32,589 research outputs found
Scalable Image Coding Using Reversible Integer Wavelet Transforms
No full textReversible integer wavelet transforms allow both lossless and lossy decoding using a single bitstream. We present a new fully scalable image coder and investigate the lossless and lossy performance of these transforms in the proposed coder. The lossless compression performance of the presented method is comparable to JPEG-LS. The lossy performance is quite competitive with other efficient lossy compression methods. This work was supported in part by the National Science Foundation under Grant No. NCR-9258374. y EDICS: 1-STIL. A. Bilgin, F. Sheng, and M. W. Marcellin are with the Department of Electrical and Computer Engineering, The University of Arizona, Tucson, AZ 85721. P. J. Sementilli is with Science Applications International Corp. (SAIC), 101 N. Wilmot Rd., Tucson, AZ 85711. Please address all correspondence to A. Bilgin. E-mail: [email protected]. Phone: (520) 621-9769. Fax: (520) 621-8076. 1 I Introduction The wavelet transform has been widely used in image compression. H..
Farklı yüzey işlemlerinin Inconel 625 süper alaşım ve AISI 321 paslanmaz çelik üzerindeki çekme ve aşınma davranışlarına etkisi
No full textAISI 321 stainless steel and Inconel 625 superalloy are utilized in an extensive range of applications such as aircraft engines, nuclear powerplants and industrial furnaces due to their excellent mechanical properties at high temperatures. The surface treatment of these materials is necessary due to the extreme work ing environments. Boronizing and WC coating is the most important surface hard ening processes. In the current work, the effect of boronizing and WC coating on the wear performance and tensile behavior of AISI 321 and Inconel 625 at room and high temperature were investigated. Furthermore, damage mechanisms and fracture morphologies were observed using Scanning Electron Microscopy (SEM) and optical profilometry. According to room temperature tensile test results, yield strength (YS) and ultimate tensile strength (UTS) of the samples are reduced after the boronizing process. This strength reduction may be attributed to the softening of the material throughout the boronizing process at high temperature of 1100°C. On the other hand, ductility of the Inconel 625 samples has been decreased due to dynamic strain aging at 600°C. The yield strength of the boronized samples was significantly reduced because of the decomposition of boron particles throughout tensile test at elevated temperatures. Consequently, the fracture morphology observations revealed that the main fracture mechanism of both coated and uncoated conditions at high temperature was a ductile fracture represented by deep dimples. However, the boronized sample was drastically affected by grain growth during boronizing process and decomposition of dispersed particles. In contrast, the strain to failure of the WC coated sample was decreased due to the fast fracture of the ceramic WC layer at both room and high temperature tensile tests. Furthermore, results of SEM revealed that particle decomposition occured on the fracture surface of the boronized 321 stainless steel represented by dispersed boron particles on the edges of the dimples after failure at high temperature. Due to the high hardness and heat resistance of WC coated layer, the friction coefficient of the sample was higher than that of boronized and uncoated conditions at room tempearature. It was seen that the wear rates of boronized and WC coated AISI 321 were extremely lower than that of uncoated sample. On the other hand, at 600°C, WC coated wear rate was still lower but uncoated and boronized samples’ values were similar to the room temperature results. Inspection of room temperature the wear test results revealed that the wear rates of Inconel 625 uncoated and coated samples were similar to the results of AISI 321. WC coated samples’ wear rate was tremendously lower than the others. At high temperature, the boronized Inconel 625 had higher friction coefficient than the WC coated sample. A fluctuation was also noticed, which is linked to boron particle aggregation on the surface at high temperatures.AISI 321 paslanmaz ¸celik ve Inconel 625 s¨uper ala¸sımı, y¨uksek sıcaklıklardaki m¨ukemmel mekanik ¨ozelliklerinden dolayı u¸cak motorları, n¨ukleer santraller ve end¨ustriyel fırınlar gibi geni¸s bir uygulama yelpazesinde kullanılmaktadır. Zorlu ¸calı¸sma ko¸sulları nedeniyle, bu malzemeler ¨uzerine y¨uzey i¸slemleri uygu lamak bir gereksinim haline gelmi¸stir. Borlama ve Tungsten Karb¨ur (WC) kaplama en ¨onemli y¨uzey sertle¸stirme i¸slemlerindendir. Mevcut ¸calı¸smada, AISI 321 ve In conel 625’in oda sıcaklı˘gı ve y¨uksek sıcaklıktaki a¸sınma performansı ve ¸cekme davranı¸sı ¨uzerine borlama ve Tungsten Karb¨ur kaplamanın etkisi ara¸stırılmı¸stır. Ayrıca, Taramalı Elektron Mikroskobu (SEM) ve optik profilometri kullanılarak hasar mekanizmaları ve kırılma morfolojileri g¨ozlemlenmi¸stir. Oda sıcaklı˘gında ¸cekme testi sonu¸clarına g¨ore borlama i¸sleminden sonra nu munelerin akma dayanımı (YS) ve nihai ¸cekme dayanımı (UTS) azalmaktadır. Bu mukavemet azalması, 1100°C’lik y¨uksek sıcaklıkta borlama i¸slemi boyunca malzemenin yumu¸samasına ba˘glanabilir. Ote yandan Inconel 625 numunelerinin ¨ s¨unekli˘gi, 600°C’de dinamik gerinim ya¸slanması nedeniyle azalmı¸stır. Borlanmı¸s numunelerin akma mukavemeti, y¨uksek sıcaklıklarda ¸cekme testi boyunca bor par¸cacıklarının ayrı¸sması nedeniyle ¨onemli ¨ol¸c¨ude azalmı¸stır. Sonu¸c olarak, kırılma morfolojisi g¨ozlemleri, y¨uksek sıcaklıkta hem kaplamalı hem de kaplamasız ko¸sulların ana kırılma mekanizmasının, derin ¸cukurlarla temsil edilen s¨unek bir kırılma oldu˘gunu ortaya koymu¸stur. Bununla birlikte, borlanmı¸s numune, borlama i¸slemi sırasında tane b¨uy¨umesinden ve da˘gılmı¸s par¸cacıkların ayrı¸smasından b¨uy¨uk ¨ol¸c¨ude etk ilenmi¸stir. Buna kar¸sılık, seramik WC tabakasının hem oda sıcaklı˘gında hem de y¨uksek sıcaklıktaki ¸cekme testlerinde ani kırılması nedeniyle WC kaplı numunenin s¨unekli˘gi azalmı¸stır. Ayrıca, taramalı elektron mikroskobu sonu¸cları, y¨uksek sıcaklıkta kırılmadan sonra ¸cukurların kenarlarında da˘gılmı¸s bor par¸cacıkları g¨or¨ulen bor lanmı¸s 321 paslanmaz ¸celi˘gin kırılma y¨uzeyinde par¸cacık ayrı¸smasının meydana geldi˘gini ortaya koymu¸stur. WC tabakasının y¨uksek sertli˘gi ve ısı direnci nedeniyle, a¸sınma testinde WC kaplı AISI 321’in s¨urt¨unme katsayısı borlanmı¸s ve kaplamasız numunelere g¨ore daha y¨uksek ¸cıkmı¸stır. Borlanmı¸s ve WC kaplı AISI 321’in a¸sınma oranı, oda sıcaklı˘gında kaplanmamı¸s numuneden ¸cok daha d¨u¸s¨ukt¨ur. Ote yandan, 600 ¨ °C’de WC kaplı numunenin a¸sınma oranı hala d¨u¸s¨ukken kaplamasız ve borlanmı¸s nu munelerin de˘gerleri, y¨uzeyin delaminasyonu nedeniyle hemen hemen aynıdır. Inconel 625’in kaplanmamı¸s ve kaplanmı¸s numunelerin a¸sınma hızı davranı¸sı AISI 321’in sonu¸clarına benzerdir. WC kaplı numunelerin a¸sınma hızının di˘gerlerinden ¸cok daha d¨u¸s¨uk oldu˘gu g¨or¨ulm¨u¸st¨ur. Y¨uksek sıcaklıkta, borlanmı¸s Inconel 625, WC kaplı numuneden daha y¨uksek bir s¨urt¨unme katsayısına sahiptir. Y¨uksek sıcaklıktaki s¨urt¨unme katsayısı grafi˘ginde y¨uzeyde bor par¸cacıklarının birikimiyle ba˘glantılı bir dalgalanma g¨ozlenmi¸stir
Landsat MSS classification of fire fuel types in Wood Buffalo National Park, northern Canada
No full textJ1: Global Ecology & Biogeography Letters; M3: Article; Milne, David Franklin, Steven E. Wilson, Bradley A. Ghitter, Geoff Heathcott, Mark McCaffrey, Thomas M. Ow, Charlotte F. Y.; Source Information: Mar1994, Vol. 4 Issue 2, p33; Subject Term: FOREST fires; Author-Supplied Keyword: Canada (Wood Buffalo National Park); Author-Supplied Keyword: Forest fire; Author-Supplied Keyword: Fuel type classification; Author-Supplied Keyword: Landsat data; Number of Pages: 0p; Document Type: Articl
Synthesis and biological evaluation of some 1,3-benzoxazol-2(3H)-one hybrid molecules as potential antioxidant and urease inhibitors
No full textA new series of 1,3-benzoxazol-2(3H)-one hybrid compounds, including coumarin, isatin 1,3,4-triazole and 1,3,4-thiadiazole moieties, were synthesized and biologically evaluated for their antioxidant capacities and anti-urease properties. The synthesized benzoxazole-coumarin (6a e) and benzoxazole-isatin (10a c) hybrids showed remarkable urease inhibitory activities with IC50 ( M), ranging from 0.0306 ± 0.0030 to 0.0402 ± 0.0030, while IC50 of standard thiourea is 0.5027 ± 0.0293. The synthesized benzoxazole-triazole (8a c) and benzoxazole-thiadiazole (9a c) hybrids showed similar urease inhibitory activities with IC50 ( M), ranging from 0.3861 ± 0.0379 to 0.5126 ± 0.0345. The antioxidant activity of the synthesized compounds was evaluated for their antioxidant activities, such as reducing power and ABTS (2,2 -azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt) radical scavenging. The results of ABTS radical scavenging activities of some of the synthesized molecules showed higher activities than standard Trolox, SC50 ( M) = 213.04 ± 18.12. One benzoxazole-coumarin (6f), two benzoxazole-isothiocyanate (7b, 7c), and two benzoxazole-triazole (8b, 8c) derivatives showed higher activities (SC50 ( M) values, 82.07 ± 10.34, 120.19 ± 7.30, 104.58 ± 10.55, 153.26 ± 7.14, and 144.82 ± 10.68, respectively) than standard Trolox, (SC50 ( M) = 213.04 ± 18.12).This work was supported by Research Fund of Recep Tayyip Erdogan University under the Project Number of FBA 2018 858
The long-wavelength view of GG Tau A: rocks in the ring world
No full textWe present the first detection of GG Tau A at centimetre wavelengths, made with the Arcminute Microkelvin Imager Large Array at a frequency of 16 GHz (λ = 1.8 cm). The source is detected at >6 σrms with an integrated flux density of S16GHz = 249 ± 45 µJy. We use these new centimetre-wave data, in conjunction with additional measurements compiled from the literature, to investigate the long-wavelength tail of the dust emission from this unusual protoplanetary system. We use an MCMC-based method to determine maximum likelihood parameters for a simple parametric spectral model and consider the opacity and mass of the dust contributing to the microwave emission. We derive a dust mass of Md ~ 0.1 Msun, constrain the dimensions of the emitting region and find that the opacity index at λ > 7 mm is less than unity, implying a contribution to the dust population from grains exceeding ~4 cm in size. We suggest that this indicates coagulation within the GG Tau A system has proceeded to the point where dust grains have grown to the size of small rocks with dimensions of a few centimetres. Considering the relatively young age of the GG Tau association in combination with the low derived disc mass, we suggest that this system may provide a useful test case for rapid core accretion planet formation models
Letter from Cedrick M. Shimo to the Office of Redress Administration, June 4, 1991
No full textA letter from Cedrick M. Shimo to the Office of Redress Administration arguing that John Y. Udaka is entitled to a redress payment.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
Los jesuitas expulsos literatos en la Italia del Setecientos : éxitos y fracasos
No full textLa historiografía ha definido a los jesuitas españoles expulsos como "mediatores" entre dos culturas: durante el largo exilio italiano (1767-1815) ellos, gracias a la habilidad sincrética propia de la Compañía de Jesús, llegaron a producir una "cultura hispano italiana", según la célebre definición de M. Batllori. El propósito de mi intervención es ofrecer unas breves reflexiones sobre unas figuras de ex-jesuitas epañoles "literatos", particularmente Juan Andrés y Esteban Arteaga. Aunque varios expulsos alcanzaron un buen éxito literario, la mayoría de ellos experimentó los sinsabores, las miserias y las dificultades económicas propias del amplio sector de la intelectualidad que intentó emerger en el difícil escenario de la República literaria europea del siglo XVIII, un sector que el gran especialista en la Ilustración francesa Robert Darnton ha definido como Grub street.Expelled Spanish jesuits have been regarded by current Historiography as "cultural mediators": during their long exile in Italy (1767-1815), they developed a "Spanish Italian culture" (according to M. Batllori's definition) thanks to a meaningful syncretic approach. The author offers some brief reflections on those expelled jesuits who decided to porsue a litterary career, with a specific focus on Juan Andrés and Esteban Arteaga. Through several spanish fathers achieved a good literary success, the majority of them suffered the typical failures, delusions and troubles experienced by eighteenth century men of letters, especially those who belonged to a sector of the Republic of Letters called by Robert Darnton "Grub Street"
Nonstrangulating small colon obstruction caused by a submucosal haematoma
No full textS. Stahel, C. B. Riley, M. Wichtel and P.-Y. Daous
Overview of the Author Profiling Task at PAN 2013
No full text[EN] This overview presents the framework and results for the Author Profiling
task at PAN 2013. We describe in detail the corpus and its characteristics,
and the evaluation framework we used to measure the participants performance to
solve the problem of identifying age and gender from anonymous texts. Finally,
the approaches of the 21 participants and their results are described.The author profiling task @PAN-2013 was an activity of the WIQ-EI IRSES project (Grant No. 269180) within the FP 7 Marie Curie People Framework of the European Commission. We want to thank the Forensic Lab of the Universitat Pompeu Fabra Barcelona for sponsoring the award for the winner team. The work of the first author was partially funded by Autoritas Consulting SA and by Ministerio de Economía y Competitividad de España under grant ECOPORTUNITY IPT-2012-1220-430000. The work of the second author was in the framework the DIANA-APPLICATIONS-Finding Hidden Knowledge in Texts: Applications (TIN2012-38603-C02-01) project, and the VLC/CAMPUS Microcluster on Multimodal Interaction in Intelligent Systems. The work of fifth author was funded in part by the Swiss National Science Foundation (SNF) project "Mining Conversational Content for Topic Modelling and Author Identification (ChatMiner)" under grant number 200021_130208.Rangel, F.; Rosso, P.; Koppel, M.; Stamatatos, E.; Inches, G. (2013). Overview of the Author Profiling Task at PAN 2013. CLEF Conference on Multilingual and Multimodal Information Access Evaluation. 352-365. https://riunet.upv.es/handle/10251/46636S35236
CONTRIBUTION TO THE STUDY OF PARTIAL DIFFERENTIAL EQUATIONS OF ELLIPTIC TYPE
No full textEn este artículo se presentan los resultados más importantes de mi trabajo de investigación en el estudio de la existencia y de las propiedades de las soluciones de ecuaciones diferenciales parciales no lineales.
Donde λ ∈ R, Ω es un dominio acotado en RN con frontera suave, ∆ = n i=0 ∂/∂x2 i es el operador de Laplace y f : R → R es una función no lineal. Se presentan teoremas obtenidos utilizando teoría de bifurcación, métodos variacionales y un principio de minimax desarrollado por el autor en colaboración con A. Castro y J. M. Neuberger ([Cas-Cos-Nu1], 1997). Además, se incluyen algunos algoritmos para construir y visualizar soluciones a problemas no lineales del tipo (1) y una serie de preguntas abiertas.In this paper I present the most important results of my research studying the solutions of nonlinear partial differential equations of the type.
In this study, we focus on nonlinear partial differential equations of the form ∆u + λf(u) = 0 in Ω, u = 0 on ∂Ω, where λ ∈ R, Ω is a smooth bounded domain in RN, ∆ = Σ ∂²/∂x²ᵢ is the Laplacian operator, and f : R → R is a nonlinear function. Our theorems were obtained using bifurcation theory, variational methods, and a minmax principle developed by the author in collaboration with A. Castro and J. M. Neuberger ([Cas-Cos-Nu1], 1997). We also present some theorems related to algorithms for approximating solutions to nonlinear problems of type (1), along with a set of open questions
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