The Pentagram, No. 1

Welcome to the verse of a bunch of guys who think writing should be part of every educated man\u27s experience. We are a group sanctioned by none, other than our own selves, sanctioned with our own belief that we have something to say. Spend a few minutes with us. Be you science student, English student, agriculture student, whatever your forte we believe there is interest for you in the following pages. Who are we? Students too. But students egotistical enough to want to have our ideas, any ideas, spread throughout a few minds other than our own. We have talked to ourselves and to each other. Now we want to talk to you. Glance through the following pages. If you see something of value, talk about it.https://scholarworks.sfasu.edu/pentagram/1000/thumbnail.jp

Tracer-based assessment of flow paths, storage and runoff generation in northern catchments : a review

Peer reviewedPostprin

Differential Energy-Loss Cross Sections for Ionization of Atomic Hydrogen by 25-200-keV Protons

Ionization continuum cross sections, differential in energy loss, have been determined from the energy-loss spectra of 25-, 50-, 75-, 145-, and 200-keV protons scattered from atomic hydrogen. The theoretical differential cross sections in the Glauber and Born approximations that are presented show that the theory and the experimental results for 200-keV proton impact agree very well, but below 200 keV there are differences. These differences, which are more pronounced at the lower projectile energies, may be explained in terms of charge transfer to the continuum, which is not treated in our Born and Glauber calculations of direct Coulomb ionization. The total ionization cross sections obtained by integrating the differential cross sections are in reasonable agreement with ionization cross-section measurements that have been obtained from crossed-beam experiments

The Pentagram, No. 1

Welcome to the verse of a bunch of guys who think writing should be part of every educated man\u27s experience. We are a group sanctioned by none, other than our own selves, sanctioned with our own belief that we have something to say. Spend a few minutes with us. Be you science student, English student, agriculture student, whatever your forte we believe there is interest for you in the following pages. Who are we? Students too. But students egotistical enough to want to have our ideas, any ideas, spread throughout a few minds other than our own. We have talked to ourselves and to each other. Now we want to talk to you. Glance through the following pages. If you see something of value, talk about it.https://scholarworks.sfasu.edu/pentagram/1000/thumbnail.jp

Reflections on the Cost of Low-Cost Whole Genome Sequencing: Framing the Health Policy Debate

The cost of whole genome sequencing is dropping rapidly. There has been a great deal of enthusiasm about the potential for this technological advance to transform clinical care. Given the interest and significant investment in genomics, this seems an ideal time to consider what the evidence tells us about potential benefits and harms, particularly in the context of health care policy. The scale and pace of adoption of this powerful new technology should be driven by clinical need, clinical evidence, and a commitment to put patients at the centre of health care policy

The Pentagram, No. 2

With the second issue, the editors with to thank all of those who have contributed to the Pentagram. Students and faculty interest has made this issue possible. Your interest and contributions will make future issues possible.https://scholarworks.sfasu.edu/pentagram/1001/thumbnail.jp

Mars Earth Return Vehicle (MERV) Propulsion Options

The COMPASS Team was tasked with the design of a Mars Sample Return Vehicle. The current Mars sample return mission is a joint National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) mission, with ESA contributing the launch vehicle for the Mars Sample Return Vehicle. The COMPASS Team ran a series of design trades for this Mars sample return vehicle. Four design options were investigated: Chemical Return /solar electric propulsion (SEP) stage outbound, all-SEP, all chemical and chemical with aerobraking. The all-SEP and Chemical with aerobraking were deemed the best choices for comparison. SEP can eliminate both the Earth flyby and the aerobraking maneuver (both considered high risk by the Mars Sample Return Project) required by the chemical propulsion option but also require long low thrust spiral times. However this is offset somewhat by the chemical/aerobrake missions use of an Earth flyby and aerobraking which also take many months. Cost and risk analyses are used to further differentiate the all-SEP and Chemical/Aerobrake options

Differential Cross Sections for Electron Capture from Helium by 25- to 100-keV Incident Protons

Experimentally and theoretically determined differential cross sections are reported for electron capture in collisions of protons with helium atoms for incident proton energies of 25, 30, 50, and 100 keV and for center-of-mass scattering angles of 0.0 to 2.0 mrad. The magnitudes of the experimentally determined differential cross sections decrease from 10-10 to 10-12 cm2/sr within the 0.0-0.8-mrad range of the center-of-mass scattering angle. At approximately 0.8 mrad a distinct change in the slope of the differential cross section is observed. The experimental results which are for capture into all bound states of hydrogen are compared with the theoretical results of a calculation for capture into the ground state using the two-state two-center atomic expansion method in the eikonal approximation. Good agreement between the theoretical and the experimental results is obtained with a static potential which accounts for screening of the helium nucleus by a single passive electron

Human Exploration Using Real-Time Robotic Operations (HERRO)- Crew Telerobotic Control Vehicle (CTCV) Design

The HERRO concept allows real time investigation of planets and small bodies by sending astronauts to orbit these targets and telerobotically explore them using robotic systems. Several targets have been put forward by past studies including Mars, Venus, and near Earth asteroids. A conceptual design study was funded by the NASA Innovation Fund to explore what the HERRO concept and it's vehicles would look like and what technological challenges need to be met. This design study chose Mars as the target destination. In this way the HERRO studies can define the endpoint design concepts for an all-up telerobotic exploration of the number one target of interest Mars. This endpoint design will serve to help planners define combined precursor telerobotics science missions and technology development flights. A suggested set of these technologies and demonstrator missions is shown in Appendix B. The HERRO concept includes a crewed telerobotics orbit vehicle as well three Truck rovers, each supporting two teleoperated geologist robots Rockhounds (each truck/Rockhounds set is landed using a commercially launched aeroshell landing system.) Options include a sample ascent system teamed with an orbital telerobotic sample rendezvous and return spacecraft (S/C) (yet to be designed). Each truck rover would be landed in a science location with the ability to traverse a 100 km diameter area, carrying the Rockhounds to 100 m diameter science areas for several week science activities. The truck is not only responsible for transporting the Rockhounds to science areas, but also for relaying telecontrol and high-res communications to/from the Rockhound and powering/heating the Rockhound during the non-science times (including night-time). The Rockhounds take the place of human geologists by providing an agile robotic platform with real-time telerobotics control to the Rockhound from the crew telerobotics orbiter. The designs of the Truck rovers and Rockhounds will be described in other publications. This document focuses on the CTCV design