7,745 research outputs found
Ceramic component reliability with the restructured NASA/CARES computer program
The Ceramics Analysis and Reliability Evaluation of Structures (CARES) integrated design program on statistical fast fracture reliability and monolithic ceramic components is enhanced to include the use of a neutral data base, two-dimensional modeling, and variable problem size. The data base allows for the efficient transfer of element stresses, temperatures, and volumes/areas from the finite element output to the reliability analysis program. Elements are divided to insure a direct correspondence between the subelements and the Gaussian integration points. Two-dimensional modeling is accomplished by assessing the volume flaw reliability with shell elements. To demonstrate the improvements in the algorithm, example problems are selected from a round-robin conducted by WELFEP (WEakest Link failure probability prediction by Finite Element Postprocessors)
Seasonal variability in ichthyoplankton abundance and assemblage composition in the northern Gulf of Mexico off Alabama
Multiyear ichthyoplankton surveys used to monitor larval fish seasonality, abundance, and assemblage structure can provide early indicators of regional ecosystem changes.
Numerous ichthyoplankton surveys have been conducted in the northern Gulf of Mexico, but few have had high levels of temporal resolution and sample replication. In this study, ichthyoplankton samples were collected monthly (October 2004–October 2006) at a single station off the coast of
Alabama as part of a long-term biological survey. Four seasonal periods were identified from observed and
historic water temperatures, including a relatively long (June–October) “summer” period (water temperature >26°C). Fish egg abundance, total larval abundance, and larval
taxonomic diversity were significantly related to water temperature (but not salinity), with peaks in the spring,
spring–summer, and summer periods, respectively. Larvae collected during the survey represented 58 different
families, of which engraulids, sciaenids, carangids, and clupeids were the most prominent. The most abundant taxa collected were unidentified engraulids (50%), sand seatrout
(Cynoscion arenarius, 7.5%), Atlantic bumper (Chloroscombrus chrysurus, 5.4%), Atlantic croaker (Micropogonias undulatus, 4.4%), Gulf menhaden (Brevoortia patronus, 3.8%), and unidentified gobiids (3.6%). Larval
concentrations for dominant taxa were highly variable between years, but the timing of seasonal occurrence for
these taxa was relatively consistent. Documented increases in sea surface temperature on the Alabama shelf may have various implications for larval fish dynamics, as indicated by the presence of tropical larval forms (e.g., fistularids, labrids, scarids, and acanthurids) in our ichthyoplankton collections and in recent juvenile surveys
of Alabama and northern Gulf of Mexico seagrass habitats
Protecting Teachers or Protecting Children? Media Representations of Vergara v. California
Over the past five years, the laws governing teachers’ employment have been at the center of legal and political conflicts in state courts and elections across the United States.  Vergara v. California challenged five California state statutes that provide employment protections for teachers. Drawing on the theory of political spectacle, we conducted a media content analysis of 42 print news media articles published prior to the court’s decision in June 2014.  Two aspects of political spectacle, the use of metaphor and the illusion of rationality were the most salient and deployed in ways that were more closely aligned with the student plaintiffs’ claims than the statutes’ defenders. We conclude by highlighting how the framing of these and other similar stories may shape subsequent debates about public education in the United States.En la última década las leyes que rigen el empleo de docentes han estado en el
centro de los conflictos jurĂdicos y polĂticos en los tribunales estatales y las
elecciones en los Estados Unidos. El caso Vergara v. California desafiĂł cinco leyes
del estado de California que proporcionan protecciĂłn laboral a los docentes. Basándonos en la teorĂa del espectáculo polĂtico, analizamos el contenido de 42
artĂculos publicadas en la prensa antes de la decisiĂłn de la corte en junio de 2014. Dos aspectos de la teorĂa de espectáculo polĂtico, el uso de metáforas y la ilusiĂłn de
la racionalidad fueron los más destacados y usados de manera estrechamente
alineadas con las demandas sobre los estatutos de los estudiantes en detrimento de
las demandas de la defensa. Concluimos, poniendo de relieve la forma en que este
tipo de encuadramiento sobre esta y otras historias similares puede afectar futuros
debates sobre la educaciĂłn pĂşblica en los Estados Unidos
In vitro Accelerated Aging of Composites and a Sealant
The in vitro accelerated aging of conventional and microfilled composite restorative materials and a sealant was studied. Volume loss/surface area ranged from 2.0 to 7.3 x 10-3 mm3/mm2 after 900 h of aging. Surface morphology changed more dramatically for the conventional composites than for the other materials. Changes in surface chemistry as measured by FTIR-ATR were observed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67091/2/10.1177_00220345810600090701.pd
Treatment of hemorrhagic hepatic cysts with omentalization in a serval.
A 2 year old, spayed female African serval was evaluated for a history of abdominal distention. Physical examination findings were consistent with cranial abdominal masses and anemia. Abdominal imaging revealed soft tissue opacity masses in the cranial abdomen and hypoechoic cysts arising from the liver parenchyma. Conservative management failed to improve clinical signs, and a midline exploratory laparotomy was performed. Three large hemorrhagic cysts were visualized occupying a significant amount of the liver parenchyma. The cysts were drained, omentalized and partially closed with a surgical stapler and suture. Histopatological evaluation of the resected tissue was consistent with a chronic hepatic hematoma. The patient recovered well and was discharged 3 days postoperatively. Two years later, the patient was readmitted with the same clinical signs and large multiple hepatic cysts involving most of the liver lobes. These were surgically omentalized similarly to the previous surgery and the patient recovered well postoperatively. Two years later, return to normal life and no recurrence of the cysts was reported
L1551NE - Discovery of a Binary Companion
L1551NE is a very young (class 0 or I) low-mass protostar located close to
the well-studied L1551 IRS5. We present here evidence, from 1.3mm continuum
interferometric observations at ~1'' resolution, for a binary companion to
L1551NE. The companion, whose 1.3mm flux density is ~1/3 that of the primary
component, is located 1.43'' (~230 A.U. at 160pc) to the southeast. The
millimeterwave emission from the primary component may have been just barely
resolved, with deconvolved size ~0.82"x0.70" (~131x112 A.U.). The companion
emission was unresolved (<100 A.U.). The pair is embedded within a flattened
circum-binary envelope of size ~5.4'' x 2.3'' (~860 x 370 A.U.). The masses of
the three components (i.e. from the cicumstellar material of the primary star
and its companion, and the envelope) are approximately 0.044, 0.014 and 0.023
Mo respectively.Comment: 8 pages, 1 figur
Color Stability of New Composite Restorative Materials Under Accelerated Aging
The color stability of seven microfilled and conventional composites under conditions of accelerated aging was evaluated by reflection spectrophotometry. During early aging the composites generally became darker, more chromatic, and more opaque. The in vitro color stability of the microfilled composites was better and less influenced by erosion than the conventional composites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66615/2/10.1177_00220345800590120801.pd
Creep Life Prediction of Ceramic Components Using the Finite Element Based Integrated Design Program (CARES/Creep)
The desirable properties of ceramics at high temperatures have generated interest in their use for structural applications such as in advanced turbine systems. Design lives for such systems can exceed 10,000 hours. Such long life requirements necessitate subjecting the components to relatively low stresses. The combination of high temperatures and low stresses typically places failure for monolithic ceramics in the creep regime. The objective of this work is to present a design methodology for predicting the lifetimes of structural components subjected to multiaxial creep loading. This methodology utilizes commercially available finite element packages and takes into account the time varying creep stress distributions (stress relaxation). In this methodology, the creep life of a component is divided into short time steps, during which, the stress and strain distributions are assumed constant. The damage, D, is calculated for each time step based on a modified Monkman-Grant creep rupture criterion. For components subjected to predominantly tensile loading, failure is assumed to occur when the normalized accumulated damage at any point in the component is greater than or equal to unity
Seasonal Variability in Ichthyoplankton Abundance and Assemblage Composition in the Northern Gulf of Mexico off Alabama
Multiyear ichthyoplankton surveys used to monitor larval fish seasonality, abundance, and assemblage structure can provide early indicators of regional ecosystem changes. Numerous ichthyoplankton surveys have been conducted in the northern Gulf of Mexico, but few have had high levels of temporal resolution and sample replication. In this study, ichthyoplankton samples were collected monthly (October 2004–October 2006) at a single station off the coast of Alabama as part of a long-term biological survey. Four seasonal periods were identified from observed and historic water temperatures, including a relatively long (June–October) “summer” period (water temperature \u3e26°C). Fish egg abundance, total larval abundance, and larval taxonomic diversity were significantly related to water temperature (but not salinity), with peaks in the spring, spring–summer, and summer periods, respectively. Larvae collected during the survey represented 58 different families, of which engraulids, sciaenids, carangids, and clupeids were the most prominent. The most abundant taxa collected were unidentified engraulids (50%), sand seatrout (Cynoscion arenarius, 7.5%), Atlantic bumper (Chloroscombrus chrysurus, 5.4%), Atlantic croaker (Micropogonias undulatus, 4.4%), Gulf menhaden (Brevoortia patronus, 3.8%), and unidentified gobiids (3.6%). Larval concentrations for dominant taxa were highly variable between years, but the timing of seasonal occurrence for these taxa was relatively consistent. Documented increases in sea surface temperature on the Alabama shelf may have various implications for larval fish dynamics, as indicated by the presence of tropical larval forms (e.g., fistularids, labrids, scarids, and acanthurids) in our ichthyoplankton collections and in recent juvenile surveys of Alabama and northern Gulf of Mexico seagrass habitats
Joining up health and bioinformatics: e-science meets e-health
CLEF (Co-operative Clinical e-Science Framework) is an MRC sponsored project in the e-Science programme that aims to establish methodologies and a technical infrastructure forthe next generation of integrated clinical and bioscience research. It is developing methodsfor managing and using pseudonymised repositories of the long-term patient histories whichcan be linked to genetic, genomic information or used to support patient care. CLEF concentrateson removing key barriers to managing such repositories ? ethical issues, informationcapture, integration of disparate sources into coherent ?chronicles? of events, userorientedmechanisms for querying and displaying the information, and compiling the requiredknowledge resources. This paper describes the overall information flow and technicalapproach designed to meet these aims within a Grid framework
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