Use of the task configuration system (TCS) for the design and on-line optimization of power plants operating with variable loads

The main purpose of this work is to show the ability of the TCS (task configuration system) to perform both the design and the operation optimization of power plants. The TCS is a module that permits to set the main task of each one of the equipments of the system and consequently setting how they respond to variable loads. In this work, the TCS was applied to a micro cogeneration plant of 60 kW in which both the electrical and the thermal loads were variable. Primarily, the design optimization of the nominal power of the equipments and of the TCS configuration was performed for the loads and electricity/fuel costs assumed in the design. After this operational optimizations in cases where the loads and electricity/fuel costs were doubled and then halved in relation to the standard case were performed. The results presented the TCS in a very robust way in most of the cases even the operational conditions being very different from the originally assumed. Based on the results, it is possible to defend the use of the TCS to decrease the risk of high initial investments made in cogeneration systems.     

Mate (<Emphasis Type="Italic">Ilex paraguariensis</Emphasis>) as a source of water extractable antioxidant for use in chicken meat

Aqueous extract of mate, made from dried leaves of Ilex paraguariensis, St. Hilaire, was shown to be effective during chilled storage for up to 10 days in protecting lipids and vitamin E against oxidation in pre-cooked meat balls made from chicken breast added 0.5% salt and packed in atmospheric air. Extracts made with water, methanol, ethanol or 70% aqueous acetone were evaluated by comparing (1) total phenolic content, (2) radical scavenging capacity, (3) effect on lipid oxidation in a food emulsion model, and in liposomes. Based on the three-step evaluation, aqueous mate extract was preferred for food use. Dried leaves were further compared to dried rosemary leaves in chicken meat balls, and mate (0.05 and 0.10%) found to yield equal or better protection than rosemary at the same concentration against formation of secondary lipid oxidation products.     

Volatile compounds as potential defective coffee beans’ markers

Although Brazil is the largest raw coffee producer and exporter in the world, a large amount of its Arabica coffee production is considered inappropriate for exportation. This by-product of coffee industry is called PVA due to the presence of black (P), green (V) and sour (A) defective beans, which are known to contribute considerably for cup quality decrease. Data on the volatile composition of Brazilian defective coffee beans are scarce. In this study, we evaluated the volatile composition of defective coffee beans (two lots) compared to good quality beans from the respective lots. Potential defective beans’ markers were identified. In the raw samples, 2-methylpyrazine and 2-furylmethanol acetate were identified only in black-immature beans and butyrolactone only in sour beans, while benzaldehyde and 2,3,5,6-tetramethylpyrazine showed to be potential markers of defective beans in general. In the roasted PVA beans, pyrazine, 2,3-butanediol meso, 2-methyl-5-(1-propenyl)pyrazine, hexanoic acid, 4-ethyl-guayacol and isopropyl p-cresol sulfide also showed to be potential defective coffee beans’ markers.     

Sense of control predicts depressive and anxious symptoms across the transition to parenthood.

In this study, the authors examined the relationship between sense of control and depressive and anxious symptoms for mothers and fathers during the 1st year of parenthood. Participants were 153 dual-earner, working-class couples who were recruited during the 3rd trimester of pregnancy at prenatal education courses. Data were collected 1 month antenatally and 1, 4, 6, and 12 months postnatally. Sense of control was decomposed into 2 distinct parts: an enduring component and a malleable component that changes with context. Consistent with a cognitive theory of emotional problems, results demonstrated that a sense of control served a protective function for mental health outcomes. A higher sense of enduring control predicted lower levels of psychological distress for new parents, and increases in control over time predicted decreases in depression and anxiety. Findings hold implications for interventions with expectant parents, such as expanding prenatal education courses to include strategies for enhancing and maintaining a sense of personal control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Voidage distribution around bubbles in a fluidized bed: Influence on throughflow

In this work, a new method for measuring void fraction distribution around endogenous bubbles in a 2D fluidized bed is presented. The technique is based on illuminating a transparent-wall 2-dimensional bed with diffuse light from the rear and recording the distribution of light that penetrates the bed. The recording is made with a high speed video-camera, which gives frames with grey level corresponding to the light penetration and from which the voidage distribution around the bubbles can be determined. In this way, voidage distribution in the region very close to the bubble contour (r/R_b ? 1.2) is obtained, which was not possible in previous studies due to limitations in spatial resolution. A correlation is proposed for the voidage at the contour of the bubble, with the voidage depending on the radial position and the polar angle ε(r, θ).In addition, the effect of the voidage distribution on the throughflow crossing the bubbles was studied and an increase of 20% was determined for the average bubble geometry of the more than 100 bubbles analysed.     

Chemometric Analysis of <Superscript>1</Superscript>H NMR Fingerprints of <Emphasis Type="Italic">Coffea arabica</Emphasis> Green Bean Extracts Cultivated under Different Planting Densities

High planting density has been used to increase coffee production but there are few studies related to the variations it provokes in metabolite compositions. The use of ¹H NMR data associated with chemometric techniques allows the determination of metabolic fingerprints and verification of metabolic changes when coffee is subjected to high planting densities. The aim of this work is to investigate ¹H NMR spectral data of green bean extracts of Coffea arabica cv. IAPAR 59 grown in a square pattern at two planting densities, 6000 and 10,000 plants ha^?1. Thirty extracts were obtained using a simplex centroid design with four solvents (ethanol, acetone, dichloromethane, and hexane). The lyophilized extracts were dissolved in DMSO-d₆ to obtain the ¹H NMR spectra. The spectral data were analyzed with principal component (PCA) and cluster analyses (CA). Significant differences between ethanolic and non-ethanolic extracts were found by PCA. Only the ethanolic mean spectrum showed characteristic chemical shifts of sugars and trigonelline. Acetone extracts were separated by cluster analysis.     

Simultaneous analysis of carbohydrates and volatile fatty acids by HPLC for monitoring fermentative biohydrogen production

The production of biohydrogen through anaerobic fermentation has received increasingly attention and has great potential as an alternative process for clean fuel production in the future. The monitoring of the stages of anaerobic fermentation provides relevant information about the bioprocess. The objective of this study is to propose a novel methodology for simultaneous analysis of sucrose, glucose, fructose and volatile fatty acids (VFAs), such as, acetic, propionic, isobutyric and butyric during anaerobic fermentation by using high-performance liquid chromatography (HPLC). The following chromatographic conditions were optimized: column Aminex HPX-87H, mobile phase consisting of H₂SO₄ 0.005 mol/L, flow rate of 1.0 mL/min and temperature of 55 °C. Sucrose, glucose and fructose were analyzed by refractive index detector (RI) while acetic, propionic, isobutyric and butyric acids were analyzed by ultraviolet (UV) detection at 210 nm. Some analytical parameters of validation, such as, linearity, selectivity, repeatability, intermediate precision, limit of detection and quantification, accuracy and robustness were evaluated. The proposed methodology was successfully applied in the determination of substrates and metabolites during different stages of biohydrogen production.     

Population structure and effects of inbreeding on milk yield and quality of Murrah buffaloes

To provide data for conservation, selection, and expansion programs of buffalo herds, this study evaluated the history of a population of Murrah buffaloes based on population structure and the effect of inbreeding on accumulated 305-d milk yield (MY), fat yield (FY), protein yield (PY), mozzarella production (MProd), and somatic cell score (SCS). The usefulness of including the individual inbreeding coefficient (F) or individual increase in inbreeding coefficient (ΔF) in the model to describe inbreeding depression was evaluated. Pedigree information from 8,054 animals born between 1976 and 2008 and 4,497 lactation records obtained from 12 herds were used. The realized effective population size was 40.10 ± 1.27, and the mean F of the entire population was 2.14%. The ratio between the number of founders and ancestors demonstrated the existence of a bottleneck in the pedigree of this population, which may contribute to a reduction of genetic diversity. The effect of F on MY, FY, PY, MProd, and SCS was −1.005 kg, −0.299 kg, −0.246 kg, −1.201 kg, and −0.002 units, and the effect of ΔF transformed to equivalent F (%) for a mean of 2.57 equivalent generations was −4.287 kg, −0.581 kg, −0.383 kg, −2.001 kg, and −0.007 units, respectively. The inbreeding depression observed may have important economic repercussions for production systems. The ΔF can be considered the better of the two indicators of inbreeding depression due to its properties that prevent underestimation of this effect. A designed mating system to avoid inbreeding may be applied to this population to maintain genetic diversity.     

Are electronic white canes better than traditional canes? A comparative study with blind and blindfolded participants

Visually impaired individuals often rely on assistive technologies such as white canes for independent navigation. Many electronic enhancements to the traditional white cane have been proposed. However, only a few of these proof-of-concept technologies have been tested with authentic users, as most studies rely on blindfolded non-visually impaired participants or no testing with participants at all. Experiments involving blind users are usually not contrasted with the traditional white cane. This study set out to compare an ultrasound-based electronic cane with a traditional white cane. Moreover, we also compared the performance of a group of visually impaired participants (N = 10) with a group of blindfolded participants without visual impairments (N = 31). The results show that walking speed with the electronic cane is significantly slower compared to the traditional white cane. Moreover, the results show that the performance of the participants without visual impairments is significantly slower than for the visually impaired participants. No significant differences in obstacle detection rates were observed across participant groups and device types for obstacles on the ground, while 79% of the hanging obstacles were detected by the electronic cane. The results of this study thus suggest that electronic canes present only one advantage over the traditional cane, namely in its ability to detect hanging obstacles, at least without prolonged practice. Next, blindfolded participants are insufficient substitutes for blind participants who are expert cane users. The implication of this study is that research into digital white cane enhancements should include blind participants. These participants should be followed over time in longitudinal experiments to document if practice will lead to improvements that surpass the performance achieved with traditional canes.