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  <element name="WarrantsToPurchaseCommonStockNumberOfSharesPerWarrant" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="inrd_WarrantsToPurchaseCommonStockNumberOfSharesPerWarrant" substitutionGroup="xbrli:item" />
  <element id="inrd_EarningsPerShareDilutedConversionNotes" name="EarningsPerShareDilutedConversionNotes" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="inrd_EarningsPerShareDilutedAccruedInterestOnConvertibleNotes" name="EarningsPerShareDilutedAccruedInterestOnConvertibleNotes" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="inrd_EarningsPerShareDilutedWarrants" name="EarningsPerShareDilutedWarrants" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="inrd_EarningsPerShareDilutedStockOptions" name="EarningsPerShareDilutedStockOptions" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="inrd_ConvertibleSubordinatedDebt1500000Member" name="ConvertibleSubordinatedDebt1500000Member" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <element id="inrd_ConvertibleSubordinatedDebt1000000Member" name="ConvertibleSubordinatedDebt1000000Member" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <element id="inrd_NumberOfSharesAndWarrantsComprisedInUnit" name="NumberOfSharesAndWarrantsComprisedInUnit" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="inrd_DebtInstrumentMonthlyPayment" name="DebtInstrumentMonthlyPayment" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <element id="inrd_InvestmentWarrantsExercisePrice1" name="InvestmentWarrantsExercisePrice1" nillable="true" type="num:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <element id="inrd_PaycheckProtectionProgramLoanMember" name="PaycheckProtectionProgramLoanMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <element id="inrd_LongTermNotesPayableOther" name="LongTermNotesPayableOther" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <element id="inrd_GainLossOnLoanForgiveness" name="GainLossOnLoanForgiveness" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <element id="inrd_DefinedContributionPlanCashContributions" name="DefinedContributionPlanCashContributions" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
</schema>