Nonpolar resistance switching of metal/binary-transition-metal oxides/metal sandwiches: homogeneous/inhomogeneous transition of current distribution

Exotic features of a metal/oxide/metal (MOM) sandwich, which will be the basis for a drastically innovative nonvolatile memory device, is brought to light from a physical point of view. Here the insulator is one of the ubiquitous and classic binary-transition-metal oxides (TMO), such as Fe2O3, NiO, and CoO. The sandwich exhibits a resistance that reversibly switches between two states: one is a highly resistive off-state and the other is a conductive on-state. Several distinct features were universally observed in these binary TMO sandwiches: namely, nonpolar switching, non-volatile threshold switching, and current--voltage duality. From the systematic sample-size dependence of the resistance in on- and off-states, we conclude that the resistance switching is due to the homogeneous/inhomogeneous transition of the current distribution at the interface.Comment: 7 pages, 5 figures, REVTeX4, submitted to Phys. Rev. B (Feb. 23, 2007). If you can't download a PDF file of this manscript, an alternative one can be found on the author's website: http://staff.aist.go.jp/i.inoue

Economic effects of stimulating business R&D

The main question dealt with in this paper is: what are the economic effects of these financial government incentives? The answer is of particular importance with a view to the question whether the government should intensify, or conversely, cut down on its R&D incentives policy. The economic effects of these R&D incentives are determined by a multitude of factors; factors which also tend to interact. In addition to the spillover effects referred to above, the main decisive factors are: the extent to which the government incentives really do lead to an increase in business R&D, and the direct effects of this extra R&D on business performance. A total of 12 mechanisms are distinguished, all of which have an effect on the economic effects of R&D incentives. These twelve mechanisms are placed in a total framework in this paper. All in all, this paper shows that the economic effects of the government?s stimulation of business R&D are particularly beneficial. The paper also sets out the mechanisms that lead to this result, and which mechanisms are of particular importance in this respect

Optimized alkylated cyclodextrin polysulphates with reduced risks on thromboembolic accidents improve osteoarthritic chondrocyte metabolism

Objectives. To compare the ability of different cyclodextrin polysulphate (CDPS) derivatives to affect human articular cartilage cell metabolism in vitro

Superconductor-insulator transition in nanowires and nanowire arrays

Superconducting nanowires are the dual elements to Josephson junctions, with quantum phase-slip processes replacing the tunneling of Cooper pairs. When the quantum phase-slip amplitude ES is much smaller than the inductive energy EL, the nanowire responds as a superconducting inductor. When the inductive energy is small, the response is capacitive. The crossover at low temperatures as a function of ES/EL is discussed and compared with earlier experimental results. For one-dimensional and two-dimensional arrays of nanowires quantum phase transitions are expected as a function of ES/EL. They can be tuned by a homogeneous magnetic frustration.Comment: 15 pages, 10 figure

Ratchet Effect in Surface Electromigration: Smoothing Surfaces by an ac Field

We demonstrate that for surfaces that have a nonzero Schwoebel barrier the application of an ac field parallel to the surface induces a net electro- migration current that points in the descending step direction. The magnitude of the current is calculated analytically and compared with Monte Carlo simulations. Since a downhill current smoothes the surface, our results imply that the application of ac fields can aid the smoothing process during annealing and can slow or eliminate the Schwoebel-barrier-induced mound formation during growth.Comment: 4 pages, LaTeX, 4 ps figure

National land use specific reference values: a basis for maximum values in Dutch soil policy

The National Institute for Public Health and the Environment has derived Reference Values for maximum permissible soil pollution. The Netherlands Ministry of Housing, Spatial Planning and the Environment (VROM) used these values as a basis for the maximum values for soil pollution. The ministry set these values down according to a proposal for an update of soil policy and the Soil Protection Act in 2003. Reference values refer to allowed concentrations of pollutants in soil, depending on the land use. The soil concentrations of pollutants with values below these concentrations meet all the requirements. The risks for humans, the ecosystem and agriculture were analyzed as critical factors, with risk thresholds derived for different types of land use, such as playgrounds, gardens, and agricultural and nature areas. Furthermore, an accelerated procedure was used to compile a complete list of reference values in 2006. The RIVM used state-of-the-art knowledge to complete the 'old' knowledge for information on toxicity of substances; figures were used where knowledge gaps occurred. A recommendation for the coming years is to address resulting inconsistencies in the list of reference values.Het RIVM heeft de referentiewaarden afgeleid waarmee het ministerie van VROM de maximaal toelaatbare bodemverontreinigingen onderbouwt (maximale waarden). Het ministerie heeft deze normen ingesteld in lijn met zijn voorstel uit 2003 om het bodembeleid en de Wet bodembescherming te actualiseren. Referentiewaarden zijn concentraties van verontreinigende stoffen in de bodem die, afhankelijk van het bodemgebruik, zijn toegestaan. Onder deze concentraties voldoet de bodem aan alle eisen. Voor verschillende vormen van bodemgebruik, zoals landbouw, kinderspeelplaatsen of industrie, zijn grensgehalten voor risico's bepaald. Dat zijn bijvoorbeeld, afhankelijk van het gebruik, risico's voor de mens, voor het ecosysteem en voor de landbouw. Het RIVM heeft gebruikgemaakt van een versnelde procedure om in 2006 een compleet voorstel van referentiewaarden gereed te hebben. Die snelheid was ingegeven door de werkgroep NOBO (normstelling en bodemkwaliteitsbeoordeling). Deze werkgroep heeft tevens uitgangspunten en beslissingen geformuleerd op basis waarvan het RIVM de referentiewaarden heeft afgeleid. Het RIVM heeft voor zijn onderzoek zo veel mogelijk gebruikgemaakt van de nieuwste kennis en inzichten, voor zover die beschikbaar zijn. Deze informatie is aangevuld met 'oude' kennis over stoffen. Deze combinatie heeft evenwel tot inconsistenties geleid in de afleiding van referentiewaarden. Het RIVM beveelt daarom aan de komende jaren aandacht te besteden aan de inconsistenties en zwakke plekken van de referentiewaarden

The opposite of Dante's hell? The transfer of ideas for social housing at international congresses in the 1850s–1860s

With the advent of industrialization, the question of developing adequate housing for the emergent working classes became more pressing than before. Moreover, the problem of unhygienic houses in industrial cities did not stop at the borders of a particular nation-state; sometimes literally as pandemic diseases spread out 'transnationally'. It is not a coincidence that in the nineteenth century the number of international congresses on hygiene and social topics expanded substantially. However, the historiography about social policy in general and social housing in particular, has often focused on individual cases because of the different pace of industrial and urban development and is thus dominated by national perspectives. In this paper, I elaborate on transnational exchange processes and local adaptations and transformations. I focus on the transfer of the housing model of SOMCO in Mulhouse, (a French house building association) during social international congresses. I examine whether cross-national networking enabled and facilitated the implementation of ideas on the local scale. I will elaborate on the transmission and the local adaptation of the Mulhouse-model in Belgium. Convergences, divergences, and different factors that influenced the local transformations (personal choice, political situation, socioeconomic circumstances) will be taken into accoun