Volumetric Effects in Coal Sorption Capacity Measurements

Many types of materials e.g., rubber, polymer, coal, change their volume and structure after absorption of gaseous and liquid substances. Various kinds of volume changes affect the accuracy of absorption measurements by gravimetric and manometric methods, the two major techniques currently employed. The errors associated with the volumetric effects, specifically, the case of carbon dioxide sorption on coal, were investigated. It was demonstrated that the resulting error in the buoyancy correction in the gravimetric method is equivalent to the corresponding error in the assumed void volume in the manometric method. It is suggested that the integration of the two methods, combined with the binary gas mixture technique of in‐situ volume measurement, will contribute to dramatically improve the accuracy of absorption measurements for plastic materials.     

Income, health status, and insurance coverage of small group employees in a voluntary purchasing arrangement

The ongoing health care reform discussion has highlighted the problems of insuring small group employees. Several state and private initiatives have attempted to address some of these problems through the formation of voluntary small group purchasing arrangements. This article uses data from one such initiative, Health Care Group of Arizona (HCGA), to describe the income, health status, and prior insurance of small group employees who enrolled in prepaid health plans through HCGA. It also compares employee enrollees to nonenrollees along these dimensions. The findings suggest that HCGA enrollees had relatively low incomes and that about three-quarters were without health insurance prior to enrollment. Higher income employee enrollees were more likely to report health conditions at enrollment even after controlling for other factors including age. Enrollees were less likely than nonenrollees to have prior health insurance but were more likely to be drawn from lower income groups and to report recent health conditions.     

Process integration of Pr-based high-k gate dielectrics

We present the process integration of the Pr-based high-k oxides Pr₂O₃, PrTi_xO_y and Pr_xSi_yO_z for CMOS devices. MOS structures were grown in form of p⁺ poly-Si/Pr-based dielectric/Si(100) by MBE. RIE with CF₄/O₂ plasma was used to selectively remove the poly-Si layer. It was found that the Pr-based oxides layers can be dissolved with high selectivity in diluted H₂SO₄ solutions. Details of the etch kinetics of Pr-based oxides and poly-Si were studied. Electrical characteristics of MOS stacks with integrated Pr_xSi_yO_z are presented.     

Development of Flexible Micro-Thermo-electrochemical Generators Based on Ionic Liquids

The unfavourable relationship between electrical and thermal conductivity limits the choice of solid-state materials for thermoelectric generators (TEG). Among ionic liquids (IOL), it appears that a large variety of thermoelectric (TE) materials with promising high Seebeck coefficients have potential for development. Furthermore, the novel solid-on-liquid deposition technology (SOLID) allows the encapsulation of liquid TE materials to create new, highly integrated TEG devices. Following this vision, this paper studies a large number of IOLs looking at TE-relevant parameters such as thermal and electrical conductivity, Seebeck coefficient and temperature-dependent viscosity. We show that positive and negative Seebeck coefficients can be obtained, depending on the molecular structure and the viscosity of the IOL. The properties of single-junction TEGs are presented in terms of I–V characteristics correlated with the IOL properties. We prove that the limiting effect of conversion efficiency is the current density that can be extracted from a device rather than the Seebeck coefficient.     

“Finite element modeling of the effect of heat input on residual stresses in dissimilar joints”

In the present study, a thermo-elastic–plastic model was developed in order to evaluate the residual stresses in dissimilar automatic tungsten inert gas (TIG) welds between plain carbon steel CK4 and a ferritic stainless steel AISI409. The effect of welding heat input on the magnitude and the distribution of residual stresses was investigated and the results of simulation were validated by X-ray diffraction measurements. It is shown that the calculated residual stresses are in good agreement with the residual stresses determined experimentally. It was found that the magnitudes of stresses at the weld center line increases with increasing the welding speed.     

(Super)hydrophobic and Multilayered Amphiphilic Films Prepared by Continuous Assembly of Polymers

The continuous assembly of polymers (CAP) is used to fabricate tailored nanocoatings on a wide variety of substrates. Ring‐opening metathesis polymerization (ROMP) is used to mediate the CAP process (CAP_ROMP) to assemble specifically designed macromolecules into nanoengineered crosslinked films. Different films composed of single or multiple macromolecules are used to tune the surface wetting characteristics on various planar substrates, including porous substrates such as filter paper and cotton, and non‐porous subtrates such as aluminium foil and glass. By judicious selection of the macromolecules, these substrates, which are hydrophilic in nature, can be rendered (super)hydrophobic. The robustness of the ROMP catalysts and the reinitiation ability of the CAP_ROMP approach allow the production of layered multicomponent amphiphilic films with on‐demand switchable wettability. Such functional nanocoatings can be potentially applied as self‐cleaning surfaces, as waterproof woven fabrics, and for the next generation of microelectronic devices.     

Effects of Heat-treatments on the Mechanical Strength of Coated YSZ: An Experimental Assessment

The mechanical strength of thin, symmetric sandwich specimens consisting of a dense yttria-stabilized zirconia (YSZ) substrate coated with a porous NiO–YSZ layer at both major faces was investigated. Specimens were loaded in uniaxial tension to failure following heat treatments at various temperatures. In comparison with the YSZ material, the failure strength of coated specimens was found to increase for heat treatments at 1100°C, but decreased again with further increased heat-treatment temperatures.     

The Evolution of Tumor-Targeted Drug Delivery: From the EPR Effect to Nanoswimmers

Therapeutic nanotechnologies have made great progress over the past decade. Skepticism has been replaced by the understanding that precision at the nanoscale allows improved treatment modalities in humans. Principles for designing tumor-targeted drug delivery systems are described. At first, the enhanced permeability and retention (EPR) effect was the major targeting mode, with up to 10 % of the injected dose actually reaching tumors. To improve cellular uptake, sugars, antibodies, peptides or other ligands were added to the surface of nanotherapeutics. These can be coupled with external magnetic fields or ultrasonic waves to propel iron oxide or gas-filled particles towards the disease site. Next-generation drug delivery systems will be capable of autonomously swimming towards the disease site and penetrating deep tissue, independent of blood or lymphatic flow. This has been shown to some extent with modified, drug-producing, bacteria. Interestingly, sperm may be nature’s best example of a multifunctional, targeted, high-fidelity, self-propelled, delivery system that we can learn from.     

Harnessing Enzymatic Promiscuity in Myxochelin Biosynthesis for the Production of 5‐Lipoxygenase Inhibitors

The siderophore myxochelin A is a potent inhibitor of human 5‐lipoxygenase (5‐LO). To clarify whether the iron‐chelating properties of myxochelin A are responsible for this activity, several analogues of this compound were generated in the native producer Pyxidicoccus fallax by precursor‐directed biosynthesis. Testing in a cell‐free assay unveiled three derivatives with bioactivity comparable with that of myxochelin A. Furthermore, it became evident that inhibition of 5‐LO by myxochelins does not correlate with their iron affinities.