Orbital moment and electrical field gradient on dilute transitional impurities in iron hosts

ABSTRACT Electrical fields and current can permeabilize bacterial membranes, allowing for the penetration of naked DNA. Given that the environment is subjected to regular thunderstorms and lightning discharges that induce enormous electrical perturbations, the possibility of natural electrotransformation of bacteria was investigated. We demonstrated with soil microcosm experiments that the transformation of added bacteria could be increased locally via lightning-mediated current injection. The incorporation of three genes coding for antibiotic resistance (plasmid pBR328) into the Escherichia coli strain DH10B recipient previously added to soil was observed only after the soil had been subjected to laboratory-scale lightning. Laboratory-scale lightning had an electrical field gradient (700 versus 600 kV m−1) and current density (2.5 versus 12.6 kA m−2) similar to those of full-scale lightning. Controls handled identically except for not being subjected to lightning produced no detectable antibiotic-resistant clones. In addition, simulated storm cloud electrical fields (in the absence of current) did not produce detectable clones (transformation detection limit, 10−9). Natural electrotransformation might be a mechanism involved in bacterial evolution.

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Natural Electrotransformation of Lightning-Competent Pseudomonas sp. Strain N3 in Artificial Soil Microcosms

Applied and Environmental Microbiology ◽

10.1128/aem.72.4.2385-2389.2006 ◽

2006 ◽

Vol 72 (4) ◽

pp. 2385-2389 ◽

Cited By ~ 22

Author(s):

Hélène Cérémonie ◽

François Buret ◽

Pascal Simonet ◽

Timothy M. Vogel

Keyword(s):

Gene Transfer ◽

Horizontal Gene Transfer ◽

Residence Time ◽

Lightning Strike ◽

Pseudomonas Sp ◽

Electrical Field ◽

Soil Microcosms ◽

Electrical Fields ◽

Cell Lysate ◽

Electrical Field Gradient

ABSTRACT The lightning-competent Pseudomonas sp. strain N3, recently isolated from soil, has been used to study the extent of natural electrotransformation (NET) or lightning transformation as a horizontal gene transfer mechanism in soil. The variation of electrical fields applied to the soil with a laboratory-scale lightning system provides an estimate of the volume of soil affected by NET. Based on the range of the electric field that induces NET of Pseudomonas strain N3, the volume of soil, where NET could occur, ranges from 2 to 950 m3 per lightning strike. The influence of DNA parameters (amount, size, and purity) and DNA soil residence time were also investigated. NET frequencies (electrotransformants/recipient cells) ranged from 10−8 for cell lysate after 1 day of residence in soil to 4 × 10−7 with a purified plasmid added immediately before the lightning. The electrical field gradient (in kilovolts per cm) also played a role as NET frequencies ranging from 1 × 10−5 at 2.3 kV/cm to 1.7 × 10−4 at 6.5 kV/cm.

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Characterization of Photochemically or Electrochemically Reduced Blue Titanium Dioxide

Zeitschrift für Naturforschung B ◽

10.1515/znb-1990-0618 ◽

1990 ◽

Vol 45 (6) ◽

pp. 864-870 ◽

Cited By ~ 13

Author(s):

R. P. Muller ◽

J. Steinle ◽

H. P. Boehm

Keyword(s):

Titanium Dioxide ◽

Dynamic Equilibrium ◽

Inert Gases ◽

Blue Colour ◽

Electrical Field ◽

Trapped Electrons ◽

Surface Sites ◽

Electrical Field Gradient ◽

Reduced Surface

Blue TiO2 which is formed under UV irradiation under inert gases in the presence of hole scavengers is characterized. The concentration of surface-trapped electrons which cause the blue colour was analytically determined after irradiation in the presence of methanol or other organic compounds. The saturation concentration is controlled by a dynamic equilibrium of photoreduction and reoxidation of the reduced surface sites which leads to H2 formation. The blue colour can also be produced by chemical or electrochemical reduction. Mobility of the surface-trapped electrons in an electrical field gradient is demonstrated. The reduced TiO2 is similar to a hydrogen titanium bronze.

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Analytical modeling of reservoir effect on electromigration in Cu interconnects

Journal of Materials Research ◽

10.1557/jmr.2007.0001 ◽

2007 ◽

Vol 22 (1) ◽

pp. 152-156 ◽

Cited By ~ 2

Author(s):

Zhenghao Gan ◽

A.M. Gusak ◽

W. Shao ◽

Zhong Chen ◽

S.G. Mhaisalkar ◽

...

Keyword(s):

Analytical Model ◽

Analytical Modeling ◽

Interface Energy ◽

Design Guidelines ◽

Void Size ◽

Electrical Field ◽

Electrical Field Gradient ◽

Damascene Interconnects ◽

Extension Length ◽

Electron Wind

Electromigration (EM) in Cu dual-damascene interconnects with extensions (also described as overhangs or reservoirs) ranging from 0 to 120 nm in the upper metal (M2) was investigated by an analytical model considering the work of electron wind and surface/interface energy. It was found that there exists a critical extension length beyond which increasing extension lengths ceases to prolong electromigration lifetimes. The critical extension length is a function of void size and electrical field gradient. The analytical model agrees very well with existing experimental results. Some design guidelines for electromigration-resistant circuits could be generated by the model.

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Fabrication and Characterization of 3-D Photonic Crystals of Various Microspheres by Electrophoretic Self-Assembly

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.654.106 ◽

2015 ◽

Vol 654 ◽

pp. 106-113

Author(s):

Rong Fuh Louh ◽

Yi Jui Huang ◽

Ya Chih Tsai ◽

Danny Ho ◽

Doris Liao

Keyword(s):

Self Assembly ◽

Metallic Nanoparticles ◽

Counter Electrode ◽

Colloidal Stability ◽

Sol Gel ◽

Electrical Field ◽

Electrical Field Gradient ◽

Inverse Opal Structure ◽

Planar Wave ◽

High Dielectric

Fabrication of high sphericity, monodispersed microspheres (100~600 nm) of various oxides (SiO2, TiO2, ZnO, In2O3, SnO2) via sol-gel process and polystyrene (PS) microspheres (200~400 nm) via emulsion polymerization is presented. A high colloidal stability suspension was obtained by adjusting the zeta potential of such spheres and pH of the colloid. The 3-D photonic crystal (PhC) templates of opaline structure on ITO-coated glasses and silicon wafers were easily formed under electrophoretic self-assembly (EPSA) of microspheres under the influence of exerting electrical forces. Different setups of counter-electrode were attempted to establish an electrical field. The lattice constant of an ordered opal structure by EPSA can also be tuned by the electrical field gradient. Interestingly various self-assembled 3-D structures of silica microspheres in either symmetrical curvilinear profile or triangular ridges can be produced through EPSA route using specific counter-electrode setups. The measured optic properties of such 3-D PhC templates manifest photonic bandgap (PBG) based on planar-wave expansion (PWE) simulation to verify the existence of real PBG in PhC samples with tunable nanostructures. The PS PhC templates are currently used to easily transform into inverse opal structure (IOS) by infiltrating sol of other oxides with high dielectric constant (e.g. ZnO or TiO2) and filled with metallic nanoparticles (Ni or Cu) by electrochemical deposition or chemical bath deposition (CBD).

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