Bittersweet chocolates containing prebiotic and sweetened with stevia (Stevia rebaudiana Bertoni) with different Rebaudioside A contents: multiple time–intensity analysis and physicochemical characteristics

The objective of this study was to evaluate the time–intensity profile of the sensory attributes possibly affected in sugar‐free and low‐fat chocolates containing inulin and stevia with different rebaudioside A contents, such as sweetness, bitterness and melting rate. The bittersweet chocolates were analysed by the multiple time–intensity analysis. The time–intensity profile for the sweetness stimulus was similar for all chocolate samples. The differences between the contents of rebaudioside A were not perceived by the assessors. In relation to the bitterness stimulus, the low‐fat samples had a more accentuated perception of this attribute by the assessors, with significant differences for Imax and Area when compared to the sugar‐free samples. The stimulus melting in the mouth was more affected in the low‐fat samples. The sensory results obtained in this study are useful for food industry and researchers working with sweeteners and prebiotics in food, especially in chocolates.     

A multistage stochastic programming asset-liability management model: an application to the Brazilian pension fund industry

This paper proposes a multistage stochastic programming approach for the asset-liability management of Brazilian pension funds. We generate asset price scenarios with stochastic differential equations—Geometric Brownian Motion model for stocks and Cox–Ingersoll–Ross model for fixed income securities. Intertemporal solvency regulatory rules for Brazilian pension funds are considered endogenously in the model and enforced with a combinatorial constraint. A VaR probabilistic constraint is incorporated to obtain a positive funding ratio at each time period with high probability. Our approach uses multiple trees to provide a representative characterization of the uncertainty and is not computationally prohibitive. We evaluate the insolvency probability under different initial funding ratios through extensive simulations. The study reveals that the likely decrease of interest rate premiums in the next years will force pension fund managers to significantly change their portfolio strategies. They will have to take more risk in order to deliver the cash flows required to cover the liabilities and satisfy the regulatory constraints.     

Kinetic study on the thermal degradation of heavy oil in presence of SBA-15 containing aluminum and cerium

In research for materials that can be applied in processing heavy oil (petroleum), this work proposes to synthesize mesoporous heterogeneous catalysts, type SBA-15, with the addition of cerium metal and aluminum. These catalysts were characterized by X-ray diffraction, scanning electron micrographs coupled to energy dispersive spectrometry, spectroscopy in the infrared region by Fourier transform, N₂ adsorption and desorption and thermal analysis-thermogravimetry. Thermal tests were performed to evaluate the thermal and catalytic degradation process with a sample of heavy oil (°API = 14). Through the non-isothermal kinetic model of Ozawa Flynn Wall (OFW) some parameters for determining the apparent activation energy of decomposition were obtained. The petroleum with 12% of Ce₅Al₅₀SBA-15 showed a catalytic activity for this material. It has been seen that there was a decrease in the Ea in model free of the order from 89.0 to 104.9 kJ mol^?1 in α = 50% ± 10%, and it was repeated from the first percentage until the last showing performance of Ce₅Al₅₀SBA-15 as a catalyst.     

Acoustic emission from low-cycle high-stress-intensity fatigue

This paper presents the findings of an Advanced Research Projects Agency (ARPA) study, the overall objective of which was to develop a nondestructive testing technique to determine flaw criticality based on acoustic emission. The research included an evaluation of sensors and instrumentation systems, using several materials and material conditions loaded in low-cycle, high-stress-intensity fatigue.The materials used for the study were D6aC tempered at 600 and 1100°F, annealed and solution-treatedand-aged 6A1-4V titanium and 7075-T6 aluminum. The test specimen was the precracked, single-edgenotch tension specimen; macrocracking was detected by crack-opening-displacement (COD) gage and micro-cracking by acoustic emission. The acoustic-emission system utilized 400 and 1000 kHz band-pass filtering at 100db gain. The output signals of the totalizer and the COD gage were recorded on a single strip chart using a dual-pen recorder. The specimens were subjected to low-cycle, high-stress-intensity fatigue at 6 c/min. In some tests, cycling was begun in air and finished in water.Acoustic emission was demonstrated to be highly effective as a non-destructive test method for following crack growth in low-cycle high-stress-intensity fatigue; acoustic emission confirmed the existence of periods of dormancy punctuated by periods of active fatigue crack growth. Using a dual-pen, strip-chart recorder displaying both crack-opening-displacement and stress-wave count on the same chart, it was a simple matter not only to observe if there was crack growth in each individual cycle but also where in the cycle it occurred. Moreover, the process of stress-corrosion cracking during low-cycle, high-stress-intensity fatigue was readily detected by a marked increase in the stress-wave count rate.The utility of acoustic emission as a precursor of imminant failure was demonstrated for low-cycle, high-stress-intensity fatigue as well as for the case of environmentally assisted fatigue. Plots of cumulative stress-wave count vs cycle number consistently showed a marked increase in count rate several (10–20 or more) cycles before fracture.     

Applying the Oscillation Test Strategy to FPAA’s Configurable Analog Blocks

This paper presents the application of the oscillation test methodology as an alternative to test configurable analog blocks of Field Programmable Analog Arrays. The blocks of the device under test are first configured to behave as oscillators. Then, the output frequency and amplitude are observed to obtain the signature of the fault-free circuit. During test, this signature is compared to the actual output signal. Experimental results show the effectiveness of the method in detecting parametric and large deviation faults of the tested components.A paper based on this work was presented at the Fourth IEEE Latin American Test Workshop, Natal, Brazil, February 2003.Tiago Roberto Balen was born in Erechim, Brazil, in 1979. He received the Electrical Engineering degree from the Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil in 2004. At present, he is M.Sc. student in the Electrical Engineering Department and works in the Prototyping and Test Laboratory at UFRGS. His research interests include analog and mixed-signal design and test, built-in self-test and design-for-testability. He has published papers on FPAA testing in important conferences, such as the VLSI Test Symposium (VTS) and the International Test Conference (ITC).Antonio Andrade, Jr., received the Electrical Engineering degree from the Universidade Federal da Bahia (UFBA), Salvador, Brazil, in 2003, and is currently pursuing the M.Sc. degree at Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. His experience as a researcher includes the design of a temperature controller using thermo-resistive sensors and FPGA prototyping, at the Instrumentation Laboratory in UFBA, in 2001, a 2-month scholarship from Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, Brazil, in 2002, and 2 years as a graduate student at the Prototyping and Test Laboratory, at UFRGS. His primary research topics include Mixed-Signal Circuit and Systems Testing as well as fast system prototyping in platforms as FPGAs and FPAAs, having published papers in important conferences, such as the VLSI Test Symposium (VTS) and International Test Conference (ITC), in the field of FPAA testing.Florence Azaïs received the Ph.D. degree in electrical engineering from the University of Montpellier, France in 1996. She is currently working in the Microelectronics department of the Laboratory of Computer Science, Robotics and Microelectronics of Montpellier (LIRMM) as a researcher of the National Council of Scientific Research (CNRS). Since 1993, she has been interested in the general domain of test and reliability of integrated circuits and systems. Her main research interests include fault modeling, analog and mixed-signal circuit testing, MEMS testing, reliability and failure analysis of integrated systems. She has authored or co-authored over 80 international papers on these topics. She also served as a member of the Program Committee of several international conferences (DATE, ICCD, ETS, IMSTW, LATW).Marcelo Lubaszewski received the Electrical Engineering and M.Sc. degrees from the Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil, in 1986 and 1990, respectively. In 1994, he received the Ph.D. degree from the Institut National Polytechnique de Grenoble (INPG), France. In 2001, he joined the Laboratoire dInformatique, Robotique et Microélectronique de Montpellier in France as an Invited Researcher for 3 months and, in 2004, the Instituto de Microelectrónica de Sevilla (IMSE) in Spain for 1 year. He is currently with UFRGS, where he has been an Associate Professor since 1990. His primary research interests include design and test of mixed-signal, micro-electro-mechanical and core-based systems, self-checking and fault-tolerant architectures, and computer-aided testing. He has published over 150 papers in international journals and conferences on these topics. Dr. Lubaszewski has served as the general chair or program chair of the Symposium on Integrated Circuits and Systems Design (SBCCI) and of the Latin American Test Workshop (LATW), and as a member of the Organizing or the Program Committee of the VLSI Conference, the International Mixed-Signals Testing Workshop, the Asian Test Symposium, the European Design and Test Conference, the Design of Complex Integrated Systems Conference, the European Test Symposium and the GHz/Gbps Test Workshop. He has also served as a Guest Editor of the Journal of Electronic Testing: Theory and Applications and as an Associate Editor of the Design and Test of Computers Magazine.Michel Renovell is head of the Microelectronics Department at LIRMM (Laboratory of Computer Science, Automation and Microelectronics of Montpellier). His research interests include: Fault modeling, Analog testing and FPGA testing. He is Vice-Chair of the IEEE TTTC (Test Technology Technical Committee). He is a member of the editorial board of JETTA and the editorial board of IEEE Design & Test. Michel has been General Chair of the International Mixed Signal Testing Workshop IMSTW2000, the Field Programmable Logic Conference FPL2002 and the European Test Symposium ETS2004.     

Addition effects of bovine blood globin and sodium caseinate on the quality characteristics of raw and cooked ham pâté

The incorporation of 3% globin bovine extracted by the acidified acetone (AG) and carboxymethylcellulose (CG) methods as replacer for sodium caseinate (CA) in ham paté was evaluated. The raw paté batter was evaluated for salt-soluble protein content (SSP), water holding capacity (WHC) and raw batter stability (RBS). The results of CG were similar to those of CA, having both improved two of the three paramaters studied, and AG was the most deleterious, having decreased SSP, WHC and RBS. Only the AG incorporation had unfavorable effects on the cooked ham paté, decreasing the pH and increasing the thiobarbituric acid reactive substances (TBARS) over the storage period (0-45 days). The results suggest CG as the best replacer for CA as the emulsifying agent for ham paté.     

The 2-D-3-D crossover in modulation-doped GaAs-Ga1-xAlxAs quantum wells

We report on a method to analyze the 2-D-3-D crossover in n-type modulation-doped quantum wells. Finite well barrier, first and second subband population, many-body effects, and residual doping are included in our calculation. We found that the 2-D-3-D crossover remarkably depends not only upon the geometrical parameters, as for instance, the spacer layer width and quantum-well width, but also upon a residual p-type doping intentionally introduced. A diagram showing the 2-D-3-D dimensional crossover is presented     

Investigation of the magnetic field dependence of electronic andoptical properties in one-side modulation-doped GaAs-Ga1-xAlxAs quantum wells

The magnetic field dependence of the two-dimensional electron density, ground state energy, Fermi energy, photoluminescence transition energy, and oscillator strength are systematically studied in GaAs-Ga _1-xAl_xAs one-side modulation-doped quantum wells (QW's). Coupled Schrodinger and Poisson equations are solved self-consistently by means of the extended Fang-Howard variational approach. The calculation is performed within the effective mass approximation, considering finite well barriers and assuming exchange-correlation correction of the conduction band edge. We found an oscillatory behavior, similar to the ordinary Shubnikov-De Haas oscillation, for the magnetic dependence of all properties investigated. In particular, the calculated magnetic dependence of the oscillator strength is compared with experimental data