4.2.1 Quantifying thermal energy

Thermal energy is associated with random motion – that is, in effect, a definition. Because it is random, it only makes sense to talk about it in connection with a large population of atoms. I began with fifty million million million silicon atoms – that should be enough. If whatever motion they have is random, some may have lots of it, others very little. With such a large population it is reasonable to try to think about an average motion or, better, to define an average energy of the p
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2.4 Summary of Section 2

  • Thermometers sense temperature. They are transducers providing observable and quantifiable signals in variables other than temperature. Thermometers are calibrated to give numbers in accord with an internationally agreed scale. Various attributes influence the selection of an instrument for a task.

  • Temperature can determine the rate at which certain physical and chemical changes proceed, and whether some changes can occur at all.

  • <
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1 Temperature – problem or solution?

‘Have you taken the temperature effects into account?’ (Figure 1) is nearly always a valid question in any discussion about a proposed engineering solution. Everything has a temperature, and everything behaves differently at different temperatures. It therefore deserves its own special plac
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5.8 Plagiarism

Referencing is not only useful as a way of sharing information, but also as a means of ensuring that due credit is given to other people’s work. In the electronic information age, it is easy to copy and paste from journal articles and web pages into your own work. But if you do use someone else’s work, you should acknowledge the source by giving a correct reference.

Taking someone's work and not indicating where you took it from is termed plagiarism and is regarded as an infringemen
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5.4.2 Leadership expectations

  • Largely because of expectations created in childhood (our ‘inner child of the past’), we have many unconscious expectations of leaders, and may well harbour resentments, anxieties, suspicions, subservience, passive resistances and attitudes to leadership that have little relationship to current adult realities.

  • The leader needs to be able to manage these feelings and his or her own responses to them.

  • Leaders will tend t
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5.3.2 Style theories

Style theories are based on the assumption that it is the style of leadership that matters. The alternative styles are generally phrased in terms of ‘task centred’ or ‘person centred’; these have also been called ‘structuring’ and ‘supporting’ styles, corresponding roughly to the ‘scientific’ and ‘social relations’ styles of management.

The leadership styles are not mutually exclusive and can be represented in the form of a grid, as in Author(s): The Open University

5.2.2 Owning problems

Problem ownership is a tricky issue. It's also an issue that good leaders get right instinctively, and poor leaders get wrong consistently. The point is that there are two distinct classes of problems faced by leaders. The first consists of problems which are owned by the group members. Examples include when some additional resources are required, when instructions are not understood or when members complain that something is wrong. Under these conditions the leader's function is to provide p
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4.4.1 Task-oriented behaviours

Estimating and planning

The project manager, or someone under his or her direction, has to collect information about what exactly needs to be done and how it is to be organised; how much it will cost and how long it will take; and the interdependencies of various tasks, skills and other resources. The results are a project plan and a project budget.

Assembling a team

A project team can make or break a project. Often the project manager has little say in who
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3.2.5 Group development

Next on the list of priorities in the functioning of groups is the process of group development. One popular conception of the way in which groups ‘gel’ and become effective was first suggested by Tuckman (1965) and then extended by Tuckman and Jensen (1977). Tuckman originally identified four stages in this development process, which he named ‘forming’, ‘storming’, ‘norming’ and ‘performing’. These stages (see Author(s): The Open University

3.1 Belonging to a group

Because work groups are of central significance in the functioning of an organisation they have been studied intensively, and much has been written about group processes. In this reading it would be inappropriate to attempt to review this vast literature, which covers an enormous range of topics and aspects of groups. Instead, I focus attention here on two particular aspects of groups. First, I examine the nature of the contracts within a group: what it is that people gain from belonging to a
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2.3.5 Mixed structures

Teams often have mixed structures:

  • some members may be employed to work full time on the project and be fully responsible to the project manager. Project managers themselves are usually employed full time.

  • others may work part time, and be responsible to the project manager only during their time on the project. For example, internal staff may well work on several projects at the same time. Alternatively, an external consultant workin
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6.4.2 Manufacturing the boat

Filling the mould is a serious problem in injection moulding: the lower the MFI, the more difficult it is to push molten polymer down narrow tubes into a metal mould. The engineers at Rolinx, the trade moulders who initiated the thermoplastic project, were working at the limits of their machinery in moulding such large objects in one operation. In the event, they were forced to blend the low MFI copolymer grade with a higher MFI grade material (GY702M) in order to achieve their objective (
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4.5.2 Commercial copolymers

The main reason for copolymerizing different monomers is to adjust the physical properties of a given homopolymer to meet a specific demand. SBR elastomer, for example (Table 1), based on 24 wt% styrene monomer shows better mechanical properties and better resistance to degradation than polybutadiene alone. By increasing the s
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3.3.2 Benzene, toluene and xylene

In addition to benzene itself, the catalytic reformer also produces ethylbenzene, toluene and the isomeric xylenes directly. The demand for ethylbenzene is always great as a source of styrene monomer, but toluene does not find great use apart from a relatively small application in polyurethane. This is why most toluene is de-alkylated to increase overall benzene production. A similar problem exists with the xylenes:

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2.5.3 Structure and the glass transition temperature

There is a relation between the ease of chain rotation (controlling conformation) and the locked-in configuration of polymer backbone chains. It is most easily appreciated by examining the effect of different backbone configurations on the glass-transition temperature or Tg. As already noted above, the Tg is the temperature when a rigid amorphous thermoplastic becomes elastomeric, and its stiffness drops steeply. How can this transition temperature be inter
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1.2.2 Thermoplastics and thermosets

As already stated, polymers including rigid plastics were first developed in the last century from natural precursors. The sealing wax employed by the Victorians, for example, was usually based on the natural polymer shellac, an exudate of the Indian lac insect. Shellac is an early natural thermoplastic – defined as a material which softens and hardens reversibly on heating and cooling. In theory these reversible physical changes will take place without a corresponding change in the chemica
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3.3 Optical amplifiers

Figure 22 shows in outline one possible structure for an Erbium-doped fibre amplifier (EDFA).

Figure 22
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2.3 Attenuation

Activity 2

At approximately what wavelength is the attenuation of optical fibre lowest? What, approximately, is the attenuation at that wavelength? What other wavelengths are used and why?


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Activity answers

Study Note: As outlined in the text I have not provided answers to all Activities. This is for two reasons:

  1. For some activities only you can devise the answer and any I gave would be distracting or unhelpful.

  2. For others in-text answers are given.


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Learning outcomes

By the end of this unit you should be able to:

  • discuss what ethics is and what constitutes an ethical issue;

  • identify and discuss ethical issues that arise in the media, in routine conversations and, in particular, in your own everyday professional practice;

  • discuss the role of emotions in ethical deliberations;

  • discuss how negotiation might resolve apparent ethical differences;

  • identify and discuss the ethical issues p
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