2.4 Modern mine planning

Once the geological data gathered during the exploration phase has been evaluated, geologists will estimate the quality and quantity of coal present. Coal reserves (in tonnes) are calculated from volume × density (Section 5). The volume of coal is controlled by seam area and seam thickness.

Hence:

tonnage = seam area × se
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1.1 Introduction

There are many environmental reasons why coal is a rather undesirable source of energy. Burning it introduces large amounts of gases into the atmosphere that harm the environment in a variety of ways, as well as other, solid waste products. Coal extraction leads to spoil heaps and mines that scar the landscape, land subsidence that affects roads and buildings, and in some cases water pollution.

With apparently so little going for it, why do we rely so much on coal to meet our energy nee
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2.6 Underground mining

Coal extraction is of course less straightforward using underground mining techniques. The associated costs are higher, and these begin with the sinking of two shafts, an 'upcast' and a 'downcast' shaft for ventilation (Figure 22). Sinking these to a depth of a kilometre may take a few years and during this time,
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Learning outcomes

After studying this course, you should be able to:

  • explain the principles that underlie the ability of various natural phenomena to deliver solar energy

  • outline the technologies that are used to harness the power of solar energy

  • discuss the positive and negative aspects of solar energy in relation to natural and human aspects of the environment.


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Supporters of traditional marriage rally in Washington
Thousands who support traditional marriage gathered in front of the U.S. Capitol to march to the Supreme Court ahead of this week's hearing on gay marriage. Rough Cut (no reporter narration). Subscribe: http://smarturl.it/reuterssubscribe More updates and breaking news: http://smarturl.it/BreakingNews Reuters tells the world's stories like no one else. As the largest international multimedia news provider, Reuters provides coverage around the globe and across topics including business, financi
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1.1 How has the human population grown?

For most of human history there have been relatively few people in the world. Figure 2 shows that only over the last 50 years have numbers really shot up, and that, at the turn of the century, the population reached over six billion.

Figure 2Author(s): The Open University

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時計台サロン「未来を創る北大農学の使命」の映像を公開しました。Podcast
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International dream comes true for Blair composition major
Vanderbilt sophomore Jacob Beranek loves music and his Czech heritage. These passions recently converged in an incredible opportunity for the talented music composition major.
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References

Huse, M. and Kuriyan, J. (2002) The conformational plasticity of protein kinases, Cell, 109, pp. 275–282.
Lipscomb, W. N., Reeke, G. N. Jr, Hartsuck, J. A., Quiocho, F. A. and Bethge, P. H. (1970) The structure of carboxypeptidase A. 8. Atomic interpretation at 0.2 nm resolution, a new study of the complex of glycyl-L-tyrosine with CPA, and mechanistic deduction
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2 High- to medium-enthalpy steam fields

When the geothermal gradient heats water above the temperature at which it boils at atmospheric pressure, at a depth accessible to drilling, conditions can favour using natural geothermal steam to generate electricity. Typically, the pressure can be several tens to hundreds of times that of the atmosphere. Even at 200 °C, high pressure can ensure that much of the fluid in a geothermally heated aquifer remains in the liquid state. Author(s): The Open University

6 Permeability

It is important to distinguish clearly between porosity and permeability. Porosity is a measure of how much water can be stored in a rock, whereas permeability is a measure of the properties of a rock which determine how easily water and other fluids can flow through it (see Section 4). Permeability depends on the extent to which p
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5.3 The redshift of the 3 K radiation

The temperature, T, of the radiation is proportional to the most probable photon energy, E, which as we have said is proportional to f, and hence inversely proportional to the wavelength λ. Thus,

According to Equation 1, we have for the
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2.2 Winning coal in former times

Coal was probably first used as a fuel by early Chinese civilizations, and there is evidence for coal working in the UK since Roman times. However, early approaches to mining were limited by the available technology, and left much of the coal behind.

At first, coal was dug from seams exposed at the surface in shallow excavations into valley sides that followed the coal seam. The amount of coal that could be extracted from these trenches and from adits (short horizontal tunnels) w
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7.5 Summary of Section 7

  1. Site-directed mutagenesis is an important technique for studying protein function. Using recombinant DNA technology, selected amino acids can be substituted with different residues to alter the structure and function of a protein. One widely used method employs primer extension. SDM studies can help identify residues that are critical for interactions or catalytic activity.

  2. Protein–protein interactions can be studied in a number of different
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Conclusion

  1. Eutrophication is a process in which an ecosystem accumulates mineral nutrients. It can occur naturally, but is usually associated with human activity that releases nutrients into the environment.

  2. Anthropogenic eutrophication has caused a widespread loss of biodiversity in many systems. Recent attempts to reverse the process are proving difficult and expensive.

  3. Symptoms of eutrophication are most readily seen in aquatic systems,
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Sargassum Fish
The sargassum fish can camouflage itself to look exactly like a sargassum plant and ambush unsuspecting prey with deadly ease. See these fish in action as well as learn information about them. The video can be used with a lesson on animal defenses and adaptations, specifically camouflage, protective resemblance, and mimicry. Run time 01:42.
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RVC 25 - The Role of Mitochondria in Health and Disease
Mitochondria are cell organelles which play a critical role in energy supply in most higher organisms. But how did that role develop and how do they achieve this function? In the latest episode of the RVC Podcast Dr Michelangelo Campanella discusses these questions and relates his research findings on how poor mitochondrial function can contribute greatly to disease processes.
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5.9 Membrane filtration

Membrane filtration is a process whereby particles smaller than about 10−2 mm (which can pass through sand filters) are removed using synthetic polymeric membranes and a high pressure. The membrane effectively acts as a sieve.

It is increasingly becoming popular as an advanced treatment process for water (especially for removal of Cryptosporidium) and wastewater (where water reuse takes place), and various possibilities are:

  • <
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7.340 Immune Evasion: How Sneaky Pathogens Avoid Host Surveillance (MIT)
Every infection consists of a battle between the invading pathogen and the resisting host. To be successful, a pathogen must escape the many defenses of the host immune system until it can replicate and spread to another host. A pathogen must prevent one of three stages of immune function: detection, activation, or effector function. Examples of disease-specific immune evasion and the mechanisms used by pathogens to prevail over their hosts' immune systems are discussed. Also considered is what
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Content within individual OCW courses is (c) by the individual authors unless otherwise noted. MIT OpenCourseWare materials are licensed by the Massachusetts Institute of Technology under a Creative C

An Implementation Brief: Evaluation of an Android-based mHealth System for Population Surveillance i
By: Jamia Presented by Zeshan A. Rajput
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