Characterizing droplet combustion of pure and multi-component liquid fuels in a microgravity environment

The importance of understanding the effects of fuel composition, length scales, and other parameters on the combustion of liquid fuels has motivated the examination of simple flames which have easily characterized flow fields and hence, the potential of being modeled accurately. One such flame for liquid fuel combustion is the spherically symmetric droplet flame which can be achieved in an environment with sufficiently low gravity (i.e., low buoyancy). To examine fundamental characteristics of spherically symmetric droplet combustion, a drop tower facility has been employed to provide a microgravity environment to study droplet combustion. This paper gives a brief review of results obtained over the past three years under NASA sponsorship (grant NAG3-987)

Validity of effective material parameters for optical fishnet metamaterials

Although optical metamaterials that show artificial magnetism are mesoscopic systems, they are frequently described in terms of effective material parameters. But due to intrinsic nonlocal (or spatially dispersive) effects it may be anticipated that this approach is usually only a crude approximation and is physically meaningless. In order to study the limitations regarding the assignment of effective material parameters, we present a technique to retrieve the frequency-dependent elements of the effective permittivity and permeability tensors for arbitrary angles of incidence and apply the method exemplarily to the fishnet metamaterial. It turns out that for the fishnet metamaterial, genuine effective material parameters can only be introduced if quite stringent constraints are imposed on the wavelength/unit cell size ratio. Unfortunately they are only met far away from the resonances that induce a magnetic response required for many envisioned applications of such a fishnet metamaterial. Our work clearly indicates that the mesoscopic nature and the related spatial dispersion of contemporary optical metamaterials that show artificial magnetism prohibits the meaningful introduction of conventional effective material parameters

Hope\u27s Village of San Luis Obispo Charging Cabinet

This paper will review the steps the students took to provide Hope\u27s Village of SLO with a new charging cabinet. Hope\u27s Village of SLO is a local non profit that provides support for the central coast homeless community. Becky Jorgensen, who leads the organization, reached out to the students expressing her want for a new cabinet that people could use to charge their phones and tablets. The students then conceptualized the design with the help of an architecture student, applied for and received funding from the Alliance Group, purchased all materials and built the cabinet. This paper will walk you through all the steps the students took to curate this project as well as the steps to build the cabinet in the event this senior project is repeated

Singular electrostatic energy of nanoparticle clusters

The binding of clusters of metal nanoparticles is partly electrostatic. We address difficulties in calculating the electrostatic energy when high charging energies limit the total charge to a single quantum, entailing unequal potentials on the particles. We show that the energy at small separation $h$ has a strong logarithmic dependence on $h$. We give a general law for the strength of this logarithmic correction in terms of a) the energy at contact ignoring the charge quantization effects and b) an adjacency matrix specifying which spheres of the cluster are in contact and which is charged. We verify the theory by comparing the predicted energies for a tetrahedral cluster with an explicit numerical calculation.Comment: 17 pages, 3 figures. Submitted to Phys Rev

Faking like a woman? Towards an interpretative theorization of sexual pleasure.

This article explores the possibility of developing a feminist approach to gendered and sexual embodiment which is rooted in the pragmatist/interactionist tradition derived from G.H. Mead, but which in turn develops this perspective by inflecting it through more recent feminist thinking. In so doing we seek to rebalance some of the rather abstract work on gender and embodiment by focusing on an instance of 'heterosexual' everyday/night life - the production of the female orgasm. Through engaging with feminist and interactionist work, we develop an approach to embodied sexual pleasure that emphasizes the sociality of sexual practices and of reflexive sexual selves. We argue that sexual practices and experiences must be understood in social context, taking account of the situatedness of sex as well as wider socio-cultural processes the production of sexual desire and sexual pleasure (or their non-production) always entails interpretive, interactional processes

Can kunzea oil (Kunzea ambigua) control head lice (Pediculus humanus capitis)?

SUMMARYHead lice (Pediculus humanus capitis) infestations are a public health concern. The insecticidal properties of the Australian native plantKunzea ambigua(commonly known as tick bush) have been documented. In this study, we tested activity of kunzea oil (KO) against head lice throughin vitrobioassays. Head lice were exposed to filter paper treated with either KO, as either a 5 or 100% oil, or commercial formulations containing either permethrin or tea tree oil (TTO) for 120 min. Head lice exposure to KO, both as a 5 and 100% solution oil, resulted in 100% mortality within 120 min with a mean survival times of 17·1 and 34·8 min, respectively. There was no significant difference between the mean mortality of head lice exposed to 5% KO (17·1 ± 1·0; 95% CI: 115·2–19·0) and 5% TTO (21·2 ± 1·9; 95% CI: 17·4–25·1). This study revealed, for the first time, that KO holds great potential as an effective alternative to current active ingredients contained within commercial pediculicide formulations.</jats:p

Rotations associated with Lorentz boosts

It is possible to associate two angles with two successive non-collinear Lorentz boosts. If one boost is applied after the initial boost, the result is the final boost preceded by a rotation called the Wigner rotation. The other rotation is associated with Wigner's O(3)-like little group. These two angles are shown to be different. However, it is shown that the sum of these two rotation angles is equal to the angle between the initial and final boosts. This relation is studied for both low-speed and high-speed limits. Furthermore, it is noted that the two-by-two matrices which are under the responsibility of other branches of physics can be interpreted in terms of the transformations of the Lorentz group, or vice versa. Classical ray optics is mentioned as a case in point.Comment: LaTeX, 16 Pages, 4 epsfigure

Climatology of the Southeastern United States Continental Shelf Waters

Data from 2872 hydrographic stations have been used to determine the oceanographie climatology of the southeastern United States continental shelf waters. The data were sorted by each degree of latitude and by depth into three zones (0–20 m, 21–40 m, 41–60 m). Inner shelf water temperatures were similar to adjacent land air temperatures, while outer shelf temperatures were moderated by the Gulf Stream. Minimum and maximum water temperatures occurred in Georgia and South Carolina inner shelf water. Bottom temperatures were unusually low off Florida in the summer probably because of shelf break upwelling. Surface salinity was lowest adjacent to the rivers and reached minimums in the spring at the time of high runoff. An exception to this occurred in the fall, when strong southward winds apparently advected low salinity coastal water southward and offshore flow was restricted. Heat flux was calculated from changes in monthly mean depth-averaged inner shelf water temperatures. Heating occurred from March through July with maximum rates of 103 W m−2. Cooling occurred from October through February with maximum rates of −90 W m−2. Bulk stratification was estimated from the difference in near-surface and near-bottom monthly mean density. In the spring, stratification increases in inner shelf areas because of decreasing winds and increasing heat flux and runoff. By summer the whole shelf is highly stratified reflecting the contrast between high surface water temperatures and cooler bottom waters. Highest bulk stratification is found over the outer shelf. Stratification decreased with the approach offall with the associated cooling and high winds. Mean flow at midshelf was northward and appears to be produced by an along-shelf slope of sea level of oceanic origin