Determination of anisotropic parameters,in situ, using a multi‐offset vertical seismic profile

1999 ◽  
Author(s):  
Jennifer M. Leslie ◽  
Don C. Lawton
Keyword(s):  
Seismic Profile ◽  
Vertical Seismic Profile

Reflectivity randomness revisited

Geophysics ◽  
1999 ◽  
Vol 64 (5) ◽  
pp. 1630-1636 ◽  
Author(s):  
Ayon K. Dey ◽  
Larry R. Lines
Keyword(s):  
Seismic Data ◽  
Real Data ◽  
Seismic Profile ◽  
Synthetic Seismograms ◽  
Seismic Exploration ◽  
Well Log ◽  
Simple Test ◽  
Vertical Seismic Profile ◽  
Seismic Reflectivity

In seismic exploration, statistical wavelet estimation and deconvolution are standard tools. Both of these processes assume randomness in the seismic reflectivity sequence. The validity of this assumption is examined by using well‐log synthetic seismograms and by using a procedure for evaluating the resulting deconvolutions. With real data, we compare our wavelet estimations with the in‐situ recording of the wavelet from a vertical seismic profile (VSP). As a result of our examination of the randomness assumption, we present a fairly simple test that can be used to evaluate the validity of a randomness assumption. From our test of seismic data in Alberta, we conclude that the assumption of reflectivity randomness is less of a problem in deconvolution than other assumptions such as phase and stationarity.

Determination of salt proximity by wave‐field imaging of transmitted energy

Geophysics ◽  
1988 ◽  
Vol 53 (8) ◽  
pp. 1109-1112 ◽  
Author(s):  
George A. McMechan ◽  
Liang‐Zie Hu ◽  
Douglas Stauber
Keyword(s):  
Acoustic Waves ◽  
Seismic Profile ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Vertical Seismic Profile ◽  
Wave Fields ◽  
Time Migration ◽  
Vsp Data ◽  
Field Imaging

Prestack reverse‐time migration for acoustic waves has recently been developed for vertical seismic profile (VSP) data (Chang and McMechan, 1986) and for cross‐hole (CH) data (Hu et al., 1988). Both sets of authors use the same migration software and produce images from the scattered (reflected and diffracted) energy in the recorded wave fields.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

Trace Pair Filtering for Separation of Upgoing and Downgoing Waves in Vsp (Vertical Seismic Profile)

1990 ◽  
Vol 45 (2) ◽  
pp. 181-203
Author(s):  
F. Glangeaud ◽  
P. Durand ◽  
J. L. Mari ◽  
F. Coppens
Keyword(s):  
Seismic Profile ◽  
Vertical Seismic Profile

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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