Single-element solution comparisons with a high-performance inductively coupled plasma optical emission spectrometric method.

A solution-based inductively coupled plasma optical emission spectrometric (ICP-OES) method is described for elemental analysis with relative expanded uncertainties on the order of 0.1% relative. The single-element determinations of 64 different elements are presented, with aggregate performance results for the method and parameters for the determination of each element. The performance observed is superior to that previously reported for ICP-OES, resulting from a suite of technical strategies that exploit the strengths of contemporary spectrometers, address measurement and sample handling noise sources, and permit rugged operation with small uncertainty. Taken together, these strategies constitute high-performance ICP-OES.     

Numerical Calculations of Spray Roasting Reactors of the Steel Industry with Special Emphasis on Fe2O3‐Particle Formation

This work presents numerical calculations for the lay‐out of spray roasting reactors for the steel industry. In these reactors, a pickling liquor based on water and HCl containing FeCl₂ is regenerated in a combustor leading to the formation of Fe₂O₃ particles. For the lay‐out of these reactors, detailed knowledge of the flow and temperature field, the associated gas phase reactions, and especially, of the formation of the Fe₂O₃ particles is required. An extended particle formation model is presented which is based on earlier work. Finally, results for an industrial spray roasting reactor are given showing the potential of the numerical tools developed for the improvement of the technical lay‐out of such thermal reactors.     

Use and abuse of the children's depression inventory.

This study investigated current uses of the Children's Depression Inventory (CDI), a frequently cited self-report measure for children's depressive symptomatology. Recently published studies of "childhood depression" were reviewed: Half of them used the CDI. Of these studies, 68% did not use a clinical or structured interview to determine diagnostic status. When the CDI was used alone to assess depressive symptoms, 44% of studies referred to high CDI scorers as "depressed" without providing a clear cautionary statement (i.e., either stating that the CDI cannot be used to diagnose depression or clarifying limitations regarding generalization of findings from a nonclinical to a clinical sample). These results are similar to those previously published regarding the Beck Depression Inventory, and they suggest a need for caution in the administration and interpretation of results from self-report inventories for children's depressive symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Solubility of C60

All the published data on the solubility of C₆₀ in 140 organic and inorganic solvents are summarized and the critical features of the experimental techniques are treated. Data on die temperature dependence of solubility are also listed and analyzed. Experimental evidences on the molecular state of dissolved C₆₀ as well as the interactions between the solute and solvents are discussed.     

Fracture testing of bulk silicon microcantilever beams subjected toa side load

A custom experimental system was developed to fracture silicon microcantilever beams in side loading (i.e., the load was applied in the noncompliant direction), and the resulting force/deflection (stiffness) characteristics were obtained. A finite element model of these structures was analyzed using ABAQUS, and the resulting model stiffness correlated well with the experimental data. Fracture types were divided into two categories, {111} and {110}, according to the type of silicon crystalline plane along which fracture occurred. The initiation location of each fracture type was identified. The fracture stress (strength) in the beam was obtained from the stress produced in the model at the fracture initiation site for a load equivalent to the experimental fracture force. Numerous beams were tested, and the statistical results were compiled. The distributions and statistical data from each of the fracture types were compared to each other and to previously acquired results from front/back loading (i.e., loading in the compliant direction) of these same structures. Side-loading results indicated that the {110} fracture type had a greater fracture strength than the {111} type. Based on a comparison of the side loading data with the front/back loading data, it was concluded that side wall roughness and especially the edge roughness greatly affected the fracture strength of the silicon micromechanical structures     

Bound-to-continuum and two-phonon resonance, quantum-cascade lasersfor high duty cycle, high-temperature operation

Recent advances in quantum-cascade (QC) laser active-region design are reviewed. Based on a rate equation model of the active region, we show why new gain regions. based on a two-phonon resonance or a bound-to-continuum transition exhibit significantly better performance than the traditional design based on a three-quantum-well active region. Threshold current densities as low as 3 kA/cm² at T=300 K, operation with a peak power of 90 mW at 425 K, single-mode high-power operation up to temperatures above 330 K at λ≈16 μm and continuous wave operation up to T=311 K are demonstrated. QC lasers able to operate at high duty cycles (50%) on a Peltier cooler were used in a demonstration of a 300-MHz free-space optical link between two buildings separated by 350 m     

Progress in high field MRI at the University of Florida.

In this article we report on progress in high magnetic field MRI at the University of Florida in support of our new 750MHz wide bore and 11.7T/40cm MR instruments. The primary emphasis is on the associated rf technology required, particularly high frequency volume and phased array coils. Preliminary imaging results at 750MHz are presented. Our results imply that the pursuit of even higher fields seems warranted.