Cryptanalaysis of an EPCC1G2 Standard Compliant Ownership Transfer Scheme

Recently, Chen and Chien have proposed a novel ownership transfer scheme with low implementation costs and conforming to the EPC Class-1 Generation-2 standard. The authors claimed that the proposed scheme is able to resist all attacks, and hence it has better security and performance than its predecessors. However, in this paper we show that the protocol fails short of its security objectives, and it is even less secure than the previously proposed schemes. In fact, we describe several attacks which allow to recover all the secret information stored in the tag. Obviously, once this information is known, tags can be easily traced and impersonated.     

Anionic copolymerization of butadiene and styryl-terminated polystyrene macromonomers

Summary For the preparation of graft copolymers of the type poly (butadiene-g-styrene), possibilities were investigated both of obtaining a living anionic copolymerization of butadiene and styryl-terminated polystyrene macromonomers and of assessing the necessary analytical prerequisites for determining the conversion. The course of this copolymerization can be observed by combining gravimetry with SEC. With the initiator system sodium tert-butoxide /n-butyl lithium there are only a few deviations from the statistically ideal course of copolymerization and the macromonomer is almost completely incorporated into the copolymer.     

Parameterization of the inherent optical properties of Murchison Bay, Lake Victoria

Lake Victoria, Africa's largest freshwater lake, suffers greatly from negative changes in biomass of species of fish and also from severe eutrophication. The continuing deterioration of Lake Victoria's ecological functions has great long-term consequences for the ecosystem benefits it provides to the countries bordering its shores. However, knowledge about temporal and spatial variations of optical properties and how they relate to lake constituents is important for a number of reasons such as remote sensing, modeling of underwater light fields, and long-term monitoring of lake waters. Based on statistical analysis of data from optical measurements taken during half a year of weekly cruises in Murchison Bay, Lake Victoria, we present a three-component model for the absorption and a two-component model for the scattering of light in the UV and the visible regions of the solar spectrum along with tests of their ranges of validity. The three-component input to the model for absorption is the chlorophyll-a (Chl-a), total suspended materials concentrations, and yellow substance absorption, while the two-component input to the model for scattering is the Chl-a concentration and total suspended materials.     

Nonaqueous capillary zone electrophoresis of synthetic organic polypeptides

Poly(Nepsilon-trifluoroacetyl-L-lysine) was used as a model solute to investigate the potential of nonaqueous capillary electrophoresis (NACE) for the characterization of synthetic organic polymers. The information obtained by NACE was compared to that derived from size exclusion chromatography (SEC) experiments, and the two techniques were found to be complimentary for polymer characterization. On one hand, NACE permitted (i) the separation of oligomers according to their molar mass and (ii) the separation of the polymers according to the nature of the end groups. On the other hand, SEC experiments were used for the characterization of the molar mass distribution for higher molar masses. Due to the tendency of the solutes (polypeptides) to adsorb onto the fused-silica capillary wall, careful attention was paid to the rinsing procedure of the capillary between runs in order to keep the capillary surface clean. For that purpose, the use of electrophoretic desorption under denaturating conditions was very effective. Optimization of the separation was performed by studying (i) the influence of the proportion of methanol in a methanoVacetonitrile mixture and (ii) the influence of acetic acid concentration in the background electrolyte. Highly resolved separation of the oligomers (up to a degree of polymerization n of approximately 50) was obtained by adding trifluoroacetic acid to the electrolyte. Important information concerning the polymer conformations could be obtained from the mobility data. Two different plots relating the effective mobility data to the degree of polymerization were proposed for monitoring the changes in polymer conformations as a function of the number of monomers.     

Haemodynamics in the mouse aortic arch computed from MRI-derived velocities at the aortic root

Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic arch using measured inflow velocities, and to relate the resulting shear stress patterns to known locations of high- and low-lesion prevalence. Blood flow velocities were measured in the aortic root of C57/BL6 mice using phase-contrast MRI. Arterial geometries were obtained by micro-CT of corrosion casts. These data were used to compute blood flow and wall shear stress (WSS) patterns in the arch. WSS profiles computed using realistic and idealized aortic root velocities differed significantly. An unexpected finding was that average WSS in the high-lesion-probability region on the inner wall was actually higher than the WSS in the low-probability region on the outer wall. Future studies of mouse aortic arch haemodynamics should avoid the use of idealized inflow velocity profiles. Lesion formation does not seem to uniquely associate with low or oscillating WSS in this segment, suggesting that other factors may also play a role in lesion localization.     

空间规划的三个目标：可持续发展、社会福利、善治

当前．空间冲突不仅在数量上不断增加．而且也日益复杂．这是由于人口以及各种活动的增长不断加大了对空间的需求而导致的直接结果。因为空间（space）是不能被制造的．对于这一人类不可或缺的资源．我们应该特别关注，因此综合性和持续性的规划是必不可少的。     

A fast beam pulsing system for isotope ratio measurements

We describe an efficient, precise and fast beam pulsing system for accelerator mass spectrometry. Precision of isotope ratio measurements for carbon are on the order of 1%. Thus the δ¹³C values needed for radiocarbon age calculation corrections can be determined during an AMS run.     

Calcium removal from industrial wastewater by bio‐catalytic CaCO3 precipitation

High concentrations of soluble calcium in industrial wastewater present problems due to the calcification of downstream processing. The current trend towards circuit closure and increased water re‐use will escalate this problem. We investigated ureolytic microbial carbonate precipitation as a novel process for removing excess calcium from industrial effluents. Two laboratory‐scale reactors, both with a hydraulic retention time of 8 h, were fed with 1.8 dm³ of anaerobic effluent (about 11 mM Ca²⁺) from a paper recycling plant. Both reactors were inoculated with pre‐cultivated calcareous sludge and the treatment reactor was additionally dosed with urea to a final concentration of 8.3 mM . Even though the anaerobic wastewater was saturated as such with respect to CaCO₃, urea addition and hydrolysis was shown to be a pre‐requisite for precipitation. Almost all (85–90% w/v) of the soluble calcium was precipitated as CaCO₃ and removed through sedimentation in the treatment reactor. This bio‐catalytic process presents an uncomplicated and efficient method for the removal of calcium from industrial wastewater. Copyright © 2003 Society of Chemical Industry     

Der Stickstoff der Gasphasen bei den Reaktionen zwischen Eisenschmelzen und Silikatschlacken im Graphittiegel

Hinzutreten des Stickstoffs des Luftgases zu Eisenschmelze und Schlacke im Graphittiegel trotz des Entstehens von Kohlenmonoxyd aus den Reaktionen des Kohlenstoffs. Verschiedene Orte der Reaktionen, zwei Gasphasen. Analytische Bestimmung verschiedener Verbindungen des Stickstoffs in den erstarrten Schlacken. Stickstoffaufnahme durch Eisenschmelzen und CaO-Al₂O₃(10%)-SiO₂- sowie CaO-Al₂O₃(10%)-MgO(10%)-SiO₂-Schlacken verschiedener Basizität bei 1550 °C in 1 h. Einfluß des Mengenverhältnisses von Eisenschmelze und Schlacke auf die Stickstoffaufnahme beider. Wirkung von Flußspatzusätzen, 5% CaF₂, auf die Reaktionen des Stickstoffs bei 0,5 und 2 h Reaktionszeit. Verhalten des Stickstoffs bei und nach dem Speichern der Reduktionswirkung des Kohlenstoffs durch die Schlacke. Nitride und Zyanide als Reduktionsmittel, ein Problem der Kinetik der Bildung von Gasphasen aus Flüssigkeiten. Wirkung des Zusatzes von Eisenoxyden zu stickstoffhaltigen Schlacken.