39,732 research outputs found
Optical monitoring system
Instrument can measure optical transmission, reflectance, and scattering. This information can be used to identify changes in optical properties or deviations from required optical standards. Device consists of monochromatic source, photo detector, transfer mirror, and hemiellipsoid. System might be used to measure optical properties of thin film
Reformulation in planning
Reformulation of a problem is intended to make the problem more amenable to efficient solution. This is equally true in the special case of reformulating a planning problem. This paper considers various ways in which reformulation can be exploited in planning
Human acclimation and acclimatization to heat: A compendium of research, 1968-1978
Abstracts and annotations of the majority of scientific works that elucidate the mechanisms of short-term acclimation to heat in men and women are presented. The compendium includes material from 1968 through 1977. Subject and author indexes are provided and additional references of preliminary research findings or work of a peripheral nature are included in a bibliography
Pidgin in the Classroom: Hawai`i\u27s English Standard Schools, Americanization, and Hawaiian Identity, 1920-1960
From 1924 to 1960 some of Hawai`i\u27s public schools were segregated institutions. Unlike the segregated schools of the mainland, the main goal of the English Standard schools, as they were known, was to ensure that English-speaking children be taught in environments free from Pidgin and other native languages spoken by the majority of Hawai`i\u27s school children. Because this segregation was linguistically-based, it was possible for children of all races and ethnicities to attend English Standard schools, but there can be no doubt that they were heavily dominated by white students in the early years of the program, much to the satisfaction of many whites throughout the Islands. Over time, though, this would change as more and more non-white students gained admission. Even though this was true, it was clear that Hawaiians were not entirely comfortable with the process of segregating students, and this was increasingly the case as the Territory of Hawai`i inched closer and closer to Statehood. This study is particularly concerned with the collective identity that developed in the period between the various groups of peoples on the Islands including: Chinese, Japanese, Native Hawaiian, Korean, Puerto Rican, and Portuguese, among others. Further, this work offers insight into the process undergone by these people as they moved from their own separate identities to a collective Hawaiian one, whose cornerstone was and continues to be the language of Pidgin. A myriad of primary and secondary sources were consulted concerning the protests, support, and ambivalence the segregated schools were met with by administrators, parents, and students. The result is a window into the process whereby Hawaiians made clear what they were willing to accept from the mainland, and what was simply too foreign and too at odds with the collective Hawaiian identity that had developed in the period. Indeed, Hawaiians, by phasing out the tracking of students into separate schools and classrooms based on their mastery of proper English by 1960, would highlight the fact that separation was unacceptable in the new state of Hawai`i. Ultimately, the practice stood in sharp contrast to what they envisioned for themselves as both Hawaiians and Americans
Magnetodielectric coupling in Mn3O4
We have investigated the dielectric anomalies associated with spin ordering
transitions in the tetragonal spinel MnO, using thermodynamic,
magnetic, and dielectric measurements. We find that two of the three magnetic
ordering transitions in MnO lead to decreases in the temperature
dependent dielectric constant at zero applied field. Applying a magnetic field
to the polycrystalline sample leaves these two dielectric anomalies practically
unchanged, but leads to an increase in the dielectric constant at the
intermediate spin-ordering transition. We discuss possible origins for this
magnetodielectric behavior in terms of spin-phonon coupling. Band structure
calculations suggest that in its ferrimagnetic state, MnO corresponds
to a semiconductor with no orbital degeneracy due to strong Jahn-Teller
distortion.Comment: 6 pages, 7 figure
First International Conference on Laboratory Research for Planetary Atmospheres
Proceedings of the First International Conference on Laboratory Research for Planetary Atmospheres are presented. The covered areas of research include: photon spectroscopy, chemical kinetics, thermodynamics, and charged particle interactions. This report contains the 12 invited papers, 27 contributed poster papers, and 5 plenary review papers presented at the conference. A list of attendees and a reprint of the Report of the Subgroup on Strategies for Planetary Atmospheres Exploration (SPASE) are provided in two appendices
Fluorescent visualization of a spreading surfactant
The spreading of surfactants on thin films is an industrially and medically
important phenomenon, but the dynamics are highly nonlinear and visualization
of the surfactant dynamics has been a long-standing experimental challenge. We
perform the first quantitative, spatiotemporally-resolved measurements of the
spreading of an insoluble surfactant on a thin fluid layer. During the
spreading process, we directly observe both the radial height profile of the
spreading droplet and the spatial distribution of the fluorescently-tagged
surfactant. We find that the leading edge of spreading circular layer of
surfactant forms a Marangoni ridge in the underlying fluid, with a trough
trailing the ridge as expected. However, several novel features are observed
using the fluorescence technique, including a peak in the surfactant
concentration which trails the leading edge, and a flat, monolayer-scale
spreading film which differs from concentration profiles predicted by current
models. Both the Marangoni ridge and surfactant leading edge can be described
to spread as . We find spreading exponents, and for the ridge peak and
surfactant leading edge, respectively, which are in good agreement with
theoretical predictions of . In addition, we observe that the
surfactant leading edge initially leads the peak of the Marangoni ridge, with
the peak later catching up to the leading edge
- ā¦