Simulation and experimental verification of W-band finite frequency selective surfaces on infinite background with 3D full wave solver NSPWMLFMA

We present the design, processing and testing of a W-band finite by infinite and a finite by finite Grounded Frequency Selective Surfaces (FSSs) on infinite background. The 3D full wave solver Nondirective Stable Plane Wave Multilevel Fast Multipole Algorithm (NSPWMLFMA) is used to simulate the FSSs. As NSPWMLFMA solver improves the complexity matrix-vector product in an iterative solver from O(N(2)) to O(N log N) which enables the solver to simulate finite arrays with faster execution time and manageable memory requirements. The simulation results were verified by comparing them with the experimental results. The comparisons demonstrate the accuracy of the NSPWMLFMA solver. We fabricated the corresponding FSS arrays on quartz substrate with photolithographic etching techniques and characterized the vector S-parameters with a free space Millimeter Wave Vector Network Analyzer (MVNA)

Low energy measurement of the 7Be(p,gamma)8B cross section

We have measured the cross section of the 7Be(p,gamma)8B reaction for E_cm = 185.8 keV, 134.7 keV and 111.7 keV using a radioactive 7Be target (132 mCi). Single and coincidence spectra of beta^+ and alpha particles from 8B and 8Be^* decay, respectively, were measured using a large acceptance spectrometer. The zero energy S factor inferred from these data is 18.5 +/- 2.4 eV b and a weighted mean value of 18.8 +/- 1.7 eV b (theoretical uncertainty included) is deduced when combining this value with our previous results at higher energies.Comment: Accepted for publication in Phys. Rev. Let

Solar Fusion Cross Sections

We review and analyze the available information for nuclear fusion cross sections that are most important for solar energy generation and solar neutrino production. We provide best values for the low-energy cross-section factors and, wherever possible, estimates of the uncertainties. We also describe the most important experiments and calculations that are required in order to improve our knowledge of solar fusion rates.Comment: LaTeX file, 48 pages (figures not included). To appear in Rev. Mod. Phys., 10/98. All authors now listed. Full postscript version with figures available at http://www.sns.ias.edu/~jnb/Papers/Preprints/nuclearfusion.htm

Attending school after treatment for a brain tumor: Experiences of children and key figures

Reintegration into school is a milestone for childhood brain tumor survivors, as well as for their parents, teachers, and healthcare providers. We explored their experiences following the school re-entry by conducting semi-structured interviews. Thematic analysis resulted in four main themes: "school performance," "psychosocial well-being," "support and approach," and "communication and collaboration." Children were pleased to return to school despite confrontation with adverse outcomes. Parents, teachers, and healthcare providers identified current and future concerns and challenges, as well as opportunities for academic and personal development. Their experiences highlight the importance of coordinated and systematic follow-up in close collaboration with healthcare providers