A Three-dimensional CFD Study on Multiphase Flow in an FCC Regenerator Integrated with Oxy-combustion

A vital process for converting heavy petroleum productions is Fluid Catalytic Cracking (FCC). As a major source of CO2 emissions, the regenerator reactor in the FCC unit accounts for about 20-35% of the refinery's total emissions. A common method for reducing CO2 emissions from the FCC regenerator is oxy-combustion, which has different advantages with regard to reducing energy penalties and associated costs. In this study, a computational fluid dynamic (CFD) study was used to examine the hydrodynamic characteristics of solid particles and gas inside the FCC regenerator, allowing CO2 to be captured more efficiently. Utilizing Ansys Fluent platform, the Eulerian-Eulerian model was applied with granular flow kinetic theory. In the simulations, different mesh sizes were tested, and the hydrodynamics of the oxy-combustion regenerator were evaluated by adjusting CO2 flow rates to achieve similar fluidization behaviors. The CFD results indicated that the conventional drag model accurately predicted the density phases within the bed. In oxy-combustion, CO2, due to its density, naturally creates a smaller dense phase compared to air-combustion. Moreover, optimizing the fluidizing gas velocities resulted in enhanced particle mixing, resulting in a distributed flow with vortices within the dense phases due to a reduction in gas velocity. To improve the environmental performance of the FCC unit, this research provides valuable insight into the hydrodynamics of solid catalysts used in the oxy-combustion process

Multimodal person recognition for human-vehicle interaction

Next-generation vehicles will undoubtedly feature biometric person recognition as part of an effort to improve the driving experience. Today's technology prevents such systems from operating satisfactorily under adverse conditions. A proposed framework for achieving person recognition successfully combines different biometric modalities, borne out in two case studies

Comparative evaluation of shear bond strength of three flowable compomers on enamel of primary teeth: An in-vitro study

Background: The aim of the present study was to determine Shear bond strength (SBS) of different flowable compomers on the enamel surface of primary teeth. The null hypothesis to be tested was that none of the flowable compomer would differ significantly from the other two with respect to SBS. As a result, the tested materials that have the easiest application on child patient is preferred. Material and Methods: Sixty newly extracted non carious primary molars were selected. The buccal surface was cleaned and polished to obtain a flat enamel surface. The specimens were randomly divided into three groups of 20 teeth each, based on the flowable compomers applied, as follows: group I: Dyract Flow® (Dentsply, Konstanz, Germany); group II: Twinky Star Flow® (Voco, Cuxhaven, Germany); and group III: R&D Series Nova Compomer Flow® (Imicryl, Konya, Turkey). Results: SBS in group II (6.78± 0.45 MPa) were significantly lower than groups I and III (8.30 ± 0.29 and 8.43 ± 0.66 MPa, respectively) (P<.001). No significant difference was found between groups I and III (P<.05). Conclusions: Significant differences existed between the SBS of the groups. Therefore, the null hypothesis was rejected. Flowable compomers can provide adequate SBS with self-etching system at restoration of primary teeth. Thus, successful restorations in pediatric patients can be done in a practical way. © Medicina Oral S.L

ANALYSIS OF SHORT TRACK SPEED SKATERS COURAGE LEVELS FROM DIFFERENT VARIABLES

The object of this work is to analyze the courage levels of short track speed skaters from different variables. The study has been carried out on a total of 20 individuals, including 6 women and 14 men, who performed as short track speed skaters in Erzurum province of Turkey in 2017. DBA courage scale developed by (Imamoğlu, 1998) has been applied to skaters in the study9. SPSS 21 package program has been used for the analysis of the data. In the analysis of the data, frequency distribution for the demographic characteristics, T test to examine the relationship between two independent variables and courage level and ANOVA Variance analysis tests have been used to examine the relationship between more than two variables and courage level. The difference between the variables has been interpreted based on p 0.05 relevance level. According to the findings, it is determined that there is a significant difference between the level of courage of the athletes and being a national athlete. It is also determined that there is no significant difference between gender, education level, age, type of school they attended, educational background of mother and father and mother and father’s occupations. It is observed that, courage levels of national athletes are higher than that of non-national athletes. It is proposed that, it is important to determine the variables that will positively influence the level of courage for the athletes to be successful in sports and daily life.  Article visualizations

Research for University Students’ Levels of Dealing with Stress from Different Types of Variables

This research aims to investigate university students’ levels of dealing with stress, from different types of variables. The study was carried out on a total of 500 individuals, including 346 female and 154 male students studying at Atatürk University Kazim Karabekir Faculty of Education in 2016/2017 academic year. In this work, Oral, Çok ve Kutlu (2005) "The Level of dealing with Stress in Educational System" scale was for the students. SPSS 21 package program was used in the analysis of the data. For the analysis of the data, and in determining the demographics, the frequency distribution was used. T test was applied to examine the relationship between two independent variables and stress coping sub-dimensions and Anova Warians analysis tests were used to examine the relationship between two and over variables and stress subscale sub-dimensions. The difference between the variables has been interpreted on the basis of p0.05 significance level. According to the findings, it was found that, there is a significant difference between individuals' stress coping sub-dimensions and gender, book reading habits and spare time activity. There was no significant difference between age, family structure and monthly income variables.It was found out that the scores of female students were higher than the average scores of male students with regard to studying from students' gender and stress coping levels subscales, preparing for an exam and affective, behavioral sub-dimensions. The students who stated that they had the habit of reading books, were found to have high scores in studying, preparing for an exam and the affective behavioral sub-dimensions. It was deduced that the students who spent their leisure time with their family got higher scores from students who spent their spare times with their friends or alone, with regard to studying, preparing for an exam and the affective behavioral sub-dimensions.In order to make students, more effective and successful in educational system, the factors that affect the stress levels should be determined and similar studies are necessary in order to have positive effects for students, which, constitutes the part of the proposal of our study. Keywords: University student, Stress, Dealing with stres

A Case study of light pollution in France after the change in legislation

France issued a decree to restrict and prohibit mainly outdoor lighting effective from January 1st, 2019. Effectiveness of this legislation has been evaluated in this study using GIS data which was first used in \cite{2020MNRAS.493.1204A} (so called astroGIS database - \url{astrogis.org}). A subset of Artificial Light layer of astroGIS database has been adapted for years between January 2012 and December 2019. During 2019, radiance of $1.9 \times 10^{9}$ W cm$^{-2}$ sr$^{-1}$ has been released into space. Annual light pollution in France decreased by 6\% after the enactment of artificial light legislation. France continue to have potential Dark Sky Park locations for example cities like Indre, Lot, Nievre and Creuse having the lowest light pollution values. A strong correlation between population and light pollution ($R\simeq 0.83$) has been observed. A similar but a weak correlation can also be observed for GDP ($R\simeq 0.28$). However, it is still too early to justify whether the improvements observed in the dataset are due to the enactment of the legislation or not.Comment: 10 pages, 4 figures, 2 tables, Submitted to Astrophysics and Space Scienc

The temporal analysis of light pollution in Turkey using VIIRS data

© 2021, The Author(s), under exclusive licence to Springer Nature B.V.Artificial Light pollution (AL) in Turkey and in Turkish observatories between 2012–2020 have been studied using the archival data of Visible Infrared Imaging Radiometer Suite (VIIRS) instrument. The astroGIS database has been used in processing the data (astrogis.org) Aksaker et al. (2020a). The total energy released to space from Turkey increased by 80% in 2019 with respect to 2012. In the span of the dataset, a steady and continuous increase has been observed throughout all cities of the country. On the other hand, Dark Sky Park locations, East and Southeast Anatolian regions and mostly rural areas around the cities kept their AL level constant. Four demographic parameters have been studied and they were found to be correlated very well with AL: Population (R≃ 0.90); GDP (R≃ 0.87); Total Power Consumption (R≃ 0.66) and Outdoor Lightening (R≃ 0.67). Contrary to countries acting to prevent AL increases, Turkey seems to be at the beginning of an era where AL will arithmetically increase throughout the country and enormous amount of energy will continuously escape to space and therefore will be wasted. Therefore, a preventive legislation, especially for invaluable astronomical site locations such as TURAG, TUG, DAG and ÇAAM where each is counted as a truly dark site due to their SQM values, has to be enacted in Turkey, in very near future

A novel index in healthy infants and children — subarachnoid space: ventricle ratio

Background: The subarachnoid space (SAS) and ventricular width (VW) in normalinfants and children were studied with ultrasonography to provide the objectivemeasurement and define a normal range for these measurements. The additional aim was to determine the stable ratio as a SAS/VW.Materials and methods: A total of 100 healthy subjects, including 48 males and52 females, were studied. The cases were divided into 3 age groups: 0–6 months(n = 65), 7–12 months (n = 24) and &gt; 13 months (n = 11). Transfontanel ultrasonography was performed in all the cases. SAS, VW and the SAS/VW ratios were calculated. The study was approved by the ethical committee. All parents wereinformed about the sonographic examination and their approvals were taken.Results: SAS was calculated as 3.1 (0.5–6) mm and VW was calculated as 3.6(1.3–5) mm. SAS/VW ratio was 0.9 ± 0.3. There was no statistically significant difference among SAS, VW and SAS/VW ratios in 3–97 percentile group (p &gt; 0.05).Conclusions: Ultrasonography can be used as a practicable and reproducible modalityin the measurement of SAS and VW in healthy children. It is a non-invasivemethod and allows for serial follow-up. SAS/VW ratio can be used as an index inhealthy children

ÖĞRETMEN ADAYLARININ OKUL UYGULAMALARINDAN DOYUMLARINI YORDAYICI FAKTÖRLER

Bu araştırmada, Selçuk Üniversitesi Eğitim Fakültesi Ortaöğretim Bölümlerinde okumakta olan 286 son sınıf öğrencilerinin okul uygulamalarıile ilgili doyumlarınıyordayıcıfaktörler incelenmiştir. Veri toplama aracıolarak Aksu ve Demirtaş 2006 tarafından geliştirilen anket formu kullanılmıştır. Bu ankete öğretmen adaylarının okul uygulamalarından doyumlarınıve okul uygulamalarındaki teknoloji kullanımınıölçen iki tane bölüm eklenmiştir. Ayrıca çalışma grubunun profilini çıkarmak amacıyla öğretmen adaylarının anabilim dalı, cinsiyeti, öğretim tekniği, bilgisayar ve internet sahipliği sorulmuştur. Bu çalışmada, uygulama okul ortamı, müdürü, öğretmeni, öğretim elemanı, öğretmen adayı, öğretmen adayıdoyumu ve teknoloji kullanımının hepsinin birbiri ile istatistiksel olarak anlamlıdüzeyde ilişkili olduğu görülmüştür. Öğretmen adaylarının okul uygulamalarından doyumlarınıyordama da; uygulama öğretmeni, öğretim elemanı, okul müdürü ve teknoloji kullanımının istatistiksel olarak anlamlıdüzeyde önemli faktörler olduğu tespit edilmiştir