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Gelao, Gennaro, Roberto Marani e Anna Gina Perri. "Self Heating and IR Emission Effects Simulation of Radiative Heater on Power MOS AC Switch". International Journal of Emerging Technology and Advanced Engineering 12, n. 6 (2 giugno 2022): 115–22. http://dx.doi.org/10.46338/ijetae0622_15.
Testo completoAbstract (sommario):
High power IR heaters are very common but some have high switch on current due to the high difference of the electric resistance at ambient temperature and at steady state temperature. In this paper we develop a thermal model of these IR heaters considering the radiated power which is proportional to the fourth power of the temperature, according to the Stefan Boltzmann law. We propose a new circuit based on a series of two power MOS and simulate the switching, showing the temperature and heat flux inside the heater and MOSFET. Keywords— IR emission effects, Radiate Heater, MOSFET Devices, Modelling, Advanced Design System (ADS).
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Zhang, Zhi Guo, Chen Lin, Da Kui Feng e Ray Still. "Improving Plastic Thermoform Quality with Uniform Heating Technology". Advanced Materials Research 97-101 (marzo 2010): 204–8. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.204.
Testo completoAbstract (sommario):
The experimental studies were conducted to study the plastic thermoforming heating process. The heaters performance has been evaluated from two different ways: heating water calorimeter for heating efficiency and heating plastics for thermoform processes. The studies of the heaters include gas-fired heater and electric heater. Transient heating processes of plastics were also studied to investigate the heater’s performance on plastics. The surface temperature of plastic at the end of heating process was measured by IR camera. The heating cycle time, surface temperature uniformity of plastic and energy consumed for the heating cycle by different heaters were discussed. The pros and cons of different heaters for plastic heating process were also discussed in this paper.
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Tikhomirov, D. A., A. V. Khimenko, S. S. Trunov e A. V. Kuzmichev. "Energy-saving automated IR heater for calves". IOP Conference Series: Earth and Environmental Science 848, n. 1 (1 settembre 2021): 012088. http://dx.doi.org/10.1088/1755-1315/848/1/012088.
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Liess, M. "A new low-cost hydrogen sensor build with a thermopile IR detector adapted to measure thermal conductivity". Journal of Sensors and Sensor Systems 4, n. 2 (8 settembre 2015): 281–88. http://dx.doi.org/10.5194/jsss-4-281-2015.
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Abstract. It is demonstrated how a commercially available MEMS thermopile infrared radiation sensor can be used as thermal conductivity gas detector (TCD). Since a TCD requires a heater while IR-thermopile sensors have no integrated heater, the thermopile itself is used as heater and temperature sensor at the same time. It is exposed to the measured gas environment in its housing. It is shown that, by using a simple driving circuitry, a mass-produced low-cost IR sensor can be used for hydrogen detection in applications such as hydrogen safety and smart gas metering. The sensor was tested to measure hydrogen in nitrogen with concentration of 0–100 % with a noise equivalent concentration of 3.7 ppm.
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Çat, Yunus, Veysel Baran e Süleyman Özçelik. "EMI Shielding Effectiveness and Heater Behavior for Ge IR Windows". physica status solidi (a) 216, n. 14 (24 aprile 2019): 1900005. http://dx.doi.org/10.1002/pssa.201900005.
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Buffel, B., K. Leeman e F. Desplentere. "Pulsed IR Heating of Thermoplastic Sheets for Thermoforming Applications". International Polymer Processing 36, n. 4 (1 settembre 2021): 388–97. http://dx.doi.org/10.1515/ipp-2020-3981.
Testo completoAbstract (sommario):
Abstract This study presents the pulsed heating strategy as an advancement of the current state of the art in industry towards the theoretically fastest method of heating a thermoplastic sheet. Experimental temperature measurements are combined with an explicit finite difference numerical model to describe the pulsed heating method and indicate its added value in IR heating of thermoplastic sheets. Different process settings are evaluated and indicate the effect of the applied heat flux and the time interval tOFF during pulsed heating. When switched off, the residual heating of the heater elements is able to partially compensate for the convective heat losses at the surface of the sheet. This results in a more uniform temperature distribution through thickness without slowing down the overall heating process. The study shows that this effect is lost when the time interval in which the heater element is switched off, increases. Applying pulsed heating opens up a large processing window to control the through-thickness temperature difference. When the total amount of applied thermal energy is taken into account, pulsed heating is able to increase the overall heating rate and simultaneously keep the temperature difference through thickness limited.
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Voronin, Anton S., Fedor S. Ivanchenko, Michael M. Simunin, Yuri V. Fadeev, Aleksey V. Shiverskiy e Stanislav V. Khartov. "Sol-Gel Lithography Method for Production of Flexible Transparent Ir-Heater". Journal of Siberian Federal University. Engineering & Technologies 8, n. 7 (novembre 2015): 861–66. http://dx.doi.org/10.17516/1999-494x-2015-8-7-861-866.
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Pettersson, Magnus, e Stig Stenström. "Modelling of an electric IR heater at transient and steady state conditions". International Journal of Heat and Mass Transfer 43, n. 7 (aprile 2000): 1209–22. http://dx.doi.org/10.1016/s0017-9310(99)00201-x.
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Pettersson, Magnus, e Stig Stenström. "Modelling of an electric IR heater at transient and steady state conditions". International Journal of Heat and Mass Transfer 43, n. 7 (aprile 2000): 1223–32. http://dx.doi.org/10.1016/s0017-9310(99)00202-1.
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Son, Jung Min, Jun Hyung Lee, Jungwoo Kim e Young Hak Cho. "Temperature distribution measurement of Au micro-heater in microfluidic channel using IR microscope". International Journal of Precision Engineering and Manufacturing 16, n. 2 (febbraio 2015): 367–72. http://dx.doi.org/10.1007/s12541-015-0048-7.
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Issacci, F., Y. Zvirin e G. Grossman. "Heat Transfer Analysis of a Finned Solar Air Heater". Journal of Solar Energy Engineering 110, n. 2 (1 maggio 1988): 145–55. http://dx.doi.org/10.1115/1.3268245.
Testo completoAbstract (sommario):
A theoretical method is presented for the investigation of a reflective fin solar air heater. The heat transfer processes include radiation in both the solar and IR spectra, mixed convection (forced and natural) in the air and conduction in the fins. The governing equations have been solved numerically to obtain the velocity and temperature fields in the developing and developed flow regions. The efficiency of the finned structure is then calculated, and the results of a parametric study are shown. It has been found that natural convection effects are significant and strong buoyancy leads to separation and reversed flow. The efficiency increases with lower surface emissivity and lower thermal conductivity of the fins.
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Mihai, Laura, Razvan Mihalcea, Roxana Tomescu, Costel Paun e Dana Cristea. "Selective Mid-IR Metamaterial-Based Gas Sensor System: Proof of Concept and Performances Tests". Nanomaterials 12, n. 6 (18 marzo 2022): 1009. http://dx.doi.org/10.3390/nano12061009.
Testo completoAbstract (sommario):
In this paper, we propose a highly selective and efficient gas detection system based on a narrow-band IR metasurface emitter integrated with a resistive heater. In order to develop the sensor for the detection of specific gases, both the microheater and metasurface structures have been optimized in terms of geometry and materials. Devices with different metamaterial structures and geometries for the heater have been tested. Our prototype showed that the modification of the spectral response of metasurface-based structures is easily achieved by adapting the geometrical parameters of the plasmonic micro-/nanostructures in the metasurface. The advantage of this system is the on-chip integration of a thermal source with broad IR radiation with the metasurface structure, obtaining a compact selective radiation source. From the experimental data, narrow emission peaks (FWHM as low as 0.15 μm), corresponding to the CO2, CH4, and CO absorption bands, with a radiant power of a few mW were obtained. It has been shown that, by changing the bias voltage, a shift of a few tens of nm around the central emission wavelength can be obtained, allowing fine optimization for gas detection applications.
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Marchuk, Igor, Andrey Karchevsky, Anton Surtaev e Oleg Kabov. "Heat Flux at the Surface of Metal Foil Heater under Evaporating Sessile Droplets". International Journal of Aerospace Engineering 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/391036.
Testo completoAbstract (sommario):
Evaporating water drops on a horizontal heated substrate were investigated experimentally. The heater was made of a constantan foil with the thickness of 25 μm and size of 42 × 35 mm2. The temperature of the bottom foil surface was measured by the infrared (IR) camera. To determine the heat flux density during evaporation of liquid near the contact line, the Cauchy problem for the heat equation was solved using the temperature data. The maximum heat flux density is obtained in the contact line region and exceeds the average heat flux density from the entire foil surface by the factor of 5–7. The average heat flux density in the region wetted by the drop exceeds the average heat flux density from the entire foil surface by the factor of 3–5. This fact is explained by the heat influx from the foil periphery to the drop due to the relatively high heat conductivity coefficient of the foil material and high evaporation rate in the contact line region. Heat flux density profiles for pairs of sessile droplets are also investigated.
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Kim, Cheol Jin, In Sup Ahn, Kwon Koo Cho, Sung Gap Lee e Jun Ki Chung. "LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes". Key Engineering Materials 336-338 (aprile 2007): 505–8. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.505.
Testo completoAbstract (sommario):
LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.
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Lu, Yiping, Hasan Nasir, David Faucheaux e Srinath V. Ekkad. "Film Cooling Measurements for Novel Hole Configurations". Journal of Heat Transfer 128, n. 8 (1 agosto 2006): 737. http://dx.doi.org/10.1115/1.2221300.
Testo completoAbstract (sommario):
Experimental Procedure: •Blower is set appropriately for required mainstream velocity •Heater is turned on and allowed to heat the air to a desired mainstream temperature •The coolant air is provided from separate compressed air supply and is metered for flow measurement •The mainstream and coolant are triggered at the same instant when the IR system starts taking images and saving to hard drive at set intervals •Images are saved then processed to calculate the heat transfer coefficients and film effectiveness using the theory
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Lielāmurs, Edgars, Andrejs Cvetkovs, Rihards Novickis e Kaspars Ozols. "Infrared Image Pre-Processing and IR/RGB Registration with FPGA Implementation". Electronics 12, n. 4 (9 febbraio 2023): 882. http://dx.doi.org/10.3390/electronics12040882.
Testo completoAbstract (sommario):
Infrared imaging sensors are frequently used in thermal signature detection applications in industrial, automotive, military and many other areas. However, advanced infrared detectors are generally associated with high costs and complexity. Infrared detectors usually necessitate a thermoelectric heater–cooler for temperature stabilization and various computationally complex preprocessing algorithms for fixed pattern noise (FPN) correction. In this paper, we leverage the benefits of uncooled focal plane arrays and describe a complete digital circuit design for Field Programmable Gate Array (FPGA)-based infrared image acquisition and pre-processing. The proposed design comprises temperature compensation, non-uniformity correction, defective pixel correction cores, spatial image transformation and registration with RGB images. When implemented on Xilinx Ultrascale+ FPGA, the system achieves a throughput of 30 frames per second using the Fraunhofer IMS Digital 17 μm QVGA-IRFPA with a microbolometer array size of 320 × 240 pixels and an RGB camera with a 1024 × 720 resolution. The maximum ratio of the standard deviation to the mean of 0.35% was achieved after FPN correction.
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Zhang, Xiaoxin, Semiramis Friedrich e Bernd Friedrich. "Characterization and Interpretation of the Aluminum Zone Refining through Infrared Thermographic Analysis". Materials 11, n. 10 (19 ottobre 2018): 2039. http://dx.doi.org/10.3390/ma11102039.
Testo completoAbstract (sommario):
High purity metals are nowadays increasingly in demand to serve in electronic, photovoltaic, and target materials industries. The zone refining process is the most common way to achieve high purity in the final step of metal purification. Zone length and crystal growth rate are the main parameters that control the zone refining process. To determine these values, information about temperature profiles in the molten zone is necessary due to its direct correlation with these values. As the determination of this profile is not practically achievable in the present, the novel approach of applying an infrared (IR) camera during the zone refining of 2N8 aluminum is the focus of the investigation in this work. The whole temperature profile of the region near the molten zone was recorded by IR camera during the entire running process. The zone length and the crystal growth rate at each thermographic image shooting moment were successfully extracted by thermographic analysis. Results showed that both factors varied significantly, which is in contrast to the assumption in literature about their stability while running under constant input power and heater movement velocity, though noticeable purification took place in all of these experiments. However, the impurity concentration during refinement fluctuated remarkably. This was well-demonstrated by the tendency of variation in crystal growth rate attained in this work. These results provide a better understanding of the mechanisms of zone refining with an inductive heater and contributes to the optimization of the process.
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Tuxun, Hairegu, Zefeng Cai, Min Ji, Baobao Zhang, Chengyun Zhang, Jinping Li, Xudong Yu, Zhengkun Fu, Zhenglong Zhang e Hairong Zheng. "Controlling and probing heat generation in an optical heater system". Nanophotonics 11, n. 5 (27 gennaio 2022): 979–86. http://dx.doi.org/10.1515/nanoph-2021-0604.
Testo completoAbstract (sommario):
Abstract Understanding how plasmonic nanostructures generate heat upon exposure to light, and thus increase the local temperature of the surrounding medium is important for many applications. Reliable temperature manipulation requires analyzing the local temperature distribution as a function of laser density. In this work, an optical heating system containing silver nano-islands (Ag NIs) is designed to enable heat generation at the micro/nanometer scale and the local temperature can reach 1458 K. The heat generation by Ag NIs exposed to near-IR laser light, and the temperature distribution, are detected in situ via the fluorescence intensity ratio technique. It was found that the temperature of the system can be controlled by changing the excitation power. Furthermore, the temperature-dependent UCL of a single Y2O3:Yb3+/Er3+ microrod is studied by taking advantage of the controllable local temperature in the optical heating system. It was found that the color of the upconversion luminescence can be tuned by managing the local temperature, and conversely, the local temperature at the optical heater can be monitored by observing the color change of the rare-earth microrod. The real-time manipulation of plasmonic heating offers an opportunity to control outcomes of thermo-plasmonic effects, which then enables a myriad of practical applications.
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Haustein, H. D., W. Rohlfs, F. Al-Sibai e R. Kneer. "Evaluation of the sensitivity and response of IR thermography from a transparent heater under liquid jet impingement". Journal of Physics: Conference Series 395 (26 novembre 2012): 012083. http://dx.doi.org/10.1088/1742-6596/395/1/012083.
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Zou, Jiaona, Alex Fauler, Alexander S. Senchenkov, Nikolai N. Kolesnikov e Michael Fiederle. "Analysis of Te Inclusion Striations in (Cd,Zn)Te Crystals Grown by Traveling Heater Method". Crystals 11, n. 6 (8 giugno 2021): 649. http://dx.doi.org/10.3390/cryst11060649.
Testo completoAbstract (sommario):
The growth of (Cd,Zn)Te (CZT) crystals and the improvement of the crystal quality are part of a research project towards experiments under microgravity using the Traveling Heater Method (THM). In order to determine the experimental parameters, we performed a detailed ground-based program. Three CZT crystals with a nominal Zn content of 10% were grown using THM from a Te-rich solution. The size and distribution of the Te inclusions were evaluated by transmission infrared microscopy (IR). From the three-dimensional mapping of the inclusions, we observed striation-like patterns in all of the crystals. The correlation between the growth parameters and the formation of these striations was explored and discussed. We found that the inclusion striations are related to periodic temperature variations.
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Hosseinionari, Hadi, Milad Ramezankhani, Rudolf Seethaler e Abbas S. Milani. "Development of a Computationally Efficient Model of the Heating Phase in Thermoforming Process Based on the Experimental Radiation Pattern of Heaters". Journal of Manufacturing and Materials Processing 7, n. 1 (10 febbraio 2023): 48. http://dx.doi.org/10.3390/jmmp7010048.
Testo completoAbstract (sommario):
In this study, an accurate and computationally efficient model for the heating process of thin thermoplastic sheets during thermoforming is developed. This model opens the door to efficient training of model-free control approaches in thermoforming applications, which often require extensive training data that would be significantly costly and time-consuming to generate using physical setups. This model takes into account heat transfer via radiation between heaters and the sheet, heat transfer via conduction through the sheet, and heat transfer via convection between the sheet and the ambient. In this paper, rather than using an analytical relationship for the view factor, an experiment is designed to determine the exact radiation pattern of the heater on the sheet and the fraction of infrared emission absorbed by the sheet. Comparing the output temperature profile on the sheet from the designed model to IR images from a laboratory-scale heating system indicates that the mean square error is reduced by around four times when compared to traditional models with analytical view factors. Moreover, a comparison of the computation time with COMSOL software for a scenario with the same configuration of computation hardware reveals that the designed model is almost ten times faster.
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Nakouzi, S., F. Berthet, D. Delaunay, Y. Le Maoult, Fabrice Schmidt e Vincent Sobotka. "Optimization of the Incident IR Heat Flux upon a 3D Geometry Composite Part (Carbon/Epoxy)". Key Engineering Materials 504-506 (febbraio 2012): 1085–90. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.1085.
Testo completoAbstract (sommario):
The main purpose of this study is to cure a 3D geometry composite part (carbon fiber reinforced epoxy matrix) using an infrared oven. The work consists of two parts. In the first part, a FE thermal model was developed, for the prediction of the infrared incident heat flux on the top surface of the composite during the curing process. This model was validated using a reference solution based on ray tracing algorithms developed in Matlab®. Through the FE thermal model, an optimization study on the percentage power of each infrared heater is performed in order to optimize the incident IR heat flux uniformity on the composite. This optimization is performed using the Matlab® optimization algorithms based on Sequential Quadratic Programming and dynamically linked with the FE software COMSOL Multiphysics®. In a second part, the optimized parameters set is used in a model developed for the thermo-kinetic simulations of the composite IR curing process and the predictions of the degree of cure and temperature distribution in the composite part during the curing process.
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Ganesan, Sivaramakrishnan, Sophie Maricot, Jean-Francois Robillard, Etienne Okada, Mohamed-Taieb Bakouche, Laurent Hay e Jean-Pierre Vilcot. "Plasmonic Layer as a Localized Temperature Control Element for Surface Plasmonic Resonance-Based Sensors". Sensors 21, n. 6 (13 marzo 2021): 2035. http://dx.doi.org/10.3390/s21062035.
Testo completoAbstract (sommario):
Surface plasmon resonance (SPR) sensing is a well-established high-sensitivity, label-free and real-time detection technique for biomolecular interaction study. Its primary working principle consists of the measurement of the optical refractive index of the medium that is in close vicinity of the sensor surface. Bio-functionalization techniques allow biomolecular events to be located in such a way. Since optical refractive indices of any medium varies with the temperature, the place where the measurement takes place shall be within a temperature-controlled environment in order to ensure any temperature fluctuation is interpreted as a biomolecular event. Since the SPR measurement probes the sensed medium within the penetration depth of the plasmonic wave, which is less or in the order of 1 µm, we propose to use the metallic film constituting the detection surface as a localized heater aiming at controlling finely and quickly the temperature of the sensed medium. The Joule heating principle is then used and the modeling of the heater is reported as well as its validation by thermal IR imaging. Using water as a demonstration medium, SPR measurement results at different temperatures are successfully compared to the theoretical optical refractive index of water versus temperature.
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Abdul Majeed E. Ibrahim, Raid A.Isma'l e Wlla M. Mohammed. "Study the electrical properties of ZnOSiO2 detector prepared by free rappid thermal oxidation". Tikrit Journal of Pure Science 22, n. 4 (28 gennaio 2023): 139–46. http://dx.doi.org/10.25130/tjps.v22i4.744.
Testo completoAbstract (sommario):
Zinc thin films deposited on (n-type)silicon at 510o C with oxidation times (10,20,30,35) sec have been oxidized. Zinc have been deposited by thermal diffusion method using heater instead of conventional furnace .It is found that we can get zinc oxide with outoxegen and closed farneces rapidly. The electrical properties in dark show that the detector is shottky diode, and the best time to obtain the detector is 35 sec, and the ideality factor is 3.3 with a work function of 0.58 ev. It is found that the resalts at light power (50,100,150,200,250) mw/cm2.Show that the detector oxidiced in 35 sec have detectivity factor 540.8 and have a high responsivity which enable the detector to detect the IR signals.
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Shen, Chih-Hsiung, e Jung-Jie Wu. "A New Electro-Optical-Thermal Modelling for Non-Dispersive IR Sensing Technique of Gas Concentration". Applied Sciences 12, n. 15 (2 agosto 2022): 7772. http://dx.doi.org/10.3390/app12157772.
Testo completoAbstract (sommario):
In this research, a new electro-optical-thermal modeling is proposed and built by simulation program with integrated circuit emphasis (SPICE). In particular, it is constructed for use in the non-dispersive infrared (NDIR) sensing technique of gas concentration. This model, based on the theory of circuitry and the Beer-Lambert law, includes various equivalent elements for the optics, sensor, and circuits. To build and investigate the validity of the proposed model, an NDIR for measurement of CO2 is built with the hybrid combination of a thermopile sensor with a specific wavelength filter, an infrared micro electro mechanical systems (MEMS) heater, an optical tube, amplification circuits with a chopper amplifier, advanced RISC machine (ARM)-based micro processing unit and discrete electronic devices. The thermal properties of the light source with periodic modulation have been studied from the output signal of a thermopile within the limit of modulation frequency. Based on the thorough measurements of output signals and transient responses, the thermal and optical parameters of the sensor and optical components for this model are extracted. The comparison of the simulation and experimental data of the NDIR measurement for different CO2 concentrations shows a great agreement with a maximum error of 0.27% at 3500 ppm. This approach allows for the development of a high-level sensor and circuit integrated simulation based on the most fundamental principles and multiple variables.
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Vahidi, Afsaneh, Hamideh Vaghari, Yahya Najian, Mohammad Javad Najian e Hoda Jafarizadeh-Malmiri. "Evaluation of three different green fabrication methods for the synthesis of crystalline ZnO nanoparticles using Pelargonium zonale leaf extract". Green Processing and Synthesis 8, n. 1 (28 gennaio 2019): 302–8. http://dx.doi.org/10.1515/gps-2018-0097.
Testo completoAbstract (sommario):
Abstract Zinc oxide nanoparticles (ZnO NPs) were green synthesized using Pelargonum zonale leaf extract under three different heating methods, and their characteristics were evaluated using X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay and antibacterial well diffusion method. The FT-IR analysis indicated that the Pelargonium leaf extract contained hydroxyl and amide I groups which were related to the proteins, carbohydrate, tannins and phenolic compounds of the extract and had an essential role in the reduction of the zinc ions and synthesis of the ZnO NPs. The obtained results revealed that the synthesized spherical individual ZnO NPs as well as the number of aggregates using microwave irradiation, autoclave and conventional heating (heater-stirrer) methods had average crystalline size of 51, 60 and 61 nm. Furthermore, antioxidant activities of the fabricated ZnO NPs were 7.8, 4.1 and 5.5% by using conventional heating, autoclave and microwave irradiation, respectively. The obtained results indicated that all the formed ZnO NPs had bactericidal effects against to the both Gram negative and Gram positive bacteria strains. However, the synthesized ZnO NPs using conventional heating method had the highest antibacterial activities toward both studied bacteria strains.
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Megido, Adiel, e Eko Ariyanto. "SISTEM KONTROL SUHU AIR MENGGUNAKAN PENGENDALI PID. DAN VOLUME AIR PADA TANGKI PEMANAS AIR BERBASIS ARDUINO UNO". Gema Teknologi 18, n. 4 (30 aprile 2016): 21. http://dx.doi.org/10.14710/gt.v18i4.21912.
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Adiel Megido, Eko Ariyanto in this paper explain that the temperature control system on water heaters that use electric heaters, generally uses ON-OFF voltage control. Apart from this system being less efficient in using electricity, the limited range of voltage settings provided also lacks the output accuracy value required by the control system. So that for some applications it can cause a response to the temperature control system that oscillates. Another alternative in controlling the heating voltage is by using the PID control method (Proportional - Integral - Derifative), this method provides a wider range of voltage settings, so that it can provide the output accuracy value needed by the control system, thus making it possible to obtain system responses finer (minimum oscillation amplitude). In addition to problems with the temperature control system, the water volume control system in the water heater tank generally still uses probes that are installed at certain levels. The limitations in reading each change in height / volume of water causes the system output to be less linear (discrete). To produce linear readings and outputs in each change in water volume, a voltage divider can be used. In this final project design will use an electric water heater tank as a medium to determine the ability of the PID controller to control water temperature according to the set-point and control the height / volume of water in the tank using a voltage divider. Keywords : PID (Proporsional – Integral – Derifatif), Berosilasi, Set-pointReferencesMalvino, Albert Paul. 1981. Prinsip-prinsip Elektronik edisi kedua. Jakarta: Erlangga.Gunterus, Frans. 1994. Falsafah Dasar : Sistem Pengendalian Proses.Jakarta:Elex Media KomputindoEfendy, Marwan.n.d. Bab 1 Sistem Pengendalian. Surakarta: Universitas Muhamadiyah SurakartaBolton, W. 2009. Sistem Instrumentasi dan Sistem Kontrol. Jakarta:ErlanggaOgata, Katsuhiko. 1996. Teknik Kontrol Automatik Jilid 1-2, Diterjemahkan oleh Ir. Edi Laksono. Jakarta : Erlangga.sPetruzella, Frank D. 1996. Elektronika Industri. Yogyakarta: Andi Yogyakarta.Rashid, H Muhammad. 1999. Elektronika Daya Jilid 1. Jakarta: Prehalindo.Michael Tooley, BA. 2003. Rangkaian Elektronik Prinsip dan Aplikasi Edisi kedua. Jakarta : Erlangga.Bishop, Owen. 2004. Dasar-Dasar Elektronika. Jakarta : Erlangga.Majid, Saifulloh Agung. 2009. Pengontrolan Temperatur Menggunakan Metode Kontrol PID Berbasis Mikrokontroler AT90S8515. Semarang: Jurusan Teknik Elektro Fakultas Teknik Universitas Diponegoro.Surono, dkk. 2009. Bahasa Indonesia Untuk Perguruan Tinggi. Semarang: Farindo Press.Laksono, Suryo Krido, Sumardi, dan Aris Triwiyatno. 2010. Pengaturan Sudut Fasa Berbasis Logika Fuzzy Untuk Sistem Pengaturan Temperatur. Semarang: Jurusan Teknik Elektro Fakultas Teknik Universitas Diponegoro.Firsyari, Akhmad Salmi, Purwanto, M Aziz Muslim. 2013. Sistem Pengendalian Suhu Pada Proses Distilasi Vakum Bioetanol Dengan Menggunakan Arduino. Semarang: Jurusan Teknik Elektro Fakultas Teknik Universitas Diponegoro.Azaria Mutia Suriatmadja. 2013. Modul Kontrol Temperatur Air Berbasis PID Menggunakan Matlab Simulink. Semarang: PSD III Teknik Elektronika Jurusan Teknik Elektro Politeknik Negeri Semarang
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Kim, Hye-In, Bong-Geon Chae, Pil-Gyeong Choi, Mun-Shin Jo, Kyoung-Muk Lee e Hyun-Ung Oh. "Thermal Design of Blackbody for On-Board Calibration of Spaceborne Infrared Imaging Sensor". Aerospace 9, n. 5 (16 maggio 2022): 268. http://dx.doi.org/10.3390/aerospace9050268.
Testo completoAbstract (sommario):
In this study, we propose a thermal design for an on-board blackbody (BB) for spaceborne infrared (IR) sensor calibration. The main function of the on-board BB is to provide highly uniform and precise radiation temperature reference sources from 0 °C to 40 °C during the calibration of the IR sensor. To meet the functional requirements of BB, a BB thermal design using a heater to heat the BB during sensor calibration and heat pipes to transfer residual heat to the radiator after calibration is proposed and investigated both numerically and experimentally. The main features of the proposed thermal design are a symmetric temperature gradient on the BB surface with less than 1 K temperature uniformity, ease of temperature sensor implementation to estimate the representative surface temperature of the BB, a stable thermal interface between the heat pipes and BB, and a fail-safe function under one heat pipe failure. The thermal control performance of the BB is investigated via in-orbit thermal analysis, and its effectiveness is verified via a heat-up test of the BB under ambient conditions. These results indicate that the temperature gradient on the BB surface was obtained at less than 1 K, and the representative surface temperature could be estimated with an accuracy of 0.005 °C via the temperature sensor.
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Nakouzi, Sawsane, Florentin Berthet, Yannick Le Maoult e Fabrice Schmidt. "Simulations of an Infrared Composite Curing Process". Key Engineering Materials 554-557 (giugno 2013): 1517–22. http://dx.doi.org/10.4028/www.scientific.net/kem.554-557.1517.
Testo completoAbstract (sommario):
Epoxy resins have several applications in the aerospace and automobile industry. Because of their good adhesive properties, superior mechanical, chemical and thermal properties, and resistance to fatigue and micro cracking, they produce high performance composites. In the technology presented here, the composite is cured in an IR oven which includes halogen lamps. The liquid resin infusion (LRI) process is used to manufacture the composite, whereby liquid resin is infused through a fiber reinforcement previously laid up in a one-sided mold. These epoxy resins release an exothermic heat flux during the curing process, which can possibly cause an excessive temperature in the thickness. Consequently, for the production of high performance composites, it is necessary to know the thermal behavior of the composite during curing. Therefore, IR interactions with the graphite/epoxy system were modeled as a surface radiation transport. In our work, we have studied IR interactions with the composite, which is placed in an IR oven. Using an IR spectrometer Bruker Vertex 70 (1-27 μm), we measured radiative properties and determined the fraction of IR rays absorbed by the composite. Since it is necessary to optimize the manufacturing time and costs and to determine the performance of these composites, the purpose of this study is to model the IR curing of a composite part (carbon fiber reinforced epoxy matrix) in the infrared oven. The work consists in two parts. In the first part, a FE thermal model based on radiosity method was developed, for the prediction of the infrared incident heat flux on the top surface of the composite during the curing process. This model was validated using a reference solution based on ray tracing algorithms developed in Matlab® (In-lab software called Rayheat based on ray tracing algorithms is used to compute the radiative heat flux that impacts the composite). Through the FE thermal model, an optimization study on the percentage power of each infrared heater is performed in order to optimize the incident IR heat flux uniformity on the composite. This optimization is performed using the Matlab® optimization algorithms based on Sequential Quadratic Programming method. In a second part, the optimized parameters set is used in a three-dimensional numerical model which is developed in the finite element commercial software Comsol Multiphysics ™, where the heat balance equation is coupled with the cure kinetic model of the resin. This numerical model allows calculation of the temperature distribution in the composite during curing, which is a key parameter that affects its mechanical properties. In this model, we can predict also the evolution of the degree of cure as function of time. Experimental measurements were used to validate simulations of the whole infrared composite curing process. Keywords: Curing composite, infrared oven, Radiation, Optimization, Epoxy resin, Carbon fibers.
30
Radev, Dimitar D., e Ivan Uzunov. "Nanosized Silicon Carbide Obtained from Rice Husks". Solid State Phenomena 159 (gennaio 2010): 153–56. http://dx.doi.org/10.4028/www.scientific.net/ssp.159.153.
Testo completoAbstract (sommario):
Two ways to obtain nanosized silicon carbide (SiC) powders from the products of thermal decomposition of rice hulls and posterior thermal and chemical treatment of SiO2-C precursors are shown in the present paper. The reagents and products were analyzed using BET, DTA, IR, XRD and SEM/TEM. Precursors obtained from rice husks containing pure SiO2 and a controlled SiO2-C ratio were used for the synthesis of SiC. The synthesis of SiC proceeded for 30-45 min in a graphite heater furnace under protective Ar atmosphere at relatively low temperatures (1450oC-1550oC). Nanosized dimensions of reagents obtained from rice husks and their high activity allow obtaining SiC in relatively milder thermal regimes. TEM and XRD analysis revealed synthesis of nanostructured mainly β-SiC with a mean crystallite size of 40-100 nm. Due to their purity and nano-scale properties, the products obtained are appropriate for production of bulk SiC or design of SiC–based ultra high-temperature materials using the methods of powder metallurgy.
31
Saidho’jaeva, Nafisa. "CALCULATION OF THE CHAIN DRIVE OF A MECHANIZED CHAMBER-CHAIN DRYING PLANT FOR DRYING MELON FRUITS". Technical Sciences 4, n. 1 (30 gennaio 2021): 29–35. http://dx.doi.org/10.26739/2181-9696-2021-1-5.
Testo completoAbstract (sommario):
The article deals with the calculation of the drive and chain transmission of the newly created mechanized drying plant for drying melon slices. The essence of the utility model: the machine contains a horizontal tunnel chamber, inside which is mounted a chain conveyor with driving and driven sprockets, load-carrying elements, the IR emitters with reflectors on top of the camera mounted electric air heater, fan, an annular heat exchanger equipped with inlet and outlet nozzles of the drying agent. On the branches of the conveyor chain, lodgments with folding clamps are mounted, on which load-bearing elements are fixed, which are used as wooden poles. The calculation of the drive and chain transmission of the drying plant conveyor was carried out according to the existing method according to the scheme shown in the figure. Thus, the main parameters of the drive and chain transmission parts of the mechanized chamber-chain drying plant for drying melon fruits were determined by calculation
32
Hodes, Marc, Randy D. Weinstein, Stephen J. Pence, Jason M. Piccini, Lou Manzione e Calvin Chen. "Transient Thermal Management of a Handset Using Phase Change Material (PCM)". Journal of Electronic Packaging 124, n. 4 (1 dicembre 2002): 419–26. http://dx.doi.org/10.1115/1.1523061.
Testo completoAbstract (sommario):
The power density of portable electronic devices continues to increase because packaging advances reduce their size even as features are added and enhanced. Designing thermal management systems to accommodate steady-state conditions as opposed to fixed duty cycles can substantially increase cost, size, and weight. The feasibility of transient thermal management of handsets using phase change materials (PCMs) was experimentally investigated using an ABS handset mock-up. At selected intervals of time, the nonuniform case temperature of the handset was measured using an infrared (IR) camera, while thermocouples measured the temperatures of the PCM and simulated power amplifier (heater). Transient and steady-state heat transfer rates by natural convective and radiation from the handset to the environment were numerically computed from the temperature data in the thermal images. The effects of PCM material, power supplied to the handset, and handset orientation on the time required for the handset case to reach a given (maximum) temperature and “recovery” time were examined.
33
Chung, Jun Ki, Sung Yeal Bae, Sung Gap Lee, Chan Park, Sang Im Yoo e Cheol Jin Kim. "Development of Cube-Textured Ni and Ni-W Alloy Tapes by Focused Infrared Heating". Materials Science Forum 510-511 (marzo 2006): 258–61. http://dx.doi.org/10.4028/www.scientific.net/msf.510-511.258.
Testo completoAbstract (sommario):
We fabricated bi-axially textured pure Ni and Ni–5at.%W (Ni-5W) alloy tapes for the application of rechargeable battery cathode and coated superconductor, where the controlled microstructure of the substrate plays a critical role. The sintered Ni or Ni-W rods were cold-rolled into the thin tapes of 80 ~ 100 µm thickness, and the tapes were heat-treated for texture development with a line focused infrared heater. The temperature was maintained at 800 ~ 1050 °C, using a 1kW double ended linear halogen lamp in 96%Ar-4%H2 atmosphere. The (2 0 0) texture of Ni tape was successfully formed through optimization of the recrystallization infrared heating condition for the cold rolled Ni tapes. The full width half maximum of the Ni tapes was less than 10o, and the grain size was 20 ~ 40 µm. Focused IR-heating resulted in a better texture development and smaller grain size compared to the conventional resistive heating because of the steep temperature gradient.
34
Truong, Thuy-Kieu. "Robust Joule-heating induced transmittance modulation of CNT-sheet-paraffin based smart window". Advances in Natural Sciences: Nanoscience and Nanotechnology 13, n. 1 (24 febbraio 2022): 015001. http://dx.doi.org/10.1088/2043-6262/ac5499.
Testo completoAbstract (sommario):
Abstract Intelligent window with transmittance change has enabled significant advantages for the smart building. Moreover, such a window with the user’s control to ensure privacy could be obtained by the electrical power. Thanks to the horizontally aligned carbon nanotube (CNT)-sheet-like-film from drawable CNT forest, the CNT-sheet was employed as the Joule-heating induced transparent heater to modulate the transmittance change of paraffin corresponding to its solid to liquid phase change. A facile approach was used to fabricate the sandwich-like smart window cell from the CNT-sheet-paraffin nanocomposite. CNT-sheet from the CNT forest was transferred on the glass substrate and then densified by ethanol. Optical microscopy, scanning electron microscopy (SEM), and infrared (IR) thermal mapping microscopy were carried out to characterize the uniformity of the aligned-CNT-sheet. Significantly, the IR microscopy results showed its homogenous Joule-heating generation without any hot spot. The sandwich cell was made from the CNT-coated substrates and was infiltrated by the melted paraffin in between the substrates. UV–vis spectra with electrical power DC application were used to measure such smart window structures. The results showed the Joule-heating induced uniform heat generator of CNT sheet driving the solid to liquid phase change of paraffin, increasing the transmittance of the intelligent window cell six times in the visible light range. Those results have shown promise for developing the facile smart window, especially for the curve window of vehicles.
35
Liu, Xingliang, Guiyun Tian, Yu Chen, Haoze Luo, Jian Zhang e Wuhua Li. "Non-Contact Degradation Evaluation for IGBT Modules Using Eddy Current Pulsed Thermography Approach". Energies 13, n. 10 (21 maggio 2020): 2613. http://dx.doi.org/10.3390/en13102613.
Testo completoAbstract (sommario):
In this paper, a non-contact degradation evaluation method for insulated gate bipolar transistor (IGBT) modules is proposed based on eddy current pulsed thermography approach. In non-contact heat excitation procedures, a high-power induction heater is introduced to generate heat excitation in IGBT modules. The thermographs of the whole temperature mapping are recorded non-invasively by an IR camera. As a result, the joint degradation of IGBT modules can be evaluated by the transient thermal response curves derived from the recorded thermographs. Firstly, the non-destructive evaluation principle of the eddy current pulsed thermography (ECPT) system for an IGBT module with a heat sink is introduced. A 3D simulation module is built with physical parameters in ANSYS simulations, and then thermal propagation behavior considering the degradation impact is investigated. An experimental ECPT system is set up to verify the effectiveness of the proposed method. The experimental results show that the delay time to peak temperature can be extracted and treated as an effective indicative feature of joint degradation.
36
Bayramov, Tarkhan Khakim ogly. "Study of perspective methods for pasteurization of milk for farming". Agrarian Scientific Journal, n. 6 (19 giugno 2020): 76–80. http://dx.doi.org/10.28983/asj.y2020i6pp76-80.
Testo completoAbstract (sommario):
The article considers an experimental actinator using simultaneous exposure of a thin layer of milk to the flow of infrared and ultraviolet rays. The actinator consists of a vertical cylindrical body inside which a cylinder is coaxially located, an IR heater made of transparent quartz glass and wound spirally (of nichrome wire) located on its upper part of the former of a thin layer of milk in the form of a hollow ball connected to the working cylinder in the bottom parts of the drive of the finished product in the form of a truncated cone and a nozzle for removal of the finished product, a UV irradiation lamp, a cruciform liquid dispenser contained inside the forms a thin layer of milk, connected to it by a branch pipe for feeding the initial product, connected with it through a pipeline, a tap for adjusting the pressure and flow of milk, a pump and a tank for the initial product with a tap. The methodological basis for the calculation was used analytical development of heat exchange by radiation.
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Zahorulko, Andrii, Aleksey Zagorulko, Maryna Yancheva, Maksym Serik, Sergei Sabadash e Marina Savchenko-Pererva. "PROBATION OF THE APPARATUS FOR LOW-TEMPERATE PROCESSING OF MEAT CULINARY PRODUCTS BY IR-RADIATION". EUREKA: Life Sciences 1 (31 gennaio 2019): 35–43. http://dx.doi.org/10.21303/2504-5695.2019.00837.
Testo completoAbstract (sommario):
The improvement of existent technological processes of making meat culinary products and development of the correspondent principally new resource-effective equipment is an urgent task. There was probated the developed apparatus of the low-temperature processing of meat culinary products by IR-radiation with the further qualitative assessment of ready culinary products for solving it. The results of the conducted studies provide making high-quality, juicy meat products without a crust that generally provides spreading the assortment of products under conditions of their low-temperature processing in a price category, attractive for a consumer. A flexible film resistive electric heater of the radiating type (FFREhRT) was used as a heating element for providing the even low-temperature processing of meat products at the expanse of taking the working geometry of a chamber of the apparatus by it. For providing the autonomy of the work of air-ejecting ventilators, there was offered to use Peltier elements that allow to transform secondary heat of FFREhRT in the low-voltage feeding tension and to provide cooling of the external surface of the apparatus synchronously. The apparatus is mobile that provides its displacement directly in places of realization. At the studies, there was established the culinary readiness degree of meat products of the spheric form with diameter 0,1±0,01m by reaching temperature 53…85 оС in the product center. The evenness of the heat flow distribution within the working chamber was proved by the data, obtained from thermocouples, placed on the metal spheric model of a meat product sample in real time by 7 thermocouples. As a result of analyzing the geometric model of placing Peltier elements, it has been established, that for providing the low-voltage tension of ventilators at level 3,55 V, 10 successively connected elements are necessary. The offered innovative construction-technological solutions allow to make high-quality, juicy meat products without a crust that generally provides spreading the assortment of products under conditions of their low-temperature processing.
38
Tsikhan, O. I., S. I. Madveika, S. V. Bordusau, A. L. Barakhoev e P. V. Kamlach. "Study of the influence of ozone-air mixture supply conditions on the process of the photoresist removal from the silicon wafer surface". Doklady BGUIR 18, n. 6 (1 ottobre 2020): 57–65. http://dx.doi.org/10.35596/1729-7648-2020-18-6-57-65.
Testo completoAbstract (sommario):
The study is devoted to the research of the dependence of the processing results of photoresistive films on the silicon wafers surface in an ozone environment on the conditions and parameters of the process. The high oxidizing potential of ozone justifies the possibility of its use for removing organic films under atmospheric pressure. The experiments were carried out using the developed research bench, in which the mode and method of heating, as well as the method of supplying gas to the surface of the photoresist, were varied. Silicon wafers with a formed 1,35-μm thick masking photoresist film were used as experimental samples. It was found expedient that uniform heating of the plate over its entire surface can be achieved using a ceramic IR heater. When the ozone-air mixture was introduced into the center of the heated sample, the presence of the removed photoresist residues was observed, which was associated with a temperature drop in its surface area. To solve this problem, the computer models of the temperature regimes of the reaction volume elements were calculated. They showed that the scattering of the working gas flow over the surface of the silicon wafer would significantly increase the efficiency of photoresist removal, and with a good selection of the treatment regime it would ensure complete removal of the photoresist. The data obtained were experimentally confirmed by using an ozone-air mixture flow separator. Experiments were carried out to study the effect of the distance from the wafer surface to the working gas inlet on the photoresist removal rate. They showed that a decrease in the distance reduces the ozone loss due to thermal decomposition and, consequently, increases the material removal rate.
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Xu, Li, Wei-Chia Weng e Ying-Chin Yeh. "Continuous Wave Laser Nanowelding Process of Ag Nanowires on Flexible Polymer Substrates". Nanomaterials 11, n. 10 (27 settembre 2021): 2511. http://dx.doi.org/10.3390/nano11102511.
Testo completoAbstract (sommario):
In this paper we present the laser nanowelding process of silver nanowires (AgNWs) deposited on flexible polymer substrates by continuous wave (CW) lasers. CW lasers are cost-effective and can provide moderate power density, somewhere between nanosecond pulsed lasers and flash lamps, which is just enough to perform the nanowelding process efficiently and does not damage the nanowires on the polymer substrates. Here, an Nd:YAG CW laser (wavelength 532 nm) was used to perform the nanowelding of AgNWs on polyethylene terephthalate (PET) substrates. Key process parameters such as laser power, scan speed, and number of scans were studied and optimized, and mechanisms of observed phenomena are discussed. Our best result demonstrates a sheet resistance of 12 ohm/squ with a transmittance at λ = 550 nm of 92% for AgNW films on PET substrates. A transparent resistive heater was made, and IR pictures were taken to show the high uniformity of the CW laser nanowelded AgNW film. Our findings show that highly effective and efficient nanowelding can be achieved without the need of expensive pulse lasers or light sources, which may contribute to lower the cost of mass producing AgNWs on flexible substrates.
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Cieślikiewicz, Łukasz, Piotr Łapka, Michał Wasik, Michał Kubiś, Karol Pietrak, Tomasz S. Wiśniewski, Piotr Furmański e Mirosław Seredyński. "Development of the experimental stand for investigation of heating and drying phenomena in the porous building materials with one surface of the sample exposed to the flowing air". E3S Web of Conferences 70 (2018): 03003. http://dx.doi.org/10.1051/e3sconf/20187003003.
Testo completoAbstract (sommario):
The paper presents development of the experimental stand for investigation of heating and drying phenomena in the porous building materials with one surface of the sample exposed to the flowing air. Moreover, results of preliminary measurements which verify the range of operating conditions achieved by the stand are shown. These conditions were assumed in the following range: 15℃-60℃, 10-90% and 0.1-10 m/s for temperature, relative humidity and velocity of the flowing air, respectively. In order to control the parameters of air used for heating and drying of porous materials, a closed-loop concept of the stand was proposed and equipped with several elements, i.e., the cooler (vapour condenser), fan with variable rotational speed, humidifier and heater. Furthermore, two parallel measurement ducts which allow to obtain two air streams with identical parameters were proposed. This enables two measurements at one time as well as faster verification of the repeatability of the performed measurements. The temperature measurements at the top surface and inside the sample are carried out applying the IR thermography and several K-type thermocouples, respectively, while overall moisture amount and the moisture content distribution in the specimen are found using tensometric force and electrical resistance meters, respectively.
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Erhard, Patricia, Jan Angenoorth, Joachim Vogt, Johannes Spiegel, Florian Ettemeyer, Wolfram Volk e Daniel Günther. "Characterization of Slurry-Cast Layer Compounds for 3D Printing of High Strength Casting Cores". Materials 14, n. 20 (16 ottobre 2021): 6149. http://dx.doi.org/10.3390/ma14206149.
Testo completoAbstract (sommario):
Additive manufacturing of casting cores and molds is state of the art in industrial application today. However, improving the properties of chemically bonded casting cores regarding temperature stability, bending strength, and surface quality is still a major challenge. The process of slurry-based 3D printing allows the fabrication of dense structures and therefore sinterable casting cores. This paper presents a study of the slurry-based fabrication of ceramic layer compounds focusing on the drying process and the achievable properties in slurry-based 3D printing of casting cores. This study aims at contributing to a better understanding of the interrelations between the drying conditions in the 3D printing process and the properties of sintered specimens relating thereto. The drying intensity influenced by an IR heater as well as the drying periods are varied for layer thicknesses of 50, 75, and 100 µm. Within this study, a process window applicable for 3D printing of sinterable casting cores is identified and further indications are given for optimization potentials. At layer heights of 75 µm, bending strengths between ~8 and 11 MPa as well as densities of around 50% of the theoretical density were achieved. Since the mean roughness depth Rz is determined to be <30 µm in plane, an application of slurry-based 3D printing in investment casting is conceivable.
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Richter, Daniel, Andreas Richter e Kay Dornich. "Lexsyg — A new system for luminescence research". Geochronometria 40, n. 4 (1 dicembre 2013): 220–28. http://dx.doi.org/10.2478/s13386-013-0110-0.
Testo completoAbstract (sommario):
Abstract The newly developed lexsyg system by Freiberg Instruments is a versatile luminescence reader, suited for research on the luminescence of materials, fundamental research in luminescence dating, but also for routine mass measurements in retrospective dosimetry as well as in dating application. The 80 sample storage wheel is disconnected from the measurement chamber and therefore crosstalk of optical stimulation is absent and cross-irradiation is negligible from the α- and β-sources, which are providing very uniform irradiations, with the latter especially designed for radiofluores-cence (RF) measurement. Optical excitation sources and filter wheels to vary detection wavelengths can be programmed to change at almost any time within measurement sequences, including the auto-mated change of an optional wheel holding up to four different detectors. Thermoluminescence meas-urements and preheating are possible with a versatile heater, which can be programmed for linear or non-linear heating or cooling, as well as holding a temperature constant. Rates as well as durations can be varied, together with individual ramping, staging and cooling for an almost unlimited number of steps. Violet- and IR-lasers, green and blue LED-arrays can be operated in continuous (CW) or modulated mode (linear/non-linear), and optionally for pulsed as well as time resolved luminescence detection. Six arrays of power LEDs allow the simulation of different bleaching regimes (‘solar simu-lator’), while luminescence detection can be achieved by a variety of photomultiplier tubes and by CCD cameras for spatially resolved measurements and luminescence spectra.
43
Tesfaye Kebede, Ali, Esakki Balasubramanian, AS Praveen, Lade Rohit e Kumar Arvind. "Preliminary investigations on extrusion of high viscosity slurry using direct writing technique". International Journal for Simulation and Multidisciplinary Design Optimization 11 (2020): 15. http://dx.doi.org/10.1051/smdo/2020012.
Testo completoAbstract (sommario):
Traditionally solid propellants are manufactured using casting and molding techniques. The effective burning rate of solid propellants is strongly depended on its cross section and geometry. The preparation of mold and mandrel for the manufacturability of various geometric profiles are tedious, time consuming, increases the cost and more human efforts are needed. In order to mitigate these issues, a disruptive technology called additive manufacturing (AM) is in the verge of development. Although the method is effective, additional study must be conducted to improve the flow characteristics of slurries for the high solid loading and there is a huge necessity to reduce the prolonged curing time. The present study focuses on preliminary investigations of extrusion of high viscosity slurry using a pneumatically driven extrusion system. The slurry was prepared with a 80 wt.% solid loading of NaCl having particle sizes of 45 µm and 150 µm, 15.6 wt.% HTPB, 2.2 wt.% TDI, 2.2 wt.% DOA and 0.03 wt.% of ferric acrylacetonate. The slurry was extruded with an aid of pneumatically controlled extruder and each layer was formed. Formed by extruding the slurry using 1.65 mm internal diameter nozzle. Infrared (IR) heater was utilized to transfer the radiational energy for partial curing of each layer and thereby adhesion of other layer was guaranteed. Simulation is performed to determine the temperature distribution using ANSYS platform for comparing the curing temperature of the printed part top surface. Preliminary experiments confirm that extrusion of slurry and heating of each layer can be effectively achieved with the proposed 3D printing technique. Three tensile specimens were produced in accordance with ASTMD 412-C and their corresponding mechanical properties are evaluated. The printed parts have the tensile strength of 0.7 MPa, elongation of 4.85 % and modulus of elasticity of 18.5 MPa which are comparable with the properties of conventional casted part.
44
Lietzke, A., A. D. McInturff, R. M. Scanlan, R. Bossert, S. Feher, S. A. Gourlay, M. J. Lamm et al. "Superfluid performance of Tevatron IR quad heaters". IEEE Transactions on Appiled Superconductivity 7, n. 2 (giugno 1997): 606–9. http://dx.doi.org/10.1109/77.614577.
Testo completo
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Stenholm, L. G. "The Origin of AGN-IR Emission". Symposium - International Astronomical Union 159 (1994): 336. http://dx.doi.org/10.1017/s0074180900175400.
Testo completoAbstract (sommario):
Advanced multi dimension radiative transfer calculations for an AGN source with a dust disk shows that the AGN-IR emission can be due to reradiation from heated dust in a thick disk. The models produces a weak silicate feature for a wide range of physical conditions, in agreement with the observations.
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Zagoruyko, M. G., e S. A. Pavlov. "RESEARCH ON KINETICS OF IR-DRYING OF RAPE SEEDS". Vestnik of Ulyanovsk state agricultural academy 230 (25 settembre 2021): 6–11. http://dx.doi.org/10.18286/1816-4501-2021-3-6-11.
Testo completoAbstract (sommario):
The article considers the results of rapeseed drying, which was carried out by convective method on mine, mounted, bunker, as well as recirculation dryers designed for grain drying. Impulse IR drying allowed to intensify the process while preserving the seed quality. Combined method of IR-drying is more effective, in particular, in a fluidized layer at low intensity of the IR-flow, when irradiation is combined with air heating, including oscillation, alternating the supply of heated and outside air in case of continuous IR-irradiation. The duration of IR-drying is calculated for both constant and oscillating heat supplies. The modes of combined IR-drying are experimentally defined. The object of the study was the technological process of drying of rape seeds in a fluidized layer with intensive mixing of the material. The total power of the IR flow and convectively heated heat-transfer agent did not exceed the limiting seed temperature. The calculation of the combined drying duration was carried out similarly to convective drying, and the effect of IR radiation was estimated by the equivalent temperature of the drying agent. A range of experiments was carried out with the IR flow impact on damped rapeseeds when blowing with external and heated air with formation of a fluidized layer. The thickness of the rapeseed layer was changed from 0.05 m to 0.1 m, the speed of the drying agent was 0.65 m / s. The power of the IR lamp varied from 400 W / m2 to 900 W / m2. Seed germination was determined before and after the experiments. The combined IR-drying duration of rape seeds in a fluidized layer was calculated. Well-known calculation expressions for convective drying were used, which included the heat transfer coefficient, moisture removal, specific heat of moisture evaporation, the temperature difference between the drying agent and the mean of the material, as well as the proportion of heat that was used for moisture evaporation, but with an equivalent temperature of the drying agent. The duration of IR drying was calculated in the same way as for convective drying, taking into account the equivalent temperature of the drying agent. It was established that a rational mode of rapeseed IR-drying requires the power of the IR-flow of 0.65 kW / m2, with a variable 5-minute blowing of a rapeseed layer with a height of 0.1 m heated by 25 ° C and outside air with a temperature of 15 ... 20 ° C.
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Tissue, B. M., Lizhu Lu, Li Ma, Weiyi Jia, M. L. Norton e W. M. Yen. "Laser-heated pedestal growth of laser and IR-upconverting materials". Journal of Crystal Growth 109, n. 1-4 (febbraio 1991): 323–28. http://dx.doi.org/10.1016/0022-0248(91)90198-e.
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Sinanoglou, Vassilia J., Angeliki Kavga, Irini F. Strati, Georgios Sotiroudis, Dimitra Lantzouraki e Panagiotis Zoumpoulakis. "Effects of Infrared Radiation on Eggplant (Solanum melongena L.) Greenhouse Cultivation and Fruits’ Phenolic Profile". Foods 8, n. 12 (2 dicembre 2019): 630. http://dx.doi.org/10.3390/foods8120630.
Testo completoAbstract (sommario):
The implementation of Infrared (IR) radiation in heated greenhouses possesses the advantage of high directional control and focused compensation of energy losses, appropriate for creating local microclimate conditions in highly energy-consuming systems, such as greenhouses. Moreover, it can efficiently maintain favorable environmental conditions at the plant canopy. The present study studies the application of Infrared (IR) heating in an experimental greenhouse with eggplant (Solanum melongena L.) cultivation. The experimental results are presented from a full cultivation period inside two identical, small scale experimental greenhouses, with IR and forced air heating system, respectively. The effects of IR heating over plant growth parameters, including the yield of the fruits as well as the total phenolic content and the antioxidant profile of eggplants fruits’ extracts are measured and discussed. The results indicate a greater uniformity production in the IR heating greenhouse in terms of antioxidant and radical scavenging activities, as well as the total phenolic content. Moreover, the phenolic profile of eggplant fruits from both greenhouses revealed the existence of numerous bioactive compounds, some of which were only characteristic of the eggplant fruits from IR heated greenhouses.
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Rydfjord, Jonas, Fredrik Svensson, Magnus Fagrell, Jonas Sävmarker, Måns Thulin e Mats Larhed. "Temperature measurements with two different IR sensors in a continuous-flow microwave heated system". Beilstein Journal of Organic Chemistry 9 (10 ottobre 2013): 2079–87. http://dx.doi.org/10.3762/bjoc.9.244.
Testo completoAbstract (sommario):
In a continuous-flow system equipped with a nonresonant microwave applicator we have investigated how to best assess the actual temperature of microwave heated organic solvents with different characteristics. This is non-trivial as the electromagnetic field will influence most traditional methods of temperature measurement. Thus, we used a microwave transparent fiber optic probe, capable of measuring the temperature inside the reactor, and investigated two different IR sensors as non-contact alternatives to the internal probe. IR sensor 1 measures the temperature on the outside of the reactor whilst IR sensor 2 is designed to measure the temperature of the fluid through the borosilicate glass that constitutes the reactor wall. We have also, in addition to the characterization of the before mentioned IR sensors, developed statistical models to correlate the IR sensor reading to a correct value of the inner temperature (as determined by the internal fiber optic probe), thereby providing a non-contact, indirect, temperature assessment of the heated solvent. The accuracy achieved with these models lie well within the range desired for most synthetic chemistry applications.
50
Johnson, Curtis E., Jean M. Bennett e Melvin P. Nadler. "Oxidation of diamond windows". Journal of Materials Research 10, n. 10 (ottobre 1995): 2555–63. http://dx.doi.org/10.1557/jmr.1995.2555.
Testo completoAbstract (sommario):
Diamond windows were heated at 700-900 °C in air for short times to better define the limits of application at high temperature. The infrared (IR) transmission of polished chemical vapor deposition (CVD) diamond windows was reduced after heating in a furnace at 800 °C for 75 s, while heating at 700 °C for 75 s produced little change. The 800 °C heating caused increased visible light scatter, and increased scatter appears to be mainly responsible for the reduced IR transmission. The forward scatter at 10.6 μm for the CVD diamond samples was 0.8% before heating, 2.8% after heating at 800 °C for 75 s, and 6.2% after heating at 800 °C for 255 s. Single crystal (110) type IIa diamond exhibited little change in IR transmission when heated at 800 °C in air for 255 s, while heating for 555 s at 800 °C caused a significant drop in IR transmittance (6-12%). A slight drop in IR transmittance (1-5%) occurred for a type IIa diamond when heated at 900 °C for 45 s. The etched surfaces were characterized by differential interference contrast optical microscopy, scanning electron microscopy, and Talystep surface profiles. Etched features are concentrated at grain boundaries (for the CVD samples) and at sites with residual damage from mechanical polishing that could not be seen before the heat treatment. Deep etch pits formed at grain boundaries that extend into the bulk of samples.