368 research outputs found
Operating characteristics of the Langley Mach 7 Scramjet Test Facility
Operating characteristics of the Langley Mach 7 Scramjet Test Facility are described. The facility is designed for testing airframe integrated scramjet (supersonic combustion ramjet) engine models. Features include duplication of the flight Mach number total enthalpy, flight altitude simulation, and simulation of engine airframe integration effects such a bow shock wave precompression and boundary layer ingestion by the engine. Data obtained from facility calibration and from tests of a hydrogen burning, airframe integrated scramjet are discussed. An adverse interaction between the facility flow and the scramjet engine flow during combustion of the fuel is described
Transformation kinetics of alloys under non-isothermal conditions
The overall solid-to-solid phase transformation kinetics under non-isothermal
conditions has been modeled by means of a differential equation method. The
method requires provisions for expressions of the fraction of the transformed
phase in equilibrium condition and the relaxation time for transition as
functions of temperature. The thermal history is an input to the model. We have
used the method to calculate the time/temperature variation of the volume
fraction of the favored phase in the alpha-to-beta transition in a zirconium
alloy under heating and cooling, in agreement with experimental results. We
also present a formulation that accounts for both additive and non-additive
phase transformation processes. Moreover, a method based on the concept of path
integral, which considers all the possible paths in thermal histories to reach
the final state, is suggested.Comment: 16 pages, 7 figures. To appear in Modelling Simul. Mater. Sci. En
Thermal remote sensing from Airborne Hyperspectral Scanner data in the framework of the SPARC and SEN2FLEX projects: an overview
The AHS (Airborne Hyperspectral Scanner) instrument has 80 spectral bands covering the visible and near infrared (VNIR), short wave infrared (SWIR), mid infrared (MIR) and thermal infrared (TIR) spectral range. The instrument is operated by Instituto Nacional de Técnica Aerospacial (INTA), and it has been involved in several field campaigns since 2004. <br><br> This paper presents an overview of the work performed with the AHS thermal imagery provided in the framework of the SPARC and SEN2FLEX campaigns, carried out respectively in 2004 and 2005 over an agricultural area in Spain. The data collected in both campaigns allowed for the first time the development and testing of algorithms for land surface temperature and emissivity retrieval as well as the estimation of evapotranspiration from AHS data. Errors were found to be around 1.5 K for land surface temperature and 1 mm/day for evapotranspiration
Land-atmosphere exchanges of water and energy in space and time over a heterogeneous land surface
Genome-wide Linkage Scan to Identify Loci for Age at First Cigarette in Dutch Sibling Pairs
Most smokers begin smoking during adolescence and early age of smoking initiation is related to more frequent current smoking, daily smoking and more dependent smoking (Everret et al., 1999; Lando et al.
Standard of civilization, nomadism and territoriality in nineteenth-century international society
In this chapter, the encounter between the Russian Empire and the nomads of the Eurasian steppe in the nineteenth century is analyzed using the theoretical framework of the standard of civilization. The creation of the Westphalian state-model in Europe in the seventeenth century, linked to the later emergence of the notion of the standard of civilization led to the ‘othering’ of the nomads of the Eurasian steppe as barbarians, as a threat to the borders of civilized Europe. The chapter presents also an argument to define ‘territoriality’ as not only an institution of international society of the time but also as a distinctive quality and requirement for being considered ‘civilized’. In this analytical framework, the nomads become the ‘other’, the ‘alien’, the ‘menace’, onto which projections of rationality and modernity were cast in order to prevent threats to Russia’s European and civilized identity. The chapter sheds light on the encounter between ‘fixed’ and ‘mobile’ units in the course of expansion of international society; contextualizes the role played by nomadic tribes in resisting the application of Westphalian spatial categories in the Eurasian space; and scrutinizes what the role of nomads was in constructing a European, civilized identity.PostprintPeer reviewe
Comparison of DNA testing strategies in monitoring human papillomavirus infection prevalence through simulation
Routine Opt-Out HIV Testing Strategies in a Female Jail Setting: A Prospective Controlled Trial
Background: Ten million Americans enter jails annually. The objective was to evaluate new CDC guidelines for routine optout HIV testing and examine the optimal time to implement routine opt-out HIV testing among newly incarcerated jail detainees. Methods: This prospective, controlled trial of routine opt-out HIV testing was conducted among 323 newly incarcerated female inmates in Connecticut’s only women’s jail. 323 sequential entrants to the women’s jail over a five week period in August and September 2007 were assigned to be offered routine opt-out HIV testing at one of three points after incarceration: immediate (same day, n = 108), early (next day, n = 108), or delayed (7 days, n = 107). The primary outcome was the proportion of women in each group consenting to testing. Results: Routine opt-out HIV testing was significantly highest (73%) among the early testing group compared to 55 % for immediate and 50 % for 7 days post-entry groups. Other factors significantly (p = 0.01) associated with being HIV tested were younger age and low likelihood of early release from jail based on bond value or type of charge for which women were arrested. Conclusions: In this correctional facility, routine opt-out HIV testing in a jail setting was feasible, with highest rates of testing if performed the day after incarceration. Lower testing rates were seen with immediate testing, where there is a high prevalence of inability or unwillingness to test, and with delayed testing, where attrition from jail increases with each passing day
HIV and Hepatitis B and C incidence rates in US correctional populations and high risk groups: a systematic review and meta-analysis
A review on experimental and clinical genetic associations studies on fear conditioning, extinction and cognitive-behavioral treatment
Fear conditioning and extinction represent basic forms of associative learning with considerable clinical relevance and have been implicated in the pathogenesis of anxiety disorders. There is considerable inter-individual variation in the ability to acquire and extinguish conditioned fear reactions and the study of genetic variants has recently become a focus of research. In this review, we give an overview of the existing genetic association studies on human fear conditioning and extinction in healthy individuals and of related studies on cognitive-behavioral treatment (CBT) and exposure, as well as pathology development after trauma. Variation in the serotonin transporter (5HTT) and the catechol-o-methyltransferase (COMT) genes has consistently been associated with effects in pre-clinical and clinical studies. Interesting new findings, which however require further replication, have been reported for genetic variation in the dopamine transporter (DAT1) and the pituitary adenylate cyclase 1 receptor (ADCYAP1R1) genes, whereas the current picture is inconsistent for variation in the brain-derived neurotrophic factor (BDNF) gene. We end with a discussion of the findings and their limitations, as well as future directions that we hope will aid the field to develop further
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