Inductive interaction between closely spaced steeply dipping tabular conductors located in a resistive host

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1052-1058 ◽  
Author(s):  
K. Duckworth ◽  
B. Clement
Keyword(s):  
Scale Model ◽  
Strong Increase ◽  
Initial Increase ◽  
Moving Source ◽  
Model Studies ◽  
Coil System ◽  
True Target ◽  
Physical Scale ◽  
Inductive Interaction ◽  
The Individual

Physical scale‐model studies of the responses provided by horizontal coplanar and vertical coincident coil moving‐source electromagnetic systems when operated over closely spaced, steeply dipping, tabular conductors located in a resistive host are presented. For separations of the conductors that permit separate anomalies to be identified, the detected effect of inductive interaction between the conductors depends on the configuration of the exploration device. As conductors are moved closer together, the horizontal coplanar coil system produces responses for each conductor that become progressively weaker than the individual responses when each conductor is isolated. By comparison, vertical coincident coils detect an initial increase of the anomalies from the individual conductors as the conductor separation is reduced until just before the separate anomalies merge. As the anomalies merge, the vertical coincident coil responses decline in magnitude. After the anomalies merge and present the appearance of the response of a single conductor, both coil systems record an expected strong increase of response which exceeds the response when the conductors are in contact. These mutual inductive interactions cause significant variations in the depth estimates provided by horizontal coplanar coils. Depth estimates provided by vertical coincident coils are always smaller than the true target depths. The vertical coincident coil configuration displays an ability to identify separate conductors at significantly smaller conductor separations than can the horizontal coplanar coils.

scholarly journals Multiphasic Study of Fluid-Dynamics and the Thermal Behavior of a Steel Ladle during Bottom Gas Injection Using the Eulerian Model

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1082
Author(s):  
Antonio Urióstegui-Hernández ◽  
Pedro Garnica-González ◽  
José Ángel Ramos-Banderas ◽  
Constantin Alberto Hernández-Bocanegra ◽  
Gildardo Solorio-Díaz
Keyword(s):  
Heat Exchange ◽  
Thermal Behavior ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Steel Slag ◽  
Scale Model ◽  
Discrete Ordinates ◽  
Transfer Model ◽  
Steel Ladle ◽  
Physical Scale

In this work, the fluid dynamic and thermal behavior of steel was analyzed during argon gas stirring in a 140-t refining ladle. The Eulerian multiphase mathematical model was used in conjunction with the discrete ordinates (DO) thermal radiation model in a steel-slag-argon system. The model was validated by particle image velocimetry (PIV) and the analysis of the opening of the oil layer in a physical scale model. The effect of Al2O3 and Mg-C as a refractory in the walls was studied, and the Ranz-Marshall and Tomiyama models were compared to determine the heat exchange coefficient. The results indicated that there were no significant differences between these heat exchange models; likewise, the radiation heat transfer model adequately simulated the thermal behavior according to plant measurements, finding a thermal homogenization time of the steel of 2.5 min for a gas flow of 0.45 Nm3·min−1. Finally, both types of refractory kept the temperature of the steel within the ranges recommended in the plant; however, the use of Al2O3 had better heat retention, which would favor refining operations.

scholarly journals Roughness Lengths for Momentum and Heat Derived from Outdoor Urban Scale Models

2007 ◽  
Vol 46 (7) ◽  
pp. 1067-1079 ◽  
Author(s):  
M. Kanda ◽  
M. Kanega ◽  
T. Kawai ◽  
R. Moriwaki ◽  
H. Sugawara
Keyword(s):  
Wind Direction ◽  
Roughness Length ◽  
Scale Dependence ◽  
Scale Model ◽  
Small Scale ◽  
Physical Scale ◽  
Scale Models ◽  
Roughness Lengths ◽  
Urban Sites ◽  
Obstacle Height

Abstract Urban climate experimental results from the Comprehensive Outdoor Scale Model (COSMO) were used to estimate roughness lengths for momentum and heat. Two different physical scale models were used to investigate the scale dependence of the roughness lengths; the large scale model included an aligned array of 1.5-m concrete cubes, and the small scale model had a geometrically similar array of 0.15-m concrete cubes. Only turbulent data from the unstable boundary layers were considered. The roughness length for momentum relative to the obstacle height was dependent on wind direction, but the scale dependence was not evident. Estimated values agreed well with a conventional morphometric relationship. The logarithm of the roughness length for heat relative to the obstacle height depended on the scale but was insensitive to wind direction. COSMO data were used successfully to regress a theoretical relationship between κB−1, the logarithmic ratio of roughness length for momentum to heat, and Re*, the roughness Reynolds number. Values of κB−1 associated with Re* for three different urban sites from previous field experiments were intercompared. A surprising finding was that, even though surface geometry differed from site to site, the regressed function agreed with data from the three urban sites as well as with the COSMO data. Field data showed that κB−1 values decreased as the areal fraction of vegetation increased. The observed dependency of the bulk transfer coefficient on atmospheric stability in the COSMO data could be reproduced using the regressed function of Re* and κB−1, together with a Monin–Obukhov similarity framework.

Multiple Haemoglobins of the Atlantic Salmon (Salmo salar)

1968 ◽  
Vol 25 (12) ◽  
pp. 2651-2663 ◽  
Author(s):  
N. P. Wilkins
Keyword(s):  
Life Cycle ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gel Electrophoresis ◽  
Initial Increase ◽  
Small Fish ◽  
Starch Gel Electrophoresis ◽  
Complete Development ◽  
Starch Gel ◽  
The Individual

The haemoglobins of over 500 salmon of different lengths, from Scotland, Greenland, and Canada have been analysed by vertical starch–gel electrophoresis at pH 8.1. Complex ontogenetic variations, involving an initial increase and later reduction in the number of fractions evident, have been observed among the anodally migrating haemoglobins. The variations observed have been correlated with changes in length, and the complete development of the anodal haemoglobin complex from the single fraction of small fish to the nine-fraction pattern of adults is outlined. The individual haemoglobin fractions appear to represent structurally distinct molecules whose regulated occurrence at different phases of the life cycle is discussed at the individual and population levels.

AN EXPERIMENTAL STUDY ON THE RELATIVE MOTIONS BETWEEN A FLOATING HARBOUR TRANSHIPPER AND A FEEDER VESSEL IN REGULAR WAVES

2021 ◽  
Vol 154 (A2) ◽  
Author(s):  
G J Macfarlane ◽  
T Lilienthal ◽  
R J Ballantyne ◽  
S Ballantyne
Keyword(s):  
Open Water ◽  
Scale Model ◽  
Regular Waves ◽  
Inclement Weather ◽  
Port Operations ◽  
Physical Scale ◽  
Feeder Vessel ◽  
Primary Advantage ◽  
Exposed Location ◽  
Relative Motions

The Floating Harbour Transhipper (FHT) is a pioneering logistics solution that was designed to meet the growing demands for coastal transhipment in the mining sector as well as commercial port operations. The primary advantage of the FHT system is that it can reduce transhipment delays caused by inclement weather, by reducing relative motions between the FHT and feeder vessel. The feeder is sheltered when inside the FHT well dock when compared to the more exposed location when a feeder is in a traditional side-by-side mooring arrangement. This paper discusses previously published studies into the relative motions of vessels engaged in side-by-side mooring arrangements and also presents details and results from a series of physical scale model experiments. In these experiments, both side-by-side and aft well dock mooring arrangements are investigated. The results provide strong evidence that the FHT well dock concept can significantly reduce the heave, pitch and roll motions of feeder vessels when transhipping in open seas – this being the cornerstone of any successful open water transhipment operation.

scholarly journals The Influence of Belief, Utility of Information, and Group Support on Selective Exposure to Pornography Among Teenagers in Jakarta, Indonesia

2018 ◽  
Vol 7 (2.29) ◽  
pp. 557
Author(s):  
Inge Hutagalung
Keyword(s):  
High School Students ◽  
Structural Equation ◽  
Selective Exposure ◽  
Scale Model ◽  
Equation Modeling ◽  
Social Aspect ◽  
Group Support ◽  
Validity And Reliability ◽  
Utility Of Information ◽  
The Individual

Festinger’s (1) hypothesis cites belief as a variable that influences selective exposure. However, a review of other experts’ research proves that selective exposure is not only affected by the psychological aspect but by the message and the social aspect as well. In contrast to previous scholars who focused only on one variable, the researcher examines belief, utility of information, and group support simultaneously and integrates them into a model. The research design is a case study involving the use of pornographic information. This study’s subjects comprise 400 senior high school students in Jakarta, Indonesia. The relationships among the variables were tested by using structural equation modeling. The validity and reliability analyses utilized the LISREL 8.80 application. A questionnaire with a Likert-scale model was used as the data collection method. The structural test results show that the theoretical models for the three variables have a significant effect on selective exposure (t value ≥ 1.96). On the other hand, the findings also prove that communication in the context of selective information on pornography is divided into three levels. First, at the intrapersonal level, the individual holds on to his or her belief in selecting the information. Second, at the interpersonal or group level, the individual adjusts his or her belief to the existing reality (environment or social group). Third, at the mass communication level, the individual selects the information according to its utility, that is, to fulfill the need for information.  

scholarly journals THE USE OF ARRAY PROCESSORS FOR NUMERICAL MODELLING OF TIDAL ESTUARY DYNAMICS

1980 ◽  
Vol 1 (17) ◽  
pp. 142
Author(s):  
D. Prandle ◽  
E.R. Funke ◽  
N.L. Crookshank ◽  
R. Renner
Keyword(s):  
Numerical Model ◽  
Numerical Modelling ◽  
Hybrid Model ◽  
Numerical Models ◽  
Computer Time ◽  
Scale Model ◽  
Hybrid Modelling ◽  
Tidal Propagation ◽  
Physical Scale ◽  
Array Processors

The use of array processors for the numerical modelling of estuarine systems is discussed here in the context of "hybrid modelling", however, it is shown that array processors may be used to advantage in independent numerical simulations. Hybrid modelling of tidal estuaries was first introduced by fiolz (1977) and later by Funke and Crookshank (1978). In a hybrid model, tidal propagation in an estuary is simulated by dynamically linking an hydraulic (or physical) scale model of part of the estuary to a numerical model of the remaining part in a manner such that a free interchange of flow occurs at the interface(s). Typically, the elevation of the water surface at the boundary of the scale model is measured and transmitted to the numerical model. In return, the flow computed at the boundary of the numerical model is fed directly into the scale model. This approach enables the extent of the scale model to be limited to the area of immediate interest (or to that area where flow conditions are such that they can be most accurately simulated by a scale model). In addition, since the region simulated by the numerical model can be extended almost indefinitely, the problems of spurious reflections from downstream boundaries can be eliminated. In normal use, numerical models are evaluated on the basis of computing requirements, cost and accuracy. The computer time required to simulate one tide cycle is, in itself, seldom of interest except in so far as it affects the above criteria. However in hybrid modelling this parameter is often paramount since concurrent operation of the numerical and scale models requires that the former must keep pace with the latter. The earlier hybrid model of the St. Lawrence (Funke and Crookshank, 1978) involved a one-dimensional numerical model of the upstream regions of the river. However, future applications are likely to involve extensive two-dimensional numerical simulation.

scholarly journals Effect of Gamma Radiation on Characteristic of bipolar junction Transistors (BJTs )

2021 ◽  
pp. 1-9
Author(s):  
Abdenabi Ali Elamin ◽  
Waell H Alawad
Keyword(s):  
Gamma Radiation ◽  
Power Supplies ◽  
Strong Increase ◽  
Bipolar Junction Transistors ◽  
Bipolar Junction Transistor ◽  
Before And After ◽  
Junction Transistor ◽  
The Individual ◽  
Silicon Transistor ◽  
Different Doses

This paper describes the effects of 60Cogamma radiation hardness of characteristic and parameters of Bipolar Junction Transistors in order to analyze the performance changes of the individual devices used in nuclear field. Bipolar Junction Transistor (BJT) of the type (BC-301) (npn) silicon, Transistor was irradiated by gamma radiation using 60Cosource at different doses (1, 2, 3, 4, and 5) KGy. The characteristics and parameter of Bipolar Junction Transistor was studied before and after irradiated by using Transistor Characteristics Apparatus with regulated power supplies. Obtained result showed that, the saturation voltage VCE(sat) of Bipolar Junction Transistor decreased because of the gain degradation of the transistor and increased silicon resistivity, Another parameter of a bipolar junction transistor affected by ionizing radiation is a collector-base leakage current, a strong increase of the current is caused by the build-up charge near the junction.

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