DC-DC Boost Converter with Constant Output Voltage for Grid Connected Photovoltaic Application System

The main purpose of this paper is to introduce an approach to design a DC-DC boost converter with constant output voltage for grid connected photovoltaic application system. The boost converter is designed to step up a fluctuating solar panel voltage to a higher constant DC voltage. It uses voltage feedback to keep the output voltage constant. To do so, a microcontroller is used as the heart of the control system which it tracks and provides pulse-width-modulation signal to control power electronic device in boost converter. The boost converter will be able to direct couple with grid-tied inverter for grid connected photovoltaic system. Simulations were performed to describe the proposed design. Experimental works were carried out with the designed boost converter which has a power rating of 100 W and 24 V output voltage operated in continuous conduction mode at 20 kHz switching frequency. The test results show that the proposed design exhibits a good performance

The experience of animal therapy in residential aged care in New Zealand : a narrative analysis : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Psychology at Massey University, Wellington, New Zealand

Volunteer-led animal visitation programmes are common within Aged Residential Care facilities in New Zealand. Visits by animals and handlers, often referred to as Animal Therapy, are primarily social and intended to improve the quality of life of people in residential care. Animal Therapy has been shown to have both physiological and psychological benefits for older people, including improvements in outlook and social interaction. Very little research has been conducted in New Zealand, particularly on the informal animal visitation programmes typical in care facilities in New Zealand. This project examined the experience of animal therapy in aged residential care. In-depth interviews were conducted with seven older people about their experiences of animal therapy, and analysed using narrative analysis. Older people in residential care do value animal therapy, but it is narrated as a fleeting pleasure, rather than having a long-lasting or far-reaching impact on the daily experience of residential care. In some ways, the structure of the AAA programme may underscore the challenges to everyday autonomy and identity in the everyday lived experience of residential aged care. This can be used to develop services that acknowledge the context of living in aged care for residents

Dynamic scaling theory of the forced translocation of a semi-flexible polymer through a nanopore

We present a theoretical description of the dynamics of a semi-flexible polymer being pulled through a nanopore by an external force acting at the pore. Our theory is based on the tensile blob picture of Pincus in which the front of the tensile force propagates through the backbone of the polymer, as suggested by Sakaue and recently applied to study a completely flexible polymer with self-avoidance, by Dubbledam et al. For a semi-flexible polymer with a persistence length P , its statistics is self-avoiding for a very long chain. As the local force increases, the blob size starts to decrease. At the blob size P/a^2 , where a is the size of a monomer, the statistics becomes that of an ideal chain. As the blob size further decreases to below the persistence length P, the statistics is that of a rigid rod. We argue that semi-flexible polymer in translocation should include the three regions: a self-avoiding region, an ideal chain region and a rigid rod region, under uneven tension propagation, instead of a uniform scaling picture as in the case of a completely flexible polymer. In various regimes under the effect of weak, intermediate and strong driving forces we derive equations from which we can calculate the translocation time of the polymer. The translocation exponent is given by \alpha=1+\mu, where \mu is an effective exponent for the end-to-end distance of the semi-flexible polymer, having a value between 1/2 and 3/5, depending on the total contour length of the polymer. Our results are of relevance for forced translocation of biological polymers such as DNA through a nanopore.Comment: 21 pages, 3 figure

Fast Disk Conformal Parameterization of Simply-connected Open Surfaces

Surface parameterizations have been widely used in computer graphics and geometry processing. In particular, as simply-connected open surfaces are conformally equivalent to the unit disk, it is desirable to compute the disk conformal parameterizations of the surfaces. In this paper, we propose a novel algorithm for the conformal parameterization of a simply-connected open surface onto the unit disk, which significantly speeds up the computation, enhances the conformality and stability, and guarantees the bijectivity. The conformality distortions at the inner region and on the boundary are corrected by two steps, with the aid of an iterative scheme using quasi-conformal theories. Experimental results demonstrate the effectiveness of our proposed method