921 research outputs found

    Application of novel techniques for interferogram analysis to laser-plasma femtosecond probing

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    Recently, two novel techniques for the extraction of the phase-shift map (Tomassini {\it et.~al.}, Applied Optics {\bf 40} 35 (2001)) and the electronic density map estimation (Tomassini P. and Giulietti A., Optics Communication {\bf 199}, pp 143-148 (2001)) have been proposed. In this paper we apply both methods to a sample laser-plasma interferogram obtained with femtoseconds probe pulse, in an experimental setup devoted to laser particle acceleration studies.Comment: Submitted to Laser and Particle Beam

    Line spectroscopy with spatial resolution of laser-plasma X-ray emission

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    High dynamic range, space-resolved X-ray spectra of an aluminum laser–plasma in the 5.5–8 Å range were obtained using a TlAP crystal and a cooled CCD camera as a detector. This technique was used to investigate the emission region in the longitudinal direction over a distance of approximately 350 μm from the solid target surface. These data show that the electron density profile varies by two orders of magnitude with the temperature ranging from about 180 eV in the overdense region to about 650 eV in the underdense region. Accordingly, different equilibria take place across the explored region which can be identified with this experimental technique. Detailed studies on highly ionized atomic species in different plasma conditions can therefore be performed simultaneously under controlled conditions

    Expanding Semiflows on Branched Surfaces and One-Parameter Semigroups of Operators

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    We consider expanding semiflows on branched surfaces. The family of transfer operators associated to the semiflow is a one-parameter semigroup of operators. The transfer operators may also be viewed as an operator-valued function of time and so, in the appropriate norm, we may consider the vector-valued Laplace transform of this function. We obtain a spectral result on these operators and relate this to the spectrum of the generator of this semigroup. Issues of strong continuity of the semigroup are avoided. The main result is the improvement to the machinery associated with studying semiflows as one-parameter semigroups of operators and the study of the smoothness properties of semiflows defined on branched manifolds, without encoding as a suspension semiflow

    New energy downstream. Emerging business models and innovative best practices: an economic, institutional, and behavioral focus

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    Thanks to policy pressure and technological progress, modern energy systems are going through an increasing decentralization and decarbonization process. Digitalization and decarbonization, in this context, represent key enablers, as they unlock new opportunities of actors across the value chain (i.e., consumers, prosumers, retailers, traders, producers, network operators, and policy makers), providing them with new solutions. The combination of digital technologies and renewable energy solutions is already playing a pivotal role in the energy sector. The increasing attention toward clean energy sources, Internet of Things, Artificial Intelligence, Big Data, Cloud, 5 G, and Blockchain technologies are influencing changes both in energy companies’ value creation strategies and in customer behavior as well as in policy and regulatory frameworks. This transition will define the economic and legal environment able to accommodate an ever-increasing number and variety of alternative business models and new solutions. All these new aspects are expected to have an impact on long-time established roles, particularly by creating trust and empowering consumers on one side, and by disrupting traditional business models on the other. Ideally, this transformative process should be able to set out cost-effective and economically productive pathway, resulting in a clean, dynamic, and resilient energy economy dominated by renewables – while ensuring stable and affordable energy supplies, providing universal energy access, and enabling robust economic growth

    Acceleration with Self-Injection for an All-Optical Radiation Source at LNF

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    We discuss a new compact gamma-ray source aiming at high spectral density, up to two orders of magnitude higher than currently available bremsstrahlung sources, and conceptually similar to Compton Sources based on conventional linear accelerators. This new source exploits electron bunches from laser-driven electron acceleration in the so-called self-injection scheme and uses a counter-propagating laser pulse to obtain X and gamma-ray emission via Thomson/Compton scattering. The proposed experimental configuration inherently provides a unique test-bed for studies of fundamental open issues of electrodynamics. In view of this, a preliminary discussion of recent results on self-injection with the FLAME laser is also given.Comment: 8 pages, 10 figures, 44 references - Channeling 2012 conferenc

    Differences in gene expression profiles of seven target proteins in third-stage larvae of anisakis simplex (Sensu stricto) by sites of infection in blue whiting (micromesistius poutassou)

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    The third-stage larvae of the parasitic nematode genus Anisakis tend to encapsulate in different tissues including the musculature of fish. Host tissue penetration and degradation involve both mechanic processes and the production of proteins encoded by an array of genes. Investigating larval gene profiles during the fish infection has relevance in understanding biological traits in the parasite’s adaptive ability to cope with the fish hosts’ defense responses. The present study aimed to investigate the gene expression levels of some proteins in L3 of A. simplex (s.s.) infecting different tissues of blue whiting Micromesistius poutassou, a common fish host of the parasite in the NE Atlantic. The following genes encoding for Anisakis spp. proteins were studied: Kunitz-type trypsin inhibitor (TI), hemoglobin (hb), glycoprotein (GP), trehalase (treh), zinc metallopeptidase 13 (nas 13), ubiquitin-protein ligase (hyd) and sideroflexin 2 (sfxn 2). Significant differences in gene transcripts (by quantitative real-time PCR, qPCR) were observed in larvae located in various tissues of the fish host, with respect to the control. ANOVA analysis showed that relative gene expression levels of the seven target genes in the larvae are linked to the infection site in the fish host. Genes encoding some of the target proteins seem to be involved in the host tissue migration and survival of the parasite in the hostile target tissues of the fish host

    The far-infrared/radio correlation for a sample of strongly lensed dusty star-forming galaxies detected by Herschel

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    We investigate the radio/far-infrared (FIR) correlation for a sample of 28 bright high-redshift (1 z 4) star-forming galaxies selected in the FIR from the Herschel -ATLAS fields as candidates to be strongly gravitationally lensed. The radio information comes either from high sensitivity dedicated Australia Telescope Compact Array observations at 2.1 GHz or from cross-matches with the FIRST surv e y at 1.4 GHz. By taking advantage of source brightness possibly enhanced by lensing magnification, we identify a weak evolution with redshift out to z 4 of the FIR-to-radio luminosity ratio q FIR . We also find that the q FIR parameter as a function of the radio power L 1 . 4 GHz displays a clear decreasing trend, similarly to what is observed for optically/radio- selected lensed quasars found in literature, yet co v ering a complementary region in the q FIR –L 1 . 4 GHz diagram. We interpret such a behaviour in the framework of an in situ galaxy formation scenario, as a result of the transition from an early dust-obscured star-forming phase (mainly pinpointed by our FIR selection) to a late radio-loud quasar phase (preferentially sampled by the optical/radio selection)

    The Effect of Learning Organization Environment and Innovative Work Behavior Under the Moderation Role of Employee Engagement in Public Sector Organization

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    The main objective of the study is to explore the impact of learning organization environment on innovative work behavior. The study results show that learning organization environment explained a significant relation with innovative work behavior also with the mediator variable that is employee engagement. Convenience sampling is used as the sampling strategy. This survey is based on questionnaire and data is collected from 140 managers of Public sector organizations located in Faisalabad. To analyses the data, SPSS version 23.0 is used. To check the relationship between the variables correlation analysis is used and to checks the effect between variables linear regression analysis is used. Thus, all the hypotheses showed significant results. Keywords: Learning Organization environment, innovative work behavior, employee engagemen

    Multi-GeV Electron Spectrometer

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    The advance in laser plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1pC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented challenges in the design and construction of such a device. We will present the design considerations for this spectrometer and the first results from a prototype.Comment: 7 pages, 6 figures, submitted to NIM
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