Lise Öğrencilerinde Trafik, Madde Kullanımı ve Toplumsal Konumla İlgili Risk Alma Davranışı

In this research we have tried to explain the relationship between trafficing, drug abuse and social status with risk taking behavior according to the levels of self- esteem and gender of the high school students evaluated. The design of the research was based on a descriptive model. The study was carried out on 922 students, 472 female and 450 male participants who are state high school students in Samsun. The students’ risk taking behavior was measured by means of the “The Adolescent Risk Taking Behavior Questionnaire” which was developed by Kıran (2002). The students’ self-esteem levels were measured by means of the “Self- Esteem Inventory for High School Students” which was developed by Güngör(1989). When analyzing the data, the t-test technique was used. The research indicated that there are many significant differences regarding the students’ use of drugs in relation to the level of their self-esteem and their risk taking behavior in relation to their social status. The findings obtained show that as levels of self-esteem decrease, the tendency to use drugs and become involved in risk taking behavior related to social status also increases. In addition, more boys than girls show a tendency to traffic, drug abuse and risk taking behavior. To summarize; high school students are really in need of psychological help regarding the issue that risk-taking behavior leads to danger.Bu araştırmada, lise öğrencilerinde trafik, madde kullanımı ve toplumsal konumla ilgili risk alma davranışı ile özsaygı düzeyi ve cinsiyet arasındaki ilişkiler incelenmiştir. Araştırma kapsamına alman bireyler, Samsun il merkezinde devlet liselerinde öğrenim gören 472 kız, 450 erkek, toplam 922 öğrenciden oluşmaktadır. Araştırmada veri toplama aracı olarak, Kıran (2002) tarafından geliştirilen Ergenlerde Risk Alma Ölçeği ve Güngör (1989) tarafından geliştirilen Lise Öğrencileri Özsaygı Envanteri kullanılmıştır. Verilerin analizinde ise t-testi tekniği kullanılmıştır. Araştırmada, özsaygı düzeyine göre öğrencilerin madde kullanımı ve toplumsal konumla ilgili risk alma davranışı arasında anlamlı farklılıkların olduğu saptanmıştır. Ayrıca, cinsiyete göre trafik, madde kullanımı ve toplumsal konumla ilgili risk alma davranışı arasında da anlamlı farklılıkların olduğu saptanmıştır. Araştırmada; erkek öğrencilerde trafik, madde kullanımı ve toplumsal konumla ilgili risk alma eğiliminin, kız öğrencilere göre daha yüksek düzeyde olduğu saptanmıştır. Elde edilen bulgular, lise öğrencilerinde özsaygı düzeyi düştükçe madde kullanımı ve toplumsal konumla ilgili risk alma ve tehlikeye atılına eğiliminin yükseldiğini göstermektedir. Sonuç olarak, lise öğrencilerinin trafik, madde kullanımı, toplumsal konumla ilgili risk alma ve tehlikeye atılma konusunda psikolojik desteğe ihtiyaç duydukları ileri sürülebilir

Low metabolic activity of biofilm formed by Enterococcus faecalis isolated from healthy humans and wild mallards (Anas platyrhynchos)

It is widely known that Enterococcus faecalis virulence is related to its biofilm formation. Although Enterococci are common commensal organisms of the gastrointestinal tract, the difference between commensal and pathogen strains remain unclear. In this study, we compare the biochemical profile of the biofilms formed by two groups of medical and two groups of commensal strains. The medical strains were isolated as pathogens from infections of urinary tract and other infections (wounds, pus and bedsores), and the commensal strains were taken from faeces of healthy volunteers and faeces of wild mallards (Anas platyrhynchos) living in an urban environment. The properties of biofilms formed by medical and commensal strains differed significantly. Commensal strains showed lower metabolic activity and glucose uptake and higher biofilm biomass than the medical ones. Consistent with glucose uptake experiments, we found that the glucose dehydrogenase gene was more expressed in medical strains. These results indicate that higher metabolic activity and lower protein concentration of E. faecalis cells within biofilms are formed during infections.This work was supported by the Medical University of Gdansk research grant (GUMed W-65) and was financed partly by University of Gdansk research grant (BW 1440-5-0099-7). We are grateful to Katarzyna Zolkos for her help in catching mallards and Magdalena Remisiewicz for correcting the English. Catarina Seabra helped in preparing assays

Instrumentation and Aerothermal Postflight Analysis of the Rocket Technology Flight Experiment ROTEX-T

Based on experience gathered during the hypersonic flight experiments SHEFEX-I and SHEFEX-II the German Aerospace Center (DLR) performed the flight experiment ROTEX-T (ROcket Technology EXperiment-Transition). ROTEX-T was successfully launched on 19th July 2016 at 06:05 am CEST from the Esrange Space Center near Kiruna in northern Sweden. ROTEX-T was a low cost flight experiment mission without inertial measurement unit, reaction control system or parachute. The payload reached an altitude of 183 kilometers, performed a ballistic re-entry with a total flight time of approximately 446 seconds and was afterwards recovered by helicopter. A unique and modular data acquisition system with sampling rates of 20 Hz, 1 kHz, 10 kHz and 2000 kHz was developed for ROTEX-T to study also instationary aerothermal phenomena

Plasma flow modeling for Huels-type arc heater with turbulent diffusion

In this study, we developed an analytical model for the flow field in the Huels-type arc-heated wind tunnel (L2K) of the German Aerospace Center. This flow-field model can be used to accurately reproduce the discharge behavior in the heating section and expansion in the nozzle section of L2K. It includes the radiation transport and turbulent flow as well as thermochemical nonequilibrium models, which are tightly coupled with electric field calculations. In addition, we considered the turbulent diffusion model for the mass conservation of the species and performed numerical simulations for several cases with and without the turbulent diffusion model. Computations were conducted to obtain the general characteristics of an arc-heated flow containing an arc discharge and supersonic expansion. We verified that radiation and turbulence play important roles in the transfer of heat from the high-temperature core flow to the outer cold gas in the heating section of L2K. In addition, we performed parametric studies that involved varying the degree of turbulent diffusion. The results showed that turbulent diffusion has a large influence on the formation of the arc discharge in the heating section and on the enthalpy distribution at the nozzle exit

Aerothermodynamic Design of Space Vehicles: Experiment and CFD

Aerothermodynamics is aimed at determining forces, moments and thermal loads of a spacecraft being launched or returning from orbit. The right shape as well as accurate prediction of the thermal loads determines the selection and dimensioning of thermal protection systems and load carrying structures, the guidance navigation and control of the vehicle as well as numerous mechanical and electrical subsystems. Therefore, aerothermodynamics represents a key technology for the development of space transportation systems. The aerothermodynamic behaviour of space transportation systems needs to be verified by computations using advanced numerical tools, experimental investigations in ground based experimental facilities and by flight tests and is essential for the optimization of aerodynamic shapes. The aerothermodynamics team of DLR was involved during the last 15 years in numerous national, European and international space projects. Relevant examples are the European Hermes program, the German Sänger project, the European flight experiment ARD (Atmospheric Re-entry Demonstrator) or the development of the crew rescue vehicle of the international space station (X-38/CRV). The latter was investigated in the framework of a cooperation between the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). During this period major ground based test facilities, were designed and built at DLR. Important facilities with view to the design of spacecraft are the High Enthalpy Shock Tunnel Göttingen (HEG), the Trisonic Test Section Köln (TMK), the Hypersonic Wind Tunnel Köln (H2K) and the Arc Heated Facility Köln (L3K). The HEG is one of the major European ground based test facilities for the investigation of re-entry flows. In this free piston driven shock tunnel, hypersonic flows with total enthalpies up to 22 MJ/kg resulting in a free stream velocity of approximately 6 km/s can be generated. In such re-entry flows, classic aerodynamic problems are coupled with the influence of chemical reactions generated in the hot shock layer of a space vehicle by temperatures in excess of 10000 K. The operating conditions of HEG are designed in such a way that the oxygen and nitrogen dissociation relaxation behind the bow shock at model scale is equivalent to the full scale version at free flight conditions. The TMK and H2K are cold hypersonic wind tunnels. Their main purpose is to perform force, pressure and flow field measurements as basis for the design of high speed vehicles. The TMK allows to consider the Mach number range 0.5 to 5.7 with a special transonic test section and the H2K covers the range from M=5.3 to 11.2 applying different nozzles. The main purpose of the L3K is the characterization and qualification of thermal protection components of re-entry vehicles. Additionally, modern numerical tools were developed at DLR which allow the efficient computation of hot and cold hypersonic flows past complex configurations. Current and future activities are aimed at developing and further increasing the efficiency of numerical procedures, including the fluid-structure coupling, as well as the further improvement and development of facilities and measurement techniques in order to shorten analysis and development times and also to reduce design margins. The complexity of the design of space transportation vehicles and re-entry flows requires that experiments in ground based facilities are strongly linked with Computational Fluid Dynamics (CFD) investigations. These common activities range from the calibration process of the facility and the study of basic aerodynamic configurations, which are well suited to look at fundamental aspects of high enthalpy flow fields, to the investigation of realistic configurations. In the present paper some selected results obtained by the strong link between experiments and numerical rebuilding will be discussed

Evaluation of visual acuity results and complication incidence during the transition period to phacoemulsification

Ocak 1995-Temmuz 1995 tarihleri arasında kliniğimizde fakoemül-sifikasyon ile göz içi lens implantasyonu yapılan olgularda görme sonuçlarını ve komplikasyon insidansıu analiz etmek amacıyla yapılan bu çalışmada yaşlan 27 ile 85 arasında değişen 69 hastanın 81 gözüne 3.2/5.2 mm skleral tünel insizyonu ile D.O.R.C (Harmo¬ny) marka vitrektomi cihazının phacoemulsification ünitesi kullanılarak lensektomi ve göz içi lens implantasyonu gerçekleştirildi. Hastaların takip süreleri 2 ile 7 ay arasında değişmekteydi. Posto-peratuvar dönemde 60 gözde (%89.5) 5/10 ve üzerinde görme elde edildi. Operasyon sırasında arka kapsül rüptürü olan 6 olgudan 4'ünde nükleus emülsifikasyonu sırasında, 2'sinde de korteks aspirasyonu sırasında arka kapsül rüptürü meydana geldi. 4 olguda nükleus fragmanları vitre içine disloke oldu. Arka kapsül rüptürü olan bir olguda ön kapsül önüne, bir olguda da kapsül içine GİL implantasyonu gerçekleştirildi. Silikon lens implante edilen bir olguda ön kapsül önüne, bir olguda da kapsül içine GİL implantasyonu gerçekleştirildi. Silikon lens implante edilen bir olguda operasyondan 1 gün sonra steril endoftalmi gelişti ve bu olguya lens explantasyonu ve vitrektomi uygulandı. Fakoemülsifikasyon tekniğinin öğrenme döneminde komplikasyon oranının yüksek olması en önemli dezavantajıdır. Buna rağmen postoperatuvar erken dönemde astigmatizmanın az olması, hızlı görsel rehabilitasyon sağlaması, insizyona bağlı daha az komplikasyon oluşturması katarakt cerrahisinde küçük insizyon ve fakoemülsifikasyon tekniğinin tercih edilmesine yol açmaktadır. Olgulanmızdaki görme sonuçlan ve komplikasyon insidansı fakoemülsifikasyona yeni başlayan (geçen) cerrahlar için aydınlatıcı olabilir.We analysed the visual outcome and incidence of complication in cases who underwent phacoemulsification and IQL implantation from January 1995 through July 1995. We performed phacoemusification and IOL implantation to 81 eyes of 69 patients aged 27-85 throught 3.2/5.2 mm şderal tunnel insicion with the phacoemulsification unit of D.O.R.C. In the postoperatuar period visual acuity was 5/10 or more in 60 eyes (%89.5). Peroperatuar posterior capsular rupture occured during nucleus emulsification in 4 cases, during cortex aspiration in 2 cases. In two of these cases we implanted IOL, one on anterior capsule the others in the bag. We performed lens eplantation and vitrectomy to a case in whom steril endophthalmitis developed at the first day following silicon lens implantation. The most important disadvantage of phacoemulsification technique is the high complication rate in the education period. However early visual rehabilitation, reduction in complications due to insicion and low rate of astigmatism results with the preferance of this technique. Visual outcomes and incidence of complications in our cases can enlighten surgeons who newly begin to perform phacoemulsification

Experimental and numerical analysis of the structure of pseudo-shock systems in laval nozzles with parallel side walls

Detailed numerical and experimental investigations of pseudo-shock systems in a Laval nozzle with parallel side walls are carried out. The location of the pseudo-shock system is defined in this system of two choked Laval nozzles by the ratio of the critical cross sections A2*/A1*, the stagnation pressure loss across the shock system and viscous losses. The wall pressure distributions and high-speed schlieren videos recorded in the experiments are compared to the results of a steady and an unsteady numerical simulation. For the steady case, good agreement is found between the calculated and measured shock structure and pressure distribution along the primary nozzle wall, except for a remaining slight deviation in the shock position. For the unsteady case, in which asymmetric shock configurations are observed, deviations of the results with respect to the stochastic wall attachment of the shock system are given which indicate the necessity of further investigations on that topic