Experimental investigation of an Al2O3/distilled water nanofluid used in the heat pipes of heat exchangers

This study investigates the thermal performance of a heat pipe heat recovery system in air-to-air heat recovery systems using a nanofluid of Al2O3 (aluminum oxide) particles and distilled water. The experimental setup used 15 wickless vacuumed copper pipes with a length of 1000 mm, a 10.5 mm inner diameter and a 12 mm outer diameter. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volume of the heat pipes was filled with working fluids. Experiments were carried out at temperatures between 25 degrees C and 90 degrees C by using five different cooling air flows (40 g/s, 42 g/s, 45 g/s, 61 g/s and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine the heat removed from the condensation section. Experiments were performed for distilled water and Al2O3 nanofluid, respectively, and the results were compared with each other. As a result of the experiments, it was observed that using a nanofluid as the working fluid increased the efficiency of the heat pipe. The highest efficiency (eta = 59%) was obtained in the experiments carried out using an Al2O3 nanofluid at a heating power of 3 kW and an air flow of 112 g/s.This work was supported by Scientific Research Projects Coordination Unit of Karabuk University. Project Number: "KBU-BAP-14/2-DR-018"

Influences of alumina and fly ash nanofluid usage on the performance of recuperator including heat pipe bundle

4th International Conference on Computational and Experimental Science and Engineering (ICCESEN)Energy efficiency becomes one of the most attracting study areas in the world because of the rising environmental issues. It is widely known that a plenty of energy efficiency applications are performed in heat transfer devices. In this regard, it is aimed to improve the thermal performance of recuperator, an air–air heat exchanger, including heat pipe bundle by utilizing a nanofluid, which is the mixture of nanoparticles of a metal oxide and deionized water, by this experimental study. The tests were conducted by filling the heat pipe at the rate of 1/3 of heat pipe volume both deionized water and alumina nanofluid, respectively. Coolant air was used to determine how much heat could be extracted from the condenser section. The findings obtained from the tests show that thermal performance of a heat pipe bundle-including recuperator was remarkably enhanced when nanoparticles containing working fluid was used as the working fluid in place of deionized water. The maximum improvement was achieved as 37.04% during the tests conducted at 6 kW heater power.Scientific Research Projects Coordination Unit of Karabuk University Project Number is "KBu-BAP-14/2-DR-018

2-DIMENSIONAL FLOW INVESTIGATION FOR COMPLEX GEOMETRIES AT LOW REYNOLDS NUMBER

Bu çalışmada, Sonlu farklar tekniği kullanılarak, sıkıştırılamaz viskoz bir akışkan için tek tüp, tüp demeti, tek aerofoil kanat ve bir eksenel türbinin kaskat kanadı üzerinde akış incelenmesi yapılmıştır. Kullanılan yöntem, akışkanın Kararlı, Sıkıştırılamaz ve Laminer sabit viskoziteli akımda subsonic hız kabulü ile Süreklilik ve Navier-Stokes denklemlerinin Akım Fonksiyonu-Vorticity metoduyla çözümünden ibarettir. Çalışılan farklı geometrik yapılar Reynolds sayısının 1000 değerinde nümerik olarak çalışılmış olup elde edilen sonuçlar grafik ortama aktarılarak daha önceki çalışmalarla karşılaştırılmıştır. Tek tüp ve tüp demeti üzerine yapılan incelemede, akış yoğunluğuna etki eden viskoz tabaka etkileşimi gözlemlenmiştir. Kaskat kanatlar üzerinde yapılan çalışmadan elde edilen sonuçlar ise, rotor ve stator kanatları arasında oluşan bölgesel ve kanat izi vortekslerinin akış kararlılığına olan etkisi net olarak gözlemlenmektedir. In this study, the flow around the single circular cylinder, tube banks, aerofoil blade and a axial turbine blades have been investigated using finite difference computational technique for steady incompressible viscid flow approach. The Computational Technique used is a stream function-vorticity formulation of the Laminar flow, steady state incompressible, continuity. Loss generation and 2-D flow behaviour at the stator-rotor stage were computed at steady flow and Reynolds number of 1000 by solving Navier stokes equations. In the flow investigation of the single circular cylinder and the tube banks, the fluid density has been intreacted by viscous sublayer. The result of cascade blades shown that there was expansion between the stator and the rotor blades which is resulted from vortex motion

The importance of immature granulocyte and immature reticulocyte fraction for the severity of acute bronchiolitis

The immature granulocyte (IG) and immature reticulocyte fraction (IRF) are new analytical parameters of the complete blood count, that have been studied as biomarkers of several inflammatory conditions. Here, our aim is to determine the effectiveness of IG and IRF percentages for the severity of acute bronchiolitis (AB). A single-center, prospective study was performed in patients who were hospitalized for acute bronchiolitis and healthy children were included as a control group. The demographic characteristics, white blood cell (WBC) count, platelet (PLT) count, eosinophil%, IG%, and IRF% values were analysed. Receiver operating characteristics (ROC) analysis was used to compare the diagnostic accuracies and predictive performances. We enrolled 168 infants in the acute bronchiolitis group and 80 in the control group. The Clinical Severity Score (CSS) showed that 48, 93, and 27 patients had mild, moderate, and severe bronchiolitis, respectively. The WBC, PLT, and IRF value were significantly higher in patients (p 12.4, with a sensitivity of 53% and specificity of 88% (Areas under the curves (AUC):0.701,p<0.001). The WBC count, PLT count, and IRF value increased in the AB group. The IRF percentage can be used to predict the clinical severity of AB in children

Factors that Affect Prognosis and Morbidity in Pediatric Patients with Carbon Monoxide Poisoning

Introduction:Carbonmonoxide poisoning continues to be a major health problem worldwide, especially in developing countries, and constitutes an important part of the patients admitted to the pediatric emergency clinics due to poisoning. The aim of this study was to evaluate the correlation between clinical severity, morbidity, hospital stay, intensive care need, and full systemic effects in patients who were followed up and treated for carbon monoxide poisoning in our pediatric emergency clinic.Methods:The study was performed between January 2013 and 2015. We included patients under 18 years of age who were admitted to the pediatric emergency with carbon monoxide poisoning. Assessments were made prospectively. The epidemiological characteristics, complaints, physical examination and vital findings of all patients were recorded. Carboxyhemoglobin (COHb) level, oxygen saturation, electrocardiography, complete blood count, liver and kidney functions, and cardiac enzymes were studied, and Glasgow Coma scale (GCS) was calculated.Results:The mean length of hospital stay for 232 patients was calculated as 7.08±1 hours and the mean duration of exposure to carbon monoxide gas was 3.17±2.5 hours. Higher COHb levels and cardiotoxicity were detected in patients with a longer duration of exposure and a lower GCS and an increased intensive care need (p<0.01). There was no correlation between COHb levels and clinical severity, GCS, or intensive care unit need. However, it was found that high COHb levels (especially above 30%) increased cardiac injury and neurological symptoms but did not cause a permanent sequela (p<0.05). None of the patients had permanent neurological, cardiac, or renal damage.Conclusion:We found that duration of exposure is the most important and accurate parameter for the evaluation of clinical course and morbidity. In patients with high COHb levels, the effects are more prominent, however, we considered that there was no change in sequelae at long-term follow up

Evaluation of historical thinking skills of 8th grade students’ opinions on the steps towards modernization in Turkey8. sınıf öğrencilerinin Türkiye’de çağdaşlaşmaya yönelik adımlar konusundaki görüşlerinin tarihsel düşünme becerisi açısından değerlendirilmesi

The aim of this study is to examine the historical thinking skills of 8th grade students on the steps towards Turkish modernization. The purpose of education in Turkey is declared to develop the young who are modern, adopted the principles and reforms of Atatürk, understand Turkish history and culture, equipped with the basic democratic values and respect for human rights, sensitive to the environment, interpret, use and regulate knowledge in the context of social and cultural construct based on their experiences, have improved social participation skills, are active and productive in social life, know their rights and responsibilities, become worldwide people with emphasis on universal values. In this context, there is a need to develop students' historical thinking skills considering the education’s objective of raising the "modern individual". Thus, it is discussed (regarded) by improving historical thinking skills students will gain skills of understanding, evaluating and analyzing causal relationships between historical matters. Therefore, it is important that the term of “modernization” is understood and interpreted by students of how they use historical thinking skills and dialect. Qualitative research method was applied by using semi-structured individual interviews. Interviews, were carried out with 24 volunteer 8th year students at a middle socio-economic statue secondary school in İzmir in 2012-2013 academic year. At the evaluation stage, an inductive content analysis was carried out. Results indicate that students have deficiencies in historical thinking skills and dialect of comparing “modernization” in Turkey to the world countries, but in a theoretical context they see modernization as a necessity and a step forward to development process. These findings identify the importance of the need for development of students’ historical thinking skills and ability via open and hidden curriculum of history teaching. Özet Araştırmanın amacı 8. sınıf öğrencilerinin Türkiye’de çağdaşlaşmaya yönelik adımlar konusunda tarihsel düşünme becerilerini incelemektir. Ülkemizde eğitimin amacı genel olarak, çağdaş, Atatürk ilke ve inkılâplarına bağlı, Türk milletinin milli ve kültürel değerlerini kavramış, hür ve bilimsel düşünme gücüne sahip, insan haklarına saygılı, yaşadığı çevreye duyarlı, bilgiyi deneyimlerine göre yorumlayıp sosyal ve kültürel bağlam içinde oluşturan, kullanan ve düzenleyen, sosyal katılım becerileri gelişmiş, sosyal yaşamda etkin, üretken, haklarını ve sorumluluklarını bilen, dünya insanı olan, evrensel değerlere önem veren, Türk milletini çağdaş uygarlığın yapıcı, yaratıcı ve seçkin bir ortağı haline getirme hedefinde olan gençler yetiştirmek olarak belirlenmiştir. Bu bağlamda, eğitimin “çağdaş birey” yetiştirme hedefi düşünüldüğünde, öğrencilerde tarihsel düşünme becerisi geliştirmenin bir gereklilik olduğu görülmektedir. Bununla birlikte, tarihsel düşünme becerisi geliştirmenin öğrencilerde tarihsel olaylara yönelik anlama, yorumlama, nedensel ilişkileri analiz etme gibi özellikleri kazandıracağı düşünülmektedir. Bu anlamda öğrenciler tarafından, "çağdaşlaşma" kavramının tarihsel düşünme becerileri doğrultusunda nasıl algılandığı, tarihsel akıl yürütme bağlamında nasıl değerlendirildiği oldukça önemlidir. Çalışma, nitel araştırma deseninde yapılandırılmış ve veri toplama tekniği olarak da yarı yapılandırılmış bireysel görüşme tekniği uygulanmıştır. Görüşmeler, 2012-2013 eğitim- öğretim yılında İzmir ilinde bulunan orta sosyo-ekonomik düzeyden bir ortaokulda 24 gönüllü sekizinci sınıf öğrencisi ile yürütülmüştür. Görüşme verilerinin çözümlenmesi ise içerik analizi ile gerçekleştirilmiştir. Araştırma sonucunda, öğrencilerin çağdaşlaşma kavramı açısından Türkiye ve dünya ülkeleri bağlamında, karşılaştırmalı bir bakış açısına ve tarihsel akıl yürütme becerisine yeterince sahip olmadıkları ancak kavramsal düzeyde, çağdaşlaşmayı bir gereklilik, ilerlemeye dönük bir adım ve sürekli devam eden bir süreç olarak gördükleri belirlenmiştir. Bu bulgular, tarih öğretiminin açık ve örtük eğitim programları aracılığıyla tarihsel düşünme ve akıl yürütme becerilerinin geliştirilmesi açısından önemli olduğunu ve desteklenmesi gerektiğini hatırlatmaktadır

Development and management of ovarian hyperstimulation syndrome in spontaneous singleton pregnancy

Ovarian hyperstimulation syndrome (OHSS) is one of the most life-threatening complications of ovulation induction. However, rarely, OHSS can develop spontaneously during pregnancy without induction of ovulation. It has been shown in the literature that some diseases such as polycystic ovary syndrome (PCOS), hypothyroidism, and pituitary adenoma may accompany spontaneous OHSS. Spontaneous OHSS should be included in the differential diagnosis in first-trimester pregnancies with nausea, vomiting, and acute abdomen. The focus should be on preventing possible complications and initiating early treatment immediately after diagnosis

Clinical and Electrophysiological Characteristics of Patients with Juvenile Absence Epilepsy in a Turkish Cohort

Juvenile absence epilepsy is an epileptic syndrome that usually begins between the ages of 9-13 and is classified in the group of genetic generalized epilepsies, in which absence seizures are seen mainly but may also be accompanied by motor seizures in the follow-up. In our study, 33 patients who were followed up in our clinic with the diagnosis of juvenile absence epilepsy between 2010-2022 were evaluated retrospectively. Thirteen of them were excluded from the study due to insufficient clinical or electrophysiological knowledge, being diagnosed with another epileptic syndrome during follow-up. The mean age of the 20 patients included in the evaluation was 16.8 years; The mean age of seizure onset was 10.6 years. All patients had absence seizures, which were not seen more often than once a day, 40% had additional generalized tonic-clonic seizures, and 20% had focal electroencephalographic abnormalities in addition to generalized discharges on electroencephalography. Seizures recurred in 3 of 5 patients whose treatment was terminated. It was found that currently 85% of the patients continued treatment with valproic acid and monotherapy was sufficient. While there are generalized discharges at the time of diagnosis electrophysiologically, focal findings tend to occur in the follow-up; This was also found to be important in the evaluation of seizure recurrence and treatment options in patients with long-term follow-up

Do Renal Cysts Affect the Success of Extracorporeal Shockwave Lithotripsy? A Retrospective Comparative Study

The aim of this study was to assess the effect of simple renal cysts on extracorporeal shockwave lithotripsy (SWL) in patients with calyceal renal calculi. Patients with simple renal cysts >35 mm and ipsilateral renal calculi 40 years that had renal calculi 0.05), which was 33.3% in group 1 and 68.2% in the control group (P=0.017). The presence of renal cysts in a patient with calculi requires that an individualized treatment plan be devised, so as to provide the patient with the most effective treatment