498 research outputs found
Community Policing: Reinventing the Wheel?
Community Policing (CP) has been a much used, overused and abused term. Many blindly adopt it, others blindly reject it. This brief article argues that a cogent policing strategy that deploys CP should start with the focus on the epidemiology of crime and the understanding of how crime is produced. There is no need to reinvent the wheel of policing strategies. Just drive it
Hypersonic Aerothermoelastic Studies for Reusable Launch Vehicles
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77241/1/AIAA-2004-1590-254.pd
Aeroelastic and Aerothermoelastic Vehicle Behavior in Hypersonic Flow
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76797/1/AIAA-2005-3305-890.pd
Thermal Stability and Rehybridization of Carbon Bonding in Tetrahedral Amorphous Carbon
We preform a quantitative investigation of the energetics of thermally induced sp3 â sp2 conversion of carbon-carbon bonds in tetrahedral amorphous carbon (ta-C) films by using near edge x-ray absorption fine structure (NEXAFS) and Raman spectroscopy. We investigate the evolution of the bonding configuration in ta-C thin films subjected to high temperature annealing in flowing Argon gas using a rapid thermal annealing furnace over the range of 200-1000 ÂșC. We observe no substantial change in bonding structure below 600 ÂșC, and by 1000 ÂșC a significant increase in the sp2 bonding in the film is observed. No oxygen bonding is detected in the NEXAFS spectra, but we do observe an isosbestic point, demonstrating that the thermally driven sp3 â sp2 conversion reaction occurs without passing through an intermediate transition state. This allows us to use NEAFS spectra of thermally annealed ta-C films to quantitatively determine that the activation energy for directly converting the sp3-bonded carbon to the s
Incidence and Severity of Lymphoedema following Limb Salvage of Extremity Soft Tissue Sarcoma
Background and Purpose. Lymphoedema is a serious complication following limb salvage for extremity soft tissue sarcomas (STSs) for which little is known. We aimed to evaluate its incidence, its, severity and its associated risk factors.
Material and Method. Patient and tumor characteristics, treatment modalities and complications and functional outcomes (MSTS 1987, TESS), and lymphoedema severity (Stern) were all collected from prospective databases. Charts were retrospectively abstracted for BMI and comorbidities.
Results. There were 289 patients (158 males). Mean age was 53 (16â88). Followup ranged between 12 and 60 months with an average of 35 and a median of 36 months. Mean BMI was 27.4 (15.8â52.1). 72% had lower extremity tumors and 38% upper extremity. Mean tumor size was 8.1âcm (1.0â35.6âcm). 27% had no adjuvant radiation, 62% had 50âGy, and 11% received 66âGy. The incidence of lymphoedema was 28.8% (206 none, 58 mild, 22 moderate, 3 severe, and 0 very severe). Mean MSTS score was 32 (11â35) and TESS was 89.4 (32.4â100). Radiation dose was significantly correlated with tumor size > 5âcm (P = 0.0001) and TESS score (P = 0.001), but not MSTS score (P = 0.090). Only tumor size > 5âcm and depth were found to be independent predictors of significant lymphoedema.
Conclusion. Nine percent of STS patients in our cohort developed significant (grade â„ 2) lymphoedema. Tumor size > 5âcm and deep tumors were associated with an increased occurrence of lymphoedema but not radiation dosage
Proton decay via dimension-six operators in intersecting D6-brane models
We analyze the proton decay via dimension six operators in supersymmetric
SU(5)-Grand Unified models based on intersecting D6-brane constructions in Type
IIA string theory orientifolds. We include in addition to 10* 10 10* 10
interactions also the operators arising from 5-bar* 5-bar 10* 10 interactions.
We provide a detailed construction of vertex operators for any massless string
excitation arising for arbitrary intersecting D-brane configurations in Type
IIA toroidal orientifolds. In particular, we provide explicit string vertex
operators for the 10 and 5-bar chiral superfields and calculate explicitly the
string theory correlation functions for above operators. In the analysis we
chose the most symmetric configurations in order to maximize proton decay rates
for the above dimension six operators and we obtain a small enhancement
relative to the field theory result. After relating the string proton decay
rate to field theory computations the string contribution to the proton
lifetime is tau^{ST}_p =(0.5-2.1) x 10^{36} years, which could be up to a
factor of three shorter than that predicted in field theory.Comment: 46 pages, 2 figures references added, minor correction
Influence of Surface Passivation on the Friction and Wear Behavior of Ultrananocrystalline Diamond and Tetrahedral Amorphous Carbon Thin Films
Highly sp3-bonded, nearly hydrogen-free carbon-based materials can exhibit extremely low friction and wear in the absence of any liquid lubricant, but this physical behavior is limited by the vapor environment. The effect of water vapor on friction and wear is examined as a function of applied normal force for two such materials in thin film form: one that is fully amorphous in structure (tetrahedral amorphous carbon, or ta-C) and one that is polycrystalline with sp3 to disordered sp2 bonding is observed, no crystalline graphite formation is observed for either film. Rather, the primary solid-lubrication mechanism is the passivation of dangling bonds by OH and H from the dissociation of vapor-phase H2O. This vapor-phase lubrication mechanism is highly effective, producing friction coefficients as low as 0.078 for ta-C and 0.008 for UNCD, and wear rates requiring thousands of sliding passes to produce a few nanometers of wear
Prospectus, May 7, 1971
PREPAREDNESS PROGRAM GIVES SECOND CHANCE; VIC Helps To Rehabilitate Youth; Nurses, Hygienists In Health Week ; One Way or Two?; Student Deferment May End; One Man Band; Bull Sheet: Elections, Game Week, Sisters, Hot Line, Wit n\u27 Wisdom, Counselor Appts., Tau Epsilon, Voting, New Paperbacks, Anti War Activities, IOC, Vets Meeting, About Drugs, Need Help, Book Depository, LRC File, Poncho Pilot; Parkland Belts Walbash Twice; P.C. Board Holds Elections-- Consider Nepotism Policy; PC Faculty Art Exhibit; Know Your Candidate: Student Government Elections, Will They Pass or Fail?; David A. Friedmann, President; Robert D. Bales, President; John Stuckey, Vice President; Bob Hilton, Treasurer; Diane Topping, Secretary; Becky Terrell, Convocations; Terry Cassidy, Campus Organizationshttps://spark.parkland.edu/prospectus_1971/1007/thumbnail.jp
A review of varietal change in roots, tubers and bananas: consumer preferences and other drivers of adoption and implications for breeding
This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoption of new varieties of bananas in Uganda, cassava in Nigeria, potato in Kenya, sweetpotato in Uganda and yams in C^ote d'Ivoire. The review explored three hypotheses about drivers of varietal change. There was a strong confirmation for the hypothesis that insufficient priority given to consumer-preferred traits by breeding programmes contributes to the limited uptake of modern varieties (MVs) and low varietal turnover. Lack of evidence meant the second hypothesis of insufficient attention to understanding and responding to gender differences in consumer preferences for quality and post-harvest traits was unresolved. The evidence on the third hypothesis about the informal seed system contributing to slow uptake of MVs was mixed. In some cases, the informal system has contributed to rapid uptake of MVs, but often it appears to be a barrier with inconsistent varietal naming a major challenge
Origin of the Ocean on the Earth: Early Evolution of Water D/H in a Hydrogen-rich Atmosphere
The origin of the Earth's ocean has been discussed on the basis of
deuterium/hydrogen ratios (D/H) of several sources of water in the solar
system. The average D/H of carbonaceous chondrites (CC's) is known to be close
to the current D/H of the Earth's ocean, while those of comets and the solar
nebula are larger by about a factor of two and smaller by about a factor of
seven, respectively, than that of the Earth's ocean. Thus, the main source of
the Earth's ocean has been thought to be CC's or adequate mixing of comets and
the solar nebula. However, those conclusions are correct only if D/H of water
on the Earth has remained unchanged for the past 4.5 Gyr. In this paper, we
investigate evolution of D/H in the ocean in the case that the early Earth had
a hydrogen-rich atmosphere, the existence of which is predicted by recent
theories of planet formation no matter whether the nebula remains or not. Then
we show that D/H in the ocean increases by a factor of 2-9, which is caused by
the mass fractionation during atmospheric hydrogen loss, followed by deuterium
exchange between hydrogen gas and water vapor during ocean formation. This
result suggests that the apparent similarity in D/H of water between CC's and
the current Earth's ocean does not necessarily support the CC's origin of water
and that the apparent discrepancy in D/H is not a good reason for excluding the
nebular origin of water.Comment: Accepted to Icaru
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