1,134 research outputs found
Historical Analysis of International Trade Flows in Forest Products - A Preliminary Paper
In this paper we outline some ideas on how to study the past behavior of the structure and dynamic changes in international flows of wood and wood products. We present some results of a share structure analysis carried out for three products and three years (Sawnwood, Pulp and Newsprint in 1971, 1975, and 1979) based on UN trade matrices as reported by importers. We also comment on the currently available FAO and UN data and their quality. This paper is a prelude to a detailed trade analysis for 13 products over the last two decades, which will be completed in the Forest Sector Project
An Historical Analysis of International Trade in Forest Products
In order to examine the long-term development of international trade in wood products, it is useful to study the patterns of past behaviour of trade. In this paper we therefore present an analysis of the structural characteristics of international trade in wood products over the last twenty years. The analysis reveals the structure of trade flows and their tendencies over time, together with the effects that trade policies have had on trade patterns. An attempt is then made to develop an understanding of the factors which have influenced these trade flows, via the application of gravitational models
A tensile strength apparatus with the facility to monitor negative pore-water pressure
This paper presents a new testing method for investigating the behaviour of clayey geomaterials subjected to a tensile (negative) total stress. The method includes the use of high capacity tensiometers to measure the pore-water pressure of the test specimen, an aspect which has not been demonstrated in any other direct tensile testing method. This addition allows interpretation of failure data in terms of effective stress rather than total stress, which is the approach that should be pursued in the saturated range. The test specimen shape and loading method have been modified from those commonly seen in existing literature to ensure that the direction of the major principal stress in the failure zone coincides with the direction of the externally applied tensile force, allowing for a more accurate analysis of tensile failure. Results are shown for saturated specimens and compared to results obtained for the same soil in uniaxial compression, using a modified version of the presented uniaxial tensile method, and a triaxial compression test. It is demonstrated that crack initiation occurs by shear failure if the data is interpreted in terms of effective stress rather than total stress, and that the failure mechanisms under tension do not differ from compression
A Share Structure Analysis of International Trade Flows in Some Forest Products 1962-1981
In this paper, we present the detailed results of a share structure analysis of international trade flows of Sawnwood (Coniferous and Non-Coniferous separately) Panels, Furniture, and Builders' woodwork plus prefabricated buildings, over the years 1962 to 1981. The analysis is based on UN importers' data, supplemented by exporters' reports where the former give no data, and excludes intra-regional trade. In future the analysis will be completed for other products, and these results will also be updated as improvements to the Forest Sector Project database are completed. Changes that are being made to the trade database are outlined
Problems and Prospects of Developing Countries in Forestry and Wood-Processing Industries. Report from an IIASA/UNIDO Workshop
This paper reports in a summary form on the discussions during a workshop organized by IIASA and UNIDO in January 1983. The workshop treated problems and prospects relating to developing countries in the sectors of forestry and wood-processing industries. The results of the workshop will be used in IIASA's project "Structural Change in the Forest Sector" and in UNIDO's work on its world-wide study on wood and wood processing industries. The invited participants came mainly from developing countries and from the two institutions mentioned.
The issues raised during the meeting are summarized systematically in Figure 2. The main concern of the meeting related to the sustainability of the wood resources, over-exploitation and depletion and suitable counter-balancing measures, such as afforestation, reforestation, and more efficient use of available resources. Trade patterns were also discussed. A global trade model for forestry industry products was presented
Recommended from our members
Development of interconnected silicon micro-evaporators for the on-detector electronics cooling of the future ITS detector in the ALICE experiment at LHC
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The design of the future High Energy Physics (HEP) particle detectors for the upgrade of the LHC (Large Hadron Collider) experiments at CERN (European Organization for Nuclear Research) is pushing technological frontiers to the limit trying to reach unprecedented accuracy in particles identification and particle production dynamics in ultra-relativistic hadron collisions. The thermal management of the on-detector electronics and the development of low mass integrated cooling systems have become a crucial task in the design of silicon tracking detectors for HEP applications. In this paper, we present a novel concept of low mass interconnected silicon microchannel devices for the future Inner Tracking System of the ALICE (A Large Ion Collider Experiment) detector at LHC. This innovative design achieves the requirements of the detector while minimizing the total material budget
On the implementation of a recently proposed dosimetric formalism to a robotic radiosurgery system
The aim of this work is to implement a recently proposed dosimetric formalism for nonstandard fields to the calibration and small field output factor measurement of a robotic stereotactic radiosurgery system
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
- …