917 resultados para electromagnetic processing of materials (EPM)
Resumo:
This study examined the properties of ERP effects elicited by unattended (spatially uncued) objects using a short-lag repetition-priming paradigm. Same or different common objects were presented in a yoked prime-probe trial either as intact images or slightly scrambled (half-split) versions. Behaviourally, only objects in a familiar (intact) view showed priming. An enhanced negativity was observed at parietal and occipito-parietal electrode sites within the time window of the posterior N250 after the repetition of intact, but not split, images. An additional post-hoc N2pc analysis of the prime display supported that this result could not be attributed to differences in salience between familiar intact and split views. These results demonstrate that spatially unattended objects undergo visual processing but only if shown in familiar views, indicating a role of holistic processing of objects that is independent of attention.
Resumo:
Lignocellulosicwaste from the pineapple production is a raw material useful for the xylose production by hydrolysis and it can be converted to xylitol. The objective of this work was to study the hydrolysis of pineapple peel with sulfuric acid at variable concentration (2-6%), reaction time (0-350 min) and temperature at 98 ˚C. The concentration of xylose, glucose and degradation products as acetic acid and furfural was determined. Optimal conditions found for hydrolysis were 6% H2SO4 at 98 ˚C for 83 min which yield was 26,9 g xylose/L, 2,61 g glucose/L, 7,71 g acetic acid/L and 0,29 g furfural/L.
Resumo:
Hierarchical structure with nested nonlocal dependencies is a key feature of human language and can be identified theoretically in most pieces of tonal music. However, previous studies have argued against the perception of such structures in music. Here, we show processing of nonlocal dependencies in music. We presented chorales by J. S. Bach and modified versions inwhich the hierarchical structure was rendered irregular whereas the local structure was kept intact. Brain electric responses differed between regular and irregular hierarchical structures, in both musicians and nonmusicians. This finding indicates that, when listening to music, humans apply cognitive processes that are capable of dealing with longdistance dependencies resulting from hierarchically organized syntactic structures. Our results reveal that a brain mechanism fundamental for syntactic processing is engaged during the perception of music, indicating that processing of hierarchical structure with nested nonlocal dependencies is not just a key component of human language, but a multidomain capacity of human cognition.
Resumo:
Reverse osmosis (RO) brine produced at a full-scale coal seam gas (CSG) water treatment facility was characterized with spectroscopic and other analytical techniques. A number of potential scalants including silica, calcium, magnesium, sulphates and carbonates, all of which were present in dissolved and non-dissolved forms, were characterized. The presence of spherical particles with a size range of 10-1000nm and aggregates of 1-10 microns was confirmed by transmission electron microscopy (TEM). Those particulates contained the following metals in decreasing order: K, Si, Sr, Ca, B, Ba, Mg, P, and S. Characterization showed that nearly one-third of the total silicon in the brine was present in the particulates. Further, analysis of the RO brine suggested supersaturation and precipitation of metal carbonates and sulphates during the RO process should take place and could be responsible for subsequently capturing silica in the solid phase. However, the precipitation of crystalline carbonates and sulphates are complex. X-ray diffraction analysis did not confirm the presence of common calcium carbonates or sulphates but instead showed the presence of a suite of complex minerals, to which amorphous silica and/or silica rich compounds could have adhered. A filtration study showed that majority of the siliceous particles were less than 220nm in size, but could still be potentially captured using a low molecular weight ultrafiltration membrane. © 2015 Elsevier Ltd.
Resumo:
In most countries along with various food products, fish sausage is supplied in different formulas. Unfortunately, in our country because of different reasons, production and supply of fish sausage in industrial level has not yet been successful and some efforts taken, has also been doomed to failure or not welcomed. Fat fish is a rich source of poly unsaturated fatty acids (PUFA) and co-3. In this research, efforts have been made to produce and enrich sausage with fish oil and maintenance of fatty acids has also been experimented using gas chromatography along with heating process. The stages of producing ground fish and fish sausage are as the following: Transferring and preparing fish, washing the cleared fish, filleting, separating fillet steak, washing and drying them, Refining meat, Producing and homogenizing mixture from basic ingredients in a cutter, filling, knotting and heat processing. The fish sausage produced by this method tried and welcomed by the subjects. In the product in which fish meat was used, the subjects was not recognized fish flavor and taste and when in addition to fish meat, fish oil was used during enrichment, the flavor and taste of fish was considered as highly acceptable. TVN measurement of the produced fish sausage was kept in the refrigerator in two month was at a maximum of 16.5, the amount of peroxide was at a maximum 1.5% after the period of two months. During this period the Colony count was at maximum of 19.5 x 104, the high maximum of the number of coliforms was 10/gr, and for mold and yeast 83/gr , but Escherichia coli, Staphylococcus aureus, Salmonella and Clostridium perfringens were not found. The protein of the resulting product was 15-18%, lipid at about 11-15% and moisture 60-65%. Comparing fatty acids, including unsaturated fatty acids in ground and oil fish used in producing fish sausage with those of fish sausage showed that the heat used in processing had the least effect on fatty acids of the meat and oil used here and the resulting fish sausage is considered as food for good health.
Resumo:
Recent research on affective processing has suggested that low spatial frequency information of fearful faces provide rapid emotional cues to the amygdala, whereas high spatial frequencies convey fine-grained information to the fusiform gyrus, regardless of emotional expression. In the present experiment, we examined the effects of low (LSF, <15 cycles/image width) and high spatial frequency filtering (HSF, >25 cycles/image width) on brain processing of complex pictures depicting pleasant, unpleasant, and neutral scenes. Event-related potentials (ERP), percentage of recognized stimuli and response times were recorded in 19 healthy volunteers. Behavioral results indicated faster reaction times in response to unpleasant LSF than to unpleasant HSF pictures. Unpleasant LSF pictures and pleasant unfiltered pictures also elicited significant enhancements of P1 amplitudes at occipital electrodes as compared to neutral LSF and unfiltered pictures, respectively; whereas no significant effects of affective modulation were found for HSF pictures. Moreover, mean ERP amplitudes in the time between 200 and 500ms post-stimulus were significantly greater for affective (pleasant and unpleasant) than for neutral unfiltered pictures; whereas no significant affective modulation was found for HSF or LSF pictures at those latencies. The fact that affective LSF pictures elicited an enhancement of brain responses at early, but not at later latencies, suggests the existence of a rapid and preattentive neural mechanism for the processing of motivationally relevant stimuli, which could be driven by LSF cues. Our findings confirm thus previous results showing differences on brain processing of affective LSF and HSF faces, and extend these results to more complex and social affective pictures.
Resumo:
The role of odors in the long-distance navigation of birds has elicited intense debate for more than half a century. Failure to resolve many of the issues fueling this debate is due at least in part to the absence of controls for a variety of non-specific effects that odors have on the navigational process. The present experiments were carried out to investigate whether the olfactory inputs are involved only in “activation” of neuronal circuitry involved in navigation or are also playing a role in providing directional information. Experienced adult pigeons were exposed to controlled olfactory stimuli during different segments of the journey (release site vs. displacement + release site). Protein levels of IEGs (immediate early genes used to mark synaptic activity) were analyzed in areas within the olfactory/navigation avian circuitry. The results indicate that 1) exposure to natural odors at the release site (and not before) elicit greater activation across brain regions than exposure to filtered air, artificial odors, and natural odors along the entire outward journey (from home to the release site, inclusive); 2) activation of the piriform cortex in terms of odor discrimination is lateralized; 3) activation of the navigation circuitry is achieved by means of lateralized activation of piriform cortex neurons. Altogether, the findings provide the first direct evidence that activation of the avian navigation circuitry is mediated by asymmetrical processing of olfactory input occurring in the right piriform cortex.
Resumo:
Discretion plays a role in nearly every facet of the American criminal justice system. It is widely regarded as necessary to do justice but is not without criticisms – especially when it leads to unfavorable or disparate treatment. The role of discretion in sexual assault cases has been particularly scrutinized. Since the majority of sexual assaults do not fit stereotypic beliefs about what constitutes a “real rape” and “genuine victim,” criminal justice officials use their discretion to filter these cases out of the justice system. This study explored this issue by examining two stages of the criminal justice process: the police decision to refer cases for prosecution and the prosecutorial decision to accept referred cases. In doing so, it contributes to this body of literature in three ways. First, it included sexual assault cases that involve Alaska Native victims and suspects. Second, it addressed a gap in the theoretical scholarship by examining the downstream nature of police decision-making. And finally, it examined the formal reasons prosecutors give for charge dispositions. This study found a significant amount of attrition of sexual assault cases as they progressed through the criminal justice system. Moreover, a combination of legally relevant and extralegal factors was found to be important, but not consistently across all types of sexual assaults. Among legal factors, the number of victim injuries was the most consistent predictor. Among extralegal factors, cases that involved Alaska Native suspects had significantly higher odds of case referral and case acceptance compared to white suspects. The effect of suspect race was particularly pronounced in cases with a white victim. Additionally, the findings suggest that not only are Native American defendants more likely to have their cases referred by police, but once referred, they are also more likely to have them accepted for prosecution. Contrary to expectations, victim-suspect relationship, specifically non-stranger assaults, increased the odds of police referral compared to stranger cases. However, the opposite appears to be true for the decision to prosecute cases. Once referred, prosecutors were five times more likely to accept sexual assaults perpetrated by strangers. The implications of these findings are also discussed.
Resumo:
New and promising treatments for coronary heart disease are enabled by vascular scaffolds made of poly(L-lactic acid) (PLLA), as demonstrated by Abbott Vascular’s bioresorbable vascular scaffold. PLLA is a semicrystalline polymer whose degree of crystallinity and crystalline microstructure depend on the thermal and deformation history during processing. In turn, the semicrystalline morphology determines scaffold strength and biodegradation time. However, spatially-resolved information about the resulting material structure (crystallinity and crystal orientation) is needed to interpret in vivo observations.
The first manufacturing step of the scaffold is tube expansion in a process similar to injection blow molding. Spatial uniformity of the tube microstructure is essential for the consistent production and performance of the final scaffold. For implantation into the artery, solid-state deformation below the glass transition temperature is imposed on a laser-cut subassembly to crimp it into a small diameter. Regions of localized strain during crimping are implicated in deployment behavior.
To examine the semicrystalline microstructure development of the scaffold, we employed complementary techniques of scanning electron and polarized light microscopy, wide-angle X-ray scattering, and X-ray microdiffraction. These techniques enabled us to assess the microstructure at the micro and nano length scale. The results show that the expanded tube is very uniform in the azimuthal and axial directions and that radial variations are more pronounced. The crimping step dramatically changes the microstructure of the subassembly by imposing extreme elongation and compression. Spatial information on the degree and direction of chain orientation from X-ray microdiffraction data gives insight into the mechanism by which the PLLA dissipates the stresses during crimping, without fracture. Finally, analysis of the microstructure after deployment shows that it is inherited from the crimping step and contributes to the scaffold’s successful implantation in vivo.
Resumo:
International audience
Resumo:
The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with renewable carbon from biomass as possible, innovative R&D activities must strive to enhance the current biorefinery process and secure our energy future. Much of my Ph.D. research effort is centered on the study of electrocatalytic conversion of biomass-derived compounds to produce value-added chemicals, biofuels and electrical energy on model electrocatalysts in AEM/PEM-based continuous flow electrolysis cell and fuel cell reactors. High electricity generation performance was obtained when glycerol or crude glycerol was employed as fuels in AEMFCs. The study on selective electrocatalytic oxidation of glycerol shows an electrode potential-regulated product distribution where tartronate and mesoxalate can be selectively produced with electrode potential switch. This finding then led to the development of AEMFCs with selective production of valuable tartronate or mesoxalate with high selectivity and yield and cogeneration of electricity. Reaction mechanisms of electrocatalytic oxidation of ethylene glycol and 1,2-propanediol were further elucidated by means of an on-line sample collection technique and DFT modeling. Besides electro-oxidation of biorenewable alcohols to chemicals and electricity, electrocatalytic reduction of keto acids (e.g. levulinic acid) was also studied for upgrading biomass-based feedstock to biofuels while achieving renewable electricity storage. Meanwhile, ORR that is often coupled in AEMFCs on the cathode was investigated on non-PGM electrocatalyst with comparable activity to commercial Pt/C. The electro-biorefinery process could be coupled with traditional biorefinery operation and will play a significant role in our energy and chemical landscape.
Resumo:
This thesis presents a system for visually analyzing the electromagnetic fields of the electrical machines in the energy conversion laboratory. The system basically utilizes the finite element method to achieve a real-time effect in the analysis of electrical machines during hands-on experimentation. The system developed is a tool to support the student's understanding of the electromagnetic field by calculating performance measures and operational concepts pertaining to the practical study of electrical machines. Energy conversion courses are fundamental in electrical engineering. The laboratory is conducted oriented to facilitate the practical application of the theory presented in class, enabling the student to use electromagnetic field solutions obtained numerically to calculate performance measures and operating characteristics. Laboratory experiments are utilized to help the students understand the electromagnetic concepts by the use of this visual and interactive analysis system. In this system, this understanding is accomplished while hands-on experimentation takes place in real-time.