The evaluation of a gas mixture having an atomic composition similar to that of A-150 TE-plastic has been extended to a high energy neutron therapy beam. A-150 gas, air and methane-based TE gas were each flowed through A-150 plastic-walled ion chambers ...

Research during the period July 1980 through September 1981 at University of Wisconsin Department of Medical Physics is summarized. Topics covered include: development of an Al50 plastic equivalent gas for proportional counter applications; quantum effici...

Two recently developed A 150 plastic-equivalent gas mixtures have been tested for suitability in proportional counter applications. Methane- and propane-based "tissue-equivalent" gases were also included for comparison purposes. Event-size weighted dose distributions were measured in a 14.8-MeV neutron beam. Resolution was found to be independent of ...

Research during the period July 1980 through September 1981 at University of Wisconsin Department of Medical Physics is summarized. Topics covered include: development of an Al50 plastic equivalent gas for proportional counter applications; quantum efficiency comparisons for Al50 plastic-equivalent gases; ...

theories as yield surfaces do in classical plasticity. ... equivalent, particularly with regard to quantifying the multiaxial behavior of anisotropic ...

The General Atomic Company High Temperature Gas-Cooled Reactor (HTGR) is housed within a prestressed concrete reactor vessel (PCRV). Various carbon steel structural members serve as closures at penetrations in the vessel. A program of testing and evaluation is underway to determine the need for reference fracture toughness (K/sub IR/) and indexing procedures for these ...

Measurements of central axis depth charge distributions (CADCD) in a p(66)Be(49) clinical neutron beam using A-150 TE plastic ionization chambers (IC) have shown that these distributions are dependent on the gas type filling the ICs. IC volumes from 0.1 to 8 cm/sup 3/ and nine different gases were investigated. Off axis ratios and ...

Compositions of matter that have the radiation response of animal muscle tissue, bone, or air were prepared. These compositions are composed of specific proportions of three or more of the following constituents: polyethylene plastic, polyamide plastic, oil furnace black, silica, and calcium fluoride. (AEC)

The interface effects arising in the measurement of absorbed dose by ionization chambers, owing to the inhomogeneity between the walls and the gas, have been evaluated by an analytical model. The geometrical situation considered here is appropriate for representing the behaviour of a plane-parallel ionization chamber exposed to a radiotherapeutic beam of protons. Two gases, ...

Secondary recovery in all its forms is gaining ground in Latin America. Until recently, Venezuela was about the only country with large-scale facilities to inject water, gas, and steam. As recently as 1965, Mexico's Poza Rico oil field had the only other major secondary recovery project in the area--a 150,000 bwpd flood. ...

Page 1. AD-A150 693 NAVAL POSTGRADUATE SCHOOL Monterey, California Reproduced From Best Available Copy TFHES!S ...

Low-pressure proportional counters (LPPCs) with walls made from the elements C, Mg, Al, Si, Fe and Zr and from the chemical compounds A-150 plastic, AlN, Al2O3, SiO2 and ZrO2 were used to measure neutron fluence-to-kerma conversion coefficients at energies up to 66 MeV. The LPPCs served to measure the absorbed dose deposited in the gas ...

Verification testing of the Siemens Barrier Sunlight V-40R-A150 UV System was completed at the UV Validation and Research Center of New York (UV Center), located in Johnstown, NY. The V-40R System supplied by Siemens utilizes 40 high-output, low-pressure amalgam lamps, oriented ...

A significant problem in measurement of microdosimetric spectra of low energy X rays has been the perturbing influence of the counters used in experiments. The conventional proportional counters used in microdosimetry have employed electrode structures of stainless steel. Since photoelectric cross-sections are highly sensitive to atomic number (approximately proportional to z/sup 4/), the ...

A significant problem in measurement of microdosimetric spectra of low energy X rays has been the perturbing influence of the counters used in experiments. The conventional proportional counters used in microdosimetry have employed electrode structures of stainless steel. Since photoelectric cross-sections are highly sensitive to atomic number (approximately proportional to z/sup 4/), the ...

Effective atomic numbers for photon energy absorption (Zpeaeff) and effective atomic numbers for photon interaction (Zpieff) of some low-Z substances of dosimetric interest such as A-150 tissue-equivalent plastic (A150TEP), alanine, bakelite, Gafchromic sensor (GS), plastic scintillator (PS), polyethylene, mylar, polystyrene, perspex, radiochromic dye film ...

Tissue equivalent proportional counters (TEPC) are used for medical and space activities whenever a combination of high and low LET (lineal energy transfer) radiations are present. With the frequency and duration of space activities increasing, exposure to fast heavy ions from galactic cosmic radiation and solar events is a major concern. The optimum detector geometry is spherical; to obtain an ...

Page 1. AD/A150 234 THE ACCESS CONTROL FACILITY 2 (ACF2) 1 P ... SIC> FINAL EVALUATION REPORT The Access Control Facility 2. * (ACF2) ...

A short review of theoretical and experimental studies of superdeformation and hyperdeformation is presented. Recent results, based on calculations carried out in a four dimensional deformation space, are presented. Very extended nuclear shapes ranging in mass from A=150 to A=200 are discussed.

the area to which state law regulating solid waste disposal facilities may be ... source data that are assumed to meet National Map Accuracy Standards. ...

The radiation quality of negative and positive pions of initial momentum 168 MeV/c has been determined at eight different depths in a liquid phantom. The measurements were made with a 2.5 cm diameter spherical proportional counter with Shonka A-150 neutro...

... Anode Current 172 I 1 mA 150 pA ... of the SMA bulkhead connectors mounted to package are connected to an individual array with a gold wire bond. ...

A significant problem in measurement of microdosimetric spectra of low energy X rays has been the perturbing influence of the counters used in experiments. In order to perform accurate measurement with /sup 125/I photons and other soft X rays having energies less than 100 keV, a special counter was constructed having no metal parts. The construction is of the grid-defined ...

The tissue-equivalent proportional counter (TEPC)-based dosemeters used on the International Space Station have exceeded their planned useful lives, and are scheduled to be replaced with the new units taking advantage of improved technology. The original TEPC detectors used cylindrical geometry with field tubes to achieve good energy resolution and minimum sensitivity to noise created by ...

The radiation quality of negative and positive pions of initial momentum 168 MeV/c has been determined at eight different depths in a liquid phantom. The measurements were made with a 2.5 cm diameter spherical proportional counter with Shonka A-150 neutron tissue equivalent plastic walls. The gas pressure in the sensitive ...

A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and ...

A computer simulation of the interactions of 50 MeV d/sup +/ on Be and 42 MeV p/sup +/ on Be neutron spectra with ICRU muscle tissue and Shonka A-150 tissue equivalent plastic was performed to allow computation of the charged particle spectra that result. Nuclear data were obtained from the Evaluated Nuclear Data File (ENDF) whenever possible and from the ...

A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and ...

A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and ...

within c;i~iiig 31 \\+h le a150 ac!jsig as a seal ta rroeat portions at ;he ozeo r ~ d s t!)creof. f ~ t the i2et end of auy cn5cat-d high-pressure iilpul ...

of equal length centered on solstice and equinox days under low (F10.7A 150, 1973]. The variation of NmF2 in autumn is intermediate between spring and summer, and the spring NmF2 is basically larger than the autumn one. Overall, the daytime NmF2 is highest in winter and lowest in summer

High-spin nuclear phenomena in the mass region around A-150 have been studied by in-beam gamma -ray and electron spectroscopy. Recent results for the nuclei (148)Gd, (149)Er, (152)Dy and (154)Dy are summarized. The first in-beam experiments at ATLAS using...

Large pore (a = 150-200 A) wormlike and highly oriented cubic (IM3m space group) and 2D-hexagonal (P6m) mesostructured xerogels have been reproducibly synthesised by Evaporation-Induced Self Assembly (EISA). Mesostructure control was attained by changing the template (nonionic block copolymer) and water (h = [H2O]/[Si]) ratio. PMID:12430410

Seeds of Pisum sativum were irradiated in dry condition to doses between 400 and 12,000 r (20 mA, 150 kv). From 1000 r and up the plastid apparatus of the young plants was disturbed and the leaves were not a normal green. A mosaic mottling ranging from green to white resulted. Other observations and conclusions were made. (T.R.H.)

The study examined the accuracy of a new saliva-alcohol test device (Enzymatics, Inc. 'Q.E.D. -A150') at nine different BACs under three temperature conditions. However, it did not assess the saliva collection procedures. the findings indicate that the de...

A laser direct write and doping (LDWD) system is designed and utilized for direct metallization and selective area doping in different SiC polytypes, GaN and in dielectrics including AlN. Laser direct metallization in 4H- and 6H-SiC generates metal-like conductive phases that are produced as both rectifying and ohmic contacts without metal deposition. Nd:YAG (lambda = 532, 1064 nm) nanosecond ...

In this study, a microwave re-entrant cavity discharge system and a direct current (DC) plasmatron are used to investigate flame enhancement and nitric oxide (NO) formation using laser and optical diagnostics. The uniqueness of this study lies in the direct coupling concept, a novel highly efficient strategy used here for the first time. To investigate combustion dynamics of direct microwave ...

Since the new ABET accreditation system was first introduced to American engineering education in the middle 1990s as Engineering Criteria 2000, most discussion in the literature has focused on how to assess Outcomes 3a–3k and relatively little has concerned how to equip students with the skills and attitudes specified in those outcomes. This ...

This paper reviews the most recent advances in the understanding of the physics of superdeformed nuclei from the point of view of the experimentalists. It covers among other subjects the following topics: (1) the discovery of a new region of superdeformed nuclei near A=190, (2) the surprising result of the occurrence of bands with identical transition energies in neighboring superdeformed nuclei ...

High-spin nuclear phenomena in the mass region around A-150 have been studied by in-beam ..gamma..-ray and electron spectroscopy. Recent results for the nuclei /sup 148/Gd, /sup 149/Er, /sup 152/Dy and /sup 154/ Dy are summarized. The first in-beam experiments at ATLAS using the Purdue superconducting electron spectrometer are also described. 11 refs., 2 ...

In the paper we demonstrate the application of the positron annihilation experimental technique based on the scan of the positron implantation profile for observation of the recrystallization process in the subsurface zone (SZ). The SZ was created in the copper sample whose surface was exposed to a sandblasting treatment and then annealed at different temperatures. Application of 68Ge/68Ga ...

The thermal defect, defined as the fraction of absorbed radiation energy which is not converted to heat energy in the calorimetric dosimetry absorber was investigated for A-150 tissue-equivalent plastic. Studies to measure the thermal defect as a function of proton energy and for various energies of alpha particles and the heavy recoil nuclei produced in tissue by neutrons are proposed along with ...

The abilities of Sepharose 2B (Pharmacia), Controlled Pore Glass (Electro-Nucleonics) and Bio-Gel A150m (Bio-Rad) to purify small unilamellar vesicles prepared by sonication and the ethanol-injection methods were compared. The Bio-Gel causes complete aggregation of the sonicated vesicles and partial aggregation of the ethanol-injection vesicles. Both ...

Isoscalar giant resonances of arbitrary multipolarity in deformed nuclei are studied with the help of the variational principle within the framework of the nuclear elastic vibration. Particular attention is given to the fragmentation of the giant monopole and quadrupole resonances. It is shown how the nuclear surface deformation contributes to the fragmentation through the coupling between the ...

The reactions (sup 84)Kr+(sup 197)Au and (sup 84)Kr+(sup nat)U were studied at an incident energy of E/A=150 MeV employing the large-volume neutron multiplicity meter ORION. The observed correlations between the atomic number of projectile-like nuclei (PL...