of early embryonic mortalities (12.37%) was determined in the group treated with green LED light-ing (P < 0.05), whereas it was discovered that the lowest mean in terms of late embryonic mortalities (13.59%) was in the group treated with blue LED lighting (P < 0.05). During the test time, the green LED group showed higher averages in terms of the number of peeps and first defecation time as response to environmental stimuli (P < 0.05). The highest mean for jumping (7.6 times) was detected in the group treated with blue LED lighting (P < 0.05). In conclusion, it was revealed that the blue and green LED lighting applied to the Japanese quail eggs in incubation had no effects on incubation traits, growth, and slaughter-carcass traits but had positive effects on some behavioral traits.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2209-A]We thank the Scientific and Technological Research Council of Turkey (TUBITAK) for the financial support of this study with Project No. 2209-A

Evaluation of Conservation Problems for Restoration of Great Karaosmanoğlu Khan, İzmir, Turkey

Ottoman khans, built in the cities, are cultural assets that need to be preserved as they reflect the social, cultural and economic condition of the cities of the time when they were built. Great Karaosmanoğlu Khan, which is located in Kemeraltı, the historical market district of İzmir, Turkey, is one of the surviving khans that has considerably preserved its original architectural characteristics. The khan dates back to the beginning of the 19th century and is still used for commercial purposes. However, it has been subjected to partial demolishment and a series of inappropriate interventions. These inappropriate interventions and neglected condition also brought some material problems to the building. The aim of this study is to evaluate all these problems and present restoration decisions for conservation of the building. The restoration proposal aims to preserve the remaining original characteristics, to reveal the lost values within the scope of contemporary conservation theory as well as to find a compatible use for the building

Evaluation of the Oxidative Effect of Long-Term Repetitive Hyperbaric Oxygen Exposures on Different Brain Regions of Rats

Hyperbaric oxygen (HBO2) exposure affects both oxidative and antioxidant systems. This effect is positively correlated with the exposure time and duration of the treatment. The present study aims enlightening the relation of HBO2 with oxidative/antioxidant systems when administered in a prolonged and repetitive manner in brain tissues of rats. Sixty rats were divided into 6 study (n = 8 for each) and 1 control (n = 12) group. Rats in the study groups were daily exposed 90-min HBO2 sessions at 2.8 ATA for 5, 10, 15, 20, 30 and 40 days. One day after the last session, animals were sacrificed; their whole brain tissue was harvested and dissected into three different regions as the outer grey matter (cortex), the inner white matter and cerebellum. Levels of lipid peroxidation and protein oxidation and activities of superoxide dismutase and glutathione peroxidase were measured in these tissues. Malondialdehyde, carbonylated protein and glutathione peroxidase levels were found to be insignificantly increased at different time-points in the cerebral cortex, inner white matter and cerebellum, respectively. These comparable results provide evidence for the safety of HBO treatments and/or successful adaptive mechanisms at least in the brain tissue of rats, even when administered for longer periods

Galectin-3: a novel blood test for the classification of patients with COPD. An observational study

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is one of the major causes of mortality and mortality affecting the whole world. In the inflammatory process, lectin is elevated and consequently, Galectin-3 expression is increased. This relation has been revealed by studies on coronary diseases. However, studies on the association of Galectin-3 with COPD and even other pulmonary diseases have been limited, although it has been studied and described on cardiologic patients. For this reason, in this study Galectin-3 levels in different stages of COPD patients were investigated and whether Galectin-3 could be a guide clinically.  MATERIAL AND METHODS: This is an observational prospective study, approved by local ethic committee (30112015-12), which included three groups of patients, COPD exacerbation, COPD stable and control group, admitted to tertiary healthcare between 01.09.2016 and 01.09.2017.  RESULTS: 137 subjects were included in the study. The mean age of patients in the study was 70.6. Galectin- 3 level in the group of COPD (exacerbation and stable) was significantly lower than the control group (p &lt; 0.001). The Galectin-3 level was significantly lower in COPD exacerbation group than groups of stable COPD and control. And also, Galectin-3 level was significantly lower in stable COPD group than the control group (p values: 0.034, 0.001 and 0.013, respectively). The ROC analysis for the Galectin-3 levels between the COPD patients (exacerbation and stable) and the control group is shown in Figure 2 (AUC = 0.784). When the cut-off points of Galectin-3 is selected as 11.4; for this cut-off point, sensitivity is 83% and specificity is 71% for this cut-off point (AUC: 0.79 %95 GA: 0.70–0.86 p &lt; 0.001).  CONCLUSIONS: COPD is a disease with high mortality and morbidity and efforts are being made to identify its severity and exacerbations with various biomarkers. In this study, Galectin-3 levels were found to be lower in patients with stable COPD group according to the control group. In addition, galactin-3 levels were found to be lower in COPD exacerbation group according to both Stable COPD group and control group. Although a certain threshold value was found in this study, more studies are needed to determine this threshold value more precisely. However, it is clear that these data are promising