The Resonance Peak in Sr2_2RuO4_4: Signature of Spin Triplet Pairing

We study the dynamical spin susceptibility, $\chi({\bf q}, \omega)$, in the normal and superconducting state of Sr$_2$RuO$_4$. In the normal state, we find a peak in the vicinity of ${\bf Q}_i\simeq (0.72\pi,0.72\pi)$ in agreement with recent inelastic neutron scattering (INS) experiments. We predict that for spin triplet pairing in the superconducting state a {\it resonance peak} appears in the out-of-plane component of $\chi$, but is absent in the in-plane component. In contrast, no resonance peak is expected for spin singlet pairing.Comment: 4 pages, 4 figures, final versio

Document mark-up for different users and purposes

Semantic enhancement of texts aids their use by researchers. However, mark-up of large bodies of text is slow and requires precious expert resources. The task could be automated if there were marked-up texts to train and test mark-up tools. This paper looks at the re-purposing of texts originally marked-up to support taxonomists to provide computer scientists with training and test data for their mark-up tools. The re-purposing highlighted some key differences in the requirements of taxonomists and computer scientists and their approaches to mark-up

Water management for sustainable irrigated agriculture in the Zayandeh Rud Basin, Esfahan Province, Iran

Irrigation systemsCropping systemsIrrigated farmingRiver basinsTopographyGeomorphologyClimateHydrologyWater qualityGroundwaterSoil salinitySustainable agricultureIranEsfahan ProvinceZayandeh Rud BasinChadegan Reservoir

Evolution of helicity in NOAA 10923 over three consecutive solar rotations

We have studied the evolution of magnetic helicity and chirality in an active region over three consecutive solar rotations. The region when it first appeared was named NOAA10923 and in subsequent rotations it was numbered NOAA 10930, 10935 and 10941. We compare the chirality of these regions at photospheric, chromospheric and coronal heights. The observations used for photospheric and chromospheric heights are taken from Solar Vector Magnetograph (SVM) and H_alpha imaging telescope of Udaipur Solar Observatory (USO), respectively. We discuss the chirality of the sunspots and associated H_alpha filaments in these regions. We find that the twistedness of superpenumbral filaments is maintained in the photospheric transverse field vectors also. We also compare the chirality at photospheric and chromospheric heights with the chirality of the associated coronal loops, as observed from the HINODE X-Ray Telescope.Comment: 8 pages, 4 figure

Signal specific electric potential sensors for operation in noisy environments

Limitations on the performance of electric potential sensors are due to saturation caused by environmental electromagnetic noise. The work described involves tailoring the response of the sensors to reject the main components of the noise, thereby enhancing both the effective dynamic range and signal to noise. We show that by using real-time analogue signal processing it is possible to detect a human heartbeat at a distance of 40 cm from the front of a subject in an unshielded laboratory. This result has significant implications both for security sensing and biometric measurements in addition to the more obvious safety related applications

3,3′,5,5′-Tetra­nitro­biphen­yl

The title compound, C12H6N4O8, is a biphenyl system that was synthesized as a building block for a new series of anti­malarial compounds. The aromatic rings are oriented at a dihedral angle of 45.5 (2)°, and inter­molecular short O⋯O contacts form a chain along the b axis. The strength of the inter­actions involved in this chain cause one of the rings to be slightly distorted, with the torsion angle between the nitro groups being 23.4 (2)°, whereas, in the other ring, both nitro systems are parallel, forming an angle of 9.6 (2)° with the plane of the aromatic ring to which they are bound. Furthermore, the three ring C atoms around the ring–ring linkage belong to a plane inclined by 4.5 (1)° in relation to the plane containing the other three C atoms, i.e. (NO2–)C—C—C(NO2). This distortion of the ring causes uncommonly short intermolecular O⋯O [3.038 (2) Å] and O⋯C [3.000 (4) and 3.214 (1) Å] contacts