Efficiency and Reliability Analysis of AC and 380V DC Data Centers

The rapid growth of the Internet has resulted in colossal increase in the number of data centers. A data center consume a tremendous amount of electricity resulting in high operation cost. Even a slight improvement in the power distribution system of a data center could save millions of dollars in electricity bills. Benchmarks for both AC and 380V DC data centers are developed and efficiency analyses thereof have been performed for an entire year. The efficiency of the power distribution system can be increased if number of power conversion stages can be reduced and more efficient converters are used. Use of wide band gap (WBG) converters will further improve the overall system efficiency because of its high efficiency. The results shows that 380V DC data centers are more efficient than AC data centers with and without PV integration. Using 380V DC distribution system not only improve the efficiency of the system, but it saves millions of dollars by decreasing system downtime. Maintaining high availability at all times is very critical to data centers. The distribution system with higher number of series components is more likely to fail, resulting in increased downtime. This study aims at comparing reliabilities of AC against 380V DC architecture. Reliability assessment was done for both AC and DC systems complying with Tier IV standard. The analysis was done for different level of redundancy (eg. N, N+1, N+2) in the UPS system for both AC and DC systems. Monte Carlo simulation method was used to perform the reliability calculations. The simulation results showed that the 380V DC distribution system has higher level of reliability than AC distribution system in data centers but only up to certain level of redundancy in the UPS system. The reliability level of AC system will approach to that of a DC system when a very high level of redundancy in the UPS system is considered, but this will increase the overall cost of a data center

Using Personal and Social Responsibility Model for Gaining Leadership Behavior in Students

In the research, it was aimed to teach responsibility to the students, ensure and develop awareness of leadership behavior using a leadership program, and also examine the effectiveness of the Teaching Personal and Social Responsibility (TPSR) model in terms of forming a leadership behavior. The study group consisted of 55 students in high school 1st grade attending Ankara Turkish Volleyball Federation Sports High School. In the study, mixed methods pattern with embedded semi-experimental pretest-posttest control group was used. While a 32-hour leadership program was being applied to the students in the experimental group, the current curriculum was continued to be taught for the students in the control group. As data collection tools, the Personal and Social Responsibility Behavior Scale, the Leader Behavior Description Questionnaire, a semi-structured individual interview form, and field notes were used. For findings; descriptive statistics and One-way Analysis of covariance (ANCOVA) were used in the analysis of quantitative data, and content analysis method was used in the analysis of qualitative data. As a result, the leadership program including 16 lectures delivered during eight weeks was effective in terms of teaching responsibility to the students of Sports High School and forming and developing leadership behaviors

Teaching Developmentally Appropriate Warm-Up Drills in Physical Education

The warm-up is the most important part of the physical education classes, where the student’s interest and attention are drawn and motivated towards the lesson purpose. However, many physical education teachers do not give enough attention to the beginning and warm-up part of the lesson when planning their lessons. Faigenbaum & McFarland (2007) stated that warm-up activities help prepare students for dynamic activities and increase their lesson time with physical activity. Warm-up in physical education classes is a part that should emphasize, primarily since it constitutes a basis for the main phase. Therefore, the purpose of this article is to provide some developmentally appropriate warm-up examples to increase the quality of the physical education lesson

Examining the Relationship between Academic Motivation and Social-Emotional Competency in Student-Athletes

The purpose of this correlational study was to examine the relationship between academic motivation and social-emotional competency of student-athletes in terms of gender, grade, and doing active sports. The study group consisted of 200 volunteer student-athletes studying at a Sports High School. The Academic Motivation Scale and the Delaware Social-Emotional Competency Scale were used. According to the results, there was a significant difference between the mean scores related to the sub-dimensions of “Intrinsic motivation (IM)-to accomplish, Extrinsic motivation (EM)-introjected regulation, and amotivation” according to the variable of doing active sports, and “self-awareness, social-awareness, and EM-identified regulation” according to gender variable by independent sample t-test. The one-way ANOVA analysis results showed that there was a significant difference between the mean scores of “self-awareness, social-awareness, and IM-to know” sub-dimensions according to the variable of grade. The Pearson Moments Multiplication Correlation test showed that there was a negative relationship between the sub-dimensions self-awareness and social-awareness via EM-identified regulation. This study showed a low negative correlation between academic motivation and social-emotional competency on student-athletes. Significant differences were found between various sub-dimensions according to the variable of gender, grade, and doing active sports

Performance Enhancement of Radial Distribution System via Network Reconfiguration: A Case Study of Urban City in Nepal

Increasing unplanned energy demand increase has led to network congestion, increases power losses and poor voltage profile. To decrease these effects of an unmanaged power system, distribution network reconfiguration provides an effective solution. This paper deals with improving the power losses and poor voltage profile of the Phulchowk Distribution and Consumer Services (DCS) via the implementation of an optimum reconfiguration approach. A Genetic Algorithm (GA) is developed for the optimization. Further, it tries to answer to what extent can we improve the distribution system without overhauling the entire network. The developed simulation algorithm is firstly put into work on the IEEE 33 bus system to better its voltage profile and the poor power losses. The effectiveness of the developed system is validated as it reduced the voltage drop by 5.66% and the power loss by 25.96%. With the solution validated, the algorithm is further implemented in the case of Pulchowk DCS. After reconfiguring the system in different individual cases, optimum network reconfiguration is selected that improved the voltage profile by 3.85%, and the active and reactive power losses by 44.29% and 45.54% respectively from the base case scenario

Sorumluluk Davranışlarının Kazandırılmasında Bireysel ve Sosyal Sorumluluk Modelinin Kullanılması: TVF Spor Lisesi Örneği

The objective of this study was to determine the effect of the Teaching Personal and Social Responsibility (TPSR) model upon bringing responsibility behaviors in students via physical activities and to examine whether students take their responsibility behaviors outside the gym or not. The study group consisted of 55 students receiving education in the 10th grade of Ankara Turkish Volleyball Federation (TVF) Sports High School. In the study, mixed methods pattern with embedded quasi-experimental pretest-posttest control group was used. While the students in the experimental group applied the TPSR program for 32 hours, the students in the control group continued the present curriculum. For the results; in the analysis of quantitative data, the descriptive statistics obtained from the Personal and Social Responsibility Scale and the One-Way Covariance Analysis (ANCOVA), and the percentage analysis obtained from the student behavior assessment rubric were used. In the analysis of qualitative data, content analysis method was used for reflection time assessment form and semi-structured individual interviews. The results of ANCOVA and percentage analysis showed that there were significant differences between the total scores of the experimental group and the control group; posttest and retention test scores significantly increased in students in the experimental group and decreased in students in the control group. As a result of the content analysis, the data acquired from the reflection time form and interviews presented some evidences concerning the responsibility behaviors. It was determined that parent cooperation had positive contributions to taking responsibility behaviors outside the gym and encouraging them. As a consequence, the TPSR model of 32 hours was effective upon bringing responsibility behaviors in Sport High School students.Bu çalışmanın amacı, öğrencilere fiziksel aktivite yoluyla sorumluluk davranışlarını kazandırmada Bireysel ve Sosyal Sorumluluk Modelinin (BSSM) [Teaching Personal and Social Responsibility Model (TPSR)] etkisini belirlemek ve öğrencilerin sorumluluk davranışlarını spor salonu dışına aktarıp aktarmadıklarını incelemektir. Araştırma grubunu Ankara Türkiye Voleybol Federasyonu (TVF) Spor Lisesi’nin 10. sınıfında öğrenim gören 55 öğrenci oluşturmuştur. Araştırmada, gömülü yarı-deneysel ön-test son-test kontrol gruplu karma yöntemler deseni kullanılmıştır. Deney grubundaki öğrencilere 32 saatlik BSSM programı uygulanırken, kontrol grubundaki öğrencilerle mevcut öğretim programına devam edilmiştir. Bulgular için; nicel verilerin analizinde, Bireysel ve Sosyal Sorumluluk Ölçeğinden elde edilen tanımlayıcı istatistik ve Tek Yönlü Kovaryans Analizi (ANCOVA), öğrenci davranışı değerlendirme rubriğinden elde edilen yüzdelik analizi; nitel verilerin analizinde, yansıtma zamanı değerlendirme formu ve yarı-yapılandırılmış görüşmeler için içerik analizi yönteminden yararlanılmıştır. ANCOVA ve yüzdelik analizi sonuçlarında, deney ve kontrol gruplarının toplam puanları arasında anlamlı farklar olduğu, deney grubu öğrencilerinin son-test ve kalıcılık testi toplam puanlarında anlamlı bir şekilde artış olduğu, kontrol grubu öğrencilerinin toplam puanlarında ise düşüş olduğu gözlenmiştir. İçerik analizi sonucunda, yansıtma zamanı formundan ve görüşmelerden elde edilen veriler, sorumluluk davranışlarının kazanımına ilişkin kanıtlar ortaya koymuştur. Sorumluluk davranışlarının spor salonu dışına aktarımında ve teşvik edilmesinde veli işbirliğinin olumlu yönde katkıları olduğu tespit edilmiştir. Sonuç olarak, Spor Lisesindeki öğrencilere sorumluluk davranışlarının kazandırılmasında 32 saatlik BSSM etkili olmuştur

Green bio-inspired synthesis, characterization and activity of silver nanoparticle forms of Centaurea virgata Lam. and the isolated flavonoid eupatorin

A green synthesis method of silver nanoparticles (AgNPs) using Centaurea virgata Lam. extract and the isolated compound eupatorin was investigated in this study. Ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM)/energy-dispersive X-ray (EDX) spectroscopy, thermal gravimetric analysis, X-ray diffraction analysis and zeta potential were used for characterization of AgNPs. The UV-Vis spectrum exhibited a characteristic absorption band at 420 nm for monodisperse nanoparticles. FTIR measurements also proved the formation. X-ray diffraction patterns showed peaks at (110) and (112), which are characteristic for hexagonal crystals and also showed peaks at (111), (200) and (240), which are characteristic for orthorhombic crystals. The TEM images of AgNPs show that the morphology of AgNPs was predominantly spherical. Obtained AgNPs were highly stable according to the zeta potential values. The nitric oxide scavenging activity, which is also related to anticancer activity, of AgNPs was evaluated. It can be concluded that C. virgata Lam. extract and eupatorin can be used as a reducing agent for potential antioxidant AgNP formation. © 2017 Walter de Gruyter GmbH, Berlin/Boston