The Effect of Problem Posing Oriented Calculus-2 Instruction on Academic Success

Hayri Akay,Nihat Boz 한국수학교육학회 2009 수학교육연구 Vol.13 No.2

Free Fatty Acid Accumulation by Mesophilic Lactic Acid Bacteria in Cold-Stored Milk

Hayri Co?kun,Eda ?d? 한국미생물학회 2004 The journal of microbiology Vol.42 No.2

This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bacteria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree values than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.

Anatomy, Variants, and Pathologies of the Superior Glenohumeral Ligament: Magnetic Resonance Imaging with Three-Dimensional Volumetric Interpolated Breath-Hold Examination Sequence and Conventional Magnetic Resonance Arthrography

Hayri Ogul,Leyla Karaca,Cahit Emre Can,Berhan Pirimoglu,Kutsi Tuncer,Murat Topal,Aylin Okur,Mecit Kantarci 대한영상의학회 2014 Korean Journal of Radiology Vol.15 No.4

The purpose of this review was to demonstrate magnetic resonance (MR) arthrography findings of anatomy, variants, and pathologic conditions of the superior glenohumeral ligament (SGHL). This review also demonstrates the applicability of a new MR arthrography sequence in the anterosuperior portion of the glenohumeral joint. The SGHL is a very important anatomical structure in the rotator interval that is responsible for stabilizing the long head of the biceps tendon. Therefore, a torn SGHL can result in pain and instability. Observation of the SGHL is difficult when using conventional MR imaging, because the ligament may be poorly visualized. Shoulder MR arthrography is the most accurately established imaging technique for identifying pathologies of the SGHL and associated structures. The use of three dimensional (3D) volumetric interpolated breath-hold examination (VIBE) sequences produces thinner image slices and enables a higher in-plane resolution than conventional MR arthrography sequences. Therefore, shoulder MR arthrography using 3D VIBE sequences may contribute to evaluating of the smaller intraarticular structures such as the SGHL.

Performance Analysis of Cooperative System with Best Relay Selection in Presence of Co-Channel Interference

Hayri Aslan,Muhammet Ali Karabulut,Hacı ?lhan,Ozgur Ozdemir 대한전자공학회 2017 대한전자공학회 학술대회 Vol.2017 No.1

In this paper, we study effects of co-channel interference in decode-and-forward based cooperative communication systems with best relay selection using cooperative-maximum ratio combining (C-MRC), link-adaptive regeneration (LAR) and maximum ratio combining (MRC) at the destination over Rayleigh fading channels. In order to increase the performance of system, we use the best relay selection criteria where selected relay has the minimum bit error probability of proposed system. We assume that the destination terminal is corrupted by multiple co-channel interferences, while the relay terminals are perturbed by only additive white Gaussian noise (AWGN). The Monte Carlo simulations are provided to confirm analytical results and illustrate the effect of interference.

Effect of rapid screening parameters on seismic performance of RC buildings

Hayri B. Ozmen,Mehmet Inel 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.4

This study investigates the effects of soft story, short columns, heavy overhangs, pounding, and construction and workmanship quality parameters on seismic response of reinforced concrete buildings through nonlinear static and dynamic procedures. The accounted parameters are selected for their common use in rapid screening of RC buildings. The 4- and 7-story buildings designed according to pre-modern codes are used to reflect majority of the existing building stock. The relative penalty scores are employed in this study to evaluate relative importance of certain irregularities in the existing rapid seismic assessment procedures. Comparison of relative scores for the irregularities considered in this study show that the overall trend is similar. The relatively small differences may be accounted for regional construction practices. It is concluded that initial-phase seismic assessment procedures based on architectural features yield in somewhat similar results independent of their bases. However, the differences in the scores emphasize the proper selection of the method based on the regional structure characteristics.

Free Fatty Acid Accumulation by Mesophilic Lactic Acid Bacteria in Cold-Stored Milk

Coskun, Hayri,Ondul, Eda The Microbiological Society of Korea 2004 The journal of microbiology Vol.42 No.2

This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bac-teria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree val-ues than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.

Comparison of Coskun and Lichteinstein hernia repair methods for groin hernia

Tolga Dinc,Hayri Mukerrem Cete,Barı? Saylam,Mehmet Vasfi Ozer,Arife Polat Duzgun,Faruk Co?kun 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.89 No.3

Purpose: Coskun hernia repair technique has been reported to be an effective new fascia transversalis repair with its short-term follow-up results. Our aim is to determine the results of Coskun hernia repair technique and to compare it with Lichtenstein technique. Methods: At this comparative retrospective study a total of 493 patients, who had groin hernia repair procedure using Coskun or Lichtenstein technique, between January 1999 and March 2010 were enrolled into the study. Patients were reached by telephone and invited to get a physical examination. Results: Out of 493 groin hernia repairs, 436 (88.5%) were carried out by residents and 57 (11.5%) by attending surgeons. Lichtenstein technique was the choice in 241 patients and 252 patients underwent Coskun hernia repair technique. Groin hernia recurrence was detected in 8 patients (3.1%) in Coskun hernia repair group and 7 patients (2.9%) in Lichtenstein group. Comparison of early complication rates in Coskun group (3.9%) and Lichtenstein group (4.5%) showed no significant difference. Late complication rates were significantly higher in Lichtenstein group (1.2% vs. 4.9%). The operation time was shorter in Coskun group (44 minutes) than in Lichtenstein group (60 minutes). Subgroup of patients, whose hernia repair operations were carried out by attending surgeons, had a recurrence rate of 0% and 3.8%, in Coskun group and Lichtenstein group, respectively. Conclusion: This study showed that Coskun hernia repair technique has a similar efficacy with Lichtenstein repair, on follow-up.

Seismic performance evaluation of school buildings in Turkey

Mehmet Inel,Hayri Baytan Ozmen,Huseyin Bilgin 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.5

This study evaluates seismic performance of the school buildings with the selected template designs in Turkey considering nonlinear behavior of reinforced concrete components. Six school buildings with template designs were selected to represent major percentage of school buildings in medium-size cities located in high seismic region of Turkey. Selection of template designed buildings and material properties were based on field investigation on government owned school buildings in several cities in western part of Turkey. Capacity curves of investigated buildings were determined by pushover analyses conducted in two principal directions. The inelastic dynamic characteristics were represented by equivalent single-degree-offreedom (SDOF) systems and their seismic displacement demands were calculated under selected ground motions. Seismic performance evaluation was carried out in accordance with recently published Turkish Earthquake Code that has similarities with FEMA-356 guidelines. Reasons of building damages in past earthquakes are examined using the results of performance assessment of investigated buildings. The effects of material quality on seismic performance of school buildings were investigated. The detailed examination of capacity curves and performance evaluation identified deficiencies and possible solutions for template designs.

Headache related to mask use of healthcare workers in COVID-19 pandemic

( Cansu Köseoğlu Toksoy ),( Hayri Demirbaş ),( Erhan Bozkurt ),( Hakan Acar ),( Ülkü Türk Börü ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.2

Background: It has been reported that a new type of headache may develop as a result of face mask use during the COVID-19 pandemic. The aim of this study is to investigate the clinical features of face mask-related headache during the COVID-19 pandemic. Methods: This is a cross-sectional study carried out on healthcare workers at the Afyonkarahisar Health Sciences University. The number of workers at our university was established. Sample size was calculated using the G*Power program. A questionnaire consisting of questions relating to pre-existing headache, an aggravation in headache, and de-novo headache was filled out by 3 neurologists with all participants. Results: Data was collected from a total of 375 participants, after the exclusion of 5 individuals who refused to participate. Out of all participants, 26 (6.9%) used a filtering mask, 274 (73.1%) used a surgical mask, 75 (20.0%) participants used a combination of both masks. The number of participants with preexisting headache was 114 (30.4%) had pre-existing headache. Of those with pre-existing headache, 77 (67.5%) healthcare workers had reported an aggravation in their headache after mask use. De-novo headache was observed in 116 (30.9%) of participants. De-novo headache characteristics included throbbing in 17 (14.7%) participants and pressing in 99 (85.3%) participants. In addition, symptoms such as tachypnea, sleep disturbance, and fatigue were found to be significantly higher. Conclusions: This study indicates that healthcare workers develop headaches due to use of masks during the COVID-19 outbreak.

Seismic performance evaluation of school buildings in Turkey

Inel, Mehmet,Ozmen, Hayri Baytan,Bilgin, Huseyin Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.5

This study evaluates seismic performance of the school buildings with the selected template designs in Turkey considering nonlinear behavior of reinforced concrete components. Six school buildings with template designs were selected to represent major percentage of school buildings in medium-size cities located in high seismic region of Turkey. Selection of template designed buildings and material properties were based on field investigation on government owned school buildings in several cities in western part of Turkey. Capacity curves of investigated buildings were determined by pushover analyses conducted in two principal directions. The inelastic dynamic characteristics were represented by equivalent single-degree-of-freedom (SDOF) systems and their seismic displacement demands were calculated under selected ground motions. Seismic performance evaluation was carried out in accordance with recently published Turkish Earthquake Code that has similarities with FEMA-356 guidelines. Reasons of building damages in past earthquakes are examined using the results of performance assessment of investigated buildings. The effects of material quality on seismic performance of school buildings were investigated. The detailed examination of capacity curves and performance evaluation identified deficiencies and possible solutions for template designs.