Resolution of slowness and reflectors in crosswell tomography with transmission and reflection traveltimes

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. VE321-VE335 ◽  
Author(s):  
Kenneth P. Bube ◽  
Robert T. Langan
Keyword(s):  
Field Experiments ◽  
Oil Field ◽  
Data Sets ◽  
Traveltime Tomography ◽  
Velocity Models ◽  
West Texas ◽  
Well Spacing ◽  
High Level ◽  
Transmission And Reflection

We sometimes encounter situations in seismic imaging in which knowing the position of key reflectors between wells would be very useful. In many crosswell data sets, both transmission and reflection traveltimes for selected reflectors can be picked. We investigated the possibility that transmission-plus-reflection crosswell traveltime tomography can determine the position of these reflectors with a high level of accuracy, thereby providing an independent way of verifying (and perhaps improving) the position of these reflectors obtained from crosswell reflection imaging. We studied the effect of combining reflection traveltimes for selected reflectors with transmission traveltimes on the resolution of the interwell slowness field and depth determination of selected reflectors. We found that theoretically, the position of reflectors is determined uniquely from transmission and reflection traveltimes in a linearized continuum formulation ofcrosswell tomography. We also computed diagonal elements of the resolu-tion matrix for two crosswell geometries based on field experiments conducted in a west Texas oil field to see what effect noise has on the accuracy of our determination of reflector depths. These computational results indicate that reflector positions are indeed very well determined for these geometries, with expected errors of [Formula: see text] of the well spacing when noise in traveltimes is [Formula: see text]. Because reflector-position parameters are so well determined, including reflection traveltimes does not degrade the resolution of the slowness field as a result of introducing additional reflector-depth parameters. Actually, the resolution of the slowness field, particularly near reflectors, improves by including reflection traveltimes, in spite of the fact that we must solve for these additional depth parameters. The improvement in slowness resolution should provide velocity models that can yield more accurate reflection images.

Electromagnetic traveltime tomography: Application for reservoir characterization in the Lost Hills oil field, California

Geophysics ◽  
2005 ◽  
Vol 70 (3) ◽  
pp. G51-G58 ◽  
Author(s):  
Tae Jong Lee ◽  
Toshihiro Uchida
Keyword(s):  
Reservoir Characterization ◽  
Fresnel Zone ◽  
Region Of Interest ◽  
Oil Field ◽  
Data Sets ◽  
Traveltime Tomography ◽  
Conductivity Structure ◽  
Before And After ◽  
Conductivity Image ◽  
Induction Logs

Electromagnetic (EM) traveltime tomography has been applied for reservoir characterization at the Lost Hills oil field, California. Four data sets at frequencies of 24, 90, 370, and 1000 Hz were obtained along a pair of monitoring boreholes located 80.5 m apart. Traveltime information was first extracted from these EM data sets using a wavefield transform with a ray series approximation. The conductivity contrast of each layer is no greater than two in the region of interest, so the first arrivals can be estimated within 5% error by the approximate scheme. A nonlinear traveltime tomography algorithm adopting a Fresnel zone concept was then applied to obtain the conductivity model between the boreholes. The resultant conductivity image represents the conductivity structure between the boreholes. This image is consistent with the results of both a finite-difference inversion and the induction log obtained prior to waterflooding. Comparing the two conductivity images with the induction logs, we observe major differences in the fracture-dominant resistive reservoir layer, which may have been caused by changes in reservoir condition before and after waterflooding.

High‐resolution crosswell imaging of a west Texas carbonate reservoir: Part 5—Core analysis

Geophysics ◽  
1995 ◽  
Vol 60 (3) ◽  
pp. 712-726 ◽  
Author(s):  
Richard C. Nolen‐Hoeksema ◽  
Zhijing Wang ◽  
Jerry M. Harris ◽  
Robert T. Langan
Keyword(s):  
Wave Velocity ◽  
Field Experiments ◽  
Velocity Ratio ◽  
Carbonate Reservoir ◽  
P Wave ◽  
Core Analysis ◽  
S Wave ◽  
Traveltime Tomography ◽  
West Texas ◽  
P Wave Velocity

We conducted a core analysis program to provide supporting data to a series of crosswell field experiments being carried out in McElroy Field by Stanford University’s Seismic Tomography Project. The objective of these experiments is to demonstrate the use of crosswell seismic profiling for reservoir characterization and for monitoring [Formula: see text] flooding. For these west Texas carbonates, we estimate that [Formula: see text] saturation causes P‐wave velocity to change by −1.9% (pooled average, range = −6.3 to +0.1%), S‐wave velocity by +0.6% (range = 0 to 2.7%), and the P‐to‐S velocity ratio by −2.4% (range = −6.4 to −0.3%). When we compare these results to the precisions we can expect from traveltime tomography (about ±1% for P‐ and S‐wave velocity and about ±2% for the P‐to‐S velocity ratio), we conclude that time‐lapse traveltime tomography is sensitive enough to resolve changes in the P‐wave velocity, S‐wave velocity, and P‐to‐S velocity ratio that result from [Formula: see text] saturation. We concentrated here on the potential for [Formula: see text] saturation to affect seismic velocities. The potential for [Formula: see text] saturation to affect other seismic properties, not discussed here, may prove to be more significant (e.g., P‐wave and S‐wave impedance).

Direct phase determination in electron crystallography: small organic molecules

1992 ◽  
Vol 50 (2) ◽  
pp. 1166-1167
Author(s):  
Douglas L. Dorset
Keyword(s):  
Organic Molecules ◽  
Data Sets ◽  
Temperature Structure ◽  
3D Analysis ◽  
Intensity Data ◽  
Electron Crystallography ◽  
Phase Determination ◽  
Measured Intensity ◽  
3D Data

The quantitative use of electron diffraction intensity data for the determination of crystal structures represents the pioneering achievement in the electron crystallography of organic molecules, an effort largely begun by B. K. Vainshtein and his co-workers. However, despite numerous representative structure analyses yielding results consistent with X-ray determination, this entire effort was viewed with considerable mistrust by many crystallographers. This was no doubt due to the rather high crystallographic R-factors reported for some structures and, more importantly, the failure to convince many skeptics that the measured intensity data were adequate for ab initio structure determinations.We have recently demonstrated the utility of these data sets for structure analyses by direct phase determination based on the probabilistic estimate of three- and four-phase structure invariant sums. Examples include the structure of diketopiperazine using Vainshtein's 3D data, a similar 3D analysis of the room temperature structure of thiourea, and a zonal determination of the urea structure, the latter also based on data collected by the Moscow group.

Influence of a chemical preparation of triazole50% cs on sowing the winter wheat against rust

2020 ◽  
Vol 3 (9) ◽  
pp. 231-233
Author(s):  
AliyevSh.K. ◽  
TuychiyevI.U ◽  
Karimov N ◽  
Umaraliev.M.I
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
Yellow Rust ◽  
Biological Efficiency ◽  
Chemical Preparation ◽  
Seed Growth ◽  
Biological Farming ◽  
The Given ◽  
Farming Efficiency

The article is focused on the data of the carried works on studying biological efficiency of fungi Triazole 50% on sowing the winter wheat against yellow rust as well as on the height, development and fertility of the wheat. On May 5, 2019 from 9 to 10 o’clock under the temperature 21-23 field experiments of Triazol 50% CS manufactured by the firm “Agroximstar” (Uzbekistan) were carried out on winter wheat as a protector of seeds of winter wheat of Pervitsa sort against the disease of yellow rustin the irrigated conditions in an experimental field of the Institute “Istiklal” of Andijan district of Andijan region. The aim of the given research is to study biological-farming efficiency and determination of optimal norms of preparation expenses and to study the influence of fungicide on the height and development as well as on the fertility of the wheat. The received data showed that the preparation Triazole 50% CS effected on the pathogen of yellow rust favorably and besides that it didn’t effect on seed growth and energy of growth negatively.

Immediate implantation in a patient with chronic generalized parodontitis and apical granuloma

2019 ◽  
Vol 24 (2) ◽  
pp. 145-149
Author(s):  
A. I. Musienko ◽  
K. I. Nesterova
Keyword(s):  
Tooth Extraction ◽  
Tooth Root ◽  
Duration Of Treatment ◽  
Promising Direction ◽  
Aesthetic Result ◽  
Bone Atrophy ◽  
Alveolar Tissue ◽  
High Level ◽  
Immediate Implantation

Relevance. Rehabilitation of patients with moderate to severe generalized periodontitis is a leading problem in periodontology. It was the determination of the prospects for immediate implantation in patients with chronic periodontitis, combined with the pathology of the tooth root and maxillary sinus.Materials and methods. A group of 94 people with periodontitis and chronic odontogenic rhinosinus was observed who underwent sinus surgical treatment, tooth extraction and one-stage implantation with FRP growth factor according to the author's technology.Results. The method showed high efciency on the basis of assessing the clinical, aesthetic result and restoration of bone density after surgery.Conclusions. The developed technology is a promising direction, it allows to combine a high level of sanation of alveolar tissue with the advantages of immediate implantation, prevents bone atrophy, helps reduce the duration of treatment and the number of surgical and orthopedic interventions.

Methodical approaches to managing economic safety of tourism enterprises

2020 ◽  
pp. 160-164
Author(s):  
Leonid Tsubov ◽  
Oresta Shcherban
Keyword(s):  
Safety Management ◽  
Integrated Approach ◽  
Small Enterprise ◽  
Complex Nature ◽  
Efficient Management ◽  
Tourism Enterprises ◽  
High Level ◽  
Functional Components ◽  
Stimulation Control

The set of scientific-methodological tools to secure the mechanism of economic safety management of tourism entrepreneurship is examined as an aggregate of methods, tools, and conceptual activities directed at maintaining the high level of economic safety of tourism entrepreneurship. The features of managing the tourism enterprise and economic safety are analyzed. The basic valuation principles of the reliability and efficiency of the economic safety of the tourism enterprise are determined. The basic tasks of ensuring the economic safety of a small enterprise are outlined. The need to use the integrated approach that secures more opportunities to avoid threats and limits the danger of their emergence is emphasized. The most important principles for securing the economic safety of the tourism enterprise on the microeconomic level are described. Possible practical methods of risk management for the implementation of adopted decisions are proposed. The paper proves the fact that the complex nature of the management of the economic safety of the tourism enterprise and securing the sufficiently efficient management system of detecting and eliminating the threats are provided by the establishment of the management of the economic safety system of the tourism enterprise and its functional components. Research of the methodical approaches to the management of the tourism enterprises’ economic safety allows building and describing the functional structure of the mechanism of management of the tourist enterprise’s economic safety (it is formalized and described by 5 functions: determination of aims; planning; organization and adjusting; motivation and stimulation; control and monitoring).

Gas-Liquid Chromatographic Determination of Technical Chlordane Residues in Food Crops: Interpretation of Analytical Data

1975 ◽  
Vol 58 (5) ◽  
pp. 1051-1061
Author(s):  
William P Cochrane ◽  
James F Lawrence ◽  
Young W Lee ◽  
Ronald B Maybury ◽  
Brian P Wilson
Keyword(s):  
Field Experiments ◽  
Stationary Phases ◽  
Analytical Data ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Food Crops ◽  
Liquid Chromatographic Determination ◽  
Consistent Method ◽  
Liquid Chromatographic

Abstract An interlaboratory investigation of technical chlordane residues in food crops was carried out to determine the most practical and consistent method of reporting results. Using a technical chlordane reference standard, 8 gas chromatographic stationary phases were studied for their resolution capabilities. The best separations were obtained with SE-30 and its OV-1 equivalent. Using these columns and electron capture detection, potatoes and carrots from supervised field experiments were analyzed in duplicate and quantitated by using 4 methods of calculation. The data were statistically treated to determine the precision and bias for each method. Also, 1 sample was analyzed in duplicate on 2 different occasions by 6 laboratories to substantiate the initial conclusions. Based on the criterion of high precision it is suggested that a comparison of total area under the chromatogram of the sample with total area of a standard technical chlordane be the method of quantitation. Only peaks which are common to both standard and sample have any significance in this type of calculation.

scholarly journals Study of Well Waters from High-Level Natural Radiation Areas in Northern Vietnam

2021 ◽  
Vol 18 (2) ◽  
pp. 469
Author(s):  
Van-Hao Duong ◽  
Thanh-Duong Nguyen ◽  
Miklos Hegedus ◽  
Erika Kocsis ◽  
Tibor Kovacs
Keyword(s):  
Natural Radionuclide ◽  
World Health ◽  
Natural Radiation ◽  
Lifetime Cancer Risk ◽  
Northern Vietnam ◽  
Health Organization ◽  
High Level ◽  
Radiological Hazard Indices ◽  
Well Waters

The determination of natural radionuclide concentrations plays an important role for assuring public health and in the estimation of the radiological hazards. This is especially true for high level radiation areas. In this study, 226Ra, 228Ra and 238U concentrations were measured in well waters surrounding eight of the high-level natural radiation areas in northern Vietnam. The 226Ra, 228Ra and 238U activity concentrations vary from <1.2 × 10−3–2.7 (0.46), <2.6 × 10−3–0.43 (0.07) and <38 × 10−3–5.32 Bq/L (0.50 of median), respectively. 226Ra and 238U isotopes in most areas are in equilibrium, except for the DT-Thai Nguyen area. The calculated radiological hazard indices are generally higher than WHO (World Health Organization) recommendations. Average annual effective dose and excess lifetime cancer risk values due to drinking well water range from to 130 to 540 μSv/year and 7.4 × 10−6 to 3.1 × 10−5, respectively.

scholarly journals Constraints on neutrino non-standard interactions from LHC data with large missing transverse momentum

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
DianYu Liu ◽  
ChuanLe Sun ◽  
Jun Gao
Keyword(s):  
Transverse Momentum ◽  
Neutral Current ◽  
Data Sets ◽  
Leading Order ◽  
Missing Transverse Momentum ◽  
Upper Limit ◽  
Theoretical Predictions ◽  
Parton Showering ◽  
Single Jet

Abstract The possible non-standard interactions (NSIs) of neutrinos with matter plays important role in the global determination of neutrino properties. In our study we select various data sets from LHC measurements at 13 TeV with integrated luminosities of 35 ∼ 139 fb−1, including production of a single jet, photon, W/Z boson, or charged lepton accompanied with large missing transverse momentum. We derive constraints on neutral-current NSIs with quarks imposed by different data sets in a framework of either effective operators or simplified Z′ models. We use theoretical predictions of productions induced by NSIs at next-to-leading order in QCD matched with parton showering which stabilize the theory predictions and result in more robust constraints. In a simplified Z′ model we obtain a 95% CLs upper limit on the conventional NSI strength ϵ of 0.042 and 0.0028 for a Z′ mass of 0.2 and 2 TeV respectively. We also discuss possible improvements from future runs of LHC with higher luminosities.

Colorimetric Determination of Aklomide (2-Chloro-4-Nitrobenzamide) in Poultry Feed

1969 ◽  
Vol 52 (3) ◽  
pp. 438-441
Author(s):  
Glenn M George ◽  
A C Daftsios ◽  
Joseph L Morrison
Keyword(s):  
Nitro Group ◽  
Poultry Feed ◽  
Colorimetric Determination ◽  
Average Recovery ◽  
Low Level ◽  
Color Development ◽  
Titanium Trichloride ◽  
High Level

Abstract The coccidiostat aklomide is extracted from feed with methanol and assayed colorimetrically by reduction of the nitro group to anamine with titanium trichloride and subsequent color development with t he Bratton-Marshall reaction. Thirteen laboratories studied the method collaboratively on two levels of medicated feed. Overall average recovery was 106.5% of the oretical for the low level and 104.5% of the oretical for the high level. The method is recommended for adoption as official first action

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