WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14517/18

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Now showing 1 - 20 of 45

Analysis and Implementation of Sensorless Pmsm Drive With Reduced Dc-Link Capacitance Under Parameter Variations
(Ieee, 2024) Sumsek, Reha Ozgur; Calik, Ramazan; Yavuz, Fikri Serkan; Kivanc, Omer Cihan
In AC drives used in heating, ventilation and air-conditioning applications, film capacitors are becoming widespread instead of electrolytic capacitors in DC-link. These drives with reduced capacitor value provide cost and volume advantages. However, dc-link oscillation increases due to the reduced capacity value. These oscillations cause instability, overvoltage and an increase in total harmonic distortion (THD). On the other hand, the winding temperatures of these motors, which operate continuously under rated operating conditions, reach 80 degrees C. The stator resistance and rotor flux value, which change with the increase in temperature, cause these drives, controlled without sensors, to operate even more unstable. In this study, a hybrid approach is proposed to improve the performance of the inverter using a 16 mu F film capacitor at the dc-link and to reduce the THD. The active damping method regulates the inverter output voltage for DC-link voltage stabilization. A permanent magnet synchronous machine (PMSM) sensorless speed control based on stator feedforward voltage estimation and a model reference adaptive system (MRAS) based on a multiparameter estimation algorithm is performed to minimize the effects of parameter variations. As a result of the experimental studies, it is observed that the grid input current complies with the IEC61000-3-2 standard, even under severe parameter variations.
Analysis of the Factors Affecting the Latency Period and Type of Birth in Patients With Preterm Prematur Rupture of Membranes
(Dokuz Eylul Univ inst Health Sciences, 2022) İlhan, Yunus; Kuzu, Ozan; Gozel, Sercan; Yumru, Ayşe Ender
Purpose: To determine the factors associated with the latent period in patients with preterm premature rupture of membranes (PPROM). Material and Methods: 53 patients who applied to our clinic within 1 year and were diagnosed with PPROM and met the inclusion criteria participated in this prospective cross-sectional study. Factors thought to affect the latent period in these patients were examined in terms of delivery time and mode. Results: Latent period; was negatively correlated with dilatation and positively correlated with collum length. The mean latent time of patients with contraction was statistically significantly lower than those without. In another model, gestational week, collum length and birth weight were found to be the most significant factors associated with the latent period. In the latent period groups; Statistically, a significant difference was found in the mean dilatation and collum length. The contraction rate was higher in those with a latency period of 2 days or less. Conclusion: Latent duration is inversely proportional to dilatation and directly proportional to collum length. Uterine contraction is higher in patients with a latency period of fewer than 2 days. Other statistically significant factors related to the latent period are the gestational week and the fetal weight.
Asthmatic Patients: Is Homocysteine an Issue?
(Galenos Publ House, 2024) Keskinel, Ilkay; Gunturk, Arzu; Eryilmaz, Muzeyyen
Objective: Understanding the causes of asthma is crucial for developing new therapeutic modalities. Homocysteine (HCY) is an intermediate in methionine metabolism. Elevated HCY levels may indicate folate and vitamin B12 deficiencies, which are cofactors for the methylation of HCY to methionine. The relationship between hyperHCY mia and atherosclerosis is well-documented, and it is considered a cause of cardiovascular, neurodegenerative, and ocular diseases. HyperHCY mia may also cause atopy and, consequently, asthma. We aimed to evaluate the levels of HCY, vitamin B12, and folic acid in asthmatic patients and healthy adults, as well as to determine whether correlations exist between these levels and lung function, eosinophil counts, total immunoglobulin E (IgE), and eosinophilic cationic protein (ECP) levels in asthmatic subjects. Methods: A total of 142 asthmatic patients and 36 healthy controls were enrolled in the study. Folic acid, vitamin B12, total IgE, ECP, eosinophil percentage, eosinophil counts, and HCY levels were evaluated in both groups. Results: HCY, vitamin B12, and folic acid levels did not significantly differ between patients with asthma and controls. There was a statistically significant positive correlation (at the 0.95 confidence level) between HCY values and forced vital capacity, peak expiratory flow (PEF), and eosinophil counts in patients with asthma. Folic acid levels correlated positively only with PEF%, whereas vitamin B12 levels did not correlate with any functional parameters or atopic markers like IgE and ECP. Conclusion: Should large-scale randomized controlled trials conclusively establish HCY as a causative factor of asthma, metabolic interventions to lower HCY levels using methyl donors could be considered alongside conventional asthma treatments.
Attıtudes of Female Employees In Nutrıtıon of 9 Months-6 Years Old Chıldren In Covıd-19
(Jpms Publ, 2024) Demir, Ibrahim; Onal, Ayse Emel; Ayvaz, Ozkan; Onal, Mehmet Erinc; Onal, Emel Ruya; Yildiz, Sevda Ozel
Background: We aimed to determine the factors affecting the nutritional attitudes of female hospital workers toward their children between 9 months and 6 years of age during the COVID-19 pandemic.Methods: Our study, which is an original article, was conducted with female employees working in the hospital and having children between the ages of 9 months and 6 years. The impact of changes in work and home life during COVID-19 on changes in child care and child nutrition has been questioned. Result: Statistical significance was detected between the scale and questions such as the frequency of anxiety regarding the child's illness during the COVID19 process, the decrease in the child's appetite, changes in the child's eating pattern, the mother's relationship with the environment and social relations, and the child's sleep pattern. Conclusion: A significant relationship was found between inadequate/unbalanced nutrition and educational status and between the reaction to others' opinions sub-dimension and age groups. Moreover, another significant relationship was found between the frequency of anxiety about the child's illness and the scale, and between the change in the child's nutrition pattern and the scale. The COVID-19 pandemic affected the attitudes of female employees towards the nutrition of their children.
Autoimmune Encephalitis and Musicogenic Epilepsy: a Case of Gad65 Antibody-Associated Seizure
(Wiley, 2025) Mohammadi-Asl, Ali; Bahadori, Amir Reza; Sabzgolin, Iman; Davari, Afshan; Razmafrooz, Mohammad; Tafakhori, Abbas; Ranji, Sara
Musicogenic epilepsy (ME) is a rare form of reflex epilepsy with a prevalence of 1 in 10,000,000. Recent research suggests a potential link between ME and autoimmune encephalitis, particularly involving glutamic acid decarboxylase 65-isoform (GAD65) antibodies. A 48-year-old female presented with a one-year history of music-triggered seizures. Her episodes were characterized by an initial aura followed by unresponsiveness and oral automatisms. Electroencephalography revealed abnormalities in the left anterior temporal lobe and temporal leads. Laboratory studies showed positive anti-GAD65 antibodies. The patient was treated with a combination of antiepileptic medication (Lamotrigine) and corticosteroids and intravenous immunoglobulin. This case contributes to the growing evidence supporting an association between ME and autoimmune mechanisms, particularly GAD65 antibody-mediated autoimmunity. It highlights the importance of screening autoimmune factors in ME patients and highlights the need for further research into targeted treatment strategies.
Capital: an Introduction To the Three Volumes
(Palgrave Macmillan, 2024) Savran, Sungur
Capital: the Book of Communism
(Palgrave Macmillan, 2024) Savran, Sungur
Comparative Analysis of Transaction Performance in Different Virtualization Environments
(Istanbul Univ, 2024) Candemir, Ali Ihsan; Incereis, Nilgun
Virtualization technologies are increasing in importance day by day. The selection of virtualization software is an important factor to realize efficient use of physical hardware. In this study, the Ubuntu 22.04 LTS operating system was run on VirtualBox, VMware, and Docker, which are widely used virtualization software. Then, the Tiobench, Compress-7zip, C-ray, Smallpt, Tachyon, and OSBench tests were performed on the Ubuntu operating system with the Phoronix Test Suite software, and the test results were analyzed and compared. The results demonstrate that Docker outperformed the other virtualization technologies, although not in every test. Owing to its rapid deployment and efficient use of resources, Docker is suitable for applications that require agility and scalability. However, traditional virtualization technologies, such as VMware, may be more suitable for applications that require high security and extensive resource management. In addition, this study provides information that can guide users in selecting virtualization software.
Comparison of Posterior and Antero-Lateral Renal Tumors in Retroperitoneal Laparoscopic Partial Nephrectomy: a Propensity Score Matching Analysis
(Codon Publications, 2023) Anil, Hakan; Yildiz, Ali; Guzel, Ahmet; Akdemir, Serkan; Karamik, Kaan; Arslan, Murat
This study aimed to compare the antero-lateral and posterior localized renal masses in laparoscopic partial nephrectomy with the retroperitoneal approach in terms of operative, functional, and oncological outcomes. Patients who underwent retroperitoneal laparoscopic partial nephrec-tomy by a single surgeon between January 2013 and January 2021 were included in the study. A one-to-one propensity score matching (PSM) analysis was conducted to obtain two balanced groups. The patients were divided into two groups as posterior and antero-lateral according to the localization of the mass. A total of 239 patients were included in the PSM analysis, with 65 patients allocated to each group. The mean operative time was 79.2 & PLUSMN; 11.2 min in the posterior group, while it was 90.0 & PLUSMN; 11.6 min in the antero-lateral group (P < 0.001). Warm ischemia time was 15.9 & PLUSMN; 2.4 min in the posterior group and 18.6 & PLUSMN; 2.7 min in the antero-lateral group (P < 0.001). The median decrease in eGFR at 1 year was 4.8 (IQR, 2.9-6.9) mL/min in the posterior group and 5.0 (IQR, 2.8-11) mL/min in the antero-lateral group (P = 0.219). The warm isch-emia time and clamping technique were found to be significant factors for predicting eGFR change after surgery (13:0.693, 95% CI: 0.39-0.99, P < 0.001; 13:6.43, 95% CI: 1.1-11.7, P = 0.017, respectively). We report that retroperitoneal laparoscopic partial nephrectomy provided longer warm ischemia and operative time for antero-lateral renal masses than posterior masses. However, long-term oncological and functional results were similar for both localizations.
Confusions Concerning Sraffa (and Marx): Reply To Critics
(Palgrave Macmillan, 2024) Savran, Sungur
The Controversy Between the Neo-Ricardians and the Marxists
(Palgrave Macmillan, 2024) Savran, Sungur
COVID-19 Seroprevalence in Cirrhotic Patients and Effect of COVID-19 Infection on Liver Cirrhosis by Clinical Form in the Postinfectious Period
(Galenos Publ House, 2024) Oenal, Ugur; Oezbey, Dogukan; Bakkaloglu, Oguz Kagan; Eskazan, Tugce; Kurt, Enes Ali; Hatemi, Ali Ibrahim; Sonsuz, Abdullah
Introduction: There are very few studies demonstrating the seroprevalence of coronavirus disease-2019 (COVID-19) in patients with cirrhosis worldwide and in Turkey. This study aimed to investigate the seroprevalence of COVID-19 in patients with cirrhosis and its effect on liver cirrhosis by clinical form in the postinfectious period. Methods: The study included 174 patients with cirrhosis. Patients with COVID-19 were identified using anti-severe acute respiratory syndrome-coronavirus-2-immunoglobulin G (SARS-CoV-2-IgG) and COVID-19 polymerase chain reaction assays and were divided into symptomatic and asymptomatic groups. The last polyclinic records of the patients before infection or testing were determined as 1 st examination and the date of blood collection for anti-SARS-CoV-2-IgG was determined as the 2 nd examination. Examination findings and liver tests of the patients in both periods were recorded; Child-Pugh Score (CPS) and Model for End Stage Liver Disease (MELD)-Na scores were calculated. Additionally, patients were evaluated for newly developed hepatic decompensation. Results: The seropositivity of anti-SARS-CoV-2-IgG was detected in 35.6% of our patients, and the rate of those who had symptomatic COVID-19 infection was 23.6%, whereas the rate of those who had asymptomatic infection was 12%. There was no significant difference in liver tests, CPS, and MELD-Na scores before and after COVID-19 infection between symptomatic and asymptomatic patients, and new decompensation was found in 9.6% of patients with COVID-19 infection. Conclusion: The incidence of COVID-19 among patients with liver cirrhosis is notably high. Although high decompensation rates were reported in the acute phase of the disease, such rates were not observed in the postinfectious period. Ultimately, our results indicated no significant difference in the course of existing liver disease according to clinical form.
Critique of Political Economy
(Palgrave Macmillan, 2024) Savran, Sungur
(De)securitization of the Kurdish Issue in Turkey: the Nexus of Foreign Policy and Domestic Politics in the Twenty-First Century
(Palgrave Macmillan, 2023) Balaban, Gokce
Design of a Position Controlled Electric Actuator Used in Fluid Control Valves
(IEEE, 2016) Tosun, Gurkan; Kivanc, O. Cihan; Oguz, Ender; Mutlu, Yasar; Ustun, Ozgur
Valves are the main elements for controlling fluids in industry and other application areas. To control flow precisely, valves need a controlled action which leads to implement actuators, gear systems and electronic controllers. Increasing dominance of electrical actuators due to the advantages of easy control and intervention and space-efficient designs brings seldom implementation of hydraulic and pneumatic actuation. In fluid control applications, the main target is to obtain the right position, i.e. angle for rotary actuators, for adjusting flow rate. In this study, the design and implementation of a position controlled electrically actuated valve used for fluid control are presented. The design phases of system universal power supply and electronic control system are given and the experimental results of position control which are representing the validation the design study is also discussed. Also a special current control scheme is used to overcome transient disruptions.
Effect of External Innovation Capacity on Company Level Innovativeness
(Management & Business Acad, 2021) Okatan, Kagan; Alankus, Orhan Behic
This study focuses on the correlation of national innovation inputs and the external innovation environment with the company-level innovation output. Since all companies are aiming at sustainable innovation to ensure sustainable profit growth, the current literature has highlighted the need for a well-structured internal innovation system for innovation success and discussed the factors affecting the performance of organisations. The internal innovation system has its own dimensions that affect the success of the whole system and emphasize the significant impact of firms on innovation results. Do all companies with a high internal innovation competency and a suitable corporate culture have the chance to become worldwide innovative? What are the impacts of the external environment where the companies are located on the innovation success? And how big is the importance of external environmental inputs? This study seeks to answer these questions and draws attention to the appropriate external environment and conditions to increase firms' innovation competencies.
Factors Affecting Thyroid Volume and the Incidence of Nodules With Goiter School-Aged Children
(Istanbul Univ, 2024) Kaba, Sultan; Dogan, Murat; Yavuz, Alpaslan; Kilic, Sinan
Objective: This study aimed to analyze the associations between age, sex, anthropometric factors, and thyroid volume as well as to determine the prevalence of goiter and thyroid nodules in school children. Methods: This study included schools governed by the Ministry of Education in Van province. Sonographic evaluations of thyroid glands were conducted in children aged 6-17 years, and measurements of weight, height, waist circumference, hip circumference, and skinfold thickness were obtained from the participants. Results: A total of 2284 school children were included in the study. The median age of the participants was 11.08 years. It was observed that thyroid volume exhibited a positive correlation with age, body surface area, body mass index, height, weight, waist circumference, hip circumference, triceps skinfold thickness, and subscapular skinfold thickness (p < 0.008). When assessing the association between age and goiter prevalence based on World Health Organization parameters, 10.2% of children and adolescents developed goiter, and 0.8% of these cases also had a nodule. Among girls, the rates were 9.4% and 1% for goiter and nodules, respectively, whereas among boys, the rates were 11.3% and 0.7%, respectively. Conclusions: Thyroid volume was affected by age, weight, subcutaneous tissue thickness, waist circumference, and BSA. Goiter remains a serious public health problem among school-age children in Van province.
Features Of Popular Sport Movies
(Ataturk Universitesi, 2022) Çetinkaya, G.; Kizilçam, M.
The aim of our study is to try to reveal the general features of popular sports movies. The research was pre-pared with the qualitative method and designed in the descriptive survey model. In this context, all sports movies in the IMDb database were scanned and 307 popular movies were included in the study. The data obtained through the SPSS 25.0 program were analyzed. According to the research findings; It is seen that American cinema leads popular sports movies (71.7%). It has been determined that sports is an important content in British cinema (8.5%) and Indian cinema. Boxing (11.7%), American football (11.1%), baseball (9.8%), racing sports (7.8%), basketball (7.2%), football (6.8%), and combat sports (6.2%) are other sports branches that are frequently featured in the films that are the subject of the research. The main theme that stands out in the movies is drama (65.80%). It was found that the other mostly covered themes were comedy (41.69%) and biography (22.80%). It is observed that popular sports movies make a great profit (69.34%). The arithmetic mean of the scores of the movies from the audience was found to be 6.75 out of 10. The metascore arithmetic mean is 48.57 out of 100. It has been concluded that popular sports films, which are one of the important contents for world cinema, have been appreciated by the audience in general, but cannot show the same success in the critics of cinema professionals. © Author(s).
Gender Equality in Turkey
(Palgrave Macmillan, 2023) Alemdar, Zeynep
Human Papilloma Virus Frequency and Genotypes; Evaluation of the 4879 Screenings Made With Polymerase Chain Reaction and Chip Array Between 2001 and 2019 in Istanbul
(Kare Publ, 2021) Vural, Gurcan; Polat, Nedim
Objectives: The aim of this study is the documentation of human papilloma virus (HPV) frequency and types seen in the city of Istanbul, Turkey, as well as evaluation of the relationship between these subtypes and cytological and pathological diagnoses. Methods: 4879 cases were studied in our molecular pathology department between 2001 and 2019 in Istanbul. Between 2001 and 2010, 1692 cases were screened for HPV 6, 11, 16, 18, 31, and 33 by conventional hybridization and polymerase chain reaction (PCR). Since 2011, up to 49 HPV typing has been performed for 3187 cases with chip array. The cases were referred to the pathology center and the hospital pathology department by clinicians for screening before HPV vaccination and on the observation of precancerous changes and koilocyts in cytological-histopathological evaluations. Results: In this study, the frequency of HPV was found to be 10.8% (527 HPV-positive cases). Among these, 348 cases were high-risk groups, whether or not they were previously associated with a low-risk group. When we look at the distribution of the cases according to the high-risk HPV types, HPV 16 is the most common type. The frequencies of occurrence of other HPV types are as following: HPV-16: 41.7%, HPV-31: 11.7%, HPV-52: 7.9%, HPV-51: 7.1%, HPV-33: 6.9%, HPV-45: 6.5%, HPV-18: 6.3%, HPV-39: 6.1%, and HPV-58: 5.8%. It was further found that multiple infections were 28% of high grade squamous intraepithelial lesion cases. HPV frequency was 38% and 72%, respectively, in cases with cytologically or histopathological precancerous, low-grade squamous intraepithelial lesion, and HSIL changes. As a final note, HPV was detected in 9 of 10 cases with cervical cancer (90%). Only 1 adenocarcinoma case detected in the series was a double infection with HPV types 18 and 45. Conclusion: HPV 16 was the most common type found in this study. It is followed by types 31, 52, 51, 33, 45, 18, 39, and 58, respectively. The most common association observed in double infections was between HPV 16 and 58. It was also observed that the incidence of HPV in the city of Istanbul, Turkey, was similar to other developed countries. As a final note, in addition to screening tests, PCR and chip array studies should be conducted and the community should be informed about preventive medicine and the importance of condom use.

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