scholarly journals A Visible and Near-IR Tunnel Photosensor with a Nanoscale Metal Emitter: The Effect of Matching of Hot Electrons Localization Zones and a Strong Electrostatic Field

2019 ◽  
Vol 9 (24) ◽  
pp. 5356
Author(s):  
Alexander Yakunin ◽  
Nikolay Aban’shin ◽  
Garif Akchurin ◽  
Yuri Avetisyan ◽  
Alexander Loginov ◽  
...  
Keyword(s):  
Electrostatic Field ◽  
Strong Field ◽  
Ballistic Transport ◽  
Light Response ◽  
Photoelectric Effect ◽  
Hot Electrons ◽  
Localization Zone ◽  
Wide Range ◽  
Blade Tip ◽  
Increased Strength

The results of the research and design of a novel vacuum photosensor with a planar molybdenum blade structure are presented. The advanced prototype implements the principle of an increasing penetrability of the Schottky barrier for the metal–vacuum interfaces under the action of an external strong electrostatic field. Theoretical and experimental substantiation of the photosensor performance in a wide range of wavelengths (from 430 to 680 nm and from 800 to 1064 nm) beyond the threshold of the classical photoelectric effect is given. The finite element method was applied to calculate distribution of the optical and electrostatic fields inside the photosensor structure. The sensor current-to-light response was studied using the periodic pulsed irradiation with the tunable wavelength. It was shown that the nanoscale localization zones of two types are formed near the surface of the blade tip: the zone of an increased concentration of hot electrons localized inside the molybdenum blade, and the zone with an increased strength of the external electrostatic field localized outside the blade. In general, the mutual positions of these zones may not coincide, whereas the position of the first-type localization zone significantly varies with the changes in the wavelength of the irradiating light. This causes features in the spectrum of the quantum yield of the photosensor such as expressed non-monotonic behavior and occurrence of sharp dips. The design of the photosensor that provides matching of the positions for both types of localization zones was proposed; the manufactured prototypes of the designed device were experimentally studied. In the designed photosensor, the ballistic transport of photoelectrons in the vacuum gap with a strong field provides a possibility for the creation of ultra-fast optoelectronic devices, such as modulators, detectors, and generators.

A Review: Natural Fiber as Reinforcement in Waste Paper Recycling and its Processing Methods

2013 ◽  
Vol 315 ◽  
pp. 443-447 ◽  
Author(s):  
S.K.A. Saferi ◽  
Y. Yusof
Keyword(s):  
Natural Fiber ◽  
Natural Fibers ◽  
Strength Properties ◽  
Hibiscus Cannabinus ◽  
Waste Paper ◽  
Kenaf Fiber ◽  
Healthy Environment ◽  
Wide Range ◽  
Increased Strength ◽  
The Right

As demand for clean and healthy environment, people make many alternate solutions to save the environment. To save trees and overcome landfill of waste material and waste disposal by burning activities issues (cause to losing energy and increase pollution), people nowadays take recycling as a recovery. Recycling waste paper into new product increased over the years. Shortage of wood supply required new sources of natural fiber for papermaking industry. Many researchers have studied new sources of natural fibers from non wood materials, such as oil palm residues, kenaf (Hibiscus Cannabinus), pineapple leaf, banana, and coconut fiber. Kenaf is choose as reinforcement agent for recycled waste paper to maximize the use of kenaf in industry application due its wide range of advantages where pineapple leaf are choose as reinforcement agent because abundantly of these material in Malaysia. Reinforcement of natural fiber into waste paper during recycling process expected to increased strength properties of final product. To understand the right and suitable processing method for kenaf fiber and pineapple leaf leaves previous work from other researchers are studied to investigate pulping procedure of natural fiber and its effect on mechanical strength.

scholarly journals Measurements of Strain on 310 mm Torque Converter Turbine Blades

2004 ◽  
Vol 10 (1) ◽  
pp. 55-63
Author(s):  
P. O. Sweger ◽  
C. L. Anderson ◽  
J. R. Blough
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Torque Converter ◽  
Operating Conditions ◽  
Surface Strain ◽  
Speed Ratio ◽  
Constant Input ◽  
Wide Range ◽  
Blade Tip ◽  
Input Torque

An automotive torque converter was tested in order to determine the effect of converter operating condition and turbine blade design on turbine blade strain in the region of the inlet core tab restraint. The converter was operated over a wide range of speed ratios (0 to 0.95) at constant input torque and a stall condition for two input torques. Foil-type strain gages in combination with wireless microwave telemetry were used to measure surface strain on the turbine blade. Strain measurements were made on two turbine blade designs.The steady component of strain over the range of speed ratios suggests the effect of both torque loading and centrifugal loading on the turbine blade tip. The unsteady strain was greatest at stall condition and diminished as speed ratio increased. Greater input torque at stall condition resulted in both greater steady strain and greater unsteady strain. The spectral distribution of strain over the range of tested speed ratios displayed an increase in low-frequency broadband fluctuations near stall condition. A blade-periodic event is observed which correlates to the pump-blade passing frequency relative to the turbine rotating frame. Reducing the blade-tip surface area and increasing the inlet-tab root radius reduced the range of steady strain and magnitude of unsteady strain imposed near the inlet core tab restraint over the range of operating conditions.

scholarly journals Fabrication of TiO2@Yeast-Carbon Hybrid Composites with the Raspberry-Like Structure and Their Synergistic Adsorption-Photocatalysis Performance

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Dang Yu ◽  
Bai Bo ◽  
He Yunhua
Keyword(s):  
Methylene Blue ◽  
Hybrid Composites ◽  
Light Response ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Wide Range ◽  
Excellent Photocatalytic Activity ◽  
Ft Ir ◽  
Enhanced Adsorption

In the present work, we report the preparation and photocatalytic properties of TiO2@yeast-carbon with raspberry-like structure using a pyrolysis method. The products are characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis (TGA-DTA), Fourier transformed infrared spectroscopy (FT-IR), and ultraviolet visible spectroscopy (UV-VIS), respectively. The results show that the hybrid TiO2@yeast-carbon microspheres have ordered elliptic shapes of uniform size (length = 3.5±0.3 μm; width = 2.5±0.5 μm). UV-VIS ascertains that the as-prepared microspheres possess an obvious light response in a wide range of 250–400 nm. In the decomposition of typical model pollutants including methylene blue and congo red, the hybrid composites exhibited excellent photocatalytic activity for the methylene blue due to the enhanced adsorption ability. Further investigation reveals that the combined effect of adsorption from the yeast-carbon core and photocatalytic degradation from the attached TiO2nanoparticles were responsible for the improvement of the photocatalytic activities. Hereby, the raspberry-like TiO2@yeast-carbon has promising applications in water purification.

scholarly journals Dielectrophoresis Response of Water-in-Oil-in-Water Double Emulsion Droplets with Singular or Dual Cores

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1121
Author(s):  
Tianyi Jiang ◽  
Yankai Jia ◽  
Haizhen Sun ◽  
Xiaokang Deng ◽  
Dewei Tang ◽  
...  
Keyword(s):  
Electric Fields ◽  
Strong Field ◽  
Microfluidic Channel ◽  
Double Emulsion ◽  
Multiple Emulsion ◽  
Field Frequency ◽  
Emulsion Droplets ◽  
Oil In Water ◽  
Wide Range ◽  
Double Emulsion Droplets

Microfluidic technologies have enabled generation of exquisite multiple emulsion droplets, which have been used in many fields, including single-cell assays, micro-sized chemical reactions, and material syntheses. Electrical controlling is an important technique for droplet manipulation in microfluidic systems, but the dielectrophoretic behaviors of multiple emulsion droplets in electrical fields are rarely studied. Here, we report on the dielectrophoresis response of double emulsion droplets in AC electric fields in microfluidic channel. A core-shell model is utilized for analyzing the polarization of droplet interfaces and the overall dielectrophoresis (DEP) force. The water-in-oil-in-water droplets, generated by glass capillary devices, experience negative DEP at low field frequency. At high frequency, however, the polarity of DEP is tunable by adjusting droplet shell thickness or core conductivity. Then, the behavior of droplets with two inner cores is investigated, where the droplets undergo rotation before being repelled or attracted by the strong field area. This work should benefit a wide range of applications that require manipulation of double emulsion droplets by electric fields.

scholarly journals LOFT: the Large Observatory For X-ray Timing

2012 ◽  
Vol 8 (S290) ◽  
pp. 163-170
Author(s):  
Tomaso M. Belloni ◽  
Enrico Bozzo ◽  
Keyword(s):  
General Relativity ◽  
Strong Field ◽  
Compact Objects ◽  
High Time Resolution ◽  
General Description ◽  
X Ray ◽  
Equation Of States ◽  
Wide Range ◽  
First Time ◽  
New Discovery

AbstractLOFT, the large observatory for X-ray timing, is a new mission concept competing with other four candidates for a launch opportunity in 2022-2024. LOFT will be performing high-time resolution X-ray observations of compact objects, combining for the first time an unprecedented large collecting area for X-ray photons and a spectral resolution approaching that of CCD-based X-ray instruments (down to 200 eV FWHM at 6 keV). The operating energy range is 2-80 keV. The main science goals of LOFT are the measurement of the neutron stars equation of states and the test of General Relativity in the strong field regime. The breakthrough capabilities of the instruments on-board LOFT will permit to open also new discovery windows for a wide range of Galactic and extragalactic X-ray sources.In this contribution, we provide a general description of the mission concept and summarize its main scientific capabilities.

New Approach to “High-Temperature” Quantum Switch and Quantum Field Effect Transistor

1998 ◽  
Vol 510 ◽  
Author(s):  
E.Z. Meilikhov ◽  
B.A. Aronzon ◽  
D.A. Bakaushiin ◽  
V.V. Ryl'kov ◽  
A.S. Vedeneev
Keyword(s):  
Ballistic Transport ◽  
Oxide Semiconductor ◽  
New Approach ◽  
Natural Properties ◽  
Small Quantum ◽  
Quantum Device ◽  
Wide Range ◽  
Bottle Neck ◽  
Effect Transistor ◽  
Nitride Oxide

AbstractWe report results of studying some natural properties of highly disordered mesoscopic systems which seem to be promising for elevating quantum device work temperatures up to 77-300 K. They are FET-type Si-MNOS (metal-nitride-oxide-semiconductor) structures with built-in charge concentrations being so high that the systems remain to be strongly disordered even at room temperature. Disorder of studied structures could be controlled by varying charged traps concentration at the SiO2-Si3N4 interface that induce strong potential fluctuations. Important feature of the structures is the possibility to vary the built-in charge over a wide range (up to 1013 CM−2) that results in varying the disorder range. The conductance of such a system is shown to be controlled by the single small quantum-sized region with a ballistic transport which is a saddle-point region of the fluctuation relief. Narrowness of that “bottle neck” (comparable with the electron wavelength) results in quantizing conductance of the structure, and if the disorder is high enough, the conductance for some gate voltages shows a real tendency to reach a plateau at the quantum value e2/h. What is important, that tendency occurs a∼t high temperatures (77-300 K).

FREQUENCY EFFECTS AND CLASSICAL PATHS IN STRONG-FIELD IONIZATION

1995 ◽  
Vol 04 (03) ◽  
pp. 687-700
Author(s):  
H. R. REISS
Keyword(s):  
High Frequency ◽  
Field Experiments ◽  
Strong Field ◽  
Polarized Light ◽  
High Energy ◽  
Frequency Theory ◽  
Photoelectron Spectra ◽  
Energy Conditions ◽  
Circularly Polarized Light ◽  
Wide Range

The ability of the SFA (strong-field approximation) to predict the ionization of atoms at all frequencies is explored at low frequency by comparison with experiment. Excellent agreement is found over a very wide range of high intensities. At high frequency, where no precision strong-field experiments are available, a comparison is made between predictions of the SFA and a high-frequency theory due to Gavrila. Agreement in transition rates is very good. The disagreement in the assignment of energy conditions at high frequencies is explained as a difference in interpretation brought about by the gauge transformation employed by Gavrila. An examination of semiclassical path behavior of a photoelectron after ionization gives insight on the lower limits of intensity for which the SFA is applicable, and makes transparent the meaning of a recently applied Coulomb correction to the SFA for circularly polarized light. A related examination for linearly polarized light gives an effective high energy limit for intense-field photoelectron spectra.

scholarly journals Photosynthetic Light Response of Six Clonal Selections of the Sweet Potato Cultivar `Beauregard'

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 605f-606
Author(s):  
Jeffrey T. Baker ◽  
Marvin L. Baker ◽  
D. Ron Earhart ◽  
Leonard M. Pike ◽  
Kil S. Yoo ◽  
...  
Keyword(s):  
Agricultural Research ◽  
Dark Respiration ◽  
Potato Cultivar ◽  
Light Response ◽  
Field Trials ◽  
Quality Characteristics ◽  
Parameter Estimates ◽  
Wide Range ◽  
Leaf Photosynthetic Rate ◽  
Extension Center

Eight individual potatoes, exhibiting a wide range of quality characteristics, were cloned at the Texas A&M Vegetable Improvement Center, College Station, Tex., in order to produce a large number of slips for field trials. Leaf photosynthetic light response for six of these clonal selections was determined during a greenhouse experiment conducted at the Texas A&M Univ. Agricultural Research and Extension Center at Overton, Tex. Photosynthesis data were fit to a rectangular hyperbola in order to estimate light saturated leaf photosynthetic rate (Amax), quantum efficiency (QE), and dark respiration rate (Rd). Significant differences (P ≥ 0.05) were detected in all three of these parameter estimates among the six clonal selections. Parameter estimates ranged from 23.4 to 28.8 μmol (CO2) m-2·s-1, 0.056 to 0.071 mol (CO2)/mol (photons), and –0.9 to –2.0 μmol (CO2) m-2·s-1 for Amax, QE, and Rd, respectively. However, these differences were not clearly related to quality characteristics determined for these clones in field trials.

scholarly journals Hydrogen-related challenges for the steelmaker: the search for proper testing

2017 ◽  
Vol 375 (2098) ◽  
pp. 20160408 ◽  
Author(s):  
R. G. Thiessen
Keyword(s):  
Standardized Test ◽  
High Strength Steels ◽  
High Strength ◽  
Advanced High Strength Steels ◽  
Passenger Safety ◽  
Transportation Sector ◽  
Wide Range ◽  
Increased Sensitivity ◽  
Stress States ◽  
Increased Strength

The modern steelmaker of advanced high-strength steels has always been challenged with the conflicting targets of increased strength while maintaining or improving ductility. These new steels help the transportation sector, including the automotive sector, to achieve the goals of increased passenger safety and reduced emissions. With increasing tensile strengths, certain steels exhibit an increased sensitivity towards hydrogen embrittlement (HE). The ability to characterize the material's sensitivity in an as-delivered condition has been developed and accepted (SEP1970), but the complexity of the stress states that can induce an embrittlement together with the wide range of applications for high-strength steels make the development of a standardized test for HE under in-service conditions extremely challenging. Some proposals for evaluating the material's sensitivity give an advantage to materials with a low starting ductility. Despite this, newly developed materials can have a higher original elongation with only a moderate reduction in elongation due to hydrogen. This work presents a characterization of new materials and their sensitivity towards HE. This article is part of the themed issue ‘The challenges of hydrogen and metals’.

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