Social meaning of personal computers for managers and professionals: methodology and results

The social meaning of personal computers for 34 managers and professionals was measured using a situational approach. The results, in general, indicated a positive perception towards computers within the context of their work situations. The methodology was developed in an attempt to overcome some of the difficulties of traditional measures of attitudes. The advantages and the limitations of the method, as well as the process by which impressions are formed, are discussed.     

Solar photocatalytic degradation of real textile effluents by associated titanium dioxide and hydrogen peroxide

The present work investigated the photodegradation of real textile effluents by advanced oxidative process (AOP) using TiO₂/H₂O₂/sunlight system. The procedures were carried out at ambient conditions in March 2005. The results were evaluated by COD reduction concomitant to the increase in inorganic ion concentration (mineralization) and the analysis of the effluent characteristic spectral wavelengths: 228, 254, and 284 nm (simple aromatic compounds), 310 nm (conjugated aromatic compounds), and 390, 450, and 530 (color). As this study is not restricted to the decolorization process, it allows a more reliable evaluation of effluent mineralization. The results indicate that solar radiation is as efficient as or even more efficient than artificial radiation was in previous studies and that it also allows a reduction in effluent treatment operational costs.     

Two‐dimensional fluorescence as a fingerprinting tool for monitoring wastewater treatment systems

BACKGROUND: The use of two‐dimensional (2D) fluorescence for monitoring complex biological systems requires careful assessment of the effect of chemical species present, which may be fluorescent and/or may interfere with the fluorescence response of target fluorophores. Given the complexity of fluorescence data (excitation emission matrices—EEMs), the challenge is how to recover the information embedded into those EEMs that can be related quantitatively with the observed performance of the biological processes under study. RESULTS: This work shows clearly that interference effects (such as quenching and inner filter effects) occur due to the presence of multiple species in complex biological media, such as natural water matrices, wastewaters and activated sludge. A statistical multivariate analysis is proposed to recover quantitative information from 2D fluorescence data, correlating EEMs with the observed performance. A selected case study is discussed, where 2D fluorescence spectra obtained from the effluent of a membrane bioreactor were compressed using PARAFAC and successfully correlated with the effluent chemical oxygen demand, using projection to latent structures modelling. CONCLUSION: This study demonstrates the potential of using 2D fluorescence spectroscopy as a status fingerprint. Additionally, it is shown how statistical multivariate data analysis can be used to correlate EEMs with selected performance parameters for monitoring of biological systems. Copyright © 2011 Society of Chemical Industry     

A survey of the current photovoltaic equipment industry in Brazil

The use of renewable alternative sources of energy in the world has been growing in the last few decades due to concerns about dependence on fossil sources and to environmental reasons, related to climatic change and its effects on mankind. Tax and/or financial incentives have been instituted for the population, to have access to renewable source technologies, and for the local equipment industry, to develop more quickly. In Brazil, the PV (photovoltaic) equipment to convert solar into electricity is more often used in low income rural communities, located distant from the grid network, for rural electrification, water pumping and public illumination. However, since there is no currently specific regulatory incentive mechanism for this source in the country, the Brazilian PV equipment industry has not made great advances and the market is largely dominated by multinationals. Against this background, a survey of the current PV equipment industry in Brazil is extremely relevant, especially in the event of a national program development to promote the use of this technology, stimulate the domestic industry and reduce the dependence on imported equipment.     

Anxiety and the Archive: Understanding Plagiarism Detection Services as Digital Archives

Based on a case study of the popular plagiarism detection service Turnitin, particularly its “Legal Document,” this article contends that plagiarism detection services should be viewed as digital archives. Services like Turnitin not only seek to regulate what constitute original texts and appropriate writing practices but also to advance conceptions of the work that archives should do in storing and circulating texts in digital spaces. This article concludes that the services we sometimes use to ensure the integrity of students’ texts can themselves be of questionable integrity—largely through the design of their archives. As increasing numbers of texts take digital form, the problems and promise of digital archives will demand thoughtful responses that do not rush to replace questionable writing and research practices with equally troubling pedagogical and archival ones. These thoughtful responses start with exploring the use of plagiarism detection service archival technology in unadvertised ways.     

Study of major aromatic compounds in port wines from carotenoid degradation

The carotenoids degradation and the formation of volatiles were examined by simulating Port wine aging. A two year old red Port wine was saturated with oxygen, supplemented with lutein and β-carotene and kept at 60 °C during 87 h. A similar study was performed in a model wine solution. Results showed that the percentage decrease in lutein levels was, respectively, 79% and 95%, in the wine model solution and in the Port wine, and 55% and 10% for β-carotene, indicating that lutein was more sensitive to degradation than β-carotene. Two other unknown degradation carotenoid compounds were identified by HPLC/DAD (reverse phase λ_max: 422; 445; 475 and 422; 445; 472) in the lutein supplemented wine. Levels of β-ionone and β-cyclocitral increased (2.5 times) in both, wine and wine model solution, supplemented with β-carotene. Along with these compounds, the same behaviour was observed in β-damascenone in the supplemented lutein wine and wine model solution. New insights were provided into the understanding of aroma modifications occurring during Port wine aging. The relationship between carotenoid molecules (β-carotene and lutein) and some volatiles has also been provided.     

Solving some combinatorial problems on arrays with one-way dataflow

In this paper we present algorithms for solving some combinatorial problems on one-dimensional processor arrays in which data flows in only one direction through the array. The problems we consider are: ranking the elements in a chain of sizen, rooting a spanning tree withn vertices, and computing biconnected components of a connected graph withn vertices. We show that each of these problems can be solved using arrays of sizen in which the data enters at the first cell and flows through the array in only one direction until it leaves the last cell as output. We also show how the biconnectivity algorithm for the array yields a new sequential algorithm for computing biconnected components which uses onlyO(n) locations of random access memory.