Biogenic versus abiogenic emissions from agriculture in the Netherlands and options for emission control in tomato cultivation

In this paper, present-day emissions of greenhouse gases and acidifying compounds from agriculture are analysed at the farm level. Quantitative estimates are given for these emissions from three nested systems in the Netherlands: the agricultural sector, greenhouse horticulture, and tomato cultivation under glass. Total emissions are subdivided into emissions from biogenic sources and abiogenic sources. We conclude that, although most of the emissions from the agricultural sector have biogenic sources, those from abiogenic sources should not be neglected. Abiogenic emissions are mainly from greenhouse horticulture. The cost-effectiveness of options to reduce carbon dioxide (CO₂) and nitrogen oxides (NO_x) emissions from on-farm combustion of natural gas in tomato cultivation under glass is analysed. An inventory is given of technical reduction options that are presently available in practice. Based on information about the costs and the reduction potential of each option, cost-efficiency curves are derived for both types of emissions. Relative to a situation where none of the described options were applied (early nineties), CO₂ and NO_x emissions from tomato cultivation can be reduced at most by about 70% and 75%, respectively, by combinations of technical options. This revised version was published online in August 2006 with corrections to the Cover Date.     

Solution calorimetry: A novel perspective into the dissolution process of food powders

The enthalpy of dissolution of two food powders, maltodextrin and skim milk, was studied by means of isothermal solution calorimetry. The effects of the moisture content and the physical state of the samples were investigated. A reduced exothermic response was found as the moisture content of the samples increased. It was shown that this effect is reversible upon re-drying of the solid, unless crystallization occurs. In the skim milk powder, crystallization of lactose occurred, leading to a less exothermic response. In addition, the dissolution kinetics of single particles was followed in situ with real time video acquisition and a novel image analysis technique. The data showed a significant effect of the physical state of the powder on the dissolution kinetics. Fully amorphous skim milk powder dissolved significantly faster than the recrystallized counterpart. A clear relation was observed between the physical state of the powders, their thermodynamic response and the dissolution kinetics.     

Sheeting interaction failure, from yield-line to two-strip model

This paper presents 20 years of research on failure of sheeting subjected to combined concentrated load and bending moment, performed at Technische Universiteit Eindhoven. The aim of this research is to develop accurate, insight providing design rules using simple mechanical models, based on observed failure modes. The paper summarizes the performed experiments, finite-element simulations, and analytical models. It is concluded that mechanical models may be feasible only for sheeting without stiffeners in web and flanges. For sheeting with stiffeners, the models become so complex that it is not likely that they will lead to simple design rules.     

Editors of medical journals: Who and from where

The representation of scientists from different countries in the editorial boards of the most influential journals from 48 fields of biomedical and clinical research was studied. Scientists from the USA were best represented, followed by scientists from the UK, FRG, Switzerland, Japan, Sweden, Canada, The Netherlands and Italy. The scientifically most productive countries provided most of the editors. For Dutch editors a strong correlation was found between the number of editorships held and the number of papers authored or measures of scientific eminence. Conceivably, scientific productivity and eminence may be important reasons for being asked as an editor. However, national biases play a role too in the composition of editorial boards.     

New,Non‐quinone Fluorogeldanamycin Derivatives Strongly Inhibit Hsp90

Streptomyces hygroscopicus is a natural producer of geldanamycin. Mutasynthetic supplementation of an AHBA‐blocked mutant with all possible monofluoro 3‐aminobenzoic acids provided new fluorogeldanamycins. These showed strong antiproliferative activity and inhibitory effects on human heat shock protein Hsp90. Binding to Hsp90 in the low nanomolar range was determined from molecular modelling, AFM analysis and by calorimetric studies.     

Does remediation save lives? — On the cost of cleaning up arsenic-contaminated sites in Sweden

Sweden has only just begun remediation of its many contaminated sites, a process that will cost an estimated SEK 60,000 million (USD 9100 million). Although the risk assessment method, carried out by the Swedish EPA, is driven by health effects, it does not consider actual exposure. Instead, the sites are assessed based on divergence from guideline values. This paper uses an environmental medicine approach that takes exposure into account to analyse how cancer risks on and near arsenic-contaminated sites are implicitly valued in the remediation process. The results show that the level of ambition is high. At 23 contaminated sites, the cost per life saved varies from SEK 287 million to SEK 1,835,000 million, despite conservative calculations that in fact probably underestimate the costs. It is concluded that if environmental health risks are to be reduced, there are probably other areas where economic resources can be used more cost-effectively.     

Yttrium incorporation in Cr2AlC: On the metastable phase formation and decomposition of (Cr,Y)2AlC MAX phase thin films

Herein we report on the synthesis of a metastable (Cr,Y)₂AlC MAX phase solid solution by co-sputtering from a composite Cr–Al–C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760°C led to the formation of phase pure (Cr,Y)₂AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr₂AlC, Y₅Al₃, and Cr-carbides. In contrast to pure Cr₂AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by ∼200°C for 5 at.% Y compared to Cr₂AlC. Calculations predicting the metastable phase formation of (Cr,Y)₂AlC and its decomposition are in excellent agreement with the experimental findings.     

Modifications in Booth's method for the spectrophotometric determination of?-carotene in vegetables

Summary Booth's method for the spectrophotometric determination ofß-carotene gives reliable results, but the extraction method is very laborious and tedious. Removal of the acetone from the extract and elution of the acetone-free extract on the adsorption column also require much time and attention. The authors describe the modifications made to these three parts of Booth's method for the determination of carotene. The simultaneous application of Booth's original method and of the modified method to samples of carrots, five leafy vegetables and four brassicas gave, in general, corresponding results. With brassicas a tendency was observed for the modified method to yield lower carotene contents. Using the modified method, with pureß-carotene added to samples of carrots and spinach, the authors found recoveries of 98%–100% and 86%–88% respectively.

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Modifikationen der spektrophotometrischenß-Carotin-Bestimmung nach Booth in Gemüse

Zusammenfassung Die Ergebnisse der spektrophotometrischenß-Carotin-Bestimmung nach Booth sind zuverlässig, aber die damit verbundene Extraktionsmethode ist arbeitsintensiv und strapaziös. Auch das Entfernen von Aceton aus dem Extrakt und das Eluieren des acetonfreien Extrakts auf der Säule erfordert viel Zeit und Aufmerksamkeit. Die Autoren beschreiben die von ihnen angebrachten Modifikationen dieserß-Carotin-Bestimmung in den drei Stufen. Die gleichzeitige Anwendung der ursprünglichen Methode nach Booth und deren Modifikation brachte bei Karotten, fünf Blattgemüsen und vier Kohlarten im allgemeinen ähnliche Ergebnisse. Bei den Kohlarten war die Tendenz zu beobachten, daß mit der modifizierten Methode dieß-Carotingehalte etwas niedriger waren. Die modifizierte Methode hatte eine Rückgewinnungsquote von 98–100% bzw. 86–88% bei einem Zusatz von reinemß-Carotin zu Karotten- und Spinatproben.