Solving the contact problem of functionally graded layers resting on a HP and pressed with a uniformly distributed load by analytical and numerical methods

Murat Yaylacı,Bahar Şengül Şabano,Mehmet Emin Özdemir,Ahmet Birinci 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.3

The aim of this study is to examine the frictionless double receding contact problem for two functionally graded (FG) layers pressed with a uniformly distributed load and resting on a homogeneous half plane (HP) using analytical and numerical methods. The FG layers are made of a non-homogeneous material with an isotropic stress-strain law with exponentially varying properties. It is assumed that the contact at the FG layers and FG layer-HP interface is frictionless. The body force of the FG layers and homogeneous HP are ignored in the study. Firstly, an analytical solution for the contact problem has been realized using the theory of elasticity and the Fourier integral transform techniques. Then, the problem modeled and two-dimensional analysis was carried out by using the ANSYS package program based on FEM. Numerical results for contact lengths and contact pressures between FG layers and FG layer-HP were provided for various dimensionless quantities including material inhomogeneity, distributed load width, the shear module ratio, and the heights of the FG layers for both methods. The results obtained using FEM were compared with the results found using the analytical formulation. It was found that the results obtained from analytical formulation were in perfect agreement with the FEM study.

Examining Knowledge, Skill, Stress, Satisfaction, and Self-Confidence Levels of Nursing Students in Three Different Simulation Modalities

Üzen Cura Şengül,Kocatepe Vildan,Yıldırım Dilek,Küçükakgün Hilalnur,Atay Selma,Ünver Vesile 한국간호과학회 2020 Asian Nursing Research Vol.14 No.3

Purpose: The aim of this study was to compare the effect of different simulation modalities on knowledge, skill, stress, satisfaction, and self-confidence levels of students receiving undergraduate education in three nursing schools. Method: This was an experimental study. Students applied the scenario of “Respiratory Sounds Assessment” which was prepared according to three different simulation modalities. In the study, the standardized patient, high-fidelity simulation, and partial task trainer were used as simulation modalities. Results: An increase was observed in postpractice knowledge levels of the three groups which had similar knowledge levels before the practice. Virtual Analog Scale stress levels of the students in the standardized patient group were higher than those of others. The students’ mean scores of satisfaction in learning were higher in the standardized patient group. The students in the partial task trainer group had lower scores of self-confidence in learning. Skill scores of the students were lower in the standardized patient practice than those in others. Conclusion: Simulation-based experiences give students the opportunity of experiencing situations they may experience in the actual practice beforehand. Therefore, this may increase their performance in real practices, as reality increases in the standardized patient group.

Effects of cyanocobalamin and its combination with morphine on neuropathic rats and the relationship between these effects and thrombospondin-4 expression

Neslihan Düzenli,Sibel Ülker,Gülgün Şengül,Buse Kayhan,Aytül Önal 대한통증학회 2022 The Korean Journal of Pain Vol.35 No.1

Background: Thrombospondin-4 (TSP4) upregulates in the spinal cord following peripheral nerve injury and contributes to the development of neuropathic pain (NP). We investigated the effects of cyanocobalamin alone or in combination with morphine on pain and the relationship between these effects and spinal TSP4 expression in neuropathic rats. Methods: NP was induced by chronic constriction injury (CCI) of the sciatic nerve. Cyanocobalamin (5 and 10 mg/kg/day) was administered 15 days before CCI and then for 4 and 14 postoperative days. Morphine (2.5 and 5 mg/kg/day) was administered only post-CCI. Combination treatment included cyanocobalamin and morphine, 10 and 5 mg/kg/day, respectively. All drugs were administered intraperitoneally. Nociceptive thresholds were detected by esthesiometer, analgesia meter, and plantar test, and TSP4 expression was assessed by western blotting and fluorescence immunohistochemistry. Results: CCI decreased nociceptive thresholds in all tests and induced TSP4 expression on the 4th postoperative day. The decrease in nociceptive thresholds persisted except for the plantar test, and the increased TSP4 expression reversed on the 14th postoperative day. Cyanocobalamin and low-dose morphine alone did not produce any antinociceptive effects. High-dose morphine improved the decreased nociceptive thresholds in the esthesiometer when administered alone but combined with cyanocobalamin in all tests. Cyanocobalamin and morphine significantly induced TSP4 expression when administered alone in both doses for 4 or 14 days. However, this increase was less when the two drugs are combined. Conclusions: The combination of cyanocobalamin and morphine is more effective in antinociception and partially decreased the induced TSP4 expression compared to the use of either drug alone.

Effect of Partial Replacement of Soybean and Corn with Dietary Chickpea (Raw, Autoclaved, or Microwaved) on Production Performance of Laying Quails and Egg Quality

Ahmet Yusuf Ş,engü,l,Sü,leyman Ç,aliş,lar 한국축산식품학회 2020 한국축산식품학회지 Vol.40 No.3

This study was conducted to investigate whether adding different levels of raw or differently processed chickpea into different diets of laying quails affected live weight, feed intake, feed efficiency, egg weight and internal and external egg quality. Chickpea was used as raw, autoclaved or microwave-processed, and it was involved in the diets on two different levels (20% and 40%). The sample was divided into 7 groups including the control, 20% and 40% raw, 20% and 40% autoclaved, and 20% and 40% microwaveprocessed groups. 336 ten-week-old female laying quails were used in the study, and the experiment continued for 19 weeks. In the study, the differences among the groups were insignificant in terms of live weight, feed intake, feed efficiency, egg weight and egg quality characteristics such as shell thickness, shell weight, yolk weight, yolk color and albumin index. The differences were significant in terms of the shape index, Haugh unit (p<0.05) and yolk index (p<0.01). Consequently, it was observed that different thermal processes on chickpeas did not usually have a significant effect on the yield performance of the quails, and the results that were obtained were similar to the other groups. However, it was determined that some egg quality characteristics were affected by the autoclaving and microwaving processes. Between the thermal processes, it may be stated that autoclaving provided better results.

Intra-network Dynamics in E-business Models

Jingyu Yan,Woon Kian Chong,Yan Sun,K. L Man,Nan Zhang,Kaiyu Wan,Eng Gee Lim 한국산업정보학회 2014 한국산업정보학회 학술대회논문집 Vol.2014 No.1

Amputation of Glans Penis: A Rare Circumcision Complication and Successful Management with Primary Anastomosis and Hyperbaric Oxygen Therapy

Gökhan Faydaci,Kuyumcuoğlu Uğur,Celik Osman,Şengül Şermin,Eryıldırım Bilal 대한비뇨의학회 2011 Investigative and Clinical Urology Vol.52 No.2

Penile amputation is an uncommon condition that requires immediate surgical replantation. Routine standardized procedures for dealing with this medical condition do not exist. We describe a case of complete guillotine-type glans penis amputation and review the relevant literature. We performed urethral end-to-end approximation and glanular anastomosis and then applied hyperbaric oxygen therapy postoperatively. We obtained very good cosmetic and functional results.

Pomegranate Seed Extract Attenuates Chemotherapy-Induced Acute Nephrotoxicity and Hepatotoxicity in Rats

Kerim Çayır,Ali Karadeniz,Nejdet Şimşek,Serap Yıldırım,Emre Karakuş,Adem Kara,Hürrem Turan Akkoyun,Emin Şengül 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.10

Cisplatin (CDDP), one of the most active cytotoxic agents against cancer, has adverse side effects, such as nephrotoxicity and hepatotoxicity. The present study was designed to investigate the potential protective effect of pomegranate seed extract (PSE) against oxidative stress caused by CDDP injury of the kidneys and liver by measuring tissue biochemical and antioxidant variables and immunohistochemically testing caspase-3–positive cells. Twenty-four Sprague–Dawley rats were divided into 4 groups: control; CDDP: injected intraperitoneally with CDDP (7 mg/kg body weight, single dose); PSE: treated for 15 consecutive days by gavage with PSE (300 mg/kg per day); and PSE+CDDP: treated by gavage with PSE 15 days after a single injection of CDDP. The degree of protection against CDDP injury afforded by PSE was evaluated by determining the levels of malondialdehyde as a measure of lipid peroxidation. The levels of glutathione and activities of glutathione peroxidase, glutathione S-transferase, and superoxide dismutase were estimated from liver and kidney homogenates; the liver and kidney were also histologically examined. PSE elicited a significant protective effect toward liver and kidney by decreasing the level of lipid peroxidation; elevating the levels of glutathione S-transferase; and increasing the activities of glutathione peroxidase, glutathione S-transferase, and superoxide dismutase. These biochemical observations were supported by immunohistochemical findings and suggested that PSE significantly attenuated nephrotoxicity and hepatotoxicity by the way of its antioxidant, radical-scavenging, and antiapoptotic effects. This PSE extract could be used as a dietary supplement in patients receiving chemotherapy medications.

Synthesis and Application of Novel Magnetite Nanoparticle Based Azacrown Ether for Protein Recognition

Mevlüt Bayrakcı,Esra Maltaş,Şengül Yiğiter,Mustafa Özmen 한국고분자학회 2013 Macromolecular Research Vol.21 No.9

This article is the first report showing the human serum albumin (HSA) binding studies by using a new magnetite nanoparticle containing azacrown ether moieties via solid-liquid extraction process. The structure of the newly prepared magnetite nanoparticle was clarified by using attenuated total reflectance (ATR) infrared spectroscopy,scanning electron microscopy (SEM), UV-vis and elemental analysis. Analytic results indicated that modification of the surface of the magnetite nanoparticles with azacrown ether derivative was successfully carried out. The protein binding studies exhibited that the modified magnetite nanoparticles could be efficiently used for the binding of the human serum albumin (HSA) in aqueous solutions via non-covalent interaction between crown ether cavity and amino group of the protein.