http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Experimental study on standard and innovative bolted end-plate beam-to-beam joints under bending
Levente Katula,László Dunai 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.6
The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and momentdistance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.
Levent Selçuk,H. Süleyman Gökçe 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.6
The point load strength (Is(50)) is an alternative mechanical parameter to predict the compressive strength of concrete. The scope of this investigation is to develop an empirical equation relating the point load strength and compressive strength of concrete. In this context, crushed limestone aggregates at two different strength levels were used in concrete mixture. Point load strength and compressive strength tests on concrete specimens which had 6 different compressive strengths were performed for each limestone aggregate. A series of regression analyses was applied using any general statistical package to evaluate the ratio of point load strength test to cube compressive strength of concrete, (Is(50)/fcu). The accuracy and reliability of the equation in this investigation was assessed by means of the Mean Absolute Percent Error (MAPE). The relative error can be considered reasonably well for the empirical relationship. The ratio of Is(50)/fcu was also verified by a large database collected from previous studies. The proposed equation is quite compatible with the database. Furthermore, the ratio of Is(50)/fcu indicates significant material property of concrete and defines the material constant in strength criterions. It can be used to estimate the axial compressive strength of concrete under confining stress without performing triaxial tests, considered Hoek-Brown and Johnson empirical failure criterions.
Visual Evoked Potentials in Guillain-Barré Syndrome
Levent Güngör,,İnci Güngör,Hilal Eser Öztürk,Musa Kazım Onar 대한신경과학회 2011 Journal of Clinical Neurology Vol.7 No.1
Background and Purpose:Guillain-Barré syndrome (GBS) is an acute demyelinating polyneuropathy with various clinical features. Optic neuritis occurs in rare cases. In this study we determined the incidence and patterns of visual evoked potential (VEP) abnormality in GBS in association with ophthalmologic findings. Methods:Thirty-two patients with a diagnosis of GBS were included in the study. The correlation between pathologic VEPs and categories of neurologic deficit and electrophysiological findings were examined statistically. Results:The patients ranged in age from 19 to 77 years. Five cases (16%) had abnormal VEPs. All five of these patients exhibited increased P100 latency differences between the two eyes. Other abnormalities were prolonged p100 latency, increased interocular amplitude difference, and distorted p100 configuration. Pathologic signs on ophthalmologic examination were observed in 80% of patients with abnormal VEPs. VEP abnormality was never present in pure axonal forms. There was no significant correlation between pathologic VEP and cerebrospinal fluid protein level or categories of neurologic deficits. Conclusions:Involvement of the optic pathways is not a frequent finding in GBS. When present it is always asymmetric and generally accompanied with pathologic findings on ophthalmologic examination. VEPs may be abnormal in different clinical variants of GBS, and especially in demyelinating forms.
Levent Cerit,Hamza Duygu,Kamil Gulsen,Hatice S Kemal,Barcın Ozcem,Ozlem Balcioglu,Aziz Gunsel,Ozgur Tosun,Volkan Emren 대한심장학회 2016 Korean Circulation Journal Vol.46 No.6
Background and Objectives: The relationship of synergy between percutaneous coronary intervention with taxus and cardiac surgery (SYNTAX) score and development of atrial fibrillation (AF) after coronary artery bypass surgery (CABG) has not been studied. Therefore, we assessed the relationship between the SYNTAX score and development of AF after CABG (POAF). Subjects and Methods: The medical records of consecutive patients, who underwent CABG surgery from January 2013 to September 2015, were retrospectively reviewed for the development of AF in the postoperative period. SYNTAX score, clinical and echocardiographic parameters were evaluated. The independent variables for the development of POAF were defined and their predictive values were measured. Results: The study group consisted of 106 patients, of which 36 (34%) developed POAF. Age, hypertension, stroke, chronic obstructive pulmonary disease (COPD), heart failure (HF), diabetes mellitus (DM), left atrial diameter, neutrophil/lymphocyte ratio, platelet large cell ratio, creatinine, blood urea nitrogen and SYNTAX score were identified as important variables for the development of POAF. However, in logistic regression analysis COPD (OR=19.313, 95% CI=2.416-154.407, p=0.005), HF (OR=28.362, 95% CI=2.034-395.515, p=0.013), SYNTAX score (OR=0.863, 95% CI=0.757-0.983, p=0.026), and DM (OR=20.770, 95% CI=3.791-113.799, p<0.001) appeared as independent variables predicting the development of POAF. In receiver operation characteristic analysis, SYNTAX score (≥22.25) (AUC=0.777, 95% CI=0.676-0.877, p<0.001) was one of the strongest predictors for the development of POAF. Conclusion: The SYNTAX score level was independently associated with the development of AF after CABG.
CoNeT Mobile Laboratory for Ethernet Based I/O Systems in Industrial Applications
Levent Ucun,Onur Akbatı,Galip Cansever 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
This paper studies Ethernet based I/O systems in industrial applications. This study is involved in CoNeT, the European Union funded project, which stands for Cooperative Network Training. The project aims at training of automation engineers, maintenance engineers, process workers and students both graduate and undergraduate in modern wired and wireless industrial network technology applied to control operations and automated solutions. Seven modules dealing with different subjects about industrial automation have been designed in the concept of the project. This study has been carried out to design the first module which is about training in Ethernet based I/O systems. Mobile laboratory involving different industrial communication devices from different automation manufacturers has been founded and industrial application-oriented experiments have been designed to be carried out in the mobile laboratory.