Electric Sign Research Articles

Ferroelectric control of layer-polarized anomalous Hall effects in bilayer and trilayer RuCl2

Layer-polarized anomalous Hall effect (LP-AHE) attracts great interest in the fields of both condensed-matter physics and device applications. However, previous research on implementing the LP-AHE based on the paradigm of topological systems and persistent electric fields has hindered its further development. Here, we go beyond the paradigm and for the first time explore the LP-AHE in polar stacked trilayers, in addition to the bilayer. A general design principle for realizing the layer-locked valleys, spins, Berry curvatures and LP-AHE in bilayer and trilayers is mapped out based on comprehensive analysis of symmetry. Bilayers and trilayers, formed by polar stacking ferrovalley monolayers typically possessing ferromagnetism and hexagonal structure, exhibits valley polarization and out-of-plane electron polarization. Through interlayer sliding, the electric polarization and sign of valley polarization can be simultaneously reversed, yielding the sliding ferroelectricity and ferroelectricity-valley coupling. Owing to the MˆzTˆ symmetry between AB and BA stacked bilayers, the interlayer sliding lead to the opposite sign of Berry curvatures and anomalous Hall velocity, implementing the LP-AHE. The interlayer sliding and Mˆz symmetry between ABC and CBA stacked trilayer lead to the layer controllable LP-AHE. We further demonstrate the feasibility of this design principle in the bilayer and trilayer constructed from ferrovalley H–RuCl2 monolayers through first-principles calculations. Our work not only provides a new route to control the valley-dependent logic state without an external magnetic field, but also greatly enrich the research on LP-AHE.

Modeling of high-field-side high-density regime in the Globus-M2 tokamak

Formation of a high-field-side high-density (HFSHD) regime and the role of the high-field-side (HFS) poloidal electric field in the scrape-off layer of the spherical tokamak Globus-M2 are analyzed using SOLPS-ITER edge plasma simulations. The dependence of the HFS poloidal electric field sign and, consequently, radial drift fluxes on the discharge density is discussed. It is demonstrated that the HFS poloidal electric field is the key element in the formation of a HFSHD regime in the Globus-M2 tokamak as in ASDEX Upgrade. It is demonstrated that the physics of HFSHD formation in a small spherical tokamak is similar to that suggested by Kaveeva et al (2009 36th EPS Conf. on Plasma Physics) and is in line with experimental observations and modeling, performed later on ASDEX Upgrade.

A Survey on Sign Language Recognition and Training Module

Communication among the deaf and non-verbal communities has long reliedon sign language recognition. From all researchers around from early electric signal-based sign language identification to more recent recognition using machine/deep learning techniques, the globe has tried to automate this process. The main objective of this research is Recognition of sign language based on key point detection (SLR).American Sign Language (ASL), primarily ASL pickle data, is the subject of this work. The model was trained using a variety of machine learning algorithms, including randomforest, support vector machine, and k closest neighbor. Lastly, utilizing evaluation criteria such as f1score, precision, and recall, the best model is chosen from the model testing. A straightforward GUI is created to collect user input, and the best machine learning model makes the forecast. Also, a Training tool is created for the purpose of learning the American sign language which will create a major difference for non-verbalcommunities

Electric shock sign after digital nerve injury; report of a case and review of literature.

Introduction and importanceDigital nerve lacerations are rationally common, especially following penetrating injuries. The majority of patients suffer from numbness as the main complaint. However, electric shock pain is a rare manifestation of partial nerve injury.Case presentationA 65-year-old woman with partial digital nerve injury and an electric shock sign due to a 1 cm laceration on the volar side of the proximal phalanx three weeks earlier. The surgical exploration revealed a neuroma-like mass in the digital nerve; however, the continuity of the nerve was grossly intact.Clinical discussionDue to the superficiality of digital nerves, penetrating nerve injuries are rationally common in this area. Laceration of the digital nerve could lead to loss of sensation, clumsiness, and even loss of function. Gradually, neuroma formation would add a local pain and electric shock sign to the mentioned symptoms.ConclusionElectric shock sign is characteristic for partial digital nerve injury with unknown mechanism. It seems the symptoms would be progressive and more complicated with neuroma formation.Level of evidenceV.

The Hill Cumorah: Restoring a Sacred Site

The Hill Cumorah: Restoring a Sacred Site

Regulatory Induced Risk Aversion in Coal Contracting at US Power Plants: Implications for Environmental Policy

Seminal work argues that electric utilities sign long-term contracts with coal suppliers prior to making relationship-specific investments in order to avoid the possibility of ex post hold-up. This paper provides empirical evidence that risk aversion also plays an important role in the coal contracting behavior of US power plants. Specifically, I show that plants facing more spot coal price uncertainty sign longer duration coal contracts, purchase contract coal from a larger number of origin counties, and pay higher contract coal prices. One plausible mechanism for this risk aversion is that regulators are less likely to incorporate high input cost realizations into the regulated output price they set for electric utilities. Using my estimate of plant-level risk aversion, I calculate that the ratio of the aggregate costs incurred by plants under cap and trade relative to a carbon tax is 1.27. This highlights the importance of implementing climate policy that limits carbon price volatility.

Piezoelectric Devices in Biomedical Applications

Piezoelectricity is a nature of material imbalance that prompts the change of electric signs into actual misshaping and on the other hand actual deformity into an electric sign. The past decade has witnessed significant advances in medically

Time-reversal-symmetric topological magnetoelectric effect in three-dimensional topological insulators

One of the hallmarks of time-reversal-symmetric topological insulators in three dimensions is the topological magnetoelectric effect (TME). So far, a time-reversal breaking variant of this effect has attracted much attention, in the sense that the induced electric charge changes sign when the direction of an externally applied magnetic field is reversed. Theoretically, this effect is described by the so-called axion term. Here, we discuss a time-reversal-symmetric TME, where the electric charge depends only on the magnitude of the magnetic field but is independent of its sign. We obtain this nonperturbative result by a combination of analytic and numerical arguments, and suggest a mesoscopic setup to demonstrate it experimentally.

Effect of c-axis inclination angle on the properties of ZnO/Zn1 − xCdxO/ZnO quantum wells

The development of optoelectronic devices based on highly-promising Zn1−xCdxO semiconductor system demands deep understanding of the properties of the Zn1−xCdxO-based quantum wells (QWs). In this regard, we carried out a numerical study of the polarization-related effects in polar, semi-polar and non-polar ZnO/Zn1−xCdxO/ZnO QWs with different parameters of the quantum well structure. The effects of well width, barrier thickness, cadmium content in the active layer and c-axis inclination angle on the distribution of the electron and hole wave function and transition energy were investigated using the 6×6k·p Hamiltonian and one-dimensional self-consistent solutions of nonlinear Schrödinger–Poisson equations with consideration of spatially varying dielectric constant and effective mass. The strong sensitivity of the internal electric field, transition energy and overlap integral to cadmium content and well thickness in the angle range from 0 to 40° was revealed. An unexpected change of the internal electric field's sign was observed at the angles ranging from 70 to 90°. We also found a difference in the electronic properties between (0001)-, (112̅2)- and (101̅0)-oriented QWs.

Frank J. Sprague Invents: The Constant-Speed dc Electric Motor [History

ON A MISERABLY COLD SPRING day in 1998, it became necessary to clean out a little-used storage barn in Williamstown, Massachusetts, so that it could be sold. The barn was part of the estate of Robert C. Sprague, who had died in 1991. Although the winter snow was mostly gone, a misty drizzle made the muddy walk down to the barn?s entrance slippery and treacherous. Once used to house riding horses, the stalls were long gone and the building was almost completely filled with rotting wet hay and broken pieces of equipment, along with seemingly useless files that once belonged to electrical inventor Frank Julian Sprague, Robert?s father. The inventor had died in 1934, nearly 60 years before his son, and it seemed impossible that the barn could still hold anything of value. The building was sagging, and, once inside, broken light bulbs and wooden supports from Frank Sprague?s failed late 1920s programmable electric sign business made moving around nearly impossible and dangerous. With its stagnant hay and years of collected rodent droppings, the space reeked, and it seemed best to get a front loader, empty out the structure, take the contents to the dump, and hope for a buyer who could see more value than was apparent.

Multifluid Eulerian model of an electrospray in a host gas

AbstractAn Eulerian multifluid model is used to describe the evolution of an electrospray plume and the flow induced in the surrounding gas by the drag of the electrically charged spray droplets in the space between an injection electrode containing the electrospray source and a collector electrode. The spray is driven by the voltage applied between the two electrodes. Numerical computations and order-of-magnitude estimates for a quiescent gas show that the droplets begin to fly back toward the injection electrode at a certain critical value of the flux of droplets in the spray, which depends very much on the electrical conditions at the injection electrode. As the flux is increased toward its critical value, the electric field induced by the charge of the droplets partially balances the field due to the applied voltage in the vicinity of the injection electrode, leading to a spray that rapidly broadens at a distance from its origin of the order of the stopping distance at which the droplets lose their initial momentum and the effect of their inertia becomes negligible. The axial component of the electric field first changes sign in this region, causing the fly back. The flow induced in the gas significantly changes this picture in the conditions of typical experiments. A gas plume is induced by the drag of the droplets whose entrainment makes the radius of the spray away from the injection electrode smaller than in a quiescent gas, and convects the droplets across the region of negative axial electric field that appears around the origin of the spray when the flux of droplets is increased. This suppresses fly back and allows much higher fluxes to be reached than are possible in a quiescent gas. The limit of large droplet-to-gas mass ratio is discussed. Migration of satellite droplets to the shroud of the spray is reproduced by the Eulerian model, but this process is also affected by the motion of the gas. The gas flow preferentially pushes satellite droplets from the shroud to the core of the spray when the effect of the inertia of the droplets becomes negligible, and thus opposes the well-established electrostatic/inertial mechanism of segregation and may end up concentrating satellite droplets in an intermediate radial region of the spray.

Floating Potential of an Electron Emitting Collector that Terminates a Bounded Plasma System

AbstractPotential formation in one‐dimensional bounded plasma system terminated by a floating, electron emitting collector is studied by a fully kinetic one‐dimensional model and particle‐in‐cell (PIC) computer simulation. As the electron emission from the collector is gradually increased, the floating potential of the collector and the electric field at the collector both increase quite strongly. When the critical emission is reached, the electric field becomes zero. If the emission is increased further, the electric field changes sign and becomes positive and a virtual cathode is formed in front of the collector. The floating potential of the collector also increases, but much more slowly, than below the critical emission level. If the ratio between the temperatures of the emitted and of the bulk electrons is high enough, the floating potential of the collector may even exceed the zero potential of the source, but in this case the simulation becomes unstable, when the positive ions start to flow back from the collector towards the source. Simulation results obtained below the critical emission level are in very good agreement with the model, provided that the particle densities obtained from the simulation are normalized correctly. In this case the potential and electric field profiles found from the PIC simulation match almost perfectly to the profiles obtained from the numerical solution of the Poisson equation (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Valley-kink in bilayer graphene atν=0: A charge density signature for quantum Hall ferromagnetism

We investigate interaction-induced valley domain walls in bilayer graphene in the $\ensuremath{\nu}=0$ quantum Hall state, subject to a perpendicular electric field that is antisymmetric across a line in the sample. Such a state can be realized in a double-gated suspended sample, where the electric field changes sign across a line in the middle. The noninteracting energy spectrum of the ground state is characterized by a sharp domain wall between two valley-polarized regions. Using the Hartree-Fock approximation, we find that the Coulomb interaction opens a gap between the two lowest-lying states near the Fermi level, yielding a smooth domain wall with a kink configuration in the valley index. Our results suggest the possibility to visualize the domain wall via measuring the charge density difference between the two graphene layers, which we find exhibits a characteristic pattern. The width of the kink and the resulting pattern can be tuned by the interplay between the magnetic field and the gate electric fields.

The Light Bulb, Cystoscopy, and Thomas Alva Edison

Thomas Alva Edison was an icon of American achievement who literally invented the 20th century. Although best known as the inventor of the electric light bulb, the phonograph, and motion pictures, he also left a lasting legacy via peripheral developmental applications, such as endoscopes. A review of published urologic writings about incandescent cystoscopes was cross-referenced to writings about or from Edison. Important events that allowed transference of technology from the Edison laboratory to clinical practice were emphasized. Edison was born in 1847 while Lincoln was serving in Congress; he died in 1931 when Hoover struggled with the Great Depression. Edison's life spanned the formative period of America that Henry Adams called the "coming of age." Edison received a Sprengel vacuum device in late 1879, and as usual, he was able to tweak the machine to better performance. For 5 days in October, 16 to 21, he improved the vacuum from 1/100,000 to 1/1,000,000 atm, and his first incandescent bulb burned softly. On December 21, 1879, he leaked the story to N.Y. Herald journalist Marshall Fox, and the world was notified of the light bulb. Special Christmas light visits started in Menlo Park just 4 days later. Edison patented the screw cap for easy changes, and the first bulbs sold for 40 cents (cost $1.40). 100,000 bulbs sold in 1882, 4 million by 1892, and 45 million in 1903. Immediately, competitors and specialty manufacturers entered the market. Dr. Henry Koch and Charles Preston in Rochester, N.Y., developed a smaller, low amperage bulb that could be fitted to medical devices. No discussion of electricity and modern applications would be complete without some discussion of Thomas Alva Edison and his sentinel contributions. The first church, post office, and ship were illuminated in 1892. The first hotel, theater, and electric sign were in 1893. The rapidity of dispersal and secondary applications of Edison's inventions is typified by the rise of cystoscopes. Nitze used a modified Edison bulb in his second and third generation scopes by 1887-1888 within 8 years of discovery.

Electric field-controlled sign of the capacitance in metal–carbon nitride–metal devices

Frequency and temperature dependent capacitance measurements were performed on metal–amorphous carbon nitride–metal sandwich structures. Negative capacitance effects occur under high electric field conditions for both polarities of the applied voltage. This low frequency behavior is shown to be incompatible with parasitic inductance effects. The dependence of negative apparent capacitance on frequency and temperature is discussed in the framework of field-assisted hopping transitions between localized states.

Magnetoelectric control of domain walls in a ferrite garnet film

A displacement of magnetic domain walls under the effect of an electric field is observed in epitaxial ferrite garnet films (on substrates with the (210) orientation). The displacement of the domain walls changes to the opposite when the electric field changes sign, and it is independent of the direction of magnetization in the domains. The mechanism proposed for explaining the observed phenomenon is based on the inhomogeneous magnetoelectric effect.

Intraoperative intraperitoneal (IP) chemotherapy with cisplatin and escalated dose of epinephrine in patient with recurrent peritoneal carcinomatosis of ovarian cancer: A phase I study

16019 Background: IP epinephrine (E) has been shown to enhance the accumulation and antitumor activity of IP cisplatin in rats with peritoneal carcinomatosis (Duvillard et al. Int J Cancer, 1999). E induces a vasoconstriction of peritoneal vascular bed which limits platin peritoneal leakage and enhances drug penetration into tumor nodules. Results of a phase I study with the association of IP E and IP cisplatin in patient with refractory peritoneal carcinomatosis has been reported (Molucon-Chabrot et al, Anticancer Drugs, 2006). We conducted a phase I study to evaluate intraoperative IP chemotherapy with the association of cisplatin and escalated dose of E. Methods: 18 patients (pts) with recurrent ovarian cancer were enrolled. The median age was 56 years old (range 42–66). After an optimal cytoreductive surgery, IP chemotherapy was performed during surgery by filling twice the peritoneal cavity with 3 liters of an isotonic saline pre heated at 37°C and 90 mg of cisplatin associated with increasing concentrations of E during 1 hour. Results: E was escalated according to the following dosage: 0, 1, 2, 3 mg/L (3 pts by step). No toxicity was observed during and after intraoperative IP chemotherapy in the first 10 patients. The 2nd patient included in the 3 mg/L level of E experienced a tachycardia ≥ 120/min, ventricular extrasystoles (VES) ≥ 2/min, increase of troponine plasmatic concentration without significant electric sign of cardiac ischemia. The 3rd patient at this level experienced a tachycardia ≥ 120/min with ventricular VES ≥ 2/min and no increase of troponine concentration or electric sign of cardiac ischemia. According to the protocol design, 6 additional patients were included in the lower dose of 2 mg/L of E and no toxicity occurred. One can consider that the recommended dose of E was established. Conclusion: The combination of IP E with IP cisplatin in intraoperative chemotherapy after optimal cytoreductive surgery is feasible. The limiting toxicity was the cardiovascular effect which occurred with 3 mg/L dose of E. A phase II-III study is planned to investigate if IP chemotherapy adds to a second look surgery for the initial treatment of stage III ovarian carcinoma. No significant financial relationships to disclose.

Hydrostatic Pressure Studies of GaN/AlGaN/GaN Heterostructure Devices with Varying AlGaN Thickness and Composition

AbstractGaN-based heterostructure devices are of interest for pressure and stress sensing applications due to their potential for use at high temperatures and in caustic environments. We have grown n-GaN/u-AlGaN/n-GaN heterostructure devices on sapphire substrates by organometallic vapor phase epitaxy (OMVPE) using the epitaxial layer overgrowth (ELO) method. The devices were fabricated with varying AlGaN layer thickness and composition. Current-voltage (I-V) characteristics were obtained to characterize the performance of these devices under hydrostatic pressures up to 500 MPa. For a fixed bias, the current was observed to decrease in magnitude with increasing hydrostatic pressure for all devices tested. The current modulation is attributed to piezoelectric effects. Specifically, the polarization charge densities at both GaN/AlGaN interfaces are sensitive to changes in the hydrostatic pressure, and these charges affect the shape of the potential barrier and the current. Changes in the AlGaN layer thickness and composition modify the interfacial polarization, with thicker AlGaN layers and higher Al content increasing the effect of pressure on the observed I-V characteristics. The decreases in current magnitude with increasing pressure are linear over the pressure range tested. In order to quantify the performance of these devices, we calculate a pressure gauge factor based on a normalized change in current divided by the change in pressure. Values obtained range from 0.1–1.0 GPa−1, consistent with our previously published results for a single device. In addition, the turn-on voltages under both forward and reverse bias conditions are observed to increase with increasing AlGaN layer thickness and composition, a result that agrees with our device model. These turn-on voltages are governed by different mechanisms in the forward and reverse bias directions. Under forward bias, the mechanism is a transition from a thermionic to a tunneling process. However, under reverse bias, the turn-on occurs when the total electric field changes sign in the AlGaN layer.

Gertrude Stein: The Language that Rises 1923-1934 (review)

Reviewed by: Gertrude Stein: The Language that Rises 1923–1934 John Whittier-Ferguson Gertrude Stein: The Language that Rises 1923–1934. Ulla Dydo . Evanston: Northwestern University Press, 2003. Pp. xvi + 686. $49.95 (cloth). Over the past couple of decades, the American academy has witnessed the steady and remarkable advance of Gertrude Stein into classrooms (both graduate and undergraduate), conferences, journals, and books. She has not yet recaptured the position of stardom that she achieved in the fall of 1934, when she returned to America for her lecture tour and famously saw, upon her arrival in New York City, "an electric sign moving around a building and it said Gertrude Stein has come" or, later in that same remarkable tour, when she and Alice Toklas were invited to the White House for a visit: "Mrs. Roosevelt was there and gave us tea."1 But she is now central to more and more discussions of modernism; her texts have found their way back into print—she commands symbolically resonant positions in volumes 99 and 100 of the Library of America; and even the notorious difficulty of her writing seems likely to diminish under the sustained scrutiny and exegeses of her critics. The Making of Americans or "Stanzas in Meditation" may never find themselves quite as fully glossed as the Wake or the Cantos, but teachers and students alike no longer treat her work as material only for insiders, or for jokes and baffled resignation. No one has done more to advance our understanding of Stein's most challenging texts than Ulla Dydo, a Professor Emerita at the City University of New York who knows better than anyone else alive Stein's published work and the extensive archive of Stein's papers housed at the Beinecke library at Yale. Her Stein Reader (1993), with its judicious selections and its enormously helpful notes for each piece, brought Stein into classrooms and made reading and teaching her work considerably less daunting than it had been before. Her essays on "Stanzas in Meditation" and Stein's compositional practices were among the first to use material in the Stein archive to help us read texts that were extraordinarily resistant to interpretation. Her edition, with Edward Burns and William Rice, of the correspondence between Stein and Thornton Wilder (1996)—characterized, like the Reader, by informative, [End Page 723] essential notes—gave us the chance to see a side of Stein (and a kind of writing) that we had never seen before. And now, with Dydo's ambitious new book on the most challenging period of Stein's writing, we have an important, extensive study that works year by year, manuscript by manuscript, through everything that Stein wrote in what is arguably the most productive and least studied period of her career. Only Dydo could have written this book; few, I believe, will find themselves equipped or even inclined to take its method as their own. "I read and commented chronologically on all her texts up to 1932," she tells us in her introduction, "preserving sequence and context unbroken" (4). Appended to The Language that Rises is a useful "chronological listing" of all of Stein's works from this span of fruitful years, arranged in order of composition. It is one of those documents in a scholarly book—like a great many of the extensive footnotes in this work—that take up comparatively little space between the covers but is manifestly the result of many years of immersion in the material. This is a book that will prove essential to anyone studying Stein, particularly to those reading not her "audience writing" like The Autobiography of Alice B. Toklas but her privately resonant, opaque work from this crucial and understandably less studied period preceding the publication of the Autobiography. Since it is organized chronologically, with Dydo working text by text, year by year from 1923 to 1934–35, readers will likely often use portions of this book selectively—as a reference, a starting point, a guide to the biographical and textual ingredients, the origins and echoes, the raw material of Stein's and Toklas's daily life that finds its way, transformed, refracted, cut and recombined, into pieces of...

Edge and scrape-off layer tokamak plasma turbulence simulation using two-field fluid model

A novel two-dimensional (2D) fluid model is proposed for investigating flux-driven plasma turbulence in the tokamak edge and scrape-off layer (SOL). Unlike most previous turbulence simulations of this region, the 2D model treats the two regions in a consolidated manner with a smooth transition region in between. The unified 2D model is simpler and less computer intensive than 3D models, but captures most features of the 3D edge and 2D SOL turbulence. It also illustrates the influence of tokamak edge turbulence on the SOL transport, something not captured by earlier 2D SOL simulations. Existence of an equilibrium radial electric field in the edge and SOL regions has been found. Two different plasma conductivity models have been used for the simulations. Turbulence in the edge is characterized by radially elongated streamers and zonal flows. The streamer structures occasionally break mainly in a region where the radial electric field changes sign. A phenomenological condition for the breaking has been obtained. Effective diffusion co-efficient and density front propagation speed from the simulation have been calculated. Statistical properties of the particle transport obtained from this simulation are compared with earlier flux-driven 2D SOL turbulence simulations and also with Aditya tokamak results.