The Quadratic Coefficient of the Electron Cloud Mapping

The Electron Cloud is an undesirable physical phenomenon which might produce single and multi-bunch instability, tune shift, increase of pressure ultimately limiting the performance of particle accelerators. We report our results on the analytical study of the electron dynamics.Comment: 5 pages, 7 figures, presented at ECLOUD12: Joint INFN-CERN-EuCARD-AccNet Workshop on Electron-Cloud Effects, La Biodola, Isola d Elba, Italy, 5-9 June 201

Maps for Electron Clouds: Application to LHC Conditioning

In this communication we present a generalization of the map formalism, introduced in [1] and [2], to the analysis of electron flux at the chamber wall with particular reference to the exploration of LHC conditioning scenarios.Comment: 3 pages, 4 figure

Economic reasoning and interaction in socially extended market institutions

An important part of what it means for agents to be situated in the everyday world of human affairs includes their engagement with economic practices. In this paper, we employ the concept of cognitive institutions in order to provide an enactive and interactive interpretation of market and economic reasoning. We challenge traditional views that understand markets in terms of market structures or as processors of distributed information. The alternative conception builds upon the notion of the market as a scaffolding institution. Introducing the concept of market as a socially extended cognitive institution we go beyond the notion of scaffolding to provide an enactive view of economic reasoning that understands the market participant in terms of social interactive processes and relational autonomy. Markets are more than inert devices for information processing; they can be viewed as highly scaffolded, where strong constraints and incentives predictably direct agents\u27 behavior. Building on this idea we argue that markets emerge from (a) the economic interaction of both supply and demand sides, in continual and mutual interplay, and (b) more basic social interactions. Consumer behavior in the marketplace is complex, not only contributing to determine the market price, but also extending the consumer\u27s cognitive processes to reliably attain a correct evaluation of the good. Moreover, this economic reasoning is socially situated and not something done in isolation from other consumers. From a socially situated, interactive point of view buying or not buying a good is something that enacts the market. This shifts the status of markets from external institutions that merely causally affect participants\u27 cognitive processes to social institutions that constitutively extend these cognitive processes. On this view the constraints imposed by social interactions, as well as the possibilities enabled by such interactions, are such that economic reasoning is never just an individual process carried out by an autonomous individual, classically understood. In this regard, understanding the concept of relational autonomy allows us to see how economic reasoning is always embodied, embedded in, and scaffolded by intersubjective interactions, and how such interactions make the market what it is

A Formula of the Electron Cloud Linear Map Coefficient in a Strong Dipole

Electron cloud effects have recognized as as one of the most serious bottleneck for reaching design performances in presently running and proposed future storage rings. The analysis of these effects is usually performed with very time consuming simulation codes. An alternative analytic approach, based on a cubic map model for the bunch-to-bunch evolution of the electron cloud density, could be useful to determine regions in parameters space compatible with safe machine operations. In this communication we derive a simple approximate formula relating the linear coefficient in the electron cloud density map to the parameters relevant for the electron cloud evolution with particular reference to the LHC dipoles.Comment: 3 pages, 5 figures. Proceeding of IPAC 201

Nonlinear modelling of the seismic response of masonry structures: Calibration strategies

In this paper, a simple and practitioners-friendly calibration strategy to consistently link target panel-scale mechanical properties (that can be found in national standards) to model material-scale mechanical properties is presented. Simple masonry panel geometries, with various boundary conditions, are utilized to test numerical models and calibrate their mechanical properties. The calibration is successfully conducted through five different numerical models (most of them available in commercial software packages) suitable for nonlinear modelling of masonry structures, using nonlinear static analyses. Firstly, the panel stiffness calibration is performed, focusing the attention to the shear stiffness. Secondly, the panel strength calibration is conducted for several axial load ratios by attempts using as reference the target panel strength deduced by well-known analytical strength criteria. The results in terms of panel strength for the five different models show that this calibration strategy appears effective in obtaining model properties coherent with Italian National Standard and Eurocode. Open issues remain for the calibration of the post-peak response of masonry panels, which still appears highly conventional in the standards

A framework for application partitioning using trusted execution environments

The size and complexity of modern applications are the underlying causes of numerous security vulnerabilities. In order to mitigate the risks arising from such vulnerabilities, various techniques have been proposed to isolate the execution of sensitive code from the rest of the application and from other software on the platform (such as the operating system). New technologies, notably Intel’s Software Guard Extensions (SGX), are becoming available to enhance the security of partitioned applications. SGX provides a trusted execution environment (TEE), called an enclave, that protects the integrity of the code and the confidentiality of the data inside it from other software, including the operating system. However, even with these partitioning techniques, it is not immediately clear exactly how they can and should be used to partition applications. How should a particular application be partitioned? How many TEEs should be used? What granularity of partitioning should be applied? To some extent, this is dependent on the capabilities and performance of the partitioning technology in use. However, as partitioning becomes increasingly common, there is a need for systematization in the design of partitioning schemes. To address this need, we present a novel framework consisting of four overarching types of partitioning schemes through which applications can make use of TEEs. These schemes range from coarse-grained partitioning, in which the whole application is included in a single TEE, through to ultra-fine partitioning, in which each piece of security-sensitive code and data is protected in an individual TEE. Although partitioning schemes themselves are application-specific, we establish application-independent relationships between the types we have defined. Since these relationships have an impact on both the security and performance of the partitioning scheme, we envisage that our framework can be used by software architects to guide the design of application partitioning schemes. To demonstrate the applicability of our framework, we have carried out case studies on two widely-used software packages, the Apache web server and the OpenSSL library. In each case study, we provide four high level partitioning schemes - one for each of the types in our framework. We also systematically review the related work on hardware-enforced partitioning by categorising previous research efforts according to our framework

Modification of the organic acid profile of grapes due to climate changes alters the stability of red wine phenolics during controlled oxidation

The effect of the main grape organic acids (tartaric, malic and citric) on the degradative oxidation of red wine was investigated by NMR, HPLC and spectrophotometry. Wines featuring the same pH value of 3.2 with different combinations of organic acids were prepared. Results showed that tartaric acid preserved native anthocyanins from oxidative degradation more than malic and citric acids, with malic acid being the one favoring oxidations the most and, consequently, acetaldehyde production. Wines richer in malic acids showed the highest reactivity towards saliva proteins and a potential higher astringency. Given the wide changes in tartaric/malic acid ratio with climate, these results can help to act in vineyard, as well as in winery, to manage the malic/tartaric acid ratio with the aim of improving red wine longevity