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Sample records for magateh zayavlyaet chto

  1. Determination of tritiated formaldehyde in effluents from tritium facilities

    SciTech Connect

    Belot, Y.; Camus, H.; Marini, T. )

    1992-03-01

    Recent observations suggested that formal-dehyde can be incorporated in vegetation at a very high rate. In this paper, the authors develop a methodology for determining tritiated formaldehyde (CHTO) in gaseous effluent containing HTO and HT as dominant species. CHTO being very soluble in water is collected in a solution of carrier formaldehyde. This carrier is necessary for precipitating for formaldehyde derivative of dimedone and collecting it by filtration. The precipitate, which contains the formaldehyde hydrogens, is freed from exchangeable tritium, dried in oven, and combusted to water for tritium determination. CHTO can thus be separated from HTO with a high efficiency, leading to the possibility of determining accurately 1 Bq of CHTO in as much as 5 {times} 10{sup 4} Bq of HTO. The methodology has been applied in preliminary experiments to determine the ratio of CHTO to HTO in effluent from a tritium-handling facility and effluent released from solid miscellaneous wastes.

  2. Temporal changes of surface wave velocity associated with major Sumatra earthquakes from ambient noise correlation

    PubMed Central

    Xu, Zhen J.; Song, Xiaodong

    2009-01-01

    Detecting temporal changes of the medium associated with major earthquakes has implications for understanding earthquake genesis. Here we report temporal changes of surface wave velocity over a large area associated with 3 major Sumatra earthquakes in 2004, 2005, and 2007. We use ambient noise correlation to retrieve empirical Green's function (EGF) of surface waves between stations. Because the process is completely repeatable, the technique is powerful in detecting possible temporal change of medium. We find that 1 excellent station pair (PSI in Indonesia and CHTO in Thailand) shows significant time shifts (up to 1.44 s) after the 2004 and 2005 events in the Rayleigh waves at 10–20 s but not in the Love waves, suggesting that the Rayleigh time shifts are not from clock error. The time shifts are frequency dependent with the largest shifts at the period band of 11–16 s. We also observe an unusual excursion ∼1 month before the 2004 event. We obtain a total of 17 pairs for June, 2007 to June, 2008, which allow us to examine the temporal and spatial variation of the time shifts. We observed strong anomalies (up to 0.68 s) near the epicenter after the 2007 event, but not in the region further away from the source or before the event or 3 months after the event. The observations are interpreted as stress changes and subsequent relaxation in upper-mid crust in the immediate vicinity of the rupture and the broad area near the fault zone. PMID:19667205

  3. Regional and Upper-Mantle Structure Model of Peninsular India and Relevance to High-Frequency Lg Seismograms

    NASA Astrophysics Data System (ADS)

    Saikia, C. K.

    2003-12-01

    The primary objective of this study is to develop regional and upper-mantle crustal structures of Peninsular India for estimating source parameters of smaller seismic events. To this end, we modeled regional seismograms generated by the May 21, 1997 Jabalpur earthquake in central India which occurred in the lower crust at a depth of 35 km. It was recorded at many teleseismic stations with usable signal-to-noise ratio, including several broadband regional stations in India. Teleseismic P waves were used to establish the complexity of the source process, focal mechanism and source depth of the earthquake by modeling amplitude and travel times of the pP and sP depth phases relative to the P wave onsets. Regional waveforms from this master event with known source parameters were used to develop corresponding Greens' functions for the paths to stations, namely Bhopal (BHPL), Bilaspur (BLSP) and Hyderabad (HYB). The complexity in teleseismic P and sP can also be observed in Pn and sPn with excellent compatibility. These same features can be identified in upper-mantle triplications at LSA (Δ =12° ), NIL (Delta=12° ), CHTO (Δ =18° ), and AAK (Delta=20° ) when modeled with existing shield models. The upper-mantle Pn phases (i.e., pP, sP, sPn, sSP, sPP, sPPPP etc.) can be positively identified in these observations and were found to be sensitive to the presence of gradient in the transition zones, especially beneath the 400 km discontinuity. The usefulness of these Green's functions is demonstrated by modeling the regional and sparse teleseismic data for a small earthquake (April 4, 1995) located near the Indian Nuclear Test Site at Pokhran. This study also establishes a regional waveguide for the path from the Pokhran Test Site to station Nilore (NIL) in Pakistan. We have also extended these regional models to have the capability of generating high-frequency Lg waves by introducing thin layers in the crust with alternating high and low-velocity distribution.