2,072 research outputs found
Coolant passage heat transfer with rotation
The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques, and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades
Thermoluminescence fading studies: Implications for long-duration space measurements in Low Earth Orbit
Within a 1.5 year comprehensive fading experiment several batches of
LiF:Mg,Ti and LiF:Mg,Cu,P thermoluminescence detectors (TLDs) were studied. The
TLDs originated from two manufacturers and were processed by three laboratories
using different annealing and readout conditions. The TLDs were irradiated with
two radiation modalities (gamma-rays and thermal neutrons) and were stored at
two temperatures (-17.4C and +18.5C). The goal of the experiment was to verify
the stability of TLDs in the context of their application in long-term
measurements in space. The results revealed that the response of all TLDs is
stable within 10% for the studied temperature range. No influence of the
radiation type was found. These results indicate that for the properly
oven-annealed LiF TLDs, fading is not a significant problem, even for measuring
periods longer than a year
Effectiveness of 4 Pulpotomy Techniques—Randomized Controlled Trial
Pulpotomy is the accepted therapy for the management of cariously exposed pulps in symptom-free primary molars; however, evidence is lacking about the most appropriate technique. The aim of this study was to compare the relative effectiveness of the Er:YAG laser, calcium hydroxide, and ferric sulfate techniques with that of dilute formocresol in retaining such molars symptom-free. Two hundred primary molars in 107 healthy children were included and randomly allocated to one of the techniques. The treated teeth were blindly re-evaluated after 6, 12, 18, and 24 months. Descriptive data analysis and logistic regression analysis, accounting for each patient's effect by a generalized estimating equation (GEE), were used. After 24 months, the following total and clinical success rates were determined (%): formocresol 85 (96), laser 78 (93), calcium hydroxide 53 (87), and ferric sulfate 86 (100). Only calcium hydroxide performed significantly worse than formocresol (p = 0.001, odds ratio = 5.6, 95% confidence interval 2.0-15.5). In conclusion, calcium hydroxide is less appropriate for pulpotomies than is formocresol
Effects of rotation on coolant passage heat transfer. Volume 1: Coolant passages with smooth walls
An experimental program was conducted to investigate heat transfer and pressure loss characteristics of rotating multipass passages, for configurations and dimensions typical of modern turbine blades. The immediate objective was the generation of a data base of heat transfer and pressure loss data required to develop heat transfer correlations and to assess computational fluid dynamic techniques for rotating coolant passages. Experiments were conducted in a smooth wall large scale heat transfer model
Is a combination of varenicline and nicotine patch more effective in helping smokers quit than varenicline alone? A randomised controlled trial
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Performance of distributed mechanisms for flow admission in wireless adhoc networks
Given a wireless network where some pairs of communication links interfere
with each other, we study sufficient conditions for determining whether a given
set of minimum bandwidth quality-of-service (QoS) requirements can be
satisfied. We are especially interested in algorithms which have low
communication overhead and low processing complexity. The interference in the
network is modeled using a conflict graph whose vertices correspond to the
communication links in the network. Two links are adjacent in this graph if and
only if they interfere with each other due to being in the same vicinity and
hence cannot be simultaneously active. The problem of scheduling the
transmission of the various links is then essentially a fractional, weighted
vertex coloring problem, for which upper bounds on the fractional chromatic
number are sought using only localized information. We recall some distributed
algorithms for this problem, and then assess their worst-case performance. Our
results on this fundamental problem imply that for some well known classes of
networks and interference models, the performance of these distributed
algorithms is within a bounded factor away from that of an optimal, centralized
algorithm. The performance bounds are simple expressions in terms of graph
invariants. It is seen that the induced star number of a network plays an
important role in the design and performance of such networks.Comment: 21 pages, submitted. Journal version of arXiv:0906.378
Working Toward Social Justice: Center for Research on Minority Health Summer Workshop on Health Disparities
Health disparities research encompasses a complex web of areas of cross-disciplinary expertise from fields such as health policy, public health, economics, sociology, psychology, anthropology, communications, genetics, biology, environmental science, ethics, and law. Dissemination of health disparities research is paramount to educating and training professionals, academics, community leaders, students and others about the subject area, and providing them with the necessary tools to affect change and eliminate health disparities. This paper chronicles the development of a unique health disparities and social justice research educational program held annually by The University of Texas M. D. Anderson Cancer Center, Center for Research on Minority Health. The program is composed of a college semester course and summer workshop, which in the past five years, has become a preeminent program in the United States. The program's impetus, premise, evaluation, and future directions are discussed
- …