Distant-neighbor exchange constants from magnetization steps inZn1−xCoxTe

1992 ◽  
Vol 46 (18) ◽  
pp. 11617-11625 ◽  
Author(s):  
T. Q. Vu ◽  
V. Bindilatti ◽  
Y. Shapira ◽  
E. J. McNiff ◽  
C. C. Agosta ◽  
...  
Keyword(s):  
Exchange Constants ◽  
Distant Neighbor

Distant-neighbor exchange constants in Mn-based dilute magnetic semiconductors

1999 ◽  
Vol 85 (8) ◽  
pp. 5950-5952 ◽  
Author(s):  
V. Bindilatti ◽  
E. ter Haar ◽  
N. F. Oliveira ◽  
Y. Shapira ◽  
M. T. Liu
Keyword(s):  
Magnetic Semiconductors ◽  
Dilute Magnetic Semiconductors ◽  
Exchange Constants ◽  
Distant Neighbor

Distant-Neighbor Exchange Constants in Dilute Magnetic Semiconductors

1998 ◽  
Vol 80 (24) ◽  
pp. 5425-5428 ◽  
Author(s):  
V. Bindilatti ◽  
E. ter Haar ◽  
N. F. Oliveira ◽  
Y. Shapira ◽  
M. T. Liu
Keyword(s):  
Magnetic Semiconductors ◽  
Dilute Magnetic Semiconductors ◽  
Exchange Constants ◽  
Distant Neighbor

Clay liner materials for land disposal of hazardous non-metal wastes

1996 ◽  
Vol 33 (8) ◽  
pp. 71-77
Author(s):  
I. M.-C. Lo ◽  
H. M. Liljestrand ◽  
J. Khim ◽  
Y. Shimizu
Keyword(s):  
Sorption Capacity ◽  
Organic Anion ◽  
Surface Exchange ◽  
Clay Liner ◽  
Effective Removal ◽  
Exchange Constants ◽  
Anionic Species ◽  
Surface Ligand ◽  
Land Disposal

Simple land disposal systems for hazardous and mixed wastes contain heavy metal cationic species through precipitation and ion exchange mechanisms but typically fail by releasing soluble organic and inorganic anionic species. To enhance the removal of anions from leachate, clays are modified with coatings of iron or aluminium cations to bridge between the anionic surface and the anionic pollutants. A competitive surface ligand exchange model indicates that surface coatings of 10 meq cation/gm montmorillonite under typical leachate conditions increase the inorganic anion sorption capacity by at least a factor of 6 and increase the intrinsic surface exchange constants by more than a factor of 100. Similarly, metal hydroxide coatings on montmorillonite increase the organic anion sorption capacity by a factor of 9 and increase the intrinsic surface exchange constants by a factor of 20. For historical concentrations of non-metal anions in US hazardous and mixed waste leachate, sorption onto natural clay liner materials is dominated by arsenate sorption. With cation coatings, anion exchange provides an effective removal for arsenate, selenate, phenols, cresols, and phthalates. Engineering applications are presented for the use of modified clays as in situ barriers to leachate transport of anionic pollutants as well as for above ground treatment of recovered leachate.

Estimation of the exchange constants in the Fe sublattice of the Y2Fe17 and Y2Fe17N3−δ compounds from the analysis of Mössbauer measurements

1994 ◽  
Vol 130 (1-3) ◽  
pp. 57-62 ◽  
Author(s):  
M.S. Anagnostou ◽  
I. Panagiotopoulos ◽  
A. Kostikas ◽  
D. Niarchos ◽  
G. Zouganelis
Keyword(s):  
Mössbauer Measurements ◽  
Exchange Constants

scholarly journals The effect of pollen source on seed traits and dispersability in the heterocarpic annual Crepis sancta

2020 ◽  
Author(s):  
Efrat Dener ◽  
Hagai Shemesh ◽  
Itamar Giladi
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Seed Traits ◽  
Dispersal Strategy ◽  
Physiological Constraints ◽  
Dispersal Traits ◽  
Distant Neighbor ◽  
The Common ◽  
Nonsignificant Effect ◽  
Crepis Sancta

Abstract Aims The evolution and expression of dispersal-related traits are intertwined with those of other life-history functions and are manifested within various physiological constraints. Such a relationship is predicted between inbreeding levels and dispersability, which may be anatomically and ontogenetically linked so that the selection pressures on one may affect the other. While both the effect of inbreeding on reproductive success and on dispersal strategies received much attention, only a few studies considered both simultaneously. Furthermore, such studies often rely on two dichotomic representations of breeding and dispersal: using selfing vs. outcrossing as a representation of breeding level, and dispersal ratio as the sole representation of dispersal strategy. Methods Here we used pollination experiments in the heterocarpic Crepis sancta (Asteraceae) to expand in two different manners on the common practice of using dichotomic representations of breeding and dispersal. First, we used pollination treatments that represent a continuum from selfing through pollination by kin to pollination by a distant neighbor. Second, we measured a whole set of continuous morphological and dispersal-related traits, in addition to measurements of reproductive success and dispersal ratio. Important findings The proportion of developed capitula and the number of both dispersed and non-dispersed achenes were significantly lower in the self-pollination treatment in comparison to the out-crossed treatments. The effect of pollen sources on dispersal ratio was not statistically significant, though self-pollinated plants rarely produced non-dispersing seeds. Achene’s biomass increased with distance between parent plants, but pappus width did not, leading to a nonsignificant effect of pollination on falling velocity. Overall, pollen source affected mainly traits that were associated with reproductive output, but it had no clear effect on predominately dispersal-related traits. Such differences in the response of reproduction and dispersal traits to variation in pollen source suggest that dispersal-related selection is probably weak and/or masked by other forces.

scholarly journals Modelling the ecosystem effects of nitrogen deposition: Model of Ecosystem Retention and Loss of Inorganic Nitrogen (MERLIN

1997 ◽  
Vol 1 (1) ◽  
pp. 137-158 ◽  
Author(s):  
B. J. Cosby ◽  
R. C. Ferrier ◽  
A. Jenkins ◽  
B. A. Emmett ◽  
R. F. Wright ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Soil Solution ◽  
Nitrogen Uptake ◽  
Inorganic Nitrogen ◽  
Balance Model ◽  
Litter Production ◽  
Catchment Scale ◽  
Exchange Constants ◽  
External Sources ◽  
Carbon Productivity

Abstract. A catchment-scale mass-balance model of linked carbon and nitrogen cycling in ecosystems has been developed for simulating leaching losses of inorganic nitrogen. The model (MERLIN) considers linked biotic and abiotic processes affecting the cycling and storage of nitrogen. The model is aggregated in space and time and contains compartments intended to be observable and/or interpretable at the plot or catchment scale. The structure of the model includes the inorganic soil, a plant compartment and two soil organic compartments. Fluxes in and out of the ecosystem and between compartments are regulated by atmospheric deposition, hydrological discharge, plant uptake, litter production, wood production, microbial immobilization, mineralization, nitrification, and denitrification. Nitrogen fluxes are controlled by carbon productivity, the C:N ratios of organic compartments and inorganic nitrogen in soil solution. Inputs required are: 1) temporal sequences of carbon fluxes and pools- 2) time series of hydrological discharge through the soils, 3) historical and current external sources of inorganic nitrogen; 4) current amounts of nitrogen in the plant and soil organic compartments; 5) constants specifying the nitrogen uptake and immobilization characteristics of the plant and soil organic compartments; and 6) soil characteristics such as depth, porosity, bulk density, and anion/cation exchange constants. Outputs include: 1) concentrations and fluxes of NO3 and NH4 in soil solution and runoff; 2) total nitrogen contents of the organic and inorganic compartments; 3) C:N ratios of the aggregated plant and soil organic compartments; and 4) rates of nitrogen uptake and immobilization and nitrogen mineralization. The behaviour of the model is assessed for a combination of land-use change and nitrogen deposition scenarios in a series of speculative simulations. The results of the simulations are in broad agreement with observed and hypothesized behaviour of nitrogen dynamics in growing forests receiving nitrogen deposition.

scholarly journals Magnetic Anisotropy, Spin Pinning, and Exchange Constants of (Ga,Mn)As Films

2007 ◽  
Vol 43 (6) ◽  
pp. 3019-3021 ◽  
Author(s):  
Ying-Yuan Zhou ◽  
Yong-Jin Cho ◽  
Zhiguo Ge ◽  
Xinyu Liu ◽  
Malgorzata Dobrowolska ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Exchange Constants
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