High‐pressure processing effects on the mechanical,barrier and mass transfer properties of food packaging flexible structures: a critical review

Food products can be high‐pressure processed (HPP) either in bulk or prepackaged in flexible or semi‐rigid packaging materials. In the latter case the packaging material is subjected, together with the food, to high‐pressure treatment. A number of studies have been performed to quantify the effects of high‐pressure processing on the physical and barrier properties of the packaging material, since the integrity of the package during and after processing is of paramount importance to the safety and quality of the food product. This article reviews the results of published research concerning the effect of HPP on packaging materials. Copyright © 2004 John Wiley & Sons, Ltd.     

Family preservation using multisystemic therapy: An effective alternative to incarcerating serious juvenile offenders.

Multisystemic therapy (MST) delivered through a community mental health center was compared with usual services delivered by a Department of Youth Services in the treatment of 84 serious juvenile offenders and their multiproblem families. Offenders were assigned randomly to treatment conditions. Pretreatment and posttreatment assessment batteries evaluating family relations, peer relations, symptomatology, social competence, and self-reported delinquency were completed by the youth and a parent, and archival records were searched at 59 wks postreferral to obtain data on rearrest and incarceration. In comparison with youths who received usual services, youths who received MST had fewer arrests and self-reported offenses and spent an average of 10 fewer weeks incarcerated. In addition, families in the MST condition reported increased family cohesion and decreased youth aggression in peer relations. The relative effectiveness of MST was neither moderated by demographic characteristics nor mediated by psychosocial variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Microscopic study of the transformation of sphalerite particles during the roasting of zinc concentrate

The formation of zinc ferrite (ZnFe₂O₄) during the roasting of iron-bearing zinc concentrates requires substantial additional processing to recover the zinc from this compound by leaching and to eliminate the iron from the leachate. The phase changes that occur in the particles of a typical industrial zinc sulfide concentrate during roasting in a fluidized bed at 1223 K were investigated by the use of light microscopy, electron microprobe analysis, and SEM with EDS. The processes which the iron undergoes during its eventual transformation into ferrite have been clarified by examination of the phases and the morphology of partially roasted marmatitic sphalerite particles (Zn, Fe)S, and by reference to the known phase equilibria involved in the Zn-Fe-S-0 system. The oxidation of ironbearing sphalerite occurs in three stages. The first involves the selective diffusion of most of the iron to the particle surface resulting in the formation of an iron oxide shell enclosing a largely unreacted zinc sulfide kernel. In the second stage, this kernel is oxidized to form a solid solution of zinc oxide and iron oxide. The iron is initially present in the ferrous state but, with the disappearance of the sulfide kernel, is oxidized to ferric iron. In the final stage, this dissolved iron oxide and the iron oxide shell react with the surrounding zinc oxide to form the refractory spinel zinc ferrite.     

New titanium applications on the Boeing 777 airplane

When rolled out for its first customer in 1995, the 777 will be the first new Boeing commercial airplane in more than ten years. Since the introduction of the last two Boeing planes, the 767 and 757, the science and technology of titanium alloys has come a long way. Some of the advances have led to new applications of titanium\3-with its accompanying performance benefits\3-on the 777.     

Use of a mathematical model in predicting the density of glass for controlling a tank furnace

Translated from Steklo i Keramika, No. 1, pp. 11–12, January, 1992.     

IMPROVING THE QUALITY OF TIMBER FROM RED BEECH (N. FOSCA) BY INTERMITTENT DRYING

The effect of cycling the external conditions on the timber quality and drying time during seasoning has been studied for red beech (Nothofagus fusca), a difficult-to-dry New Zealand hardwood, inalaboratorybatchdryer. Intermittent drying at anair temperature of 45°C and a wet-bulb depression of 10°C takes longer to yield a given moisture content than continuous drying under the same conditions, but produces timber without honeycomb or severe case-hardening as observed in continuous drying. The experiments also indicate that the timber can tolerate a higher air temperature (55°C) in intermittent drying at the same wet-bulb depression with less case-hardening and without showing honeycomb compared with continuous drying at 45°C, having a similar total drying time. Intermittent drying at a slightly higher dry-bulb temperature (60°C) and a much higher wet-bulb depression (18°C) gives a similar degree of case-hardening to that found in samples dried continuously at a dry-bulb temperature of 45°C.     

Interfacial chemistry and adhesive durability

The improved understanding of adsorption chemistry which has arisen from the development of new surface analytical techniques during the last twenty years has had a major effect on the understanding of catalytic reaction mechanisms. However, there are many other areas of technology where Interfacial chemistry has a determining role but where the understanding is much less developed. In this paper examples are presented of the role of interfacial chemistry in adhesion. In particular, It Is shown that modification of a surface to the extent of just a few atomic layers in depth can have dramatic effects on the performance of adhesive bonds, particularly when exposed to hostile environmental conditions. These examples will be used to highlight a need for greater fundamental understanding of the interfacial chemistry of adhesion and also other technologies where interface effects are dominant.