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1.
This paper completes our treatment of radiant flux through pairs of apertures. In Part II, we obtained approximate equations for rectangular apertures in parallel planes, with the restriction that two apertures be identical and that one be directly above the other. Here we generalize to the case of any apertures that fit into a rectangular grid. The idea for this generalization originated with Ondracek but it is here expressed in matrix notation, which allows coefficients Fij to be obtained rather simply. 相似文献
2.
Equations for the calculation of radiant power F through two apertures in series are well known. A characteristic of these formulae is that they give F as a small difference between two large terms. Evidently, the flux through the apertures must decrease as the spacing between them increases; and for large spacing, the inverse-square relation must hold. Instead of exhibiting this behaviour in an obvious manner, however, the traditional equations give the specious impression of an increase in F with increase in spacing. The paper develops an approximate formulae that applies to apertures in the shape of any regular polygon and that shows clearly how the inverse square relation is approached for large separation. 相似文献
3.
The purpose of the paper has been to present simplified methods that will expedite the calculation of ceiling lighting (Type II). Approximate formulas have been given, which allow ordinary slide-rule calculations to be made very easily for the usual range of variables. Only with rooms having very high domance (or perhaps with extraordinarily high floor reflectance) are the complicated equations of the previous paper (1) needed. These approximate formulas can be represented also by alignment charts, Figs. 2 to 5, which further simplify the work.Either the formulas or the charts may be used to investigate the effect of a change in ?1, ?2, or ?3. However, if reflectances are standardized at recommended values, other methods are possible.In particular, one may use graphs (Fig. 6) or a slide-rule (Figs. 7 and 8). The method of calculation chosen for a specific problem will depend on the problem and on the preferences of the designer. The previous equations and tables (3) may always be used; but in most cases, time can be saved by employing the short-cuts given in the present paper. 相似文献
4.
A study is made of separability conditions for the Helmholtz and Laplace equations. Attention is confined to the most useful case for physical applications; namely,
- 1.
- (a) The coordinate system is either cylindrical or it has rotational symmetry, and 相似文献
5.
Previous interflectance tables have dealt principally with three basic types of lighting (Types I, II, and III). The present paper extends the scope of the interflection method by showing how it can be applied to rooms lighted by hanging luminaires. It is found that most cases arising in practice can be covered by six canonic distributions. The effect of mounting height is handled by means of a simple equation. 相似文献
6.
Researchers in the field of gifted education are becoming increasingly aware that a variety of research approaches can make contributions to research on giftedness. This paper describes task analysis, a research methodology derived from counseling process research. Task analysis appears to be a useful research approach for building theoretical models of how therapeutic and educational interventions can facilitate positive changes in gifted children. The paper traces the historical development of task analysis methodology, describes the steps involved in conducting a rational‐empirical task analysis of change processes, and provides an example of how task analysis methodology might be applied to investigations of change processes in the field of gifted education. 相似文献
7.
8.
Nancy L. Halliday Mary B. Moon Daniel L. O'Donoghue Britta M. Thompson Sheila M. Crow 《Anatomical sciences education》2019,12(4):399-406
The University of Oklahoma College of Medicine has conducted an annual Anatomical Donor Luncheon where families of the anatomical donors met anatomy dissection groups of medical students. The luncheon presented an opportunity for donor family members to share the life story of their loved one with the medical students prior to the start of the anatomy course. This study was designed to understand the impact of the Anatomical Donor Luncheon on families of the donors. Seven families in two different focus groups were included to explore the reactions and attitudes of the donor families to meeting the medical students. Conversations were digitally recorded and transcribed. Qualitative analysis of textual data were coded by three investigators using the Constant Comparative Method. To provide evidence of validity, a form of member checking was utilized. For further triangulation, an analyst not involved in conducting the focus groups or analyzing the data, re-coded all data. This analyst used categories and themes identified by the original analysts, ensuring validity of the themes and any negative cases (data not supporting or contradictory of the established categories and themes). One meta-theme and three sub-themes were identified. The meta-theme was Donor Family Participants Experience Transformation and Closure, and sub-themes were Motivators for Participation, Optimal Venue Factors, and Optimal Medical Student–Anatomical Donor Family Interactions. Study findings indicated the Anatomical Donor Luncheon facilitated closure on the death of their loved one, and transformed their apprehension about the luncheon and body donation into an attitude of gratitude and appreciation. 相似文献
9.
Kristina L. Kendall David H. Fukuda Parker N. Hyde Abbie E. Smith-Ryan Jordon R. Moon Jeffrey R. Stout 《Journal of sports sciences》2017,35(7):624-633
The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM. 相似文献
10.