Thermoelasticity and generalized thermoelasticity viewed as wave hierarchies

It is seen how to write the standard\^E form of the four partial differential equations in four unknowns of anisotropic thermoelasticity as a single equation in one variable, in terms of isothermal and isentropic wave operators. This equation, of diffusive type, is of the eighth order in the space derivatives and seventh order in the time derivatives and so is parabolic in character. After having seen how to cast the 1D diffusion equation into Whitham's wave hierarchy form it is seen how to recast the full equation, for uni-directional motion, in wave hierarchy form. The higher order waves are isothermal and the lower order waves are isentropic or purely diffusive. The wave hierarchy form is then used to derive the main features of the solution of the initial value problem, thereby bypassing the need for an asymptotic analysis of the integral form of the exact solution. The results are specialized to the isotropic case. The theory of generalized thermoelasticity associates a relaxation time with the heat flux vector and the resulting system of equations is hyperbolic in character. It is seen also how to write this system in wave hierarchy form which is again used to derive the main features of the solution of the initial value problem. Simpler results are obtained in the isotropic case.Comment: 16 page

Varying the texture: a study of art, learning and multimedia

Art Explorer is an innovative multimedia system being designed and developed within the Institute of Educational Technology, at The Open University. Based on an analogy to dreams, Art Explorer is structured into several episodes. Each episode is designed to help beginning students of Art History foster personal constructs about paintings and develop a richer understanding of how their perceptions of paintings work. This discussion focuses on the pedagogic rationale motivating Art Explorer's development and is structured around two strands of a design story. First, it highlights the research behind the design. The reported research is about learners' problems - most specifically about the varying conceptual, perceptual and affective challenges learners face as they begin to study Art History. But, more broadly, it is about the problems faced by learners as they begin academic study and seek to engage with the knowledge and methods of discipline experts. Secondly, and it is argued, as a second pedagogic priority, the spotlight shifts to multimedia. The discussion tracks design decisions that aim both to exploit the potential of the medium and to match pre-identified learner needs. The ingredients of Art Explorer are described to illustrate some of the rich potential of the medium for negotiating understanding between teacher and learner

Transition to organic food in Danish public procurement: can a top-down approach capture the practice?

This paper is addressing the attention towards organic transition processes which takes place in a Danish political context at the moment. With departure in the explicit propositions in an organic vision 2020 launched by the Danish government the practice in public kitchens is presented and discussed. The main findings in several recent studies address the lack of relations between key actors in the field and the challenges in embedding the change into a resilient practice. Especially the relation between kitchen staff and the public administrations seems to be lacking. The political aim is translated into an economic support program dedicated only the teaching of kitchen staff, but does not see the relational character of the transition. Concluding remarks underlines the complexity of a transition approach and problematizes the narrow focus on educational activities as the primary initiative to make farmers and public kitchens convert their production to organic

Odd Harmonious Labeling of Some Graphs

The labeling of discrete structures is a potential area of research due to its wide range of applications. The present work is focused on one such labeling called odd harmonious labeling

Perspectives from agriculture: advances in livestock breeding - implications for aquaculture genetics

In this paper we present livestock breeding developments that could be taken into consideration in the genetic improvement of farmed aquaculture species, especially in freshwater fish. Firstly, the current breeding objective in aquatic species has focused almost exclusively on the improvement of body weight at harvest or on growth related traits. This is unlikely to be sufficient to meet the future needs of the aquaculture industry. To meet future demands breeding programs will most likely have to include additional traits, such as fitness related ones (survival, disease resistance), feed efficiency, or flesh quality, rather than only growth performance. In order to select for a multi-trait breeding objective, genetic variation in traits of interest and the genetic relationships among them need to be estimated. In addition, economic values for these traits will be required. Generally, there is a paucity of data on variable and fixed production costs in aquaculture, and this could be a major constraint in the further expansion of the breeding objectives. Secondly, genetic evaluation systems using the restricted maximum likelihood method (REML) and best linear unbiased prediction (BLUP) in a framework of mixed model methodology could be widely adopted to replace the more commonly used method of mass selection based on phenotypic performance. The BLUP method increases the accuracy of selection and also allows the management of inbreeding and estimation of genetic trends. BLUP is an improvement over the classic selection index approach, which was used in the success story of the genetically improved farmed tilapia (GIFT) in the Philippines, with genetic gains from 10 to 20 per cent per generation of selection. In parallel with BLUP, optimal genetic contribution theory can be applied to maximize genetic gain while constraining inbreeding in the long run in selection programs. Thirdly, by using advanced statistical methods, genetic selection can be carried out not only at the nucleus level but also in lower tiers of the pyramid breeding structure. Large scale across population genetic evaluation through genetic connectedness using cryopreserved sperm enables the comparison and ranking of genetic merit of all animals across populations, countries or years, and thus the genetically superior brood stock can be identified and widely used and exchanged to increase the rate of genetic progress in the population as a whole. It is concluded that sound genetic programs need to be established for aquaculture species. In addition to being very effective, fully pedigreed breeding programs would also enable the exploration of possibilities of integrating molecular markers (e.g., genetic tagging using DNA fingerprinting, marker (gene) assisted selection) and reproductive technologies such as in-vitro fertilization using cryopreserved spermatozoa

Emissions of N2O and NO from fertilized fields: summary of available measurement data

Information from 846 N2O emission measurements in agricultural fields and 99 measurements for NO emissions was summarized to assess the influence of various factors regulating emissions from mineral soils. The data indicate that there is a strong increase of both N2O and NO emissions accompanying N application rates, and soils with high organic-C content show higher emissions than less fertile soils. A fine soil texture, restricted drainage, and neutral to slightly acidic conditions favor N2O emission, while (though not significant) a good soil drainage, coarse texture, and neutral soil reaction favor NO emission. Fertilizer type and crop type are important factors for N2O but not for NO, while the fertilizer application mode has a significant influence on NO only. Regarding the measurements, longer measurement periods yield more of the fertilization effect on N2O and NO emissions, and intensive measurements (=1 per day) yield lower emissions than less intensive measurements (2–3 per week). The available data can be used to develop simple models based on the major regulating factors which describe the spatial variability of emissions of N2O and NO with less uncertainty than emission factor approaches based on country N inputs, as currently used in national emission inventories

A Study On The Implementation Of Rotation Roles To Improve Students’ English Skill At The Second Year Of SMP Muhammadiyah 2 Karanganyar

This research aims at (1) describing a study on the implementation of rotating roles to improve students english skill of the second year of SMP Muhammadiya2 Karanganyar and (2) finding the problems faced by the students and the teacher during the teaching and learning speaking skill using retelling story. In collection the data, the writer used obsecrvation, interview, and document. This research paper is about a study on the implementation of rotating roles to improve students english skill of the second year of SMP Muhammadiya2 Karanganyar. Rotating Role is a kind of method to develop the student’s competence in vocabulary mastery, to comprehend the story, to develop their creativity to Improving by their own words and develop their own imagination about the story. Retelling story is independent work task. The students do the task independently, based on their own competence. The results of the research show that: 1) teaching speaking using retelling story influences the students speaking master, 2) The students are very enthusiastic in learning speaking, most of them have high motivation in joining the class and great part of the students participate to be active in front of the class. 3) Teaching speaking using retelling story is very effective

LHC-B Ring Imaging Cherenkov Detector

The progress towards the realisation of the LHC-B Ring Imaging Cherenkov detector is reported.Comment: 5 pages. 5 postscript figures + 1 postscript preprint logo + 1 LaTeX file + 1 style file. Also available at http://ppewww.ph.gla.ac.uk/preprints/97/14/ Invited talk given at Beauty'9

Modelling global annual N2O and NO emissions from fertilized fields

Information from 846 N2O emission measurements in agricultural fields and 99 measurements for NO emissions was used to describe the influence of various factors regulating emissions from mineral soils in models for calculating global N2O and NO emissions. Only those factors having a significant influence on N2O and NO emissions were included in the models. For N2O these were (1) environmental factors (climate, soil organic C content, soil texture, drainage and soil pH); (2) management-related factors (N application rate per fertilizer type, type of crop, with major differences between grass, legumes and other annual crops); and (3) factors related to the measurements (length of measurement period and frequency of measurements). The most important controls on NO emission include the N application rate per fertilizer type, soil organic-C content and soil drainage. Calculated global annual N2O-N and NO-N emissions from fertilized agricultural fields amount to 2.8 and 1.6 Mtonne, respectively. The global mean fertilizer-induced emissions for N2O and NO amount to 0.9% and 0.7%, respectively, of the N applied. These overall results account for the spatial variability of the main N2O and NO emission controls on the landscape scal

A reconfigurable hybrid intelligent system for robot navigation

Soft computing has come of age to o er us a wide array of powerful and e cient algorithms that independently matured and in uenced our approach to solving problems in robotics, search and optimisation. The steady progress of technology, however, induced a ux of new real-world applications that demand for more robust and adaptive computational paradigms, tailored speci cally for the problem domain. This gave rise to hybrid intelligent systems, and to name a few of the successful ones, we have the integration of fuzzy logic, genetic algorithms and neural networks. As noted in the literature, they are signi cantly more powerful than individual algorithms, and therefore have been the subject of research activities in the past decades. There are problems, however, that have not succumbed to traditional hybridisation approaches, pushing the limits of current intelligent systems design, questioning their solutions of a guarantee of optimality, real-time execution and self-calibration. This work presents an improved hybrid solution to the problem of integrated dynamic target pursuit and obstacle avoidance, comprising of a cascade of fuzzy logic systems, genetic algorithm, the A* search algorithm and the Voronoi diagram generation algorithm