170,013 research outputs found
Radicals in the Atmosphere: A Changing World!
No full textGeorge, Christian Behnke, Wolfgang Zetzsch, Corneliu
Nachweis von atmosphärischem NO im ppb-Bereich mittels Fluoreszenzanregung durch NO-[gamma]-Banden
No full textKohse-Höinghaus K, Biermann HW, Zetzsch C, Stuhl F. Nachweis von atmosphärischem NO im ppb-Bereich mittels Fluoreszenzanregung durch NO-[gamma]-Banden. Zeitschrift für Naturforschung, A: Physical Sciences. 1976;31:239-243
Detection of NH (X3 [Sigma]-) by resonance fluorescence in the pulsed vacuum UV photolysis of NH3 and its application to reactions of NH radicals
No full textHansen I, Kohse-Höinghaus K, Zetzsch C, Stuhl F. Detection of NH (X3 [Sigma]-) by resonance fluorescence in the pulsed vacuum UV photolysis of NH3 and its application to reactions of NH radicals. Chemical Physics Letters. 1976;42(2):370-372.Using resonance fluorescence the kinetics of NH (X3 [Sigma]-) was studied in the pulsed vacuum UV photolysis of mixtures of NH3 and NO. The rate constant of the reaction NH + NO was determined to be (4.7 = 1.2) x lO - 11 cm 3 molecule - 1 s -
Kinetic mechanism for the formation of ClNO2 from the reaction of gaseous N2O5 with NaCl solution
No full textS.489-493The uptake of N2O5 by moist NaCl aerosol has been shown to lead to the formation of ClNO2 and HNO3 in smog chamber experiments. Model calculations indicate that the formation of ClNO2 may be an important source of atomic Cl under the tropospheric conditions of the high northern latitudes (Zetzsch and Behnke, 1992). Halogen atoms (Cl and Br) may also be the cause of tropospheric ozone degradation during the arctic spring (Barrie et al., 1988; Sturges and Shaw, 1993; Jobson et al., 1994). Here we present results from wetted-wall flowtube experiments at various concentrations of NaCl and NaNO3. The yield of ClNO2 after N2O5 injection as well as the uptake of ClNO2 are measured at 18+-0.5 degrees C
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Mass accommodation: Uptake coefficients of N2O5 on pure water and on NaCl containing droplets. A contribution to subproject HALIPP
No full textS.1090-1095Dinitrogen pentoxide (N2O5) is an important constituent in the atmosphere. It plays the role of a night-time reservoir of NO3 radicals. The heterogeneous reactions of N2O5 with aqueous aerosols may convert this reservoir to HNO3 (that is photolysed only slowly in the troposphere). This heterogeneous sink of N2O5 is believed to terminate the reaction cycle of NOx, mainly responsible for the formation of tropospheric ozone. Recently, it has been shown that N2O5 may also react with NaCl salt to form nitryl chloride (ClNO2), a photolytic precursor of the highly reactive atomic chlorine. Behnke and Zetzsch showed that nitryl chloride is also formed in deliquescent aqueous aerosols and even in dilute solutions. With regard to these observations, it appears important to understand the efficiency of the heterogeneous reactions of N2O5 with aqueous surfaces. Therefore, we studied the uptake of N2O5 by water and NaCl solution (at 1 mol/l) using the droplet train technique
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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