The behavior of bonded doubler splices for composite sandwich panels

The results of an investigation into the behavior of adhesively bonded doubler splices of two composite material sandwich panels are presented. The splices are studied from three approaches: analytical; numerical (finite elements); and experimental. Several parameters that characterize the splice are developed to determine their influence upon joint strength. These parameters are: doubler overlap length; core stiffness; laminate bending stiffness; the size of the gap between the spliced sandwich panels; and room and elevated temperatures. Similarities and contrasts between these splices and the physically similar single and double lap joints are discussed. The results of this investigation suggest several possible approaches to improving the strength of the sandwich splices

Explaining Violation Traces with Finite State Natural Language Generation Models

An essential element of any verification technique is that of identifying and communicating to the user, system behaviour which leads to a deviation from the expected behaviour. Such behaviours are typically made available as long traces of system actions which would benefit from a natural language explanation of the trace and especially in the context of business logic level specifications. In this paper we present a natural language generation model which can be used to explain such traces. A key idea is that the explanation language is a CNL that is, formally speaking, regular language susceptible transformations that can be expressed with finite state machinery. At the same time it admits various forms of abstraction and simplification which contribute to the naturalness of explanations that are communicated to the user

Coherent Pion Production by Neutrinos

I concentrate in this article on the reaction--coherent pion production by neutrinos incident on nuclei. A special effort is made in order to describe the approximations entering the calculation. I conclude that the reaction is well understood and with appropriate data for hadronic reactions is can be computed for low and high energies. Because of shortage of space I omitted the resonance analysis, which is described in articles with my collaborators.Comment: 4 pages. Proceedings of Conf. to be published by APS-Proceeding

Automated Fixing of Programs with Contracts

This paper describes AutoFix, an automatic debugging technique that can fix faults in general-purpose software. To provide high-quality fix suggestions and to enable automation of the whole debugging process, AutoFix relies on the presence of simple specification elements in the form of contracts (such as pre- and postconditions). Using contracts enhances the precision of dynamic analysis techniques for fault detection and localization, and for validating fixes. The only required user input to the AutoFix supporting tool is then a faulty program annotated with contracts; the tool produces a collection of validated fixes for the fault ranked according to an estimate of their suitability. In an extensive experimental evaluation, we applied AutoFix to over 200 faults in four code bases of different maturity and quality (of implementation and of contracts). AutoFix successfully fixed 42% of the faults, producing, in the majority of cases, corrections of quality comparable to those competent programmers would write; the used computational resources were modest, with an average time per fix below 20 minutes on commodity hardware. These figures compare favorably to the state of the art in automated program fixing, and demonstrate that the AutoFix approach is successfully applicable to reduce the debugging burden in real-world scenarios.Comment: Minor changes after proofreadin

COLD AIR REFRIGERATING MACHINES WITH MECHANICAL, THERMAL AND MATERIAL REGENERATION

The cold air refrigerating machines are practically of the same age as the vaporisation- compression-type refrigerating machines, however, the former ones were put in actual operation only during the past decades. As the principal reason for it, their lower economi- cal efficiency can be considered. However, the vaporisation-compression-type refrigerating machines cause heavy pollution to the environment (gap of ozone layer problem), there- fore the interest in the cold air refrigerating machines has been greatly aroused lately. In the paper, the operation, theory and application possibilities of the cold air refrigerating machines are dealt with, especially considering the air- conditioning of motor vehicles. The improvement of the economy of cold air refrigerating machines is especially paid great attention in this paper. In addition, the possibilities of applying heat exchangers, as well as the cooling process of the operating-medium during compression with the help of liquid charge are examined

Lifetime reduction of surface states at Cu, Ag and Au(111) caused by impurity scattering

We present density-functional results on the lifetime of the (111) surface state of the noble metals. We consider scattering on the Fermi surface caused by impurity atoms belonging to the 3d and 4sp series. The results are analyzed with respect to film thickness and with respect to separation of scattering into bulk or into surface states. While for impurities in the surface layer the overall trends are similar to the long-known bulk-state scattering, for adatom-induced scattering we find a surprising behavior with respect to the adatom atomic number. A plateau emerges in the scattering rate of the 3d adatoms, instead of a peak characteristic of the d resonance. Additionally, the scattering rate of 4sp adatoms changes in a zig-zag pattern, contrary to a smooth parabolic increase following Linde's rule that is observed in bulk. We interpret these results in terms of the weaker charge-screening and of interference effects induced by the lowering of symmetry at the surface

Modeling Lepton-Nucleon Inelastic Scattering from High to Low Momentum Transfer

We present a model for inclusive charged lepton-nucleon and (anti)neutrino-nucleon cross sections at momentum transfer squared, $Q^2$, $\sim1 {\rm GeV}^2$. We quantify the impact of existing low-Q charged-lepton deep-inelastic scattering (DIS) data on effects due to high-twist operators and on the extraction of parton distribution functions (PDFs). No evidence is found for twist-6 contributions to structure functions (SF), and for a twist-4 term in the logitudinal SF at $x\gtrsim0.1$. We find that DIS data are consistent with the NNLO QCD approximation with the target mass and phenomenological high twist corrections. For $Q^2<1 {\rm GeV}^2$, we extend extrapolation of the operator product expansion, preserving the low-$Q$ current-conservation theorems. The procedure yields a good description of data down to $Q^2\sim 0.5 {\rm GeV}^2$. An updated set of PDFs with reduced uncertainty and applicable down to small momentum transfers in the lepton-nucleon scattering is obtained.Comment: 10 pages, 6 figures, proceedings of the 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia, Illinois, 30 May - 3 Jun 200

Transaction costs and their implications to formation of contractual arrangements: aspects of machinery contracting by family farmers in the centro-serra region of Rio Grande do Sul.

A mecanização da produção agrícola desempenha um importante e crescente papel no curso do desenvolvimento agrícola e rural. A mecanização oferece diversas melhorias potenciais nos sistemas de produção tais como o incremento da produtividade da terra e do trabalho, a redução dos riscos, e aumento da qualidade e segurança alimentar de produtos de origem animal e vegetal. Entretanto, os investimentos necessários para compra de máquinas, especialmente para pequenos produtores, podem não ser a opção de menor custo em comparação com a obtenção de serviços de mecanização por meio de diferentes arranjos contratuais. Para .. escolher a melhor forma de contratar serviços de mecanização é necessário avaliar tanto os . custos convencionais das máquinas quanto os custos de transação, O principal objetivo desta pesquisa foi estimar a importância dos custos de transação na tomada de decisão sobre a seleção de arranjos contratuais alternativos para contratação de serviços de mecanização. Nossa hipótese era de. que os custos de transação podem ser maiores que os custos das máquinas, podendo, com isso, ser de cruclal Importância na seleção do tipo de arranjo contratual para contratar serviços de mecanização. Os dados empíricos de custos de máquinas e de transação foram coletados junto a agricultores familiares da Região Centro-Serra (RS), os quais contrataram serviços de colheita para milho de diferentes fornecedores formais e informais. Os resultados mostraram que os custos de transação podem ser mais elevados que os custos das máquinas e, com isso, influenciam de forma significativa a preferência agricultores familiares por determinado tipo de arranjo contratual para obtenção de serviços de mecanização. ABSTRACT - The mechanization of agricultural production plays an important and in course of time increasing role in the course of agricultural and rural development. Mechanization offers several potential improvements to farming systems such as increased land and labor productivity, reduction of risks, and increase of quality and food safety of animal and plant products. However, investments in own machinery, in particular for small holders, may not be the least-cost option in comparison with outsourcing the required machinery services through different contractual relationships. To choose the optimal contract for obtaining machinery services, it is necessary to evaluate conventional machinery costs as well as transaction costs. The main objective of this research was to assess the role of transaction costs in the choice among alternative contractual arrangements for provision of machinery services. Our hypothesis was that transaction costs can be higher than machinery costs, and therefore, they can play a leading role in the choice of contractual arrangements for provision of machinery services. The empirical data on conventional machinery and transaction costs were collected from farms in Southern Brazil that procure services for maize harvest through various informal and formal contractual forms. We found that transaction costs can be higher than conventional machinery costs, and therefore, influence the choice of contractual arrangement