Laser cladding is one kind of advanced surface modification technology and has the abroad prospect in making the wear-resistant coating on metal substrates. However, the application of laser cladding technology does not achieve the people's expectation in the practical production because of many...

Ceramic coatings were formed on a pure aluminum substrate in an aqueous solution of phosphate salt, using the pulsating micro-arc oxidation method. XRD indicated that the film composed of pure γ-Al2O3. SEM showed that the surface of the film was micro-porous with 1–5 μm pores. EDS gave the...

Ceramic-like coatings were deposited on the substrate of the AZ91 alloy by micro-arc oxidation (MAO). Many methods like X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron diffraction spectroscopy (EDS) were used to analyze the structure and composition of the coating. XRD...

Ti and its alloys are considered to be very promising in biological material field. But their biological activity and corrosion resistance in body fluid still need to be improved. As a novel technique for surface treatment, Micro-arc oxidation (MAO) is attracting interest from those who want to...

It is thought that the PEO (plasma electrolysis oxidation) coatings are difficult to be prepared on the cast Al–Si alloys because these alloys contain lots of pure silicon phases. In the present study, oxide coatings with a thickness of about 10 μm were deposited on the substrate of the ZL109...

Micro-arc oxidation (MAO) is a novel technique for producing oxide films on metals like Al, Mg, Ti and Zr. A ceramic-like film containing Ca and P was deposited on Ti-6Al-4V substrate by MAO in an electrolytic solution using a pulsed power supply. XRD indicated that the film was a mixture of...

Many hedge funds attempt to achieve high returns by employing leverage. However, it is difficult to track the degree of leverage used by hedge funds over time because detailed timely information about their positions in asset markets is generally unavailable. This paper discusses how to combine...

We examine the effects of smoothed hedge fund returns on standard deviation, skewness, and kurtosis of return and on correlation of returns and cross-sectional volatility and covariance of returns using an MA(2)-GARCH(1,1)-skewed-t representation of returns instead of the traditional MA(2) model...

In this paper, we estimate alpha for major hedge fund indexes. To set the stage, we examine several alternative methods for replicating Hedge Fund Research Inc. hedge fund indexes. The replication methods include stepwise regression, variations of the lasso shrinkage method, principal component...

This paper describes the structure of a rule-based econometric forecasting system designed to produce multi-equation econometric models. The paper describes the functioning of a working system which builds the econometric forecasting equation for each series submitted and produces forecasts of...