Bioresponse to nanotubes: surface chemistry of carbon nanotubes impacts the growth and expression of water channel protein in tomato plants (small 15/2012)

A tomato plant grows on medium supplemented with multi-walled carbon nanotubes. The correlations between the level of aggregation, the type of functional group on the surface of applied carbon nanotubes, plant growth performance and the expression of tomato water channel protein in the cell membranes of roots exposed to multi-walled carbon nanotubes are documented and discussed by A. S. Biris, M. V. Khodakovskaya, and co-workers.     

Phase Equilibria of “Cu2O”-“FeO”-CaO-MgO-Al2O3 Slags at PO2 of 10-8.5 atm in Equilibrium with Metallic Copper for a Copper Slag Cleaning Production

Limited data are available on phase equilibria of the multicomponent slag system at the oxygen partial pressures used in the copper smelting, converting, and slag-cleaning processes. Recently, experimental procedures have been developed and have been applied successfully to characterize several complex industrial slags. The experimental procedures involve high-temperature equilibration on a substrate and quenching followed by electron probe X-ray microanalysis. This technique has been used to construct the liquidus for the “Cu₂O”-“FeO”-SiO₂-based slags with 2 wt pct of CaO, 0.5 wt pct of MgO, and 4.0 wt pct of Al₂O₃ at controlled oxygen partial pressures in equilibrium with metallic copper. The selected ranges of compositions and temperatures are directly relevant to the copper slag-cleaning processes. The new experimental equilibrium results are presented in the form of ternary sections and as a liquidus temperature vs Fe/SiO₂ weight ratio diagram. The experimental results are compared with the FactSage thermodynamic model calculations.     

Phase Equilibria Studies of the Cu-Fe-O-Si System in Equilibrium with Air and with Metallic Copper

Phase equilibria of the Cu-Fe-O-Si system have been investigated in equilibrium: (1) with air atmosphere at temperatures between 1373?K and 1673?K (1100?°C and 1400?°C) and (2) with metallic copper at temperatures between 1373?K and 1573?K (1100?°C and 1300?°C). High-temperature equilibration/quenching/electron-probe X-ray microanalysis (EPMA) techniques have been used to accurately determine the compositions of the phases in equilibrium in the system. The new experimental results are presented in the form of ??Cu₂O??-??Fe₂O₃??-SiO₂ ternary sections. The relationships between the activity of CuO_0.5(l) and the composition of slag in equilibrium with metallic copper are discussed. The phase equilibria information of the Cu-Fe-O-Si system is of practical importance for industrial copper production processes and for the improvement of the existing thermodynamic database of copper-containing slag systems.     

Mixed-dimensional elements in transient thermal analysis of gradient coils

ABSTRACT

This article proposes a numerical formulation for handling mixed-dimensional elements embedded in a standard three-dimensional (3d) mesh, avoiding thus the volume meshing of filaments and strips. The method is then applied to predict the temperature heating and cooling profile of gradient coils in magnetic resonance imaging. These coils are typically constructed from copper wires or tracks and embedded in an epoxy layer. It was found that the new method significantly reduces the computational time of steady-state and transient simulations, with speedups in the range of 3.5-5. The method proved to be accurate, with relative errors below 0.5% for steady-state simulations and 1.5% with respect to a complete 3d simulation.     

Robust algorithms for automated chemical shift calibration of 1D 1H NMR spectra of blood serum

In biofluid NMR spectroscopy, the frequency of each resonance is typically calibrated by addition of a reference compound such as 3-(trimethylsilyl)-propionic acid- d 4 (TSP) to the sample. However biofluids such as serum cannot be referenced to TSP, due to shifts resonance caused by binding to macromolecules in solution. In order to overcome this limitation we have developed algorithms, based on analysis of derivative spectra, to locate and calibrate (1)H NMR spectra to the alpha-glucose anomeric doublet. We successfully used these algorithms to calibrate 77 serum (1)H NMR spectra and demonstrate the greater reproducibility of the calculated chemical-shift corrections ( r = 0.97) than those generated by manual alignment ( r = 0.8-0.88). Hence we show that these algorithms provide robust and reproducible methods of calibrating (1)H NMR of serum, plasma, or any biofluid in which glucose is abundant. Precise automated calibration of complex biofluid NMR spectra is an important tool in large-scale metabonomic or metabolomic studies, where hundreds or even thousands of spectra may be analyzed in high-resolution by pattern recognition analysis.     

Formation of Soy Protein Isolate Cold-set Gels: Protein and Salt Effects

ABSTRACT: The influence of protein and calcium concentration on soy protein cold-set gel formation and rheology has been investigated. Cold-set gels can be formed at soy protein concentrations from 6% to 9% and calcium concentrations from 10 to 20 mM. Gel properties can be modulated by changing the protein and/or CaCl₂ concentrations. An increase in CaCl₂ concentration from 10 to 20 mM increased gel opacity while an increase in protein concentration from 6% to 9% decreased opacity. Water-holding capacity improved with increasing protein concentration and decreasing CaCl₂ concentration. The elastic modulus (G') increased with protein and calcium chloride concentrations. Microscopy revealed an increase in the diameters of aggregates and pores as CaCl₂ concentration increased and as protein concentration decreased. Cold-set gels with a broad range of characteristics can be obtained from soy protein.     

Structural optimal design of systems with imprecise properties: a possibilistic approach

The optimization problem of structural systems with imprecise properties on the basis of a possibilistic approach is considered. System imprecisions are defined by fuzzy numbers and characterized by membership functions. A methodology for the efficient solution of the optimization process is presented. A two-step method is used to include the imprecision within the optimization, where high quality approximations are used for the evaluation of structural responses. The approximations are constructed using concepts of intermediate response quantities and intermediate variables. The approach is basically an algebraic process which can be implemented very efficiently for the optimal design of general structural systems with imprecise parameters. The method provides more information to the designer than is available using conventional design tools. The effectiveness of the methodology and the interpretation of the results are illustrated by the solution of two example problems.     

Improved Turnover Numbers in Palladium‐Catalyzed Bisdiene Cyclization‐Trapping using N‐Heterocyclic Carbene Ligands

An optimized palladium‐N‐heterocyclic carbene catalyst system effects the palladium‐catalyzed bisdiene cyclization‐trapping with phenol at the 0.01% catalyst loading level with a TON of 7.6×10³ and TOF of 280 h⁻¹, values much higher than typically found for this and related carbocyclizations. The reaction scales well and the trans‐substituted six‐membered ring product is obtained in excellent yield on a 10‐mmole scale without further optimization of the catalyst system or reaction conditions.     

Biomass and nutrient removal by willow clones in experimental bioenergy plantations in New York State

The development of short-rotation intensive cultural (SRIC) willow systems as a source of bioenergy and bioproducts is growing in the northeastern and midwestern United States. Important data for sustainable management such as nutrient removal and nutrient use efficiency in willow bioenergy plantations is lacking. This study reports wood biomass production, annual removal of nutrients, and nutrient use efficiency in experimental plantings of SRIC willow and poplar at Tully, New York. Effects of clone, fertilization, irrigation, planting density, and harvest cycle were analyzed.

Annual biomass production of 15–22 dryMg/ha removed 75–86, 10–11, 27–32, 52–79 and 4–5 kg/ha/year of N, P, K, Ca and Mg, respectively. For all the variables studied, the responses depended on clone. Fertilization and irrigation increased rates of nutrient removal by means of increased biomass production. Unlike planting density, harvest cycle significantly affected rates of nutrient removal and nutrient use efficiency. For clone SV1 (Salix dasyclados), an irrigated and fertilized planting with a density of 36,960 trees/ha harvested on a 3-year rotation had the highest biomass production and nutrient use efficiency, and the lowest rates of nutrient removal. The annual harvest cycle had the lowest nutrient use efficiency and the highest annual removal of nutrients suggesting that this choice would be most appropriate for biomass crops that are to be used as buffer strips to manage nutrient runoff from agricultural fields. An appropriate choice of clone, planting density, and harvest cycle could tailor the rates of nutrient removal and nutrient use efficiency to match the objective of the planting.