<?xml version="1.0" encoding="UTF-8"?><marc:collection xmlns:marc="http://www.loc.gov/MARC21/slim">
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    <marc:leader>00000nam  2200000zi 4500</marc:leader>
    <marc:controlfield tag="001">9.892127</marc:controlfield>
    <marc:controlfield tag="003">CaOODSP</marc:controlfield>
    <marc:controlfield tag="005">20221107173100</marc:controlfield>
    <marc:controlfield tag="006">m     o  d f      </marc:controlfield>
    <marc:controlfield tag="007">cr |n|||||||||</marc:controlfield>
    <marc:controlfield tag="008">201005s1992    oncd    ob   f|0| 0 eng d</marc:controlfield>
    <marc:datafield tag="040" ind1=" " ind2=" ">
      <marc:subfield code="a">CaOODSP</marc:subfield>
      <marc:subfield code="b">eng</marc:subfield>
      <marc:subfield code="e">rda</marc:subfield>
      <marc:subfield code="c">CaOODSP</marc:subfield>
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    <marc:datafield tag="043" ind1=" " ind2=" ">
      <marc:subfield code="a">n-cn---</marc:subfield>
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    <marc:datafield tag="086" ind1="1" ind2=" ">
      <marc:subfield code="a">Co24-3/7-92-001E-PDF</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="100" ind1="1" ind2=" ">
      <marc:subfield code="a">Chow, S.M., </marc:subfield>
      <marc:subfield code="e">author.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="245" ind1="1" ind2="0">
      <marc:subfield code="a">Propagation characteristics of radio waves in potash tunnels and its impact on radio systems / </marc:subfield>
      <marc:subfield code="c">by S.M. Chow.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="264" ind1=" " ind2="1">
      <marc:subfield code="a">Ottawa : </marc:subfield>
      <marc:subfield code="b">Department of Communications, </marc:subfield>
      <marc:subfield code="c">1992.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="300" ind1=" " ind2=" ">
      <marc:subfield code="a">1 online resource (15 pages) : </marc:subfield>
      <marc:subfield code="b">charts.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="336" ind1=" " ind2=" ">
      <marc:subfield code="a">text</marc:subfield>
      <marc:subfield code="b">txt</marc:subfield>
      <marc:subfield code="2">rdacontent</marc:subfield>
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    <marc:datafield tag="337" ind1=" " ind2=" ">
      <marc:subfield code="a">computer</marc:subfield>
      <marc:subfield code="b">c</marc:subfield>
      <marc:subfield code="2">rdamedia</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="338" ind1=" " ind2=" ">
      <marc:subfield code="a">online resource</marc:subfield>
      <marc:subfield code="b">cr</marc:subfield>
      <marc:subfield code="2">rdacarrier</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="490" ind1="1" ind2=" ">
      <marc:subfield code="a">CRC report ; </marc:subfield>
      <marc:subfield code="v">CRC-RP-92-001</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="500" ind1=" " ind2=" ">
      <marc:subfield code="a">Digitized edition from print [produced by Innovation, Science and Economic Development Canada].</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="500" ind1=" " ind2=" ">
      <marc:subfield code="a">"July 1992."</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="504" ind1=" " ind2=" ">
      <marc:subfield code="a">Includes bibliographical references (page 7).</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="520" ind1=" " ind2=" ">
      <marc:subfield code="a">"This report shows that radio waves at about 900 MHz can propagate in the tunnels of a potash mine with low loss and low multipath distortion. These results were first derived using a theoretical model and were later confirmed by measurements. The attenuation of radio waves per unit distance in a potash tunnel within this frequency band is less than the attenuation in a coaxial cable. This result is important because many commercial systems such as cellular radio, radio LANs and personal communication systems operate in this frequency band and can be adapted to work in a potash mine, replacing the more expensive leaky feeder systems used in other types of underground mines"--Abstract.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="650" ind1=" " ind2="0">
      <marc:subfield code="a">Radio wave propagation.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="650" ind1=" " ind2="0">
      <marc:subfield code="a">Potash.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="650" ind1=" " ind2="6">
      <marc:subfield code="a">Ondes radioélectriques</marc:subfield>
      <marc:subfield code="x">Propagation.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="650" ind1=" " ind2="6">
      <marc:subfield code="a">Potasse.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="710" ind1="1" ind2=" ">
      <marc:subfield code="a">Canada. </marc:subfield>
      <marc:subfield code="b">Department of Communications, </marc:subfield>
      <marc:subfield code="e">issuing body.</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="830" ind1="#" ind2="0">
      <marc:subfield code="a">CRC report ;</marc:subfield>
      <marc:subfield code="v">CRC-RP-92-001.</marc:subfield>
      <marc:subfield code="w">(CaOODSP)9.882492</marc:subfield>
    </marc:datafield>
    <marc:datafield tag="856" ind1="4" ind2="0">
      <marc:subfield code="q">PDF</marc:subfield>
      <marc:subfield code="s">1.47 MB</marc:subfield>
      <marc:subfield code="u">https://publications.gc.ca/collections/collection_2020/isde-ised/Co24/Co24-3-7-92-001-eng.pdf</marc:subfield>
    </marc:datafield>
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