BikeShare Business Model For Cal Poly- San Luis Obispo

With the increasing admittance of students into colleges and universities across the nation, the need for alternate modes of transportation is becoming more pressing. College and university campuses, as well as small cities, in which there is a college or university, are being overloaded with student cars. In San Luis Obispo specifically, parking on campus as well as downtown can be extremely difficult to find. Traffic is also getting progressively worse, especially at the hour when class begins/ends and student arrive to or leave campus. Financial reasons are yet another deterrent for students at Cal Poly. Parking permits, gas, and costs associated with owning a car make it even more difficult for students to be able to afford driving. City busses have attempted to resolve this issue, but with their set schedules, routes, and capacity, they only provide a band-aid solution. BikeShare seeks to solve this problem by offering students an affordable means of transportation, which they will have access to at all times. San Luis Obispo is the town to start this new sustainable movement in, and when proven successful, others will follow in its wake. SLO is constantly seeking to make the town a better place to live as seen through its implementation of a no plastic bag policy in grocery stores, elimination of drive-thrus, limiting outdoor smoking, and hosting a weekly farmers market. These are just a few of the successful policies and events that have been brought to SLO and have become part of its culture. As not only an innovative green idea, but also a practical means of transportation, the implementation of a BikeShare system in SLO will further this image that it is creating for itself. BikeSharing will give students and residents of SLO an alternate mode of transportation in the sharing of these communal bikes. After implementation and expansion of this program, financial success is expected as well. Through the acquisition of membership fees, payment from advertisements, government grants, and donations, BikeShare is believed to be a self-sustaining, if not profitable business. After developing and analyzing various BikeShare models, the model in which the remote bike locking system which uses existing bike racks around San Luis Obispo to lock the bike up at was decided upon. This was due to its low start up cost paired with the relative security of the bikes and preferences over other models by both users as well as from the business’ point of view

Rapid assembly of highly-functionalised difluorinated cyclooctenones via ring-closing metathesis

Building block methodology from trifluoroethanol and ringclosing metathesis using a Fürstner modification of Grubbs’ conditions allows the rapid synthesis of novel difluorinated cyclooctenones

Simulations ofthe 100kW TJNAF FEL using a step-tapered undulator

The Thomas Jefferson National Accelerator Facility (TJNAF) free electron laser (FEL) can be upgraded to operate at 100kW average power in the near future using a configuration that recirculates the electron beam to recover energy. It is important to extract the maximum energy from the electron beam in a pass through the undulator while inducing the minimum amount of exhaust energy spread. A larger energy extraction reduces the requirement for a large recirculating current, while a smaller exhaust energy spread allows the intense electron beam to be recirculated without damaging components. To improve FEL performance, we explore the use of the step-tapered undulator, which alters the resonance condition halfway through the undulator. Short pulses complicate the desired interaction. Comparisons are made to the conventional periodic and linearly-tapered undulators.The authors are grateful for the support of the Office of Naval Research, Thomas Jefferson National Accelerator Facility, and contributions of Dave Douglas of TJNAF

Simulations of the TJNAF FEL with tapered and inversely tapered undulators

Experiments using the TJNAF FEL have explored the operation with both tapered and inversely tapered undulators. We present here numerical simulations using the TJNAF experimental parameters, including the effects of taper. Singlemode simulations show the effect of taper on gain. Multimode simulations describe the evolution of short optical pulses in the far infrared, and show how taper affects single-pass gain and steady-state power as a function of desynchronism. A short optical pulse presents an ever-changing field strength to each section of the electron pulse so that idealized operation is not possible. Yet, advantages for the recirculation of the electron beam can be explored.The authors are grateful for support by the Naval Postgraduate School

Highly stable fullerene-based porous molecular crystals with open metal sites

The synthesis of conventional porous crystals involves building a framework using reversible chemical bond formation, which can result in hydrolytic instability. In contrast, porous molecular crystals assemble using only weak intermolecular interactions, which generally do not provide the same environmental stability. Here, we report that the simple co-crystallization of a phthalocyanine derivative and a fullerene (C60 or C70) forms porous molecular crystals with environmental stability towards high temperature and hot aqueous base or acid. Moreover, by using diamond anvil cells and synchrotron single-crystal measurements, stability towards extreme pressure (>4 GPa) is demonstrated, with the stabilizing fullerene held between two phthalocyanines and the hold tightening at high pressure. Access to open metal centres within the porous molecular co-crystal is demonstrated by in situ crystallographic analysis of the chemisorption of pyridine, oxygen and carbon monoxide. This suggests strategies for the formation of highly stable and potentially functional porous materials using only weak van der Waals intermolecular interactions

To the skin and beyond: the immune response to African trypanosomes as they enter and exit the vertebrate host

African trypanosomes are single-celled extracellular protozoan parasites transmitted by tsetse fly vectors across sub-Saharan Africa, causing serious disease in both humans and animals. Mammalian infections begin when the tsetse fly penetrates the skin in order to take a blood meal, depositing trypanosomes into the dermal layer. Similarly, onward transmission occurs when differentiated and insect pre-adapted forms are ingested by the fly during a blood meal. Between these transmission steps, trypanosomes access the systemic circulation of the vertebrate host via the skin-draining lymph nodes, disseminating into multiple tissues and organs, and establishing chronic, and long-lasting infections. However, most studies of the immunobiology of African trypanosomes have been conducted under experimental conditions that bypass the skin as a route for systemic dissemination (typically via intraperitoneal or intravenous routes). Therefore, the importance of these initial interactions between trypanosomes and the skin at the site of initial infection, and the implications for these processes in infection establishment, have largely been overlooked. Recent studies have also demonstrated active and complex interactions between the mammalian host and trypanosomes in the skin during initial infection and revealed the skin as an overlooked anatomical reservoir for transmission. This highlights the importance of this organ when investigating the biology of trypanosome infections and the associated immune responses at the initial site of infection. Here, we review the mechanisms involved in establishing African trypanosome infections and potential of the skin as a reservoir, the role of innate immune cells in the skin during initial infection, and the subsequent immune interactions as the parasites migrate from the skin. We suggest that a thorough identification of the mechanisms involved in establishing African trypanosome infections in the skin and their progression through the host is essential for the development of novel approaches to interrupt disease transmission and control these important diseases

Exposure to dietary mercury alters cognition and behavior of zebra finches

Environmental stressors can negatively affect avian cognitive abilities, potentially reducing fitness, for example by altering response to predators, display to mates, or memory of locations of food. We expand on current knowledge by investigating the effects of dietary mercury, a ubiquitous environmental pollutant and known neurotoxin, on avian cognition. Zebra finches Taeniopygia guttata were dosed for their entire lives with sub-lethal levels of mercury, at the environmentally relevant dose of 1.2 parts per million. In our first study, we compared the dosed birds with controls of the same age using tests of three cognitive abilities: spatial memory, inhibitory control, and color association. In the spatial memory assay, birds were tested on their ability to learn and remember the location of hidden food in their cage. The inhibitory control assay measured their ability to ignore visible but inaccessible food in favor of a learned behavior that provided the same reward. Finally, the color association task tested each bird\u27s ability to associate a specific color with the presence of hidden food. Dietary mercury negatively affected spatial memory ability but not inhibitory control or color association. Our second study focused on three behavioral assays not tied to a specific skill or problem-solving: activity level, neophobia, and social dominance. Zebra finches exposed to dietary mercury throughout their lives were subordinate to, and more active than, control birds. We found no evidence that mercury exposure influenced our metric of neophobia. Together, these results suggest that sub-lethal exposure to environmental mercury selectively harms neurological pathways that control different cognitive abilities, with complex effects on behavior and fitness

Transmission of High-Power Electron Beams Through Small Apertures

Tests were performed to pass a 100 MeV, 430 kWatt c.w. electron beam from the energy-recovery linac at the Jefferson Laboratory's FEL facility through a set of small apertures in a 127 mm long aluminum block. Beam transmission losses of 3 p.p.m. through a 2 mm diameter aperture were maintained during a 7 hour continuous run.Comment: arXiv admin note: text overlap with arXiv:1305.019

Simulation of Particle Size Effect on Dynamic Properties and Fracture of PTFE-W-Al Composites

Recent investigations of the dynamic compressive strength of cold isostatically pressed composites of polytetrafluoroethylene (PTFE), tungsten (W) and aluminum (Al) powders show significant differences depending on the size of metallic particles. The addition of W increases the density and overall strength of the sample. To investigate relatively large deformations multi-material Eulerian and arbitrary Lagrangian-Eulerian methods, which have the ability to efficiently handle the formation of free surfaces, were used. The calculations indicate that the increased strength of the sample with fine metallic particles is due to the formation of force chains under dynamic loading. This phenomenon occurs even at larger porosity of the PTFE matrix in comparison with samples with larger particle size of W and higher density of the PTFE matrix.Comment: 5 pages, 6 figure