Search results for "icp"
showing 10 items of 139 documents
Monthly Bonaire coral Sr/Ca and oxygen isotope data from 118 kyr ago (coral BON-5-D)
2015
The end of the last interglacial period, ~118 kyr ago, was characterized by substantial ocean circulation and climate perturbations resulting from instabilities of polar ice sheets. These perturbations are crucial for a better understanding of future climate change. The seasonal temperature changes of the tropical ocean, however, which play an important role in seasonal climate extremes such as hurricanes, floods and droughts at the present day, are not well known for this period that led into the last glacial. Here we present a monthly resolved snapshot of reconstructed sea surface temperature in the tropical North Atlantic Ocean for 117.7±0.8 kyr ago, using coral Sr/Ca and d18O records. W…
Determination of trace elements in gluten-free food for celiac people by ICP-MS
2014
Abstract This paper is the first analytical approach to the study of twenty heavy metals in the gluten-free foods for celiac people. Only the ICP-MS technique was used. One of the advantages about the use of ICP-MS for this characterization is the high sensitivity that improved the limits of quantification levels for some elements that are present at low quantities in some samples. The concentration values of As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn in seventeen gluten-free food samples are reported. The highest arsenic and molybdenum levels were measured in Rice noodle from China (0.088 and 0.47 mg kg − 1 , respectively). The highest concentrations of some metal…
Provenance of Early Bronze Age Metal Artefacts in Western Switzerland Using Elemental and Lead Isotopic Compositions
2011
3D telpas modeļa veidošana no punkta mākoņiem
2021
Pasaulē, kas strauji kustās uz priekšu, 2D attēli ir pietiekami, lai dotu priekšstatu par notiekošo telpā, bet izveidojot 2D projekciju attēla formā no 3D pasaules, procesā tiek zaudēta telpiskā informācija. Savukārt, lai pilnībā aprakstītu telpā notiekošo un par to izdarītu secinājumus, nepieciešams šo informāciju iegūt atpakaļ. Bakalaura darba mērķis ir izpētīt kādas ir šī brīža industrijas metodes gan telpiskās informācijas iegūšanai, gan telpas rekonstrukcijai, analizēt iegūtos rezultātus, un izdarīt secinājumus. Darba ietvaros tika ievākta informācija par pieejamām metodēm, kas ļauj iegūt telpisko informāciju un metodēm, ko izmanto telpas rekonstrukcijai. Tika arī izveidota programmatū…
Rīgas pilsētas salūta radītā gaisa piesārņojuma izvērtēšana, raksturojot aerosolu daļiņās
2017
Rīgas pilsētas salūta radītā gaisa piesārņojuma izvērtēšana, raksturojot aerosolu daļiņas. Guļa A., zinātniskā vadītāja Dr. ķīm., docente Osīte A. Maģistra darbs, 44 lappuses, 16 attēli, 14 tabulas, 43 literatūras avoti, 4 pielikumi. Latviešu valodā. Darbā ir apkopota informācija par pirotehnikas izstrādājumu sastāvu, uguņošanas radīto gaisa piesārņojumu ar smalkajām aerosolu daļiņām un to analīzes iespējām. Eksperimentāli veikta gaisa aerosolu daļiņu frakcionēšana. Realizēta smalkās un rupjās frakcijas daļiņu paraugu masas un skaita koncentrāciju noteikšana gan ikdienā, gan uguņošanas epizožu laikā. Uz filtra uztvertie gaisa aerosolu daļiņu paraugi metālisko elementu analīzei ar ICP-MS sag…
δ30Si and δ29Si Determinations on USGS BHVO-1 and BHVO-2 Reference Materials with a New Configuration on a Nu Plasma Multi-Collector ICP-MS
2008
We report silicon isotopic determinations for USGS rock reference materials BHVO-1 and BHVO-2 using a Nu Plasma multi-collector (MC)-ICP-MS, upgraded with a new adjustable entrance slit, to obtain medium resolution, as well as a stronger primary pump and newly designed sampler and skimmer cones ("B" cones). These settings, combined with the use of collector slits, allowed a resolution to be reached that was sufficient to overcome the (NO)-N-14-O-16 and N-14(2) interferences overlying the Si-30 and the Si-28 peaks, respectively, in an earlier set-up. This enabled accurate measurement of both delta Si-30 and delta Si-29. The delta value is expressed in per mil variation relative to the NBS 28…
Major and Trace Element Geochemistry of the European Kupferschiefer – An Evaluation of Analytical Techniques
2018
Simple and rapid techniques are needed for routine quantitative chemical bulk-rock analyses of Kupferschiefer, a black shale containing variable amounts of silicates, base metal sulphides, carbonates and an organic content of up to 30 weight percent. In this study, WD-XRF, TXRF, and ICP-OES of acid- as well as peroxide-digested samples were tested as potential techniques based on their availability and adaptability to analyse major (Si, Ti, Al, Mg, Ca, Fe, K, but also Cu, Zn, Pb) and selected trace (Ag, As, Ba, Co, Mo, Ni, V) element concentrations. Because of the absence of a suitable reference material, a comparative study was undertaken using instrumental neutron activation analysis to a…
Development and Optimization of Pre-Concentration Procedure of Rare-Earth Elements (REEs) in Their Minerals, Using Microwave - Assisted Sample Dissol…
2015
Abstract The aim of this research was to develop and optimize a procedure for determination of REEs in xenotime and monazite samples collected from Bangka Island, which were compared to Standard Monazite (71 AG) of Bureau of Analyzed Samples, London. ICP-OES method was used for the determination. The samples were dried and sterilized by heating for a week at 110 °C, before digesting with nitric acid and hydrofluoric acid, using a microwave-assisted digestion system. After a careful line selection, at the detection limits for all REEs in the ng/mL the REEs were reliably obtained at the 0.09 – 38% level.
Modificēto litija ortosilikāta minilodīšu radiolīze
2015
Modificēto litija ortosilikāta minilodīšu radiolīze. Valtenbergs O., zinātniskie vadītāji pētnieks, Mg. chem. Zariņš A. un docente, Dr. chem. Vita Rudoviča, zinātniskais konsultants vad. pētn. Dr. chem. Ķizāne G. Bakalaura darbs, 40 lappuses, 19 attēli, 8 tabulas, 26 literatūras avoti, 2 pielikumi, Latviešu valodā. Darbā apkopota informācija par kodoltermisko sintēzi, ITER un tā testa blanketa moduļiem, tritija ģenerējošo keramiku un to sintēzi, un radiācijas defektu un radiolīzes produktu veidošanos un noteikšanas metodēm, kā arī elementu kvantificēšanas metodēm. Eksperimentālajā daļā apstarotas standarta un modificētas litija ortosilikāta (Li4SiO4) minilodītes ar paātrinātajiem elektronie…