Istanbul Technical University Research Articles

The prediction of undergraduates’ self-regulation strategies, motivational beliefs, attitudes towards English, and speaking anxiety on foreign language classroom anxiety

Individual differences are considered as important factors in the language learning process. Apart from individual differences, affective factors such as attitudes and motivation of individuals and their anxiety levels which affect the individuals’ language learning directly or indirectly are also believed as significant impacts in this process. Therefore, the purpose of the present study is to examine the relationship between self-regulation strategies, motivational beliefs, attitudes, speaking anxiety and foreign language classroom anxiety and to investigate the predictive power of these variables for foreign language classroom anxiety. The relational model was used in the current study. The research group included 320 male (65.6 %) and 168 female (34.4 %) English preparatory students at Istanbul Technical University. Attitudes toward English Lesson Scale, Foreign Language Speaking Anxiety Questionnaire, The Motivational Strategies for Learning Questionnaire, and Foreign Language Classroom Anxiety Scale were used as the data collection tool. The statistical methods used for analyses were correlation and multiple regression. The findings indicated that there is a significant positive correlation between foreign language classroom anxiety and self-regulation, test anxiety, and foreign language speaking anxiety. Also, there is significant negative correlation between foreign language classroom anxiety and self-efficacy intrinsic value perception, and attitude towards English. Moreover, self-efficacy, test anxiety, attitude towards English, and foreign language speaking anxiety are predictors of the university students’ foreign language classroom anxiety.

Hydrophobic coatings from photochemically prepared hydrophilic polymethacrylates via electrospraying

Istanbul Technical University; Scientific and Technological Research Council of Turkey (TUBITAK)

Why Do Students Who Are Eligible to Enter University Fall into Academic Probation and What Possibilities Are There for Effective Interventions?

Probation is the academic status of students who do not meet minimum academic criteria of Grade Point Average (GPA) as specified by the university. Probation furthermore restricts the amount of credits that can be loaded. It is a growing problem with many different causes. It has been studied for many years with e.g. The Student Adaptation to College Questionnaire (SACQ) consists of four subscales that are social adjustment, personal-emotional adjustment, academic adjustment and institutional attachment (Gerdes & Mallinckrodt, 1994). In 2014, Istanbul Technical University (ITU) Dean of Student and Registrar’s Office published the General Statistical Evaluation Report highlighting the issue of academic probation. In this study the authors aimed to identify the reasons of academic probation and to set up an intervention model at the University Career Centre. For this purpose, semi-structured interviews and group discussions were conducted with 182 undergraduate academic probation students from 13 faculties. Data analysis using Qualitative Data Analysis Software (MAXQDA) was used to identify the reasons for academic probation. Once the reasons had been identified, existing tools were improved and new tools were developed. After the implementation of various intervention measures such as promoting career summits, setting up a web portal, informing the administration of the university of the importance and necessity of creating open areas, the results were analysed. At the end of a two-year period of strenuous efforts, the effectiveness of those measures was evident as the probation rate had dropped from 23.46% to 17.08% (ITU Dean of Student and Registrar’s Office, 2014, 2016).

Spring tube braces for seismic isolation of buildings

A new low-cost seismic isolation system based on spring tube bracings has been proposed and studied at the Structural and Earthquake Engineering Laboratory of Istanbul Technical University. Multiple compression-type springs are positioned in a special cylindrical tube to obtain a symmetrical response in tension and compression-type axial loading. An isolation floor, which consists of pin-ended steel columns and spring tube bracings, is constructed at the foundation level or any intermediate level of the building. An experimental campaign with three stages was completed to evaluate the capability of the system. First, the behavior of the spring tubes subjected to axial displacement reversals with varying frequencies was determined. In the second phase, the isolation floor was assessed in the quasi-static tests. Finally, a ¼ scaled 3D steel frame was tested on the shake table using actual acceleration records. The transmitted acceleration to the floor levels is greatly diminished because of the isolation story, which effects longer period and higher damping. There are no stability and self-centering problems in the isolation floor.

Indoor and outdoor pullout tests for retrofit anchors in low strength concrete

In this study, pullout capacities of post-installed deformed bars anchored in low strength concrete using different bonding materials are investigated experimentally. The experimental study was conducted under outdoor and indoor conditions; on the beams of an actual reinforced concrete building and on concrete bases constructed at Istanbul Technical University (ITU). Ready-mixed cement based anchorage mortar with modified polymers (M1), ordinary cement with modified polymer admixture (M2), and epoxy based anchorage mortar with two components (E) were used as bonding material. Furthermore, test results are compared with the predictions of current analytical models. Findings of the study showed that properly designed cement based mortars can be efficiently used for anchoring deformed bars in low quality concrete. It is important to note that the cost of cement based mortar is much lower with respect to conventional epoxy based anchorage materials.

An Investigation into University Students⿿ Foreign Language Speaking Anxiety

How anxiety affects the learning a foreign language is a focus in the current studies such as Horwitz's (1986), and MacIntyre and Gardner's (1994). Taking into consideration this focus, the aim of this study is to identify whether the students⿿ foreign language speaking anxiety demonstrate significant differences in terms of their gender, language level, receiving English preparatory training, and the kind of high school they graduated from. The research group included 320 male (65.6%) and 168 female (34.4%) English preparatory students at Istanbul Technical University. Foreign Language Speaking Anxiety Questionnaire developed by Horwitz, Horwitz and Cope (1986) and adapted in Turkish by Saltan (2003) was used as the data collection tool. Data were analysed using independent samples T-test and one-way ANOVA. According to T-test results, it was seen that female students⿿ score is higher than male students⿿. Also, it could be reported anxiety of students who have received English preparatory training are lower based on T-test results. Moreover, ANOVA results indicated the students⿿ language level and the kind of high school do not affect their speaking anxiety. In a nutshell, the foreign language speaking anxiety is affected by gender and receiving English preparatory training.

Analysing University English Preparatory Class Students⿿ Self-regulation Strategies and Motivational Beliefs Using Different Variables

Abstract Learning English which is the most widely used foreign language has become a necessity in globalised world. Yet, in Turkey, some problems exist about it thanks to lack of motivation and knowledge about self-regulation strategies. In this study, it was tried to explore if the students⿿ self-regulation strategies and motivational beliefs show significant differences in terms of gender, language level, receiving English preparatory training, and the kind of high school. The research group included 320 male (65.6%) and 168 female (34.4%) English preparatory students at Istanbul Technical University. Motivated Strategies for Learning Questionnaire developed by Pintrinch and De Groot (1990) and adapted in Turkish by Uredi (2005) was used as the data collection tool. Data were analysed using independent samples t-test, one-way ANOVA and the Scheffe's test via SPSS 20.0 software program. T-test findings indicated female students⿿ cognitive strategies dimension score is higher. Yet, there are no significant differences in the students⿿ self-regulation strategies and motivational beliefs according to receiving preparatory training. The ANOVA test's result demonstrated high school differentiation does not affect self-regulation strategies and motivational beliefs. However, the Scheffe's test results revealed the students⿿ self-regulation, cognitive strategies and intrinsic value perception change over depending on language level.

Examination of University Students⿿ Foreign Language Classroom Anxiety

Abstract Anxiety has been found to interfere with many types of learning. And, many researches such as MacIntyre and Gardner (1989) indicate there is a negative relationship between anxiety and second language learning achievement. In current study, it was aimed to determine whether the students⿿ foreign language classroom anxiety (FLCA) display significant differences on the basis of gender, language level, receiving English preparatory training, and the kinds of high school they graduated from. The research group included 320 male (65.6%) and 168 female (34.4%) English preparatory students at Istanbul Technical University. Foreign Language Classroom Anxiety Scale developed by Horwitz, Horwitz and Cope (1986) and adapted in Turkish by Aydin (2001) was used as the data collection tool. Data were analysed using independent samples t-test, one-way ANOVA and the Scheffe's post-hoc test. T-test results showed female students⿿ FLCA score is higher. But, there was not a statistically significant relationship between FLCA and receiving preparatory training. ANOVA results indicated high school differentiation does not affect it. Yet, Scheffe's test findings demonstrated the students⿿ FLCA change over depending on their language level. In other words, female students are more appropriate to suffer from FLCA and FLCA is affected by students⿿ language level.

DEFORMATION MONITORING OF RETROFITTED SHORT CONCRETE COLUMNS WITH LASER SENSOR

Abstract. This paper presents one of the applications of monitoring mechanical tests carried out in Construction Materials Laboratory of Istanbul Technical University. In Turkey, as in many countries, large amount of existing buildings exposed to seismic hazard, therefore various analytical and experimental studies are being conducted to contribute to the solution of the problem. One of the new generation retrofitting techniques is to strength the structural members by using Fiber Reinforcing Polymer (FRP). This study summarize the results of monitoring of deformations short concrete column samples under the incremental compression load. In this study, result of two rectangular short columns are given. One of them was tested as a reference sample, the other sample were tested after strengthening by PET reinforced polymer composite materials. Besides conventional displacement and strain measurement systems, laser scanning method was used to get three dimensional deformed shape of sample at each selected steps.

DEFORMATION MONITORING OF RETROFITTED SHORT CONCRETE COLUMNS WITH LASER SENSOR

This paper presents one of the applications of monitoring mechanical tests carried out in Construction Materials Laboratory of Istanbul Technical University. In Turkey, as in many countries, large amount of existing buildings exposed to seismic hazard, therefore various analytical and experimental studies are being conducted to contribute to the solution of the problem. One of the new generation retrofitting techniques is to strength the structural members by using Fiber Reinforcing Polymer (FRP). This study summarize the results of monitoring of deformations short concrete column samples under the incremental compression load. In this study, result of two rectangular short columns are given. One of them was tested as a reference sample, the other sample were tested after strengthening by PET reinforced polymer composite materials. Besides conventional displacement and strain measurement systems, laser scanning method was used to get three dimensional deformed shape of sample at each selected steps.

Library cooperation in Turkey: the results of a survey of ILL librarians in higher education

Purpose The purpose of this study is to investigate library cooperation among the libraries of Turkish higher education institutions in the changing global environment. Design/methodology/approach This study has been carried out with ILL librarians working in state and foundation university libraries in Turkey. The survey was sent to 140 inter library loan (ILL) librarians who were asked to answer 35 questions both open and closed. There were 100 responses which is an excellent response rate of 72 per cent. It was conducted with VETI (Data Collection and Statistics), which is a web-based form application developed by Istanbul Technical University. Findings Turkish libraries are taking the opportunities offered by technical developments to serve their users with instant information by providing access to electronic resources and transferring their collections to electronic media. Reconstruction of ILL services to fulfill users’ needs is inevitable because of the increasing expectations of users and emerging alternatives to access information. Originality/value This is the first systematic national investigation into the state of ILL in Turkish libraries.

A Final Touch for the Environmental Engineering Students at the Onset of their Profession: Senior-Year Graduation Design Project – Case Study for 2014-2015

This study reports the results of problem/design-based education offered by the Environmental Engineering Department of Istanbul Technical University (ITU) through an example of the senior-year Graduation Design Project (GDP), and the outcomes of introducing new environmental management considerations to environmental system design, and impacts of those on the senior-year Environmental Engineering undergraduate students. Overall outcomes of the study and the student entries gathered on risk assessment, uncertainty, sustainability, life-cycle-assessment, and resilience issues demonstrated that inclusion of those environmental management considerations to the senior-year GDP, as well as the new and improved approaches about handling the problem/design-based education, significantly broadened the perspective of the senior-year students at the onset of their profession.

Cyclic behaviour of diagonally-stiffened beam-to-column connections of corrugated-web I sections

Corrugated web profiles are generally used in single story long span structures though there exists limited number of researches about the performance of the connections. Besides there is a rising demand for utilization of corrugated web profiles in construction of low-rise moment resisting frames. This paper aims to evaluate the behaviours of two distinct types of beam-to-column connections namely; i. Conventional types: thick flat plate is used in the panel zone and its near-vicinity, ii. Alternative types: single or double stiffeners are used at both faces in the corrugated-web panel zone. The latter provides key advantages particularly for fabrication. The full scale beam-to-column connections were tested in the Structural and Earthquake Engineering Laboratory of Istanbul Technical University (ITU). In comparing the stiffness and strength characteristics of the tested connections, single and double diagonally-stiffened connections exhibited comparable behaviour to the specimens with flat plate panel zones. The finite element models of all the tested connections were produced with ABAQUS. The analytical results are in good agreement up to an inter-story drift angle of 0.04rad with the experimental ones.

Neutron Activation Analysis of Soil Samples from Different Parts of Edirne in Turkey*

The concentrations of constituent elements were determined in soil samples collected from different parts of the Maritza Basin, Edirne, Turkey. Neutron activation analysis, an extremely accurate technique, and the comparator method (using a standard) were applied for the first time in this region. After preparing the soil samples for neutron activation analysis, they were activated with thermal neutrons in a nuclear reactor, TRIGA-MARK II, at Istanbul Technical University. The activated samples were analyzed using a high-efficiency high-purity germanium detector, and gamma spectrometry was employed to determine the elemental concentration in the samples. Eight elements (chromium, manganese, cobalt, zinc, arsenic, molybdenum, cadmium, and barium) were qualitatively and quantitatively identified in 36 samples. The concentrations of some elements in the soil samples were high compared with values reported in the literature.

An Investigation on the Mass Attenuation Coefficients of W-VC-C and W-VC-TiC-C Composites for Gamma Radioisotopes

An Investigation on the Mass Attenuation Coefficients of W-VC-C and W-VC-TiC-C Composites for Gamma Radioisotopes A.B. Tugrula∗, E. Demir, O. Yilmaz, S. Sonmez, M.L. Ovecoglu and B.Buyuk Istanbul Technical University (ITU), Institute of Energy, Ayazaga Campus, 34469, Istanbul, Turkey Istanbul Technical University (ITU), Particulate Materials Laboratories, Dept. of Metallurgical and Materials Engineering, Ayazaga Campus, 34469, Sariyer, Istanbul, Turkey

Bone tissue engineering using STRO-1 positive porcine dental germ stem cells encapsulated in a poly-ethylene glycol based hydrogel

Event Abstract Back to Event Bone tissue engineering using STRO-1 positive porcine dental germ stem cells encapsulated in a poly-ethylene glycol based hydrogel Görke Gürel Peközer1, 2*, Mustafa Ramazanoğlu3*, Karl Andreas Schlegel4* and Gamze Köse2* 1 Istanbul Technical University, Molecular Biology-Genetics and Biotechnology, Turkey 2 Yeditepe University, Genetics and Bioengineering, Turkey 3 İstanbul University, Oral Surgery, Turkey 4 Friedrich-Alexander-University of Erlangen-Nuremberg, Maxillofacial Surgery, Germany There are a large number of people suffering from an organ or tissue loss due to injury, infection or disease. Although therapies like surgical reconstruction, transplantation or usage of prosthesis have saved and improved countless lives, they remain imperfect solutions due to occurrence of infection, chronic irritation, donor shortages, tissue rejection, and longer term complications such as development of malignant tumour. Although bone has an inherent ability to heal without leaving a scar, critical size defects fail to heal without intervention. The implantation of an engineered scaffold material with osteogenic cells seems to be a promising approach to achieve an optimal bone healing in critical-sized defects, since cell-mediated osteogenesis, especially at the centre of the defect, would be beneficial when combined with the osteoconductive effect of the bone graft material[1]. Mesenchymal stem cells (MSCs) isolated from various sources can be used for this purpose. The isolation of MSCs from dental tissues is easy, cost effective and does not raise additional safety and ethical concerns since they are obtained during regular orthodontic procedures. In this study, domestic pig was used as model organism for the isolation and transplantation of TGSCs due to its anatomical, physiologic, and metabolic similarities with humans. Bone structure and size are also important for the choice of pig to study bone tissue engineering. STRO-1 is a useful MSC marker that distinguishes only a subpopulation of MSCs that shows characteristics like high clonogenicity and multipotency differentiating to fibroblasts, smooth muscle cells, adipocytes, osteoblasts, and chondrocytes[2]. In this study, mandibular third molar tooth germs were surgically removed from the jaws of 6-month-old domestic pigs. Porcine TGSCs (PTGSCs) were isolated by explant culture technique after mincing the entire tooth germ tissue, including the dental mesenchyme and its surrounding follicle. PTGSCs were characterized by flow cytometry and by osteogenic, chondrogenic and adipogenic differentiation. Passage 3 PTGSCs were then tagged with STRO-1 antibody. Cells that express STRO-1 were sorted as STRO-1(+) cells and cells that do not express STRO-1 were sorted as STRO-1(-) cells by FACS Aria III. STRO-1 (+), STRO-1 (-) and unsorted cells were compared for their proliferation capacity by MTS assay and osteogenic differentiation capabilities in vitro by a quantitative calcium deposition assay and von Kossa staining. STRO-1 (+) and unsorted cells were also used for healing of critical-size bone calvarial defects of pigs in vivo with the use of a novel poly-ethylene glycol based hydrogel (PEG-hydrogel / MX10) and Bone Ceramic as scaffold. According to in vitro studies, STRO-1(+) cells showed to be more clonogenic exhibiting higher proliferation rates compared to STRO-1(-) and unsorted cells, whereas unsorted cells performed better shown by calcium deposition and von Kossa staining when they were osteogenically induced indicating the importance of a heterogenous niche for their role in osteogenesis. According to in vivo studies, novel PEG-hydrogel and Bone Ceramic was found to be an effective carrier for stem cell transplantation. Although transplantation of pTGSCs with PEG-hydrogel and Bone Ceramic facilitated the healing of defects, STRO-1(+) cells did not perform better than unsorted cells. Furthermore, in vivo studies also revealed the importance of osteogenic induction prior to implantation of cells to defects since osteogenically induced groups of either STRO-1(+) or unsorted cells led to increased bone density compared to non-induced groups. PEG-hydrogel-Bone Ceramic combination and use of pTGSCs facilitated the healing of bone defect without any significant effect created by STRO-1(+) cells. Thus, STRO-1 sorting of pTGSCs is not an effective strategy to enhance the osteogenic capacity of TGSCs since they possibly perform their role when they are in interactions with other cells in a heterogenous niche. International Team for Implantation (ITI), Basel, Switzerland; The Scientific and Technological Research Council of Turkey (TUBITAK), Ankara, Turkey

Variations and relations of meteorological parameters between upwind and downwind small-scale wind turbine rotor area

Renewable energy sources are becoming increasingly important due to climate change and the energy crisis. Wind energy projects and applications in particular have been growing recently. Meteorological parameters such as wind speed, ambient temperature, relative humidity, and air pressure directly affect wind turbine electricity generation. Understanding the relationships among these parameters is necessary to determine wind energy potential and to predict electricity generation. The current work is based on data obtained from a 1.5 kW wind turbine constructed in Istanbul Technical University's meteorological park in Turkey. A one minute time interval was used in the data analysis. In this study, upwind/downwind meteorological variables of the wind turbine rotor area were investigated and analyzed in detail. It was observed that the turbine used in this study performs better under low wind speed conditions than under high wind speed conditions. The difference in relative humidity between the upwind and downwind rotor area reached 4%. It is also important to note that, depending on wind speed, temperature differences between the upwind and downwind rotor area reached 5%. Equations for upwind/downwind variables were obtained for each meteorological parameter.

Implementation of k0-INAA standardisation at ITU TRIGA Mark II research reactor, Turkey based on k0-IAEA software

Abstract The purpose of this study is to test the applicability of k 0 -INAA method at the Istanbul Technical University TRIGA Mark II research reactor. The neutron spectrum parameters such as epithermal neutron flux distribution parameter ( α ), thermal to epithermal neutron flux ratio ( f ) and thermal neutron flux ( φ th ) were determined at the central irradiation channel of the ITU TRIGA Mark II research reactor using bare triple-monitor method. HPGe detector calibrations and calculations were carried out by k 0 -IAEA software. The α , f and φ th values were calculated to be −0.009, 15.4 and 7.92·10 12 cm −2 s −1 , respectively. NIST SRM 1633b coal fly ash and intercomparison samples consisting of clay and sandy soil samples were used to evaluate the validity of the method. For selected elements, the statistical evaluation of the analysis results was carried out by z -score test. A good agreement between certified/reported and experimental values was obtained.

Prediction of wave resistance by a Reynolds-averaged Navier–Stokes equation–based computational fluid dynamics approach

The prediction of wave resistance in naval architecture is an important aspect especially at high Froude numbers where a great percentage of total resistance of ships and submerged bodies is caused by waves. In addition, during hull form optimization, wave resistance characteristics of a ship must closely be observed. There are potential, viscous and experimental methods to determine the wave resistance of a ship. Reynolds-averaged Navier–Stokes equation–based methods usually follow the experimental method that determines the form factor first. However, it is proven in recent studies that the form factor changes with the Reynolds number. As the Reynolds number increases, this change in the form factor is being neglected. In this study, a Reynolds-averaged Navier–Stokes equation–based prediction of wave resistance is presented that overcomes this flaw. The methodology is validated with the benchmark problems of submerged and surface-piercing bodies to determine the effectiveness of the proposed method. The method is also validated by experiments carried out at the Ata Nutku Ship Model Testing Laboratory of Istanbul Technical University for a totally submerged ellipsoid and the benchmark KRISO Containership. Results reveal the robustness of the present methodology.

Comparison of simulated and measured spectra from an X-ray tube for the energies between 20 and 35 keV

Design and production of a simple and low cost X-ray imaging system that can be used for light industrial applications was targeted in the Nuclear Physics Laboratory of Istanbul Technical University. In this study, production, transmission and detection of X-rays were simulated for the proposed imaging device. OX/70-P dental tube was used and X-ray spectra simulated by Geant4 were validated by comparison with X-ray spectra measured between 20 and 35keV. Relative detection efficiency of the detector was also determined to confirm the physics processes used in the simulations. Various time optimization tools were performed to reduce the simulation time.