COST ANALYSIS IN REINFORCED CONCRETE CANTILEVER RETAINING WALLS

COST ANALYSIS IN REINFORCED CONCRETE CANTILEVER RETAINING WALLSAbstractMany factors are effective in the design of cantilever retaining walls. These factors are; factors such as wall height, soil internal friction angle, surcharge loads, groundwater level, seismic effects and frost effects. These factors directly affect the design of the retaining walls and therefore the cost of them. In this study, the effects of wall height, soil internal friction angle and surcharge loads, which are the factors affecting the design, were investigated. For this purpose, solutions of 64 different cantilever retaining wall designs were made separately at 4, 6, 8 and 10 m wall height, 24, 26, 28, 30° internal friction angles and under 10, 15, 20, 25 kN/m2 surcharge loads and their costs were calculated. With these solutions, analysis of variance (ANOVA) was performed using the full factorial design method and the effects of wall height, internal friction angle and surcharge load variables on cost were investigated. Thus, cost changes of cantilever retaining walls at different wall heights, internal friction angles and surcharge loads were investigated. IdeCAD Static v10.09 software was used for solutions of cantilever retaining wall designs and Minitab v17 software was used for ANOVA.Keywords: Reinforced concrete retaining walls, Cost Analysis, Full Factorial Design Analysis, ANOVA.BETONARME KONSOL İSTİNAT DUVARLARINDA MALİYET ANALİZİÖzetBetonarme istinat duvarlarının tasarımında birçok faktör etkili olmaktadır. Bu faktörler; duvar yüksekliği, zemin içsel sürtünme açısı, sürşarj yükleri, yeraltı su seviyesi, sismik etkiler ve don tesirleri gibi faktörler olarak sıralanabilir. Bu faktörler istinat duvarlarının tasarımını ve dolayısıyla maliyetini doğrudan etkilemektedir. Bu çalışmada tasarıma etki eden faktörlerden olan duvar yüksekliği, zemin içsel sürtünme açısı ve sürşarj yüklerinin tasarımdaki etkileri araştırılmıştır. Bu amaçla 4, 6, 8 ve 10 m duvar yüksekliğinde, 24, 26, 28, 30° içsel sürtünme açılarında ve 10, 15, 20, 25 kN/m2 sürşarj yükleri altında ayrı ayrı olarak 64 farklı betonarme konsol istinat duvarı tasarımının çözümleri yapılmış ve bunların maliyetleri hesaplanmıştır. Bu çözümler ile tam faktöriyel tasarım metodu kullanılarak varyans analizleri (ANOVA) yapılmış ve yükseklik, içsel sürtünme açısı ve sürşarj yükü değişkenlerinin maliyet üzerine etkileri araştırılmıştır. Böylelikle betonarme konsol istinat duvarlarının farklı duvar yüksekliğinde, içsel sürtünme açısında ve sürşarj yüklerinde maliyet değişimleri incelenmiştir. Betonarme konsol istinat duvarlarının çözümleri için ideCAD Statik v 10.09 yazılımı ve ANOVA için de Minitab v17 yazılımı kullanılmıştır.Anahtar Kelimeler: Betonarme Konsol İstinat Duvarı, Maliyet Analizi, Tam Faktöriyel Tasarım Analizi, ANOV

Computational Study of High Speed Blade–Vortex Interaction

This thesis presents inviscid compressible simulations for the orthogonal blade-vortex interaction. A numerical model between the tail rotor of a helicopter and the trailing vortex system formed by the main rotor blades is assumed. The study takes a ‘building-block’ approach to investigating this problem. Firstly, the impulsive instantaneous blocking of the axial core flow by a flat plate is considered. In the second step, the three-dimensional gradual cutting of the vortex by a sharp flat-plate that moves at a finite speed through the vortex is performed. Finally the chopping of the vortex by a blunt leading edge aerofoil, which incorporates both the blocking effect and also the stretching and distortion of the vortex lines is studied. The solutions reveal that the compressibility effects are strong when the axial core flow of the vortex is impulsively blocked. This generates a weak shock-expansion structure propagating along the vortex core on opposite sides of the cutting surface. The shock and expansion waves are identified as the prominent acoustic signatures in the interaction. In a simplified, two-dimensional axisymmetric model, the modelling of the physical evolution of the vortex, including the evolution of the complex vortical structures that controls the vortex core size near the cutting surface, are studied. Furthermore, the three dimensional simulations revealed that there is a secondary and a tertiary noise sources due to compressibility effects at the blade leading edge and due to the shock-vortex interaction taking place on the blade, which is exposed to a transonic free-stream flow

Examination of Science Achievement in the 8th Grade Level in Turkey in Terms of National and International Exams Depending upon Various Variables

The aim of the present study is to examine the effect of demographic characteristics of students in Turkey upon their performance in TIMSS, an international assessment exam and Secondary Education Transition Examination which is a national exam (OGS). One of the fields of sciences, biology is taken into account as student performance. As a result of the t-test analysis, it was determined that gender has a statistically significant effect on the students’ TIMSS and TEOG exam results; besides, it was found that female students are more successful compared to boys Whether students receive private tutoring which refers to the economic characteristics of the students has not statistically significant effect on TIMSS biology scores, while it has a positive and significant impact upon OGS biology scores.  Moreover, findings revealed that parental educational level has a positive and significant effect on TIMSS and OGS scores of the students. Keywords: TIMSS, TEOG, science achievement, Turkey, private tutorin

Isogeometric mindlin-reissner inverse-shell element formulation for complex stiffened shell structures

Structural health monitoring (SHM) is a technology that is used to improve the safety, stability, and availability of large engineering structures. One important aspect of SHM is the ability to perform real-time reconstruction of the full-field structural displacements, also known as shape sensing. The inverse Finite Element Method (iFEM) is a technique that has been used for three-dimensional shape sensing of structures using strain data. On the other hand, Isogeometric Analysis (IGA) is a method that utilizes smooth spaces of functions, such as non-uniform rational B-splines, to solve structural problems and has gained significant attention in recent times. In this study, the authors propose a new method for shape sensing of complex stiffened shell structures by combining IGA with the iFEM method. The goal of this research is to accurately reconstruct the complex geometry of the structure without the need for a fine numerical discretization or mesh. To achieve this, the authors have developed an isogeometric Mindlin-Reissner inverse-shell element (IgaiMin) to implement the coupling between IGA and iFEM. The proposed method is validated by solving problems involving simple plates, tee junctions, and partly clamped stiffened panels representing ship structures

Influence des facteurs environnementaux sur la distribution et la composition des communautés végétales dans la vallée de la Kizilirmak, région de la mer Noire, Turquie

La présente étude examine le rôle des facteurs environnementaux dans la distribution des associations végétales dans la vallée de la Kizilirmak dans le nord de la Turquie. Elle fournit une analyse quantitative des relations végétation – environnement sur un site de cette vallée. Cent trente parcelles de végétation ont été échantillonnées et analysées à l’aide de TWINSPAN et d’une analyse des correspondances détendancées (DCA) afin d’identifier les principales communautés végétales et de déterminer les gradients environnementaux auxquels elles sont associées. Onze associations et six sous-associations ont été déterminées à l’aide de TWINSPAN dont le dendrogramme individualise trois grands groupes végétaux dans la vallée de la Kizilirmak : les sclérophylles, les xérophylles et les mésophylles. Les principaux axes de la DCA représentent les gradients d’altitude, d’humidité relative et de pH du sol. Des indices de diversité de Shannon et de richesse spécifique ont été calculés pour les associations étudiéesThe aim of this study is to explore the influence of environmental factors on the distribution of plant associations in Kizilirmak Valley, in northern Turkey. This paper provides a quantitative analysis of the vegetation–environment relationships for a study site in this valley. 130 vegetation plots were sampled and analysed using two-way indicator species analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA) in order to identify the principal vegetation communities and determine the environmental gradients associated with these. Eleven associations and six sub- associations were found by using TWINSPAN. There were three main vegetation groups, namely sclerophyllous, xerophyllous and mesophyllous according to TWINSPAN dendrogram, in Kizilirmak valley. The principal DCA axes represent gradients of elevation, relative humidity and soil pH. Shannon diversity index and species richness were also calculated for studied plant association

Echocardiographic evaluation of diastolic functions in patients with polycystic ovary syndrome: A comperative study of diastolic functions in sub-phenotypes of polycystic ovary syndrome

Background: Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder among reproductive-aged women. It is known to be associated with cardiovascular diseases. The aim of this study was to determine and compare the echocardiographic data of patients according to the phenotypes of PCOS. Methods: This study included 113 patients with PCOS and 52 controls. Patients were classified into four potential PCOS phenotypes. Laboratory analyses and echocardiographic measurements were performed. Left ventricular mass was calculated by using Devereux formula and was indexed to body surface area. Results: Phenotype-1 PCOS patients had significantly higher homeostasis model assessment — insu­lin resistance (HOMA-IR) (p = 0.023), free testosterone (p < 0.001), LDL cholesterol levels (p < 0.001) and free androgen index (p < 0.001) compared with the control group. There were significant differences between groups regarding the septal thickness, posterior wall thickness, Left ventricular ejection frac­tion, E/A ratio and left ventricular mass index (for all, p < 0.05). PCOS patients with phenotype 1 and 2 had significantly higher left ventricular mass index than the control group (p < 0.001). In univariate and multivariate analyses, PCOS phenotype, modified Ferriman-Gallwey Score and estradiol were found as variables, which independently could affect the left ventricular mass index. Conclusions: This study showed that women in their twenties who specifically fulfilled criteria for PCOS phenotype-1 according to the Rotterdam criteria, had higher left ventricular mass index and decreased E/A ratio, which might be suggestive of early stage diastolic dysfunction. (Cariol J 2017; 24, 4: 364–373

Endothelial function in patients with familial Mediterranean fever-related amyloidosis and association with cardiovascular events

Objectives. Secondary amyloidosis is the most important complication of FMF and endothelial function is more severely impaired. Elevated asymmetric dimethyl arginine (ADMA) may mediate the excess cardiovascular disease (CVD) risk of this group. We aimed to compare endothelial function characteristics, including ADMA, in patients with FMF-related amyloidosis and primary glomerulopathies and to define risk factors for a CVD event. Methods. We undertook a cross-sectional study with prospective follow-up including consecutive patients with FMF-related amyloidosis (n = 98) or other non-diabetic glomerulopathies (n = 102). All patients had nephrotic-range proteinuria and normal glomerular filtration rate. Flow-mediated dilatation (FMD) was assessedand ADMA levels, CRP and pentraxin 3 (PTX3) were determined. Patients were followed for cardiovascular events. Results. Amyloidosis patients secondary to FMF showed higher levels of ADMA, CRP and PTX3 and lower FMD as compared with patients with other glomerulopathies. Cardiovascular events (n = 54) were registered during 3 years of follow-up. Increased ADMA levels and lower FMD were observed in patients with cardiovascular risk in both groups, but especially in individuals with amyloidosis.Conclusion. Patients with FMF-related amyloidosis have increased CVD event risk, probably related to the high ADMA levels, elevated inflammatory markers and decreased FMD measures observed in these patients

Vertically oriented low-dimensional perovskites for high-efficiency wide band gap perovskite solar cells

Controlling crystal growth alignment in low-dimensional perovskites (LDPs) for solar cells has been a persistent challenge, especially for low-n LDPs (n 1.7 eV) impeding charge flow. Here we overcome such transport limits by inducing vertical crystal growth through the addition of chlorine to the precursor solution. In contrast to 3D halide perovskites (APbX3), we find that Cl substitutes I in the equatorial position of the unit cell, inducing a vertical strain in the perovskite octahedra, and is critical for initiating vertical growth. Atomistic modelling demonstrates the thermodynamic stability and miscibility of Cl/I structures indicating the preferential arrangement for Cl-incorporation at I-sites. Vertical alignment persists at the solar cell level, giving rise to a record 9.4% power conversion efficiency with a 1.4 V open circuit voltage, the highest reported for a 2 eV wide band gap device. This study demonstrates an atomic-level understanding of crystal tunability in low-n LDPs and unlocks new device possibilities for smart solar facades and indoor energy generation