Search results for "Mass"
showing 10 items of 9693 documents
Preconcentration and speciation analysis of mercury : 3D printed metal scavenger-based solid-phase extraction followed by analysis with inductively c…
2021
A selective method for preconcentration and determination of methylmercury (MeHg) and inorganic mercury (iHg) in natural water samples at the ng L−1 level has been developed. The method involves adsorption of Hg species into a 3D printed metal scavenger and sequential elution with acidic thiourea solutions before ICP-MS determination. Experimental parameters affecting the preconcentration of MeHg and iHg such as the sample matrix, effect of the flow rate on adsorption, eluent composition, and elution mode have been studied in detail. The obtained method detection limits, considering the preconcentration factors of 42 and 93, were found to be 0.05 ng L−1 and 0.08 ng L−1 for MeHg and iHg, res…
Hiilen taustavaikutukset muovien lisäaineille induktiivisesti kytketyssä plasmassa
2017
Tässä tutkielmassa tarkasteltiin hiilen matriisivaikutuksia induktiivisesti kytkettyä plasmaa (ICP) hyödyntävissä analyysimenetelmissä. Kirjallisessa osassa on tarkasteltu erilaisia kiinteiden näytteiden esikäsittelymenetelmiä kiinnittäen huomiota jäännöshiilimääriin. Lisäksi läpi käydään ICP-tekniikoiden teoriaa, laitteistoa ja häiriöitä, painotuksen ollessa hiilen aiheuttamissa ongelmatekijöissä. Kokeellisessa osassa tutkittiin onko hiilellä merkittäviä vaikutuksia muovien hivenaineille (As, Cd, Cr, Pb, Sb, Sn, Zn, S) sellaisissa pitoisuuksissa, joita jäännöshiilipitoisuudelta voidaan odottaa kiinteiden näytteiden esikäsittelyn jälkeen. Jäljitellen sertifioituja muovimateriaaleja valmiste…
Observation of an ultralow-Q-value electron-capture channel decaying to 75As via a high-precision mass measurement
2022
A precise determination of the atomic mass of 75As has been performed utilizing the double Penning trap mass spectrometer, JYFLTRAP. The mass excess is measured to be −73035.519(42)keV/c2, which is a factor of 21 more precise and 1.3(9)keV/c2 lower than the adopted value in the newest Atomic Mass Evaluation (AME2020). This value has been used to determine the ground-state–to–ground-state electron-capture decay Q value of 75Se and β− decay Q value of 75Ge, which are derived to be 866.041(81) keV and 1178.561(65) keV, respectively. Using the nuclear energy-level data of 860.00(40) keV, 865.40(50) keV (final states of electron capture), and 1172.00(60) keV (final state of β− decay) for the exc…
Mass of astrophysically relevant 31Cl and the breakdown of the isobaric multiplet mass equation
2015
The mass of $^{31}$Cl has been measured with the JYFLTRAP double Penning trap mass spectrometer at the Ion-Guide Isotope Separator On-Line (IGISOL) facility. The determined mass-excess value, -7034.7(34) keV, is 15 times more precise than in the Atomic Mass Evaluation 2012. The quadratic form of the isobaric multiplet mass equation for the T=3/2 quartet at A=31 fails ($\chi^2_n$=11.6) and a non-zero cubic term, d=-3.5(11) keV, is obtained when the new mass value is adopted. $^{31}$Cl has been found to be less proton-bound with a proton separation energy of $S_p$=265(4) keV. Energies for the excited states in $^{31}$Cl and the photodisintegration rate on $^{31}$Cl have been determined with s…
Self-Complementary Dimers of Oxalamide-Functionalized Resorcinarene Tetrabenzoxazines
2018
Self‐complementarity is a useful concept in supramolecular chemistry, molecular biology and polymeric systems. Two resorcinarene tetrabenzoxazines decorated with four oxalamide groups were synthesized and characterized. The oxalamide groups possessed self‐complementary hydrogen bonding sites between the carbonyls and amide groups. The self‐complementary nature of the oxalamide groups resulted in self‐included dimeric assemblies. The hydrogen bonding interactions within the tetrabenzoxazines gave rise to the formation of dimers, which were confirmed by single‐crystal X‐ray diffractions analysis and supported by NMR spectroscopy and mass spectrometry. The self‐included dimers were connected b…
Ion mobility-mass spectrometry of supramolecular complexes and assemblies
2019
Despite their structural and functional differences, synthetic supramolecular assemblies share many similarities with biological assemblies, especially enzymes. The assemblies can be on the same length scale, and their structures and guest binding are typically governed by non-covalent interactions. Thus, only relatively weak interactions define the shape of a synthetic supramolecule or the secondary and tertiary structure of a protein, such that the resulting dynamism makes structure elucidation challenging. For biomolecules such as peptides, proteins, glycans and lipids this has often been tackled using ion mobility–mass spectrometry (IM-MS), whereby analyte ions are separated according t…
Insediamenti rurali a corte nella Sicilia occidentale : la tenuta dello Zucco di Henri d’Orléans, duca d’Aumale
2010
Lo studio indaga sulle trasformazioni del complesso rurale fortifi cato a corte chiusa della Tenuta dello Zucco, fl orida realtà agricola siciliana ottocentesca inserita, in Provincia di Palermo nel territorio di Carini, all’interno di un grande ex feudo. Il bene rurale, oggi in stato di parziale abbandono, conobbe, dalla metà dell’Ottocento, con l’intraprendenza imprenditoriale e la disponibilità fi nanziaria del proprietario Henri d’Orléans, duca d’Aumale, il suo massimo splendore architettonico e produttivo. Dopo una disamina morfo/tipologica sugli insediamenti rurali a corte della Sicilia occidentale, il volume ricostruisce, attraverso fonti bibliografi che, fotografi che, iconografi ch…
Diversité taxonomique, phylogénétique et fonctionnelle de trois syntaxons des prairies permanentes
2014
National audience
The implementation of massive open online courses for training future engineers in higher education
2019
This paper investigates the features of the implementation, conduct, analysis and prospects for the use of massive, open online courses. The article deals with the main advantages and disadvantages of massive open online courses, presents a comparative analysis of research into implementation of massive, open online courses. The article outlines the basic course requirements. It contains an analysis of the current state of such courses in higher educational institutions. The article presents a number of recommendations for the development of the education system towards democratization of higher education
Reflections on the modern mass university and the question of the autonomy of thinking
2001
The article examines the concepts of massification and globalisation of higher education and contrasts them with some concepts from developmental psychology. The traditional task of universities is to train autonomous, self-directed and critical citizens who think scientifically. In this article I shall ask whether these tasks are possible in massified, marketised and globalised universities. My main aim is to draw on empirical findings to open theoretical perspectives on the topic. peerReviewed