809 research outputs found
Start to end simulations of the ERL prototype at Daresbury Laboratory
Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will serve as a research and development facility for the study of beam dynamics and accelerator technology important to the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives of the ERLP are the demonstration of energy recovery and of energy recovery from a beam disrupted by an FEL interaction as supplied by an infrared oscillator system. In this paper we present start-to-end simulations of the ERLP including such an FEL interaction. The beam dynamics in the highbrightness injector, which consists of a DC photocathode Gun and a superconducting booster, have been modelled using the particle tracking code ASTRA. After the booster the particles have been tracked with the code elegant. The 3D code GENESIS 1.3 was used to model the FEL interaction with the electron beam at 35 MeV. A brief summary of impedance and wakefield calculations for the whole machine is also given
A practical <i>O</i>(<i>n</i> log<sup>2</sup> <i>n</i>) time algorithm for computing the triplet distance on binary trees
Geometric representations for minimalist grammars
We reformulate minimalist grammars as partial functions on term algebras for
strings and trees. Using filler/role bindings and tensor product
representations, we construct homomorphisms for these data structures into
geometric vector spaces. We prove that the structure-building functions as well
as simple processors for minimalist languages can be realized by piecewise
linear operators in representation space. We also propose harmony, i.e. the
distance of an intermediate processing step from the final well-formed state in
representation space, as a measure of processing complexity. Finally, we
illustrate our findings by means of two particular arithmetic and fractal
representations.Comment: 43 pages, 4 figure
Histological Evaluation of the Biocompatibility of Polyurea Crosslinked Silica Aerogel Implants in a Rat Model: A Pilot Study
Background: Aerogels are a versatile group of nanostructured/nanoporous materials with physical and chemical properties that can be adjusted to suit the application of interest. In terms of biomedical applications, aerogels are particularly suitable for implants such as membranes, tissue growth scaffolds, and nerve regeneration and guidance inserts. The mesoporous nature of aerogels can also be used for diffusion based release of drugs that are loaded during the drying stage of the material. From the variety of aerogels polyurea crosslinked silica aerogels have the most potential for future biomedical applications and are explored here. Methodology: This study assessed the short and long term biocompatibility of polyurea crosslinked silica aerogel implants in a Sprague-Dawley rat model. Implants were inserted at two different locations a) subcutaneously (SC), at the dorsum and b) intramuscularly (IM), between the gluteus maximus and biceps femoris of the left hind extremity. Nearby muscle and other internal organs were evaluated histologically for inflammation, tissue damage, fibrosis and movement (travel) of implant. Conclusion/Significance: In general polyurea crosslinked silica aerogel (PCSA) was well tolerated as a subcutaneous and an intramuscular implant in the Sprague-Dawley rat with a maximum incubation time of twenty months. In some cases a thin fibrous capsule surrounded the aerogel implant and was interpreted as a normal response to foreign material. No noticeable toxicity was found in the tissues surrounding the implants nor in distant organs. Comparison was made with control rats without any implants inserted, and animals with suture material present. No obvious or noticeable changes were sustained by the implants at either location. Careful necropsy and tissue histology showed age-related changes only. An effective sterilization technique for PCSA implants as well as staining and sectioning protocol has been established. These studies further support the notion that silica-based aerogels could be useful as biomaterials. © 2012 Sabri et al
Bedingungen und Methoden zur Erhöhung der Leistungsbereitschaft junger WerktÀtiger im Prozeà der Meisterung des wissenschaftlich-technischen Fortschritts: (Komplexstudie 84 "Leistung") ; Schnellinformation
1984 wurden 3500 junge WerktĂ€tige in der DDR befragt zu folgenden Themen: Leistungsbereitschaft und Leistungsverhalten im ArbeitsprozeĂ; Zusammenhang zwischen Leistung und Einstellung zum "wissenschaftlich-technischen Schöpfertum"; politische Organisiertheit, insbesondere in der FDJ; Grad der Informiertheit ĂŒber die wirtschaftlichen Programme und Zielstellungen der SED. Nur 36 Prozent sind der Auffassung, ĂŒber den wissenschaftlich-technischen "Höchststand" auf ihrem Arbeitsgebiet gut und umfassend informiert zu sein. Relativ gering ist auch das Interesse an Jugendforschungskollektiven. (psz
SAT-based Explicit LTL Reasoning
We present here a new explicit reasoning framework for linear temporal logic
(LTL), which is built on top of propositional satisfiability (SAT) solving. As
a proof-of-concept of this framework, we describe a new LTL satisfiability
tool, Aalta\_v2.0, which is built on top of the MiniSAT SAT solver. We test the
effectiveness of this approach by demonnstrating that Aalta\_v2.0 significantly
outperforms all existing LTL satisfiability solvers. Furthermore, we show that
the framework can be extended from propositional LTL to assertional LTL (where
we allow theory atoms), by replacing MiniSAT with the Z3 SMT solver, and
demonstrating that this can yield an exponential improvement in performance
Choreography, controversy and child sex abuse: Theoretical reflections on a cultural criminological analysis of dance in a pop music video
This article was inspired by the controversy over claims of âpedophilia!!!!â undertones and the âtriggeringâ of memories of childhood sexual abuse in some viewers by the dance performance featured in the music video for Siaâs âElastic Heartâ (2015). The case is presented for acknowledging the hidden and/or overlooked presence of dance in social scientific theory and cultural studies and how these can enhance and advance cultural criminological research. Examples of how these insights have been used within other disciplinary frameworks to analyse and address child sex crime and sexual trauma are provided, and the argument is made that popular cultural texts such as dance in pop music videos should be regarded as significant in analysing and tracing public perceptions and epistemologies of crimes such as child sex abuse
Development of mobile sensors for estimation of grain qualities and contaminants to enhance nutrition and safety of grain-products in developing countries; current status
The governments of several developing countries responded to their population âmalnutrition crisisâ (P.Webb et al., 2018), among others, by promotion of crops of high nutritional value and their enhanced usage for food products formulations (e.g. âMillet Missionâ in India or âBlending Policyâ in Kenya). Simultaneously, several CGIAR crop improvement programs-initiated the development of nutritionally enhanced crop cultivars (e.g. ICRISAT, CIAT, IIT). In developing countries, the promotion of novel cultivars is generally a slow and tedious process, especially if the improved grain (quantity or quality) doesnât ultimately result in the economic incentives (e.g. the market price). Thus far, there is no economic advantage directly linked to the trade of bio-fortified crop cultivars in developing countries which does prevents their accelerated adoption. This may change if/once the necessary information on a crops value is enabled
Low percentage of clinically relevant pistachio nut and mango co-sensitisation in cashew nut sensitised children
Background: Cashew nut, pistachio nut and mango belong to the Anacardiaceae family and are botanically related. Therefore, cashew nut sensitised children are frequently advised to eliminate cashew nuts and pistachio nuts from their diet. The âImprovement of Diagnostic mEthods for ALlergy assessment (IDEAL trial number NTR3572) study showed that cashew nut sensitised children were co-sensitised to pistachio nut in 98% of cases and to mango in 21% of cases. The aim of this follow-up study to IDEAL is to assess the clinical relevance of co-sensitisation to pistachio nut and mango in cashew nut sensitised children. Methods: Children were recruited from the study: âImprovement of Diagnostic mEthods for ALlergy assessment (IDEAL trial number NTR3572). Inclusion criterion for the IDEAL study was sensitization to cashew nut as demonstrated by either SPT or sIgE, and a clinical history of reactions to cashew nuts or no previous (known) exposure. Sensitized children who were tolerant to cashew nuts were excluded. Inclusion criterion for this IDEAL follow-up study was co-sensitization to pistachio nut, regardless the result of the DBPCFC with cashew nut. In this follow-up study a double-blind placebo-controlled food challenge with pistachio nut and an open food challenge with mango were performed. Results: Twenty-nine children (mean age of 11.6 years, 62% male) were included. Pistachio nut sensitisation was clinically relevant in only 34% of cashew-sensitised children and only 31% of cashew challenge positive children. None of the children was challenge positive to mango. Conclusion: Although co-sensitisation between cashew nut and pistachio nut was observed in 98%, pistachio nut sensitisation was only clinically relevant in 34% of the children. Therefore, a challenge test with pistachio nut is recommended in children with cashew nut and pistachio nut sensitisation.</p
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