5.5 Indoor pollutants

Before leaving air pollution you might reflect that many of us spend most of our time indoors where the air quality can differ from that outside the building.

Question 30

In what ways will the air be different inside a building?


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5.3 Global warming

Media attention has been such that it would be hard to have missed the fact that global warming is considered to be a ‘bad thing’. Why should this be so? What is so wrong with being a bit warmer? Anyway, is global warming really occurring and, if it is, what are the causal factors responsible for it?

Let us deal with this last question first. As we sit on a beach in summer, or in a sunny window seat in winter, we are aware of the Earth being warmed by the Sun. In fact the Earth is w
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6.2 The hierarchy of human needs

A second approach is to look at the human needs and wants from a more theoretical perspective. One such model was developed in the 1950s and 1960s by Abraham Maslow. Although it exists in many variants it is generally known as Maslow's hierarchy of human needs. In the most common interpretations it places the fundamental material needs of survival, such as food, shelter and safety at the base of a triangle, rising through social needs of belonging in human society, to
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4.4 Discussion

In this second case study, I have described two different trends in energy use by cold appliances over the last few decades. On the one hand the efficiency with which appliances use electrical energy has improved but, in spite of this, their consumption of electricity has increased significantly in recent decades. Since 2000 consumption has started to decline, probably as a result of the introduction of minimum energy standards. The trend will only continue if we demand and use the most energ
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5.4 Social bookmarks

If you find you have a long unmanageable list of favourites/bookmarks you might like to try social bookmarks as an alternative.

Activity 14 – what you need to know about social bookmarks

Read 7 things you should know about so
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4.6 P is for Provenance

The provenance of a piece of information (i.e. who produced it? where did it come from?) may provide another useful clue to its reliability. It represents the 'credentials' of a piece of information that support its status and perceived value. It is therefore very important to be able to identify the author, sponsoring body or source of your information.

Why is this important?

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4.5 M is for Method

Method is about the way in which a piece of information is produced. This is quite a complex area as different types of information are produced in different ways. These are a few suggestions to look out for:

Opinions – A lot of information is based on the opinion of individuals. They may or not be experts in their field (see P for Provenance) but the key message is to be clear that it is just an opinion and must be valued as such.

Research – You don’t have t
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Introduction

The internet provides a world of information, but how do you find what you are looking for? This unit will help you discover the meaning of information quality and teach you how to evaluate the material you come across in your study of technology. You will learn how to plan your searches effectively and be able to experiment with some of the key resources in this area.

This unit is an adapted extract from the Open University course Author(s): The Open University

5.6.3 Conformation and crystallinity

If there are key connections between the chain configuration and crystallisation, you might also expect some more subtle effects from rotation about chain bonds. After all, polymer chains must be able to twist into the regular conformation demanded for crystal structures (Figure 57(a)). And what influence will rotation have on
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Stage 2: Analysis of the existing situation (where are we now?)

Having defined and agreed on the problem, it is necessary to decide on the system in which you consider it plays a part. In practice the two stages are closely linked and the analysis of the existing system nearly always means a redefinition or refinement of the problem or opportunity. Identifying and defining the problem and the system or systems that relate to it are critical for the success of subsequent analysis.


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2.4.1 Multimode distortion

With multimode fibre, the main cause of pulses spreading is the multiple paths that signals can traverse as they travel along the fibre. This phenomenon of multimode distortion is illustrated in Figure 5.


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6.1 Articulating your appreciation of complexity

I have organized the material in this section so that you can follow the activity route shown in Figure 6.

This section is primarily concerned with what can be understood by the term complexity, and how to compare it with the ideas of difficulty and mess. To do this, you are firs
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8.3.2 Sputter etching: argon ion etching of gold

One commercial process for cutting inkjet printer nozzles uses sandblasting. Not surprisingly, the surface finish is rather poor and there are issues with particles contaminating the devices. However, it is a physical process very like this that we need if we are to achieve a vertical etch profile.

The key is directed bombardment by highly energetic particles. When processing on the microscale, these particles are not sand grains but ions accelerated towards the surface by an electric f
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Learning outcomes

After you have completed this unit you should be able to:

  • describe how to use metal–oxide–semiconductor (MOS) structures for light capture, switches and latches;

  • distinguish between CMOS and CCD strategies for image capture.


Author(s): The Open University

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2.4 Early disasters

Many of the earliest bridges were simply a wooden trestle type of construction, an efficient and easy-to-build structure, yet providing a secure and safe passage for heavy metal trains. Although we tend to associate such structures with the United States, they were in fact widely used in Britain in the early days of steam locomotion. However, they had a limited lifetime owing to rot, so were gradually replaced by wrought iron girder bridges, often laid on brick or masonry piers.

Designe
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Introduction

This unit starts by giving an overview of the two main categories of disasters: disasters of natural origin and disasters of human origin. It then analyses the Tay Bridge disaster, which was caused by mechanical failure.

Inevitably, human factors emerge as important in many major disasters. They may involve the failure by engineers, designers or managers to recognise faults in safety-critical products, or managers overriding the design team for other reasons – such as keeping to a dea
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3.1 Introduction

I've an opera here you shan't escape – on miles and miles of recording tape.

Flanders, M. and Swann, D. (1977) ‘The Song of Reproduction’ from The Songs of Michael Flanders and Donald Swann, London, Elm Tree Books and St George's Press, p. 99

Sounds, pictures, measurement data, financial statistics, personal details, etc. can all be recorded and stored on magnetic media, i.e. m
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5.5 Multiple-cause diagrams

Multiple-cause diagrams are another way of using interconnectedness to structure a complex situation. In this case, the interconnectedness is that of causation. Multiple-cause diagrams represent both sufficient and contributory cause, without making a distinction between them. Drawing multiple-cause diagrams allows for the identification of systems of causation. Such a system can be pictured as an interconnected group of events or effects; the effect is of a system that behaves
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4 Introduction

(Please refer to Reading 4: Learning to act: managing and systems practice, by Andy Lane) This unit teaches some aspects of systems thinking and practice. But what does it mean to be a systems practitioner, and is it different to being a manager? This reading attempts to answer those questions.

First, I believe a good systems practitioner will be more competent at handling complex situations, more capable of managing their working and domestic lives, and more able to learn not only how
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7.1 Some basic principles of religious studies

Remember that in Section 4 I suggested that possible reasons for studying religion could be clustered together under two broad headings:

  1. to understand the society in which we live, the culture we inherit and the wider world of which we are a part;

  2. as part of a personal quest for religious
    Author(s): The Open University

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