Unsteady free convection flow in the stagnation-point region of a rotating sphere

The unsteady free convection boundary-layer flow in the forward stagnation-point region of a sphere, which is rotating with time-dependent angular velocity in an ambient fluid, has been studied. Both constant wall temperature and constant hear flux conditions have been considered. The non-linear coupled parabolic partial differential equations governing the flow have been solved numerically using an implicit finite-difference scheme. The skin friction and the heat transfer are enhanced by the buoyancy force. The effect of the buoyancy force is found to be more pronounced for smaller Prandtl numbers than for larger Prandtl numbers. For a given buoyancy force, the heat transfer increases with an increase in Prandtl number, but the skin friction decreases.

Unsteady free convection flow in the stagnation-point region of a three-dimensional body

The unsteady free convection flow in the stagnation-point region of a heated three-dimensional body placed in an ambient fluid is studied under boundary layer approximations. We have considered the case where there is an initial steady state that is perturbed by a step-change in the wall temperature. The non-linear coupled partial differential equations governing the free convection flow are solved numerically using a finite difference scheme. The presented results show the temporal development of the momentum and thermal boundary layer characteristics.

Use of the FAR guide to present a pedagogical analogical model of gel electrophoresis in year 10 Science

This paper is a qualitative, practice based study describing the use of the Focus-Action-Reflection (FAR) Guide (Harrison and Treagust, 2000) to address the shortcomings of a pedagogical analogical model in Year 10 Science. The aim of this paper is to present my experience of the FAR Guide in relation to an analogical model that gave rise to perceived shortcomings by both teachers and students. This study found the FAR Guide to be a highly valuable tool, transforming the presentation of the analogical model, and enabling students to develop a deeper understanding of the nature of scientific knowledge.

Drink driving among Indigenous people in Far North Queensland and northern New South Wales: A summary of the qualitative findings

Purpose In response to the threat that drink drivers pose to themselves and others, drink driving programs form an important part of a suite of countermeasures used in Australia and internationally. Unlike New Zealand/Aotearoa, United States and Canada that have programs catering for their First Peoples, all Australian programs are designed for the general driver population. The aim of this study was to identify the factors that contribute to Indigenous drink driving in order to inform appropriate recommendations related to developing a community-based program for Indigenous communities. Broader drivers licensing policy recommendations are also discussed. Methods A sample of 73 Indigenous people from Queensland and in New South Wales with one or more drink driving convictions completed a semi-structured interview in respect of the to their drink driving behaviour. Participants were asked to disclose information regarding their drink driving history, and alcohol and drug use. If participants self-reported no longer drink driving, they were probed about what factors had assisted them to avoid further offending. Results Key themes which emerged to maintain drink driving include motivations to drink and drive, and belief in the ability to manage the associated risks. Factors that appeared to support others from avoiding further offending include re-connecting with culture and family support. Conclusions and Implications A range of recommendations regarding delivery and content of a program for regional and remote communities as well as other policy implications are discussed.

Free Energy Gap Dependence of the Electron-Transfer Rate from the Inverted to the Normal Region

numerical study of the free energy gap (FEG) dependence of the electron-transfer rate in polar solvents is presented. This study is based on the generalized multidimensional hybrid model, which not only includes the solvent polarization and the molecular vibration modes, but also the biphasic polar response of the solvent. The free energy gap dependence is found to be sensitive to several factors, including the solvent relaxation rate, the electronic coupling between the surfaces, the frequency of the high-frequency quantum vibrational mode, and the magnitude of the solvent reorganization energy. It is shown that in some cases solvent relaxation can play an important role even in the Marcus normal regime. The minimal hybrid model involves a large number of parameters, giving rise to a diverse non-Marcus FEG behavior which is often determined collectively by these parameters. The model gives the linear free energy gap dependence of the logarithmic rate over a substantial range of FEG, spanning from the normal to the inverted regime. However, even for favorable values of the relevant parameters, a linear free energy gap dependence of the rate could be obtained only over a range of 5000-6000 cm(-1) (compared to the experimentally observed range of 10000 cm(-1) reported by Benniston et al.). The present work suggests several extensions/generalizations of the hybrid model which might be necessary to fully understand the observed free energy gap dependence.

Immunochemical approach to the mapping of an assembled epitope of human chorionic gonadotropin: Proximity of CTP-alpha to the receptor binding region of the beta-subunit

A single-step solid-phase RIA (SS-SPRIA) developed in our laboratory using hybridoma culture supernatants has been utilised for the quantitation of epitope-paratope interactions. Using SS-SPRIA as a quantitative tool for the assessment of epitope stability, it was found that several assembled epitopes of human chorionic gonadotropin (hCG) are differentially stable to proteolysis and chemical modification. Based on these observations an approach has been developed for identifying the amino acid residues constituting an epitopic region. This approach has now been used to map an assembled epitope at/near the receptor binding region of the hormone. The mapped site forms a part of the seat belt region and the cystine knot region (C34-C38-C88-C90-H106). The carboxy terminal region of the alpha-subunit forms a part of the epitope indicating its proximity to the receptor binding region. These results are in agreement with the reported receptor binding region identified through other approaches and the X-ray crystal structure of hCG.

Inertial mass of a vortex in cuprate superconductors

We present here a calculation of the inertial mass of a moving vortex in cuprate superconductors. This is a poorly known basic quantity of obvious interest in vortex dynamics. The motion of a vortex causes a dipolar density distortion and an associated electric field which is screened. The energy cost of the density distortion as well as the related screened electric field contributes to the vortex mass, which is small because of efficient screening. As a preliminary, we present a discussion and calculation of the vortex mass using a microscopically derivable phase-only action functional for the far region which shows that the contribution from the far region is negligible and that most of it arises from the (small) core region of the vortex. A calculation based on a phenomenological Ginzburg-Landau functional is performed in the core region. Unfortunately such a calculation is unreliable; the reasons for it are discussed. A credible calculation of the vortex mass thus requires a fully microscopic non-coarse-grained theory. This is developed, and results are presented for an s-wave BCS-like gap, with parameters appropriate to the cuprates. The mass, about 0.5m(e) per layer, for a magnetic field along the c axis arises from deformation of quasiparticle states bound in the core and screening effects mentioned above. We discuss earlier results, possible extensions to d-wave symmetry, and observability of effects dependent on the inertial mass. [S0163-1829(97)05534-3].

Evidence for Permo-Triassic collision in Far East Asia: The Korean collisional orogen

Eclogites from paragneiss in the Korean Peninsula are characterized by a peak pressure assemblage of garnet + omphacite + quartz + rutile, that is overprinted by multiphase symplectites involving augite, amphibole, orthopyroxene, ilmenite and plagioclase and by a similar high-pressure assemblage with a pronounced absence of the omphacite component in clinopyroxene formed during the peak and orthopyroxene in the retrograde stage. Eclogites were metamorphosed at a minimum pressures of not, vert, similar 20–23 kbar at temperatures of not, vert, similar 840–1000 °C, equivalent to a crustal depth of not, vert, similar 70–75 km, whereas high-pressure granulite in Late Paleozoic rocks underwent metamorphic conditions of not, vert, similar 18–19 kbar at not, vert, similar 950 °C with a minimum crustal depth of not, vert, similar 60–65 km. The presence of the eclogites and high-pressure granulite suggests deep-seated subduction of crustal complexes with metamorphism at different crustal levels. The eclogites were exhumed quickly resulting in near- isothermal decompression. On the other hand, the multistage exhumation of the high-pressure granulites suggests retrograde overprinting after initial decompression. The similarity of these petrological characteristics, metamorphic conditions and also the regional structural styles with those of the Sulu belt (China) strongly suggests the existence of a Permo-Triassic Alpine-type “Korean collision belt” in Far East Asia. This model provides a better understanding of the paleogeograpic evolution of Permo-Triassic East Asia, including a robust tectonic correlation of the Korean collision belt with the Qinling–Dabie–Sulu collision belt.

Lopsided spiral galaxies

The light distribution in the disks of many galaxies is ‘lopsided’ with a spatial extent much larger along one half of a galaxy than the other, as seen in M101. Recent observations show that the stellar disk in a typical spiral galaxy is significantly lopsided, indicating asymmetry in the disk mass distribution. The mean amplitude of lopsidedness is 0.1, measured as the Fourier amplitude of the m=1 component normalized to the average value. Thus, lopsidedness is common, and hence it is important to understand its origin and dynamics. This is a new and exciting area in galactic structure and dynamics, in contrast to the topic of bars and two-armed spirals (m=2) which has been extensively studied in the literature. Lopsidedness is ubiquitous and occurs in a variety of settings and tracers. It is seen in both stars and gas, in the outer disk and the central region, in the field and the group galaxies. The lopsided amplitude is higher by a factor of two for galaxies in a group. The lopsidedness has a strong impact on the dynamics of the galaxy, its evolution, the star formation in it, and on the growth of the central black hole and on the nuclear fuelling. We present here an overview of the observations that measure the lopsided distribution, as well as the theoretical progress made so far to understand its origin and properties. The physical mechanisms studied for its origin include tidal encounters, gas accretion and a global gravitational instability. The related open, challenging problems in this emerging area are discussed.

Synthesis and Spectroscopic Investigations of Complexes of Lanthanide Nitrates with N-(4-Hethyl-2-Pyridyl)-Acetamide

New complexes of Lanthanide nitrates with N-(4-methyl-2-pyridyl)-acetamide (4-me-aapH) of the general formulae. [Ln(4-me-aapH)2] [NO3] (where Ln=La=La-Yb and Y)have been synthesized and haracterised by chemical analysis, molar conductivity and physical methods such as infrared, 13C NMR an electronic spectra in the visible region. Molar conductance and infrared data point to the presence to the coordinated nitrates groups. Infrared and 13C NMR data have been interpreted in terms of the coordination of the legand to the metal ion through the oxygen of the secondary amide and nitrogen of the hetrocyclic ring, in a bidentate fashion. Coordination number of ten seems probable for the complexes.

Infrared spectroscopic study of the rotation of the NH 4+ ion in ammonium halides

Infrared correlation functions, have been obtained from the analysis of band shapes of the 1400 cm−1 bending mode of NH4Cl, NH4Br and NH4I in both the Pm3m and Fm3m phases. The NH 4 + ion seems to undergo relatively free rotation in the high temperature Fm3m phases of these halides.

Infrared Spectra and Conformation of N-Acetylthiourea

Infrared spectra of N-acetylthiourea (ATU) and its N,N,N′-trideuterated compound have been examined in the range 4000–50 cm−1. A complete vibrational assignment with a normal coordinate treatment based on a Urey-Bradley type intramolecular potential function supplemented with valence force function for the out of plane and torsional modes is proposed and the feature of the thioureido vibrations explained. A molecular orbital study by the CNDO/2 method of ATU and its oxygen analog is undertaken and the results are analyzed for a comparative study of the molecular electronic structure and conformation.

He II spectra of La, Ce and Yb: Novel features in the valence band region

He II photoelectron spectra of La, Ce and Yb show features which cannot be explained in terms of single electron excitations. It is proposed that these are due to formation of electron-hole paris.

Governance Matters : China's Developing Western Region with a Focus on Qinghai Province

This study is about governance in contemporary China. The focus is on Qinghai Province, one of the twelve provincial-level units included in the western region development strategy launched in 2000 by the government of China. Qinghai, the subject of the case study, is not a very well-known province. Hence, this study is significant, because it provides new knowledge about the province of Qinghai, its governance and diverse challenges, and deepens one s overall knowledge regarding China. Qinghai province is one of the slowest developing regions of China. My research problem is to analyze to what extent provincial development correlates with the quality of governance. The central concept of this research is good governance. This dissertation employs a grounded theory approach while the theoretical framework of this study is built on the Three World s approach of analyzing the three main themes, namely, the environment, economic development, and cultural diversity, and to support the empirical work. Philosophical issues in the humanities and contemporary theories of governance are brought in to provide deeper understanding of governance, and to understand to what extent and how characteristics of good governance (derived from the Western canon) are combined with Chinese tradition. A qualitative research method is chosen to provide a deeper understanding of the contemporary challenges of Qinghai (and China) and to provide some insight into the role and impact of governance on provincial development. It also focuses on the Tibetan ethnic group in order to develop as full an understanding as possible about the province. The challenges faced by Qinghai concern in particular its environment, economic development, and cultural diversity, all of which are closely interrelated. The findings demonstrate that Qinghai Province is not a powerful actor, because it has weak communications with the central government and weak collaboration with its stakeholders and civil society. How Qinghai s provincial government conducts provincial development remains a key question in terms of shaping the province s future. The question is how is Qinghai s government best able to govern in a way that is beneficial for the people. This study demonstrates that this is a significant question that challenges governance everywhere, and particularly in China given the absence of democracy. This study provides the ingredients for reflection as to how provincial government can be motivated to choose to govern in a sustainable way, instead of leaning on growth factors with too little consideration about the impact on the environment and the people.