Browsing by Area "Chemija / Chemistry (N003)"
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;Staišiūnas, Laurynas ;Grigucevičienė, Asta ;Leinartas, Konstantinas ;Miečinskas, PovilasInternational conference of Lithuanian Society of Chemistry " Chemistry and Chemical Technology 2016" : Lithuanian Academy of Sciences, Vilnius, Lithuania, April 28-29, 2016 : book of abstracts4 Publication Electrochemical synthesis of photoactive carbon-carbide structure on silicon in molten saltresearch article; ;Fray, Derek J. ;Kalinauskas, Putinas ;Valsiūnas, Ignas ;Niaura, Gediminas ;Selskis, AlgirdasJasulaitienė, VitalijaElectrochemistry communications. New York : Elsevier Science, 2018, vol. 90., p. 6-10Carbon-carbide coatings on silicon with a distinctively developed surface were electrochemically synthesized in molten CaCl2 using Si-SiO2 precursor and a graphite anode. Energy-dispersive X-ray spectroscopy showed approximately one quarter of the structure (in at.%) was composed of carbon. X-ray diffraction identified crystalline phases of graphite, silicon carbide and carbonate. X-ray photoelectron spectroscopy identified the carbide/ carbon concentration ratio varied from 0.2 in the external region of the structure to 0.7 at the silicon substrate boundary. Mott-Schottky analysis showed p-type semiconductivity of the structure with high density of charge carriers N > 1016 cm−3. The surfaces absorbed over 90% of white light in a broad region of wavelengths from 400 nm to 1100 nm. The obtained composite is promising for application as an antireflection and protective coating or a photoelectrode.1Scopus© Citations 7WOS© IF 4.197WOS© AIF 4.672Scopus© SNIP 1.037 Publication Geocheminiai tyrimų metodai archeologijoje – taikymo galimybės[Geochemical methods of investigation in archaeology – possibilities of application]research article; ; ;Karmaza, Bronislavas ;Merkevičius, Algimantas ;Nemickienė, Rėda ;Rackevičius, Gintautas ;Sarcevičius, Saulius ;Stakėnienė, Rimutė ;Strazdas, Dainius ;Širvydaitė, Simona ;Vaitkevičius, GediminasZinkutė, RimantėMetodai Lietuvos archeologijoje : mokslas ir technologijos praeičiai pažintiStraipsnyje atskleidžiamos geocheminių tyrimų sudedamosios dalys ir konkrečiais taikymo archeologijoje pavyzdžiais parodoma, kokią įtaką rezultatams ir jų interpretacijai turi analizės metodas bei bandinių paruošimo būdas, kintamųjų atranka, taikant daugiamačius statistinius metodus, kaip ieškoma indikatorinių rodiklių ir kaip jie vizualizuojami geocheminiuose žemėlapiuose.1 Publication Investigation of ferment preparation influence upon the quality of biological wastewater treatment[Исследование влияния ферментного препарата на качество биологической очистки сточных вод]research article; Journal of environmental engineering and landscape management. , 2003, vol. 11, no. 3., p. 126-1321 - research article
;Leinartas, Konstantinas; ;Staišiūnas, Laurynas ;Grigucevičienė, Asta ;Miečinskas, Povilas ;Vaičiūnienė, Jūratė ;Jasulaitienė, Vitalija ;Kondrotas, RokasJuškėnas, RemigijusJournal of alloys and compounds. Lausanne : Elsevier, 2016, vol. 661., p. 322-330Mg–Nb alloy films have been formed in a wide range of Nb concentrations using the magnetron sputtering technique. The systems are of interest in biomedical applications in-vivo. A distinctive distribution of Nb over Mg matrix was determined by scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. Corrosion behaviour was studied in a balanced salt solution with a physiological pH. Experiments were performed by solution analysis, dc-voltammetry, quartz crystal microgravimetry, X-ray photoelectron spectroscopy and electron microscopy. Quasi-passivity was reached at Nb/Mg atomic concentration ratio of one quarter. It has been shown that corrosion activity could be adjusted according to biomedical requirements by varying Nb concentration.1Scopus© Citations 6WOS© IF 3.133WOS© AIF 3.778Scopus© SNIP 1.326 - research article
;Abromaitis, V. ;Svaikauskaite, J. ;Sulciute, A. ;Sinkeviciute, D. ;Zmuidzinaviciene, N. ;Misevicius, S. ;Tichonovas, M. ;Urniezaite, I. ;Jankunaite, D. ;Urbonavicius, M. ;Varnagiris, S.; ;Baranauskis, K.Martuzevicius, D.Journal of environmental management, p. 1-14The purpose of this study was to evaluate the performance of synthesized TiO2 nanotube arrays (NTAs) for the removal of the COVID-19 aided antibiotic ciprofloxacin (CIP) and the textile dye methylene blue (MB) from model wastewater. Synthesis of TiO2 NTAs showed that anodization potential and calcination temperatures directly influence nanotube formation. The increased anodization potential from 10 to 40 V resulted in the development of larger porous nanotubes with a diameter of 36–170 nm, while the collapse of the tubular structure was registered at the highest applied potential. Furthermore, it was found that the 500 °C calcination temperature was the most prominent for the formation of the most photocatalytically active TiO2 NTAs, due to the optimal anatase/rutile ratio of 4.60. The degradation of both model compounds was achieved with all synthesized TiO2 NTAs; however, the most photocatalytically active NTA sample was produced at 30 V and 500 °C. Compared to photocatalysis, CIP degradation was greatly enhanced by 5–25 times when ozone was introduced to the photocatalytic cell (rates 0.4–4.2 × 10−1 min−1 versus 0.07–0.2 × 10−1 min−1). This resulted in the formation of CIP degradation by-products, with different mass-to-charge ratios from [M+H]+ 346 to 273 m/z. Even though the CIP degradation pathway is rather complex, three main mechanisms, decarboxylation, hydroxylation reaction, and piperazine ring cleavage, were proposed and explained. Furthermore, treated samples were placed in contact with the crustaceans Daphnia magna. It was found that 100% mortality was achieved when approximately 60% of the remaining TOC was present in the samples, indicating that toxic degradation by-products were formed.9Scopus© Citations 6WOS© IF 8.7WOS© AIF 6.5Scopus© SNIP 1.849 - conference paper
; ;Kalinauskas, Putinas ;Coxon, Paul R.Fray, Derek J.International conference of Lithuanian Society of Chemistry " Chemistry and Chemical Technology 2016" : Lithuanian Academy of Sciences, Vilnius, Lithuania, April 28-29, 2016 : book of abstracts3 - conference paper
;Grigucevičienė, Asta ;Staišiūnas, Laurynas ;Leinartas, Konstantinas ;Kondrotas, Rokas ;Miečinskas, Povilas6th Baltic electrochemistry conference "Electrochemistry of functional interfaces and materials" : Helsinki, Finland, June 15-17, 2016 : book of abstracts1 Publication A sustainable approach to oil spill clean-upconference paper ;Picazo Espinosa, Rafael; ; Aquatic and coastal ecosystems: challenges and opportunities towards sustainable development : book of abstracts : November 16-17, 2023, Rostock2 Publication Synthesis of new [1,2,4]triazolo[4,3-a][1,5]benzodiazepine derivatives[Naujų [1,2,4]triazolo[4,3-a][1,5]benzdiazepino darinių sintezė]research article; ;Stumbrevičiūtė, Zita ;Jančienė, Regina ;Klimavičius, Kazimieras Algirdas ;Staniulytė, Zita ;Palaima, AlgirdasPuodžiūnaitė, Benedikta DalėChemija. Vilnius : Lietuvos mokslų akademijos leidykla, 2011, vol. 22, no. 1., p. 60-64The synthetic pathway of various novel tricyclic [1,2,4]triazolo[4,3-a][1,5]benzodiazepine derivatives via thioether and hydrazine derivatives of 1,5-benzodiazepine as starting materials is described.1WOS© IF 0.586WOS© AIF 4.738Scopus© SNIP 0.643 Publication Utilisation of lignin waste for preventing soil erosion[Lignino panaudojimo dirvožemio erozijos prevencijai galimybės]research article; ; ; Shulga, GaliaAplinkos tyrimai, inžinerija ir vadyba = Environmental research, engineering and management. Kaunas : Technologija, 2006, Nr. 1 (35)., p. 43-51The problem of hydrolysed lignin waste utilisation is studied, with proposing to use it for sand and light soil erosion prevention. For this purpose a system using a different thickness of lignin layers with a polymer conditioner was created. Vegetative covering was formed in the upper layer. Soil and drainage water impact on waste was evaluated. A comprehensive study of waste showed that the concentrations of some metals and sulphates in soil and drainage water exceeded the MAC. Potential waste use patterns were given after evaluation of the situation.2