Search results for "Hydrogen"

Translocation of Cations During Sorption of Copper in the System Solution - Algae (Spirogyra sp.)/Translokacja Kationów Podczas Procesu Sorpcji Miedz…

2014

Zbadano kinetykę procesu sorpcji kationów miedzi w glonach Spirogyra sp. oraz towarzyszące mu procesy sorpcji kationów wodorowych i procesy uwalniania do roztworu kationów związanych w glonach: Na+, Mg2+, K+ i Ca2+. Stwierdzono, że w układzie statycznym, przy stałym stosunku masy glonów do objętości roztworu, procesy te zachodzą równocześnie, przy czym należy przypuszczać, że ilość uwalnianych soli ma wpływ na parametry heterofazowej równowagi wymiany jonowej. W warunkach prowadzenia eksperymentu ilość uwolnionych kationów była blisko 10-krotnie większa niż ilość kationów sorbowanych. Porównano parametry równowagi wyznaczone z modelu reakcji pseudo-drugiego rzędu z parametrami uzyskanymi po…

Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups☆

2013

Background Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. Objectives To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. Material and methods Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glut…

Very strong −N–X+⋯−O–N+ halogen bonds

2016

A new (-)N-X(+)(-)O-N(+) paradigm for halogen bonding is established by using an oxygen atom as an unusual halogen bond acceptor. The strategy yielded extremely strong halogen bonded complexes with very high association constants characterized in either CDCl3 or acetone-d6 solution by (1)H NMR titrations and in the solid-state by single crystal X-ray analysis. The obtained halogen bond interactions, RXB, in the solid-state are found to be in the order of strong hydrogen bonds, viz. RXB ≈ RHB.

Effect of ozone and hydrogen peroxide on off-flavor compounds and water quality in a recirculating aquaculture system

2022

The recirculating aquaculture system (RAS) is an ever-developing technology for producing fish with a low environmental impact. However, off-flavors can be a major problem in RAS fish production. Off-flavor compounds are of microbial origin and are accumulated in fish flesh. They typically cause a musty and earthy taste and odor, which consumers find unacceptable. Here we hypothesized that oxidizing compounds such as ozone (O3), hydrogen peroxide (H2O2), and their combinations, referred to as advanced oxidation processes (AOP)s, can remove or decrease these compounds in water and prevent their accumulation in fish. In this study, four different oxidative treatments (O3 low (0.4 mg O3 L−1), …

Analysis of the Role of the Latvian Natural Gas Network for the use of Future Energy Systems: Hydrogen from Res

2021

The research has been funded by the Ministry of Economics of the Republic of Latvia, project “Trends, Challenges and Solutions of Latvian Gas Infrastructure Development (LAGAS)”, project No. VPP EM-INFRA-2018/1-0003.

Dynamic evolution of the hemin – hydrogen peroxide – sulfite reaction upon addition of a zwitterionic surfactant

2008

Reduction and catalytic behaviour of heterobimetallic copper–lanthanide oxides

2008

Abstract The reduction of the heterobimetallic copper–lanthanide oxides 2CuO·CeO2 and 3CuO·Ln2CuO4 (Ln = La, Pr, Nd) was studied by H2-TG/DTA and H2-TPR. All systems exhibit two main reduction steps accompanied by mass losses in the temperature range 20–1000 °C. The first step was attributed to CuO reduction, whereas the second step is due either to copper reduction in the Ln2CuO4 phase with the concomitant formation of Ln2O3 or to the surface reduction of CeO2. The products were characterized by XRD, SEM, EDX, and BET techniques and are better described as supported copper type materials. They were active for the mesityl oxide (4-methyl-2-penten-2-one) gas phase hydrogenation.

Synthesis, structural and spectroscopic characterization of the α,ω-diammonioalkane hexabromorhodates( III) [H3N(CH2)xNH3]2[H5O2][RhBr6]Br2 (x = 3, 4…

2002

The reaction of rhodium(III) chloride trihydrate with 1,3-diaminopropane and 1,4-diaminobutane in concentrated hydrobromic acid results in the formation of the bis(α,ω-diammonioalkane) diaquahydrogen(1+) hexabromorhodate(III) dibromides [H3N(CH2)xNH3]2[H5O2][RhBr6]Br2 (x = 3, 4). Dark red single crystals were obtained by diffusion-controlled crystallization at room temperature. Both compounds crystallize in space group type P1̄ and their structures are closely related. In view of crystal engineering they are inorganic-organic hybrid materials built up from octahedral [RhBr6]3−, simple Br− and flexible chain-like [H3N(CH2)xNH3]2+ ions with the [H5O2]+ and further Br− ions incorporated and th…

Effect of atomic layer deposited zinc promoter on the activity of copper-on-zirconia catalysts in the hydrogenation of carbon dioxide to methanol

2023

Funding Information: The work at Aalto University has been financially supported by the Academy of Finland (COOLCAT consortium, decision no. 329977 and 329978 ; ALDI consortium, decision no. 331082 ). This work made use of Aalto University Bioeconomy, OtaNano and RawMatters infrastructure. Hannu Revitzer (Aalto University) is thanked for the ICP-OES analysis, Aalto workshop people (especially Seppo Jääskeläinen) for working on the reactor modifications. The DFT calculations were made possible by computational resources provided by the CSC — IT Center for Science, Espoo, Finland ( https://www.csc.fi/en/ ) and computer capacity from the Finnish Grid and Cloud Infrastructure (urn:nbn:fi:resear…

Single hollow fiber SLM extraction of polyamines followed by tosyl chloride derivatization and HPLC determination

2007

Determination of polyamines in biological fluids possesses medical diagnostic relevance. Despite the vast panel of analytical methods developed for polyamines they are not applied in routine clinical usage, mainly due to the time and labor consuming sample preparation step and complicated derivatization procedures. Thus, new simpler methods are needed. This paper describes a single hollow fiber SLM extraction method of polyamines followed by simple pre-column derivatization with tosyl chloride and HPLC-UV analysis. The influence of different parameters such as the extraction time, organic phase composition, acceptor pH, donor pH, acceptor volume, donor volume and stirring speed on the trans…