Methyl methacrylate in external fixation of supracondylar humerus fractures: An experimental study

GÜLEÇ, Ali | ACAR, Mehmet Ali | AYDIN, Bahattin Kerem | DEMİR, Teyfik | ÖZKAYA, Mustafa

Supracondylar humerus fractures are common fractures around the elbow. Open fractures, comminuted metaphyseal fractures and also fractures with bone loss may need to be treated with external fixators. The aim of this study is to compare two different external fixators, tubular external fixators and polymethyl methacrylate with K wires external fixators, with regard to stiffness and stability for metaphyseal-diaphyseal osteotomies of distal humerus close to the joint. Six matched pairs (24 specimens) of second-generation sawbone humerus were prepared in a standard fashion to create a metaphysea ...Daha fazlası

A Correlation Improvement Technique for Model Updating of Structures

ALTUNEL, Fatih | ÇELİK, Mehmet | ÇALIŞKAN, Mahmut

This study proposes a new correlation improvement technique for the optimum node removal location to get improved modal assurance criterion (MAC) matrix. The technique is applied to updating of the finite element model (FEM) of a structure. The developed routine is tried on a utility helicopter. It is proven that it is capable of showing better performance than the coordinate MAC (coMAC), commonly used in such analyses. Commercial software is utilized for the finite element analysis of the helicopter fuselage and tail. Experimental modal analyses are also performed for updating the model for t ...Daha fazlası

Sexual Life of Women with Multiple Sclerosis: A Qualitative Study

YILMAZ, Sema | GÜMÜŞ, Haluk | ODABAŞ, Ömer Faruk | AKKURT, Halil Ekrem | YILMAZ, Halim

Objectives: To define the thoughts, emotions, experiences and perceptions of women with multiple sclerosis (MS) and to determine sexual, physical, and emotional effects of MS on patients. Methods: Twenty-one women were included into this qualitatively designed study. Results: Three baseline themes were defined as “uncertainty” arising from complaints due to numbness in extremities and loss of sense, balance or vision, “alterations in sexual life,” and “inability” as a result of deformities in marital status and gender role. Conclusion: Healthcare providers should evaluate MS patients meticulou ...Daha fazlası

Türk Parlamento Tarihinde Çift Meclisli Yasama Sistemi Bakımından "Meclis-i Ayan"

Do we need a transforaminal lumbar interbody fusion cage to increase the stability of functional spinal unit when comparing unilateral and bilateral fixation?

ULUTAŞ, Murat | ÖZKAYA, Mustafa | YAMAN, Onur | DEMİR, Tevfik

Transforaminal lumbar interbody fusion was an alternative to posterior lumbar interbody fusion for decompression surgeries. This study investigates the biomechanical responses of the unilateral and bilateral pedicle screw fixations with/without transforaminal lumbar interbody fusion cages under axial compression, flexion, and torsional loads. Ovine vertebrae were used in this study. Cadavers, randomly divided into five, were intact control group, bilateral pedicle screw fixation group, bilateral pedicle screw fixation group with transforaminal lumbar interbody fusion cage, unilateral pedicle s ...Daha fazlası

Comparison of rigid and semi-rigid instrumentation under acute load on vertebrae treated with posterior lumbar interbody fusion/transforaminal lumbar interbody fusion procedures: An experimental study.

ÖNEN, Mehmet Reşid | BAŞGÜL, Cemile | YILMAZ, İlhan | ÖZKAYA, Mustafa | DEMİR, Teyfik | NADERİ, Sait

Rigid and semi-rigid fixations are investigated several times in order to compare their biomechanical stability. Interbody fusion techniques are also preferable for maintaining the sagittal balance by protecting the disk height. In this study, the biomechanical comparison of semi-rigid and rigid fixations with posterior lumbar interbody fusion or transforaminal lumbar interbody fusion procedures is conducted under trauma. There were four different test groups to analyze the effect of acute load on treated ovine vertebrae. First and second groups were fixed with polyetheretherketone rods and tr ...Daha fazlası

Estimation of long-term monthly temperatures by three different adaptive neuro-fuzzy approaches using geographical inputs

KİŞİ, Özgür | DEMİR, Vahdettin | SUNGWON, Kim

This paper investigates the accuracy of three different adaptive neuro-fuzzy inference systems (ANFISs), ANFIS with grid partition (ANFIS-GP), ANFIS with substructive clustering (ANFIS-SC), and ANFIS with fuzzy c means (ANFIS-FCM) in estimation of long-term monthly air temperatures. Data of 71 stations in Turkey are used in the applications. The periodicity (month of the year) and geographical variables (latitude, longitude, and altitude) are used as inputs to the models. ANFIS models are also compared with artificial neural networks (ANNs) and multilinear regression (MLR). Three ANFIS methods ...Daha fazlası

Biomechanical comparison of transdiscal fixation and posterior fixation with and without transforaminal lumbar interbody fusion in the treatment of L5–S1 lumbosacral joint

ÖZALP, Hakan | ÖZKAYA, Mustafa | YAMAN, Onur | DEMİR, Teyfik

Transdiscal screw fixation is generally performed in the treatment of high-grade L5–S1 spondylolisthesis. The main thought of the study is that the biomechanical performances of the transdiscal pedicle screw fixation can be identical to standard posterior pedicle screw fixations with or without transforaminal lumbar interbody fusion cage insertion. Lumbosacral portions and pelvises of 45 healthy lambs’ vertebrae were dissected. Animal cadavers were randomly and equally divided into three groups for instrumentation. Three fixation systems, L5–S1 posterior pedicle screw fixation, L5–S1 posterior ...Daha fazlası

Shock failure analysis of metallic structures by using strain energy density method

ÇELİK, Mehmet | MERCİMEK, Ümit | KADIOĞLU, Suat

Failure of metallic structures operating under shock loading is a common occurrence in engineering applications. It is difficult to estimate the response of complicated systems analytically, due to structure's dynamic characteristics and varying loadings. Therefore, experimental, numerical, or a combination of both methods is used for evaluations. In this study, test pieces made of two different materials are subjected to shock loads stemming from firing of a Gatling gun. Strain measurements are made, and finite element analysis of the test piece is performed. As a result of this study, strain ...Daha fazlası

On the Interpretation of Melt Quality Assessment of A356 Aluminum Alloy by the Reduced Pressure Test: The Bifilm Index and Its Physical Meaning

ULUDAĞ, Muhammet | ÇETİN,Remzi | DIŞPINAR, Derya | TİRYAKİOĞLU, Murat

The oxide layer on liquid aluminum serves as a protective property to prevent the alloy from further oxidation. However, it has the potential to be a source of porosity when entrained into the bulk of the liquid. For this reason, oxides entrained into aluminum castings have been shown to degrade casting quality. In the current study, the effectiveness of the reduced pressure test in assessing the quality of A356 alloy melts has been investigated under various conditions obtained by changing six different melt parameters. Several metrics, including average pore size, number density of pores, bi ...Daha fazlası

Using Internet: A Mechanism to Develop Market Share

MOSTAVAFI SHIRAZI, Seyedeh Fatemeh

This chapter presents the subject area of the Internet as an international form of media and examines related issues. It begins by considering the Internet as a source of information in various forms of social network sites that enables any individual to post their experiences, opinions and evaluations of tourism destination. This provides a summary of the existing state of knowledge concerning to social network sites and word of mouth (WMO) recommendation. In addition, it serves to clarify the associated word of mouth and market share development. Introduction Using the Internet as an interna ...Daha fazlası

Calixarene assembly with enhanced photocurrents using P(SNS-NH2)/CdS nanoparticle structure modified Au electrode systems

SAYIN, Serkan | AZAK, Hacer | YILDIZ, Hüseyin Bekir | ÇAMURLU, Pınar | UYSAL AKKUŞ, Gülderen | TOPPARE, Lale | ERSÖZ, Mustafa

Two novel calix[n]arene-adorned gold electrodes producing high photocurrent intensities were successfully constructed by embedding gold electrode surfaces with both P(4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine) conducting polymer and 4-mercaptoboronic acid-functionalized semiconductor CdS nanoparticles to facilitate the binding of calix[n]arene sulfonic acids with nanoparticles. This structure enabled an electron transfer cascade that both induced effective charge separation and efficiently generated photocurrent. The prepared electrodes were used to generate photocurrent by relying o ...Daha fazlası