Study of the dependence of 198Au half-life on source geometry

We report the results of an experiment to determine whether the half-life of \Au{198} depends on the shape of the source. This study was motivated by recent suggestions that nuclear decay rates may be affected by solar activity, perhaps arising from solar neutrinos. If this were the case then the $\beta$-decay rates, or half-lives, of a thin foil sample and a spherical sample of gold of the same mass and activity could be different. We find for \Au{198}, $(T_{1/2})_{\rm foil}/(T_{1/2})_{\rm sphere} = 0.999 \pm 0.002$, where $T_{1/2}$ is the mean half-life. The maximum neutrino flux at the sample in our experiments was several times greater than the flux of solar neutrinos at the surface of the Earth. We show that this increase in flux leads to a significant improvement in the limits that can be inferred on a possible solar contribution to nuclear decays.Comment: 5 pages, 1 figur

Discrete ordinates-Monte Carlo coupling: A comparison of techniques in NERVA radiation analysis

In the radiation analysis of the NERVA nuclear rocket system, two-dimensional discrete ordinates calculations are sufficient to provide detail in the pressure vessel and reactor assembly. Other parts of the system, however, require three-dimensional Monte Carlo analyses. To use these two methods in a single analysis, a means of coupling was developed whereby the results of a discrete ordinates calculation can be used to produce source data for a Monte Carlo calculation. Several techniques for producing source detail were investigated. Results of calculations on the NERVA system are compared and limitations and advantages of the coupling techniques discussed

Validity of the Reynolds Adolescent Depression Scale with a Rural Sample

The problem that was investigated in the current study was that the norms of the Reynolds Adolescent Depression Scale (RADS) (Reynolds, 1987) may have had limited generalizability to students attending Paris High School and Mayo Middle School in rural Paris, Illinois because it was normed on normal subjects in only one urban/suburban school district in Wisconsin. The purposes of the current study were to establish Paris norms for the RADS and to fulfill Paris\u27 need for an instrument to efficiently and inexpensively assess students suspected of having depression. This investigator hypothesized that the norms on the RADS would differ between Paris and the standardization sample and that female students would, as a whole, score higher than males. Results indicated that as a whole, female students scored 5.72 points higher than male students, although not significantly higher. It appears that the Paris and the standardization norm tables for the entire samples, that is not divided by gender, grade, or age, appear roughly equivalent. It is concluded that the Paris sample does not accurately represent the population of Paris adolescents and that the applicability of both the total standardization and Paris norm tables is unknown for students who were not in the sample. Due to the fact that standard scores based on Paris raw data and Paris descriptive statistics differ significantly from standard scores based on Paris raw data and standardization descriptive statistics, more research is needed to determine whether either norm table is applicable for Paris as a whole. Suggestions for future research and limitations of the current study are discussed

Validity of the Reynolds Adolescent Depression Scale with a Rural Sample

The problem that was investigated in the current study was that the norms of the Reynolds Adolescent Depression Scale (RADS) (Reynolds, 1987) may have had limited generalizability to students attending Paris High School and Mayo Middle School in rural Paris, Illinois because it was normed on normal subjects in only one urban/suburban school district in Wisconsin. The purposes of the current study were to establish Paris norms for the RADS and to fulfill Paris\u27 need for an instrument to efficiently and inexpensively assess students suspected of having depression. This investigator hypothesized that the norms on the RADS would differ between Paris and the standardization sample and that female students would, as a whole, score higher than males. Results indicated that as a whole, female students scored 5.72 points higher than male students, although not significantly higher. It appears that the Paris and the standardization norm tables for the entire samples, that is not divided by gender, grade, or age, appear roughly equivalent. It is concluded that the Paris sample does not accurately represent the population of Paris adolescents and that the applicability of both the total standardization and Paris norm tables is unknown for students who were not in the sample. Due to the fact that standard scores based on Paris raw data and Paris descriptive statistics differ significantly from standard scores based on Paris raw data and standardization descriptive statistics, more research is needed to determine whether either norm table is applicable for Paris as a whole. Suggestions for future research and limitations of the current study are discussed

Electrolysis of simulated lunar melts

Electrolysis of molten lunar soil or rock is examined as an attractive means of wresting useful raw materials from lunar rocks. It requires only hat to melt the soil or rock and electricity to electrolyze it, and both can be developed from solar power. The conductivities of the simple silicate diopside, Mg CaSi2O6 were measured. Iron oxide was added to determine the effect on conductivity. The iron brought about substantial electronic conduction. The conductivities of simulated lunar lavas were measured. The simulated basalt had an AC conductivity nearly a fctor of two higher than that of diopside, reflecting the basalt's slightly higher total concentration of the 2+ ions Ca, Mg, and Fe that are the dominant charge carriers. Electrolysis was shown to be about 30% efficient for the basalt composition

Cyclicality and the relationship between neuroticism, communication, and relationship satisfaction in cohabiting couples

Master of ScienceDepartment of Family Studies and Human ServicesJared R. AndersonAmber V. VennumThe present study sought to extend the research on cyclical, or on-again/off-again relationships, by examining whether a history of cyclicality moderated the association between neuroticism and relationship satisfaction. A second goal of this study was to examine the direct and indirect effects of neuroticism on relationship satisfaction through communication. The sample consisted of cohabiting cyclical (n = 1,055) and noncyclical (n = 2,527) couples from a larger dataset collected by the RELATE Institute. Results showed that cyclical partners reported higher levels of neuroticism, higher levels of conflict, lower levels of positive communication, and lower levels of relationship satisfaction than noncyclical couples. Direct actor paths from neuroticism to satisfaction were significant for cyclical and noncyclical females and males. Only the direct partner path from female neuroticism to male satisfaction was significant, and was only significant for cyclical couples. All indirect actor and partner paths were significant for cyclical and noncyclical females and males. Further, a history of cyclicality significantly moderated the direct paths from male communication to male and female relationship satisfaction, indicating this relationship is stronger for cyclical couples

Magnetic field tuning of coplanar waveguide resonators

We describe measurements on microwave coplanar resonators designed for quantum bit experiments. Resonators have been patterned onto sapphire and silicon substrates, and quality factors in excess of a million have been observed. The resonant frequency shows a high sensitivity to magnetic field applied perpendicular to the plane of the film, with a quadratic dependence for the fundamental, second and third harmonics. Frequency shift of hundreds of linewidths can be obtained.Comment: Accepted for publication in AP

On the properties of superconducting planar resonators at mK temperatures

Planar superconducting resonators are now being increasingly used at mK temperatures in a number of novel applications. They are also interesting devices in their own right since they allow us to probe the properties of both the superconductor and its environment. We have experimentally investigated three types of niobium resonators - including a lumped element design - fabricated on sapphire and SiO_2/Si substrates. They all exhibit a non-trivial temperature dependence of their centre frequency and quality factor. Our results shed new light on the interaction between the electromagnetic waves in the resonator and two-level fluctuators in the substrate.Comment: V2 includes some minor corrections/changes. Submitted to PR

Recent trends in the timing of first sex and marriage among young women in Ethiopia

Ethiopia has been characterized by  high  population  growth.  Recent social  and  economic developments have the potential to alter reproductive patterns in the country. Some of these developments include sustained economic growth, urbanization, rapid growth in school enrollments, expansion of primary health care, and a rise in contraceptive access and use. In other national contexts, these developments have been associated with a gradual decoupling of the transition into sexual activity and marriage among young women. We investigate recent trends in the transition into first sex and marriage among three cohorts of Ethiopian women. Methods: Using data from the 2000, 2005, and 2011 Ethiopia Demographic and Health Surveys (DHS) we estimate survival curves and discrete-time hazards models to examine recent trends in age at first sex and first marriage among women ages 20-29. Results: Across the three survey years the median age at first sex has remained relatively stable at 17 years, although the median age at marriage has increased from 17 to 18 years between the 2005 and 2011 surveys. Net of the effects of education and place of residence, there is evidence of a slight trend away from premarital first sex to sexual initiation in the context of marriage. However, among the most educated women and women living in urban areas (who are a small minority of women), there is a much greater tendency to initiate sexual activity outside of marriage compared to women with little schooling and women living in rural areas, and once they have begun sexual activity they tend to wait longer before they get married. We also find evidence in the most recent survey that women who have first sexual intercourse before marriage are delaying marriage more than was the case among earlier cohorts