<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-18T21:42:50Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/40464" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/40464</identifier><datestamp>2022-01-13T07:54:36Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131024</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Yukikazu Iwasa.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Pavão, Erica Medeiros</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Dept. of Mechanical Engineering.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Mechanical Engineering</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2008-02-27T22:28:24Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2008-02-27T22:28:24Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2007</dim:field>
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   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">191734014</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references (p. 30).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">Different magnetic strengths in MRIs produce different reactions and provide more insight into what being imaged. Being able to more quickly switch between two or more different magnet strengths would allow scientists in research to be able to gather more useful data. Replacing the persistent-current switch (PCS), which needs to be warmed beyond its critical temperature at times in order to charge or discharge the magnet, with a mechanical switch that can be kept at its superconducting stage may be able to speed up the charging/discharging process. A malleable superconductor would be needed for the current pending design of this switch. A superconducting solder with a critical temperature above 4.2K would be ideal. This experiment uses a bucket Dewar and a cryocooler to attempt to cool the solders to 4.2K and determine at which temperature they become superconducting. The setup, however, was not capable of measuring any of the four tested solders' critical temperature. Reasons for this may include poor thermal contact between the sample and the cryocooler and excessive noise that overpowers small voltages.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Erica Medeiros Pavão.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">S.B.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">30 p.</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Mechanical Engineering.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Critical temperatures of superconducting solders</dim:field>
   <dim:field mdschema="dc" element="type" lang="en_US">Thesis</dim:field>
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   	&lt;Title>Critical temperatures of superconducting solders&lt;/Title>
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   	&lt;PublicationDate>2007&lt;/PublicationDate>
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        	&lt;DisplayName>Pavão, Erica Medeiros&lt;/DisplayName>
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    &lt;Keyword>Mechanical Engineering.&lt;/Keyword>
   	&lt;Abstract>Different magnetic strengths in MRIs produce different reactions and provide more insight into what being imaged. Being able to more quickly switch between two or more different magnet strengths would allow scientists in research to be able to gather more useful data. Replacing the persistent-current switch (PCS), which needs to be warmed beyond its critical temperature at times in order to charge or discharge the magnet, with a mechanical switch that can be kept at its superconducting stage may be able to speed up the charging/discharging process. A malleable superconductor would be needed for the current pending design of this switch. A superconducting solder with a critical temperature above 4.2K would be ideal. This experiment uses a bucket Dewar and a cryocooler to attempt to cool the solders to 4.2K and determine at which temperature they become superconducting. The setup, however, was not capable of measuring any of the four tested solders&amp;apos; critical temperature. Reasons for this may include poor thermal contact between the sample and the cryocooler and excessive noise that overpowers small voltages.&lt;/Abstract>
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