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A. Zarei Hanzaki Ph.D. Student R. Pandi Ph.D. Student P. D. Hodgson S. Yue 《Metallurgical and Materials Transactions A》1993,24(12):2657-2665
In the processing of steel, the design of any kind of heat treatment and/or thermomechanical processing schedule, to obtain
a given microstructure, is greatly facilitated by the knowledge of the austenite-to-ferrite transformation characteristics.
In the past, isothermal and continuous cooling tests were used in the laboratory to create time-temperature-transformation
and continuous cooling transformation diagrams, respectively, which then served as the source of transformation data. The
problem with such information is that it is only truly applicable to one particular microstructure, usually one resulting
from a simple reheating cycle in the austenite region. Most industrial steel processing operations additionally involve several
stages of high-temperature deformation leading to changes in the microstructure emerging from the final pass. To account for
this situation, a novel laboratory method for the determination of the transformation characteristics, based on continuous
cooling deformation testing, was developed. A major attraction of this test technique is that the specific microstructure,
for which the transformation characteristics are required, can be generated by hot deformation and then immediately evaluated
by continuous cooling deformation. In this article, the basic continuous cooling deformation test technique and general methods
of data analysis are illustrated, using results from several different grades of steel.
Formerly with the Department of Mining and Metallurgical Engineering, McGill University 相似文献
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This paper investigates what impact optical node failures may have on wavelength-division-multiplexed networks, in which reliable end-to-end optical circuits are provisioned dynamically. At the node level, the optical cross-connect (OXC) equipment availability measure is estimated using proven component level availability models. At the network level, end-to-end optical circuits are provisioned only when the level of connection availability required by the application can be guaranteed. With the objective of yielding efficient utilization of the network resources, i.e., fibers and OXCs, circuit redundancy is achieved by means of shared path protection (SPP) switching, in combination with differentiated reliability (DiR). The resulting optimal routing and wavelength assignment problem is proven to be NP-complete. To produce suboptimal solutions in polynomial time, a heuristic technique is presented, which makes use of a time-efficient method to estimate the end-to-end circuit availability in the presence of multiple (link and node) failures. Using the proposed heuristic, a selection of representative OXC architectures and optical switching technologies is examined to assess the influence of the node equipment choice on the overall network performance. 相似文献
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A novel stochastic optimisation approach to solve constrained economic load dispatch problem using hybrid bacterial foraging (BF) technique is presented. in order to explore the search space for finding the local minima of the current location, the simplex algorithm called nelder-mead is used along with BF algorithm. the proposed methodology easily takes care of solving non-convex economic dispatch problems along with different constraints such as transmission losses, dynamic operation constraints (ramp rate limits) and prohibited zones. simulations were performed over various standard test systems with different number of generating units and comparisons are performed with other existing relevant approaches. the findings affirmed the robustness and proficiency of proposed methodology over other existing techniques. 相似文献
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In this article, we report in situ fabrication of meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) nanostructures with excitonic absorption on glass substrate. The exposure of TPPS thin film coated on a glass plate to HCl vapor resulted in the formation of nanostructures of TPPS. The formed TPPS nanostructures on glass plate were characterized by UV-vis, steady state emission spectral techniques, atomic force microscopy, and high resolution transmission electron microscopy (HR-TEM). A new sharp and intense absorption band (excitonic band) at 490 nm was observed for TPPS nanostructures on glass plate. Protonation of tertiary nitrogen atoms of TPPS ring by HCl molecules leads to the formation of nanostructures of J-aggregates of TPPS on glass surface. The height of the TPPS nanostructures was found to be 50-170 nm with an average width of 100 nm. HR-TEM images showed that the formed TPPS J-aggregates consist of tiny nanorods. The size of the nanostructures was tuned successfully by varying the concentration of TPPS used for thin film preparation. 相似文献
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Sekaran Muthamil Selvan Kabali Vijai Anand Kasivelu Govindaraju Selvaraj Tamilselvan Vijayakumar Ganesh Kumar Kizhaeral Sevathapandian Subramanian Malaisamy Kannan Kalimuthu Raja 《IET nanobiotechnology / IET》2018,12(8):1042
In the present study, high purity copper oxide nanoparticles (NPs) were synthesised using Tridax procumbens leaf extract. Green syntheses of nano‐mosquitocides rely on plant compounds as reducing and stabilising agents. Copper oxide NPs were characterised using X‐ray diffraction (XRD) analysis, Fourier transform infrared (FT‐IR), Field‐emission scanning electron microscopy with energy dispersive spectroscopy, Ultraviolet–visible spectrophotometry and fluorescence spectroscopy. XRD studies of the NPs indicate crystalline nature which was perfectly matching with a monoclinic structure of bulk CuO with an average crystallite size of 16 nm. Formation of copper oxide NPs was confirmed by FT‐IR studies and photoluminescence spectra with emission peaks at 331, 411 and 433 nm were assigned to a near‐band‐edge emission band of CuO in the UV, violet and blue region. Gas chromatography–mass spectrometry studies inferred the phytochemical constituents of the leaf extract. Larvicidal activity of synthesised NPs using T. procumbens leaf extract was tested against Aedes aegypti species (dengue, chikungunya, zika and yellow fever transmit vector).Inspec keywords: photoluminescence, spectrophotometry, thermal analysis, chromatography, nanoparticles, antibacterial activity, field emission electron microscopy, microorganisms, wide band gap semiconductors, scanning electron microscopy, X‐ray diffraction, copper compounds, ultraviolet spectra, nanofabrication, X‐ray chemical analysis, crystallites, visible spectra, field emission scanning electron microscopy, nanobiotechnology, semiconductor materials, semiconductor growth, fluorescence, mass spectraOther keywords: energy dispersive spectroscopy, ultraviolet–visual spectrophotometry, fluorescence spectroscopy, chikungunya, green synthesis, mosquito larvicidal activity, zika, X‐ray diffraction analysis, field‐emission scanning electron microscopy, XRD, gas chromatography–mass spectrometry, copper oxide nanoparticles, dengue, tridax procumben leaf extract, nanomosquitocides, FTIR, monoclinic structure, crystallite size, photoluminescence spectra, near‐band‐edge emission band, phytochemical constituents, Aedes aegypti species, yellow fever transmit vector, CuO 相似文献
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Perumal Karthikeyan Krishnapillai Ramkumar Kalimuthu Pandi Aqsa Fayyaz Sankaran Meenakshi Chang Min Park 《Ceramics International》2021,47(3):3692-3698
Industrial use of heavy metals and dyes critically depends on the effective handling of industrial effluents. Effective remediation of industrial effluents using various adsorbent materials has thus become critical. In this paper, we study two-dimensional MXenes as an adsorbent for removing Cr(VI) and methyl orange (MO) in waters. The physico-chemical performance of MXenes was studied using X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer?Emmett?Teller, scanning electron microscopy, high resolution-transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy techniques. The adsorption system, including influence of contact time, pH of solutions, co-ions, and desorption experiments were performed for effective Cr(VI) and MO removal. The Cr(VI) and MO removal rate of the MXenes was very fast, and the kinetic system was driven by pseudo-second-order kinetics. The sorption isotherm closely well-tailored with the Langmuir isotherm, and the maximum removal efficiencies were 104 and 94.8 mg/g for Cr(VI) and MO, respectively. The MXenes was successfully regenerated by 0.1 M NaOH aqueous solution and can be repeatedly recycled. The uptake of Cr(VI) and MO by the MXenes was mainly due to chemical adsorption, namely electrostatic adsorption, complexation, surface interactions, and ion exchange mechanisms. This investigation demonstrates the selectivity and feasibility of the MXenes as a real adsorbent for eliminating Cr(VI) and MO from the aqueous environment. 相似文献
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Sethu Ramalingam Piramanayagam Mayandi Kalimuthu Rajini Nagarajan Abdul Munaf Abdul Karim Sait Rajesh Kanna Krishnamoorthy Sikiru Oluwarotimi Ismail Suchart Siengchin Faruq Mohammad Hamad A. Al-Lohedan 《应用聚合物科学杂志》2021,138(18):50338
Availability of additive manufacturing has influenced the scientific community to improve on production and versatility of the components created with several associated technologies. Adding multiple substances through superimposing levels is considered as a part of three-dimensional (3D) printing innovations to produce required products. These technologies are experiencing an increase in development nowadays. It requires frequently adding substance and has capacity to fabricate extremely complex geometrical shapes. However, the fundamental issues with this advancement include alteration of capacity to create special products with usefulness and properties at an economically viable price. In this study, significant procedural parameters: layer designs/ patterns (hexagonal, rectangular and triangular) and infill densities (30%, 40%, and 50%) were considered to investigate into their effects on mechanical behaviors off fused deposition modeling or 3D-printed onyx-carbon fiber reinforced composite specimens, using a high-end 3D printing machine. Mechanical (tensile and impact) properties of the printed specimens were conclusively analyzed. From the results obtained, it was observed that better qualities were achieved with an increased infill density, and rectangular-shaped design exhibited an optimum or maximum tensile strength and energy absorption rate, when compared with other counterparts. The measurable relapse conditions were viably evolved to anticipate the real mechanical qualities with an accuracy of 96.4%. In comparison with other patterns, this was more closely predicted in the rectangular design, using regression models. The modeled linear regression helps to define the association of two dependent variables linked with properties of the dissimilar composite material natures. The models can further predict response of the quantities before and also guide practical applications. 相似文献