Non-contact 3D acquisition system based on stereo vision and laser triangulation

This paper proposes a novel contact 3D acquisition system based on stereo vision and laser triangulation. The system is composed by several software modules for data acquisition purposes, data calibration, data processing and data reconstruction of 3D scenes. Different 3D image techniques, such as, polynomial determination, cubic spline interpolation and hierarchical space decomposition were used. To validate this method, a simple laboratory prototype machine was built for the purpose of road profile acquisition, road macro and mega texture characterization. In this paper, only the results and discussion of road profile acquisition are presented.     

Natural ventilation and indoor air quality in educational buildings: experimental assessment and improvement strategies

Indoor environmental conditions in classrooms, in particular temperature and indoor air quality, influence students’ health, attitude and performance. In recent years, several studies regarding indoor environmental quality of classrooms were published and natural ventilation proved to have great potential, particularly in southern European climate. This research aimed to evaluate indoor environmental conditions in eight schools and to assess their improvement potential by simple natural ventilation strategies. Temperature, relative humidity and carbon dioxide concentration were measured in 32 classrooms. Ventilation performance of the classrooms was characterized using two techniques, first by fan pressurization measurements of the envelope airtightness and later by tracer gas measurements of the air change rate assuming different envelope conditions. A total of 110 tracer gas measurements were made and the results validated ventilation protocols that were tested afterward. The results of the ventilation protocol implementation were encouraging and, overall, a decrease on the CO₂ concentration was observed without modifying the comfort conditions. Nevertheless, additional measurements must be performed for winter conditions.     

IT in lean-based manufacturing industries: systematic literature review and research issues

This systematic literature review is the first to explore the role of IT in lean manufacturing contexts, characterising literature on the field, identifying and exploring the main issues approached, and identifying potential future lines of research. Grounded on an accurate screening process, 124 papers were selected for analysis from the SCOPUS and the ISI Web of Knowledge databases. The structured content analysis process highlights five key issues approached in literature: (1) software and technologies used, (2) benefits achieved through applying IT in lean manufacturing, (3) importance of IT integration, (4) IT and lean as complementary or independent options and (5) role of human resources. Despite an apparent scepticism concerning compatibility between IT and lean, claiming that IT may lead to processes’ complexity, extra tasks, resource consuming, among other issues, among other key findings, the review shows that several different IT instruments may boost improvements, acting as a facilitator in developing lean industrial environments, especially when lean-based improvement processes are introduced first, and then IT infrastructures. Because both IT and Lean may require significant investments in terms of managerial attention, employees’ capabilities and financial resources, it is important for management to balance investment decisions. Authors point to several shortcomings in literature which represent significant opportunities for further research: (1) significant lack of integrated comprehensive frameworks, (2) lack of knowledge concerning hybrid manufacturing systems, supply chains as research unit of analysis, how organisations can respond to staff resistance, and role of IT across the distinctive stages of lean maturity.     

Selection of optimal operating conditions based on minimum energy consumption for an acrylonitrile recovery unit

The selection of the optimal operating conditions for an industrial acrylonitrile recovery unit was conducted by the systematic application of the response surface methodology, based on the minimum energy consumption and products specifications as process constraints. Unit models and plant simulation were validated against operating data and information. A sensitivity analysis was carried out in order to identify the set of parameters that strongly affect the trajectories of the system while keeping products specifications. The results suggest that energy savings of up to 10% are possible by systematically adjusting operating conditions.     

Lipoprotein responses to fish, coconut and soybean oil diets with and without cholesterol in the Syrian hamster

Thirty-six young male Syrian hamsters were fed with test diets containing coconut oil, soybean oil or fish oil with and without 0.5% cholesterol for 6 weeks. Without dietary cholesterol supplementation, animals on the fish oil diet had significantly lower plasma total triglyceride (TG) and total cholesterol than those on the coconut oil or soybean oil diet. The decrease of TG was seen mainly in the very low density lipoprotein (VLDL) fraction. The degree of decrease in cholesterol was similar in all of the lipoprotein fractions. With 0.5% dietary cholesterol supplementation, there was no significant difference in plasma TG level among the three dietary groups. However, the fish oil group had significantly higher plasma cholesterol than the coconut oil and soybean oil groups. The increase of cholesterol was mainly in the VLDL and low density lipoprotein (LDL) fractions. In contrast to the plasma cholesterol level, the hepatic cholesteryl ester content was significantly lower in the cholesterol-supplemented fish oil group than in the coconut oil and soybean oil counterparts. The cholesterol-supplemented fish oil group showed higher liver microsomal acyl-coenzyme A:cholesterol acyltransferase activity than the other two groups, while there was no significant difference in the excretion of fecal neutral and acidic sterols among the three dietary groups.