1,803 research outputs found

    A critical comparison of approaches to resource name management within the IEC common information model

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    Copyright @ 2012 IEEEElectricity network resources are frequently identified within different power systems by inhomogeneous names and identities due to the legacy of their administration by different utility business domains. The IEC 61970 Common Information Model (CIM) enables network modeling to reflect the reality of multiple names for unique network resources. However this issue presents a serious challenge to the integrity of a shared CIM repository that has the task of maintaining a resource manifest, linking network resources to master identities, when unique network resources may have multiple names and identities derived from different power system models and other power system applications. The current approach, using CIM 15, is to manage multiple resource names within a singular CIM namespace utilizing the CIM “IdentifiedObject” and “Name” classes. We compare this approach to one using additional namespaces relating to different power systems, similar to the practice used in CIM extensions, in order to more clearly identify the genealogy of a network resource, provide faster model import times and a simpler means of supporting the relationship between multiple resource names and identities and a master resource identity.This study is supported by the UK National Grid and Brunel University

    Modern concepts in non-surgical esthetics; a review

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    New non-surgical esthetics is the most dynamic field in contemporary medicine. At the same time, it is greatly influenced by our contemporary society. This paper reviews modern methods used in non-surgical esthetics, especially in Romania. From injectology and non-surgical face lifting to non-surgical body contouring, we analyzed all procedures performed by Romanian physicians, and we show the advantages and disadvantages of the advanced esthetic procedures. Injectology typically implies hyaluronic acid, botox and mesotherapy (for wrinkles and rejuvenation). Laser and radiofrequency treatment are used for wrinkles as well, with fewer unwanted adverse reactions and results exceeding those of injectables. Non-surgical lifting has gained more ground because it requires little recovery time and the results are very positive. Elective treatment for facial discoloration is the laser approach. For non-surgical body contouring, cryolipolisis, vacuum, radio frequency, and infrared systems have all revolutionized this part of esthetics, but each has limitations, and only after establishing the correct course of action, might we think of achieving favorable results and thus raising to the expectations of patients

    Inflammatory Markers Associated With Subclinical Coronary Artery Disease: The Multicenter AIDS Cohort Study.

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    BackgroundDespite evidence for higher risk of coronary artery disease among HIV+ individuals, the underlying mechanisms are not well understood. We investigated associations of inflammatory markers with subclinical coronary artery disease in 923 participants of the Multicenter AIDS Cohort Study (575 HIV+ and 348 HIV- men) who underwent noncontrast computed tomography scans for coronary artery calcification, the majority (n=692) also undergoing coronary computed tomography angiography.Methods and resultsOutcomes included presence and extent of coronary artery calcification, plus computed tomography angiography analysis of presence, composition, and extent of coronary plaques and severity of coronary stenosis. HIV+ men had significantly higher levels of interleukin-6 (IL-6), intercellular adhesion molecule-1, C-reactive protein, and soluble-tumor necrosis factor-α receptor (sTNFαR) I and II (all P<0.01) and a higher prevalence of noncalcified plaque (63% versus 54%, P=0.02) on computed tomography angiography. Among HIV+ men, for every SD increase in log-interleukin-6 and log intercellular adhesion molecule-1, there was a 30% and 60% increase, respectively, in the prevalence of coronary stenosis ≥50% (all P<0.05). Similarly, sTNFαR I and II in HIV+ participants were associated with an increase in prevalence of coronary stenosis ≥70% (P<0.05). Higher levels of interleukin-6, sTNFαR I, and sTNFαR II were also associated with greater coronary artery calcification score in HIV+ men (P<0.01).ConclusionsHigher inflammatory marker levels are associated with greater prevalence of coronary stenosis in HIV+ men. Our findings underscore the need for further study to elucidate the relationships of inflammatory pathways with coronary artery disease in HIV+ individuals

    Measuring Thermal Profiles in High Explosives using Neural Networks

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    We present a new method for calculating the temperature profile in high explosive (HE) material using a Convolutional Neural Network (CNN). To train/test the CNN, we have developed a hybrid experiment/simulation method for collecting acoustic and temperature data. We experimentally heat cylindrical containers of HE material until detonation/deflagration, where we continuously measure the acoustic bursts through the HE using multiple acoustic transducers lined around the exterior container circumference. However, measuring the temperature profile in the HE in experiment would require inserting a high number of thermal probes, which would disrupt the heating process. Thus, we use two thermal probes, one at the HE center and one at the wall. We then use finite element simulation of the heating process to calculate the temperature distribution, and correct the simulated temperatures based on the experimental center and wall temperatures. We calculate temperature errors on the order of 15{\deg}C, which is approximately 12% of the range of temperatures in the experiment. We also investigate how the algorithm accuracy is affected by the number of acoustic receivers used to collect each measurement and the resolution of the temperature prediction. This work provides a means of assessing the safety status of HE material, which cannot be achieved using existing temperature measurement methods. Additionally, it has implications for range of other applications where internal temperature profile measurements would provide critical information. These applications include detecting chemical reactions, observing thermodynamic processes like combustion, monitoring metal or plastic casting, determining the energy density in thermal storage capsules, and identifying abnormal battery operation

    Microstructure of nanocrystalline diamond powders studied by powder diffractometry

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    High resolution x-ray diffraction peaks of diamond nanosize powders of nominal sizes ranging from 5 to 250 nm were analyzed and provided information on grain structure, average size of crystallites, and concentration of dislocations. Selected samples were heat treated at 1670 K at pressures 2.0 and 5.5 GPa or had surface modified by outgassing, heat treatment at vacuum conditions, and by controlled adsorption of gases. The apparent lattice parameter method was applied to characterize the structure of a shell-core model of nanosize particles. The multiple whole profile fitting provided information on crystallite sizes and density of dislocations. Population of dislocations increased with applied pressure, while strain and interplanar distances in the surface layers decreased. Adsorption of foreign gases on the grain surface modified the structure of the surface layers but did not affect dislocations near the center of the grains

    Arterio-Venous Fistula Using Nonpenetrating Titanium Clips (VCS)

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    Rezumat Fistulã arterio-venoasã cu clipuri metalice nepenetrante Accesul vascular la hemodializã este însoåit în continuare de o morbiditate foarte mare. Tromboza datoratã hiperplaziei neointimale este una din principalele cauze de nefuncåionalitate a accesului vascular. Scopul lucrãrii este de a prezenta tehnica realizãrii anastomozei arterio-venoase folosind clipurile de titan nepenetrante(VCS) şi rezultatul acesteia. Material şi metodã: Pacientului K.L. de 47 ani aflat în evidenåa Clinicii de Nefrologie din 2005 pentru insuficienåã renalã cronicã i s-a efectuat în octombrie 2006 o fistulã arteriovenoasã clasicã între artera radial şi vena cefalicã a antebraåului. Aceastã fistulã nu a funcåionat motiv pentru care în ianuarie 2007 s-a efectuat anastomoza arterio-venoasã cu clipuri de titan nepenetrante între artera brahialã şi vena medianã a antebraåului. Rezultate: Anastomoza a fost realizatã în 17 minute. Dupã declamparea arterelor s-a obåinut puls şi tril la nivelul venei mediane a antebraåului şi la nivelul venei cefalice. Nu au fost complicaåii intraoperatorii şi postoperatorii imediate. La 5 sãptãmâni postoperator s-a efectuat prima hemodializã. Fistula este funcåionalã la 58 de luni de la efectuarea ei. Concluzii: Realizarea anastomozelor arterio-venoase pentru acces la hemodializã cronicã cu material nepenetrant poate fi o soluåie de reducere a complicaåiilor postoperatorii şi de prelungire a patenåei fistulelor. Cuvinte cheie: hemodializã, fistulã arterio-venoasã, clipuri de titan nepenetrante Abstract Vascular access in haemodialysis is still accompanied by a high morbidityrate. Neointimal hyperplasia due to thrombosis is one of the main causes of vascular access failure. The purpose of this paper is to present the use of non-penetrating titanium clips (VCS) forthe creation of an arteriovenous fistula and its outcome. Materials and Methods: A male patient, 47 years old, with end-stage renal disease -ESRD -(2005) was addressed to our service, for a vascular access reintervention, after a failed forearm radio-cephalic fistula performed 3 months before. In January 2007, an arteriovenousfistula between thebrachial artery and themedian cubital vein using non-penetratingtitanium clips (Anastoclip VCS) was created. Results: The vascular anastomosis was performed in 17 min. After unclamping the artery, a solid pulse and consistent thrill were obtained at the level of the cubital fossa. The postoperative course was uneventful. The arteriovenous fistula remains functional 60 months post-surgery. Conclusions: The Anastoclip VCS system is versatile, safe to manipulate and enables fast anastomosis. Arteriovenous anastomosis performed with non-penetrating clips may be a solution with the potential to reduce postoperative complications and extend arteriovenous fistula patency in ESRD

    Characterization of defect structures in nanocrystalline materials by X-ray line profile analysis

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    X-ray line profile analysis is a powerful alternative tool for determining dislocation densities, dislocation type, crystallite and subgrain size and size-distributions, and planar defects, especially the frequency of twin boundaries and stacking faults. The method is especially useful in the case of submicron grain size or nanocrystalline materials, where X-ray line broadening is a well pronounced effect, and the observation of defects with very large density is often not easy by transmission electron microscopy. The fundamentals of X-ray line broadening are summarized in terms of the different qualitative breadth methods, and the more sophisticated and more quantitative whole pattern fitting procedures. The efficiency and practical use of X-ray line profile analysis is shown by discussing its applications to metallic, ceramic, diamond-like and polymer nanomaterials

    DEAR project: Lunar dust surface interactions, risk and removal investigations

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    The DEAR project (Dusty Environment Application Research) investigates the interaction between lunar regolith and surfaces and components relevant for lunar exploration. Based on the TUBS regolith simulant which is representative in chemistry, size and shape properties to Moon soils to study the regolith transport, adhesion and strategies for cleaning. The regolith simulant will be applied to thermal, structural, optical sensor, sealing and other astronautic systems, providing input for requirements, justification and verification. The key applications are split in human space flight regolith investigations, wrinkled surface with random movement and hardware surfaces, flat material defined movement. The paper provides an overview of the DEAR project including a discussion of the first results, in particular vibration, shock and micro-vibration on regolith bearing surfaces. The investigation shall enable better understand the regolith layers interaction and the release mechanism, as well as potential cross contamination and cleaning strategies. The research is complemented by simulation of the regolith motion as parameter surface plasma interactions. The project is funded and supported by the European Space Agency (ESA). DEAR specifically addresses the development and testing of lunar dust removal strategies on optics, mechanisms and human space flight hardware (e.g., space suits). As the Moons regolith is known to be highly abrasive, electrically chargeable, and potentially chemically reactive, lunar dust might reduce the performance of hardware, such as cameras, thermal control surfaces and solar cells. The dust can cause malfunction on seals for on/off mechanisms or space suits. Of particular interest are risk assessment, avoidance, and cleaning techniques such as the use of electric fields to remove lunar dust from surfaces. Representative dust (e.g., regolith analogues of interesting landing sites) will be used in a dedicated test setup to evaluate risks and effects of lunar dust. We describe designs and methods developed by the DEAR consortium to deal with the regolith-related issues, in particular an electrode design to deflect regolith particles, cleaning of astronautical systems with CO2, design of a robotic arm for the testing within the DEAR chamber, regolith removal via shock, and regolith interaction with cleanroom textile
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