703 research outputs found
The Role of Television Sports Programs in Shaping Awareness of Physical Health among Jordanian University Students
The studys objectives were to ascertain the volume of television sports programming watched by college students in Jordanian universities as well as how these programs influenced their understanding of physical fitness. This was accomplished by using a survey method on 400 students from Yarmouk University and Zarqa University, who made up an equally stratified sample. The findings showed that men watch more television sports programming than women. Additionally, people who regularly exercise tend to watch these programs more than those who do not exercise at all. The results also showed that Yarmouk University students, as opposed to students at Al-Zarqa University, had a greater understanding of physical fitness due to the large part of television sports programs. Additionally, these programs have a more significant impact on influencing students in scientific colleges knowledge of physical health than they do on students in art colleges. Furthermore, compared to people who dont engage in any physical activities, they have a more significant impact on forming this awareness in people who regularly exercise. The findings also showed that the importance of television sports programs in influencing participants awareness of physical health increased with the participants intensity of watching
Low-temperature far-infrared ellipsometry of convergent beam
Development of an ellipsometry to the case of a coherent far infrared
irradiation, low temperatures and small samples is described, including a
decision of the direct and inverse problems of the convergent beam ellipsometry
for an arbitrary wavelength, measurement technique and a compensating
orientation of cryostat windows. Experimental results are presented: for a gold
film and UBe13 single crystal at room temperature (lambda=119 um), temperature
dependencies of the complex dielectric function of SrTiO3 (lambda=119, 84 and
28 um) and of YBa2Cu3O7-delta ceramic (lambda=119 um).Comment: 14 pages, 6 figure
Terahertz spectroscopy of hydrogen sulfide
Pure rotational transitions of hydrogen sulfide (H2S) in its ground and first excited vibrational states have been recorded at room temperature. The spectrum comprises an average of 1020 scans at 0.005 cm−1 resolution recorded in the region 45–360 cm−1 (1.4 to 10.5 THz) with a globar continuum source using a Fourier transform spectrometer located at the AILES beamline of the SOLEIL synchrotron. Over 2400 rotational lines have been detected belonging to ground vibrational state transitions of the four isotopologues H232S, H233S, H234S, and H236S observed in natural abundance. 65% of these lines are recorded and assigned for the first time, sampling levels as high as J=26 and Ka=17 for H232S. 320 pure rotational transitions of H232S in its first excited bending vibrational state are recorded and analysed for the first time and 86 transitions for H234S, where some of these transitions belong to new experimental energy levels. Rotational constants have been fitted for all the isotopologues in both vibrational states using a standard effective Hamiltonian approach. Comprehensive comparisons are made with previously available data as well as the data available in HITRAN, CDMS, and JPL databases. The 91 transitions assigned to H236S give the first proper characterization of its pure rotational spectrum
Optical properties of heavily boron-doped nanocrystalline diamond films studied by spectroscopic ellipsometry
The optical properties of heavily boron-doped nanocrystalline diamond films grown by microwave plasma enhanced chemical vapor deposition on silicon substrates are presented. The diamond films are characterized by spectroscopic ellipsometry within the midinfrared, visible, and near-ultraviolet regions. The ellipsometric spectra are also found to be best described by a four-phase model yielding access to the optical constants, which are found distinct from previous nanocrystalline diamond literature values. The presence of a subgap absorption yielding high extinction coefficient values defined clearly the boron incorporated films in comparison to both undoped and composite films, while refractive index values are relatively comparable
Polarization resolved angular patterns in nematic liquid crystal cells
We study the angular structure of polarization of light transmitted through a
nematic liquid crystal (NLC) cell by theoretically analyzing the polarization
state as a function of the incidence angles. For a uniformly aligned NLC cell,
the matrix formalism and the orthogonality relations are used to
derive the analytical expressions for the transmission and reflection matrices.
The polarization resolved angular patterns in the two-dimensional projection
plane are characterized in terms of the polarization singularities: C points
(points of circular polarization) and L lines (lines of linear polarization).
In the case of linearly polarized plane waves incident on the homeotropically
aligned cell, we present the results of detailed theoretical analysis
describing the structure of the polarization singularities. We apply the theory
to compute the polarization patterns for various orientational structures in
the NLC cell and discuss the effects induced by the director orientation and
biaxiality.Comment: pdflatex, rextex4, 22 pages, 7 figures (jpeg
Insight into the structure-property relationship of UO nanoparticles
Highly crystalline UO nanoparticles (NPs) with sizes of 2–3 nm were produced by fast chemical deposition of uranium(IV) under reducing conditions at pH 8–11. The particles were then characterized by microscopy and spectroscopy techniques including high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), high-energy resolution fluorescence detection (HERFD) X-ray absorption spectroscopy at the U M edge and extended X-ray absorption fine structure (EXAFS) spectroscopy at the U L edge. The results of this investigation show that despite U(IV) being the dominant oxidation state of the freshly prepared UO NPs, they oxidize to UO with time and under the X-ray beam, indicating the high reactivity of U(IV) under these conditions. Moreover, it was found that the oxidation process of NPs is accompanied by their growth in size to 6 nm. We highlight here the major differences and similarities of the UO NP properties to PuO, ThO and CeO NPs
Nematic liquid crystal alignment on chemical patterns
Patterned Self-Assembled Monolayers (SAMs) promoting both homeotropic and planar degenerate alignment of 6CB and 9CB in their nematic phase, were created using microcontact printing of functionalised organothiols on gold films. The effects of a range of different pattern geometries and sizes were investigated, including stripes, circles and checkerboards. EvanescentWave Ellipsometry was used to study the orientation of the liquid crystal (LC) on these patterned surfaces during the isotropic-nematic phase transition. Pretransitional growth of a homeotropic layer was observed on 1 ¹m homeotropic aligning stripes, followed by a homeotropic mono-domain state prior to the
bulk phase transition. Accompanying Monte-Carlo simulations of LCs aligned on nano-patterned surfaces were also performed. These simulations also showed the presence of the homeotropic mono-domain state prior to the transition.</p
Assessment of platelet function in patients with stroke using multiple electrode platelet aggregometry: a prospective observational study
Background
There is a link between high on-treatment platelet reactivity (HPR) and adverse vascular events in stroke. This study aimed to compare multiple electrode platelet aggregometry (MEA), in healthy subjects and ischaemic stroke patients, and between patients naive to antiplatelet drugs (AP) and those on regular low dose AP. We also aimed to determine prevalence of HPR at baseline and at 3–5 days after loading doses of aspirin.
Methods
Patients with first ever ischaemic stroke were age and sex-matched to a healthy control group. Three venous blood samples were collected: on admission before any treatment given (baseline); at 24 h and 3–5 days after standard treatment. MEA was determined using a Mutliplate® analyser and agonists tested were arachidonic acid (ASPI), adenosine diphosphate (ADP) and collagen (COL).
Results
Seventy patients (mean age 73 years [SD 13]; 42 men, 28 women) were age and sex-matched to 72 healthy subjects. Thirty-three patients were on antiplatelet drugs (AP) prior to stroke onset and 37 were AP-naive. MEA results for all agonists were significantly increased in AP-naive patients compared to healthy subjects: ADP 98 ± 31 vs 81 ± 24, p < 0.005; ASPI 117 ± 31 vs 98 ± 27, p < 0.005; COL 100 ± 25 vs 82 ± 20, p < 0.005. For patients on long term AP, 33% (10/30) of patients were considered aspirin-resistant. At 3–5 days following loading doses of aspirin, only 11.1% were aspirin resistant based on an ASPI cut-off value of 40 AU*min.
Conclusions
Many patients receiving low dose aspirin met the criteria of aspirin resistance but this was much lower at 3–5 days following loading doses of aspirin. Future studies are needed to establish the causes of HPR and potential benefits of individualizing AP treatment based on platelet function testing
Surface Deposition and Phase Behavior of Oppositely Charged Polyion–Surfactant Ion Complexes. Delivery of Silicone Oil Emulsions to Hydrophobic and Hydrophilic Surfaces
The adsorption from mixed polyelectrolyte-surfactant solutions at hydrophobized silica surfaces was investigated by in situ null-ellipsometry, and compared to similar measurements for hydrophilic silica surfaces. Three synthetic cationic copolymers of varying hydrophobicity and one cationic hydroxyethyl cellulose were compared in mixtures with the anionic surfactant sodium dodecylsulfate (SDS) in the absence or presence of a dilute silicone oil emulsion. The adsorption behavior was mapped while stepwise increasing the concentration of SDS to a polyelectrolyte solution of constant concentration. The effect on the deposition of dilution of the bulk solution in contact with the surface was also investigated by gradual replacement of the bulk solution with 1 mM aqueous NaCl. An adsorbed layer remained after complete exchange of the polyelectrolyte/surfactant solution for aqueous NaCl. In most cases, there was a codeposition of silicone oil droplets, if such droplets were present in the formulation before dilution. The overall features of the deposition were similar at hydrophobic and hydrophilic surfaces, but there were also notable differences. SDS molecules adsorbed selectively at the hydrophobized silica surface, but not at the hydrophilic silica, which influenced the coadsorption of the cationic polymers. The largest amount of deposited material after dilution was found for hydrophilic silica and for the least-hydrophobic cationic polymers. For the least-hydrophobic polyions, no significant codeposition of silicone oil was detected at hydrophobized silica after dilution if the initial SDS concentration was high
- …