Search results for "AO"
showing 10 items of 3887 documents
Gas Phase Charged Aggregates of Bis(2-ethylhexyl)sulfo-succinate (AOT) and Divalent Metal Ions. First evidence of AOT solvated aggregates
2011
Assembling and chelating properties of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) towards divalent metal ions have been investigated in the gas phase by electrospray ionization mass spectrometry. A variety of positively charged monometallated and mixed metal aggregates are formed. Interestingly, several ions contain solvent (MeOH, H2O) molecules and constitute the most abundant AOT cationic aggregates not containing sodium. These species are the first example of solvated AOT-metal ion aggregates in the gas phase. By increasing the surfactant aggregation number, the abundance of solvated species becomes lower than that of unsolvated ones. Decompositions of ionic species have been studied…
Do electrospray mass spectra of surfactants mirror their aggregation state in solution?
2011
One important feature in the gas phase chemistry of surfactants is to ascertain whether their aggregates produced by electrospray ionization reflect those formed in the starting solution. With this aim, we have performed ESI-MS, ESI-MS/MS and ER-MS spectra of bis(2-ethylhexyl)sulfosuccinate (AOTNa) solutions in different solvents, i.e. water, water/methanol, methanol and n-hexane. The results clearly indicate that, notwithstanding the strongly different aggregation state in solution (direct micelles in water and in water/methanol, molecular dispersion in methanol and reverse micelles in n-hexane) and marked effects of the solvent polarity on the total ionic current, the surfactant aggregate…
Opsi popsi porkkanaa : luokanopettajaopiskelijat opetussuunnitelman käyttäjinä
2010
Tiivistelmä Peltonen, K. & Ryynänen, M. 2010. Opsi popsi porkkanaa – Luokanopettajaopiskelijat opetussuunnitelman käyttäjinä. Jyväskylän yliopisto. Opettajankoulutuslaitos. Kasvatustieteen pro gradu -tutkielma, 95 sivua + liitteet 3 sivua. Tutkielmassamme tarkastelemme, millaisia käsityksiä ja käyttökokemuksia päättövaiheen luokanopettajaopiskelijoilla on perusopetuksen opetussuunnitelman perusteista. Selvitimme, minkälaisilla tekijöillä on merkitystä opiskelijan opetussuunnitelman käytön kannalta ja miten opiskelija on hyödyntänyt opetussuunnitelmaa opetuksen suunnittelussa päättöharjoittelussa. Fenomenologis-hermeneuttisen tutkimusotteen ohella olemme tarkastelleet aihettamme kriittisen t…
Nuorten koulupoissaolot : kurkistus koulupoissaolokäsitteisiin ja -tekijöihin sekä tukitoimiin
2021
Tutkimukset osoittavat, että pitkittyneet koulupoissaolot aiheuttavat ongelmia nuorille, vanhemmille, kouluille ja koko yhteiskunnalle. Koulupoissaolotyyppien avulla voidaan tunnistaa nuoresta, huoltajasta ja koulusta johtuva poissaolo. Koulupoissaolojen taustalla voi olla jopa 60 eri syytekijää, joita on tärkeä oppia tunnistamaan. Kolmitasoisen tuen mallia voidaan käyttää apuna koulupoissaoloihin puuttumisessa. Koulupoissaoloihin on tärkeä puuttua varhaisessa vaiheessa niin koulupoissaolojen kuin koulupudokkuuden näkökulmista. peerReviewed
Use of Fe and Al containing electrocoagulation sludge as an adsorbent and a catalyst in water treatment
2023
In this study, three different electrocoagulation (EC) sludges were studied as an adsorbent (removal of humic acids) and as a catalyst [catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA)]. The sludges originated from electrocoagulation process in which aluminum (Al) and iron (Fe) electrodes were used for the treatment of mining industry wastewater. All the materials were used as dried sludge and calcined material. The stability of these materials was studied in neutral and alkaline conditions with analysis of the leached iron content in solution. Based on the EC sludge characterization with X-ray fluorescence (XRF), X-ray diffractometer (XRD), and diffuse-reflectance infrared Four…
Comment améliorer la prévision des ventes pour le marketing ? Les apports de la théorie du chaos
2013
La littérature en marketing constate un décalage entre les avancées réalisées par les chercheurs qui développent de nouvelles méthodes de prévision des ventes, et l'usage massif de méthodes traditionnelles reposant sur l'hypothèse de linéarité des processus analysés. Cette recherche expose la contribution potentielle de la théorie du chaos à l'amélioration de la prévision des ventes. Une illustration de ces apports est proposée avec une application à la prévision des ventes de consoles de jeux vidéo au Japon. Les résultats mettent en évidence la capacité de la méthode proposée à détecter la présence de chaos dans la série et montrent la possibilité de préciser l'horizon de prévisibilité des…
Genetic Factors as Promising Biomarkers of Sporadic Ascending Aortic Aneurysm
2014
Thoracic aorta shows various changes with advancing age and a progressive deterioration in structure and function. As a result, vascular remodeling (VR) and medial degeneration (MD) occur. VR and MD are typical entities of sporadic thoracic aortic aneurysm (TAA), actually considered a common and serious health risk and a pathology by unclear mechanisms. Increased activity of the coagulation system, inflammation, activation of extracellular matrix remodeling and endothelial dysfunction pathways have been recently evidenced to have a key role in its onset. Thus, polymorphisms of the coagulation system [fibrinogen (rs1800790); Factor II ( rs1799963); Factor V (rs6025); Factor VII (rs121964926)…
A Network-Based Framework for Mobile Threat Detection
2018
Mobile malware attacks increased three folds in the past few years and continued to expand with the growing number of mobile users. Adversary uses a variety of evasion techniques to avoid detection by traditional systems, which increase the diversity of malicious applications. Thus, there is a need for an intelligent system that copes with this issue. This paper proposes a machine learning (ML) based framework to counter rapid evolution of mobile threats. This model is based on flow-based features, that will work on the network side. This model is designed with adversarial input in mind. The model uses 40 timebased network flow features, extracted from the real-time traffic of malicious and…
Support vector machine integrated with game-theoretic approach and genetic algorithm for the detection and classification of malware
2013
Abstract. —In the modern world, a rapid growth of mali- cious software production has become one of the most signifi- cant threats to the network security. Unfortunately, wides pread signature-based anti-malware strategies can not help to de tect malware unseen previously nor deal with code obfuscation te ch- niques employed by malware designers. In our study, the prob lem of malware detection and classification is solved by applyin g a data-mining-based approach that relies on supervised mach ine- learning. Executable files are presented in the form of byte a nd opcode sequences and n-gram models are employed to extract essential features from these sequences. Feature vectors o btained are…
Fractal dynamics in chaotic quantum transport
2013
Despite several experiments on chaotic quantum transport in two-dimensional systems such as semiconductor quantum dots, corresponding quantum simulations within a real-space model have been out of reach so far. Here we carry out quantum transport calculations in real space and real time for a two-dimensional stadium cavity that shows chaotic dynamics. By applying a large set of magnetic fields we obtain a complete picture of magnetoconductance that indicates fractal scaling. In the calculations of the fractality we use detrended fluctuation analysis -- a widely used method in time series analysis -- and show its usefulness in the interpretation of the conductance curves. Comparison with a s…