Normal stress pattern of the pubic symphysis

Cigdem Icke,Juergen Koebke 대한해부학회 2014 Anatomy & Cell Biology Vol.47 No.1

The pelvic ring is stressed by external forces: by partial body weight, by ligament tension, and by muscles forces stabilizing the hip joints. For the symphysis ossis pubis there exist data concerning the type and magnitude of stresses. In oneleg-standing pressure, shear forces are predominant, and in both-leg-standing tensile forces are acting on the pelvic ring. Rupture of the symphysis is problematic due to the variety of its movements. Most literature descriptions of stress in the symphysis reflect only the frontal plane. Our intention was to make morphological as well as experimental investigations on the symphysis ossis pubis to delineate how it will be stressed in the horizontal plane. Twenty pubic bones taken from embalmed adult human cadavers (12 male, 8 female) were used. Horizontal and frontal slices (3 mm thick) of the symphyseal part of the os pubis were made. X-rays and densitometric analysis were performed. The width of the symphysis cartilage in the dorsal and the ventral regions was measured on 15 whole skeleton specimens coming from adult human cadavers. For experimental study an embalmed pelvic ring which had no abnormality was used. The symphysis pubis was cut completely in the midsagittal plane and then the ring was stressed via the cranial sacrum. Our results demonstrate that the symphysis is stressed by bending in the horizontal plane in one-leg-standing. In both-leg-standing the symphysis is stressed by tensile forces.

Changes in Morphological and Physiological Traits and Stress-Related Enzyme Activities of Green Bean (Phaseolus vulgaris L.) Genotypes in Response to Waterlogging Stress and Recovery Treatment

Cigdem Aydogan,Ece Turhan 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.3

The morphological and physiological parameters were measured for 15 green bean genotypes, and enzymatic activities were measured for two genotypes (tolerant and sensitive) grown under controlled greenhouse conditions during waterlogging stress and recovery periods. Plants were exposed to waterlogging stress for 7 days followed by 7 days of recovery. The leaf area and color, leaf relative water content and turgid losses, and the degree of cell membrane injury were determined. ‘Şeker Fasulye’ genotype was relatively tolerant among the genotypes studied. Besides, waterlogging treatment caused the loss of sampled organs in the sensitive genotypes, ‘40 Günlük’, ‘L3’, and ‘L4’. After these three genotypes, the ‘L1’ genotype was found to be sensitive. Therefore, enzymatic activities were measured for ‘Şeker Fasulye’ and ‘L1’. Nicotinamide adenine dinucleotide phosphate oxidase [NAD(P)H oxidase, EC.1.6.3.1] activity increased during waterlogging treatment and decreased during the recovery period. To the contrary, waterlogging treatment degraded catalase (CAT, EC.1.11.1.6) and glutathione reductase (GR, EC.1.6.4.2) activities in leaves and roots. The activity of both enzymes increased during recovery treatment. In conclusion, leaf area, cell membrane injury, and stress-related enzyme activities were found to be an effective means for determining a green bean genotype’s response to waterlogging stress.

Modeling of Buckling Restrained Braces (BRBs) using Full-Scale Experimental Data

Cigdem Avci-Karatas,Oguz C. Celik,S. Ozmen Eruslu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

Hysteretic performance of buckling restrained braces (BRBs) having various core materials, namely, steel and aluminum alloy and with various end connections are numerically investigated. As a computational tool, nonlinear finite element analyses (FEAs) are performed to better model the hysteretic behavior. For the simulation, various aspects such as 1) stress – strain relationship including the strain hardening effect 2) von Mises yield criterion 3) contact surface parameters between the core metal and surrounding high strength grout and 4) friction are defined. Experimental results from near-full scale cyclic tests on two steel core BRBs having steel casing as a restraining environment (named as BRB-SC4 and BRB-SC5) and an aluminum alloy core & aluminum alloy casing tube (named as BRB-AC3) are used in the analyses. All cyclically tested specimens have been designed according to AISC Seismic Provisions. Numerical results obtained from 3D models developed in ANSYS-Workbench give satisfactory response parameters when compared with the experimental ones (e.g., hysteretic curves, dissipated energies). Further, a convergence analysis regarding element numbers in the developed model is conducted for each BRB specimen. Finally, key issues that influence the hysteretic modeling of BRBs are identified.

Application of Machine Learning in Prediction of Shear Capacity of Headed Steel Studs in Steel–Concrete Composite Structures

Cigdem Avci-Karatas 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.2

Headed studs are generally utilized as shear connectors at the interface between steel and concrete in composite structures primarily to transfer longitudinal shear force. This paper presents regression methodologies to predict the shear capacity of headed steel studs by using the concepts of minimax probability machine regression (MPMR) and extreme machine learning (EML). MPMR is carried out based on a minimax probability machine classifi cation. EML is an updated version of a single hidden layer feedforward network. From the experimental data presented in extensive literature, key input parameters infl uencing the shear capacity have been identifi ed and consolidated. The identifi ed parameters include (i) steel stud shank diameter, (ii) compressive strength of concrete, and (iii) tensile strength of headed steel stud. After careful examination of the data and their limits, about 70–75% of the mixed dataset comprising the range of the values has been used for developing MPMR and EML-based models. The input data has been normalized based on the limits of individual parameters. The remaining data has been utilized for verifi cation of the developed models. It is observed that the predicted shear strength capacity is comparable with the experimental observations. Further, the effi cacy of the models has been evaluated through several statistical parameters, namely; root mean square error, mean absolute error, the coeffi cient of effi ciency, root mean square error to observation’s standard deviation ratio, normalized mean bias error, performance index, and variance account factor. It is found that the R2 value is 0.9913 and 0.9479, respectively, for the models developed based on the concepts of MPMR and EML, indicating that the predicted value is closer to the experimental data.

Synthesis and Spectral Properties of Novel Thionaphtoquinone Dyes

Cigdem Sayil,Cemil Ibis 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.5

2,3-Dichloro-1,4-naphtoquinone 1 compound was reacted with octadecanethiol 2 in two different mole ratio. Compound 3 was obtained from the reaction of 1 and 2 in 1:2 mole/mole ratio. Compounds 7 and 8 were obtained from reaction of 1 and 2 in 1:1 mole/mole ratio and known compound 9 was synthesized as by-product in this reaction. Novel compounds 5a-e were obtained from reaction of 1 and related thiols 4a-e. Known compounds 6c and 6e were synthesized as by-product in this reaction. The structures of the compounds were characterized by elemental analysis, UV-vis, FTIR, 1H-NMR, 13C-NMR and Mass spectroscopies.

The communicative competences of students and teachers in different levels of education in North Cyprus

Cigdem Hursen,Zehra Ozcınar,Fezile Ozdamlı,Huseyin Uzunboylu 서울대학교 교육연구소 2011 Asia Pacific Education Review Vol.12 No.1

This study was conducted in order to determine the beliefs of students and teachers in different levels of education about their communicative competences. The study group of this research is consisted of 600 secondary school, high school and undergraduate students and 41 of their teachers. In this study, it is observed that not a significant correlation at a considerable degree exists in the communicative competences of students with their teachers, who are from different nationalities, gender and levels. Furthermore, regarding students, educated at different levels, no relation has been observed in their communicative competences with their teachers. Moreover, while students consider their communicative competences with their teachers to be moderately adequate, teachers consider their communicative competences with their students to be adequate in general.

Some notes on compact sets in soft metric spaces

Cigdem Gunduz Aras,Murat Ibrahim Yazar,Sadi Bayramov 원광대학교 기초자연과학연구소 2017 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.14 No.4

The first aim of this study is to define soft sequential compact metric spaces and to investigate some important theorems on soft sequential compact metric space. Second is to introduce $\tilde{\varepsilon}-$net and totally bounded soft metric space and study properties of this space. Third is to define Lebesque number for soft sets and soft uniformly continuous mapping and investigate some theorems in detail.

Prediction of ultimate load capacity of concrete-filled steel tube columns using multivariate adaptive regression splines (MARS)

Cigdem Avci-Karatas 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.4

In the areas highly exposed to earthquakes, concrete-filled steel tube columns (CFSTCs) are known to provide superior structural aspects such as (i) high strength for good seismic performance (ii) high ductility (iii) enhanced energy absorption (iv) confining pressure to concrete, (v) high section modulus, etc. Numerous studies were reported on behavior of CFSTCs under axial compression loadings. This paper presents an analytical model to predict ultimate load capacity of CFSTCs with circular sections under axial load by using multivariate adaptive regression splines (MARS). MARS is a nonlinear and non-parametric regression methodology. After careful study of literature, 150 comprehensive experimental data presented in the previous studies were examined to prepare a data set and the dependent variables such as geometrical and mechanical properties of circular CFST system have been identified. Basically, MARS model establishes a relation between predictors and dependent variables. Separate regression lines can be formed through the concept of divide and conquers strategy. About 70% of the consolidated data has been used for development of model and the rest of the data has been used for validation of the model. Proper care has been taken such that the input data consists of all ranges of variables. From the studies, it is noted that the predicted ultimate axial load capacity of CFSTCs is found to match with the corresponding experimental observations of literature.

Artificial Neural Network (ANN) Based Prediction of Ultimate Axial Load Capacity of Concrete-Filled Steel Tube Columns (CFSTCs)

Cigdem Avci-Karatas 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.5

Concrete-fi lled steel tube columns (CFSTCs) are preferred due to enhanced ductility and energy absorption. The capability of an artifi cial neural network (ANN) based analytical model on estimating the ultimate load capacity of circular CFSTCs under axial loadings has been investigated in this study. To provide a better prediction in modeling, 150 comprehensive experimental data were obtained from circular CFSTC’s geometrical and mechanical properties, such as height, diameter, thickness, the yield stress of steel, unconfi ned concrete strength, Young’s modulus of steel and concrete, etc., were examined. The backpropagation-training practice available in ANN was used to update the weights of each layer based on the network output error. For feedforward–backpropagation, the Levenberg–Marquardt algorithm was employed. The eff ectiveness of the ANN model was developed using general-purpose software MATLAB ® by training and predicting the ultimate load capacity of circular CFSTCs. Finally, about 75% of the data were used for ANN training, and the remaining 25% was used for testing the ANN model. The results show that the predicted values of ultimate load capacity using the ANN model agree well with that of the corresponding experimental observations, and the percentage diff erence is about ± 10%. Additionally, a new engineering index, a20-index, was predicted to further verify the reliability of the model. The fi ndings of this article are new and will signifi cantly contribute to the existing technology of ANN-based modeling in composite construction.

Selection of Psychrotrophic Leuconostoc spp. from Native Fruits, and Studies on Their Dextransucrases

Cigdem Ileri Yamaner,Ismail Yavuz Sezen,Aziz Tanriseven 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.1

Present study was aimed at selection of psychrotrophic Leuconostoc spp., having dextransucrase activity from native fruits and sauerkraut. Fifty-six colonies of lactic acid bacteria producing dextransucrase were isolated and characterized by physiological-biochemical methods. Seven isolates with high dextransucrase activities (0.68-1.63 IU/mL) were studied in detail including characterization by 16S rDNA sequence comparison. It was found that these isolates grow faster and produced dextransucrase earlier than Leuconostoc mesenteroides B512FMC-13Glc, a mutant form of the commercial strain. Molecular weights of the dextransucrases produced by 7isolates were determined and acceptor reactions using maltose were studied. Dextranase hydrolysis products of dextrans produced by new enzymes were similar to those of commercially produced B-512 F dextran. The new dextransucrases could find industrial uses and the strains isolated (AN 39-1, Or2p-2, Mu3, and Mu10) could be used as prebiotic producing starters in food fermentations due to having high dextransucrase activity and their growth at 4℃.