Mechanisms of Malt Extract Development in Barleys from Different European Regions: I. Effect of Environment and Grain Protein Content on Malt Extract Yield

Malt extract yield (EXT) and barley protein content (BPROT) data from 346 EBC trials located across all the EBC countries, and composed of many different varieties, from the years 1980, 1982 to 1990, inclusive, and 1993 to 1995, thus covering 13 seasons, were used to detect regional trends affecting the negative correlation between these two variables. Quadratic curves were fitted to data from each European region (North, Central, West and South), all of which showed very high coefficients of determination (r²). A common trend in all regions, and also in the overall European analysis, was of EXT decreasing when BPROT increased, although the extent of decrease varied among the regions. Two different geographical patterns of variation in EXT with changes in BPROT have been observed, on the one hand those of the Iberian Peninsula and West region, and on the other, those of the North and Central regions. In the first case, the rate of decrease in EXT was almost constant across the full range of variation of BPROT, whereas, in the second case, the decrease in EXT grew progressively with increases in BPROT. Therefore, although “Bishop's law” on EXT decrease with BPROT increase holds true as a general statement, it would be necessary to take climatic differences into account when estimating EXT values from BPROT data.     

Mechanism of degradation of nitrilotriacetic acid by heterogeneous photocatalysis over TiO2 and platinized TiO2

TiO₂-heterogeneous photocatalysis of nitrilotriacetic acid (NTA) at pH 2.5 was studied to establish the kinetic regime and the reaction mechanism. Pure Degussa P-25 and Hombikat UV100 commercial samples were compared. A Langmuirian behavior was observed over P-25. Platinization of the Hombikat sample (0.5 wt.%) caused an important increase on the photocatalytic rate with a change in the kinetics from zero order in the pure precursors to first order in the platinized sample. The nature of the intermediates and their evolution with time were compared on all systems. Glycine, iminodiacetic and oxamic acids have been identified in different proportions, together with ammonium and glycolic acid, depending on the catalyst used. The rapid depletion of NTA was not accompanied by a corresponding total organic carbon (TOC) reduction, but 84% of TOC decrease was obtained on P25 after 24 h, a very reasonable result for refractory compounds. A detailed mechanism is proposed for the photocatalytic reaction, suggested to be the same over the three catalysts here tested.     

The effects of tasks on integrating information from multiple documents.

The authors examine 2 issues: (a) how students integrate information from multiple scientific documents to describe and explain a physical phenomenon that represents a subset of the information in the documents; and (b) the role of 2 sorts of tasks to achieve this type of integration, either writing an essay on a question requiring integration across texts or answering shorter intratext questions that require students to integrate information within a single text, while superficial and deep comprehension measurements are obtained. Undergraduate students answered 1 of the 2 types of questions, and their reading times were recorded. Half of the sample thought aloud. Results showed that the integration question increased integration and decreased the processing of isolated units of information, which enhanced deep learning, whereas no differences between the 2 sorts of tasks on memory recall were apparent. This research also provides evidence for the discrepancy between training and posttraining effects (R. A. Schmidt & R. A. Bjork, 1992). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using EIS to analyse samples of Al–Mg alloy AA5083 treated by thermal activation in cerium salt baths

This paper describes a study undertaken of the morphological and anticorrosive characteristics of surface layers formed on the Al–Mg alloy AA5083 from solutions of Ce(III), by means of various heat treatments while immersed in baths of cerium salts. SEM/EDS studies have demonstrated the existence of a heterogeneous layer formed by a film of aluminium oxide/hydroxide on the matrix and a series of dispersed islands of cerium deposited on the cathodic intermetallics. With the object of evaluating the degree of protection provided by the layers formed and of characterising the particular contribution of the electrochemical response of the system in NaCl, the results obtained by means of EIS are presented and discussed.     

Evaluation of barley and triticale as feed ingredients in growing Iberian pigs: amino acid and carbohydrate ileal digestibility

BACKGROUND: Iberian pig production is linked to the use of the Mediterranean woodland, where the use of local feed resources is of paramount importance for the sustainability of the system. The aim of the present work was to explore the potential of triticale cv. Camarma as compared to barley cv. Esgueva in Iberian pig feeding by studying their respective ileal digestibilities of amino acids and carbohydrates in animals cannulated at the end of the ileum. RESULTS: Leu, Met and Tyr had (P < 0.05) greater standardised ileal digestibilities (SID) in pigs fed triticale diet. There was a trend (P = 0.07) towards greater SID of Thr in pigs fed the barley diet. The least digestible indispensable amino acids were Ile (74.6% SID) for barley and Thr (78.9% SID) for triticale. Except for β‐glucans, apparent ileal digestibilities (AIDs) of individual non‐starch polysaccharide (NSP), sugars and starch were greater in pigs fed triticale (P < 0.05). Nevertheless, total amounts of NSP digested were greater in pigs fed the barley diet (P < 0.05). CONCLUSION: Overall, triticale cv. Camarma had greater amino acid and carbohydrate AID than barley cv. Esgueva and may represent a valuable grain for Iberian pig feeding. Copyright © 2008 Society of Chemical Industry     

Family conflict and intragroup marginalization as predictors of acculturative stress in Latino college students.

This study examined the impact of family conflict and intragroup marginalization on acculturative stress in 188 bicultural Latino college students. Results showed that low parental income, low acculturation, perceived family conflict, and perceived intragroup marginalization were related to higher acculturative stress for participants. Intragroup marginalization accounted for a statistically significant proportion of the variance in acculturative stress after all variables were controlled. The findings emphasize the need to recognize culture-specific stressors of college students. Implications for mental health providers are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An XPS study of tarnishing of a gold mask from a pre-Columbian culture

The tarnishing originated on a hammered gold mask was analysed. Red tarnishing was observed after three years of storage in an indoor environment in the Gold Museum of Banco de la República, Bogotá, Colombia. Silver sulphide (Ag₂S) and silver sulphate (Ag₂SO₄) compounds were identified as the origin of the tarnishing phenomenon, which is attributed to environmental contamination. Atomic absorption spectroscopy (AAS) and X-ray photoelectron spectroscopy (XPS) techniques were used.     

Effects of a mixture of stabilizers on the structure and mechanical properties of polyethylene during reprocessing

The properties of two polyethylenes [a high‐density polyethylene (HDPE) and a low‐density polyethylene (LDPE)] were studied after several extrusion cycles. To reduce the degradation effects during the reprocessing, a mixture of two stabilizers was added to the formulations. The predominant degradation mechanism was chain scission for the HDPE and chain branching and crosslinking for the LDPE. For both polyethylenes the FTIR spectra exhibited a growth in the number of carbonyl groups as a function of the number of extrusion cycles. Their tensile properties were degraded with the reprocessing but both polyethylenes maintained their nearly constant thermal behavior and crystallinity. The addition of a primary phenolic antioxidant and a secondary phosphite antioxidant preserved the melt behavior of virgin materials after the reprocessing and reduced the degradation effects. From the tensile tests, the efficiency of the antioxidants in the LDPE was very high and, after the reprocessing, the material retained the mechanical properties of virgin LDPE. The efficiency of the antioxidants for the HDPE was not significant. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3910–3916, 2004