X-ray and EUV Observations of Simultaneous Short and Long Period Oscillations in Hot Coronal Arcade Loops

We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme ultraviolet (EUV) channels (131, 94, 1600, 304 \AA) observed by the Fermi GBM (Gamma-ray Burst Monitor) and SDO/AIA, respectively, during a C-class flare. The estimated period of oscillation and decay time in the X-ray channel (6-12 keV) was about 202 s and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 \AA channels. Simultaneously, AIA hot channels (94 and 131 \AA) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 s and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km/s for about 115 Mm loop length, which is roughly consistent with the sound speed at the temperature about 10-16 MK (480-608 km/s). These EUV oscillations are consistent with the SOHO/SUMER Doppler-shift oscillations interpreted as the global standing slow magnetoacoustic wave excited by a flare. The flare occurred at one of the footpoints of the arcade loops, where the magnetic topology was a 3D fan-spine with a null-point. Repetitive reconnection at this footpoint could cause the periodic acceleration of non-thermal electrons that propagated to the opposite footpoint along the arcade and precipitating there, causing the observed 202-s periodicity. Other possible interpretations, e.g. the second harmonics of the slow mode are also discussed.Comment: ApJ (in press), 13 pages, 6 figure

Solvable Potentials from Supersymmetric Quantum Mechanics

A recurrence relation of Riccati-type differential equations known in supersymmetric quantum mechanics is investigated to find exactly solvable potentials. Taking some simple {\it ans\"atze}, we find new classes of solvable potentials as well as reproducing the known shape-invariant ones.Comment: 14 pages, Late

The rhetorical approach to 1 Thessalonians in light of funeral oration

The present dissertation is a study of the rhetorical approach to 1 Thessalonians, particularly funeral oration. Though many scholars have interpreted 1 Thessalonians in light of thematic perspective, mirror reading, and epistolary approach, this dissertation asserts that Paul employs elements of epideictic funerary oratory to persuade his audience in writing 1 Thessalonians. Moreover, the dissertation shows that Paul’s use of funerary language with some twists in meaning and purpose illustrates that Paul employs topoi and the purpose of funeral oration in 1 Thessalonians. Encountering the growing persecution, sufferings, and even death of members, the believers of Thessalonica needed encouragement and Paul as a rhetorical strategist needed rhetorical strategies to answer these problems, that is, Greco-Roman funeral oration. The dissertation includes various components to support the thesis: the history of interpretation; the philosophy and theology of death; extant funeral oratory in Athens, Romans, and Jewish orations; funeral orations in rhetorical handbooks; and the comparison and parallel between 1 Thessalonians and funeral oration. The goal is to prove the fact that Paul employs elements of funeral oratory to persuade his audience in writing 1 Thessalonians. Consequently, the dissertation proves it by showing how funeral orations shed light on the whole of 1 Thessalonians in the exordium (1:2-3), the narratio (1:4-3:10), the consolation and exhortation (4:1-5:15), and peroratio with prayer (5:16-28).https://place.asburyseminary.edu/ecommonsatsdissertations/1558/thumbnail.jp

The impacts of Delphi communication structure on small and medium sized asynchronous virtual teams

The improvement of Internet technology has motivated distributed work groups to collaborate without meeting face to face. Although asynchronous meetings through Web-based group communications systems enable groups dispersed temporarily and geographically to collaborate more flexibly, parallel and non-linear communication among dispersed members also challenge effective and efficient group coordination. Moreover, the Web-based asynchronous meeting is distinguished not only from the face-to-face meeting but also from the synchronous computer-supported meeting in terms of coordination process. However, previous asynchronous group communications or virtual team research focused more on the comparison of this new type of meeting with the face-to-face meeting. Not many research efforts have been exerted to improve the productivity of this new form of meeting and find ways to overcome its disadvantages. Facilitation was proved effective to enhance the productivity of synchronous meetings. However the effect of structured discussion through facilitation was not clear in asynchronous meeting settings even though facilitation is a common practice in asynchronous group communication systems. This study examined the effect of a facilitated structure in improving the productivity of asynchronous decision-making groups. Delphi was chosen as the facilitated structure because it has been widely used as the paper-and-pencil-based structure to facilitate dispersed experts in collecting their opinions. In this study a computer-based Delphi structure was implemented through asynchronous Computer-Mediated Communication. A 2X2 controlled experiment was conducted to investigate the effect of Delphi structure on the effectiveness of small-sized (5-6 members) and medium-sized (10-12 members) asynchronous computer-supported groups. The formal facilitation using Delphi structure was effective to improve the productivity of asynchronous groups in generating more ideas. On the contrary, informal leadership by group coordinators seems to have played a more important role in producing better reports. In terms of per person ideas, small-sized groups were more productive, even though medium-sized groups produced more total ideas than small-sized groups. The superiority of Delphi groups and small-sized groups is related to their higher equality of participation. This result suggests that in asynchronous meetings, equal participation of group members in discussion is important in improving idea generation productivity while in synchronous meetings, the process loss of production blocking plays a crucial role