scholarly journals Broadband focusing of acoustic plasmons in graphene with an applied current

2021 ◽  
Vol 104 (16) ◽  
Author(s):  
Michael Sammon ◽  
Dionisios Margetis ◽  
E. J. Mele ◽  
Tony Low
Keyword(s):  
2002 ◽  
Vol 1 (2) ◽  
pp. 273
Author(s):  
Alex Furman ◽  
A. W. Warrick ◽  
Ty P. A. Ferré

2019 ◽  
Vol 17 (1) ◽  
pp. 1017-1025
Author(s):  
Mohamed Réda Arhoutane ◽  
Muna Shueai Yahya ◽  
Miloud El Karbane ◽  
Kacem El Kacemi

AbstractIn the context of environmental protection, where there is a need to develop effective operations for carrying out appropriate treatment of polluted water by pharmaceuticals. Therefore, the present study aims at evaluating the degradation for gentamicin through electro-Fenton (EF) operation, through taking into consideration the effect of several parameters of experimental in the process, namely, the concentration of initial gentamicin, the applied current and the Fe+2 (II) quantities. The (EF) operation employed involves a carbon-felt as cathode and platinum as anode at pH 3. Studies for the gentamicin kinetics is monitored by HPLC giving a pseudo-first order reaction following by a chemical oxygen demand, with a reached degree of mineralization 96% after of four hours of treatment through current 100 mA/cm2 with 0.1 mM of Fe+2. We find that the degradation for molecule of gentamicin is accompanied by an augmentation of the biodegradability, assesse through the Biochemical Oxygen Demand (BOD5) on chemical oxygen demand (COD) ratio, that augmentation from 0 to 0.41 before treatment after 30 min for EF treatment, showing that there is potential for conjugation of the EF process and the biological process. Furthermore, the by-products have been identified on the basis of HPLC-MS/MS results.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
M. Behbahani ◽  
M.R. Alavi Moghaddam ◽  
M. Arami

The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electrolyte salt was NaCl with the maximum defluoridation efficiency of 98.5% compared to KNO3 and Na2SO4. The increase of NaCl had no effect on defluoridation efficiency. Number of electrodes had little effect on the amounts of Al3+ ions released in the solution and as a result defluoridation efficiency. Almost the same fluoride removal efficiency obtained for different interelectrode distances.


2021 ◽  
Vol 317 ◽  
pp. 3-9
Author(s):  
Muhammad Suffian Sazali ◽  
Norazila Ibrahim ◽  
Zakiah Mohamed ◽  
Rozilah Rajmi ◽  
Ahmad Kamal Yahya

La0.7Ba0.3Mn1-xFexO3 (x = 0 and 0.02) were prepared by using solid state synthesis method to investigate the effect of Fe3+ substitution at Mn-site on electrical behaviour and structural properties. An analysis of X-ray diffraction, XRD data using refinement method shown both x = 0 and x = 0.02 samples were in single phased and crystallized in rhombohedral structural with Pnma space group. From ρ vs T curves shown resistivity decreased under increased of applied current of 10 mA to 20 mA for both samples in the temperature range of 20 K-300 K. The larger electroresistance, ER effect observed for x = 0.02 in temperature range of 20 K – 180 K compared to x = 0 sample is suggested due to the development of filamentary conduction path under increased of applied current. It is suggested that Fe substitution enhanced magnetic inhomogeneity which contribute to the growth of formation of conductive path under increased of applied current, lead to increase of ER effect. In the temperature range of 180 K – 300 K, the observed decreased in ER for Fe substituted sample (x = 0.02) is suggested due to the increased of scattering effect and reduction of available hopping site in metallic region and insulating region, respectively. Restriction in the movement of charge carrier had weakened the ER effect for Fe substituted sample. The observed ER effect indicates the compound has a potential for application such as for non-volatile memory elements.


Science ◽  
2014 ◽  
Vol 345 (6197) ◽  
pp. 637-640 ◽  
Author(s):  
Stuart Licht ◽  
Baochen Cui ◽  
Baohui Wang ◽  
Fang-Fang Li ◽  
Jason Lau ◽  
...  

The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm−2) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm−2 current density decreased to 1.0 V.


2017 ◽  
Vol 48 (1) ◽  
pp. 48-54 ◽  
Author(s):  
YanJu YANG ◽  
ZhengWu XIA ◽  
YanHong LI ◽  
Hui XIA ◽  
GuoQiang LIU ◽  
...  

1969 ◽  
Vol 53 (4) ◽  
pp. 471-486 ◽  
Author(s):  
T. Hidaka ◽  
H. Kuriyama

Field stimulation of the jejunum elicited successively an action potential of spike form, a slow excitatory depolarization, a slow inhibitory hyperpolarization, and a postinhibitory depolarization as a rebound excitation. The slow depolarization often triggered the spike. The inhibitory potential showed lower threshold than did the excitatory potential. Both the excitatory potentials were abolished by atropine and tetrodotoxin. Effective membrane resistance measured by the intracellular polarizing method was reduced during the peak of the excitatory potential, but the degree of reduction was smaller than that evoked by iontophoretic application of acetylcholine. Conditioning hyperpolarization of the muscle membrane modified the amplitude of the excitatory potential. The estimated reversal potential level for the excitatory potenialt was about 0 mv. No changes could be observed in the amplitude of the inhibitory potential when hyperpolarization was induced with intracellularly applied current. Low [K]o and [Ca]o blocked the generation of the excitatory potential but the amplitude of the inhibitory potential was enhanced in low [K]o. Low [Ca]o and high [Mg]o had no effect on the inhibitory potential.


1979 ◽  
Vol 82 (1) ◽  
pp. 227-238
Author(s):  
M. ANDERSON

1. Intracellular recordings were made from the myoepithelial cells of the proventriculus of the marine polychaete worm Syllis spongiphila. Overshooting responses were elicited either by carbamylcholine added to the bathing medium or by directly applied intracellular current pulses. 2. In control artificial sea water (ASW) directly applied current pulses elicited regenerative responses of 68–119 mV in amplitude and 70–1800 ms in duration; these responses were associated with contractions of the myoepithelial cells. 3. Both pharmacologically and electrically elicited responses were reversibly abolished in Ca-free ASW and were unaffected by TTX or lowsodium solutions. Regenerative responses were elicited by direct intracellular stimulation in calcium-free ASW containing 1 mM-B2+ or 10 mM-Sr2+. Directly elicited responses were blocked reversibly in ASW containing calcium and 15-20 mM-Co2+ or 2.5-10 mM-Ni2+; they were blocked irreversibly in ASW containing calcium and 10 mM-La3+ or 100 μM-Zn2+. 4. Regenerative responses were elicited in Ca-free solutions containing 10-50 mM-Mn2+; these responses were not associated with contractions, were consistently of longer duration than responses elicited in control ASW, and were blocked by 20 mM-Co2+ or 10 mM-La3+. The overshoots of Mn2+ responses elicited in both Na-free and Na-containing, Ca-free solutions increased as the external concentration of Mn2+ was increased, with a slope of about 27 mV per 10-fold change in concentration of Mn2+. In Cacontaining solutions the slope was reduced to about 15mV per 10-fold change. 5. The results indicate that the myoepithelial cells generate Ca-spikes and that Mn2+ ions, in addition to Sr2+ and Ba2+ ions, pass through the Ca2+ channels of the myoepithelial cell membranes. Although Mn^ can replace Ca2+ in generating spikes, it apparently cannot replace Ca2+ in initiating contraction, and it many compete with Ca2+ in activating repolarization of the cell.


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