Energy Efficiency Analysis: Biomass-to-Wheel Efficiency Related with Biofuels Production, Fuel Distribution, and Powertrain Systems

BACKGROUND: Energy efficiency analysis for different biomass-utilization scenarios would help make more informed decisions for developing future biomass-based transportation systems. Diverse biofuels produced from biomass include cellulosic ethanol, butanol, fatty acid ethyl esters, methane, hydrogen, methanol, dimethyether, Fischer-Tropsch diesel, and bioelectricity; the respective powertrain systems include internal combustion engine (ICE) vehicles, hybrid electric vehicles based on gasoline or diesel ICEs, hydrogen fuel cell vehicles, sugar fuel cell vehicles (SFCV), and battery electric vehicles (BEV). METHODOLOGY/PRINCIPAL FINDINGS: We conducted a simple, straightforward, and transparent biomass-to-wheel (BTW) analysis including three separate conversion elements--biomass-to-fuel conversion, fuel transport and distribution, and respective powertrain systems. BTW efficiency is a ratio of the kinetic energy of an automobile's wheels to the chemical energy of delivered biomass just before entering biorefineries. Up to 13 scenarios were analyzed and compared to a base line case--corn ethanol/ICE. This analysis suggests that BEV, whose electricity is generated from stationary fuel cells, and SFCV, based on a hydrogen fuel cell vehicle with an on-board sugar-to-hydrogen bioreformer, would have the highest BTW efficiencies, nearly four times that of ethanol-ICE. SIGNIFICANCE: In the long term, a small fraction of the annual US biomass (e.g., 7.1%, or 700 million tons of biomass) would be sufficient to meet 100% of light-duty passenger vehicle fuel needs (i.e., 150 billion gallons of gasoline/ethanol per year), through up to four-fold enhanced BTW efficiencies by using SFCV or BEV. SFCV would have several advantages over BEV: much higher energy storage densities, faster refilling rates, better safety, and less environmental burdens

Virologisch onderzoek van explosies van gastro-enteritis in 1994-1995

Deels gepubliceerd in Journal of Infectious Diseases<br>"Small-round-structured viruses" (SRSV) kunnen explosies van gastro-enteritis veroorzaken. Om te onderzoeken in welke mate dit ook in Nederland het geval is, werden alle explosies van gastro-enteritis waarbij diagnostische ondersteuning werd gevraagd van het laboratorium voor Virologie (RIVM) gedurende twee jaar onderzocht op aanwezigheid van SRSV met behulp van een nieuw ontwikkelde test op basis van RT-PCR. Daarnaast werden de gevonden SRSV stammen met behulp van immuno-electronenmicroscopie en sequentie-analyse onderzocht om de antigene en genetische variabiliteit in kaart te brengen. Om dit te kunnen doen werd een generische RT-PCR ontwikkeld waarmee 85% van de SRSV uit de tot nu toe bekende antigene groepen kon worden aangetoond. SRSV werden met electronenmicroscopie en met deze RT-PCR aangetoond in 91% van de gemelde explosies (n=22). Sequentie-analyse van de PCR producten liet zien dat de explosie stammen sterk geclusterd waren. Het merendeel van de SRSV stammen in 1994 is nauw verwant met de twee recent beschreven antigene typen SRSV Toronto virus en Mexico virus. In 1995 vond er een shift plaats naar circulatie van een ander antigeen type (Grimsby), dat genetisch sterk verschilt van de 1994 stammen (27% nt sequentie divergentie). Een vergelijkbare indeling werd gemaakt op basis van antigene typering van de stammen met behulp van immuno-EM. De waargenomen clustering is een sterke aanwijzing voor epidemische verspreiding van SRSV door Nederland.To study the role of 'Small-round-structured viruses' (SRSV) in outbreaks of gastroenteritis in the Netherlands and to evaluate the genetic and antigenic relationships between strains, all outbreaks of gastroenteritis that were reported to RIVM in 1994 and 1995 (n=22) were investigated by EM, single round RT-PCR, and automated sequencing. To enable this, a generic SRSV-specific primer pair was developed which could detect 85% of all known circulating antigenic groups. SRSV could be detected by EM in 86% and by RT-PCR in 91% of the reported outbreaks of gastroenteritis. Partial sequence analysis of the polymerase region of these viruses revealed that there was an apparent clustering of outbreak strains. The majority of the 1994 strains form a tight cluster and are similar to the recently described Toronto virus and Mexico virus. In 1995 there was a shift towards the circulation of a distinct SRSV type, Grimsby, which was quite distinct (27% nt sequence divergence) from the 1994 strains. The molecular typing of the 1994 and 1995 strains was concordant with antigenic typing by SPIEM. These tight clusters of different types of SRSV strongly suggest epidemic spread of SRSV in the Netherlands.RIV

Coordination Chemistry and Asymmetric Catalysis with a Chiral Diphosphonite

The improved synthesis of the chiral diphosphonite, XantBino (1), based on a xanthene backbone and bearing chiral binaphthyl groups on both P-atoms is described together with its PdII and RhI complexes. The 31P NMR spectra of both complexes point out that the two phosphorus atoms are chemically inequivalent. The complex cis-[PdCl2(1)] (2) is structurally characterized by NMR spectroscopy and X-ray crystallography. The molecular structure reveals an unusually small bite angle for this member of the xantphos family of only 100°. The rhodium-catalyzed asymmetric hydroformylation of styrene and vinyl acetate as well as the asymmetric hydrogenation of methyl (Z)-2-acetamidocinnamate, applying this chiral diphosphonite 1, are described. Low enantiomeric excesses are obtained in the asymmetric hydroformylation, while use of the catalyst precursor [Rh(cod)(1)]BF4 (3) results in a promising enantiomeric excess in the Rh-catalyzed asymmetric hydrogenation