The Different Catalytic Routes for Methane Valorization: An Assessment of Processes for Liquid Fuels

Scope of Review. This review is written from the point of view of the process design engineer trying to find the best catalytic options for upgrading methane. It is not intended to be a review of catalytic principles. In fact, actual catalysts used are only mentioned in passing. If the reader wishes to explore this aspect further, there are many recent review articles that can be used and these are referred to at an appropriate time and place.     

Resin Ion Exchange and Liquid-Liquid Extraction of Indium and Thallium from Chloride Media

Separation procedures of indium and thallium for both future investigation of superheavy element 113 and fundamental research of its light homologues have been developed. Two chemical methods, namely ion exchange and solvent extraction, have been applied. Cation exchange behavior in hydrochloric acid media and the reversibility of the In and Tl elution order due to oxidation state of the latter are described. Extraction of Tl(I), Tl(III), and In(III) from aqueous HCl solutions with and without tri-n-butyl phosphate into the ionic liquid 1-butyl-3-methyl imidazolium bis(trifluoromethanesulfonyl)imide has been investigated. The extraction efficiencies of Tl(I) and In(III) have been found to be much lower than those of Tl(III) both with and without an organic ligand. The extraction mechanism is suggested. Suggestions for both liquid and gas phase experiments aimed at element 113 studies have been considered based on the results observed.     

Medium-voltage reduced-voltage autotransformer starter failures-explaining the unexplained

For the past century the autotransformer, or "Korndorfer" starter, has been a standard in the electrical industry. However, for more than the past 30 years the autotransformer starter has been experiencing unexplained "high-voltage stress" failures in typical applications. These failures have been reported on 2400-V starters from South America to 11000-V starters in the North Sea. In most cases, the zero tap or the turns close to the zero tap are involved in the failure. This paper discusses the failure mode and the corrective action that prevents "high-voltage stress" failures.     

The statistics of NBTI-induced V/sub T/ and /spl beta/ mismatch shifts in pMOSFETs

Negative bias temperature instability (NBTI) is a pFET degradation mechanism that can result in threshold voltage shifts up to 100 mV or more, even in very thin oxide devices. Since analog circuits that utilize matched pairs of devices, such as current mirrors and differential pairs, generally depend on V/sub T/ matching considerably better than this, NBTI-induced V/sub T/ mismatch shift may represent a serious reliability concern for CMOS analog applications. Furthermore, induced /spl beta/ mismatch shift (affecting drain current level at a fixed gate overdrive voltage) may also impact drain current and transconductance mismatch. In this paper, experimental results of the statistics and scaling properties of NBTI-induced V/sub T/ and /spl beta/ mismatch shifts in saturation, and models describing these results, are presented.     

Harnessing the Chemistry of the Indole Heterocycle to Drive Discoveries in Biology and Medicine

Indole-containing compounds demonstrate an array of biological activities relevant to numerous human diseases. The biological activities of diverse indole-based agents are driven by molecular interactions between indole agent and critical therapeutic target. The chemical inventory of medicinally useful or promising indole compounds spans the entire structural spectrum, from simple synthetic indoles to highly complex indole alkaloids. In an analogous fashion, the chemistry behind the indole heterocycle is unique and provides rich opportunities for extensive synthetic chemistry, enabling the construction and development of novel indole compounds to explore chemical space. This review will present heterocyclic chemistry of the indole nucleus, indole compounds of clinical use, complex indole alkaloids and indole-inspired discovery efforts by multiple research groups interested in using novel indole-containing small molecules to drive discoveries in human biology and medicine.     

Distributed model predictive control of an experimental four-tank system

A distributed model predictive control (DMPC) framework is proposed. The physical plant structure and the plant mathematical model are used to partition the system into self-sufficient estimation and control nodes. Local measurements at the nodes are used to estimate the relevant plant states. This information is then used in the model predictive control calculations. Communication among relevant nodes during estimation and control calculations provides improvement over the performance of completely decentralized controllers. The DMPC framework is demonstrated for the level control of an experimental four-tank system. The performance of the DMPC system for disturbance rejection is compared with other control configurations. The results indicate that the proposed framework provides significant improvement over completely decentralized MPC controllers, and approaches the performance of a fully centralized design.     

Effects of soil composition and mineralogy on remote sensing of crop residue cover

The management of crop residues (non-photosynthetic vegetation) in agricultural fields influences soil erosion and soil carbon sequestration. Remote sensing methods can efficiently assess crop residue cover and related tillage intensity over many fields in a region. Although the reflectance spectra of soils and crop residues are often similar in the visible, near infrared, and the lower part of the shortwave infrared (400-1900 nm) wavelength region, specific diagnostic chemical absorption features are evident in the upper shortwave infrared (1900-2500 nm) region. Two reflectance band height indices used for estimating residue cover are the Cellulose Absorption Index (CAI) and the Lignin-Cellulose Absorption (LCA) index, both of which use reflectances in the upper shortwave infrared (SWIR). Soil mineralogy and composition will affect soil spectral properties and may limit the usefulness of these spectral indices in certain areas. Our objectives were to (1) identify minerals and soil components with absorption features in the 2000 nm to 2400 nm wavelength region that would affect CAI and LCA and (2) assess their potential impact on remote sensing estimates of crop residue cover. Most common soil minerals had CAI values ≤ 0.5, whereas crop residues were always > 0.5, allowing for good contrast between soils and residues. However, a number of common soil minerals had LCA values > 0.5, and, in some cases, the mineral LCA values were greater than those of the crop residues, which could limit the effectiveness of LCA for residue cover estimation. The LCA of some dry residues and live corn canopies were similar in value, unlike CAI. Thus, the Normalized Difference Vegetation Index (NDVI) or similar method should be used to separate out green vegetation pixels. Mineral groups, such as garnets and chlorites, often have wide ranges of CAI and LCA values, and thus, mineralogical analyses often do not identify individual mineral species required for precise CAI estimation. However, these methods are still useful for identifying mineral soils requiring additional scrutiny. Future advanced multi- and hyperspectral remote sensing platforms should include CAI bands to allow for crop residue cover estimation.     

MULTIMEDIA NETWORKING A Leading-Edge Communication Technology

The realization of digital multimedia's full business potential requires networking. This article discusses the value-added benefits to the corporation of networked multimedia as well as the choice of architectures and technologies needed to deliver multimedia networking solutions.