6,760 research outputs found
Bismuth oxide based ceramics with improved electrical and mechanical properties: Part II. Structural and mechanical properties
Coprecipitation as a method of preparation for bismuth oxides based ceramics yields relatively strong and machineable materials in comparison with the solid state reaction. Compositions within the system (1âx)Bi2O3|xEr2O3 containing up to twenty five mole percent of erbium oxide show a slow transition on heating at 900 K from a cubic to a hexagonal (rhombohedral) phase. The resulting hexagonal phase is stable up to 1000 K where it transforms back to the cubic phase. Long term heating at 775 K causes formation of traces of â - bismuth oxide in these samples, but the material itself remains cubic. Compositions containing thirty mole percent of erbium oxide do not show any such changes and hence are suitable for application purposes
Detecting Controversies in Online News Media
This paper sets out to detect controversial news reports using online discussions as a source of information. We define controversy as a public discussion that divides society and demonstrate that a content and stylometric analysis of these debates yields useful signals for extracting disputed news items. Moreover, we argue that a debate-based approach could produce more generic models, since the discussion architectures we exploit to measure controversy occur on many different platforms
Mach's Principle and Model for a Broken Symmetric Theory of Gravity
We investigate spontaneous symmetry breaking in a conformally invariant
gravitational model. In particular, we use a conformally invariant scalar
tensor theory as the vacuum sector of a gravitational model to examine the idea
that gravitational coupling may be the result of a spontaneous symmetry
breaking. In this model matter is taken to be coupled with a metric which is
different but conformally related to the metric appearing explicitly in the
vacuum sector. We show that after the spontaneous symmetry breaking the
resulting theory is consistent with Mach's principle in the sense that inertial
masses of particles have variable configurations in a cosmological context.
Moreover, our analysis allows to construct a mechanism in which the resulting
large vacuum energy density relaxes during evolution of the universe.Comment: 9 pages, no figure
Lesion Eccentricity Plays a Key Role in Determining the Pressure Gradient of Serial Stenotic Lesions:Results from a Computational Hemodynamics Study
Purpose: In arterial disease, the presence of two or more serial stenotic lesions is common. For mild lesions, it is difficult to predict whether their combined effect is hemodynamically significant. This study assessed the hemodynamic significance of idealized serial stenotic lesions by simulating their hemodynamic interaction in a computational flow model. Materials and Methods: Flow was simulated with SimVascular software in 34 serial lesions, using moderate (15Â mL/s) and high (30Â mL/s) flow rates. Combinations of one concentric and two eccentric lesions, all 50% area reduction, were designed with variations in interstenotic distance and in relative direction of eccentricity. Fluid and fluidâstructure simulations were performed to quantify the combined pressure gradient. Results: At a moderate flow rate, the combined pressure gradient of two lesions ranged from 3.8 to 7.7Â mmHg, which increased to a range of 12.5â24.3Â mmHg for a high flow rate. Eccentricity caused an up to two-fold increase in pressure gradient relative to concentric lesions. At a high flow rate, the combined pressure gradient for serial eccentric lesions often exceeded the sum of the individual lesions. The relative direction of eccentricity altered the pressure gradient by 15â25%. The impact of flow pulsatility and wall deformability was minor. Conclusion: This flow simulation study revealed that lesion eccentricity is an adverse factor in the hemodynamic significance of isolated stenotic lesions and in serial stenotic lesions. Two 50% lesions that are individually non-significant can combine more often than thought to hemodynamic significance in hyperemic conditions. Graphical Abstract: (Figure presented.).</p
Tackling the Algorithmic Control Crisis -the Technical, Legal, and Ethical Challenges of Research into Algorithmic Agents
Algorithmic agents permeate every instant of our online existence. Based on our digital profiles built from the massive surveillance of our digital existence, algorithmic agents rank search results, filter our emails, hide and show news items on social networks feeds, try to guess what products we might buy next for ourselves and for others, what movies we want to watch, and when we might be pregnant. Algorithmic agents select, filter, and recommend products, information, and people; they increasingly customize our physical environments, including the temperature and the mood
Follow-up of colorectal cancer patients: quality of life and attitudes towards follow-up.
The aims of our study were to assess the effect of follow-up on the quality of life of colorectal cancer patients and to assess the attitudes of patients towards follow-up as a function of patient characteristics. Patients who had been treated with curative intent were selected from four types of hospitals. Eighty-two patients were interviewed using a structured questionnaire, whereas 130 patients received the questionnaire by mail. To assess the effect of follow-up on the quality of life, the interviewed patients were randomly allocated to three groups and interviewed at different times in relation to the follow-up visit. Analysis did not show an effect of the follow-up visit on quality of life. Patients reported a positive attitude towards follow-up: it reassured them, they judged the communication with the physician to be positive, and they experienced only slight nervous anticipation and few other disadvantages. Patients reported a strong preference for follow-up, and a large majority would prefer follow-up even if it would not lead to earlier detection of a recurrence. Apart from living situation, no patient characteristics were clearly associated with the attitude towards follow-up. Implications for clinical practice are discussed
Acute Pancreatitis Complicated with Choledochal Duct Rupture
Recurrent acute pancreatitis is a rare clinical entity in childhood with unknown incidence (Rosendahl et al., 2007) and often occurring in a familial context. Genetic factors such as PRSS1 mutations (cationic trypsinogen gene) can be found in some patients. However, many remain idiopathic. The natural history remains poorly documented and the most frequent complications reported are pain, exocrine pancreatic insufficiency, diabetes mellitus, and pancreatic adenocarcinoma after long-standing hereditary pancreatitis. We describe a patient with hereditary pancreatitis in whom a mild pancreatitis episode was complicated by a perforation of the ductus choledochus
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