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New Measurements (new + measurement)
Selected AbstractsMolecular modeling of H2 purification on Na-LSX zeolite and experimental validationAICHE JOURNAL, Issue 1 2005B. Weinberger Analysis of hydrogen purification process by adsorption in the dehydrated Na-LSX zeolite is described. New measurements of hydrogen and nitrogen adsorption selectivity of this zeolite have been performed up to a pressure of 20 MPa and at temperatures of 273, 293 and 313 K, by using a gravimetric-volumetric method. Structural characterizations were realized by helium density displacement, nuclear magnetic resonance, X-ray diffraction and scanning electronic microscopy. Furthermore, Monte Carlo simulations of gas adsorption were performed in a zeolite model of Na-LSX, using pair potentials to represent the interaction between gas molecules and zeolite atoms. Comparison of simulation results and experimental data enabled testing of the validity of such a modeling of the gas-zeolite interaction. © 2004 American Institute of Chemical Engineers AIChE J, 51:142,148, 2005 [source] An Abnormal Right Ventricular Apical Angle is Indicative of Global Right Ventricular ImpairmentECHOCARDIOGRAPHY, Issue 5 2006Angel López-Candales M.D. The presence of right ventricular (RV) dysfunction is an adverse prognostic indicator but current echocardiographic methods have some limitations. RV apical angles in systole and diastole were correlated with known parameters of RV function in patients without pulmonary hypertension (Group 1) and in patients with pulmonary hypertension (Group 2). RV apical angles were significantly smaller in both systole (22 ± 7°) and diastole (33 ± 6°) in Group 1 patients when compared to Group 2 (54 ± 18°, p < 0.0001 and 59 ± 17°, p < 0.0001, respectively). RV apical angles, both in systole and diastole, were strongly correlated with RV end-systolic area (R = 0.89, p < 0.0001) and end-diastolic area (R = 0.81, p < 0.0001), respectively. Similarly, the apical systolic and diastolic angle correlated well with decreased tricuspid annular plane systolic excursion (TAPSE, R =,0.76 and R =,0.73, p < 0.001) as well as with decreased RV fractional area change (R =,0.81 and R =,0.77, p < 0.001). Therefore, we conclude that this new measurement of RV apical angle is simple and useful to quantify RV apical structural and functional abnormalities that are well correlated with global RV impairment in patients with chronic pulmonary hypertension. [source] Nuevo energy gives better share price performance through new measurementNATURAL GAS & ELECTRICITY (PREVIOUSLY : NATURAL GAS), Issue 11 2000Douglas L. Foshee [source] NMR nomenclature: Nuclear spin properties and conventions for chemical shifts (IUPAC recommendations 2001),CONCEPTS IN MAGNETIC RESONANCE, Issue 5 2002Robin K. Harris Abstract A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, ,, of the resonance frequency of a given nuclide to that of the primary reference, the 1H resonance of tetramethylsilane (TMS) in dilute solution (volume fraction, , < 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples and values of , for secondary references on the unified scale are listed, many of which are the results of new measurements. Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, ,, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic-angle spinning. In all, nine new recommendations relating to chemical shifts are made. Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with non-zero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and linewidth factors (where appropriate). © 2001 IUPAC. Concepts Magn Reson 14:326,346, 2002 [source] Oxidation of small alkenes at high temperatureINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 12 2002Barbara Heyberger If the mechanism of formation of alkenes, the main primary products of the combustion of alkanes above 1000 K, is now well understood, their ways of degradation have been much less studied. Following a previous modeling of the oxidation of propene in a static and a jet-stirred reactors by using an automatically generated mechanism, the present paper shows new validations of the same mechanism for ignition delays in a shock tube. It also describes the extension of the rules used for the automatic generation to the case of 1-butene. The predictions of the mechanism produced for the oxidation of 1-butene are compared successfully with two sets of experimental results: the first obtained in a jet-stirred reactor between 900 and 1200 K; the second being new measurements of ignitions delays behind reflected shock waves for temperatures from 1200 up to 1670 K, pressures from 6.6 to 8.9 atm, equivalence ratios from 0.5 to 2, and with argon as bath gas. Flux and sensitivity analyses show that the role of termination reactions involving the very abundant allylic radicals is less important for 1-butene than for propene. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 666,677, 2002 [source] High-resolution real-time recording with microelectrode biosensors reveals novel aspects of adenosine release during hypoxia in rat hippocampal slicesJOURNAL OF NEUROCHEMISTRY, Issue 6 2003B. G. Frenguelli Abstract We have used improved miniaturized adenosine biosensors to measure adenosine release during hypoxia from within the CA1 region of rat hippocampal slices. These microelectrode biosensors record from the extracellular space in the vicinity of active synapses as they detect the synaptic field potentials evoked in area CA1 by stimulation of the afferent Schaffer collateral-commissural fibre pathway. Our new measurements demonstrate the rapid production of adenosine during hypoxia that precedes and accompanies depression of excitatory transmission within area CA1. Simultaneous measurement of adenosine release and synaptic transmission gives an estimated IC50 for adenosine on transmission in the low micromolar range. However, on reoxygenation, synaptic transmission recovers in the face of elevated extracellular adenosine and despite a post-hypoxic surge of adenosine release. This may indicate the occurrence of apparent adenosine A1 receptor desensitization during metabolic stress. In addition, adenosine release is unaffected by pharmacological blockade of glutamate receptors and shows depletion on repeated exposure to hypoxia. Our results thus suggest that adenosine release is not a consequence of excitotoxic glutamate release. The potential for adenosine A1 receptor desensitization during metabolic stress implies that its prevention may be beneficial in extending adenosine-mediated neuroprotection in a variety of clinically relevant conditions. [source] NMR nomenclature: nuclear spin properties and conventions for chemical shifts.MAGNETIC RESONANCE IN CHEMISTRY, Issue 7 2002Applied Chemistry., IUPAC Recommendations 2001., International Union of Pure Abstract An Addendum has been published for this article in Magnetic Resonance in Chemistry 40(9) 2002, 622. A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, ,, of the resonance frequency of a given nuclide to that of the primary reference, the 1H resonance of tetramethylsilane (TMS) in dilute solution (volume fraction, , < 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples, and values of , for secondary references on the unified scale are listed, many of which are the results of new measurements. Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, ,, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic-angle spinning. In all, nine new recommendations relating to chemical shifts are made. Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with non-zero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and linewidth factors (where appropriate). Copyright 2001 IUPAC. Reprinted with permission from Pure Appl. Chem. 2001; 73: 1795. [source] Polymerization and Sickle Cell Disease: A Molecular ViewMICROCIRCULATION, Issue 2 2004FRANK A. FERRONE ABSTRACT The present molecular-level understanding of polymerization and sickling is reviewed for 2 central questions in sickle hemoglobin pathophysiology, viz., what determines when cells sickle, and what determines when cells get stuck. The description of sickling includes the central aspects of the double nucleation mechanism, as well as recent results on the effects of crowding, with an emphasis on the physiological applicability of this fundamental knowledge. In considering when cells get stuck, new measurements of individual fiber stiffness and the processes of depolymerization are also considered. Finally, a fundamental connection is shown between thermodynamics and rheology. [source] The age, metallicity and ,-element abundance of Galactic globular clusters from single stellar population modelsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007Jon T. Mendel ABSTRACT Establishing the reliability with which stellar population parameters can be measured is vital to extragalactic astronomy. Galactic globular clusters (GCs) provide an excellent medium in which to test the consistency of single stellar population (SSP) models as they should be our best analogue to a homogeneous (single) stellar population. Here we present age, metallicity and ,-element abundance measurements for 48 Galactic GCs as determined from integrated spectra using Lick indices and SSP models from Thomas, Maraston & Korn, Lee & Worthey and Vazdekis et al. By comparing our new measurements to independent determinations we are able to assess the ability of these SSPs to derive consistent results , a key requirement before application to heterogeneous stellar populations like galaxies. We find that metallicity determinations are extremely robust, showing good agreement for all models examined here, including a range of enhancement methods. Ages and ,-element abundances are accurate for a subset of our models, with the caveat that the range of these parameters in Galactic GCs is limited. We are able to show that the application of published Lick index response functions to models with fixed abundance ratios allows us to measure reasonable ,-element abundances from a variety of models. We also examine the age,metallicity and [,/Fe],metallicity relations predicted by SSP models, and characterize the possible effects of varied model horizontal branch morphology on our overall results. [source] Speckle observations with PISCO in Merate: VIII.ASTRONOMISCHE NACHRICHTEN, Issue 3 2010Astrometric measurements of visual binaries in 200, new orbits of the multiple system Zeta Aqr Abstract We present relative astrometric measurements of visual binaries made during the second semester of 2007, with the speckle camera PISCO at the 102 cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 283 new measurements of 279 objects, with angular separations in the range 0,.17,4,.4, and an average accuracy of 0,.014. The mean error on the position angles is 0°.6. Most of the position angles were determined without the usual 180° ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. We also present the new orbit we have computed for Zeta Aqr AB (ADS 15971), for which our measurements lead to large residuals with the previously computed orbit. We were also able to compute the elements of the perturbation orbit Bb-P caused by an invisible companion, whose mass is estimated at 0.7 M, (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The building blocks of young AGNs: A progress report on follow-up projects with the CORALZ sampleASTRONOMISCHE NACHRICHTEN, Issue 2-3 2009K.-H. Mack Abstract This paper summarizes some of the ongoing projects on the CORALZ sample, the first statistically complete sample of young radio galaxies. The low redshift of the sources in the sample (z < 0.16) makes them excellent targets for a comprehensive and homogeneous follow-up in virtually all bands of the electromagnetic spectrum. Here we report on the almost completed radio continuum observations which confirm the relatively young ages of the sources in the CORALZ sample. The radio spectra in addition with new measurements at 250 GHz indicate a large fraction of sources with excess mm-emission, probably due to radiation of cold dust. These sources are also excellent candidates for detection ofmolecular gas, which we have traced through CO observations in the 3-mm band in several cases. Additional molecules as H2O or OH are being observed. The atomic gas content is disclosed by H I absorption observations (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Speckle observations with PISCO in Merate: VI.ASTRONOMISCHE NACHRICHTEN, Issue 1 2009Astrometric measurements of visual binaries in 200 Abstract We present relative astrometric measurements of visual binaries made during the second semester of 2006, with the speckle camera PISCO at the 102 cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 175 new measurements of 169 objects, with angular separations in the range 0,.1,4,.2, and an average accuracy of 0,.01. The mean error on the position angles is 0°.6. Most of the position angles could be determined without the usual 180° ambiguity with the application of triplecorrelation techniques and/or by inspection of the long integration files. We also present the new orbits we have computed for ADS 11479, 11584 and 16538, for which our measurements lead to large residuals and/or for which the revision was justified by the significant number of observations made since the last orbit computation (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 2452: Patients in the DARC: drops revealing retinal ganglion cells in vivoACTA OPHTHALMOLOGICA, Issue 2010MF CORDEIRO Purpose To provide a review of current & future DARC imaging technologies and their application to neuroprotection Methods Currently, lowering IOP remains the only clinical therapy available in the treatment of glaucoma, despite the evidence that vision loss can continue in the presence of "significant" IOP reduction. Neuroprotection has been increasingly recognized as an important alternative treatment approach, but its emergence has also highlighted the need for both better defined end-points in clinical glaucoma research, as well as earlier and better detection and measures of progression. This could have been a factor in the recent memantine trial. A recent FDA/NEI meeting on end-points in glaucoma emphasized the need for new measurements. As the RGC is the primary injured neuron in this disease, it would seem logical that any modality that could directly measure RGC dysfunction and disease would be ideal. Perhaps the greatest changes that we have encountered recently are in the field of imaging technologies, which have only relatively recently been applied to the eye. Results Advances in this area have allowed unprecedented in vivo access to the retinal layers, using many different properties of light to differentiate cellular structures. DARC is a technology shortly to enter clinical trials which allows the visualization of "sick" RGCs. Conclusion Over the next few years, developments in therapy & diagnostic using DARC should offer great potential in glaucoma and other neurodegenerative conditions. Commercial interest [source] | ||||||||||||||||