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Institution

Simón Bolívar University

EducationCaracas, Venezuela
About: Simón Bolívar University is a education organization based out in Caracas, Venezuela. It is known for research contribution in the topics: Population & Crystallization. The organization has 5912 authors who have published 8294 publications receiving 126152 citations.


Papers
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Journal ArticleDOI
10 Sep 2000
TL;DR: In this paper, a mathematical model of the structural system is linked to an approximate minimization algorithm to find the settings of select manufacturing parameters, which optimize the mechanical performance of the component.
Abstract: The high degree of automation of Solid Freeform Fabrication (SFF) processing and its ability to create geometrically complex parts to precise dimensions provide it with a unique potential for low volume production of rapid tooling and functional components. A factor of significant importance in the above applications is the capability of producing components with adequate mechanical performance (e.g., stiffness and strength). This paper introduces a strategy for optimzing the design of Fused-Deposition Acrylonitrile-Butadiene-Styrene (FD-ABS: P400) components for stiffness and strength under a given set of loading conditions. In this strategy, a mathematical model of the structural system is linked to an approximate minimization algorithm to find the settings of select manufacturing parameters, which optimize the mechanical performance of the component. The methodology is demonstrated by maximizing the load carrying capacity of a two-section cantilevered FD-ABS beam.

127 citations

Journal ArticleDOI
Jean Bousquet, Peter Hellings1, Ioana Agache2, A. Bedbrook  +315 moreInstitutions (141)
TL;DR: The aim of the novel ARIA approach is to provide an active and healthy life to rhinitis sufferers, whatever their age, sex or socio-economic status, in order to reduce health and social inequalities incurred by the disease.
Abstract: The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma and rhinitis and (3) to develop guidelines with all stakeholders that could be used globally for all countries and populations. ARIA-disseminated and implemented in over 70 countries globally-is now focusing on the implementation of emerging technologies for individualized and predictive medicine. MASK [MACVIA (Contre les Maladies Chroniques pour un Vieillissement Actif)-ARIA Sentinel NetworK] uses mobile technology to develop care pathways for the management of rhinitis and asthma by a multi-disciplinary group and by patients themselves. An app (Android and iOS) is available in 20 countries and 15 languages. It uses a visual analogue scale to assess symptom control and work productivity as well as a clinical decision support system. It is associated with an inter-operable tablet for physicians and other health care professionals. The scaling up strategy uses the recommendations of the European Innovation Partnership on Active and Healthy Ageing. The aim of the novel ARIA approach is to provide an active and healthy life to rhinitis sufferers, whatever their age, sex or socio-economic status, in order to reduce health and social inequalities incurred by the disease.

127 citations

Journal ArticleDOI
TL;DR: In this paper, successive self-nucleation and annealing (SSA) was used to characterize polyolefins with very dissimilar molecular structures and the optimum conditions to thermally fractionate any suitable polymer sample with SSA.
Abstract: A new technique to thermally fractionate polymers using DSC has been recently developed in our laboratory. The applications of the novel successive self-nucleation and annealing (SSA) technique to characterize polyolefins with very dissimilar molecular structures are presented as well as the optimum conditions to thermally fractionate any suitable polymer sample with SSA. For ethylene/α-olefin copolymers, the SSA technique can give information on the distribution of short chain branching and lamellar thickness. In the case of functionalized polyolefins, detailed examinations of SSA results can help to establish possible insertion sites of grafted molecules. The application of the technique to characterize crosslinked polyethylene and crystallizable blocks within ABC triblock copolymers is also presented.

126 citations

Journal ArticleDOI
TL;DR: In this paper, anodic aluminum oxide (AAO) templates with 20, 35, and 60 nm cylindrical pores were prepared and subsequently infiltrated with poly(ethylene oxide), PEO, polyethylene, PE, and polyethylenes block polystyrene diblock copolymers of various compositions.
Abstract: Porous anodic aluminum oxide (AAO) templates with 20, 35, and 60 nm cylindrical pores were prepared and subsequently infiltrated with poly(ethylene oxide), PEO, polyethylene, PE, and polyethylene-block-polystyrene diblock copolymers, PE-b-PS, of various compositions. The crystallization of the nanocylinders within the AAO templates was studied by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). A clear change from heterogeneous to homogeneous bulk nucleation was detected in the PEO before and after infiltration within a 20 nm template, respectively. The homogeneously nucleated nanocylinders needed extreme supercooling in order to crystallize, and their low crystallization temperature was successfully correlated with the volume of the crystallizing phase. 2D-WAXD measurements demonstrated that the PEO chains within the crystals formed inside the nanocylinders, preferentially orient perpendicular to the cylinder axis. This chain orientation is probably due to the easier cryst...

124 citations

Journal ArticleDOI
TL;DR: In this paper, two FCC catalysts with a 60m average size, prepared with different crystallite sizes (0.4 and 0.9 m), are studied in terms of total acidity, energy of ammonia desorption, specific surface area, relative amount of Bronsted and Lewis acid sites, crystallite and particle size, and micropore size distribution.
Abstract: Two FCC catalysts with a 60m average size, prepared with different crystallite sizes (0.4 and 0.9 m), are studied in terms of total acidity, energy of ammonia desorption, specific surface area, relative amount of Bronsted and Lewis acid sites, crystallite and particle size, and micropore size distribution. Characterization of these catalysts is relevant in view of their application to test the extent of intracrystallite diffusive transport influence on the overall catalytic cracking rates as developed, in separate studies [Ind. Eng. Chem. Res. 42 (2003) 4162] in a novel CREC Riser Simulator. © 2004 Elsevier B.V. All rights reserved.

124 citations


Authors

Showing all 5925 results

NameH-indexPapersCitations
Franco Nori114111763808
Ignacio Rodriguez-Iturbe9633432283
Ian W. Hamley7846925800
Francisco Zaera7343219907
Thomas G. Habetler7339520725
Douglas L. Jones7051221596
I. Taboada6634613528
Enrique Herrero6424211653
Rudi Studer6026819876
Alejandro J. Müller5842012410
David Padua5824311155
Rudolf Jaffé5818210268
Luis Balicas5732814114
Volker Abetz5538611583
Ananias A. Escalante511608866
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20232
202220
2021286
2020384
2019340
2018312