Processing and morphology of molecularly imprinted nylon thin films

The characterization of thin, selectively imprinted films of nylon‐6 was performed. Amino acids were used as template molecules. Spin‐cast films were prepared with sizes ranging from 2 μm to 300 nm, depending on the nylon and template concentration in the casting solution. The morphological characteristics of the film surface were examined by atomic force microscopy, and the structure within the films was observed by freeze‐fracture scanning electron microscopy. The film activity was clearly coordinated with the appearance of nanometer‐sized pores both on the surface and within the film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2919–2926, 2006     

Application of active coke in processes of SO2- and NOx-removal from flue gases

In the field of flue gas cleaning, active coke plays an important role as adsorbant and catalyst. In the temperature range usually prevailing downstream of the air preheater of power plants, SO₂ becomes adsorbed on carbonaceous materials and in a consecutive step is catalysed by the carbonaceous surface and converted to sulphuric acid. The quality demands for a cyclic regenerative process for SO₂ removal are fulfilled by the active coke which is used in the BF-process. The same active coke catalyses the reaction of NO with NH₃ to N₂ and steam. This is the basis for processes for simultaneous SO₂ and NO_x removal. By the addition of ammonia the SO₂ removal by active coke is improved. Two processes are described and results from the laboratory and from the demonstration plant for the BF-process are presented. These show that SO₂ removal efficiences exceed 95% and NO conversions of > 80% can be realized without problems. The cost of the processes using active coke with ammonia addition are comparable with those of wet flue gas desulphurization processes without any additional equipment should NO have to be removed.     

Invariant‐set‐based fault diagnosis in Lure systems

In this paper, we present an invariant‐set‐based method for actuator and sensor fault detection and isolation in Lure systems. The Lure plant is controlled by an observer‐based feedback tracking controller, designed for the nominal (fault‐free) system. Suitable residual signals are constructed from measurable system outputs and estimates associated with the nominal observer. Faults are diagnosed by online contrasting the residual signal trajectories against sets of values that the residuals are shown to attain under healthy or faulty operation. These values are obtained via set‐invariance analysis of the system closed‐loop trajectories. Copyright © 2013 John Wiley & Sons, Ltd.     

Quantitative analysis of small angle neutron scattering data from montmorillonite dispersions

A new model is presented which can describe quantitatively the small angle neutron scattering from montmorillonite-type clay dispersions and polymer-clay nanocomposites. The model is shown to be able to describe well the data from a series of dilute montmorillonite in water dispersions in which the deuterium content of the water phase is varied. The fits combined with information from other techniques suggest strongly that H-D exchange occurs in the montmorillonite-water dispersions. Deviations from Q⁻² behaviour often observed experimentally for clay dispersions are convincingly explained by the presence of a small proportion of tactoids.     

Unusual Activity Enhancement of NO Conversion over Ag/Al2O3 by Using a Mixed NH3/H2 Reductant Under Lean Conditions

Addition of H₂ to a NO/NH₃/O₂/H₂O feed for selective catalytic reduction of nitrogen oxide over Ag/Al₂O₃ catalysts causes an unusual enhancement of activity, e.g., the marginal activity (<10%) of 1 wt% Ag impregnated on γ-Al₂O₃ or mesoporous Al₂O₃ modifications is boosted to nearly 100% over a broad temperature range from 200 to 550°C at a space velocity of 30,000cm³g^?1h^?1). Contrary, silver on SiO₂ or α-Al₂O₃ shows no improvement of activity in the presence of H₂. The effect is tentatively attributed to a higher percentage of intermediary nano-sized Ag clusters on high-surface area Al₂O₃ in the presence of hydrogen. This promotes oxygen activation and hence NO oxidation to reactive intermediate nitrite species. The required dispersion of Ag cannot be stabilized on SiO₂ or α-Al₂O₃.     

Autogenous welding of Hastelloy X to Mar-M 247 by laser

Mar-M 247, a nickel-base cast alloy, is used widely in aeroengines for parts such as blades, vanes and airfoil. Hastelloy X is one of the most oxidation- and corrosion-resistant nickel-base wrought alloys. In order to join such alloys in aeroengine manufacturing, laser beam welding has been carried out with lap and butt joints using a 1.2 and a 6.0 kW CO₂ laser. Cracks in the fusion zone can be eliminated by deliberate misalignments in the ranging of the laser beam by 0.2−0.3 mm onto Hastelloy X. Correlations between cracking behavior, hardness of the beads and misalignments have been investigated. Metallurgical analysis using electron microscopes has revealed the redistribution of alloy elements, the microstructures of the fusion zone and microfissures in the heat-affected zone (HAZ).     

Preparation,characterization and wear behaviour of TiNx-coated cermets obtained by plasma-enhanced chemical vapour deposition

Commercial cermet inserts were coated with titanium nitride by plasma-enhanced chemical vapour deposition (PECVD) using a pulsed direct current (d.c.) glow discharge. The influence of the coating parameters on the deposition rate, on the layer composition, on the layer-substrate interface, on the structure and on the microhardness of the layers was investigated for deposition temperatures in the range 500–700 °C. The adhesive strengths, and some mechanical properties, of the coated cermets were characterized by scratch tests, by friction wear investigations and by measurement of the transverse rupture strength. The wear behaviour was examined in the cutting tests. It was found that TiN _x -coatings deposited with a sufficiently high deposition rate and plasma power density have a low oxygen and chlorine content and that they are nearly stoichiometric. The layers usually have a columnar structure with a 200 texture. A granular, equiaxed structure was observed within a small range of deposition conditions. In interrupted and continuous turning tests with steel and grey cast iron, a high cutting performance of the coated inserts, which depended on the coating thickness and on the deposition temperature, was achieved.     

Overcoming Anode Instability in Solid-State Batteries through Control of the Lithium Metal Microstructure

Enabling the lithium metal anode (LMA) in solid-state batteries (SSBs) is the key to developing high energy density battery technologies. However, maintaining a stable electrode–electrolyte interface presents a critical challenge to high cycling rate and prolonged cycle life. One such issue is the interfacial pore formation in LMA during stripping. To overcome this, either higher stack pressure or binary lithium alloy anodes are used. Herein, it is shown that fine-grained (d = 20 µm) polycrystalline LMA can avoid pore formation by exploiting the microstructural dependence of the creep rates. In a symmetric cell set-up, i.e., LiǀLi_6.25Al_0.25La₃Zr₂O₁₂(LLZO)ǀLi, fine-grained LMA achieves > 11.0 mAh cm⁻² compared to ≈ 3.6 mAh cm⁻² for coarse-grained LMA (d = 295 µm) at 0.1 mA cm⁻² and at moderate stress of 2.0 MPa. Smaller diffusion lengths (≈ 20 µm) and higher diffusivity pathway along dislocations (D_d ≈ 10⁻⁷ cm² s⁻¹), generated during cell fabrication, result in enhanced viscoplastic deformation in fine-grained polycrystalline LMA. The electrochemical performances corroborate well with estimated creep rates. Thus, microstructural control of LMA can significantly reduce the required stack pressure during stripping. These results are particularly relevant for “anode-free” SSBs wherein both the microstructure and the mechanical state of the lithium are critical parameters.     

Integrative computational approach to evaluate risk genes for postmenopausal osteoporosis

In recent years, numerous studies reported over a hundred of genes playing roles in the etiology of postmenopausal osteoporosis (PO). However, many of these candidate genes were lack of replication and results were not always consistent. Here, the authors proposed a computational workflow to curate and evaluate PO related genes. They integrate large‐scale literature knowledge data and gene expression data (PO case/control: 10/10) for the marker evaluation. Pathway enrichment, sub‐network enrichment, and gene–gene interaction analysis were conducted to study the pathogenic profile of the candidate genes, with four metrics proposed and validated for each gene. By using the authors'' approach, a scalable PO genetic database was developed; including PO related genes, diseases, pathways, and the supporting references. The PO case/control classification supported the effectiveness of the four proposed metrics, which successfully identified eight well‐studied top PO genes (e.g. TGFB1, IL6, IL1B, TNF, ESR2, IGF1, HIF1A, and COL1A1) and highlighted one recently reported PO genes (e.g. IFNG). The computational biology approach and the PO database developed in this study provide a valuable resource which may facilitate understanding the genetic profile of PO.Inspec keywords: biology computing, genetics, diseases, boneOther keywords: risk genes, postmenopausal osteoporosis, integrative computational approach, gene expression data, gene‐gene interaction analysis, IL1B, TNF, ESR2, HIF1A, COL1A1, PO genes     

Two-channel switched reluctance starter/generator results

Measured data and simulation results for a two-channel experimental switched-reluctance-motor (SRM)-based aircraft engine starter/generator system are presented. The two channels of the system provide power to two separate and independent loads. The results presented document the performance capability of this system with both channels operating simultaneously. Both measured and predicted system performance are presented and compared. In addition, operating characteristics that are unique to this SRM-based system are described. Of particular interest are the interactions between the two separate channels when one channel experiences a load transient and the other channel does not. The source of channel interactions is described, and measured data is provided. The issue of clearing load faults is also addressed. Design results for adding this capability to the experimental system are described