Components of an American Indian Computer Science Transfer Degree Program*

From 1995 to 1997, a culturally relevant transfer degree program was developed at a tribally controlled Community College in Minnesota. Broad traditional values held in common by most indigenous peoples formed the backbone of the project. These values led to the formulation of several significant components of culturally sensitive programs, which were enhanced by classroom practices adopted and distilled during more than two decades of teaching from middle school to the graduate level. Many of these coincided with and reinforced traditional American Indian values. In addition, practical lessons were learned while creating this new model of education. Our conclusion: the core of minority‐centered education should be good teaching strategies applied to a specific population but applicable to and effective for all students.     

Detection of shock-wave-induced internal stresses in Cu-Al-Ni shape memory alloy by means of acoustic technique

1. The present results indicate that the stress-induced β₁→γ₁′ martensitic transformation occurs for an impact duration of 2 × 10⁻⁶ s. This time interval appears to be sufficient also for the subsequent deformation of the γ₁′ martensitic phase to occur.2. A structure memory effect has been found: Cu-Al-Ni austenitic crystals, shock-loaded at room temperature to induce γ₁′–martensite, recall during subsequent temperature-induced martensitic transformation the martensitic variant structure (elastic properties) formed under the shock loading.3. Elastic properties of quenched β₁′ and γ₁′ crystals of the Cu-Al-Ni system are extremely sensitive to the shock-wave loading. Mechanisms of these effects, as well as of the structure memory effect, include the generation of internal stresses due to the high elastic anisotropy of the martensitic phases. These internal stresses either change the distribution of martensitic variants or govern the formation of the martensitic variant structure during the temperature-induced martensitic transformation. The generation of high internal stresses by impact loading of the β₁′ martensitic phase is also detected by several anelastic phenomena.4. In contrast to elastic and anelastic properties, transformation temperatures are insensitive to the impact loading, pointing to the difference of structural elements responsible for the anelastic effects and for the interval and hysteresis of the thermoelastic martensitic transformation.     

Structuring scientific activities by co-author analysis

In this paper we apply ‘co-author analysis’ to create from a large set of publications clusters of collaborating researchers within a faculty of chemical engineering. Results have been discussed with an expert. The co-author clusters appeared to be meaningful, with respect to the identification of research groups, the relations within these groups, as well as to relations between these groups and changes in time. Also differences between ISI-based and non-ISI based maps proved to be consistent with the expert's opinion. Many clusters represent collaborating authors grouped around a full professor, mostly the department chairman. Co-author analysis can be used, for example, as an important tool in evaluative bibliometrics in order to make a first identification of research groups in ‘unknown’ universities or organizations.     

Comparative study of the surface oxidation behaviour of amorphous and crystallized Fe67Co18B14Si1 metallic glass

The oxidation of amorphous and crystallized specimens of the metallic glass Fe₆₇Co₁₈B₁₄Si₁ were studied under controlled conditions using Auger electron spectroscopy and X-ray photo-electron spectroscopy. The different oxides were characterized as boron and iron oxide forming in that sequence for both the amorphous and crystalline specimens. No cobalt oxide was detected. A higher oxygen uptake was measured for the amorphous than for the crystalline specimens. Comparison with the literature shows that the difference in oxygen uptake is heavily composition dependent. The oxidation of the amorphous specimens constitutes a driving force for boron to segregate to the surface and causes a boron enriched layer. Segregation of boron and cobalt occurs during annealing and the sequence of the enriched layers is influenced by environmental conditions.     

Extinction Behavior of Dry Snow in the 18-to 90-GHz Range

The extinction properties of several dry snow types were examined in the 18-to 90-GHz range. The snow types ranged from newly fallen snow to refrozen snow, and the density and mean grain size varied from 0.17 to 0.39 g/cm3 and from 0.2 to 1.6 mm, respectively. From measurements of the transmission loss as a function of sample thickness at a temperature of -15°C, the extinction coefficient and the surface scattering loss (due to surface roughness at the front and back surfaces of the snow slab) were determined for each snow type. The experimental values were compared against theoretical results computed according to the strong fluctuation theory. In general, good agreement with the experimental data was obtained at 18, 35, and 60 GHz when the grain size used in the theoretical calculations was chosen to be slightly smaller than the observed snow-particle size. However, the extinction coefficient of large-grained refrozen snow as predicted by the strong fluctuation theory is much larger at 90 GHz than the values determined experimentally. The attenuation in snow was observed to increase only slightly with increasing temperature in the -35 to -1°C range.     

A functional processor for the relational algebra on a microcomputer

We have built on the U.C.S.D. P-system (running on an IBM Personal Computer) a relational algebra processor, MRDS/FS, which is extremely powerful and which supports a functional syntax for the programmer-user. The relational algebra is provided in the extended operators μ-join, σ-join, project and select. The domain algebra is fully implemented for the first time, giving operations on attributes: arithmetic, logic, comparison and four different categories of aggregation of these. A strictly functional syntax is provided, permitting user-defined functions using the relational and domain algebras as primitive operations. An interactive editor permits the creation, copying and changing of both relations and user-defined functions.     

On the behaviour of a translating vapour bubble under the influence of a pressure step—numerical solutions of implosion and fragmentation

The implosion of a translating, originally spherical, free vapour bubble due to a pressure step is described by numerical solution of the basic equations. The treatment is based on the application of a combination of the mathematical methods of collocation and characteristics. The behaviour of a vapour bubble is a generalization of gas bubble behaviour due to the incorporation of the effect of phase transition at the bubble wall. Contrary to a gas bubble, a vapour bubble diminishes completely during the implosion. The theoretical predictions include bubble shape and fragmentation in qualitative agreement with new experimental results.     

A test reaction for titanium silicalite catalysts

The catalytic hydroxylation of phenol to hydroquinone and catechol can be used for checking the quality of titanium silicate catalysts since the selectivity of these catalysts is strongly affected by the presence of small amounts of non-framework titania. Titanium silicates prepared by modification of [Al]ZSM-5 exhibits the same catalytic properties as hydrothermally synthesized TS-1 of high purity.     

Deviant of diverse peer groups? The peer affiliations of aggressive elementary students.

This study examined peer affiliations of aggressive children in a sample of 948 students (496 girls, 452 boys) from 59 elementary classrooms (4th-6th grades). Groups were identified as zero aggressive, nonaggressive, aggressive, and mixed. The deviant peer group hypothesis was partially supported. Two thirds of aggressive boys and one half of aggressive girls were members of nonaggressive or mixed peer groups. Unpopular aggressive boys were most likely to be members of nonaggressive groups, whereas popular aggressive boys were most likely to be in aggressive and mixed groups. Aggressive and nonaggressive associates tended to he similar on key social characteristics (i.e., popularity, athleticism, leadership). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Macrozoobenthos of floodplain waters of the rivers rhine and meuse in the Netherlands: A structural and functional analysis in relation to hydrology

The river systems of the Rhine and Meuse include a large number of floodplain waters showing differences in hydrology and geomorphology. A classification of 100 water bodies based on their macroinvertebrate communities has been worked out as a tool for ecological management. Analyses were performed on structural (species composition) and functional (trophic relations) aspects of macrozoobenthos in relation to hydrological, vegetational, and physicochemical parameters. Based on the classification of macroinvertebrate communities, three major groups of water bodies can be distinguished, which are related to the frequency of inundation. The flood frequency constitutes the major environmental gradient which structures the zoobenthos communities in the Dutch floodplain waters. Faunal composition is mediated by substrate availability, water chemistry, and the availability of nutritional resources. This typology serves as a basis for the prediction of the impact of hydrology changes on the macrozoobenthic communities of floodplain waters of highly eutrophic and polluted rivers.