Analysis of the effects of baffles on combustion instability

An analytical model has been developed for predicting the effects of baffles on combustion instability. This model has been developed by coupling an acoustic analysis of the wave motion within baffled chambers with a model for the oscillatory combustion response of a propellant droplet developed by Heidmann. A computer program was developed for numerical solution of the resultant coupled equations. Diagnostic calculations were made to determine the reasons for the improper prediction. These calculations showed that the chosen method of representing the combustion response was a very poor approximation. At the end of the program, attempts were made to minimize this effect but the model still improperly predicts the stability trends. Therefore, it is recommended that additional analysis be done with an improved approximation

The temporal changes in the emission spectrum of Comet 9P/Tempel 1 after Deep Impact

The time dependence of the changes in the emission spectra of Comet 9P/Tempel 1 after Deep Impact are derived and discussed. This was a unique event because for the first time it gave astronomers the opportunity to follow the time history of the formation and decay of O(1S), OH, CN, C2, C3, NH, and NH2. Least squares fits of a modified Haser model with constraints using known rate constants were fit to the observed data. In the case of OH a simple two-step Haser model provides a reasonable fit to the observations. Fitting the emissions from O(1S), CN, C2, C3, NH, and NH2 requires the addition of a delayed component to a regular two or three step Haser model. From this information a picture of the Deep Impact encounter emerges where there is an initial formation of gas and dust, which is responsible for the prompt emission that occurs right after impact. A secondary source of gas starts later after impact when the initial dust has dissipated enough so that solar radiation can reach the surface of freshly exposed material. The implications of this and other results are discussed in terms of the implications on the structure and composition of the comet's nucleus.Comment: Accepted for publication in The Astrophysical Journal; 26 pages including 8 figures and 1 tabl

Results of ultra-low level 71ge counting for application in the Gallex-solar neutrino experiment at the Gran Sasso Underground Physics Laboratory

It has been experimentally verified that the Ultra-Low-Level Counting System for the Gallex solar neutrino experiment is capable of measuring the expected solar up silon-flux to plus or minus 12% during two years of operation

Bodyspace at the pub: sexual orientations and organizational space

In this article we argue that sexuality is not only an undercurrent of service environments, but is integral to the way that these workspaces are experienced and negotiated. Through drawing on Sara Ahmed’s (2006a) ‘orientation’ thesis, we develop a concept of ‘bodyspace’ to suggest that individuals understand, shape and make meaning of work spaces through complex sexually-orientated negotiations. Presenting analysis from a study of UK pubs, we explore bodyspace in the lived experience of workplace sexuality through three elements of orientation: background; bodily dwelling; and lines of directionality. Our findings show how organizational spaces afford or mitigate possibilities for particular bodies, which simultaneously shape expectations and experiences of sexuality at work. Bodyspace therefore provides one way of exposing the connection between sexual ‘orientation’ and the lived experience of service sector work

Bandgap narrowing in Mn doped GaAs probed by room-temperature photoluminescence

The electronic band structure of the (Ga,Mn)As system has been one of the most intriguing problems in solid state physics over the past two decades. Determination of the band structure evolution with increasing Mn concentration is a key issue to understand the origin of ferromagnetism. Here we present room temperature photoluminescence and ellipsometry measurements of Ga_{100%-x}Mn_{x}As alloy. The up-shift of the valence-band is proven by the red shift of the room temperature near band gap emission from the Ga_{100%-x}Mn_{x}As alloy with increasing Mn content. It is shown that even a doping by 0.02 at.% of Mn affects the valence-band edge and it merges with the impurity band for a Mn concentration as low as 0.6 at.%. Both X-ray diffraction pattern and high resolution cross-sectional TEM images confirmed full recrystallization of the implanted layer and GaMnAs alloy formation.Comment: 24 pages, 7 figures, accepted at Phys. Rev. B 201

The Effect of Statewide Residency Restrictions on Sex Offender Post-Release Housing Mobility

Securing stable housing may be difficult for returning offenders in general, and these concerns may be exacerbated for sex offenders. In addition to the barriers faced by other returning offenders, sex offenders face intense stigma and once released to the community, they are also subject to additional legal restrictions. The current study explores the effect of statewide residency restriction policies on housing mobility using a unique sample of male sex offenders released in a Midwestern state. The research is based on a quasi-experimental cohort control group design and it describes the frequency and correlation of movement for pre- and post-statewide residency restriction legislation samples. Sex offenders released after the implementation of residency restrictions moved more often and had relatively high degrees of housing mobility compared to offenders released prior to the legislation. The results have important implications for reentry programming and post-release services for sex offenders

Comparison of indoor temperatures of homes with recommended temperatures and effects of disability and age: an observational, cross-sectional study.

OBJECTIVES: We examine if temperatures in winter in English homes meet the recommendation of being at least 18°C at all times. We analyse how many days meet this criterion and calculate the hours per day and night being at/above 18°C. These metrics are compared between households with occupants aged above 64 years or having a long-term disability (LTD) and those younger and without disability. DESIGN: Cross-sectional, observational. SETTING: England. PARTICIPANTS: 635 households. OUTCOMES MEASURES: (1) Mean temperatures, (2) proportion of days of the measurement period meeting the criterion, (3) average hours at/above 18°C, (4) average hours at night at/above 18°C. RESULTS: Mean winter temperatures in the bedroom were MBR=18.15°C (SD=2.51), the living room MLR=18.90°C (SD=2.46) and the hallway MHall=18.25°C (SD=2.57).The median number of days meeting the criterion was 19-31%. For the living room, more days meet the criterion in the group with a LTD (Mdisability=342 vs Mno_disability=301, 95% CI 8 to 74), and with someone over 64 years present (Mabove64=341, Mbelow65=301 95%, CI 8 to 74).The median number of hours/day meeting the criterion was 13-17. In the living room, households with a disability had more hours at 18°C (Mdisability=364, Mno_disability=297, 95% CI 17 to 83) as did the older age group (Mabove64=347, Mbelow65=296, 95% CI 18 to 84). In the hallway, more hours met the criterion in households with a disability (Mdisability=338, Mno_disability=302, 95% CI 3 to 70).247 homes had at least nine hours of at least 18°C at night; no effect of age or disability. CONCLUSIONS: Many households are at risk of negative health outcomes because of temperatures below recommendations

Quantum Otto heat engine based on a multiferroic chain working substance

We study a quantum Otto engine operating on the basis of a helical spin-1/2 multiferroic chain with strongly coupled magnetic and ferroelectric order parameters. The presence of a finite spin chirality in the working substance enables steering of the cycle by an external electric field that couples to the electric polarization. We observe a direct connection between the chirality, the entanglement and the efficiency of the engine. An electric-field dependent threshold temperature is identified, above which the pair correlations in the system, as quantified by the thermal entanglement, diminish. In contrast to the pair correlations, the collective many-body thermal entanglement is less sensitive to the electric field, and in the high temperature limit converges to a constant value. We also discuss the correlations between the threshold temperature of the pair entanglement, the spin chirality and the minimum of the fidelities in relation to the electric and magnetic fields. The efficiency of the quantum Otto cycle shows a saturation plateau with increasing electric field amplitude.DFG/SFB/762DFG/BE 2161/5-1DFG/QUESTDFG/Graduiertenkolleg/1729DFG/SFB/TR 8