Industry-supported, and standardized modular platform:interconnecting fluidic circuit board and microfluidic building blocks

The research done is focussed on improving the gap between the number of academic proof of concept microfluidic devices and the number of commercial application. A start is made by analysing the factors that inhibit the commercialization of microfluidics. It turns out there are multiple: their multidisciplinary nature, the need for high volume production, the lack of focus due to their broad applicability. To overcome these inhibiting factors an industry-supported, and standardized modular platform is introduced and supported by the European MFManufacturing project. This platform consists out of two parts, the interconnecting fluidic circuit board and the microfluidic building blocks. This platform overcomes some of the inhibiting factors by using the building blocks. They are usable in multiple system, resulting in higher volumes. The building blocks make designing new systems easier. The design effort can be done in several stages, without the need to redo ever stage for a new system. The standardization of the platform is mainly concerned about interoperability, examples are fixed dimensions for the outside dimensions of the microfluidic building blocks and the locations of the interconnects. A library with building blocks and their characterization was also started, including a pressure sensor, valve and reservoir. Also different types of fluidic circuit board were demonstrated. To be able to effectively design new microfluidic systems, a new computer aided design tool was also developed in the MFManufacturing project.To check how well the new standardized platform performs two systems are designed according to it. An AC coulter counter and a cell culturing platform containing 192 individual culture chambers. The AC coulter counter system demonstrates the possibility of the platform to include electrical connection and mix multiple materials in a single system while maintaining a compact footprint of a credit card size. The cell culturing platform consists out of 3 microfluidic building blocks each containing 64 chamber. The fluidic circuit board has integrated valves to be able to individually activate or deactivate a building block. By using multiplexing in the building blocks and a chip select in the fluidic circuit board, over thousand valves can be controlled by only 16 external lines. Hereby greatly reducing the complexity of the setup. At the end of the MFManufacturing project a new Microfluidic Consortium was formed with members from existing project and new external member. In this new Microfluidic Consortium several workshop have been organized to continue standardization in the microfluidic field

A morphometric analysis of vegetation patterns in dryland ecosystems

Vegetation in dryland ecosystems often forms remarkable spatial patterns. These range from regular bands of vegetation alternating with bare ground, to vegetated spots and labyrinths, to regular gaps of bare ground within an otherwise continuous expanse of vegetation. It has been suggested that spotted vegetation patterns could indicate that collapse into a bare ground state is imminent, and the morphology of spatial vegetation patterns, therefore, represents a potentially valuable source of information on the proximity of regime shifts in dryland ecosystems. In this paper, we have developed quantitative methods to characterize the morphology of spatial patterns in dryland vegetation. Our approach is based on algorithmic techniques that have been used to classify pollen grains on the basis of textural patterning, and involves constructing feature vectors to quantify the shapes formed by vegetation patterns. We have analysed images of patterned vegetation produced by a computational model and a small set of satellite images from South Kordofan (South Sudan), which illustrates that our methods are applicable to both simulated and real-world data. Our approach provides a means of quantifying patterns that are frequently described using qualitative terminology, and could be used to classify vegetation patterns in large-scale satellite surveys of dryland ecosystems

Self-organization of hydrophobic soil and granular surfaces

Soil can become extremely water repellent following forest fires or oil spillages, thus preventing penetration of water and increasing runoff and soil erosion. Here the authors show that evaporation of a droplet from the surface of a hydrophobic granular material can be an active process, lifting, self-coating, and selectively concentrating small solid grains. Droplet evaporation leads to the formation of temporary liquid marbles and, as droplet volume reduces, particles of different wettabilities compete for water-air interfacial surface area. This can result in a sorting effect with self-organization of a mixed hydrophobic-hydrophilic aggregate into a hydrophobic shell surrounding a hydrophilic core

Introduction to “The social theories of classical political economy and modern economic policy”

This is the first-ever English translation of an 1891 essay by Carl Menger published in the most important newspaper of the Habsburg Empire, the Neue Freie Presse. Menger writes the piece as a defense of classical political economy in general and of Adam Smith in particular, focusing on misinterpretations of Smith’s work by the Younger Historical School in Germany. The essay reveals that Menger saw himself as working in a liberal tradition going back to Smith and classical political economy, rather than as a marginalist revolutionary who broke with classical political economy. It is a rare instance where Menger, holding the chair of economic theory at the University of Vienna, publicly expresses recommendations on economic policy. The essay represents Smith and the other classical political economists as socially motivated scholars concerned with just reforms to benefit ordinary people. Menger argues that the classical political economists were inclined toward liberal reforms but were by no means rigid exponents of laissez-faire. The essay is preceded here by an introduction authored by the translators Erwin Dekker and Stefan Kolev

DNA Translocation through Graphene Nanopores

Nanopores -- nanosized holes that can transport ions and molecules -- are very promising devices for genomic screening, in particular DNA sequencing. Both solid-state and biological pores suffer from the drawback, however, that the channel constituting the pore is long, viz. 10-100 times the distance between two bases in a DNA molecule (0.5 nm for single-stranded DNA). Here, we demonstrate that it is possible to realize and use ultrathin nanopores fabricated in graphene monolayers for single-molecule DNA translocation. The pores are obtained by placing a graphene flake over a microsize hole in a silicon nitride membrane and drilling a nanosize hole in the graphene using an electron beam. As individual DNA molecules translocate through the pore, characteristic temporary conductance changes are observed in the ionic current through the nanopore, setting the stage for future genomic screening

Mathematical Psychology

This article appeared originally in 1930, in Dutch, under the title “Mathematiese Psychologie” in Mens en Maatschappij. Translated and annotated by Conrad Heilmann, Stefan Wintein, Ruth Hinz, and Erwin Dekker, it is accompanied—in the present issue—by the article “No Envy: Jan Tinbergen on Fairness” written by Conrad Heilmann and Stefan Wintein