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1
Yasnohorodskyi, M. A. "The use of various materials as a metal component in a metamaterial thermophotovoltaic emitter." Radiotekhnika, no. 210 (September 28, 2022): 160–66. http://dx.doi.org/10.30837/rt.2022.3.210.13.
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Thermophotovoltaics (TPV) is a process by which photons emitted by a heat emitter are converted into electrical energy by a photovoltaic cell. Selective heat emitters that can survive temperatures at or above 1000°C have the potential to significantly improve the energy conversion efficiency of a PV cell by limiting the emission of photons with energies below the band gap energy of a photovoltaic cell.
 Waste heat can be a valuable source of energy if we can find a way to harvest it efficiently. Deviations from ideal absorption and ideal blackbody behavior lead to light losses. For selective emitters, any light emitted at wavelengths outside the bandgap energy of the photovoltaic system may not be efficiently converted, reducing efficiency. In particular, it is difficult to avoid emission associated with phonon resonance for wavelengths in the deep infrared, which cannot be practically converted. An ideal emitter would not emit light at wavelengths other than the bandgap energy, and much TFP research is devoted to designing emitters that approximate better this narrow emission spectrum.
 TPV systems usually consist of a heat source, a radiator and a waste heat removal system. TFV cells are placed between the emitter, often a metal or similar block, and the cooling system, often a passive radiator.
 Efficiency, heat resistance and cost are the three main factors for choosing a TPF emitter. The efficiency is determined by the absorbed energy relative to the incoming radiation. High temperature operation is critical because efficiency increases with operating temperature. As the temperature of the emitter increases, the radiation of the black body shifts toward shorter waves, which allows for more efficient absorption by photocells. This paper demonstrates the feasibility of using materials such as platinum, gold, and nichrome as a metal component in a metamaterial emitter with respect to their absorption and thermal stability.
2
Anttu, Nicklas, Henrik Mäntynen, Anastasiia Sorokina, Pyry Kivisaari, Toufik Sadi, and Harri Lipsanen. "Geometry Tailoring of Emission from Semiconductor Nanowires and Nanocones." Photonics 7, no. 2 (2020): 23. http://dx.doi.org/10.3390/photonics7020023.
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Semiconductor nanowires are of interest as light emitters in applications such as light-emitting diodes and single-photon sources. Due to the three-dimensional geometry in combination with a size comparable to the wavelength of the emitted light, nanowires have shown strong scattering effects for the emitted light. Here, we demonstrate with electromagnetic modeling that the emission properties of nanowires/nanocones show a complicated dependence on the geometry of the nanowire/nanocone, the shape and position of the emitter region, and the polarization of the emitter. We show that with proper design, the extraction efficiency can close in on 80% for as-grown single nanowires/nanocones. Importantly, we demonstrate how the internal quantum efficiency of the emitter plays a large role in the design process. A considerably different geometry design approach should be undertaken at low and high internal quantum efficiency. Due to the complicated design optimization, we strongly recommend the use of electromagnetic modeling of the emission to give guidance for suitable designs before starting the fabrication and processing of nanowire/nanocone-based light emitters.
3
Liu, Bai, Fang, Ni, Lu, and Xu. "A Pragmatic Bilayer Selective Emitter for Efficient Radiative Cooling under Direct Sunlight." Materials 12, no. 8 (2019): 1208. http://dx.doi.org/10.3390/ma12081208.
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Radiative cooling can make the selective emitter cool below ambient temperature without any external energy. Recent advances in photonic crystal and metamaterial technology made a high-efficiency selective emitter achievable by precisely controlling the emitter’s Infrared emission spectrum. However, the high cost of the photonic crystals and meta-materials limit their application. Herein, an efficient bilayer selective emitter is prepared based on the molecular vibrations of functional nanoparticles. By optimizing the volume fraction of the functional nanoparticles, the bilayer selective emitter can theoretically cool 36.7 °C and 25.5 °C below the ambient temperature in the nighttime and daytime, respectively. Such an efficient cooling performance is comparable with the published photonic crystal and metamaterial selective emitters. The rooftop measurements show that the bilayer selective emitter is effective in the ambient air even under direct sunlight. The relatively low cost and excellent cooling performance enable the bilayer selective emitter to have great potential for a practical purpose.
4
Li, Zhangyan, Liming Yu, Na Li, Liuhong Chang, and Ningbo Cui. "Influence of Flushing Velocity and Flushing Frequency on the Service Life of Labyrinth-Channel Emitters." Water 10, no. 11 (2018): 1630. http://dx.doi.org/10.3390/w10111630.
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Dripline flushing is an effective way to relieve emitter clogging and extend the longevity of drip irrigation systems. This laboratory study was conducted at Kunming University of Science and Technology to evaluate the effect of three targeted flushing velocities (0.3, 0.6, and 0.9 m/s) and four flushing frequencies (no flushing, flushing daily, and flushing every three or five days) on the emitter’s service life and the particle size distribution of the sediment discharged from emitters and trapped in an emitter channel. The gradation of particle size was analyzed by a laser particle size analyzer. The experiment results suggested that flushing velocity and flushing frequency had a significant effect on the service life of emitters, and the emitter’s service life was extended by 30.40% on average under nine different flushing treatments. Flushing can effectively reduce the accumulation of sediments in the dripline and decrease the probability of coarse particles flowing into emitters and fine particles aggregating and cementing in the labyrinth channel, thus relieving the emitter clogging. Therefore, dripline flushing can effectively slow down clogging in muddy water drip irrigation system. The recommended flushing velocity should be set at 0.6 m/s, and the flushing intervals should be shortened.
5
NAWAZ, A., S. TAHIR, A. ALI, et al. "EFFECT OF PHOSPHOROUS/BORON DOPING PROFILE DIFFERENCES ON THE PERFORMANCE OF SILICON SOLAR CELLS." Journal of Ovonic Research 16, no. 1 (2020): 63–70. http://dx.doi.org/10.15251/jor.2020.161.63.
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This research work was done under title “Effect of phosphorous/boron doping profile differences on the performance of silicon solar cells”. Emitter diffusion either phosphorous or boron is quite challenging in photovoltaic industry. It directly affects the emitter saturation current density and the emitter quantum efficiency of silicon solar cells. Our main objective was to make the comparison of both phosphorous and boron diffused emitters for different peak dopant concentrations in silicon solar cells. It was done by using EDNA 2 simulations. We used different parameters in EDNA 2 and simulated the high efficiency solar cells with boron as back ground and phosphorous as emitter. Then we simulated the solar cells with phosphorous as back ground and boron as emitter. We varied the peak dopant concentration of phosphorous as well boron from 1.6E+17 to 3.9E+20. The best internal quantum efficiency of emitter for phosphorous diffused emitters was 95.1 %, obtained at 1.6E19 (cm-3 ) with an effective emitter depth of 0.675 (µm). However, the best internal quantum efficiency of emitter for boron diffused emitters was 80.6 %, obtained at 3.9E19 (cm-3 ). It has an effective emitter depth of 0.732 (µm) that is greater than obtained from phosphorous diffused emitters. We concluded that the phosphorous diffused emitters have much better performance than boron diffused emitter in silicon solar cells. They have better internal quantum efficiency of emitters at lower peak dopant concentration. They have lower emitter sheet resistance with lower effective emitter depth, as also required during silicon solar cell fabrication.
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KOH, W. S., and L. K. ANG. "SIMULATION OF HIGH CURRENT FIELD EMISSION FROM VERTICALLY WELL-ALIGNED METALLIC CARBON NANOTUBES." International Journal of Nanoscience 03, no. 04n05 (2004): 677–84. http://dx.doi.org/10.1142/s0219581x04002528.
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We have studied the intense electron beams emitted from multiple metallic, vertical and well-aligned Carbon Nanotube (CNT) field emitters. A two-dimensional (2D) particle-in-cell simulation code MAGIC2D is used to obtain the I–V characteristics near to the apex of the emitters' surface for a given applied electric field and field enhancement factor over a wide range of parameters. The effects of electron space charge and electric field shielding from neighboring emitters are compared in low current and high current regimes. It is found that the electron space charge is dominant in high current regime, where the Fowler–Nordheim (FN) law becomes the 2D Child–Langmuir (CL) law. The emitter spacing, number of emitters, and emitter's uniformity are also particularly studied, and they are more critical in low current regime. Smooth transition from the FN law to CL law is demonstrated.
7
Zhou, Hongxu, Yunkai Li, Youheng Fang, Yang Xiao, and Qiang Li. "Assessment of Flat Emitter Anti-Clogging Performance in Drip Irrigation Systems." Transactions of the ASABE 62, no. 3 (2019): 641–53. http://dx.doi.org/10.13031/trans.13151.
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Abstract. Selecting drip emitters with excellent anti-clogging performance (AP) is vital to ensure the safe operation of drip irrigation systems. However, previous researchers have not reached a consensus on emitter selection and evaluation standards based on emitter AP. In this study, eight types of flat emitters were selected as experimental objects, and high-sand surface water was used as the water source to test the AP of emitters with three experimental treatments. The emitter total coefficient of evaluation index (ETEI) was applied to analyze the relative differences in AP of the emitters, and then the mechanism leading to those differences was explored. The results indicated that there were significant variations in AP among different emitters, and four evaluation indices had good consistency in evaluating emitter AP. Small-discharge emitters showed good anti-clogging ability. Emitters with large cross-section average velocity (v), not just with high discharge (Q), should be identified as having excellent AP. The combination of emitter structural parameters, mainly width-depth ratio (W/D), relative radius (A1/2/L), and flow path length (L), made significant differences in the v of emitters under the same operating conditions. Higher v caused a significant linear decrease in key clogging components, solid particles (SD), CaCO3 and MgCO3 precipitates (C-MP), extracellular polymeric substances (EPS), and microbial activity (MA), of the clogging material inside the emitter. This study provides a reference for the selection and development of emitter products with high-efficiency AP. Keywords: Anti-clogging ability, Emitter discharge, Evaluation indices, Micro-irrigation, Uniformity.
8
Jonsson, Robert H., and Johannes Knörzer. "Chain-mapping methods for relativistic light-matter interactions." Quantum 8 (January 30, 2024): 1237. http://dx.doi.org/10.22331/q-2024-01-30-1237.
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The interaction between localized emitters and quantum fields, both in relativistic settings and in the case of ultra-strong couplings, requires non-perturbative methods beyond the rotating-wave approximation. In this work we employ chain-mapping methods to achieve a numerically exact treatment of the interaction between a localized emitter and a scalar quantum field. We extend the application range of these methods beyond emitter observables and apply them to study field observables. We first provide an overview of chain-mapping methods and their physical interpretation, and discuss the thermal double construction for systems coupled to thermal field states. Modelling the emitter as an Unruh-DeWitt particle detector, we then calculate the energy density emitted by a detector coupling strongly to the field. As a stimulating demonstration of the approach's potential, we calculate the radiation emitted from an accelerated detector in the Unruh effect, which is closely related to the thermal double construction as we discuss. We comment on prospects and challenges of the method.
9
Almario-Narváez, Johana, Javier Enrique Vélez-Sánchez, and María Jaqueline Molina-Ochoa. "Emitter clogging when using water from a tributary of the Bogotá River in Colombia." Agronomía Colombiana 34, no. 2 (2016): 260–66. http://dx.doi.org/10.15446/agron.colomb.v34n2.56890.
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An experiment was conducted to study the behavior of three types of emitters used in Colombia under real-work conditions using water from the Neusa River, a tributary of the Bogotá River. The emitters included: an in-line turbulent-flow emitter (E1), an integrated turbulent-flow emitter (E2), and an integrated self-regulated turbulent-flow emitter (E3). The operation and quality of the emitters were evaluated taking into account the flow decrease trend over time (RF), the flow reduction percentage of the emitters (qr), the coefficient of variation (Cv), the Christiansen uniformity coefficient (CU), and the emission uniformity (EU). The results indicated that the water quality in general affected the performance of the emitters over time, depending on the characteristics and properties of the emitters. The EU and CU decreased in the three emitter types as the experiment progressed and the Cv and qr increased. The E2 emitter showed a lower Cv and qr and a higher CU and EU than the E1 and E3 emitters.
10
Li, Xiao Quan. "The Fabrication Study of Branched Cathode Electrode for Field Emitter in a FED Panel." Advanced Materials Research 459 (January 2012): 652–55. http://dx.doi.org/10.4028/www.scientific.net/amr.459.652.
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Using carbon nanotubes as field emitters, the field emission display panel with branched cathode electrode was fabricated. For the cathode faceplate, the branched cathode electrode was composed of the emitter conducting layer and the emitter supporting layer. On the emitter supporting layer surface the carbon nanotubes field emitters were prepared, and the emitter conducting layer would be covered with the emitter insulation layer. The applied cathode potential would be conducted by the emitter conducting layer, which could decrease the additional voltage drop. The good field emission characteristic for the fabricated field emission display panel was confirmed.
11
POHER, Claude, and Danielle POHER. "Transient Luminous Events, into the Stratosphere and the Mesosphere, observed during violent thunderstorms lightning, are explained thanks to laboratory jets of photons in air, occuring during emission of Gravitational Quanta." Advances in Social Sciences Research Journal 8, no. 5 (2021): 261–81. http://dx.doi.org/10.14738/assrj.85.10216.
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 Abstract : A Gravitational field emitter, as we patented in 2006, is composed of an “active” material squeezed between two metallic electrodes. The active material is superconducting, with conductive or insulating grains added inside, to get local electric fields during brief electric discharges made into that emitter. Along such a discharge, the emitter propels itself, by anisotropic re-emission of interacting Gravitational Quanta. These emitted quanta accelerate distant matter particles placed along their trajectory. With early YBCO superconducting material emitters, cooled down by liquid nitrogen, we observed systematically a bright emission of light into the bath. This light emission is caused by nitrogen molecules’ ionization by gravitational quanta push. In 2012, the partial superconducting behavior of natural Graphite, at room temperature, was discovered, so we built new emitters from Graphite. These shown the same propelling effect as the early ones made of YBCO, with a lower performance. Here we record and discuss light emission in the form of jets of photons, in air, at room temperature, and pressure, during strong electric discharges into Graphite based emitters. These results enhance the confirmation of predictions from our theoretical Quantum model of Inertia and Gravitation. They explain also the enigmatic Transient Luminous Events observed in the atmosphere over thunderstorms clouds.
 
 
 
12
Mostafa, Harby, and Wael Sultan. "Hydraulic evaluation of locally modified emitter under laboratory conditions." Journal of Water Supply: Research and Technology-Aqua 67, no. 3 (2018): 291–96. http://dx.doi.org/10.2166/aqua.2018.123.
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Abstract Drip irrigation systems have become a major part of developing agriculture in Egypt and the aim of this research was to obtain the best performance from irrigation systems management using locally modified and original emitters. The experiments were carried out at the National Irrigation Laboratory of the Agricultural Engineering Research Institute. The emitters were tested and calibrated under different operating pressures (0.50, 0.75, 1 and 1.25 bar) to determine emitter flow rates and emitter emission uniformity (EU) and manufacturing variation coefficient (CV). The original emitter performance was determined using the relationship between emitter flow rate (2 lh−1) and operating pressure, with data indicating that the EU was 98.5%, at a CV of 2.3% and actual flow rate was 1.8 lh−1 for the original emitter. The EU was 93.8% with a CV of 5.2% and actual flow rate of 2.02 lh−1 for the modified emitter. For original emitter performance at 4 lh−1, data indicated that the EU was 96%, with a CV of 4.8% and actual flow rate of 3.78 lh−1. The EU for the modified emitter was 95% with a CV of 2.7% and actual flow rate of 4.5 lh−1. The emitter exponent values were 0.41 to 0.44 for modified and 0.37 to 0.38 for original emitters.
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Olesiński, Adam, and Zbigniew Piotrowski. "An Adaptive Energy Saving Algorithm for an RSSI-Based Localization System in Mobile Radio Sensors." Sensors 21, no. 12 (2021): 3987. http://dx.doi.org/10.3390/s21123987.
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In localization systems based on the emission of reference radio signals, an important issue related to the reliability of sensor operation is the problem of operating time and power of the emitted reference radio signal. There are many localization methods that have proven useful in practice and that use a reference radio signal for this purpose. In the issue of determining the location of radio emitters, various radio signal propagation models are used to determine the effective range and distance of the sensor-receiver from the radio emitter. This paper presents an adaptive power control algorithm for a transmitter, as a reference emitter, operating in power-saving mode. An important advantage of the presented solution is the adjustment of the localization system accuracy at the assumed level of energy radiated by radio emitters based on the RSSI signal received power estimation.
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Dobrzański, Maciej, and Robert Cichowicz. "Analysis of Ammonia Emissions from Thermal Sludge Treatment Plants." Rocznik Ochrona Środowiska 26 (December 13, 2024): 716–27. https://doi.org/10.54740/ros.2024.063.
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The article presents an analysis of the spatial dispersion of ammonia in the troposphere, emitted from the thermal treatment of sludge from the sewage treatment plant in Łódź. The study aimed to assess the impact of the emitter on the air quality in the nearby single-family housing estate. The results of field measurements of ammonia concentration were compared with computer simulations based on data measured at the emitter. Mobile measuring equipment mounted on a transport platform and an unmanned aerial vehicle was used to conduct field measurements, which were then subjected to analytical processing in ArcGis Pro software. Computer simulation of ammonia dispersion from two 25 m high chimneys was conducted in the OPA03 program. Both field measurements and simulation data showed a negligible impact of the emitter on the ammonia concentration in the air. This is primarily due to the low concentration of emitted ammonia at the chimney outlet and the emitter's location relative to the buildings, considering the dominant wind directions. Field studies have shown that the emission of ammonia in the analyzed area may be to a greater extent caused by the sewage collection station from sewage disposal vehicles and the composting plant, which are located close to the analyzed emitter and the residential area.
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Papadaki, Margarita-Georgia, Nikolaos Kyvelos, Emmanuel Paspalakis, and Vassilios Yannopapas. "Modification of the Emission Spectrum of a Quantum Emitter in the Vicinity of Bismuth Chalcogenide Microparticles." Photonics 10, no. 6 (2023): 658. http://dx.doi.org/10.3390/photonics10060658.
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We examine theoretically the effect of bismuth chalcogenide microparticles on the spontaneous emission of a double-V-type quantum emitter in free space. We have found, in particular, that the presence of a single microparticle causes a high degree of quantum interference in the way the quantum emitter releases energy in the process of spontaneous emission. This, in turn, leads to significant changes in the spectrum of the emitted energy. The quantum emitter’s initial state is crucial to how the energy is released in the presence of the microparticle. This observation has potential implications for quantum computing, particularly for reading the state of atomic qubits. When two microparticles are present, the effect is more pronounced, particularly when the quantum emitter is located in the gap between the particles.
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Al-Mefleh, Naji K., Samer Talozi, and Khaled Abu Naser. "Assessment of Treated Wastewater Reuse in Drip Irrigation under Different Pressure Conditions." Water 13, no. 8 (2021): 1033. http://dx.doi.org/10.3390/w13081033.
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This study aims to investigate the influence of treated wastewater (TWW) on the hydraulic performance of drip irrigation emitters. A field experiment was conducted in order to test two types of online emitters, a low pressure (LP) and a standard pressure (SP), at different working pressures (0.25 bar, 0.50 bar, and 1.00 bar) using TWW. The emitters were initially evaluated in the laboratory and the field for the discharge exponent (X), discharge coefficient (Kd), average emitter discharge (Qavg), coefficient of variation (CV), distribution uniformity (DU), the mean discharge ratio (Dra), and the main degree of clogging (DC). The main effect of the emitters on the hydraulic parameters of irrigation performance was not significant, while the operational pressure and operational time of irrigation had a significant effect. For the LP emitter, the average emitter discharge was 7.6, 7.7, and 7.8 Lh−1 at 0.25, 0.50, and 1.00 bar, respectively. For the SP emitter, the average emitter discharge was 7.6, 7.8, and 7.8 Lh−1 at 0.25, 0.50, and 1.00 bar, respectively. The EU values for the LP and SP emitters varied from low to moderate at 0.25 bar, as the EU values at 0.50 and 1.00 bar were considered high for both emitter types.
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Al-Mefleh, Naji K., Ibrahim Bashabsheh, Samer Talozi, and Taha A. Al-Issa. "Field evaluation of the performance of different irrigation emitter types using treated wastewater." Water Quality Research Journal 50, no. 3 (2015): 240–51. http://dx.doi.org/10.2166/wqrjc.2015.043.
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Experimental tests are carried out to evaluate the impact of treated wastewater (TWW) on the discharge of five different types of emitters which are commonly used. Two water qualities, fresh water (FW) and treated wastewater, and five types of emitters, GR, Nein (NE), Edin (ED), Corona (CO), and Rain Bird (RB) are tested. The values of chemical properties for FW show mostly low clogging potential on emitter performance. The clogging potential for TWW varied from low to medium. The exception was for pH where there was severe clogging potential for both water types. The performance of emitters was tested by measuring the emitter discharge and estimating the average emitter discharge (Qavg), coefficient of variation (CV), emission uniformity coefficient (EU), and Christiansen uniformity coefficient (CU). The average discharges for different types of emitters were analyzed and compared at P ≤ 0.05. The CO and RB emitter types did not show any signs of clogging whereas the GR, NE, and ED emitter types showed signs of clogging. The results of CV, EU, and CU values showed that the performances of emitter types GR, NE, ED were classified as low or moderate clogging potential. In contrast, the CO and RB emitters were classified as moderate or high clogging potential.
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Lemetayer, J., C. Marion, D. Fabre, and F. Plouraboué. "Multi-inception patterns of emitter array/collector systems in DC corona discharge." Journal of Physics D: Applied Physics 55, no. 18 (2022): 185203. http://dx.doi.org/10.1088/1361-6463/ac4e35.
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Abstract Multiple emitters systems have been previously used so as to increase charge density in the drift region, many times without producing sensible increment neither in total current nor ionic wind. This contribution focuses on analyzing the detailed physics behind this failure, that is named ‘multiple emitters un-scalability’. It is established that multiple emitters un-scalability is related to the inability of multiple corona discharge inceptions when increasing the emitter number and/or density. This confirms recent findings that corona discharge inception is shielded by electro-static interactions between emitters. This contribution demonstrates that this shielding can be balanced by emitter/collector electrostatic interactions depending on the considered configuration. For sufficiently close collector-emitter distances, ignition starts at the array center, whereas, on the contrary, when the collector is distant, the ignition not only starts at the array’s periphery but might also be limited there. It is also demonstrated that emitter/emitter electrostatic interactions can be balanced by emitter/collector ones, depending of their chosen configuration. This lead to a variety of multi-inception patterns, the condition of which are analyzed. Intermediate configurations for which the collector is neither sufficiently close nor distant from the emitter array center provide a variety of multi-inception patterns that are hereby analyzed. Combining finite element computations of multi-inception drift-diffusion modeling with experimental measurements, provides a coherent picture explaining why multiple emitters sources systems do not lead to full ignition, and also exhibit conditions for which it does, leading to multiple emitters scalable systems.
19
Oh, Minsu, Kevin Grossklaus, and Thomas E. Vandervelde. "Large-area 1D selective emitter for thermophotovoltaic applications in the mid-infrared." Journal of Vacuum Science & Technology B 41, no. 1 (2023): 012203. http://dx.doi.org/10.1116/6.0002198.
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Two- or three-dimensionally patterned subwavelength structures, also known as metamaterials, have the advantage of arbitrarily engineerable optical properties. In thermophotovoltaic (TPV) applications, metamaterials are commonly used to optimize the emitter’s radiation spectrum for various source temperatures. The output power of a TPV device is proportional to the photon flux, which is proportional to the emitter size. However, using 2D or 3D metamaterials imposes challenges to realizing large emitters since fabricating their subwavelength features typically involves complicated fabrication processes and is highly time-consuming. In this work, we demonstrate a large-area (78 cm2) thermal emitter. This emitter is simply fabricated with one-dimensional layers of silicon (Si) and chromium (Cr), and therefore, it can be easily scaled up to even larger sizes. The emissivity spectrum of the emitter is measured at 802 K, targeting an emission peak in the mid-infrared. The emissivity peak is ∼0.84 at the wavelength of 3.75 μm with a 1.2 μm bandwidth. Moreover, the emission spectrum of our emitter can be tailored for various source temperatures by changing the Si thickness. Therefore, the results of this work can lead to enabling TPV applications with higher output power and lower fabrication cost.
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Wierzbińska, Monika. "The Effect of Point Emitter Geometric Parameters on Dustfall." Chemistry-Didactics-Ecology-Metrology 21, no. 1-2 (2016): 83–95. http://dx.doi.org/10.1515/cdem-2016-0007.
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AbstractIn this paper, the modeling results are presented of point emitter geometric parameters determining the dispersion of dust pollution in the atmospheric air and finally also dustfall. The parameters include: the height and diameter of the emitter. Using the maps generated by “Ek100w” programme of Atmoterm company from Opole, Poland, an analysis of the PM10 dustfall value distribution on the analyzed area has been made. Fraction of dust - PM10 - was emitted from emitters of various working parameters. Three situations were analyzed: emission from a one-family (detached) building, from and industrial plant and from a power plant. Different heights and diameters for the above cases were analyzed. What results from the work, is that the mentioned parameters have a significant influence on the value of dustfall on the area surface at different distances from the emitter. With the increase of the height and diameter of the emitter, the values of dustfall decrease. The distance of the maximal values occurrence also increases. Results of similar analysis and available tools allow to design emission in practice, and thus allow a maximal limitation of ambient concentration of pollution and dustfall in areas especially exposed to industrial and superficial emission.
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A. N., Kunapara, Subbaiah R., and Patel G. R. "Approximation of the Pressure-discharge Curve in Inline Drip Irrigation System." Journal of Scientific Research and Reports 30, no. 8 (2024): 35–45. http://dx.doi.org/10.9734/jsrr/2024/v30i82222.
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The efficiency of drip irrigation systems depends directly on the uniformity of water discharge from emission devices. Ideally, all emitters should discharge equal amounts of water, but variations occur due to hydraulic and manufacturing factors. This study established the pressure-discharge relationship curve and determined emitter flow variation caused by the hydraulic and the manufacturer’s coefficients of variation for 2 and 4 lph inline emitters. The power exponent and constant of the pressure-discharge curve were determined by measuring the emitter flow rates at operating pressures ranging from 0.2 to 3.0 kg/cm². The emitter flow rates of 100 emitters were measured at an operating pressure of 1.0 kg/cm² to determine the manufacturing coefficient (Vm) and emitter flow variation (qvar(m)). The discharge exponent was found to be 0.46 for both emitter flow rates, with proportionality constants of 0.692 for 2 lph and 1.387 for 4 lph emitters respectively. The results showed a strong correlation between pressure and flow rate, with RMSE values of 0.51 and 0.34 lph, and coefficients of determination of 0.988 and 0.991 for 2 and 4 lph emitters, respectively. High manufacturing precision was indicated by low Vm values of 0.0491 for 2 lph and 0.055 for 4 lph emitters, while qvar(m) values were 0.261 for 2 lph and 0.283 for 4 lph emitters. Total coefficient of variation (Vq) values were 0.1 for 2 lph and 0.14 for 4 lph emitters, with total emitter flow variations (qvar) of 0.29 for 2 lph and 0.39 for 4 lph emitters. The study established the pressure-discharge curve for inline drip irrigation systems, emphasizing the critical relationship between pressure and flow rate. The derived chart from pressure discharge relationship is a valuable tool for estimating emitter flow variation due to hydraulic variation within the same subunit. Precise manufacturing and effective management of hydraulic variations are essential for ensuring uniform water distribution, optimizing drip irrigation systems, and ultimately enhancing crop yield and resource utilization.
22
AL-agele, Hadi A., Lloyd Nackley, and Chad Higgins. "Testing Novel New Drip Emitter with Variable Diameters for a Variable Rate Drip Irrigation." Agriculture 11, no. 2 (2021): 87. http://dx.doi.org/10.3390/agriculture11020087.
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This research presents a new variable rate drip irrigation (VRDI) emitter design that can monitor individual water drops. Conventional drip systems cannot monitor the individual water flow rate per emitter. Application uniformity for conventional drip emitters can be decreased by clogged emitters, irregular emitter orifices, and decreases in pressure. A VRDI emitter can overcome the irrigation challenges in the field by increasing water application uniformity for each plant and reducing water losses. Flow rate is affected by the diameter of the delivery pipe and the pressure of the irrigation delivery system. This study compares the volumetric water flow rate for conventional drip emitters and new VRDI emitters with variable diameters inner (1 mm, 1.2 mm, 1.4 mm, and 1.6 mm) and outside (3 mm, 3.5 mm, 4 mm, and 4.5 mm) with three pressures (34 kPa, 69 kPa, and 103 kPa). The tests revealed that the new VRDI emitter had flow rates that increased as the operating pressure increased similar to a conventional drip tube. The flow rate was slightly increased in the VRDI with pressure, but even this increase did not show large changes in the flow rate. The flow rate of the conventional drip tube was 88% larger than the VRDI emitter for all pressures (p < 0.05). However, operating pressure did not affect the drop sizes at the VRDI emitter, but the generalized linear mixed models (GLM) results show that volume per drop was impacted by the outside diameter of the VRDI outlet (p < 0.05). The interaction between the inner and outside diameter was also significant at p < 0.01, and the interaction between outside diameter and pressure was statistically significant at p < 0.01. The electronic components used to control our VRDI emitter are readily compatible with off-the-shelf data telemetry solutions; thus, each emitter could be controlled remotely and relay data to a centralized data repository or decision-maker, and a plurality of these emitters could be used to enable full-field scale VRDI.
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Sorokina, Anastasiia, Harri Lipsanen, and Nicklas Anttu. "Designing outcoupling of light from nanostructured emitter in stratified medium with parasitic absorption." Journal of Applied Physics 131, no. 22 (2022): 223104. http://dx.doi.org/10.1063/5.0088387.
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We demonstrate dipole-based modeling for designing nanostructured emitters in a stratified surrounding medium in the presence of parasitic absorption, while giving equivalent information about far-field emission as Lorentz reciprocity. We consider the challenging modeling case of a single nanowire with a parasitically absorbing planar top contact layer. The main advantage of our approach is the use of a near-field-to-far-field transformation (NFFT) adapted for stratified surrounding, which speeds up the simulations compared to approaches without such a NFFT. We show how the thickness of the contact layer, nanowire geometry, emitter position within the nanowire, refractive index of encapsulation layer, and orientation of the dipole moment of the emitter strongly affect the extraction of internally emitted photons.
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Santalices, David, Juan Meléndez, and Susana Briz. "Virtual Spectral Selectivity in a Modulated Thermal Infrared Emitter with Lock-In Detection." Sensors 22, no. 14 (2022): 5451. http://dx.doi.org/10.3390/s22145451.
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The need for affordable low-power devices has led MEMS-based thermal emitters to become an interesting option for optical gas sensors. Since these emitters have a low thermal mass, they can be easily modulated and combined with a lock-in amplifier for detection. In this paper, we show that the signal measured by a lock-in amplifier from a thermal emitter that varies its temperature periodically can have different spectral profiles, depending on the reference signal used. These virtual emitters appear because the Fourier series expansion of the emitted radiance, as a function of time, has different coefficients for each wavelength, and this spectral signature, which is different for each harmonic, can be retrieved using a reference signal that corresponds to its frequency. In this study, the effect is first proved theoretically and then is measured experimentally. For this purpose, we performed measurements with an IR camera provided with six different spectral filters of a modulated emitter, in combination with lock-in amplification via software. Finally, we show a potential application of this effect using multiple virtual emitters to gain spectral selectivity and distinguish between two gases, CO2 and CH4.
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Keyes, E. P., and N. G. Tarr. "Effect of annealing on polysilicon emitter transistors." Canadian Journal of Physics 67, no. 4 (1989): 179–83. http://dx.doi.org/10.1139/p89-031.
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The effect of 900 °C furnace annealing on transistors with in situ phosphorus-doped polysilicon emitters has been investigated. For devices with chemically grown interfacial oxides, annealing is essential to give acceptable emitter resistance and emitter Gummel numbers. For devices lacking an intentionally grown interfacial oxide, annealing is necessary to reduce the emitter resistance to a tolerable level, but it simultaneously lowers the emitter Gummel number.
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Ariandi, Lalu Muhammad, Guyup Mahardhian Dwi Putra, and Sirajuddin Haji Abdullah. "ANALISIS KOMPOSISI SERBUK GERGAJI TERHADAP KONDUKTIVITAS HIDROLIK PIPA MORTARI IRIGASI TETES BAWAH PERMUKAAN TANAH (Analysis of Sawdust Ratio on Hydraulic Conductivity in Subsurface Mortari Pipe of Drip Irrigation )." Jurnal Ilmiah Rekayasa Pertanian dan Biosistem 6, no. 1 (2018): 39–52. http://dx.doi.org/10.29303/jrpb.v6i1.70.
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Mortari emitter of sawdust (SG) can solve problem faced by farmers in dryland on irrigating their land. Aim of this research was to design an emitter by determining its mixture ratio and thickness. This research used experimental method by conducting experiment in laboratory. Observed parameters to determine water discharge were flow velocity, hydraulic conductivity value, coefficient of variation, and coefficient of uniformity. Ratio of cement, sand and sawdust to made sawdust (SG) mortari emitter were varied, i.e. P1 (1:2:2); P2 (2:1:3); P3 (2:4:4); P4 (2:2:2); and P5 (2:3:1). Result showed that the hydraulic conductivity could be classified as very low since K < 0.0036 cm/hour. The water discharge, flow velocity, and coefficient of uniformity were decreased in every reservoir elevation. Sawdust (SG) mortar emitter of P5 had the highest seeping ability and P3 had the lowest. The coefficient of uniformity (CU) value was 78,74%-80.64%. The use of Sawdust (SG) mortar emitter can be adjusted to the water discharge required by any plant type. The P3 emitter is suitable for plant which requires low water discharge and the P5 emitter is suitable for the high one. 
 Keywords: water discharge, SG mortar emitter, hydraulic conductivity
 
 ABSTRAK
 Emiter mortari serbuk gergaji (SG) dapat memecahkan masalah yang dihadapi para petani lahan kering dalam mengairi lahannya. Tujuan dilakukan penelitian ini adalah dapat merancang sebuah emiter dengan menentukan komposisi dan ketebalan emiter. Metode yang digunakan dalam penelitian ini adalah metode eksperimental dengan percobaan laboratorium. Parameter untuk menjawab tujuan penelitian adalah mencari nilai debit aliran yang dapat dihasilkan emiter mortari SG dengan menentukan kecepatan aliran, nilai konduktivitas hidrolik, koefisien variasi dan koefisien keseragaman. Emiter mortari SG dalam pengujian dilakukan dengan mencampurkan semen, pasir, dan serbuk gergaji masing-masing dengan 5 perbandingan, yaitu P1 (1:2:2); P2 (2:1:3); P3 (2:4:4); P4 (2:2:2); dan P5 (2:3:1). Nilai konduktivitas hidrolik didapatkan hasil pengkelasan dalam kategori sangat rendah karena memiliki nilai K<0,0036 cm/jam. Debit aliran, kecepatan aliran, dan koefisien keseragaman mengalami penurunan setiap ketinggian reservoir. Dimana emiter mortari SG dengan perlakuan P5 memiliki kemampuan merembeskan air dengan nilai tertinggi dan P3 pada emiter dengan kemampuan terendah. Nilai koefisien keseragaman pada emiter mortari SG terdapat keragaman dengan nilai CU sebesar 78,74%-80,64 %. Penggunaan emiter mortari SG dapat disesuaikan dengan jumlah kebutuhan debit air yang dibutuhkan oleh jenis tanaman. Emiter P3 baik digunakan pada tanaman dengan debit air rendah dan emiter P5 baik untuk tanaman dengan debit air tinggi.
 Kata kunci: debit aliran, emiter mortari SG, konduktivitas hidrolik
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Singh, Gaurav, Debabrata Biswas, and Raghwendra Kumar. "The transition from thermionic to space charge limited emission for needle-like surfaces—A particle-in-cell simulation study." Physics of Plasmas 29, no. 10 (2022): 103303. http://dx.doi.org/10.1063/5.0109510.
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We perform particle-in-cell simulations of thermionic emission from hemi-ellipsoidal shaped needle emitters. The Schottky corrected Richardson–Dushman equation is used to compute the emitted current from the curved emitter surface. It is shown that the transmitted thermionic current increases with cathode temperature before eventually settling to the enhanced space charge limited (SCL) current. It is further shown that the critical temperature at which transition to the saturation region occurs increases with the height of the emitter, leading to a softening in the transition. This may be attributed to the non-uniformity in the cathode work function as in planar diodes. The SCL current is found to increase linearly with the electrostatic apex field enhancement factor as predicted recently [Singh et al., Phys. Plasmas 27, 104501 (2020)].
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fraas, Lewis M., and Kuanrong Qiu. "Ceramic IR Emitter with Spectral Match to GaSb PV Cells for TPV." MRS Proceedings 1493 (2013): 11–22. http://dx.doi.org/10.1557/opl.2012.1706.
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ABSTRACTA high temperature ceramic selective emitter for thermophotovoltaic (TPV) electric generators is described with a spectral match to GaSb IR cells. While solar cells generate electricity quietly and are lightweight, traditional solar cells are used with sunlight and only generate electricity during the day. Workers at JX Crystals invented the GaSb IR cell as a booster cell to demonstrate a solar cell conversion efficiency of 35%. JX Crystals now makes these IR cells. In TPV, these cells can potentially be used with flame heated ceramic emitters to generate electricity quietly day and night. One of the most important requirements for TPV is a good spectral match between the ceramic IR emitted and the IR PV cells. The first problem is to find, demonstrate, and integrate a doped ceramic IR emitter with a spectral match to these GaSb cells. Recently, nickel oxide and cobalt oxide doped MgO-based ceramics have been shown experimentally and theoretically to have spectral selectivity but no attempts have been made to integrate these ceramic IR emitters into a fully operational TPV generator. Herein, we review the history of TPV and note that a key to future progress will be the integration of an appropriate ceramic emitter with cells and a burner to demonstrate an operational TPV generator. Integrating TPV into a residential boiler is discussed as a potential future large volume commercial market.
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Liu, Jiang, and John J. Hren. "SEM and Field Mmission study of silicon field emitter array." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (1992): 1140–41. http://dx.doi.org/10.1017/s042482010013033x.
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Arrays of nanometer-scale field emitters have recently become attractive candidates for device applications where high frequency and high current are desirable attributes. High emission current can be obtained from densely packed Spindt-type emitter arrays with very low extraction voltage. Concern with the optimum geometrical shape of each emitter and the fraction of active emitters, makes a combined study of field emission and scanning electron microscopy especially useful.Several geometrical structures, as well as several materials, have been used to fabricate the field emitter arrays. The present study concentrates on silicon-base emitters fabricated at the Microelectronics Center of North Carolina (MCNC). Each emitter has a pyramidal structure, fabricated by anisotropic chemical etching of highly doped (ND = 1017 cm−3) n-type silicon. Figure 1 shows a SEM micrograph of a typical Si field emitter with a radius of curvature less than 30 nm. The field required for electron emission, about 3 × 107 V/cm, is created by a relatively low voltage applied to the extraction gate, a metal film less than one micron distant and deposited over a dielectric layer of silicon oxide (Figures 2 and 3).
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Li, Xiao Quan. "A Fabrication of the High Emitter-Isolating-Layer for Printed Cold Cathode in Field Emission Display Panel." Advanced Materials Research 459 (January 2012): 567–70. http://dx.doi.org/10.4028/www.scientific.net/amr.459.567.
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Using black insulation slurry as manufacture material, the high emitter-isolating-layer was fabricated on the cathode plate. The high emitter-isolating-layer which possessed good insulation performance was composed of many parallel emitter-isolation-stripes, which the bottom cathode electrode would be exposed in the center of the emitter-isolation-stripe. The carbon nanotube paste was prepared onto the cathode plate to form the field emitters. And the field emission display panel with high emitter-isolating-layer was demonstrated, which the better field emission property including the large emission current and stable electron emission was confirmed.
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Vukic, Vladimir, and Predrag Osmokrovic. "Impact of forward emitter current gain and geometry of pnp power transistors on radiation tolerance of voltage regulators." Nuclear Technology and Radiation Protection 25, no. 3 (2010): 179–85. http://dx.doi.org/10.2298/ntrp1003179v.
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Low-dropout voltage regulators with various geometries and technological realisations of serial pnp power transistors were exposed to ionizing radiation. Although devices with vertical emitters were considered much less susceptible to the influence of radiation on forward emitter current gain than circuits with round emitters, the experiment showed a similar degradation of current gain in both cases. The main reason of high radiation susceptibility of the examined vertical serial pnp transistor is the implementation of an interdigitated emitter, with high perimeter-to-area ratio, causing the great increase of serial transistor?s base current, but a minor influence on the maximum output current. Transistors with round emitters with small perimeter-to-area ratio expressed a moderate current gain degradation, but a rapid fall of the emitter injection efficiency, causing a significant decrease of the maximum output current. Regardless of the similar forward emitter current gain degradation, reliability and operational characteristics of two types of low-dropout voltage regulators were completely different.
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Vladimir, Dj. Vukić, and V. Osmokrović Predrag. "Impact of forward emitter current gain and geometry of PNP power transistors on radiation tolerance of voltage regulators." Nuclear Technology & Radiation Protection 25, no. 3 (2010): 179–85. https://doi.org/10.2298/NTRP1003179V.
Full textAbstract:
Low-dropout voltage regulators with various geometries and technological realisations of serial pnp power transistors were exposed to ionizing radiation. Although devices with vertical emitters were considered much less susceptible to the influence of radiation on forward emitter current gain than circuits with round emitters, the experiment showed a similar degradation of current gain in both cases. The main reason of high radiation susceptibility of the examined vertical serial pnp transistor is the implementation of an interdigitated emitter, with high perimeter-to-area ratio, causing the great increase of serial transistor’s base current, but a minor influence on the maximum output current. Transistors with round emitters with small perimeter-to-area ratio expressed a moderate current gain degradation, but a rapid fall of the emitter injection efficiency, causing a significant decrease of the maximum output current. Regardless of the similar forward emitter current gain degradation, reliability and operational characteristics of two types of low-dropout voltage regulators were completely different.
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Lezier, G., P. Koleják, J. F. Lampin, K. Postava, M. Vanwolleghem, and N. Tiercelin. "Fully reversible magnetoelectric voltage controlled THz polarization rotation in magnetostrictive spintronic emitters on PMN-PT." Applied Physics Letters 120, no. 15 (2022): 152404. http://dx.doi.org/10.1063/5.0080372.
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THz polarization control upon generation is a crucially missing functionality. THz spintronic emitters based on the inverse spin Hall effect (ISHE) allow for this by the strict implicit orthogonality between their magnetization state and the emitted polarization. This control was until now only demonstrated using cumbersome external magnetic field biasing to impose a polarization direction. We present here an efficient voltage control of the polarization state of terahertz spintronic emitters. Using a ferromagnetic spin pumping multilayer exhibiting simultaneously strong uniaxial magnetic anisotropy and magnetostriction in a crossed configuration, an emitter is achieved where, in principle, the stable magnetization direction can be fully and reversibly controlled over a 90° angle span only by an electric voltage. To achieve this, an engineered rare-earth based ferromagnetic multilayer is deposited on a piezoelectric [Formula: see text] (PMN-PT) substrate. We demonstrate experimentally a reversible 70° THz polarization rotation by sweeping the substrate voltage over 400 V. This demonstration allows for a fully THz polarization controlled ISHE spintronic terahertz emitter not needing any control of the magnetic bias.
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Arai, Fumihito, Pou Liu, Lixin Dong, and Toshio Fukuda. "Field Emission Properties of Individual Carbon Nanotubes in Nanorobotic Manipulation and Electron-Beam-Induced Deposition." Journal of Robotics and Mechatronics 16, no. 6 (2004): 597–603. http://dx.doi.org/10.20965/jrm.2004.p0597.
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Field emission properties of individual multi-walled carbon nanotubes (MWNTs) were studied in nanorobotic manipulation and electron-beam-induced deposition (EBID). Nanotube emitters are constructed by picking up and assembling individual nanotubes on a commercially available atomic force microscope (AFM) cantilever or a tungsten probe. The relationship between field emission current and interelectrode distance was obtained by changing the distance between the tip of the nanotube emitter and the counterpart anode, which can be potentially applied as the principle for an approaching sensor to detect nanometer scale distance by observing field emission current in real time. Field emission current on a microampere scale from a CNT emitter was shown to be strong enough for EBID without obviously degrading emitters. Deposit topology was related to current density or the emitter shape, suggesting that information on emitter geometry could be obtained from EBID deposits. Energy dispersive X-ray spectrometry (EDS) analysis of deposits from W(CO)6showed that the tungsten mass exceeds 80% on the average among compositions. Much higher voltage may degrade the emitter, and saturated current may be used to adjust the emitter length in a controlled way.
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Imastira, Suhardi, A. Munir, A. Azis, and H. Mubarak. "Identification of the potential use of sago midrib (Metroxylon sp.) as drip irrigation emitters for chili plants." IOP Conference Series: Earth and Environmental Science 1230, no. 1 (2023): 012151. http://dx.doi.org/10.1088/1755-1315/1230/1/012151.
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Abstract Drip irrigation is an irrigation system that can save water by releasing a regulated amount of water and nutrients to the roots of plants using emitters. The use of emitters is one of the additional costs in the use of drip irrigation systems. Estimating the potential of fronds as emitters are done by measuring saturated hydraulic conductivity. The method used is falling head to determine the ability of emitter material made from sago fronds to pass water that can be used to meet the water needs of chili plants. The results showed that the average hydraulic conductivity value at the end sample was higher than the middle and base samples. The hydraulic conductivity values of the tip, middle and base are 0.0077 (m/s), 0.0022 (m/s), and 0.0020 (m/s), respectively. So that the tip-sample can be used as a drip irrigation emitter. The discharge produced by the emitters of tip samples 1 and 2 amounted to 1.252 and 1.424 l/day. Based on this discharge, the number of droppers for each phase of chili plant growth using sago frond emitters, namely at the base and center, requires two emitters in months 3 and 4. Meanwhile, the end frond emitter only requires two emitters in month three, and in other growth phases only requires one emitter.
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Zhang, Yijie, Tianshun Zhang, Yang Yu, Pan Guo, Lingqiong Kong, and Qingsong Duan. "Factors Influencing Emitter Clogging Caused by Negative Pressure in Potted Yunnan Laterite with Root-Zone Infiltration Irrigation." Transactions of the ASABE 62, no. 4 (2019): 887–98. http://dx.doi.org/10.13031/trans.13211.
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Abstract. In this study, an equivalent mechanical model was established for the clogging induced by soil suction under negative pressure during root-zone infiltration irrigation in a crop-free pot, and a state diagram was plotted for the clogging process induced by a single soil suction factor under negative pressure. Three groups of impact factor experiments were conducted using three different emitters: a flow-adjustable emitter with eight horizontal outlets (emitter L), a flow-adjustable emitter with two vertical outlets (emitter Q), and an anti-clogging material wrapped around the outer surface of emitter L (emitter K). The first group of experiments investigated the influence of irrigation pressure, the variation of irrigation pressure (range of 0.02 to 0.12 MPa), and the amount of sediment inside emitter L in Yunnan laterite. For the second group of experiments, two soil types (Yunnan laterite and yellow sand), two single-event irrigation volumes (170 and 250 mL), and two numbers of irrigation events (8 and 16) were used to quantitatively analyze the sediment content in emitter L. The third group of experiments used emitters L, Q, and K and involved quantitative analysis of the clogging differences in the different emitter types with two soil types (Yunnan laterite and yellow sand) and two numbers of irrigation events (24 and 64). Statistical analysis showed that irrigation pressure, soil type, irrigation pattern, and emitter type were significant (p &lt; 0.05) for the amount of sediment due to negative suction inside the emitter. The results demonstrate that emitter clogging induced by negative pressure tends to first decrease and then increase with increasing irrigation pressure. The amount of sediment that accumulates within an emitter is influenced by both the soil suction effect under negative pressure as well as soil flushing under positive pressure. Within emitter L, clogging induced by soil suction under negative pressure was more likely to occur when using Yunnan laterite rather than yellow sand soil. When both soil types were used in the test, emitter L was observed to be more prone to clogging induced by negative pressure compared to emitter Q, whereas emitter K exhibited the best anti-clogging performance. This study provides a quantitative account of the factors associated with clogging induced by negative pressure, and it provides a theoretical and experimental basis for gaining an in-depth understanding of emitter clogging during root-zone infiltration irrigation in Yunnan laterite. Keywords: Emitter, Negative-pressure clogging, Pot environment, Root-zone infiltration irrigation, Yunnan laterite.
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Nakano, Takeo, Hyuga Taniguchi, Nanako Dei, et al. "Structure optimization of Spindt-type emitter fabricated by triode high power pulsed magnetron sputtering." Journal of Vacuum Science & Technology B 40, no. 6 (2022): 063201. http://dx.doi.org/10.1116/6.0002201.
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Spindt-type emitters were fabricated with cavities made of Al/Mo/SiO2 using the triode high power pulsed magnetron sputtering method. We explored the process parameters (gas pressure and voltage of the additional cap electrode) to optimize the sharpness of the emitter shape. We found that the intermediate pressure and voltage were suited to obtain sharp emitters. Further, we elucidated the crucial effect of the cavity dimensions, such as the cavity depth and hole diameter in the cavity ceiling, on the emitter shape. At a cavity depth of 480 nm, the aspect ratio (AR) of the emitter increased monotonously with an increase in the hole diameter. With a large hole diameter (900 nm) and even shallower cavity (380 nm depth), we attempted to reoptimize the process parameters. Consequently, a very sharp emitter cone structure with an AR exceeding 1.3 was obtained. The cap voltage that produced the optimum AR was found to decrease for the larger-hole and shallower-depth cavities. Finally, the applicability of the process for preparing a working emitter is discussed.
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Zhu, Tianfei, Jia Zeng, Feng Wen, and Hongxing Wang. "Determining the Dependence of Single Nitrogen−Vacancy Center Light Extraction in Diamond Nanostructures on Emitter Positions with Finite−Difference Time−Domain Simulations." Nanomaterials 14, no. 1 (2023): 99. http://dx.doi.org/10.3390/nano14010099.
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In this study, we obtained a diamond nanocone structure using the thermal annealing method, which was proposed in our previous work. Using finite–difference time–domain (FDTD) simulations, we demonstrate that the extraction efficiencies of nitrogen–vacancy (NV) center emitters in nanostructures are dependent on the geometries of the nanocone/nanopillar, emitter polarizations and axis depths. Our results show that nanocones and nanopillars have advantages in extraction from emitter dipoles with s− and p−polarizations, respectively. In our simulations, the best results of collection efficiency were achieved from the emitter in a nanocone with s−polarization (57.96%) and the emitter in a nanopillar with p−polarization (38.40%). Compared with the nanopillar, the photon extraction efficiency of the emitters in the nanocone is more sensitive to the depth and polarization angle. The coupling differences between emitters and the nanocone/nanopillar are explained by the evolution of photon propagation modes and the internal reflection effects in diamond nanostructures. Our results could have positive impacts on the design and fabrication of NV center−based micro− and nano−optics in the future.
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Li, Peng, Hao Li, Jinshan Li, Xiuqiao Huang, Yang Liu, and Yue Jiang. "Effect of Aeration on Blockage Regularity and Microbial Diversity of Blockage Substance in Drip Irrigation Emitter." Agriculture 12, no. 11 (2022): 1941. http://dx.doi.org/10.3390/agriculture12111941.
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Aerated drip irrigation is rendered as a new water-saving irrigation method based on drip irrigation technology, which is endowed with the function of effectively alleviating the problem of rhizosphere hypoxia in crop soil, enhancing the utilization rate of water and fertilizer; as a result, it improves the harvest and quality of crops. However, clogged emitters are important indexes, among others, that pose an influence to the service effect and life duration of drip irrigation systems. At present, the working principle and mechanism of the influence of air feeding on the blockage of drip irrigation emitters remain unclear. Therefore, based on the two gas filling methods of the micro/nano bubble generator and Venturi injector, the dynamic change process for the average flow ratio of an air-filled drip irrigation emitter was studied by the method of emitter plugging test. 16S rRNA sequencing was used to analyze the microbial diversity of the emitter plugs. The results show that the air injection can pose influence on the clogging procedure of drip irrigation emitters, and more importantly, it makes the distribution of blocked emitters more uniform, thus improving the uniformity of the system. Different filling methods have different effects on the blockage of the emitter. Among them, the blockage time of drip irrigation system under the micro/nano aerated drip irrigation (MAI) mode is 5.73 times longer than that under unaerated drip irrigation (UVI), and similarly, Venturi gas drip irrigation (VAI) is close to that under UVI. The filling method changed the microbial diversity of the blockage in the emitter. Among them, the number of operational taxonomic unit (OTU) unique to MAI was 2.1 times that of UVI, and the number of OTU unique to VAI was 1.3 times that of UVI. Meanwhile, gas addition will inhibit the growth of Nitrospirae and Proteobacteria microbial communities and promote the growth of Firmicutes and Actinobacteria microbial communities. Furthermore, the increase in microbial extracellular polymer in the plugging material of the emitter was inhibited and the plugging process of the emitter was slowed down. The research results are of great significance in the disclosure of the clogging mechanism of drip irrigation emitter and constructing the green, anti-blockage technology of aerated drip irrigation.
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Zhang, Peng, Jeongho Park, Steven Fairchild, et al. "Temperature Comparison of Looped and Vertical Carbon Nanotube Fibers during Field Emission." Applied Sciences 8, no. 7 (2018): 1175. http://dx.doi.org/10.3390/app8071175.
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Carbon nanotube (CNT) fiber-based emitters have shown great potential to deliver stable, high current beams for various potential applications. Because of joule heating, CNT field emitters are heated to high temperatures during field emission. It is important to improve the thermal management of emitters to increase their reliability and prevent premature failure. This paper compares the field emission characteristics and the temperature distribution of a new configuration of a looped CNT fiber emitter with a traditional single vertical CNT fiber emitter. It is found that the maximum temperature of the looped fiber emitter (~300 °C) is significantly reduced compared to that of the vertical fiber (~600 °C) at the same emission current of 3 mA. The experimentally measured temperature distribution is compared with a recent theory on joule heating of a one-dimensional conductor. This study provides new insights into the design of high performance field emitters.
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Gil, M., L. Rodríguez-Sinobas, R. Sánchez, and L. Juana. "Evolution of the spherical cavity radius generated around a subsurface drip emitter." Biogeosciences Discussions 7, no. 2 (2010): 1935–58. http://dx.doi.org/10.5194/bgd-7-1935-2010.
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Abstract. The emitter discharge in subsurface drip irrigation can be affected by soil properties. A positive pressure develops at the emitter outlet where a spherical cavity is assumed to form. In steady-state conditions, the pressure in the soil relates to soil hydraulic properties, the emitter discharge, and the cavity radius. This pressure in the soil is very sensitive to the cavity radius. In this paper, the development of the cavity around the emitter outlet was measured for various emitter discharges in laboratory tests carried out in containers with uniform loamy soils. A trend between soil pressure and emitter discharge was established that illustrates the performance of buried emitters in the field. Its application to the prediction of water distribution in subsurface drip irrigation units and its effect on the estimation of irrigation performance is also shown.
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Gil, M., L. Rodríguez-Sinobas, R. Sánchez, and L. Juana. "Evolution of the spherical cavity radius generated around a subsurface drip emitter." Biogeosciences 7, no. 6 (2010): 1983–89. http://dx.doi.org/10.5194/bg-7-1983-2010.
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Abstract. The emitter discharge in subsurface drip irrigation can be affected by soil properties. A positive pressure develops at the emitter outlet where a spherical cavity is assumed to form. In steady-state conditions, the pressure in the soil relates to soil hydraulic properties, the emitter discharge, and the cavity radius. This pressure in the soil is very sensitive to the cavity radius. In this paper, the development of the cavity around the emitter outlet was measured for various emitter discharges in laboratory tests carried out in containers with uniform loamy soils. A trend between soil pressure and emitter discharge was established that illustrates the performance of buried emitters in the field. Its application to the prediction of water distribution in subsurface drip irrigation units and its effect on the estimation of irrigation performance are also shown.
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Radi, Haider Mohsen, and Ali Hamdhi Dheyab. "Improving the Regularity of water Distribution of the Double-pipe Irrigation system and its impact on soil and Plant properties." Kufa Journal for Agricultural Sciences 17, no. 1 (2025): 107–22. https://doi.org/10.36077/kjas/2025/v17i1.12271.
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A field experiment was conducted for the autumn agricultural season 2022 at the Agricultural Research Station - University of Basra - Karma Ali site Located between -30 500 latitude and -47 740, to study the effect of the experiment factors, which are the distance factor between the emitter holder with distances of 0-15-30 centimeters using double pipes, and the distance factor between the emitters by three coefficients 20-25-30 centimeters, between the emitters and the emitter discharge factor with two coefficients of 5-8 liters per hour-1. In the values of moisture content and electrical conductivity, The experiment treatments are distributed into three replicates by using a factorial experiment conducted in a randomized complete block design (RCBD). showed that the use of double pipes at a distance of 15 cm between the pipes recorded the highest moisture content, followed by the zero distance between the pipes. While the highest moisture content was recorded at a distance of 20 cm between the emitters when using a discharge of 8 liters per hour-1. As for the electrical conductivity, the coefficient of distance showed 15 centimeters between the emitter holder, followed by the zero distance coefficient between the emitter holder with less electrical conductivity, and increases with increasing distance from the center of the marz. While the lowest electrical conductivity was recorded at the distance of 20 between the emitters and increased with the distance between the emitters. As for the discharge, the discharge has achieved 8 liters hour-1 less electrical conductivity, with the highest moisture content and the lowest electrical conductivity recorded at the treatment 15-20-8 for the distance between the emitter holder and the distance between the emitters and discharge, respectively.
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Cai, Yaohui, Xiao Zhao, Pute Wu, Lin Zhang, Delan Zhu, and Junying Chen. "Effect of Soil Texture on Water Movement of Porous Ceramic Emitters: A Simulation Study." Water 11, no. 1 (2018): 22. http://dx.doi.org/10.3390/w11010022.
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Choosing reasonable design parameters for ceramic emitters used in subsurface irrigation is important for reducing the deep percolation of water and improving the water use efficiency. Laboratory experiments and numerical simulations with the HYDRUS-2D software were carried out to analyze the effect of soil texture on the infiltration characteristics of porous ceramic emitters used for subsurface irrigation. HYDRUS-2D predictions of emitter discharge in soil and wetting front are in agreement with experimental results, and the HYDRUS-2D model can be used to accurately simulate soil water movement during subsurface irrigation with ceramic emitters in different soil textures. Results show that soil texture has a significant effect on emitter discharge, soil matrix potential around the emitter, and wetting front. For 12 different soil textures, the aspect ratio of the wetting front is basically between 0.84–1.49. In sandy soil, the wetting front mainly appears as an ellipse; but in the clay, the wetting front is closer to a circle. As irrigation time increases, emitter discharge gradually decreases to a stable value; however, emitter discharge in different texture soils is quite different. In order to improve the crop water use efficiency in sandy soil, soil water retention can be improved by adding a clay interlayer or adding water retention agent, reducing the risk of deep percolation and improving the water use efficiency.
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Germershausen, Sven, Lars Bartholomäus, Ulf Seidel, et al. "Investigation of Emitter Homogeneity on Laser Doped Emitters." Energy Procedia 8 (2011): 232–37. http://dx.doi.org/10.1016/j.egypro.2011.06.129.
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NISHINO, HITOSHI, SHINYA YOSHIDA, AKIRA KOJIMA, et al. "Fabrication of Pierce‐Type Nanocrystalline Si Electron‐Emitter Array for Massively Parallel Electron Beam Lithography." Electronics and Communications in Japan 99, no. 5 (2016): 11–19. http://dx.doi.org/10.1002/ecj.11804.
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SUMMARYThis paper reports on the development of a fundamental process for a Pierce‐type nanocrystalline Si (nc‐Si) electron emitter array for massively parallel electron beam (EB) lithography based on active‐matrix operation using a large‐scale integrated circuit (LSI). The emitter array consists of 100 × 100 hemispherical emitters formed by isotropic wet etching of Si. EB resist patterning was demonstrated by 1:1 projection exposure using a discrete emitter array at CMOS‐compatible operating voltages. Isolation trenches filled with benzocyclobutene (BCB) were fabricated in the Si substrate for independent control of each emitter using the LSI. The integration process of the emitter array with LSI and an extraction electrode plate was also developed based on Au‐In and polymer bonding technologies.
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Boo, Hyunpil, Jong-Han Lee, Min Gu Kang, et al. "Effect of High-Temperature Annealing on Ion-Implanted Silicon Solar Cells." International Journal of Photoenergy 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/921908.
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P-type and n-type wafers were implanted with phosphorus and boron, respectively, for emitter formation and were annealed subsequently at 950∼1050∘Cfor 30∼90 min for activation. Boron emitters were activated at1000∘Cor higher, while phosphorus emitters were activated at950∘C. QSSPC measurements show that the impliedVocof boron emitters increases about 15 mV and theJ01decreases by deep junction annealing even after the activation due to the reduced recombination in the emitter. However, for phosphorus emitters the impliedVocdecreases from 622 mV to 560 mV and theJ01increases with deep junction annealing. This is due to the abrupt decrease in the bulk lifetime of the p-type wafer itself from 178 μs to 14 μs. PC1D simulation based on these results shows that, for p-type implanted solar cells, increasing the annealing temperature and time abruptly decreases the efficiency (Δηabs=−1.3%), while, for n-type implanted solar cells, deep junction annealing increases the efficiency andVoc, especially (Δηabs=+0.4%) for backside emitter solar cells.
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S Rana, SC Nayak, AP Sahu, and SD Sharma. "Earthen Emitters - A New Concept for Micro-irrigation." Journal of Agricultural Engineering (India) 38, no. 4 (2001): 10–16. http://dx.doi.org/10.52151/jae2001384.0982.
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Experiments on hydraulics of four types of on-line earthen emitters of 10 cm length and 2 cm outside diameter, prepared by using sand, local clay and saw dust in different proportions; were conducted. The discharges of different types of earthen emitters placed above the soil surface i.e. in open air and of those placed in the soil and top flushed with the soil surface were determined under different heads. The wetting front advance at 30 min intervals for all types of earthen emitters were prepared. At the end of 150 min of each emitter testing, wetted soil samples were collected for moisture status determination. The results indicated that the emitter discharges increased with the increase of head and decrease of clay content in the emitter. The maximum horizontal diameter and the total depth of wetting front advance increased with the increase of elapsed time, head and decrease of clay content in the emitter. The peripheral moisture content was found to be more than the wilting point of the soil, thus, providing a suitable moisture regime to the root zone of crops for proper growth.
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Gao, Xu, Jing Zhou, and Xiao Du. "Experimental Research on and Optimization of Plasma Emitter Sources." Sensors 25, no. 6 (2025): 1715. https://doi.org/10.3390/s25061715.
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Traditional emitters used for downhole acoustic detection have limited radiation frequency and energy, making it difficult to transmit high-precision acoustic signals over long distances. This paper presents a plasma emitter in which high-pressure discharge generates a powerful spherical impulse wave with a wide frequency range. First, the discharge characteristics of the plasma needle-plate emitter are analyzed using high-voltage discharge experiments and discharge simulation models for underwater emitters. Subsequently, advanced modifications are made to the structure of the needle–plate emitter to meet the requirements of downhole detection. A new type of hollow needle–plate emitter with a spherical tip is developed. The results show that the structural optimization of the hollow needle–plate emitter with a spherical tip resulted in a 27.2% increase in impulse wave amplitude, a 28.1% improvement in electro-acoustic conversion efficiency, and a radiation frequency band covering up to 100 kHz. This development is conducive to more accurate and longer-range downhole structure detection. The detection range outside the borehole can reach tens to hundreds of meters. This enables the precise control of the wellbore path and reduces the demands on the rig’s build rate. The emitter has significant application potential in areas such as onshore and offshore oil and gas exploration, unconventional resource detection, impulse wave fracturing and wellbore clearance, and rescue and U-well drilling.
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Zhu, Zhao-Zhao, Zheng Feng, and Jian-Wang Cai. "Field-free spintronic terahertz emitters based on IrMn/Fe/Pt exchage bias heterostructures." Acta Physica Sinica 71, no. 4 (2022): 048703. http://dx.doi.org/10.7498/aps.71.20211831.
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Spintronic terahertz (THz) emitter has more advantages such as lower cost, broader spectrum and easier operation than the commercial THz emitters, and thus has become a focus of research towards the next-generation THz source. However, in such a spintronic THz emitter, an external magnetic field is technologically required to align the orientation of the magnetization, which is detrimental for practical applications. Here, a spintronic terahertz emitter based on IrMn/Fe/Pt exchange bias structure is presented. By means of ultrafast spin injection on Fe/Pt interface followed by the spin-to-charge conversion in Pt, plus the effective magnetic field originating from the IrMn/Fe interface, the THz pulse with considerable intensity can be generated in such a structure without the assistance of external field. Besides, the remanent magnetization for thin Fe layer is enhanced by inserting an ultrathin Cu layer between the IrMn surface and the Fe surface, which is beneficial to the field-free THz emission. The range of obtained dynamic THz spectrum exceeds 60 dB and the positive saturation field can reach up to ~ –10 mT by optimizing the multilayer thickness, meeting the standard for commercial application. By rotating the sample, it is found that the polarization direction of the generated THz wave circulates simultaneously and keeps perpendicular to the direction of exchange bias field in the film plane. Moreover, we design a spin valve THz emitter based on the structure of IrMn/Fe/Pt/Fe by adding a free ferromagnetic Fe layer into the exchange bias multilayers. The emitted THz pulse amplitude is larger for the antiparallel alignment of the Fe layers at zero field than for the parallel alignment or exchange bias structure. The present work shows that the spin terahertz emitter based on IrMn/Fe/Pt exchange bias structure can produce the considerable terahertz signals without external field. Furthermore, the polarization direction of the emitted THz signal can be easily manipulated by rotating the sample. Because of this series of advantages, such exchange bias heterostructures are expected to play an important role in designing the next-generation THz source.