Two-digit number comparison: Decade-unit and unit-decade produce the same compatibility effect with number words.

This study explored the processing of 2-digit number words by examining the unit-decade compatibility effect in Spanish. Participants were required to choose the larger of 2-digit number words presented in verbal notation. In compatible trials the decade and unit comparisons led to the same response (e.g., 53–68) while in incompatible trials the decade and unit comparisons led to different responses (e.g., 59–74). Participants were slower on compatible trials as compared to incompatible trials. In Experiments 2 and 3, we evaluated whether the reverse compatibility effect in Spanish was only due to a pure left-to-right encoding which favours the decade processing in this language (decade-unit order). When participants processed 2-digit number words presented in reverse form (in the unit-decade order), the same reverse compatibility effect was found. This pattern of results suggests that participants have learnt a language-dependent process for analysing written numbers which is used irrespective of the specific arrangement of units and decades in the comparison task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of ethylene and 1‐MCP treatments on strawberry fruit ripening

BACKGROUND: Strawberry is a soft fruit, considered as non‐climacteric, being auxins the main hormones that regulate the ripening process. The role of ethylene in strawberry ripening is currently unclear and several studies have considered a revision of the possible role of this hormone. RESULTS: Strawberry fruit were harvested at the white stage and treated with ethephon, an ethylene‐releasing reagent, or 1‐methylcyclopropene (1‐MCP), a competitive inhibitor of ethylene action. The effects of the treatments on fruit quality parameters and on the activity of enzymes related to anthocyanin synthesis and cell wall degradation were evaluated. Some aspects of ripening were accelerated (anthocyanin accumulation, total sugar content and increment of phenylalanine ammonia‐lyase (PAL; EC 4.3.1.24) and β‐galactosidase (EC 3.2.1.23) activities), while others were repressed (chlorophyll levels and increment of endo‐1,4‐β‐glucanase (EC 3.2.1.4) and β‐xylosidase (EC 3.2.1.37) activities) or unchanged (reducing sugar content, pH, titratable acidity and α‐L ‐arabinofuranosidase (EC 3.2.1.55) activity) by ethylene. 1‐MCP treatment caused the opposite effect. However, its effects were more pronounced, particularly in anthocyanin accumulation, phenolics, PAL and polygalacturonase (EC 3.2.1.15 and EC 3.2.1.67) activities. CONCLUSION: These observations probably indicate that strawberry produces low levels of ethylene that are sufficient to regulate some ripening aspects. Copyright © 2010 Society of Chemical Industry     

Multi-objective optimization of pulsed gas metal arc welding process based on weighted principal component scores

Most welding processes present large sets of correlated quality characteristics. With this particularity in mind, we present a multi-objective optimization technique based on Principal Component Analysis (PCA) and response surface methodology (RSM). This two-fold technique utilizes PCA to factorize the original welding responses. The original responses—obtained through a Central Composite Design—are then replaced by the resulting principal component scores. The technique’s advantage is that it reduces the data set and still considers the correlation among the responses. Quite often, however, the first principal component alone cannot explain the amount of variance–covariance structure of the welding responses. In this paper, we remedy this shortfall by proposing an objective function established in terms of the most significative principal component scores (weighted by their respective eigenvalues). Experimental results were obtained with a multiresponse pulsed gas metal arc welding process. These results, when compared with other strategies of multiresponse combination, verify the adequacy of our proposed approach.     

Integrated Process for Purification of Low Grade Talc Ores

This study examines the development of an integrated process for separation and purification of low grade talc ores. This procedure involves leaching with HCl to dissolve gangue minerals and to purify a low purity talc ore containing up to 40% gangue minerals. Also, all cations from gangue minerals are recovered as hydroxides via selective precipitation. The effects of acid concentration, talc/acid solution ratio, time, and reaction temperature on talc purification were studied and the optimal conditions were determined. Laboratory-scale tests revealed that the resulting talc is free of gangue minerals, consisting of small particles with nanometric thicknesses. Reactants are fully consumed during dissolution and byproducts like ammonium chloride could be recirculated and reused. Resulting hydroxides can be used as a coagulation aid for water treatment.     

Physicochemical and antioxidant properties of non‐refined sugarcane alternatives to white sugar

Antioxidant properties of commercial sugarcane‐derived products were analysed to study their suitability for being used as functional ingredients. Cane honey, several jaggeries and several brown sugars were selected from the market and analysed in terms of physicochemical characteristics and antioxidant properties, and compared with white refined sugar (twelve products in total). Moisture, water activity, total soluble solids, pH, colour and sugar profile are reported. As for antioxidant properties, total phenols and flavonoid content, as well as antiradical ability (DPPH˙ and the TEAC‐ABTS methods), are given. All sugarcane products contained phenols and flavonoids and exhibited in vitro antioxidant activity, determined by degree of refining. Among the alternatives analysed, jaggeries and cane honey showed the best antioxidant properties. Thermal treatment did not significantly affect the antioxidant capacity of sugarcane products, especially jaggeries. As sugar‐rich products are widely consumed worldwide, the use of non‐refined sugarcane derivatives in food formulation is encouraged.     

Effect of ethanol on the antimicrobial properties of chlorhexidine over oral biofilm

The aim of this study was to evaluate the effect of 95% ethanol irrigation, with 5 or 10 min of action, on the antibacterial properties of 2% chlorhexidine (CHX), on oral biofilm, evaluated with confocal laser scanning microscopy (CLSM). Oral biofilm development was induced in 80 sterilized bovine dentin blocks, distributed in two groups (5 or 10 min) and 4 subgroups, according to time and the solution used: Saline (SALINE5, SALINE10); Saline followed by CHX (SALINE/CHX5, SALINE/CHX10); Ethanol (ETHANOL5, ETHANOL10), Ethanol followed by CHX (ETHANOL/CHX5, ETHANOL/CHX10). The surface of the block was dyed with Live/Dead^® BacLight. Images from different areas were analyzed by BioImage L program. The total biovolum (µm³), biovolum of live cells (green), percentage of live cells of the thickness of the biofilm visualized in CLSM and on surface biofilm were evaluated. Total biovolum and biovolum of living cells showed similar results among the different groups (p > .05). The percentage of living cells in total thickness of the biofilm also was similar among the groups (p > .05), except ETHANOL5, SALINE/CHX10, ETHANOL10, and ETHANOL/CHX10 that showed lower percentage than SALINE5 (p < .05). The ETHANOL10 and ETHANOL/CHX10 also showed lower percentage of living cells than ETHANOL/CHX5 and SALINE10 (p < .05). In relation to biofilm surface, SALINE/CHX5, SALINE/CHX10, ETHANOL5, ETHANOL10, ETHANOL/CHX5, and ETHANOL/CHX10 showed a lower percentage of living cells percentage than SALINE5 and SALINE10 groups (p < .05). Therefore, ethanol has no effect on antimicrobial properties of 2% chlorhexidine, prior when used as endodontic irrigating solution.     

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.     

Filter & hold: a mixed continuous‐/discrete‐time technique for time‐constant scaling

The work reported in this paper introduces a periodic switching technique applied to continuous‐time filters, whose outcome is an equivalent filter with scaled time‐constants. The principle behind the method is based on a procedure that extends the integration time by periodically interrupting the normal integration of the filter. The net result is an up scaling of the time constant, inversely proportional to the switching duty‐cycle. This is particularly suitable for reducing the area occupied by passive devices in integrated circuits, as well as to accurately calibrate the filter dynamics. Previous works have been following this concept in an entirely continuous‐time perspective, either focusing on specific circuits or using approximations to provide an extended analysis. This paper includes input/output sampling to derive a closed‐form representation for the scaling technique herein coined as ‘Filter & Hold’ (F&H). A detailed mathematical analysis is described, demonstrating that the F&H concept represents an exact filtering solution. Simulation results and experimental measurements are provided to further validate the theoretical analysis for an F&H vector‐filter prototype. Copyright © 2014 John Wiley & Sons, Ltd.