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This paper provides an overview of the role computer software plays within police forces with particular attention paid to crime analysis and investigation computer systems. A distinction is made between major crime (e.g. murder, violent assault, rape, etc.) and volume crime (e.g. domestic burglary, shoplifting, etc.). Illustrative systems that are in practical use for tackling both major and volume crime are described. Particular attention is paid to the attempts that have been made to apply artificial intelligence techniques to tackling the volume crime of burglary. A topic of current research is the use of data mining techniques for automatically detecting patterns in reported crimes. The paper concludes by looking at the problems and benefits such systems may bring.

The purpose of this paper is to acquire sealing properties of supercritical CO₂ (S-CO₂) T-groove seal under ultra-high-speed conditions by thermo-elastohydrodynamic lubrication (TEHL) analysis.

Considering the choked flow effect, the finite difference method is applied to solve the gas state equation, Reynolds equation and energy equation. The temperature, pressure and viscosity distributions of the lubricating film are analyzed, and sealing characteristics is also obtained.

The face distortions induced by increasing rotational speed leads to the convergent face seal gap. When the linear velocity of rotation exceeds 400 m/s, the maximum temperature difference of the sealing film is approximately 140 K, and the viscosity of CO₂ is altered by 17.80%. Near the critical temperature point of CO₂, while the seal temperature increases by 50 K, the opening force of the T-groove non-contact seal enhances by 20% and the leakage rate declines by 80%.

The TEHL characteristics of the T-groove non-contact seal are numerically analyzed under ultra-high-speed, considering the real gas effect and choked flow effect. In the supercritical conditions, the influence of rotational speed, seal temperature, seal pressure and film thickness on sealing performance and face distortions is analyzed.

The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO₂ (S-CO₂) spiral groove face seals in the supercritical regime.

The spiral groove face seal was used as the research object. The distribution of lubricating film pressure and temperature was analysed by solving the gas state, Reynolds and energy equations using the finite difference method. Furthermore, the influence law of sealing performance was obtained.

Close to the critical temperature of S-CO₂, face distortions produced by increasing pressure lead to divergent clearance and resulted in reduced opening force. In the state of S-CO₂, the face distortions generated by increasing seal temperature lead to convergent clearance, which enhances the opening force. In addition, near the critical temperature of S-CO₂, the opening force may be reduced by 10%, and the leakage rate of the seal sharply increases by a factor of four.

The thermoelastohydrodynamic characteristics of supercritical CO₂ face seals are illustrated considering the actual gas effect including compressibility, heat capacity and viscosity. Face distortions and sealing performance were calculated under different seal pressures and seal temperatures in the supercritical regime, as well as with N₂ for comparison.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0169/

This paper aims to acquire the phase distribution and sealing performance of supercritical carbon dioxide (SCO₂) dry gas seals with phase transitions.

The SCO₂ spiral groove dry gas seal is taken as the research object. The finite differential method is applied to solve the governing equations. Furthermore, the phase distribution and the sealing performance are obtained. Compared to the ideal gas model, the effect of phase transitions on sealing performance is also explored.

Vaporization is likely to occur near the inner radius when SCO₂ dry gas seals are operated near the critical point. Whether phase transitions are considered in the model affects the sealing performance seriously. When phase transitions are considered, the sealing performance depends significantly on the working conditions, and unexpected results are produced when inlet conditions approach the critical point.

The numerical model for SCO₂ dry gas seals with phase transitions is established. The phase distribution and the sealing performance of SCO₂ dry gas seals are explored.

The purpose of this article is to introduce the themed section of History of Education Review on “The History of Knowledge and the History of Education”, comprising four empirical articles that together seek to bring the history of education into fuller dialogue with the approaches and methods of the nascent field of the history of knowledge.

This introductory article provides a broad overview of the history of knowledge for the benefit of historians of education, introduces the four themed section articles that follow, and draws out some of their overarching themes and concepts.

The history of knowledge concept of “arenas of knowledge” emerges as generative across the themed section. Authors also engage with problems of the legitimacy of knowledges, and with pedagogy as practice. In addition, focusing on colonial and postcolonial contexts raises reflexive questions about history of knowledge approaches that have so far largely been developed in European and North American scholarship.

The history of education has not previously been strongly represented among the fields that have gone into the formation of the history of knowledge as a synthetic, interdisciplinary approach to historical studies. Nor have historians of education much engaged with its distinguishing concepts and methodologies. The themed section also extends the history of knowledge itself through its strong focus on colonial and postcolonial histories.

This chapter draws on developmental intergroup theory, parental ethnic-racial socialization literature, anti-bias curricula, and prejudice intervention studies to address the appropriateness of discussing race and racism in early childhood settings. Existing literature about teacher discussions surrounding race and racism is reviewed, best practices are shared, and the need for more research in this area is highlighted. The construct of parental ethnic-racial socialization is mapped onto early childhood anti-bias classroom practices. The chapter also outlines racial ideologies of teachers, specifically anti-bias and colorblind attitudes, and discusses how these ideologies may manifest in classroom practices surrounding race and racism. Colorblind ideology is problematized and dissected to show that colorblind practices may harm children. Young children’s interpretations of race and racism, in light of children’s cognitive developmental level, are discussed. Additionally, findings from racial prejudice intervention studies are applied to teaching. Early literacy practices surrounding race and racism are outlined with practical suggestions for teachers and teacher educators. Moreover, implications of teacher practices surrounding race and racism for children’s development, professional development, and teacher education are discussed.

This study attempted to clarify the relationship of power of school heads and participation of English teachers in school decisions. A deliberate sample of eight schools was drawn from the schools in the northwest of England. The major criteria for selection were: size (medium to large); location(urban‐suburban and reasonably accessible from Manchester); and representatives of the types of schools found in that geographic area. A descriptive analysis indicated that English teachers do perceive themselves participating in most decision areas. At a second level of analysis the relationship between status and intensity of participation was computed with r = .544 for the 103 members of staff (p<.001). An implication is that competence is a criterion for status position, leading to involvement and hence power in the social system. The final analysis dealt with implications of use of power from a description of participation patterns. The clusterings found lend credence to the belief that English heads are controlling those areas of power where tangible rewards and punishments are evident. They appear to be supporting participatory management in such other areas as those where teachers do not desire involvement or those which carry minimal expenditure of organizational resources.

The purpose of this paper is to encourage re‐reading and re‐evaluation of a series of educational polemics published in the UK in the 1960s and 1970s, the Black Papers. These works proposed, for the most part, avowedly conservative views on education: condemning so‐called “progressive” teaching methods and the re‐organisation of secondary schools in the UK (especially England) into non‐selective comprehensives. It is argued, however, that much said and written about the Black Papers since has concentrated only on selected “high profile” contributors, to the neglect of other contributors, often anonymous, whose comments were sometimes more measured/thoughtful.

The work proceeds first by re‐visiting the facts surrounding the writing of the Black Papers and their critical reception. It then analyses the nature of the contributors and describes selected essays not usually referred to when the Black Papers are discussed by historians and others.

The work finds that the Black Papers are often infuriatingly and unhelpful polemical in nature but that much written about them since has concentrated only on selected contributors, ignoring others who were more measured.

The work is perhaps the first critical re‐reading of the Black Papers in any depth in several decades. It does not simply dismiss them as hysterical rants by ill‐informed authors and suggests that they re‐pay careful attention, despite their often polemical nature.

Using material from contemporary New Zealand experience as a case study, this paper presents a functional analysis of the organizational problems facing secondary schools, develops a typology of dilemmas posed as a result of these problems, and discusses the manner in which various educational agencies, including the central Department, Teachers' Organizations and the recent Educational Development Conference have attempted to persuade schools to resolve these dilemmas in particular ways. Comments are also made on the internal characteristics of schools which may influence their resolution of these dilemmas in different ways thus leading to a growing heterogeneity within the state educational system.