LIMITATIONS OF THE REFLECTION SEISMIC METHOD; LESSONS FROM COMPUTER SIMULATIONS

Geophysics ◽  
1970 ◽  
Vol 35 (4) ◽  
pp. 551-573 ◽  
Author(s):  
M. Turhan Taner ◽  
Ernest E. Cook ◽  
Norman S. Neidell
Keyword(s):  
Synthetic Seismograms ◽  
Seismic Exploration ◽  
Basic Approach ◽  
Seismic Method ◽  
Reflection Seismic ◽  
Recent Developments ◽  
Ground Coverage ◽  
Linear And Nonlinear ◽  
Interval Velocities ◽  
Made In

Piece‐wise local linearity of the subsurface reflectors and uniqueness of primary reflection travel path between particular source‐receiver pairs are two of the fundamental assumptions of multiple ground coverage reflection seismic techniques as currently employed. Some recent developments in seismic exploration which spring from the progress made in velocity determination techniques violate these fundamental assumptions with potentially serious consequences such as spurious geometries after migration and unrealistic interval velocities. In this paper we apply analytic techniques and computer simulation to linear and nonlinear subsurface models in order to obtain better definitions of the limitations of the reflection seismic method. The resulting lessons are of immediate practical value in seismic interpretation and clarify a variety of commonly occurring but puzzling situations such as phantom faults, incomplete contacts and segmented reflectors at unconformities, and apparent reversal of dip. In its basic approach this work has much in common with the generation and study of synthetic seismograms. Examination of the groundwork of the seismic method provides a firm base for extending its use.

SEISMIC EXPLORATION OF THE DENVER‐JULESBURG BASIN

Geophysics ◽  
1952 ◽  
Vol 17 (2) ◽  
pp. 334-343
Author(s):  
B. F. Rummerfield
Keyword(s):  
Seismic Activity ◽  
Resolving Power ◽  
Seismic Exploration ◽  
Velocity Variation ◽  
Seismic Method ◽  
Subsurface Structures ◽  
Weathered Zone ◽  
Recent Developments ◽  
Elevation Changes

Recent developments in northeastern Colorado and southwestern Nebraska have resulted in a marked increase in seismic activity within the Denver‐Julesburg Basin. The low relief of many of the subsurface structures, coupled with the extraneous effects of weathered zone, elevation changes, surface deposits, and velocity variation taxes the resolving power of the seismic method and the interpretative ability of the geophysicist.

scholarly journals Recent advances in the electrochemical construction of heterocycles

2014 ◽  
Vol 10 ◽  
pp. 2858-2873 ◽  
Author(s):  
Robert Francke
Keyword(s):  
Heterocyclic Compounds ◽  
Elevated Temperatures ◽  
Ring Formation ◽  
Environmentally Benign ◽  
Heterocyclic Chemistry ◽  
Ambient Conditions ◽  
Recent Developments ◽  
Strong Acids ◽  
Selection Of ◽  
Made In

Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.

China’s shadow banking sector: beneficial or harmful to economic growth?

2015 ◽  
Vol 7 (4) ◽  
pp. 421-445 ◽  
Author(s):  
James R. Barth ◽  
Tong Li ◽  
Wen Shi ◽  
Pei Xu
Keyword(s):  
Economic Growth ◽  
Banking Sector ◽  
Commercial Banking ◽  
Global Perspective ◽  
Shadow Banking ◽  
Content Type ◽  
Wide Range ◽  
Recent Developments ◽  
Major Factors ◽  
Made In

Purpose – The purpose of this paper is to examine recent developments pertaining to China’s shadow banking sector. Shadow banking has the potential not only to be a beneficial contributor to continued economic growth, but also to contribute to systematic instability if not properly monitored and regulated. An assessment is made in this paper as to whether shadow banking is beneficial or harmful to China’s economic growth. Design/methodology/approach – The authors start with providing an overview of shadow banking from a global perspective, with information on its recent growth and importance in selected countries. The authors then focus directly on China’s shadow banking sector, with information on the various entities and activities that comprise the sector. Specifically, the authors examine the interconnections between shadow banking and regular banking in China and the growth in shadow banking to overall economic growth, the growth in the money supply and the growth in commercial bank assets. Findings – Despite the wide range in the estimates, the trend in the size of shadow banking in China has been upward over the examined period. There are significant interconnections between the shadow banking sector and the commercial banking sector. Low deposit rate and high reserve requirement ratios have been the major factors driving its growth. Shadow banking has been a contributor, along with money growth, to economic growth. Practical implications – The authors argue that shadow banking may prove useful by diversifying China’s financial sector and providing greater investments and savings opportunities to consumers and businesses throughout the country, if the risks of shadow banking are adequately monitored and controlled. Originality/value – To the authors’ knowledge, this paper is among the few to systematically evaluate the influence of shadow banking on China’s economic growth.

scholarly journals Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

2020 ◽  
Vol 16 ◽  
pp. 305-316 ◽  
Author(s):  
Clément Ghiazza ◽  
Anis Tlili
Keyword(s):  
Organic Compounds ◽  
Crucial Role ◽  
Copper Catalysis ◽  
Chemistry Major ◽  
Recent Developments ◽  
Made In

Copper catalysis and, more generally, copper chemistry are pivotal for modern organofluorine chemistry. Major advances have been made in the field of trifluoromethylselenolations of organic compounds where copper catalysis played a crucial role. Recent developments in this field are highlighted in this minireview.

Ras proteins as therapeutic targets

2018 ◽  
Vol 46 (5) ◽  
pp. 1303-1311 ◽  
Author(s):  
Atanu Chakraborty ◽  
Emily Linnane ◽  
Sarah Ross
Keyword(s):  
Therapeutic Strategies ◽  
Targeted Therapeutics ◽  
Ras Proteins ◽  
Ras Genes ◽  
Small Molecule Drug ◽  
Oncogenic Mutations ◽  
Recent Developments ◽  
Novel Therapeutic Strategies ◽  
Novel Therapeutic ◽  
Made In

Oncogenic mutations in RAS genes underlie the pathogenesis of many human tumours, and there has been intense effort for over 30 years to develop effective and tolerated targeted therapeutics for patients with Ras-driven cancers. This review summarises the progress made in Ras drug discovery, highlighting some of the recent developments in directly targeting Ras through advances in small molecule drug design and novel therapeutic strategies.

The Indian Farming-Community and their Health-Concerns for a Sustainable Agriculture

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Developing Countries ◽  
Well Being ◽  
Intervention Strategies ◽  
Health Concerns ◽  
Work Related ◽  
Farming Community ◽  
Recent Developments ◽  
Health Disorders ◽  
The Government ◽  
Made In

The exposure of farmers to agricultural hazards and risks has been increased in their work-places with the recent developments in agricultural sectors in most of the developing countries. This higher expose may be due to the enhanced need in meeting the food as well as monetary demand of farming house-holds. The agricultural-productivity has also been reduced in developing countries because of the exposure of farmers to work-related stresses affecting their well-being. Thus, an attempt was made in this study for exploring the mental-health disorders among the farmers and the farming-community in the state of Odisha in India for undertaking possible intervention strategies by the government and competent authorities.

scholarly journals Ice Thickness and Sea Depth Derived from Reflection-Seismic Measurements on the Central Part of Filchner-Ronne Ice Shelf, Antarctica

1988 ◽  
Vol 11 ◽  
pp. 14-18 ◽  
Author(s):  
J. Determann ◽  
F. Thyssen ◽  
H. Engelhardt
Keyword(s):  
Drill Hole ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Reflection Seismic ◽  
Seismic Records ◽  
3D Processing ◽  
Seismic Measurements ◽  
Good Agreement ◽  
Made In

In January 1986, reflection-seismic measurements were made in the central part of Filchner-Ronne Ice Shelf, north of Henry and Korff ice rises, by a German oversnow traverse. With the help of a newly developed “ice streamer”, two people were able to obtain seismic records nearly every 5km over a distance of 150km within 3d. Processing of digitally recorded seismograms yielded profiles of ice thickness and sea depth. The ice thickness varies from 400 to 500 m and is in good agreement with the thickness of 465 m at a drill hole. The reflection-seismic results are comparable with those obtained from aerogeophysical measurements.

scholarly journals Recent Advances in Palladium-Catalyzed Isocyanide Insertions

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4906
Author(s):  
Jurriën W. Collet ◽  
Thomas R. Roose ◽  
Bram Weijers ◽  
Bert U. W. Maes ◽  
Eelco Ruijter ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Building Blocks ◽  
Insertion Reactions ◽  
Chemical Reagents ◽  
The Past ◽  
Recent Advances ◽  
Recent Developments ◽  
Palladium Catalyzed ◽  
Made In ◽  
Rapid Incorporation

Isocyanides have long been known as versatile chemical reagents in organic synthesis. Their ambivalent nature also allows them to function as a CO-substitute in palladium-catalyzed cross couplings. Over the past decades, isocyanides have emerged as practical and versatile C1 building blocks, whose inherent N-substitution allows for the rapid incorporation of nitrogeneous fragments in a wide variety of products. Recent developments in palladium catalyzed isocyanide insertion reactions have significantly expanded the scope and applicability of these imidoylative cross-couplings. This review highlights the advances made in this field over the past eight years.

A Discussion on natural strain and geological structure - The finite element method and the solution of some geophysical problems

1976 ◽  
Vol 283 (1312) ◽  
pp. 139-151 ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geological Structure ◽  
The Finite Element Method ◽  
Recent Developments ◽  
Limited Application ◽  
Discrete Problems ◽  
The Finite Difference Method ◽  
Made In ◽  
Element Method

The finite element method has become established as a powerful tool for the solution of many problems of continuum mechanics where its physical interpretation, by analogy with discrete problems of structural analysis permits the user to exercise a considerable degree of insight and judgement in its use. Further it is now a recognized mathematical procedure of approximation which embraces many older methodologies (such as the finite difference method) as a subclass. In the field of geological studies its impact is fairly recent and only a limited application has been made to date. The techniques used here have been limited to those established over a decade ago in the parallel fields and recent developments and possibilities barely touched upon. In this paper the author therefore attempts to ( a ) outline some of the general mathematical and practical aspects of the method with illustrations from various fields which are relevant to geological problems, ( b ) survey accomplishments already made in geology and geotechnical fields, and ( c ) suggest some possible new extensions of application.

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