Dissolved organic carbon of coal slurry transport water

The qualitative and quantitative occurrence and fate of dissolved organic carbon (DOC) leaching into coal slurry transport water was examined in laboratory-generated coal slurries and wastewaters from the Black Mesa coal slurry pipeline. Laboratory slurries were formulated for both western coals (Wyodak, Montana Rosebud and Black Mesa) and eastern coals (Illinois No. 6 and Pittsburgh No. 8). Sephadex G-25 elution profiles and ultrafiltration studies indicate that the majority of the organic compounds in western coal slurry wastewaters were lower (less than 1000) molecular weight species (62% for Wyodak and 74% for Montana Rosebud). Biochemical Oxygen Demand (BOD) for these particular wastewaters ranged from 50 to 150 mg l⁻¹ as determined through the use of an electrolytic respirometer. Also, there was a concomitant 51–74% reduction in the DOC levels in the wastewaters. This removal was primarily due to the removal of the lower (< 1000) molecular weight compounds by the seed inoculum. There was no evidence for the presence of mutagenic organics in the raw wastewater.     

Kinetic analysis of the crystallization of poly(p-phenylene sulphide)

Growth rates of spherulites were measured in poly(p-phenylene sulphide) crystallized from the melt and the quenched glass over the temperature range 100°C–280°C, possibly the most extensive overall range yet reported for any polymer and, as such, most propitious for study of régime III crystallization. For a medium M.wt. polymer, a régime II → III transition was obtained at 208°C using values of transport parameters common to many polymers ($\text{U1 = 1400}\text{cal mol}{}^{\mathrm{?1}}$, T_∞ ? T_g = 30°C) together with experimentally determined values of T⁰_m(315°C) and T_g(92°C). Under these conditions, the régime III/II slope ratio was found to be 2.07 (i.e. only 3.5% higher than predicted by régime theory), and reasonable estimates of surface free energies and of the work of chain folding were obtained. Other choices of the transport terms, including WLF and zero values, did not allow successful kinetic analyses. Although a régime I → II transition is predicted to occur at the high-temperature end of our growth-rate data, we found no experimental evidence for it. For a low M.wt. polymer, our analysis showed that régime III kinetics is obeyed at low temperatures, while at higher ones there is a continuous departure from that behaviour without, however, full attainment of régime II kinetics.     

Outcomes related to burn-related child abuse: a case series

Nationally, approximately 10% of child abuse cases involve burning, and up to 20% of pediatric burn admissions involve abuse or neglect. Historically, these cases have been more difficult to prosecute than nonburn cases for multiple reasons. Between 1995 and 1999, there were 285 pediatric (under 18) patients admitted to the Spectrum Health Regional Burn Center. Of these cases, 18 of the alleged perpetrators were legally investigated for suspicion of child abuse, and 7 received punitive sentences. We found that men tended to be prosecuted and convicted more often than women and that cases involving multiple instances of injury tended to be prosecuted more frequently. Similarly, we found that cases involving more severe injuries tended to be prosecuted more successfully. There are many psychological and social factors involved in handling burn abuse cases. However, by successful prosecution of these crimes, victims tend to fare better both socially and psychologically.     

Nanoweb Formation: 2D Self‐Assembly of Semiconductor Gallium Oxide Nanowires/Nanotubes

This paper reports a method to produce networks of crystalline gallium oxide comprised of one‐dimensional (1D) nanostructures. Because of the unique arrangement of wires, these crystalline networks are termed as ‘nanowebs’. Nanowebs are of great technological interest since they contain wire densities of the order of 10⁹ cm^–2. A possible mechanism for the fast self‐assembly of crystalline metal oxide nanowires involves multiple nucleation and coalescence via oxidation–reduction reactions at the molecular level. The preferential growth of nanowires parallel to the substrate enabled them to coalesce into regular polygonal networks. The individual segments of the polygonal network consist of both nanowires and nanotubules of β‐gallium oxide. Individual wire properties contribute to a nanoweb’s overall capacity and the implications for devices based on nanowebs are expected to be enormous.     

Linked influence of pH and cations on fatty-acid monolayer integrity related to high-quality Langmuir-Blodgett films

This study shows the connection between the morphological structure of transferred films and the chemical composition of the monolayer before transfer. The stability of a behenic acid monolayer depends on the linked influence of the type of cation and of the pH value in the aqueous subphase. The stability of the monolayer is assessed by the expansion of the solid-packed state and by the relaxation time. Its integrity is characterized by the number of crystal defects which appear in transferred Langmuir-Blodgett (LB) films as seen through Nomarski microscope observations. Both stability and integrity are greatly improved when Cd²⁺ or Mn²⁺are added to the subphase at pH 5.75 and 6 respectively. In these conditions, the transfer is very efficient and the LB films thus obtained are of very high quality. The pH values of the subphase at which the molecules of behenic acid are transformed into bivalent salts differ significantly according to the nature of the cation involved. Comparing infrared spectra of the LB films, it appeared that the relative amount of acid/salt found in the monolayer was practically the same with a subphase containing either Cd²⁺ at pH 5.75 or Mn²⁺ at pH 6. This suggests that the ratio of acidic and salt forms would be a key parameter for obtaining high-quality LB films.     

Link budget analysis for multistandard receiver architectures

As devices shrink, creating integrated circuits (ICs) that work with the required accuracy becomes more difficult due to issues related to device physics. Receivers are part of an area referred to as "mixed-signal design," meaning that both analog and digital circuitry will be on the same IC. This too presents many challenging issues, as the analog circuitry is highly sensitive to disruptions caused by the noisy digital circuitry. Therefore, accurate modeling and simulation is crucial in the design of wireless receivers to ensure the best possible operation of the fabricated IC. Through simulation and modeling a designer can determine if receiver architecture will meet the required specifications and pinpoint the possible problems before valuable time is spent developing the actual circuit. This article will present design issues for multistandard wireless receivers to give the reader an understanding of the challenges involved in link-budget analysis. TITAN (Toolbox for Integrated Transceiver Analysis), a link-budget analysis tool developed at The Ohio State University Analog VLSI Laboratory, will be presented as an example of a tool for receiver simulation. To determine design performance, various requirements must be translated to model parameters. Among the requirements for receivers are noise floor (NF), second- and third-order distortion (IP2 and IP3, respectively), reciprocal mixing, and phase noise. TITAN offers a graphical interface and encapsulated models to the designer, eliminating the possibility of formula corruption. The interface provides a more intuitive and sophisticated way of setting up the simulation and provides the designer with more readable results. Additionally, a blocking profile component allows the architecture to be tested across multiple standards.     

Variable reluctance rotor structures-their influence on torqueproduction

Switched reluctance (SR) motors with differing structures are compared in terms of their torque prediction capabilities. The first structure is doubly salient with conventional laminations, also referred to as the CRS motor. The second has semiclosed stator slots and a cylindrical rotor with anisotropic magnetic properties arising from axial laminations interleaved with nonmagnetic material, also referred to as the CRR motor. The second structure has been claimed, on theoretical grounds, to be the superior structure in terms of torque per stator volume. The present comparison, based on RMS currents, concludes that the torque produced by the conventionally laminated motor is approximately 2.5 times that of the anisotropic design when the two copper losses are equalized. However, when the CRR motor has been optimized in terms of magnetic and electric loading, the CRS motor is still twice as torque productive. These results reverse the benefits previously claimed for the anisotropic motor design     

Renal nerve responses to somatic nerve activation in stroke-prone spontaneously hypertensive rats

Antidepressant-induced adverse sexual effects are becoming more frequently reported by patients who require pharmacotherapy. A MED-LINE search was conducted to generate articles reporting such events. We report here on the sexual side effects associated with tricyclics, monoamine oxidase inhibitors including moclobemide, selective serotonin reuptake inhibitors, bupropion, and on the newer antidepressants venlafaxine and nefazadone. We conclude that adverse sexual effects are an increasingly important side effect of antidepressant medications, and patients must be routinely asked about their occurrence.