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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

High Temperature Seals for Solid Oxide Fuel Cells

Parihar, Shailendra S. 04 April 2007 (has links)
No description available.
152

Thermo-mechanical Behavior of Glass Based Seals for Solid Oxide Fuel Cells

Singh, Sandeep January 2010 (has links)
No description available.
153

An administrative impression : A study on late Middle Kingdom administrative seals – from El-Lahun to the Southern Frontier / Ett administrativt avtryck : En studie av administrativa sigill från det sena mellersta riket – från El-Lahun till den södra fronten

El Mogy, Josef January 2022 (has links)
By analyzing the corpus of administrative seals from the late Middle Kingdom, this study attempts to identify what type of administration was in practice. This was achieved mainly through the use of an observational and comparative approach in the analysis of institutional and title-seals from four late Middle Kingdom sites. It has been concluded that royal mortuary complexes and Nubian military installations were administered on both a local and a centralized level. On the one hand, individuals mentioned on title-seals could be linked to various local departments attested on institutional seals. In most cases, they were affiliated to certain areas of activity linked to a specific institution. Additionally, at all sites represented in the study, traces of the central administration remain – evident from the accumulation of title-seals belonging to royal officials and extra-local institutional seals coming from royal donations. While each site displayed a unique institutional structure, parallels could be made between them. Late Middle Kingdom administrative seals point to a societal structure which in some sense was rigid, particularly on a local level. However, local activities appear to have also been overseen and operated by a mobile class of higher officials. / Genom att analysera sena mellersta rikets administrativa sigillkorpus söker denna studie att utröna vilken typ av administration som bedrevs. Detta har genomförts framför allt genom att observationsstudier samt komparativa tillvägagångsätt har tillämpats i analysen av institutionella sigill samt titelsigill från fyra historiska platser daterade till det sena mellersta riket. Studien visar på att både kungliga gravkomplex samt nubiska militära installationer administrerades på en lokal och centraliserad nivå. Å ena sidan har individer som omnämns på titelsigill kunnat länkas samman till olika lokala institutioner som även attesterats på institutionella sigill. I de flesta fall var dessa individer anslutna till arbetsområden tillhörande en viss institution. Vid samtliga platser kvarstår dock spår av en centraladministration –vilket ter sig tydligt i förekommandet av titelsigill tillhörande kungliga ämbetsmän samt icke-lokala institutionella sigill från kungliga donationer. Även fastän varje enskild plats hade en distinkt institutionell uppbyggnad kunde paralleller dras mellan dem. Mellersta rikets administrativa sigill tyder på en samhällsstruktur som på ett antal plan, särskilt på en lokal nivå, var fast. Samtidigt styrdes dessa lokala verksamheter emellertid av en mer rörlig klass av högre tjänstemän.
154

Analysis of Seismic Signatures Generated from Controlled Methane and Coal Dust Explosions in an Underground Mine

Murphy, Michael M. 10 December 2008 (has links)
Examination of seismic records during the time interval of the Sago Mine disaster in 2006 revealed a small amplitude signal possibly associated with an event in the mine. Although the epicenter of the signature was located in the vicinity where the explosion occurred, it could not be unequivocally attributed to the explosion. More needs to be understood about the seismicity from mine explosions in order to properly interpret critical seismic information. A seismic monitoring system located at NIOSH's Lake Lynn Experimental Mine has monitored nineteen experimental methane and dust based explosions. The objective of the study was to analyze seismic signatures generated by the methane and dust explosions to begin understanding their characteristics at different distances away from the source. The seismic signatures from these different events were analyzed using standard waveform analysis procedures in order to estimate the moment magnitude and radiated seismic energy. The procedures used to analyze the data were conducted using self-produced programs not available with existing commercial software. The signatures of the explosions were found to be extremely complex due a combination of mine geometry and experimental design, both of which could not be controlled for the purposes of the study. Geophones located approximately 600 m (1970 ft) and over from the source collected limited data because of the attenuation of the seismic waves generated by the methane explosion. A combination of the methods used to characterize the seismic signatures allowed for differentiation between experimental designs and the size of the explosion. The factors having the largest impact on the signatures were the mine geometry, size of the methane explosion, construction of the mine seal and location of the mine seal. A relationship was derived to correlate the radiated seismic energy to the size of the explosion. Recommendations were made, based upon the limitations of this study, on methods for better collection of seismic data in the future. / Ph. D.
155

Seal Counting on our Plages (S.C.O.O.P.)

Kharwa, Kaanan 01 September 2024 (has links) (PDF)
The Vertebrate Integrative Physiology (VIP) lab monitors the population of northern elephant seals at the largest mainland breeding colony, located at Piedras Blancas (San Simeon, CA). As the population expands, more human-seal interactions and conflicts over land use occur. The VIP lab's work informs California State Parks and helps with the management of the rookery. Currently, members of the VIP lab fly a drone over the beaches, capture multiple images, and manually count the seals, which takes around 14 to 21 hours of analysis per survey. Machine learning methods such as Convolutional Neural Networks (CNN) and Region-based Convolutional Neural Networks (RCNN) have been shown to quickly and accurately determine the count but require lots of data, which is not feasible for this task due to the 79 available beach images. By dividing larger beach images into smaller sub-images, it is possible to generate more data, facilitating the use of deep learning techniques. This thesis outlines a pipeline to use these sub-images and determine the seal count of a beach image.
156

Towards a performance related seal design method for Bitumen and modified road seal binders

Milne, Terence Ian 12 1900 (has links)
Thesis(PhD (Civil Engineering))-- University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Bitumen based road surfacing seals and asphalt wearing courses have been used by society's Engineers "to counter the damage to the existing unsurfaced roadways by the newly developed automobile with its rubber driving wheels" since the early 1900's. Early experiments were conducted with both tar and bitumen to find a suitable material to alleviate the situation, and ongoing research has been carried out through the past century and into the new millennium, throughout the world, examining improvements, from materials used, to design and construction methods. However, there is still much to be understood, improved and refined, when considering road surfacing seal design. Pavement designers have the choice of utilizing either an asphalt (graded aggregate remanufactured with a bitumen binder and applied as a complete product) or a surfacing seal (including variations of bitumen binder sprayed onto the road surface, with the addition of single size stones, either in one or two layers of binder and aggregate, i.e. single or double seals) as a pavement wearing course. Current road surfacing seal design practice depends on empirical analysis and experience, being primarily a volumetric based assessment of bitumen application. This research project assesses South African seal design philosophy, investigates design areas where review or updating is required to accommodate changing bitumen sources and types, and traffic loading. Seal performance criteria are examined, with the development of a matrix of influences on seal performance. Using this, the need for a seal design method based on mechanistic material properties is proposed, and the prototype example of such a numerical model using finite element method is presented. To contribute further towards a performance related seal design method, the feasibility of modelling of road surfacing seals using mechanistic principles was examined. The potential of developing failure and fatigue criteria or relationships to enable assessment of the expected seal performance, with inclusion of different component material characteristics and variations, varying traffic and environmental conditions, was also examined. From assessment of literature, and understanding of the components of the seal, pavement, and influencing factors, a choice of numerical model of seal performance was made. The Finite Element Method (FEM) Analysis was selected for the purpose of modelling seal performance. The model was developed to enable examination of the interaction of individual seal components (i.e. stone and bitumen), at micro-mechanic scale. The prototype 3-dimensional numerical seal model was undertaken in 2002 and 2003 at Technical University Delft, using the CAPA research program. On the basis of the linear calculations the developed numerical prototype model is able to provide insight into seal behaviour and distinction between mechanical (seal geometry) and chemical (components) seal aspects, and insight into stress and strain development in the different seal types. Simulations of different seal, environmental and traffic scenarios are provided to demonstrate the potential of the model (excluding seal aggregate interlock and embedment effects at prototype stage). In order to provide data for the verification of the prototype numerical model, and to further contribute to the development of a performance related seal design method, performance tests were developed, with a new tool for assessment of comparative seal performance using the Model Mobile Load Simulator Accelerated Pavement Testing apparatus. The performance of each different seal binder type - Penetration grade Mumen, SBS, SBR, EVA and Bitumen Rubber - was undertaken. A methodology for the assessment of in-service seal performance was developed, and the performance of the respective seals reported. The results of this examination showed that each binder type has its unique contribution to seal performance. These new performance tests will be able to assist designers in the added determination of the fundamental binder properties on seal performance, and the seals' ability to contribute to the overall performance of the pavement. An additional comparative performance test method was developed to enable assessment of the effect of ageing and moisture, to complement the MMLS results. In summary, the performance testing has assisted in identifying the critical parameters a seal designer should consider during the design process. From this research, it is evident that the current seal design method requires further development to able designers to predict the effect of: Varying axle loads, tyre pressures and design speed; Varying characteristics of the different binders, (i.e. temperature - viscosity relationships, adhesion and visco-elastic behaviour); on the performance of seals. The major areas for suggested improvement in current seal design methods towards a performance based design method are: inclusion of variable traffic load and environmental characteristics, including temperature and moisture influences, and inclusion of mechanistic material characteristics into the design methodology. / AFRIKAANSE OPSOMMING: Bitumengebaseerde padoppervlakseellae en asfaltslytlae is sedert die 1900's deur ingenieurs gebruik as teenwig teen die skade wat die pas ontwikkelde voertuig met sy rubberwiele aan bestaande ryvlakke sonder oppervlakbehandeling aangerig het. In vroeëre eksperimente wat daarop gemik was om 'n geskikte materiaal te vind om die probleem teen te werk, is 'n kombinasie van teer en bitumen gebruik. Sedertdien word voortgesette navorsing steeds wêreldwyd gedoen om verbeterings te ondersoek, nie net ten opsigte van materiale nie maar ook ontwerp- en konstruksiemetodes. Wat die ontwerp van padoppervlakseëling betref is daar egter heelwat wat reg begryp, verbeter en verfyn moet word. Plaveiselontwerpers het die keuse om of 'n asfalt te gebruik (gegradeerde aggregaat voorafvervaardig met 'n bitumen bindmiddel en aangewend as 'n klaarproduk), of 'n oppervlakseël (een laag of twee lae [m.a.w. enkel- of dubbelseël] bitumen bindmiddel met aggregaat [enkelgrootte klippies] bygevoeg, gespuit op die padoppervlak). In die praktyk berus die ontwerp van padoppervlakseëling tans op empiriese analise en ervaring (wat hoofsaaklik 'n volumetriesgebaseerde assessering van die aanwending van bitumen is). Hierdie navorsingsprojek doen 'n waardebepaling van die Suid-Afrikaanse filosofie van seëlontwerp, en ondersoek ontwerpterreine wat hersiening of bywerking benodig om vir veranderende bitumenbronne en -tipes, asook verkeerslading, voorsiening te maak. Met die ontwikkeling van 'n matriks van die invloede op seëlprestasie is die kriteria vir seëlprestasie ondersoek. Op grond daarvan word aangevoer dat daar 'n behoefte is aan 'n seëlontwerpmetode gebaseer op die meganistiese eienskappe van materiaal, en word 'n voorbeeld van 'n numeriese modelprototipe wat die eindige-element-metode gebruik, voorgelê. Ten einde 'n verdere bydrae te lewer tot die ontwikkeling van 'n prestasiegerigte seëlontwerpmetode, is die uitvoerbaarheid van die modellering van padoppervlakseëllae gebaseer op meganistiese beginsels, ondersoek. Daar is ook ondersoek ingestel na die potensiaal vir die ontwikkeling van kriteria vir die vasstel van mislukking en vermoeidheid of verhoudinge wat die assessering van die verwagte seëlprestasie (ingesluit die verskillende kenmerke en variasies van seëlkomponentmateriaal en wisselende verkeers- en omgewingsomstandighede) moontlik kan maak. Met oorweging van die bestudeerde literatuur en 'n begrip van die komponente van seël, plaveisel en inwerkende faktore, is 'n keuse van 'n numeriese model vir seëlprestasie gemaak. Die eindige-element-metode (Finite Element Method [FEM]) is gekies as die analitiese metode vir die modellering van seëlprestasie. Die model is ontwikkel om die ondersoek van die interaksie tussen individuele seëlkomponente (klip en bitumen) op mikromeganiese skaal moontlik te maak. Die ontwikkeling van die driedimensionele, numeriese, model-seëlprototipe is tussen 2002 en 2003 by die Delft Tegniese Universiteit gedoen, met gebruikmaking van die CAPA-navorsingsprogram. Wat lineêre berekenings betref, kan die ontwikkelde numeriese modelprototipe 'n insig gee in seëlgedrag en in die onderskeid tussen aspekte van seëlgeometrie (meganies) en seëlkomponente (chemies), asook in die spanning- en vervormingsontwikkeling van die verskillende tipes seël. Simulasies van verskillende seël-, omgewings- en verkeerscenario's word voorgestel om die potensiaal van die modelprototipe te demonstreer. Met die oog daarop om data vir die verifikasie van die numeriese modelprototipe te voorsien, en om verder tot die ontwikkeling van 'n prestasiegerigte seëlontwerpmetode by te dra, is prestasietoetse, met 'n nuwe instrument vir die assessering van vergelykende seëlprestasie met behulp van die Model Mobile Load Simulator Accelerated Pavement Testing apparaat, ontwikkel. Die prestasie van elke verskillende tipe seëlbindmiddel- penetrasiegraad bitumen, SBS, SBR, EVA en bitumenrubber - is getoets. 'n Metodologie vir die assessering van die ingebruiksprestasie van seëllae is ontwikkel, en daar is verslag gedoen oor die prestasie van die verskillende seëllae. Die resultate van die ondersoek het getoon dat elke tipe bindmiddel 'n eie unieke bydrae tot die prestasie van die seël lewer. Die nuwe prestasietoets sal ontwerpers help met die bepaling van die grondliggende bindmiddeleienskappe wat by seëlprestasie ter sprake is, asook van die seël se vermoë om tot die algehele prestasie van die plaveisel by te dra. 'n Bykomende prestasievergelykingstoetsmetode vir die assessering van die effek van veroudering en vogtigheid is ontwikkel om die MMLS-resultate aan te vul. Ter opsomming, die prestasietoetsing het bygedra tot die identifisering van die kritiese parameters wat die seëlontwerper tydens die ontwerpproses in gedagte behoort te hou. Die navorsing wat gedoen is, dui daarop dat die huidige seëlontwerpmetode verder ontwikkel moet word om ontwerpers in staat te stel om die effek van die volgende te kan voorspel: Wisselende aslas, banddruk en ontwerpspoed; Verskillende kenmerke van die verskillende bindmiddels (bv. temperatuur viskositeitsverhoudinge, vashegting en viskoëlastiese gedrag). Wat huidige seëlontwerpmetodes betref, is die hoofterreine waarop 'n verbetering voorgestel word, die insluiting van veranderlike verkeerslas- en omgewingskenmerke, ingesluit die invloed van temperatuur en vogtigheid, en insluiting van meganistiese kenmerke van materiaal in die ontwerpmetodologie.
157

Surface run-off behaviour of bitumen emulsions used for the construction of seals

Kashaya, Asiimwe Annie 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Factors influencing surface run-off of bitumen emulsions were studied in order to understand binders for use in the construction of surfacing seals. Run-off of the binder from the road surface causes an inconsistent film thickness leading to ravelling (Johannes, Hanz & Bahia n.d.) and bleeding at the upstream and downstream regions, respectively. There is currently no accepted specification for surface run-off viscosity. Practice mainly relies on empirical tests and experience. As the establishment of such a specification encompasses performance of the binder in various environments or field conditions, this study was undertaken to determine performance of the selected binder. Viscosity was kept constant by spraying the emulsion at a constant temperature and also holding the pavement temperature constant. In order to study the run-off behaviour of the binder, run-off tests were conducted at various gradients, texture depths and spray rates. Surfacing seals of various texture depths were constructed in the laboratory. Using a spray bar, the emulsion was sprayed at various spray rates. The sample surfaces were tilted to various gradients. Results portrayed the effects of the three factors (spray rate, gradient and texture depth) on the amount of runoff. An increase in the magnitude of the factors resulted in a variation in the runoff (increase or decrease). One notable finding was that the runoff from the 9.5 mm seal was less than that from the 13.2 mm seal. The other significant finding was that spray rate had the largest effect on runoff, followed by texture depth, and gradient. / AFRIKAANSE OPSOMMING: Sekere eienskappe wat oppervlakdreinering van bitumen emulsies op paaie beinvloed, is bestudeer om sodoende binders wat gebruik word in die konstruksie van die seëls beter te verstaan. Afloop van die binder vanaf die padoppervlak kan lei tot die vorming van ‘n laag met ongelyke dikte wat moontlike rafeling (Johannes, Hanz & Bahia nd) en bloeing vanuit die onderkant van die pad tot gevolg kan hê. Daar is tans geen aanvaarde spesifikasies wat hierdie verskynsels inperk nie. Konstruksie praktyk berus hoofsaaklik op empiriese toetse en ondervinding. Hierdie studie is dus onderneem om prestasie van die geselekteerde binder vas te stel. Viskositeit was konstant gehou deur die aangewende emulsie en padtemperatuur konstant te hou. Ten einde die afloopgedrag van die binder te bestudeer, is toetse uitgevoer op verskeie hellings, tekstuurdieptes en aanwendingskoerse. Seëls van die verskillende tekstuurdieptes is gebou in die laboratorium, en emulsies op hierdie oppervlaktes aangewend. Die toetsoppervlakte is gekantel om die vereiste helling te kry. Resultate vir die drie faktore wys die invloed op afloop. ‘n Toename in die grootte van die faktore het gelei tot 'n variasie in die afloop (toename of afname). Een noemenswaardige bevinding was dat die afloop van die seël van 9,5 mm minder was as dié van die seël van 13,2 mm. Belangrike bevindinge sluit ook in dat die spuitkoers die grootste invloed het op afloop, gevolg deur die tekstuur diepte en die gradiënt.
158

會計師事務所提供網站認證服務之評估:需求面觀點

王品傑 Unknown Date (has links)
美國會計師協會(AICPA)與加拿大會計師協會(CICA)在1998年推出WebTrust網站安全認證服務,以提供類似於財務報表簽證的方式,對網站之服務提供認證。WebTrust希望透過會計師在財務認證上之品牌聲譽及獨立性,並藉由提供較廣泛、較深度之服務內容,以取得消費者的青睞。本研究係探討國內網站認證市場之需求面,主要之研究發現為消費者對於網站認證標章有一定程度的了解,並認為WebTrust的服務內容相當重要。在網站認證服務競爭優勢之評估方面,會計師具有公信力及客觀之優勢。相較於其他網站認證機構而言,消費者認為會計師較適合提供隱私性服務。此外,本研究發現消費者對於網站認證標章有過度的期待,可能因而產生期望落差。相關業者在提供網站認證服務時,可能會產生潛在之訴訟風險,宜妥為管理及因應。 / The WebTrust assurance service was created through a joint effort between the American Institute of Certified Public Accountants (AICPA) and the Canadian Institute of Chartered Accountants (CICA) in 1998. WebTrust uses an approach similar to the attestation of financial statements and provides assurance services to Web hosts. Utilizing the CPAs’ reputations and independence and more complete coverage of its assurance services, WebTrust aims to establish its presence in the Web assurance market. This study examines the demand side of Web assurance services. Our results show that consumers have fundamental understanding of Web assurance seals and recognize the importance of Web assurance services as provided by WebTrust. In addition, CPAs have advantage in credibility and objectivity over others Web assurance providers, and are more suitable in providing privacy assurance. It’s worthy noting, however, that there is an expectation gap between consumers and Web assurance providers. When offering Web assurance services, a provider may face the potential risk of lawsuit and should address the issue properly.
159

Developing Mass Spectrometric Methods for Distinguishing Isomers, Characterizing Complex Mixtures and Determining the Capability of Organic Compounds to Swell Aircraft O-ring Seals

Mark Romanczyk (6263273) 10 May 2019 (has links)
<p>The research described in this dissertation focuses on several areas: developing analytical methods to distinguish structural isomers, identifying the chemical compositions of aviation fuels and evaluating the effectiveness of organic dopants to swell aircraft o-ring seals. Chapter 2 discusses fundamental aspects of mass spectrometry, and ionization methods and the instrumentation used to complete this research. </p> <p>Chapter 3 discusses and compares two activation methods used to distinguish ionized structural isomers. Ionized naphthene-containing aromatic structural isomers were subjected to collision-activated dissociation (CAD) in an ion trap (ITCAD) and to medium-energy collision-activated dissociation (MCAD) in an octupole collision cell, both in the energy-resolved mass spectrometry mode (ERMS). MCAD was shown to be superior over ITCAD at the structural differentiation of the ionized isomers. </p> <p>Determination of the chemical compositions of petroleum-based jet and diesel fuels, potential alternative fuels and fuel blending components by using a GCxGC/(EI)TOF MS is discussed in chapter 4. The ability to determine the chemical compositions of fuels and to correlate the identified compounds and their concentrations to the physical and chemical properties and aircraft performance of the fuels is vital for the development of future resilient, alternative fuels. The chemical compositions of petroleum-based fuels were found to be different from potential alternative fuels.</p> <p>Chapter 5 discusses the effectiveness of aromatic and nonaromatic compounds in swelling air craft o-ring seals, which prevents leaks in the fuel circulation systems. The aim of this study was to identify aromatic and nonaromatic compounds that most effectively swell o-ring seals. Steric effects were shown to decrease the efficiency of the compounds to swell seals. Ethylbenzene and indane were found to swell o-ring seals more effectively than any other compounds studied, including a currently approved alternative fuel. </p>
160

Análise Morfológica e Ultra-estrutural do Coração do Lobo-Marinho-do-Sul (Arctocephus australis, Zimmermann, 1783) / Morphological and Ultrastructural Analysis of the Heart of the Southern-Fur-Seal (Arctocephalus australis, Zimmermamm, 1783)

Guimarães, Juliana Plácido 15 December 2009 (has links)
O lobo-marinho-do-sul pertencente à ordem Carnivora, subordem Pinnipedia e família Otariidae habita ambientes aquáticos e terrestres e, desta forma, apresentando alterações morfofisiológicas adaptativas importantes, entre elas o sistema cardíaco. O coração é o órgão muscular central do sistema circulatório que tem como função o transporte de oxigênio e nutrientes para os tecidos, assim como o transporte de dióxido de carbono. Considerando a importância deste órgão para o funcionamento geral dos demais sistemas corpóreos, este trabalho teve por objetivo descrever a morfologia e aspectos morfométricos do coração a fim de estabelecer comparações entre o coração do lobo-marinho-do-sul com outros pinípedes e carnívoros terrestres. Para tanto, foram utilizados corações de lobo-marinho-do-sul (Arctocephalus australis) que vierem a óbito por causas naturais. Após análise macroscópica e realização de mensurações, os corações foram analisados em nível de microscopia de luz, microscopia eletrônica de varredura, por meio de crio fratura em nitrogênio líquido, e microscopia eletrônica de transmissão. As características topográficas e morfológicas do coração do lobo-marinho-do-sul são descritas. O órgão é quase totalmente envolto pelo pulmão e revestido pelo pericárdio tendo uma forma alongada e achatada. Os aspectos ultra-estruturais apresentaram a disposição de fibras musculares dos átrios e ventrículos com as características típicas de fibras cardíacas revelando os feixes de miofibrilas, mitocôndrias com as cristas mitocondriais nítidas, junções em forma de placas, anastosmoses entre os feixes de miofibrilas e grânulos elétron-densos, nátrio-uréticos, próximo ao núcleo das células musculares ou ao longo da disposição de mitocôndrias das fibras musculares de átrios. / The southern-fur-seal belongs to the order Carnivora, suborder Pinnipedia and Otariidae family lives in aquatic and terrestrial environments and thus presenting important adaptive morpho-physiological changes, between then the cardiovascular system. The heart is the central muscular organ of the circulatory system whose function is to transport oxygen and nutrients to tissues, as well as the transport of carbon dioxide. Considering the importance of this organ to the overall functioning of other body systems, this study was to aim to describe the morphology and morphometric aspects of the heart in order to establish comparisons between the heart of the southern-fur-seals with other pinnipeds and terrestrial carnivores. Therefore, hearts of southern-fur-seals (Arctocephalus australis) were used that come to death by natural pathologies. After macroscopic analysis and execution of measurements, the hearts were analyzed at the level of light microscopy, scanning electron microscopy, using cryo fracture in liquid nitrogen, and transmission electron microscopy. The heart of the fur seal-of-south is surrounded almost entirely by the lung and covered by the pericardium, having long, flat in shape. The ultrastructural aspects presented the dispositive of muscle fibers of the atrium and ventricles under the typical cardiac fibers revelry the myofibrils bundles, mitochondria with mitochondrial cristal, junction in form of plates, anastomosis between the myofibrils bundles, and electron dense granules like natriun-uretriz near to nuclear of muscle cells or along the disposal of mitochondria of the muscle fibers of atrium.

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