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Determination of structural behavior of Bosporus suspension bridge considering construction stages and different soil conditions

  • Gunaydin, Murat;Adanur, Suleyman;Altunisik, Ahmet Can;Sevim, Baris;Turker, Emel
    • Steel and Composite Structures
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    • v.17 no.4
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    • pp.405-429
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    • 2014
  • In this paper, it is aimed to determine the structural behavior of suspension bridges considering construction stages and different soil conditions. Bosporus Suspension Bridge connecting the Europe and Asia in Istanbul is selected as an example. Finite element model of the bridge is constituted using SAP2000 program considering existing drawings. Geometric nonlinearities are taken into consideration in the analysis using P-Delta large displacement criterion. The time dependent material strength of steel and concrete and geometric variations is included in the analysis. Time dependent material properties are considered as compressive strength, aging, shrinkage and creep for concrete, and relaxation for steel. To emphases the soil condition effect on the structural behavior of suspension bridges, each of hard, medium and soft soils are considered in the analysis. The structural behavior of the bridge at different construction stages and different soil conditions has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. At the end of the analyses, variation of the displacement and internal forces such as bending moment, axial forces and shear forces for bridge deck and towers are given in detail. Also, displacement and stresses for bridge foundation are given with detail. It can be seen from the analyses that there are some differences between both analyses (with and without construction stages) and the results obtained from the construction stages are bigger. It can be stated that the analysis without construction stages cannot give the reliable solutions. In addition, soil condition have effect on the structural behavior of the bridge. So, it is thought that construction stage analysis using time dependent material properties, geometric nonlinearity and soil conditions effects should be considered in order to obtain more realistic structural behavior of suspension bridges.

The effect of mortar type and joint thickness on mechanical properties of conventional masonry walls

  • Zengin, Basak;Toydemir, Burak;Ulukaya, Serhan;Oktay, Didem;Yuzer, Nabi;Kocak, Ali
    • Structural Engineering and Mechanics
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    • v.67 no.6
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    • pp.579-585
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    • 2018
  • Masonry walls are of a complex (anisotropic) structure in terms of their mechanical properties. The mechanical properties of the walls are affected by the properties of the materials used in wall construction, joint thickness and the type of masonry bond. The carried-out studies, particularly in the seismic zones, have revealed that the most of the conventional masonry walls were constructed without considering any engineering approach. Along with that, large-scale damages were detected on such structural elements after major earthquake(s), and such damages were commonly occurred at the brick-joint interfaces. The aim of this study was to investigate the effect of joint thickness and also type of mortar on the mechanical behavior of the masonry walls. For this aim, the brick masonry walls were constructed through examination of both the literature and the conventional masonry walls. In the construction process, a single-type of brick was combined with two different types of mortar: cement mortar and hydraulic lime mortar. Three different joint thicknesses were used for each mortar type; thus, a total of six masonry walls were constructed in the laboratory. The mechanical properties of brick and mortars, and also of the constructed walls were determined. As a conclusion, it can be stated that the failure mechanism of the brick masonry walls differed due to the mechanical properties of the mortars. The use of bed joint thickness not less than 20 mm is recommended in construction of conventional masonry walls in order to maintain the act of brick in conjunction with mortar under load.

Estimation of probabilistic hazard for Bingol province, Turkey

  • Balun, Bilal;Nemutlu, Omer Faruk;Benli, Ahmet;Sari, Ali
    • Earthquakes and Structures
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    • v.18 no.2
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    • pp.223-231
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    • 2020
  • Due to the fact that Bingöl province is at the intersection of the North Anatolian Fault and the Eastern Anatolian Fault, the seismicity of the region is important. In this study, probabilistic seismic hazard analyzes (PSHA) were conducted to cover the boundaries of Bingöl province. It occurred since 1900, the seismicity of the region was obtained statistically by considering the earthquake records with a magnitude greater than 4 and the Gutenberg-Richter correlation. In the study, magnitude-frequency relationship, seismic hazard and repetition periods were obtained for certain time periods (10, 20, 30, 40, 50, 75 and 100 years). Once a project area determined in this study, which may affect the peak ground acceleration according to various attenuation relationships are calculated and using the Turkey Earthquake Hazard Map, average acceleration value for Bingöl province were determined. As a result of the probabilistic seismic hazard analysis, the project earthquakes with a probability of exceeding 50 years indicate that the magnitude of the project earthquake is 7.4 and that the province is in a risky area in terms of seismicity. The repetition periods of earthquakes of 6.0, 6.5, 7.0 and 7.5 are 42, 105, 266 and 670 years respectively. Within the province of Bingöl; the probability of exceeding 50 years is 2%, 10% and 50%, while the peak ground acceleration values are 1.03 g, 0.58 g and 0.24 g. As a result, probabilistic seismic hazard analysis shows that the seismicity of the region is high and the importance of considering the earthquake effect during construction is emphasized for this region.

Risk of Gastric Cancer in Children with Helicobacter pylori Infection

  • Cam, Sebahat
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9905-9908
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    • 2014
  • Background: Helicobacter pylori (H. pylori) is the most common chronic infectious agent in the stomach. Most importantly, it may lead to atrophy, metaplasia and cancer. The aim of this study was to investigate the incidence of H. pylori infection and to detect early mucosal changes that may lead to malignant degeneration in children. Materials and Methods: Children who underwent upper gastrointestinal endoscopy were included. Familial history of gastric cancer was noted. Endoscopic examinations were performed by a single pediatric gastroenterologist. A minimum of three biopsy samples were collected during endoscopy. The patients were accepted as H. pylori infected if results of biopsies and rapid urease test were both positive. Biopsies were evaluated for the presence and degree of chronic inflammation, the activity and severity of gastritis, glandular atrophy and intestinal metaplasia. Results: A total of 750 children (388 boys, 362 girls) were evaluated in our study, with a mean age of 10.1 years. A total of 390 patients (52%) were found to be infected with H. pylori. Among the H. pylori infected patients, 289 (74%) were diagnosed to have chronic superficial gastritis, 24 (6.2%) had gastric atrophy. Most strikingly, intestinal metaplasia was observed in 11 children, all were in the H. pylori positive group. There was no difference in the mean of age, gender and socioeconomic class between H. pylori infected and non-infected groups. The frequency of gastric cancer in family members (4 in number) was higher in patients with H. pylori infection. No gastric cancer case was reported from the parents of non-infected children. The worst biopsy parameters (atropy and metaplasia) were improved after H. pylori eradication on control endoscopy. Conclusions: The current study shows a higher prevalence of familial history of gastric cancer in H. pylori infected children. Intestinal metaplasia was also higher in the infected children. Eradication of H. pylori infection for this risk group may prevent subsequent development of gastric cancer.

Effects of Self-Concept Levels and Perceived Academic Achievements of Turkish Students on Smoking Perceptions

  • Sert, Hilal Parlak;Bektas, Murat;Ozturk, Candan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1307-1312
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    • 2014
  • Background: The objective of this study was to examine the effect of self-concept levels and perceived academic achievements of sixth, seventh and eighth grade primary school students upon their perceptions about smoking. Method: The data were collected with the Socio-Demographic Data Collection Form, Pier-Herris Self-Concept scale and Children's Decision Balance Scale. The study sample consisted of 374 students receiving education in the sixth, seventh and eighth grades of three primary schools, which were selected among primary schools of Izmir Provincial Directorate for National Education representing three socio-economic groups with a simple random sampling method. The data were collected in December 2012-January 2013. Percentages and the t test were used in the evaluation of the data. Results: While students with a positive self-concept had score averages of $7.12{\pm}2.18$ regarding the lower dimension of smoking pros and $29.0{\pm}2.47$ regarding the lower dimension of smoking cons, their counterparts with a negative self-concept had score averages of $8.61{\pm}3.76$ (p=0.000) and $28.1{\pm}3.49$ (p=0.004), respectively. According to self-perception, there was statistical difference between perceptions of students regarding smoking (p<0.01). While students perceiving themselves successful had score averages of $7.81{\pm}3.13$ and $28.5{\pm}3.19$ regarding the lower dimension of smoking benefit and harm, students perceiving themselves unsuccessful had score averages of $8.27{\pm}3.39$ (p=0.333) and $29.01{\pm}2.05$ (p=0.235), with no difference determined. Conclusion: Students with a positive self-perception had a low perception of smoking pros and a high perception of smoking cons. Perception of academic achievement did not affect the pros and cons perceptions of children regarding smoking.

Can Breast Asymmetry Following the Treatment of Juvenile Idiopathic Scoliosis with Growing Rod Be Prevented? : A Preliminary Analysis

  • Atici, Yunus;Polat, Baris;Erdogan, Sinan;Gurpinar, Tahsin;Demiroz, Serdar
    • Journal of Korean Neurosurgical Society
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    • v.63 no.2
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    • pp.228-236
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    • 2020
  • Objective : It can be assumed that the progression of scoliosis in the juvenile period will increase the asymmetry in the rib cage, and thus will contribute to an increase in the breast asymmetry (BA) in the future. We are looking for answers to the questions; "How will the breasts look with respect to each other and what is the possibility of developing BA in the early follow-up period following the early surgical treatment and final fusion surgery of juvenile idiopathic scoliosis (JIS)?" For this reason, in this study, we aimed to evaluate the breast asymmetries of patients in the period after the final fusion. Methods : Following growing rod treatment, final fusion was achieved in 12 females with JIS. We used the anthropomorphic measurement of the modified BREAST-V formula to assess whether there was an asymmetry between the breasts after an average of 4.8 years (2-11) following final fusion. Results : In comparison, the mean volume of the left breast (222.4 mL [range, 104.1-330.2]) was larger than the mean volume of the right breast volume (214.5 mL [range, 95.2-326.7]) (p=0.034). The left breast was larger in 75% of the patients. BA was observed in 50% of the patients. No correlation was detected between the Cobb angle of the patient after final fusion and BA (p=0.688). Conclusion : In the late follow-up period, BA was detected in 50% of the patients with JIS who achieved final fusion after treatment with growing rod. In majority of the patients, left breast was larger. The patients with JIS and their families can be informed prior to the operation about the probability of BA seen in the follow-up period after fusion.

Lack of any Association between Blood Groups and Lung Cancer, Independent of Histology

  • Oguz, Arzu;Unal, Dilek;Tasdemir, Arzu;Karahan, Samet;Aykas, Fatma;Mutlu, Hasan;Cihan, Yasemin Benderli;Kanbay, Mehmet
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.453-456
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    • 2013
  • Introduction: Lung cancer, the leading cause of cancer deaths, is divided into 2 main classes based on its biology, therapy and prognosis: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Many cases are at an advanced stage at diagnosis, which is a major obstacle to improving outcomes. It is important to define the high risk group patients for early diagnosis and chance of cure. Blood group antigens are chemical components on erythrocyte membranes but they are also expressed on a variety of epithelial cells. Links between ABO blood groups with benign or malignant diseases, such as gastric and pancreas cancers, have been observed for a long time. In this study, we aimed to investigate any possible relationship between lung cancer histological subtypes and ABO-Rh blood groups. Materials and Methods: The files of 307 pathologically confirmed lung cancer patients were reviewed retrospectively. Cases with a serologically determined blood group and Rh factor were included and those with a history of another primary cancer were excluded, leaving a total of 221. The distribution of blood groups of the lung cancer patients were compared with the distribution of blood groups of healthy donors admitted to the Turkish Red Crescent Blood Service in our city in the year 2012. Results: There was no significant difference between patients with lung cancer of either type and the control group in terms of distribution of ABO blood groups and Rh factor (p: 0.073). There was also no relationship with non small cell cancer histological subtypes. Conclusions: In this study, we found no relationship between the ABO-Rhesus blood groups and NSCLC and SCLC groups. To our knowledge this is the first analysis of ABO blood groups in SCLC patients.

Frequency of Cigarette Smoking Among Psychiatric Inpatients Evaluated by the Fagerstrom Test for Nicotine Dependence

  • Tanriover, Ozlem;Karamustafalioglu, Nesrin;Tezvaran, Zehra;Kaplan, Asli;Tomruk, Nesrin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.579-582
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    • 2013
  • Background: In this study our aim was to determine the rate of smoking in a sample of psychiatric in-patients with diagnoses of schizophrenia, bipolar disorder and major depression and to examine factors related to smoking status and the level of dependence in this population. Materials and Methods: A total of 160 people were included in this descriptive study. 80 were inpatients with schizophrenia, bipolar disorder and major depression and 80 people without any psychiatric diagnoses were included as a control group. The participants were interviewed face-to face using a semi-structured questionnaire and Fagerstrom Test for Nicotine Dependence was used to define smoking habits. Results: The mean age of the participants was $37.24{\pm}12.19$ years ranging from 18 to 81 years, 54.4% of the participants were (n=87) female, and 45.6% cases (n=73) were male. 70% (n=56) of the patients and 55% of the control group were smoking and the difference was statistically significant (p<0.01). Total score of Fagerstrom Test for Nicotine Dependence in the patient group was statistically significantly higher than in the control group (p<0.01). Conclusions: In our sample, the frequency of cigarette smoking and nicotine dependence among psychiatric inpatients was high, posing a high risk for smoking related diseases including cancers; therefore there should be counseling on tobacco control and smoking cessation programming targeting this population.

Is catechol-o-methyltransferase gene polymorphism a risk factor in the development of premenstrual syndrome?

  • Deveci, Esma Ozturk;Incebiyik, Adnan;Selek, Salih;Camuzcuoglu, Aysun;Hilali, Nese Gul;Camuzcuoglu, Hakan;Erdal, Mehmet Emin;Vural, Mehmet
    • Clinical and Experimental Reproductive Medicine
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    • v.41 no.2
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    • pp.62-67
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    • 2014
  • Objective: The objective of this study was to investigate whether there was a correlation between catechol-o-methyltransferase (COMT) gene polymorphism, which is believed to play a role in the etiology of psychotic disorders, and premenstrual syndrome (PMS). Methods: Fifty-three women with regular menstrual cycles, aged between 18 and 46 years and diagnosed with PMS according to the American Congress of Obstetrics and Gynecology criteria were included in this study as the study group, and 53 healthy women having no health problems were selected as the controls. Venous blood was collected from all patients included in the study and kept at $-18^{\circ}C$ prior to analysis. Results: There was no significant difference between the groups in terms of demographic features such as age, body mass index, number of pregnancies, parity, and number of children. No statistically significant difference was observed in terms of COMT gene polymorphism (p=0.61) between women in the PMS and the control groups. However, a significant difference was found between arthralgia, which is an indicator of PMS, and low-enzyme activity COMT gene (Met/Met) polymorphism (p=0.04). Conclusion: These results suggested that there was no significant relationship between PMS and COMT gene polymorphism. Since we could not find a direct correlation between the COMT gene polymorphism and PMS, further studies including alternative neurotransmitter pathways are needed to find an effective treatment for this disease.

Enhancement of nuclear radiation shielding and mechanical properties of YBiBO3 glasses using La2O3

  • Issa, Shams A.M.;Ali, Atif Mossad;Tekin, H.O.;Saddeek, Y.B.;Al-Hajry, Ali;Algarni, Hamed;Susoy, G.
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1297-1303
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    • 2020
  • In this study, nuclear radiation shielding and rigidity parameters of Y (0.1-x)B0.6Bi1.8O3La2x glassy system were investigated in order to determine it's suitability for use as nuclear radiation shielding materials. Therefore, a group of bismuth borate glass samples with La2O3 additive were synthesized using the technique of melt quenching. According to the results, the increase of the La2O3 additive increases the density of the glass samples and the mass attenuation coefficient (μm) values, whereas the half-value layer (HVL) and mean free path (MFP) values decrease. The effective atomic number (Zeff) is also enhanced with an increment of both mass removal cross section for neutron (ΣR) and absorption neutron scattering cross section (σabs). In addition to the other parameters, rigidity parameter values were theoretically examined. The increase of La2O3 causes some other important magnitudes to increase. These are the average crosslink density, the number of bonds per unit volume, as well as the stretching force constant values of these glass samples. These results are in concordance with the increase of elastic moduli in terms of the Makishima-Mackenzie model. This model showed an increase in the rigidity of the glass samples as a function of La2O3.