Precision of quasi-optical null-balanced bridge techniques for transmission and reflection coefficient measurements

The precision of quasioptical null-balanced bridge instruments for transmission and reflection coefficient measurements at millimeter and submillimeter wavelengths is analyzed. A Jones matrix analysis is used to describe the amount of power reaching the detector as a function of grid angle orientation, sample transmittance/reflectance and phase delay. An analysis is performed of the errors involved in determining the complex transmission and reflection coefficient after taking into account the quantization error in the grid angle and micrometer readings, the transmission or reflection coefficient of the sample, the noise equivalent power of the detector, the source power and the post-detection bandwidth. For a system fitted with a rotating grid with resolution of 0.017 rad and a micrometer quantization error of 1 μm, a 1 mW source, and a detector with a noise equivalent power 5×10−9 W Hz−1/2, the maximum errors at an amplitude transmission or reflection coefficient of 0.5 are below ±0.025.

Commercial property loan valuations in the UK : the changing landscape of practice and liability

This paper is the first of two which aim to examine the major legal liability implications of changes to the commercial property loan valuation process caused by the recession in the UK property market and to make recommendations to valuers and their professional institutions to improve the quality of the process and the result. This paper identifies the market background to commercial property lending and discusses the implications of the falls in value for lenders and valuers. These include two major strands; first, the outcome of discussions between the representative bodies of these two groups and, second, the increasing litigation caused by lenders suing valuers for professional negligence. The discussions between representative groups have driven a debate on the valuation process leading to a number of reports and guidance notes. This paper discusses the outcomes paying particular attention to the basis of valuation for loan purposes and the provision of additional information in valuation reports. This paper also reviews the legal framework which influences the relationship between the lenders and valuers and discusses the duty of care. The role of instructions in the valuation process, the significance of the identity of the person to be advised and the possibility of a conflict of interest arising are all considered. The paper also addresses the issue of the standards required of a commercial loan valuer, including how this is interpreted by the courts and the legal status of professional guidance notes. The paper concludes by identifying potential areas for dispute within the loan valuation process and raising a number of research questions concerning the operation of this process which are addressed in a following paper.

Commercial property loan valuations in the UK : implications of current trends in practice and liability

This paper is the second of two papers which aim to examine the major legal liability implications of changes to the commercial property loan valuation process caused by the recession in the UK property market and to make recommendations to valuers and their professional institutions to improve the quality of the process and the result. The objectives of this paper are to address a number of the practical implications of changes to the loan valuation process within the context of legal liability. The results of an interview survey of lenders and valuers are reported and analysed. The survey examined the loan valuation process including the selection and instruction of valuers, bases of valuation and valuation reporting. In the selection and instruction process, the findings of the survey reveal two potential problems within the valuer/lender relationship. First, valuers still occasionally accept instructions from borrowers and this could lead to a conflict of interest as lenders may rely on the survey. Second, the occasional lack of formal instructions prior to the delivery of reports casts doubt on the valuer’s ability to correctly identify the needs of clients. Regarding the basis of valuation, it was found that valuers are providing valuations on bases which they do not think are appropriate. Valuers may be legally liable if they do not inform clients of their reservations and this situation must be urgently addressed. The survey also confirms previous research that valuation reports are considered to be light on contextual information concerning markets. The paper concludes by making a number of specific recommendations concerning possible improvements to the commercial property loan valuation process.

Incorporating creativity into teachers practice and self-concept of professional identity

The study explores what happens to teachers practice and ’ professional identity when they adopt a collaborative action research approach to teaching and involve external creative partners and a university mentor. The teachers aim to nurture and develop the creative potential of their learners through empowering them to make decisions for themselves about their own progress and learning directions. The teachers worked creatively and collaboratively designing creative teaching and learning methods in support of pupils with language and communication difficulties. The respondents are from an English special school, primary school and girls secondary school. A mixed methods methodology is adopted. Gains in teacher confidence and capability were identified in addition to shifts in values that impacted directly on their self-concept of what it is to be an effective teacher promoting effective learning. The development of their professional identities within a team ethos included them being able to make decisions about learning that are based on the educational potential of learners that they proved resulted in elevated standards achieved by this group of learners. They were able to justify their actions on established educational principles. Tensions however were revealed between what they perceived as their normal required professionalism imposed by external agencies and the enhanced professionalism experienced working through the project where they were able to integrate theory and practice.

Evolutionary developmental biology: impact on systematic theory and practice, and the contribution of systematics

Evolutionary developmental genetics brings together systematists, morphologists and developmental geneticists; it will therefore impact on each of these component disciplines. The goals and methods of phylogenetic analysis are reviewed here, and the contribution of evolutionary developmental genetics to morphological systematics, in terms of character conceptualisation and primary homology assessment, is discussed. Evolutionary developmental genetics, like its component disciplines phylogenetic systematics and comparative morphology, is concerned with homology concepts. Phylogenetic concepts of homology and their limitations are considered here, and the need for independent homology statements at different levels of biological organisation is evaluated. The role of systematics in evolutionary developmental genetics is outlined. Phylogenetic systematics and comparative morphology will suggest effective sampling strategies to developmental geneticists. Phylogenetic systematics provides hypotheses of character evolution (including parallel evolution and convergence), stimulating investigations into the evolutionary gains and losses of morphologies. Comparative morphology identifies those structures that are not easily amenable to typological categorisation, and that may be of particular interest in terms of developmental genetics. The concepts of latent homology and genetic recall may also prove useful in the evolutionary interpretation of developmental genetic data.