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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.
51

Application of the Moving-Bed Syngas Chemical Looping Process for High Syngas and Methane Conversion and Hydrogen Generation

Tong, Andrew S. 09 September 2014 (has links)
No description available.
52

Iron-Based Coal Direct Chemical Looping Process: Operation of Sub Pilot Scale Unit with Ohio #6 Bituminous Coal

pottimurthy, yaswanth 28 July 2017 (has links)
No description available.
53

Attrition Behavior of Oxygen Carrier Particles and Pressure Fluctuations in Chemical Looping Systems

Shah, Vedant Ravindra 15 August 2018 (has links)
No description available.
54

The Feasibility Study of Perovskite Oxygen Carriers for Chemical Looping Combustion

Gholami, Mahsa January 2016 (has links)
No description available.
55

Making Change Intelligible: Why The Study of Human Kinds Is Just Science As Usual

Ali, Mohamed 04 May 2023 (has links)
This paper challenges the notion that the social sciences require a fundamentally different methodology from the natural sciences due to the interactivity of human kinds. By examining the concept of classificatory looping and its impact on human kinds, the author argues that understanding the causal pathways and utilizing behavioral science can offer reliable generalizations about human kinds. The paper presents examples such as the Buraku of Japan and African Americans to demonstrate how behavioral science can be employed to predict changes in properties of social groups. It posits that the social sciences can operate in a manner similar to the natural sciences by examining generic human tendencies that hold broadly across diverse social contexts. This exploration ultimately supports the unity thesis, emphasizing that social sciences can indeed gain a scientific understanding of human kinds comparable to the knowledge offered by natural sciences. / Master of Arts / This paper explores the idea that social sciences, which study human behavior and societies, can use methods similar to those in natural sciences, which study the natural world. The challenge lies in the fact that human behavior can change based on how people are classified, making it difficult to establish reliable patterns. The author argues that by understanding the reasons behind these changes and applying insights from behavioral science, we can still make valid generalizations about human behavior. Real-life examples, such as the Buraku people of Japan and African Americans, are used to demonstrate how behavioral science can help predict changes in social groups. By focusing on common human tendencies that apply across different social contexts, the paper supports the idea that social sciences can gain valuable insights into human behavior, much like the natural sciences do.
56

A construção da cena: Cindy Sherman e Stan Douglas / -

Flávia Tresinari Bertinato 02 December 2013 (has links)
Esta pesquisa tenciona investigar a produção artística de Cindy Sherman (1954-) e Stan Douglas (1960-), partindo da observação dos procedimentos por eles adotados para a produção de suas obras e de seu interesse comum pela natureza da cultura de massa. Pretende-se, ainda, evidenciar os tipos de convenções próprias dos suportes das mídias utilizados para suas imagens e o modus operandi que as mantêm. Grosso modo, entende-se por imagens subsidiadas pela mídia de massa aquelas que são expostas visando ao acesso em grande escala e de forma imediatista. / This study aims to shed light on the work of Cindy Sherman (1954-) and Stan Douglas (1960-), and proposes as its start-point not only the procedures that have been used by both of the artists in their creative process, but also the interest they have demonstrated in the mass culture as a subject for their work. In addiction to that, we intend to evince the type of conventions specific to the media in relation to its images and their modus operandi. By and large, it is well known that the repertoire of images subsidized by mass media correspond to those exposed in order to provide immediate access and in large scale.
57

A construção da cena: Cindy Sherman e Stan Douglas / -

Bertinato, Flávia Tresinari 02 December 2013 (has links)
Esta pesquisa tenciona investigar a produção artística de Cindy Sherman (1954-) e Stan Douglas (1960-), partindo da observação dos procedimentos por eles adotados para a produção de suas obras e de seu interesse comum pela natureza da cultura de massa. Pretende-se, ainda, evidenciar os tipos de convenções próprias dos suportes das mídias utilizados para suas imagens e o modus operandi que as mantêm. Grosso modo, entende-se por imagens subsidiadas pela mídia de massa aquelas que são expostas visando ao acesso em grande escala e de forma imediatista. / This study aims to shed light on the work of Cindy Sherman (1954-) and Stan Douglas (1960-), and proposes as its start-point not only the procedures that have been used by both of the artists in their creative process, but also the interest they have demonstrated in the mass culture as a subject for their work. In addiction to that, we intend to evince the type of conventions specific to the media in relation to its images and their modus operandi. By and large, it is well known that the repertoire of images subsidized by mass media correspond to those exposed in order to provide immediate access and in large scale.
58

Zur Bedeutung ungleichen Längenwachstums bei der Bildung der embryonalen Herzschleife - Untersuchungen an einem physikalischen Modell / Cardiac looping may be driven by compressive loads resulting from unequal growth of the heart and pericardial cavity - Observations on a physical simulation model

Bayraktar, Meric 28 September 2015 (has links)
Der Prozess der Umformung des geraden embryonalen Herzschlauchs in eine helikal gewundene Herzschleife wird Cardiac looping genannt. Diese Schleifenbildung wird als einer der wesentlichen Formbildungsprozesse des Wirbeltierherzens angesehen, da er die Bauelemente/Segmente des sich entwickelnden Herzens (Sinus venosus, Vorhöfe, Ventrikel, große arterielle Gefäßstämme) annähernd in ihre definitiven topographischen Beziehungen zueinander bringt. Störungen des Cardiac looping führen zu komplexen angeborenen Herzfehlern mit abnormen Verbindungen zwischen den Segmenten des vierkammerigen Herzens (z. B. Double-outlet right ventricle, Congenitally corrected TGA). Die Herzschleifenbildung läuft bei allen Wirbeltierspezies in ähnlicher Weise ab und führt im Normalfall zur Ausbildung einer linksgewundenen Herzschleife, die allgemein als D-Loop bezeichnet wird, da ihre Ventrikel anfänglich nach rechts verlagert werden. Rechtsgewundene Herzschleifen sind äußerst seltene Ergebnisse des Cardiac looping, die sich z. B. beim Situs inversus finden. Sie werden allgemein als L-Loop bezeichnet, da ihre Ventrikel anfänglich nach links verlagert werden.  Das wissenschaftliche Interesse am Phänomen des Cardiac looping fokussiert sich im Wesentlichen auf zwei Fragen: (1.) Welche Faktoren führen zur helikalen Verformung des embryonalen Herzschlauchs? (2.) Welche Faktoren sind dafür verantwortlich, dass bei allen bisher untersuchten Wirbeltieren während der Embryogenese normalerweise nur D-Loops erzeugt werden? Während der letzten zwei Jahrzehnte wurde eine Vielzahl an Genen identifiziert, die wichtige Rollen beim Cardiac looping spielen. Die Frage, wie diese genetischen Informationen in mechanische Kräfte übersetzt werden, welche die Formänderungen der Herzschleife bewirken, blieb bisher größtenteils unbeantwortet. Die älteste Hypothese zur Mechanik des Cardiac looping schreibt die Formänderungen der Herzschleife (ventrale Biegung → einfache helikale Windung → komplexe helikale Windung) Kompressionsbelastungen zu, die aus dem ungleichen Längenwachstum des Herzens und der Perikardhöhle resultieren sollen.  In der vorliegenden Studie wurde die physikalische Plausibilität dieser Hypothese, die ich als wachstumsbedingtes Buckling bezeichne, zum ersten Mal experimentell geprüft. Anhand eines physikalischen Simulationsmodells konnte ich zeigen, dass wachstumsbedingtes Buckling eines geraden elastischen Stabs (Modell des Herzschlauchs) innerhalb einer ihn einengenden halbkugeligen Höhle (Modell der Perikardhöhle) eine Abfolge von Formänderungen erzeugen kann, die derjenigen entspricht, die bei der embryonalen Herzschleifenbildung beobachtet wird. Meine Experimente haben weiterhin gezeigt, dass durch Wachstum bedingtes Buckling unter bilateral symmetrischen Bedingungen links- und rechtshändige Helices in einem Zahlenverhältnis von nahezu 1:1 erzeugt. Bereits geringfügige Links- oder Rechtsverschiebungen des caudalen Endes des elastischen Stabs vor Beginn des simulierten Längenwachstums reichten aus, um den Bucklingprozess in eine Richtung zu lenken, bei der es ausschließlich zur Erzeugung von D- bzw. L-Loops kam. Die biologische Relevanz dieser am physikalischen Modell erhobenen Daten wird anhand von Beobachtungen an biologischen Modellen (Embryonen von Zebrafisch, Krallenfrosch, Axolotl, Huhn, Maus) diskutiert. Hierbei komme ich zu folgenden Schlüssen: (1.) Aus ungleichem Längenwachstum des Herzens und der Perikardhöhle resultierende Kompressions¬belastungen des Herzschlauchs dürften wichtige Beiträge zum Cardiac looping leisten. (2.) Asymmetrische Positionierungen des venösen Herzpols könnten diese Kräfte in Richtung einer 100%igen Erzeugung eines D- bzw. L-Loops lenken.
59

Techno-economic study of the calcium looping process for CO2 capture from cement and biomass power plants

Ozcan, Dursun Can January 2014 (has links)
The first detailed systematic investigation of a cement plant with various carbon capture technologies has been performed. The calcium looping (Ca-looping) process has emerged as a leading option for this purpose, since this process applied to a cement plant provides an opportunity to use the CaO purge for clinker production. The Ca-looping process is comprised of two interconnected reactors where the carbonator captures CO2 from flue gases and the calciner regenerates the CaCO3 into CaO by oxy-combustion. Fully integrated process flowsheets have been developed and simulated in UniSim Design Suite from Honeywell. The detailed carbonator model has been implemented using Matlab and incorporated into UniSim to provide a full flowsheet simulation for an exemplary dry-feed cement plant as a user-defined operation. The base cement plant simulation was also modified to integrate three different carbon capture processes: membrane; indirect calcination; and amine-scrubbing. Furthermore, an advanced configuration of Ca-looping process has been investigated where the energy intensive air separation unit was replaced with a chemical looping combustion (CLC) cycle. Each case has been optimised to minimise its energy consumption and compared in terms of levelised cost of cement and its resulting cost of CO2 avoided at the same CO2 avoidance rate. The proposed integration of the Ca-looping process is capable of achieving over 90% CO2 avoidance with additional fuel consumption of 2.5 to 3.0 GJth/ton CO2 avoided. By using an advanced configuration of the Ca-looping process with a CLC cycle, the additional fuel consumption can be reduced to 1.7 GJth/ton CO2 avoided, but the cost of the oxygen carrier is the major concern for this system. Among the other CO2 capture options, the membrane process is a promising alternative for the Ca-looping process since it has a potential of achieving the target CO2 avoidance rate and purity requiring lower energy consumption. The indirect calcination process provides moderate levels of CO2 avoidance (up to 56%) without a need of an external capture process whereas the integration of the amine process in a cement plant is challenging as a result of the requirement of steam for solvent regeneration. Furthermore, considering zero net CO2 emissions associated with biomass combustion systems, a novel concept has been analysed to capture of CO2 in-situ with the Ca-looping process while operating the combustor of a dedicated biomass power plant at sufficiently low temperature. This process is capable of achieving 84% overall CO2 capture rate with an energy penalty of 5.2% when a proper heat exchanger network is designed with the support of a pinch analysis. The techno-economic performance of the biomass power plant with in-situ Ca-looping CO2 capture process was compared with that of the alternative biomass-air-fired and biomass-oxy-fired power plants.
60

Avaliação de ensaios simulativos de corrosão e biocorrosão em sistemas estático e dinâmico de revestimentos aplicados em aço carbono

Rosângela Santos Vieira, Magda 31 January 2008 (has links)
Made available in DSpace on 2014-06-12T17:38:11Z (GMT). No. of bitstreams: 2 arquivo3828_1.pdf: 4684455 bytes, checksum: 46054e6422517113c139a624d80d96ab (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O custo global ocasionado pela corrosão representa uma elevada perda econômica. Várias são as tentativas de retardar o processo de corrosão, destacando-se o uso de revestimentos metálicos e orgânicos. Neste trabalho, avaliaram-se as propriedades anticorrosivas de revestimentos aplicados sobre aço carbono utilizados nas áreas industriais como alternativas de proteção anticorrosiva, sendo eles: esquemas de pintura, galvanização a quente e sistema duplex, que consiste na associação da galvanização e pintura. Os ensaios foram realizados em sistema estático de imersão e em sistema dinâmico do tipo looping, contendo água do mar da região do Complexo Portuário e Industrial de SUAPE (Ipojuca PE), onde se encontra instalada a empresa Termoelétrica de Pernambuco (TERMOPE). Para avaliação da influência biocorrosiva no processo de deterioração do metal base e dos revestimentos, os ensaios de imersão em sistema estático foram conduzidos em duas condições: meio estéril (com biocida) e meio não estéril (sem biocida), sendo monitorados ao longo do tempo os parâmetros microbiológicos do meio. Para avaliação do desempenho anticorrosivo dos revestimentos, utilizou-se o monitoramento eletroquímico através da medida de potencial de circuito aberto e da técnica de Espectroscopia de Impedância Eletroquímica (EIS). A técnica de EIS apresentou-se bastante sensível à presença de defeitos nos revestimentos e também apresentou respostas diferenciadas para o comportamento dos revestimentos em meio estéril e meio não estéril. O ensaio em looping mostrou-se mais severo do que o ensaio em sistema estático, sendo a corrosividade obtida em cada sistema, respectivamente classificada como, alta e moderada. O processo biocorrosivo para o meio estático teve uma contribuição aproximada 15,27% para a corrosão observada no metal não revestido, após 75 dias de exposição. O processo de formação de biofilme ao longo do tempo foi mais acentuado no sistema dinâmico do tipo looping, onde, devido ao processo de recirculação da água observou-se um aumento significativo da quantidade de microrganismos presentes no meio

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