Physicochemical and mineralogical characteristics of soil/saprolite cores from a field research site, Tennessee

Site characterization is an essential initial step in determining the feasibility of remedial alternatives at hazardous waste sites. Physicochemical and mineralogical characterization of U-contaminated soils in deeply weathered saprolite at Area 2 of the DOE Field Research Center (FRC) site, Oak Ridge, TN, was accomplished to examine the feasibility of bioremediation. Concentrations of U in soil–saprolite (up to 291 mg kg–1 in oxalate-extractable Uo) were closely related to low pH (ca. 4–5), high effective cation exchange capacity without Ca (64.7–83.2 cmolc kg–1), amorphous Mn content (up to 9910 mg kg–1), and the decreased presence of relative clay mineral contents in the bulk samples (i.e., illite 2.5–12 wt. %, average 32 wt. %). The pH of the fill material ranged from 7.0 to 10.5, whereas the pH of the saprolite ranged from 4.5 to 8. Uranium concentration was highest (about 300 mg kg–1) at around 6 m below land surface near the saprolite–fill interface. The pH of ground water at Area 2 tended to be between 6 and 7 with U concentrations of about 0.9 to 1.7 mg L–1. These site specific characteristics of Area 2, which has lower U and nitrate contamination levels and more neutral ground water pH compared with FRC Areas 1 and 3 (ca. 5.5 and

Radiative rates for transitions in Fe XVII

Energies of the lowest 157 levels belonging to the (1s(2)) 2s(2)2p(6), 2s(2)p(5)3l, 2s(2)2p(5)4l, 2s(2)2p(5)4l, 2s2p(5)5l, 2s2p(6)4l and 2s2p(6)5l configurations of Fe XVII have been calculated using the GRASP code of Dyall et al. (1989). Additionally, radiative rates, oscillator strengths, and line strengths are calculated for all electric dipole (E I), magnetic dipole (M I), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among these levels. Comparisons are made with the results already available in the literature, and the accuracy of the data is assessed. Our energy levels are expected to be accurate to better than M whereas results for other parameters are probably accurate to better than 20%.

Randomised controlled trial of home-based walking programmes at and below current recommended levels of exercise in sedentary adults

Objectives: To determine, using unsupervised walking programmes, the effects of exercise at a level lower than currently recommended to improve cardiovascular risk factors and functional capacity.

The impact of the intrinsic and extrinsic resistances of double gate SOI on RF performance

In this paper, the analogue performance of a 65 nm node double gate Sol (DGSOI) is qualitatively investigated using MixedMode simulation. The intrinsic resistance of the device is optimised by evaluating the impact of the source/drain engineering using variation of spacers and doping profile on the RF key figures of merit such as f(T), and f(MAX). It is evident that longer spacers, which approach the length of the gate offer better RF performance irrespective of the profile as long as the doping gradient at the gate edge is <7 nm/decade. Analytical expressions, which reflect the dependence of f(T), and fMAX on extrinsic source, drain and gate resistances R-S, R-D and R-G have been derived. While R-D and R-S have equal effect on f(T), R-D appears to be more influential than R-S in reducing f(MAX). The sensitivity of f(MAX) to R-S and R-D. has been shown to be greater than to R-G. (c) 2006 Elsevier Ltd. All rights reserved.

The structure of [Co(H-tptz)Cl-3] center dot H2O (tptz=2,4,6-tri(2-pyridyl)-1,3,5-triazine) prepared by crystallization from the ionic liquid, N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide

The structure of tris-chloro[2,6-bis(2'-pyridyl)-4-(2'-pyridinium)-1,3,5-triazine]cobalt(II) monohydrate, [Co(C18H13N6)Cl-3]center dot H2O (C2/c (No. 15), a = 7.783(11), b = 22.42(3), c = 11.001(15) angstrom, beta = 90.05(2)degrees), crystallized from the open air reaction of CoCl2 and 2,4,6-tri(2-pyridyl)-1,3,5-triazine in the ionic liquid, N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide is reported. The structure consists of six coordinate cobalt in an octahedral geometry bonded to the tridentate tptz ligand and three chlorines. The non-coordinating pyridyl group in the tptz ligand is protonated (with the protonated nitrogen crystallographically disordered over two possible sites), providing overall charge neutrality for the complex.

Priming of CD8+ and CD4+ T Cells in Experimental Leishmaniasis Is Initiated by Different Dendritic Cell Subtypes

The biological role of Langerin(+) dendritic cells (DCs) such as Langerhans cells and a subset of dermal DCs (dDCs) in adaptive immunity against cutaneous pathogens remains enigmatic. Thus, we analyzed the impact of Langerin(+) DCs in adaptive T cell-mediated immunity toward Leishmania major parasites in a Lang-DTR mouse model that allows conditional diphtheria toxin (DT)-induced ablation of The biological role of Langerin+ dendritic cells (DCs) such as Langerhans cells and a subset of dermal DCs (dDCs) in adaptive immunity against cutaneous pathogens remains enigmatic. Thus, we analyzed the impact of Langerin+ DCs in adaptive T cell-mediated immunity toward Leishmania major parasites in a Lang-DTR mouse model that allows conditional diphtheria toxin (DT)-induced ablation of Langerin+ DCs in vivo. For the first time, infection experiments with DT-treated Lang-DTR mice revealed that proliferation of L. major-specific CD8+ T cells is significantly reduced during the early phase of the immune response following depletion of Langerin+ DCs. Consequently, the total number of activated CD8+ T cells within the draining lymph node and at the site of infection is diminished. Furthermore, we show that the impaired CD8+ T cell response is due to the absence of Langerin+ dDCs and not Langerhans cells. Nevertheless, the CD4+ T cell response is not altered and the infection is cleared as effectively in DT-treated Lang-DTR mice as in control mice. This clearly demonstrates that Langerin+ DCs are, in general, dispensable for an efficient adaptive immune response against L. major parasites. Thus, we propose a novel concept that, in the experimental model of leishmaniasis, priming of CD4+ T cells is mediated by Langerin− dDCs, whereas Langerin+ dDCs are involved in early priming of CD8+ T cells.

Influence of preparation conditions on the characteristics of activated carbons produced in laboratory and pilot scale systems

The central theme of this investigation is to evaluate the feasibility of using bituminous coal as a precursor material for the production of chars and activated carbons using physical and chemical activation processes. The chemical activation process was accomplished by impregnating the raw materials with different dehydrating agents in different ratios and concentrations, prior to heat treatment (ZnCl2, KCl, KOH, NaOH and Fe2(SO4)3·xH2O). Steam activation of the precursor material was adopted for the preparation of activated carbon using physical activation technology. Different types of bituminous coal; namely, contaminated Columbian (contaminated with pet. coke), pure Columbian, Venezuelan and New Zealand bituminous coal were used in the production processes. BET surface area, micropore area, pore size distribution and total pore volume of the chars and activated carbons were determined from N2 adsorption/desorption isotherm, measured at 77 K. Charring conditions, charring temperature of 800 °C and charring time of 4 h, proved to be the optimum conditions for preparing chars. Contaminated Columbian were found to be the best precursor material for the production of char with reasonable physical characteristics (surface area = 138.1 m2 g-1 and total pore volume of 8.656 × 10-0.2 cm3 g-1). An improvement in the physical characteristics of the activated carbons was obtained upon the treatment of coal with dehydrating agents. Contaminated Columbian treated with 10 wt% ZnCl2 displayed the highest surface area and total pore volume (surface area = 231.5 m2 g-1 and total pore volume = 0.1227 cm3 g-1) with well-developed microporisity (micropore area = 92.3 m2 g-1). Venezuelan bituminous coal using the steam activation process was successful in producing activated carbon with superior physical characteristics (surface area = 863.50 m2 g-1, total pore volume = 0.469 cm3 g-1 and micropore surface area = 783.58 m2 g-1).