Sugarcane bagasse and leaves: foreseeable biomass of biofuel and bio‐products

Sugarcane is among the principal agricultural crops cultivated in tropical countries. The annual world production of sugarcane is ～1.6 billion tons, and it generates ～279 million metric tons (MMT) of biomass residues (bagasse and leaves). Sugarcane residues, particularly sugarcane bagasse (SB) and leaves (SL) have been explored for both biotechnological and non‐biotechnological applications. For the last three decades, SB and SL have been explored for use in lignocellulosic bioconversion, which offers opportunities for the economic utilization of residual substrates in the production of bioethanol and value‐added commercial products such as xylitol, specialty enzymes, organic acids, single‐cell protein, etc. However, there are still major technological and economic challenges to be addressed in the development of bio‐based commercial processes utilizing SB and SL as raw substrates. This article aims to explore SB and SL as cheaper sources of carbohydrates in the developing world for their industrial implications, their use in commercial products including commercial evaluation, and their potential to advance sustainable bio‐based fuel systems. Copyright © 2011 Society of Chemical Industry     

Interactive multi-frame reconstruction for mobile devices

The small size of handheld devices, their video capabilities and multiple cameras are under-exploited assets. Properly combined, the features can be used for creating novel applications that are ideal for pocket-sized devices, but may not be useful in laptop computers, such as interactively capturing and analyzing images on the fly. In this paper we consider building mosaic images of printed documents and natural scenes from low resolution video frames. High interactivity is provided by giving a real-time feedback on the video quality, while simultaneously guiding the user’s actions. In our contribution, we analyze and compare means to reach interactivity and performance with sensor signal processing and GPU assistance. The viability of the concept is demonstrated on a mobile phone. The achieved usability benefits suggest that combining interactive imaging and energy efficient high performance computing could enable new mobile applications and user interactions.     

Characterization of natural rubber/gold nanoparticles SERS‐active substrate

Natural rubber/gold nanoparticles membranes (NR/Au) were studied by ultrasensitive detection and chemical analysis through surface‐enhanced Raman scattering and surface‐enhanced resonance Raman scattering in our previous work (Cabrera et al., J. Raman Spectrosc. 2012, 43, 474). This article describes the studies of thermal stability and mechanical properties of SERS‐active substrate sensors. The composites were prepared using NR membranes obtained by casting the latex solution as an active support (reducing/establishing agents) for the incorporation of colloidal gold nanoparticles (AuNPs). The nanoparticles were synthesized by in situ reduction at different times. The characterization of these sensors was carried out by thermogravimetry, differential scanning calorimetry, scanning electron microscopy (SEM) microscopy, and tensile tests. It is suggested an influence of nanoparticles reduction time on the thermal degradation of NR. There is an increase in thermal stability without changing the chemical properties of the polymer. For the mechanical properties, the tensile rupture was enhanced with the increase in the amount of nanoparticles incorporated in the material. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Improving the relaxivity by dimerizing Gd-AAZTA: Insights for enhancing the sensitivity of MRI contrast agents

The synthesis of a dimeric derivative of Gd-AAZTA is reported. It retains the basic properties of the parent complex (q = 2, high stability) and displays a relaxivity of 14.0 mM^?1 s^?1 at 20 MHz and 298 K. The outstanding relaxivity is the result of the increased molecular reorientational time and of the contribution arising from 4 to 5 water molecules in the second coordination sphere of the Gd(III) ions.     

Modelling Bonded Shape Memory Alloy Vibration Attenuators Elements Using the Finite-Element Method

Shape memory alloys (SMAs) present the capability to develop large forces and displacements with low power consumption. Due their special characteristics, SMAs have been used in many different applications. Pseudoelastic hysteresis loop observed in austenitic SMAs is associated with energy dissipation. Therefore, pseudoelastic SMA elements can be used as vibration attenuators. Joining methods present some technological challenges for the use of these elements. Welding can strongly affect the properties of the alloy. Mechanical joints using rivets and screws are commonly used but promote stress concentration effects. The use of adhesives offers some benefits, being an alternative to be investigated. This work presents a numerical model based on the finite-element method and experimental procedures to study the behaviour of bonded vibration attenuators with SMA elements. The proposed model considers the pseudoelastic behaviour of SMA elements, and a cohesive zone model was used to study the union between absorber and an aluminium plate. Finally, several loading conditions were analysed with the proposed models to assess the capability of bonded pseudoelastic SMA elements to dissipate energy. The proposed geometry allows the elements to actuate as an efficient vibration attenuator, in particular when submitted to axial loading.     

Structural properties of magnetic nanoparticles determine their heating behavior - an estimation of the in vivo heating potential

Magnetically induced heating of magnetic nanoparticles (MNP) in an alternating magnetic field (AMF) is a promising minimally invasive tool for localized tumor treatment by sensitizing or killing tumor cells with the help of thermal stress. Therefore, the selection of MNP exhibiting a sufficient heating capacity (specific absorption rate, SAR) to achieve satisfactory temperatures in vivo is necessary. Up to now, the SAR of MNP is mainly determined using ferrofluidic suspensions and may distinctly differ from the SAR in vivo due to immobilization of MNP in tissues and cells. The aim of our investigations was to study the correlation between the SAR and the degree of MNP immobilization in dependence of their physicochemical features.In this study, the included MNP exhibited varying physicochemical properties and were either made up of single cores or multicores. Whereas the single core MNP exhibited a core size of approximately 15 nm, the multicore MNP consisted of multiple smaller single cores (5 to 15 nm) with 65 to 175 nm diameter in total. Furthermore, different MNP coatings, including dimercaptosuccinic acid (DMSA), polyacrylic acid (PAA), polyethylenglycol (PEG), and starch, wereinvestigated. SAR values were determined after the suspension of MNP in water. MNP immobilization in tissues was simulated with 1% agarose gels and 10% polyvinyl alcohol (PVA) hydrogels.The highest SAR values were observed in ferrofluidic suspensions, whereas a strong reduction of the SAR after the immobilization of MNP with PVA was found. Generally, PVA embedment led to a higher immobilization of MNP compared to immobilization in agarose gels. The investigated single core MNP exhibited higher SAR values than the multicore MNP of the same core size within the used magnetic field parameters. Multicore MNP manufactured via different synthesis routes (fluidMAG-D, fluidMAG/12-D) showed different SAR although they exhibited comparable core and hydrodynamic sizes. Additionally, no correlation between ζ-potential and SAR values after immobilization was observed.Our data show that immobilization of MNP, independent of their physicochemical properties, can distinctly affect their SAR. Similar processes are supposed to take place in vivo, particularly when MNP are immobilized in cells and tissues. This aspect should be adequately considered when determining the SAR of MNP for magnetic hyperthermia.     

Comparison of two processes for treating rice husk ash for use in high performance concrete

Rice husk ashes (RHA) have been used as pozzolanic admixtures for high performance concrete (HPC). This study reports on a chemical treatment before burning that improves the effectiveness of the RHA. The resulting ash (ChRHA) was compared to ash produced by conventional incineration (TRHA). The digestive chemical treatment before burning produced an RHA with properties comparable to silica fume. The ChRHA was highly amorphous, white in color, presented higher specific surface area and exhibited greater pozzolanic activity. The fresh and hardened properties of HPC made with different percentages of these RHAs were compared. The hardened concrete testing included the determination of the modulus of elasticity and the compressive and flexural properties. It was shown that ChRHA and TRHA were effective supplementary cementing materials, although concrete mixes required higher dosages of superplasticizer compared to the control concrete mix.     

A systematic review of domain analysis tools

The domain analysis process is used to identify and document common and variable characteristics of systems in a specific domain. In order to achieve an effective result, it is necessary to collect, organize and analyze several sources of information about different applications in this domain. Consequently, this process involves distinct phases and activities and also needs to identify which artifacts, arising from these activities, have to be traceable and consistent. In this context, performing a domain analysis process without tool support increases the risks of failure, but the used tool should support the complete process and not just a part of it. This article presents a systematic review of domain analysis tools that aims at finding out how the available tools offer support to the process. As a result, the review identified that these tools are usually focused on supporting only one process and there are still gaps in the complete process support. Furthermore, the results can provide insights for new research in the domain engineering area for investigating and defining new tools, and the study also aids in the identification of companies’ needs for a domain analysis tool.     

Application of the GUM approach to estimate uncertainty in measurements of sustainability systems

This work incorporates measurement uncertainty estimation into the model framework proposed by dos Santos and Brandi (Clean Technol Environ Policy, doi: 10.1007/s10098-015-0919-8, 2015). It brings the metrology science procedures to sustainability situations by incorporating the use of the GUM framework (GUF) together with the Monte Carlo method (MCM) (BIPM, Evaluation of measurement data—guide to the expression of uncertainty in measurement 2008a; Evaluation of measurement data—Supplement 1 to the “Guide to the expression of uncertainty in measurement”—propagation of distributions using a Monte Carlo method 2008b). The GUF uses the law of propagation of uncertainties and the MCM the propagation probability distributions. This scheme is applied to analyze the Integration and Logistic Infrastructure sustainability dimension of a biofuel supply chain in six countries (Santos et al. 2014). An initial set of specific indicators (input quantities) satisfying well-established criteria is used to aggregate indicators in a methodological manner into a single aggregate indicator. The Canberra and the normalized Euclidean distances are assumed as model functions. As recommended by the GUM approach, Supplement 1 (BIPM, Evaluation of measurement data—Supplement 1 to the “Guide to the expression of uncertainty in measurement”—propagation of distributions using a Monte Carlo method 2008b) is used to compare the GUF and the MCM results, adopting the GUM recommendation to perform the MCM with 10⁶ random trials. This allows the determination of the numerical statistical results with the precision level required for comparing the sustainability level of the six countries. It was shown that the use of the GUF is not validated to treat the adopted model functions. The two fundamental reasons are the limitation of the GUF concerning the truncation of the Taylor’s expansion and the deviation of the probability density function from the normal distribution (BIPM, Evaluation of measurement data—Supplement 1 to the “Guide to the expression of uncertainty in measurement”—propagation of distributions using a Monte Carlo method 2008b; Couto et al., Theory and applications of Monte Carlo simulations 2013). This result was predictable because of the nonlinear dependence on the indicators of the Canberra and the normalized Euclidean distances. The MCM calculations have shown that the uncertainties depend on the choice of the aggregate metrics, consequently affecting the countries sustainability ranking. The results demonstrate that Canberra and the Euclidean metrics separate the developed from the developing countries in clusters. The calculations for the single sustainability indicator and its uncertainty suggest that the Euclidean distance separates the countries better than the Canberra distance and, thus, it may be considered more adequate to represent the sustainability metrics Integration and Logistic Infrastructure sustainability dimension of a biofuel supply chain.