6,658 research outputs found

    The minimal B-L model naturally realized at TeV scale

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    In a previous paper, we have proposed the minimal B-L extended standard model as a phenomenologically viable model that realizes the Coleman-Weinberg-type breaking of the electroweak symmetry. Assuming the classical conformal invariance and stability up to the Planck scale, we will show in this paper that the model naturally predicts TeV scale B-L breaking as well as a light standard-model singlet Higgs boson and light right-handed neutrinos around the same energy scale. We also study phenomenology and detectability of the model at the Large Hadron Collider (LHC) and the International Linear Collider (ILC).Comment: 24pages, 8figure

    Standardisation of magnetic nanoparticles in liquid suspension

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    Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way

    Speech recognition in noise with active and passive hearing protectors: a comparative study

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    The perceived negative influence of standard hearing protectors on communication is a common argument for not wearing them. Thus, augmented protectors have been developed to improve speech intelligibility. Nevertheless, their actual benefit remains a point of concern. In this paper, speech perception with active earplugs is compared to standard passive custom-made earplugs. The two types of active protectors included amplify the incoming sound with a fixed level or to a user selected fraction of the maximum safe level. For the latter type, minimal and maximal amplification are selected. To compare speech intelligibility, 20 different speech-in-noise fragments are presented to 60 normal-hearing subjects and speech recognition is scored. The background noise is selected from realistic industrial noise samples with different intensity, frequency, and temporal characteristics. Statistical analyses suggest that the protectors' performance strongly depends on the noise condition. The active protectors with minimal amplification outclass the others for the most difficult and the easiest situations, but they also limit binaural listening. In other conditions, the passive protectors clearly surpass their active counterparts. Subsequently, test fragments are analyzed acoustically to clarify the results. This provides useful information for developing prototypes, but also indicates that tests with human subjects remain essential.Full Tex

    Chern-Simons matrix model: coherent states and relation to Laughlin wavefunctions

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    Using a coherent state representation we derive many-body probability distributions and wavefunctions for the Chern-Simons matrix model proposed by Polychronakos and compare them to the Laughlin ones. We analyze two different coherent state representations, corresponding to different choices for electron coordinate bases. In both cases we find that the resulting probability distributions do not quite agree with the Laughlin ones. There is agreement on the long distance behavior, but the short distance behavior is different.Comment: 15 pages, LaTeX; one reference added, abstract and section 5 expanded, typos correcte

    An investigation into the effects of solvent content on the image quality and stability of ink jet digital prints under varied storage conditions

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    Increasing numbers of galleries, museums and archives are including ink jet printed materials into their collections, and therefore displays. There is evidence that the instability of these prints is such that images can suffer deterioration in print quality or in extreme cases, a loss of information over an extended period of time. This is shorter than the period typically required for perceptible deterioration to occur in many other paper-based artworks. The image stability of prints is affected by a number of factors some of which have already been studied. However the role played by the ink solvent in the loss of image quality has yet to be explored. This paper will outline research being undertaken to investigate the effects of solvent content which may increase/promote the loss in image quality of the hard copy prints when stored or displayed under a range of temperature and humidity conditions

    Resonant Leptogenesis in the Minimal B-L Extended Standard Model at TeV

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    We investigate the resonant leptogenesis scenario in the minimal B-L extended standard model(SM) with the B-L symmetry breaking at the TeV scale. Through detailed analysis of the Boltzmann equations, we show how much the resultant baryon asymmetry via leptogenesis is enhanced or suppressed, depending on the model parameters, in particular, the neutrino Dirac Yukawa couplings and the TeV-scale Majorana masses of heavy degenerate neutrinos. In order to consider a realistic case, we impose a simple ansatz for the model parameters and analyze the neutrino oscillation parameters and the baryon asymmetry via leptogenesis as a function of only a single CP-phase. We find that for a fixed CP-phase all neutrino oscillation data and the observed baryon asymmetry of the present universe can be simultaneously reproduced.Comment: 25 pages, 15 figures, version to be published in Phys. Rev.

    On-the-fly laser machining: a case study for in situ balancing of rotative parts

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    On-the-fly laser machining is defined as a process that aims to generate pockets/patches on target components that are rotated or moved at a constant velocity. Since it is a nonintegrated process (i.e., linear/rotary stage system moving the part is independent of that of the laser), it can be deployed to/into large industrial installations to perform in situ machining, i.e., without the need of disassembly. This allows a high degree of flexibility in its applications (e.g., balancing) and can result in significant cost savings for the user (e.g., no dis(assembly) cost). This paper introduces the concept of on-the-fly laser machining encompassing models for generating user-defined ablated features as well as error budgeting to understand the sources of errors on this highly dynamic process. Additionally, the paper presents laser pulse placement strategies aimed at increasing the surface finish of the targeted component by reducing the area surface roughness that are possible for on-the-fly laser machining. The overall concept was validated by balancing a rotor system through ablation of different pocket shapes by the use of a Yb:YAG pulsed fiber laser. In this respect, first, two different laser pulse placement strategies (square and hexagonal) were introduced in this research and have been validated on Inconel 718 target material; thus, it was concluded that hexagonal pulse placement reduces surface roughness by up to 17% compared to the traditional square laser pulse placement. The concept of on-the-fly laser machining has been validated by ablating two different features (4 × 60 mm and 12 × 4 mm) on a rotative target part at constant speed (100 rpm and 86 rpm) with the scope of being balanced. The mass removal of the ablated features to enable online balancing has been achieved within < 4 mg of the predicted value. Additionally, the error modeling revealed that most of the uncertainties in the dimensions of the feature/pocket originate from the stability of the rotor speed, which led to the conclusion that for the same mass of material to be removed it is advisable to ablate features (pockets) with longer circumferential dimensions, i.e., stretched and shallower pockets rather than compact and deep

    Laughlin Wave Function and One-Dimensional Free Fermions

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    Making use of the well-known phase space reduction in the lowest Landau level(LLL), we show that the Laughlin wave function for the ν=1m\nu = {1\over m} case can be obtained exactly as a coherent state representation of an one dimensional (1D)(1D) wave function. The 1D1D system consists of mm copies of free fermions associated with each of the NN electrons, confined in a common harmonic well potential. Interestingly, the condition for this exact correspondence is found to incorporate Jain's parton picture. We argue that, this correspondence between the free fermions and quantum Hall effect is due to the mapping of the 1D1D system under consideration, to the Gaussian unitary ensemble in the random matrix theory.Comment: 7 pages, Latex , no figure
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