Atılım Academic Archive (Atılım University)
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Reevaluation of Plate-Fin Heatsink Natural Convection Correlations for Sideways and Three-Dimensional Inclinations
No full textThe common orientations of the plate-fin heat sink for natural convection cooling of electronics are vertical and upward-facing horizontal. However, depending on various use scenarios, the heat sink may be inclined, intentionally or otherwise. In our previous papers concerning this subject, the author proposed a set of correlations for plate-fin heat sinks covering all inclination angles backward and forward (pitch rotation) from the vertical position of the heat sink. The set was based on a series of computational simulations with a validated model. At the time, tilting the heat sink sideways (roll rotation) was not considered. In the present study, though, the sideways inclination of the plate-fin heat sinks is simulated using our previous model only by adjusting the direction of the gravitational acceleration vector, thus requiring no additional validation. It is determined that the previously proposed correlation is valid up to 80 degrees sideways inclinations of the heat sink. Interesting flow structures are observed when the heat sink is tilted 90 degrees sideways. Furthermore, it is demonstrated that the correlation surprisingly remains valid if the heat sink is simultaneously rotated in both axes (pitch and roll).The author gratefully appreciates Prof. Dr. Ilker Tari for the original suggestion for this area of investigation
Savaş Sonrası ABD’de Anti-Komünist Söylemin Yaygınlaştırılması: Foreign Affairs Dergisi Vaka Analizi
No full textLiberal demokrasilerde politikaların kamuoyu ile uyumlu bir şekilde yapıldığına inanılır. Dış politika yapımı da bu durumun istisnası değildir. Karar vericiler belirli bir karar verirken çoğu zaman gelecekteki seçimleri akıllarında tutarlar. Bundan ötürüdür ki dış politika yapım süreçlerinde kamuoyu belirleyici bir faktör haline gelmektedir. Bu makale kamuoyu-dış politika yapımı ilişkisine farklı bir bakış açısı getirmeyi amaçlamaktadır. Şöyle ki, devlet ve özel sektör deneyimine sahip uzmanlar tarafından yazılan düşünce kuruluşu makaleleri yoluyla siyasi kararlar ve kamuoyu arasında ortak bir söylemsel çerçeve yaratılarak, kamuoyunun rızası sağlanmakta ve böylece resmi politikalara uyumlandırılmaktadır. Bu çalışma, Soğuk Savaş’ın başlarında, ABD başkanlarının resmi dış politika beyanlarının meşrulaştırılma sürecinde, Foreign Affairs dergisinde yayınlanan makaleler ile olan metinsel ilişkiler araştırılmaktadır. Makale, Truman Doktrini ile Foreign Affairs Dergisi’nden seçilmiş makaleler arasındaki anti-komünist söylem bağlamındaki metinsel ilişkiyi post-yapısalcı bir pencereden incelemektedir. Lene Hansen'in Model 2 söylem analizini kullanıldığı makale, bu iki tür metnin söylemsel bağlarını araştırmaktadır. Makalede Foreign Affairs Dergisindeki yazıların metinlerarası olarak Truman Doktrini ile bağlantılı olduğu ve doktrinin açıklanması öncesinde ve sonrasında Amerikan kamuoyunun gözünde resmi ABD dış politikasını meşrulaştırdığı sonucuna varılmıştır
Ecofeminist Concerns as Reflected in Margaret Atwood's Oryx and Crake and Doris Lessing's the Cleft
Full text linkBu tez, Margaret Atwood'un Oryx ve Crake ve Doris Lessing'in The Cleft adlı eserlerindeki ekofeminist kuramının yansımalarını incelemektedir. Bu çalışmanın amacı, ekofeminizmin tarihsel arka planını öne çıkartarak ve eko-eleştri ile feminism arasında bağlantılar kurarak ekofeminist edebiyat teorisini araştırmaktır. Ekofeminist teoriye genel bakışın büyük kısmı, Greta Gaard, Patrick Murphy ve Ynestra King gibi alandaki akademisyenlerin eserleri aracılığıyla incelenmiştir. Bu çalışmada araştırılan ecofeminist kaygılar arasında antroposentrizm, fallosentrizm, kadınların ve doğanın metalaştırılması, cinsiyet dinamikleri, çevresel bozulma, kurumsal açgözlülük ve pervasız genetik mühendisliği yer almaktadır. Distopik romanlar Oryx ve Crake ve The Cleft bağlamında, çalışma bu kaygıların nasıl yansıtıldığını incelemektedir.This thesis examines the ecofeminist concerns as reflected in Margaret Atwood's Oryx and Crake and Doris Lessing's The Cleft. The aim of this study is to investigate ecofeminist literary theory by focusing on the historical background of ecofeminism and making linkages between ecocriticism and feminism. The majority of the overview of ecofeminist theory is examined through the works of reputable scholars in the field, such as Greta Gaard, Patrick Murphy, and Ynestra King. Among the ecofeminist concerns that are investigated in this work are anthropocentrism, phallocentrism, commodification of women and nature, gender dynamics, environmental degradation, corporate greed and reckless genetic engineering. Within the context of the dystopian novels Oryx and Crake and The Cleft, the study examines the ways in which these concerns are reflected
Effect of Training Based on Travelbee's Human-To Relationship Model on Prenatal Attachment, Fear of Childbirth, and Anxiety in Pregnant Women with Fear of Childbirth: A Randomized Controlled Trial
No full textPURPOSE: To investigate the effects of education provided to pregnant women with fear of childbirth according to Travelbee's Human-to-Human Relationship Model on fear of birth, prenatal attachment, and anxiety. METHOD: This prospective, randomized controlled study was conducted between June and August 2023. Participants included 62 pregnant women divided into intervention and control groups. Pregnant primiparous women who had fear of childbirth were selected for the intervention group, receiving an eight-session educational program based on Travelbee's model. RESULTS: At the end of the educational program, decreased fear of childbirth, lower anxiety, and higher prenatal attachment were detected in the intervention group. Results showed a statistically significant difference in the intervention group compared to the control group. CONCLUSION: Birth preparation education prepared according to Travelbee's model is an effective method for reducing pregnant women's fear of childbirth and anxiety and increasing prenatal attachment level
Observations on Nist Sp 800-90b Entropy Estimators
No full textRandom numbers play a crucial role in cryptography since the security of cryptographic protocols relies on the assumption of the availability of uniformly distributed and unpredictable random numbers to generate secret keys, nonce, salt, etc. However, real-world random number generators sometimes fail and produce outputs with low entropy, leading to security vulnerabilities. The NIST Special Publication (SP) 800-90 series provides guidelines and recommendations for generating random numbers for cryptographic applications and describes 10 black-box entropy estimation methods. This paper evaluates the effectiveness and limitations of the SP 800-90 methods by exploring the accuracy of these estimators using simulated random numbers with known entropy, investigating the correlation between entropy estimates, and studying the impacts of deterministic transformations on the estimators.Scientific and Technological Research Council of Turkiye (TUBITAK)Open access funding provided by the Scientific and Technological Research Council of Turkiye (TUBITAK).Science Citation Index Expande
Factors Affecting Influenza and Pneumococcal Vaccination Rates in Hemodialysis Patients: a Multicenter Study
No full textSelen, Tamer; Merhametsiz, OzgurPurpose: In patients with end-stage renal disease (ESRD), infections, particularly pneumonias, are the most common cause of hospital admissions and death after cardiovascular diseases. It is recommended that dialysis patients receive the pneumococcal vaccine every five years and the influenza vaccine annually. Our study aims to determine the awareness and factors affecting influenza and pneumococcal vaccination rates in hemodialysis patients. Patients and Methods: This cross-sectional study was conducted on patients undergoing regular hemodialysis treatment in 10 different hemodialysis centers across 4 cities. After excluding patients with less than one year of hemodialysis duration and those under 18 years of age, 548 patients were included in the study. Patients were administered a 20-item survey via face-to-face interview and electronic medical records. Results: Out of the 548 patients, only 19 (3.5%) had knowledge about the pneumococcal vaccine, while 238 (43.4%) had knowledge about the influenza vaccine. There were 220 patients (20.1%) who had knowledge about both vaccines. Among the patients, 95 (17.3%) had received the pneumococcal vaccine, with 41.1% of them having received it five years ago or more. A significant proportion (33.7%) of the patients could not recall the timing of their vaccination. While 183 (33.4%) patients had not received the influenza vaccine, only 140 (25.5%) had been vaccinated regularly every year. The reasons for not receiving the influenza and pneumococcal vaccines were stated as "I do not feel the need because I do not get the flu" (25%) and "I do not know about the pneumonia vaccine" (36.7%), respectively. The ROC curve analysis for the influenza questionnaire score showed an AUC of 0.822 (95% CI 0.787-0.856), with a p-value of <0.001. The statistically significant cutoff value for predicting influenza vaccination was determined to be 2.5. In the univariate analysis, dialysis duration (HD duration), diabetes mellitus (DM), and vascular access type were found to be statistically significant. In the multivariate logistic regression analysis, dialysis duration and DM were identified as independent factors predicting a higher level of knowledge about the influenza vaccine (p=0.009, 0.003, and p=0.041). The ROC curve analysis for the pneumococcal questionnaire score showed an AUC of 0.920 (95% CI 0.886-0.955), with a p-value of <0.001. The statistically significant cutoff value for predicting pneumococcal vaccination was determined to be 3.5. In the univariate analysis, residence, dialysis duration, and education level were found to be statistically significant. In the multivariate logistic regression analysis, dialysis duration and education level were identified as independent factors predicting a higher level of knowledge about the pneumococcal vaccine (p=0.038, 0.040, and p=0.010). physicians, nurses and nephrologists on this issue will increase vaccination rates.Science Citation Index Expanded - Social Science Citation Inde
Effect of COVID-19 Infection on the Performance of Elite Adolescent Overhead Athletes
No full textBackground: COVID-19 might have a negative impact on sports performance. There are few studies in the literature that assess how the sports performance of adolescent athletes is affected by COVID-19. Objective: This study aimed to compare the sports performance of adolescent overhead athletes who had COVID-19 infection with those who had not. Methods: The study involved adolescent elite overhead athletes from basketball, volleyball, handball, and tennis. Athletes’ performance were assessed using core muscle endurance, hand grip strength, upper extremity functional performance, reaction time and agility performance, and the 3-min step test. Results: Study included 47 adolescent overhead athletes (mean age 15.15 ± 1.51 years). The COVID-19 group showed significantly higher Borg Scale scores and decrease in oxygen saturation levels only after the step test (p = 0.02, p = 0.02, respectively). Additionally, COVID-19 group had lower grip strength in both right and left hands compared to the non-COVID group (p = 0.01, p = 0.05, respectively). No significant association was found between core muscle power and endurance, upper extremity functional performance, reaction time and agility performance (p > 0.05). Conclusions: Our results showed reduced hand grip strength and increased fatigue following COVID-19 infection in adolescent overhead athletes. Time period after COVID-19 infection had a negative correlation with sports performance and core endurance. © 2025 Elsevier B.V., All rights reserved
Yetişkin Bireylerde DASH Diyetinin Mental Sağlık ile İlişkisinin Değerlendirilmesi
No full textAmaç: Bu çalışmanın amacı yetişkin bireylerde Hipertansiyonu Durdurmak için Diyet Yaklaşımları (Dietary Approaches to Stop Hypertension-DASH) diyetinin mental sağlık ile ilişkisinin araştırılmasıdır. Bireyler ve Yöntem: Çalışma, 30 Haziran-10 Eylül 2024 tarihleri arasında Ankara’da yaşayan 20-64 yaş arası 400 yetişkin birey ile yürütülmüştür. Araştırma verileri araştırmacılar tarafından hazırlanan anket formu kullanılarak yüz yüze görüşme yöntemiyle toplanmıştır. Anket formu; genel bilgiler, DASH Diyet Kalitesi Ölçeği ve Warwick-Edinburg Mental İyi Oluş Ölçeği (Warwick-Edinburg Mental Well-Being Scale-WEMWBS) olmak üzere üç bölümden oluşmuştur. Mental sağlık ile DASH diyetine uyum arasındaki ilişkinin belirlenmesi için potansiyel karıştırıcı faktörlere (yaş, cinsiyet, gelir düzeyi, öğrenim durumu, sigara içme, alkol tüketimi, fiziksel aktivite düzeyi ve beden kütle indeksi) düzeltmeler yapılarak doğrusal regresyon modelleri oluşturulmuştur. Bulgular: DASH diyetine uyum durumları incelendiğinde, bireylerin %72.0’sinin düşük, %25.2’sinin orta, %2.8’inin yüksek uyum gösterdiği saptanmıştır. DASH diyetine orta ve yüksek uyum gösterenlerde, düşük uyum gösterenlere göre kadınların ve fiziksel aktivite düzeyi yüksek olanların sıklığı ile ortalama yaşın daha yüksek olduğu bulunmuştur (p<0.05). Her gün meyve ve sebze tüketenlerin sıklığı DASH diyetine orta ve yüksek uyum gösteren bireylerde düşük uyum gösterenlerden daha yüksektir (p<0.05). DASH diyetine orta ve yüksek uyum gösteren bireylerde WEMWBS puanının düşük uyum gösterenlerden daha yüksek olduğu belirlenmiştir (p<0.05). Potansiyel karıştıcı faktörlere göre yapılan düzeltmelerde DASH diyet uyumundaki bir puan artışın, WEMWBS puanında 0.195 puan artışla ilişkili olduğu saptanmıştır (p<0.05). Sonuç: Bu çalışmanın sonuçları, DASH diyetine daha yüksek uyumun daha iyi mental sağlık ile ilişkili olduğunu göstermiştir. Toplumda mental sağlığın iyileştirilmesi ve ilişkili sağlık sorunlarının azaltılması için beslenme programları ve eğitimler ile DASH diyetine uyum teşvik edilebilir
Microscopic Entropy of Static Black Holes in 3d Lovelock Gravities
Full text linkOzsahin, Hikmet/0000-0003-1705-0357; Guajardo Rui-Perez, Luis/0000-0001-7591-7233; Alkac, Gokhan/0000-0002-1965-0199We give a microscopic derivation of the semiclassical entropy of static black holes in 3D Lovelock gravities, which are certain 3D Horndeski theories that were recently discovered from higher-dimensional Lovelock gravities via various methods and admit black hole solutions analogous to higher-dimensional ones. Assuming the ground state is described by the soliton obtained from the black hole solution by performing a double Wick rotation, we reproduce the semiclassical entropy from the Cardy formula without central charges for the asymptotic growth of the number of states. We explain in detail how the mass of the soliton, which is needed in the Cardy formula, can be computed in the minisuperspace formalism.TUBITAK [124F058]ACKNOWLEDGMENTS G. A. is supported by TUB & Idot; TAK Grant No. 124F058. L. G. thanks Instituto de Matematicas, Universidad de Talca, for its hospitality during the preparation of this work.Science Citation Index Expande