Manisa Celal Bayar Üniversitesi Akademik Arşiv Sistemi
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Effect of mesh and its localisation on testicular flow and spermatogenesis in patients with groin hernia
No full textIn this study, the long-term effects of mesh and its localisation (i.e. anterior or posterior) on testicular perfusion and testicular function were evaluated in groin hernia patients. Testicular function has been evaluated with spermiogram and testicular perfusion with colour Doppler ultrasonography. Group I : consisted of 30 posterior preperitoneal mesh repair patients Group 11 : consisted of 30 anterior tension-free repair patients. The operation types were randomised with a systematic sampling method. There was no statistically significant difference between pre-operative and postoperative spermiogram results for both groups. No statistically significant difference was found between the two groups in terms of Doppler flow parameters (PSV, EDV, RI and PI) for pre-operative, early and late postoperative periods. When Doppler flow parameters were compared for group I, statistically significant differences were found between preoperative and early postoperative values. No statistically significant difference was found between pre-operative and late postoperative values. This is also true for early postoperative values versus late postoperative values. When Doppler flow parameters were compared for group II, statistically significant differences were found between pre-operative and early postoperative values. No statistically significant difference was found between pre-operative and late postoperative values. This is also true for early postoperative values versus late postoperative values. These results support the idea that inguinal mesh application is still a safe procedure in patients with no children or who are undergoing infertility treatment, where testicular function is important
FT-IR, FT-Raman, NMR and UV-Vis spectra and DFT calculations of 5-bromo-2-ethoxyphenylboronic acid (monomer and dimer structures)
No full textIn this study, the Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of 5-bromo-2-ethoxyphenylboronic acid (5Br2EPBA) are recorded in the solid phase in the region 4000400 cm(-1) and 3500-10 cm(-1), respectively. The H-1, C-13 and DEPT nuclear magnetic resonance (NMR) spectra are recorded in DMSO solution. The UV-Vis absorption spectrum of 5Br2EPBA is saved in the range of 200-400 nm in ethanol and water. The following theoretical calculations for monomeric and dimeric structures are supported by experimental results. The molecular geometry and vibrational frequencies in the ground state are calculated by using DFT methods with 6-31 G(d,p) and 6-311 G(d,p) basis sets. There are four conformers for the present molecule. The computational results diagnose the most stable conformer of 5Br2EPBA as Trans-Cis (TC) form. The complete assignments are performed on the basis of the total energy distribution (TED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method in parallel quantum solutions (PQS) program. The H-1 and C-13 NMR chemical shifts of 5Br2EPBA molecule are calculated by using the Gauge Invariant Atomic Orbital (GIAO) method in DMSO and gas phase for monomer and dimer structures of the most stable conformer. Moreover, electronic properties, such as the HOMO and LUMO energies (by TD-DFT and CIS methods) and molecular electrostatic potential surface (MEPs) are investigated. Stability of the molecule arising from hyper-conjugative interactions, charge delocalization is analyzed using natural bond orbital (NBO) analysis. Nonlinear optical (NLO) properties and thermodynamic features are presented. All calculated results are compared with the experimental data of the title molecule. The correlation of theoretical and experimental results provides a detailed description of the structural and physicochemical properties of the title molecule. (C) 2014 Elsevier B.V. All rights reserved
Low-velocity impact behaviors of sandwich composites with different structural configurations of foam core: numerical study and experimental validation
No full textSandwich composites have very weak properties as well as superior properties. Damages will be invisible and may create huge problems due to the high strength difference of composite components. To investigate sandwich composites, numerical studies' importance is so high because experimental studies require high labor and are time-consuming. In this study, low-velocity impact properties of the configurations of sandwich composites with E-glass fiber/epoxy and PVC foam core are investigated numerically, and the results are compared with experimental results. Reference sandwich composite, and four different types of configurations are modeled with homogenized properties. Numerical simulations are performed using the material models of rigid impactor, foam core, and composite material models of LS-DYNA software. Numerical and experimental results of these sandwich composites are compared in terms of contact force-time and contact force-displacement curves, core/facesheet debonding areas, peak contact forces, absorbed energy, maximum displacement, and contact time; a good agreement is obtained
Investigation of damaged formwork timber beam retrofitting with anchoraged CFRP strip under different loading
No full textConstruction of high -rise structures, formwork systems that can be installed quickly, resistant to external loads, can be used more than once, have become a necessity. Timber and composite timber materials are preferred in the formation of such formwork systems due to their durability, ease of assembly, light weight and easy to use more than one time. Formwork beams are the most commonly used structural component in the formation of such formwork systems, and these beams can be damaged for different reasons during their lifetime. In this study, H20 top P type timber formwork beams with 1800 and 2450 mm length which is among the products of DOKA(c) company is damaged under the effect of static loading up to a high load level of 85% of the maximum ultimate capacity and after being retrofitted using anchored CFRP strips, performance and behavior of the beams under the influence of various loading types such as static, fatigue and impact are investigated experimentally. Two different lengths of retrofitted timber formwork beams were tested by applying monotonic static, fatigue and impact loading and comments were made about the effects of the retrofit method on performance under different loading types
Free vibrations analysis of fluid conveying nanobeam based on nonlocal elasticity theory
No full textIn this study, linear vibration analysis of a nanobeam conveying fluid is investigated under simple-simple and clamped-clamped boundary conditions. Eringen's nonlocal elasticity theory is applied to Euler-Bernoulli beam model. Nonlocal elasticity theory is a popular growing technique for the mechanical analyses of MEMS and NEMS structures. The Hamilton's principle is employed to derive the governing equations and boundary conditions. Non-dimensional form of equations is obtained. The obtained equations of motion and boundary conditions are independent from material and geometric structure. It is assumed that fluid velocity is harmonically changed about a constant average speed. Approximate solutions were obtained using the Method of Multiple Scales, a perturbation method. The first term in perturbation series composes linear problem. Natural frequencies and mode shapes are calculated by solving the linear problem for different boundary conditions. For both boundary conditions, the natural frequencies are decreased by increasing the nonlocal parameter (gamma)and the fluid velocity (nu(0)). The results are presented and interpreted by graphics
Transient left paraduodenal hernia
No full textA 52-year-old woman with acute deterioration of recurrent abdominal pain was admitted to the hospital. Spiral computed tomography (CT) of abdomen was performed. A left paraduodenal hernia was identified on CT. There was no clinical sign or imaging finding suggesting intestinal obstruction or mesenteric ischemia. She refused surgical intervention since her pain was intermittant and decreasing. On the fifth day of hospitalization the patient's pain resolved completely and the follow-up CT demonstrated regression of the herniation. (c) 2005 Elsevier Ltd. All rights reserved
A portfolio construction framework usingLSTM-based stock markets forecasting
No full textA novel framework that injects future return predictions into portfolio constructionstrategies is proposed in this study. First, a long-short-term-memory (LSTM) model is trained to learn the monthly closing prices of the stocks. Then these predictions are used in the calculation of portfolio weights. Five different portfolio construction strategies are introduced including modifications to smart-beta strategies. The suggested methods are compared to a number of baseline methods, using the stocks of BIST30 Turkey index. Our strategies yield a very high mean annualized return (25%) which is almost 50% higher than the baseline approaches. The mean Sharpe ratio of our strategies is 0.57, whereas the compared methods' are 0.29 and -0.32. Comprehensive analysis of the results demonstrates that utilizing predicted returns in portfolio construction enables a significant improvement on the performance of the portfolios
The synergistic effect of Er3+ and Ho3+ on temporal color tuning of upconversion emission in a glass host via a facile excitation modulation technique for anti-counterfeiting applications
No full textLanthanide-doped upconversion luminescent materials are highly promising for diverse applications, e.g., solid-state lighting, volumetric displays, and anti-counterfeiting, owing to their unique optical feature of color-tunable emission under near-infrared excitation. Hence, in this study, emission color tuning of Er3+/Ho3+ ions in a fixed glass host is investigated via a facile excitation modulation technique. The upconversion emission color from green to yellowish is tuned successfully by regulating the frequency of the irradiation source. The population and depopulation rates of related transitions are investigated through time-resolved photoluminescence and Judd-Ofelt analysis in order to elucidate the proposed mechanism of color tuning. Upconversion quantum yield values are measured in the range of 0.12 to 0.17% for a better comparison of the emission properties. Additionally, thermal, and structural properties are investigated to reveal the favorable properties of the selected tellurite glass host. Ultimately, several patterns are designed and constructed by a screen-printing technique using powdered glass to demonstrate its suitability as a multicolor imaging method for anti-counterfeiting applications. The temporal color tuning of upconversion emission via a facile excitation modulation technique in a glass host clearly indicates that the proposed Er3+/Ho3+ co-doped glasses can be potentially applied in the state-of-the-art technologies, especially for anticounterfeiting purposes
Does Microwave Exposure at Different Doses in the Pre/Postnatal Period Affect Growing Rat Bone Development?
No full textEffects of pre/postnatal 2.45 GHz continuous wave (CW), Wireless -Fidelity (Wi-Fi) Microwave (MW) irradiation on bone have yet to be well defined. The present study used biochemical and histological methods to investigate effects on bone formation and resorption in the serum and the tibia bone tissues of growing rats exposed to MW irradiation during the pre/postnatal period. Six groups were created: one control group and five experimental groups subjected to low-level different electromagnetic fields (EMF) of growing male rats born from pregnant rats. During the experiment, the bodies of all five groups were exposed to 2.45 GHz CW-MW for one hour/day. EMF exposure started after fertilization in the experimental group. When the growing male rats were 45 days old in the postnatal period, the control and five experimental groups' growing male and maternal rats were sacrificed, and their tibia tissues were removed. Maternal rats were not included in the study. No differences were observed between the control and five experimental groups in Receptor Activator Nuclear factor-kB (RANK) biochemical results. In contrast, there was a statistically significant increase in soluble Receptor Activator of Nuclear factor-kB Ligand (sRANKL) and Osteoprotegerin (OPG) for 10 V/m and 15 V/m EMF values. Histologically, changes in the same groups supported biochemical results. These results indicate that pre/postnatal exposure to 2.45 GHz EMF at 10 and 15 V/m potentially affects bone development