New results for virial coefficients of hard spheres in D dimensions

We present new results for the virial coefficients B_k with k <= 10 for hard spheres in dimensions D=2,...,8.Comment: 10 pages, 5 figures, to appear in conference proceedings of STATPHYS 2004 in Pramana - Journal of Physic

SDSS J122958.84+000138.0: A Compact, Optically red galaxy

We report a new compact galaxy, SDSS J122958.84+000138.0 (SDSS J1229+0001), which has unique morphological and stellar population properties that are rare in observations of the nearby universe. SDSS J1229+0001 has an $r$-band absolute magnitude (M$_{r}$) and half-light radius (R$_{h}$) of $-$17.75 mag and 520 pc, respectively. Located in a fairly low density environment, morphologically it is akin to a typical early-type galaxy as it has a smooth appearance and red colour. But, interestingly, it possesses centrally concentrated star forming activity with a significant amount of dust. We present an analysis of structural and stellar population properties using archival images and VLT/FORS2 spectroscopy. Analysis of UKIDSS H-band image shows that the observed light distribution is better fitted with two components S\'ersic function with inner and outer component effective radii 190 and 330 pc, respectively. Whereas, overall half-light radius measured in H-band is much smaller compared to optical, i.e 290 pc. We prepared a Spectral Energy Distribution (SED) from optical to FIR and interpret it to derive star-formation rate, dust mass and stellar mass. We find that the SDSS J1229+0001 has dust mass M$_{dust}$ = 5.1 $\times$ 10$^{5}$ M_{\sun} with a dust to stellar mass ratio log(M$_{dust}$/M$_{*}$) = $-$3.5. While the observed stellar population properties are -- to some extent -- similar to that of a typical S0 galaxy, a unified view from stellar population and structural properties may suggests that SDSS J1229+0001 is a {\it smoking gun} example of a compact early-type galaxy in formation.Comment: 10 pages, Accepted MNRA

Opportunities for Dutch Biorefineries

Deze Roadmap Bioraffinage beschrijft een aantal mogelijke routes naar de ontwikkeling en implementatie van een bioraffinage-gerelateerde Bio-based Economy in Nederland. De Roadmap combineert korte- en middellange termijn mogelijkheden (commerciële implementatie, demonstratie plants, pilot plants en gerelateerd toegepast onderzoek) met strategisch onderzoek voor de langere termijn. Tevens zijn vier z.g. Moonshots uitgewerkt, als voorziene bioraffinagestrategieën met een grote potentie voor de Nederlandse economi

Serpentine Soils Do Not Limit Mycorrhizal Fungal Diversity

Background: Physiologically stressful environments tend to host depauperate and specialized biological communities. Serpentine soils exemplify this phenomenon by imposing well-known constraints on plants; however, their effect on other organisms is still poorly understood.Methodology/Principal Findings: We used a combination of field and molecular approaches to test the hypothesis that serpentine fungal communities are species-poor and specialized. We conducted surveys of ectomycorrhizal fungal diversity from adjacent serpentine and non-serpentine sites, described fungal communities using nrDNA Internal Transcribed Spacer (ITS) fragment and sequence analyses, and compared their phylogenetic community structure. Although we detected low fungal overlap across the two habitats, we found serpentine soils to support rich fungal communities that include representatives from all major fungal lineages. We failed to detect the phylogenetic signature of endemic clades that would result from specialization and adaptive radiation within this habitat.Conclusions/Significance: Our results indicate that serpentine soils do not constitute an extreme environment for ectomycorrhizal fungi, and raise important questions about the role of symbioses in edaphic tolerance and the maintenance of biodiversity.</p

Scattering properties of a cut-circle billiard waveguide with two conical leads

We examine a two-dimensional electron waveguide with a cut-circle cavity and conical leads. By considering Wigner delay times and the Landauer-B\"{u}ttiker conductance for this system, we probe the effects of the closed billiard energy spectrum on scattering properties in the limit of weakly coupled leads. We investigate how lead placement and cavity shape affect these conductance and time delay spectra of the waveguide.Comment: 18 pages, 11 figures, accepted for publication in Phys. Rev. E (Jan. 2001

Financieel-economische aspecten van Biobrandstofproductie : deskstopstudie naar de invloed van co-productie van bio-based producten op de financiële haalbaarheid van biobrandstoffen

Door uitvoering van een deskstop studie heeft WUR, in samenwerking met ECN, onderzocht of co-productie van biobrandstoffen en bio-based producten leidt tot meer marktcompetitieve biobrandstofproductie. De centrale vraagstelling van de studie was of aangetoond kan worden dat “co-productie” resulteert in realisatie van meer marktcompetitieve waardeketens voor grootschalige en duurzame inzet van biomassa in de biobased economy. De studie naar de financiële haalbaarheid van een twaalftal biobrandstofketens laten zien dat co-productie van biobrandstoffen tezamen met bio-based producten een goede methode is om additionele waarde toe te kennen aan de totale biomassa-product-keten. De co-producten die tezamen met biobrandstoffen geproduceerd kunnen worden zijn zeer divers. In het algemeen bestaat er voor deze co-producten een omvangrijke afzetmarkt, en gaat het om producten die op dit moment grotendeels uit aardolie vervaardigd worden. Technologieën voor productie en toepassing van hoogwaardige co-producten die naast biobrandstoffen uit biomassa geproduceerd kunnen worden bevinden zich in verschillende stadia van ontwikkeling