A model for the kinetics of a solar-pumped long path laser experiment

A kinetic model for a solar-simulator pumped iodine laser system is developed and compared to an experiment in which the solar simulator output is dispersed over a large active volume (150 cu cm) with low simulator light intensity (approx. 200 solar constants). A trace foreign gas which quenches the upper level is introduced into the model. Furthermore, a constant representing optical absorption of the stimulated emission is introduced, in addition to a constant representing the scattering at each of the mirrors, via the optical cavity time constant. The non-uniform heating of the gas is treated as well as the pressure change as a function of time within the cavity. With these new phenomena introduced into the kinetic model, a best reasonable fit to the experimental data is found by adjusting the reaction rate coefficients within the range of known uncertainty by numerical methods giving a new bound within this range of uncertainty. The experimental parameters modeled are the lasing time, laser pulse energy, and time to laser threshold

A simple model of space radiation damage in GaAs solar cells

A simple model is derived for the radiation damage of shallow junction gallium arsenide (GaAs) solar cells. Reasonable agreement is found between the model and specific experimental studies of radiation effects with electron and proton beams. In particular, the extreme sensitivity of the cell to protons stopping near the cell junction is predicted by the model. The equivalent fluence concept is of questionable validity for monoenergetic proton beams. Angular factors are quite important in establishing the cell sensitivity to incident particle types and energies. A fluence of isotropic incidence 1 MeV electrons (assuming infinite backing) is equivalent to four times the fluence of normal incidence 1 MeV electrons. Spectral factors common to the space radiations are considered, and cover glass thickness required to minimize the initial damage for a typical cell configuration is calculated. Rough equivalence between the geosynchronous environment and an equivalent 1 MeV electron fluence (normal incidence) is established

Correlation of AH-1G helicopter flight vibration data and tailboom static test data with NASTRAN analytical results

Level flight airframe vibration at main rotor excitation frequencies was calculated. A NASTRAN tailboom analysis was compared with test data for evaluation of methods used to determine effective skin in a semimonocoque sheet-stringer structure. The flight vibration correlation involved comparison of level flight vibration for two helicopter configurations: clean wing, at light gross weight and wing stores at heavy gross weight. In the tailboom correlation, deflections and internal loads were compared using static test data and a NASTRAN analysis. An iterative procedure was used to determine the amount of effective skin of buckled panels under compression load

Criterion for Dominance of Directional over Size Fluctuations in Destroying Order

For systems exhibiting a second-order phase transition with a spontaneously broken continuous O(N)-symmetry at low temperature, we give a criterion for judging at which temperature T_K long-range directional fluctuations of the order field destroy the order when approaching the critical temperature from below. The temperature T_K lies always significantly below the famous Ginzburg temperature T_G at which size fluctuations of finite range in the order field become important.Comment: Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of paper also at http://www.physik.fu-berlin.de/~kleinert/re3.html#29

Novel Techniques to Eradicate Energy Inefficiencies That Abbreviate The Lifetime of The Cell Phone Based WSNs

The Cell Phone Based WSN of compressed micro-sensors for data acquirement and supervise some surroundings distinctiveness, such as noise, trembling, temperature, and strain. These sensors are entrenched devices accomplished of data communication. In numerous of applications, sensor nodes are deployed over a geo-graphically large region. Due to their configuration, data of measured values must be transferred among stations through these sensor nodes. For this reason a successful, energy efficient routing protocol should be implemented to avoid data loss and additional challenges within limited energy levels. This paper presents a cell phone based routing algorithm for wireless sensor networks, based on the selection of the scheme of dynamic nodes. The key objective is to boost the lifetime of a sensor network while not cooperation data delivery. Significant tasks such as, scrutinize, supervise and determine of energy levels of nodes are handled by these independent mechanisms

Design comparison of cesium and potassium vapor turbine-generator units for space power

Design comparison of cesium and potassium vapor turbogenerator units for space power plant

The Arecibo Dual-Beam Survey: The HI Mass Function of Galaxies

We use the HI-selected galaxy sample from the Arecibo Dual-Beam Survey (Rosenberg & Schneider 2000) to determine the shape of the HI mass function of galaxies in the local universe using both the step-wise maximum likelihood and the 1/V_tot methods. Our survey region spanned all 24 hours of right ascension at selected declinations between 8 and 29 degrees covering ~430 deg^2 of sky in the main beam. The survey is not as deep as some previous Arecibo surveys, but it has a larger total search volume and samples a much larger area of the sky. We conducted extensive tests on all aspects of the galaxy detection process, allowing us to empirically correct for our sensitivity limits, unlike the previous surveys. The mass function for the entire sample is quite steep, with a power-law slope of \alpha ~ -1.5. We find indications that the slope of the HI mass function is flatter near the Virgo cluster, suggesting that evolutionary effects in high density environments may alter the shape of the HI mass function. These evolutionary effects may help to explain differences in the HI mass function derived by different groups. We are sensitive to the most massive sources (log M > 5x10^10 M\solar) over most of the declination range, \~1 sr, and do not detect any massive low surface brightness galaxies. These statistics restrict the population of Malin 1-like galaxies to <5.5x10^-6 Mpc^-3.Comment: ApJ accepted, 12 page

Ground state energy of the modified Nambu-Goto string

We calculate, using zeta function regularization method, semiclassical energy of the Nambu-Goto string supplemented with the boundary, Gauss-Bonnet term in the action and discuss the tachyonic ground state problem.Comment: 10 pages, LaTeX, 2 figure

Stress in trade union officials: an issue for managerial concern?

This study examines stress levels in, and a range of stressors experienced by, officials from a trade union within the fire and rescue service (n = 85). Findings indicate dissatisfaction with aspects of the work of union officials. Additionally, respondents exhibited excessive levels of stress resulting from the service’s organisational structure and their role within it. The benefits of the union role to the service are noted; and it is suggested that consideration be given to effecting change in organisational structure, climate, and practice in the fire and rescue service, and to improving support for union officials