994 resultados para lei de Beer-Lambert


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Analisa o crescimento da literatura produzida sobre a Lei de Lotka, assim como o crescimento dos autores produtores dessa literatura, de 1922 a 2003. Nesse período o crescimento da literatura segue o modelo exponencial, com taxa média de crescimento de 7,5% ao ano e taxa de duplicação a cada 9,6 anos. Também o número de autores produtores da literatura cresce à proporção de 7,3% ao ano, com período de duplicação a cada 10 anos. A estatística indica bom ajuste ao modelo exponencial, com R² de 0,985 para a literatura e 0,992 para os autores, ambos a um nível de significância de 0,01.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Lambert-Eaton myasthenic syndrome is a paraneoplastic syndrome that may reveal a primitive tumor. Neuroblastoma in children and small cell lung carcinoma in adults are the leading tumors revealed or expressed by paraneoplastic phenomena. The clinical neurologic manifestations of Lambert-Eaton myasthenic syndrome are muscular weakness, sleepiness, absence of reflexes, and dysautonomia. Neurologic manifestations are explained by the induction of an autoimmune response because of the presence of antigens that are expressed by the tumor. Neurologic paraneoplastic disorders may also be the result of toxicity of drugs, coagulopathy, infection, or metabolic diseases. We describe the case of a 13-month-old child with unusual neurologic symptoms because of the presence of an abdominal neuroblastoma.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Collection : Les archives de la Révolution française ; 8.676

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Collection : Les archives de la Révolution française ; 8.575

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This review focuses on the role of proteins in the production and maintenance of foam in both sparkling wines and beer. The quality of the foam in beer but especially in sparkling wines depends, among other factors, on the presence of mannoproteins released from the yeast cell walls during autolysis. These proteins are hydrophobic, highly glycosylated, and their molecular masses range from 10 to 200 kDa characteristics that allow mannoproteins to surround and thus stabilize the gas bubbles of the foam. Both the production and stabilization of foam also depend on other proteins. In wine, these include grape-derived proteins such as vacuolar invertase; in beer, barley-derived proteins, such as LTP1, protein Z, and hordein-derived polypeptides, are even more important in this respect than mannoproteins

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract: Since ancient times, people have attributed a variety of health benefits to moderate consumption of fermented beverages such as wine and beer, often without any scientific basis. There is evidence that excessive or binge alcohol consumption is associated with increased morbidity and mortality, as well as with work related and traffic accidents. On the contrary, at the moment, several epidemiological studies have suggested that moderate consumption of alcohol reduces overall mortality, mainly from coronary diseases. However, there are discrepancies regarding the specific effects of different types of beverages (wine, beer and spirits) on the cardiovascular system and cancer, and also whether the possible protective effects of alcoholic beverages are due to their alcoholic content (ethanol) or to their non-alcoholic components (mainly polyphenols). Epidemiological and clinical studies have pointed out that regular and moderate wine consumption (one to two glasses a day) is associated with decreased incidence of cardiovascular disease (CVD), hypertension, diabetes, and certain types of cancer, including colon, basal cell, ovarian, and prostate carcinoma. Moderate beer consumption has also been associated with these effects, but to a lesser degree, probably because of beer"s lower phenolic content. These health benefits have mainly been attributed to an increase in antioxidant capacity, changes in lipid profiles, and the anti-inflammatory effects produced by these alcoholic beverages. This review summarizes the main protective effects on the cardiovascular system and cancer resulting from moderate wine and beer intake due mainly to their common components, alcohol and polyphenols.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper aims to present some features of the Industrial Property Law now in force in Brazil, as far as they could be regarded to the activities of research and development in the field of Chemistry and related areas, not only in the chemical industry but also in the university. By means of analysis of the main articles and paragraphs, which could deal with the mentioned activities, the author points out the scope and limitations of that law and explains the meaning of common technical terms usually found in patent concerns. Ultimately, a brief discussion on the actual and the potential role of the Brazilian university in the sphere of the Industrial Property is made.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper deals with Carathédory's formulation of the second law of thermodynamics. The material is presented in a didatical way, which allows a second year undergraduate student to follow the formalism. An application is made to an ideal gas with two independent variables. A criticism to Carnot formulation of the second law and an investigation of the historical origins of the Carathéodory formalism are also presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Beer brewing is an intricate process encompassing mixing and further elaboration of four essential raw materials, including barley malt, brewing water, hops and yeast. Particularly hops determine to a great extent typical beer qualities such as bitter taste, hoppy flavour, and foam stability. Conversely, hop-derived bitter acids account for an offending lightstruck flavour, which is formed on exposure of beer to light. These various processes are presented in detail, while due emphasis is placed on state-of-the-art hop technology, which provides brewers with efficient means to control bitterness, foam, and light-stability thereby allowing for the production of beers with consistent quality.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Entropy is a concept that has long stimulated human curiosity, resulting in an huge intelectual production. The same has not occurred for the first law of thermodynamics, perhaps because of its apparent obviousness. In this article the first law presentation, as displayed in most traditional physical chemistry textbooks, is criticized. An alternative view is suggested, in accordance with temporal thermodynamics. The time derivative local form of the second law is used to stress the entropy concept implications on the notion of internal energy.