333 research outputs found
Research summary
The final report for progress during the period from 15 Nov. 1988 to 14 Nov. 1991 is presented. Research on methods for analysis of sound propagation through the atmosphere and on results obtained from application of our methods are summarized. Ten written documents of NASA research are listed, and these include publications, manuscripts accepted, submitted, or in preparation for publication, and reports. Twelve presentations of results, either at scientific conferences or at research or technical organizations, since the start of the grant period are indicated. Names of organizations to which software produced under the grant was distributed are provided, and the current arrangement whereby the software is being distributed to the scientific community is also described. Finally, the names of seven graduate students who worked on NASA research and received Rensselaer degrees during the grant period, along with their current employers are given
Coping on Womenâs Back. Social capital-vulnerability links through a gender lens
Abstract Processes of migration are embedded in social networks, more recently conceptualised as social capital, from sending households to migrantsâ formal and informal associations at their destinations. These processes are often assumed to reduce individuals, households and economiesâ vulnerabilities and thus attract policy-makersâ attention to migration management. The paper aims to conceptualise the gendered interface between social capital and vulnerability. It utilises Bourdieuâs notion of social capital as an analytical starting point. To illuminate our conceptual thoughts we refer to empirical examples from migration research from various Asian countries.
Bourdieuâs theory highlights the social construction of gendered vulnerability. It goes beyond that by identifying the investment in symbolic capital of female honour as an indirect investment in social and, ultimately, economic capital. This gender-differentiated unequal investment and these capitalsâ incomplete fungibility, though, makes women not just indirect members of social networks but mere objects contributing as âsymbolic currencyâ within them, often without being able to capitalise on the very relations. Based on Bourdieuâs theory, we suggest a shift from the investigation of womenâs exclusion from and gender inequality within social networks to an analysis of masculine domination. It appears to be directly associated with the degree of vulnerability that women experience
Interference-filter-stabilized external-cavity diode lasers
We have developed external-cavity diode lasers, where the wavelength
selection is assured by a low loss interference filter instead of the common
diffraction grating. The filter allows a linear cavity design reducing the
sensitivity of the wavelength and the external cavity feedback against
misalignment. By separating the feedback and wavelength selection functions,
both can be optimized independently leading to an increased tunability of the
laser. The design is employed for the generation of laser light at 698, 780 and
852 nm. Its characteristics make it a well suited candidate for space-born
lasers.Comment: 12 pages, 5 figure
Improvement in patient-reported sleep in type 2 diabetes and prediabetes participants receiving a continuous care intervention with nutritional ketosis
Nonclassical correlations of phase noise and photon number in quantum nondemolition measurements
The continuous transition from a low resolution quantum nondemolition
measurement of light field intensity to a precise measurement of photon number
is described using a generalized measurement postulate. In the intermediate
regime, quantization appears as a weak modulation of measurement probability.
In this regime, the measurement result is strongly correlated with the amount
of phase decoherence introduced by the measurement interaction. In particular,
the accidental observation of half integer photon numbers preserves phase
coherence in the light field, while the accidental observation of quantized
values increases decoherence. The quantum mechanical nature of this correlation
is discussed and the implications for the general interpretation of
quantization are considered.Comment: 16 pages, 5 figures, final version to be published in Phys. Rev. A,
Clarifications of the nature of the measurement result and the noise added in
section I
Dynamics of Excited Electrons in Copper and Ferromagnetic Transition Metals: Theory and Experiment
Both theoretical and experimental results for the dynamics of photoexcited
electrons at surfaces of Cu and the ferromagnetic transition metals Fe, Co, and
Ni are presented. A model for the dynamics of excited electrons is developed,
which is based on the Boltzmann equation and includes effects of
photoexcitation, electron-electron scattering, secondary electrons (cascade and
Auger electrons), and transport of excited carriers out of the detection
region. From this we determine the time-resolved two-photon photoemission
(TR-2PPE). Thus a direct comparison of calculated relaxation times with
experimental results by means of TR-2PPE becomes possible. The comparison
indicates that the magnitudes of the spin-averaged relaxation time \tau and of
the ratio \tau_\uparrow/\tau_\downarrow of majority and minority relaxation
times for the different ferromagnetic transition metals result not only from
density-of-states effects, but also from different Coulomb matrix elements M.
Taking M_Fe > M_Cu > M_Ni = M_Co we get reasonable agreement with experiments.Comment: 23 pages, 11 figures, added a figure and an appendix, updated
reference
Entanglement of Atomic Ensembles by Trapping Correlated Photon States
We describe a general technique that allows for an ideal transfer of quantum
correlations between light fields and metastable states of matter. The
technique is based on trapping quantum states of photons in coherently driven
atomic media, in which the group velocity is adiabatically reduced to zero. We
discuss possible applications such as quantum state memories, generation of
squeezed atomic states, preparation of entangled atomic ensembles and quantum
information processing
Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence
Background
The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo.
Findings
In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%).
Conclusions
This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms
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