GRAVITY VERTICAL GRADIENT MEASUREMENTS FOR THE DETECTION OF SMALL GEOLOGIC AND ANTHROPOGENIC FORMS

Geophysics ◽  
1976 ◽  
Vol 41 (5) ◽  
pp. 1016-1030 ◽  
Author(s):  
Zbigniew J. Fajklewicz
Keyword(s):  
Detailed Analysis ◽  
Research Work ◽  
Vertical Gradient ◽  
Industrial Applications ◽  
New Method ◽  
Topographic Correction ◽  
Engineering Problems ◽  
Mine Workings ◽  
The Difference ◽  
Gradient Measurements

The gravity tower vertical gradient has been applied to the solution of a number of important geologic, mining, and engineering problems, particularly to the search for and investigation of geologic structures and the detection of caverns and old mine workings. The effective application of the method depends upon recognizing the difference between the theoretical gravity vertical gradient [Formula: see text] and the gradient [Formula: see text] measured by means of a tower and gravimeter. The former is a derivative of the function g, the latter its differential quotient. Consequently, the differences between [Formula: see text] and [Formula: see text] in the same point may attain high values. Thus, e.g., for a sphere with a radius of 1 m, a density of 2.0 gm/cc and the depth of occurrence of its center equaling 1.2 m, the difference of the theoretical absolute amplitudes [Formula: see text] Eötvös units. Application of the method of the gravity tower vertical gradient on an industrial scale was possible due to the introduction of (1) a new design of the measuring tower, (2) detailed analysis of errors, and (3) a new method of calculating the topographic correction of the gravity vertical gradient. The paper sums up the results of five years of research work and industrial applications. During that period several thousand measurements of the gravity vertical gradient were made.

On: “Gravity vertical gradient measurements for the detection of small geologic and anthropogenic forms” by Z. J. Fajklewicz (GEOPHYSICS, October 1976, p. 1016–1030)

Geophysics ◽  
1977 ◽  
Vol 42 (4) ◽  
pp. 872-873
Author(s):  
Stephen Thyssen‐Bornemisza
Keyword(s):  
Research Work ◽  
Vertical Gradient ◽  
Gravity Gradient ◽  
Wind Gust ◽  
Near Surface ◽  
New Methods ◽  
Vertical Gravity Gradient ◽  
Surface Variation ◽  
Gradient Measurements ◽  
Vertical Gravity

In his paper, Fajklewicz discusses the improvement of vertical gravity gradient measurements arising from a very stable tower apparently not affected by wind gust vibration and climatic changes. Further, the lower plate where the gravity meter is resting can be changed in position to avoid possible disturbances from surface and near‐surface variation, and new methods for correcting and interpreting observed gradients over the vertical interval of about 3 m are presented. Some 1000 field stations were observed, including research work and industrial application.

GRADIENT MEASUREMENTS IN AEROMAGNETIC SURVEYING

Geophysics ◽  
1965 ◽  
Vol 30 (5) ◽  
pp. 891-902 ◽  
Author(s):  
Peter Hood
Keyword(s):  
Optical Pumping ◽  
Vertical Gradient ◽  
Horizontal Distance ◽  
Total Field ◽  
Highly Sensitive ◽  
Geophysical Information ◽  
The Difference ◽  
Gradient Measurements ◽  
First Vertical Derivative ◽  
Depth Of Burial

The recent development of highly sensitive magnetometers, such as the optical‐pumping varieties, has made feasible the measurement of the first vertical derivative of the total field (∂ΔT/∂h) in aeromagnetic surveys. This is accomplished by using two sensitive magnetometer heads separated by a constant vertical distance, and recording the difference in outputs. The effect of diurnal is thus eliminated in the resultant differential output, and this is an especially desirable feature in northern Canada where the diurnal variation is usually much greater than is found in more southerly magnetic latitudes. Moreover, steeply dipping geological contacts in high‐magnetic latitudes are outlined by the resultant zero‐gradient contour. It is also possible to obtain the depth of burial of the contact from the graph of (∂ΔT/∂h) versus (x∂ΔT/∂x) where x is the horizontal distance measured from the contact. Similar quantitative interpretations may be made for the point pole and dipole. The data reduction necessary to produce a vertical‐gradient map is much simpler than with the total‐field case because no datum levelling is necessary. Since the aircraft track will be available from the main compilation it is only necessary to plot the resultant vertical‐gradient values on the track map and contour. Thus, two maps will be obtained for little more than the price of one but with a greatly increased gain in geophysical information concerning the geometry of the causative bodies. Actually, a first‐derivative map is difficult (and therefore costly) to produce by any other means. The measurement of the vertical gradient would appear to be the main advantage to using hundredth‐gamma magnetometers in aeromagnetic surveys, since those types presently in service are sensitive enough for the effective delineation of total‐field anomalies.

On: “Gravity vertical gradient measurements for the detection of small geologic and anthropogenic forms” by Zbigniew J. Fajklewicz (GEOPHYSICS, October 1976, p. 1016–1030)

Geophysics ◽  
1977 ◽  
Vol 42 (5) ◽  
pp. 1066-1067
Author(s):  
Avner A. Arzi
Keyword(s):  
Ground Surface ◽  
Vertical Gradient ◽  
Powerful Method ◽  
Gravity Measurements ◽  
The Difference ◽  
Gradient Measurements ◽  
Tower Height

Microgravimetry is indeed a powerful method for the detection of many small geologic and anthropogenic bodies (Arzi, 1975). Fajklewicz essentially advocates a particular procedure for microgravimetric surveys. Whereas gravity measurements are usually performed at the ground surface, Fajklewicz simultaneously performs measurements also at a surface situated 3 m above ground, using a portable tower. His data are presented as a map of the difference between the bottom and the top measurements. This difference (which may be measured in gradient units after being divided by the tower height) is called the Gravity Tower Vertical Gradient (GTVG). Similar procedures have been occasionally employed for various purposes (Thyssen‐Bornemisza, 1976). My main comments on the paper by Fajklewicz are as follows.

On: “Gravity Vertical Gradient Measurements for the Detection of Small Geologic and Anthropogenic Forms” by Z. J. Fajklewicz (GEOPHYSICS, October 1976, p. 1016–1030)

Geophysics ◽  
1977 ◽  
Vol 42 (7) ◽  
pp. 1484-1485
Author(s):  
Zofia Mortimer
Keyword(s):  
Vertical Gradient ◽  
Density Contrast ◽  
Mine Workings ◽  
Gradient Measurements

In his paper Fajklewicz discusses the use of the gravity tower vertical gradient [Formula: see text] for the detection of small, shallow bodies that show a density contrast with the surroundings (geologic structures, caverns and old mine workings). The reasons given by the author for such application of [Formula: see text] are the properties of the gravity vertical gradient and the vast experience of many years.

Isatin: A Scaffold with Innumerable Biodiversity

2020 ◽  
Vol 20 ◽  
Author(s):  
Priyobrata Nath ◽  
Agnish Mukherjee ◽  
Sougata Mukherjee ◽  
Sabyasachi Banerjee ◽  
Samarpita Das ◽  
...  
Keyword(s):  
Biological Effects ◽  
Scientific Information ◽  
Research Work ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Biologically Relevant ◽  
Extensive Information ◽  
Relevant Compound ◽  
A Minor ◽  
Clinical Conditions

: Isatin is an endogenous and a significant category of fused heterocyclic component, widely been a part of several potential biologically useful synthetics. Since its discovery, tons of research work has been conducted with respect to the synthesis, chemical properties, and biological and industrial applications. It contains indole nucleus having both lactam and keto moiety which while being a part of a molecular framework exerted several biological effects, viz.; antimicrobial, antitubercular, anticonvulsant, anticancer etc. Isatin derivatives are synthetically significant substrates, which can be utilized for the synthesis of huge diversified chemical entities of which few members emerged to be a drug. The reason for this review is to provide extensive information pertaining to the chemistry and its significance in altering several pathological states of isatin and its derivatives. A Structure Activity Relationships study thus developed through a gamut of scientific information indicates the importance of mostly electron withdrawing groups, halogens, nitro, alkoxy and to a minor extent groups with positive inductive effects, such as methyl at position 1, 5, 6 and 7 of isatin in alleviating several clinical conditions. It is also observed from the survey that the presence of two oxo groups at position 2 and 3 sometimes become insignificant as fusion with a heterocycle at those position resulted in a biologically relevant compound.

Study of pumping effect in flow-through electrolysers

1983 ◽  
Vol 48 (8) ◽  
pp. 2232-2248 ◽  
Author(s):  
Ivo Roušar ◽  
Michal Provazník ◽  
Pavel Stuhl
Keyword(s):  
Natural Convection ◽  
Balance Equation ◽  
Volume Fraction ◽  
Industrial Applications ◽  
Pumping Effect ◽  
Flow Through ◽  
The Mean ◽  
The Difference

In electrolysers with recirculation, where a gas is evolved, the pumping of electrolyte from a lower to a higher level can be effected by natural convection due to the difference between the densities of the inlet electrolyte and the gaseous emulsion at the outlet. An accurate balance equation for calculation of the rate of flow of the pumped liquid is derived. An equation for the calculation of the mean volume fraction of bubbles in the space between the electrodes is proposed and verified experimentally on a pilot electrolyser. Two examples of industrial applications are presented.

scholarly journals Comparison of Fracture Resistance in Thermal and Self-Curing Acrylic Resins—An In Vitro Study

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1234
Author(s):  
António Sérgio Silva ◽  
Aurora Carvalho ◽  
Pedro Barreiros ◽  
Juliana de Sá ◽  
Carlos Aroso ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
Research Work ◽  
Testing Machine ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Thermosetting Resins ◽  
Acrylic Resins ◽  
The Difference

Thermal and self-curing acrylic resins are frequently and versatilely used in dental medicine since they are biocompatible, have no flavor or odor, have satisfactory thermal qualities and polishing capacity, and are easy and fast. Thus, given their widespread use, their fracture resistance behavior is especially important. In this research work, we comparatively analyzed the fracture resistance capacity of thermo and self-curing acrylic resins in vitro. Materials and Methods: Five prosthesis bases were created for each of the following acrylic resins: Lucitone®, ProBase®, and Megacryl®, which were submitted to different forces through the use of the CS® Dental Testing Machine, usually mobilized in the context of fatigue tests. To this end, a point was defined in the center of the anterior edge of the aforementioned acrylic resin bases, for which the peak tended until a fracture occurred. Thermosetting resins were, on average, more resistant to fracture than self-curable resins, although the difference was not statistically significant. The thermosetting resins of the Lucitone® and Probase® brands demonstrated behavior that was more resistant to fracture than the self-curing homologues, although the difference was not statistically significant. Thermosetting resins tended to be, on average, more resistant to fracture and exhibited the maximum values for impact strength, compressive strength, tensile strength, hardness, and dimensional accuracy than self-curing resins, regardless of brand.

scholarly journals Construction of new solitary wave solutions of generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony and simplified modified form of Camassa-Holm equations

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 896-909 ◽  
Author(s):  
Dianchen Lu ◽  
Aly R. Seadawy ◽  
Mujahid Iqbal
Keyword(s):  
Solitary Wave ◽  
Nonlinear Partial Differential Equations ◽  
Research Work ◽  
Traveling Wave Solutions ◽  
Elliptic Functions ◽  
Mapping Method ◽  
New Method ◽  
Auxiliary Equation ◽  
Solitary Wave Solutions ◽  
Wave Solutions

AbstractIn this research work, for the first time we introduced and described the new method, which is modified extended auxiliary equation mapping method. We investigated the new exact traveling and families of solitary wave solutions of two well-known nonlinear evaluation equations, which are generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony and simplified modified forms of Camassa-Holm equations. We used a new technique and we successfully obtained the new families of solitary wave solutions. As a result, these new solutions are obtained in the form of elliptic functions, trigonometric functions, kink and antikink solitons, bright and dark solitons, periodic solitary wave and traveling wave solutions. These new solutions show the power and fruitfulness of this new method. We can solve other nonlinear partial differential equations with the use of this method.

Development and Achievements of SSM Processes for High Performance Components

2016 ◽  
Vol 256 ◽  
pp. 319-327 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Ivano Gattelli
Keyword(s):  
Industrial Development ◽  
High Performance ◽  
Rear Axle ◽  
Research Work ◽  
Industrial Applications ◽  
Alternative Methods ◽  
Front Suspension ◽  
Large Numbers ◽  
Automotive Parts ◽  
High Level

During the last decades under the enthusiastic and competent guidance of Mr Chiarmetta SSM processes attained in Italy at Stampal Spa (Torino) an unquestionable high level of industrial development with the production of large numbers of high performance automotive parts, like variety of suspension support, engine suspension mounts, steering knuckle, front suspension wheel, arm and rear axle. Among the most highlighted findings SSM processes demonstrated their capability to reduce the existing gap between casting and forging, moreover during such a processes there are the opportunity to better control the defect level.Purpose of this paper is to highlight the research work and the SSM industrial production attained and developed by Mr G.L. Chiarmetta, as well as to give an overview concerning some alternative methods for the production of enhanced performance light alloys components for critical industrial applications and to present an analysis of a new rheocasting process suitable for the manufacturing of high performance industrial components.

Remaining useful life estimation based on the joint use of an observer and a hidden Markov model

2021 ◽  
pp. 1748006X2110443
Author(s):  
Toufik Aggab ◽  
Pascal Vrignat ◽  
Manuel Avila ◽  
Frédéric Kratz
Keyword(s):  
Markov Models ◽  
Hidden Markov ◽  
Practical Interest ◽  
Markov Property ◽  
Rolling Bearing ◽  
Industrial Applications ◽  
Remaining Useful Life ◽  
Discrete Observations ◽  
Useful Life ◽  
The Difference

We propose an approach for failure prognosis based on the estimation of the Remaining Useful Life (RUL) of a system in a situation in which monitoring signals providing information about its degradation evolution are not measured and no operating model of the system is available. These conditions are of practical interest for industrial applications such as mechanical (e.g. rolling bearing) or electrical (e.g. wind turbine) devices or equipment-critical components (e.g. batteries) in which the addition of sensors to the system is not feasible (e.g. space limitations for sensors, cost, etc.). The approach is based on an estimation of the system degradation using residual generation (where the difference between the system and the observer outputs is processed) and Hidden Markov Models with discrete observations. The prediction of the system RUL is given by the Markov property concerning the mean time before absorption. The approach comprises two phases: a training phase to model the degradation behavior and an “on-line” use phase to estimate the remaining life of the system. Two case studies were conducted for RUL prediction to verify the effectiveness of the proposed approach.

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