• Non ci sono risultati.

Fatigue Behavior of Shot Peened Notched Specimens: Effect of the Residual Stress Field Ahead of the Notch Root

N/A
N/A
Protected

Academic year: 2021

Condividi "Fatigue Behavior of Shot Peened Notched Specimens: Effect of the Residual Stress Field Ahead of the Notch Root"

Copied!
9
0
0
Mostra di più ( pagine)

Testo completo

(1)

Procedia Engineering 109 ( 2015 ) 80 – 88

1877-7058 © 2015 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) doi: 10.1016/j.proeng.2015.06.210

ScienceDirect

;;,,,,WDOLDQ*URXSRI)UDFWXUH0HHWLQJ,*);;,,,

)DWLJXHEHKDYLRURIVKRWSHHQHGQRWFKHGVSHFLPHQVHIIHFWRIWKH

UHVLGXDOVWUHVVILHOGDKHDGRIWKHQRWFKURRW

0%HQHGHWWL

D

9)RQWDQDUL

D

%:LQLDUVNL

E

3-:LWKHUV

E

0$OODKNDUDPL

F

-&

+DQDQ

F



aUniversity of Trento, via Sommarive 9, 38123 Trento, Italy bUniversity of Manchester, Grosvenor Street, Manchester, M13 9PL, U.K. cOklahoma State University, 700 N. Greenwood Ave., 74106 Tulsa, OK, U.S.A.

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‹7KH$XWKRUV3XEOLVKHGE\(OVHYLHU/WG 3HHUUHYLHZXQGHUUHVSRQVLELOLW\RIWKH*UXSSR,WDOLDQR)UDWWXUD ,*)  Keywords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



&RUUHVSRQGLQJDXWKRU7HOID[ E-mail address:YLJLOLRIRQWDQDUL#LQJXQLWQLW

© 2015 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

(2)

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¶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rRIPP µµEOXQW´QRWFK PP µµVKDUS´QRWFK DQGPP µµYHU\VKDUS´QRWFK KDYLQJWKHRUHWLFDOVWUHVVFRQFHQWUDWLRQIDFWRURIDQG UHVSHFWLYHO\

&RQWUROOHGVKRWSHHQLQJRQDOOVSHFLPHQVVLGHVLQFOXGLQJQRWFKURRWZDVSHUIRUPHG'HWDLOVDERXWWKHSURFHVVDQG WKHDLUEODVWPDFKLQHFDQEHIRXQGLQ5HI>@7KHWUHDWPHQWHPSOR\VVPDOOFHUDPLFEHDGVOHDGLQJWRDJHQWOHDQG VXSHUILFLDO HIIHFW DOORZLQJ IRU EHWWHU FRYHUDJH RI VPDOO JHRPHWULFDO GHWDLOV DQG KLJKHU IDWLJXH SHUIRUPDQFH DV FRPSDUHGZLWKODUJHUVKRWV

3XOVDWLQJ R  ORDGFRQWUROOHGSRLQWEHQGLQJIDWLJXHWHVWVDUHFDUULHGRXWLQDLUDWURRPWHPSHUDWXUHDQGDW DQRPLQDOIUHTXHQF\RI+]XVLQJDUHVRQDQWWHVWLQJPDFKLQH5XPXO0LNURWURQN1HTXLSSHGZLWKDN1ORDG FHOO'LIIHUHQWVWUHVVOHYHOVFRUUHVSRQGLQJWRIDWLJXHOLYHVLQWKHUDQJHEHWZHHQQHDUO\DQGF\FOHVDUHFRQVLGHUHG

(3)



6SHFLPHQ U PP  %OXQWQRWFKHG  6KDUSQRWFKHG  9HU\VKDUSQRWFKHG  )LJ*HRPHWU\RIQRWFKHGVSHFLPHQVXVHGLQWKLVVWXG\$OOGLPHQVLRQVDUHJLYHQLQPP 7ZRW\SHVRIIDWLJXHFXUYHVDUHREWDLQHGLHZLWKRXWDQGZLWKNQHHORFDWHGDURXQGIDWLJXHF\FOHV7KHIRUPHU IDWLJXHFXUYHVFRUUHVSRQGLQJWRRIIDLOXUHSUREDELOLW\DUHUHSUHVHQWHGE\D61FXUYHLQWKHIRUPRI     k P P Nf V V u     D 7KHODWWHUIDWLJXHFXUYHVFRUUHVSRQGLQJWRRIIDLOXUHSUREDELOLW\DUHUHSUHVHQWHGE\D61FXUYHLQWKHIRUP RI    P P f k N V V     E ,WVKRXOGEHQRWHGWKDWWKHPHDQLQJRIWKHFRHIILFLHQWVRI(TV DE LVGLIIHUHQWEXWWKH\KDYHEHHQWDNHQWKHVDPH IRUDFRQFLVHSUHVHQWDWLRQLQ7DEOH,QERWKFDVHVWKHXQFHUWDLQW\UDQJHLVDVVXPHGWREHFRQVWDQWDQGDSSUR[LPDWHG E\LWVFHQWURLGYDOXH$VDUHSUHVHQWDWLYHYDOXHRIWKHVFDWWHUWKHIROORZLQJH[SUHVVLRQLVXVHG    P  P TV V V     PPGHQRWHWKHDQGOHYHOVRIIDLOXUHSUREDELOLW\UHVSHFWLYHO\7KHQRWFKVHQVLWLYLW\IDFWRUqDWDJLYHQ QXPEHURIF\FOHVWRIDLOXUHNfLVFRPSXWHGDV



    f f P smooth f f f f t P notched f K N N q N K N K N V V      7KHPRGLILFDWLRQVRIWKHVXUIDFHOD\HUVSURGXFHGE\VKRWSHHQLQJZHUHLQYHVWLJDWHGLQ>@WKURXJKVXUIDFHURXJKQHVV DQGLQGHSWK56PHDVXUHPHQWVXQGHUWDNHQRQSODLQVDPSOHV

7KH 56 ZHUH PHDVXUHG LQ WKH QRWFKHG SHHQHG VDPSOHV DORQJ WKH QRWFK ELVHFWRU WKURXJK WZR FRPSOHPHQWDU\ H[SHULPHQWDOWHFKQLTXHV L —;5'DQG LL ȝ+'ȝ6& 7KH—;5'PHDVXUHPHQWVDUHPDGHHPSOR\LQJD%UXNHU¶V''LVFRYHU;5'PLFURGLIIUDFWRPHWHUHTXLSSHGZLWK D*HQHUDO$UHD'LIIUDFWLRQ'HWHFWLRQ6\VWHP *$''6 DQG+L6WDU'DUHDGHWHFWRU7XEHSDUDPHWHUVRIN9 P$XVLQJ&X.ĮUDGLDWLRQDWDGHWHFWRUGLVWDQFHRIFPFRYHULQJDSSUR[LPDWHO\DQDUHDRIƒLQșDQGƒLQȖ ZLWKƒUHVROXWLRQ$IRFXVLQJRSWLFZDVXVHGWRDFKLHYHDEHDPGLDPHWHURIȝP7KHVXUIDFH56SURILOHDORQJ WKHQRWFKELVHFWRUZDVPDSSHGWKURXJKPHDVXUHPHQWVVSDFHG—PDSDUWVWDUWLQJIURPWKHQRWFKWLS7KH&X.D UDGLDWLRQGXHWRLWVKLJKSHQHWUDWLRQGHSWK |PP FDSWXUHVLQIRUPDWLRQDERXW56VWKURXJKRXWWKHHQWLUHVXUIDFH OD\HUPRGLILHGE\WKHSHHQLQJWUHDWPHQW

7KH ȝ+' DQG ȝ6& PHDVXUHPHQWV DUH SHUIRUPHG RQ VSHFLPHQV WKDW KDG EHHQ SUHYLRXVO\ SROLVKHG XVLQJ HPHU\ SDSHUV JULWUDQJLQJIURPWR DEUDVLYHDTXHRXVVXVSHQVLRQV SDUWLFOHVL]HUDQJLQJIURPWRȝP DQG

(4)

ȝPFROORLGDOVLOLFDVROXWLRQ,QWKLVZD\DVXUIDFHOD\HURIDERXWȝPWKLFNQHVVLVUHPRYHG$VVKRZQLQ>@ WKHUHPRYDORIDWKLQVXUIDFHOD\HUGRHVQRWVLJQLILFDQWO\DIIHFWWKH56GLVWULEXWLRQLQWKHXQGHUO\LQJPDWHULDO$VHULHV RIPLFURKROHV —PLQGLDPHWHUDQG—PGHHS DQGPLFURVORWV —PORQJ—PZLGHDQG—PGHHS DUH),%HG DORQJWKHQRWFKELVHFWRUXVLQJDQ)(,1RYD1DQRODEL'DYLV/D9LVLRQ',&VRIWZDUHLVXVHGWRUHFRUGWKHVXUIDFH UHOD[DWLRQVDVWKHKROHVDQGWKHVORWVDUHPLOOHG)XUWKHUGHWDLOVRQERWKPHDVXUHPHQWVWHFKQLTXHVFDQEHIRXQGLQ>@ ([SHULPHQWDOUHVXOWV 3.1. Fatigue behavior 7KHUHVXOWVRIWKHSXOVDWLQJEHQGLQJIDWLJXHWHVWVDVZHOODVWKH3IDWLJXHOLQHVDUHFRPSDUHGLQ)LJVDDQGE IRUXQSHHQHGDQGSHHQHGVSHFLPHQVUHVSHFWLYHO\7KHSDUDPHWHUVUHSUHVHQWLQJWKHIDWLJXHFXUYHVFRUUHVSRQGLQJWR RIIDLOXUHSUREDELOLW\DFFRUGLQJWR(TV  DQGWKHUHVXOWVVFDWWHUH[SUHVVHGE\(T  DUHOLVWHGLQ7DEOH





)LJ61FXUYHVRIWKHSODLQDQGQRWFKHGVSHFLPHQV D DVUHFHLYHG E SHHQHGVSHFLPHQV5XQRXWWHVWVDUHPDUNHGE\DUURZV $OOWKH61RIWKHDVUHFHLYHGFRQGLWLRQ ILJD VKRZDNQHHDURXQGuF\FOHV7KHVWUHVVUDLVHUVVXSSUHVVWKH

RFFXUUHQFH RI IDLOXUHV DW IDWLJXH OLYHV ORQJHU WKDQ u F\FOHV LQ WKH DVUHFHLYHG PDWHULDO DQG WKLV SKHQRPHQRQ

EHFRPHVPRUHUHPDUNDEOHZLWKLQFUHDVLQJQRWFKVHYHULW\6LPLODUEHKDYLRUFDQEHREVHUYHGIRUWKHSHHQHGVDPSOHV FDUU\LQJWKHYHU\VKDUSQRWFK2QWKHFRQWUDU\WKH61FXUYHVRIWKHEOXQWDQGVKDUSQRWFKHGSHHQHGVDPSOHVVWHDGLO\ GHFOLQHZLWKWKHIDWLJXHOLIHVKRZLQJRFFXUUHQFHRIIDLOXUHWKURXJKRXWWKHH[SORUHGOLIHLQWHUYDO ILJE 

7DEOH3ULQFLSDOUHVXOWVRIWKHIDWLJXHWHVWV

6DPSOHJHRPHWU\ &RQGLWLRQ :|KOHUFXUYH *DLQ  

(TXDWLRQ k V3 03D  TV #uF\FOHV #uF\FOHV

6PRRWK $VUHFHLYHG E  u

  

 

3HHQHG% D    

%OXQWQRWFKHG 5  $VUHFHLYHG E  u    

3HHQHG% D    

6KDUSQRWFKHG 5  $VUHFHLYHG E  u

      3HHQHG% D     9HU\VKDUSQRWFKHG 5 

$VUHFHLYHG E  u  

  3HHQHG% E  u  



7KHSHHQLQJWUHDWPHQWZDVHIIHFWLYHLQSURORQJLQJWKHIDWLJXHOLIHRIWKHPDWHULDODVZHOODVLQUHGXFLQJWKHODUJH VFDWWHULQIDWLJXHUHVXOWVGLVSOD\HGE\WKHYLUJLQPDWHULDO7KHLPSURYHPHQWGHSHQGVRQERWKWKHDSSOLHGORDGDQGWKH QRWFKVHYHULW\7KHLQFUHPHQWLQIDWLJXHUHVLVWDQFHGXHWRVKRWSHHQLQJVWHDGLO\GHFOLQHVGXULQJIDWLJXHOLIHIRUVPRRWK

(5)

DQGEOXQWQRWFKHGVSHFLPHQVEHLQJPRUHUHPDUNDEOHDWKLJKORDGOHYHOVFRUUHVSRQGLQJWRVKRUWHUIDWLJXHOLYHVOHDGLQJ WRKLJKHUYDOXHVRIWKHVORSHLQWKH3IDWLJXHOLQH:KLOHWKHSODLQIDWLJXHSHUIRUPDQFHDWF\FOHVRIWKHSHHQHG

YDULDQWVLVFRPSDUDEOHZLWKWKDWRIWKHYLUJLQPDWHULDODQLQFUHPHQWRIDERXWLQWKHIDWLJXHUHVLVWDQFHRIEOXQW QRWFKHGVSHFLPHQVLVVWLOOSUHVHQWLQWKLVIDWLJXHUHJLPH2QWKHFRQWUDU\WKHLQFUHPHQWGXHWRVKRWSHHQLQJLVHYHQ KLJKHUIRUORQJHUWKDQIRUVKRUWHUIDWLJXHLQWKHFDVHRIVKDUSQRWFKHVDQGIRUYHU\VKDUSQRWFKHV







)LJ1RWFKVHQVLWLYLW\IDFWRUGHSHQGHQFHXSRQQRWFKURRWUDGLXVIRUDIDWLJXHOLYHFRUUHVSRQGLQJWR D uDQG E uF\FOHV



)LJXUHVDDQGELOOXVWUDWHWKHGHSHQGHQFHRIWKHQRWFKVHQVLWLYLW\IDFWRUqRQWKHQRWFKURRWUDGLXVrIRUDIDWLJXH OLIH RI u DQG u UHVSHFWLYHO\ $ UHPDUNDEOH UHGXFWLRQ LQ QRWFK VHQVLWLYLW\ GXH WR VKRW SHHQLQJ LV HYLGHQW

HVSHFLDOO\IRUWKHEOXQWQRWFK57KHGHSHQGHQFHRIWKHIDFWRUqXSRQWKHQRWFKURRWUDGLXVIRUWKHXQSHHQHGVDPSOHV LVZHOOUHSUHVHQWHGE\WKH3HWHUVRQHTXDWLRQ   q a r      ZKHUHWKHPDWHULDOFKDUDFWHULVWLFOHQJWKaUDQJHVEHWZHHQDQGPP&RQYHUVHO\IRUWKHSHHQHGYDULDQWV WKHIDFWRUqVHHPVWREHQRWFRUUHODWHGWRWKHQRWFKURRWUDGLXV$QDYHUDJHYDOXHZDVIRXQGFRPSULVHGEHWZHHQ DQGDWWKHORZHVWDQGKLJKHVWIDWLJXHOLIHUHVSHFWLYHO\1RWDEO\IRUWKHYHU\VKDUSQRWFKHGVSHFLPHQVWKHq IDFWRURIWKHXQSHHQHGVDPSOHVLVORZHUDWVKRUWHUDQGKLJKHUDWORQJHUIDWLJXHOLIHZLWKUHVSHFWWRWKHSHHQHGVDPSOHV 7KLVFRQILUPVWKDWWKHSHHQLQJWUHDWPHQWRQWKHPRVWVHYHUHQRWFKHVLVPRUHHIIHFWLYHLQWKHYHU\KLJKF\FOHIDWLJXH UHJLPH

3.2. Residual stress field around the notch

)LJXUHDVKRZVWKHDYHUDJHRIWKHWZR—;5'PHDVXUHPHQWVSHUIRUPHGRQRSSRVLWHIURQWDOIDFHVDVDIXQFWLRQRI WKHyFRRUGLQDWH DVGHILQHGLQ)LJ DOLJQHGZLWKWKHQRWFKELVHFWRUDQGFHQWUHGRQWKHQRWFKDSH[,WFDQEHQRWHG WKDWWKHORQJLWXGLQDO56FRPSRQHQWLQFUHDVHVPRYLQJWRZDUGWRWKHQRWFKDQGWKDWWKHVWUHVVFRQFHQWUDWLRQHIIHFWVFDOHV ZLWKWKHVHYHULW\RIWKHQRWFK7KHUHJLRQDIIHFWHGE\WKHQRWFKVSDQVRYHUDERXWPPIURPWKHQRWFKURRW )LJXUHELOOXVWUDWHVWKHDYHUDJHRIWKHWZR),%',&PHDVXUHPHQWVXQGHUWDNHQE\WKHPLFURKROHDQGPLFURVORW WHFKQLTXHVRQWKHQRWFKHGVDPSOHVDIWHUUHPRYLQJWKHRXWHUPPWKLFNVXUIDFHOD\HUIURPWKHIURQWDOIDFH7KH),% ',&GDWDPDWFKWKHWUHQGVLQWKH—;5'PHDVXUHPHQWV7KHH[SHULPHQWDOUHVXOWVZHUHXVHGLQ>@WRUHFRQVWUXFW

(6)

WKHZKROH56ILHOGDFWLQJRQWKHQRWFKV\PPHWU\SODQH6SHFLILFDOO\WKH56DKHDGRIWKHQRWFKZDVLQWURGXFHGLQWR WKHILQLWHHOHPHQWPRGHOWKURXJKDWHPSHUDWXUHILHOGUHSURGXFLQJWKHHIIHFWRIWKHSHHQLQJWUHDWPHQWDSSOLHGWRWKH IURQWDODQGODWHUDOVXUIDFHDVZHOODVWKHERXQGDU\HIIHFWVDWWKHQRWFKURRWHGJH







)LJ5HVXOWVRIWKHPHDVXUHPHQWVLQWHUPVRIORQJLWXGLQDO56GLVWULEXWLRQDORQJWKHQRWFKELVHFWRU D $YHUDJHRIWZRPHDVXUHPHQWVWDNHQ ZLWKWKH—;5'WHFKQLTXH E $YHUDJHRIWKHPHDVXUHPHQWVWDNHQZLWK),%',&—+'DQG—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eq DORQJWKHQRWFKELVHFWRURYHUDPDWHULDOFKDUDFWHULVWLFOHQJWKLHTXDOVWKHSODLQIDWLJXHVWUHQJWKf7KLVZDVDVVXPHG WREHWKDWRIWKHXQSHHQHGPDWHULDOVLQFHWKHZRUNKDUGHQLQJLQWURGXFHGE\VKRWSHHQLQJH[HUWVDQHJOLJLEOHLQIOXHQFH RQWKHIDWLJXHUHVLVWDQFH>@ ,QWKHSUHVHQWZRUNWKHDVVXPSWLRQVUHJDUGLQJWKHIDWLJXHSURSHUWLHVRIWKHSHHQHGPDWHULDODUHUHWDLQHGZKHUHDV WKHWKHRU\RIFULWLFDOGLVWDQFHLVDSSOLHGLQDGLIIHUHQWZD\,QVWHDGRIDYHUDJLQJWKHHTXLYDOHQWVWUHVVDORQJWKHQRWFK ELVHFWRUO\LQJRQWKHIURQWDOVXUIDFHWKHDYHUDJHLVFRPSXWHGRYHUDVTXDUHDUHDO\LQJRQWKHQRWFKV\PPHWU\SODQHLQ RUGHUWRFDSWXUHWKHLQGHSWKYDULDWLRQRIWKH56ILHOG     L L eqdzdy f L

³ ³

V     







(7)

D  E   F  G   H  I  )LJ&RQWRXUSORWVRIWKHUHFRQVWUXFWHG56ILHOG D  F  H ORQJLWXGLQDO E  G  I WUDQVYHUVDOUHVLGXDOVWUHVV D  E EOXQWQRWFK5 F  G VKDUS QRWFK5 H  I YHU\VKDUSQRWFK5

(8)

7KH&URVVODQGFULWHULRQZDVDGRSWHGIRUPRGHOOLQJWKHVWUHVVFRQGLWLRQVDWQRWFKHVVLQFHWKHORDGLQJLVSURSRUWLRQDO DQGWKHFULWHULRQSURYHGWRVXFFHVVIXOO\SUHGLFWWKHIDWLJXHUHVSRQVHRISHHQHGFRPSRQHQWVZKHQWKHIDWLJXHEHKDYLRU LVFRQWUROOHGE\VXUIDFHFUDFNLQLWLDWLRQ>@6SHFLILFDOO\WKH&URVVODQGFULWHULRQLQFOXGHVWKH9RQ0LVHVHTXLYDOHQW VWUHVVDPSOLWXGHVVM,aDQGWKHPD[LPXPK\GURVWDWLFSUHVVXUHpPD[LQHTQ8QGHUEHQGLQJIDWLJXHWHVWVDWQRPLQDO

VWUHVVDPSOLWXGHVaDQGORDGUDWLRRVVM,aDQGpPD[DUHH[SUHVVHGLQWHUPVRIWKHSULQFLSDOVWUHVVHV¶DPSOLWXGHE\HTQ

  PD[ eq VM a C p f C V V D ˜ E    

                PD[      VM a a a a a a a RS RS RS a a a R p V V V V V V V V V V V V V               7KHPDWHULDOSURSHUWLHVDCDQGECZHUHGHWHUPLQHGLQ>@DWVHYHUDOIDWLJXHOLYHVIURPWHQVLRQWRUVLRQDQGLQSKDVH FRPELQHGWHQVLRQ±WRUVLRQWHVWV7KHFULWLFDOGLVWDQFHLKDVEHHQFKRVHQHTXDOWRWKH(O+DGGDGGLVWDQFH>@ZKLFK LVDIXQFWLRQRIERWKWKHUDQJHRIWKHWKUHVKROGVWUHVVLQWHQVLW\IDFWRUIRUFUDFNSURSDJDWLRQ



 th K R MPa m ' >@ DQGSODLQIDWLJXHVWUHQJWKUDQJHDWKLJKQXPEHURIF\FOHVWRIDLOXUH   f MPa ' >@ GHWHUPLQHGDWWKHVDPHORDGUDWLRR     th K L mm f S §' · ¨ ¸ ' © ¹      7KHFRPSDULVRQEHWZHHQWKHH[SHULPHQWDOGDWDDQGWKHPHDQIDWLJXHFXUYHVFDOFXODWHGDFFRUGLQJWRWKHDERYH SURFHGXUHLVVKRZQLQ)LJ 



)LJ&RPSDULVRQEHWZHHQH[SHULPHQWDOGDWDDQGFDOFXODWHGIDWLJXHFXUYHVRIWKHSHHQHGVDPSOHV

'HVSLWH D VOLJKW WHQGHQF\ RI WKH &URVVODQG FULWHULRQ WRRYHUHVWLPDWH WKH IDWLJXHUHVLVWDQFH LQ WKH PHGLXPF\FOH UHJLPHDVDOUHDG\REVHUYHGLQ>@WKHSURSRVHGIDWLJXHFDOFXODWLRQPHWKRG\LHOGVDFFXUDWHHVWLPDWLRQVRIWKHIDWLJXH EHKDYLRURISHHQHGQRWFKHGVSHFLPHQV$FFRUGLQJO\WKHUHODWLYHHUURULVORZHUWKDQZLWKLQWKHHQWLUHH[SORUHG IDWLJXHOLIHLQWHUYDO,QDGGLWLRQLWFDQEHQRWHGWKDWWKHSUHGLFWHGIDWLJXHFXUYHVIRUVKDUSDQGYHU\VKDUSQRWFKHVGR QRWVKRZWKHFKDQJHLQVORSHDURXQGIDWLJXHF\FOHVGLVSOD\HGE\WKHH[SHULPHQWDOGDWD7KLVFRXOGEHH[SODLQHG

(9)

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

7KH QRWFK IDWLJXH VWUHQJWK RI VKRW SHHQHG $O7 DOOR\ KDV EHHQ H[SHULPHQWDOO\ LQYHVWLJDWHG H[SORULQJ IDWLJXHOLYHVEHWZHHQDQG7KHIDWLJXHLPSURYHPHQWGXHWRSHHQLQJZDVGLVFXVVHGDFFRXQWLQJIRUWKHUHVLGXDO

VWUHVVHIIHFWV7KHUHVLGXDOVWUHVVILHOGDKHDGRIWKHQRWFKURRWZDVQXPHULFDOO\VLPXODWHGVWDUWLQJIURPH[SHULPHQWDO YDOXHVPHDVXUHGDORQJWKHQRWFKELVHFWRUZLWKQRQGHVWUXFWLYHDQGGHVWUXFWLYHWHFKQLTXHVQDPHO\PLFUR;5'DQG ),%',&PLFURVORWFXWWLQJDQGPLFURKROHGULOOLQJ7KHIROORZLQJFRQFOXVLRQVFDQEHGUDZQ

 6KRW SHHQLQJ VWURQJO\ LPSURYH WKH IDWLJXH EHKDYLRU RI $ODOOR\V HYHQ LQ WKH SUHVHQFH RI JHRPHWULFDO GLVFRQWLQXLWLHVUHVXOWLQJLQJUHDWO\UHGXFHGQRWFKVHQVLWLYLW\

 7KHVKDUSQRWFKHVLQGXFHDUHPDUNDEOHUHVLGXDOVWUHVVFRQFHQWUDWLRQZKRVHHQWLW\VFDOHVZLWKWKHQRWFKVHYHULW\  7KH QRWFK IDWLJXH EHKDYLRU FDQ EH VDWLVIDFWRULO\ VLPXODWHG E\ WKH &URVVODQG FULWHULRQ LQFRUSRUDWLQJ UHVLGXDO VWUHVVHV DQG FRPELQHG ZLWK DQ DUHD PHWKRG EDVHG RQ WKH FULWLFDO GLVWDQFH WKHRU\ WR DFFRXQW IRU WKH QRWFK VHQVLWLYLW\

5HIHUHQFHV

>@ .$6RDG\/LIHDVVHVVPHQWPHWKRGRORJLHVLQFRUSRUDWLQJVKRWSHHQLQJSURFHVVHIIHFWVPHFKDQLVWLFFRQVLGHUDWLRQRIUHVLGXDOVWUHVVHVDQG VWUDLQKDUGHQLQJ3DUWWKHHIIHFWRIVKRWSHHQLQJRQIDWLJXHUHVLVWDQFH0DWHU6FL7HFKQRO  ± >@ .$6RDG\%*0HOORU3$65HHG/LIHDVVHVVPHQWPHWKRGRORJLHVLQFRUSRUDWLQJVKRWSHHQLQJSURFHVVHIIHFWVPHFKDQLVWLFFRQVLGHUDWLRQ RIUHVLGXDOVWUHVVHVDQGVWUDLQKDUGHQLQJ3DUWDSSURDFKHVWRIDWLJXHOLILQJDIWHUVKRWSHHQLQJ0DWHU6FL7HFKQRO  ± >@ 0%HQHGHWWL9)RQWDQDUL36FDUGL&/$5LFDUGR0%DQGLQL5HYHUVHEHQGLQJIDWLJXHRIVKRWSHHQHG7DOXPLQLXPDOOR\7KH UROHRIUHVLGXDOVWUHVVUHOD[DWLRQ,QW-)DWLJXH   >@ 0%HQHGHWWL9)RQWDQDUL%'0RQHOOL1XPHULFDOVLPXODWLRQRIUHVLGXDOVWUHVVUHOD[DWLRQLQVKRWSHHQHGKLJKVWUHQJWKDOXPLQLXPDOOR\V XQGHUUHYHUVHEHQGLQJIDWLJXH$60(-(QJ0DWHU7HFKQRO   >@ 0%HQHGHWWL9)RQWDQDUL&6DQWXV0%DQGLQL1RWFKIDWLJXHEHKDYLRXURIVKRWSHHQHGKLJKVWUHQJWKDOXPLQLXPDOOR\VH[SHULPHQWVDQG SUHGLFWLRQVXVLQJDFULWLFDOGLVWDQFHPHWKRG,QW-)DWLJXH  ±

>@ 0 %HQHGHWWL 9 )RQWDQDUL 0 %DQGLQL $ VLPSOLILHG DQG IDVW PHWKRG WR SUHGLFW SODLQ DQG QRWFK IDWLJXH RI VKRW SHHQHG KLJKVWUHQJWK DOXPLQLXPDOOR\VXQGHUUHYHUVHEHQGLQJ6XUIDFH &RDWLQJV7HFKQRORJ\  ± >@ 0%HQHGHWWL9)RQWDQDUL0%DQGLQL'7D\ORU0XOWLD[LDOIDWLJXHUHVLVWDQFHRIVKRWSHHQHGKLJKVWUHQJWKDOXPLQXPDOOR\V,QW-)DWLJXH   ±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± >@ $+1RURR]L**OLQND6/DPEHUW3UHGLFWLRQRIIDWLJXHFUDFNJURZWKXQGHUFRQVWDQWDPSOLWXGHORDGLQJDQGDVLQJOHRYHUORDGEDVHGRQ HODVWRSODVWLFFUDFNWLSVWUHVVHVDQGVWUDLQV(QJ)UDFW0HFK  ± >@ 0%HQHGHWWL9)RQWDQDUL%'0RQHOOL3ODLQIDWLJXHUHVLVWDQFHRIVKRWSHHQHGKLJKVWUHQJWKDOXPLQLXPDOOR\VHIIHFWRIORDGLQJUDWLR 3URFHGLD(QJ  ±

Riferimenti

Documenti correlati

Factors that may contribute to the high prevalence of VDID in people with mental disorders include diet low in vitamin D, poor sunlight exposure, decrease in cutaneous vitamin

Si è visto come il principale responsabile della radiotossicità a lungo termine delle scorie, anche nell’ipotesi di riciclare tutto il plutonio in esse presente, sia il Cm 244 che

In ultimo, e non per importanza , la mia infinita gratitudine va ai miei genitori che mi hanno dato la possibilità di studiare e di arrivare dove sono adesso : grazie per la loro

Con specifi co riferimento agli esami di Stato conclusivi della scuola secondaria di secondo grado, la Commissione esaminatrice deve tenere in debita considerazione le

An example of a successful biomarker for neurodegen- erative disorders, and speci fically of conversion from early stage of dementia of Alzheimer ’s disease or Lewy body

The combination of drug treatment and zinc restores p53 oncosuppressive activity, thus redu- cing the chemoresistance of mutant p53-carrying cancer cells with increased cancer

Esso intende privi­ legiare la sua continuità / discontinuità con la matrice europea weberiana; collocare la sua impostazione in un particolare periodo della storia

vers la fin du V e siècle et fut utilisé jusqu’à la fin du siècle suivant (fig. Plus fréquemment, cependant, ce sont les grandes artères de commu- nication régionale

Home Alerts Feedback Articles Online First Current Issue Past Issues Meeting Abstracts Info for Authors Subscribers Advertisers Librarians Reviewers About Cancer Research About

The small pyxis of RP IV Mottled ware (T. 14), with fine incised decoration and four perforations below the rim, is comparable to RP IV Punctured ware in the Phylactou

In conclusion, our investigation clearly demonstrates the presence of appreciable quantum correlations in an OMC where each site consists of two localized, optical and mechan-

(Low-cost Social Housing Plan) is an urban planning tool. More specifically, it is an implemental plan included in the municipal, town, and urban development plan. The

outcome of the nucleophilic addition of organolithiums to the C=N double bond of the oxazoline ring, we considered the stereodynamic model proposed for oxazolinylaziridines (Scheme

LH FRORFDWLRQ ZLWK WKH 5DYHQVYLHZ ZDVWHZDWHU WUHDWPHQW SODQW DQG IOXH JDV FRQYH\HG IURP WKH %DWK /DIDUJH.

In

34 Also at Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia.. Petersburg State Polytechnical

The hardening parameters K α vary with the plastic loading. To model this, we assume that there exist some internal variables that characterize the condition, i.e.

results_elpropr_(inputfilename) is an Excel file containing the calculated elastic properties of the laminate as a function of the number of cycles (N) or – in case

We showed analytically and numerically that the effects of considering muscular fatigue in an eight hours work shift are a decrement in throughput (due to the slowdown of the

The studies were identi fied by using a combination of the following text words from the inception to May 2018: endometrial hyperplasia; endometrial cancer; endometrioid

This paper describes a simple comparison of the distributions of land cover features identified from volunteered data contributed by different social groups – in this case

I also declare, I confirm, I certify and I sign that I will not publish this paper or an important part of the paper in any other Journal (inside or outside WSEAS)

Al Premio “Top of the PID IGF” rientrano di diritto nella valutazione tutti i progetti delle singole imprese o gruppi di imprese che si sono candidati al “Top of the PID 2021” e che