0000000000807145

AUTHOR

Galina Dobele

showing 4 related works from this author

Characterization of softwood and hardwood lignoboost kraft lignins with emphasis on their antioxidant activity

2014

Fractionation of softwood and hardwood LignoBoost kraft lignins, using sequential extraction with organic solvents of increasing hydrogen-bonding ability (dichloromethane, n-propanol, and methanol), was carried out. Using SEC, analytical pyrolysis, FTIR and UV/VIS spectroscopy, and chemical analytical methods, four fractions were obtained and characterized in terms of their yield, composition, functionality, lignin structural features, and antioxidant properties. In tests with free radicals (ABTS●+, DPPH●, O2●-) and the ORAC (oxygen radical absorbance capacity) assay, the high radical scavenging capacity of the lignin’s soluble fractions was demonstrated. The antioxidant activity of the fra…

ORAC assayEnvironmental EngineeringSoftwoodABTSOxygen radical absorbance capacityLignoBoost kraft ligninDPPHAntioxidant propertieslcsh:Biotechnologytechnology industry and agricultureBioengineeringmacromolecular substancesFractionationDPPH●chemistry.chemical_compoundchemistryABTS●+lcsh:TP248.13-248.65HardwoodOrganic chemistryLigninSolvent fractionationWaste Management and DisposalKraft paperO2●- assays
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The effects of woodchip- and straw-derived biochars on the persistence of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) in soils

2014

Sorption and degradation are the primary processes controlling the efficacy and runoff contamination risk of agrochemicals. This study assessed the influence of two biochars, made from woodchips and straw at a pyrolysis temperature of 725°C and applied to a loamy sand and a sandy soil in the concentration of 5.3 g 100 g(-1) sandy soil and 4.1 g 100 g(-1) loamy sand soil, or 53 t ha(-1) for both soil types, on degradation of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA). Soils were spiked with 50 mg MCPA kg(-1) soil. In the sandy soil, significantly more MCPA remained after 100 days if amended with straw-derived biochar in comparison to wood-derived biochar. Both biochars types si…

Health Toxicology and MutagenesisGermination2-Methyl-4-chlorophenoxyacetic AcidMCPASoilchemistry.chemical_compoundBiocharSoil PollutantsHerbicidesChemistrySecaleTemperaturePublic Health Environmental and Occupational HealthSoil classificationGeneral MedicineHydrogen-Ion ConcentrationStrawPollutionBiodegradation EnvironmentalAgronomyCharcoalLoamSeedsSoil waterWoodchipsPhytotoxicityAdsorptionPorosityEcotoxicology and Environmental Safety
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Wood and Black Liquor-Based N-Doped Activated Carbon for Energy Application

2021

The research was funded by the Latvian Council of Science project “Nanostructured Nitrogenated Carbon Materials as Promoters in Energy Harvesting and Storage Technologies”, project No LZP-2018/1-0194, “New biomass origin materials hybrid carbon composites for energy storage” project No LZP-2020/2-0019 and postdoc project “Nitrogen and phosphorus-containing biomass based activated carbons for fuel cells and supercapacitors” project No 1.1.1.2/VIAA/4/20/596.

Materials scienceGeography Planning and Developmentchemistry.chemical_elementBiomassLi-ion batteriesTJ807-83002 engineering and technologyfuel cellsManagement Monitoring Policy and LawPorous structure010402 general chemistryTD194-1957. Clean energy01 natural sciencesRenewable energy sourcesCatalysismedicineGE1-350BiomassCharFuel cellsActivated carbonsSupercapacitorporous structurebiomassactivated carbonsEnvironmental effects of industries and plantsRenewable Energy Sustainability and the EnvironmentNanoporous021001 nanoscience & nanotechnology0104 chemical sciencesEnvironmental sciencesChemical engineeringchemistry13. Climate action:NATURAL SCIENCES [Research Subject Categories]0210 nano-technologyCarbonBlack liquorActivated carbonmedicine.drugSustainability
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Structure of nanoporous carbon materials for supercapacitors

2012

Activated carbons with highly developed porous structure and nanosized pores (8 - 11 A) were prepared from alder wood using thermochemical activation method with sodium hydroxide. Properties of the obtained activated carbons were examined by benzene and nitrogen sorption, X-Ray diffraction and Raman spectroscopy. Tests of activated carbons as electrodes in supercapacitors were performed as well. It was found that specific surface area of above mentioned activated carbons was 1800 m 2 /g (Dubinin - Radushkevich). Raman spectroscopy demonstrated the presence of ordered and disordered structures of graphite origin. The performance of activated carbons as electrodes in supercapacitors have show…

SupercapacitorMaterials scienceInorganic chemistrychemistry.chemical_elementSorptionchemistry.chemical_compoundsymbols.namesakechemistrySodium hydroxideSpecific surface areasymbolsGraphiteBenzeneRaman spectroscopyCarbonIOP Conference Series: Materials Science and Engineering
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