Transient Heat Conduction Due To A Circular Pipe Buried In A Half-space

This thesis considers the two-dimensional transient heat conduction problems due to a circular cylinder held at one constant temperature and immersed in a conducting medium with its axis parallel to a plane surface held at another constant temperature. In the conducting medium each phase is assumed to have constant properties.;Approximate perturbation solutions are obtained for: (i) the simple problem, in which the boundary temperatures are such that no change-of-phase takes place in the medium and (ii) the non-linear two-phase problem where change-of-phase occurs at a temperature between the boundary temperatures.;These analyses are mathematical idealisations of the physical problem of, say, a pipe containing a warm liquid flowing through a cold environment (or its converse) and, in case (ii), melting the frozen material near the pipe.;Although numerical methods of solution for both of these cases are available, the convenience and usefulness of simple analytical approximations is obvious. In the case of the non-linear problem, the accuracy of the methods employed is questionable

Vagal nerve stimulation therapy: what is being stimulated?

Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity

On the emergence of the Λ{\bf\Lambda}CDM model from self-interacting Brans-Dicke theory in d=5{\bf d= 5}

We investigate whether a self-interacting Brans-Dicke theory in $d=5$ without matter and with a time-dependent metric can describe, after dimensional reduction to $d=4$, the FLRW model with accelerated expansion and non-relativistic matter. By rewriting the effective 4-dimensional theory as an autonomous three-dimensional dynamical system and studying its critical points, we show that the $\Lambda$CDM cosmology cannot emerge from such a model. This result suggests that a richer structure in $d=5$ may be needed to obtain the accelerated expansion as well as the matter content of the 4-dimensional universe.Comment: 7 pages, 7 figure

Vagal Nerve Stimulation Therapy: What Is Being Stimulated?

Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity

How affective-motivational variables and approaches to learning predict mathematics achievement in upper elementary levels

The relationship between students' motivation and attitudes towards mathematics, the approaches to learning they use, and their achievement in mathematics has been widely documented in middle school and further academic levels. However, the empirical research in earlier educational stages remains scarce. This study analyzed the predictive value of affective-motivational variables and deep and surface approaches to learning on mathematics achievement in a sample of 524 upper elementary students. Multiple linear regression analysis was used to examine the predictors of mathematics achievement. Mathematics enjoyment positively predicted mathematics achievement and age and the use of the surface approach to learning negatively predicted mathematics achievement. The variables in the model explained 21.3% of the variance in mathematics achievement. Mean differences in the affective-motivational variables and approaches to learning occurred between students with very high and very low achievement in Mathematics, yielding further evidence of important differences between the achievement extremes

Constructing the eastern european other: The horsemeat scandal and the migrant other

The Horsemeat scandal in the UK in 2013 ignited a furore about consumer deception and the bodily transgression of consuming something so alien to the British psyche. The imagination of the horse as a noble and mythic figure in British history and sociological imagination was invoked to construct the consumption of horsemeat as a social taboo and an immoral proposition in the British media debates. This paper traces the horsemeat scandal and its media framing in the UK. Much of the aversion to horsemeat was intertextually bound with discourses of immigration, the expansion of the EU and the threat in tandem to the UK. Food as a social and cultural artefact laden with symbolic meaning and national pride became a platform to construct the ‘Other’ – in this case the Eastern European Other. The media debates on the horsemeat scandal interwove the opening up of the EU and particularly UK to the influx of Eastern European migration. The horsemeat controversy in implicating the Eastern Europeans for the contamination of the supply chain became a means to not just construct the ‘Other’ but also to entwine contemporary policy debates about immigration. This temporal framing of contemporary debates enables a nation to renew and contemporise its notions of ‘otherness’ while sustaining an historic social imaginary of itself

(Arecaceae: Calamoideae), an Amazonian palm with cultivation purposes in Peru

The plant. The aguaje (Mauritia flexuosa L. f.) is an Amazonian palm which grows naturally on flooded soils, forming dense gatherings called aguajales in Peru. It can reach a height of 35–40 m. Each tree has an average of 8 inflorescences per year and each inflorescence produces about 900 fruits. This palm is in the domestication process. A dwarf form, recently discovered, could permit the improvement of the methods of production. The fruit. The fruit is an ellipsoid oval-shaped drupe, covered by red or dark red-coloured cornea scales. It measures (5 to 7) cm long and (4 to 5) cm in diameter. The pulp has a high content of β-carotene (260 mg·100 g–1 of pulp). Marketing. Marketing is carried out for fruits coming from the natural environment. There is a local consumption of approximately 150 t·month–1 and it can be of raw or processed fruit. For this fruit’s demand, it is necessary to cut down approximately 24 000 palms a year. Discussion. The aguaje has big social and economical importance to these regions' inhabitants. It represents great potential for the national as well as the international market. The Research Institute of the Peruvian Amazon (IIAP) is devel-oping technologies for agronomical management of the species, and for production and proc-essing of the fruit. Studies on aguaje growth and genetic diversity in the natural conditions also have to be carried out

Closed-form approximations to solutions of plasmon dispersion at a dielectric/conductor interface

The dispersion equation for surface plasmons (SPs) at a dielectric/conductor interface has been studied extensively with respect to the design of plasmonic devices. A key design requirement is the reduction of clamping in the propagating SP polariton wave. Satisfaction of this constraint requires that an "electron gas" in a conducting medium, such as a doped semiconductor, move along the interface at speeds that approximate the polariton wave speed. At these low relative speeds, the efficient exchange of energy between the drifting electrons and a traveling SP polariton may he enabled. The ill-conditioned, eighth-order, complex coefficients dispersion equation derived earlier is dependent upon six parameters that vary over many orders of magnitude. The dispersion equation is also found to be singular in regions of practical interest, and, taken together, these properties have hampered the success of numerical investigations. Therefore, the dispersion equation is analytically investigated here, and closed-form results are found for the parametric dependence of the surface polariton's propagation constant on five dimensionless groups. These new solutions show how compensation of propagation losses without the use of structures can he achieved and provide avenues that guide device design. The closed-form results are used to initialize numerical optimization by providing sufficiently accurate starting points within the parameter space that avoid numerical ill-conditioning.Web of Science545art. no. 720040

Networked Mathematical Model

The mathematical model is stored in a zip file. The model is written in JAVA. There is a readme file that explains how to compile and run the file. If there are any questions please contact the first author and full assistance will be supplied