6,651 research outputs found
Making Classrooms Culturally Sensitive
It is felt by many that as American schools and educators become more and more sensitive to the diversity of their community, their students can be guided to appreciate and respect these differences and to coexist peacefully. Various combinations of cultures such as African-Americans, Irish and German-Americans, Hispanics, Chinese-Americans to name a few, are learning how to work and live together while maintaining their own cultural heritage. The students of today who embrace their cultural heritage are trying to keep the values of their parents and grandparents, and still fit in with the students and cultures surrounding them. This dual search often confuses students and causes anxiety as they seek their own identity but attempt to live with other cultures. School systems and individual schools themselves can be extremely powerful agents in this process by providing insights to difficult cultural questions and issues facing students. Of course, a diverse school faculty can help by modeling behaviors that encourage classrooms to be settings where differences can be observed and studied. These same classrooms can help students begin to share, respect, and learn how to work with others. But it all starts by discovering and acknowledging individual and cultural differences and then by focusing on those things common to the group. To get a better picture classrooms that strive to be sensitive and aware four steps/stages for investigating cultural differences in classrooms have been developed and will now be discussed
Characterizing meteorological forecast impact on microgrid optimization performance and design
A microgrid consists of electrical generation sources, energy storage assets, loads, and the ability to function independently, or connect and share power with other electrical grids. Thefocus of this work is on the behavior of a microgrid, with both diesel generator and photovoltaic resources, whose heating or cooling loads are influenced by local meteorological conditions. Themicrogrid\u27s fuel consumption and energy storage requirement were then examined as a function of the atmospheric conditions used by its energy management strategy (EMS). A fuel-optimal EMS, able to exploit meteorological forecasts, was developed and evaluated using a hybrid microgrid simulation. Weather forecast update periods ranged from 15 min to 24 h. Four representative meteorological sky classifications (clear, partly cloudy, overcast, or monsoon) were considered. Forall four sky classifications, fuel consumption and energy storage requirements increased linearly with the increasing weather forecast interval. Larger forecast intervals lead to degraded weather forecasts, requiring more frequent charging/discharging of the energy storage, increasing both the fuel consumption and energy storage design requirements. The significant contributions of this work include the optimal EMS and an approach for quantifying the meteorological forecast effects on fuel consumption and energy storage requirements on microgrid performance. The findings of this study indicate that the forecast interval used by the EMS affected both fuel consumption and energy storage requirements, and that the sensitivity of these effects depended on the 24-hour sky conditions
Optimizing astrophotonic spatial reformatters using simulated on-sky performance
One of the most useful techniques in astronomical instrumentation is image
slicing. It enables a spectrograph to have a more compact angular slit, whilst
retaining throughput and increasing resolving power. Astrophotonic components
like the photonic lanterns and photonic reformatters can be used to replace
bulk optics used so far. This study investigates the performance of such
devices using end-to-end simulations to approximate realistic on-sky
conditions. It investigates existing components, tries to optimize their
performance and aims to understand better how best to design instruments to
maximize their performance. This work complements the recent work in the field
and provides an estimation for the performance of the new components.Comment: Conference proceedings in SPIE 2018 Austin Texa
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Macular Pigment and Visual Function in Patients With Glaucoma: The San Diego Macular Pigment Study.
PurposeAlthough recent studies have shown that macular pigment (MP) is significantly lower in glaucoma patients, this relationship merits further investigation.MethodsThis cross-sectional study included 85 glaucoma patients and 22 controls. All subjects had standard automated perimetry (SAP) and retinal nerve fiber layer (RNFL) thickness measurements. Intake of lutein (L) and zeaxanthin (Z) was estimated using a novel dietary screener. The Heidelberg Spectralis dual-wavelength autofluorescence (AF) technology was employed to study the relationship between MP and glaucoma. The association between MP volume and glaucoma was investigated using linear regression models accounting for potential confounding factors.ResultsGlaucoma patients had significantly worse SAP mean deviation (MD) and lower RNFL thickness in the study eye compared to control subjects (P < 0.001 for both). MP (volume) was comparable between groups (P = 0.436). In the univariable model, diagnosis of glaucoma was not associated with MP volume (R2 = 1.22%; P = 0.257). Dietary intake of L and Z was positively and significantly related to MP in the univariable (P = 0.022) and multivariable (P = 0.020) models.ConclusionsThese results challenge previous studies that reported that glaucoma is associated with low MP. Dietary habits were found to be the main predictor of MP in this sample. Further research is merited to better understand the relationship between glaucoma, MP, and visual performance in these patients
Stress distribution within circumferential clasp arms
An analysis of stress distributions within circumferential clasp arms with various tapers, was undertaken in an effort to (1) determine the area of maximum stress concentration in both tapered and non-tapered clasps, and (2) to compare this point of maximum stress concentration with the area of frequent clasp breakage. The non-tapered clasp showed better distribution of stresses than the tapered clasps. The less favourable stress concentrations could result in eventual failure of the clasp when coupled with other factors such as porosities. The maximum shear stresses in the non-tapered clasp also were lower than those in the tapered clasps. As the taper of the clasp became more accentuated, the magnitude of the stresses increased and shifted towards the tip of the clasp. The maximum tensile stress calculated in a replica of a chromium–cobalt–nickel clasp was in the order of 34 MN/m 2 which is well below the ultimate tensile strength of the alloy. This observation leads to the proposal that failure of clasps is a function not only of design but also of other variables, such as porosities, surface irregularities, and fatigue.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71998/1/j.1365-2842.1976.tb01453.x.pd
Natural Wormholes as Gravitational Lenses
Visser has suggested traversable 3-dimensional wormholes that could plausibly
form naturally during Big Bang inflation. A wormhole mouth embedded in high
mass density might accrete mass, giving the other mouth a net *negative* mass
of unusual gravitational properties. The lensing of such a gravitationally
negative anomalous compact halo object (GNACHO) will enhance background stars
with a time profile that is observable and qualitatively different from that
recently observed for massive compact halo objects (MACHOs) of positive mass.
We recommend that MACHO search data be analyzed for GNACHOs.Comment: 4 pages; plus 4 figures; ReV_TeX 3.0; DOE/ER/40537-001/NPL94-07-01
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