Influence of Copper Layer Content in the Elastic and Damping Behavior of Glass-Fiber/Epoxy-Resin Composites

The impact in the elastic behavior and internal friction, caused by the introduction of Copper layers in Glass-Fiber/Epoxy Resin composites and temperature effects, were studied and evaluated recurring to Dynamic Mechanical Analysis. It is shown that the introduction of Copper layers increases the storage modulus of the composites and delays their glass transition temperature, however, it allows a faster transformation. Additionally, it is concluded that the introduction of Copper layers elevates the internal friction during the glass transition phase by the inversion of the deformation mechanism due to thermal expansion and increase in the Poisson’s ratio of the epoxy resin to a value near 0.5 where its deformation is approximately isochoric. This increase in damping capacity is relevant in application with cyclic fatigue and mechanical vibration.     

Construction of baselines for VoIP traffic management on open MANs

In the last century, owing to the constant evolution of technologies telecommunication networks have become increasingly robust, being able to support multiple services. These services are part of the heterogeneous network traffic that can be carried through the Internet. Many of these services, including VoIP, are latency sensitive. In other words, this means that their quality depends directly on the network quality of service. Since users tend to become more sensitive with the instability and unavailability of the network, it is important to improve traffic management. A particular type of data that could be used to improve VoIP traffic management is the Internet Protocol Detail Record (IPDR). IPDRs are tickets created by all VoIP call attempts which contain a group of information related to the call history. Because of its full range of information, IPDRs can be used to create VoIP traffic baselines. This paper presents the development of baselines based on IPDRs to support VoIP traffic management in open‐access Metropolitan Area Networks (MAN). Copyright © 2013 John Wiley & Sons, Ltd.     

Evaluation of Porous Structure of Cement Pastes Made with Residual Rice Husk Ash

In several countries, the residual RHA （rice husk ash） has been produced in rice processing industries or in thermoelectric plants that use rice husk to generate heat and/or electrical energy, usually without burning process control. This causes a reduction in the amorphous silica content of residual RHA, which distinguishes them from the RHA produced according to controlled burning process, which is totally amorphous and considered a highly reactive pozzolan. In this paper, the hydration products and the porous structure of binders paste were studied by replacing, in weight of 5%, 10% and 20% of Portland cement OPC （ordinary Portland cement）, by residual RHAs named A and B, which have high and low content of amorphous silica, respectively, using microstructure evaluation techniques as XRD （X-ray diffraction）, TG （thermogravimetric） tests and MIP （mercury intrusion porosimetry）. A reducing the size of the pores of the pastes was observed according to the increase of content replacement of RHA A and RHA B.     

Scenario evaluation for the management of household solid waste in small Brazilian municipalities

As achieving Brazil’s National Policy on Solid Waste-based goals effectively is not simple, there are alternatives such as intermunicipal cooperation by consortium or privatization. Therefore, this study aimed to evaluate the Greenhouse Gas emissions and energy use of six scenarios in two landfills contexts (private and consortium) for small municipalities (less than 100,000 inhabitants as per Brazilian standards) located in São Paulo, Brazil. Through the technique of scenario building and method of Waste Reduction Model was possible to obtain the total energy, the amount of carbon dioxide equivalent (CO₂E) and carbon equivalent (CE) emissions. The best scenario integrates composting and recycling, reducing 72 % for CO₂E and CE emissions, and saving about 410 % in energy. The landfill consortium will only take advantage, if the location is the most ideal as far as possible. Small municipalities that do not dispose their waste in landfills compatible with regulatory standards may seek for intermunicipal cooperation and adopt integrated waste-management programmes to reduce their environmental impacts.     

In search of computer-aided social support in non-communicable diseases care

Non-communicable diseases burden is well-known and care for these diseases goes beyond patients’ engagement, extending to their family, friends, and acquaintances. The ability of social relations in alleviating the harmful effects of health risks is known as social support. Computing can be used to promote social support to enhance the care of non-communicable diseases. However, it is unclear how computing obtains such enhancement. This paper presents a systematic review, in the form of a mapping study, aiming to answer how computing enhances non-communicable diseases care by using social data and by promoting social support. It also looks for available computing models focused on social support promotion in non-communicable diseases care. The study was guided by a two-phase process review, resulting in 38 reviewed papers from journals, conferences, and chapters in the period from 2010 to 2016. In general, the reviewed papers focus on controlled trials, frameworks and systems, knowledge discovery, simulation models or social media usage analysis. Knowledge discovery was the predominant subject, followed by social media usage analysis, and frameworks and systems.     

Biochemical Characterization of Purified Esterase from Soybean (Glycine max) Seed

Alkaline esterase (carboxylic‐ester hydrolases; EC 3.1.1.1) extracted from germinated soybean seeds (Glycine max) was purified approximately 3.6 times by chromatography in a DEAE‐cellulose anion exchange column and filtration in Sephadex G100 gel. The molecular mass of the enzyme was estimated at 45 kDa by gel electrophoresis (SDS‐PAGE). The purified enzyme showed a specific activity of 5.6 U mg^?1 using p‐nitrophenyl butyrate as substrate. The esterase showed optimal activity at 47 °C in moderately alkaline pH, low stability in temperatures higher than 50 °C, and high stability at pH values between 6 and 9.5. The Ca²⁺ and Co²⁺ ions proved to have a positive effect on enzyme activity; however, Hg²⁺ completely inhibited esterase activity. Using p‐nitrophenyl butyrate as substrate, the enzyme showed a K_m of 0.39 mM, V_max of 31.5 mM mg^?1 min^?1 and k_cat 7.60 × 10⁶ s^?1. Regarding substrate affinity, the enzyme showed greater activity for substrates containing short‐chain fatty acids, especially p‐nitrophenyl acetate. Such characteristics give the enzyme great potential for application in the production of low molecular weight esters, in the food industry, and in chemical products. This enzyme is another new member of the family of lipases and esterases from vegetable seeds with high activity and stability in alkaline pH.     

Evaluation of mass loss of weld-deposited hardfacing with cored wire Ti-FeCrC alloy

In this article, we have studied the mass loss of hardfacing applied by flux-cored arc welding. Heat input, shielding gas and number of layers of coating were changed to application of Fe–Cr–Ti–C self-shielded tubular wire. Overlapping beads were deposited on plates of carbon steel AISI 1020 to analyse the mass loss, hardness and microstructure. For the analysis of mass loss, beads were deposited forming overlapping layers of coatings. Hardness measurements were performed on the surface of the specimens of wear. A rubber wheel abrasion tester was used to access the mass loss of coatings. The coatings had retained austenite and martensite microstructure with carbides finely dispersed in the matrix. The main factors that contributed to the increase in mass loss were the cracks due to higher cooling rate of the samples deposited with low heat input, the dilution in the first layer of all samples also contributed to the increase in mass loss. The smallest mass losses were those deposited coatings with high heat input, the second and fourth layers, the samples AC2, AC4 and AS2. The volume fraction of titanium carbides contributed to the decrease in the mean free path between the particles of carbides and increased the wear resistance of the coatings.