Analysis of Flatness Measurement and Form Stability of a Granite Surface Plate

It is rather difficult to compare quantitatively flatness measuring results of one and the same object (e.g. in case of a long-term stability investigation) or the results of a series of products (e.g. from the same machinetool in order to indicate machinetool-influences). An extension of a computerprogram applied to the evaluation of flatness measurement (as described in the CIRP-Annals, vol. 26 (1977), no.1), separates the form deviations of a surface into a geometrical part and a random part.\ud The geometric part consists of a best-fitting non-flat, reference plane, composed of the single curvature of a sphere and the double curvature of a real twisted plane. Three parameters (the dimensionless curvature parameters of sphericity and torsion, together with the direction of the torsionvector) are able to characterize the geometrical part of the surface; a fourth one is a measure for the random part.\ud Advantages of the method are demonstrated with the aid of a long-term investigation into the form stability of a granite surface plate.\ud Another extension of the program makes it now possible to measure surfaces with non-rectangular contours in the same way as it is being done in case of a rectangular surface plate.\u

A study of resonance tongues near a Chenciner bifurcation using MatcontM

MatcontM is a matlab toolbox for numerical analysis of bifurcations of fixed points and periodic orbits of maps. It computes codim 1 bifurcation curves and supports the computation of normal coefficients including branch switching from codim 2 points to secondary curves. Recently, the initialization and computation of connecting orbits was improved. Moreover, a graphical user interface was added enabling interactive control of all these computations. To further support these computations it allows to compute orbits of the map and its iterates and to represent them in 2D, 3D and numeric windows. We demonstrate the use of the toolbox in a study of Arnol'd tongues near a degenerate Neimark-Sacker (Chenciner) bifurcation. Here we illustrate the recent theory of [Baesens&Mackay,2007] how resonance tongues interact with a quasi-periodic saddle-node bifurcation of invariant curves in maps. Using normal form coefficients we find evidence for one of their cases, but not the other. Actually, we find another unfolding, i.e. a third possibility. We also find a structure that resembles a quasi-periodic cusp bifurcation of invariant curves

Special branches: organic greenhouse production, bulbs, ornamentals and aquaculture

Organic production methods are gaining ground in Dutch specialised production branches. Interest is growing among greenhouse horticulturalists and growers of flower bulbs, ornamentals and mushrooms. In organic horticulture Dutch research is unique in the world in thinking up innovative concepts and pioneering solutions. Ultimately this will also inspire change in the conventional secto

NOTES ON SOME MALAYSIAN SPECIES OF ANTHOCEROS L. (HEPATICAE)-”I

 1. The present paper is mainly based on studies on the spot of some members of the genus Anthoceros. Detailed descriptions and figures taken for the greatest part from living plants are given and notes on ecology and synonymy added.All species are treated as members of the genus Anthoceros, in which Aspiromitus Steph.and Phaeoceros Prosk. are included.2. Several of the species treated in this paper are very common in the cultivated area of West Java and their distribution is probably much wider than known at present and their number of synonyms larger.About forty badly described species of Stephani, based on material from tropical Asia, need a revision by a monographer. 3. Anthoceros tjibodensis W. Meijer appears in this paper as a new name for Anthoceros polyandrus Steph

Forming the Moon from terrestrial silicate-rich material

Recent high-precision measurements of the isotopic composition of lunar rocks demonstrate that the bulk silicate Earth and the Moon show an unexpectedly high degree of similarity. This is inconsistent with one of the primary results of classic dynamical simulations of the widely accepted giant impact model for the formation of the Moon, namely that most of the mass of the Moon originates from the impactor, not Earth. Resolution of this discrepancy without changing the main premises of the giant impact model requires total isotopic homogenisation of Earth and impactor material after the impact for a wide range of elements including O, Si, K, Ti, Nd and W. Even if this process could explain the O isotope similarity, it is unlikely to work for the much heavier, refractory elements. Given the increasing uncertainty surrounding the giant impact model in light of these geochemical data, alternative hypotheses for lunar formation should be explored. In this paper, we revisit the hypothesis that the Moon was formed directly from terrestrial mantle material. We show that the dynamics of this scenario requires a large amount of energy, almost instantaneously generated additional energy. The only known source for this additional energy is nuclear fission. We show that it is feasible to form the Moon through the ejection of terrestrial silicate material triggered by a nuclear explosion at Earths core-mantle boundary (CMB), causing a shock wave propagating through the Earth. Hydrodynamic modelling of this scenario shows that a shock wave created by rapidly expanding plasma resulting from the explosion disrupts and expels overlying mantle and crust material.Comment: 26 pages, 5 figures, 1 tabl

LIVESTOCK TO 2020: THE REVOLUTION CONTINUES

This paper was presented at the INTERNATIONAL TRADE IN LIVESTOCK PRODUCTS SYMPOSIUM in Auckland, New Zealand, January 18-19, 2001. The Symposium was sponsored by: the International Agricultural Trade Research Consortium, the Venture Trust, Massey University, New Zealand, and the Centre for Applied Economics and Policy Studies, Massey University. Dietary changes, especially in developing countries, are driving a massive increase in demand for livestock products. The objective of this symposium was to examine the consequences of this phenomenon, which some have even called a "revolution." How are dietary patterns changing, and can increased demands for livestock products be satisfied from domestic resources? If so, at what cost? What will be the flow-on impacts, for example, in terms of increased demands for feedgrains and the pressures for change within marketing systems? A supply-side response has been the continued development of large-scale, urban-based industrial livestock production systems that in many cases give rise to environmental concerns. If additional imports seem required, where will they originate and what about food security in the importing regions? How might market access conditions be re-negotiated to make increased imports achievable? Other important issues discussed involved food safety, animal health and welfare and the adoption of biotechnology, and their interactions with the negotiation of reforms to domestic and trade policies. Individual papers from this conference are available on AgEcon Search. If you would like to see the complete agenda and set of papers from this conference, please visit the IATRC symposium web page at: http://www1.umn.edu/iatrc.intro.htmDemand and Price Analysis, Production Economics,

Helicity Amplitudes for Charmonium Production in Hadron-Hadron and Photon-Hadron Collisions

We present the gluon-gluon and photon-gluon helicity amplitudes for color singlet and octet charmonium production in polarized and unpolarized hadron-hadron and photon-hadron collisions.Comment: 11 pages amstex no figure

Famous numbers on a Chessboard

In this article it is shown how famous numbers like Pascal’s triangle, the Fibonaccinumbers, Catalan’s triangle, Delannoy’s square array, the Pell numbers and Schröder’striangle can be constructed on a chessboard with a rook, knight, bishop, king or queen.Furthermore, several new triangle sums, which are all named after chess pieces that areleapers and add up numbers according to the way they leap, are introduced. Finally anew theory of how Hipparchus, who lived around 150 BC, might have calculated histwo famous numbers with the aid of a ‘chessboard’ is presented

A Model for Internet Traffic Growth

A simple model that let us predict the doubling time of Internet traffic ispresented. The growth of this traffic depends on three factors, that is the doublingtime of the number of users that are online, the doubling time of the time that theyspend online and the doubling time of the bandwidth provided to the end user bytelecommunication networks. The first and the second depend primarily on marketingstrategies while the last one depends on Moore's Law. In 2006 in Europe these threedoubling times led to an expected doubling time for the traffic on the Internet ofroughly 1.2 years. The real value of the doubling time of the traffic of a group ofEuropean Internet Exchanges agrees well with the expected value