Inner products and orthogonality in color recording filter design

We formalize ideas of orthogonality and inner products implicit in the development of a number of figures of merit (FOM) of color recording filters. We show that, in negligible measurement noise, the data dependence of each FOM based on linear color correction is equivalent to a choice of inner product (and hence of orthogonality). Further, we show that optimal sensors with respect to noise sensitivity are simply defined as orthogonal with respect to this inner product. We also develop the idea of a generalized Q-factor by generalizing the Euclidean inner product to include all inner products. Simulations demonstrate the utility of our analytical results.     

Superconducting state parameters of binary metallic glasses

Ashcroft’s empty core (EMC) model potential is used to study the superconducting state parameters (SSP) viz. electron–phonon coupling strength λ, Coulomb pseudopotential μ^*, transition temperature T_C, isotope effect exponent and effective interaction strength N₀V of some binary metallic glasses based on the superconducting (S), conditional superconducting (S′) and non-superconducting (NS) elements of the periodic table. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru–Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used for the first time with EMC potential in the present investigation to study the screening influence on the aforesaid properties. The T_C obtained from IU-local field correction function are found an excellent agreement with available theoretical or experimental data. In the present computation, the use of pseudo-alloy-atom model (PAA) is proposed and found successful. The present work yield results in qualitative agreement with such earlier reported values either theoretical or experimental which confirm the superconducting phase in all metallic glasses. A strong dependency of the SSP of the metallic glasses on the valence Z is found.     

Superconducting state parameters of ternary metallic glasses

The well-known empty core (EMC) model potential of Ashcroft was used to study the theoretical investigation of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential µ*, transition temperature T _C, isotope effect exponent α and effective interaction strength N _O V of some ternary metallic glasses. Most recent local field correction function due to Sarkar et al is used to study the screening influence on the aforesaid properties. Quadratic T _C equations have been proposed and found successful. Also, the present findings are found to be in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in the ternary superconductors. The pseudo-alloy-atom (PAA) model was applied for the first time instead of Vegard’s law.     

One-dimensional multipulse laser machining of structural alumina: evolution of surface topography

The development and understanding of laser–material interactions have steered to the machining of advanced structural ceramics. At one point, it was nearly impossible to machine effectively using various conventional machining techniques. Nevertheless, achieving a higher material removal rate along with a good surface finish is a critical issue. In this study, a multistep computational model based on COMSOL? Multiphysics was designed and developed to study the influence of multiple laser pulses on the evolution of surface roughness of alumina. The computational model employed the various heat transfer and hydrodynamic boundary conditions and thermomechanical properties for better prediction of surface roughness under various laser processing conditions. The results indicate that, as the pulse rate increases, the surface roughness also increases. The results of the computational model are also validated by experimental observations with reasonably close agreement.     

Overcoming SU-8 stiction in high aspect ratio structures

Deep X-ray lithography is a well known technique used for making high aspect ratio structures (HARS). However, well known difficulties arise in the creation of some HARS; adhesion of the developed resist structures to the plating base commonly fails, and when resist structures are densely packed features can clump together. This in turn can exacerbate adhesion failure. The problem of clumping is sometimes known as stiction. In this paper we describe an idea involving a low dose UV second exposure that can help overcome stiction in certain designs and thus promote adhesion and the retention of the designed structure.AGP acknowledges receipt of an Australian Research Council QEII fellowship. This work was supported by the Australian Synchrotron Research Program, which is funded by the Commonwealth of Australia under the Major National Research Facilities Program.     

Mechanochemical Polishing of Silicon Nitride

Two oxides of iron, Fe₂O₃ and Fe₃O₄, were identified as suitable soft abrasives for mechanochemical polishing of Si₃N₄. Removal rates up to 1.6 μ.m /h were observed when hot-pressed Si₃N₄ samples were mechanochemically polished using these abrasives on a linen plastic lap. The polished surfaces were flat and scratch-free, with a peak-to-valley roughness of <20 nm. Auger electron spectroscopy of these surfaces revealed a thin layer (≤10 nm) of a silicon oxynitride that contained carbon and ∼0.5 at.% iron.     

Full-scale hydrogen anodes for immersed-tank electrowinning

Full-scale (1.2 m²) immersed-tank hydrogen-diffusion anodes have been prepared by a newly patented lamination technique onto metallic sheet substrates. The use of such free-standing electrodes has been characterized in the electrowinning of zinc, but the electrodes are also suitable for use in the electrowinning of other metals and in electroplating. The electrodes may find application in processes where voltage savings of approximately 1.8–2.0 V versus oxygen evolution are of importance, or where parasitic anodic oxidations need to be eliminated. The hydrogen-diffusion anode structure developed incorporates a novel microporous polymeric coating designed to prevent both the percolation of feed hydrogen through the electrode to the electrolyte and the seepage of electrolyte into the gas plenum.     

Induction of P-selectin by oxidized lipoproteins. Separate effects on synthesis and surface expression

Leukocyte binding to the endothelium is one of the earliest events in the occurrence of atherosclerosis. Leukocyte adhesion molecules involved in this process have not been definitely identified. We have found that treatment of human aortic endothelial cells (HAECs) with minimally modified low-density lipoprotein (MM-LDL) for 24 hours caused a 2- to 3-fold increase of P-selectin protein, with little change in P-selectin surface expression. A 15-minute histamine treatment of cells exposed to MM-LDL caused a 50% to 100% increase in P-selectin surface expression compared with cells not treated with the lipoprotein. This increase resulted in a 2-fold increase in binding of leukocytes to the endothelium. Immunostaining of permeabilized HAECs after MM-LDL treatment also revealed a highly reproducible increase in intracellular P-selectin associated with rod-shaped structures, typical of Weibel-Palade bodies. Oxidized phospholipids were shown to be mainly responsible for the action of MM-LDL. This increased P-selectin expression was associated with MM-LDL-induced cAMP elevation. Like histamine, highly oxidized low-density lipoprotein, especially the oxidized fatty acids, caused immediate redistribution of P-selectin to the cell surface followed by reinternalization. Immunohistochemical staining showed that endothelial cells on human fatty streak lesions expressed increased levels of P-selectin compared with nonlesion areas. These studies suggest that P-selectin may play an important role in early recruitment of mononuclear cells to the subendothelium in human atherosclerosis and that oxidized lipoproteins may contribute to the increased expression of this molecule by increasing intracellular stores and causing redistribution to the cell surface.     

Mathematical methods for the design of color scanning filters

The problem of the design of color scanning filters is addressed in this paper. The problem is posed within the framework of the vector space approach to color systems. The measure of the goodness of a set of color scanning filters presented in earlier work is used as an optimization criterion to design color scanning filters modeled in terms of known, smooth, nonnegative functions. The best filters are then trimmed using the gradient of the mean square DeltaE(ab) error to obtain filters with a lower value of perceptual error. The results obtained demonstrate the utility of the method.     

Investigation of the Relative Affinity of Doxorubicin for Neutral and Negatively Charged Particulate Carriers

Microparticles produced from polyisobutylcyano-acrylate (IBCA) and polyglutaraldehyde (PGA) were investigated for their relative affinity and surface characteristics using doxorubicin (DOX) as a model drug. IBCA microparticles have been reported to exhibit neutral hydrophobic surface features, whereas PGA microparticles have been shown to possess negatively charged carboxyl groups on their surface. The adsorption of DOX on the surface of these particles was studied by adding the drug to preformed microparticles. The amount of drug adsorbed was determined by centrifugation and analysis of the supernatant for the free drug by HPLC. The adsorption data was examined by Langmuir, Scatchard, and Hill equations. The results indicate that IBCA micropatricles have a higher adsorption capacity for DOX, however PGA microparticles demonstrated a higher relative affinity for the drug molecule. Additionally, both microparticles presented curvilinear Scatchard plots indicating the possibility of more than one type of binding sites for the drug on the surface of these particles. It appears that strong electrostatic attraction may exist between the positively charged amino group on DOX and the negatively charged carboxyl groups of PGA microparticles.