999 resultados para Teoria da escolha racional
Resumo:
Calculations based on density functional theory at the B3LYP hybrid functional level applied to periodic models have been performed to characterize the structural and electronic properties of PbTiO3. Two different slab terminations (PbO and TiO2) have been considered to obtain and discuss the results of band structure, density of states, charge distribution on bulk and surface relaxation. It is observed that the relaxation processes are most prominent for the Ti and Pb surface atoms. The electron density maps confirm the partial covalent character of the Ti-O bonds. The calculated optical band gap and other results are in agreement with experimental data.
Resumo:
The experiment introduces the undergraduate students to the crystal field theory. The electronic spectra of the octahedral complexes of [Ni(L)n]2+ (L = H2O, dmso, NH3 and en) obtained in the experiment are used to calculate 10Dq and B parameters. The experiment shows how the parameters can be calculated and correlated with the nature of the ligands and the field intensities produced.
Resumo:
Desde la epistemolog��a constructivista se considera la cognici��n como la actividad b��sica del vivir: interpretar la experiencia, otorgar significado al flujo de los acontecimientos. Por tanto, no se la ve como una actividad intelectual, racional o mental sino hol��stica porque implica al sujeto en su totalidad; aunque se pueda manifestar en forma de pensamientos, emociones, im��genes, etc. Las distintas terapias cognitivas de inspiraci��n constructivista comparten la visi��n de la persona como un agente que construye de forma proactiva los acontecimientos, incorporando los significados generados en un sistema cuyo n��cleo es el sentido de identidad. Los esfuerzos para promover el cambio pueden provocar resistencias a menos que se armonicen con la necesidad esencial de la persona de proteger su sentido de identidad, continuidad y, en consecuencia, su unicidad.
Resumo:
Sobre els conceptes de la moral, els valors i l'educaci��
Resumo:
El treball que es presenta cont�� un text articulat sobre la part de teoria general del contracte (arts. 612-1 i seg��ents) del llibre sis�� del Codi Civil de Catalunya. El proc��s de codificaci�� civil que es viu a Catalunya justifica aquest treball, que podria ser ��til per a elaboraci�� del llibre sis�� del CCCat dedicat a les obligacions i els contractes. El treball consta d���una proposta de text articulat, amb el seus respectius comentaris a cada article. Es tracta del cap��tol segon del t��tol primer del llibre sis��, i es divideix en les seg��ents seccions: 1) El contracte, els seus elements essencials, i la seva efic��cia; 2) La formaci�� del contracte; 3) La interpretaci�� del contracte; i 4) La inefic��cia del contracte, que inclou l���an��lisi dels vicis del consentiment. El treball ha pres com a refer��ncia les principals propostes d���harmonitzaci�� del dret contractual (Principis Unidroit [PICC], Principis de Dret Contractual Europeu [PECL], Marc Com�� de Refer��ncia [DCFR], i l���Instrument Opcional sobre Compravenda Europea [CESL] i la regulaci�� dels codis m��s moderns (entre ells, el del Quebec, l���Holand��s, el Portugu��s o l���Itali��) i les seves propostes de reforma (el projecte Terr�� a Fran��a, i la Propuesta de Modificaci��n del C��digo Civil Espa��ol en materia de obligaciones y contratos). En la proposta presentada s���incorporen institucions no regulades en el Codi civil espanyol actualment vigent a Catalunya en la seva condici�� de dret supletori, i s���omplen algunes llacunes d���aquest cos legal. Es poden citar, entre elles, les cl��usules abusives dels contractes, el canvi en les circumst��ncies essencials del contracte, el contracte per a persona per designar, la responsabilitat per culpa in contrahendo, les cartes d���intencions, el r��gim de l���oferta i l���acceptaci�� del contracte, els contractes preparatoris, els drets de prefer��ncia, la possibilitat d���anul��laci�� del contracte per concessi�� d���un avantatge injust a alguna de les parts, i el r��gim dels contractes en frau de creditors.
Resumo:
La visualitzaci�� cient��fica estudia i defineix algorismes i estructures de dades que permeten fer comprensibles conjunts de dades a trav��s d���imatges. En el cas de les aplicacions m��diques les dades que cal interpretar provenen de diferents dispositius de captaci�� i es representen en un model de v��xels. La utilitat d���aquest model de v��xels dep��n de poder-lo veure des del punt de vista ideal, ��s a dir el que aporti m��s informaci��. D���altra banda, existeix la t��cnica dels Miralls M��gics que permet veure el model de v��xels des de diferents punts de vista alhora i mostrant diferents valors de propietat a cada mirall. En aquest projecte implementarem un algorisme que permetr�� determinar el punt de vista ideal per visualitzar un model de v��xels aix�� com tamb�� els punts de vista ideals per als miralls per tal d���aconseguir el m��xim d���informaci�� possible del model de v��xels. Aquest algorisme es basa en la teoria de la informaci�� per saber quina ��s la millor visualitzaci��. L���algorisme tamb�� permetr�� determinar l���assignaci�� de colors ��ptima per al model de v��xels
Resumo:
Leishmania causes tegumental and visceral diseases called leishmaniasis. Disease control is possible interrupting the transmission cycle, but HIV co-infection, chemotheraphy toxicity and lack of a vaccine are paramount difficulties. So, is necessary to study new Leishmania molecules and investigate the possibility to develop rational drugs using these molecules as targets. Leishmania express many peptidases during their life, and cysteine are the most abundant protease and many inhibitors were developed but failed to kill parasites. On the other hand, inhibitors of serine proteases killed promastigotes, indicating the possibility of these enzymes to be important targets in the development of anti-Leishmania drugs.
Resumo:
We describe herein the synthesis and characterization of the complexes KNiF3, [Ni(en)3]I2, [Ni(en)3]Cl2, [Ni(acac)2(H2O)2], [Ni(en)2(H2O)2]Cl2 and [Ni(NH3)6](BF4)2 (en = ethylenediamine, acac- = acetylacetonate) performed in the inorganic synthesis major course at the Chemistry Institute of UFRGS (Universidade Federal do Rio Grande do Sul). The compounds were characterized by infrared and electronic spectroscopy and the electrolytic conductivity was measured. The parameters 10Dq and B were obtained from the electronic spectra and the nefelauxetic and spectrochemical series were determined. The obtained spectrochemical series was F- < acac- < NH3 < en and the nefeulaxetic series was en < NH3 < acac- < F-.
Resumo:
The year 2013 marks the centennial of that wondrous year in which Niels Bohr proposed a novel theory about the constitution of atoms and small molecules after which the way we regard atoms and their behaviour began to be drastically altered. Bohr drew on several sources for his original description of the atoms, most importantly on spectroscopy and Balmer's equation thereof, the new quantum hypothesis advanced a few years earlier by Planck, and the planetary atom proposed by Rutherford. Although Bohr's ideas were to be eventually overtaken by the advent of quantum mechanics, his theory was the basis of a new thinking about atoms and molecules which constitutes an invaluable asset in the development of science ever since.
Resumo:
This paper reports the use of alternative materials for teaching experimental chemistry. In this context, nimesulide and propranolol tablets were used to teach chemical concepts about acid-base reactions according to Br��nsted-Lowry protonic Theory. Important topics of Organic, Analytical and Pharmaceutical Chemistry were discussed, such as purification by acid-base extraction, solubility of organic compounds in aqueous solutions, buffers, the dissociation constant (pKa), potentiometric titration and ionization of drugs in biological fluids. The purification of propranolol and nimesulide from tablets produced yields of 75% and 90%, respectively. The experimental values of pKa for both drugs were in agreement with those from the literature.
Resumo:
Kirjallisuusarvostelu