2,275 research outputs found
Innovative HVAC Cycles for Severe Part Load Conditions in the Humid Climate
This paper reports observations by the authors made in the course of performing field surveys and detailed analyses of approximately three
hundred U. S. Navy buildings located in a humid
climate. In the course of this work humidity
related problems were found in many of the
buildings.
Face & bypass control is suggested as one of
the best methods of achieving passive humidity
control under common difficult part load conditions. However, some conditions cannot be handled
without additional measures. This paper explores
techniques, other than reheat, as means for improving
space comfort conditions under the worst
conditions.
It is shown that pre-cooling or desiccant
dehumidification of ventilation air can offer
substantially improved performance, especially in
conjunction with varying the ventilation air quantity as a percentage of supply air
Innovative HVAC Cycles for Severe Part Load Conditions in the Humid Climate
This paper reports observations by the authors made in the course of performing field surveys and detailed analyses of approximately three
hundred U. S. Navy buildings located in a humid
climate. In the course of this work humidity
related problems were found in many of the
buildings.
Face & bypass control is suggested as one of
the best methods of achieving passive humidity
control under common difficult part load conditions. However, some conditions cannot be handled
without additional measures. This paper explores
techniques, other than reheat, as means for improving
space comfort conditions under the worst
conditions.
It is shown that pre-cooling or desiccant
dehumidification of ventilation air can offer
substantially improved performance, especially in
conjunction with varying the ventilation air quantity as a percentage of supply air
R&D ERL: Photocathode Deposition and Transport System
The purpose of the photocathode deposition and transport system is to (1) produce a robust, high yield multialkali photocathode and (2) have a method of transporting the multialkali photocathode for insertion into a super conducting RF electron gun. This process is only successful if a sufficient quantum efficiency lifetime of the cathode, which is inserted in the SRF electron gun, is maintained. One important element in producing a multialkali photocathode is the strict vacuum requirements of 10{sup -11} torr to assure success in the production of longlived photocathodes that will not have their QE or lifetime depleted due to residual gas poisoning in a poor vacuum. A cutaway view of our third generation deposition system is shown in figure 1. There are certain design criteria and principles required. One must be able to install, remove, rejuvenate and replace a cathode without exposing the source or cathode to atmosphere. The system must allow one to deposit Cs, K, and Sb on a cathode tip surface at pressures in the 10{sup -10} to 10{sup -9} torr range. The cathode needs to be heated to as high as 850 C for cleaning and maintained at 130 C to 150 C during deposition. There should also be the capability for in-situ QE measurements. In addition the preparation of dispenser photocathodes must be accounted for, thus requiring an ion source for cathode cleaning. Finally the transport cart must be mobile and be able to negotiate the ERL facility labyrinth
Exploring the concept of pain of Australian children with and without pain: Qualitative study
© 2019 Author(s). Objective A person's concept of pain can be defined as how they understand what pain actually is, what function it serves and what biological processes are thought to underpin it. This study aimed to explore the concept of pain in children with and without persistent pain. Design In-depth, face-to-face interviews with drawing tasks were conducted with 16 children (aged 8-12 years) in New South Wales, Australia. Thematic analysis was used to analyse and synthesise the data. Setting Children with persistent pain were identified from a pain clinic waiting list in Australia, and children without pain were identified through advertising flyers and email bulletins at a university and hospital. Participants Eight children had persistent pain and eight children were pain free. Results Four themes emerged from the data: â € my pain-related knowledge', â € pain in the world around me', â € pain in me' and â € communicating my concept of pain'. A conceptual framework of the potential interactions between the themes resulting from the analysis is proposed. The concept of pain of Australian children aged 8-12 years varied depending on their knowledge, experiences and literacy levels. For example, when undertaking a drawing task, children with persistent pain tended to draw emotional elements to describe pain, whereas children who were pain free did not. Conclusions Gaining an in-depth understanding of a child's previous pain-related experiences and knowledge is important to facilitate clear and meaningful pain science education. The use of age-appropriate language, in combination with appropriate assessment and education tasks such as drawing and discussing vignettes, allowed children to communicate their individual concept of pain
Measurement of the Dielectric Strength of Titanium Dioxide Ceramics
Titanium dioxide ceramics (TiO2) are candidate materials for high energy density pulsed power devices. Experiments to quantify the dielectric strength of TiO2 have been performed on a limited number of unoptimized samples. A high voltage test set was constructed to test the titanium dioxide. All samples had a relative dielectric constant of 100, all samples were of 3 mm nominal thickness, and all tests were performed in water dielectric to reduce the effect of the triple point field enhancement at the electrode edge. Both single layer and laminated samples were tested and the breakdown field strengths were recorded. Voltage risetimes varied slightly around 400 ns depending upon the size of the test sample area. Areas varied from \u3c 0.2 cm^2 to \u3e 100 cm^2. Both single layer and laminated material showed a strong area effect where the dielectric strength dropped off as area to the -0.17 and -0.1 power respectively. Effective areas of the electrodes were calculated using a field solver program. Breakdown field strengths varied from 469 kV/cm to 124 kV/cm in the single layer specimens, and from 556 kV/cm to 261 kV/cm in the laminates over an increasing area range. Energy density calculations for the material show that at areas of approximately 100 cm^2 the laminates can store nearly 3 times more energy than single layers
Signals for strange quark contributions to the neutrino (antineutrino) scattering in quasi-elastic region
Strange quark contributions to the neutrino (antineutrino) scattering are
investigated on the elastic neutrino-nucleon scattering and the
neutrino-nucleus scattering for 12C target in the quasi-elastic region on the
incident energy of 500 MeV, within the framework of a relativistic single
particle model. For the neutrino-nucleus scattering, the effects of final state
interaction for the knocked-out nucleon are included by a relativistic optical
potential. In the cross sections we found some cancellations of the strange
quark contributions between the knocked-out protons and neutrons. Consequently,
the asymmetries between the incident neutrino and antineutrino which is the
ratio of neutral current to charged current, and the difference between the
asymmetries are shown to be able to yield more feasible quantities for the
strangeness effects. In order to explicitly display importance of the
cancellations, results of the exclusive reaction 16O(\nu, \nu' p) are
additionally presented for detecting the strangeness effects.Comment: 14 pages, 8 figures, submitted to Phys. Lett.
Assessing the Educational Quality of Training Videos for Collection of a Nasopharyngeal Swab
Introduction: The SARS-CoV-2 pandemic has forced healthcare systems to disseminate their training materials quickly and broadly, including instruction on identifying cases of infection through correct nasopharyngeal swabbing. Incorrect nasopharyngeal swabbing technique leads to substandard sampling, patient discomfort, and increased risk of complications. We set out to evaluate the quality of educational videos on the nasopharyngeal swab procedure.
Methods: Using video search engines, videos on nasopharyngeal swabbing were identified and distributed to two reviewers. The quality of videos was assessed using a scoring system that examined indications, contraindications, personal protective equipment use, swab depth, swab angle, and audiovisual quality. Descriptive statistics and Spearman’s correlation coefficients were utilized to analyze video quality and its association with individual video characteristics.
Results: Videos received an average composite score of 5.4 (range: 0-10), with about half of all videos properly discussing and demonstrating the nasopharyngeal swab technique. Over 62% of reviews indicated that the reviewer would not recommend the video to a trainee, with the vast majority identifying improper swab technique as the main factor. There were no statistically significant associations between video score and publication date, number of views, and subscribers to the publisher.
Conclusion: Our study shows a glaring lack of quality educational videos on the nasopharyngeal swab procedure. Health care providers should be cautious when using educational videos to learn procedures as popularity may not be associated with accuracy
Anisotropic optical response of the diamond (111)-2x1 surface
The optical properties of the 21 reconstruction of the diamond (111)
surface are investigated. The electronic structure and optical properties of
the surface are studied using a microscopic tight-binding approach. We
calculate the dielectric response describing the surface region and investigate
the origin of the electronic transitions involving surface and bulk states. A
large anisotropy in the surface dielectric response appears as a consequence of
the asymmetric reconstruction on the surface plane, which gives rise to the
zigzag Pandey chains. The results are presented in terms of the reflectance
anisotropy and electron energy loss spectra. While our results are in good
agreement with available experimental data, additional experiments are proposed
in order to unambiguously determine the surface electronic structure of this
interesting surface.Comment: REVTEX manuscript with 6 postscript figures, all included in uu file.
Also available at http://www.phy.ohiou.edu/~ulloa/ulloa.html Submitted to
Phys. Rev.
Recommended from our members
R&D ERL: Photocathode Deposition and Transport System
The purpose of the photocathode deposition and transport system is to (1) produce a robust, high yield multialkali photocathode and (2) have a method of transporting the multialkali photocathode for insertion into a super conducting RF electron gun. This process is only successful if a sufficient quantum efficiency lifetime of the cathode, which is inserted in the SRF electron gun, is maintained. One important element in producing a multialkali photocathode is the strict vacuum requirements of 10{sup -11} torr to assure success in the production of longlived photocathodes that will not have their QE or lifetime depleted due to residual gas poisoning in a poor vacuum. A cutaway view of our third generation deposition system is shown in figure 1. There are certain design criteria and principles required. One must be able to install, remove, rejuvenate and replace a cathode without exposing the source or cathode to atmosphere. The system must allow one to deposit Cs, K, and Sb on a cathode tip surface at pressures in the 10{sup -10} to 10{sup -9} torr range. The cathode needs to be heated to as high as 850 C for cleaning and maintained at 130 C to 150 C during deposition. There should also be the capability for in-situ QE measurements. In addition the preparation of dispenser photocathodes must be accounted for, thus requiring an ion source for cathode cleaning. Finally the transport cart must be mobile and be able to negotiate the ERL facility labyrinth
- …