560 resultados para Pós-Colonial
Resumo:
Os hematomas parietais de alças intestinais por trauma abdominal fechado, determinando rápida obstrução luminal, são lesões raras e podem ser confundidas com afecções neoplásicas estenosantes (parietais ou por mecanismo de compressão extrínseca). Neste estudo é relatado um caso de obstrução intestinal por hematoma parietal da terceira porção duodenal pós-trauma e são discutidos o diagnóstico por imagem e o tratamento para tal obstrução.
Resumo:
Pseudocistos pulmonares são lesões raras que se desenvolvem no parênquima pulmonar após traumas fechados e de grande energia, cujo diagnóstico se baseia na associação da história clínica com exames de imagem. Relata-se a seguir um pseudocisto pulmonar ocorrido no parênquima contralateral ao trauma em um homem de 31 anos que apresentou episódio de hemoptise após queda durante partida de futebol.
Resumo:
The post-graduate teaching of chemistry in Brazil over the last years is discussed, including comparisons with some other sciences and also experiences in the United States and the United Kingdom. We have also compared the more recent situation with the previous decade, which leads us to a favourable conclusion as to the results obtained in the teaching of post-graduate students in chemistry. Some conclusions and recommendations are made with respect to the near future.
Resumo:
A broad picture of the graduate programs in chemistry in Brazil is analyzed from the data collected during the period 1996/1997 for evaluation by CAPES. The results are compared with those from previous evaluations, indicating significant quantitative and qualitative progresses.
Resumo:
This article discusses the processes inherent in the production of salpeter in Colonial Brazil. In the main, the texts seen here present recipes accompanied by chemical explanations of the processes which denote a knowledge of science at the time. Various difficulties confronting the authors, however, prevented an effective contribution to the development of techniques for the production of salpeter. Consequenttly, at the end of the Nineteenth Century, Brazilian rulers are still facing many problems to obtain this precious material.
Resumo:
The preparation of gamma-LiAlO2 by coprecipitation and sol-gel synthesis was investigated. Ceramic powders obtained by coprecipitation synthesis were prepared from aqueous solutions of aluminum and lithium nitrates using sodium hydroxide as precipitant agent. By sol-gel synthesis, the ceramic powders were prepared from hydrolysis of aluminum isopropoxide. The materials obtained by two routes of synthesis were dried at 80ºC and calcined at 550, 750, 950 and 1150ºC. The characterization was done by X-ray diffraction, infrared spectroscopy, emission and absorption atomic spectrometry, helium picnometry, specific surface area (BET method) and scanning electronic microscopy. Mixtures of crystalline phases were obtained by coprecipitation synthesis: 80ºC- LiAl2(OH)7.2H2O + Al(OH)3; 550 and 750ºC- alpha-LiAlO2 + eta-Al2O3; 950 and 1150ºC- gamma-LiAlO2 + LiAl5O8. Chemical analysis showed molar ration Al/Li @ 3. Crystalline single-phases were obtained by sol-gel synthesis above 550ºC: 550ºC-alpha-LiAlO2; 750, 950 and 1150ºC-gamma-LiAlO2. These powders presented molar ration Al/Li @ 1. Thus, gamma-LiAlO2 crystalline phase was obtained at 750ºC by sol-gel synthesis while by coprecipitation synthesis, a mixture of crystalline phases was obtained. These results showed the superiority of the sol-gel synthesis for the preparation of pure gamma-LiAlO2.
Resumo:
The teaching apprenticeship established by CAPES for post-graduation scholarship beholders has been discussed and the criterion adopted for the implementation in the post-graduation in Inorganic Chemistry Program presented. A teaching plan for the new subject is proposed, based on the experience gained through a first group. An instrument for evaluation of the student's performance has been developed and analyzed. Aspects like knowledge, clearness, enthusiasm, confidence, good manage on the audio-visual resources, class length are mentioned by degree of importance and the major difficulties faced and pointed out by the students.
Resumo:
The graduate programs in Chemistry were evaluated and classified from the data collected for the period 1998-2000 by CAPES, the Minister of Education agency that is responsible for the regulation and support of this level of human resources formation. The next classification will be made in 2004, from the data of the period 2001-2003. The years in between, like the present year, are used for an evaluation without classification, from what comments are emitted to the programs to know how their data are improving or not, before the new ranking reporting. The progresses in the area of chemistry in Brazil are analysed from the confrontation of the present data with that of all previous evaluations, since 1983. The results confirm that the research and graduate formation in the area of Chemistry is continuously improving in Brazil, particularly during the last seven years.
Resumo:
Organic residue analysis of archaeological potsherds is a well-established method for determining the uses of European and North American pottery vessels. In the present work we assess if the organic residues identified in Brazilian potsherd extracts are related to commodity processes (e.g. cooking or surface treatment) or to other non-archaeological sources, using as a model potsherds recovered from the Rio do Meio site (Santa Catarina Island). The potsherd extracts are dominated by saturated fatty acids (Ac16:0, with lower abundances of Ac14:0 and Ac18:0). Our studies provide evidence that the organic residues preserved in the Brazilian archeological potsherds are related to foodstuffs and surface treatment processes of the pottery vessels.
Resumo:
The article presents a brief analysis on chemistry post-graduate students' perception on teaching in higher education. This study was done based on the context of students' formation in chemistry post-graduate programs and makes suggestions on how to improve the formation process of post-graduate students in order to decrease the rupture between teaching and research in chemistry post-graduate programs.
Resumo:
European naturalists explored Brazil in long scientific expeditions and published accounts that make up a rich and still largely untapped historiographic source for the understanding of the history of chemistry. The production of indigo dye, the manufacture of limestone, extraction and purification of saltpeter and the production of salt are discussed. Lime was used to whitewash walls and, mixed with whale oil, as cement to glue stones in buildings of the colonial period. It was prepared by burning seashells in specifically designed ovens. Saltpeter was produced by reacting naturally occurring calcium and magnesium nitrate with potassium-rich wood ashes to yield KNO3. NaCl was obtained by evaporating seawater under the sun. Indigo, a native plant, was cultivated and processed to produce the renowned dye, which was exported to Europe.