2,256 research outputs found

    Moving across scales: a quantitative assessment of X-ray CT to measure the porosity of rocks

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    We apply multidimensional X-ray CT to quantify the porosity of Berea Sandstone by using both medical- and synchrotron-based X-ray radiation, so as to produce images of the same sample with mm- and micron-resolution, respectively. Three different samples are used and the obtained tomograms are compared by considering the spatial distribution of porosity values for the range of voxel sizes 0.25-16 mm3. The agreement between the two independent techniques is assessed by means of the concordance correlation coefficient. Statistically significant correlations are found for each sample up to the maximum resolution of the medical CT scanner, i.e. for images with a voxel size of (0.5x0.5x1) mm3. The direct comparison of images obtained by medical- and synchrotron-based X-ray radiation has a dual benefit. First, it objectively informs the segmentation step required for the binarization of the high-resolution synchrotron images that is otherwise prone to operator bias; in this context, the applicability of the proposed workflow is demonstrated with two widely applied locally adaptive thresholding algorithms, namely the hysteresis and the watershed methods. Secondly, once this calibration has occurred, the coupling of the two techniques allows analyzing porosity heterogeneity across a range of length-scales that spans over more than eight orders of magnitudes. We anticipate that the ability to perform a true multi-scale experiment may represent the required point of departure for developing up-scaling approaches that capture the inherently complex heterogeneity of rocks

    PERANCANGAN ARSITEKTUR MENGGUNAKAN KERANGKA KERJA ZACHMAN UNTUK SISTEM INFORMASI PERUMAHAN DAN PERMUKIMAN (SIPERKIM)

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    Enterprise architecture plan of Karawang public housing agency information system designed using Zachman framework and used as reference for planning an enterprise architecture SETTLEMENT AND HOUSING AREA INFORMATION SYSTEM so that able to build an integrated information system to make the good governance comes true, especially in applications. Data collections have been done by Interviews and document analysis. Analysis parameters used are Strenghts, Weakness, Opportunities, threats (SWOT) dan Value Chain. This Enterprise architecture planning intends to build integrated information system from villages to cities through Karawang public housing agency. The result of this research is a blueprint on zachman framework that can be seen from planner and owner perspective with 4 sides, they are Data (what), Function (how), Network (where), and people (who), so that it can support application process in Karawang public housing agency

    Anisotropy effects on the magnetic excitations of a ferromagnetic monolayer below and above the Curie temperature

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    The field-driven reorientation transition of an anisotropic ferromagnetic monolayer is studied within the context of a finite-temperature Green's function theory. The equilibrium state and the field dependence of the magnon energy gap E0E_0 are calculated for static magnetic field HH applied in plane along an easy or a hard axis. In the latter case, the in-plane reorientation of the magnetization is shown to be continuous at T=0, in agreement with free spin wave theory, and discontinuous at finite temperature T>0T>0, in contrast with the prediction of mean field theory. The discontinuity in the orientation angle creates a jump in the magnon energy gap, and it is the reason why, for T>0T>0, the energy does not go to zero at the reorientation field. Above the Curie temperature TCT_C, the magnon energy gap E0(H)E_0(H) vanishes for H=0 both in the easy and in the hard case. As HH is increased, the gap is found to increase almost linearly with HH, but with different slopes depending on the field orientation. In particular, the slope is smaller when HH is along the hard axis. Such a magnetic anisotropy of the spin-wave energies is shown to persist well above TCT_C (T1.2TCT \approx 1.2 T_C).Comment: Final version accepted for publication in Physical Review B (with three figures

    Energy refurbishment of the general physiology institute at Sapienza university campus

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    The energy requalification of the existing building heritage is one of the pillars European Union energy policy. A large part of the building heritage was built without taking into consideration the problem of energy consumption. With the aim of energy efficiency and energy savings in electrical uses, there are wide and diversified possibilities for improvement, including interventions on the building envelope and on the systems, with the introduction, where possible, of renewable energy sources. In this context, the redevelopment of historic buildings constitutes an important challenge, which involves both historical-artistic aspects and technological aspects relating to the improvement of energy efficiency and comfort. A critical analysis of every possibility is essential to preserve the balance between efficiency and architecture. The purpose of the study is the energy retrofitting of the Institute of General Physiology located within the "Sapienza" University campus. The proposed interventions include the renovation of the whole building envelope, investigated by thermographic surveys, and the installation of new heating and cooling systems. The results were analysed to identify the best intervention for a sustainable energy renovation of the historic building, taking into account the preservation of its architectural values and making it suitable for modern use

    Nekrasov-Shatashvili limit of the 5D superconformal index

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    C. P. is supported by the Royal Society through a University Research Fellowship. A. P. and D. R. G. are partly supported by the Spanish Government Grant No. MINECO-13-FPA2012-35043-C02-02. In addition, they acknowledge financial support from the Ramon y Cajal Grant No. RYC-2011-07593 as well as the EU CIG Grant No. UE-14-GT5LD2013-618459. The work of A. P. is funded by the Asturian Government SEVERO OCHOA Grant No. BP14-003

    Validity and reliability of the Structured Clinical Interview for Depersonalization-Derealization Spectrum (SCI-DER).

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    This study evaluates the validity and reliability of a new instrument developed to assess symptoms of depresonalization: the Structured Clinical Interview for the Depersonalization-Derealization Spectrum (SCI-DER). The instrument is based on a spectrum model that emphasizes soft-signs, sub-threshold syndromes as well as clinical and subsyndromal manifestations. Items of the interview include, in addition to DSM-IV criteria for depersonalization, a number of features derived from clinical experience and from a review of phenomenological descriptions. Study participants included 258 consecutive patients with mood and anxiety disorders, 16.7% bipolar I disorder, 18.6% bipolar II disorder, 32.9% major depression, 22.1% panic disorder, 4.7% obsessive compulsive disorder, and 1.5% generalized anxiety disorder; 2.7% patients were also diagnosed with depersonalization disorder. A comparison group of 42 unselected controls was enrolled at the same site. The SCI-DER showed excellent reliability and good concurrent validity with the Dissociative Experiences Scale. It significantly discriminated subjects with any diagnosis of mood and anxiety disorders from controls and subjects with depersonalization disorder from controls. The hypothesized structure of the instrument was confirmed empirically

    Environmental impacts of reusable transport items: A case study of pallet pooling in a retailer supply chain

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    Manufacturing, storage, and transportation processes are typically facilitated by pallets, containers, and other reusable transport items (RTIs) designed to guarantee many cycles along a lifespan of several years. As a consequence, both supply and reverse transportation of RTIs need to be managed to avoid stockout along the supply chain and the unsustainable production of new tools from virgin materials. This paper focuses on the business of pallet management by analyzing the transport operations of a pallet pooling network serving a large-scale nationwide retailer. The pooler is responsible for supplying, collecting, and refurbishing pallets. The combination of the pooler's management strategies with different retailer network configurations results in different pooling scenarios, which are assessed and compared in this paper through a what-if analysis. The logistical and environmental impacts generated by the pallet distribution activities are quantified per each scenario through a tailored software incorporating Geographic Information System (GIS) and routing functionalities. Findings from this analysis suggest how to reduce vehicle distance traveled (vehicles-km) by 65% and pollutant emissions by 60% by combining network infrastructures and pooling management strategies-identifying an empirical best practice for managers of pallet businesses

    Environmental impacts of reusable transport items: A case study of pallet pooling in a retailer supply chain

    Get PDF
    Manufacturing, storage, and transportation processes are typically facilitated by pallets, containers, and other reusable transport items (RTIs) designed to guarantee many cycles along a lifespan of several years. As a consequence, both supply and reverse transportation of RTIs need to be managed to avoid stockout along the supply chain and the unsustainable production of new tools from virgin materials. This paper focuses on the business of pallet management by analyzing the transport operations of a pallet pooling network serving a large-scale nationwide retailer. The pooler is responsible for supplying, collecting, and refurbishing pallets. The combination of the pooler's management strategies with different retailer network configurations results in different pooling scenarios, which are assessed and compared in this paper through a what-if analysis. The logistical and environmental impacts generated by the pallet distribution activities are quantified per each scenario through a tailored software incorporating Geographic Information System (GIS) and routing functionalities. Findings from this analysis suggest how to reduce vehicle distance traveled (vehicles-km) by 65% and pollutant emissions by 60% by combining network infrastructures and pooling management strategies-identifying an empirical best practice for managers of pallet businesses
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