Satellite remote-sensing monitoring of a railway construction project

Current satellite remote-sensing technologies enable the timely and detailed monitoring of human activities on the Earth’s surface. Sub-metre spatial resolution satellite images can picture the ongoing works of railway and highway construction. The synoptic view of satellite images is useful to assist the monitoring and management of such construction projects. In this article, we present an integrated remote-sensing change detection framework applied to monitoring the Light Rail Transport construction in Kuala Lumpur, Malaysia, using sub-metre optical remote-sensing images, Pleiades. Focusing on the known local area surrounding a construction site, the recognition process starts from the completion stage, checking conditions based on pre-defined rules, applying the recognition process corresponding to that stage, or moving to the immediately preceding stage if appropriate. The process ends when a new stage is identified and recorded into a spatio-temporal database or it reaches the previously detected stage as retrieved from the database. The experiment proved the effectiveness of the proposed framework, with an overall accuracy of about 80% and a low false detection rate. The proposed framework can be extended to monitor other similar scheduled works. Future studies will integrate multi-sensor satellite images including synthetic aperture radar images to expand further the practicality of the framework.     

Intermittency phenomena in electrical connectors

Fretting is known to be a major cause of contact deterioration and failure, particularly in tin-plated contacts. During fretting the contact resistance generally increases slowly with time. Superimposed on this slow increase in contact resistance are rapid changes in contact resistance within fractions of a second, called intermittences or short duration discontinuities. Although intermittences have been reported by several authors, they are frequently overlooked in traditional fretting experiments and not much is known about their origin. The present study aims at filling this gap. A test apparatus has been built to measure the contact voltage-drop profile during an intermittence and fretting experiments on tin-plated copper contacts have been carried out. The results lead to a set of requirements for a model to explain intermittency phenomena     

Structure formation of slag-soil construction materials

It has been demonstrated that mainly amorphous new formations grow during the hydration and strengthening of dump ferrous slag from different metallurgical processes, with or without activators (additions of 2–3% of Portland cement) and mixed with natural soils. Their high rates of strength, and water and frost resistance render of these new materials appropriate for the construction of roads and airfield runways, levee cores, industrial and municipal dumps, building foundations, etc. In addition to their economic advantages, these materials are extremely easy to use and do not create new residues.

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Résumé Il a été démontré que la plupart des nouvelles formations amorphes croissent durant l'hydratation et le renforcement de déchets de scories ferreuses issus de différents processus métalurgiques, avec ou sans activateurs (addition de 2–3% de ciment Portland) et mélangés avec des sols naturels. Leur haute résistance et leur capacité à accepter l'eau et le gel rendent ces nouveaux matériaux appropriés pour la construction de routes et de pistes d'aéroports, de basements de digues, de décharges industrielles et municipales, de fondations d'immeubles, etc. En plus de leurs avantages économiques, ces matériaux sont très facilement utilisables et ne produisent pas de résidus supplémentaires.

     

Hexabromocyclododecane enantiomers: microsomal degradation and patterns of hydroxylated metabolites

The degradation of the enantiomers of α-, β-, and γ-hexabromocyclododecane (HBCD) by phase I metabolism was investigated using induced rat liver microsomes. HBCD isomers were quantified using HPLC-MS/MS (ESI(-)) after separation on a combination of a reversed phase and a chiral analytical column. The degradation of all six isomers followed first-order kinetics and the estimated half-lives ranged from 6.3 min for both β-HBCD enantiomers to 32.3 min in case of (+)-γ-HBCD. (+)-α- and (-)-γ-HBCD displayed significantly shorter half-lives than their corresponding antipodes. It could be shown that this degradation led to a significant enrichment of the first eluting enantiomers (-)-α- and (+)-γ-HBCD. Individual patterns of mono- and dihydroxylated derivatives obtained from each α- and γ-HBCD enantiomer were seen to be distinctly characteristic. The patterns of monohydroxylated HBCD derivatives detected in liver and muscle tissues of pollack, mackerel and in herring gull eggs were largely similar to those observed in the in vitro experiments with rat liver microsomes. This enabled individual hydroxy-HBCDs to be assigned to their respective parent HBCD enantiomers.     

CFD in der chemischen Verfahrenstechnik aus industrieller Sicht

Computational fluid dynamics (CFD) is increasingly becoming established as a tool for analysis and design in the chemical industry. Several projects from various areas are introduced as examples of CFD projects from the perspective of the CFD user in chemical industry. The areas chosen are based on those in a process chain: transportation, mixing, reaction, and separation of materials. The most important steps and decisions in the use of CFD are presented from the perspective of the process engineer. This paper attempts to convey an appreciation for the possibilities and opportunities, but also for the limits of computational fluid dynamics.     

Germination induces the glucosylation of the Fusarium mycotoxin deoxynivalenol in various grains

In food, the mycotoxin deoxynivalenol (DON) often occurs in conjunction with its 3-β-d-glucopyranoside (D3G). The transformation of DON to D3G through glucosylation is catalysed by plant enzymes, however, the exact circumstances are not well understood. In order to investigate the role of enzymatic glucosylation in germinating grains, DON treated kernels were steeped and germinated under laboratory conditions. Furthermore, the effect of malting on the DON content of the contaminated barley was investigated. In all cases, DON and its derivatives were quantified by HPLC-MS/MS before, during and after the experiments. Amongst the six tested cereals; wheat, rye, barley, spelt, and millet transformed DON to D3G during germination whilst the oats were inactive. For wheat, barley, and spelt the initial DON content was reduced by 50%, with the loss being almost entirely accounted for by D3G formation. As D3G might be cleaved during digestion, the elevated D3G concentration may obscure the toxicologically relevant DON content in processed food and beer. The germination process has a major influence on the “masking” of DON, leading to high quantities of D3G that may be missed in common mycotoxin analyses.