Efficient CAD-based triangulation of unordered 3D data

Abstract. The paper proposes a new method for efficient triangulation of large, unordered sets of 3D points using a CAD model comprising NURBS entities. It is primarily aimed at engineering applications involving analysis and visualisation of measured data, such as inspection, where a model of the object in question is available. Registration of the data to the model is the necessary first step, enabling the triangulation to be efficiently performed in 2D, on the projections of the measured points onto the model entities. The derived connectivity is then applied to the original 3D data. Improvement of the generated 3D mesh is often necessary, involving mesh smoothing, constraint-based elimination of redundant triangles and merging of mesh patches. Examples involving random measurements on aerospace and automotive free-form components are presented. Received: 30 August 1999 / Accepted: 10 January 2000     

The use of allele-specific recombinant Fc gamma receptor IIIb antigens for the detection of granulocyte antibodies

The Fcgamma receptor IIIb (FcgammaRIIIb) for the Fc domain of IgG is expressed exclusively on neutrophils. The FcgammaRIIIb bears allotypic polymorphisms referred to as NA1, NA2, and SH, which are known for their frequent involvement in alloimmune and autoimmune neutropenias as well as in transfusion reactions. The bactericidal capacity of isolated neutrophils is easily activatable, and activation results in self-desintegration, thus preventing storage of neutrophils. As a result, only freshly isolated granulocytes can be used for antibody screening, often making it impossible to use typed panel cells. To provide a readily available source of typed panel cells, we therefore established stable mammalian cells expressing recombinant NA1, NA2, and SH antigens. We isolated mRNA from typed neutrophils and then transcribed it in cDNA. The cDNA that codes for the different forms of the FcgammaRIIIb was amplified by polymerase chain reaction and was subsequently subcloned into the mammalian expression vector pcDNA3. Chinese hamster ovary (CHO) cells were transfected with allele-specific constructs, and stable cell lines expressing FcgammaRIIIb were selected by flow cytometry. Because human sera show high background fluorescence with transfectants in flow cytometry, the monoclonal antibody-specific isolation of granulocyte antigens (MAIGA) assay was performed. By MAIGA assay, we tested 14 well-characterized human alloantibodies directed against the antigens NA1, NA2, and SH; 5 FcgammaRIIIb-specific isoantibodies; and 12 FcgammaRIIIb-reactive autoantibodies. Except one NA1- and one SH-specific alloantibody, all other antibodies could be identified by the use of CHO transfectants. In contrast to neutrophils, fixed CHO cells can be stored at 4 degrees C for at least 4 weeks or stored frozen for a longer period. This longer shelf life of the transfected CHO cells compared with isolated neutrophils will simplify the detection of the clinically most important FcgammaRIIIb-reactive alloantibodies and autoantibodies.     

Noniterative Method to Approximate the Effective Load Carrying Capability of a Wind Plant

The effective load carrying capability (ELCC) is considered the preferred metric to evaluate the capacity value of added wind generation. However, the classical method of computing this metric requires substantial reliability modeling and an iterative process that is quite computationally intensive. Consequently, a noniterative method of estimating a wind plant's ELCC is proposed in this paper. Inspired by Garver's approximation and derived based on well-known reliability concepts, the proposed method provides an excellent approximation while requiring only minimal reliability modeling and no computationally-intensive iterative process. It computes ELCC estimates from a single function using only the wind plant's multistate probabilistic representation and a graphically determined parameter that characterizes the existing power system. After presenting the complete mathematical derivation of this function, the method is applied to compute the ELCC estimates of various wind plants at different penetration levels. It is shown that the resultant ELCC estimates only slightly overestimate the classically computed values by relative errors of 2.5% or less. Furthermore, the proposed method yields more accurate ELCC estimates than the capacity factor approximation, which is commonly used to approximate the ELCC of a wind plant.     

An Efficient,Stable and Reusable Palladium Nanocatalyst: Chemoselective Reduction of Aldehydes with Molecular Hydrogen in Water

Palladium nanoparticles (Pd‐BNP) stabilized by a binaphthyl‐backbone can be efficiently used for the chemoselective reduction of aldehydes in the presence of hydrogen at room temperature in water. The Pd‐BNP catalyst is easily recovered and reused for five catalytic cycles.

     

Dissolution of waste plastics in biodiesel

The dissolution behavior of polystyrene (PS) and low‐density polyethylene (LDPE) in biodiesel was investigated with an eye towards developing methods to dispose waste plastics by burning them with fuel. To complement and guide the experimental investigations, molecular dynamics simulations were performed to calculate solubility parameters, cohesive energy densities, Flory‐Huggins χ parameters and phase diagrams of the target systems. Dissolution kinetics of PS and LDPE in methyl esters was monitored by gravimetry, from which parameters such as dissolution rates, activation energies, and scaling indices were estimated. The shear viscosity of the polymer solutions was measured to ascertain their suitability as fuel mixtures. The dissolution of PS in biodiesel appears to be controlled by the diffusion of polymer chains through a boundary layer adjacent to the polymer/solvent interface. Taken together, the experimental and modeling studies provide a predictive toolbox to design biodiesels of different compositions that will dissolve commodity polymers such as PS and LDPE to be used as fuels in engines. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Superior Analog Performance due to Source-Gate Overlap in Vertical Line-Tunneling FETs and Their Circuits

Silicon - This paper presents a Vertical Line-Tunneling FET (VLTFET) optimized for superior performance in analog applications. The saturation mechanism, DC, and small-signal behaviors are...     

Control system design for recycle systems

This paper considers the control system design for recycle systems. We derive a condition which quantifies the effect of recycling on closed-loop performance. The condition is independent of control/controller structure. With insight from this condition, we develop a set of heuristics for properly designing a controller without detailed knowledge of recycle dynamics for the important special case where the system is represented by a first-order-plus-time-delay model and where the IMC tuning rules are used. The heuristics require only a minimal amount of information on the recycle dynamics. Their effectiveness is illustrated on a reactor/feed-effluent heat exchanger/furnace process under various conditions.     

The Annual Black Start Service Selection Analysis of ERCOT Grid

This paper evaluates ERCOT's existing annual Black Start service selection analysis and subsequently presents novel selection procedures. ERCOT procures Black Start resources annually through a competitive process. It selects and awards contracts to qualifying resources after completing a Black Start unit selection analysis, which selects a group of Black Start resources that meet a set of system selection criteria consisting of system reliability and minimum cost parameters. A current analysis methodology exists, but due to its inherent limitations, it is very labor intensive. Further analysis methodology development is performed to streamline the selection process, enable additional functions, reduce the manual intervention of personnel, and overall to improve the selection analysis. This paper analyzes the current Black Start automatic program analysis, and proposes new methodologies, programming improvements, and enhanced user ability.