Search results for "Photos"
showing 10 items of 701 documents
The organizational use of online stock photos: The impact of representing senior citizens as eternally youthful
2018
The digital divide due to age is declining quickly. But this does not necessarily mean that the willingness to use stock photos depicting older people accompanying digital information is the same among all senior citizens. Three research questions are at the core of this paper: (1) To which extent can various senior citizens (women and men, younger old and older old, living alone or together, full of vitality or fragile) identify with online stock photos of older people accompanying information about pensions, income, health and housing?, (2) Which are the connotations of the visual signs used in such stock photos? and (3) What are the policy implications for organizations aiming at offerin…
Salinity-induced responses and resistance in Trifolium repens L.
2015
Abstract White clover ( Trifolium repens L.) is a commonly cultivated legume with good ground cover potential often used with companion grass species in urban grassed areas. The effect of increased soil salinity on plant growth is an urgent problem in cities where NaCl is used as a de-icing material. The aim of this research was to examine the effect of different salinity levels and K supply-induced responses and tolerance in the T. repens L. variety ‘Daile’, a variety which is used in urban greenery. To analyze the impact of increased soil salinity and the antagonistic effect of K, the effect of gradually increasing NaCl (0, 20, 40, 60, 80, 100 mM) and K (+0, +100, +200, +300 mg/L) levels …
The polarimetric and helioseismic imager on solar orbiter
2020
This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, as well as hosting the potential of a rich return in further science. SO/PHI measures the Zeeman effect and the Doppler shift in the FeI 617.3nm spectral line. To this end, the instrument carries out narrow-band imaging…
Photoinduced effects on the magnetic properties of the (Fe0.2Cr0.8)1.5[Cr(CN)6] Prussian blue analogue
2019
International audience; One of the most attractive characteristics of some Prussian blue derivatives is the sensitivity of their magnetic properties to the irradiation with light. In this work photoinduced effects in the (Fe0.2Cr0.8)1.5[Cr(CN)6]·15H2O PBA have been studied by means of X-ray-based spectroscopies and magnetometry. It is found that the photosensitivity of this compound is mostly centred on the Fe cations: the exposure to green light induces a transfer of electrons from them to the Cr that provokes a reversal of the previously existing linkage isomerization and increases the elastic strain caused by the misfit of the unit cells of the Fe–NC–Cr and Cr–NC–Cr sublattices. The gree…
Reintroducing photosynthesis.
2011
This article reports on conceptual difficulties related to photosynthesis and respiratory metabolism of a Plant Physiology course for undergraduate students that could hinder their better learning of metabolic processes. A survey of results obtained in this area during the last 10 academic years was performed, as well as a specific test, aimed to find out prior conceptual schemes in the students. The test included only basic, general questions on plant metabolism, and was passed on the first day of the course. Scores obtained by different groups of students were compared. Survey of students' performance in previous years shows that questions on plant metabolism result in significantly lower…
Study of the diurnal cycle of stressed vegetation for the improvement of fluorescence remote sensing
2006
Chlorophyll fluorescence (Chf) emission allows estimating the photosynthetic activity of vegetation - a key parameter for the carbon cycle models - in a quite direct way. However, measuring Chf is difficult because it represents a small fraction of the radiance to be measured by the sensor. This paper analyzes the relationship between the solar induced Chf emission and the photosynthetically active radiation (PAR) in plants under water stress condition. The solar induced fluorescence emission is measured at leaf level by means of three different methodologies. Firstly, an active modulated light fluorometer gives the relative fluorescence yield. Secondly, a quantitative measurement of the Ch…
PV effect of fullerene/poly(3-hexylthiophene) blend sensitized by phthalocyanine having infrared absorption CT band
2008
An attempt was made to extend the photosensitivity spectral range of fullerene/poly(3-hexylthiophene) blend to NIR region by adding extra electron donor — hydroxygallium phthalocyanine (GaOHPc) with a strong and wide intermolecular charge transfer (CT) band around 830 nm. Multilayer cells of ITO/PEDOT: PSS/6 GaOHPc/P3HT: C61(CO2Et)2 have been prepared by spin coating with vacuum evaporated Al or In top electrodes. Significant photosensitivity of the cells was in 370–900 nm spectral range. However charge carrier photogeneration efficiency was 3 times higher for illumination in P3HT absorption band as compared with the GaOHPc CT band at 830 nm. But when GaOHPc was mixed in the blend forming P…
Structure and mixed spin state of the chloroiron(III) complex of 2,3,7,8,12,13,17,18-octaphenyl-5,10,15,20-tetraphenylporphyrin, Fe(dpp)Cl
2002
Abstract The chloroiron(III) complex Fe(dpp)Cl (1) of the peripherally crowded 2,3,7,8,12,13,17,18-octaphenyl-5,10,15,20-tetraphenylporphyrin or dodecaphenylporphyrin (dpp), has been synthesized and characterized by X-ray crystallography, normal-coordinate structural decomposition analysis (NSD), EPR and Mossbauer spectroscopy and magnetic susceptibility measurements. The dpp ligand present in the crystal structure of this molecule is predominantly saddle-shaped. It is also ruffled and slightly domed according to an analysis of the out-of-plane distortions performed by using NSD. This saddle deformation is significantly smaller than those observed in the chloroiron(III) complexes of the β-p…
Effects of 2-month ozone exposure in spinach leaves on photosynthesis, antioxidant systems and lipid peroxidation
2003
The photosynthesis response, antioxidant systems and lipid peroxidation were studied in leaves from spinach plants (Spinacia oleracea L.) in response to ozone fumigation, ambient air and charcoal filtered air treatments. The photosynthetic activity was tested through gas exchange and chlorophyll a fluorescence measurements. Ambient air and ozone fumigation caused a decrease in the photosynthetic rate (25% and 63%, respectively) mainly due to a reduced mesophyll activity, as evidenced by the increased intercellular CO, concentration. These data agree with a large reduction in the non-cyclic electron flow (7% and 16%), a lower capacity to reduce the quinone pool and a higher development of no…
Response of Spinach Leaves (Spinacia oleracea L.) to Ozone Measured by Gas Exchange, Chlorophyll a Fluorescence, Antioxidant Systems, and Lipid Perox…
2004
Spinach (Spinacia oleracea L. cv. Clermont) leaves grown in open-top chambers and exposed to three different concentrations of ozone were measured for gas exchange, chlorophyll a fluorescence, antioxidant systems, and lipid peroxidation at the end of growing season. High O-3 concentration reduced F-v/F-m, indicating that the efficiency in the energy conversion of photosystem 2 (PS2) was altered. The rate of non-cyclic electron transport rate and the capacity to reduce the quinone pool were also affected. The development of non-photochemical quenching was not high enough to decrease the photon excess in the PS2. The limitation of photosynthetic activity was probably correlated with stomata c…