27,723 research outputs found
Fire extinguishing apparatus having a slidable mass for a penetrator nozzle
A fire extinguishing apparatus for delivering an extinguishing agent through a tarrier surrounding a structure into its interior includes an elongated tubular nozzle body which has a pointed penetrating head carried on one end of the tubular body. A source of extinguishing agent coupled to the opposite end of the tubular body is fed through and passes through passages adjacent the head for delivering the extinguishing agent to the interior of the structure. A slidable mass is carried on the tubular body on a remote end of the tubular body from the penetrating head. By manipulating the slidable mass and bringing such in contact with an abutment the force imparted to the tubular body causes the head to penetrate the structure
The contrasting physiological and subjective effects of chewing gum on social stress
Uncertainty exists with respect to the extent to which chewing gum may attenuate stress-induced rises in cortisol secretion (Scholey et al., 2009; Smith, 2010; Johnson et al., 2011). The present study used the Trier Social Stress Task (TSST: Kirschbaum et al., 1993), a task known to elevate cortisol secretion (Kudielka et al., 2004), in order to examine the moderating physiological and subjective effects of chewing gum on social stress. Forty participants completed the TSST either with or without chewing gum. As expected, completion of the TSST elevated both cortisol and subjective stress levels, whilst impairing mood. Although gum moderated the perception of stress, cortisol concentrations were higher following the chewing of gum. The findings are consistent with Smith (2010) who argued that elevations in cortisol following the chewing of gum reflect heightened arousal. The findings suggest that chewing gum only benefits subjective measures of stress. The mechanism remains unclear; however, this may reflect increased cerebral blood flow, cognitive distraction, and/or effects secondary to task facilitation
Phenomenology for the decay of energy-containing eddies in homogeneous MHD turbulence
We evaluate a number of simple, one‐point phenomenological models for the decay of energy‐containing eddies in magnetohydrodynamic(MHD) and hydrodynamicturbulence. The MHDmodels include effects of cross helicity and Alfvénic couplings associated with a constant mean magnetic field, based on physical effects well‐described in the literature. The analytic structure of three separate MHDmodels is discussed. The single hydrodynamic model and several MHDmodels are compared against results from spectral‐method simulations. The hydrodynamic model phenomenology has been previously verified against experiments in wind tunnels, and certain experimentally determined parameters in the model are satisfactorily reproduced by the present simulation. This agreement supports the suitability of our numerical calculations for examining MHDturbulence, where practical difficulties make it more difficult to study physical examples. When the triple‐decorrelation time and effects of spectral anisotropy are properly taken into account, particular MHDmodels give decay rates that remain correct to within a factor of 2 for several energy‐halving times. A simple model of this type is likely to be useful in a number of applications in space physics, astrophysics, and laboratory plasma physics where the approximate effects of turbulence need to be included
Discovery of a Non-Thermal Galactic Center Filament (G358.85+0.47) Parallel to the Galactic Plane
We report the discovery of a new non-thermal filament, G358.85+0.47, the
``Pelican'', located ~225 pc in projection from SgrA, and oriented parallel to
the Galactic plane. VLA continuum observations at 20 cm reveal that this 7'
(17.5 pc) structure bends at its northern extension and is comprised of
parallel strands, most apparent at its ends. Observations at 6 and 3.6 cm
reveal that the Pelican is a synchrotron-emitting source and is strongly
linearly polarized over much of its extent. The spectral index of the filament
changes from alpha(20/6)=-0.8 to alpha(6/3.6)=-1.5. The rotation measures
exhibit a smooth gradient, with values ranging from -1000 rad/m2 to +500
rad/m2. The intrinsic magnetic field is well-aligned along the length of the
filament. Based on these properties, we classify the Pelican as one of the
non-thermal filaments unique to the Galactic center. Since these filaments
(most of which are oriented perpendicular to the Galactic plane) are believed
to trace the overall magnetic field in the inner Galaxy, the Pelican is the
first detection of a component of this field parallel to the plane. The Pelican
may thus mark a transition region of the magnetic field orientation in the
inner kiloparsec of the Galaxy.Comment: 6 pages, 4 figures, to appear in ApJ Letters; Figs. 2 & 3 are color
.ps files and best viewed in colo
High floc strength with aged polyelectrolytes
The ageing of powdered polyelectrolyte solutions has shown that while the viscosity of these solutions decreases rapidly with time, the flocculation performance and the strength of the flocs produced does not alter over periods >200 days. This was shown for polyacrylamides of cationic, anionic and non-ionic charge. The use of tap or deionized water did not adversely affect the results unless a biocide capable of associating with the polyelectrolyte was added. These results contradict the common belief that solutions made with powdered polyelectrolytes should not be stored for long periods of time as their performance decreases after being stored for several days. The results indicate that powdered polyelectrolyte solutions are suitable for intermittent process operations, such as sewer overflow treatment and that dosing and handling of the solutions can be made easier by ageing of the solutions
Exploring Consumer and Patient Knowledge, Behavior, and Attitude Toward Medicinal and Lifestyle Products Purchased From the Internet: A Web-Based Survey.
BACKGROUND: In recent years, lifestyle products have emerged to help improve people's physical and mental performance. The Internet plays a major role in the spread of these products. However, the literature has reported issues regarding the authenticity of medicines purchased from the Internet and the impact of counterfeit medicines on public health. Little or no data are available on the authenticity of lifestyle products and actual toxicity associated with their use and misuse. OBJECTIVE: Our aim was to investigate consumer and patient attitudes toward the purchase of lifestyle products from the Internet, their knowledge of product authenticity and toxicity, and their experiences with counterfeit lifestyle products. METHODS: A Web-based study was performed between May 2014 and May 2015. Uniform collection of data was performed through an anonymous online questionnaire. Participants were invited worldwide via email, social media, or personal communication to complete the online questionnaire. A total of 320 participants completed the questionnaire. RESULTS: The results of the questionnaire showed that 208 (65.0%) participants purchased lifestyle products from the Internet mainly due to convenience and reduced cost. More than half (55.6%, 178/320) of participants purchased cosmetic products, whereas only a minority purchased medicinal products. Yet, 62.8% (201/320) of participants were aware of the presence of counterfeit lifestyle products from the Internet, and 11.9% (38/320) experienced counterfeit products. In only 0.9% (3/320) of those cases were counterfeit lifestyle products reported to authorities. Moreover, 7.2% (23/320) of the participants experienced adverse effects due to counterfeit lifestyle products. CONCLUSIONS: In summary, patients experienced counterfeit lifestyle products that resulted in adverse effects on their health. Although certain adverse effects were reported in this study, counterfeit products were underreported to authorities. Further public awareness campaigns and patient education are needed
Investigation of static eccentricity fault frequencies using multiple sensors in induction motors and effects of loading
A significant number of studies have been reported in the literature on the detection of eccentricity faults in induction machines; however these have generally used one type of sensor such as current or vibration, and not studied in detail the effect of loading. This paper examines the use of fault frequency components in the current, flux and vibration sensor signals with the aim of both detecting and estimating the severity of static eccentricity faults in the presence of load variations. The research is based on an extensive series of sensor measurements taken using a specially modified 2.2kW induction machine under varying conditions of static eccentricity and loading.R. Supangat, J. Grieger, N. Ertugrul, W.L. Soong, D.A. Gray, C. Hanse
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