Conversion of fern (Pteris vittata L.) biomass from a phytoremediation trial in sub- and supercritical water conditions

Uncontaminated and As-contaminated fronds of Pteris vittata L., an As-hyperaccumulator fern used to phytoextract As from contaminated soils and water, were converted by sub-critical water (300 °C, 25 Pa) and supercritical water (400 °C, 25 Pa) treatments. Frond biomass was reduced between 70 and 77%. Compared to sub-critical conditions, supercritical conditions decreased C and inorganic contents in both the solid and liquid phases for uncontaminated and contaminated fronds and promoted CH₄ formation. Higher As, Fe and Zn contents in contaminated fronds promoted decreasing C contents and the formations of cyclopentenones and benzenediols in the liquid phase. Al, Fe, P, Zn and Ca mainly remained in the solid phase whereas As and S were transferred to the liquid phase for both phytomasses. As the temperature increased from 300 °C to 400 °C, the concentrations of cyclopentenones and phenols in the liquid phase rose while those of guaiacols and other compounds decreased for both phytomasses. Arsenic in the liquid phase was removed by sorption on hydrous iron oxide.     

On Joint Order Statistics in Correlated Nakagami Fading Channels

In this letter, the joint probability density function (pdf) of the order statistics for a set of correlated Nakagami-m fading channels is derived. This result is useful in analyzing the performance of a variety of diversity schemes which involve branch selection. The derivation also yields a computationally efficient method for obtaining the marginal pdf of the p-th order statistic for a set of correlated Nakagami-m fading channels.     

Solution of laue back reflection patterns of sapphire crystals using a computer technique

A computer algorithm for the rapid solution of Laue back reflection patterns of sapphire crystals is described, (although other hexagonal systems could be indexed with minor changes). Reflections of planes having indices (3, 3, 3) and lower are indexed without using Wulff nets, Greninger charts, and so forth. Any film to specimen distance may be used and the systematic errors associated with this measurement are minimized to determine its best value. The computational scheme compares the angles associated with the reflections from the X-ray patterns and the true interplanar angles which are calculated from the computer program.     

Analysis of nitrate and nitrite in foodstuffs: A critical review

A general review is presented of published methods for the determination of nitrate and nitrite levels in foodstuffs especially meat. Published methods show wide variations in techniques for extraction, clean-up (clearing) of extracts and final determinative steps and these are critically compared. The effect of interferences due to the presence of ascorbate, sulphite and phosphate together with the formation of a “meat blank” when nitrate is reduced to nitrite with spongy cadmium are discussed. Newer techniques based on the use of ion selective electrodes and automated techniques are outlined and the application of techniques such as amperometry, liquid chromatography, ion exchange and spectrophotometry are listed.     

Spatio-temporal effects of multimedia objects storage and delivery for video-on-demand systems

As the number of video streams to be supported by a digital video delivery system (DVDS) increases, an improved understanding of the necessity for reliable and cost-efficient support for a considerable number of video streams (in the magnitude of tens of thousands), and the dependency largely on software capabilities emerges. Even in the presence of an optimal hardware configuration, or model, and associated costs, using software to exploit the underlying hardware capabilities is of paramount importance. Although a number of DVDSs have become operational, their ability to deliver the required services mainly depends on the small number of streams supported and the hardware trade-offs. It is imperative that current software developments account for the eventual scalability of the number of video streams without commensurate increase in hardware. In this paper, we present strategies for the management of video streams in order to maintain and satisfy their space and time requirements. We use a DVDS architectural model with functionally dichotomized nodes: a single-node partition is responsible for data retrieval, while the remaining partition of nodes accepts user requests, determines object locations, and routes requests through the network that connects both partitions. We present a detailed analysis of the issues related to queuing I/O requests and data buffering. The discussion includes the requirements for arranging and scheduling I/O requests and data buffers, with the objective of guaranteeing the required data availability rates for continuous media display.     

The simultaneous determination of both the quantity and the fatty acid composition of the triglycerides in three to ten microliters of plasma

An integrated system using chromatography on silica gel-impregnated glass paper, an internal standard and gas-liquid chromatography (GLC) makes possible the isolation of triglycerides, the determination of triglyceride, fatty acid composition, and the quantitative determination of triglyceride. Recoveries are good and values for total triglyceride obtained by this system compare favorably with values obtained by application of the hydroxamate colorimetric method to the triglyceride eluate from silicic acid columns. The fatty acid composition of the cholesteryl ester (CE) fraction is obtainable at the same time by GLC of methyl esters prepared from the CE fractions which also appears as a distinct spot on these chromatograms. Also, a densitometric method is described for triglyceride determination by photometry of the charred spots obtained after chromatography on the gel-paper. Presented at the AOCS Meeting, Houston, April, 1965     

Conditioning and personality: A study of normal and neurotic subjects.

"Pavlov's concepts of excitation and inhibition were related to the dimension of introversion-extraversion in normal and neurotic subjects. Normal and neurotic subjects were conditioned, using the eyeblink and PGR reflexes. It was found that (a) anxiety states conditioned much better than hysterics, and (b) conditionability is related to introversion-extraversion and not to neuroticism." 37 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrical detection of DNA hybridization based on enzymatic accumulation confined in nanodroplets

Electrical monitoring of DNA hybridization is one way to reduce the cost and size of the DNA chip reader in comparison with the more classical optical detection. Within electrical methods, electrochemical detection shows very high performances in terms of accuracy and sensitivity, especially when an enzymatic accumulation is used to amplify the signal. However, signal multiplexing for miniaturized systems based on both enzymatic accumulation and electrochemical detection remains challenging due to the Brownian diffusion of the detected product of the enzymatic reaction. We present here a DNA chip with electrical detection based on the following sequence: (i) hybridization of nucleic acids and washing in a liquid layer as usual, (ii) formation of independent nanodroplets on each detection site, (iii) enzymatic accumulation in each droplet avoiding cross-contamination between neighboring sites, and (iv) electrochemical detection of the product accumulated during the enzymatic reaction. The simple and fast transition from the liquid layer (hybridization step) to an array of nanodroplets (enzymatic accumulation and detection steps) was performed through the filling of the hybridization chamber with a solution containing the enzymatic substrates, the drawing of this solution, and the simultaneous creation of droplets thanks to retention areas based on circular rims or hydrophilic rings. Using this approach, hybridization is achieved in a liquid layer as usual, followed by the enzymatic accumulation in nanodroplets to avoid the cross-talk between neighboring sites. Moreover, working in droplets enables a fast increase in the concentration of the product generated by the enzymatic reaction and thus an improvement of the detection limit of the system.     

DYNAMIC EFFECTS OF BUBBLE MOTION

The dynamic effects of the motion of single bubbles entrained in a liquid are investigated. Extensive original experimental results are presented on the pressures associated with the motion of large, isolated spherical cap air bubbles rising both freely and through constricting orifices in a vertical cylindrical pipe filled with quiescent water. The pressures, measured at the pipe wall, were found to be as high as the dynamic bubble pressure for translational bubble motion, and an order of magnitude larger for oscillatory bubble motion following bubble formation.