Operation: Eco-Garden

Community gardens on college campuses provide numerous benefits for the surrounding community. One successful local garden is the Derbyshire Place community garden located in Daytona Beach. The garden has improved the physical wellness of residents through increased access to fruits and vegetables with Food stamps-eligible flea markets and rentable garden beds for $25 per year. The garden also provides opportunities for outdoor exercise, and improving the community relations and interactions between groups of varying demographic backgrounds. We wish to do the same here at the Daytona Campus and through this research project we seek the encouraged support, approval, development and establishment of an on-campus garden for the betterment of the campus community. If approved, the overall wellbeing of the campus community would be increased as noted in the local community and at other institutions. The ideal location of the garden would be on top of the roof next to the Starbucks. Our plan is to inform members of the community about the benefits of a community garden through a short video dicussing benefit of a community garden. The video would walk the viewer through the Derbyshire community garden and showcase the provided rescores and opportunities provided. Before posing an open-formatted question of how a similar garden on campus could benefit students and faculty followed by a few concept designs of the community garden on campus. All in order to encourage and promote discussion and support of a on-campus community garden. After the viewer watches the video, we intend to have them complete a survey that would provide valuable data for support and tweaking of the final design of the garden. The survey will utilize closed-ended questions to gather quantitative data such as sample size, demographics and plant preferences. To ensure that the garden is serving the community, additional qualitative data would be collected such as community feedback or idea pertaining to the layout use or layout aesthetic of the garden

The accretion disk in the post period-minimum cataclysmic variable SDSS J080434.20+510349.2

This study of SDSS0804 is primarily concerned with the double-hump shape in the light curve and its connection with the accretion disk in this bounce-back system. Time-resolved photometric and spectroscopic observations were obtained to analyze the behavior of the system between superoutbursts. A geometric model of a binary system containing a disk with two outer annuli spiral density waves was applied to explain the light curve and the Doppler tomography. Observations were carried out during 2008-2009, after the object's magnitude decreased to V~17.7(0.1) from the March 2006 eruption. The light curve clearly shows a sinusoid-like variability with a 0.07 mag amplitude and a 42.48 min periodicity, which is half of the orbital period of the system. In Sept. 2010, the system underwent yet another superoutburst and returned to its quiescent level by the beginning of 2012. This light curve once again showed a double-humps, but with a significantly smaller ~0.01mag amplitude. Other types of variability like a "mini-outburst" or SDSS1238-like features were not detected. Doppler tomograms, obtained from spectroscopic data during the same period of time, show a large accretion disk with uneven brightness, implying the presence of spiral waves. We constructed a geometric model of a bounce-back system containing two spiral density waves in the outer annuli of the disk to reproduce the observed light curves. The Doppler tomograms and the double-hump-shape light curves in quiescence can be explained by a model system containing a massive >0.7Msun white dwarf with a surface temperature of ~12000K, a late-type brown dwarf, and an accretion disk with two outer annuli spirals. According to this model, the accretion disk should be large, extending to the 2:1 resonance radius, and cool (~2500K). The inner parts of the disk should be optically thin in the continuum or totally void.Comment: 12 pages, 15 figures, accepted for publication in A&

Simulation of a microgrid for a non-interconnected zone that integrates renewable energies

This paper develops a simulation of a small electrical network (Microgid) that integrates renewable energies, the model of the micro network is made up of a solar energy source, a wind energy source, an energy storage element, a non-renewable source such as a diesel generator. The model of the microgrid represent a non-interconnected area from the electrical network in Colombia. The non-interconnected areas sometimes depend on unreliable connections to the grid integration of renewable energies could be the best option to guarantee energy in these sectors and allow generating projects with social impact. A possible solution to this deficit of energy is to supplement the production of energy with renewable energy plants from resources as sun or wind. The simulated model allowed to study the effects of the network in island mode and in interconnected mode, showing the imbalances that can be obtained by integrating renewable energies and storage systems. It is verified that with an inclusion of more than 30% of power in renewable energies there is the possibility of having load imbalances, which affect the frequency and cause instability in the network. It also verifies how a control system can regulate the load balance but must interact with the other energy sources

Scaling differences between large interplate and intraplate earthquakes

A study of large intraplate earthquakes with well-determined source parameters shows that these earthquakes obey a scaling law similar to large interplate earthquakes, in which M_0 ∝ L^2 or u = αL, where L is rupture length and u is slip. In contrast to interplate earthquakes, for which α ≈ 1 × 10^(−5), for for the intraplate events α ≈ 6 × 10^(−5), which implies that these earthquakes have stress drops about 6 times higher than interplate events. This result is independent of focal mechanism type. This implies that intraplate faults have a higher frictional strength than do plate boundaries, and hence that faults are velocity or slip weakening in their behavior. This factor may be important in producing the concentrated deformation that creates and maintains plate boundaries

Constant mean curvature solutions of the Einstein-scalar field constraint equations on asymptotically hyperbolic manifolds

We follow the approach employed by Y. Choquet-Bruhat, J. Isenberg and D. Pollack in the case of closed manifolds and establish existence and non-existence results for the Einstein-scalar field constraint equations on asymptotically hyperbolic manifolds.Comment: 15 page