Mass by energy loss quantitation as a practical submicrogram balance

A simple device integrating a thin film support and a standard microcentrifuge tube can be used for making solutions of accurately known concentration of any organic compound in a single step, avoiding serial dilution and the use of microgram balances. Nanogram to microgram quantities of organic material deposited on the thin film are quantified by ion energy loss and transferred to the microcentrifuge tube with high recovery.     

TRENDS IN THE INTERNATIONAL PRODUCTION AND TRADE IN PETROCHEMICALS

The United States, Western Europe, Japan and other historically important producers of commodity petrochemicals have lost the cost advantage in the world markets to certain energy rich industrially developing nations. This wilt cause major restructuring of the world industry. Here we report on a quantitative study of the trends and limits of future changes in the production and trade in petrochemicals     

Soy protein containing isoflavones favorably influences macrophage lipoprotein metabolism but not the development of atherosclerosis in CETP transgenic mice

The possibility that soy protein containing isoflavones influences the development of experimental atherosclerosis has been investigated in ovariectomized mice heterozygous for the human CETP transgene and for the LDL-receptor null allele (LDLr^+/− CETP^+/−). After ovariectomy at 8 wk of age they were fed a fat/cholesterol-rich diet for 19 wk and divided into three experimental groups: dietary unmodified soy protein containing isoflavones (mg/g of diet), either at low-dose (Iso Low, 0.272, n=25), or at high-dose (Iso High, 0.535, n=28); and the atherogenic diet containing an isoflavone-depleted alcohol-washed soy protein as a control group (n=28). Aortic root lipid-stained lesion area (mean μm²×10³±SD) did not differ among Iso Low (12.3±9.9), Iso High (7.4±6.4), and controls (10.7±12.8). Autoantibody titers against plasma oxidized LDL did not differ among the experimental groups. Using the control mice as the reference value (100%), in vitro mouse peritoneal macrophage uptake of labeled acetylated LDL-cholesterol was lower in the Iso High (68%) than in the Iso Low (85%) group. The in vitro percent removal by exogenous HDL of labeled unesterified cholesterol from macrophages previously enriched with human [4-¹⁴C]-cholesteryl oleate acetylated LDL was enhanced in the Iso High group (50%). In spite of these in vitro potentially antiatherogenic actions, soy protein containing isoflavones did not modify the average size of lipid-stained area in the aortic root.     

Hydrogen Oxidation Catalyzed by Pt Supported on Carbon Nanofibers with Different Graphite Sheet Orientations

The kinetic study of hydrogen oxidation with or without the presence of CO has been used as a tool to study the relative oxygen and CO adsorption strength on Pt nanoparticles, which are important parameters for fuel cell catalysts. It was found that the activation energy, which is determined by the oxygen binding energy, is influenced by the CNF graphite sheet orientation, CNF oxygen groups and catalyst preparation method. A weaker bonding of oxygen was indicated for Pt nanoparticles supported on platelet compared to Pt on fishbone CNFs. Moreover, oxygen seemed to be more strongly bonded to Pt particles on CNFs prepared by deposition–precipitation compared to those prepared by incipient wetness impregnation and a metal-oxide colloid method. Enhanced CO-adsorption was indicated for Pt supported on carbon nanofibers with introduced oxygen groups.     

Influence of Synthesis Conditions for ZSM-5 on the Hydrothermal Stability of Cu-ZSM-5

The influence of syntheses parameters of zeolite ZSM-5 on the lean NO _x reduction activity and hydrothermal stability of Cu-ZSM-5 has been investigated. The hydrothermal stability of Cu-ZSM-5 was found to depend on the aluminium source used and on the presence of Ca(OH)₂ in the synthesis mixture for ZSM-5.     

Analyses of the grouting results for a section of the APSE tunnel at Äspö Hard Rock Laboratory

The grouting results for a tunnel at a depth of 450 m in crystalline rock at Äspö HRL were studied. The aims were to investigate whether the methodology used resulted in a successful grouting design and producing a sufficiently dry tunnel, and whether grout penetration and inflow into the finished tunnel corresponded to the predictions. An analysis was made of data from an original cored borehole, drilled before the tunnel was constructed and mapped thoroughly with regard to fractures and transmissivities. The predicted inflow into the tunnel was calculated and found to be four times higher than the measured inflow. The latter was 5 l/min along the 70 m tunnel, considered to be a good result at the current depth. New cored control boreholes were drilled along a section of the tunnel. The inflow positions and quantities in these holes, and the positions of grout found in the corresponding cores, were compared with the data from the original borehole. It was found that at the predicted positions of larger fractures, grout was observed and there was no inflow, showing that these had been successfully sealed. At the predicted positions of small fractures, no grout was visible in the cores, and small inflows showed that the grout had not sealed these fractures. The results indicated that cement-based grout successfully sealed fractures down to a hydraulic aperture of about 50 μm but not below 30 μm. This concurs with the initial design aimed at sealing fractures larger than 50 μm.     

On multi‐cell admission control in CDMA networks

We consider a multi‐cell (MC) code division multiple access (CDMA) system that supports multiple service classes, including peak rate allocated and elastic ones. Peak rate allocated sessions—when admitted into the system—transmit at a constant bit rate, while elastic sessions can be slowed down at the expense of increasing their residency time. Admitted sessions cause an instantaneous bit rate‐dependent interference in neighbour cells. In this rather general setting, we propose a method to calculate the class‐wise blocking probabilities as the functions of the estimated so‐called inter‐cell coupling factors. In the paper this coupling factor is the ratio between the uplink path gains to different Node‐B:s (that can be easily obtained in a CDMA system from pilot measurement reports), but our model could include other coupling measures as well. We find that when these coupling factors are underestimated, the system may get into false states (FSs) or false rate states (FRSs) that lead to violating the noise rise threshold. As traffic becomes increasingly elastic, the probability of FSs decreases, but the probability of FRSs increases. Based on numerical results, we make the point that as the traffic becomes more elastic, avoiding the underestimation of these coupling factors as well as exercising MC admission control plays an increasingly important role in guaranteeing proper service quality. Copyright © 2007 John Wiley & Sons, Ltd.