1,996 research outputs found
Crisis and protection in the automotive industry : a global value chain perspective
In this paper the authors apply global value chain (GVC) analysis to recent trends in the global automotive industry, with special attention paid to government interventions triggered by the recent economic crisis. The authors first highlight some of the defining characteristics of GVCs in this important industry, especially the unusually strong regional structure of production and sales. National political institutions create pressure for local content, which drives production close to end markets, where it tends to be organized nationally or regionally. They then examine policy reactions to the recent economic crisis, and provide some discussion of the government interventions in the industry. The authors end with a number of policy conclusions that highlight the likely impact of the interventions on the evolution GVCs and the growth of the industry in developing countries.Markets and Market Access,Economic Theory&Research,Labor Policies,Water and Industry,Debt Markets
Effects of the crisis on the automotive industry in developing countries : a global value chain perspective
This paper applies global value chain analysis to study recent trends in the global automotive industry. The authors pay special attention to the effects of the recent economic crisis on the industry in developing countries. The principal finding is that the crisis has accelerated pre-crisis trends toward greater importance of the industry in the South. More rapid growth of car ownership is the impetus, but the co-location and close interaction of suppliers and lead firms in this industry is an important catalyst. Opportunities to move up in the value chain for suppliers in emerging economies have proliferated and are likely to become even stronger now that an increasing number of new models are developed specifically for markets in developing countries. The co-location of assembly and parts plants in national and regional production systems has largely confined the impact of sales declines during the crisis to each country/region. In addition, the different development strategies followed by countries like Mexico, China, and India are slowly converging as their industries gain size and independence.Markets and Market Access,Microfinance,Labor Policies,Economic Theory&Research,Debt Markets
A mathematical model of the CH-53 helicopter
A mathematical model suitable for real time simulation of the CH-53 helicopter is presented. This model, which is based on modified nonlinear classical rotor theory and nonlinear fuselage aerodynamics, will be used to support terminal-area guidance and navigation studies on a fixed-base simulator. Validation is achieved by comparing the model response with that of a similar aircraft and by a qualitative comparison of the handling characteristics made by experienced pilots
Some aspects of tensile and shear fatigue in carbon fibre reinforced plastics, including hoop-wound tubes.
Results of zero-tension fatigue tests are presented for flat sheet unidirectional 0° and angle-plied +/-45° carbon fibre reinforced plastics. Torsional-shear and transverse fatigue tests were made on hoop-wound tubes. These have shown that surface finish has a significant role in determining the fatigue performance of CFRP.A method is presented for assessing the fatigue stress bandwidth in zero-tension fatigue at 0° CFRP. A mechanism of fatigue failure in 0° CFRP is also postulated. Fatigue induced creep effects were observed during shear loadings and these are shown to relate to cracking and crack growth in +/-45° material. A shell theory analysis of tubular CFRP test-pieces was made which demonstrates the suitability of this specimen for 0° longitudinal and 90° hoop-windings. Hoop-wound tubes were used to show that the mutual interactions between shear and transverse elastic properties are not significantly affected by transverse fatigue stresses
Speciation without chromatography: Part I. Determination of tributyltin in aqueous samples by chloride generation, headspace solid-phase microextraction and inductively coupled plasma time of flight mass spectrometry
An analytical procedure was developed for the determination of tributyltin in aqueous samples. The relatively high volatility of the organometal halide species confers suitability for their headspace sampling from the vapour phase above natural waters or leached solid samples. Tributyltin was collected from the sample headspace above various chloride-containing matrices, including HCl, sodium chloride solution and sea-water, by passive sampling using a polydimethylsiloxane/divinylbenzene (PDMS/DVB)-coated solid-phase microextraction (SPME) fiber. Inductively coupled plasma time-of-flight mass spectrometry (ICP-TOFMS) was used for detection following thermal desorption of analytes from the fiber. A detection limit of 5.8 pg ml–1(as tin) was realized in aqueous samples. Method validation was achieved using NRCC PACS-2 (Sediment) certified reference material, for which reasonable agreement between certified and measured values for tributyltin content was obtained
Cereal polysaccharides with special reference to the hemicelluloses of rye
The water soluble polysaccharide isolated from rye flour
gave on hydrolysis, Xylose (60%), arabinose (29%) and glucose (5%).
After methylation of the hemicellulose, the sugars obtained on
hydrolysis of the product were separated on a cellulose column,
giving 2:3:5-tri-O-methyl-L-arabinose (5 parts), 2:3-di-0-methyl-
D-xylose,(6) 2-0-methy1 -D-xylose (5) and a small amount of D-xylose.
The general structure of the xylan is therefore similar to other
known araboxylans, having a backbone of l:4 linked xylopyranose
units with terminal arabinose units linked through position 3.
In the isolation of the trisaccharide, Q-L-arabofuranosyl (1->3)-
0-D -xylopyranosyl (1->4) -D-xylopyranose, it has been shown that
some of the arabinose units are in the form of single side chains.
4-0-Methyl-D-xylose has been synthesised from D-arabinose,
and it has been shown to degrade in alkali giving mainly formic
acid and xyloisosaccharinic acid, which is the expected product
from sugars with 1:4-linked xylose residues.
The action of alkali on various cereal xylans has been
studied. The degradation products have been shown to include
formic, lactic acids together xyloisosaccharinolactone and small
quantities of xylometasaccharinolactones. Xylometasaceharinolactone
has been found to be present in the hydrolysis products of the
alkali stable rye polysaccharide. The mechanisms for the
degradation and stopping reactions are discussed.
Two unsuccessful attempts have been made to synthesise
1:5-dihydroxypentan-2:3-dione
How Do We Define Value Chains and Production Networks?
Summaries This article is intended to contribute to the process of building a set of tools that will help advance the debate on the shape and trajectory of global economic integration. The article uses a ‘Value?chain’ approach to construct a set of conceptual terms and concepts intended to better specify the concrete actors in the global economy as well as the linkages that bind them into a larger whole. I propose a set of terms and concepts that specify three critical value chain dimensions: organizational scale, geographic scale and types of value chain productive actors. The article also lays out a distinction between value chains and production networks
Symplectic algorithm for constant-pressure molecular dynamics using a Nose-Poincare thermostat
We present a new algorithm for isothermal-isobaric molecular-dynamics
simulation. The method uses an extended Hamiltonian with an Andersen piston
combined with the Nos'e-Poincar'e thermostat, recently developed by Bond,
Leimkuhler and Laird [J. Comp. Phys., 151, (1999)]. This
Nos'e-Poincar'e-Andersen (NPA) formulation has advantages over the
Nos'e-Hoover-Andersen approach in that the NPA is Hamiltonian and can take
advantage of symplectic integration schemes, which lead to enhanced stability
for long-time simulations. The equations of motion are integrated using a
Generalized Leapfrog Algorithm and the method is easy to implement, symplectic,
explicit and time reversible. To demonstrate the stability of the method we
show results for test simulations using a model for aluminum.Comment: 7 page
Adjusting the melting point of a model system via Gibbs-Duhem integration: application to a model of Aluminum
Model interaction potentials for real materials are generally optimized with
respect to only those experimental properties that are easily evaluated as
mechanical averages (e.g., elastic constants (at T=0 K), static lattice
energies and liquid structure). For such potentials, agreement with experiment
for the non-mechanical properties, such as the melting point, is not guaranteed
and such values can deviate significantly from experiment. We present a method
for re-parameterizing any model interaction potential of a real material to
adjust its melting temperature to a value that is closer to its experimental
melting temperature. This is done without significantly affecting the
mechanical properties for which the potential was modeled. This method is an
application of Gibbs-Duhem integration [D. Kofke, Mol. Phys.78, 1331 (1993)].
As a test we apply the method to an embedded atom model of aluminum [J. Mei and
J.W. Davenport, Phys. Rev. B 46, 21 (1992)] for which the melting temperature
for the thermodynamic limit is 826.4 +/- 1.3K - somewhat below the experimental
value of 933K. After re-parameterization, the melting temperature of the
modified potential is found to be 931.5K +/- 1.5K.Comment: 9 pages, 5 figures, 4 table
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