Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2018 ( 1 )

2017 ( 1 )

2016 ( 2 )

2015 ( 19 )

Custom range...

Search Results: 1 - 10 of 1083 matches for " Juana Silber "
All listed articles are free for downloading (OA Articles)
Page 1 /1083
Display every page Item
Role of Weak Molecular Interactions in the Mechanism of Action of a Series of Antihelmintics
Marisa Santo,Liliana Giacomelli,Mario Reta,Rosa Cattana,Juana Silber,Antonio Chana,Mercedes Rodriguez,Carmen Ochoa
Molecules , 2000, DOI: 10.3390/50300317
Abstract: Different physicochemical properties such as solute-solute and solute-solvent interactions, tautomerism, lipophilicity and solubility in water were determined for a serie of 6,7-diaryl-pteridines in order to relate those properties with their nematocide action.
Electrochemical nitration of naphthalene in micellar systems
Cortona, Mariana N;Vettorazzi, Nelio R;Silber, Juana J;Sereno, Leonides E;
Journal of the Brazilian Chemical Society , 1997, DOI: 10.1590/S0103-50531997000400010
Abstract: the nitration of naphthalene (naph) at a pt electrode in nano2 aqueous solutions in the absence and presence of a non-ionic surfactant, brij 35, was studied. the electrochemical behavior of the reactants naph and nano2 and their mixture was investigated by cyclic voltammetry to determine their electrolysis conditions. the peak current of naph decreases monotonically with the nano2 concentration, indicating that the oxidation product of no2- ion interacts with naph·+. controlled potential electrolysis were carried out and the products were analyzed by hplc. 1-nitronaphthalene, 2-nitronaphthalene, 1,2-naphthoquinone, 1,4-naphthoquinone and 1,1'-binaphthyl (binaph) were obtained in the micellar solution while in the absence of brij 35 only naphthoquinones and binaph were detected. the higher selectivity for 2-no2naph in comparison to non-aqueous homogeneous media may be induced by the micelles microenvironment.
Broken symmetries and pattern formation in two-frequency forced Faraday waves
Jeff Porter,Mary Silber
Physics , 2002, DOI: 10.1103/PhysRevLett.89.084501
Abstract: We exploit the presence of approximate (broken) symmetries to obtain general scaling laws governing the process of pattern formation in weakly damped Faraday waves. Specifically, we consider a two-frequency forcing function and trace the effects of time translation, time reversal and Hamiltonian structure for three illustrative examples: hexagons, two-mode superlattices, and two-mode rhomboids. By means of explicit parameter symmetries, we show how the size of various three-wave resonant interactions depends on the frequency ratio m:n and on the relative temporal phase of the two driving terms. These symmetry-based predictions are verified for numerically calculated coefficients, and help explain the results of recent experiments.
Resonant triad dynamics in weakly damped Faraday waves with two-frequency forcing
Jeff Porter,Mary Silber
Physics , 2003, DOI: 10.1016/j.physd.2003.09.044
Abstract: Many of the interesting patterns seen in recent multi-frequency Faraday experiments can be understood on the basis of three-wave interactions (resonant triads). In this paper we consider two-frequency forcing and focus on a resonant triad that occurs near the bicritical point where two pattern-forming modes with distinct wavenumbers emerge simultaneously. This triad has been observed directly (in the form of rhomboids) and has also been implicated in the formation of quasipatterns and superlattices. We show how the symmetries of the undamped unforced problem (time translation, time reversal, and Hamiltonian structure) can be used, when the damping is weak, to obtain general scaling laws and additional qualitative properties of the normal form coefficients governing the pattern selection process near onset; such features help to explain why this particular triad is seen only for certain "low" forcing ratios, and predict the existence of drifting solutions and heteroclinic cycles. We confirm the anticipated parameter dependence of the coefficients and investigate its dynamical consequences using coefficients derived numerically from a quasipotential formulation of the Faraday problem due to Zhang and Vinals.
Rouge y tacos al volante: la relación entre autos y mujeres en el ámbito turístico de Argentina
Estudios y perspectivas en turismo , 2010,
Abstract: gender and cars is the issue that concerns this article, which aims to show how the relationship has evolved between the woman and the car in argentina and how it has been shaped in automobile museums. while many women today have their own car or choose to buy the family car, culturally there are still many things to do in this regard. the presence of women in museums is very cut and arguably are spaces unique to a preserve of men that women can only go to admire, even in the case studies are beginning to see a promising future. this absence of women in the cultural history of the cars are added cultural prejudices about the relationship between women and cars, which are visible even in the ads about cars. we conducted a content analysis of argentine museums, through direct visits or their internet portals, and applied a semi-structured interview to people in charge of the promotion or management of these museums. it also conducted a survey of advertisements in two magazines specialized in argentina. finally, to provide additional information, we analyzed 5 blogs about cars written by women and aimed at them.
Las estrategias de reformulación: el paso desde un texto-fuente a un texto de divulgación didáctica
Literatura y lingüística , 2005, DOI: 10.4067/S0716-58112005000100011
Abstract: this study examines how educational or popularization texts are reformulations of source or primary texts. the reformulated text comes from texts for students of a technical college in valparaiso. the methodology for determining the type of reformulating strategy that has been applied in order to convert law in educational expositive texts consists in comparing both texts, law and its reformulation, determining if the difference between them is due to an expansion, reduction, or content-variation strategy. the results show a higher incidence of reduction strategy above expansion and content-variation strategies
Antipoda. Revista de Antropología y Arqueología , 2009,
Abstract: one of the main concerns at the heart of documentary film is the relationship between reality and its representation; or in other words, about what we consider to be an appropriate and faithful documentation of reality. the history of documentary traditionally has been depicted as the constant oscillation between the aspiration of achieving a factual representation of reality, and the impossibility of doing so (bruzzi, 2000: 4). thus, this perspective has led to a tension between objective documentation and the subjective presence of the filmmaker, which has positioned these two components at extremes that seem irreconcilable. nevertheless, some filmmakers have challenged this vision of documentaries through films that force the viewer to reconsider this perspective by merging the boundaries between creating and documenting. i will argue that this is the case of chris marker's sans soleil (1983) and chantal akerman's news from home (1977), two films that while positioning the identity of the filmmaker at the center of their concern offer interesting perspectives about the negotiation between objectivity and subjectivity in documentary films.
Trauma Social, Modernidad e Identidades Sustraídas: Nuevas Formas de Acción Social
Psykhe (Santiago) , 2006, DOI: 10.4067/S0718-22282006000200002
Abstract: this research looks at the main aspects that constitute individual and group subjectivity, underlying a social practice whose goal is to give meaning to the memory of chile's recent social trauma. the study is based on eight in-depth individual interviews of funa comission members, whose ages go from 20 to 29 years old. the central elements of discourse are analyzed looking at the encounter between ideological and affective loyalties and the new representation belonging to modern times. findings shows that integration of new social referents introduce a change at the individual, grupal and institucional level process and allows a gradual change of historical damage anf marginality to the recovery of main identity dimensions.
Las estrategias cognitivo-retóricas y la dimensión dialéctica de la argumentación oral en una clase de lengua castellana y comunicación
Revista signos , 2007, DOI: 10.4067/S0718-09342007000100007
Abstract: this study constitutes a preliminary research about oral argumentation in classrooms. it?s based on an 11th grade spanish language and communication lesson in private subsidized schools in the city of valparaiso, chile. on the one hand, it tries to determine the dialectics of argumentative interaction observed both in the teacher?s turns and when students discuss about an issue, in this case, ?teenagers pregnancy?; and the cognitive-rhetorical strategies used by the students when they state their argument, on the other hand. the corpus of analysis is a video recorded and transcribed sequence of 45 minutes developed in the setting of the previously mentioned subject lesson. during the sequence, the teacher manages and negotiates time allowed each speaker, stating the initial thesis or reformulating it, as well as the closure. although, students? participation proves to be reduced, those who interact are able to support or refute the stated theses with arguments which are the result of their own experience. once the students and the teacher are engaged in the argumentative interaction, the most applied cognitive-rhetorical strategy by the former is ?causality?; this means that the arguments are mainly based on the perception of the real, that is to say, according to the topics they are interested in. in the case of the teacher, participation is marked by the ?reformulation? as a way to guide the argumentative interaction towards agreement
Enfoques de proceso en la producción de textos escritos
Revista signos , 2002, DOI: 10.4067/S0718-09342002005100014
Abstract: one of the agents producing a real transformation of surveys on written text production, has been the inclusion of the "processing" concept. in fact, this impact has even led some researchers to demand a change in paradigms. other researchers, however, have only considered the importance ascribed to the concept as a response to educational interests, lacking a sound theoretical basis. the objective of this paper is to revise the most significant contributions of the cognitive and socio-cognitive theoretical models formulated during the past few decades, establishing to what extent they are genuine theoretical models or simple methodological propositions and how recent proposals could make up an integrative model.
Page 1 /1083
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.