77 research outputs found
Impact of reactor environment on quenching heat transfer of accident tolerant fuel cladding
No full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2018Cataloged from student-submitted PDF version of thesis. Page 123 blank.Includes bibliographical references (pages 106-116).Development of accident tolerant fuels (ATF) for light water reactors (LWRs) came into focus for the nuclear engineering community after the accidents at Fukushima-Daiichi. The primary focus of the ATF program is to identify alternative fuel and cladding technologies that may provide enhanced safety, competitiveness, and economics. The new fuel design must also be compatible with present-day LWR design. For near-term applications, coatings on the nominal Zirconium-based cladding material and other metallic materials are being considered to improve the corrosion resistance and reduce the generation of hydrogen at high temperatures. Major ATF coating choices under consideration include chromium as a coating, iron-chromium-aluminum alloys (FeCrAl) as cladding and molybdenum as a coating, which have demonstrated better mechanical and oxidation behavior during the experimental testing.Thermal-fluids characteristics are pivotal for a robust testing of ATF concepts as the proposed candidates may have an entirely different thermal-hydraulic behavior when compared to Zircaloy-4. ATF coatings may display very different boiling characteristics as a result of different microstructures and surface characteristics. In the present work, transient boiling heat transfer during quenching of the candidate ATF claddings on vertical rodlets is studied experimentally. The candidate ATF material (chromium, FeCrAl, and molybdenum) are applied on Zircaloy-4 rodlets. The vertical solid rodlets are heated to temperatures up to 1000 °C and are quenched in a saturated pool of water at atmospheric pressure. The temperature variation during the quenching of rodlets was recorded insitu with synchronized visualization of boiling regimes over the test specimen using a high-speed video camera.The quench performance of the ATF coatings was analyzed based on the examination of various surface parameters such as wettability, roughness, emissivity and capillary wicking. In order to obtain a more realistic picture of the candidate performance during the emergency cooling reflood phase in a nuclear reactor, the coated rodlets are also oxidized in an autoclave before quenching. The performance of the candidate claddings is evaluated after oxidation and the surface characterized. It was observed from the post-test analysis that the surface characteristics and oxidation had a significant impact on the quench performance of ATF coatings, which varied between different coating materials. In order to better understand the thermal margins in a reactor specific environment, an analysis was performed on samples after exposing them to gamma rays. The gamma rays tend to change the surface wettability through a phenomenon called Radiation Induced Surface Activation.A Gammacell 220E irradiator that uses 12 cobalt-60 pencil sources, arranged axially in a sample chamber at MIT, was used to irradiated the samples. The results of water quenching and contact angle studies showed a higher Leidenfrost temperature and wettability in both samples exposed to gamma irradiation. The detailed microscopic analysis attributed the enhanced wettability to oxidation of the surface under gamma irradiation.by Arunkumar Seshadri.S.M.S.M. Massachusetts Institute of Technology, Department of Nuclear Science and Engineerin
Different quantities of manganese oxide nanoparticles incorporated feed on the growth and haematological traits of common carp Cyprinus carpio var. communis
No full textIn recent times, nanoparticles have been used as raw ingredients for biofertilizers, mineral supplements in animal feed, and pharmaceuticals. Manganese plays a vital role in enhancing fish\u27s growth and biological function. The present research work aimed to analyze the various quantities of manganese oxide nanoparticles on common carp growth and its haematological traits. Synthesized manganese oxide (Mn3O4) nanoparticles were illustrated using UV-visible Spectroscopy (UV-Vis), Scanning Electron Microscope (SEM), Energy Dispersive X–Ray Spectroscopy (EDAX), X–Ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Six different feeds were prepared by incorporating different quantities of manganese oxide nanoparticles (Feed I (control-0mg), Feed II(3mg/100g), Feed III(6mg/100g), Feed IV(9mg/100g), Feed V(12mg/100g), and Feed VI(15mg/100g)) with common ingredients such as groundnut oil cake, fish meal, tapioca flour, and wheat flour. On the completion of 21 days, feed utilization and haematological characteristics of Common carp were assessed. The UV-Vis showed that manganese oxide nanoparticles exhibit strong adsorption peaks at 220nm. SEM image observed at the wavelength range from 9.22 nm to 9.35 nm. The size of the particles was in the 45-55 nm range. The EDAX spectrum recorded two peaks between 0.40 and 6 kev. The XRD graph shows that the diffraction peaks are indexed as 103, 004, 213, 204, 303, and 215. FT-IR spectrum measured at the wavelength range from 500-4000cm-1. Most of the growth parameters and haematological parameters were higher in feed III, containing 6mg of Manganese oxide nanoparticles. Therefore, results show that manganese oxide incorporated feed enhances the growth and haematological traits in common carp compared to control feed.
Stability of n-Dimensional Additive Functional Equation in Generalized 2-Normed Space
No full textIn this paper, the author established the general solution and generalized Ulam-Hyers-Rassias stability of n-dimensional additive functional equatio
Investigations on optical properties of Eu3+ ion doped magnesium telluroborate glasses for red laser applications
No full textScreening of Pediocin Pa-1 Producing Lactic Acid Bacteria by Pcr
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Generalized Ulam- Hyers Stability of Derivations of a AQ- Functional Equation
No full textIn this paper, the author established the generalized Ulam- Hyers stability of Deriva-tions of additive and quadratic (AQ)- functional equation f(x+ y) + f(x − y) = 2f(x) + f(y) + f(−y). RESUMEN En este art́ıculo el autor establece la estabilidad generalizada Ulam-Hyers de deriva-ciones de la ecuación (AQ)-funcional cuadrática y aditiva f(x+ y) + f(x − y) = 2f(x) + f(y) + f(−y)
- …
