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Study region The largest inland river basin in China (the Tarim River Basin) Study focus This study introduces a novel classification scheme for dry and warm snow droughts with focus on their duration, severity, and intensity. The Nonparametric Standardized SWE Index (NSWEI) and the Standardized Precipitation Index (SPI) were employed to assess these drought types. The optimal parameters-based geographical detector (OPGD) model and machine learning (including random forest model and Shapley-XGBoost algorithm) were applied to reveal the spatial and time dynamic driving forces of droughts. New hydrological insights for the regions Results indicated that warm-type droughts occurred more frequently and with greater intensity, exhibiting a larger spatial coverage compared to dry-type droughts, which can be attributed to warm-type droughts dominated by temperature and vapor pressure deficit, whereas dry-type are predominantly influenced by relative humidity and solar radiation. Moreover, the dynamics of snow droughts exhibited a contrasting pattern between the south (experiencing an upward trend) and the north (experiencing a descending trend). In the south, dry-type droughts were exacerbated by the strength of North Pacific Oscillation (PDO)-precipitation coupling, while warm-type droughts are influenced by the strength of North Atlantic Oscillation (NAO)-precipitation coupling and El Niño Southern Oscillation (ENSO)-precipitation.

This paper reviews the third biennial challenge on spectral reconstruction from RGB images, i.e., the recovery of whole-scene hyperspectral (HS) information from a 3-channel RGB image. This challenge presents the "ARAD_1K" data set: a new, larger-than-ever natural hyperspectral image data set containing 1,000 images. Challenge participants were required to recover hyper-spectral information from synthetically generated JPEG-compressed RGB images simulating capture by a known calibrated camera, operating under partially known parameters, in a setting which includes acquisition noise. The challenge was attended by 241 teams, with 60 teams com-peting in the final testing phase, 12 of which provided de-tailed descriptions of their methodology which are included in this report. The performance of these submissions is re-viewed and provided here as a gauge for the current state-of-the-art in spectral reconstruction from natural RGB images.

This paper reviews the third biennial challenge on spectral reconstruction from RGB images, i.e., the recovery of whole-scene hyperspectral (HS) information from a 3-channel RGB image. This challenge presents the "ARAD_1K"data set: a new, larger-than-ever natural hyperspectral image data set containing 1,000 images. Challenge participants were required to recover hyper-spectral information from synthetically generated JPEG-compressed RGB images simulating capture by a known calibrated camera, operating under partially known parameters, in a setting which includes acquisition noise. The challenge was attended by 241 teams, with 60 teams com-peting in the final testing phase, 12 of which provided de-tailed descriptions of their methodology which are included in this report. The performance of these submissions is re-viewed and provided here as a gauge for the current state-of-the-art in spectral reconstruction from natural RGB images.

Control schemes based on electromyography (EMG) have demonstrated their superiority in human-robot cooperation due to the fact that motion intention can be well estimated by EMG signals. However, there are several limitations due to the noisy nature of EMG signals and the inaccuracy of EMG-force/torque estimation, which might deteriorate the stability of human-robot cooperation movement. To improve the movement stability, an EMG-based admittance control scheme (EACS) was proposed, comprised of an EMG-driven musculoskeletal model (EDMM), an admittance filter and an inner position controller. To investigate the performance of EACS, a series of sinusoidal tracking tasks were conducted with 12 healthy participants and 4 stroke survivors in an ankle exoskeleton in comparison with the EMG-based open-loop control scheme (EOCS). The experimental results indicated that both EACS and EOCS could improve stroke survivors' ankle range of motion (ROM). The experimental results of both healthy participants and stroke survivors showed that the assistance torque, tracking error and jerk values of EACS were lower than those of EOCS. The interaction torque of EACS decreased towards the increasing assistance ratio while that of EOCS increased. Moreover, the EMG levels of tibialis anterior (TA) decreased towards the increasing assistance ratio but were higher than those of EOCS. EACS was effective in improving movements stability, and had the potential to be applied in robot-assisted rehabilitation training to address the foot-drop problem.

Low surface roughness, low residual stress, and(002) textured aluminum nitride(AlN) thin films are favored for applications in microelectronic and optoelectronic devices. In this paper, AlN thin films were deposited by reactive high power pulsed magnetron sputtering(HPPMS). The effect of aluminum target sputtering mode and sputtering power on thin film residual stress, crystalline structure, surface roughness, and morphology of AlN thin films was studied. The results indicate that, with Al target sputtering mode transfer from metallic mode to transitional and compound modes, respectively, the number of Al species decrease, and ion-to-neutral ratio of Al species increase. Comparing the AIN thin film deposited in compound mode with that deposited in transitional mode, the latter exhibited lower surface roughness and residual stress. In addition, AlN thin film with (002) texture and lower residual stress is obtained by increasing sputtering power in transitional mode. For fabricating AIN film via reactive HPPMS with a particular (002) texture, low surface roughness, and residual stress, sputtering the target in the transitional mode with high sputtering power is optimal.

MiRNAs (microRNAs) are frequently aberrantly expressed in many cancers. MiR-873 has been revealed to be downregulated in colorectal cancer and glioblastoma. However, its function remains unclear. Here, we report that miR-873 is downregulated in breast cancer compared with normal tissue. Enforced expression of miR-873 decreases the transcriptional activity of ER (estrogen receptor) α but not ERβ through the modulation of ERα phosphorylation in ER positive breast cancer cells. We also found that MiR-873 inhibits breast cancer cell proliferation and tumor growth in nude mice. Reporter gene assays revealed cyclin-dependent kinase 3 (CDK3) as a direct target of miR-873. CDK3 was shown to be overexpressed in breast cancer and phosphorylate ERα at Ser104/116 and Ser118. Furthermore, we found that Mir-873 inhibits ER activity and cell growth via targeting CDK3. Interestingly, miR-873 was observed to be downregulated in tamoxifen resistant MCF-7/TamR cells, while CDK3 is overexpressed in these cells. More importantly, re-expression of miR-873 reversed tamoxifen resistance in MCF-7/TamR cells. Our data demonstrate that miR-873 is a novel tumor suppressor in ER positive breast cancer and a potential therapeutic approach for treatment of tamoxifen resistant breast cancer.

In this paper, carbon-doped Ti-O films were prepared on silicon wafer and stainless steel by reaction magnetron sputtering using CO 2 as carbon and oxygen source. By changing the ratio of CO 2 /O 2 , a series of films with different composition can be obtained. X-ray photoelectron spectroscopy (XPS) was employed to analyze composition of as-prepared films. The result proved that carbon was doped into titanium successfully. Ultraviolet-visible (UV-Vis) spectrophotometer in the wavelength range of 250- 900 nm was used to record the absorbance of as-prepared film samples. The photocatalytic activities of as-prepared films were evaluated by measuring the decolorization rate of methyl orange under UV light irradiation. The results showed that as-prepared carbon-doped Ti-O films have fairly photocatalysis activity, which to be hoped to become candidate materials for photocatalyst. © 2013 Elsevier B.V. All rights reserved.

The mood-stabilizing and anticonvulsant drug valproic acid (VPA) inhibits histone deacetylases (HDACs). The aim of the present study was to determine the effect of HDAC inhibition on overall and target gene promoter-associated histone methylation in rat cortical neurons and astrocytes. We found that VPA and other HDAC inhibitors, including sodium butyrate (SB), trichostatin A (TSA), and the Class I HDAC inhibitors MS-275 and apicidin all increased levels of histone 3 lysine 4 dimethylation and trimethylation (H3K4Me2 and H3K4Me3); these processes are linked to transcriptional activation in rat cortical neurons and astrocytes. VPA, SB, TSA, MS-275, and apicidin also upregulated levels of the neuroprotective heat shock protein 70 (HSP70) in rat astrocytes. Moreover, Class I HDAC inhibition by VPA and MS-275 increased H3K4Me2 levels at the HSP70 promoter in astrocytes and neurons. We also found that VPA treatment facilitated the recruitment of acetyltransferase p300 to the HSP70 promoter and that p300 interacted with the transcription factor NF-Y in astrocytes. Taken together, the results suggest that Class I HDAC inhibition is key to upregulating overall and gene-specific H3K4 methylation in primary neuronal and astrocyte cultures. In addition, VPA-induced activation of the HSP70 promoter in astrocytes appears to involve an increase in H3K4Me2 levels and recruitment of p300. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.

A normal-reverse flotation process is described for the removal of dolomite from a hard-to-treat collophane ore grading 17.96% P2O5 and 2. 31% MgO. A concentrate grading more than 30% P2O5 and less than 1% MgO was obtained. The highly selective anionic fatty acid collector G4 and synthetic tannin depressant S721 were used and the mechanisms of adsorption on collophanite and depression of dolomite investigated using FTIR spectroscopy., A normal-reverse flotation process is described for the removal of dolomite from a hard-to-treat collophane ore grading 17.96% P2O5 and 2. 31% MgO. A concentrate grading more than 30% P2O5 and less than 1% MgO was obtained. The highly selective anionic fatty acid collector G4 and synthetic tannin depressant S721 were used and the mechanisms of adsorption on collophanite and depression of dolomite investigated using FTIR spectroscopy.

Porous alpha- tricalcium phosphate (α-TCP) was implanted in rabbit and dog models to investigate its induction of calcium phosphate (Ca-P) formation. The morphology and structure of the formed Ca-Ps were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The results showed an animal-dependent behavior of in vivo Ca-P formation. There were flake-like octacalcium phosphate (OCP) precipitates in the rabbit but rod-like hydroxyapatite (HA) precipitates in the dog model. In addition, high-resolution TEM (HRTEM) image revealed that there was OCP structure in certain portions of the rod-like HA precipitates in the dog model. And the orientation relation of OCP/HA was deduced as OCP (010)//HA (01̄0) and OCP (001)//HA (001̄). This implied that the in vivo HA was formed via OCP precursor phase.

Amorphous carbon films have been applied in biomedical fields as potential biocompatible materials with wettability that can be adjusted by doping with other elements, including F, Si, Ti, O and N. In this study, nitrogen-doped hydrogenated amorphous carbon (a-C:H:N) films were deposited by PIII-D using C2H2 + N-2 gas mixtures. The biocompatibility and anti-thrombotic properties of the films were assessed in vitro. The surface morphology and surface wettability of the films were characterized using atomic force microscopy (AFM) and a contact angle method. The results show no cytotoxicity for all films, and films with appropriate nitrogen doping possess much better endothelial cell growth and anti-thrombotic properties. (c) 2005 Elsevier B.V. All rights reserved.

Amorphous carbon (a-C) film deposition was studied theoretically by molecular-dynamics simulations in the temperature range of 100-873 K. For each temperature the simulations yield a mixture of sp2 and sp3 hybrids, which allows for the sp2 and sp3 fractions, and size and type of the sp2 clusters to be calculated. In parallel, the bonding structure of a-C thin films prepared by filtered cathodic vacuum arc (FCVA) at different substrate temperatures was analysed by x-ray absorption near edge spectroscopy (XANES) and Raman techniques. In addition, the optical properties of these films were determined from spectroscopic ellipsometry (SE). Both, theory and experiment, show a transition from diamond-like to graphite-like films as the substrate temperature exceeds a certain threshold, in agreement with previous observations. The evolution of the sp2 clusters, as defined by the number of consecutive sp2 atoms, and of sp2 sites rings with substrate temperature was computed from the simulated films. The results indicate an increase of sp2 clustering with temperature and a pronounced promotion of six to ten membered rings for substrate temperatures above the transition threshold. The further formation of these rings above the transition temperature does not correlate with the sp2 content and suggests an in-situ sp2 rearrangement process during deposition. The evolution of the sp2 networks predicted by the simulations will be contrasted with the data from the XANES and Raman investigations. Finally, the correlation of sp2 arrangement and of observed optical properties will be discussed.

Amorphous carbon (a-C) film deposition was studied theoretically by molecular-dynamics simulations in the temperature range of 100-873 K. For each temperature the simulations yield a mixture of sp2 and sp3 hybrids, which allows for the sp2 and sp3 fractions, and size and type of the sp2 clusters to be calculated. In parallel, the bonding structure of a-C thin films prepared by filtered cathodic vacuum arc (FCVA) at different substrate temperatures was analysed by x-ray absorption near edge spectroscopy (XANES) and Raman techniques. In addition, the optical properties of these films were determined from spectroscopic ellipsometry (SE). Both, theory and experiment, show a transition from diamond-like to graphite-like films as the substrate temperature exceeds a certain threshold, in agreement with previous observations. The evolution of the sp2 clusters, as defined by the number of consecutive sp2 atoms, and of sp2 sites rings with substrate temperature was computed from the simulated films. The results indicate an increase of sp2 clustering with temperature and a pronounced promotion of six to ten membered rings for substrate temperatures above the transition threshold. The further formation of these rings above the transition temperature does not correlate with the sp2 content and suggests an in-situ sp2 rearrangement process during deposition. The evolution of the sp2 networks predicted by the simulations will be contrasted with the data from the XANES and Raman investigations. Finally, the correlation of sp2 arrangement and of observed optical properties will be discussed.

The albumin adsorption on non-hydrogenated amorphous carbon films with different diamond-like character (i.e. sp3 content) is addressed. The films were produced by ion beam assisted deposition and by filtered cathodic vacuum arc deposition to obtain a wide range of sp3 contents. A combination of the spectroscopic ellipsometry, Raman spectroscopy and elastic recoil detection analysis was used for characterization of the films. It is shown that an increase of the deposition temperature leads to a decrease of the film band gap, density and a shift of the Raman G-band position. The wettability of the film is not influenced by its sp3 content. Albumin adsorption on the surface depends more on its wetting behavior than on the sp3 content. In addition, Ar ion treatment of the layers can be used to reduce the amount of adsorbed proteins.

Diamond like carbon (DLC) is known to posses high mechanical hardness and chemical inertness along with good bloodcompatibility. The latter is determined by protein - DLC surface interaction that is not properly addressed in the literature. These properties of DLC are determined to a large extent by sp3 bonds fraction and hydrogen content. Therefore, DLC films with different sp3 content have been produced by Ion Beam Assisted Deposition (IBAD) (low sp3) and Filtered Cathodic Vacuum Arc (FCVA) (high sp3) by changing deposition parameters. The films were characterized by spectrocopic ellipsometry (SE) within the wavelength range l=300-1700 nm after deposition. The spectral dependences of ellipsometric parameters, D and Y, were acquired in autoretarder mode of VASE spectroscopic ellipsometer (J.A. Woolam Co., Inc., USA). To improve the quality of SE data reduction, multiple sample analysis was carried out for set of different thickness DLC samples produced by IBAD at the same deposition parameters on different substrates. The optical constants of DLC both with low and high content of sp3 bonds were parameterized in semiconductor model approach [2]. The SE data reduction yielded refraction and absorption index values, film thickness, band gap values of the DLC and surface roughness. Relation of SE results for samples produced by FCVA with Raman scattering data, which demonstrate D and G bands displacements, allowed proper characterization of the bonding structure of DLCs and estimation of sp3/sp2 fraction ratio. By using film thickness from SE results DLC film densities were estimated due to elastic recoil detection analysis (ERDA). ERDA also demonstrated only low amount of hydrogen mainly near film-substrate interface in DCLs produced by FCVA technique. Thus, it demonstrates that DLC properties modification is due to sp3/sp2 ratio variation and are not caused by variation of hydrogen content. Deposition of human serum albumin labeled by fluorescein on DLC layers with d

Diamond like carbon (DLC) is known to posses high mechanical hardness and chemical inertness along with good bloodcompatibility. The latter is determined by protein - DLC surface interaction that is not properly addressed in the literature. These properties of DLC are determined to a large extent by sp3 bonds fraction and hydrogen content. Therefore, DLC films with different sp3 content have been produced by Ion Beam Assisted Deposition (IBAD) (low sp3) and Filtered Cathodic Vacuum Arc (FCVA) (high sp3) by changing deposition parameters. The films were characterized by spectrocopic ellipsometry (SE) within the wavelength range l=300-1700 nm after deposition. The spectral dependences of ellipsometric parameters, D and Y, were acquired in autoretarder mode of VASE spectroscopic ellipsometer (J.A. Woolam Co., Inc., USA). To improve the quality of SE data reduction, multiple sample analysis was carried out for set of different thickness DLC samples produced by IBAD at the same deposition parameters on different substrates. The optical constants of DLC both with low and high content of sp3 bonds were parameterized in semiconductor model approach [2]. The SE data reduction yielded refraction and absorption index values, film thickness, band gap values of the DLC and surface roughness. Relation of SE results for samples produced by FCVA with Raman scattering data, which demonstrate D and G bands displacements, allowed proper characterization of the bonding structure of DLCs and estimation of sp3/sp2 fraction ratio. By using film thickness from SE results DLC film densities were estimated due to elastic recoil detection analysis (ERDA). ERDA also demonstrated only low amount of hydrogen mainly near film-substrate interface in DCLs produced by FCVA technique. Thus, it demonstrates that DLC properties modification is due to sp3/sp2 ratio variation and are not caused by variation of hydrogen content. Deposition of human serum albumin labeled by fluorescein on DLC layers with d

Diamond like carbon (DLC) is known to posses high mechanical hardness and chemical inertness along with good bloodcompatibility. The latter is determined by protein - DLC surface interaction that is not properly addressed in the literature. These properties of DLC are determined to a large extent by sp3 bonds fraction and hydrogen content. Therefore, DLC films with different sp3 content have been produced by Ion Beam Assisted Deposition (IBAD) (low sp3) and Filtered Cathodic Vacuum Arc (FCVA) (high sp3) by changing deposition parameters. The films were characterized by spectrocopic ellipsometry (SE) within the wavelength range l=300-1700 nm after deposition. The spectral dependences of ellipsometric parameters, D and Y, were acquired in autoretarder mode of VASE spectroscopic ellipsometer (J.A. Woolam Co., Inc., USA). To improve the quality of SE data reduction, multiple sample analysis was carried out for set of different thickness DLC samples produced by IBAD at the same deposition parameters on different substrates. The optical constants of DLC both with low and high content of sp3 bonds were parameterized in semiconductor model approach [2]. The SE data reduction yielded refraction and absorption index values, film thickness, band gap values of the DLC and surface roughness. Relation of SE results for samples produced by FCVA with Raman scattering data, which demonstrate D and G bands displacements, allowed proper characterization of the bonding structure of DLCs and estimation of sp3/sp2 fraction ratio. By using film thickness from SE results DLC film densities were estimated due to elastic recoil detection analysis (ERDA). ERDA also demonstrated only low amount of hydrogen mainly near film-substrate interface in DCLs produced by FCVA technique. Thus, it demonstrates that DLC properties modification is due to sp3/sp2 ratio variation and are not caused by variation of hydrogen content. Deposition of human serum albumin labeled by fluorescein on DLC layers with d

Hydroxyapatite (HA) coated Ti alloy is a promising material for biomedical implants. The successful applications of such implants rely on fundamental understandings of mechanical behavior of the HA coatings, particularly, the fatigue resistance. In this work the mechanical stability of HA coatings under cyclic loading was systematically investigated using four-point bending tests and the indentation tests in both air and simulated body fluid (SBF). Also, a shear cyclic test was developed for the coatings, considering the coatings of implants often failure under shearing loading in human body. Experiments revealed the conventional cyclic bending tests could not effectively evaluate the fatigue resistance of the HA coatings on Ti substrates. The contact fatigue under indentation might represent the worst service conditions of coatings. The cyclic indentation revealed that the fatigue damages in the HA coatings were severer in SBF than in air, and thin HA coatings exhibited less fatigue damages than the thick ones. The newly developed shear test for the coatings successfully generated similar shear loading as the conventional ones, however it is easier for alignment and for adapting coating thickness variation. Using the new method, the coating resistance to cyclic shear loading was evaluated with S-N curves. Also the tests revealed the existence of threshold stress which was required to generate fatigue damages in the coating.

Hydroxyapatite (HA) coated Ti alloy is a promising material for biomedical implants. The successful applications of such implants rely on fundamental understandings of mechanical behavior of the HA coatings, particularly, the fatigue resistance. In this work the mechanical stability of HA coatings under cyclic loading was systematically investigated using four-point bending tests and the indentation tests in both air and simulated body fluid (SBF). Also, a shear cyclic test was developed for the coatings, considering the coatings of implants often failure under shearing loading in human body. Experiments revealed the conventional cyclic bending tests could not effectively evaluate the fatigue resistance of the HA coatings on Ti substrates. The contact fatigue under indentation might represent the worst service conditions of coatings. The cyclic indentation revealed that the fatigue damages in the HA coatings were severer in SBF than in air, and thin HA coatings exhibited less fatigue damages than the thick ones. The newly developed shear test for the coatings successfully generated similar shear loading as the conventional ones, however it is easier for alignment and for adapting coating thickness variation. Using the new method, the coating resistance to cyclic shear loading was evaluated with S-N curves. Also the tests revealed the existence of threshold stress which was required to generate fatigue damages in the coating.

Hydroxyapatite (HA) coated Ti alloy is a promising material for biomedical implants. The successful applications of such implants rely on fundamental understandings of mechanical behavior of the HA coatings, particularly, the fatigue resistance. In this work the mechanical stability of HA coatings under cyclic loading was systematically investigated using four-point bending tests and the indentation tests in both air and simulated body fluid (SBF). Also, a shear cyclic test was developed for the coatings, considering the coatings of implants often failure under shearing loading in human body. Experiments revealed the conventional cyclic bending tests could not effectively evaluate the fatigue resistance of the HA coatings on Ti substrates. The contact fatigue under indentation might represent the worst service conditions of coatings. The cyclic indentation revealed that the fatigue damages in the HA coatings were severer in SBF than in air, and thin HA coatings exhibited less fatigue damages than the thick ones. The newly developed shear test for the coatings successfully generated similar shear loading as the conventional ones, however it is easier for alignment and for adapting coating thickness variation. Using the new method, the coating resistance to cyclic shear loading was evaluated with S-N curves. Also the tests revealed the existence of threshold stress which was required to generate fatigue damages in the coating.

Interfacial bonding strength of coatings on orthopaedic materials, such as hydroxyapatite (HA) on titanium alloys, is commonly tested by tensile bonding tests. The actually loading of coatings in service, however, is under combined shear and compression. Conventional shear test methods are not widely used due to the alignment difficulty or inflexibility for thickness adjustment. We also found that the 4-point bending tests failed to characterize the coating fatigue resistance as a function of processing condition. Such aforementioned findings stimulated us to develop a new testing method for coating bonding strength and fatigue tests. This new method can provide combined shear and compression loading, or near pure shear on coatings. It has advantages such as simplicity, easy alignment, and flexibility for adapting coating thickness changes. (Example materials: T-6Al-4V plasma sprayed with hydroxyapatite coating.)

There is little knowledge about elastic/plastic deformation behavior of hydroxyapatite (HA) coatings on implant substrates, even though such information is valuable for mechanical stability of the HA coated implants. Note that elastic/plastic behavior of HA coatings cannot be obtained from tests of their bulk counterparts due to the well-known size effects on mechanical strength. The objective of the present study is to estimate the elastic/plastic constitutive relation of plasma sprayed HA coatings on Ti alloy substrates using a novel approach that combines the indentation tests and the non-linear finite element method. The work demonstrates that constitutive relation can be obtained by numerically simulating the indentation stress/strain curves of HA coatings.

Interfacial bonding strength of coatings on orthopaedic materials, such as hydroxyapatite (HA) on titanium alloys, is commonly tested by tensile bonding tests. The actually loading of coatings in service, however, is under combined shear and compression. Conventional shear test methods are not widely used due to the alignment difficulty or inflexibility for thickness adjustment. We also found that the 4-point bending tests failed to characterize the coating fatigue resistance as a function of processing condition. Such aforementioned findings stimulated us to develop a new testing method for coating bonding strength and fatigue tests. This new method can provide combined shear and compression loading, or near pure shear on coatings. It has advantages such as simplicity, easy alignment, and flexibility for adapting coating thickness changes. (Example materials: T-6Al-4V plasma sprayed with hydroxyapatite coating.)

There is little knowledge about elastic/plastic deformation behavior of hydroxyapatite (HA) coatings on implant substrates, even though such information is valuable for mechanical stability of the HA coated implants. Note that elastic/plastic behavior of HA coatings cannot be obtained from tests of their bulk counterparts due to the well-known size effects on mechanical strength. The objective of the present study is to estimate the elastic/plastic constitutive relation of plasma sprayed HA coatings on Ti alloy substrates using a novel approach that combines the indentation tests and the non-linear finite element method. The work demonstrates that constitutive relation can be obtained by numerically simulating the indentation stress/strain curves of HA coatings.

Interfacial bonding strength of coatings on orthopaedic materials, such as hydroxyapatite (HA) on titanium alloys, is commonly tested by tensile bonding tests. The actually loading of coatings in service, however, is under combined shear and compression. Conventional shear test methods are not widely used due to the alignment difficulty or inflexibility for thickness adjustment. We also found that the 4-point bending tests failed to characterize the coating fatigue resistance as a function of processing condition. Such aforementioned findings stimulated us to develop a new testing method for coating bonding strength and fatigue tests. This new method can provide combined shear and compression loading, or near pure shear on coatings. It has advantages such as simplicity, easy alignment, and flexibility for adapting coating thickness changes. (Example materials: T-6Al-4V plasma sprayed with hydroxyapatite coating.)

There is little knowledge about elastic/plastic deformation behavior of hydroxyapatite (HA) coatings on implant substrates, even though such information is valuable for mechanical stability of the HA coated implants. Note that elastic/plastic behavior of HA coatings cannot be obtained from tests of their bulk counterparts due to the well-known size effects on mechanical strength. The objective of the present study is to estimate the elastic/plastic constitutive relation of plasma sprayed HA coatings on Ti alloy substrates using a novel approach that combines the indentation tests and the non-linear finite element method. The work demonstrates that constitutive relation can be obtained by numerically simulating the indentation stress/strain curves of HA coatings.

The crack closure effects on fatigue crack growth are evaluated by both theoretical and experimental approaches. The theoretical approach is based asperity with finite width near a crack. The analysis indicates that asperity- induced crack closure cannot be ignored even though it is less than conventional estimation. The experimental results of fatigue crack growth in sintered steel show that the crack closure however cannot be fully responsible for observed increase of fatigue resistance with low stress ratio, R. Experimental results on sintered steel support that both K sub max and Delta K control near threshold crack growth.

The successful applications of bioactive hydroxyapatite (HA) coated Ti implants rely on the long-term stability of HA coatings in service conditions. The stability of HA coatings under cyclic loading in air and simulated body fluids (SBF) has been sporadically studied. More systematic work needs to be done to understand how fatigue damages the HA coatings. The objectives of the present study are to examine the microcracks development at various coating conditions, and also to examine the cyclic loading effects on macroscopic parameters, such as crystallinity, residual stress, coating thickness change and weight loss.

Reliability of HA coatings depends, on microstructure and chemistry of the coatings, which are affected by coating processing. Considering difference in cooling rates of molten HA particles impacting on Ti substrate, certain chemical or physical changes from near Ti interface to the coating surface might exist. The HA grain size difference with distance from the interface was observed by transmission electron microscopy. This study focused on inhomogeneous features of HA coatings in order to have a better understanding and better control of plasma sprayed HA coatings. (Substrate: titanium alloy Ti-6Al-4V.)

The crack closure effects on fatigue crack growth are evaluated by both theoretical and experimental approaches. The theoretical approach is based asperity with finite width near a crack. The analysis indicates that asperity- induced crack closure cannot be ignored even though it is less than conventional estimation. The experimental results of fatigue crack growth in sintered steel show that the crack closure however cannot be fully responsible for observed increase of fatigue resistance with low stress ratio, R. Experimental results on sintered steel support that both K sub max and Delta K control near threshold crack growth.

The successful applications of bioactive hydroxyapatite (HA) coated Ti implants rely on the long-term stability of HA coatings in service conditions. The stability of HA coatings under cyclic loading in air and simulated body fluids (SBF) has been sporadically studied. More systematic work needs to be done to understand how fatigue damages the HA coatings. The objectives of the present study are to examine the microcracks development at various coating conditions, and also to examine the cyclic loading effects on macroscopic parameters, such as crystallinity, residual stress, coating thickness change and weight loss.

Reliability of HA coatings depends, on microstructure and chemistry of the coatings, which are affected by coating processing. Considering difference in cooling rates of molten HA particles impacting on Ti substrate, certain chemical or physical changes from near Ti interface to the coating surface might exist. The HA grain size difference with distance from the interface was observed by transmission electron microscopy. This study focused on inhomogeneous features of HA coatings in order to have a better understanding and better control of plasma sprayed HA coatings. (Substrate: titanium alloy Ti-6Al-4V.)

The crack closure effects on fatigue crack growth are evaluated by both theoretical and experimental approaches. The theoretical approach is based asperity with finite width near a crack. The analysis indicates that asperity- induced crack closure cannot be ignored even though it is less than conventional estimation. The experimental results of fatigue crack growth in sintered steel show that the crack closure however cannot be fully responsible for observed increase of fatigue resistance with low stress ratio, R. Experimental results on sintered steel support that both K sub max and Delta K control near threshold crack growth.

Reliability of HA coatings depends, on microstructure and chemistry of the coatings, which are affected by coating processing. Considering difference in cooling rates of molten HA particles impacting on Ti substrate, certain chemical or physical changes from near Ti interface to the coating surface might exist. The HA grain size difference with distance from the interface was observed by transmission electron microscopy. This study focused on inhomogeneous features of HA coatings in order to have a better understanding and better control of plasma sprayed HA coatings. (Substrate: titanium alloy Ti-6Al-4V.)

The successful applications of bioactive hydroxyapatite (HA) coated Ti implants rely on the long-term stability of HA coatings in service conditions. The stability of HA coatings under cyclic loading in air and simulated body fluids (SBF) has been sporadically studied. More systematic work needs to be done to understand how fatigue damages the HA coatings. The objectives of the present study are to examine the microcracks development at various coating conditions, and also to examine the cyclic loading effects on macroscopic parameters, such as crystallinity, residual stress, coating thickness change and weight loss.

LCP, Vectra B950, reinforced polycarbonate (PC) 60 wt.% /polybutylene terephthalate (PBT) 40 wt.% blends have been studied using injection moulding process. The composites with pre-blended matrix are made by blending PC and PBT in a twin screw extruder, and then by injection moulding with LCP. Good in situ fibrillation of LCP is observed in the directly injection moulded LCP composites. The fibrillation of LCP appears to follow Taylor's droplet deformation theory. Results indicate that addition of PBT improves the skin-core distribution of LCP fibrils in the matrix and also improves the adhesion between the matrix and Vectra B950 which contains terephthalic acid.

LCP, Vectra B950, reinforced polycarbonate (PC) 60 wt.% /polybutylene terephthalate (PBT) 40 wt.% blends have been studied using injection moulding process. The composites with pre-blended matrix are made by blending PC and PBT in a twin screw extruder, and then by injection moulding with LCP. Good in situ fibrillation of LCP is observed in the directly injection moulded LCP composites. The fibrillation of LCP appears to follow Taylor's droplet deformation theory. Results indicate that addition of PBT improves the skin-core distribution of LCP fibrils in the matrix and also improves the adhesion between the matrix and Vectra B950 which contains terephthalic acid.

LCP, Vectra B950, reinforced polycarbonate (PC) 60 wt.% /polybutylene terephthalate (PBT) 40 wt.% blends have been studied using injection moulding process. The composites with pre-blended matrix are made by blending PC and PBT in a twin screw extruder, and then by injection moulding with LCP. Good in situ fibrillation of LCP is observed in the directly injection moulded LCP composites. The fibrillation of LCP appears to follow Taylor's droplet deformation theory. Results indicate that addition of PBT improves the skin-core distribution of LCP fibrils in the matrix and also improves the adhesion between the matrix and Vectra B950 which contains terephthalic acid.