What children value : a scale to guide health promotion programs

Objective. Physical activity is important for the health of all human beings. Although it is important to develop good health promotion programs for children to increase participation in physical activity, to date there appear to be no programs based on what kids value beyond health and physical activity itself. This study proposed to create a scale with strong content and face validity that could uncover what any given population of children value in life regardless of their participation in physical activity and that experts feel could be related to physical activity. These findings will allow the development of targeted health promotion programs to increase children's participation in regular physical activity. Method In this study, a combination of qualitative and quantitative approaches was used. Data were gathered from seven experts in the field, sixty-seven children in grades three to five, five parents, and three teachers. From these data response groupings were created and sent to four experts to be given single word names. The resulting nine theme names were re-worked into "child-friendly" language. Four children were then asked to discuss theme names to see if they liked and understood them. The next step involved asking children and experts to rank order the nine themes, the children in general and the experts in terms of relevance to physical activity. From these results, possible versions of the scale were then created using the combined expert/children rankings. Each version was examined for content validity. Two versions of a scale resulted. These were sent to experts, parents, teachers and children in order to determine which one they liked better and to suggest any foreseeable problems. Once this information was collected, a beta (final prototype) version of the scale was created. Results. Nine common theme names were created from the response groupings. All four children agreed that they did understand and like each of the nine theme names. Experts and teachers agreed that full coverage of the content had been achieved. Children suggested a single wording change from "Being Accepted" to "Being Included". Five themes were selected for inclusion. The beta version of the scale included 12 forced choice statements, the first ten comparing all themes against one another followed by two anchor statements. Conclusion. At the outset it was recognized that it is essential to know what children think is important in their lives in order to serve as potential benefits in the development of effective physical activity promotion programs. This study developed a scale which could be used to determine what a population of children feel is important in order to focus health promotion programs for physical activity. The scale has strong face and content validity.

Far infrared reflectance and optical properties of organic superconductor (TMTSF)2ClO4 /

Polarized reflectance measurements of the quasi I-D charge-transfer salt (TMTSFh CI04 were carried out using a Martin-Puplett-type polarizing interferometer and a 3He refrigerator cryostat, at several temperatures between 0.45 K and 26 K, in the far infrared, in the 10 to 70 cm- 1 frequency range. Bis-tetramethyl-tetraselena-fulvalene perchlorate crystals, grown electrochemically and supplied by K. Behnia, of dimensions 2 to 4 by 0.4 by 0.2 mm, were assembled on a flat surface to form a mosaic of 1.5 by 3 mm. The needle shaped crystals were positioned parallel to each other along their long axis, which is the stacking direction of the planar TMTSF cations, exposing the ab plane face (parallel to which the sheets of CI04 anions are positioned). Reflectance measurements were performed with radiation polarized along the stacking direction in the sample. Measurements were carried out following either a fast (15-20 K per minute) or slow (0.1 K per minute) cooling of the sample. Slow cooling permits the anions to order near 24 K, and the sample is expected to be superconducting below 1.2 K, while fast cooling yields an insulating state at low temperatures. Upon the slow cooling the reflectance shows dependence with temperature and exhibits the 28 cm- 1 feature reported previously [1]. Thermoreflectance for both the 'slow' and 'fast' cooling of the sample calculated relative to the 26 K reflectance data indicates that the reflectance is temperature dependent, for the slow cooling case only. A low frequency edge in the absolute reflectance is assigned an electronic origin given its strong temperature dependence in the relaxed state. We attribute the peak in the absolute reflectance near 30 cm-1 to a phonon coupled to the electronic background. Both the low frequency edge and the 30 cm-1 feature are noted te shift towards higher frequcncy, upon cntering the superconducting state, by an amount of the order of the expected superconducting energy gap. Kramers-Kronig analysis was carried out to determine the optical conductivity for the slowly cooled sample from the measured reflectance. In order to do so the low frequency data was extrapolated to zero frequency using a Hagen-Ru bens behaviour, and the high frequency data was extended with the data of Cao et al. [2], and Kikuchi et al. [3]. The real part of the optical conductivity exhibits an asymmetric peak at 35 cm-1, and its background at lower frequencies seems to be losing spectral weight with lowering of the temperature, leading us to presume that a narrow peak is forming at even lower frequencies.

Far infrared optical properties of V and Cr doped Sb2Te3 /

The far infrared reflectance of Sb2Te3 , Sbi.97Vo.o3Te3 and Sbi.94Cr .o6Te3 was measured near normal incidence at different temperatures (between 45K and 300K). The direct current resistivities of the above samples were also measured between the temperatures of 4K and 300K. Also Kramers Kronig (KK) analyses were performed on the reflectance spectra to obtain the optical conductivities. In the doped samples, it was observed that a phonon at 62cm-1 softens to about 55cm-1 on decreasing the temperature from 295K to 45K. Also, it was observed that the plasma frequency of the doped samples is independent of doping. The scattering rate for the vanadium doped sample was seen to be greater than that for the chromium doped sample despite the fact that vanadium impurity density is less than that of chromium. The Drude-Lorentz model fits to the KK optical conductivity show that the samples used in this work are conventional metals. Definitive measurements of the temperature dependence of the scattering rate across the ferromagnetic transition await equipment changes allowing measurements at low temperature using the mercury cadmium telluride (MCT) detector.

Far-infrared optical properties of the heavy fermion superconductor UB[E13]

Temperature dependent resistivity, p, magnetic susceptibility, X, and far-infrared reflectance measurements were made on the low Tc superconductor UBe13. Two variants of UBe13 have been proposed, named 'L'- (for low Tc ) and 'H'-type (for high Tc ). Low temperature resistivity measurements confirmed that our sample was of H-type and that the transition temperature was at 0.9 K. This was further confirmed with the observation of this transition in the AC-susceptibility. Low temperature reflectance measurements showed a decrease in the reflectivity as the temperature is lowered from 300 to 10 K, which is in qualitative agreement with the increasing resistivity in this temperature range as temperature is lowered. No dramatic change in the reflectivity was observed between 10 and 0.75 K. A further decrease of the reflectance was observed for the temperature of 0.5 K. The calculated optical conductivity shows a broad minimum near 80 cm-1 below 45 K. Above 45 K the conductivity is relatively featureless. As the temperature is lowered, the optical conductivity decreases. The frequency dependent scattering rate was found to be flat for temperatures between 300 and 45 K. The development of a peak, at around 70 cm-1 was found for temperatures of 45 K and below. This peak has been associated with the energy at which the transition to a coherent state occurs from single impurity scattering in other heavy fermion systems. The frequency dependent mass enhancement coefficient was found to increase at low frequencies as the frequency decreases. Its' magnitude as frequency approaches zero also increased as the temperature decreased.

Far infrared spectroscopy of heavy fermion superconductor CeCoIn5

The optical response to far infrared radiation has been measured on a mosaic of heavy fermion CeColnssingle crystals. The superconducting transition temperature of the crystals has been determined by van der Pauw resistivity and ac-susceptibility measurements as Tc = 2.3 K. The optical measurements were taken above and below the transition temperature using a 3He cryostat and step and integrate Martin-Puplett type polarizing interferometer. The absolute reflectance of the heavy fermion CeColns in the superconducting state in range (0, 100)cm-1 was calculated from the measured thermal reflectance, using the normal state data of Singley et al and a low frequency extrapolation for a metallic material in the Hagen-Rubens regime. By means of Kramers-Kronig analysis the absolute reflectance was used to calculate the optical conductivity of the sample. The real part of the calculated complex conductivity 0-(w) ofCeColns indicates a possible opening of an energy gap close to 50 em-I.

Transmission measurements using a new far-infrared set-up

A system comprised of a Martin-Puplett type polarizing interferometer and a Helium-3 cryostat was developed to study the transmission of materials in the very-far-infrared region of the spectrum. This region is of significant interest due to the low-energy excitations which many materials exhibit. The experimental transmission spectrum contains information concerning the optical properties of the material. The set-up of this system is described in detail along with the adaptations and improvements which have been made to the system to ensure the best results. Transmission experiments carried out with this new set-up for two different varieties of materials: superconducting thin films of lead and biological proteins, are discussed. Several thin films of lead deposited on fused silica quartz substrates were studied. From the ratio of the transmission in the superconducting state to that in the normal state the superconducting energy gap was determined to be approximately 25 cm-1 which corresponds to 2~/kBTc rv 5 in agreement with literature data. Furthermore, in agreement with theoretical predictions, the maximum in the transmission ratio was observed to increase as the film thickness was increased. These results provide verification of the system's ability to accurately measure the optical properties of thin low-Tc superconducting films. Transmission measurements were carried out on double deionized water, and a variety of different concentrations by weight of the globular protein, Bovine Serum Albumin, in the sol, gel and crystalline forms. The results of the water study agree well with literature values and thus further illustrate the reproducibility of the system. The results of the protein experiments, although preliminary, indicate that as the concentration increases the samples become more transparent. Some weak structure in the frequency dependent absorption coefficient, which is more prominent in crystalline samples, may be due to low frequency vibrations of the protein molecules.

Far infrared spectroscopy of heavy fermion superconductor CeCoIn5 /

The optical response to far infrared radiation has been measured on a mosaic of heavy fermion CeCoIns single crystals. The superconducting transition temperature of the crystals has been determined by van der Pauw resistivity and ac-susceptibility measurements as Tc = 2.3 K. The optical measurements were taken above and below the transition temperature using a ^He cryostat and step and integrate Martin-Puplett type polarizing interferometer. The absolute reflectance of the heavy fermion CeCoIns in the superconducting state in range (0, 100)cm~^ was calculated from the measured thermal reflectance, using the normal state data of Singley et al and a low frequency extrapolation for a metallic material in the Hagen-Rubens regime. By means of Kramers-Kronig analysis the absolute reflectance was used to calculate the optical conductivity of the sample. The real part of the calculated complex conductivity a{u)) of CeCoIns indicates a possible opening of an energy gap close to 50 cm~^.

Tunis's topographical and pictorial guide to Niagara : containing, also, a description of the route through Canada, and the great northern route, from Niagara Falls to Montreal, Boston, and Saratoga Springs. Also, full and accurate tables of distances on all railroads running to and from Niagara Falls. --

Cover title: Tunis's guide to Niagara and traveller's companion, illustrated.

Hunter's panoramic guide from Niagara Falls to Quebec /

Added title page, illustrated.

The Falls of Niagara : being a complete guide to all the points of interest around and in the immediate neighbourhood of the great cataract with views taken from sketches by Washington Friend, and from photographs. --

Includes index.