Search results for "metallit"
showing 10 items of 102 documents
Teollisuus verkottuneessa innovaatiotaloudessa : esimerkkinä Keski-Suomen konepajateollisuus
2011
Expansion and Compression of a Helicate with Central Diol-Units as Stereocontrolling Moieties
2022
The dicatechol ester ligand 2-H4 forms the compressed helicate Li4[(2)3Ti2] which upon removal of the internally bound lithium cations expands. In the compressed form, the chiral diol units control the stereochemistry of the complex which is lost upon expansion of the system. peerReviewed
Combinatorial Identification of Hydrides in a Ligated Ag40 Nanocluster with Non-compact Metal Core
2019
No formation of bulk silver hydride has been reported. Until very recently, only few silver nanoclusters containing hydrides have been successfully prepared. However, due to the lack of effective techniques and also poor stability of hydride-containing Ag nanoclusters, the identification of hydrides’ location within Ag nanoclusters is challenging and not yet achieved although some successes have been reported on clusters of several Ag atoms. In this work, we report a detailed structural and spectroscopic characterization of the [Ag40(DMBT)24(PPh3)8H12]2+ (Ag40H12) cluster (DMBT=2,4-dimethylbenzenethiol). The metal framework consists of three-concentric shells of Ag8@Ag24@Ag8 which can be de…
Catalytic effect of transition metals (copper, iron, and nickel) on the foaming and properties of sugar-based carbon foams
2019
Abstract Recently, bio-based carbon foams have gained much interest in many chemical industry fields because of their unique structure and properties. This study provides new information on the effects of catalytic metals (iron, nickel, and copper) on the foaming process. Specifically, the effects of these catalysts on the density, foam growth, and cell size and then further on the pore size distribution and specific surface areas after the physical activation are considered. Furthermore, some of the activated sugar foams were used in adsorption tests using methylene blue as adsorbent. Results showed that the highest effect on foam density was obtained using the iron catalyst in the foaming…
ReO as a Brønsted acidic modifier in glycerol hydrodeoxygenation : Computational insight into the balance between acid and metal catalysis
2023
A computational study for the competitive conversion of glycerol to 1,2-propanediol and 1,3-propanediol is presented, considering a two-step sequence of dehydration followed by hydrogenation. The elementary steps for dehydration, i.e., breaking of C–H followed by C–OH or vice versa, were studied computationally both on the Rh metal surface and the acid-modified ReOH–Rh surface in order to understand the role of the acid promoter. While the acid modifier can catalyze the C–OH cleavage, the activation energy for the C–H cleavage was found to be considerably smaller on both pure and acid-doped Rh(111) surfaces, and breaking the secondary C–H bond is kinetically favored over breaking the termin…
New applications of zoobenthos measurements for risk assessment of chemicals in aquatic ecosystems
2015
Artikkeliväitöskirja. Yhteenveto-osa ja viisi artikkelia. (Artikkelit eivät avoimesti saatavilla.) Article dissertation. An introduction and five articles (not available in this version). Benthic animals in aquatic ecosystems suffer from various anthropogenic pollutants. A challenge in risk assessment of chemicals in aquatic ecosystems (i.e. ecological risk assessment) has been to balance cost-efficiency and effectiveness in detecting early warning signals of chemicals. In this study, hyperspectral imaging and behavioural measurements were evaluated as novel applications for detecting chemical effects on benthic animals, and the reliability of the incidence of chironomid morphological defor…
X6 : teollista kehitystä Keski-Suomessa - Swing hankkeen taustaselvitys
2012
Effect of Mg2+ ions on competitive metal ions adsorption/desorption on magnesium ferrite : mechanism, reusability and stability studies
2021
The adsorption behavior of magnesium ferrite in single- and multicomponent metal ions solutions in the presence of Mg2+ ions were studied. A dramatic decrease in the adsorption capacity of magnesium ferrite towards Mn2+, Co2+, and Ni2+ ions for comparison study of single- and multicomponent solutions was established. The affinity of the sorbent in accordance with the maximum sorption capacities increases in the following order Cu2+ > Co2+ > Ni2+ > Mn2+. High efficiency of magnesium ferrite regeneration (~100%) with aqueous solutions of magnesium chloride in the concentration range of 0.001-0.1 M was shown. The low degree of toxic metal ions desorption combined with XRD, IR spectroscopy, and…
Elektroniikkajätteen typpihappoliuotus ja metallien talteenotto
2017
Tämän pro gradu -tutkielman kirjallisessa osassa käsitellään elektroniikkajätettä ja metallien talteenottoa. Erityisesti talteenottomenetelmissä keskitytään typpihappoliuoksiin, sillä kokeellisessa osassa tutkimuksen kohteena oleva liuos on typpihappo. Näiden lisäksi tarkastellaan tutkimuksen kannalta merkittävien metallien; kuparin (Cu), nikkelin (Ni), lyijyn (Pb), tinan (Sn), hopean (Ag), sinkin (Zn) sekä palladiumin (Pd) fysikaalisia ja kemiallisia ominaisuuksia. Tutkielmassa tuodaan myös esille elektroniikkajätteen ympäristövaikutukset sekä sen taloudellinen merkitys maailmassa. Elektroniikkajäte on maailman nopeinten kasvava jätefraktio. Tämä on saanut useat tahot heräämään tähän kasva…
Jalometallit ja niiden talteenotto
2016
Tämän pro gradu -tutkielman kirjallisessa osassa käsitellään jalometallien ominaisuuksia ja esiintyvyyttä. Myös jalometallien yleisimpiä yhdisteitä ja käyttökohteita teollisuudessa selvitetään. Jalometallien talteenottomenetelmistä esitellään varsinkin klassiset saostusmenetelmät, neste-nesteuutto ja ioninvaihto. Näistä painotetaan ioninvaihtomenetelmien esittelyä, sillä tutkielman kokeellisessa osassa tutkittiin jalometallien talteenottoa ioninvaihdolla. Kirjallisessa osassa esitellään myös lyhyesti induktiivisesti kytketyn plasma-emissiospektrometrin (ICP-OES) rakennetta ja käyttöä. Tutkielman kokeellisessa osassa tutkittiin jalometallien talteenottoa synteettisestä uuttoliuoksesta, hyödy…