Journal articles: 'Quenching operation'

1

Rapp, P. "Quenching gases for limited-streamer operation." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 244, no. 3 (April 1986): 430–33. http://dx.doi.org/10.1016/0168-9002(86)91064-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Slama, Salma, Mahmoud Bouhafs, Jamel Bessrour, Moez Ben Jaber, and Hassan Mokdadi. "Numerical simulation of heat transfer during leaf spring industrial quenching process." Mechanics & Industry 19, no. 3 (2018): 304. http://dx.doi.org/10.1051/meca/2018013.

Full text

Abstract:

This study is carried out in partnership with the company CAVEO, manufacturer of leaf springs for vehicles. It concerns the development of a numerical model intended to follow the space-time temperature evolution of a leaf during two processing operations: hot cambering and quenching. This leaf is of a parabolic profile, made of EN-51CrV4 steel (AISI-6150). After austenitization, it passes through a cambering operation to confer it the desired deflection and then a quenching operation. This quenching is carried out in an oil bath to achieve better mechanical properties. The prediction of the temperature during quenching involves determining the heat transfer coefficient between the leaf and the oil bath. This coefficient is determined by quenching, under the same conditions as the leaf, using a standard probe of the same steel. The numerical model is based on the resolution of the transient heat equation by considering the heat loss flows towards the heterogeneous environment (ambient air, press contact and quenching oil). The results obtained by this model give the space-time temperature evolution of the leaf from the exit of the heating furnace to the exit of the oil bath. The numerical results are compared to the experimental profiles obtained through thermographic images throughout cambering and quenching operations. These results are consistent with experimental results.

APA, Harvard, Vancouver, ISO, and other styles

3

Kayed, Somaya, Sherif Saleh, and Heba Shawkey. "ULP Super Regenerative Transmitter with Digital Quenching Signal Controller." Energies 15, no. 19 (September 28, 2022): 7123. http://dx.doi.org/10.3390/en15197123.

Full text

Abstract:

This paper demonstrates an on–off keying (OOK) super-regenerative quenching transmitter operating in 402–405 MHz MICs band applications. To reduce power consumption, the transmitter is controlled by a novel digital quenching signal controller that generates a digital control signal to start transmitter operation when a baseband signal is input to the transmitter. The digital signal controller consists of an envelope detector, a comparator, and a quench timer designed using a state machine to synchronize the operation between the digital controller and the input baseband signal. The transmitter consists of a Colpitts oscillator operating in double operating frequency followed by a frequency divider by 2; this configuration reduces system area and improves phase noise and signal spectrum. The proposed transmitter is implemented using UMC 130 nm CMOS technology and a 1.2 V supply. Simulation shows that the proposed transmitter can meet MICS band mask specifications with data rates up to 1 Mbps and total power dissipation of 537 uW.

APA, Harvard, Vancouver, ISO, and other styles

4

Estey, C. M., S. L. Cockcroft, D. M. Maijer, and C. Hermesmann. "Constitutive behaviour of A356 during the quenching operation." Materials Science and Engineering: A 383, no. 2 (October 2004): 245–51. http://dx.doi.org/10.1016/j.msea.2004.06.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Bogdanova, N., A. Kuzmin, and D. Tretyakov. "Study of cooling properties new quenching media." Journal of Physics: Conference Series 2131, no. 3 (December 1, 2021): 032063. http://dx.doi.org/10.1088/1742-6596/2131/3/032063.

Full text

Abstract:

Abstract The paper presents the results of testing the cooling capacity of a number of quenching oils using the device “IVF SMART QUENCH” of the company [[CHECK_DOUBLEQUOT_ENT]] IVF [[CHECK_DOUBLEQUOT_ENT]] (Sweden). The tests were carried out in order to expand the range of suppliers, to find alternative quenching media that match the cooling characteristics of traditionally used quenching oils. Both new and traditionally used quenching oils for volumetric quenching were tested. The cooling capacity characteristics of the Voltes 16 and Voltes 26 quenching oils were tested in comparison with the Thermo Oil 16 and Thermo Oil 26 oils used. The characteristics of Thermo Oil 16 and Thermo Oil 26 quenching oils in the “before operation” state (selected from storage tanks) were evaluated, and in the “during operation” state (selected directly from the quenching tanks). Based on the results obtained, the quenching media Thermo Oil 16 and Thermo Oil 26 produced by “TNK Lubricants” LLC in Ryazan are recommended for further practical use. The paper uses methods of statistical data processing to determine the characteristics of the stability of technological processes - the reliability and suitability indices.

APA, Harvard, Vancouver, ISO, and other styles

6

Gilles, J., B. Bourouga, and A. Sorin. "Quenching operation of aluminum alloys: measurements and numerical simulations." Revue de Métallurgie 101, no. 9 (September 2004): 695–703. http://dx.doi.org/10.1051/metal:2004105.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Hu, Chong, Teh Hua Ju, and Yong Yao. "Single-Element Passive Quenching with Active Reset Circuit for Single Photon Avalanche Diodes." Applied Mechanics and Materials 644-650 (September 2014): 3709–12. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.3709.

Full text

Abstract:

A single-element passive quenching with active reset (PQAR) circuit is proposed. Its operation mechanism is studied in theory to show that this single element, based on thyristor, can provide similar function of quenching and reset for the free-running Geiger-mode operation of single photon avalanche diodes (SPADs) as the conventional PQAR circuits, but with significant simplicity. Requirement for the thyristor is identified, and an InP sample was designed, fabricated and characterized. Future work for further demonstration is also discussed.

APA, Harvard, Vancouver, ISO, and other styles

8

Jeon, Yongjun, Hyunseok Choi, and Dongearn Kim. "Forming a Flanged Hole When Quenching Press-Hardened Steel for Mechanical Fastening." Metals 11, no. 5 (April 28, 2021): 721. http://dx.doi.org/10.3390/met11050721.

Full text

Abstract:

The recent stringent regulations on vehicle safety and reducing CO2 emissions have led to a continuous increase in the application of press-hardened steel (PHS) in automobiles. Similar to other high-strength steels, assembling PHS components using the common welding techniques employed in automotive production lines is significantly difficult because of the surface coating layers and the additives within. This difficulty in post-processing, attributed to its high strength, also limits the mechanical fastening of PHS components. Therefore, this study aims to develop a process for forming a structure enabling mechanical fastening by sequentially applying piercing and hole-flanging operations during the hot stamping process. Our experimental apparatus was designed to perform the hole-flanging operation after the piercing operation within a single stroke at a specific temperature during the quenching process of PHS. At high temperatures of 440 °C or higher, the hole-flanging process was conducted in a direction opposite to that of the piercing operation for creating the pilot hole. An extruded collar with a height of 8.0 mm and a diameter of 17.5 mm was achieved, which is hole expansion ratio(HER) of 82.5%.

APA, Harvard, Vancouver, ISO, and other styles

9

Zhang, Shi Sheng, Zhe Liu, and Zhao Xiang Zeng. "Systemic Design of Four Vat Energy-Saving Quenching Machine Controller." Advanced Materials Research 383-390 (November 2011): 1138–43. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.1138.

Full text

Abstract:

Quenching is the technology that a metal work piece heated to propriety temperature for a while is being put into quenching medium suddenly. Quenching can improve the rigidity and abrasion resistance of metal. Making use of PLC to control quenching process, the quenching has simple technology, cheap price, stable function and convenient operation. This quenching system constitutes heating system, quenching liquid cycle system, hydraulic pressure system and electric control system. The quenching machine control system introduced in this thesis has three control modes, Manual, Auto and Try-piece designed utilized S7-PLC. This system can rise and fall worktable, clamp and relax work piece, sway forward and backwards, unload-work piece control high degree by approach-switch, produce many kinds of auto-spring plate, meet the requirement of auto-spring plate nowadays. It is presented in this thesis detailed, control-demand, element list for electric control, I/O distribute list, control LAD and improved measure for system in the end.

APA, Harvard, Vancouver, ISO, and other styles

10

Wang, Jian-Guo, Yu Wang, Yuan Yao, Bang-Hua Yang, and Shi-Wei Ma. "Stacked autoencoder for operation prediction of coke dry quenching process." Control Engineering Practice 88 (July 2019): 110–18. http://dx.doi.org/10.1016/j.conengprac.2019.04.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Xu, Qing Yao, Hong Pei Wang, Xiang Chao Hu, Hai Qian, Ying Cheng Peng, Xiao Hang Ren, and Yan Jie Li. "Quenching Circuit of Avalanche Diodes for Single Photon Detection." Applied Mechanics and Materials 437 (October 2013): 1073–76. http://dx.doi.org/10.4028/www.scientific.net/amm.437.1073.

Full text

Abstract:

To reduce the afterpulsing in single photon detection based on avalanche diodes, an advanced passive quenching circuit for operation in free-running mode is developed. The measurement setup is designed. The dark count rate (DCR) and afterpulsing of Single photon avalanche diodes (SPADs) are measured. The results show that the new passive quenching circuit has a better afterpulsing performance compared to traditional circuits.

APA, Harvard, Vancouver, ISO, and other styles

12

Kurbangaleeva, M. Kh, and R. Kh Giniyatullin. "Comprehensive analysis of the treatment plant operation." IOP Conference Series: Earth and Environmental Science 839, no. 4 (September 1, 2021): 042097. http://dx.doi.org/10.1088/1755-1315/839/4/042097.

Full text

Abstract:

Abstract Comparison of the content of manganese (II) andiron (III) ion sin river water and waste water, taking in to account the differentiation of the annual cycle, is carried out. It will allow moving to a comprehensive analysis of the treatment plant. The efficiency checking of the reduction of manganese (II) and iron (III) for a certain period was carried out, taking into account the constant consumption of the volume of water. The efficiency of wastewater treatment from manganese (II) ions is on average 31%, from iron (III) ions - 35%. The results obtained indicate the need for additional measures aimed at minimizing the content of manganese (II) and iron (III) ions in the process waters before the treatment plant. To minimize the content of these ions, it is necessary to select an effective and economic mode for purifying process waters. Purification of process waters from ions of manganese (II) and iron (III) was carried out using the following reagents: potassium permanganate; sodium sulfide; soda ash and sodium phosphate in stage-to-stage processing; suspensions of strong as well as weak milk of lime and brine sludge. For the purification of process waters from ions of manganese (II) and iron (III), industrial waste was proposed: the suspension of weak lime milk obtained after washing large quenching waste(large green coke - incompletely burned material) and used for transporting small quenching waste (small waste) to the sludge collector channel, and brine sludge suspension.

APA, Harvard, Vancouver, ISO, and other styles

13

Köse-Mutlu, Börte, Tülay Ergön-Can, İsmail Koyuncu, and Chung-Hak Lee. "Quorum quenching MBR operations for biofouling control under different operation conditions and using different immobilization media." Desalination and Water Treatment 57, no. 38 (September 11, 2015): 17696–706. http://dx.doi.org/10.1080/19443994.2015.1086899.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Mukhametzyanova, G. F., N. N. Zapadnova, and E. A. Zapadnova. "Features of Technological Materials Application in Thermal Manufacturing." Materials Science Forum 946 (February 2019): 199–204. http://dx.doi.org/10.4028/www.scientific.net/msf.946.199.

Full text

Abstract:

Widely used in thermal production quenching surroundings, gas atmospheres and working mixtures for shot peening are considered. Features of materials at their use are presented and recommendations for more effective application are given. The change of quenching surroundings cooling capacity on the water-soluble polymer basis after an annual operation is shown. Hardening oils during operation are exposed to oxidation and viscosity index change, what affects on the quenched products properties. For endothermic atmospheres that are used in the parts chemical-thermal treatment the composition improvements are required. Working mixtures for shot peening must have a certain composition, properties and sizes, depending on the tasks to be solved.

APA, Harvard, Vancouver, ISO, and other styles

15

Abro, Shahid Hussain, Muhammad Sohail Hanif, and Fayaz Hussain. "On the Effect of γ-phase transformation kinetics upon microstructure response of Cold Heading Quality Steel." NUST Journal of Engineering Sciences 11, no. 2 (December 31, 2018): 51–55. http://dx.doi.org/10.24949/njes.v11i2.399.

Full text

Abstract:

Cold heading quality CHQ steel is a versatile form over other steels as they are used non-heat treated; their strengthening mechanism is achieved through cold heading operations. Metal is therefore stretched without applying any source of heat, metal flow during the cold heading operation must depend on grains flow which increases the mechanical properties such as strength, resistance to indentation and toughness. It is therefore necessary to form the isotropic grains before applying cold heading operation may increase the properties. Gamma phase formation during the heat treatment is crucial factor for cold operation. An effort is made in this research work to study and find out the Austenite nucleation and growth morphology of commercial CHQ steel through continuous heating experiments by utilizing lead-bath up-quenching technique at differentaustenizing temperature ranges. High class Optical Microscope Olympus GX51, scanning electron microscopy techniques have been utilized to reveal and interpret the microstructure and it was found that At the 740°C, the microstructure shows the lack of homogeneity in the structure hence cold-head-ability of CHQ steel is anisotropic but at the high temperature in austenite domain at 60sec the resultant austenite is highly homogenous due to high volume fraction of austenite has been formed then the cold-head-ability properties of CHQ steel turned to be isotropic. Keywords: Up-quenching, cold heading steel, gamma transformation, heating rate etc.

APA, Harvard, Vancouver, ISO, and other styles

16

NAKAJIMA, Ryuichi, Nobuaki KONISHI, Fukio KUWADA, Kazutoshi MATSUMOTO, Yoshio TANI, Takaaki KIMURA, and Toshiharu MATSUDA. "The Development and Operation of Coke Dry Quenching with Double Flues." Tetsu-to-Hagane 74, no. 6 (1988): 970–77. http://dx.doi.org/10.2355/tetsutohagane1955.74.6_970.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Kerekes, Gábor, Mária Kocsisné Baán, and Imre Felde. "Evaluation of Quenchant’s Cooling and Hardening Performance." Materials Science Forum 812 (February 2015): 345–50. http://dx.doi.org/10.4028/www.scientific.net/msf.812.345.

Full text

Abstract:

One of the most critical parts of the heat treatment process, and usually the least controllable one, is the quenching operation. Improper selection or application of a quenching medium, or a drift in its cooling characteristics during its lifetime, may result in products that do not meet specifications and therefore give rise to large additional costs to cover e.g. straightening, rework, rejection, delayed deliveries and, sometimes, lost goodwill for the heat treater. In the case of the use of aqueous polymer solutions, the thermo-kinetic parameters characterizing the heat removal capabilities of a quenchant, are variable, in a specific interval with a complex combination of temperatures (T), concentrations (C) and agitation rates (AR). When the direction and degree of change is known, the characteristics of heat removal can be efficiently modified and predicted within given limits. The aim of the work described in this paper is to investigate how the hardening power of Houghton AquaQuench BW-T depends on the complex influence and interaction of T, C and AR.

APA, Harvard, Vancouver, ISO, and other styles

18

Matyukhin, V. I., S. G. Stakheev, A. V. Matyukhina, and S. Ya Zhuravlev. "Thermal Neutralization Of Excessive Heat Transfer Agent In Coke Dry-Quenching Plants (CDQP)." KnE Materials Science 2, no. 2 (September 3, 2017): 14. http://dx.doi.org/10.18502/kms.v2i2.940.

Full text

Abstract:

The paper considers the problem of reducing emissions of harmful substances in the process of coke dry quenching. It proposes an option for thermal neutralization of excessive heat transfer agent in the coke dry-quenching plants as well as preheating of heat transfer agent and air by exhaust combustion products. The paper presents a process diagram and main process parameters of plant operation. It shows efficient recovery of secondary energy resources in the form of chemical heat in the proposed plant.

APA, Harvard, Vancouver, ISO, and other styles

19

Zisman, A. A., N. Yu Zolotorevsky, S. N. Petrov, E. I. Khlusova, and E. A. Yashina. "Local texture analysis of structure non-uniformity in low carbon high-strength steel after direct quenching." Voprosy Materialovedeniya, no. 3(103) (November 30, 2020): 9–16. http://dx.doi.org/10.22349/1994-6716-2020-103-3-09-16.

Full text

Abstract:

The direct quenching of high-strength steels after hot rolling, which enables discard of the reheating operation, is economically efficient but necessitates a careful analysis of corresponding structural features. In particular, this treatment sometimes results in extended domains of coarse bainite decreasing the fracture toughness of steel. To reveal dependence of such effects on ausforming conditions, local textures of the parent γ-phase have been reconstructed from EBSD orientation data with allowance for the inter-phase orientation relationship. According to the obtained results, the unfavorable structural non-uniformity appears in the direct quenching due to excessive work hardening of austenite at the finish rolling stage; however, the structure and properties of steel can be improved by the reheating and subsequent quenching.

APA, Harvard, Vancouver, ISO, and other styles

20

Khan, Salah Ud-Din, Yuntao Song, and Shahab Ud-Din Khan. "Thermal hydraulic analysis of China fusion engineering test reactor during thermal quenching by comparative approach of Relap5 and THEATRe codes." Modern Physics Letters B 30, no. 30 (November 7, 2016): 1650357. http://dx.doi.org/10.1142/s0217984916503577.

Full text

Abstract:

Thermal quenching in Tokamak reactor is the most obvious phenomenon happens during plasma disruption conditions. The current research is focused on the thermal behavior of different parameters of China fusion engineering test reactor (CFETR) including reactor power, pressure and mass flow rate conditions. The analysis was performed by two thermal hydraulic codes, i.e. THEATRe and Relap5. During the first phase of research, thermal quenching behavior and trends that can be possible during the reactor operation was performed. In the next phase, nodalization diagram of THEATRe and Relap5 codes were developed. The listed parameters were calculated and analyzed for the safety aspects of the reactor. The main objective of the research was to analyze the blanket system of CFETR (Tokamak) for safety concerns during disruption condition. The research will be extended to other components for safe operation of reactor as well.

APA, Harvard, Vancouver, ISO, and other styles

21

Wen, Tao, Li Zhu, and Li Sun. "Numerical Simulation of Cylindrical Hollow Steel Specimen in Quenching." Applied Mechanics and Materials 602-605 (August 2014): 693–96. http://dx.doi.org/10.4028/www.scientific.net/amm.602-605.693.

Full text

Abstract:

using finite element method to study the stress variation of cylindrical specimen during the cooling process of quenching, through the establishment of the computer models of mechanical property and thermal property, and using computer to perform the numerical simulation of temperature environment and structure in the process of quenching, simplify the operation process on one hand, and facilitate the analyses of complicated nonlinear problems on the other hand. The outcome according to the stress variation of the outside surface of cylinder indicates that during the process of quenching, the cooling speed of the inner surface of cylinder is much slower than that of the outer surface, leading to the reverse between the center stress and the outer surface stress of hollow cylinder, which finally turns into internal stress distribution of structural stress type.

APA, Harvard, Vancouver, ISO, and other styles

22

Liu, Shuang, Mujun Long, Songyuan Ai, Yan Zhao, Dengfu Chen, Yi Feng, Huamei Duan, and Mingtu Ma. "Evolution of Phase Transition and Mechanical Properties of Ultra-High Strength Hot-Stamped Steel During Quenching Process." Metals 10, no. 1 (January 16, 2020): 138. http://dx.doi.org/10.3390/met10010138.

Full text

Abstract:

Hot stamping process is widely used in the manufacture of the high strength automotive steel, mainly including the stamping and quenching process of the hot-formed steel. In the hot stamping process, the steel is heated above the critical austenitizing temperature, and then it is rapidly stamped in the mold and the quenching phase transition occurs at the same time. The quenching operation in the hot stamping process has a significant influence on the phase transition and mechanical properties of the hot-stamping steel. A proper quenching technique is quite important to control the microstructure and properties of an ultra-high strength hot-stamping steel. In this paper, considering the factors of the austenitizing temperature, the austenitizing time and the cooling rate, a coupled model on the thermal homogenization and phase transition from austenite to martensite in quenching process was established for production of ultra-high strength hot-stamping steel. The temperature variation, the austenite decomposition and martensite formation during quenching process was simulated. At the same time, the microstructure and the properties of the ultra-high strength hot-stamping steel after quenching at different austenitizing temperature were experimental studied. The results show that under the conditions of low cooling rate, the final quenching microstructure of the ultra-high strength hot-stamping steel includes martensite, residual austenite, bainite and ferrite. With the increase of the cooling rate, bainite and ferrite gradually disappear. While austenitizing at 930 °C, the tensile strength, yield strength, elongation and strength-ductility product of the hot-stamping steel are 1770.1 MPa, 1128.2 MPa, 6.72% and 11.9 GPa%, respectively.

APA, Harvard, Vancouver, ISO, and other styles

23

Hájek, Jiří, Zaneta Dlouha, and Vojtěch Průcha. "Comparison of Industrial Quenching Oils." Metals 11, no. 2 (February 2, 2021): 250. http://dx.doi.org/10.3390/met11020250.

Full text

Abstract:

This article is a response to the state of the art in monitoring the cooling capacity of quenching oils in industrial practice. Very often, a hardening shop requires a report with data on the cooling process for a particular quenching oil. However, the interpretation of the data can be rather difficult. The main goal of our work was to compare various criteria used for evaluating quenching oils. Those of which prove essential for operation in tempering plants would then be introduced into practice. Furthermore, the article describes monitoring the changes in the properties of a quenching oil used in a hardening shop, the effects of quenching oil temperature on its cooling capacity and the impact of the water content on certain cooling parameters of selected oils. Cooling curves were measured (including cooling rates and the time to reach relevant temperatures) according to ISO 9950. The hardening power of the oil and the area below the cooling rate curve as a function of temperature (amount of heat removed in the nose region of the Continuous cooling transformation - CCT curve) were calculated. V-values based on the work of Tamura, reflecting the steel type and its CCT curve, were calculated as well. All the data were compared against the hardness and microstructure on a section through a cylinder made of EN C35 steel cooled in the particular oil. Based on the results, criteria are recommended for assessing the suitability of a quenching oil for a specific steel grade and product size. The quenching oils used in the experiment were Houghto Quench C120, Paramo TK 22, Paramo TK 46, CS Noro MO 46 and Durixol W72.

APA, Harvard, Vancouver, ISO, and other styles

24

Okosun, Tyamo, Samuel Nielson, John D’Alessio, Shamik Ray, Stuart Street, and Chenn Zhou. "On the Impacts of Pre-Heated Natural Gas Injection in Blast Furnaces." Processes 8, no. 7 (July 1, 2020): 771. http://dx.doi.org/10.3390/pr8070771.

Full text

Abstract:

During recent years, there has been great interest in exploring the potential for high-rate natural gas (NG) injection in North American blast furnaces (BFs) due to the fuel’s relatively low cost, operational advantages, and reduced carbon footprint. However, it is well documented that increasing NG injection rates results in declining raceway flame temperatures (a quenching effect on the furnace, so to speak), with the end result of a functional limit on the maximum injection rate that can be used while maintaining stable operation. Computational fluid dynamics (CFD) models of the BF raceway and shaft regions developed by Purdue University Northwest’s (PNW) Center for Innovation through Visualization and Simulation (CIVS) have been applied to simulate multi-phase reacting flow in industry blast furnaces with the aim of exploring the use of pre-heated NG as a method of widening the BF operating window. Simulations predicted that pre-heated NG injection could increase the flow of sensible heat into the BF and promote complete gas combustion through increased injection velocity and improved turbulent mixing. Modeling also indicated that the quenching effects of a 15% increase in NG injection rate could be countered by a 300K NG pre-heat. This scenario maintained furnace raceway flame temperatures and top gas temperatures at levels similar to those observed in baseline (stable) operation, while reducing coke rate by 6.3%.

APA, Harvard, Vancouver, ISO, and other styles

25

Milošević, Miloš, Aleksandar Miltenović, Milan Banić, and Miša Tomić. "DETERMINATION OF RESIDUAL STRESS IN THE RAIL WHEEL DURING QUENCHING PROCESS BY FEM SIMULATION." Facta Universitatis, Series: Mechanical Engineering 15, no. 3 (December 9, 2017): 413. http://dx.doi.org/10.22190/fume170206029m.

Full text

Abstract:

Residual stresses of the rail wheels are influenced by heat treatment during the manufacturing process. The quenching process during the manufacturing results in the residual stresses within the rail wheel that may be dangerous for the rail wheel during its operation. Determination of the residual stress in the rail wheel is important for understanding the damage mechanisms and their influence on the proper work of rail wheels. This paper presents a method for determining the residual stresses in the rail wheel during the quenching process by using the directly coupled thermal-structural analysis in ANSYS software.

APA, Harvard, Vancouver, ISO, and other styles

26

Tikhontseva, N. T., I. P. Savchenko, S. M. Bityukov, O. V. Varnak, and O. A. Sofrygina. "Study of corrosion resistance of pump-compressor pipes made of ferrite-pearlite steel under the action of carbon dioxide mediums." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, no. 5 (May 26, 2021): 572–79. http://dx.doi.org/10.32339/0135-5910-2021-5-572-579.

Full text

Abstract:

To ensure required complex of steel strength properties, pipes heat treatment is widely used as a quenching for martensite followed by tempering. It is accepted, that metal microstructure formed at that, has a little effect on a steel corrosion resistance in carbon dioxide mediums. Studies were accomplished of steel microstructure effect of the carbon dioxide corrosion speed. In particular, a low-alloyed structural steel, used for production of oil field pipes was selected. As the object of the study, seamless pumpcompressor pipes (PCP), made of medium-carbon steels of several grades with chrome content about 1% (mass.), subjected to two methods of heat treatment: quenching with tempering or normalization with tempering. Corrosion resistance of the steels were accomplished under laboratory conditions of JSC “RusNITI” by application of autoclave facility imitating operation conditions parameters of a working medium at oil extraction. The speed of general metal corrosion was measured as samples mass loss during tests (from 360 to 70 hours) by gravimetric method. By the results of laboratory tests the steel 35ХГФА was recommended to the industrial production of PCP of K72 and N80 strength groups due to GOST 31446 with normalization and tempering. It was established that pipes of steel 35ХГФА with ferrite-pearlite microstructure have higher corrosion resistance in mineralized water mediums at carbon dioxide partial pressure up to 0.20 atm, comparing with regular pipes, manufactured with quenching and tempering. A complex of field tests of PCP was carried out, the pipes made of experimental steel 35ХГФА at an oil deposit. The result of operation of CPC of 88.9×6.45 mm made of steel 35ХГФА having K72 group of strength (after normalization with tempering) during 550 days under conditions of high-mineralized water phase at СО2 partial pressure up to 0.27 atm was found positive. After an intermediate inspection (550 days) the column of PCP was assembled and is in operation at present, the current running time exceeding 1000 days. Based on the results of the complex comparative tests carried out in the corrosion laboratory and under field oil extraction conditions it was established that usage of experimental steel 35ХГФА containing 1% of Cr, after application of normalization technology with tempering resulted in increasing of operating reliability of CPC.

APA, Harvard, Vancouver, ISO, and other styles

27

Xu Ming, 徐鸣, 李孟霞 Li Mengxia, 安鑫 An Xin, 卞康康 Bian Kangkang, and 施卫 Shi Wei. "Infrared quenching operation of non-linear GaAs photoconductive semiconductor switch for terahertz generation." Infrared and Laser Engineering 45, no. 4 (2016): 0425001. http://dx.doi.org/10.3788/irla201645.0425001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Buczek, A., and T. Telejko. "Inverse determination of boundary conditions during boiling water heat transfer in quenching operation." Journal of Materials Processing Technology 155-156 (November 2004): 1324–29. http://dx.doi.org/10.1016/j.jmatprotec.2004.04.192.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Abdullin, S. Yu, and A. O. Kachura. "SUBECONOMIZER FOR IMPROVENT OF ENERGY EFFICIENCY OF CDQ PLANT MODULE." Journal of Coal Chemistry 5 (2021): 12–15. http://dx.doi.org/10.31081/1681-309x-2021-0-5-12-15.

Full text

Abstract:

The article is devoted to the adjustment of the efficiency of the coke dry quenching plant (CDQP) by installing the subeconomizer in the technological scheme of coke production. A work description is presented of the subeconomizers and analyzes the advantages of the subeconomizers on the existing and new CDQP blocks. It has been emphasized that in coke production one of the most important factors is the need to work all parts of the technological chain with the full productivity. Decreased productivity or disruptions in certain areas can lead to significant losses of the final product. It is shown that the dry coke quenching plant should ensure not only stable operation of the coke battery, but also the required level of coke supply for blast furnace production. Therefore, violation of the technological regime of DCQP can critically affect the production of iron and steel. The feature of dry coke quenching technology is emphasized: the increase in productivity inevitably causes an increase of the temperature of quenched coke. It is shown that one of the ways to maintain the temperature of the quenched coke at the required level is to install a subeconomizer (SE) in the scheme of DCQP. The experience of SE "GIPROKOKS" in designing the reconstruction of existing DCQP is underlined. Data on the operation of the DCQP with the SE included in the technological scheme (which has been successfully operated for more than three years) and without it are given. SE "GIPROKOKS" studies, develops and implements new technologies that can be used in the construction of new coke plants, as well as in the reconstruction of existing ones. It is shown that the use of subeconomizers in dry coke quenching plants allows to increase the productivity of DCQP units on quenched coke by about 10 % while maintaining the required temperature and quality of the obtained coke. Keywords: dry coke quenching, temperature of quenched coke, coke yield, subeconomizer, energy efficiency. Corresponding author S.Yu. Abdullin, е-mail: abdullins1979@gmail.com

APA, Harvard, Vancouver, ISO, and other styles

30

Berezovskaya, Vera V., Eugeny A. Merkushkin, and Yu A. Raskovalova. "Structure Formation in High-Nitrogen Steel during Heat Treatment." Solid State Phenomena 284 (October 2018): 447–54. http://dx.doi.org/10.4028/www.scientific.net/ssp.284.447.

Full text

Abstract:

Steel 06Cr18Mn19Mo2N (P900N + Mo) was chosen to study the phase composition and structural transformations occurring in high-nitrogen nickel-free austenitic steels as a result of heat treatments to which they are exposed during production or operation. The methods of light and electron microscopy, X-ray diffraction and dilatometric analysis were used in the work. The heat treatment scheme included hot plastic deformation, quenching and aging over a wide temperature range. It is shown that after the hot plastic deformation and quenching from 1050-1150 °С, and also after quenching with subsequent aging at 300 and 500 °С, the structure consists of austenite and isostructural matrix of nanoscale nitrides CrN. Thermal aging of steel at 700-750 °C causes the formation of Mo2N nitrides along the grain boundaries, and at 800 °C the decomposition of austenite is accompanied by a discontinuous reaction γγdepleted + σ with the formation of the χ-phase at prolonged exposures.

APA, Harvard, Vancouver, ISO, and other styles

31

Park, Soomin, Collin J. Steen, Dagmar Lyska, Alexandra L. Fischer, Benjamin Endelman, Masakazu Iwai, Krishna K. Niyogi, and Graham R. Fleming. "Chlorophyll–carotenoid excitation energy transfer and charge transfer in Nannochloropsis oceanica for the regulation of photosynthesis." Proceedings of the National Academy of Sciences 116, no. 9 (February 11, 2019): 3385–90. http://dx.doi.org/10.1073/pnas.1819011116.

Full text

Abstract:

Nonphotochemical quenching (NPQ) is a proxy for photoprotective thermal dissipation processes that regulate photosynthetic light harvesting. The identification of NPQ mechanisms and their molecular or physiological triggering factors under in vivo conditions is a matter of controversy. Here, to investigate chlorophyll (Chl)–zeaxanthin (Zea) excitation energy transfer (EET) and charge transfer (CT) as possible NPQ mechanisms, we performed transient absorption (TA) spectroscopy on live cells of the microalga Nannochloropsis oceanica. We obtained evidence for the operation of both EET and CT quenching by observing spectral features associated with the Zea S1 and Zea●+ excited-state absorption (ESA) signals, respectively, after Chl excitation. Knockout mutants for genes encoding either violaxanthin de-epoxidase or LHCX1 proteins exhibited strongly inhibited NPQ capabilities and lacked detectable Zea S1 and Zea●+ ESA signals in vivo, which strongly suggests that the accumulation of Zea and active LHCX1 is essential for both EET and CT quenching in N. oceanica.

APA, Harvard, Vancouver, ISO, and other styles

32

Turoň, Rostislav, Michael Squerzi, Milan Hnízdil, Martin Chabičovský, Pavel Simeček, and Miroslav Kreisinger. "DEVELOPMENT OF THE TUBE QUENCHING PROTOTYPE UNIT." Acta Metallurgica Slovaca 24, no. 3 (September 26, 2018): 251. http://dx.doi.org/10.12776/ams.v24i3.1163.

Full text

Abstract:

<p class="AMSmaintext">This paper describes the stages of applied research and development leading to a functional prototype of a quenching unit. It became a part of a closed facility of process equipment for thermal treatment by refining and other methods of annealing of seamless steel tubes for the OCTG industry (Oil Country Tubular Goods), power engineering and mechanical engineering in Třinecké Železárny. The development of the prototype has been divided into several stages: mapping of the current state and critical assessment of the technical and technological level of the existing equipment in the Tube Mill, laboratory testing of tube samples cooling, including numerical simulations with the prediction of the initial settings of the process parameters for the recommendation of the technological configuration of the quenching unit prototype and finally a comprehensive technical design of the prototype quenching unit. The design of the prototype technical solution served as the basis for the creation of the detailed engineering documentation with the subsequent construction of the prototype quenching unit. The paper summarizes the procedures and results of individual development stages, including the results of measured temperatures of tubes during actual operation of the prototype and the results of additional numerical simulations of its actual cooling capacity.</p>

APA, Harvard, Vancouver, ISO, and other styles

33

Shaidurova, Galina Ivanovna, Sergey Vladimirovich Patrulin, and Aleksandr Aleksandrovich Nazartsev. "Optimization of Solid Rocket Motor Quenching in Gas Dynamic Tunnels during Firing Bench Tests." Key Engineering Materials 743 (July 2017): 269–72. http://dx.doi.org/10.4028/www.scientific.net/kem.743.269.

Full text

Abstract:

The paper presents the experimental results that allow determining optimum quenching conditions for solid rocket motors (SRM) at the stage of firing bench tests (FBT) in gas dynamic tunnels (GDT) with altitude simulation. The work describes main design approaches for quenching unit enabling reduced thermal insulation (TI) destruction by 15-20% after finish of SRM operation due to aftereffect decrease, as well as reduced values of scattering of TI undamaged layer thickness up to 10% owing to uniform cooling.If necessary, drying accompanied with emissions of TI gaseous products and remnants of k-phase fuel components is run in GDT, which allows improving environmental safety of working facilities and shortening the time for evaluation of SRM design parameters.

APA, Harvard, Vancouver, ISO, and other styles

34

Deraman, Rasdi, and M. N. Berhan. "Quenching Heat Treatment Effects on the Mechanical and Microstructure Properties of AISI 304 Type Welded by GMAW Process Using Different Shielding Gases." Applied Mechanics and Materials 465-466 (December 2013): 983–87. http://dx.doi.org/10.4028/www.scientific.net/amm.465-466.983.

Full text

Abstract:

As-received samples of an austenitic stainless steel AISI 304 type was welded by Gas metal arc welding (GMAW) robotic operation process using ER308L-Si filler metal wire. Two different atmospheres were used: 68% Argon plus 32% CO2, and 100% Argon. The aim of this study is investigates the influence of quenching heat treatment on the mechanical and microstructure properties of AISI 304 type which welded by GMAW under different shielding gas compositions. The fractured surfaces of the tensile test specimens examined using scanning electron microscopy (S.E.M). The results showed that the welding using shielding gas of 68% Argon plus 32% CO2stronger than 100% Argon. After performed quenching heat treatment process, both specimens experienced a slight decreased in hardness.

APA, Harvard, Vancouver, ISO, and other styles

35

Vasan, A., and Komaragiri Srinivasa Raju. "Comparative analysis of Simulated Annealing, Simulated Quenching and Genetic Algorithms for optimal reservoir operation." Applied Soft Computing 9, no. 1 (January 2009): 274–81. http://dx.doi.org/10.1016/j.asoc.2007.09.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Sydorchuk, О. "DIE STEEL 4Х4Н5М4Ф2 (WITHOUT FORGING TREATMENT) FOR HOT DEFORMATION OF ALUMINUM ALLOY." Innovative Materials and Technologies in Metallurgy and Mechanical Engineering, no. 2 (January 9, 2023): 46–49. http://dx.doi.org/10.15588/1607-6885-2022-2-8.

Full text

Abstract:

Purpose. Production of steel with controlled austenitic transformation during operation of the 4Х4Н5М4Ф2 grade (without forging treatment) using the technology of electroslag remelting and establishing optimal modes of heat treatment (annealing, quenching and tempering). Production of tools (matrices) from 4Х4Н5М4Ф2 steel (without forging treatment) for hot deformation of aluminum alloy at operating temperatures below the critical point A1. Research methods. Metallographic analysis of experimental die steels 4Х4Н5М4Ф2 (without forging treatment) and forged 4Х5МФ1С: study of metal structure; determination of specific resistance; determination of tensile strength; determination of hardness and impact strength. Results. The results of research on the optimization of heat treatment modes (quenching and tempering) of 4Х4Н5М4Ф2 steel (without forging treatment) are given. Adjusted chemical composition (4Х4Н5М4Ф2) and optimized mode of heat treatment of steel, which allowed to increase heat resistance up to a temperature of 650 °С. The tempering temperature of steel (475±25 °С) at which irreversible temper brittleness occurs is established. Experimental and industrial tests of steel 4Х4Н5М4Ф2 (without forging treatment) for hot deformation of AK7ч aluminum alloy are presented. It is shown that compared to forged steel H13 (an analogue of 4Х5МФ1С), which is used at one of the Chinese enterprises, the experimental steel has practically the same resistance . Scientific novelty. In the process of partial recrystallization (incomplete annealing at a temperature of 750±20 °C) of 4Х4Н5М4Ф2 steel (without forging treatment), a spheroidized carbide component is formed, which leads to an improvement in the mechanical processing of the workpiece for the manufacture of matrices. Practical value. The possibility of using steel with an adjustable austenitic transformation during operation of the 4Х4Н5М4Ф2 grade (without forging treatment) is shown for a wide range of operating temperatures of hot deformation: copper-nickel (at an operating temperature above the critical point A3) and aluminum alloy (at an operating temperature below the critical point A1) with increased service life compared to forged steel 4Х5МФ1С.

APA, Harvard, Vancouver, ISO, and other styles

37

Jiao, Xinmeng, Kang Xie, and Liping Qiu. "Membrane bioreactors for wastewater treatment: A review of microbial quorum sensing and quenching to control membrane biofouling based on engineering quorum quenching bacteria." E3S Web of Conferences 194 (2020): 04026. http://dx.doi.org/10.1051/e3sconf/202019404026.

Full text

Abstract:

Membrane bioreactor (MBR) is a kind of reputable and prospective technology for wastewater treatment and reformation applications. However, membrane fouling caused by the formation of biofilm on the membrane surface, especially biofouling, is a major obstacle that limits the energy-saving operation and maintenance of the membrane bioreactor (MBR). Microbial communication (known as Quorum Sensing (QS)) is the cause of this fouling phenomenon. A new strategy called Quorum Quenching (QQ) seems to have been successfully used for biological pollution control in wastewater treatment MBR. This review summarizes the latest findings regarding membrane fouling, QS mechanisms and QQ applications. We discussed the opportunities for further practical application of self-cleaning engineering QQ bacteria in MBR.

APA, Harvard, Vancouver, ISO, and other styles

38

Hussein, Abbas Khammas, Laith Kais Abbas, and Asraa Kareem Hameed. "Effect of Carburization Parameters on Hardness of Carburized Steel Using MOORA Approach." Al-Khwarizmi Engineering Journal 14, no. 3 (September 4, 2018): 92–99. http://dx.doi.org/10.22153/https://doi.org/10.22153/kej.2018.02.001.

Full text

Abstract:

In this research, (MOORA) approach based– Taguchi design was used to convert the multi-performance problem into a single-performance problem for nine experiments which built (Taguchi (L9) orthogonal array) for carburization operation. The main variables that had a great effect on carburizing operation are carburization temperature (oC), carburization time (hrs.) and tempering temperature (oC). This study was also focused on calculating the amount of carbon penetration, the value of hardness and optimal values obtained during the optimization by Taguchi approach and MOORA method for multiple parameters. In this study, the carburization process was done in temperature between (850 to 950 ᵒC) for 2 to 6 hours. Quenching was done for the specimens after heat treatments in furnace chamber by using different quench solutions, water, salt and polyvinyl alcohol. Analysis of variances - (ANOVA) were performed for nine experiments in order to optimize the problem that was associated with multiple criteria (parameter) to achieve maximum hardness and depth penetration. The program results showed that the optimum conditions are carburization temperature (950 oC), carburization time (2 hrs.), tempering temperature (200oC), tempering time (10 hrs.), and activator (10 wt. %). Furthermore, the best quenching media was the polyvinyl alcohol.

APA, Harvard, Vancouver, ISO, and other styles

39

Hussein, Abbas Khammas, Laith Kais Abbas, and Asraa Kareem Hameed. "Effect of Carburization Parameters on Hardness of Carburized Steel Using MOORA Approach." Al-Khwarizmi Engineering Journal 14, no. 3 (September 4, 2018): 92–99. http://dx.doi.org/10.22153/kej.2018.02.001.

Full text

Abstract:

In this research, (MOORA) approach based– Taguchi design was used to convert the multi-performance problem into a single-performance problem for nine experiments which built (Taguchi (L9) orthogonal array) for carburization operation. The main variables that had a great effect on carburizing operation are carburization temperature (oC), carburization time (hrs.) and tempering temperature (oC). This study was also focused on calculating the amount of carbon penetration, the value of hardness and optimal values obtained during the optimization by Taguchi approach and MOORA method for multiple parameters. In this study, the carburization process was done in temperature between (850 to 950 ᵒC) for 2 to 6 hours. Quenching was done for the specimens after heat treatments in furnace chamber by using different quench solutions, water, salt and polyvinyl alcohol. Analysis of variances - (ANOVA) were performed for nine experiments in order to optimize the problem that was associated with multiple criteria (parameter) to achieve maximum hardness and depth penetration. The program results showed that the optimum conditions are carburization temperature (950 oC), carburization time (2 hrs.), tempering temperature (200oC), tempering time (10 hrs.), and activator (10 wt. %). Furthermore, the best quenching media was the polyvinyl alcohol.

APA, Harvard, Vancouver, ISO, and other styles

40

Lei, X., and C. J. Lissenden. "Finite Element Simulation of Ausforming of Austempered Ductile Iron Components." Journal of Manufacturing Science and Engineering 123, no. 3 (October 1, 2000): 420–25. http://dx.doi.org/10.1115/1.1380383.

Full text

Abstract:

The mechanical properties of ductile iron can be improved by ausforming, that is, applying work during austempering. The resulting yield strength and ductility are comparable to those of SAE 4140 steel, while the density is approximately 10 percent less. The viability of manufacturing components by casting a preform, austenitizing it, quenching it to the austempering temperature, forging it, austempering it, and finally, quenching it to the net shape is investigated by simulating the forging operation with finite element analysis. The preform geometry and die set geometry are determined such that the forging operation imparts a reasonably uniform equivalent plastic strain of 20 percent to the workpiece and the prescribed final component geometry is obtained. Forging of two components of varying geometric complexity is simulated using a commercial software package. The results indicate that the geometry of the final part is reasonably close to the goal and that the equivalent plastic strain distribution is reasonably uniform—over 80 percent of the material was plastically deformed 15–25 percent. The design of the preform and die sets appears to be an excellent application for an optimization algorithm.

APA, Harvard, Vancouver, ISO, and other styles

41

Balanyuk, V., N. Kozyar, and A. Kravchenko. "PROSPECTS AEROSOL SUBLAYER QUENCHING OF ALCOHOLS." Fire Safety 35 (February 26, 2020): 5–9. http://dx.doi.org/10.32447/20786662.35.2019.01.

Full text

Abstract:

The study addresses the problems of gas alcohols and describes the factors that make the fire extinguishing efficiency of aerosol refractory gas alcohol. To date, alcohol storage facilities are not sufficiently protected, as evidenced by the fires that occur on them. The actuality of the work is emphasized by the fact that the fires at the objects for the storage and processing of alcohols and their mixtures are characterized by a high velocity of flame propagation up to 10 m / s, and the achievement of high values of temperatures inside the volume in the first minutes, the possibility of explosions of both gas and air mixtures and pressure vessels subjected to heat. The article theoretically describes the quenching process and shows that such quenching must be effective at the expense of synergies between the factors of influence. The paper presents the analysis and theoretical generalizations of the process of extinguishing alcohols and alcohol-containing liquids. The disadvantages of quenching alcohols and alcohol-containing liquids by foam agents are indicated. The process of quenching by inert gas is considered and the method of sublayer quenching of alcohols by extinguishing aerosol is proposed. It is established that sublayer quenching by aerosol occurs in 3 stages. At the first stage - at the exit of the aerosol there will be mixing of the liquid, reducing the surface temperature of the combustible liquid and equalizing the temperature on its height the column of the liquid. At the second stage - after the aerosol exits the fluid layer and enters the surface, the concentrations of the components of the combustion mixture are reduced, the radiation shielded from the combustion zone and its influence on the surface of the combustible liquid and the sides of the tank are reduced. At the third stage, when the aerosol enters the combustion zone, the following extinguishing factors are realized: inhibition, phlegmatization, cooling, and partially change of physical parameters, such as increase in pressure and volume. The combination of these factors at the same time provides a significant reduction in the time of quenching of alcohol compared to conventional methods of quenching. By the result of the analysis of the process of extinguishing alcohol and alcohol-containing mixtures by different extinguishing agents it has been theoretically substantiated and experimentally confirmed the high efficiency of sublayer quenching by gas-aerosol mixtures of alcohols and their mixtures. The advantages of this type of extinguishing are the low cost of the fire extinguishing system, the considerable period of operation, the high extinguishing efficiency and ease of maintenance and use.

APA, Harvard, Vancouver, ISO, and other styles

42

Dementiy, Yuri A., Evgeny V. Shornikov, and Kirill P. Nikolaev. "SMART ALGORITHM FOR INTERVAL ESTIMATION OF ARC-QUENCHING REACTOR PARAMETERS." Vestnik Chuvashskogo universiteta, no. 3 (September 29, 2021): 64–72. http://dx.doi.org/10.47026/1810-1909-2021-3-64-72.

Full text

Abstract:

The purpose of the arc suppression reactor is to reduce the capacitive current of the network to a safe level where the single-phase earth fault current at the fault location does not exceed five amperes. The current reduced to a permissible level prevents open arcing at the fault location. For proper operation of this device, the arc suppression reactor control automatics needs to adjust the zero-sequence circuit to resonance, which balances the capacitive current of the mains and the inductive current of the reactor. To perform this tuning, it is not necessary to have information about the absolute values of the parameters of the zero-sequence circuit, but by determining them, the automation device is able to solve a wider range of tasks related to network diagnostics and increasing the efficiency of the arc suppression reactor. In this article we consider an approach to solving the problem of parametric identification of arc suppression reactor using the method of interval estimation of object parameters. The information about the operation modes of the arc suppression reactor is obtained by means of a simulation model of the object. Using the observed values, the object parameters are obtained by use of the inverse function to the simulation model. The dependence of the object parameters on the observed parameters is approximated using upper and lower parameter estimation models. The quantile regression method was applied to tune the estimation models. The need to increase the generalization ability of the algorithm is revealed. The method of adjustment of parameters of regularization of learning process to increase generalization ability of algorithm without increase of informativity of data in a training sample is offered. The results of algorithm performance are presented on the example of magnetization branch parameters estimation of arc suppression reactor. The boundaries of the interval of equivalent magnetic core loss resistance and magnetizing inductance are obtained. The limitations of the methods are analyzed, and recommendations for improving the quality of the algorithms are given.

APA, Harvard, Vancouver, ISO, and other styles

43

Zavvari, Mahdi, and Vahid Ahmadi. "Quantum-Dot-Based Mid-IR Single-Photon Detector With Self-Quenching and Self-Recovering Operation." IEEE Electron Device Letters 34, no. 6 (June 2013): 783–85. http://dx.doi.org/10.1109/led.2013.2258396.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Serôdio, J., S. Cruz, S. Vieira, and V. Brotas. "Non-photochemical quenching of chlorophyll fluorescence and operation of the xanthophyll cycle in estuarine microphytobenthos." Journal of Experimental Marine Biology and Ecology 326, no. 2 (December 2005): 157–69. http://dx.doi.org/10.1016/j.jembe.2005.05.011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Yatsyshyn, Svyatoslav, Pylyp Skoropad, and Mikolaj Karpinski. "ELECTRICAL PROPERTIES OF TI-CU-CO-SI HIGH-ENTROPY ALLOY." Measuring Equipment and Metrology 83, no. 2 (2022): 17–20. http://dx.doi.org/10.23939/istcmtm2022.02.017.

Full text

Abstract:

To study the metrological characteristics, there were studied manufactured based on the Ti-Cu-Co-Si alloy, obtained by quenching from the melt, the sensitive element of the resistance thermotransducer. The instability of its metrological characteristics as a function of temperature up to 350 oC and operation time up to 3000 hours was investigated; it does not exceed 0.025% under the worst operating conditions. In addition, the methodological error of measurement caused by heating of the sensitive element by the measuring current was examined. It was shown that the recorded changes in electrical resistance were outside the value of the methodological error. They may be due to the presence of nanostructured fields of mechanical stresses and the formation of nanoprecipitates as a consequence of manufacturing.

APA, Harvard, Vancouver, ISO, and other styles

46

Filippov, M. A., V. A. Sharapova, L. A. Moshechkova, and S. O. Morozov. "Effect of High-Temperature Quenching on the Phase Composition, Structure, and Wear Resistance of Ni-Hard Chromium-Nickel Cast Iron." MATEC Web of Conferences 346 (2021): 02025. http://dx.doi.org/10.1051/matecconf/202134602025.

Full text

Abstract:

Metallographic, micro-X-ray spectral and X-ray structural analyses have been carried out. The quenching temperature increase from 900 to 1150 °C leads to high abrasive wear resistance in Ni-hard chromium-nickel cast iron. The initial hardness decreased before the test from 60 to 35 HRC due to the fact that the phase composition of the metal base before the wear test changes during quenching from medium-carbon martensite with secondary cementite to retained metastable austenite. It contributes to increase the crack resistance of cast iron. Austenite turns into dispersed friction martensite on the working surface in the process of wear testing or operation, as a result of the impact of abrasive particles. This martensite together with a part of cementite provides a high level of hardening and operability of the cast iron secondary microstructure.

APA, Harvard, Vancouver, ISO, and other styles

47

Farina, S., I. Labanca, G. Acconcia, M. Ghioni, and I. Rech. "10-nanosecond dead time and low afterpulsing with a free-running reach-through single-photon avalanche diode." Review of Scientific Instruments 93, no. 5 (May 1, 2022): 053102. http://dx.doi.org/10.1063/5.0086312.

Full text

Abstract:

The reduction of detector dead time represents an enabling factor in several photon counting applications. In this work, we investigate the free-running operation of reach-through single-photon avalanche diodes (SPADs) at ultra-low dead times. By employing a fast active quenching circuit with direct bonding to the detector, we are able to achieve a 10 ns dead time with a thick SPAD by Excelitas, still maintaining extremely low afterpulsing probabilities (below 1.5%).

APA, Harvard, Vancouver, ISO, and other styles

48

Yin, Fu, and El-Sankary. "A PVT-Robust Super-Regenerative Receiver with Background Frequency Calibration and Concurrent Quenching Waveform." Electronics 8, no. 10 (October 4, 2019): 1119. http://dx.doi.org/10.3390/electronics8101119.

Full text

Abstract:

A process-voltage-temperature (PVT)-robust, low power, low noise, and high sensitivity, super-regenerative (SR) receiver is proposed in this paper. To enable high sensitivity and robust-PVT operation, a fast locking phase-locked-loop (PLL) with initial random phase error reduction is proposed to continuously adjust the center frequency deviations of the SR oscillator (SRO) without interrupting the input data stream. Additionally, a concurrent quenching waveform (CQW) technique is devised to improve the SRO sensitivity and its noise performance. The proposed SRO architecture is controlled by two separate biasing branches to extend the sensitivity accumulation (SA) phase and reduce its noise during the SR phase, compared to the conventional optimal quenching waveform (OQW). The proposed SR receiver is implemented at 2.46 GHz center frequency in 180 nm SMIC CMOS technology and achieves better sensitivity, power consumption, noise performance, and PVT immunity compared with existent SR receiver architectures.

APA, Harvard, Vancouver, ISO, and other styles

49

Trusek, Anna, Maciej Wajsprych, and Andrzej Noworyta. "Low- and High-Pressure Membrane Separation in the Production of Process Water for Coke Quenching." Membranes 11, no. 12 (November 27, 2021): 937. http://dx.doi.org/10.3390/membranes11120937.

Full text

Abstract:

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage.

APA, Harvard, Vancouver, ISO, and other styles

50

Smołka, Tristan, Katarzyna Posmyk, Maja Wasiluk, Paweł Wyborski, Michał Gawełczyk, Paweł Mrowiński, Monika Mikulicz, et al. "Optical Quality of InAs/InP Quantum Dots on Distributed Bragg Reflector Emitting at 3rd Telecom Window Grown by Molecular Beam Epitaxy." Materials 14, no. 21 (October 21, 2021): 6270. http://dx.doi.org/10.3390/ma14216270.

Full text

Abstract:

We present an experimental study on the optical quality of InAs/InP quantum dots (QDs). Investigated structures have application relevance due to emission in the 3rd telecommunication window. The nanostructures are grown by ripening-assisted molecular beam epitaxy. This leads to their unique properties, i.e., low spatial density and in-plane shape symmetry. These are advantageous for non-classical light generation for quantum technologies applications. As a measure of the internal quantum efficiency, the discrepancy between calculated and experimentally determined photon extraction efficiency is used. The investigated nanostructures exhibit close to ideal emission efficiency proving their high structural quality. The thermal stability of emission is investigated by means of microphotoluminescence. This allows to determine the maximal operation temperature of the device and reveal the main emission quenching channels. Emission quenching is predominantly caused by the transition of holes and electrons to higher QD’s levels. Additionally, these carriers could further leave the confinement potential via the dense ladder of QD states. Single QD emission is observed up to temperatures of about 100 K, comparable to the best results obtained for epitaxial QDs in this spectral range. The fundamental limit for the emission rate is the excitation radiative lifetime, which spreads from below 0.5 to almost 1.9 ns (GHz operation) without any clear spectral dispersion. Furthermore, carrier dynamics is also determined using time-correlated single-photon counting.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Quenching operation'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles