Analysis of Reinforced Concrete and Composite Columns With and Without Steel Fibers

Analysis of eccentrically loaded plain and steel fiber high strength reinforced concrete and concrete-encased composite columns is presented. In the analysis procedure, the experimental nonlinear stress−strain relations are used for plain and steel fiber concrete material. The concrete compression zone of the section is divided into segmental subdivisions parallel to the neutral axis. The compression stress resultants of the concrete material and structural steel have been calculated in the centre of each segment. In the presented study, a computer program has been developed based on the proposed procedure for the prediction of ultimate strength analysis of eccentrically loaded steel fiber high strength reinforced concrete and composite columns. The main parameters of this study are the concrete compressive strength, load eccentricity, steel yield stress, slenderness effect and steel fiber content. The results show that adding steel fibers into high strength concrete significantly improves the ductility and deformability of reinforced concrete and composite columns under biaxial bending and axial load

Sociodemographic Determinants of Nonattendance in a Population-Based Mammography Screening Program in the City of Manisa, Turkey

Objectives. Community based breast cancer screening has decreased breast cancer mortality in women. This study examined the predictors of nonattendence for invitational breast cancer screening in relation to socioeconomic status in the city of Manisa, in western Turkey. Study Design. For the evaluation of the reasons for refusing to participate in the study, two districts were selected. 446 women aged between 50 and 69 years were selected from the program database by systematic random sampling. Methods. The questionnaire consisted of sociodemographic variables and the adapted version of Champion's Health Belief Model Scale. Univariete and multivariete logistic regression analysis were performed throughout the data analysis. Results. Being from an urban district and being from the western region were the risk factors for not participating in the screening program (P = 0.014, P = 0.023). A statistical significance was found between mammography-benefit, mammography-barrier and program participation (P = 0.044, P = 0.006). Although there were many more barriers for not participating in the screening program for the women of the slum district, the attendence rate of the slum district was higher than that of the urban district. Conclusions. Increased attendance may be achieved through enhancement of breast cancer awareness and by reducing some of the modifiable barriers

Designing microcapsules to save energy in buildings

Buildings consume the major portıon of the world’s energy. Improvements in building elements have been proven to significantly reduce this consumption. Integrating phase change materials (PCM) into a building’s parts is an effective solution to reduce energy consumption. PCMs help to maintain thermal comfort, reduce heating, cooling loads as well as improve passive storage of solar energy in buildings. Previous studies have concentrated on impregnating PCMs into materials like concrete mixes, gypsum wall boards, plasters, textured finishes, as well as PCM trombe walls, PCM shutters, PCM building blocks, air-based heating systems, floor heating systems, suspended ceiling boards, etc.[1]. The current challenge is to find a suitable PCM that can be safe, thermally effective and at the same time not adversely effect the durability of a building. PCMs may be in microcapsulated form to meet these challenges. The most common PCM studied previously is paraffin, be it in bulk or microencapsulated. Leakage of paraffin from porous structures, the breaking of microcapsules and the low thermal capacities of microencapsulated PCMs are the main problems that have been observed [2]. The current challenge is to find a suitable PCM that can be safe, thermally effective and at the same time not adversely effect the durability of a building. PCMs may be in microcapsulated form to meet these challenges. The most common PCM studied previously is paraffin, be it in bulk or microencapsulated. Leakage of paraffin from porous structures, the breaking of microcapsules and the low thermal capacities of microencapsulated PCMs are the main problems that have been observed [2. Paraffin is a fossil fuel derivative; thus, it is unsustainable. This study focuses on bio-based fatty acid mixtures as PCMs. We developed microcapsules of fatty acid mixtures that were tried in concrete mixes. Our design approach involved the following steps: determining and characterizing PCMs with suitable thermal properties; developing a method to synthesize microencapsulated PCMs; and finally incorporate these materials in buildings for improving thermal comfort and energy conservation. Please click Additional Files below to see the full abstract

Deflection of concrete structures reinforced with FRP bars.

yesThis paper presents an analytical procedure based on the stiffness matrix method for deflection prediction of concrete structures reinforced with fiber reinforced polymer (FRP) bars. The variation of flexural stiffness of cracked FRP reinforced concrete members has been evaluated using various available models for the effective moment of inertia. A reduced shear stiffness model was also employed to account for the variation of shear stiffness in cracked regions. Comparisons between results obtained from the proposed analytical procedure and experiments of simply and continuously supported FRP reinforced concrete beams show good agreement. Bottom FRP reinforcement at midspan section has a significant effect on the reduction of FRP reinforced concrete beam deflections. The shear deformation effect was found to be more influential in continuous FRP reinforced concrete beams than simply supported beams. The proposed analytical procedure forms the basis for the analysis of concrete frames reinforced with FRP concrete members

Insulin detemir in a twice daily insulin regimen versus a three times daily insulin regimen in the treatment of type 1 diabetes in children: A pilot randomized controlled trial

Article deposited according to agreement with BMC, December 6, 2010.YesFunding provided by the Open Access Authors Fund

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

Load-Deflection Curves of Reinforced Concrete Columns Subjected to Biaxial Bending and Axial Load

WOS: 000276283900003In the presented study, a theoretical method is proposed for the determination of the load deflection curves of reinforced concrete columns subjected to biaxial bending and axial load. The proposed method can be applicable to the polygonal sections consisted of various reinforcing steel configurations. In the proposed procedure the nonlinear behaviour of the materials are considered. Therefore, the concrete compression zone is divided into segments for the computation of concrete stresses. The proposed procedure has been compared with the results of square and L-shaped reinforced concrete columns tested under biaxial bending and axial load. The theoretical load deflection curves computed using test parameters of concrete compression strength, yield strength of steel, cross section properties and eccentricities of column specimens have been compared with the experimental curves and the results are found to be in good agreement

Design of arbitrarily shaped reinforced concrete members uunder biaxial bending and axial load

Arbitrarily shaped reinforced concrete members subjected to biaxial bending and axial load are frequently used in multi-story tall buildings and bridge piers. This type of cross sections are frequently encountered as L-shaped columns at corners of framed structures and channel and hollow box sections as staircase and elecvator shafts. Designing such members subjected to biaxial bending and axial load is more complex than rectangular shaped members with uniformly distributed reinforcement