Journal articles: 'Conduction ionique'

1

SOUQUET, J. L., and D. COPPO. "Thermodynamique des porteurs de charges dans les verres à conduction ionique." Le Journal de Physique IV 02, no. C2 (October 1992): C2–75—C2–86. http://dx.doi.org/10.1051/jp4:1992208.

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Moliton, A., J. L. Duroux, and B. Ratier. "Coefficient seebeck et méanismes de conduction dans les polymères (PPP) electroactifs dopés par implantation ionique." Journal of Polymer Science Part B: Polymer Physics 28, no. 1 (January 15, 1990): 17–33. http://dx.doi.org/10.1002/polb.1990.090280102.

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Hammou, A. "Corrélation entre l'énergie d'activation de conduction ionique et la température de fusion des oxydes électrolytes solides." Journal de Chimie Physique 94 (1997): 1543–52. http://dx.doi.org/10.1051/jcp/1997941543.

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El Omari, M., J. M. Reau, J. Senegas, J. P. Laval, and B. Frit. "Etude des proprietes de conduction ionique des solutions solides Ca1−xThxF2+2x et Ca1−xUxF2+2x." Journal of Solid State Chemistry 92, no. 2 (June 1991): 312–19. http://dx.doi.org/10.1016/0022-4596(91)90339-j.

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Alj, A., J. P. Gosse, B. Gosse, A. Denat, and M. Nemamcha. "Influence de la nature du surfactant ionique sur la conduction électrique de ses solutions dans le cyclohexane." Revue de Physique Appliquée 22, no. 9 (1987): 1043–53. http://dx.doi.org/10.1051/rphysap:019870022090104300.

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Farahat Laroussi, B., S. Khairoun, J. M. Réau, and A. Tressaud. "Etude des propriétes de conduction ionique des solutions solides Bi1-x3+ (A0,52+ B0,55+)xO1,5 + 0,25x (A  Pb, Mg; B  Nb, Ta)." Journal of Alloys and Compounds 203 (January 1994): 229–33. http://dx.doi.org/10.1016/0925-8388(94)90740-4.

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Jouini, A., M. Ferid, A. Touati, and M. Trabelsi-Ayadi. "Préparation et étude des propriétés de conduction ionique des polyphosphate mixtes de type MIMIII(PO3)4, (MI= Li, K et MIII= Y, Bi)." Journal de Physique IV (Proceedings) 113 (January 2004): 125–28. http://dx.doi.org/10.1051/jp4:20040027.

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FOURNIER, T., J. NOTS, J. MULLER, and J. JOUBERT. "Conductive ionique des phases de type pyrochlore." Solid State Ionics 15, no. 1 (February 1985): 71–74. http://dx.doi.org/10.1016/0167-2738(85)90110-9.

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Dzyaz’ko, Yu S., L. N. Ponomareva, Yu M. Vol’fkovich, V. E. Sosenkin, and V. N. Belyakov. "Conducting properties of a gel ionite modified with zirconium hydrophosphate nanoparticles." Russian Journal of Electrochemistry 49, no. 3 (March 2013): 209–15. http://dx.doi.org/10.1134/s1023193513030075.

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Morgan, S. W., and M. R. Phillips. "Time Dependent Study of the Positive ion Current in the Environmental Scanning Electron Microscope (ESEM)." Microscopy and Microanalysis 7, S2 (August 2001): 788–89. http://dx.doi.org/10.1017/s1431927600030014.

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The Environmental Scanning Electron Microscope (ESEM) is capable of image generation in a gaseous environment at sample chamber pressures of up to 20 torr. in an ESEM, low energy secondary electrons emitted from a sample surface, by virtue of the primary electron beam, are accelerated towards the positively biased metallic ring (typically +30 to +550V) Gaseous Secondary Electron Detector (GSED). As these electrons accelerate towards the ring they undergo ionizing collisions with gas molecules producing positive ions and additional electrons known as environmental secondary electrons. The environmental electrons further ionize the gas on their way to the ring producing a cascade amplification of the original signal. The amplified signal induced in the ring is used to form an image. The electric field generated between the GSED ring and the grounded stage causes the positive ions produced in the cascade to drift towards the sample, effectively neutralizing negative charge build up on the surface of a non-conducting sample.

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Griffin, Brendan J. "A New Mechanism for the Imaging of Crystal Structure in Non-Conductive Materials: An Application of Charge-Induced Contrast in the Environmental Scanning Electron Microscope (ESEM)." Microscopy and Microanalysis 3, S2 (August 1997): 1197–98. http://dx.doi.org/10.1017/s1431927600012873.

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The mechanism of the contrast in ‘environmental’ or ‘gaseous’ secondary electron images in the environmental scanning electron microscope is at best poorly understood. The original theory suggested a simple gas amplification model in which emitted secondary electrons ionise the chamber gas, leading to signal amplification and finally measurement at a biased detector. This theory is being advanced but little attention has as yet been paid to the factors which influence the actual secondary emission, although unusual contrast effects have been noted in one case. The conven-tional view is that the positive ion product of the gas-electron interaction results in charge neu-tralisation at the sample surface.The implantation and trapping of charge in non-conductive materials was recently described, in reference to electron range measurements. This work demonstrated that trapped charge influ-enced the secondary electron yield, with enhanced secondary electron emission above the region of trapped charge. The consequence is that the distribution of the trapped charge is seen as a bright circle on the surface of the specimen, centred on the point of beam exposure (Fig.l).

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Almeida-Ferreira, Catarina, Rafael Silva-Teixeira, Mafalda Laranjo, Nuno Almeida, Gonçalo Brites, João Dias-Ferreira, Inês Marques, et al. "Open-Air Cold Plasma Device Leads to Selective Tumor Cell Cytotoxicity." Applied Sciences 11, no. 9 (May 2, 2021): 4171. http://dx.doi.org/10.3390/app11094171.

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The need for effective and safe therapies for cancer is growing as aging is modifying its epidemiology. Cold atmospheric plasma (CAP) has gained attention as a potential anti-tumor therapy. CAP is a gas with enough energy to ionize a significant fraction of its constituent particles, forming equal numbers of positive ions and electrons. Timely-resolved output voltage measurement, emission spectroscopy, and quantification of reactive species (RS) in plasma-activated media (PAM) were performed to characterize the physical and chemical properties of plasma. To assess the cytotoxicity of cold atmospheric plasma in human tumors, different cell lines were cultured, plated, and exposed to CAP, followed by MTT and SRB colorimetric assays 24 h later. Human fibroblasts, phenotypically normal cells, were processed similarly. Plasma cytotoxicity was higher in cells of breast cancer, urinary bladder cancer, osteosarcoma, lung cancer, melanoma, and endometrial cancer. Cytotoxicity was time-dependent and possibly related to the increased production of hydrogen peroxide in the exposed medium. Sixty seconds of CAP exposure renders selective effects, preserving the viability of fibroblast cells. These results point to the importance of conducting further studies of the therapy with plasma.

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Fragassa, Cristiano, Marco Arru, Filippo Capelli, Ana Pavlovic, and Matteo Gherardi. "Measuring Temperatures Generated by Air Plasma Technology." Power Engineering and Engineering Thermophysics 1, no. 1 (October 31, 2022): 76–91. http://dx.doi.org/10.56578/peet010108.

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The atmospheric pressure air plasma technology is based on the general principle of transforming the air into an ideal conductor of plasma energy thanks to the application of an electric potential difference able to ionize the molecules. Applying the principle to the human surgery, it comes to be possible to assure an energy transfer from plasma-generator devices to the human tissue in a relatively simple way: passing through the air, with exceptionally limited effects in terms of tissue heating. Such a condition is very useful to assure effective treatments in surgery: less thermal damage, fewer side effects on the patient. This is also what emerged during the use of innovative devices embedding the Airplasma® technology (by Otech Industry S.r.l.), where temperatures on human tissues were measured stably below 50°C. However, the profiles assumed by the temperature along the different electrodes during the operating conditions are rather unclear. This knowledge is essential to improve the efficiency of the electrodes (through their redesign in shapes and materials) as well as to reduce the invasiveness of surgical interventions. The present work had the purpose of characterizing the most common electrodes thanks to temperature measurements carried out by infrared sensors respect to different operating conditions. A simplified finite element model was also developed to support the optimal redesign of electrodes.

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Kariev, Alisher, and Michael Green. "The Role of Proton Transport in Gating Current in a Voltage Gated Ion Channel, as Shown by Quantum Calculations." Sensors 18, no. 9 (September 18, 2018): 3143. http://dx.doi.org/10.3390/s18093143.

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Over two-thirds of a century ago, Hodgkin and Huxley proposed the existence of voltage gated ion channels (VGICs) to carry Na+ and K+ ions across the cell membrane to create the nerve impulse, in response to depolarization of the membrane. The channels have multiple physiological roles, and play a central role in a wide variety of diseases when they malfunction. The first channel structure was found by MacKinnon and coworkers in 1998. Subsequently, the structure of a number of VGICs was determined in the open (ion conducting) state. This type of channel consists of four voltage sensing domains (VSDs), each formed from four transmembrane (TM) segments, plus a pore domain through which ions move. Understanding the gating mechanism (how the channel opens and closes) requires structures. One TM segment (S4) has an arginine in every third position, with one such segment per domain. It is usually assumed that these arginines are all ionized, and in the resting state are held toward the intracellular side of the membrane by voltage across the membrane. They are assumed to move outward (extracellular direction) when released by depolarization of this voltage, producing a capacitive gating current and opening the channel. We suggest alternate interpretations of the evidence that led to these models. Measured gating current is the total charge displacement of all atoms in the VSD; we propose that the prime, but not sole, contributor is proton motion, not displacement of the charges on the arginines of S4. It is known that the VSD can conduct protons. Quantum calculations on the Kv1.2 potassium channel VSD show how; the key is the amphoteric nature of the arginine side chain, which allows it to transfer a proton. This appears to be the first time the arginine side chain has had its amphoteric character considered. We have calculated one such proton transfer in detail: this proton starts from a tyrosine that can ionize, transferring to the NE of the third arginine on S4; that arginine’s NH then transfers a proton to a glutamate. The backbone remains static. A mutation predicted to affect the proton transfer has been qualitatively confirmed experimentally, from the change in the gating current-voltage curve. The total charge displacement in going from a normal closed potential of −70 mV across the membrane to 0 mV (open), is calculated to be approximately consistent with measured values, although the error limits on the calculation require caution in interpretation.

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15

Ping, Yuan. "(Invited) Effect of Polaron Formation on Optical and Carrier Transport Properties of Transition Metal Oxides As Photoelectrodes from First-Principles Calculations." ECS Meeting Abstracts MA2022-02, no. 48 (October 9, 2022): 1843. http://dx.doi.org/10.1149/ma2022-02481843mtgabs.

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Transition metal oxides are promising photoelectrode materials for solar-to-fuel conversion applications. However, their performance is limited by the low carrier mobility (especially electron mobility) due to the formation of small polarons. Recent experimental studies have shown improved carrier mobility and conductivity by atomic doping; however the underlying mechanism is not understood. A fundamental atomistic-level understanding of the effects on small polaron transport is critical to future material design with high conductivity. In this talk, we will discuss the effect of small polaron formation on optical and carrier transport properties of transition metal oxides from first-principles calculations. First, we resolve the conflicting findings that have been reported on the optical gap of a well-known catalysis Co3O4 as an example[1]. We confirm that the formation of small hole polarons significantly influences the optical absorption spectra and introduces extra spectroscopic signature below the intrinsic band gap, leading to a 0.8 eV transition that is often misinterpreted as the band edge that defines the fundamental gap. Then we discuss the formation of small polarons' effect on carrier concentration, by resolving the controversy of nature of "shallow" or "deep" impurities of intrinsic oxygen vacancies in BiVO4 as an example[2], i.e. how to unify different experiments with the correct definition of ionization energy in polaronic oxides. We further discuss why certain dopants can have very low optimal concentrations (or very early doping bottleneck) in polaronic oxides such as Fe2O3, through a novel "electric-multipole" clustering between dopants and polarons[3]. These multipoles can be very stable at room temperature and are difficult to fully ionize compared to separate dopants, and thus they are detrimental to carrier concentration improvement. This allows us to uncover mysteries of the doping bottleneck in hematite and provide guidance for optimizing doping and carrier conductivity in polaronic oxides toward highly efficient energy conversion applications. In addition, we show the importance of synthesis condition such as synthesis temperature and oxygen partial pressure on dopant and polaron concentrations, and how to optimize the synthesis condition based on theoretical predictions[4]. At the end, we show different theoretical models for polaron mobility calculations from a macroscopic dielectric continuum picture with an example of spin polarons in CuO[5] and a microscopic polaron hopping picture by combining generalized Landau-Zener theory and kinetic Monte-Carlo samplings for doped oxides[6]. Our first-principles calculations provide important insights and suggest design principles for optimal optical and transport properties of polaronic oxides. References: [1] “Optical Absorption Induced by Small Polaron Formation in Transition Metal Oxides – The Case of Co3O4”, T. Smart, T. Pham, Y. Ping*, and T. Ogitsu*, Physical Review Materials (Rapid Communications), 3, 102401(R), (2019). [2] “The Role of Point Defects in Enhancing the Conductivity of BiVO4”, H. Seo, Y. Ping and G. Galli*, Chemistry of Materials, 30, 7793, (2018). [3] “Doping Bottleneck in Hematite: Multipole Clustering by Small Polarons”, T. Smart, V. Baltazar, M. Chen, B. Yao, K. Mayford, F. Bridges, Y. Li, and Y. Ping*, Chemistry of Materials, 33, 4390, (2021). [4] “The Critical Role of Synthesis Conditions on Small Polaron Carrier Concentrations in Hematite- A First-Principles Study”, Tyler Smart, Mingpeng Chen, Valentin Urena Baltazar, Frank Bridges, Yat Li, Yuan Ping*, under review, (2021). [5]“Mechanistic Insights of Enhanced Spin Polaron Conduction in CuO through Atomic Doping”, T. Smart, A. Cardiel, F. Wu, K. Choi and Y. Ping*, npj Computational Materials, 4, 61, (2018). [6] “Combining Landau-Zener Theory and Kinetic Monte Carlo Sampling for Small Polaron Mobility of Doped BiVO4 from First-principles”, F. Wu and Y. Ping*, Journal of Materials Chemistry A, 6, 20025, (2018).

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16

Gruchola, Salome, Andreas Riedo, Peter Keresztes Schmidt, Coenraad P. de Koning, Luca N. Knecht, Marek Tulej, Frances Westall, and Peter Wurz. "Reduction of Surface Charging Effects in Laser Ablation Ionisation Mass Spectrometry through Gold Coating." Journal of Analytical Atomic Spectrometry, 2023. http://dx.doi.org/10.1039/d3ja00078h.

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In femtosecond Laser Ablation Ionisation Mass Spectrometry (fs-LIMS) short laser pulses are used to ablate, atomise, and ionise solid sample material shot-by-shot. When ablating non-conductive samples electric charging of the...

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17

Cheng, Yufeng, Jinrui Zhang, Weizong Wang, Jiaqi Yan, and Guobiao Cai. "Stably electrospraying highly conductive sodium chloride aqueous solution coated with outer ionic liquid using coaxial capillary." Physics of Fluids, August 2, 2022. http://dx.doi.org/10.1063/5.0104334.

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Concentrated aqueous solutions with high conductivity have been proven difficult to be stably electrosprayed mainly due to their large surface tension, which will easily trigger air discharge. The ionic liquid with lower surface tension is involatile, viscous and highly conductive, and can easily achieve stable electrospray. This paper presents a more convenient method to ionize the concentrated aqueous solution than the previous attempts and proves the feasibility of coaxial electrospraying two highly conductive liquids (~1 S/m). Our method utilizes a coaxial capillary to coat the highly conducting concentrated sodium chloride (NaCl) aqueous solution (0.67 S/m) with a thin layer of immiscible ionic liquid to form a compound cone and achieve the stable coaxial electrospray. The compound cone remains static at a suitable flow rate (0.1 nl/s ∼ 1 nl/s) of ionic liquid. At a higher or lower flow rate, the compound cone elongates or shrinks and eventually vibrates. Due to the high conductivity of both liquids, the spray current does not follow the current scaling law. The spray current is mostly dominated by the NaCl solution and counter-intuitively decreases as the flow rate of ionic liquid increases due to the frequent vibration of the compound cone. The highly conducting thin layer of ionic liquid is the key to achieving stable coaxial electrospray. It lowers the surface tension of the compound cone and shields the external electric field acting at the inner aqueous solution, thus the air discharge of the aqueous solution is suppressed, and the stable compound cone can form.

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Wang, Jian-Min, Yu-Yang Songsheng, Yan-Rong Li, and Pu Du. "Final stage of merging binaries of supermassive black holes: observational signatures." Monthly Notices of the Royal Astronomical Society, November 16, 2022. http://dx.doi.org/10.1093/mnras/stac3266.

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Abstract There are increasing interests in binary supermassive black holes (SMBHs), but merging binaries with separations smaller than ∼1 light days (∼102 gravitational radii for 108M⊙), which are rapidly evolving under control of gravitational waves, are elusive in observations. In this paper, we discuss fates of mini-disks around component SMBHs for three regimes: 1) low rates (advection-dominated accretion flows: ADAFs); 2) intermediate rates; 3) super-Eddington accretion rates. Mini-disks with intermediate rates are undergoing evaporation through thermal conduction of hot corona forming a hybrid radial structure. When the binary orbital periods are shorter than sound propagation timescales of the evaporated mini-disks, a new instability, denoted as sound instability, arises because the disks will be highly twisted so that they are destroyed. We demonstrate a critical separation of Acrit( ∼ 102Rg) from the sound instability of the mini-disks and the cavity is full of hot gas. For those binaries, component SMBHs are accreting with Bondi mode in the ADAF regime, showing periodic variations resulting from Doppler boosting effects in radio from the ADAFs due to orbital motion. In the mean while, the circumbinary disks (CBDs) are still not hot enough (ultraviolet deficit) to generate photons to ionize gas for broad emission lines. For slightly super-Eddington accretion of the CBDs, Mg ii line appears with decreases of UV deficit, and for intermediate super-Eddington Balmer lines appear, but C iv line never unless CBD accretion rates are extremely high. Moreover, if the CBDs are misaligned with the binary plane, it is then expected to have optical periodical variations with about ten times radio periods.

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Khudozhitkov, V. E., A. E. Zarvin, and V. V. Kalyada. "Mass spectrometry of clustered flows during gas ionization by low-temperature plasma in the diffuser part of the nozzle." Physics of Plasmas 32, no. 3 (March 1, 2025). https://doi.org/10.1063/5.0250894.

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This paper presents a technique for mass spectrometry of an ionized cluster flow in the variant of its ionization in a supersonic nozzle when gas flows into a rarefied space. The purpose of the implementation of the methodology presented in the work is its further use for conducting research on the initiation of intracluster energy exchange. To ionize the gas flow in the nozzle, a scheme for generating an effective discharge directly in the diffuser part of a supersonic nozzle has been developed and implemented. The results obtained under the conditions of traditional mass spectrometry of neutral fluxes with particle ionization directly in the mass spectrometer detector (EBMS method) and under the conditions of ionization of a supersonic jet at a selected distance from the nozzle by a high-voltage electron beam (HVEB method) are compared with the results obtained by the discharge ionization method in the nozzle (DIN method). It has been experimentally revealed that when using the DIN method, a significantly larger number of ions are formed than when using the HVEB method, which is an undoubted advantage of the developed method. It is shown that the heating of the nozzle leads to some delay in the condensation process, but a relatively small correction of the stagnation pressure compensates for this loss. The results of trial experiments on the search for conditions for ion-cluster energy exchange are presented using the example of an argon-methane mixture flow.

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Shridharani, Sachin, and MacKenzie L. Kennedy. "Safety of Helium-Based Plasma Technology for Coagulation of Soft Tissue: A Retrospective Review." Aesthetic Surgery Journal Open Forum, November 7, 2022. http://dx.doi.org/10.1093/asjof/ojac081.

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Abstract Background The subdermal application of energy using a helium-based plasma radiofrequency (RF) device has been shown to improve skin laxity. Helium-based plasma RF technology (Renuvion; Apyx Medical, Clearwater, FL) utilizes RF to ionize helium into an electrically conductive plasma capable of coagulating and contracting soft tissue with high precision and minimal thermal spread. This study provides information on the early use of the new generation of electrosurgical generator (APYX-RS3) containing a feature that allows for quantification of the amount of energy delivered to tissue during treatments. Objective To collate procedure details, treatment settings, and safety data in patients treated with a helium-based plasma device for soft tissue coagulation. Methods A retrospective review was conducted of patients aged ≥18 years who underwent treatment with a helium-based plasma RF device (Renuvion; Apyx Medical, Clearwater, FL) for soft tissue coagulation. Demographic data, procedure details, and adverse events were collected. Results Chart review identified 47 patients with an average age of 45 years and an average BMI of 25.8 kg/m². The amount of energy (J) delivered per treatment area was greatest for abdomen, buttocks, and thighs, with an average of 13.7 kJ, 13.5 kJ, and 10.6 kJ, respectively. No serious, unexpected, or device-related AEs were reported. Conclusions The use of the generator that quantifies the energy (joules) being applied during the procedure, allows the provider to understand and optimize their energy usage. While further research is needed to establish the safety and efficacy of the device for skin tightening, this study provides important information regarding energy application.

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Journal articles on the topic 'Conduction ionique'

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