ESR studies of the effect of zeolite structures on motional dynamics of NO2

Electron spin resonance (ESR) spectroscopy was used to study the effect of zeolite structure on the motional dynamics of NO₂ adsorbed on the zeolites. The temperature-dependent ESR spectral line shapes were quantitatively analyzed using the slow-motion ESR theory. It was observed that the motional dynamics of NO₂ is strongly dependent on the structure of the zeolite (Beta-type, ZSM-5, mordenite, L-type and ferrierite zeolites). The following important observations were made. (1) In zeolites with similar channel structures, the diffusion rate of NO₂ is proportional to the channel size, and the order of the diffusion rates is Beta-type>ZSM-5>ferrierite and L-type>mordenite. (2) The diffusion of NO₂ is faster in the zeolites with multi-dimensional channels (Beta-type, ZSM-5 and ferrierite) than that in those with uni-dimensional channels (L-type and mordenite).     

What do patent examiner inserted citations indicate for a region with low absorptive capacity?

Most studies of patents citations focus on national or international contexts, especially contexts of high absorptive capacity, and employ examiner citations. We argue that results can vary if we take the region as the context of analysis, especially if it is a region with low absorptive capacity, and if we study applicant citations and examiner-inserted citations separately. Using a sample from the Valencian Community (Spain), we conclude that (i) the use of examiner-inserted citations as a proxy for applicant citations, (ii) the interpretation of non-patent references as indicators of science-industry links, and (iii) the traditional results for geographical localization are not generalizable to all regions with low absorptive capacity.     

Photodegradation of DMMP and CEES on zirconium doped titania nanoparticles

The structure and photocatalytic activity of Zr doped TiO₂ nanocrystallites with a varying Zr content between 0 and 15 wt% prepared by an efficient and environmentally benign method has been studied by vibrational spectroscopy, TEM and XRD. It is shown that the presence of Zr⁴⁺ ions stabilizes the anatase structure and delays phase transformation to rutile upon annealing as well as retarding grain coarsening. All TiO₂ samples up to 13 wt% Zr doping concentration show better or similar photoreactivity compared to P25 (Degussa) for decomposition of adsorbed 2-chloroethyl ethyl sulphide (CEES) and dimethyl methylphosphonate (DMMP) in synthetic air at room temperature. The most efficient sample for photodegradation of both CEES and DMMP is shown to be titania doped with 6.8 wt% Zr. The photodegradation of CEES is faster than DMMP under the same experimental conditions. On the undoped TiO₂ sample urea residues are detected spectroscopically. Much less is detected on the Zr doped samples. Mode resolved in situ FTIR surface spectroscopy enables distinction of CEES or DMMP, decomposition products as well as the influence of residues from the particle synthesis. This facilitates extraction of intra-comparable reaction rates. Possible explanations for the improved reactivity of the Zr doped titania are discussed.     

Computer Analysis of Impedance Effects in Large Grounding Systems

In large plants with high primary fault levels, the whole plant must be considered as forming the ground grid for the return of primary fault current. The internal impedance of the equivalent ground grid must be taken into account in grid potential rise calculations, as grid potentials transferred from one area of the plant may cause hazardous touch potentials at other locations. Field measurements and computer analyses to calculate the distribution of grid potential rise in a large grounding system are presented.     

Melagatran, a low molecular weight thrombin inhibitor, counteracts endotoxin-induced haemodynamic and renal dysfunctions in the pig

Coagulation and fibrinolysis are crucial in septic shock and inhibition of thrombin may be beneficial in this circumstance. Since porcine endotoxaemia has been found to replicate severe septic shock, a low molecular weight thrombin inhibitor, melagatran, was infused during the first 3 out of 6 h of endotoxaemia in pigs. Plasma creatinine (p <0.01) and urinary output (p <0.05) were less affected in the melagtran + endotoxin group (n=6) as compared to endotoxaemic controls (n=9). The left ventricular stroke work index, systemic vascular resistance index and oxygen extraction were all less affected (p <0.05) by endotoxin during the infusion of melagatran. The plasma concentration of melagatran declined with an apparent plasma half-life of 5 h as soon as the infusion was stopped. APTT, however, continued to increase after the infusion of melagatran had stopped and reached a maximum of 113 s at 5 h (baseline 17 s). APTT in endotoxaemic control pigs reached a maximum of 22 s. Thus, melagatran may counteract some consequences of endotoxaemia.     

The non-expression of MHC class II in trophoblast cells

We report a rare case of neurobrucellosis in a 25-year-old woman with visual impairment, bilateral hearing loss, hyperprolactinaemia and meningitis. MRI revealed a sellar and suprasellar mass with enlargement of the optic chiasm.     

Reducing the total discharge from a large WWTP by separate treatment of primary effluent overflow.

At many large wastewater treatment plants (WWTPs) the increased hydraulic load, caused by combined sewer systems during storm events, results in primary effluent overflow when the capacity of further treatment is exceeded. Due to stringent effluent standards, regulating the total discharge from the WWTPs, the Rya WWTP in G?teborg and the Sj?lunda WWTP in Malm? will have to reduce the impact of primary effluent overflow. Separate, high rate, precipitation processes operated only during high flow conditions have been investigated in pilot units at the two WWTPs. Precipitation in existing primary settlers operated at a surface loading of 3.75 m/h removed phosphorus to 0.35 mg/l. The Actiflo process was also shown to remove suspended solids and phosphorus well. BOD was reduced by 50-60%. With such processes the overall effluent concentrations from the plants can be reduced significantly. Key upgrading features are small footprints, short start up time and high efficiency.     

Melting behavior of polypropylene fibers studied by differential scanning calorimetry

Polypropylene fibers produced in a compact-spinning process were studied by differential scanning calorimetry (DSC). With unrestrained fibers, the onset of melting increases with decreasing draw ratio, increasing M_w/M_n, decreasing extrusion temperature, increasing annealing ratio, and increasing draw-down ratio. These trends are discussed in terms of restraints and reorganization. The onset of melting is shifted to lower temperatures as the heating rate increases for all combinations of material and processing parameters, indicating suppressed reorganization. At low draw ratios, the height and width of the endotherm are affected by the spinline stress, and a secondary peak or shoulder is observed on the high temperature side of the main peak. The magnitude of the secondary peak increases with decreasing M_w/M_n, increasing draw ratio, decreasing draw-down ratio, and decreasing heating rate, but its position mainly depends on the heating rate. This indicates that the secondary peak may be due to the melting of structures that have been reorganized during the heating scan. As the draw ratio increases, the melting regime broadens, especially towards lower temperatures, and several maxima emerge on the DSC curve. Reorganization and shrinkage during heating may explain these observations. © 1995 John Wiley & Sons, Inc.