Pseudo-T2 mapping for normalization of T2-weighted prostate MRI

Magnetic Resonance Materials in Physics, Biology and Medicine - Signal intensity normalization is necessary to reduce heterogeneity in T2-weighted (T2W) magnetic resonance imaging (MRI) for...     

Nano-Scratching resistance of high-chromium white cast iron and its correlation with wear of cBN tool in machining

In this paper, a nano-scratch testing approach was used to measure and evaluate the abrasion wear resistance of high-chromium white cast irons in order to understand the wear mechanism in the interaction between the high-chromium white cast iron and the cBN cutting tool during the machining process. Scratch testing was performed on a nanoindentation instrument using a diamond indenter as the scratch tool. Linear multi-pass scratches in the same path were made on pre-worn surfaces of test materials. The correlation of the scratching resistance and tool wear measured from the machining is presented by the flank wear and maximum scratch depth. The appearance of the cutting edge on a cBN tool suggests that the abrasion wear is mainly related with a combined effect of the carbides and the matrix during machining the high-chromium white cast iron.     

Extensions of structural optimization software to enable multidisciplinary applications

Applications of structural optimization are often multidisciplinary in nature and require nontraditional problem formulations.In the optimization system that has been developed, flexibility in terms of system design and problem formulation have been important aspects. A mathematical programming approach has been adopted where function values and sensitivity information is required from each discipline involved. To be able to deal with the demands of ongoing projects, a number of extensions have been implemented in recent years.The system is today used within the Saab and ABB companies. Four recent applications are presented to illustrate how the extended capabilities have been used.

Dietary factors influence the recovery rates of Helicobacter pylori in a BALB/cA mouse model

We have identified a number of type I and type II keratins in the zebrafish Danio rerio by two-dimensional polyacrylamide gel electrophoresis, complementary keratin blot-binding assay and immunoblotting. These keratins range from 56 kDa to 46 kDa in molecular mass and from pH 6.6 to pH 5.2 in isoelectric point. Type II zebrafish keratins exhibit significantly higher molecular masses (56-52 kDa) compared with the type I keratins (50-48 kDa), but the isoelectric points show no significant difference between the two keratin subclasses (type II: pH 6.0-5.5; type I: pH 6.1-5.2). According to their occurrence in various zebrafish tissues, the identified keratins can be classified into "E" (epidermal) and "S" (simple epithelial) proteins. A panel of monoclonal anti-keratin antibodies has been used for immunoblotting of zebrafish cytoskeletal preparations and immunofluorescence microscopy of frozen tissue sections. These antibodies have revealed differential cytoplasmic expression of keratins; this not only includes epithelia, but also a variety of mesenchymally derived cells and tissues. Thus, previously detected fundamental differences in keratin expression patterns between higher vertebrates and a salmonid, the rainbow trout Oncorhynchus mykiss, also apply between vertebrates and the zebrafish, a cyprinid. However, in spite of notable similarities, trout and zebrafish keratins differ from each other in many details. The present data provide a firm basis from which the application of keratins as cell differentiation markers in the well-established genetic model organism, the zebrafish, can be developed.     

Excitations and Their Temperature Dependence in Superfluid 4He Beyond the Roton

The temperature dependence of the dynamic structure factor S(Q,) for superfluid ⁴ He has been measured by inelastic neutron scattering for wave vectors between 2.3 and 2.6 Å ^–l. S(Q,) has two peaks: one sharp peak at low energies whose dispersion flattens out and whose strength decreases with increasing Q, and one broader peak at higher energies with a stronger dispersion. The first peak disappears gradually with increasing temperature, while only part of the second peak vanishes at T . This indicates the existence of a third broad contribution, related to atoms above the Bose condensate. The two-peak structure can be interpreted in terms of a Bose-condensate induced coupling of the two-particle spectrum to the one-particle spectrum. The overall temperature dependence is consistent with the density-quasiparticle picture.     

Magnetic permeability measurements in bioanalysis and biosensors

A new transducer concept in bioanalysis and biosensors, utilizing measurements of magnetic permeability, is reported. A model system based on dextran ferrofluid, concanavalin A immobilized to a carrier (Sepharose), and glucose was used to demonstrate the feasibility of this approach. Direct ferromagnetic detection of the dextran ferrofluid was achieved by using a measuring coil (transducer) in a Maxwell bridge. A sensitivity of 21 μV/(μg Fe/mL) and a rsd value of 3.8% were obtained (n = 5). It was also demonstrated that a small, non-ferromagnetic metabolite (glucose) could be detected using a competitive approach. With an increasing concentration of glucose (20-40 mM), we observed a decrease in the response (0.59-0.11 mV). Reference measurements performed on Sepharose without the biorecognition element, concanavalin A, showed no significant response (0.01 mV). Some potential advantages and drawbacks of this novel type of magnetic transducer are discussed. The advantages include very low interference from the sample matrix, as the transducer is only sensitive to ferromagnetic substances, which rarely are present in samples. In addition, it is suggested that these transducers should be free from fouling. The new transducers are proposed to provide the basis for a new group of affinity biosensors suitable for in vivo and in vitro use.     

Preparation of anchored ceramic coatings on metal substrates: a modified sol-gel technique using colloidal silica sol

A single-step dip-coating technique was developed to produce stable films or washcoats of controlled thickness, surface area and pore-size distribution on alumina whisker-covered metal substrates (both flat plates and monoliths). Dip-coating slurries were prepared by dispersing fine porous powder in a colloidal silica sol. The method provided control over coating thickness and coating properties, such as pore-size distribution and surface area. The coating thickness could be varied between approximately 2 and 40 m by selecting slurry composition and withdrawal speed in the dipping procedure. The pore-size distribution and surface area could be varied by changing type and amount of porous filler material in the dipping slurry. Uniform and bimodal pore-size distributions were obtained using silica and ZSM-5 molecular sieves, respectively, yielding coatings with surface areas between 60 and 400 m²g^–1.     

A computational study of vortex-airfoil interaction using high-order finite difference methods

Simulations of the interaction between a vortex and a NACA0012 airfoil are performed with a stable, high-order accurate (in space and time), multi-block finite difference solver for the compressible Navier-Stokes equations.We begin by computing a benchmark test case to validate the code. Next, the flow with steady inflow conditions are computed on several different grids. The resolution of the boundary layer as well as the amount of the artificial dissipation is studied to establish the necessary resolution requirements. We propose an accuracy test based on the weak imposition of the boundary conditions that does not require a grid refinement.Finally, we compute the vortex-airfoil interaction and calculate the lift and drag coefficients. It is shown that the viscous terms add the effect of detailed small scale structures to the lift and drag coefficients.     

Disruption management in the airline industry—Concepts,models and methods

This paper provides a thorough review of the current state-of-the-art within airline disruption management of resources, including aircraft, crew, passenger and integrated recovery. An overview of model formulations of the aircraft and crew scheduling problems is presented in order to emphasize similarities between solution approaches applied to the planning and recovery problems. A brief overview of research within schedule robustness in airline scheduling is included in the review, since this proactive measure is a natural complement to disruption management.