Design and fabrication of nanofluidic devices by surface micromachining

Using surface micromachining technology, we fabricated nanofluidic devices with channels down to 10?nm deep, 200?nm wide and up to 8?cm long. We demonstrated that different materials, such as silicon nitride, polysilicon and silicon dioxide, combined with variations of the fabrication procedure, could be used to make channels both on silicon and glass substrates. Critical channel design parameters were also examined. With the channels as the basis, we integrated equivalent elements which are found on micro total analysis (μTAS) chips for electrokinetic separations. On-chip platinum electrodes enabled electrokinetic liquid actuation. Micro-moulded polydimethylsiloxane (PDMS) structures bonded to the devices served as liquid reservoirs for buffers and sample. Ionic conductance measurements showed Ohmic behaviour at ion concentrations above 10?mM, and surface charge governed ion transport below 5?mM. Low device to device conductance variation (1%) indicated excellent channel uniformity on the wafer level. As proof of concept, we demonstrated electrokinetic injections using an injection cross with volume below 50?attolitres (10(-18)?l).     

Prototype Line Crawler for Power Line Inspection

In South Africa, electricity is supplied through thousands-of-kilometers of overhead power cables, which is owned by Eskom the national energy supplier. Currently monitoring of these overhead power cables are done by means of helicopter inspection flights and foot patrols, which are infrequent and expensive. In this paper, the authors present the design of a prototype power line crawler （inspection robot） for the monitoring of these overhead power lines in South Africa. The designed prototype power line crawler is capable of driving on the wire, balancing on the wire and is capable of maneuvering past certain obstacles found on the overhead power cables. The prototype power line crawler is designed to host a monitoring system that monitors the power line as the inspection robot drives on it. Various experimental tests were performed and are presented in this paper, showing the capability of performing these tasks. This prototype inspection robot ensures a platform for future development in this area.     

Status quo and future research challenges on organic food quality determination with focus on laboratory methods

Organic food quality determination needs multi‐dimensional evaluation tools. The main focus is on the authentication as an analytical verification of the certification process. New fingerprinting approaches such as ultra‐performance liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry, direct analysis in real time–high‐resolution mass spectrometry as well as crystallization with and without the presence of additives seem to be promising methods in terms of time of analysis and detecting organic system‐related parameters. For further methodological development, a system approach is recommended, which also takes into account food structure aspects. Furthermore, the authentication of processed organic samples needs more consciousness, hence most of organic food is complex and processed. © 2013 Society of Chemical Industry     

Le concept de performance:

Bien que non paru sous la forme d'un rapport de la Commission de Travail CIB W60, l'article, qui est, la traduction de la partie principale d'un rapport du Danish Building Research Institute (¹) est considéré comme un complément précieux au rapport de la Commission des ? Directives ?. Les premières parties de la publication Danoise, version originale ont déjà été adaptées pour être utilisées dans l'introduction au rapport précédent W60, sur ? Le concept de performance et sa terminologie ? (janvier/février 1975, paru dans ce journal) et on ne les répétera par conséquent pas ici.     

First tests of standardized biocrystallization on milk and milk products

The biocrystallization method has been standardized for plant products. The standardized biocrystallization method is tested on milk and butter samples from controlled feeding trials. When computerized image analysis is applied, samples from different origins (feeding regimes) can be distinguished significantly.     

Volume contents for Volume 19

Volume Contents

Volume contents for Volume 19