Numerical analysis of the thermal and thermodynamic performance of a parabolic trough solar collector using SWCNTs-Therminol®VP-1 nanofluid

In this paper, energetic and exergetic performances of a parabolic trough solar collector using single-walled carbon nanotubes (SWCNTs)-Therminol® VP-1 nanofluid were numerically investigated and presented. The main objective of this investigation was to determine the influence of high thermal conductivity SWCNTs suspended in the widely used heat transfer fluid, Therminol®VP-1 on the performance indicators of the parabolic trough solar collector. A parabolic trough system with a high concentration ratio of 113 was analyzed in this study. The thermo-physical properties of SWCNTs were taken as functions of nanotube length, nanotube diameter, and temperature, while the properties of Therminol®VP-1 were considered to be temperature dependent. The study involved determination of the actual heat flux profile through Monte Carlo ray tracing and the subsequent coupling of this heat flux profile to a computational fluid dynamics tool using user defined functions. The computational fluid dynamics tool was finite volume based, and the realizable k-ε model together with enhanced wall treatment were used for turbulence modeling. The entropy generation rates were obtained directly from the local velocity and temperature fields of the computed domain and later used in the exergy analysis. Results showed that although the heat transfer performance significantly improved with the use of SWCNTs, the increase in the thermal efficiency was not substantial. For the considered range of parameters, while the heat transfer performance increased up to 234%, the thermal efficiency increased around 4.4% as the volume fraction increased from 0 to 2.5%. The corresponding reduction in the entropy generation was about 70%.This work is based on the research supported in part by the National Research Foundation of South Africa (Grant No. 9927). This support is duly acknowledged and appreciated. Dr. Mwesigye acknowledges the support received from the school of Mechanical, Industrial and Aeronautical Engineering at the University of the Witwatersrand, Dr. Yılmaz acknowledges the support received from the Department of Automotive Engineering at Adana Science and Technology University and Prof. Meyer duly acknowledges the support received from the University of Pretoria.http://www.elsevier.com/locate/renene2019-04-01hj2017Mechanical and Aeronautical Engineerin

An assessment on the technological disasters experienced in Turkey (between the years of 2000-2020)

Günümüzde hızlı nüfus artışı, plansız yapılaşma, hızlı ve plansız sanayileşme, teknolojideki gelişmeler, ülkeler ve bölgeler arası siyasi çekişmeler, savaşlar gibi faktörler, teknoloji-insan kaynaklı olayların afetlerle sonuçlanmasına sebep olabilmektedir. Teknolojinin gelişmesi aynı zamanda sanayi, ulaşım ve endüstriyel faaliyetlerin artmasına da yol açmıştır. Gerçekleştirilen faaliyetler esnasında gerekli tedbirlere uyulmaması veya gerekli tedbirlerin alınmaması durumunda can ve mal kaybına yol açan kazaların meydana gelmesi kaçınılmaz olabilir. Dünyada yaşanan doğal ve teknolojik afetlerin kayıt altına alındığı ve arşivlendiği çeşitli uluslararası acil durum veri tabanları bulunmaktadır. Bu veri tabanları evrensel verileri ücretsiz bir şekilde kullanıcı hizmetine sunmaktadır. Bu çalışmada, 2000-2020 yılları arasında Türkiye’de meydana gelen teknolojik afetlerin dağılımları ile etkilediği kişi sayısı ve ölüm oranlarının araştırılması amaçlanmıştır. Tanımlayıcı tipte planlanan çalışmanın evrenini veri tabanında bulunan, 2000-2020 yılları arasında Türkiye’de meydana gelen teknolojik afetler oluşturmuştur. Veriler Excel ortamına aktarılmış ardından, SPSS 25.0 paket programı kullanılarak analiz edilmiştir. Veri tabanından alınan bilgilere göre Türkiye’de 2000-2020 yılları arasında 102 tane teknolojik afetin meydana geldiği görülmüştür. En fazla ölüm oranı %73,6 ile ulaşım kazaları sonucu meydana geldiği saptanmıştır. Teknolojik afetler, doğal afetlerden farklı olarak genellikle insan faaliyetlerinin bir sonucu olarak ortaya çıktığı için çeşitli tedbirlerin alınması bu afetlerin ortaya çıkmasını veya etkilerini ve ölüm oranlarını azaltabilir. Teknolojik kazalar ve bunlara bağlı afetler nedeniyle meydana gelen ölüm oranlarının azaltılabilmesi için bireysel, örgütsel ve yapısal önlemlerin alınması önem arz etmektedirToday, factors such as rapid population growth, unplanned structuring, rapid and unplanned industrialization, technological developments, political conflicts between countries and regions and wars can cause technologicalhuman-induced events to result in disasters. The development of technology has also led to an increase in industry, transport and industrial activities. In case the necessary precautions are not followed or the necessary measures are not taken during the activities carried out, it may be occur inevitable accidents which cause loss of life and property. There are various international emergency databases in which natural and technological disasters in the world are recorded and archived. These databases provide universal data free of charge to the user service. In this study, it is aimed to investigate the death rate and the number of people affected by the distribution of technological disasters occurring in Turkey between 2000 and 2020. The universe of the descriptive study planned, occurring in Turkey between the years 2000-2020, has been formed by the technological disasters in the database. The data were transferred to Excel and then analyzed using SPSS 25.0 package program. According to the information taken from the database was observed that 102 units of technological disasters ocur In Turkey between 2000 and 2020. It was determined that the highest death rate was 73.6% as a result of transportation accidents. Since technological disasters usually occur as a result of human activities, unlike natural disasters, taking various measures can reduce the occurrence or effects of these disasters and mortality rates. In order to decrease the death rates due to technological accidents and related disasters is important to take individual, organizational and structural measures

Nest survival and transplantation success of formica rufa (Hymenoptera: Formicidae) ants in Southern Turkey: A predictive approach

Research highlights: Formica rufa is used widely for biocontrol in Turkish forests. Although ecological characteristics of red wood ant habitats are well known, the statistical significance of these characteristics and their effects on nest transplantation success are largely unknown. Having such knowledge on a local scale, however, can help to predict the success of a scheduled transplantation effort, and can prevent loss of time and money. Background and objectives: In the present study, we used nest transplantation data from southern Turkey to determine habitat parameters that have a significant impact on nest survival, and to investigate possibility of predicting transplantation success from habitat parameter data. Materials and methods: Algorithms of data mining are widely used in agricultural and forestry applications for a wide range of tasks. In the present study, we used descriptive statistics to summarize the transplantation profile according to six habitat parameters (altitude, aspect, canopy closure, landform, nest substrate, and slope). We also used classification, a data mining approach, with two of its methods (decision tree and naive Bayes) to determine the most important habitat parameters for nest survival and predict nest transplantation success in southern Turkey. Results: We found that altitude, aspect, and canopy closure were the most important factors affecting transplantation success. We also show that classification methods can be used in not only classifying, but also predicting the success rate of future transplantations. Thus, we show that the possibility of success for a given area can be predicted when certain parameters are known. Conclusions: This method can assist biological control practitioners in planning biocontrol programs and selecting favorable spots for red wood ant nest transplantation. © 2020 by the authors

Personal Cyber Security Provision Scale development studyKişisel Siber Güvenliği Sağlama Ölçeği geliştirme çalışması

The aim of this study is to develop a scale to determine internet users behavior related to cyber security. In this context created an item pool in accordance with expert opinion. This item pool was administered to 810 people for exploratory factor analysis. In exploratory factor analysis; principal component analysis method which is commonly used and Varimax vertical rotation method to determine the factor structure was used. Scale was administered to 292 people and structural equation modeling approach was applied to confirmation study.As a result of factor analysis,“Personal Cyber Security Provision Scale" which consists of 5 factors and 25 items and has a good compatibility was occurred. ÖzetBu araştırmanın amacı internet kullanıcılarının siber güvenlik ile ilgili davranışlarını belirlemeye yönelik bir ölçek geliştirmektir. Bu bağlamda öncelikle uzman görüşü doğrultusunda 26 maddelik bir madde havuzu oluşturulmuştur. Bu madde havuzu yapı geçerliliğinin test edilmesi için Facebook sosyal paylaşımda bir uygulamayı kullanan 810 kişiye uygulanarak açımlayıcı faktör analizi yapılmıştır. Açımlayıcı faktör analizinde en sık kullanılan yöntem olan temel bileşenler analizi yöntemi kullanılmış, ölçekteki faktör yapısını belirlemek için ise Varimax - dikey döndürme yöntemi kullanılmıştır. Ölçeğin doğrulama çalışması için ise aynı sosyal ağ uygulamasını kullanan ve daha önce ölçeğin uygulandığı kişilerin elendiği292 kişinin verisi kullanılarak yapısal eşitlik modeli yaklaşımı uygulanmıştır. Açımlayıcı faktör analizi sonucunda 5 faktörlü ve 25 maddeden oluşan; doğrulayıcı faktör analizi sonucunda ise elde edilen uyum indekslerine göre iyi bir uyuma sahip "Kişisel Siber Güvenliği Sağlama Ölçeği" ortaya çıkmıştır

Reliability of Measurements on Plaster and Digital Models of Patients with a Cleft Lip and Palate

Objective:The purpose of this study was to determine (1) the more and less reliable measurements/methods and (2) the influence of knowledge and skill on the inter- examiner, intra-examiner, and inter-method reliability of nasolabial measurements on plaster casts and three dimensional (3D) stereophotogrammetric images of casts in infants with an unrepaired unilateral cleft lip and palate (UUCLP).Methods:Preoperative extraoral plaster casts from 42 patients with UUCLP were measured with a digital caliper, and the image acquisition of casts was performed with the 3dMDface stereophotogrammetry system (3dMD, Atlanta, GA). Two examiners (one postgraduate student, one lecturer) evaluated 19 nasolabial measurements in two separate sessions.Results:Intra-rater, inter-rater, and inter-method reliability was lower in measurements of nasal, philtral, and nasal floor width. Almost all of the interclass correlation coefficients (ICC) for measurements performed by the lecturer were above 0.75, whereas the intra-examiner reliability of some measurements performed by the postgraduate student showed low ICC (<0.75).Conclusion:Measurements of curving slopes, such as nasal width, of small dimensions, such as nostril floor width, and deformity-affected anatomic parts, such as philtrum width, presented a low reliability. Measurements on 3D images showed a higher reliability compared to plaster model measurements performed by the postgraduate student. Therefore, it may be recommended to use 3D digital images of infants with CLP for nasolabial measurements especially if performed in postgraduate settings

Clinical Characteristics and Visual Outcomes of Pediatric Optic Neuritis: A Single Center Experience

INTRODUCTION: The aim of this study was to describe the clinical characteristics, visual outcomes of pediatric patients presenting with first-episode of optic neuritis. METHODS: We reviewed medical records of the patients newly diagnosed with optic neuritis younger than 18 years between January 2014 and December 2018 retrospectively. RESULTS: Twenty-eight patients were included to this study. The mean age at first onset of optic neuritis was 13.2+-3.1 years (range 6.2-17.3 years). The mean follow-up period was 4.2+-3.2 (range 0.6-13.08) years. 7 of 28 (25%) patients had recurrent optic neuritis. Optic neuritis involvement was unilateral in 17 of 28 (60%) patients. Forty percent of the patients had idiopathic optic neuritis. Of the six patients with demyelinating lesions in cranial magnetic resonance imaging (MRI) at the first admission, three were diagnosed with multiple sclerosis (MS) at the time of first optic neuritis attack, and three were diagnosed within 13.4+-4.8 months after the first episode. Eight of 21 optic neuritis patients (38%) had oligoclonal band positivity and the incidence of MS was significantly higher in these patients (p=0.014). The mean visual acuity at nadir was 0.48+-0.27 at admission. Whereas it was 0.74+-0.31 and 0.76+-0.33 at 1 and 6 months respectively. There was a strong correlation between first and sixth-month visual acuity (r=0.98, p=0.00). DISCUSSION AND CONCLUSION: Our study demonstrated that poor visual acuity (worse than 0.5) at 1 month can predict poor vision at 6 months. The patients with demyelinating lesions in cranial MRI at their first optic neuritis episode, are more likely to develop MS during the follow-up

TASL practice guidance on the clinical assessment and management of patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease and is significantly associated with obesity, insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and cardiovascular disease. NAFLD has become the most prevalent chronic liver disease in Western countries, and the proportion of NAFLD-related cirrhosis among patients on liver transplantation waiting lists has increased. In light of the accumulated data about NAFLD, and to provide a common approach with multi-disciplines dealing with the subject, it has become necessary to create new guidance for diagnosing and treating NAFLD. This guidance was prepared following an interdisciplinary study under the leadership of the Turkish Association for the Study of the Liver (TASL), Fatty Liver Special Interest Group. This new TASL Guidance is a practical application guide on NAFLD and was prepared to standardize the clinical approach to diagnosing and treating NAFLD patients. This guidance reflects many advances in the field of NAFLD. The proposals in this guidance are meant to aid decision-making in clinical practice. The guidance is primar-ily intended for gastroenterology, endocrinology, metabolism diseases, cardi-ology, internal medicine, pediatric specialists, and family medicine specialists

Analysis of impact of supports applied to sustainable oriented agriculture: the case study of fig in Aydın

Amaç: Bu araştırma Aydın ilinde kuru incir üreten tarımsal işletmelerin sahip oldukları sürdürülebilirlik temelli sertifikaların işletmelerin verim, tarımsal gelir, sürdürülebilirliğine etkisini incelemektir. Materyal ve Yöntem: Araştırma, 2019 yılı Mayıs-Haziran aylarında Aydın ilinde farklı üretim standartlarını kullanan kurutmalık incir üreten konvansiyonel, İyi Tarım Uygulamaları, Organik Tarım olmak üzere 225 tarımsal işletmeden yüz yüze anket yöntemiyle toplanan verilerle yürütülmüştür. İşletmelerin hangi üretim şeklini benimsedikleri çoklu nominal lojistik regresyon yardımıyla belirlenmiştir. İşletmelerin ekonomik analizinin ardından sürdürülebilirlik ölçeği ile işletmelerin sürdürülebilirliği ölçülmüştür. Ekonomik göstergelere ve sürdürülebilirliğe etki eden faktörlerin etkisi uygulamanın etkisi yöntemiyle incelenmiştir. Bulgular: Etki değerleme analizleri sonucunda sertifikalı işletmeler konvansiyonel üretime göre daha sürdürülebilirlerdir. Organik tarım sertifikasına sahip tarım işletmeleri ile iyi tarım uygulamaları sertifikasına sahip tarım işletmelerinin toplam sürdürülebilirliği arasında bir fark yoktur. Sonuç: Sürdürülebilirlik temelli uygulanan standartların işletmelere etkileri araştırılmış, bu etkilerin işletmelerin sürdürülebilirliği büyük ölçüde risk altındadır. Sürdürülebilirlik artıkça incir verimi düşmekte, değişken masraflar azalmakta, brüt gelir artmaktadır. Sürdürülebilir incir üretimi için gereken destekleme modeli ortaya konmuştur.Objective: The aim of this research is to examine the effects of the sustainability-based certificates of the agricultural enterprises producing dried figs in the province of Aydın on the yield, agricultural income and sustainability of the enterprises. Material and Methods: The research was conducted with the data collected by face-to-face survey method from 225 agricultural enterprises, including conventional, Good Agricultural Practices, Organic Agriculture, which produce dried figs using different production standards in Aydın province in May-June 2019. Which mode of production the enterprises adopted was determined with the help of multiple nominal logistic regression. After the economic analysis of the enterprises, the sustainability of the enterprises was measured with the sustainability scale. The effect of the factors affecting the economic indicators and sustainability was examined by the treatment effect models. Results: As a result of impact assessment analysis, certified agriculture are more sustainable than conventional production. There is no difference between the total sustainability of enterprises with organic agriculture certificate and those with good agricultural practices certificate. Conclusion: The effects of sustainability-based standards applied to agriculture have been researched, and the sustainability of these effects is largely at risk. As sustainability increases, fig yield decreases, variable costs decrease, and gross income increases. The support model required for sustainable fig production has been put forward.İÇİNDEKİLER KABUL VE ONAY SYAFASI................................................................................................................ i TEŞEKKÜR............................................................................................................................................ ii İÇİNDEKİLER ....................................................................................................................................... ii KISALTMALAR DİZİNİ........................................................................................................................v ŞEKİLLER DİZİNİ................................................................................................................................ vi ÇİZELGELER DİZİNİ ......................................................................................................................... vii ÖZET...................................................................................................................................................... xi ABSTRACT.......................................................................................................................................... xii 1 . GİRİŞ ..................................................................................................................................................1 1.1 Dünya ve Türkiye’de İncir Üretimi....................................................................................................5 1.2 Sürdürülebilirlik Temelli Sertifikalar...............................................................................................14 2. KAYNAK ÖZETLERİ ......................................................................................................................20 3 . MATERYAL VE YÖNTEM ............................................................................................................32 3.1 . Materyal .........................................................................................................................................32 3.2 Yöntem.............................................................................................................................................35 3.2.1 Tarımsal Sürdürülebilirliğin Ölçülmesi.........................................................................................36 3.2.2 Etki Değerleme Analizi.................................................................................................................39 4 . BULGULAR.....................................................................................................................................43 4.1 İşletme Sahiplerine İlişkin Sosyo-Demografik Özellikler ...............................................................43 4.2 İşletmelerin Ekonomik Analizine İlişkin Bulgular ..........................................................................47 4.3 Pazarlamaya İlişkin Bulgular ...........................................................................................................55 4.4 İşletmelerin Sürdürülebilirlik Durumlarına İlişkin Bulgular............................................................64 iv 4.5 . Sürdürülebilirlik Temelli Sertifikaların İşletmelere Etkisine İlişkin Bulgular...............................73 5 . TARTIŞMA ......................................................................................................................................81 6 . SONUÇ VE ÖNERİLER ..................................................................................................................82 KAYNAKLAR ......................................................................................................................................87 EKLER...................................................................................................................................................96 ÖZGEÇMİŞ .........................................................................................................................................10