Ionization fronts in coupled MHD-gas simulations

Partially ionized plasmas are ubiquitous in both nature and the laboratory, and their behaviour is best described by models which take into account the interactions between the neutral and charged species. We present a new non-linear, 3-dimensional, finite difference Gas-MHD Interactions Code designed to solve simultaneously the time evolution of fluid equations of both species in the conservation form as well as collisional interactions between them via appropriate choices of source term; in particular, we present results from this code in simulating Alfvén ionization in a partially ionized plasma. In this fashion, larger changes in the ionization fraction than were addressable in the linear limit are possible. Alfvén ionization is shown to impart plasmas with an inherent resistance to rapid recombination, where the recombination itself is significant enough to drive relative motion between the ionised and neutral species at speeds in excess of the critical velocity

Methodological issues in measures of imitative reaction times

Ideomotor (IM) theory suggests that observing someone else perform an action activates an internal motor representation of that behaviour within the observer. Evidence supporting the case for an ideomotor theory of imitation has come from studies that show imitative responses to be faster than the same behavioural measures performed in response to spatial cues. In an attempt to replicate these findings, we manipulated the salience of the visual cue and found that we could reverse the advantage of the imitative cue over the spatial cue. We suggest that participants utilised a simple visuomotor mechanism to perform all aspects of this task, with performance being driven by the relative visual salience of the stimuli. Imitation is a more complex motor skill that would constitute an inefficient strategy for rapid performance

Ecological and evolutionary processes at expanding range margins

Many animals are regarded as relatively sedentary and specialized in marginal parts of their geographical distributions. They are expected to be slow at colonizing new habitats. Despite this, the cool margins of many species' distributions have expanded rapidly in association with recent climate warming. We examined four insect species that have expanded their geographical ranges in Britain over the past 20 years. Here we report that two butterfly species have increased the variety of habitat types that they can colonize, and that two bush cricket species show increased fractions of longer-winged (dispersive) individuals in recently founded populations. Both ecological and evolutionary processes are probably responsible for these changes. Increased habitat breadth and dispersal tendencies have resulted in about 3- to 15-fold increases in expansion rates, allowing these insects to cross habitat disjunctions that would have represented major or complete barriers to dispersal before the expansions started. The emergence of dispersive phenotypes will increase the speed at which species invade new environments, and probably underlies the responses of many species to both past and future climate change

Constrained action selection in children with developmental coordination disorder

The effect of advance (‘precue’) information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n = 10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic

Effective scraping in a scraped surface heat exchanger: some fluid flow analysis

An outline of mathematical models that have been used to understand the behaviour of scraped surface heat exchangers is presented. In particular the problem of the wear of the blades is considered. A simple model, exploiting known behaviour of viscous flow in corners and in wedges, and accounting for the forces on the blade is derived and solutions generated. The results shows initial rapid wear but that the wear rate goes to zero

Linking routinely collected social work, education and health data to enable monitoring of the health and health care of school-aged children in state care (‘looked after children’) in Scotland: a national demonstration project

Background and objectives: Children in state care (‘looked after children’) have poorer health than children who are not looked after. Recent developments in Scotland and elsewhere have aimed to improve services and outcomes for looked after children. Routine monitoring of the health outcomes of looked after children compared to those of their non-looked after peers is currently lacking. Developing capacity for comparative monitoring of population based outcomes based on linkage of routinely collected administrative data has been identified as a priority. To our knowledge there are no existing population based data linkage studies providing data on the health of looked after and non-looked after children at national level. Smaller scale studies that are available generally provide very limited information on linkage methods and hence do not allow scrutiny of bias that may be introduced through the linkage process. Study design and methods: National demonstration project testing the feasibility of linking routinely collected looked after children, education, and health data. Participants: All children in publicly funded school in Scotland in 2011/12. Results: Linkage between looked after children data and the national pupil census classified 10,009 (1.5%) and 1,757 (0.3%) of 670,952 children as, respectively, currently and previously looked after. Recording of the unique pupil identifier (Scottish Candidate Number, SCN) on looked after children returns is incomplete, with 66% of looked after records for 2011/12 for children of possible school age containing a valid SCN. This will have resulted in some under-ascertainment of currently and, particularly, previously looked after children within the general pupil population. Further linkage of the pupil census to the NHS Scotland master patient index demonstrated that a safe link to the child’s unique health service (Community Health Index, CHI) number could be obtained for a very high proportion of children in each group (94%, 95%, and 95% of children classified as currently, previously, and non-looked after respectively). In general linkage rates were higher for older children and those living in more affluent areas. Within the looked after group, linkage rates were highest for children with the fewest placements and for those in permanent fostering. Conclusions: This novel data linkage demonstrates the feasibility of monitoring population based health outcomes of school aged looked after and non-looked after children using linked routine administrative data. Improved recording of the unique pupil identifier number on looked after data returns would be beneficial. Extending the range of personal identifiers on looked after children returns would enable linkage to health data for looked after children who are not in publicly funded schooling (i.e. those who are pre- or post-school, home schooled, or in independent schooling)

Quantum interference in nanofractals and its optical manifestation

We consider quantum interferences of ballistic electrons propagating inside fractal structures with nanometric size of their arms. We use a scaling argument to calculate the density of states of free electrons confined in a simple model fractal. We show how the fractal dimension governs the density of states and optical properties of fractal structures in the RF-IR region. We discuss the effect of disorder on the density of states along with the possibility of experimental observation.Comment: 19 pages, 6 figure

ANALISIS PRIORITAS STRATEGI BAURAN PEMASARAN PRODUK OLAHAN SALUANG DI KECAMATAN JEKAN RAYA KOTA PALANGKA RAYA (STUDI KASUS P-IRT RIFANDA)

Tujuan dari penelitian ini untuk menganalisis strategi bauran pemasaran saluang di IRT Rifanda dan  menganalisis prioritas strategi bauran pemasaran yang tepat untuk dijalankan pada usaha saluang IRT Rifanda di Kecamatan Jekan Raya Kota Palangka Raya. Metode yang digunakan dalam penelitian ini adalah metode Analisis Hirarki Proses (AHP). Strategi pemasaran yang dijalankan oleh pelaku usaha IRT Rifanda dengan tujuan usaha yang mempengaruhi strategi pemasaran, pada strategi meningkatkan penjualan diperoleh bahwa faktor promosi dengan sub faktor diskon merupakan kriteria yang paling mempengaruhi.  Pada strategi meningkatkan pendapatan, faktor harga dengan sub faktor  bahan baku merupakan  kriteria yang paling dominan mempengaruhi.  Sedangkan pada strategi dengan tujuan memperluas pasar, diketahui kriteria yang akan berpengaruh adalah faktor tempat, dimana  sub faktor telpon memiliki nilai tinggi dibandingkan alternatif penjualan langsung, melalui supermarket dan toko

Void elimination in screen printed thick film dielectric pastes

The problem is to understand the mechanisms for the formation and evolution of defects in wet screen printed layers. The primary objective is to know how best to alter the properties of the paste (rather than the geometry of the screen printing process itself) in order to eliminate the defects. With these goals in mind the work done during the Study Group reported here was as follows; to describe a simple model for the closure of craters, a model for the partial closure of vias, a possible mechanism for the formation of pinholes and finally a more detailed consideration of the screen printing process