A new connection between the opening angle and the large-scale morphology of extragalactic radio sources

In the case of an initially conical jet, we study the relation between jet collimation by the external pressure and large-scale morphology. We first consider the important length-scales in the problem, and then carry out axisymmetric hydrodynamic simulations that include, for certain parameters, all these length-scales. We find three important scales related to the collimation region: (i) where the sideways ram-pressure equals the external pressure, (ii) where the jet density equals the ambient density, and (iii) where the forward ram-pressure falls below the ambient pressure. These scales are set by the external Mach-number and opening angle of the jet. We demonstrate that the relative magnitudes of these scales determine the collimation, Mach-number, density and morphology of the large scale jet. Based on analysis of the shock structure, we reproduce successfully the morphology of Fanaroff-Riley (FR) class I and II radio sources. Within the framework of the model, an FR I radio source must have a large intrinsic opening angle. Entrainment of ambient gas might also be important. We also show that all FR I sources with radio lobes or similar features must have had an earlier FR II phase.Comment: 14 pages, 10 figures, accepted by MNRAS, same as previous versio

"...They've learnt there's more to life than football." Evaluation of a primary school based physical activity project using the social concepts.

The fifteen-month physical activity (Pa) project was initiated by the Partnership (DfES, 2003). The project tested strategies to increase the quality and quantity of Pa in two primary schools and sought to impact on the educational attainment, behaviour, and fitness, of children at Key Stage 2 (KS2). A Pa coordinator implemented the additional Pa through breaktime activities, and school-community links. 195n children (including 35n at-risk), 2n head teachers, teachers and parents were involved. This thesis evaluated the Pa project aims, within a socio-political framework, where the current political concepts of social exclusion, social inclusion, and social capital by the Government. Multiple method research was used, using semi-structured interviews, observations, questionnaires (Harter, 1985), skill related fitness tests and document information. The quality and quantity of Pa increased at the schools, but the objective of 75% of KS2 children participating in 2 hours of Pa weekly was not met. The fitness scores improved, but there was no significant change (p˂ .05) in educational attainment, or behaviour. High levels of access and participation were achieved with 99% of eligible children attending and each child attending an average 59% of sessions. At-risk attendance was 7% higher than non at-risk, but girls participation was 14% lower than boys. Limited active participation by children occurred in the project set-up, which restricted their agency and power in the process. Social capital was fostered, resulting in the volunteers and children becoming more involved in the school and wider community

The merits of class teachers teaching design and technology against the use of the specialist teacher (Winnie the Pooh or Christopher Robin ...Who is right?)

The current debate concerned with the specialist primary teacher versus the generalist is one that has stimulated strong arguments both for and against among primary specialists. Of course, it does not have to be either/or but factors such as size of staff, tirnetabling and an uneven balance of strengths often predetermine what is or is not possible. This article seeks to highlight the argument for the class teacher teaching design and technology, whatever his/her curriculum strengths. It focuses on three main areas for discussion:knowledge of the childrencurriculum integrationclass managementIt is hoped that this article will contribute to the argument and will provoke a reader to provide another viewpoint in this topical debat

The primitive Christian attitude to the state as reflected in the New Testament writings

This thesis finds Jesus' attitude to the state normative for the whole period of the New Testament writings* The most important state for him was not Rome but the Jewish theocracy. He was greatly concerned that the latter entity would see its political responsibility in terms of the prophetic image of the suffering servant.The development of Israel as a state is traced, as is the vision of the future ideal state which, described in frankly political terms, motivated the Jews to seek recovery of independence and power, an era of peace and prosperity, of fidelity to God and his law, and of Justice and brotherly love among menThe period leading up to New Testament times is seen as an era of crisis for the Jewish nation. External forces threaten its cohesion. Some of its citizens want to compromise with intrusive foreign cultures} some want to retreat to a piestic enclave; some counsel rebellion. Jesus' answer to the crisis was in the prophetic tradition. It was to challenge the preconceptions of political morality which lay behind each of the options, and to ask men to consider themselves citizens of a kingdom whose ethic is love. In fulfilling their duty to the higher righteousness they would be good citizens of present states and exert tension on the present systems which could lead to their transformation.All the books of the Hew Testament are dealt with in the chronological order of their composition. In deciding what evidence is applicable to the subject, several themes which relate to the attitude t o the state are kept in mind.Order is Judged to be one such category. The existence of man in society is possible only when chaos is overcome by unity and order. Yet the goal of order is continually threatened by external invasions and by the attempt to introduce heightened ethical demands into society.Sschatology is another important subject because, depending on the type of eschatology which was stressed in a particular writing, we may ascertain a particular attitude to history. In some cases history is taken seriously as the normal realm of a Christian's activity. In others a non-dynamic view of history is adopted with its resultant lack of responsibility for the state.Passages dealing with universalism are also important reference points for this subject. Each person's basic political philosophy arises out of his attitude to the particular entity to which he is attached* There was a prophetic attempt to expand this consciousness toward a universal outlook in Hew Testament times.Attitudes under persecution and the theme of national identity are also dealt with fully, as is the dominant New Testament theme of suffering love. Jesus had been a loving, suffering servant within the life of his own nation. The early church understood its responsibility to society in terms of being a salty presence within history, of seeing that the kingdom ethic exerted a judging, transforming tension upon the ethic of measurable duty by which the states of the present world live

Software and hardware aspects of a microprocessor controlled lathe

A small lathe has been modified to work under microprocessor control to enhance the facilities which the lathe offers and provide a wider operating range with relevant economic gains. The result of these modifications give better operating system characteristics. A system of electronic circuits have been developed, utilising the latest technology, to replace the pegboard with the associated obsolete electrical components. Software for the system includes control programmes for the implementation of the original pegboard operation and several sample machine code programmes are included, covering a wide spectrum of applications, including diagnostic testing of the control system. It is concluded that it is possible to carry out a low cost retrofit on existing machine tools to enhance their range of capabilities

A1_5 Determining the Smallest Migratory Bird Native to Britain able to carry a Coconut

In Monty Python’s Holy Grail the opening scene contains an argument between King Arthur and a Guardsman on how King Arthur obtained the coconut in his possession. The King argues that a bird could have carried it on its return from migration, this paper discusses if any British bird is capable of thi