Improved sensitivity in grounding search system using TV signal for phase reference

Grounding search systems need improved sensitivity to search more effectively for grounding routes. The proposed method changes the phase reference signal source from the search signal to a TV signal. A minimum signal level of 17 dBuV at the antenna terminal is needed to obtain the phase reference. Experimentation using the new system demonstrated an improvement of 40 dB in the minimum detectable level and the phase measurement deviation improved from ±18 degrees to ±8 degrees.1999 International Symposium on Electromagnetic Compatibility, May 17-21, 1999, Surugadai Memorial Hall, Chuo University, Tokyo, Japa

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)

As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.Comment: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correctio

Corrected index properties for ODP Leg 127 and 128 sites

During Legs 127 and 128, we found a systematic error in the index property measurements, in that the wet bulk density, grain density, and porosity did not satisfy well-established interrelationships. We have found that an almost constant difference exists between the weight of water lost during drying and the volume of water lost. This discrepancy is independent of volume or water content of the sample. The water losses should be equal because the density of water is close to 1.0 g/cm**3. The pycnometer wet volume measurement has been identified as the source of the systematic error. The wet volume on average is 0.2 cm**3 too low. For the rare cases when the water content is negligible, there is no offset. The source of the wet volume error results from the partial vapor pressure of water in the pycnometer cell. Newly corrected tables of index properties measured during Legs 127 and 128 are included. The corrected index properties are internally consistent. The data are in better agreement with theoretical models that relate the index properties to other physical properties, such as thermal conductivity and acoustic velocity. In future, a standard volume sampler should be used, or the wet volume should be calculated from the dry volume and the water loss by weight