2.3 The Meissner effect

The second defining characteristic of a superconducting material is much less obvious than its zero electrical resistance. It was over 20 years after the discovery of superconductivity that Meissner and Ochsenfeld published a paper describing this second characteristic. They discovered that when a magnetic field is applied to a sample of tin, say, in the superconducting state, the applied field is excluded, so that B = 0 throughout its interior. This property of the superconducting s
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Introduction

This unit is from our archive and it is an adapted extract from Postgraduate research skills in science, technology, maths & computing (STM895) which is no longer in presentation. If you wish to study formally at the Open University, you may wish to explore the courses we offer in this curriculum area.

The purpose of this unit is to help those embarking on a PhD in science, technology o
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3.1 Addiction article 1

The first selected reading provides a wide ranging review of the theories associated with addiction illustrating how the subject can be investigated at a number of different levels of analysis. The second article explores one particular level further, the pharmacology of drug addiction, and asks why specific drugs are more likely to induce addictive behaviour.


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1.5 The characteristics of astronomical telescopes

Having looked at the different designs of optical telescopes and the various problems inherent in their construction, we now turn to the ways in which their performance may be characterised. We consider five main performance characteristics, each of which may be applied to both refracting telescopes and reflecting telescopes.


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1.9 Structure in the Universe

Time: 1010s to 4.2 × 1017 s (300 years to 14 billion years)

Temperature: 105 K to 2.73 K

Energy: 30 eV to 7 × 10−4eV

As the Universe cooled still further, nothing much happened for a few hundred years (between 1000 s and 1010 s). As the mean energy per particle fell below a few tens of electronvolts, so electrons began to combine with nuclei to form neutral atoms.

Gradually, as this ele
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1.8 Primordial nucleosynthesis

Time: 100 s to 1000 s

Temperature: 109 K to 3 × 108 K

Energy: 300 keV to 100 keV

As the temperature continued to decrease, protons and neutrons were able to combine to make light nuclei. This marked the beginning of the period referred to as the era of primordial nucleosynthesis (which literally means ‘making nuclei’). The first such reaction to become energetically favoured was that of a single proton and neutron comb
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1.1 A history of the Universe

In the beginning there was nothing at all. To the north and south of nothingness lay regions of fire and frost.

Snorri Sturleson, 1220 AD

The cosmos is all there is, all there ever was, and all there ever will be.

Carl Sagan, 1934–1996

The two viewpoints expressed above sum up the diffi
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6: Summary

All objects, irrespective of their mass, experience the same acceleration g when falling freely under the influence of gravity at the same point on the Earth. Close to the Earth's surface, g=9.8 m s−2. The weight of an object is the force F g due to gravity acting on the object, and for an object with mass m the weight is given by F g=mg.

If the height of an object of mass m changes by Δh, the ch
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Learning outcomes

After studying this unit you should know:

  • All objects, irrespective of their mass, experience the same acceleration g when falling freely under the influence of gravity at the same point on the Earth. The weight of an object is the force F g due to gravity acting on the object, and for an object with mass m the weight is given by F g=mg.

  • If the height of an object of mass m changes by Δh, the
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Introduction

In this unit, we describe the theory of evolution by natural selection as proposed by Charles Darwin in his book, first published in 1859, On The Origin of Species by Means of Natural Selection, or The Preservation of Favoured Races in the Struggle for Life. We will look at natural selection as Darwin did, taking inheritance for granted, but ignoring the mechanisms underlying it.

This unit is from our archive and is an adapted extracted from Discovering science (S103) whic
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7.4.2 Assumptions within models

  • recognise that theoretical models carry in-built assumptions that limit the contexts to which the theoretical models can be applied;

  • recognise that the application of theoretical models to a particular context often involves approximations concerning the phenomenon under study.


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8 Magistrates

Magistrates have been a part of the English legal system since the Justice of the Peace Act 1361. Their main role has always been in the criminal justice system. There are now over 30,000 magistrates (also known as Justices of the Peace) hearing over one million criminal cases per yea
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3.6 The law of negligence

We will now explore the law of negligence, using a Y166 family example.

Activity 4: The law of negligence

0 hours 20 minutes

Read the box below and answer the question that follows.


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3.3 Members of the UK Parliament

Before we look at what an MP does, have a go at this activity.

Activity 2: The work of a Member of the UK Parliament

0 hours 10 minutes

Take a few moments to think about what you have read s
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4.13 The disadvantages of delegated legislation

The disadvantages of delegated legislation include the following:


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4.11.2 Substantial ultra vires

This is where the delegated legislation goes beyond what Parliament intended.

In R v Secretary of State for Education and Employment, ex parte National Union of Teachers (2000) QBD, the High Court determined that an SI concerning teachers’ pay and appraisal arrangements went beyond the powers provided under the Education Act 1996. Therefore, the delegated legislation was declared to be ultra vires on substantive grounds.


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3.1 Types of Bill

Figure 7
Figure 7 The Houses of Parliament.

An Act of Parliament starts off as a Bill. A Bill is a proposal for a new piece of legislation that
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7.1 Reserved and devolved matters

As stated earlier, the UK Parliament can still legislate on reserved matters and also on devolved matters, with the agreement of the Scottish Parliament. This section looks at the law making process at Westminster. It is a very different process, which involves both the Houses of the Westminster Parliament.

An Act of the UK Parliament also starts off as a Bill, which, if approved by a majority in the House of Commons and the House of Lords, will become an Act of the Westminster Parliame
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6.7 Royal Assent

Section 32 of the Scotland Act provides that a Bill, once passed, must be submitted for Royal Assent. This is done after a period of four weeks. During that time, the Bill is subject to legal challenge by the Advocate General for Scotland, the Lord Advocate or the Attorney General, and may also be subject to an order made by the Secretary of State. The Presiding Officer may, however, submit the Bill for Royal Assent after less than four weeks if notified by all three Law Officers and the Secr
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