An integrated approach to remanufacturing: model of a remanufacturing system

Remanufacturing is the process of rebuilding used products that ensures that the quality of remanufactured products is equivalent to that of new ones. Although the theme is gaining ground, it is still little explored due to lack of knowledge, the difficulty of visualizing it systemically, and implementing it effectively. Few models treat remanufacturing as a system. Most of the studies still treated remanufacturing as an isolated process, preventing it from being seen in an integrated manner. Therefore, the aim of this work is to organize the knowledge about remanufacturing, offering a vision of remanufacturing system and contributing to an integrated view about the theme. The methodology employed was a literature review, adopting the General Theory of Systems to characterize the remanufacturing system. This work consolidates and organizes the elements of this system, enabling a better understanding of remanufacturing and assisting companies in adopting the concept.

Ammonia losses estimated by an open collector from urea applied to sugarcane straw

The quantification of ammonia (NH3) losses from sugarcane straw fertilized with urea can be performed with collectors that recover the NH3 in acid-treated absorbers. Thus, the use of an open NH3 collector with a polytetrafluoroethylene (PTFE)-wrapped absorber is an interesting option since its cost is low, handling easy and microclimatic conditions irrelevant. The aim of this study was to evaluate the efficiency of an open collector for quantifying NH3-N volatilized from urea applied over the sugarcane straw. The experiment was carried out in a sugarcane field located near Piracicaba, São Paulo, Brazil. The NH3-N losses were estimated using a semi-open static collector calibrated with 15N (reference method) and an open collector with an absorber wrapped in PTFE film. Urea was applied to the soil surface in treatments corresponding to rates of 50, 100, 150 and 200 kg ha-1 N. Applying urea-N fertilizer on sugarcane straw resulted in losses NH3-N up to 24 % of the applied rate. The amount of volatile NH3-N measured in the open and the semi-open static collector did not differ. The effectiveness of the collection system varied non-linearly, with an average value of 58.4 % for the range of 100 to 200 kg ha-1 of urea-N. The open collector showed significant potential for use; however, further research is needed to verify the suitability of the proposed method.

Intelligent tutoring system for distance education

This study aims to develop and implement a tool called intelligent tutoring system in an online course to help a formative evaluation in order to improve student learning. According to Bloom et al. (1971,117) formative evaluation is a systematic evaluation to improve the process of teaching and learning. The intelligent tutoring system may provide a timely and high quality feedback that not only informs the correctness of the solution to the problem, but also informs students about the accuracy of the response relative to their current knowledge about the solution. Constructive and supportive feedback should be given to students to reveal the right and wrong answers immediately after taking the test. Feedback about the right answers is a form to reinforce positive behaviors. Identifying possible errors and relating them to the instructional material may help student to strengthen the content under consideration. The remedial suggestion should be given in each answer with detaileddescription with regards the materials and instructional procedures before taking next step. The main idea is to inform students about what they have learned and what they still have to learn. The open-source LMS called Moodle was extended to accomplish the formative evaluation, high-quality feedback, and the communal knowledge presented here with a short online financial math course that is being offered at a large University in Brazil. The preliminary results shows that the intelligent tutoring system using high quality feedback helped students to improve their knowledge about the solution to the problems based on the errors of their past cohorts. The results and suggestion for future work are presented and discussed.

Currents controlling sedimentation, deposits recording palaeo-hydrodynamics – lessons from the continental shelf-slope system off SE South America

The continental margin off SE South America hosts one of the world’s most energetic hydrodynamic regimes but also the second largest drainage system of the continent. Both, the ocean current system as well as the fluvial runoff are strongly controlled by the atmospheric circulation modes over the region. The distribution pattern of particular types of sediments on shelf and slope and the long-term built-up of depositional elements within the overall margin architecture are, thus, the product of both, seasonal to millennial variability as well as long-term environmental trends. This talk presents how the combination of different methodological approaches can be used to obtain a comprehensive picture of the variability of a shelf and upper-slope hydrodynamic system during Holocene times. The particular methods applied are: (a) Margin-wide stratigraphic information to elucidate the role of sea level for the oceanographic and sedimentary systems since the last glacial maximum; (b) Palaeoceanographic sediment proxies combined with palaeo-temperature indicating isotopes of bivalve shells to trace lateral shifts in the coastal oceanography (particularly of the shelf front) during the Holocene; (c) Neodymium isotopes to identify the shelf sediment transport routes resulting from the current regime; (d) Sedimentological/geochemical data to show the efficient mechanism of sand export from the shelf to the open ocean; (e) Diatom assemblages and sediment element distributions indicating palaeo-salinity and the changing marine influence to illustrate the Plata runoff history. Sea level has not only controlled the overall configuration of the shelf but also the position of the main sediment routes from the continent towards the ocean. The shelf front has shifted frequently since the last glacial times probably resulting from both, changes in the Westerly Winds intensity and in the shelf width itself. Remarkable is a southward shift of this front during the past two centuries possibly related to anthropogenic influences on the atmosphere. The oceanographic regime with its prominent hydrographic boundaries led to a clear separation of sedimentary provinces since shelf drowning. It is especially the shelf front which enhances shelf sediment export through a continuous high sand supply to the uppermost slope. Finally, the Plata River does not continuously provide sediment to the shelf but shows significant climate-related changes in discharge during the past centuries. Starting from these findings, three major fields of research should, in general, be further developed in future: (i) The immediate interaction of the hydrodynamic and sedimentary systems to close the gaps between deposit information and modern oceanographic dynamics; (ii) Material budget calculations for the marginal ocean system in terms of material fluxes, storage/retention capacities, and critical thresholds; (iii) The role of human activity on the atmospheric, oceanographic and solid material systems to unravel natural vs. anthropogenic effects and feedback mechanisms