Effects of bottom-structure flexibility on water landing loads of Apollo spacecraft models

Effect of heat shield flexibility on water landing loads of Apollo spacecraft model

Exchange coupling between two ferromagnetic electrodes separated by a graphene nanoribbon

In this study, based on the self-energy method and the total energy calculation, the indirect exchange coupling between two semi-infinite ferromagnetic strips (FM electrodes) separated by metallic graphene nanoribbons (GNRs) is investigated. In order to form a FM/GNR/FM junction, a graphitic region of finite length is coupled to the FM electrodes along graphitic zigzag or armchair interfaces of width $N$. The numerical results show that, the exchange coupling strength which can be obtained from the difference between the total energies of electrons in the ferromagnetic and antiferromagnetic couplings, has an oscillatory behavior, and depends on the Fermi energy and the length of the central region.Comment: 4 pages, 6 figures, International Conference on Theoretical Physics 'Dubna-Nano2008

Bowser's Mathematical Text-Books

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Magnetic Flux Transport at the Solar Surface

After emerging to the solar surface, the Sun's magnetic field displays a complex and intricate evolution. The evolution of the surface field is important for several reasons. One is that the surface field, and its dynamics, sets the boundary condition for the coronal and heliospheric magnetic fields. Another is that the surface evolution gives us insight into the dynamo process. In particular, it plays an essential role in the Babcock-Leighton model of the solar dynamo. Describing this evolution is the aim of the surface flux transport model. The model starts from the emergence of magnetic bipoles. Thereafter, the model is based on the induction equation and the fact that after emergence the magnetic field is observed to evolve as if it were purely radial. The induction equation then describes how the surface flows -- differential rotation, meridional circulation, granular, supergranular flows, and active region inflows -- determine the evolution of the field (now taken to be purely radial). In this paper, we review the modeling of the various processes that determine the evolution of the surface field. We restrict our attention to their role in the surface flux transport model. We also discuss the success of the model and some of the results that have been obtained using this model.Comment: 39 pages, 15 figures, accepted for publication in Space Sci. Re

Is there a Subjective Element in the Refugee Convention\u27s Requirement of \u27Well-Founded Fear\u27?

Linguistic ambiguity in the refugee definition\u27s requirement of well-founded fear of being persecuted has given rise to a wide range of interpretations. There is general agreement that a fear is well-founded only if the refugee claimant faces an actual, forward-looking risk of being persecuted in her country of origin (the objective element ). But it is less clear whether the well-founded fear standard also requires a showing that the applicant is not only genuinely at risk, but also stands in trepidation of being persecuted. Beyond vague references to the subjective quality of fear, few courts or commentators have undertaken the task of explaining what justifies recognition of a subjective element in the first place. What, in the end, does subjective fear or trepidation have to do with the goals of refugee law? Reasoned explanations are in short supply. This shortfall in critical thinking has greatly complicated efforts to formulate a coherent understanding of the subjective element, and clearly to articulate its role in the analysis of well-founded fear

Is there a Subjective Element in the Refugee Convention\u27s Requirement of \u27Well-Founded Fear\u27?

Linguistic ambiguity in the refugee definition\u27s requirement of well-founded fear of being persecuted has given rise to a wide range of interpretations. There is general agreement that a fear is well-founded only if the refugee claimant faces an actual, forward-looking risk of being persecuted in her country of origin (the objective element ). But it is less clear whether the well-founded fear standard also requires a showing that the applicant is not only genuinely at risk, but also stands in trepidation of being persecuted. Beyond vague references to the subjective quality of fear, few courts or commentators have undertaken the task of explaining what justifies recognition of a subjective element in the first place. What, in the end, does subjective fear or trepidation have to do with the goals of refugee law? Reasoned explanations are in short supply. This shortfall in critical thinking has greatly complicated efforts to formulate a coherent understanding of the subjective element, and clearly to articulate its role in the analysis of well-founded fear

The Economic Contribution of Snowmobiling in Maine

Snowmobiling has been a popular winter pastime in Maine for decades. During the 2018-2019 snowmobiling season, nearly 60,000 snowmobiles were registered in Maine by resident snowmobilers, and over 25,000 snowmobiles were registered by non-residents. Since the 1998 report An Economic Evaluation of Snowmobiling in Maine, overall registrations have increased, and registrations among non-residents have more than doubled. There has been no comprehensive evaluation of snowmobiling in Maine since the 1998 report completed by the University of Maine in collaboration with the Maine Snowmobile Association and State of Maine Snowmobile Program. In order to update the information on snowmobiling related expenditures, the sociodemographic characteristics of snowmobilers in Maine, and the opinions of Maine snowmobilers on snowmobiling tourism infrastructure and issues related to snowmobiling in Maine today, a new study was commissioned by the State of Maine Snowmobile Program and the Maine Department of Agriculture, Conservation and Forestry through the University of Maine’s School of Forest Resources. The results are contained in this report. The results conclude that snowmobiling generated $459 million in direct spending across many sectors during the 2018-2019 season. Accounting for indirect and induced economic activity, the contribution of snowmobiling to Maine’s economy was over$606 million. Snowmobiling generates a significant amount of spending during the winter in Maine, especially in the rural areas which benefit from snowmobiling activity. Snowmobile related spending also directly supports 2,279 jobs in the state of Maine and indirect and induced effects of the spending support an additional 1,060 jobs. Trip-related spending accounts for approximately $209.5 million or about 46$132 million in direct spendin

Measurement of Synchrotron x-ray energies and line shapes using diffraction markers

Standard reference markers for accurate, reproducible synchrotron x-ray energies are obtained using a three Si crystal spectrometer. The first two crystals are in the monochromator and the third is used to obtain diffraction markers which monitor the energy. Then for any value of the glancing angle on the reference Si crystal the energy for the (333) diffraction must occur at 3/4 that of the (444) and 3/5 of that for the (555). This establishes for the first time an absolute synchrotron energy scale. Higher-order diffractions are used to determine excitation line profiles. We conclude that the use of reference diffractions is necessary to measure reproducible x-ray energies and to analyze the incident photons\u27 line profile. The detection of diffractions near the edge of measurement and near the Cu edge will provide a fast secondary standard which will allow comparison of edge data between different laboratories. The diffraction profiles will allow the proper analysis of spectral line widths

Solar Polar Fields During Cycles 21 --- 23: Correlation with Meridional Flows

We have examined polar magnetic fields for the last three solar cycles, {$\it{viz.}$}, cycles 21, 22 and 23 using NSO Kitt Peak synoptic magnetograms. In addition, we have used SoHO/MDI magnetograms to derive the polar fields during cycle 23. Both Kitt Peak and MDI data at high latitudes (78${^{\circ}}$--90${^{\circ}}$) in both solar hemispheres show a significant drop in the absolute value of polar fields from the late declining phase of the solar cycle 22 to the maximum of the solar cycle 23. We find that long term changes in the absolute value of the polar field, in cycle 23, is well correlated with changes in meridional flow speeds that have been reported recently. We discuss the implication of this in influencing the extremely prolonged minimum experienced at the start of the current cycle 24 and in forecasting the behaviour of future solar cycles.Comment: 4 Figures 11 pages; Revised version under review in Solar Physic