Thermal contact resistance

This work deals with phenomena of thermal resistance for metallic surfaces in contact. The main concern of the work is to develop reliable and practical methods for prediction of the thermal contact resistance for various types of surface characteristics under different conditions. In particular, consideration is restricted to the following cases: (i) rough nominally flat surfaces in a vacuum environment; (ii) rough nominally flat surfaces in a fluid environment; (iii) smooth wavy surfaces in a vacuum environment (with either of the following three types of waviness involved; spherical waviness, cylindrical waviness in one direction and cylindrical waviness in two perpendicular directions) and (iv) rough wavy surfaces in a vacuum environment. The problem is divided into three parts: thermal analysis, surface analysis and deformation analysis. The thermal analysis, based upon the proposed models, investigates the analytical solutions for the thermal contact conductance under steady state conditions. It was found convenient, due to the extensive analytical work connected with various models and different methods used here, to present all details of the thermal analysis separately in the appendices. The surface analysis, treating the surfaces as random processes with Gaussian distribution of height, relates the interface geometry to the actual contact area. The method suggested in this analysis has been checked against some autoradiographical experimental data. The deformation analysis, in its two parts, gives dependence between the load supported by the interface and (i) the actual contact area and (ii) the contact spots distribution for rough spherically wavy surfaces, respectively. The result of the first part of(cont.) the analysis is based on the plastic deformation of the surface asperities. The second part considers, through the model of the equivalent contour area, the combined effect of spherical waviness and roughness on the problem of contact spots spreading at the interface. Limitations and possible deviations of the proposed models are discussed. Prediction of the thermal contact conductance is compared with experimental data obtained in this work (in a vacuum environment) together with some data obtained by other investigators (for which necessary surface parameters were available). Agreement between the measured and predicted values was good in the whole tested range of system variables.Sponsored by the National Aeronautics and Space Administratio

Pflegerische Fallführung in der ambulanten psychiatrischen Versorgung – ein Zukunftsmodell? Erfahrungen und Erkenntnisse aus Praxis und Forschung im Diskurs/Nurse lead case management in ambulant mental health care - a model of the future? Experiences and findings of research and practice on discourse

Nurses in the position of "case leading / case responsible" carers in ambulant mental health care settings are still fairly uncommon in German speaking countries due to legal and other reasons. However, in Switzerland there are more and more mental health institutions that accept this new and extended role of nurses. The presentation provides insights into experiences as well as results of a study that focused on the topic

Paleolinguistics brings more light on the earliest history of the traditional Eurasian pulse crops

Traditional pulse crops such as pea, lentil, field bean, bitter vetch, chickpea and common vetch originate from Middle East, Mediterranean and Central Asia^1^. They were a part of human diets in hunter-gatherers communities^2^ and are one of the most ancient cultivated crops^3,4^. Europe has always been rich in languages^5^, with individual families still preserving common vocabularies related to agriculture^6,7^. The evidence on the early pulse history witnessed by the attested roots in diverse Eurasian proto-languages remains insufficiently clarified and its potential for supporting archaeobotanical findings is still non-assessed. Here we show that the paleolinguistic research may contribute to archaeobotany in understanding the role traditional Eurasian pulse crops had in the everyday life of ancient Europeans. It was found that the Proto-Indo-European language^8,9^ had the largest number of roots directly related to pulses, such as *arnk(')- (a leguminous plant), *bhabh- (field bean), *erəgw[h]- (a kernel of leguminous plant; pea), *ghArs- (a leguminous plant), *kek-, *k'ik'- (pea) and *lent- (lentil)^10,11,12^, numerous words subsequently related to pulses^13,14^ and borrowings from one branch to another^15^, confirming their essential place in the nutrition of Proto-Indo-Europeans^16,17,18^. It was also determined that pea was the most important among Proto-Uralic people^19,20,21^, while pea and lentil were the most significant in the agriculture of Proto-Altaic people^22,23,24^. Pea and bean were most common among Caucasians^25,26^, Basques^27,28^ and their hypothetical common forefathers^29^ and bean and lentil among the Afro-Asiatic ancestors of modern Maltese^30^. Our results demonstrate that pulses were common among the ancestors of present European nations and that paleolinguistics and its lexicological and etymological analysis may be useful in better understanding the earliest days of traditional Eurasian crops. We believe our results could be a basis for advanced multidisciplinary approach to the pulse crop domestication, involving plant scientists, archaeobotanists and linguists, and for reconstructing even earlier periods of pulse history

A novel metric for coronal MHD models

[1] In the interest of quantitatively assessing the capabilities of coronal MHD models, we have developed a metric that compares the structures of the white light corona observed with SOHO LASCO C2 to model predictions. The MAS model is compared to C2 observations from two Carrington rotations during solar cycle 23, CR1913 and CR1984, which were near the minimum and maximum of solar activity, respectively, for three radial heights, 2.5 R⊙, 3.0 R⊙, and 4.5 R⊙. In addition to simulated polarization brightness images, we create a synthetic image based on the field topology along the line of sight in the model. This open-closed brightness is also compared to LASCO C2 after renormalization. In general, the model\u27s magnetic structure is a closer match to observed coronal structures than the model\u27s density structure. This is expected from the simplified energy equations used in current global corona MHD models

The 2008 August 1 Eclipse Solar-Minimum Corona Unraveled

We discuss results stemming from observations of the white-light and [Fe XIV] emission corona during the total eclipse of the Sun of 2008 August 1, in Mongolia (Altaj region) and in Russia (Akademgorodok, Novosibirsk, Siberia). Corresponding to the current extreme solar minimum, the white-light corona, visible up to 20 solar radii, was of a transient type with well-pronounced helmet streamers situated above a chain of prominences at position angles 48, 130, 241 and 322 degrees. A variety of coronal holes, filled with a number of thin polar plumes, were seen around the poles. Furthering an original method of image processing, stars up to 12 magnitude, a Kreutz-group comet (C/2008 O1), and a coronal mass ejection (CME) were also detected, with the smallest resolvable structures being of, and at some places even less than, 1 arcsec. Differences, presumably motions, in the corona and prominences are seen even with the 19-min time difference between our sites. In addition to the high-resolution coronal images, which show the continuum corona (K-corona) that results from electron scattering of photospheric light, images of the overlapping green-emission-line (530.3 nm, [Fe XIV]) corona were obtained with the help of two narrow-passband filters (centered on the line itself and for the continuum in the vicinity of 529.1 nm, respectively), each with FWHM of 0.15 nm. Through solar observations, on whose scheduling and details we consulted, with the Solar and Heliospheric Observatory, Hinode's XRT and SOT, TRACE, and STEREO, as well as Wilcox Solar Observatory and SOHO/MDI magnetograms, we set our eclipse observations in the context of the current unusually low and prolonged solar minimum.Comment: Accepted in The Astrophysical Journal, 6 July 200

Aerobic capacity and respiratory patterns are better in recreational basketball-engaged university students than age-matched untrained males

Study aim: To asses and compare the aerobic capacity and respiratory parameters in recreational basketball-engaged university students with age-matched untrained young adults. Material and methods: A total of 30 subjects were selected to took part in the study based on recreational-basketball activity level and were assigned to a basketball (BG: N = 15, age 22.86 ± 1.35 yrs., body height 185.07 ± 5.95 cm, body weight 81.21 ± 6.15 kg) and untrained group (UG: N = 15, age 22.60 ± 1.50 yrs., body height 181.53 ± 6.11 cm, body weight 76.89 ± 7.30 kg). Inspiratory vital capacity (IVC), forced expiration volume (FEV1), FEV1/IVC ratio, maximal oxygen consumption (VO2max), ventilatory threshold (VO2VT) and time to exhaustion, were measured in all subjects. Student T-test for independent Sample and Cohen's d as the measure of the effect size were calculated. Results: Recreational basketball-engaged students (EG) reached significantly greater IVC (t = 7.240, p < 0.001, d = 1.854), FEV1 (t = 10.852, p < 0.001, d = 2.834), FEV1/IVC ratio (t = 6.370, p < 0.001, d = 3.920), maximal oxygen consumption (t = 9.039, p < 0.001, d = 3.310), ventilatory threshold (t = 9.859, p < 0.001, d = 3.607) and time to exhaustion (t = 12.361, p < 0.001, d = 4.515) compared to UG. Conclusions: Long-term exposure to recreational basketball leads to adaptive changes in aerobic and respiratory parameters in male university students

Observational properties of a kink unstable coronal loop

Aims. Previous work on the dynamics of the kink instability has concentrated on the evolution of the magnetic field and associated current sheets. Here we aim to determine the observational consequences of the kink instability in short coronal loops, particularly what images TRACE would record of such an instability. This paper concentrates on the internal m = 1 mode where the kink structure of the instability may not be apparent from the global field shape. This is most relevant to the observation of active region brightenings and coronal bright points. Methods. An existing fluid code was modified to include the TRACE temperature response function in order to calculate temporally and spatially averaged, line of sight images in the 171, 195 and 284 Å band passes for straight, kink unstable flux tubes. Results. Two new fluid effects of the kink instability are discovered: the circular enhancement of the density at the foot points and the appearance of a low density band running across the flux tube. The second of these effects is shown to be imagable by TRACE and hence would be a good candidate observational signature for an internal m = 1 kink unstable loop