APPLICATIONS OF THE EXPANDING REFLECTION SPREAD

Geophysics ◽  
1962 ◽  
Vol 27 (6) ◽  
pp. 981-993 ◽  
Author(s):  
A. W. Musgrave
Keyword(s):  
Average Velocity ◽  
Velocity Versus ◽  
Normal Velocity ◽  
Interval Velocity ◽  
Reflection Profile ◽  
Time Average ◽  
Record Section ◽  
Section Form

Techniques have been developed for the usefulness of the expanding reflection profile whose basic elements were described by Dix in 1955. Procedures have been established which make the shooting and interpretation of these expanding reflection spreads simpler and more reliable. Special presentations have been developed for the displaying of these profiles on record sections, and nonlinear paper has been designed for plotting the time‐squared versus distance‐squared graphs. The expanding spread is a valuable seismic tool and has numerous applications. It may be used for the identification of reflections and multiples. From the true reflections, calculations can be made to present the normal velocity survey information, i.e., time, average velocity, and interval velocity versus depth. Among other uses is the determination of the normal moveout curve. Various types of presentations are used to display expanding spreads in record section form. Also, various noise and multiple problems are exhibited.

THREE‐DIMENSIONAL SEISMIC METHOD

Geophysics ◽  
1972 ◽  
Vol 37 (3) ◽  
pp. 417-430 ◽  
Author(s):  
G. G. Walton
Keyword(s):  
Seismic Data ◽  
Average Velocity ◽  
Three Dimensional ◽  
Data Gathering ◽  
Seismic Method ◽  
Dynamic Display ◽  
Profile Line ◽  
Production Problems ◽  
Dense Coverage

The three‐dimensional seismic method is a different way of gathering and presenting seismic data. Instead of showing the subsurface beneath a profile line, 3-D displays give an, areal picture from the shallowest reflector to the deepest one that can be found seismically. Data are collected in the field with cross‐spreads that provide over 2000 evenly spaced depth points on each reflecting interface. Several variations of the cross‐spread technique give the same subsurface coverage while providing flexibility in data gathering. Because of the dense coverage, the method is best suited for problems requiring great detail, such as production problems. The usual presentation of 3-D data is a visual, moving display of emerging wavefronts covering four sq mi of surface. From this dynamic display, average velocity to each reflector and the dip direction and magnitude can be computed. The method has proved especially useful for the recognition of faults and determination of fault directions.

SEL VƏ DAŞQIN AXINLARINDA DAĞ ÇAYLARI MƏCRASININ YUYULMA DƏRİNLİYİNİN TƏYİNİ

2021 ◽  
Vol 1 (1) ◽  
pp. 82-88
Author(s):  
F.Ş., Əhmədov ◽  
R.K., Quliyev ◽  
R.Ü Əbdüləzimov
Keyword(s):  
Average Velocity ◽  
Average Diameter ◽  
Average Depth ◽  
Mountain River ◽  
Mountain Rivers ◽  
Cross Sectional ◽  
Average Width ◽  
Caucasus Mountains ◽  
Flood Flow

Abstract. The article is dedicated to the determination of the wash depth of mountain rivers in floods and overflows. As well-known, hydrotechnical equipment is exposed to destructive damages of the floods and overflows. The undersurface of bridge basement and coast guards are washed away, the surface of drainage devices in water supply and dams (Düker) at river crossings are opened up. Therefore, the protection of the equipment against the destructive damage of the floods and overflows should be ensured. To this aim, first of all, the depth of the fortification of the equipment basement in riverbeds and the width through which the river can flow should be determined and the works of installing coast guards should be accordingly implemented. Since the flow regime of rivers due to floods in the course of mountain riverbeds dramatically changes, the width, depth, roughness and cross-sectional area of the riverbed also changes. To that reason, in the smallest case, calculation formulas includes the average width and wash depth of the riverbed in the course of the floods and overflows, average diameter of undersurface soils, the slope of the location of hydrotechnical structures, velocity due to the average diameter of the riverbed soils and so on. The article contains the analyses of theoretical and practical materials about the floods and overflows in mountain rivers. For the rivers flowing through the southern hills of Great Caucasus Mountains, the expressions for determining the riverbed parameters and hydrological parameters of rivers are used. According to the expressions, average width due to non-washing of the riverbed in floods in accordance with flood flow and slope of the studied part of the riverbed, the average depth of the riverbed crossing the flood, the average velocity of the flow and the wash depth in accordance with them are determined. basing on all these, the determining method of the wash depth of mountain riverbeds in floods have been worked out and determining the wash depth have been recorded. The studied methodology can be used in determining the riverbed parameters in floods and overflows. Keywords: Flood, riverbed deformation, mountain river, wash depth, average diameter of undersurface sediments, riverbed stability, flood velocity

THE REFRACTION SEISMOGRAPH IN THE ALBERTA FOOTHILLS

Geophysics ◽  
1956 ◽  
Vol 21 (3) ◽  
pp. 828-838 ◽  
Author(s):  
G. J. Blundun
Keyword(s):  
Operating Conditions ◽  
Radio Communication ◽  
Interval Velocity ◽  
Mississippian Limestone ◽  
Interval Velocities ◽  
Definition Of ◽  
Characteristic Interval ◽  
Consequent Improvement ◽  
Continuous Determination

In the Alberta foothills the most valuable use of the refraction seismograph is for the definition of overthrust faulting in the Mississippian limestone which is overlain by a faulted, overthrust, and overturned Cretaceous section. Normally, two refracted arrivals are recorded with characteristic interval velocities of 14,000 ft/sec and 21,000 ft/sec, the former arising from an unknown Cretaceous marker, and the latter from the Mississippian. In contrast to a shot‐range of 65,000 ft required to record the refracted arrival from the Mississippian at a depth of 10,000 ft as the first event, a range of 20,000 ft permits recording it as the later event, with consequent improvement in the quality and reliability of the data, reduces the amount of surveying required together with smaller dynamite charges, and improves radio communication. A geophone spread of 6,300 ft with single geophones at 300 ft intervals recorded on 22 traces is recommended. Both in‐line and broadside refraction with the Mississippian arrival recorded as the later event have been used successfully with certain advantages to each method. The former permits continuous determination of the interval velocity of the refracted events as well as providing two‐way control; the latter is considerably faster, and often faulting may be observed directly on the seismograms without reduction of the data. Specimen seismograms are included to illustrate the two methods. Field operating conditions pertaining to survey tolerances, shot formation, size of dynamite charges, the weathering shot as a polarity check, filtering, geophone frequency, and costs are discussed.

On: “Special Report of the Subcommittee on Polarity Standards” by Ben B. Thigpen, A. E. Dalby, and Ralph Landrum (GEOPHYSICS, August 1975, p. 694–699)

Geophysics ◽  
1976 ◽  
Vol 41 (2) ◽  
pp. 324-324
Author(s):  
W. T. Valenta
Keyword(s):  
Reflection Coefficient ◽  
Compressional Wave ◽  
Velocity Versus ◽  
Reflection Coefficients ◽  
Special Report ◽  
Sonic Logs ◽  
The Relationship

In their report, the authors recommend that the arrival of a compressional wave at a geophone or hydrophone shall ultimately produce a trough (downward or leftward kick) on a seismogram; but they don’t say why. On sonic logs and displays of velocity versus time, velocity increases are up; likewise for density increases on density logs; likewise for positive reflection coefficients on reflection coefficient logs computed from the previously mentioned logs. Should not seismograms, which ideally are bandlimited reflection coefficient logs, conform to the same convention? The committee succeeded in the objectives of establishing the relationship between impulse‐source systems and vibratory‐source systems and of establishing tests for the determination of the polarity of a given system. I feel strongly that the committee should recommend that a compressional arrival shall produce a peak on a seismogram.

Simulation of Impact of Classroom Layout on Evacuation Efficiency Based on Cellular Automata

2012 ◽  
Vol 263-266 ◽  
pp. 1497-1502 ◽  
Author(s):  
Gang Xu ◽  
Zhen Yan Liang ◽  
Hai Yan Liu
Keyword(s):  
Cellular Automata ◽  
Psychological Factors ◽  
Average Velocity ◽  
Emergency Evacuation ◽  
Average Density ◽  
Average Flow Rate ◽  
Time Average ◽  
Simulation Results ◽  
The Difference ◽  
Distance Parameter

This paper, based on the principle of Cellular Automata, simulated the emergent evacuation from a floor of lecture building with different layouts inside the classrooms commonly seen in colleges in China. The psychological factors and behaviors of students during the emergent evacuation were simulated with the distance parameter as the basic judgment for evacuation direction based on Cellular Automata in the present paper. Meanwhile, the impacts of four different internal layouts on the evacuation time, average density, average velocity, and average flow rate were investigated. Simulation results show that the difference in classroom layout affects the evacuation efficiency. It also proves that the classroom layout in Room1 is the most reasonable when emergency evacuation is involved.

The Results of Experimental Determination of Air Output and Velocity of Flow in Double Skin Facades

2015 ◽  
Vol 725-726 ◽  
pp. 93-99 ◽  
Author(s):  
Mikhail Petrichenko ◽  
Nikolai Vatin ◽  
Darya Nemova ◽  
Vyacheslav Olshevskiy
Keyword(s):  
Experimental Determination ◽  
Average Velocity ◽  
Air Flow ◽  
Air Gap ◽  
Double Skin ◽  
Double Skin Facades ◽  
New Buildings

Double skin facades very popular in this time. They are applied for construction of new buildings and for reconstruction. This paper to try to consider the main problems which appear during the work with the double skin facades. In paper are presented dependence of average velocity of air flow as functions from the geometrical sizes of the ventilated air gap of double skin facades and air output as functions from the geometrical sizes of air gap. This dependences are received experimentally. The received dependences can be used at design of double skin facades for the purpose of obtaining the optimum sizes of an air gap.

Study on Three-Dimensional Turbulence Characteristics of Curved Channel Flow

2011 ◽  
Vol 94-96 ◽  
pp. 989-994
Author(s):  
Ri Sheng Wang ◽  
Kai Shi
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Channel Flow ◽  
Average Velocity ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Curved Channel ◽  
Turbulence Characteristics ◽  
Time Average ◽  
Curved Channel Flow

The paper presents an experimental study on three-dimensional turbulence characteristics of curved channel flow by Doppler meter .Measured the time-average velocity and fluctuating intensity and so on. Analysised turbulence characteristics of curved channel flow by the experimental data,and also compared the flow distribution of vertical、horizontal fluctuating intensity,get the conclusion.

Determination of Ballistic Limits of GLARE 5 Fiber-Metal Laminates: The Influences of Geometry, Thickness and Stacking Sequence

2011 ◽  
Author(s):  
A. Seyed Yaghoubi ◽  
B. Liaw
Keyword(s):  
Volume Fraction ◽  
Velocity Versus ◽  
Specimen Thickness ◽  
Stacking Sequence ◽  
Ballistic Limit ◽  
Fiber Metal Laminates ◽  
Limit Velocity ◽  
Fiber Metal ◽  
Ballistic Limit Velocity

In this paper, GLARE 5 fiber-metal laminates (FMLs) of two different geometries: 152.4mm×101.6mm (6″×4″) plate and 254mm×25.4mm (10″×1″) beam and with various thicknesses and stacking sequences were impacted by a 0.22 caliber bullet-shaped projectile using a high-speed gas gun. Velocities of the projectile along the ballistic trajectory were measured at different locations. For both geometries, the incident projectile impact velocity versus the residual velocity was plotted and numerically fitted according to the classical Lambert–Jonas equation for the determination of ballistic limit velocity, V50. The results showed that V50 varied in a parabolic trend with respect to the metal volume fraction (MVF) and the specimen thickness for both geometries. It was found that by changing the geometry from a plate to a beam, the ballistic limit velocity increased. On the other hand, changing the stacking sequence had a less pronounced effect on V50 for both geometries. The quasi-isotropic beam and plate specimens offered relatively higher ballistic limit velocities compared to other types of stacking sequences in their own geometrical groups. Furthermore, the cross-ply and unidirectional beam specimens showed relatively higher V50 compared to their plate counterparts. Experimental results showed that the ballistic limit was almost the same for the quasi-isotropic layup FMLs of both plate and beam geometries.

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