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991.
Laura Vázquez Alexis Verdú Ana Miquel Francisco Burló Angel A. Carbonell-Barrachina 《European Food Research and Technology》2007,225(5-6):757-767
Turrón has being elaborated in a traditional way; however, manufacturers are trying to (a) change production systems from discontinuous
to continuous and (b) improve quality/homogeneity of products. To get these objectives, detailed scientific information regarding
each of the unit operations involved is needed. Thus, the objective of this study was to gain as much information as possible
about the initial operation of “honey+sugars” concentration. During this stage, humidity was reduced from a 29 to 0.5% and
water activity from 0.86 to 0.18. At the same time, the soluble solid content increased from 51 to 81 Brix. 5-Hydroxymethylfurfural
increased during the heating stages and was constant during the cooling stage; however, contents were always below 40 mg kg−1. Finally during this heating step, characteristic honey volatile compounds decreased their concentration, for instance acetoin,
benzaldehyde, phenylacetaldehyde, and linalool oxide, while compounds arising from amino acids and sugars through Maillard
and Strecker degradation reactions significantly increased, for instance furfuryl alcohol, furfural and 5-methyl furfural. 相似文献
992.
Kaplan Peter S.; Zarlengo-Strouse Patricia; Kirk Lisa S.; Angel Cynthia L. 《Canadian Metallurgical Quarterly》1997,33(6):990
The role of affective correspondence between signal and outcome in associative learning was studied in 2 experiments with 4-month-olds. In Experiment 1, an infant-directed (ID) speech segment, categorized by adults as having consoling acoustic properties for infants, was either paired or unpaired with smiling or sad face reinforcers. In other groups, a sad adult-directed (AD) speech segment signaled the smiling or sad faces. Later, all speech segments were tested for their ability to increase infants' visual interest in a checkerboard. Positive summation was observed only when the consoling ID speech segment had signaled the sad face. In Experiment 2, an arousing ID speech segment signaled the smiling or sad face. Positive summation was evident in both conditions. These results show that infants sometimes selectively associate speech segments and faces. Discussion centers on the basis for the selective association. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
The effect of the presence of corrosion particles on the behavior of different structure types of cation-exchange resins during the adsorption process of 60Co from water solutions was studied. Comparative valuation of sorption behavior and capacity of polyreticular and monoreticular structure type cation-exchangers was carried out. It was found that the ion-exchange filtration efficieny depends upon the presence of corrosion particles on the surface of ion-exchange beads and in their pore structure. The cation-exchange process of 60Co is affected differently by different structure type ion-exchange resins. The fouling phenomenon caused by iron-corrosion particles during the water clean-up process at a RWCU system in BWR and by CVSE demineralizers in PWR dose not affect negative phenomenon for ion-exchange behavior of ion-exchange resins to remove polyvalent ions from the water. The polyreticular cation exchanger Amberlite 200C can better remove 60Co cations from water solutions than the monoreticular (gel type) cation-exchanger Amberlite IR 120. Evidently this is due to the true porous macroreticular structure of the cation-exchange beads. In parallel with the ion-exchange processes, the sorption process of the corrosion products situated on the larger surface area of the true physical pore structure of Amberlite 200C also plays an important role. The information obtained will be very useful to the technological service of nuclear power stations. 相似文献
994.
995.
Angel J Marzocca Carlos A Steren Roxana B Raimondo Silvina Cerveny 《Polymer International》2004,53(6):646-655
An experimental investigation was performed in order to correlate the changes observed in dynamic modulus and loss tangent of vulcanized natural rubber with its network structure. A set of samples of natural rubber vulcanized at 413 K and 433 K for different times was prepared to achieve different network structures in the compound material. These networks were analyzed by means of solid‐state NMR techniques in order to distinguish the sulfur bridges formed during vulcanization. The crosslink density was calculated using swelling techniques for each cure condition. Dynamic mechanical tests were performed using a free decay pendulum in the range of temperatures between 213 K and 373 K and oscillating frequencies between 0.1 s?1 and 20 s?1. Loss tangent data were analyzed within the frame of the KMF model and the variation of the monomeric friction coefficient with the crosslink density was obtained. This variation is a consequence of the network structure formed in the different stages of the curing process. Copyright © 2004 Society of Chemical Industry 相似文献
996.
Candan B Tamerler Angel T Martinez Tajalli Keshavarz 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(9):991-996
After an extensive fungal screening, an Ophiostoma piceae strain was selected for its ability to produce high concentrations of lipase and esterase to remove pitch components of wood pulp. Optimal conditions for growth and enzyme production were established first in shaken flasks. A medium containing rapeseed oil and mycological peptone resulted in a lipase activity of 736 U dm?3 and an esterase activity of 1569 U dm?3. When fermentation runs were implemented using the same medium under controlled conditions in 2‐dm3 fermenters, the lipase and esterase activities were increased to 1005 and 4006 U dm?3 respectively. Further scale‐up was carried out in two stages to 20 dm3 and 72 dm3 (pilot‐scale) stirred tank reactors. The results proved that the cultures could be scaled‐up successfully from shaken flasks to pilot‐scale with increases of 47% and 146% in lipase and esterase activities respectively. © 2001 Society of Chemical Industry 相似文献
997.
Creep and Microstructural Evolution at High Temperature of Liquid-Phase-Sintered Silicon Carbide 总被引:1,自引:0,他引:1
Juan J. Meléndez-Martínez Miguel Castillo-Rodríguez Arturo Domínguez-Rodríguez Angel L. Ortiz Fernando Guiberteau 《Journal of the American Ceramic Society》2007,90(1):163-169
The compressive creep characteristics at 1625°C of liquid-phase-sintered silicon carbide ceramics containing 5 and 15 wt% of crystalline Y3 Al5 O12 (YAG) as the secondary phase were studied. In the two cases, strains between 10% and 15% were reached without failure. The creep behavior was characterized by a stress exponent n ≈2, and the proportion of secondary phase was related to the creep resistance of the materials. The microstructural evolution during creep consisted firstly in the re-distribution of the secondary phase, probably as a consequence of its viscous flow at the creep conditions, and secondly an extensive nucleation and growth of cavities, which was more important for the highest YAG content. The latter reflects the carbothermal reduction that the secondary phase undergoes during creep. 相似文献
998.
999.
This article offers an analysis of the different aspects involved in each of the cultures which interact within school space public, academic, social, school and private cultures - the knowledge of which can help to clarify the body of multiple factors which condition the teaching-learning processes often included within the concept of hidden curriculum. School can be regarded as an ecological space where cultures meet and whose specific responsibility is the reflective mediation of those plural influences which different cultures permanently exert over new generations. 相似文献
1000.
E Ribera J Gómez-Jimenez E Cortes O del Valle A Planes T Gonzalez-Alujas B Almirante I Oca?a A Pahissa 《Canadian Metallurgical Quarterly》1996,125(12):969-974
BACKGROUND: It is often difficult to administer extended antibiotic therapy in the hospital for right-sided Staphylococcus aureus endocarditis. Although the effectiveness of single-drug therapy given for 4 to 6 weeks and that of two-drug therapy given for 2 weeks have been shown, no data are available on the effectiveness of short-course single-drug therapy. OBJECTIVE: To compare the efficacy of cloxacillin alone with that of cloxacillin plus gentamicin for the 2-week treatment of right-sided S. aureus endocarditis in intravenous drug users. DESIGN: Open, randomized study. SETTING: An academic tertiary care hospital in Barcelona, Spain. PATIENTS: 90 consecutive intravenous drug users who had isolated tricuspid valve endocarditis caused by methicillin-susceptible S. aureus, had no allergy to study medications, and had no systemic infectious complications that required prolonged therapy. An efficacy subset consisted of 74 of these patients who did not meet an exclusion criterion. INTERVENTION: Cloxacillin (2 g intravenously every 4 hours for 14 days) alone or combined with gentamicin (1 mg/kg of body weight intravenously every 8 hours for 7 days). MEASUREMENTS: Clinical or microbiological evidence of active infection after 2 weeks of therapy, relapse of staphylococcal infection, or death. RESULTS: In an analysis of the efficacy subset, treatment was successful in 34 of the 38 patients who received cloxacillin alone (89% [95% CI, 75% to 97%]) and 31 of the 36 patients who received cloxacillin plus gentamicin (86% [CI, 71% to 95%]). Three patients died: one in the cloxacillin group and two in the combination therapy group. Of the 37 patients who completed 2-week treatment with cloxacillin, 34 (92%) were cured, and 3 (8%) needed prolonged treatment to cure the infection. Of the 34 patients who completed 2-week treatment with cloxacillin plus gentamicin, 32 (94%) were cured and 2 (6%) required treatment for 4 weeks. One patient in the combination group had relapse. CONCLUSIONS: A penicillinase-resistant penicillin used as single-agent therapy for 2 weeks was effective for most patients with isolated tricuspid endocarditis caused by methicillin-susceptible S. aureus. Adding gentamicin did not appear to provide any therapeutic advantages. Additional studies to confirm the therapeutic equivalence of short-course therapy with penicillinase-resistant penicillin alone and therapy with combined regimens are warranted. 相似文献