Kinetics and mechanism of the reduction of Mamatwan manganese ore fines by solid carbon

A dissertation submitted to the Faculty of Engineering, University of Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering Johannesburg, 1991The kinetics of reduction of the manganese ore from the Mamatwan mine has been studied by thermogravimetric (TGA) analysis, x-ray diffraction analysis (XRD), optical microscopy, and energy dispersive analysis of x-rays (EDAX) between 1100 and 1350 degree celcius with pure graphite under argon atmosphere. It has been observed that the rate and degree of reduction increased with increasing temperature and decreasing particle size. The effect of the different reaction atmosphere has also been investigated by replacing argon atmosphere with carbonmonoxide (CO) and carbondioxide (C02)' The results clarified importance of some reactions in the reduction mechanism of the ore. In early stages of reduction, up to about 4 minutes of reaction time, carbothermic reduction of higher oxides of manqanase and iron (Mn203 and Fe2o3) to manganeous oxide (MnO) and metallic iron respectively was observed which was controlled by diffusional process across the boundary layer between the solid phases. Apparent activation energy is calculated as 61.03 kJ for this stage which corresponds to about 30 percent reduction. Metallization started as random nucleation of iron rich carbides around Mno grains inside the particle. After 30 percent reduction the formation of a silicate phase was observed. Up to 70 percent reduction at 1350oC, reduction rate was controlled by chemical reaction between oxide phase and gaseous phase with an apparent. activation energy of 153 32 kJ.MT201

Serdivan/ Sakarya Bölgesinin yerbilimleri verilerinin coğrafi bilgi sistemleri (CBS) kullanılarak yorumlanması

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Anahtar Kelimeler: Serdivan, CBS (Coğrafi Bilgi Sistemleri), ArcGIS, Harita CBS'nin alışılmış diğer veri bankalarınca avantajı, verilerin coğrafi analizlerini yapabilmesi ve verileri çok yönlü olarak görselleştirebilme unsurlarının olmasıdır. Genel veri tabanı prosedürleriyle sağlanmış olan "sorgulama ve istatistiksel analiz" ve klasik haritalarla sağlanmış olan "görselleştirme ve mekânsal analiz" gibi imkânlar, CBS' de toplanmıştır. Bu neticede CBS sistemleri olayları inceleyip araştırma, yorumlama, sonuçlandırma ve planlama faaliyetlerince, alışılmış diğer veri yönetim sistemlerine nazaran büyük üstünlük kurmaktadır. Oldukça geniş kullanım alanını kapsayan CBS, yeryüzüyle ilgili her çeşit coğrafi kaynaklı verileri işleyebilmesi sebebiylede vazgeçilmez bir araç halini almıştır. Bu bilgiler ışığında Serdivan Belediyesince onaylanan parsel bazlı zemin raporlardan elde edilen jeolojik ve jeofiziksel veriler ayıklanarak bir veri bankası elde edilmiş ve veriler ArcGIS CBS başlığı altında Serdivan bölgesinin zemin durumunu incelemek ve yorumlamak için kullanılmıştır. İncelemeler sonucunda kullanılan verilerden zemin parametre haritaları oluşturulmuş ve bölgesel anlamda genel bir bilgi verilmiştir. zemin parametre haritaları oluşturulmuş ve bölgesel anlamda genel bir bilgi verilmiştir.Keywords: Serdivan, IGS (Geographic Information Systems), ArcGIS, Map The advantage of GIS over the other conventional data banks is that, it can perform geographical analyses of data and can be used to visualized data in a versatile way. Resources such as "inquiry and statistical analysis" of general database procedures and "visualization and spatial analysis" of classical maps have been combined together in GIS. As a result, GIS systems have a great advantage over other common data management systems in examination, interpretation, finalization and planning of events. Covering a wide range of usage, GIS has become an indispensable tool for processing all kinds of geographical data related to the earth. In light of this information, the geological and geophysical data obtained from the parcel based ground reports approved by the Serdivan Municipality were sorted out and a databank obtained. ArcGIS was used to investigate and interpret the ground conditions of the Serdivan Municipality. As a result of the investigations, ground parameter maps were created from the databank and in regional sense general information were provided

Beden eğitimi derslerinde algılanan özerklik desteğinin güdülenme düzeyi ve optimal performans duygu durumu ile ilişkisi

Bu çalışmanın amacı beden eğitimi ve spor öğretmeninden kaynaklanan algılanan özerklik desteği ölçeğinin geçerlik ve güvenirlik çalışmasını gerçekleştirmek ve ortaokul öğrencilerinin beden eğitimi dersinde öğretmenden algıladıkları özerklik desteğinin güdülenme düzeyi ve optimal performans duygu durumunu yordayıp yordamadığını incelemektir. Ayrıca cinsiyete ve sınıf düzeyine göre algılanan özerklik desteği, güdülenme ve optimal performans duygu durumundaki farklar da araştırmada test edilmiştir.Geçerlik ve güvenirlik çalışmasının örneklemini Çanakkale ilinden olasılıksız örneklem yöntemlerinden uygun örnekleme yöntemi ile seçilmiş 5, 6, 7 ve 8. sınıf düzeyinde öğrenim gören 11-14 yaş aralığında, 163 kız ( Xyaş= 12.78; Ss=1.10 ) ve 139 erkek ( Xyaş= 12.75; Ss=1.04), toplam 302 (Xyaş= 12.77; Ss=1.07) öğrenci oluşturmuştur. Katılımcılara Kişisel Bilgi Formu ve Beden Eğitimi ve Spor Öğretmeni Kaynaklı Algılanan Özerklik Desteği Ölçeği uygulanmıştır. Ölçeğin yapı geçerliği Temel Bileşenler Faktör Analizi ile sınanmıştır. Temel Bileşenler Faktör Analizi Varimaks Dönüştürme sonuçları ölçeğin tek boyutlu yapısını desteklemekte ve maddeler toplam varyansın %51.10’unu açıklamaktadır. Ölçekte yer alan maddelerin faktör yük değerleri 0.66-0.77 arasında değişmektedir. Ölçeğin güvenirliğinin sınanması ölçeğin ise Cronbach Alpha iç tutarlılık α katsayısı hesaplanmıştır. Çalışmanın güvenirlik analizi bulgularına bakıldığında Cronbach Alpha katsayısının 0.91 olduğu bulunmuştur. Algılanan özerklik desteğinin optimal performans duygu durum ve güdülenmeyi belirlemede rolünü test etmek için yapılan ikinci çalışmanın örneklemini Çanakkale ilinden olasılıksız örneklem yöntemlerinden uygun örnekleme yöntemi ile seçilmiş ortaokul 5, 6, 7 ve 8. sınıfta öğrenim gören 296 kız (Xyaş=12.41;Ss=1.10) ve 269 erkek (Xyaş=12.37; Ss=1.08) toplam 566 kişi (Xyaş= 12.39; Ss= 1.12) oluşturmaktadır. Kişisel Bilgi Formu, Beden Eğitimi ve Spor Öğretmeni Kaynaklı Algılanan Özerklik Desteği Ölçeği, Beden Eğitimi Dersi Durumsal Güdülenme Ölçeği ve Beden Eğitimi Dersi Optimal Performans Duygu Durumu Ölçeği-2 ölçekleri uygulanmıştır. Katılımcıların cinsiyet ve sınıf düzeyine göre algılanan özerklik desteği, güdülenme ve optimal performans duygu durumlarında fark olup olmadığını belirlemek amacıyla bağımsız gruplarda t testi uygulanmıştır. Algılanan özerklik desteğinin güdülenme ve optimal performans duygu durumu deneyiminin yaşanmasındaki rolünü test etmek amacıyla ise Hiyerarşik Regresyon Analizi uygulanmıştır. Yapılan analizler sonucunda cinsiyete göre algılanan özerklik desteği ve güdülenmenin dışsal güdülenme ve güdülenmeme alt boyutlarında da anlamlı fark bulunmuştur (p 0.05)..Sınıf değişkenine göre yapılan analiz sonuçları, algılanan özerklik desteği, güdülenme, hür irade indeksi ve optimal performans duygu durumunda anlamlı fark olduğunu ortaya koymuştur. Hiyerarşik regresyon analizi sonuçları algılanan özerklik desteğinin güdülenmenin tüm alt boyutlarının, hür irade indeksinin ve optimal performans duygu durumunun yordayıcısı olduğunu göstermektedir. Ayrıca algılanan özerklik desteği ile güdülenmenin tüm alt boyutları, hür irade indeksi ve optimal performans duygu durumu arasında pozitif ilişki bulunmuştur. Araştırmanın sonucunda; Beden Eğitimi ve Spor Öğretmeni Kaynaklı Algılanan Özerklik Desteği Ölçeği’nin 11-14 yaş aralığında geçerli ve güvenilir bir araç olduğu elde edilmiştir. Ayrıca beden eğitimi ve spor öğretmeni kaynaklı algılanan özerklik desteğinin beden eğitimi ve spor derslerindeki güdülenmeyi ve optimal performans duygu durumunu da pozitif yönde etkileyerek derse yönelik katılımın, ilginin ve pozitif duygu durumlarının oluşturulmasına katkıda bulunduğu görülmektedir.--------------------The first purpose of this research was to examine the validty and the reliability of “Perceived Autonomy Support in Physical Education and Sport Setting from Physical Education and Sport Teacher Scale”. The secondarypurpose of this study was to determine the role of perceived autonomy support from teacher in prediction of motivation and dispositional flow in physical education classes. The study was also aimed to examine the differences in perceived autonomy support, motivation and dispositional flow with regard to gender and grade levels.The sample of the reliability and validity consist of 163 female ( Mage= 12.78±1.10 ) and 139 male ( Mage= 12.75±1.04), totally 302 (Mage= 12.77±1.07) secondary school students in Çanakkale who were selected by using convenient sampling. Personal information form and “Perceived Autonomy Support in Physical Education and Sport Setting from Physical Education and Sport Teacher Scale” were administered to all participants. The result of factor analysis for testing construct validity revealed one dimensional construct and items explained 51.10% of the total variance. Factor loading of the items ranged from 0.66 to 0.77 for total item correlations.The internal consistency coefficient of the scale (Cronbach alpha) was 0.91. For testing the role of perceived autonomy support in determining motivation and flow in physical education classes, 296 female (Mage=12.41±1.10) and 269 male (Mage=12.37±1.08) totally 566 (Mage=12.39±1.12) secondaryschool students in Çanakkale who were selected by using convenient sampling voluntarily participated in the study. Personal information form, “Perceived Autonomy Support in Physical Education and Sport Setting from Physical Education and Sport Teacher Scale”, “Situational Motivation Scale” for physical education class environment and “Dispositional Flow Scale-2” were administered to all participants. For testing sex and grade level of differences in perceived autonomy support, motivation and dispositional flow independent t-test was used. The role of perceived autonomy support from physical education teacher in prediction of motivation and dispositional flow, hierarchical regression analysis was conducted.Results indicated there was a significant sex differences in perceived autonomy support, external regulation, and amotivation and self determination index. On the other hand, no significant sex differences was found in dispositional flow. The results of grade level analysis showed that there were significant differences in perceived autonomy support, motivation, self determination index and dispositional flow. The results of hierarchical regression analysis showed that perceived autonomy support predicted the motivation, self determination index and dispositional flow and the relationship between perceived autonomy support and these variables were positive.In conclusion, “Perceived Autonomy Support in Physical Education and Sport Setting from Physical Education and Sport Teacher Scale” is valid and reliable instrument in the 11-14 age range. Furthermore, the results clearly show that perceived autonomy support from physical education teacher positively affects motivation and dispositional flow for physical education and sport classes

THE DYNAMICS BETWEEN MUTUAL FUNDS FLOWS AND STOCK RETURNS: EMPIRICAL EVIDENCE FROM THE TURKEY MARKETS

The aim of the study is searching the relationships existence and its directions between investment funds flow and earnings of market stock in Turkey for the period of 2001:4-2011:2. Specifically, we investigate the possibility of a causality mechanism through which mutual funds flows may affect stock returns and vice versa. Time series techniques used for searching this relationship between variances. Primarily to state stagnancy Phillips-Perron unit stem text techniques used, then to state the longer period relationships existence between variances Johansen- Juselius test techniques used. Because of variances are observed as integrated, by considering the possibility of existence at least there is a one way causality between variances, Granger causality test was made. As a result, findings show that there is a relationship between investment funds flow and earnings of market stock by the way there isn’t a causality relationship between investment funds flow and earnings of market stock

EFFECT OF GOLD PRICE VOLATILITY ON STOCK RETURNS:EXAMPLE OF TURKEY

This study analyzes the effect of fluctuations in gold prices on ISE 100 indexusing daily prices and the index data from 01.01.2009 to 31.12.2012. The rawdata has been converted into earningsyields and analyzed. The study firstdetermines whether or not the use of aGARCH model would beappropriate usinga heteroskedasticity test. The test resultsshow that there was an ARCH effect inboth variables, and that GARCH modeling could be used. The results obtainedfrom MGARCH modeling show that gold and stock exchange yields have beenaffected both by their own shocks and by shocks of each othe

Factors affecting work-life balance and psychological resilience levels of nurses working in internal clinics during COVID-19

Introduction and aim. COVID-19 intensity has affected both the psychology of the nurses and the balance established between their work and social lives. In this study, it was aimed to examine the work-life balance and psychological resilience levels of nurses. Material and methods. Four Hundred and seventy two nurses, working in various hospitals and internal units in Turkey, voluntarily participated in the study. Data was collected online using the Work-Life Balance Scale, Brief Psychological Resilience Scale, and the Personal Information Form. Results. The sub-dimensions of the work-life balance scale include allocation of time for yourself (β=1.892; p<0.001), life merely being based on work (β=-0.513; p<0.05) and work-life balance; affect the psychological resilience score (β=-0.364; p<0.05). Based on this, devoting time for yourself has a positive effect on psychological resilience, while others have a negative effect. The total score of the nurses on work-life balance is 51.51±7.22 and their psychological resilience score is 15.27±3.93. Conclusion. Psychological resilience is affected by educational status, marital status, having children, and working schedule; work-life balance is affected by educational status, marital status, having children, income levels, and working schedule; while work-life balance sub-dimensions are affected by education, marital status, having children, income levels, place of work and working schedule. Both work-life balance and its sub-dimensions affect the psychological resilience of nurses

From ground zero of the pandemic – nurses’ stories via Photovoice

Introduction and aim. With the ongoing COVID-19 pandemic, healthcare workers continue to work selflessly and intensively despite many occupational hazards. Although various studies have been carried out to evaluate the experiences of nurses who play an important role in the fight against the pandemic and the effects thereof, qualitative studies carried out using the photovoice technique are very limited. The aim of this study was to evaluate the experiences of nurses working during the COVID-19 pandemic and show the impact that COVID-19 has had on nurses’ work and daily life using creative photographic data. Material and methods. This qualitative study employed a participatory action research design, and photovoice technique was used. Research data were collected from nurses working in COVID-19 clinics of various hospitals between May and September 2021. Data analysis was performed via a phenomenological interpretation method. Results. Five themes emerged from the data: (1) burnout, (2) anxiety, (3) social isolation, (4) emphasis on professional value, and (5) the value of life. Each theme was presented with representative photographic and written narratives provided by the participants. Conclusion. The findings of this study suggest that nurses experience problems such as burnout, anxiety, and social isolation. All the participants associated these problems with the negative effects of the COVID-19 pandemic on work and daily life. On the other hand, the participants emphasized professional value and the value of life despite all the negativities and risks