Gazi University is a public university primarily located in Ankara, Turkey.It was established in 1926 by Mustafa Kemal Atatürk as Gazi Teacher Training Institute. In 1982, it was reorganized by merging with the Bolu Academy of Engineering and Architecture, Ankara Academy of Economics and Commercial science, the Ankara College of Technical Careers, the Ankara Girls' College of Technical Careers, and the Ankara State Academy of Engineering and Architecture to become a large metropolitan university as part of the act which created the Board of Higher Education. Prior to 1982 when the Board of Higher Education Law came into effect, institutes of higher education in Turkey were organized under different structures as universities, academies, institutes, and schools. In 1992 faculties and vocational schools in Bolu became Abant Izzet Baysal University.Gazi University comprises 21 faculties, 4 schools, 11 vocational schools of higher education, 48 research centers and 7 graduate institutes. The student enrollment of Gazi University has reached approximately 77,000 in total of whom about 1,500 come from the Turkic states of Central Asia. Five thousand students are enrolled in graduate programmes. The total size of the teaching faculty exceeds 3,000 persons. Wikipedia.
Gunlu G.,Gazi University
IEEE Transactions on Energy Conversion | Year: 2017
In battery packs, batteries need to be serially connected to obtain high voltage, connected in parallel to acquire high current, and the defected batteries need to be bypassed. In this study, dynamically reconfigurable, independent cellular switching circuits have been proposed in order to connect the batteries in desired configuration. Each cell comprises a battery, a serial switch, a bypass switch, a parallel switch, and triggering switches. The batteries within the pack can be connected in different configurations according to their operation mode such as all in serial, all in parallel, all bypassed, or hybrid (serial-parallel-bypass). The novel aspect of the proposed circuit is that only intracellular battery energy is utilized in order to trigger the switches that are controlled with a very simple circuit. Each cell is independent and completely modular. Moreover, a single mosfet is sufficient instead of two mosfets which is connected in serial in order to control the current. The complexity of the circuit has been reduced to three mosfets for each cell and its efficiency has been increased. The operation of the proposed circuit has been tested with a prototype that includes twelve batteries and its advantages have been confirmed. © 2016 IEEE.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: HEALTH-2011.4.2-1 | Award Amount: 7.78M | Year: 2011
Dobutamine and adrenaline are widely used as second line therapy for systemic hypotension in infants. Dopamine is currently the most widely used first line drug. In neonates, sustained hypotension may, and impaired organ perfusion will, cause brain injury and poor neurodevelopmental outcomes. All three catecholamines are currently used off-label and have different modes of action which may result in potentially harmful haemodynamic effects. No reliable safety or efficacy data exists for the use of these drugs in neonates or newborns. Furthermore, no uniform criteria exist to define hypotension and there is little evidence to support current intervention strategies, which vary widely. Recently, superior vena cava (SVC) flow has been proposed as a more reliable indicator of circulatory failure than low blood pressure and preliminary results suggest Dobutamine is the optimum therapeutic in such cases. NEO-CIRC proposes 1) a randomised placebo controlled trial to provide safety and efficacy data for Dobutamine as a first line inotrope for all gestational ages 2) to perform pre-clinical; pharmacokinetic; pharmacodynamic; metabolomic and pharmacogenomic studies 3) to develop improved biomarkers of hypotension 4) to develop and adapt a formulation of Dobutamine suitable for newborns with the aim to apply for a Paediatric Use Marketing Authorisation. The NEO-CIRC consortium includes international experts in neonatal medicine, pharmacology, pharmacogenomics, drug formulation and pre-clinical neonatal models and an experienced group of experienced multicentre clinical trials NICUs. Outcomes anticipated include improved biomarkers of organ perfusion; a new consensus definition of neonatal circulatory failure and answers to key clinical practice uncertainties, including variability of response to Dobutamine in common pathophysiologies seen in newborn infants impact on longer term developmental outcomes so important to the patients, families and wider society.
Turker A.R.,Gazi University
Separation and Purification Reviews | Year: 2012
This review presents the most recent applications of solid phase extraction for the separation, preconcentration and speciation of metals, metalloids, and organometals. The review focuses on solid phase, column treatments and on the applications of this technique to various samples. This review also intends to discuss some applications and limitations associated to solid phase extraction techniques due to the necessity on limited selectivity. Nevertheless, the solid phase extraction is still an efficient, sensitive and inexpensive technique to perform removal of metal ions from environmental samples, preconcentration of metal ions for analytical purposes and speciation of the metal and metalloids as shown by the variety of applications presented and discussed in this review. A literature survey of the last three years (2008-2010) offering a critical review of solid phase extraction for separation, preconcentration and speciation of metal ions from various sample matrices is provided. © 2012 Copyright Taylor and Francis Group, LLC.
Sevik S.,Gazi University
Energy Conversion and Management | Year: 2013
In this experimental study, a new type solar dryer has been designed and manufactured by using double-pass solar air collector, heat pump and photovoltaic unit. The performance of solar dryer has been tested for carrot drying. In drying system, double-pass solar air collector (DPSAC) has provided the system heat energy requirement for drying process. Constant drying air temperature has been provided with PID (proportional-integral-derivative) control. Carrot slices were dried from initial moisture content 7.76 g water/g dry matter (dry basis) to final moisture content 0.1 g water/g dry matter (dry basis) at 50 °C drying air temperature and variable air volume. Velocity of air has been changed depending upon air inlet temperature of drying cabinet. During the drying operation, the air velocity was measured 0.4-0.9 m/s. The thermal efficiency of the double-pass collector was calculated from 60% to 78% according to experimental results. Carrot slices were dried at 220 min by using double-pass solar air collector in solar-heat pump dryer. Consequently, system (solar-heat pump dryer) can be comfortably operated without the need to the heat pump under normal ambient air conditions.© 2013 Elsevier Ltd. All rights reserved.
Arikan F.,Gazi University
Expert Systems with Applications | Year: 2013
In today's severe competitive environment the selection of appropriate suppliers is a significantly important decision for effective supply chain management. Appropriate suppliers reduce purchasing costs, decrease production lead time, increase customer satisfaction and strengthen corporate competitiveness. In this study a multiple sourcing supplier selection problem is considered as a multi objective linear programming problem. Three objective functions are minimization of costs, maximization of quality and maximization of on-time delivery respectively. In order to solve the problem, a fuzzy mathematical model and a novel solution approach are proposed to satisfy the decision maker's aspirations for fuzzy goals. The proposed approach can be efficiently used to obtain non-dominated solutions. A numerical example is given to illustrate how the approach is utilized. © 2012 Elsevier Ltd. All rights reserved.
Cakir H.,Gazi University
Computers and Education | Year: 2013
Web 2.0 technologies allow average computer users to be able to publish on the Internet without having to know complex computer technical knowledge, which gives these technologies powerful potential to facilitate student engagement in various learning environments. However, a knowledge gap exists in the literature related to factors affecting student engagement with Web 2.0 technologies. The purpose of this study is to understand factors affecting student engagement in a pre-service teacher education program that uses blogs to expand in-class discussions about technology integration. First year pre-service teachers in a mathematics education department participated in the study. Data were collected with a survey that was developed to measure student engagement with blog use. Results show that student motivation, reasons to use blog in the course, and level of challenge perceived by the students affect students' engagement with blog use. Gender and technical ability of students do not impact students' engagement. As a result, blogs can be utilized to expand in-class discussions equally well for all students. © 2013 Elsevier Ltd. All rights reserved.
Karabulut H.,Gazi University
Renewable Energy | Year: 2011
In free piston Stirling engines the power generated by the engine is related to the length of the piston and displacer strokes. Length of strokes vary with respect to the hot end temperature, external load, charge pressure, rod diameter, stiffness of springs, masses of piston and displacer and static positions of the piston and displacer. When the length of displacer and piston strokes exceeds the estimated limits, some mechanical collisions occur between piston and displacer or displacer and cylinder. In this work, the dynamic model of a free piston Stirling engine working with closed and open thermodynamic cycles was derived and numerically solved for an optional pair of the piston and displacer masses. Safe ranges were investigated for the hot end temperature, charge pressure, damping coefficient of the piston motion, stiffness of the piston spring and area of the displacer rod. The stiffness of the displacer spring and static positions of the piston and displacer were optimized. Analysis indicated that, a free piston Stirling engine working with a closed thermodynamic cycle performs a stable operation within a small range of the hot end temperature and damping coefficient of the piston motion. By means of inverting the engine into an open-cycle engine, the limited range of the hot end temperature and the damping coefficient of the piston motion were partially enlarged. © 2010 Elsevier Ltd.
Sahin R.,Gazi University
Expert Systems with Applications | Year: 2011
In this article, a bi-objective facility layout problem (BOFLP) is considered by combining the objectives of minimization of the total material handling cost (quantitative) and the maximization of total closeness rating scores (qualitative), with the predetermined weights are assigned to the respective objectives. A simulated annealing (SA) algorithm is proposed to solve the BOFLP, as well as a comparison of SA with the previous works is provided. It is shown that the SA algorithm works better than the previous works; thus proving the fact that the proposed SA algorithm is an efficient method for solving BOFLP. © 2010 Elsevier Ltd. All rights reserved.
Ergenekon E.,Gazi University
Archives of disease in childhood. Fetal and neonatal edition | Year: 2013
Hypothermia is becoming a common treatment for newborns with hypoxic ischaemic encephalopathy. Cerebral metabolic effects have been studied extensively. However, acute effects on peripheral microcirculation are unknown. The effects of therapeutic hypothermia on peripheral microcirculation assessed by side-stream dark field (SDF) imaging technique are presented. Peripheral microcirculation was assessed in seven newborns undergoing selective head-cooling treatment with SDF imaging video recordings during core temperature 34°C, and then after re-warming at 37°C, and also in seven control patients with rectal temperature 37°C. Microvascular flow index (MFI) and per cent of vessels with sluggish flow were determined by using appropriate software. Sluggish microcirculation was observed during hypothermia compared with controls. MFI and per cent of vessels with sluggish flow returned to normal after re-warming. The results of this small group of newborns going through therapeutic hypothermia suggests that microcirculation is effected with this treatment. Whether this finding has other clinical impacts requires further research.
Ocak M.A.,Gazi University
Computers and Education | Year: 2011
This paper describes the findings of an exploratory, qualitative case study and examines problems and impediments faculty members encountered in blended learning environments in Turkish Higher Education system. A total of 117 faculty members from 4 universities responded to 8 interview questions. Findings were based on content analyses of interview transcripts. The results show that faculty members' problems with blended teaching resulted in the identification of three inductive categories: instructional processes, community concerns and technical issues. The eight themes emerged from these three categories include the following: (1) complexity of the instruction, (2) lack of planning and organization, (3) lack of effective communication, (4) need for more time, (5) lack of institutional support, (6) changing roles, (7) difficulty of adoption to new technologies and (8) lack of electronic means. This study indicates that teaching blended courses can be highly complex and have different teaching patterns, which, in turn, impacts successful implementation of the blended college courses. © 2010 Elsevier Ltd. All rights reserved.