Method and means for helium/hydrogen ratio measurement by alpha scattering

An apparatus for determining helium to hydrogen ratios in a gaseous sample is presented. The sample is bombarded with alpha particles created by a self contained radioactive source and scattering products falling within a predetermined forward scattering angular range impact a detector assembly. Two detectors are mounted in tandem, the first completely blocking the second with respect to incident scattering products. Alpha particle/hydrogen or alpha particle/helium collisions are identified by whether scattering product impacts occur simultaneously in both detectors or only in the first detector. Relative magnitudes of the two pulses can be used to further discriminate against other effects such as noise and cosmic ray events

Testing for Hypothetical Bias in Contingent Valuation Using a Latent Choice Multinomial Logit Model

The most persistently troubling empirical result in the contingent valuation method literature is the tendency for hypothetical willingness to pay to overestimate real willingness to pay. We suggest a new approach to test and correct for hypothetical bias using a latent choice multinomial logit (LCMNL) model. To develop this model, we extend Dempster, Laird, and Rubin’s (1977) work on the EM algorithm to the estimation of a multinomial logit model with missing information on categorical membership. Using data on both the quality of water in the Catawba River in North Carolina and the preservation of Saginaw wetlands in Michigan, we find two types of “yes” responders in both data sets. We suggest that one set of yes responses are yea-sayers who suffer from hypothetical bias and answer yes to the hypothetical question but would not pay the bid amount if it were real. The second group does not suffer from hypothetical bias and would pay the bid amount if it were real.C25, P230, Q51

Silicon-on-ceramic process: Silicon sheet growth and device development for the large-area silicon sheet task of the low-cost solar array project

The technical feasibility of producing solar cell quality sheet silicon to meet the DOE 1986 cost goal of 70 cents/watt was investigated. The silicon on ceramic approach is to coat a low cost ceramic substrate with large grain polycrystalline silicon by unidirectional solidification of molten silicon. Results and accomplishments are summarized

Identification and interpretation of patterns in rocket engine data

A prototype software system was constructed to detect anomalous Space Shuttle Main Engine (SSME) behavior in the early stages of fault development significantly earlier than the indication provided by either redline detection mechanism or human expert analysis. The major task of the research project is to analyze ground test data, to identify patterns associated with the anomalous engine behavior, and to develop a pattern identification and detection system on the basis of this analysis. A prototype expert system which was developed on both PC and Symbolics 3670 lisp machine for detecting anomalies in turbopump vibration data was checked with data from ground tests 902-473, 902-501, 902-519, and 904-097 of the Space Shuttle Main Engine. The neural networks method was also applied to supplement the statistical method utilized in the prototype system to investigate the feasibility in detecting anomalies in turbopump vibration of SSME. In most cases the anomalies detected by the expert system agree with those reported by NASA. On the neural networks approach, the results are given the successful detection rate higher than 95 percent to identify either normal or abnormal running condition based on the experimental data as well as numerical simulation

A Qualitative Study on Cancer Care Burden: Experiences of Iranian Family Caregivers.

The aim of this study was to explore the experiences of Iranian family caregivers with regard to the burden of caregiving. This is in the context of illuminating and identifying the experiences of family members from different contextual perspectives. In this qualitative study, purposive sampling was conducted in 2016. Data were collected using semistructured interviews and were analyzed using content analysis. Data analysis identified 4 categories and 8 subcategories: (1) burnout (physical problems and psychoemotional stress), (2) role conflict (balancing caring roles and family responsibilities; failure in professional or educational roles), (3) health system tensions (inadequate support from health professionals; ignorance of family members in health structure), and (4) social challenges of cancer (economic burden; taboo of cancer). In conclusion, nurses need to provide individualized support and counseling that address the sources of burden. This highlights the benefit of training health care professionals to provide culturally sensitive support based on family caregivers' needs and circumstances

Gamow-Teller transitions and deformation in the proton-neutron random phase approximation

We investigate reliability of Gamow-Teller transition strengths computed in the proton-neutron random phase approximation, comparing with exact results from diagonalization in full $0\hbar\omega$ shell-model spaces. By allowing the Hartree-Fock state to be deformed, we obtain good results for a wide variety of nuclides, even though we do not project onto good angular momentum. We suggest that deformation is as important or more so than pairing for Gamow-Teller transitions.Comment: 8 pages, 5 figures; added references, clarified discussion with regards to stabilit

A Composite Chiral Pair of Rotational Bands in the odd-A Nucleus 135Nd

High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd reaction at a 30Si bombarding energy of 133 MeV. Two Delta(I)=1 bands with close excitation energies and the same parity were observed. These bands are directly linked by Delta(I)=1 and Delta(I)=2 transitions. The chiral nature of these two bands is confirmed by comparison with three-dimensional tilted axis cranking calculations. This is the first observation of a three-quasiparticle chiral structure and established the primarily geometric nature of this phenomenon.Comment: 10 pages, 5 figures (1 in color), 1 table, submitted to Physics Review Letters, written in REVTEX4 forma