256 research outputs found

    Non-exciting wakefield structured bunches in a one-dimensional plasma model

    Get PDF
    A model of one-dimensional (1D) cold plasma with an external train of rigidly structured bunches with diverse charges has been introduced. In this model, a solution that cancels the wakefield after the train is found. The density of such bunches can be much greater than the density of the plasma, and a high amplitude electrical field arising inside the train can be used for charged-particle acceleration. In addition, analytical and numerical simulations have been performed

    Superluminal synchrotron radiation

    Get PDF
    To avoid complex computations based on wide Fourier expansions, the electromagnetic field of synchrotron radiation (SR) was analyzed using Lienard-Wiechert potentials in this work. The retardation equation was solved for ultrarelativistic movement of rotating charge at distances up to the trajectory radius. The radiation field was determined to be constricted into a narrow extended region with transverse sizes approximately the radius of trajectory divided by the particle Lorentz factor (characteristic SR length) cubed in the plane of trajectory and the distance between the observation and radiation emission point divided by the Lorentz factor in the vertical direction. The Lienard-Wiechert field of rotating charge was visualized using a parametric form to derive electric force lines rather than solving a retardation equation. The electromagnetic field of a charging point rotating at superluminal speeds was also investigated. This field, dubbed a superluminal synchrotron radiation (SSR) field by analogy with the case of a circulating relativistic charge, was also presented using a system of electric force lines. It is shown that SSR can arise in accelerators from “spot” of SR runs faster than light by outer wall of circular accelerator vacuum chamber. Furthermore, the mentioned characteristic lengths of SR in orbit plane and in vertical direction are less than the interparticle distances in real bunches in ultrarelativistic accelerators. It is indicating that this phenomenon should be taken into account when calculating bunch fields and involved at least into the beam dynamic consideration

    Molecular mechanisms of wound healing: the role of zinc as an essential microelement

    Get PDF
    Wound healing is a complex multi-phase process consisting of several phases. Each stage involves metal ions, primarily zinc, which stimulates re-epithelialization, decreases inflammation and bacterial growth. The use of known zinc-based drugs is accompanied by side effects and low efficacy due to low skin absorption. These factors significantly limit use of such drugs and highlight the urgency of finding new, more effective and safe treatmen

    Observation of Lambda H-4 hyperhydrogen by decay-pion spectroscopy in electron scattering

    Full text link
    At the Mainz Microtron MAMI, the first high-resolution pion spectroscopy from decays of strange systems was performed by electron scattering off a Be-9 target in order to study the ground-state masses of Lambda-hypernuclei. Positively charged kaons were detected by a short-orbit spectrometer with a broad momentum acceptance at zero degree forward angles with respect to the beam, efficiently tagging the production of strangeness in the target nucleus. In coincidence, negatively charged decay-pions were detected by two independent high-resolution spectrometers. About 10^3 pionic weak decays of hyperfragments and hyperons were observed. The pion momentum distribution shows a monochromatic peak at p_pi ~ 133 MeV/c, corresponding to the unique signature for the two-body decay of hyperhydrogen Lambda H-4 -> He-4 + pi-, stopped inside the target. Its binding energy was determined to be B_Lambda = 2.12 +- 0.01 (stat.) +- 0.09 (syst.) MeV with respect to the H-3 + Lambda mass

    Professional Learning Through Everyday Work: How Finance Professionals Self-Regulate Their Learning

    Get PDF
    Professional learning is a critical component of ongoing improvement and innovation and the adoption of new practices in the workplace. Professional learning is often achieved through learning embedded in everyday work tasks. However, little is known about how professionals self-regulate their learning through regular work activities. This paper explores how professionals in the finance sector (n-30) self-regulate their learning through day-to-day work. Analysis focuses on three sub-processes of self-regulated learning that have been identified as significant predictors of good self-regulated learning at work. A key characteristic of good self-regulation is viewing learning as a form of long-term, personalised self-improvement. This study provides a foundation for future policy and planning in organisations aiming to encourage self-regulated learning

    Genomic ancestry, diet and microbiomes of Upper Palaeolithic hunter-gatherers from San Teodoro cave

    Get PDF
    A combined ancient genomic, metagenomic, and paleoproteomic analysis reveals lifestyle and dietary information of Upper Palaeolithic huntergatherers from San Teodoro cave in Sicily, Italy.Recent improvements in the analysis of ancient biomolecules from human remains and associated dental calculus have provided new insights into the prehistoric diet and genetic diversity of our species. Here we present a multi-omics study, integrating metagenomic and proteomic analyses of dental calculus, and human ancient DNA analysis of the petrous bones of two post-Last Glacial Maximum (LGM) individuals from San Teodoro cave (Italy), to reconstruct their lifestyle and the post-LGM resettlement of Europe. Our analyses show genetic homogeneity in Sicily during the Palaeolithic, representing a hitherto unknown Italian genetic lineage within the previously identified Villabruna cluster. We argue that this lineage took refuge in Italy during the LGM, followed by a subsequent spread to central-western Europe. Analysis of dental calculus showed a diet rich in animal proteins which is also reflected on the oral microbiome composition. Our results demonstrate the power of this approach in the study of prehistoric humans and will enable future research to reach a more holistic understanding of the population dynamics and ecology

    Anatomical and physiological substantiations of evolutionary transformations of the human dentition system by comparing human and mammalian jaw casts.

    Get PDF
    The article considers the factors of evolution at the later stages of anthropogenesis that lead to the reduction of the dentition system due to changes in the composition of food, determines the gender and age features of the development of wisdom teeth in humans, and performs a statistical analysis of a sample of 100 people.В статье рассмотрены факторы эволюции на поздних этапах антропогенеза, приводящие к редукции зубочелюстной системы в связи с изменением состава пищи, определены половые и возрастные особенности развития зубов мудрости у человека, проведен статистический анализ выборки из 100 человек

    Mass dependence of spectral and angular distributions of Cherenkov radiation from relativistic isotopes in solid radiators and its possible application as mass selector

    Get PDF
    The first proof of principle experiment with a prototype of a Time-of-Flight (TOF) - Cherenkov detector of relativistic heavy ions (RHI) exploiting a liquid Iodine Naphthalene radiator has been performed at Cave C at GSI (Darmstadt, Germany). A conceptual design for a liquid Cherenkov detector was proposed as a prototype for the future TOF measurements at the SuperFRS by detection of total number of Cherenkov photons. The ionization energy loss of RHI in a liquid radiator decreases only slightly this number, while in a solid radiator changes sufficiently not the total number of ChR photons, but ChR angular and spectral distributions. By means of computer simulations, we showed that these distributions are very sensitive to the isotope mass, due to different stopping powers of isotopes with initial equal relativistic factors. The results of simulations for light (Li, Be) and heavy (Xe) isotopes at 500-1000 MeV/u are presented indicating the possibility to use the isotopic effect in ChR of RHI as the mass selector
    corecore