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1.
Identification of vivianite,an unusual blue pigment,in a sixteenth century painting and its implications 下载免费PDF全文
António João Cruz Erica Eires Luís Dias Teresa Desterro Carla Rego 《Color research and application》2018,43(2):177-183
Vivianite, a blue pigment employed in the past practically only in Northern and Central Europe, but with very limited use, was identified in an early sixteenth century painting, stylistically with Flemish features, from a church in Portugal. The identification of this iron phosphate mineral was made by SEM‐EDS based on the atomic ratio between phosphorus and iron in layers of blue paint (area analysis) and in particles of these same layers (spot analysis). This painting, about which there is no document to prove its authorship, becomes the first case, known in detail, of a sixteenth century painting containing vivianite. Moreover, this find and the presence of a chalk ground, also identified, strongly support the hypothesis of being a Flemish painting. 相似文献
2.
Coupling GIS with Hydrologic and Hydraulic Flood Modelling 总被引:6,自引:1,他引:5
Nunes Correia Francisco Castro Rego Filipe Da Grača Saraiva Maria Ramos Isabel 《Water Resources Management》1998,12(3):229-249
Geographic Information Systems (GIS) have been recognised as a powerful means to integrate and analyse data from various sources in the context of comprehensive floodplain management. As part of this comprehensive approach to floodplain management, it is very important to be able to predict the consequences of different scenarios in terms of flooded areas and associated risk. Hydrologic and hydraulic modelling plays a crucial role and there is much to gain in incorporating these modelling capabilities in GIS. This is still a rather complex task and research is being done on the full integration of these models. Interfacing between these models and GIS may be a very efficient way of overcoming the difficulties and getting very good results in terms of engineering practice. This paper presents results based on the use of Intergraph GIS coupled with Idrisi GIS. Using these two systems substantially increased the flexibility of using GIS as a tool for flood studies. A lumped (XSRAIN) and a distributed (OMEGA) hydrologic models were used to simulate flood hydrographs. The well known HEC-2 Hydraulic model was used to compute flooded areas. These models were applied in the Livramento catchment with very good results. The computation of flooded areas for different flood scenarios, and its representation in GIS, can be used in the assessment of affected property and associated damages. This is a very useful GIS-based approach to floodplain management. 相似文献
3.
Krauser E.W. Mathur A.P. Rego V.J. 《IEEE transactions on pattern analysis and machine intelligence》1991,17(5):403-423
A method for high-performance, software testing, called mutant unification, is described. The method is designed to support program mutation on parallel machines based on the single instruction multiple data stream (SIMD) paradigm. Several parameters that affect the performance of unification have been identified and their effect on the time to completion of a mutation test cycle and speedup has been studied. Program mutation analysis provides an effective means for determining the reliability of large software systems and a systematic method for measuring the adequacy of test data. However, it is likely that testing large software systems using mutation is computation bound and prohibitive on traditional sequential machines. Current, implementations of mutation tools are unacceptably slow and are only suitable for testing relatively small programs. The proposed unification method provides a practical alternative to the current approaches. The method also opens up a new application domain for SIMD machines 相似文献
4.
Precise timing and asynchronous I/O are appealing features for many applications. Unix kernels provide such features on a per‐process basis, using signals to communicate asynchronous events to applications. Per‐process signals and timers are grossly inadequate for complex multithreaded applications that require per‐thread signals and timers that operate at finer granularity. To respond to this need, we present a scheme that integrates asynchronous (Unix) signals with user‐level threads, using the ARIADNE system as a platform. This is done with a view towards support for portable, multithreaded, and multiprotocol distributed applications, namely the CLAM (connectionless, lightweight, and multiway) communications library. In the same context, we propose the use of continuations as an efficient mechanism for reducing thread context‐switching and busy‐wait overheads in multithreaded protocols. Our proposal for integrating timers and signal‐handling mechanisms not only solves problems related to race conditions, but also offers an efficient and flexible interface for timing and signalling threads. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
5.
The bulk polymerization of styrene in the presence of the vinyl functional sulfonic acid 2‐sulfoethylmethacrylate (SEM) was found to have utility for making polystyrenes with narrow polydispersity, bimodal polydispersity, and ultrahigh molecular weight at fast polymerization rates. Narrow polydispersity polymers were made by the addition of SEM to nitroxide‐mediated polymerizations. Bimodal polydispersity polymers were made by the ultrahigh molecular weight component being made in the presence of SEM in the absence of an initiator and the low molecular weight component being made in the presence of an initiator and/or chain‐transfer agent. Ultrahigh molecular weight monomodal polystyrenes were prepared at much faster polymerization rates than possible via spontaneous polymerization in the absence of SEM. SEM was found to be more effective, by an order of magnitude, than camphor sulfonic acid on a weight basis and, because it is copolymerized into the polymer chain, should not lead to corrosion problems during fabrication of the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 869–875, 2003 相似文献
6.
Andrielli Morais de Oliveira Flávio de Andrade Silva Eduardo de Moraes Rego Fairbairn Romildo Dias Toledo Filho 《Materials and Structures》2018,51(3):65
This paper reports the experimental findings on the tensile behavior of strain-hardening cement-based composites (SHCC). The composites were subjected to the combined effects of elevated temperatures and internal moisture condition. Uniaxial tensile tests on dumbbell-shaped SHCC specimens with in situ temperature control were performed at 22, 60 and 100 °C. In addition, the effect of the internal humidity of SHCC (95, 50, 20 and 0%) coupled to the elevated temperatures was investigated. It was shown that the tensile strength decreases and the strain capacity increases with an increase in temperature. The influence of the internal moisture conditions was more significant in high temperatures. The strain capacity reduced significantly with a decrease in the humidity level. The crack pattern of the SHCC specimens was determined. Furthermore, single fiber pullout tests were performed under the considered high temperatures condition. Finally, the results are discussed based on the thermogravimetry analysis of the PVA fiber, alterations on its microstructure and surface coating. 相似文献
7.
Da Rocha AR Alves FR Neto NM Dos Santos LF De Almeida HM De Carvalho YK Bezerra Dde O Ferraz MS Pessoa GT De Carvalho MA 《Microscopy research and technique》2012,75(10):1376-1382
Stem cells are present in the adult tissues of most diverse species. Bone marrow is recognized to be the most exploited site to obtain stem cells and cell progenitors. The objective of the present study was to characterize hematopoietic progenitor (HP) morphology and analyze the performance of adherent cell progenitors (ACPs) cultivated in vitro from black‐rumped agouti bone marrow (Dasyprocta prymnolopha). Bone marrow aspirates were obtained from tibia crest and used to prepare histological slides and identify cell morphology. Cells were also scattered on culture plates for later isolation, expansion, and quantification. Smears obtained from bone marrow demonstrated HPs at different stages of maturity. In culture, these cells showed fibroblastoid morphology and a strong tendency to form colonies, demonstrated by the presence of cell aggregates, cytoplasmic elongations lying side by side. An 80% cell confluence was observed at 18 days in culture and progressive reduction in the percentage of nonadherent mononuclear cells. After eight passes, a mean cell viability of 96.07% was observed, from a pool of 1.6 × 107 cells (ACP). Thirteen 25‐cm2 culture bottles were trypsinized, resuspended in freezing medium, stored in 14 criotubes at a concentration of 1 × 106 cells per milliliter, and placed in liquid nitrogen at ?196°C. Agouti bone marrow demonstrated high plasticity, moreover different HP lines, and a population of adherent cells demonstrated morphology similar to mesenchymal stem cells in culture. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc. 相似文献
8.
Madalena Sousa Teresa Rego Jcome Bruges Armas 《International journal of molecular sciences》2022,23(21)
Diabetes Mellitus (DM) is a complex disease with a significant impact in today’s world. Studies have emphasized the crucial role of genetics in DM, unraveling the distinction of monogenic diabetes from the most common types that have been recognized over the years, such as type 1 diabetes (T1DM) and type 2 diabetes (T2DM). A literature search was carried out to scrutinize the subtypes of maturity-onset diabetes of the young (MODY), as well as the connection between the recognized genetic and molecular mechanisms responsible for such phenotypes. Thus far, 14 subtypes of MODY have been identified. Here, the authors review the pathophysiological and molecular pathways in which monogenic diabetes genes are involved. Despite being estimated to affect approximately 2% of all T2DM patients in Europe, the exact prevalence of MODY is still unknown, enhancing the need for research focused on biomarkers. Due to its impact in personalized medicine, a follow-up of associated complications, and genetic implications for siblings and offspring of affected individuals, it is imperative to diagnose the monogenic forms of DM accurately. Currently, advances in the genetics field has allowed for the recognition of new DM subtypes, which until now were considered to be slight variations of the typical forms. New molecular insights can define therapeutic strategies, aiming for the prevention, correction, or at least delay of β-cell dysfunction. Thus, it is imperative to act in the close interaction between genetics and clinical manifestations to improve diagnosis and individualize treatment. 相似文献
9.
Joao Henrique da Silva Rego ;Antonio Alberto Nepomucenol ;Enio Pazini Figueiredo ;Nicole Pagan Hasparyk 《土木工程与建筑:英文版》2014,(11):1396-1402
In several countries, the residual RHA (rice husk ash) has been produced in rice processing industries or in thermoelectric plants that use rice husk to generate heat and/or electrical energy, usually without burning process control. This causes a reduction in the amorphous silica content of residual RHA, which distinguishes them from the RHA produced according to controlled burning process, which is totally amorphous and considered a highly reactive pozzolan. In this paper, the hydration products and the porous structure of binders paste were studied by replacing, in weight of 5%, 10% and 20% of Portland cement OPC (ordinary Portland cement), by residual RHAs named A and B, which have high and low content of amorphous silica, respectively, using microstructure evaluation techniques as XRD (X-ray diffraction), TG (thermogravimetric) tests and MIP (mercury intrusion porosimetry). A reducing the size of the pores of the pastes was observed according to the increase of content replacement of RHA A and RHA B. 相似文献
10.
Do the opportunities for learning and personal development lead to happiness? It depends on work-family conciliation. 总被引:1,自引:0,他引:1
The study shows how the perceptions of opportunities for learning and personal development predict five dimensions of affective well-being (AWB: pleasure, comfort, placidity, enthusiasm, and vigor), and how this relationship is moderated by the perceptions of work-family conciliation. A sample comprising 404 individuals was collected. The findings show the following: (1) both the perceptions of opportunities for learning and personal development and perceptions of work-family conciliation predict AWB, the happier individuals being those who have high perceptions on both variables; (2) both variables interact in predicting AWB, in such a way that perceptions of high opportunities for learning and personal development may not lead to higher AWB if work-family conciliation is low. Post hoc analysis also suggests that the relationship between the perceptions of opportunities for learning and personal development and AWB tends to be nonlinear for individuals with perceptions of low work-family conciliation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献