On the distinction between clinical process and clinical content theories.

Draws a distinction between clinical process theory, which refers to the method of investigation, and clinical content theory, which refers to the findings of an investigation. It is suggested that psychoanalysts attend to the process and attempt to specify and microanalyze it in its naturalistic context. The problem of clinical evidence is perhaps the most neglected topic in psychoanalytic therapy. The significance of broad-based mental models of human experience in understanding the therapeutic process is discussed. It is suggested that psychoanalytic therapy should be viewed as an early craft that is not yet a science. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constructal design associated with genetic algorithm to minimize the maximum deflection of thin stiffened steel plates

This paper deals with the application of stochastic technique allied to the constructal design (CD) method and computational modeling for the optimization of composed plates reinforced by stiffeners. More specifically, it seeks to determine the optimal geometric configuration of the stiffened plate that minimizes its maximum deflection. For this purpose, a simply supported rectangular plate (with no stiffeners) was adopted as a reference. Then, a set of geometric configurations was proposed, through the application of CD method, by transforming a volume fraction (ϕ) of the reference plate into longitudinal and transverse stiffeners, maintaining the total volume, in-plane dimensions, boundary conditions, and loading. Regarding the optimization procedure, the genetic algorithm (GA) was chosen as the optimization method, and the geometric parameters considered as degrees of freedom were as follows: the number of longitudinal (N_ls) and transverse (N_ts) stiffeners; the thickness of the longitudinal (t_ls) and transverse (t_ts) stiffeners; and longitudinal and transverse stiffeners' heights ratio (h_ts/h_ls). Moreover, several values of ϕ were considered. Results indicated a great influence of the geometry on the mechanical behavior of the stiffened plates, as the optimal geometric configuration obtained here led to a reduction of over 98% in the maximum deflection in comparison with the reference plate.     

Three-dimensional printing of metal parts for tooling and other applications

Three-Dimensional Printing is a Solid-Freeform Fabrication process that creates parts out of powder by spreading layers into which binder is ink-jet printed to define the part geometry of that layer. By repetition of the process layer-by-layer, three-dimensional components of very complex geometry can be created. This paper describes key aspects of the application of Three-Dimensional Printing to the fabrication of metal tooling where surface finish, dimensional accuracy, wear resistance, and process complexity impose challenging constraints on materials selection and processing.     

Joint transform correlator with spatial code division multiplexing

A joint transform correlator may suffer from overlapping of the zero diffraction order of the output, which does not contain relevant information, and the correlation peaks that appear in the first diffraction orders if objects are not sufficiently separated. Such overlapping significantly reduces the signal-to-noise ratio of the identification process. We propose a novel approach based on code division multiplexing technique in which the contrast of the identification peaks is significantly enhanced. The approach does not include placing the two objects side by side but rather includes code multiplexing them. Moreover, the code division multiplexing technique allows the space-bandwidth product to be improved. Optical implementation results are given.     

The Internal Structure of the Velvet Worm Projectile Slime: A Small-Angle Scattering Study

For prey capture and defense, velvet worms eject an adhesive slime which has been established as a model system for recyclable complex liquids. Triggered by mechanical agitation, the liquid bio-adhesive rapidly transitions into solid fibers. In order to understand this mechanoresponsive behavior, here, the nanostructural organization of slime components are studied using small-angle scattering with neutrons and X-rays. The scattering intensities are successfully described with a three-component model accounting for proteins of two dominant molecular weight fractions and nanoscale globules. In contrast to the previous assumption that high molecular weight proteins—the presumed building blocks of the fiber core—are contained in the nanoglobules, it is found that the majority of slime proteins exist freely in solution. Only less than 10% of the slime proteins are contained in the nanoglobules, necessitating a reassessment of their function in fiber formation. Comparing scattering data of slime re-hydrated with light and heavy water reveals that the majority of lipids in slime are contained in the nanoglobules with homogeneous distribution. Vibrating mechanical impact under exclusion of air neither leads to formation of fibers nor alters the bulk structure of slime significantly, suggesting that interfacial phenomena and directional shearing are required for fiber formation.     

How to Pack a Punch – Why 3D Batteries are Essential

The miniaturization of implantable medical devices, remote microsensors and transmitters, “smart” cards, and Internet of Things (IoT) systems is impeded by the absence of high‐performance micro‐size power sources. Insufficient areal energy density from thin‐film planar microbatteries has inspired a search for three‐dimensional microbatteries (3DMB) with the use of low‐cost and efficient micro‐ and nano‐scale materials and techniques. In our short review, we present our outlook on the state‐of‐the‐art development of advanced 3D‐microbattery designs and methods of the fabrication of electrode materials. Special attention is given to the 3D‐printing approach, which holds many opportunities for the mass production of microbatteries and their direct integration with electronic devices.     

Effect of ambient atmosphere on crosslinking of polysilazanes

The influence of ambient atmosphere on the crosslinking process of two commercially available polysilazanes with different molecular units in the backbone structure (one polysilazane with and one without urea units) was studied at different temperatures using oscillatory rheometry under isothermal conditions. The measurements were performed using cone/plate, plate/plate, and Couette geometries to assess the influence of the contact surface of the samples with air on their crosslinking behavior. The crosslinking process of the investigated polysilazanes in ambient atmosphere was found to occur faster than that in inert atmosphere. DSC and FTIR‐spectroscopic investigations indicate that hydrolysis and polycondensation processes occur in both polysilazanes when crosslinked in air. Interestingly, the effect of moisture was found to be more pronounced in the case of the urea derivative. The evolution of the measured complex viscosity and dynamic moduli supported this finding. Furthermore, the variation of the time derivative of complex viscosity (dη*/dt) emphasizes structural changes during crosslinking of the samples which were ascribed to their contact with the ambient atmosphere. This study emphasizes the high potential of rheometry in investigating the crosslinking behavior of polymers in inert and ambient atmosphere. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Xylella fastidiosa Esterase Rather than Hydroxynitrile Lyase

In 2009, we reported that the product of the gene SCJ21.16 (XFa0032) from Xylella fastidiosa, a xylem‐restricted plant pathogen that causes a range of diseases in several important crops, encodes a protein (XfHNL) with putative hydroxynitrile lyase activity. Sequence analysis and activity tests indicated that XfHNL exhibits an α/β‐hydrolase fold and could be classified as a member of the family of FAD‐independent HNLs. Here we provide a more detailed sequence analysis and new experimental data. Using pure heterologously expressed XfHNL we show that this enzyme cannot catalyse the cleavage/synthesis of mandelonitrile and that this protein is in fact a non‐enantioselective esterase. Homology modelling and ligand docking simulations were used to study the active site and support these results. This finding could help elucidate the common ancestor of esterases and hydroxynitrile lyases with an α/β ‐hydrolase fold.     

Strength of Green Ceramics with Low Binder Content

Acrylic-based polymers are common binders that impart high green strength (>2 MPa) at low concentrations (<5.0 vol%). Strength at low binder concentrations may be determined by chemical bonding at the ceramic–polymer interface. We have studied the binding mechanisms as a function of ceramic surface chemistry using a cross-linkable binder, which is based on a soluble poly(acrylic acid) (PAA, MW = 60 000) and glycerol. The cross-linked PAA binder system has been integrated into a solid freeform fabrication process, which provides a means of fabricating very reproducible green bodies, including SiO₂, TiO₂, Al₂O₃, multicomponent oxides, and non-oxides, with uniform density and composition. The ceramic parts contain only 2.5 vol% binder (solids basis), which increases the strength of the ceramic systems by at least a factor of 8 while the strength of Al₂O₃ components increases by a factor of ∼24 (0.3 to 7.6 MPa). Addition of the binder improves the toughness of the ceramic bodies by an order of magnitude with SiO₂ representing the largest relative increase (2.8 × 10⁻³ to 4.4 × 10⁻² MPa·m^1/2). The mechanical properties are dictated by two binding mechanisms: binder adsorption and mechanical interlocking. High green strengths result from adsorption of the binder onto the ceramic surface whereas toughness is enhanced by poor adhesion of the binder to the ceramic surface.     

Soft-sensor models to estimate the efficiency of H2S removal from an oil refinery stream of nonphenolic sour water

A large set of results of concentration of hydrogen sulfide in the feed and bottom product streams of a sour water stripper found in a typical oil refinery was experimentally obtained. The readings of H₂S concentrations were at several different operating conditions in terms of the main process variables that classically have significant effects on the efficiency of H₂S removal (E). In particular, the considered factors were the mass flow rate, and temperature of sour water fed into the stripper, the mass flow rate of external steam injected into the reboiler, the difference between the temperature of the product stream leaving and entering the reboiler, and the difference of pressure at the two ends of the tower. Three different soft-sensor models were suggested to describe the observed variation in E from 63 to 97%, namely, an equilibrium, statistical and an artificial neural network model. The best of them was the neural network one with three input variables, four neurons in the one-hidden layer, and a hyperbolic tangent function for both the output and one-hidden layers. The mean absolute relative deviation between measured and calculated E by involving this model was only approximately 2.5% with negligible tendency for the residuals. It confirms the reliability of this approach as a tool to inferential estimation of the efficiency of removal of H₂S from the sour water by stripping.