Petrofabric and dielectric anisotropy in rock

1982 ◽  
Vol 19 (1) ◽  
pp. 36-54 ◽  
Author(s):  
S. Nowina ◽  
D. W. Strangway

There is a systematic relationship between anisotropy in the fabric of rocks and anisotropy in their dielectric properties, although the relationship is difficult to express in any quantitative sense. In general, the dielectric constant K′, the dielectric loss K″, and the real conductivity σ′ are a maximum when measured along the lineation axis (L) of rock, and a minimum when measured along the foliation normal (F). In this study, rocks were measured both vacuum dried and with varying degrees of water present; the anisotropy of wet rocks is greater than when vacuum dried, due presumably to anisotropic distribution of water parallel to the petrofabric. The effects of water, however, can be eliminated by means of measurements in vacuum or, more simply, by heat drying the sample, and subsequent impregnation of the rock with a hydrophobic low-loss dielectric material (paraffin wax). This is particularly significant since it greatly reduces the cost and time involved in this type of study.Dielectric anisotropy is frequency dependent. It was largest at the lowest measurement frequencies (30 Hz) and diminished with increasing frequency. For this and other reasons, dielectric anisotropy in rock is attributed to Maxwell–Wagner effects, which are low frequency relaxation phenomena related to the shape, size, and dielectric anisotropy in rock, reflecting primarily the grain-shape and grain-aggregate-shape fabric.

2006 ◽  
Vol 274 (1608) ◽  
pp. 417-424 ◽  
Author(s):  
Diogo Manoel ◽  
Sara Carvalho ◽  
Patrick C Phillips ◽  
Henrique Teotónio

Within populations with mixed mating systems, selfing is expected to be favoured over outcrossing unless a countervailing process such as severe inbreeding depression is present. In this study, we consider the relationship between the expression of deleterious alleles and the maintenance of outcrossing in the nematode species, Caenorhabditis elegans . This species is characterized by an androdioecious breeding system composed of males at low frequency and self-fertilizing hermaphrodites that can only outcross via males. Here, we find that experimentally increasing the mutational load in four different isogenic wild isolates using 10 generations of Ethylmethane sulphonate (EMS) and UV irradiation mutagenesis significantly diminishes the cost of males. Males are maintained at higher frequencies in mutagenized versus non-mutagenized populations. Nevertheless, males still tend to be driven to low frequencies within isolates that are known to be prone to lose males. Further, we determine the viability effects of a single round of mutagen exposure and find that, for EMS, outcrossing overcomes the almost completely recessive and nearly lethal effects generated. We briefly interpret our results in light of current evolutionary theory of outcrossing rates.


Kybernetes ◽  
2019 ◽  
Vol 48 (9) ◽  
pp. 1989-2005
Author(s):  
Can Zhong Yao ◽  
Jie Luo

Purpose This research aims to focus on the problem of optimizing the layout of charging stations. Design/methodology/approach The authors estimate the total number of charging stations by the number of existing gas stations using clustering by fast search-and-find of density peaks (CFSFDP) algorithm. Findings This paper reveals the relationship between the distance and the population. Priority should be given to the short-distance and high-frequency travel charging needs in the city, followed by low frequency and travel, which can improve the use efficiency of the whole charging network. Originality/value First, the total number of charging stations is estimated by the number of existing gas stations. This method can fully consider the growth potential of charging vehicles instead of the traditional cars. Besides, the cost-benefit method is proposed to explore the marginal coverage distance of the city’s charging network and can be used to reveal the relationship between the distance and the population.


Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.


2017 ◽  
Vol 3 (1) ◽  
pp. 42
Author(s):  
Roshanira Che Mohd Noor ◽  
Nur Atiqah Rochin Demong

Providing a safe and healthy workplace is one of the most effective strategies in for holding down the cost of doing construction business. It was a part of the overall management system to facilitate themanagement of the occupational health and safety risk that are associated with the business of the organization. Factors affected the awareness level inclusive of safety and health conditions, dangerous working area, long wait care and services and lack of emergency communication werethe contributed factors to the awareness level for the operational level. Total of 122 incidents happened at Telekom Malaysia Berhad as compared to year 2015 only 86 cases. Thus, the main objective of this study was to determine the relationship between safety and health factors and the awareness level among operational workers.The determination of this research was to increase the awareness level among the operational level workerswho committing to safety and health environment.


2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.


2021 ◽  
pp. 1357633X2098277
Author(s):  
Molly Jacobs ◽  
Patrick M Briley ◽  
Heather Harris Wright ◽  
Charles Ellis

Introduction Few studies have reported information related to the cost-effectiveness of traditional face-to-face treatments for aphasia. The emergence and demand for telepractice approaches to aphasia treatment has resulted in an urgent need to understand the costs and cost-benefits of this approach. Methods Eighteen stroke survivors with aphasia completed community-based aphasia telerehabilitation treatment, utilizing the Language-Oriented Treatment (LOT) delivered via Webex videoconferencing program. Marginal benefits to treatment were calculated as the change in Western Aphasia Battery-Revised (WAB-R) score pre- and post-treatment and marginal cost of treatment was calculated as the relationship between change in WAB-R aphasia quotient (AQ) and the average cost per treatment. Controlling for demographic variables, Bayesian estimation evaluated the primary contributors to WAB-R change and assessed cost-effectiveness of treatment by aphasia type. Results Thirteen out of 18 participants experienced significant improvement in WAB-R AQ following telerehabilitation delivered therapy. Compared to anomic aphasia (reference group), those with conduction aphasia had relatively similar levels of improvement whereas those with Broca’s aphasia had smaller improvement. Those with global aphasia had the largest improvement. Each one-point of improvement cost between US$89 and US$864 for those who improved (mean = US$200) depending on aphasia type/severity. Discussion Individuals with severe aphasia may have the greatest gains per unit cost from treatment. Both improvement magnitude and the cost per unit of improvement were driven by aphasia type, severity and race. Economies of scale to aphasia treatment–cost may be minimized by treating a variety of types of aphasia at various levels of severity.


2021 ◽  
Vol 80 (3) ◽  
pp. 1963-1980
Author(s):  
Solomon Adomako ◽  
Christian John Engelsen ◽  
Rein Terje Thorstensen ◽  
Diego Maria Barbieri

AbstractRock aggregates constitute the enormous volume of inert construction material used around the globe. The petrologic description as igneous, sedimentary, and metamorphic types establishes the intrinsic formation pattern of the parent rock. The engineering properties of these rocks vary due to the differences in the transformation process (e.g. hydrothermal deposits) and weathering effect. The two most common mechanical tests used to investigate the performance of aggregates are the Los Angeles (LA) and micro-Deval (MD) tests. This study reviewed the geological parameters (including mineralogy, grain and crystal size, grain shape, and porosity) and the relationship to Los Angeles and micro-Deval tests. It was found that high content of primary minerals in rocks (e.g. quartz and feldspar) is a significant parameter for performance evaluation. Traces of secondary and accessory minerals also affect the performance of rocks, although in many cases it is based on the percentage. Furthermore, some studies showed that the effect of mineralogic composition on mechanical strength is not sufficient to draw final conclusions of mechanical performance; therefore, the impact of other textural characteristics should be considered. The disposition of grain size and crystal size (e.g. as result of lithification) showed that rocks composed of fine-grain textural composition of ≤ 1 mm enhanced fragmentation and wear resistance than medium and coarse grained (≥ 1 mm). The effect of grain shape was based on convex and concave shapes and flat and elongated apexes of tested samples. The equidimensional form descriptor of rocks somehow improved resistance to impact from LA than highly flat and elongated particles. Lastly, the distribution of pore space investigated by means of the saturation method mostly showed moderate (R = 0.50) to strong (R = 0.90) and positive correlations to LA and MD tests.


Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 672
Author(s):  
Bruce A. Young ◽  
Skye Greer ◽  
Michael Cramberg

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.


2021 ◽  
pp. 1-21
Author(s):  
Hsien-Long Huang ◽  
Li-Keng Cheng ◽  
Pi-Chuan Sun ◽  
Yi Shiuan Jiang ◽  
Hsin Hua Lin

Abstract The cost of recruitment and training of newcomers can be a burden for enterprises, causing adverse effects on human resources management. Although much research has addressed employee turnover, less attention has been paid to methods of improving the retention of new hires. This study is an empirical examination of the increase in predictive strength of antecedents of affective commitment for comparing newcomers’ workplace spirituality. The results of an employee survey completed by 237 newcomers with under two years of work experience indicate that socialization tactics have a direct impact on job embeddedness, which in turn has a direct effect on affective commitment. Workplace spirituality has a significant moderating effect on the relationship between socialization tactics and job embeddedness. Also, workplace spirituality has a significant moderating effect on the relationship between job embeddedness and affective commitment.


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