177,760 research outputs found
Implementation of a new bi-directional solar modelling method for complex facades within the ESP-r building simulation program
No full textThis paper provides an overview of a new method for modelling the total solar energy transmittance. It is implemented in the ESP-r building simulation program to model complex façades such as double glazed façades with external, internal or integrated shading devices. This new model has been validated and tested for several cases. The new model required changes to the solar control simulation algorithm and the user interface, so a new “Advanced optics menu” was also introduced into ESP-r. The paper presents the interface development and application of the new technique to different simulation configurations (especially different complex façades with shading devices) in a standard office building
Un approccio accurato per simulare le strategie di controllo solare di facciate complesse attraverso il software ESP-r e le sue differenti applicazioni
No full textQuesto lavoro riporta una panoramica delle capacità e delle possibili applicazioni di un nuovo metodo per calcolare il fattore solare (g-value) di facciate complesse. Con il nuovo metodo, che è stato implementato in ESP-r (software di simulazione energetica dinamica) gli architetti, gli ingeneri o i ricercatori possono modellare e simulare in modo accurato differenti facciate complesse (come sistemi vetrati con schermature solari).
Oggi gli architetti amano sempre più progettare i loro edifici con grandi superfici vetrate e soluzioni tecnologiche high-tech. Ma gli attuali software utilizzano metodi semplificati che non considerano le reali proprietà (geometriche, ottiche e termiche) delle facciate stesse. Per questo motivo un nuovo modello di calcolo è stato sviluppato al Fraunhofer ISE per valutare il fattore solare e colmare questo gap. Il nuovo modello, chiamato “Black Box Model” è stato implementato nel software ESP-r e permette di integrare e considerare le proprietà delle facciate complesse nel programma di simulazione stesso senza però dover modellare alcun dettaglio nel programma stesso, ma utilizzando dati precalcolati o misurati.
Il nuovo modello è stato già validato e testato per numerosi casi.
Il lavoro mostrerà il nuovo modello a le sue potenzialità in particolare per valutare l’impatto di diverse strategie di controllo solare per la gestione dei sistemi di schermatura in un ufficio standard.
I software RADIANCE/DAYSIM sono stati utilizzati per le simulazioni illuminotecniche per predire i livelli di illuminamento interno e gestire i sistemi di schermatura
Load Separation Principle in Determination of J-R curve for Ductile Polymers: Suitability of Different Material Deforrmation Functions Used in the Normalization Method
No full textThe load separation principle states thal the load, P, can be represented as the multiplication of two independent functions: a crack geometry function, G(a), and a material deformation function, H(v). The principle constitutes the theoretical basis for the single-specimen J-integral experiment and the incremental calculation of J-integral crack growth reaislance (J-R) curves. The normalization method is a new method, which assumes load separation and uses characteristic deformation properties of materials to relate load, displacement and crack length in a functional form. From the deformation material function or "material key curve", J-R curve can be developed from a single precracking experiment. This investigation deals with the applicability of the load separation criterion to evaluation of ductile fracture mechanics parameters in rubber-modified polystyrene, polypropylene, rubber-modified PMMA, ABS resin and high-density polyethylene in the bending configuration. Different mathematical relationships for the deformation function (power law function, LMN function and combined power law straight line relationship) have been proposed and compared. The resulting J-R curves are in good agreement with those obtained by the traditional multiple-specimen technique. The results presented here imply that the use of a single load-displacement method for evaluation of J-integrals for ductile polymers is possible and hence also the normalization method can be used for evaluation of J-R curves from a single-test record
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Factors influencing the daily behaviour of dissolved gaseous mercury concentration in the Mediterranean Sea
No full textCell cycle regulation of NF-YC nuclear localization
No full text: Anti-cancer properties of palm oil have been attributed to the presence of tocotrienols and carotenoids. Studies from various laboratories have shown that tocotrienol-rich fraction (TRF) of palm oil inhibits cell growth and induces apoptosis in both preneoplastic and neoplastic cells. However, the mechanism by which TRF induces apoptosis remains largely unknown. Since several chemopreventive agents have been shown to utilize p53 pathway in negative regulation of cell growth, using human colon carcinoma RKO cells which express wild type p53, we investigated the effect of TRF on components of p53 signaling network. Treatment of cells with TRF resulted in a dose- and time- dependent inhibition of growth and colony formation. Further, TRF treatment of RKO cells resulted in the induction of WAF1/p21 which appears to be independent of cell cycle regulation and is transcriptionally upregulated in p53 dependent fashion. These results were further confirmed by using cells that express luciferase from a p53 responsive promoter where TRF treatment leads to activation of p53 reporter activity. TRF treatment also resulted in alteration in Bax/Bcl2 ratio in favor of apoptosis, which was associated with the release of cytochrome c and induction of apoptotic protease-activating factor-1. This altered expression of Bcl2 family members triggered the activation of initiator caspase-9 followed by activation of effector caspase-3. These signaling cascades lead to condensed chromatin, DNA fragmentation and shrinkage of cell membrane resulting into apoptosis. Our data suggest that TRF-induced apoptosis in colon carcinoma cells is mediated by p53 signaling network which appears to be independent of cell cycle association
An overview on energy balance for a building model in temperate climate with three different simulation tools
No full textNowadays the number of environmental assessment tools (building energy simulation software) available on the market is very large. The aim of this paper is to evaluate the analogies and the differences of three common software (TRNSYS, IDA ICE and ESP-r) analysing a standard cellular model. Using a uniform set of initial data and hypothesis, the test foresees a detailed comparison in terms of different methods of evaluation for the energy balance of a building in a temperate climate. The model is design in a simplified way to achieve consistence results using the three different simulation tools (one thermal zone, fixed construction technology and ideal supply air system). As climatic conditions the same source weather file (TMY2) for Milan was used, considering it as a representative city of Italy for temperate climate with moderate external temperature. The results are based on monthly analysis for the complete year. The study aimed to show how different simulation methodologies work and the effects they have on the building energy performances evaluation. Furthermore, the benefits of using dynamic simulation tools should be analysed in order to identify how the design process could be affected by them, especially today where the request of sustainable and environmental friendly building is increased
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
NF-Y histone fold α1 helices help impart CCAAT specificity
No full textNF-Y is a conserved trimeric transcriptional activator with an extremely high specificity for CCAAT boxes. The NF-YB and NF-YC subunits have histone fold motifs with a high degree of homology to NC2α/β, a TBP-binding repressor. The histone fold is composed of three α helices, α1, α2, α3, separated by short loops. Structural data on core histones showed that α1 are involved in DNA-binding. To understand the molecular basis of NF-Y sequence-specificity, we constructed deletion and swapping mutants, in which the α1 of NC2 and archeal HMfB, a bona fide histonic protein, was placed in NF-YB and NF-YC. Our analysis indicates that (i) subunit interactions are normal; (ii) NF-YB-NF-YC and NC2α/β do not form heterodimers and NC2 cannot associate NF-YA. (iii) None of the NF-Y swaps can complex with TBP on a TATA box. (iv) Specific residues, R47 and K49 in NF-YC and N61 in NF-YB, are crucial for CCAAT-binding. We conclude that specificity of the NF-Y trimer is not due to NF-YA only, but stems in part from the contribution of the histone fold α1, particularly that of NF-YB
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