Polarization enhancement in d⃗(p⃗\vec{d}(\vec{p},2^2He)n reaction: Nuclear teleportation

I show that an experimental technique used in nuclear physics may be successfully applied to quantum teleportation (QT) of spin states of massive matter. A new non-local physical effect the `quantum-teleportation-effect' is discovered for the nuclear polarization measurement. Enhancement of the neutron polarization is expected in the proposed experiment for QT that discriminates {\it only} one of the Bell states.Comment: 3 pages, accepted for publication in J. Phys.

Reionization by Hard Photons: I. X-rays from the First Star Clusters

Observations of the Ly-alpha forest at z~3 reveal an average metallicity Z~0.01 Z_solar. The high-redshift supernovae that polluted the IGM also accelerated relativistic electrons. Since the energy density of the CMB scales as (1+z)^4, at high redshift these electrons cool via inverse Compton scattering. Thus, the first star clusters emit X-rays. Unlike stellar UV ionizing photons, these X-rays can escape easily from their host galaxies. This has a number of important physical consequences: (i) Due to their large mean free path, these X-rays can quickly establish a universal ionizing background and partially reionize the universe in a gradual, homogeneous fashion. If X-rays formed the dominant ionizing background, the universe would have more closely resembled a single-phase medium, rather than a two-phase medium. (ii) X-rays can reheat the universe to higher temperatures than possible with UV radiation. (iii) X-rays counter the tendency of UV radiation to photo-dissociate H2, an important coolant in the early universe, by promoting gas phase H2 formation. The X-ray production efficiency is calibrated to local observations of starburst galaxies, which imply that ~10% of the supernova energy is converted to X-rays. While direct detection of sources in X-ray emission is difficult, the presence of relativistic electrons at high redshift and thus a minimal level of X-ray emission may be inferred by synchrotron emission observations with the Square Kilometer Array. These sources may constitute a significant fraction of the unresolved hard X-ray background, and can account for both the shape and amplitude of the gamma-ray background. This paper discusses the existence and observability of high-redshift X-ray sources, while a companion paper models the detailed reionization physics and chemistry.Comment: Final version accepted by ApJ. 32 pages, 3 figure

Patron-client relationship in cross-cultural church planting: a case study of Cambodia Bible College, 1998 - 2015

The primary research question of this study is: ‘How does the patron-client dynamic between Korean missionaries and Cambodian church planters offer an alternative understanding of aid dependency within the discourse of mission studies?’ While the patron-client relationship has been a popular concept in social anthropology studies, its value and effects have not been sufficiently explored within mission studies; specifically the issue of aid dependency particularly between Korean missionaries and Cambodian church planters has not been the subject of focused research. The key effects of patron-client dynamics are explored in this thesis through a case study methodology, examining the Cambodia Bible College (CBC) church-planting projects in Cambodia. Qualitative data was collected primarily through semi-structured interviews and participatory focused group discussions with the CBC founder and CBC church-planting pastors. The macro-function of Microsoft Word-processing was used as the primary data analysis. Once the interview transcriptions, both in English and Korean, were complete, by coding the key terms and key ideas emergent patterns of primary and series of sub-categories were observed. From initial research data, the aid dependency issue – both healthy and unhealthy – was identified as one of the major effects in patron-client dynamics. In the CBC church-planting process, the findings show that the patron takes on three unique diachronic and progressive roles: first, the patron as a father; second, the patron as a sponsor, and third, the patron as a partner. Similarly, a client also takes on three roles: first, the client as a child; second, the client as sponsoree (client), and third, the client as a partner. Although social studies currently express the patron-client dynamics primarily in material and political terms, in the case between the founder and the CBC pastors, intangible relational assets, i.e. ‘the patron as a father', were observed. This thesis argues that ‘the patron father’, plays a significant role in developing CBC pastors as church planters, helps them access the necessary resources to establish their churches at the initial stages, and offers an alternative reading of aid dependency as a relational concept rather than an economic one. Unfortunately, although unintended by both parties, the CBC pastors have become aid-dependent, which is hindering their churches from becoming self-sustaining and which makes an equal partnership in the future difficult, pointing to a conceptual relationship between aid dependency and the patron-client relationship. The future research on aid dependency in the church planting effort, and especially in the context of Gap & Eul, will prove that “partnering” their culturally diverse perspectives can contribute to mission studies for the next generation of transnational workers

Maneuvering strategies using CMGs

This paper considers control strategies for maneuvering spacecraft using Single-Gimbal Control Momentum Gyros (CMGs). A pyramid configuration using four gyros is utilized. Preferred initial gimbal angles for maximum utilization of CMG momentum are obtained for some known torque commands. Feedback control laws are derived from the stability point of view by using the Liapunov's Second Theorem. The gyro rates are obtained by the pseudo-inverse technique. The effect of gimbal rate bounds on controllability are studied for an example maneuver. Singularity avoidance is based on limiting the gyro rates depending on a singularity index