Phase transformation of diamond-like carbon/silver composite films by sputtering deposition

This study fabricated hydrogenated diamond-like carbon/silver bioceramic films on glass substrates using radio frequency magnetron sputtering with a single silver target in an atmosphere of Ar/CH4 mixture. The effects of applied power on the composition and microstructure of bioceramic film were evaluated. A phase transformation, amorphous diamond-like carbon → nano-silver precipitation → nano-silver growth in the amorphous diamond-like carbon matrix was observed during sputtering. The film growth rate, surface roughness, silver content and size of silver nanoclusters in the films all increased with the silver target power due to the higher flux of sputtered silver species toward the substrate.     

Reranking Methods for Visual Search

Most semantic video search methods use text-keyword queries or example video clips and images. But such methods have limitations. To address the problems of example-based video search approaches and avoid the use of specialized models, we conduct semantic video searches using a reranking method that automatically reorders the initial text search results based on visual cues and associated context. We developed two general reranking methods that explore the recurrent visual patterns in many contexts, such as the returned images or video shots from initial text queries, and video stories from multiple channels.     

Visually searching the Web for content

New visual information in the form of images, graphics, animations and videos is published on the World Wide Web at an incredible rate. However, cataloging it exceeds the capabilities of current text-based Web search engines. WebSeek provides a complete system that collects visual information from the Web by automated agents, then catalogs and indexes it for fast searching and retrieval     

Nonisothermal crystallization kinetics of novel biodegradable poly(butylene succinate-co-2-methyl-1,3-propylene succinate)s

Two novel poly(butylene succinate-co-2-methyl-1,3-propylene succinate)s, PBMPSu 95/5 and PBMPSu 90/10, were characterized as having 6.5 and 10.8 mol% 2-methyl-1,3-propylene succinate (MS) units, respectively, by ¹H NMR. A differential scanning calorimeter (DSC) and a polarized light microscope (PLM) employed to investigate the nonisothermal crystallization of these copolyesters and poly(butylene succinate) (PBSu). Morphology and the isothermal growth rates of spherulites under PLM experiments at three cooling rates of 1, 2.5 and 5 °C/min were monitored and obtained by curve-fitting. These continuous rate data were analyzed with the Lauritzen-Hoffman equation. A transition of regime II→III was found at 96.2, 83.5, and 77.9 °C for PBSu, PBMPSu 95/05, and PBMPSu 90/10, respectively. DSC exothermic curves at five cooling rates of 1, 2.5, 5, 10 and 20 °C/min show that almost all of the nonisothermal crystallization occurred in regime III. DSC data were analyzed using modified Avrami, Ozawa, Mo, Friedman and Vyazovkin equations. All the results of PLM and DSC measurements reveal that incorporation of minor MS units into PBSu markedly inhibits the crystallization of the resulting polymer.     

Input electrical impedance as quality monitoring signature for characterizing resistance spot welding

Poor quality of resistance spot welding (RSW) often causes quality issues like structural integrity and noise in the car body assembly. Research activities for reliable monitoring methods of RSW quality have therefore been extensive. So far, most of the monitoring methods found in literature are good for off-line utilization only and thus very expensive to apply. This paper introduces into a real-time and in-situ RSW quality monitoring method, which takes the input electrical impedance of the welding system as the monitoring signature. This signature is obtained by probing and processing the input voltage and current throughout the welding process. As input impedance characterizes a dynamic system, its variation with time reveals the conditions of the welding process which result in the final weld quality. By recognizing the pattern of the real part by an artificial neural network, we demonstrate that the weld quality could be classified non-destructively and automatically. Due to the fast signal collecting and processing, the quality monitoring is finished almost in real-time, i.e., classification can be completed before the next welding process is started. Another feature of the method is being in-situ because monitoring action does not jeopardize the welding operation or alter any of the welding parameters in general.     

Research of antibacterial activity on silver containing yttria-stabilized–zirconia bioceramic

An antibacterial bioceramic, silver containing yttria-stabilized zirconia (YSZ), was fabricated by sintering for dental prosthesis applications. The biocompatibility, hemocompatibility and antibacterial ability of the silver containing YSZ were evaluated. The addition of silver did not cause tetragonal phase to transform into monoclinic phase and the silver containing YSZ maintained an excellent mechanical property. Furthermore, the sintered silver containing YSZ showed no toxicity and possessed a good antibacterial ability against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) cell.     

Iron oxide synthesis using a continuous hydrothermal and solvothermal system

Iron oxide synthesis via a continuous hydrothermal and solvothermal reaction were studied. In the hydrothermal synthesis, fine α-Fe₂O₃ (hematite) particles were obtained at 250–420 °C and 30 MPa. The α-Fe₂O₃ crystals were grown in sub-critical water via a dissolution and precipitation process. The growth of α-Fe₂O₃ crystals in supercritical water was suppressed due to the rather low solvent power of water. Crystalline Fe₃O₄ was obtained as the temperature was raised above the supercritical state in the solvothermal preparation. Isopropanol (IPA) was oxidized in acetone which provided a reducing atmosphere. Acetone molecule adsorption onto the Fe₃O₄ particle surface inhibited crystallite growth.     

Applications of lithographic mask technology in fabrication of diamond dresser

Microfabrication was employed in the fabrication of diamond dressers. Diamond-nickel composite was utilized for fabricating columnar cutting tips and compared with those fabricated by the brazing connective approach. In this study, microcolumns with diamond grits embedded in the nickel deposit electroplated on the substrate with guidance of the resist mold can improve the population density of working diamond grits in the diamond dresser. Moreover, the load force is dispersed on the plurality working diamond grits within one column, which in turn increasing in the durability of the dresser. This technique can produce diamond dressers with improved uniformity in both the distribution and protrusion control of microcolumn diamond cutting tips. In addition, the presently developed diamond dressers exhibit an increase in material removal rate by some 15 %, while, at the same time, maintain a relatively low worn rate as compared with the commercially available dressers. This microcolumn (e.g., diamond-nickel composite) is efficient to share the applied load and also extends tool’s life during polishing.     

Large-scale concept ontology for multimedia

As increasingly powerful techniques emerge for machine tagging multimedia content, it becomes ever more important to standardize the underlying vocabularies. Doing so provides interoperability and lets the multimedia community focus ongoing research on a well-defined set of semantics. This paper describes a collaborative effort of multimedia researchers, library scientists, and end users to develop a large standardized taxonomy for describing broadcast news video. The large-scale concept ontology for multimedia (LSCOM) is the first of its kind designed to simultaneously optimize utility to facilitate end-user access, cover a large semantic space, make automated extraction feasible, and increase observability in diverse broadcast news video data sets.