845 resultados para microstructure
Resumo:
Nano/micro grinding of tungsten carbide (WC) mould inserts was performed. A form accuracy of 〜200nm (in PV) and a surface roughness of 〜7nm were achieved. Nanoindentation revealed that small chipping or cracking occurred even at a penetration depth of 38nm, which could hinder the further improvement of surface quality during grinding. It was found that when grinding was conducted at nanometric scale, the microstructure of the work material and the morphology of the WC grains should be taken into account to enable a fully ductile removal. Copyright 2005 by the Japan Society of Mechanical Engineers
The mineralogy and microstructure of sedimentary zinc sulfides formed by bacterial sulfate reduction
Resumo:
This is the first paper to examine the microstructure of the Irish Stock Market empirically and is motivated by the adoption, on June 7th of Xetra the modern pan European auction trading system. Prior to this the exchange utilized an antiquated floor based system. This change was an important event for the market as a rich literature exists to suggest that the trading system exerts a strong influence over the behavior of security returns. We apply the ICSS algorithm of Inclan and Tiao (1994) to discover whether the change to the trading system caused a shift in unconditional volatility at the time Xetra was introduced. Because the trading mechanism can influence volatility in a number of ways we also estimate the partial adjustment coefficients of the Amihud and Mendelson (1987) model prior and subsequent to the introduction of Xetra. Although we find no evidence of volatility changes associated with the introduction of Xetra we do find evidence of an increase in the speed of adjustment (JEL: G15).
Resumo:
The purpose of this thesis is to shed more light in the FX market microstructure by examining the determinants of bid-ask spread for three currencies pairs, the US dollar/Japanese yen, the British pound/US dollar and the Euro/US dollar in different time zones. I examine the commonality in liquidity with the elaboration of FX market microstructure variables in financial centres across the world (New York, London, Tokyo) based on the quotes of three exchange rate currency pairs over a ten-year period. I use GARCH (1,1) specifications, ICSS algorithm, and vector autoregression analysis to examine the effect of trading activity, exchange rate volatility and inventory holding costs on both quoted and relative spreads. ICSS algorithm results show that intraday spread series are much less volatile compared to the intraday exchange rate series as the number of change points obtained from ICSS algorithm is considerably lower. GARCH (1,1) estimation results of daily and intraday bid-ask spreads, show that the explanatory variables work better when I use higher frequency data (intraday results) however, their explanatory power is significantly lower compared to the results based on the daily sample. This suggests that although daily spreads and intraday spreads have some common determinants there are other factors that determine the behaviour of spreads at high frequencies. VAR results show that there are some differences in the behaviour of the variables at high frequencies compared to the results from the daily sample. A shock in the number of quote revisions has more effect on the spread when short term trading intervals are considered (intra-day) compared to its own shocks. When longer trading intervals are considered (daily) then the shocks in the spread have more effect on the future spread. In other words, trading activity is more informative about the future spread when intra-day trading is considered while past spread is more informative about the future spread when daily trading is considered