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
3.10 Systems techniques The two systems methodologies provide a framework for the application of problem solving, analysis and design techniques. These fall into three groups. Diagramming: ranging from single systems maps to complex flow charts. Diagrams of one sort or another provide a method of analysis, design and communication. Modelling: simulation is used extensively to analyse the dynamics of an existing system and to predict the behaviour of a propos
7.3.6 Laser ablation deposition Another close cousin to sputter deposition is laser ablation deposition. Ion bombardment of the target is replaced by a focused pulse of light from an ultraviolet laser. Although each pulse may carry only 1 J of energy, this is delivered within 1 ns to a 1 mm spot on the target surface. This represents an astonishing power density and the target surface explodes into vapour that can be caught on the waiting wafer surface. It is vital to scan the focus point across the target surface or you wi
9.1 Frequency range The lowest frequency humans can hear is approximately 20 Hz. The upper limit for humans is nominally 20 000 Hz (20 kHz), but this limit tends to decline with age, and for most of us it is well below this figure. 8.1 The octave sound One feature of pitch that seems to be universal to all cultures is that for musical purposes the pitch range is divided into discrete steps: for instance, the notes of a scale. This is not to say that musicians rigidly adhere to those steps when they play, but the existence of such steps is fundamental to the way music is conceived and organised. Different cultures have different ways of defining the steps in their scale of pitches, but nearly all cultures take the octave as their starting po 5.4 Methodology, method, technique, and tools As you engage with systems thinking and practice you will become aware how different authors refer to systems methodologies, methods, techniques, and tools, as well as systems approaches. Having just spent some time explaining what I mean by a systems approach, I now want to distinguish between methodology, method, technique and tool. Several authors and practitioners have emphasised the significance of the term methodologies rather than methods in relation to Systems. A method i 9.8 Diagramming a complex situation Diagrams are never an end in themselves. They have a purpose. They exist in relation to a situation and can be used to cast light upon aspects of that situation or to explain it to someone. So, the next step is to look at the diagrams you have drawn and to ask yourself what you have learned about the situation. This answer may be in terms of a deeper appreciation of the situation. It may also be in terms of pointers towards possible interventions and some idea of the likely effects of s 19 Part 3: 3 Sustaining and disruptive innovation Once an innovation starts diffusing into the marketplace it can have differing degrees of impact. As mentioned in Part 1, although innovations generally offer progress, there are some that complement existing ways of doing things and some that are more dramatic in their impact. In his book called The Innovator's Dilemma Clayton M. Christensen (2003) labels these two types of innovation sustaining and disruptive. Sustaining innovations are those that improve the performance of est 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 2.6.1 Stress corrosion cracking in stainless-steel structures On 9 May 1985 the roof of a swimming pool at Uster near Zurich collapsed, killing 12 and injuring several others. The concrete roof had been held up by a set of stainless-steel tie bars, which were found after the accident to have cracked transversely (Figure 21). Chlorine is added at qui References 3.4 A note on suspense By raising various expectations in the reader's mind, a writer can create an atmosphere of suspense – the desire to turn the page and find out what happens next. How much will the story follow the reader's expectations, how much will it confound them? In this way, sus Acknowledgements This unit was written by Professor Tim Benton Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence Presenter: Tim Benton. Producer: Nick Levinson. Production Assistants: Tricia C 4 Alliteration Alliteration is the term used to describe successive words beginning with the same sound – usually, then, with the same letter. To illustrate this I would like to use a stanza from Arthur Hugh Clough's poem, ‘Natura naturans’. There is not enough space to quote the whole poem, but to give you some idea of the context of this stanza so that you can more fully appreciate what Clough is doing, it is worth explaining that ‘Natura naturans’ describes the sexual tension between a yo 1.9 Further reading Doblhofer, Ernst, Voices in Stone (Paladin, 1973; orig. edn. 1957). Not especially mathematical, but a good account of the decipherment of hieroglyphs and cuneiform texts if you want to follow that up. Flegg, Graham, Numbers (Penguin, 1984; orig. edn. 1983). A book packed with much more information about numbers and their history than we have time for during the course. Friberg, Jöran, ‘Methods and Traditions of Babylonian Mathematics’, Historia Mathematics 4.2 The ‘inadequate consciousness of the real teachings of Christianity’ Following the Introduction, Wilberforce describes what he regards as an inadequate consciousness of the real teachings of Christianity among those who profess to adhere to it. This ignorance is grounded in a widespread failure to study the Bible in any depth and detail. He then expounds the Evangelical view of human nature as fundamentally corrupt, evil and depraved, as against the ‘professed Christian’ view that it is ‘naturally pure and inclined to all virtue’. In this darkly pessim 3 Britain in the 1790s A problem that has exercised historians for many years is, put in its most concise form: why was there no revolution in Britain in the 1790s? The question is a significant one here, because religious factors have formed an important strand in the answers that have been given. The intellectual trend was set by the publication in 1913 of England in 1815, in which the French historian Elie Halévy (1870–1937) argued that the growth of Methodism in this period was a key factor in the Bri 1.3 Wilberforce’s ‘Conversion’ to Evangelicalism Wilberforce’s religious ‘conversion’ in 1785 was profound but not instantaneous. Through the influence of Isaac Milner, an Evangelical clergyman who was his companion on extended journeys on the Continent, he first became intellectually convinced of the truth of Christian doctrines that he had doubted in the early 1780s. This process of rational argument, study and consideration was characteristic of an Enlightenment way of thinking, even if the conclusion was diametrically opposed to t 4.3 Physical grounds for thinking we are immortal In section III Hume discusses what he calls physical reasons for thinking there is an afterlife. A sensible guess as to what he means by a physical reason is that it is one based on observation and experience of the physical world. He begins by asserting that physical reasons are the ones he has most respect for. (This assertion is unsurprising: his objections to moral reasons, and the metaphysical reasons we skipped, turn on the allegation that they depend on claims that go beyond wha 4.2 Moral grounds for thinking we are immortal The moral reason (as Hume calls it) for thinking that there is an afterlife has already been touched on. God, being just, would surely see to it that we are punished or rewarded for our aberrant or commendable actions; this punishment or reward doesn't take place in this life, so it must take place after our body's demise. Here is a simple statement of the reasoning:
The moral argument for supposing there is an
Activity 27 (Self-Assessment)
