Directional coupler for optical waveguides

Feasibility study of transmitting optical energy in single mode through photonic waveguides results in a conceptual directional coupler consisting of two types of optical waveguides /a stratified /core/ dielectric and a mirror wall/. Waveguide medium analysis produced formulation of mode cutoff conditions, field distributions, and propagation characteristics

Development of optical waveguides and components Progress report no. 1339, Feb. 1965 - Mar. 1966

All-solid waveguide components for slot couplers and waveguide lase

A Key to Container-Breeding Mosquitoes of Michigan (Diptera: Cllllcidae), With Notes on Their Biology

An illustrated key to larvae and notes on the biology of container-breeding mosquitoes of Michigan are presented. Two species included in the key. Aedes aegypti and Aedes albopictus. are not endemic in Michigan, but occasional introductions could occur with commercial shipments of scrap tires or other containers

Municipal accounting reform as illustrated in the city of Minneapolis, Minn.

A Paper read before the Convention of the American Society of Municipal Improvements at Montreal, September 5, 1905. As the text of this Address it is proposed to take the practical example of Accounting Reform afforded by the City of Minneapolis, the results of which are illustrated in the Financial Report of that City for the year 1904. Minneapolis was one of the first Cities to realize the importance of introducing into its various Departments comprehensive Methods of Accounting, and the Financial Report for 1904 (though by no means perfect), is of more than local importance in that it exemplifies certain principles of Accounting which, if generally adopted, would considerably assist in the solution of some important financial problems in City Government and Finance. The Report is based on a System of Accounting devised to comply strictly with the requirements of an extremely complicated local Charter. In accordance with the special desire of the City-Council it also follows the classification of Expenses called for by the Uniform System of Municipal Reports and Statistics adopted by the United States Census Bureau

Development of macroscopic waveguide and waveguide components for optical systems Final report, 28 Jan. - 28 Nov. 1964

Macroscopic waveguide and waveguide components for optical systems - laser

Health professions students' interprofessional experiences on a rural learning platform

HEALTH PROFESSIONS STUDENTS’ LEARNING EXPERIENCES ON A RURAL COLLABORATIVE LEARNING PLATFORM ABSTRACTA Faculty of Health Sciences launched a rural collaborative learning platform to cultivate interprofessional key competencies and to improve health outcomes. The purpose of the study was to describe health sciences students’ experiences of an rural collaborative learning platform. Health professions students created digital stories reflecting on their collaborative learning experiences. Purposive sampling resulted in 23 submissions. Qualitative analysis of content identified themes and categories. Three themes, namely, metaphor, critical consciousness and professional socialisation, were identified. The metaphor categories, Journey, Setting world ablaze, Water, and Puzzle, represent students’ desire to use visual cues to describe their experiences. Transformation, Personal development and Empathy signified critical consciousness. Collaborative practice, Values, Reflective practice, and Key competencies relate to professional socialisation. The researchers gained understanding of students’ experiences on an rural collaborative learning platform. Through digital stories, students became aware of professional interdependency, which linked their experiences to key interprofessional competencies.

Biomineralisation in the Palaeozoic oceans: evidence for simultaneous crystallisation of high and low magnesium calcite by phacopine trilobites

The chemical composition and microstructure of the calcite cuticles of eleven species of phacopine trilobites have been investigated by electron beam imaging, diffraction, and microanalysis, and results reveal that the lenses of their schizochroal eyes differed significantly in chemical composition from the rest of the cuticle in vivo. Apart from the eye lenses, most cuticles are inferred to have escaped extensive recrystallisation because their constituent crystals are sub-micrometre in size and have a preferred orientation that is consistent between species. Their current compositions of ~1.4 to 2.4 mol% MgCO3 are likely to be close to original values, although as they commonly luminesce and contain detectable manganese and iron, some diagenetic alteration has taken place. The associated lenses have a microstructure that is suitable for focusing light, yet are optically turbid owing to the presence within calcite of micropores and crystals of microdolomite, apatite, celestite and pyrite. The microdolomite indicates that lenses recrystallised from an original high-Mg calcite composition and this is supported by the presence of nanometre-scale modulated microstructures in both the calcite and dolomite. These lenses currently contain ~1 to 6 mol% MgCO3, and by comparison with the proportion of magnesium lost from echinoderm stereom in the same thin sections, may have contained ~7.5 mol% MgCO3 in vivo. In some samples, more extensive diagenetic alteration is evidenced by recrystallisation of the cuticle including lenses to coarse equant calcite or enrichment of the cuticle, but not necessarily the lenses, in magnesium accompanying replacement by a Mg–Fe phyllosilicate. The phacopine trilobites had to modify partition coefficients for magnesium considerably in order to grow lenses with contrasting compositions to the rest of their cuticles, and such a strong vital effect on biomineralisation suggests that incorporation of magnesium was essential for functioning of their calcite optical s

Crystallographic origins of fast-ion conduction in pyrochlore

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1998.Includes bibliographical references (p. 129-132).We have examined the crystallographic origins of fast-ion conduction in oxides with the pyrochlore structure-type, ideally A2B2O7, a superstructure of (A,B)20 3.5 defect fluorite-like array. These materials have technological promise for use in electrochemical devices such as oxygen sensors and solid-oxide fuel-cells. The pathway for ion conduction proposed by several authors has been a jump between equivalent nearest-neighbor oxygen sites through the tetrahedral edges of the relatively-immobile cation array. Substitution of a third cation species in slid-solution in the B site, A2(B-yB'y)2O7, results in a marked change in the structure and properties of the materials which is not fully understood. As the average radius of the cations occupying the B-site increases (with changing composition) towards that of the larger average radius of the cations occupying the Asite, a tendency for increasing disorder has been observed, where complete disorder corresponds to the fluorite structure. A decrease in Frenkel-defect formation-energy and an increase in the migration enthalpy accompanies the disordering. We have executed several studies of pyrochlore structures employing neutron and x-ray powder diffraction. In particular, we have focused on high-temperature in-situ experiments that should better correspond to the structure for which the conductivity measurements were made at elevated temperature ...by Kevin W. Eberman.Ph.D

Mammals, Mexico and South America

10 p. : ill. ; 24 cm.Includes bibliographical references

Is null-point reconnection important for solar flux emergence?

The role of null-point reconnection in a 3D numerical MHD model of solar emerging flux is investigated. The model consists of a twisted magnetic flux tube rising through a stratified convection zone and atmosphere to interact and reconnect with a horizontal overlying magnetic field in the atmosphere. Null points appear as the reconnection begins and persist throughout the rest of the emergence, where they can be found mostly in the model photosphere and transition region, forming two loose clusters on either side of the emerging flux tube. Up to 26 nulls are present at any one time, and tracking in time shows that there is a total of 305 overall, despite the initial simplicity of the magnetic field configuration. We find evidence for the reality of the nulls in terms of their methods of creation and destruction, their balance of signs, their long lifetimes, and their geometrical stability. We then show that due to the low parallel electric fields associated with the nulls, null-point reconnection is not the main type of magnetic reconnection involved in the interaction of the newly emerged flux with the overlying field. However, the large number of nulls implies that the topological structure of the magnetic field must be very complex and the importance of reconnection along separators or separatrix surfaces for flux emergence cannot be ruled out.Comment: 26 pages, 12 figures. Added one referenc