804 research outputs found
Investigations on optical properties of Eu3+ ion doped magnesium telluroborate glasses for red laser applications
No full textBrown tumor in mandible as a first sign of vitamin D deficiency: A rare case report and review
No full textCentral giant cell granulomas (CGCGs) are uncommon but the most aggressive benign intraosseous tumors of jaws, with an unpredictable outcome. They account for less than 7% of all benign jaw lesions, with a female to male ratio of about 2:1. The classical "brown tumor" is commonly seen in the long bones, pelvis, and ribs. Facial bone involvement is rare and usually appears as solitary or multilocular soap bubble like radiolucencies. CGCGs are traditionally treated by both surgical and intralesional injection, with a variable recurrence rate. Here, we report a 12-year-old female patient with mandibular brown tumor as a first sign of secondary hyperthyroidism induced due to vitamin D deficiency and hypocalcemia
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
Luminescence properties of Er3+ ions doped bismuth borate glasses for 1.53 µm broadband optical amplifiers
No full textStructural and optical studies on Sm3+ ions doped bismuth fluoroborate glasses for visible laser applications
No full text
Generalized Ulam–Hyers stability of (a, b; k > 0)-cubic functional equation in intuitionistic fuzzy normed spaces
No full textIn this paper, we proved the general solution in vector space and established the generalized Ulam–Hyers stability of (a, b; k> 0) - cubic functional equation a+kb2f(ax+kby)+a-kb2f(ax-kby)+k(a2-kb2)b2f(y)=k(ab)2f(x+y)+(a2-kb2)a2f(x)where a≠ ± 1 , 0 ; b≠ ± 1 , 0 ; k> 0 in Banach space and Intuitionistic fuzzy normed spaces using both direct and fixed point methods. © 2018, Forum D'Analystes, Chennai
PEMBANGUNAN KITARAN PEMANDUAN MENGGUNAKAN K-SHAPE DAN RANGKAIAN NEURAL KONVOLUSI UNTUK ANALISIS PENGUNAAN TENAGA DAN EMISI
No full textOne of the key challenges in the automotive industry is enhancing fuel efficiency and reducing emissions while meeting regulatory requirements. Common issues include the lack of context-specific driving cycles, limitations of conventional clustering methods in capturing non-linear driving behaviours, inefficiencies in real-time system integration with Siemens Totally Integrated Automation (TIA) Portal, and delays from traditional data exchange methods, leading to inaccuracies in fuel consumption and emission analysis. This research focuses on integrating MATLAB scripts for fuel consumption and emission analysis with real-time execution in the Siemens TIA Portal. A major focus is on seamless integration strategies between MATLAB and Siemens environments during execution to enhance analysis efficiency. The study involves collecting driving cycle data for Ipoh City using MATLAB Mobile and DC-TRAD and constructing the Ipoh City driving cycle using the K-shape clustering technique, which identifies complex patterns more accurately than conventional clustering methods. Additionally, a convolutional neural network (CNN) algorithm is applied for effective and precise driving cycle development. The research includes a detailed analysis of execution cycle time, fuel consumption, and emissions across both MATLAB and Siemens environments. A significant improvement in execution performance is achieved, with model cycle times in the Siemens environment reduced by over 90%, reaching a maximum of 100 milliseconds compared to 45 seconds in MATLAB. This substantial reduction in cycle time is accomplished without compromising accuracy, as the results from MATLAB are successfully replicated in the Siemens environment, leading to the selection of route 6 as the optimized route for the Ipoh City driving cycle. Addressing challenges related to computational power and system integration for real-time processing, this research outlines strategies to optimize MATLAB scripts for real-time deployment within Siemens systems. Ultimately, this integration aims to provide efficient and accurate solutions for analysing energy consumption and emissions in automotive applications, contributing valuable advancements to the field
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