*Correspondence: Annika Seppälä, Earth Observation, Finnish Meteorological Institute, Erik Palmenin Aukio 1, FI-00560 Helsinki, Finland e-mail: [email protected] Variation in solar irradiance is considered an important factor in natural climate forcing. Variations in the solar UV in particular are now regarded as a major source of decadal variability in the stratosphere, influencing surface...

Dual-LED complex modulation (DCM) and quadLED complex modulation (QCM) are state-of-the-art MIMO modulation schemes which efficiently transmit complex-valued modulation symbols in visible light communication (VLC). DCM uses two LEDs to transmit complex symbols exploiting their polar form of representation. QCM uses four LEDs to transmit complex symbols through intensity modulation to convey the...

In this paper, we first give a characterization of sub-topical functions with respect to their lower level sets and epigraph. Next, by using two different classes of elementary functions, we present a characterization of sub-topical functions with respect to their polar functions, and investigate the relation between polar functions and support sets of this class of functions. Finally, we obtai...

Aims. We aim to establish the X-ray properties of the intermediate polar candidate IGR J15094–6649 and therefore confirm its inclusion into the class. Methods. 42 856 s of X-ray data from RXTE was analysed. Frequency analysis was used to constrain temporal variations and spectral analysis used to characterise the emission and absorption properties. Results. A spin period of 809.7 ± 0.6 s is pre...

We model the spin pulse intensity and hardness ratio profiles of the isolated neutron star RXJ0720.4– 3125 using XMM-Newton data. The observed variation is approximately sinusoidal with a peak-to-peak amplitude of 15%, and the hardness ratio is softest slightly before flux maximum. By using polar cap models we are able to derive maximum polar cap sizes and acceptable viewing geometries. The inf...

An arrangement is described for performing magneto-optical Kerr effect (MOKE) spectroscopy in polar geometry with a conventional C-frame or H-frame type electromagnet. It uses an additional mirror which eliminates the need for an electromagnet pole piece with an axial hole and allows for easy switching between polar MOKE geometry and longitudinal or transverse MOKE geometries. A theoretical ana...

We present the results of a long ROSAT HRI observation of the candidate intermediate polar TW Pic. The power spectrum shows no sign of either the previously proposed white dwarf spin period or the proposed binary orbital period (1.996 hr and 6.06 hr respectively). The limits to the X-ray modulation are less than 0.3% in each case. In the absence of a coherent X-ray pulsation, the credentials of...

The flowers of the species belonging to the genus Passiflorashow a range of features that are thought to have arisen as adaptations to different pollinators. Some Passiflora species belonging to the subgenus Decaloba sect. Xerogona, show touch-sensitive motile androgynophores. We tested the role of auxin polar transport in the modulation of the androgynophore movement by applying auxin (IAA) or...

Spectral and kinetic behavior of thermal cis-to-trans isomerization of 4-aminoazobenzene (AAB) is examined in various solvents of different polarities. In contrast to azobenzene (AB), it is found the rate of thermal isomerization of AAB is highly dependent on solvent polarity. Accelerated rates are observed in polar solvents as compared to nonpolar solvents. Moreover, a decrease in the barrier ...