1,004 research outputs found
Digital Film Listings (DIGIFIL):Final Report
Final report of the Digifil project (CLARIAH, 2018) that aimed at automatically extracting, digitizing and publishing film screening data from the weekly films listings published in historical newspapers
Estimation of aerosol water and chemical composition from AERONET Sun–sky radiometer measurements at Cabauw, the Netherlands
Remote sensing of aerosols provides important information on atmospheric
aerosol abundance. However, due to the hygroscopic nature of aerosol
particles observed aerosol optical properties are influenced by atmospheric
humidity, and the measurements do not unambiguously characterize the aerosol
dry mass and composition, which complicates the comparison with aerosol
models. In this study we derive aerosol water and chemical composition by a
modeling approach that combines individual measurements of remotely sensed
aerosol properties (e.g., optical thickness, single-scattering albedo,
refractive index and size distribution) from an AERONET (Aerosol Robotic
Network) Sun–sky radiometer with radiosonde measurements of relative
humidity. The model simulates water uptake by aerosols based on the chemical
composition (e.g., sulfates, ammonium, nitrate, organic matter and black
carbon) and size distribution. A minimization method is used to calculate
aerosol composition and concentration, which are then compared to in situ
measurements from the Intensive Measurement Campaign At the Cabauw Tower
(IMPACT, May 2008, the Netherlands). Computed concentrations show good
agreement with campaign-average (i.e., 1–14 May) surface observations (mean
bias is 3% for PM<sub>10</sub> and 4–25% for the individual compounds). They
follow the day-to-day (synoptic) variability in the observations and are in
reasonable agreement for daily average concentrations (i.e., mean bias is
5% for PM<sub>10</sub> and black carbon, 10% for the inorganic salts and
18% for organic matter; root-mean-squared deviations are 26% for
PM<sub>10</sub> and 35–45% for the individual compounds). The modeled water
volume fraction is highly variable and strongly dependent on composition.
During this campaign we find that it is >0.5 at approximately 80% relative humidity
(RH) when the aerosol composition is dominated by hygroscopic inorganic salts, and
<0.1 when RH is below 40%, especially when the composition is
dominated by less hygroscopic compounds such as organic matter. The
scattering enhancement factor (f(RH), the ratio of the scattering coefficient
at 85% RH and its dry value at 676 nm) during 1–14 May is
2.6 ± 0.5. The uncertainty in AERONET (real) refractive index
(0.025–0.05) is the largest source of uncertainty in the modeled aerosol
composition and leads to an uncertainty of 0.1–0.25 (50–100%) in aerosol
water volume fraction. Our methodology performs relatively well at Cabauw,
but a better performance may be expected for regions with higher aerosol
loading where the uncertainties in the AERONET inversions are smaller
Verbetering trosvorming bij trosrozen door teelthandelingen
Het jaarrond telen van trosrozen met voldoende bloemen op het bloemgestel is voor veel telers een probleem. In dit onderzoek is onderzocht of door gewasopbouw (snoeimethode) en de keuze van cultivar en onderstam een verbetering kan worden bereikt van het percentage trossen bij trosrozen. In totaal zijn in dit onderzoek drie knipmethoden en twee cultivars vergeleken. Bij Ă©Ă©n cultivar zijn twee onderstammen, in combinatie met eigen wortel, met elkaar vergeleken. Met behulp van de gewasopbouw het percentage trossen beĂŻnvloeden is mogelijk gebleken. Een opbouw waarbij de basis van de plant dichter bij de grond blijft en waarbij er minder ogen zijn waar de plant mee uit kan lopen beĂŻnvloedt het percentage trossen en het takgewicht positief. Het aantal geoogste takken wordt echter negatief beĂŻnvloed, zodat per saldo er geen verschil in het totaal geoogste aantal kilogrammen per snoeimethode is. Bij de snoeimethode 'knotroos', waarbij contant nieuwe grondscheuten gevormd worden, is de groeiduur van knippen tot de volgende oogst langer dan bij de andere methoden
Study of the Quantum Efficiency of CsI Photocathodes Exposed to Oxygen and Water Vapour
The operation of CsI photocathodes in gaseous detectors requires special attention to the purity of the applied gas mixtures.We have studied the influence of oxygen and water vapour contaminations on the performance of CsI photocathodes for theALICE HMPID RICH prototype. Measurements were done through comparison of Cherenkov rings obtained from beamtests. Increased levels of oxygen and water vapour did not show any effect on the performance. The results of this studyfound a direct application in the way of storing CsI photocathodes over long periods nad in particular in the shipment of theHMPID prototype from CERN to the STAR experiment at BNL. (Abstract only available,full text to follow
Enrichment and characterization of dendritic cells from human bronchoalveolar lavages
In the present study about 0.3% to 1.6% of human bronchoalveolar lavage (BAL) cells were identified as typical dendritic cells (DC), having an irregular outline, lobulated nucleus, and clear distinguishable acid phosphatase activity or EBM11 (anti-CD68) reactivity in a spot near the nucleus. After DC enrichment, using transient adherence to plastic, FcR-panning, and a density metrizamide gradient, a population containing 7-8% typical DC was obtained. This DC-enriched low density fraction, containing the highest percentages of DC, very strongly induced T cell proliferation in an allogeneic mixed leucocyte reaction (MLR), which was significantly higher than that induced by other partly (un)fractionated BAL cells. These data indicate that DC seem to be the major accessory cells in the BAL fluid, and therefore may be important in the regulation of T cell immune responses in the lung
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