3.7 Moon39: Apollo 14 station C

The panorama was collected by Alan Shepard at station C-Prime. (QuickTime, 500KB, note: this may take some time to download depending on your connection speed)

3.4 Moon36: Apollo 12 station 2

Pete Conrad took this pan early in EVA-1 from a position due west of the Lunar Module. Al Bean can be seen in several frames taking documentation photos of the Solar Wind Collector (SWC) that he has just deployed. (QuickTime, 500KB, note: this may take some time to download depending on your connection speed)

2.3 Missions to the Moon

David A. Rothery Teach Yourself Planets, Chapter 6, pp. 66–75, Hodder Education, 2000, 2003.

Copyright © David Rothery

The Moon was the first extraterrestrial target for space missions. Probes have been directed towards it since almost the very dawn of the space age (see below), and it was the main focus of the 1960s–1970s ‘space race’ between the USA and the then Soviet Union. In the end, only NASA attempted to put people on the Moon, and the six suc
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3 What are compounds?

Activity 1: Elements and compounds

0 hours 10 minutes

Click on the video clip to watch Elements and Compounds, which focuses on water and its constituent elements.

Click below to v
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9.3.1 Weber's Law

Pioneering work on the relationship between ΔI and S was done by the German physiologist, Ernst Weber in the 1830s. Weber found that the increment in stimulation required for a JND was proportional to the size of the stimulus. Weber had subjects lift a small ‘standard’ weight (S) and then lift a slightly heavier ‘comparison’ (T) weight and judge which was heavier. He found that when the difference between the standard and comparison weights was small, the subjects found
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9.3 Differential sensitivity

Absolute thresholds represent only one type of threshold; one could also ask whether the subject can detect a difference between two stimuli. The threshold for detection of difference is called a difference threshold or difference limen (DL). The difference threshold is a measure of the smallest detectable difference between two stimuli. Basically it answers the psychophysical question: ‘How different must two stimuli (e.g. two weights, two colours, two sounds) b
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2.1.1 Science and regularity

‘Our experience shows that only a small part of the physical Universe needs to be studied in order to elucidate its underlying themes and patterns of behaviour. At root this is what it means for there to exist laws of Nature, and it is why they are invaluable to us. They may allow an understanding of the whole Universe to be built up from the study of small selected parts of it.”

John D. Barrow (1988), The Worl
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6 Summary

There are two areas of general concern regarding the introduction of GM crops and food: the possible impacts on human health and on the environment. For some critics of GM technology, this reflects a feeling that GM technology is unnatural, as compared to conventional crop breeding. However, many techniques used in conventional crop development, for example, intergeneric and interspecific crossing, haploid breeding and mutation breeding, are highly technological and seem very far from being n
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3.2 Integration of anatomy and behaviour with biochemical and physiological strategies in evaders

We know from Section 2.3 that small desert rodents remain cool by staying in their burrows for all or part of the day. Kangaroo rats (Dipodomys spp.; see Figure 20 in Section 2.3) depend on metabolic water as there is little or no water available in their diet of seeds. Kangaroo rats appear to be ill-adapted for
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6.3 Metabolic regulation and the midbrain

As you found in the last section, the physiological evidence points to the likelihood that different components of regulation may be regulated separately. The hypothalamus, which appears to be central to the depression and recovery of body temperature during entry to torpor and arousal, is not the only player in the control of metabolic processes underlying non-behavioural thermogenesis. In many respects, the initiation of thermogenesis is the prime event in the reactivation of a cold body: t
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4.5.6 Catalyst deterioration: summary

  1. An ability to withstand mild deactivation is built into the design of the catalytic converter. However, severe deactivation could prevent the system from meeting emissions legislation.

  2. The major causes of deactivation are thermal damage and poisoning.

  3. High temperatures may cause sintering of the metals and/or the support; this can be prevented to some extent by the addition of ceria as a structural promoter. Damaging interaction
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4.3.4 Removal of NO

Laboratory experiments have shown that, under the conditions in the catalytic converter, the decomposition of NO to O2 and N2 over noble metal catalysts is too slow to be significant. When the A/F ratio is stoichiometric (or below stoichiometry), NO can be removed by reduction with CO and/or hydrocarbons. For simplicity we shall consider only reduction with CO, as with the oxidation reaction, the situation with hydrocarbons is considerably more complicated.

In prin
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4.3 Exhaust emission characteristics

Before we consider how the three-way catalyst functions in any detail, it is important to understand how the emissions of CO, HC and NOx, from the engine depend on the ratio of air (A) to fuel (F) – the air/fuel ratio (or A/F ratio). The significance of this will become clear when we see that the ratio at which the three-way catalytic converter operates is crucial for its success.

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4.2.1 Composition

The current three-way catalyst, shown schematically in Figure 1, is generally a multicomponent material, containing the precious metals rhodium, platinum and (to a lesser extent) palladium, ceria (CeO2), γ-alumina (Al2O3), and other metal oxides. It typically consists of a ceramic mono
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9.4 Summary of Section 9

This section has illustrated what has to be done, by way of a long-term study, to yield meaningful information on the relationship between genes and development and the behaviour of the organism. It also illustrates the hugely complex nature of the relationship between genes and development and the behaviour of the organism. Yet this complexity is not the exception, it is the rule.


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7.6 Synaptogenesis

The formation of synaptic connections is an essential property of nervous system development. Synapses are formed between neurons and also with targets that are not part of the nervous system, e.g. muscle. Axon terminals, under the direction of a variety of extracellular cues, grow towards particular targets. Once they arrive at the target, they stop growing and the growth cone changes to form a synapse. As with axon growth, the formation of the synapse is dependent on an interaction between
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10.3.1 Fluid loss

During an average day, a person in a temperate climate such as the UK, loses about 2.5 litres of water.

Activity 35

How is water lost from the body?

Answer
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4.1 Introduction to minerals and why we need them

Both vitamins and minerals are essential in the diet in small quantities and so they are often grouped together as micronutrients.

Activity 24

Which items in the diet are classified as macronutrients?

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3.6.2 Riboflavin (vitamin B2)

Riboflavin or vitamin B2, which was originally known as vitamin G, is found in a wide variety of foods, including milk and dairy products. It is more stable to heat than some of the other B vitamins, but is destroyed by exposure to sunlight. Milk in a glass bottle exposed to sun, loses 10% of its riboflavin per hour. Riboflavin plays a crucial role in the metabolism of carbohydrates and proteins and is involved in many other metabolic reactions in the body.

Although riboflavi
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4 From DNA to RNA: transcription

In the process of transcription, the information in a gene, i.e. the DNA base sequence, is copied, or transcribed, to form an RNA molecule. RNA is therefore an intermediary in the flow of information from DNA to protein. Before we consider the details of transcription, we will first look at the structure of RNA.

The name ribonucleic acid suggests that RNA is chemically related to DNA. Like DNA, RNA is a chain of nucleotides.

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