3,271 research outputs found

    Polarization measurements and their perspectives: PVLAS Phase II

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    We sketch the proposal for a "PVLAS-Phase II" experiment. The main physics goal is to achieve the first direct observation of non-linear effects in electromagnetism predicted by QED and the measurement of the photon-photon scattering cross section at low energies (1-2 eV). Physical processes such as ALP and MCP production in a magnetic field could also be accessible if sensitive enough operation is reached. The short term experimental strategy is to compact as much as possible the dimensions of the apparatus in order to bring noise sources under control and to attain a sufficient sensitivity. We will also briefly mention future pespectives, such as a scheme to implement the resonant regeneration principle for the detection of ALPs.Comment: Paper submitted to the proceedings of the "4th Patras Workshop on Axions, WIMPs and WISPs", DESY, Hamburg Site /Germany, 18-21 June 200

    Paper Session III-D - Physiological and Genetic Changes to E. Coli Induced by Exposure to lead - a Two Year Study

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    It’s been proven that concentrations of lead severely harm people - primarily children. The purpose of this study is to determine whether or not continuous exposure to lead nitrate concentrations of 100 parts per billion (ppb), 200 ppb, or 300 ppb will produce mutation in Escherichia coli DNA over many generations. The hypothesis formulated was that, over time, continuous exposure to lead nitrate concentrations will produce a harmful mutation in Escherichia coli and reduce the amount of square centimeters of bacterial growth. Lead is a bluish - gray element found underground that can be obtained by mining the ore. Pure lead is very soft and bendible, and it is popular because it can easily be bent and shaped (Kendler, 1993.) More lead is used worldwide than is mined : six-and-a-half million short tons of lead is used worldwide, but only three-and-a-half million short tons is actually recovered (Kimbrough et al., 1994). The remaining three million short tons is obtained by recycling old lead and reusing it

    An Assessment of Carousel Value-Added Tax Fraud in The European Carbon Market

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    The literature on the European Union Emission Trading System (EU ETS) is by now very rich. Much is known about the efficiency, the effectiveness, and the environmental and distributional impacts of the EU ETS. Less, however, is known about the carousel value-added-tax (VAT) fraud phenomena in the European carbon market. This article evaluates the welfare effects of carousel VAT fraud in the EU ETS using a computable general equilibrium (CGE) analysis. According to our findings, if VAT fraud occurs in the EU ETS, the effects on welfare for the EU Member States are negative, with welfare loss significantly higher than the VAT fraud value. This article also discusses the reverse charge mechanism that EU Member States could adopt to reduce the VAT fraud phenomena in the European carbon market

    High discharge rate characteristics of nickel-cadmium batteries for pulse load filtering

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    Several tests of specially fabricated nickel-cadmium batteries having circular disk type electrodes were considered. These batteries were evaluated as filter elements between a constant current power supply and a five hertz pulsed load demanding approximately twice the power supply current during the load on portion of the cycle. Short tests lasting 10,000 cycles were conducted at up to a 21 C rate and an equivalent energy density of over 40 Joules per pound. In addition, two batteries were subjected to 10 to the 7 charge/discharge cycles, one at a 6.5 C rate and the other at a 13 C rate. Assuming an electrode to battery weight ratio of 0.5, these tests represent an energy density of about 7 and 14 Joules per pound respectively. Energy density, efficiency, capacitance, average voltage, and available capacity were tracked during these tests. After 10 to the 7 cycles, capacity degradation was negligible for one battery and about 20% for the other. Cadmium electrode failure may be the factor limiting lifetime at extremely low depth of discharge cycling. The output was examined and a simple equivalent circuit was proposed

    Does alexithymia have a mediating effect between impulsivity and emotional-behavioral functioning in adolescents with binge eating disorder?

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    Objective: Binge eating Disorder (BeD) has recently been included in the Dsm-5. like many other eating disorder symptoms, BED is often present in adolescence. No studies have specifically investigated the influence of impulsivity and alexithymia on the emotional-behavioural functioning of adolescents diagnosed with BeD. Method: in this study, we recruited n = 162 adolescents (age range: 14-18) and divided them into two groups: 78 adolescents diagnosed with BeD, according to the Dsm-5 criteria (group A), and 84 healthy controls (group B). participants completed the youth self-report (ysr/11-18), the toronto Alexithymia scale (tAs-20) and the Barratt impulsiveness scale (Bis-11). Results: the results showed that group A had higher scores of alexithymia, impulsivity and maladaptive emotionalbehavioural functioning than Group B. Furthermore, alexithymia had a mediating effect on the relationship between impulsivity and emotional-behavioural functioning. Conclusions: These results allow us to hypothesise that alexithymia is a key variable influencing the emotional and behavioural problems of adolescents affected by BED. Our data confirms the previous studies underlining the association of impulsivity and alexithymia with the diagnosis of BeD in adolescents, and our study contributes to the previous literature, emphasising the central role of alexithymia in the mediating effect between impulsivity and emotional and behavioural problems. these results suggest the importance of promoting prevention and treatment polices focused on alexithymia

    Surface photovoltage effects in photoemission from metal-GaP(110) interfaces: Importance for band bending evaluation

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    Photoelectron spectra from metal overlayers on GaP(110) show that the photoionization light source may induce a surface photovoltage, causing an energy shift of valence- and core-level peaks. We analyze the dependence of this surface photovoltage on metal coverage, substrate doping, and temperature. The presence of a surface photovoltage seriously affects the determination of surface band bending by photoelectron spectroscopy, a technique which is generally thought to reflect the equilibrium electronic structure of metal-semiconductor interfaces

    Surface photovoltage effects in photoemission from metal/GaP(110) interfaces: Temperature‐dependent Fermi level movement

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    In recent experiments of metal deposition onto cleaved GaP(110) surfaces we have shown that light sources used in photoelectron spectroscopy may induce a surface photovoltage (SPV), which causes a substantial deviation from the ground state potential distribution, and may induce errors in the determination of band bending by photoemission. Here we analyze the temperature‐dependent movement of the surface Fermi level in n‐ and p‐type GaP(110) surfaces as a function of indium and silver deposition, taking into account the presence of the SPV. It is found that changes in the substrate temperature not only modify the adlayer morphology and metallicity, but also the surface electron‐hole recombination rate. We observe that the temperature‐dependent shift of the semiconductor core levels is always accompanied by a similar shift of the metal core level and Fermi edge, suggesting that the reversible temperature‐dependent band bending recently reported for metal/III–V semiconductor interfaces is related to the SPV, and does not represent a ground state property of the interfacial electronic structure. Implications of these results on current models concerning Schottky barrier formation are discussed

    Thermal desorption of cryopumped gases from laser treated copper

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    Recently, laser processing of copper samples has been demonstrated to produce rough surfaces whose nanostructuring ensures unquestionable advantages for electron cloud mitigation in future particle accelerators. The actual application of laser treated surfaces in accelerators implies that this new material is compliant with many issues, going from impedance vacuum properties to many others. A significant experimental effort is therefore ongoing to study and optimize their various properties of interest. Here we analyze their vacuum behavior versus temperature. To this end, we studied thermal programmed desorption from CO, CH4{\mathrm{CH}}_{4} and H2{\mathrm{H}}_{2} once cryosorbed on laser treated copper substrate and on its flat counterpart. These molecules are typically present in the residual vacuum of any accelerator. The results show that the desorption of such gases from the laser treated substrates occurs in a much broader and higher temperature range with respect to what is observed from the flat substrate. We also show that, at equal doses, treated samples adsorb/desorb significantly more gas than their flat counterpart. These findings can be ascribed to their nanostructured porous morphology. A quantitative analysis is given, allowing to properly estimate fluctuations of the number of molecules during unavoidable temperature variations of the cryogenic vacuum system

    An adaptive stigmergy-based system for evaluating technological indicator dynamics in the context of smart specialization

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    Regional innovation is more and more considered an important enabler of welfare. It is no coincidence that the European Commission has started looking at regional peculiarities and dynamics, in order to focus Research and Innovation Strategies for Smart Specialization towards effective investment policies. In this context, this work aims to support policy makers in the analysis of innovation-relevant trends. We exploit a European database of the regional patent application to determine the dynamics of a set of technological innovation indicators. For this purpose, we design and develop a software system for assessing unfolding trends in such indicators. In contrast with conventional knowledge-based design, our approach is biologically-inspired and based on self-organization of information. This means that a functional structure, called track, appears and stays spontaneous at runtime when local dynamism in data occurs. A further prototyping of tracks allows a better distinction of the critical phenomena during unfolding events, with a better assessment of the progressing levels. The proposed mechanism works if structural parameters are correctly tuned for the given historical context. Determining such correct parameters is not a simple task since different indicators may have different dynamics. For this purpose, we adopt an adaptation mechanism based on differential evolution. The study includes the problem statement and its characterization in the literature, as well as the proposed solving approach, experimental setting and results.Comment: mail: [email protected]
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