5,168 research outputs found

    Improving an inequality for the divisor function

    Full text link
    We improve using elementary means an explicit bound on the divisor function due to Friedlander and Iwaniec. Consequently we modestly improve a result regarding a sieving inequality for Gaussian sequences.Comment: 8 pages, to appear in Bull. AustM

    Innovative Service-Based Business Concepts for the Machine Tool Building Industry

    Get PDF
    Organised by: Cranfield UniversityDuring the last decade, machine tool building companies have been forced to put innovative offers on the market. Due to the technical features of their products and the prevailing organizational structures in this sector, especially product-service systems are a promising way of creating a unique selling point. In this paper, potential new business concepts for machine tool builders will be presented which aim at fulfilling basic customer needs like the increase in quality, flexibility, productivity and the reduction of lead times, costs and risks. For the implementation of these product-service systems, practical examples are given.Mori Seiki – The Machine Tool Compan

    Optical properties of bialkali photocathodes

    Full text link
    The optical properties of the `bialkali' KCsSb and RbCsSb photomultiplier cathodes have been experimentally investigated in the visible range. The measurements carried out include the absolute reflectance at near-normal incidence, the polarization-dependent relative reflectance at various angles and the change in polarization upon reflection from the photocathode. These experimental inputs have been combined with a theoretical model to determine the complex refractive index of the photocathodes in the wavelength range 380 to 680 nm and their thickness. As a result of this work, we derive a model which predicts the fraction of light impinging on a photomultiplier tube that is reflected, absorbed or transmitted, as a function of wavelength and angle, and dependent on the medium to which the photomultiplier is coupled.Comment: 51 pages (double spacing), 16 figures, submitted for publication in NIM

    Analisis Perencanaan Suksesi pada Perusahaan Jasa Perjalanan Wisata

    Full text link
    Perusahaan ini merupakan sebuah Perusahaan keluarga yang bergerak dalam bidang jasa perjalanan wisata. Seperti yang kita ketahui di dalam Perusahaan keluarga dibutuhkan perencanaan suksesi untuk meneruskan Perusahaan tersebut. Jenis penelitian ini menggunakan metode kualitatif. Teknik sampel menggunakan teknik purposive sampling. Metode pengumpulan data dengan menggunakan teknik wawancara. Hasil analisa data diperoleh dengan menggunakan triangulasi sumber untuk mengelola data yang diperoleh, kemudian dengan hasil wawancara pada sumber lain ditarik kesimpulan apakah keduanya memiliki hubungan atau tidak. Dari hasil penelitian, subjek penelitian di dalam perencanaan suksesi secara keseluruhan sudah berjalan dengan baik. Meskipun ada beberapa masalah namun masalah tersebut diatasi dengan adanya USAha dari suksesor

    Co‐operative cross‐platform courseware development

    Get PDF
    The UKMCC (UK Mathematics Courseware Consortium) is a Consortium funded under TLTP (Training and Learning Technology Programme) to produce courseware for service mathematics teaching, using the SEFI (Société Européenne pour la Formation des Ingénieurs) syllabus. There are agreed courseware design guidelines and a simple courseware management system which allows cross‐referencing. Courseware is divided into modules, with an author as implementer for each. On any one hardware platform, a variety of authoring languages is possible. Across hardware platforms, the design guidelines ensure that conversion is possible, and will preserve look and feel. We argue here that these arrangements provide a basis for continued co‐operation between authors and future development as the technology changes

    Germanene: a novel two-dimensional Germanium allotrope akin to Graphene and Silicene

    Get PDF
    Using a gold (111) surface as a substrate we have grown in situ by molecular beam epitaxy an atom-thin, ordered, two-dimensional multi-phase film. Its growth bears strong similarity with the formation of silicene layers on silver (111) templates. One of the phases, forming large domains, as observed in Scanning Tunneling Microscopy, shows a clear, nearly flat, honeycomb structure. Thanks to thorough synchrotron radiation core-level spectroscopy measurements and advanced Density Functional Theory calculations we can identify it to a 3\sqrt{3}x3\sqrt{3}R(30{\deg}) germanene layer in coincidence with a 7\sqrt{7}x7\sqrt{7}R(19.1{\deg}) Au(111) supercell, thence, presenting the first compelling evidence of the birth of a novel synthetic germanium-based cousin of graphene.Comment: 16 pages, 4 figures, 1 tabl

    Deep mantle structure and the postperovskite phase transition

    Get PDF
    Seismologists have known for many years that the lowermost mantle of the Earth is complex. Models based on observed seismic phases sampling this region include relatively sharp horizontal discontinuities with strong zones of anisotropy, nearly vertical contrasts in structure, and small pockets of ultralow velocity zones (ULVZs). This diversity of structures is beginning to be understood in terms of geodynamics and mineral physics, with dense partial melts causing the ULVZs and a postperovskite solid–solid phase transition producing regional layering, with the possibility of large-scale variations in chemistry. This strong heterogeneity has significant implications on heat transport out of core, the evolution of the magnetic field, and magnetic field polarity reversals

    Kinetics of natural aging in Al-Mg-Si alloys studied by positron annihilation lifetime spectroscopy

    Full text link
    The process of natural aging in pure ternary Al-Mg-Si alloys was studied by positron annihilation lifetime spectroscopy in real time in order to clarify the sequence and kinetics of clustering and precipitation. It was found that natural aging takes place in at least five stages in these alloys, four of which were directly observed. This is interpreted as the result of complex interactions between vacancies and solute atoms or clusters. One of the early stages of positron lifetime evolution coincides with a clustering process observed by differential scanning calorimetry (DSC) and involves the formation of a positron trap with \sim 0.200 ns lifetime. In later stages, a positron trap with a higher lifetime develops in coincidence with the DSC signal of a second clustering reaction. Mg governs both the kinetics and the lifetime change in this stage. Within the first 10 min after quenching, a period of nearly constant positron lifetime was found for those Mg-rich alloys that later show an insufficient hardness response to artificial aging, the so-called "negative effect." The various processes observed could be described by two effective activation energies that were found by varying the aging temperature from 10 to 37\degree C.Comment: arXiv admin note: same as v2, to correct mistaken v
    corecore