Comparison of Nanosized Gold-Based and Copper-Based Catalysts for the Low-Temperature Water-Gas Shift Reaction

In this paper the catalytic performances for the low-temperature water-gas shift reaction of Au/TiO(2) type A (from World Gold Council), Au/CeO(2) (developed at UPV-CSIC), CuO/Al(2)O(3) (from BASF), and CuO/ZnO/ Al(2)O(3) (from REB Research & Consulting) have been compared. The catalysts were characterized by different techniques such as Raman spectroscopy, BET surface area measurements, temperature-programmed reduction, and high-resolution transmission electron microscopy, which gave additional information on the redox properties and textural and morphological structure of the investigated samples. The performances of these catalysts were evaluated in a wide range of operating conditions in a micro packed-bed reactor. It was observed that the presence of reaction products in the feed (CO(2) and H(2)), as well as CO and H(2)O feed concentrations, have significant effects on the catalytic performances. With a typical reformate feed the Au/CeO(2) catalyst reveals the highest CO conversion at the lowest temperature investigated (150 degrees C). However, while in the long tests performed the CuO/ZnO/Al(2)O(3) catalyst showed a good stability for the entire range of temperatures tested (150-300 degrees C), the Au/CeO(2) sample clearly showed two distinct behaviors: a progressive deactivation at lower temperatures and a good stability at higher ones. The selection of the best catalytic system is therefore clearly dependent upon the range of temperatures used

De memória, trauma e ficção: um olhar sobre a narrativa de Bernardo Kucinski

Muitos são os contratempos e prejuízos humanos associados ao período da ditadura militar no Brasil. Os processos de enrijecimento de controle estatal, as estratégias de domínio político-cultural e as tentativas de apagamento da memória marcaram o cotidiano da sociedade durante os anos que envolveram o estado de exceção. Apesar dessa realidade, os relatos de tortura e de denúncia testemunham diferentes versões para os fatos e contêm o poder de ressignificação da memória, especialmente por meio da escrita literária. Este artigo visa a propor uma breve discussão sobre os temas memória e trauma na construção ficcional, a partir da análise de contos publicados na antologia Você vai voltar pra mim e outros contos, de Bernardo Kucinski (2014)

Profiles of cognitive impairment in the continuum from normal cognition to Alzheimer's Clinical Syndrome:Contributions of the Short-term Memory Binding tests

Background: Short-term memory binding (STMB) tests assess conjunctive binding, in which participants should remember the integration of features, such as shapes (or objects) and colors, forming a unique representation in memory. In this study, we investigated two STMB paradigms: change detection (CD) and free recall (FR). Objective: To investigate the cognitive profile in the CD and FR tasks of three diagnostic groups: cognitively unimpaired (CU), mild cognitive impairment (MCI), and Alzheimer's clinical syndrome (ACS). In addition, we aimed to calculate and compare the accuracy of the CD and FR tasks to identify MCI and ACS. Methods: Participants were 24 CU, 24 MCI, and 37 ACS. The cognitive scores of the clinical groups were compared using analysis of variance (ANOVA) and receiver-operating characteristic (ROC) analyses were carried out to verify the accuracy of the STMB tasks. Results: In the CD task, CU was different from MCI and ACS (CU > MCI = ACS), while in the FR task all groups were different (CU > MCI > ACS). The ROC analyses showed an area under the curve (AUC) of 0.855 comparing CU with MCI for the CD task and 0.975 for the FR. The AUC comparing CU and ACS was 0.924 for the CD and 0.973 for the FR task. The FR task showed better accuracy to identify MCI patients, and the same accuracy to detect ACS. Conclusion: The present findings indicate that impairments in CD and FR of bound representations are features of the cognitive profiles of MCI and ACS patients