1,611 research outputs found
Towards a fuller understanding of selected molecular compounds
No full textThis work is separated into two distinct sections. The first section deals with the analysis by variable temperature single crystal X-ray diffraction of crystalline molecular materials with novel physical properties. The second section details the electron density analysis of selected crystalline compounds using high resolution, low temperature single crystal X-ray diffraction. Chapter 1 provides introduction to X-ray diffraction outlining the theory this work is based on. Chapter 2 introduces the molecular material studies based on materials containing the bis(ethylenedithio)-tetrathiaftilvalene molecule. The aim of these studies was to achieve a greater understanding of the materials and the changes they undergo when exposed to variations in temperature whilst in the crystalline state. These structural changes observed are very minor but have dramatic effects on the electrical properties of the materials studied. It became apparent that the only way to form a full understanding of these materials was to be able to 'see' the electronic configuration of the materials, not just their gross structure. The field of electron density analysis by X- ray diffraction is now a well documented area. Chapter 4 provides an introduction to the field of electron density analysis. Diffraction experiments were conducted on systems of different complexity to investigate this field and these results are reported in Chapter 5. No electron density analyses have been conducted on the molecular materials studied in Chapter 3 as yet, due to the lack of crystals of suitable quality. It was also noted that to fully categorise the nature of the physical changes occurring in these structures that a diffractometer capable of analysing these samples throughout the temperature range of their physical phenomena was needed. An outline for the development of such a diffractometer is detailed in Chapter 6, 'future works'
R&D service firms: The hidden engine of the high-tech economy?
No full textR&D service firms are highly innovative knowledge-intensive businesses. They constitute an important component of the knowledge economy, but one that is often in the shadow of the role normally attributed to universities and other public research organisations in the growth of high tech clusters and, more broadly, innovation systems. In this paper we present evidence from an in-depth analysis of the strategy, practice and impact of a sample of R&D service providers long active in the Cambridge area, the leading science and technology cluster in the UK. Based on an extensive programme of interviews with companies' CEOs and managers, we analyse: the main features of the R&D contract and the way in which this allows firms to de-risk the uncertain process of early technology development and to meet customer's needs; the services' typical organisational features and development stages; the variety of observed growth paths. We provide evidence of the significant direct and indirect contribution to innovation of these service firms and conclude by discussing the implications of this original model of technology development in relation to the early-stage financing and university-led growth debates. © 2013 Elsevier B.V
'Irretrievably broken'? introducing the life-story of the divorce reform act 1969
No full textBook synopsis: The enactment of the Divorce Reform Act 1969 was a landmark moment in family law. Coming into force in 1971, it had a significant impact on legal practice and was followed by a dramatic increase in divorce rates, reflecting changes in social attitudes.
This new interdisciplinary collection explores the background to the 1969 Act and its influence on law and society. Bringing together scholars from law, sociology, history, demography, and film and literature, it reflects on the changes to divorce law and practice over the past 50 years, and the changing impact of divorce on different people in society, particularly women.
As such, it offers a 'biography' of this important piece of legislation, moving from its conception and birth, through its reception and development, to its imminent demise. Looking to the future, and to the new law introduced by the Divorce, Dissolution and Separation Act 2020, this collection suggests ways for evaluating what makes a 'good' divorce law.
This brilliant collection gives insight not only into this crucial piece of legislation, but also into a key period of societal change
Defamation, A Camouflage of Psychic Interests: The Beginning of a Behavioral Analysis
No full textDoes the law of defamation need to be reformed? The author thinks so. Professor Probert rejects the doctrine of libel per se and questions the courts\u27 understanding and use of the term reputation. It is his belief that plaintiffs on an individual basis should have increased benefit of the knowledge accumulated by the various social sciences in proving the harm done by the alleged defamation, with more liberalization in the requirements of pleading and proof than is now generally countenanced by the courts
Seed dormancy and germination in three Crocus ser. Verni species (Iridaceae): implications for evolution of dormancy within the genus
No full textClimate warming could shift the timing of seed germination in alpine plants
No full textBackground and AimsDespite the considerable number of studies on the impacts of climate change on alpine plants, there have been few attempts to investigate its effect on regeneration. Recruitment from seeds is a key event in the life-history of plants, affecting their spread and evolution and seasonal changes in climate will inevitably affect recruitment success. Here, an investigation was made of how climate change will affect the timing and the level of germination in eight alpine species of the glacier foreland. MethodsUsing a novel approach which considered the altitudinal variation of temperature as a surrogate for future climate scenarios, seeds were exposed to 12 different cycles of simulated seasonal temperatures in the laboratory, derived from measurements at the soil surface at the study site.Key ResultsUnder present climatic conditions, germination occurred in spring, in all but one species, after seeds had experienced autumn and winter seasons. However, autumn warming resulted in a significant increase in germination in all but two species. In contrast, seed germination was less sensitive to changes in spring and/or winter temperatures, which affected only three species.ConclusionsClimate warming will lead to a shift from spring to autumn emergence but the extent of this change across species will be driven by seed dormancy status. Ungerminated seeds at the end of autumn will be exposed to shorter winter seasons and lower spring temperatures in a future, warmer climate, but these changes will only have a minor impact on germination. The extent to which climate change will be detrimental to regeneration from seed is less likely to be due to a significant negative effect on germination per se, but rather to seedling emergence in seasons that the species are not adapted to experience. Emergence in autumn could have major implications for species currently adapted to emerge in spring
Overcoming the Innovation Barrier: A Search-Selection Model of Breakthrough Innovation in Large Firms
No full textIn this chapter we explore mechanisms through which established firms can harness these fundamental enablers through adopting selection regimes that counteract the tendency to stifle or eliminate radical novelty. We begin by providing an overview of the main factors that cause established firms to oppose breakthrough innovation projects. We then conceptualize the generation of breakthrough innovation as a two stage search-selection process. The first stage, search, is aimed at increasing the likelihood of coming across new opportunities by prompting experimentation. The second stage, selection, is aimed at sifting out and supporting the implementation of the most valuable opportunities. Focusing on the selection phase, we propose three types of regime that established firms can adopt to overcome innovation barriers: (1) individual driven, (2) lead user driven and (3) application domain driven. Examples from BAE Systems, Rolls-Royce and ARM are used to illustrate the effectiveness of these selection regime
Local climate explains degree of seed dormancy in Hypericum elodes L. (Hypericaceae)
No full textSeed dormancy and germination characteristics may vary within species in response to several factors. Knowledge of such variation is crucial to understand plant evolution and adaptation to environmental changes. We examined the correlation of climate and population genetic differentiation (ISSR) with primary seed dormancy and germination behaviour in populations of the Atlantic-European soft-water pool specialist Hypericum elodes. Primary dormancy was measured by analysing seed germination response of fresh seeds and after various periods of cold stratification. Laboratory germination experiments revealed that the single most important factor for promoting germination was cold stratification prior to placing at the germination temperature. However, in agreement with their weaker primary dormancy, the seeds germinated well when fresh, and the benefit of cold stratification was more relaxed for the southern populations. Seeds of all populations demonstrated a near absolute requirement for a light and alternating temperature regime in order to germinate. The promoting effect of alternating temperatures was particularly effective at warm temperatures (mean 20 °C) but not at cool temperatures. Whilst seed germination requirements were similar among populations, the degree of primary dormancy varied considerably and was not associated with population genetic differentiation. Primary dormancy degree was instead associated with local climate: higher temperature in summer and rainfall in winter predicted weak and rapid loss of dormancy. These results suggest that seed maturation environment may play a substantial role in explaining the degree of dormancy in H. elodes, highlighting that physiological dormancy can be modulated by local climat
The structure of a pentachromium(II) extended metal atom chain at 3 K: Cotton's conjecture proven
No full textWe provide definitive experimental proof that the archetypal string-like compound [Cr5(tpda)4(NCS)2] has alternating long and short Cr–Cr separations in the solid state, as conjectured by F. A. Cotton, rather than essentially equally spaced Cr atoms, as initially claimed (H2tpda = N2,N6-di(pyridin-2-yl)pyridine-2,6-diamine). Single-crystal X-ray data collected from 292 to 3 K revealed that the misinterpretation is caused by pseudo-merohedral twinning and that bond length alternation is enhanced at low temperature
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