765 research outputs found

    The canonical effect in statistical models for relativistic heavy ion collisions

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    Enforcing exact conservation laws instead of average ones in statistical thermal models for relativistic heavy ion reactions gives raise to so called canonical effect, which can be used to explain some enhancement effects when going from elementary (e.g. pp) or small (pA) systems towards large AA systems. We review the recently developed method for computation of canonical statistical thermodynamics, and give an insight when this is needed in analysis of experimental data.Comment: 4 pages, 3 figures. Talk given in Strangeness in Quark Matter, Frankfurt am Main 2001. Submitted to J. Phys. G: Nucl. Part. Phy

    Cumulative processes related to event histories

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    Costs or benefits which accumulate for individuals over time are of interest in many life history processes. Familiar examples include costs of health care for persons with chronic medical conditions, the payments to insured persons during periods of disability, and quality of life which is sometimes used in the evaluation of treatments in terminally ill patients. For convenience, here we use the term costs to refer to cost or other cumulative measures. Two important scenarios are (i) where costs are associated with the occurrence of certain events, so that total cost accumulates as a step function, and (ii) where individuals may move between various states over time, with cost accumulating at a constant rate determined by the state occupied. In both cases, there is frequently a random variable T that represents the duration of the process generating the costs. Here we consider estimation of the mean cumulative cost over a period of interest using methods based upon marginal features of the cost process and intensity based models. Robustness to adaptive censoring is discussed in the context of the multi-state methods. Data from a quality of life study of breast cancer patients are used to illustrate the methods.Peer Reviewe

    Cumulative processes related to event histories

    Get PDF
    Costs or benefits which accumulate for individuals over time are of interest in many life history processes. Familiar examples include costs of health care for persons with chronic medical conditions, the payments to insured persons during periods of disability, and quality of life which is sometimes used in the evaluation of treatments in terminally ill patients. For convenience, here we use the term costs to refer to cost or other cumulative measures. Two important scenarios are (i) where costs are associated with the occurrence of certain events, so that total cost accumulates as a step function, and (ii) where individuals may move between various states over time, with cost accumulating at a constant rate determined by the state occupied. In both cases, there is frequently a random variable T that represents the duration of the process generating the costs. Here we consider estimation of the mean cumulative cost over a period of interest using methods based upon marginal features of the cost process and intensity based models. Robustness to adaptive censoring is discussed in the context of the multi-state methods. Data from a quality of life study of breast cancer patients are used to illustrate the methods

    A review of internet of energy based building energy management systems: Issues and recommendations

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    © 2013 IEEE. A building energy management system (BEMS) is a sophisticated method used for monitoring and controlling a building's energy requirements. A number of potential studies were conducted in nearly or net zero energy buildings (nZEBs) for the optimization of building energy consumption through efficient and sustainable ways. Moreover, policy makers are approving measures to improve building energy efficiency in order to foster sustainable energy usages. However, the intelligence of existing BEMSs or nZEBs is inadequate, because of the static set points for heating, cooling, and lighting, the complexity of large amounts of BEMS data, data loss, and network problems. To solve these issues, a BEMS or nZEB solution based on the Internet of energy (IoE) provides disruptive opportunities for revolutionizing sustainable building energy management. This paper presents a critical review of the potential of an IoE-based BEMS for enhancing the performance of future generation building energy utilization. The detailed studies of the IoE architecture, typical nZEB configuration, different generations of nZEB, and smart building energy systems for future BEMS are investigated. The operations, advantages, and limitations of the existing BEMSs or nZEBs are illustrated. A comprehensive review of the different types of IoE-based BEMS technologies, such as energy routers, storage systems and materials, renewable sources, and plug-and-play interfaces, is then presented. The rigorous review indicates that existing BEMSs require advanced controllers integrated with IoE-based technologies for sustainable building energy usage. The main objective of this review is to highlight several issues and challenges of the conventional controllers and IoE applications of BEMSs or nZEBs. Accordingly, the review provides several suggestions for the research and development of the advanced optimized controller and IoE of future BEMSs. All the highlighted insights and recommendations of this review will hopefully lead to increasing efforts toward the development of the future BEMS applications

    Review of Energy Storage System Technologies in Microgrid Applications:Issues and Challenges

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    Mineralogy of some soils from the Amazonia Sedimentary Basin.

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    ABSTRACT: The Amazonia Forest is an important biome that possesses great diversity of fauna and flora, which can play a significant role in several science areas, specially, the gene reserve for the future of humankind. Nevertheless, it is a very poorly understood environment, particularly the basis of this ecosystem, its soils. This study was conducted to gain insight in the mineralogy of important soils classes of the Amazonia sedimentary basin. The soils in the upland position in the landscape are developed from tertiary sediments belonging to the Alter do Chão series and those in the floodplain position are derived from quaternary, more specifically, Holocene´s sediments. Sand, silt and clay fractions were separated and X-ray diffraction analysis was conducted. Very simple mineralogy composed basically of quartz in the coarser fractions and kaolinite, goethite and anatase for the finer fraction was found for the Oxisol, the Ultisol and the Entisol from an upland toposequence but differences in kaolinite crystallography could be noticed among them. Gibbsite was virtually absent, in spite of the advanced degree of development of most of these soils. More distinctive mineralogy was revealed for the soils developed in the more recent sediments with quartz and feldspars in the sand and silt fractions and a suite of 2:1 minerals also appearing in their clay fraction, besides kaolinite and goethite. In one upland soil petroplinthite is the main feature and its mineralogy reflected its environment of formation which is usually associated with level to gently sloping areas with fluctuating water table

    Geotechnical characterization of Vertisols from Bahia State, Brazil.

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    Despite the existence of vertic soils with predominance of kaolinite is reported around the world, there are few studies shown the influence of this clay mineral in their geotechnical characteristics. The work aimed to perform a geotechnical characterization of Vertisols from Bahia, Brazil, besides understanding the influence of physical, chemical and mineralogical properties on the geotechnical behavior. Three Vertisols were collected in Juazeiro city, in a semi-arid region, one kaolinitic Vertisol and two smectite Vertisols. Other three Vertsols were collected in Recôncavo region, all presented clay mineralogy with codominance of smectite and kaolinite (Sm-K). A geotechnical characterization was carried out in their diagnostic horizons, determining properties such as granulometric curve, clay activity, linear expansion coefficient, compaction capacity, cohesion (c?), and internal friction angle (ϕ) of saturated soils. We observed that the clay content was the attribute that most influenced the geotechnical characteristics. All soils showed expansion potential above 0.01, considered as very high. The kaolinitic Vertisol showed the lowest clay activity. However, the clay content of 68% contributed to this soil to present an expansion potential similar to the smectite Vertisol with clay content of 35%. The major values of soil compaction were observed for the kaolinitic Vertisol, which presented greater reduction of void ratio and higher density as a function of moisture increase. For this soil, the optimal moisture content (OMC) and maximum dry density (MDD) were 22% and 1.65 g cm-3, respectively. The other soils presented OMC between 18-41% and MDD between 1.75-1.24 g cm-3. These smectite-soils, MDD decreased with increasing of OMC. All soils had low c? values, which is expected for high clay content soils. The c? values increased with increasing of kaolinite and decreased with increasing of clay content. The kaolinite Vertisol showed c? of 0.19 kgf cm-2. The c? values to Sm-K Vertisols ranged between 0.05-0.11 kgf cm-2. As for smectite-soil, c? values ranged between 0.02-0.03 kgf cm-2. Low ϕ values were observed for all soils, which indicates low shear resistance. In its turn, ϕ was more influenced by granulometry, in which higher levels of sand and gravel provided higher ϕ, independently of the type of clay. Vertisols with different mineralogy present different geotechnical characteristics. Keywords: Smectite; kaolinite; expansive soil
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