Field-free and field-stimulated electron emission from solids

Electron irradiation of solids produces a backemission of secondary electrons (energies between 0 and 50 eV) and reflected primaries (energies between 50 eV and that of the incident beam). For insulators, it is shown that an externally applied positive electric field penetrating into the solid material, energizes electrons generated by the primary irradiation and enables them to travel back to the surface of incidence and be emitted (stimulated secondary emission).

Quality management and competitiveness: the diffusion of the ISO 9000 standards in Latin America and recommendations for government strategies

Includes bibliography

Quality management, ISO 9000 and government programmes

Includes bibliography

Quality management promotion to improve competitiveness

Includes bibliography

Promoción de la calidad para mejorar la competitividad

Incluye Bibliografía

An experimental verification of newton's second law

We describe an experimental procedure to probe the validity of Newton's second law. The experimental arrangement allows us to accelerate a glider on an air track by means of forces that are both steady and known. We also show how to determine acceleration from average speeds calculated for successive time intervals of the motion measured by using several electronic counters connected to a single-crystal oscillator circuit. Within experimental errors, the experiments clearly show the proportionality between acceleration and force for a fixed mass and between acceleration and inverse of mass for a fixed force. © by the Sociedade Brasileira de Física.

Metabolismo energético do camarão da amazonia, Macrobrachium amazonicum

Pós-graduação em Biologia Geral e Aplicada - IBB

Revista de la CEPAL no.65

Distribución del ingreso, pobreza y gasto social en América Latina / José Antonio Ocampo. -- Gasto militar y el desarrollo en América Latina / Eugenio Lahera y Marcelo Ortúzar. -- Crecimiento, justicia distributiva y poiítica social / Andrés Solimano. -- Equidad, inversión extranjera y competitividad internacional / Adolfo Figueroa. -- Tensiones en ei ajuste estructural en América Latina: asignación vs. distribución / Daniel M. Schydlowsky. -- Competitividad y regulaciones laborales / Luis Beccaria y Pedro Galín. -- Familias latinoamericanas: convergencias y divergencias de modelos y políticas / Irma Arriagada. -- Los acuerdos de libre comercio y el trabajo de las mujeres: el caso de Chile / Alicia Frohmann y Pilar Romaguera. -- Evolución macroeconómica del Paraguay 1989-1997: burbuja de consumo y crisis financier / Stéphane Straub. -- Estrategias de las empresas mexicanas en sus procesos de internacionalización / Alejandra Salas-Porras. -- La regulación de la prestación privada de servicios de agua potable y alcantarillado / Terence R. Lee y Andrei S. Jouravlev. -- Promoción de la calidad para mejorar la competitividad / Hessel Schuurman.

CEPAL Review no.65

Income distribution, poverty and social expenditure in Latin America / José Antonio Ocampo. -- Military expenditure and development in Latin America / Eugenio Lahera and Marcelo Ortúzar. -- Growth, distributive justice and social policy / Andrés Solimano. -- Equity, foreign investment and international competitiveness / Adolfo Figueroa. -- Tensions in Latin American structural adjustment: allocation versus distribution / Daniel M. Schydlowsky. -- Competitiveness and labour regulations / Luis Beccaria and Pedro Galin. -- Latin American families: convergences and divergences in models and policies / Irma Arriagada. -- Free trade agreements and female labour: the Chilean situation / Alicia Frohmann and Pilar Romaguera. -- Macroeconomic trends in Paraguay from 1989 to 1997: consumption bubble and financial crisis / Stephane Straub. -- The strategies pursued by Mexican firms in their efforts to become global players / Alejandra Salas-Porras. -- Regulating the private provision of drinking water and sanitation services / Terence R, Lee and Andrei S. Jouravlev. -- Quality management promotion to improve competitiveness / Hessel Schuurman.

Sulfated polysaccharide extracted of the green algae Caulerpa racemosa increase the enzymatic activity and paw edema induced by sPLA2 from Crotalus durissus terrificus venom

Sulfated polysaccharides derived from seaweed have shown great potential for use in the development of new drugs. In this study, we observed that a low-molecular-weight sulfated polysaccharide from Caulerpa racemosa, termed CrSP, could interact with secretory phospholipase A2 (sPLA2) isolated from Crotalus durissus terrificus venom. When native sPLA2 (14 kDa) was incubated with CrSP, they formed a molecular complex (sPLA2:CrSP) with a molecular mass of 32 kDa, approximately. Size exclusion chromatography experiments suggested that CrSP formed a stable complex with sPLA2. We belived that sPLA2 and SPCr are involved an ionic interaction between negatively charged CrSP and the positively charged basic amino acid residues of sPLA2, because this interaction induced significant changes in sPLA2 enzymatic and pharmacological activities. CrSP caused a significant increase in sPLA2 enzymatic and bactericidal activity and increased its edematogenic effect. A pharmacological assay showed that the myotoxic activity of sPLA2:CrSP is unrelated to its enzymatic activity and that sPLA2:CrSP may have a practical application as a natural antibacterial agent for use in humans and commercially raised animals.

Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L.) amazonensis Promastigote

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An Evaluation of 3-Rhamnosylquercetin, a Glycosylated Form of Quercetin, against the Myotoxic and Edematogenic Effects of sPLA(2) from Crotalus durissus terrificus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Compression waves and kinetic energy losses in collisions between balls and rods of different lengths

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Escape depth of secondary electrons from electron-irradiated polymers

Measurements on polymers (Teflon FEP and Mylar) have shown that the secondary electron emission from uncharged surfaces exceeds that from surfaces containing a positive surface charge. The reduced emission of charged surfaces is due to recombination between electrons undergoing emission and trapped holes within the charged layer. During the experiments the surface of the material was kept at a negative potential to assure that all secondary electrons reaching the surface from within the material are actually emitted. An analysis of the results yielded the maximum escape depth of the secondary electrons, and showed that the ratio of the maximum escape depth of the secondaries from Mylar to the maximum escape depth from Teflon is almost the same as the ratio of the corresponding second crossover energies of this polymers.

Evaluation of potential thrombin inhibitors from the white mangrove (Laguncularia racemosa (L.) C.F. Gaertn.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)