NUMERICAL RESISTIVITY INTERPRETATION: GENERAL INHOMOGENEITY

Geophysics ◽  
1960 ◽  
Vol 25 (6) ◽  
pp. 1184-1194 ◽  
Author(s):  
K. Vozoff
Keyword(s):  
Linear Approximation ◽  
Arbitrary Function ◽  
Apparent Resistivity ◽  
Current Source ◽  
Resistivity Data ◽  
Resistivity Method ◽  
The Earth ◽  
Local Current ◽  
The Individual

A linear approximation is developed for the equation of conduction in a medium where resistivity is an arbitrary function of x, y, and z. This is applied by assuming the earth to be subdivided into small, homogeneous blocks of arbitrary resistivity. Under this approximation, the apparent resistivity is just the sum of the effects of the individual blocks. The equations are linear, and surface apparent resistivity data can be inverted to yield block resistivities. The quality of the approximation has been checked by comparison with model measurements in two situations: remote current source (telluric method), and local current source (resistivity method). It was found that the results are satisfactory provided that the proper type of expression is used for the effect of the resistivity contrast of each block.

THE USE OF CUMULATIVE RESISTANCE IN EARTH-RESISTIVITY SURVEYS

1945 ◽  
Vol 23a (4) ◽  
pp. 57-72 ◽  
Author(s):  
R. Ruedy
Keyword(s):  
Apparent Resistivity ◽  
Middle Layer ◽  
The Other ◽  
Electrode Spacing ◽  
Line Graphs ◽  
Earth Resistivity ◽  
The Earth ◽  
Straight Line ◽  
The Individual

When the soil is assumed to consist of two layers—the upper of resistivity ρ1 and the lower of resistivity ρ2—and cumulative resistances are calculated by adding or integrating the earth-resistivity functions for intervals that are a fraction of the thickness of the upper layer, a practically linear relation is obtained between the cumulative resistance and the electrode spacing until the distance between the electrodes is equal to the thickness of the upper material. Should one of the materials be at least twice as conducting as the other, the extent of the deviation from the linear law enables the determination of the depth of the upper stratum and of the ratio between the resistivities of the two layers. When three layers are present and the middle layer is at least twice as thick as the top stratum, the thicknesses may be deduced from the two departures of the cumulative resistances from the linear law. Since these conclusions are based on the theory of the individual apparent resistivity of stratified ground at various electrode spacings, they have the same range of application as the earth-resistivity curves, but the occurrence of straight line graphs facilitates the plotting and the interpretation of results based on a necessarily limited number of measurements.

scholarly journals Nacrt ekološke duhovnosti prema enciklici Laudato sì pape Franje

2019 ◽  
Vol 54 (3) ◽  
pp. 397-412
Author(s):  
Mladen Parlov
Keyword(s):  
Quality Of Life ◽  
Ecological Awareness ◽  
The Earth ◽  
Visible Matter ◽  
The Family ◽  
The World ◽  
Ecological Spirituality ◽  
The Individual ◽  
Internal Balance

In the wake of the Pope Francis' encyclical Laudato sì which talks about the Earth as a common home of all people, the author offers a draft of ecological spirituality. The beginning of true eco-spirituality is ecological conversion, which is nothing else but a renewed consciousness that from our faith and encounter with Jesus Christ we also ought to change our relationship with the world around us. Ecological conversion should help the faithful to repeatedly and correctly develop their awareness of having been created, of their own immersion into the world of creatures with which they are interconnected. Correct ecological attitude leads to internal balance of the man himself, to solidarity with others, to natural balance of all living beings and to spiritual balance with God. Ecological awareness can help not only to preserve the environment, which is one of the basic goals, but also to change the way of behaviour, which can raise the quality of life of both the individual and the family. Ecological spirituality understands and lives the sacraments in a new way, as a means of salvation and sanctification, because in the sacraments God uses the visible matter in order to communicate his (invisible) grace. Eco-spirituality calls for upbringing and adopting new attitudes in the lives of contemporary Christians which need to help them to properly treat the created world.

scholarly journals A Resistivity Survey of Phosphate Nodules in Oshoshun, Southwestern Nigeria

2018 ◽  
Vol 65 (2) ◽  
pp. 103-114 ◽  
Author(s):  
Oluseun Adetola Sanuade ◽  
Abayomi Adesola Olaojo ◽  
Adesoji Olumayowa Akanji ◽  
Michael Adeyinka Oladunjoye ◽  
Gabriel E. Omolaiye
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Inversion Algorithm ◽  
Clayey Sand ◽  
Southwestern Nigeria ◽  
Resistivity Data ◽  
Resistivity Method ◽  
Dahomey Basin ◽  
Geophysical Study ◽  
Electrical Resistivity Method

Abstract This geophysical study was carried out to determine the occurrence of phosphate nodules in the Oshoshun Formation of the Dahomey Basin, Southwestern Nigeria. The electrical resistivity method, comprising 1D vertical electrical sounding (VES; using Schlumberger array) and 2D geoelectrical imaging (using Wenner array), was used to determine the nature and depth of occurrence of the phosphate nodules. Six profile lines were established within the study area, and inverted sections were generated from the apparent resistivity data using DIPRO inversion algorithm. Five VES points were also acquired in the study area, and Win- Resist programme was used to process and interpret the field resistivity data. Four pits were dug along the profiles to verify the interpreted results. The results obtained by both techniques reveal similar geoelectric units: the top soil, clay, clayey sand and clay at different depths. These layers host pockets of phosphate nodules (78-≥651 Ωm) with varying thicknesses. The strong correlation between the lithology profiles obtained from the pits and the interpreted results of the inverted apparent resistivity sections demonstrates the efficacy of the electrical resistivity method in characterising phosphate occurrence within the formation.

scholarly journals Uncertainty of the 2D Resistivity Survey on the Subsurface Cavities

2021 ◽  
Vol 11 (7) ◽  
pp. 3143
Author(s):  
Yonatan Garkebo Doyoro ◽  
Ping-Yu Chang ◽  
Jordi Mahardika Puntu
Keyword(s):  
High Sensitivity ◽  
Two Dimensional ◽  
Model Resolution ◽  
Resistivity Data ◽  
Resistivity Method ◽  
Resistivity Model ◽  
Measured Resistivity ◽  
2D Resistivity ◽  
Subsurface Cavities

We examined the uncertainty of the two-dimensional (2D) resistivity method using conceptual cavity models. The experimental cavity study was conducted to validate numerical model results. Spatial resolution and sensitivity to resistivity perturbations were also assessed using checkerboard tests. Conceptual models were simulated to generate synthetic resistivity data for dipole-dipole (DD), pole-dipole (PD), Wenner–Schlumberger (WS), and pole-pole (PP) arrays. The synthetically measured resistivity data were inverted to obtain the geoelectric models. The highest anomaly effect (1.46) and variance (24,400 Ω·m) in resistivity data were recovered by the DD array, whereas the PP array obtained the lowest anomaly effect (0.60) and variance (2401 Ω·m) for the shallowest target cavity set at 2.2 m depth. The anomaly effect and variance showed direct dependency on the quality of the inverted models. The DD array provided the highest model resolution that shows relatively distinct anomaly geometries. In contrast, the PD and WS arrays recovered good resolutions, but it is challenging to determine the correct anomaly geometries with them. The PP array reproduced the lowest resolution with less precise anomaly geometries. Moreover, all the tested arrays showed high sensitivity to the resistivity contrasts at shallow depth. The DD and WS arrays displayed the higher sensitivity to the resistivity perturbations compared to the PD and PP arrays. The inverted models showed a reduction in sensitivity, model resolution, and accuracy at deeper depths, creating ambiguity in resistivity model interpretations. Despite these uncertainties, our modeling specified that two-dimensional resistivity imaging is a potential technique to study subsurface cavities. We inferred that the DD array is the most appropriate for cavity surveys. The PD and WS arrays are adequate, while the PP array is the least suitable for cavity studies.

INTERPRETATION OF BURIED ELECTRODE RESISTIVITY DATA USING A LAYERED EARTH MODEL

Geophysics ◽  
1978 ◽  
Vol 43 (5) ◽  
pp. 988-1001 ◽  
Author(s):  
Jeffrey J. Daniels
Keyword(s):  
Direct Current ◽  
Field Data ◽  
Apparent Resistivity ◽  
Current Source ◽  
Well Logs ◽  
Earth Model ◽  
Layered Earth ◽  
Resistivity Data ◽  
True Resistivity ◽  
Resistivity Logging

The layered earth model is a fundamental interpretation aid for direct current resistivity data. This paper presents a solution for the layered earth problem for a buried current source and a buried receiver. The model is developed for source and receiver electrodes buried anywhere within a horizontally stratified layered earth containing an arbitrary number of resistivity layers. Model results for the normal well‐logging array indicate that large departures between true and apparent resistivity can be caused by thin beds or highly resistant layers. A true resistivity distribution from well logs can be established by modeling when the effects from borehole rugosity and fluid resistivity are negligible. The equations derived for resistivity well logs can be used to interpret hole‐to‐hole, hole‐to‐surface, and conventional surface array data. A field example demonstrates that deviations between hole‐to‐hole field data and model results, based on well logs in the receiver hole, can be accounted for by combining the resistivity logging models in the receiver holes with information from geologic logs. Differences between the field data and the layered‐model results are attributed to lateral changes between or near the source and receiver holes.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

Geographical aspects of the diffusion of passive houses

2013 ◽  
Vol 4 (2) ◽  
pp. 151-156 ◽  
Author(s):  
G. Kozma ◽  
E. Molnár ◽  
K. Czimre ◽  
J. Pénzes
Keyword(s):  
Energy Consumption ◽  
Energy Resources ◽  
Substantial Part ◽  
Renewable Energy Resources ◽  
Passive House ◽  
The Earth ◽  
Passive Houses ◽  
The Individual ◽  
Geographical Locations ◽  
Over Time

Abstract In our days, energy issues belong to the most important problems facing the Earth and the solution may be expected partly from decreasing the amount of the energy used and partly from the increased utilisation of renewable energy resources. A substantial part of energy consumption is related to buildings and includes, inter alia, the use for cooling/heating, lighting and cooking purposes. In the view of the above, special attention has been paid to minimising the energy consumption of buildings since the late 1980s. Within the framework of that, the passive house was created, a building in which the thermal comfort can be achieved solely by postheating or postcooling of the fresh air mass without a need for recirculated air. The aim of the paper is to study the changes in the construction of passive houses over time. In addition, the differences between the geographical locations and the observable peculiarities with regard to the individual building types are also presented.

Manageable Self in the Early Hellenistic Era

2010 ◽  
Vol 39 (2) ◽  
pp. 34-36
Author(s):  
Vaia Touna
Keyword(s):  
Social Economic ◽  
Ancient Greece ◽  
The Self ◽  
Hellenistic Period ◽  
Political Conditions ◽  
The Individual

This paper argues that the rise of what is commonly termed "personal religion" during the Classic-Hellenistic period is not the result of an inner need or even quality of the self, as often argued by those who see in ancient Greece foreshadowing of Christianity, but rather was the result of social, economic, and political conditions that made it possible for Hellenistic Greeks to redefine the perception of the individual and its relationship to others.

Reflecting the Sky in Water

2017 ◽  
Vol 3 (1) ◽  
pp. 112-126 ◽  
Author(s):  
Ilaria Cristofaro
Keyword(s):  
The Unconscious ◽  
Related Case ◽  
Quality Of Water ◽  
Fluid Properties ◽  
Phenomenological Perspective ◽  
Auto Ethnography ◽  
The Individual ◽  
Artificial Water ◽  
Land Water

From a phenomenological perspective, the reflective quality of water has a visually dramatic impact, especially when combined with the light of celestial phenomena. However, the possible presence of water as a means for reflecting the sky is often undervalued when interpreting archaeoastronomical sites. From artificial water spaces, such as ditches, huacas and wells to natural ones such as rivers, lakes and puddles, water spaces add a layer of interacting reflections to landscapes. In the cosmological understanding of skyscapes and waterscapes, a cross-cultural metaphorical association between water spaces and the underworld is often revealed. In this research, water-skyscapes are explored through the practice of auto-ethnography and reflexive phenomenology. The mirroring of the sky in water opens up themes such as the continuity, delimitation and manipulation of sky phenomena on land: water spaces act as a continuation of the sky on earth; depending on water spaces’ spatial extension, selected celestial phenomena can be periodically reflected within architectures, so as to make the heavenly dimension easily accessible and a possible object of manipulation. Water-skyscapes appear as specular worlds, where water spaces are assumed to be doorways to the inner reality of the unconscious. The fluid properties of water have the visual effect of dissipating borders, of merging shapes, and, therefore, of dissolving identities; in the inner landscape, this process may represent symbolic death experiences and rituals of initiation, where the annihilation of the individual allows the creative process of a new life cycle. These contextually generalisable results aim to inspire new perspectives on sky-and-water related case studies and give value to the practice of reflexive phenomenology as crucial method of research.

QUALITY OF INDIVIDUAL AND GROUP LEVEL INTERVENTIONS FOR FIRST EPISODE PSYCHOSIS AT THE TERTIARY PSYCHIATRIC HOSPITAL IN UGANDA.

2020 ◽  
Author(s):  
Emmanuel Kiiza Mwesiga ◽  
Noeline Nakasujja ◽  
Lawrence Nankaba ◽  
Juliet Nakku ◽  
Seggane Musisi
Keyword(s):  
Psychiatric Hospital ◽  
Psychotic Disorders ◽  
First Episode Psychosis ◽  
First Episode ◽  
Group Level ◽  
Group Interventions ◽  
Episode Psychosis ◽  
Essential Components ◽  
The Individual

Introduction: Individual and group level interventions have the largest effect on outcomes in patients with the first episode of psychosis. The quality of these individual and group level interventions provided to first-episode psychosis patients in Uganda is unclear.Methods: The study was performed at Butabika National Psychiatric Teaching and referral hospital in Uganda. A retrospective chart review of recently discharged adult in-patients with the first episode of psychosis was first performed to determine the proportion of participants who received the different essential components for individual and group level interventions. From the different proportions, the quality of the services across the individual and group interventions was determined using the first-Episode Psychosis Services Fidelity Scale (FEPS-FS). The FEPS-FS assigns a grade of 1-5 on a Likert scale depending on the proportion of patients received the different components of the intervention. Results: The final sample included 156 first-episode psychosis patients. The median age was 27 years [IOR (24-36)] with 55% of participants of the female gender. 13 essential components across the individual and group interventions were assessed and their quality quantified. All 13 essential components had poor quality with the range of scores on the FEPS-FS of 1-3. Only one essential component assessed (use of single antipsychotics) had moderate quality.Discussion: Among current services at the National psychiatric hospital of Uganda, the essential for individual and group level interventions for psychotic disorders are of low quality. Further studies are required on how the quality of these interventions can be improved.

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