Determine Coverlay Thickness According to Air Leakage Characteristics in Open Pit to Underground Overlay

2012 ◽  
Vol 567 ◽  
pp. 88-91
Author(s):  
Chen Chao ◽  
De Qing Gan ◽  
Ling Qi Zhu ◽  
Ya Bin Zhang ◽  
Hong Jian Lu

During surface-underground combined mining, the method to control the ground air leakage is adopted by the capping layer using the fragmented rocks and the discarded tailings. In order to study the air leakage characteristic with the capping, the porosity of the rock particles of seven sizes and the air leakage characteristics of the capping were studied and the relationship between the air leakage coefficient and amount of air leakage with the capping height were found basing on the laboratory analogue simulation tests. It can provide the theoretical basis for determining the capping height of iron mine.

2012 ◽  
Vol 594-597 ◽  
pp. 2323-2330
Author(s):  
Cui Feng Du ◽  
Bin Li

The gas seepage characteristics of four kinds of broken rocks of different gradations and the relationship between the capping height and the porosity were studied by means of the simulation experiment and the theoretical analysis. The results show that the air flow in the capping layer composed of broken rocks is in the non-Darcy state which can be described as Forchheimer equation and Ergun equation. Moreover, on the basis of the experimental data, the relational expressions between the permeability, the non-Darcy β factor and the porosity were determined. Through the numerical fitting, the equation of the minimum capping height and the porosity was ultimately derived, which provided the basis and the reference for the determination of capping height and the air leakage control of mine.


1993 ◽  
Vol 2 (3) ◽  
pp. 52-55 ◽  
Author(s):  
Michael Collins ◽  
Robert McDonald ◽  
Robert Stanley ◽  
Timothy Donovan ◽  
C. Frank Bonebrake

This report describes an unusual and persistent dysphonia in two young women who had taken a therapeutic regimen of isotretinoin for intractable acne. We report perceptual and instrumental data for their dysphonia, and pose a theoretical basis for the relationship of dysphonia to this drug. We also provide recommendations for reducing the risk of acquiring a dysphonia during the course of treatment with isotretinoin.


Author(s):  
V. Tusheva

The determinants of value orientations of a teacher of higher artistic education are identified, qualitative and instrumental properties of a teacher’s consciousness are determined, the relationship between value and sense-bearing processes at the level of cultural and personal senses and outlook priorities correlated with the main messages of postnonclassical science are revealed in the article on the bases of humanistic personally oriented paradigm. Different vectors of deployment of consciousness (self-consciousness) as a teacher’s personal formation in artistic education are considered, the positions which lay the theoretical basis for the development of value and sense-oriented learning, its multicultural, pedagogical and individual-personal contexts are formulated.


2021 ◽  
pp. 106591292110072
Author(s):  
Michael Tesler

This article argues that the unusually large and persistent association between Islamophobia and opposition to President Obama helped make attitudes about Muslims a significant, independent predictor of Americans’ broader partisan preferences. After detailing the theoretical basis for this argument, the article marshals repeated cross-sectional data, two panel surveys, and a nationally representative survey experiment, to test its hypotheses. The results from those analyses show the following: (1) attitudes about Muslims were a significantly stronger independent predictor of voter preferences for congress in 2010–2014 elections than they were in 2004–2008; (2) attitudes about Muslims were a significantly stronger independent predictor of mass partisanship during Obama’s presidency than they were beforehand; and (3) experimentally connecting Obama to Democratic congressional candidates significantly increased the relationship between anti-Muslim sentiments and Americans’ preferences for Republican congressional candidates. The article concludes with a discussion of the implications of these results for American politics in the Trump era.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dexin Shen ◽  
Lingao Ju ◽  
Fenfang Zhou ◽  
Mengxue Yu ◽  
Haoli Ma ◽  
...  

AbstractProstate cancer (PCa) is one of the most commonly diagnosed human cancers in males. Nearly 191,930 new cases and 33,330 new deaths of PCa are estimated in 2020. Androgen and androgen receptor pathways played essential roles in the pathogenesis of PCa. Androgen depletion therapy is the most used therapies for primary PCa patients. However, due to the high relapse and mortality of PCa, developing novel noninvasive therapies have become the focus of research. Melatonin is an indole-like neurohormone mainly produced in the human pineal gland with a prominent anti-oxidant property. The anti-tumor ability of melatonin has been substantially confirmed and several related articles have also reported the inhibitory effect of melatonin on PCa, while reviews of this inhibitory effect of melatonin on PCa in recent 10 years are absent. Therefore, we systematically discuss the relationship between melatonin disruption and the risk of PCa, the mechanism of how melatonin inhibited PCa, and the synergistic benefits of melatonin and other drugs to summarize current understandings about the function of melatonin in suppressing human prostate cancer. We also raise several unsolved issues that need to be resolved to translate currently non-clinical trials of melatonin for clinic use. We hope this literature review could provide a solid theoretical basis for the future utilization of melatonin in preventing, diagnosing and treating human prostate cancer.


SAGE Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 215824402110095
Author(s):  
Jakub Dostál

The economic value of volunteering is an increasingly important part of volunteering management. It has become part of public policies. Some requests for proposals (RFP) enable nonprofits to include the value of volunteer time in compulsory co-financing. These RFP include the European Economic Area (EEA) Grants and Norway Grants. This article addresses the relationship in the value of volunteering, also called in-kind volunteering contributions. The research includes two case studies of finances from EEA and Norway Grants in the Czech Republic: the Czech NGO Programme, responsible for allocating grants between 2009 and 2014, and the Active Citizens Fund, responsible for allocating grants between 2014 and 2021. They share elements through the EEA and Norway Grants rules. However, they use different types of specialist replacement wages. The article summarizes the arguments for including in-kind volunteering contributions. It presents the possible values of these contributions in the selected cases, including the relationship between the type of volunteering and the number of hours necessary to achieve these values. The article defines the theoretical basis for calculating the value of in-kind volunteer contributions and illustrates this with real examples of allocations from EEA and Norway Grants.


2012 ◽  
Vol 209-211 ◽  
pp. 23-27
Author(s):  
Gang Lv

This paper mainly discusses the important role of the Chinese ancient view –“harmony between man and nature” in modern design. It focuses on the analysis of popular concepts of “environment orientation” and “people orientation” in environmental design, and holds the view that the concept of “harmony of man and nature” makes up for the deficiencies of the first two. In dealing with the relationship between man and himself or nature, the concept of “harmony between man and nature” offers a good theoretical basis which will surely become new ethics and standard in design.


2013 ◽  
Vol 671-674 ◽  
pp. 245-250
Author(s):  
Wen Hui Tan ◽  
Ya Liang Li ◽  
Cong Cong Li

At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper,a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.


1995 ◽  
Vol 156 (1-2) ◽  
pp. 167-172 ◽  
Author(s):  
U. Greiner ◽  
W. Ramm

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7537
Author(s):  
Piotr Lis ◽  
Anna Lis

The majority of education buildings in Poland are equipped with natural (gravity) ventilation, where the air inflow depends on the level of window airtightness. A complete statistical urban population of 50 school buildings in Czestochowa have been examined. The main issue to be clarified is the answer to the following questions: Is it theoretically possible to supply enough air to meet the ventilation requirements with gravity ventilation? What is the airtightness of the windows at which it will be possible? The average technical conditions of windows in the analysed buildings were bad. However, only in the case in which high external air leakage coefficient a = 7.0 m3/(h m daPa2/3) (q100KL = 32.4912 m3/(h m) is the amount of air passing through the leaks similar to the quantitative ventilation requirements for classrooms. The quantity of air flowing from the outside through modernized windows that meet the technical requirements (a = 0.6 to 1.0 m3/(m h daPa2/3)) covers on average only about 12% and about 21% of the ventilation needs. Without installing additional vents in the rooms, or better yet, installing mechanical ventilation with heat recovery, meeting the ventilation norm requirements will be impossible.


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