Rca's Planned Test Program to Compare the Performance and Life of Nicd Cells Containing Pellon 2536 in Contrast with Pellon 2505 Separator Material

RCA Astro-Electronics will be characterizing and life-testing two groups of hermetically-sealed aerospace nickel-cadmium cells to determine the effect, if any, of a separator change on cell performance. This test, designed to provide information for a specific low-Earth-orbit satellite application, will also add to the overall data-base for cells with the new separator

RCA SATCOM Battery in Orbit Performance Update and Accelerated Life Test Results

No significant degradation of nickel cadmium battery performance in SATCOM F1 and F2 after almost 8 and 7-3/4 years in orbit was shown. Battery minimum discharge voltage data are presented for these spacecraft. In addition, 2 groups of nickel cadmium cells which are representative of those in orbit are undergoing real time eclipse-reduced suntime cycling in the laboratory. These groups of cells, which are being cycled at a maximum of 53% and 62% depth of discharge (based on actual capacity), have completed 14 and 15 eclipse seasons, respectively. Data for these groups of cells are presented and are compared with the in-orbit battery data

Quenching of Cross Sections in Nucleon Transfer Reactions

Cross sections for proton knockout observed in (e,e'p) reactions are apparently quenched by a factor of ~0.5, an effect attributed to short-range correlations between nucleons. Here we demonstrate that such quenching is not restricted to proton knockout, but a more general phenomenon associated with any nucleon transfer. Measurements of absolute cross sections on a number of targets between 16O and 208Pb were analyzed in a consistent way, with the cross sections reduced to spectroscopic factors through the distorted-wave Born approximation with global optical potentials. Across the 124 cases analyzed here, induced by various proton- and neutron-transfer reactions and with angular momentum transfer l=0-7, the results are consistent with a quenching factor of 0.55. This is an apparently uniform quenching of single-particle motion in the nuclear medium. The effect is seen not only in (d,p) reactions but also in reactions with A=3 and 4 projectiles, when realistic wave functions are used for the projectiles.Comment: 5 pages, 3 figures, accepted to Physical Review Letter

Quantum and thermal spin relaxation in diluted spin ice: Dy(2-x)MxTi2O7 (M = Lu, Y)

We have studied the low temperature a.c. magnetic susceptibility of the diluted spin ice compound Dy(2-x)MxTi2O7, where the magnetic Dy ions on the frustrated pyrochlore lattice have been replaced with non-magnetic ions, M = Y or Lu. We examine a broad range of dilutions, 0 <= x <= 1.98, and we find that the T ~ 16 K freezing is suppressed for low levels of dilution but re-emerges for x > 0.4 and persists to x = 1.98. This behavior can be understood as a non-monotonic dependence of the quantum spin relaxation time with dilution. The results suggest that the observed spin freezing is fundamentally a single spin process which is affected by the local environment, rather than the development of spin-spin correlations as earlier data suggested.Comment: 26 pages, 9 figure

Bound states due to an accelerated mirror

We discuss an effect of accelerated mirrors which remained hitherto unnoticed, the formation of a field condensate near its surface for massive fields. From the view point of an observer attached to the mirror, this is effect is rather natural because a gravitational field is felt there. The novelty here is that since the effect is not observer dependent even inertial observers will detect the formation of this condensate. We further show that this localization is in agreement with Bekenstein's entropy bound.Comment: Final version to appear in PR

Lived Legal Expertise: Mobilizing the Political Agency of Incarcerated Youth

This thesis analyzes how caring relationships and an emancipatory approach to law related education (LRE) within juvenile justice facilities can cultivate political agency. I focused specifically on Camp Afflerbaugh-Paige, an LA County juvenile probation facility, in La Verne, CA, as a case study. During three months of teaching a law related education class and embedding myself at the facility with an asset-based framework, I encountered a wealth of knowledge that incarcerated juveniles possess, not from formal education or research, but based in their own lived experiences. Los Angeles County Probation spends $233,000 per student per year; assuming best intentions of those in charge and the actors, the students, with a wide array of expertise, should be thriving within these institutions and set up for success upon their release. Unfortunately, though, students’ academic, entrepreneurial, and legal expertise are criminalized rather than cultivated by the juvenile justice system. Through a policy class, the students created reforms to address the challenges of a paramilitary camp that neglects students’ emotional, physical, and mental health. The challenges in the environment complicate the political agency of students within the camp and post-release. I am making the claim that the political agency of the students is visible and the assets are tangibly cultivated by an emancipatory pedagogy, ethic of care, and the law related education curriculum

The Implications of Domestic Party Ideologies on Refugee Policy: A Case Study of Bangladesh and the Rohingya

Why do some political parties in Bangladesh discriminate against the Rohingya, while some do not? Much has been written about the conflict in Myanmar, but the plight of Rohingya in Bangladesh remains understudied. This lack of understanding is underscored by the five million Syrian refugees fleeing their own civil war that dominates the news and the attention of scholars. The Rohingya, however, are stateless: they are denied citizenship in their native Myanmar and are forced to find refuge in whichever country will take them. Much has been published that links immigration policy to security considerations and the national identity and ethnic homogeneity of the host country. I argue that it is the domestic politics of Bangladesh that directly influences the policies concerning, and subsequent treatment of, the Rohingya migrants. This leads back to the question I pose: why is it that some political parties in Bangladesh actively support the ethnic group while others actively discriminate against the Rohingya? I argue that it is the individual ideologies of that party that can be directly attributed to their stance on Rohingya. Using qualitative analysis, I measure how a party\u27s foreign policy, social policy, and political ideology affects that organization\u27s attitude toward Rohingya refugees. Understanding the largely political nature of refugee policy will allow policy-makers, intergovernmental organizations, and human rights groups to be better equipped to improve the conditions of, not only the Rohingya population, but other vulnerable refugee groups that seek safety in foreign states

Geometrical Magnetic Frustration in Rare Earth Chalcogenide Spinels

We have characterized the magnetic and structural properties of the CdLn2Se4 (Ln = Dy, Ho), and CdLn2S4 (Ln = Ho, Er, Tm, Yb) spinels. We observe all compounds to be normal spinels, possessing a geometrically frustrated sublattice of lanthanide atoms with no observable structural disorder. Fits to the high temperature magnetic susceptibilities indicate these materials to have effective antiferromagnetic interactions, with Curie-Weiss temperatures theta ~ -10 K, except CdYb2S4 for which theta ~ -40 K. The absence of magnetic long range order or glassiness above T = 1.8 K strongly suggests that these materials are a new venue in which to study the effects of strong geometrical frustration, potentially as rich in new physical phenomena as that of the pyrochlore oxides.Comment: 17 pages, 5 figures, submitted to Phys Rev B; added acknowledgement

Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice

We report a study of the low temperature bulk magnetic properties of the spin ice compound Dy2Ti2O7 with particular attention to the (T < 4 K) spin freezing transition. While this transition is superficially similar to that in a spin glass, there are important qualitative differences from spin glass behavior: the freezing temperature increases slightly with applied magnetic field, and the distribution of spin relaxation times remains extremely narrow down to the lowest temperatures. Furthermore, the characteristic spin relaxation time increases faster than exponentially down to the lowest temperatures studied. These results indicate that spin-freezing in spin ice materials represents a novel form of magnetic glassiness associated with the unusual nature of geometrical frustration in these materials.Comment: 24 pages, 8 figure