13,721 research outputs found
Femtoscopy in Relativistic Heavy Ion Collisions: Two Decades of Progress
Analyses of two-particle correlations have provided the chief means for
determining spatio-temporal characteristics of relativistic heavy ion
collisions. We discuss the theoretical formalism behind these studies and the
experimental methods used in carrying them out. Recent results from RHIC are
put into context in a systematic review of correlation measurements performed
over the past two decades. The current understanding of these results is
discussed in terms of model comparisons and overall trends.Comment: 49 pages, 16 figures; to appear in Annual Review of Nuclear and
Particle Science; final version includes minor updates in text, a few
references added, and two figures updated; Figures and numerical data tables
available at http://www.physics.ohio-state.edu/~lisa/FemtoscopyReview2005
Nanocharacterisation of precipitates in austenite high manganese steels with advanced techniques: HRSTEM and DualEELS mapping
To achieve optimal mechanical properties in high manganese steels, the precipitation of nanoprecipitates of vanadium and niobium carbides is under investigation. It is shown that under controlled heat treatments between 850°C and 950°C following hot deformation, few-nanometre precipitates of either carbide can be produced in test steels with suitable contents of vanadium or niobium. The structure and chemistry of these precipitates are examined in detail with a spatial resolution down to better than 1 nm using a newly commissioned scanning transmission electron microscope. In particular, it is shown that the nucleation of vanadium carbide precipitates often occurs at pre-existing titanium carbide precipitates which formed from titanium impurities in the bulk steel. This work will also highlight the links between the nanocharacterisation and changes in the bulk properties on annealing
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A time-strain monitoring system fabricated via offset lithographic printing
This paper reports progress in the development of strain sensors fabricated using the Conductive Lithographic Film (CLF) printing process. Strain sensitive structures printed via an unmodified offset lithographic printing press using a silver loaded conductive ink have been deposited concurrently with circuit interconnect, to form an electronic smart packaging system. A system populated with SMT components has proven successful in interpreting and logging deformation incidences subjected to a package during testing. It is proposed that with further development such a system could be printed in sync with packaging graphics using a single printing process to form an integrated time – strain monitoring system
Static correction parameters in the lower flood plain of the central Niger delta, Nigeria
Downhole seismic survey was conducted over the lower flood plain of the Central Niger Delta within the Kaiama prospect (OML 28) in an attempt to compute and determine the static correction parameters for the area.Analysis and interpretation of data from 14 downhole locations using NESURVELANA software shows that the thickness of the weathered (low velocity) layer is laterally variable from about 2.6m to 5.8 m with an average of 4.3 m. The weathering velocity ranges from 383 m/s to 985 m/s with an average value of 546 m/s. The consolidated layer below the weathered layer has a velocity ranging between 1646 and 1893 m/s with an average value of 1763 m/s. Knowledge of these computed parameters can be applied in oil and gas exploration and interpretation, also in civil engineering, where the determined LVL provides an estimate of the foundation depth for massive construction works, another area of application is in the exploration and exploitation of groundwater
Effects of Team Identification on Social and Emotional Adjustment in Higher Education
Students who highly identify with a team are likely to share a personal self-concept with larger groups in higher education. The improved self-worth is positively associated with the adjustment to college life, and is considered one of the significant predictors to achieve students’ educational goals. However, little research has been conducted to scrutinize the effects of team identification on school adjustment. The purpose of this study, therefore, was to examine direct and indirect relationships among team identification, personal self-esteem, and school adjustment. A total of 254 undergraduate students at a FBS institution in the southeastern region of the United States participated in the study. The results revealed that the higher team identification students possess, the higher personal worth they feel. In addition, team identification and personal self-esteem led to social adjustment while personal self-esteem and social adjustment had a positive impact on emotional adjustment. By understanding team identification as an important academic facilitator, administrators in both the academic and athletic fields can develop the most appropriate environment for students to enhance their adjustment to college life
COPD and cardiovascular disease
COPD is one of the major public health problems in people aged 40 years or above. It is currently the 4th leading cause of death in the world and projected to be the 3rd leading cause of death by 2020. COPD and cardiac comorbidities are frequently associated. They share common risk factors, pathophysiological processes, signs and symptoms, and act synergistically as negative prognostic factors. Cardiac disease includes a broad spectrum of entities with distinct pathophysiology, treatment and prognosis. From an epidemiological point of view, patients with COPD are particularly vulnerable to cardiac disease. Indeed, mortality due to cardiac disease in patients with moderate COPD is higher than mortality related to respiratory failure. Guidelines reinforce that the control of comorbidities in COPD has a clear benefit over the potential risk associated with the majority of the drugs utilized. On the other hand, the true survival benefits of aggressive treatment of cardiac disease and COPD in patients with both conditions have still not been clarified. Given their relevance in terms of prevalence and prognosis, we will focus in this paper on the management of COPD patients with ischemic coronary disease, heart failure and dysrhythmia.Novartis Portugal
Novartisinfo:eu-repo/semantics/publishedVersio
Cooling and control of a cavity optoelectromechanical system
We implement a cavity optoelectromechanical system integrating electrical actuation capabilities of nanoelectromechanical devices with ultrasensitive mechanical transduction achieved via intracavity optomechanical coupling. Electrical gradient forces as large as 0.40 mu N are realized, with simultaneous mechanical transduction sensitivity of 1.5 x 10(-18) mHz(-1/2) representing a 3 orders of magnitude improvement over any nanoelectromechanical system to date. Optoelectromechanical feedback cooling is demonstrated, exhibiting strong squashing of the in-loop transduction signal. Out-of-loop transduction provides accurate temperature calibration even in the critical paradigm where measurement backaction induces optomechanical correlations
Impacts of Remotely Sensed Land Use Data on Watershed Hydrologic Change Assessment
Urbanization affects the stream system of a watershed. Increased urbanization alters the land cover and surface characteristics, the stream channel characteristics, and pollutant load of a stream system by increasing the amount of impervious surface. Once rural, forest, or wetland areas are changed to streets, highways, parking lots, sidewalks, and building rooftops. This results in large volumes of runoff being generated for an intense storm over a relatively short time period. As a result, sensitive ecosystems are likely to be damaged by increased urbanization.
Projecting the impact of land use changes on a watershed scale often requires the use of remote sensing data to derive the required inputs on land cover and the related amount of impervious surface. Such forecasts are then used to devise alternative land use and stormwater control policies. One critical question that arises then is the impact of land use/land cover (LULC) mapping error on the resulting hydrologic model projections. In this research, we developed a methodology to assess those impacts. The Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) model was used to estimate the peak hydrograph for a baseline land use condition and then used to estimate the impact of LULC mapping accuracy levels on those forecasts. The Big Darby Creek Watershed located near Columbus, Ohio, which is experiencing increased urbanization, was selected to map LULC, calibrate a hydrologic model, and assess the hydrologic change due to LULC mapping error. The resulting analysis showed that modest changes in land cover classification did not produce significant impacts on the hydrologic modeling results in rural basins. However, the hydrologic changes are noticeable in urbanizing watersheds. The framework developed in this paper can be used for future modeling efforts to understand the hydrological impact of LULC change in a watershed at a large scale
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Nucleation and phase selection in undercooled melts: Magnetic alloys of industrial relevance (MAGNEPHAS)
Studies of phase selection and microstructure evolution in high-performance magnetic materials are an urgent need for optimization of production routes. Containerless solidification experiments by electromagnetic levitation and drop tube solidification were conducted in undercooled melts of Fe-Co, Fe-Ni soft magnetic, and Nd-Fe-B hard magnetic alloys. Melt undercooling under microgravity was achieved in the TEMPUS facility during parabolic flight campaigns. For Fe-Co and Fe-Ni alloys significant effects of microgravity on metastable phase formation were discovered. Microstructure modifications as well as metastable phase formation as function of undercooling and melt flow were elucidated in Nd-Fe-B. Modeling of solidification processes, fluid flow and heat transfer provide predictive tools for microstructure engineering from the melt. They were developed as a link between undercooling experiments under terrestrial and microgravity conditions and the production routes of magnetic materials
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