Transducer measures embedment stresses in electronic modules

Strain gage load transducer measures axial embedment stresses in resins used for encapsulation of welded electronic modules. It simulates the geometry of an actual electronic component and can be modified in size, shape, and operating temperature

Facilities and services in the time department of the Royal Greenwich Observatory

The history, equipment, and current work of the Royal Greenwich Observatory are briefly reviewed

Viscous relaxation and collective oscillations in a trapped Fermi gas near the unitarity limit

The viscous relaxation time of a trapped two-component gas of fermions in its normal phase is calculated as a function of temperature and scattering length, with the collision probability being determined by an energy-dependent s-wave cross section. The result is used for calculating the temperature dependence of the frequency and damping of collective modes studied in recent experiments, starting from the kinetic equation for the fermion distribution function with mean-field effects included in the streaming terms.Comment: 10 pages, 9 figures; proof version, corrected typo in Eq. (23); accepted for publication in PR

Relation between mutation yield and cell lethality over a wide range of X-ray and fission neutron doses in maize

Dry maize seeds, of a genetic stock heterozygous for the yellow-green locus (Yg^ Λ ^ ) ι were irradiated with fission neutron doses up to 2700 rads and with 250 kVp X-rays to 40 000 rads. The frequency of yellow-green (yg) sectors in seedling leaves 4 and 5 is largely a measure of the frequency of breakage (or incomplete exchange) and loss of the part of the short arm of chromosome I X carrying Yj>. Plots of dose versus yj* sector frequency per leaf show a linear increase with neutrons which reaches a maximum (leaf 4 = S. 5, leaf 5 = 2. 5) followed by a rapid decline; and a curvilinear increase with X-rays reaching a higher maximum (leaf 4 = 8. 5, leaf 5 = 3.6) followed by a decrease. The observed rise and subsequent fall of numbers of yg_ mutations can be accounted for by a model in which the decline of the curves is due to cell killing which may also be due to chromosome breakage and deletion. The interpretation is based on the principles of the dual action theory, which explains radiobiological action in terms of microdosimetry. One of the observations accounted for is the higher maximum mutation rate for X-rays as compared to neutrons

Frequency and damping of the Scissors Mode of a Fermi gas

We calculate the frequency and damping of the scissors mode in a classical gas as a function of temperature and coupling strength. Our results show good agreement with the main features observed in recent measurements of the scissors mode in an ultracold gas of $^6$Li atoms. The comparison between theory and experiment involves no fitting parameters and thus allows an identification of non-classical effects at and near the unitarity limit.Comment: 4 pages, 2 figure

Review of spectroscopic parameters for upper atmospheric measurements

The workshop included communication of spectroscopic data requirements for the planned upper atmosphere research satellite (UARS) mission, review of the status of currently available spectroscopic parameters, and recommendation of additional studies. The objectives were accomplished and resulted in a series of general and specific recommendations for laboratory spectroscopy research to meet the needs of UARS and other atmospheric remote sensing programs

Using Evidence in the development of local health policies : Some Evidence from the United Kingdom

Objectives: This paper explores the use of evidence, focusing on economic evidence in particular, in the development of local health policies through an in-depth study of Health Improvement Programmes (HImPs) in England. Methods: A questionnaire was sent to the person responsible for coordinating the development of the HImP in each of the 102 English health authorities. In addition, semi-structured interviews were conducted with 10 HImP leaders, and a random sample of 26 HImP documents was reviewed using a standard pro forma. Results: Of the 102 mail questionnaires sent out, 68 (67%) were returned. It was found that those developing HImPs had multiple objectives, only some of which (e.g., efficiency in healthcare provision) would necessarily require evidence.Where evidence was used, this was a mixture of internal (experiential) and external (empirical) evidence, with the balance (66%) being in favor of the latter. Government reports and guidance from the National Institute for Clinical Excellence (NICE), were the main sources of external evidence, rather than published papers. Key barriers to the use of economic evidence were lack of time and availability and the difficulties in synthesizing information at the local level. Conclusions: Based on responses to our survey, the main ways of increasing the use of evidence in the development of local health policies in England are to produce more evidence-based national guidance and to produce accessible summaries of the available literature for local decision makers