nūhou

Hoʻohana mākou i nā kuki e hoʻomaikaʻi i kou ʻike.Ma ka hoʻomau ʻana i kēia pūnaewele, ʻae ʻoe i kā mākou hoʻohana ʻana i nā kuki.ʻIke hou aku.
Ke hōʻike ʻia kahi ulia pōpilikia a haʻalele kekahi o nā kaʻa i ke kahua, hana pinepine ʻia nā laboratories forensic i ka hoʻihoʻi ʻana i nā hōʻike.
Loaʻa nā hōʻike koena i nā aniani haʻihaʻi, nā kukui haʻihaʻi, nā huelo, a i ʻole nā ​​bumpers, a me nā māka skid a me nā koena pena.Ke kuʻi ka kaʻa me kekahi mea a kanaka paha, e hoʻololi ʻia ka pena ma ke ʻano o nā kiko a i ʻole nā ​​ʻāpana.
ʻO ka pena kaʻa he hui paʻakikī o nā mea like ʻole i hoʻohana ʻia i nā papa he nui.ʻOiai paʻakikī kēia paʻakikī i ka nānā ʻana, hāʻawi pū ia i ka ʻike nui o ka ʻike no ka ʻike kaʻa.
ʻO Raman microscopy a me Fourier transform infrared (FTIR) kekahi o nā ʻenehana nui i hiki ke hoʻohana ʻia no ka hoʻoponopono ʻana i ia mau pilikia a me ka hoʻomaʻamaʻa ʻana i ka nānā ʻole luku ʻana i nā papa kikoʻī i ka ʻōnaehana uhi holoʻokoʻa.
Hoʻomaka ka nānā ʻana i ka pāpaʻi pena me ka ʻikepili spectral i hiki ke hoʻohālikelike ʻia i nā laʻana kaohi a i ʻole hoʻohana pū ʻia me kahi waihona e hoʻoholo ai i ka hana, ke ʻano, a me ka makahiki o ke kaʻa.
Mālama ka Royal Canadian Mounted Police (RCMP) i hoʻokahi waihona, ʻo ka waihona ʻikepili Paint Data Query (PDQ).Hiki ke kiʻi ʻia nā laboratories forensic komo i kēlā me kēia manawa e kōkua i ka mālama a hoʻonui i ka waihona.
Kuhi kēia ʻatikala i ka ʻanuʻu mua o ke kaʻina loiloi: hōʻiliʻili i nā ʻikepili spectral mai nā ʻāpana pena me ka microscopy FTIR a me Raman.
Ua hōʻiliʻili ʻia ka ʻikepili FTIR me ka Thermo Scientific™ Nicolet™ RaptIR™ FTIR microscope;ua hōʻiliʻili ʻia ka ʻikepili piha Raman me ka Thermo Scientific™ DXR3xi Raman microscope.Ua lawe ʻia nā ʻāpana pena mai nā ʻāpana ʻino o ke kaʻa: ua ʻoki ʻia kekahi mai ka ʻaoʻao o ka puka, a ʻo kekahi mai ka bumper.
ʻO ke ala maʻamau o ka hoʻopili ʻana i nā ʻāpana cross-sectional e hoʻolei iā lākou me ka epoxy, akā inā komo ka resin i ka specimen, hiki ke hoʻopili ʻia nā hopena o ka loiloi.No ka pale ʻana i kēia, ua kau ʻia nā ʻāpana pena ma waena o ʻelua mau ʻāpana poly(tetrafluoroethylene) (PTFE) ma kahi ʻāpana keʻa.
Ma mua o ka nānā ʻana, ua hoʻokaʻawale lima ʻia ka ʻāpana keʻa o ka chip pena mai ka PTFE a ua kau ʻia ka chip ma ka pukaaniani barium fluoride (BaF2).Hana ʻia ka palapala ʻāina FTIR ma ke ʻano hoʻoili me ka puka 10 x 10 µm2, kahi pahuhopu 15x a me condenser i hoʻopaʻa ʻia, a me kahi pitch 5 µm.
Ua hoʻohana ʻia nā laʻana like no ka nānā ʻana iā Raman no ka kūlike, ʻoiai ʻaʻole koi ʻia kahi ʻāpana keʻa puka aniani ʻo BaF2.He mea pono e hoʻomaopopo i ka BaF2 he Raman peak ma 242 cm-1, hiki ke ʻike ʻia ma ke ʻano he nāwaliwali nāwaliwali i kekahi spectra.ʻAʻole pono e pili ka hōʻailona me nā flakes pena.
E kiʻi i nā kiʻi Raman me ka hoʻohana ʻana i nā nui pika kiʻi o 2 µm a me 3 µm.Hana ʻia ka ʻike kikoʻī ma nā piko o nā mea nui a ua kōkua ʻia ke kaʻina ʻike e ka hoʻohana ʻana i nā ʻenehana e like me ka huli ʻana i nā mea he nui i hoʻohālikelike ʻia me nā hale waihona puke i loaʻa i ke kālepa.
Laiki.1. Kiʻikuhi o kahi laʻana pena kaʻa kaʻa maʻamau ʻehā-papa (hema).ʻO ka mosaic wikiō cross-sectional o nā ʻāpana pena i lawe ʻia mai ka puka kaʻa ('ākau).Loaʻa Kiʻi: Thermo Fisher Scientific - Nā Mea Hana a me ka Nānā Hana
ʻOiai he ʻokoʻa ka helu o nā ʻāpana kala i loko o kahi laʻana, ma kahi o ʻehā mau papa (Figure 1).ʻO ka papa i hoʻopili pololei ʻia i ka substrate metala he papa o ka electrophoretic primer (ma kahi o 17-25 µm mānoanoa) e lawelawe ana e pale i ka metala mai ke kaiapuni a lawelawe ʻo ia ma ke ʻano he mau papa no nā papa pena.
ʻO ka papa aʻe he kumu mua, putty (ma kahi o 30-35 microns ka mānoanoa) e hāʻawi i kahi ʻili maʻemaʻe no nā papa pena e hiki mai ana.A laila hele mai ka ʻaʻahu kumu a i ʻole ka lole kumu (e pili ana i 10-20 µm mānoanoa) i loko o ka puaʻa pena kumu.ʻO ka papa hope he papa pale ʻālohilohi (ma kahi o 30-50 microns mānoanoa) e hāʻawi pū ana i kahi hoʻopau nani.
ʻO kekahi o nā pilikia nui me ka nānā ʻana i ka peʻa pena, ʻaʻole pono nā papa pena a pau ma ke kaʻa mua e like me nā ʻāpana pena a me nā kīnā.Eia hou, loaʻa i nā laʻana mai nā wahi like ʻole nā ​​haku mele like ʻole.No ka laʻana, ʻo nā ʻāpana pena ma ka bumper hiki ke loaʻa i nā mea pale a me nā pena.
Hōʻike ʻia ke kiʻi ʻāpana keʻa ʻike ʻia o kahi ʻāpana pena ma ke Kiʻi 1. ʻEhā mau ʻāpana i ʻike ʻia ma ke kiʻi ʻike ʻia, e hoʻopili ʻia me nā papa ʻehā i ʻike ʻia e ka nānā ʻana i ka infrared.
Ma hope o ka palapala ʻana i ka pauku keʻa holoʻokoʻa, ʻike ʻia nā papa pākahi me nā kiʻi FTIR o nā wahi kiʻekiʻe.Hōʻike ʻia nā kiʻi kikoʻī a me nā kiʻi FTIR pili o nā papa ʻehā ma Fig.2. Ua pili ka papa mua me ka uhi ʻana i ka acrylic transparent me ka polyurethane, melamine (peak ma 815 cm-1) a me ka styrene.
ʻO ka papa ʻelua, ʻo ke kumu (ka waihoʻoluʻu) a me ka papa maʻemaʻe ua like ia me ka acrylic, melamine a me ka styrene.
ʻOiai ua like lākou a ʻaʻole i ʻike ʻia nā piko puaʻa kikoʻī, ke hōʻike mau nei ka spectra i nā ʻokoʻa, ma ke ʻano nui o ka ikaika kiʻekiʻe.Hōʻike ke kiko kiko 1 i nā piko ikaika ma 1700 cm-1 (polyurethane), 1490 cm-1, 1095 cm-1 (CO) a me 762 cm-1.
Hoʻonui ka piʻi ʻana o ke kiʻekiʻe ma ke kiko o ka papa 2 ma 2959 cm-1 (methyl), 1303 cm-1, 1241 cm-1 (ether), 1077 cm-1 (ether) a me 731 cm-1.Ua like ke kiko o ka papa honua me ka spectrum waihona o ka resin alkyd ma muli o ka waikawa isophthalic.
ʻO ke kapa hope loa o ka e-coat primer he epoxy a he polyurethane paha.ʻO ka hope, ua kūlike nā hopena me nā mea i loaʻa maʻamau i nā pena kaʻa.
Hana ʻia ka ʻikepili o nā ʻāpana like ʻole o kēlā me kēia papa me ka hoʻohana ʻana i nā hale waihona puke FTIR i kūʻai ʻia, ʻaʻole nā ​​ʻikepili pena kaʻa kaʻa, no laila ʻoiai ʻo nā pāʻani, ʻaʻole paha lākou i paʻa.
ʻO ka hoʻohana ʻana i kahi waihona i hoʻolālā ʻia no kēia ʻano loiloi e hoʻonui i ka ʻike o ka hana, ke ʻano a me ka makahiki o ke kaʻa.
Kiʻi 2. Hōʻike FTIR kikoʻī o nā papa ʻehā i ʻike ʻia ma kahi ʻāpana keʻa o ka pena puka kaʻa i ʻoki ʻia.Hoʻokumu ʻia nā kiʻi infrared mai nā ʻāpana kiʻekiʻe e pili ana i nā papa pākahi a hoʻopaʻa ʻia ma ke kiʻi wikiō.Hōʻike nā wahi ʻulaʻula i kahi o nā papa pākahi.Me ka hoʻohana ʻana i kahi puka o 10 x 10 µm2 a me ka nui ʻanuʻu o 5 µm, uhi ke kiʻi infrared i kahi ʻāpana o 370 x 140 µm2.Loaʻa Kiʻi: Thermo Fisher Scientific - Nā Mea Hana a me ka Hoʻolālā Hana
Ma ka fig.Hōʻike ʻo 3 i kahi kiʻi wikiō o kahi ʻāpana keʻa o nā ʻāpana pena bumper, ʻoi aku ka liʻiliʻi o ʻekolu papa i ʻike maopopo ʻia.
Hoʻopaʻa nā kiʻi ʻāpana ʻāpana infrared i ka loaʻa ʻana o ʻekolu papa ʻokoʻa (Fig. 4).ʻO ka ʻaoʻao waho he ʻaʻahu maʻemaʻe, ʻoi aku ka nui o ka polyurethane a me ka acrylic, i kūlike ke hoʻohālikelike ʻia me nā kikoʻī lole maʻemaʻe i nā hale waihona puke forensic kalepa.
ʻOiai ua like loa ke ʻano o ka uhi ʻana o ke kumu (ka waihoʻoluʻu) me ke ʻano o ka uhi maʻemaʻe, ʻokoʻa nō ia e ʻike ʻia mai ka papa waho.Nui nā ʻokoʻa i ka ikaika pili o nā piko.
ʻO ke kolu o ka papa e hiki ke lilo i mea bumper ponoʻī, me ka polypropylene a me ka talc.Hiki ke hoʻohana ʻia ʻo Talc ma ke ʻano he mea hoʻopihapiha hoʻopihapiha no ka polypropylene e hoʻomaikaʻi i nā ʻano hana o ka mea.
Ua kūlike nā ʻaʻahu waho ʻelua me nā mea i hoʻohana ʻia i ka pena kaʻa, akā ʻaʻole i ʻike ʻia nā piko puaʻa kikoʻī i ka lole mua.
Laiki.3. Mosaic wikiō o kahi ʻāpana keʻa o nā ʻāpana pena i lawe ʻia mai kahi pahu kaʻa.Loaʻa i ke kiʻi: Thermo Fisher Scientific - Nā Mea Hana a me ka Hoʻolālā Hana
Laiki.4. Hōʻikeʻike FTIR kikoʻī o ʻekolu papa i ʻike ʻia i loko o kahi ʻāpana keʻa o nā ʻāpana pena ma kahi pale.Hoʻokumu ʻia nā kiʻi infrared mai nā ʻāpana kiʻekiʻe e pili ana i nā papa pākahi a hoʻopaʻa ʻia ma ke kiʻi wikiō.Hōʻike nā wahi ʻulaʻula i kahi o nā papa pākahi.Me ka hoʻohana ʻana i kahi puka o 10 x 10 µm2 a me ka nui ʻanuʻu o 5 µm, uhi ke kiʻi infrared i kahi ʻāpana o 535 x 360 µm2.Loaʻa Kiʻi: Thermo Fisher Scientific - Nā Mea Hana a me ka Hoʻolālā Hana
Hoʻohana ʻia ʻo Raman imaging microscopy e kālailai i ke ʻano o nā ʻāpana keʻa e loaʻa ai ka ʻike hou e pili ana i ka hāpana.Eia naʻe, paʻakikī ka hōʻike Raman e ka fluorescence i hoʻopuka ʻia e ka hāpana.Ua hoʻāʻo ʻia kekahi mau kumu laser like ʻole (455 nm, 532 nm a me 785 nm) e loiloi i ke kaulike ma waena o ka ikaika fluorescence a me ka ikaika hōʻailona Raman.
No ka nānā ʻana i nā ʻāpana pena ma nā puka, loaʻa nā hopena maikaʻi loa e ka laser me ka lōʻihi o 455 nm;ʻoiai aia ka fluorescence, hiki ke hoʻohana ʻia kahi hoʻoponopono kumu e pale aku ai.Akā naʻe, ʻaʻole i kūleʻa kēia ala ma nā papa epoxy no ka mea ua kaupalena ʻia ka fluorescence a ua maʻalahi ka mea i ka pōʻino laser.
ʻOiai ʻoi aku ka maikaʻi o kekahi mau laser ma mua o nā mea ʻē aʻe, ʻaʻohe laser kūpono no ka nānā ʻana i ka epoxy.ʻO ka nānā ʻana o Raman cross-sectional o nā ʻāpana pena ma kahi bumper e hoʻohana ana i kahi laser 532 nm.Loaʻa ka hāʻawi fluorescence, akā hoʻoneʻe ʻia e ka hoʻoponopono kumu.
Laiki.5. Lunamaka'āinana Raman spectra o nā papa mua ʻekolu o kahi laʻana puʻupuʻu puka kaʻa ('ākau).Ua nalowale ka papa ʻehā (epoxy) i ka wā i hana ʻia ai ka hāpana.Ua hoʻoponopono ʻia ka spectra e wehe i ka hopena o ka fluorescence a hōʻiliʻili ʻia me ka laser 455 nm.Ua hōʻike ʻia kahi ʻāpana o 116 x 100 µm2 me ka nui o ka pika o 2 µm.Mosaic wikiō ʻāpana keʻa (hema hema).Kiʻi ʻāpana ʻāpana Raman Curve Resolution (MCR) multidimensional (hema hema).Loaʻa Kiʻi: Thermo Fisher Scientific - Nā Mea Hana a me ka Nānā Hana
Hōʻike ʻia ka hōʻike ʻana o Raman i kahi ʻāpana keʻa o kahi ʻāpana pena puka kaʻa ma ke Kiʻi 5;ʻAʻole hōʻike kēia hāpana i ka papa epoxy no ka mea ua nalowale i ka wā hoʻomākaukau.Eia nō naʻe, ʻoiai ua ʻike ʻia ka loiloi Raman o ka papa epoxy he pilikia, ʻaʻole i manaʻo ʻia he pilikia.
ʻO ka hele ʻana o ka styrene ma luna o ke kikoʻī Raman o ka papa 1, ʻoiai ʻoi aku ka ikaika o ka peak carbonyl ma mua o ka spectrum IR.Ke hoʻohālikelike ʻia me FTIR, hōʻike ka hōʻike Raman i nā ʻokoʻa koʻikoʻi i ka spectra o ka papa mua a me ka lua.
ʻO ka pāʻani Raman kokoke loa i ka lole kumu he perylene;ʻoiai ʻaʻole ia he hoʻohālikelike pololei, ʻike ʻia nā derivatives perylene e hoʻohana ʻia i nā puaʻa i loko o ka pena kaʻa, no laila e hōʻike paha ia i kahi puaʻa i ka papa kala.
Ua kūlike ka ʻili o ka ʻili me ka isophthalic alkyd resins, akā naʻe, ua ʻike pū lākou i ke ʻano o ka titanium dioxide (TiO2, rutile) i loko o nā laʻana, he paʻakikī ke ʻike ʻia me ka FTIR, ma muli o ke ʻoki ʻoki.
Laiki.6. Lunamakaainana Raman spectrum o kahi la'ana o na ki'i pa'i ma kahi pale (akau).Ua hoʻoponopono ʻia ka spectra e wehe i ka hopena o ka fluorescence a hōʻiliʻili ʻia me ka laser 532 nm.Hōʻike ʻia kahi ʻāpana o 195 x 420 µm2 me ka nui o ka pika o 3 µm.Mosaic wikiō ʻāpana keʻa (hema hema).Kiʻi Raman MCR o kahi ʻāpana keʻa (hema hema).Loaʻa i ke kiʻi: Thermo Fisher Scientific - Nā Mea Hana a me ka Hoʻolālā Hana
Ma ka fig.Hōʻike ka 6 i nā hopena o ka hoʻopuʻi ʻana o Raman i kahi ʻāpana keʻa o nā ʻāpana pena ma kahi pahu.Ua ʻike ʻia kahi papa hou (layer 3) ʻaʻole i ʻike mua ʻia e FTIR.
ʻO kahi kokoke loa i ka ʻaoʻao o waho he copolymer o styrene, ethylene a me butadiene, akā aia kekahi mau hōʻike o ka loaʻa ʻana o kahi mea ʻike ʻole ʻia, e like me ka mea i ʻike ʻia e kahi kiʻekiʻe carbonyl hiki ʻole ke wehewehe.
Hiki ke hoʻohālikelike ke kiko o ka ʻaʻahu kumu i ke ʻano o ka puaʻa, no ka mea, pili ka spectrum i kekahi ʻano me ka pūhui phthalocyanine i hoʻohana ʻia e like me ka puaʻa.
ʻO ka papa i ʻike mua ʻole ʻia he lahilahi loa (5 µm) a ua haku ʻia kekahi hapa o ke kalapona a me ka rutile.Ma muli o ka mānoanoa o kēia papa a me ka paʻakikī o TiO2 a me ke kalapona e ʻike me FTIR, ʻaʻole ia he mea kupanaha ʻaʻole i ʻike ʻia e ka IR analysis.
Wahi a nā hualoaʻa FT-IR, ua ʻike ʻia ka ʻehā o ka papa (ka mea bumper) he polypropylene, akā ua hōʻike pū ʻia ka loiloi Raman i ke alo o kekahi kalapona.ʻOiai ʻaʻole hiki ke kāpae ʻia ka loaʻa ʻana o ka talc i ʻike ʻia ma FITR, ʻaʻole hiki ke ʻike pololei ʻia no ka mea liʻiliʻi loa ka piko Raman e pili ana.
ʻO nā pena kaʻa he hui paʻakikī o nā meaʻai, a ʻoiai hiki i kēia ke hāʻawi i ka nui o ka ʻike e ʻike ai, hana ia i ka loiloi i mea paʻakikī nui.Hiki ke ʻike maikaʻi ʻia nā kaha kiʻi pena me ka microscope Nicolet RaptIR FTIR.
ʻO ka FTIR kahi ʻenehana loiloi non-destructive e hāʻawi i ka ʻike pono e pili ana i nā ʻāpana like ʻole a me nā ʻāpana o ka pena kaʻa.
Kūkākūkā kēia ʻatikala i ka nānā ʻana spectroscopic o nā papa pena, akā ʻo ka nānā ʻana i nā hopena, ma o ka hoʻohālikelike pololei ʻana me nā kaʻa i manaʻo ʻia a ma o nā ʻikepili spectral i hoʻolaʻa ʻia, hiki ke hāʻawi i ka ʻike kikoʻī e hoʻohālikelike i nā hōʻike i kona kumu.