Ernestas ZALECKAS | VMU - Academia.edu (original) (raw)

Papers by Ernestas ZALECKAS

Research paper thumbnail of Bicarbazole-Benzophenone Based Twisted Donor-Acceptor Derivatives as Potential Blue TADF Emitters for OLEDs

Molecules/Molecules online/Molecules annual, Apr 8, 2024

Research paper thumbnail of Carbazole core derivatives and their photophysical and electrochemical investigations supported by the theoretical calculations

Synthetic Metals, Dec 31, 2023

Research paper thumbnail of Distribution and mobility of heavy metals in sewage sludge

Rural development, 2011

This study compares the distribution of the heavy metals into different chemical fractions in sew... more This study compares the distribution of the heavy metals into different chemical fractions in sewage sludge before and after anaerobic processing. The total content of Zn, Cd and Cu in the digested sludge was above the upper permissible limits of standard criteria for on-land sludge application under LAND 20:2005. The following metal fractions were defined using sequential extraction scheme: exchangeable (F1), adsorbed (F2), oxidizable (F3, bound to organic matter), acid soluble (F4, bound to carbonates), and residual (F5, bound to silicates and detrital materials). In terms of their stability in the environment (according to fraction F5) the investigated heavy metals both in primary and digested sludge can be ranked as follows: Cr>>Pb>Ni>Cd.Cu.Zn. Anaerobic sludge treatment had no significant effect on metal mobility row, expressed as sum of fractions F1 and F2: Ni>Zn>Cu>Cd>Pb>Cr. The ranking order of heavy metal potential bioavailability, expressed as (F1-F3)/(F4+F5) ratio, was following: Cu>>Zn.Ni>Cd>>Pb.Cr. Copper, due to its high affinity for organic matter, was the only metal significantly transferred from "stable" fractions to "more mobile" fractions during the sludge digestion processVytauto Didžiojo universitetasŽemės ūkio akademij

Research paper thumbnail of Effect of substituent structure in fluorene based compounds: experimental and theoretical study

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Nov 1, 2023

Research paper thumbnail of Electroactive polymers containing pendant harmane, phenoxazine or carbazole rings as host materials for OLEDs

Dyes and Pigments, Sep 1, 2014

Polystyrenes containing electronically isolated harmane, phenoxazine or carbazole rings were synt... more Polystyrenes containing electronically isolated harmane, phenoxazine or carbazole rings were synthesized and characterized by NMR spectroscopy, elemental analysis and gel permeation chromatography. The new polymers represent amorphous materials of high thermal stability with glass-transition temperatures of 139e179 C. The electron photoemission spectra of layers of the synthesized polymers showed ionization potentials of about 5.6e6.0 eV. The polymers were tested as host materials in phosphorescent green OLEDs with bis(2-phenylpyridine)(acetylacetonato)iridium(III) as the guest. The device based on polymer containing phenoxazine fragments exhibited the best overall performance with a turn-on voltage of 2.8 V, maximum photometric efficiency of about 17 cd/A and maximum brightness of 2920 cd/m 2 .

Research paper thumbnail of New carbazole-indan-1,3-dione- based host materials for phosphorescent organic light emitting diodes

Molecular Crystals and Liquid Crystals, Nov 21, 2016

New carbazole-and indan-1,3-dione-based low molecular weight derivatives were synthesized and cha... more New carbazole-and indan-1,3-dione-based low molecular weight derivatives were synthesized and characterized by mass spectrometry and 1 H NMR spectroscopy. Thermal behaviour of the derivatives was demonstrated by thermo-gravimetric analysis and differential scanning calorimetry. The materials were found to show very high thermal stability having initial thermal degradation temperatures in the range of 398-401°C. Glass transition temperatures of the amorphous molecular materials were in the rage of 80-114°C. The derivatives were tested as host materials in blue phosphorescent organic light emitting diodes with iridium(III)[bis(4,6-difluorophenyl)pyridinato-N,C2 ]picolinate as the guests. One of the blue OLED devices demonstrated rather low turn-on voltage of 5.0 V, a maximum luminance efficiency of 2.73 cd/A and maximum brightness of about 220 cd/m 2 .

Research paper thumbnail of Electro-active polymers containing electronically isolated N-phenyl-N-naphtylamine fragments

Synthetic Metals, 2014

ABSTRACT Monomers and polymers containing electronically isolated N-phenyl-N-naphtylamine fragmen... more ABSTRACT Monomers and polymers containing electronically isolated N-phenyl-N-naphtylamine fragments were synthesized and characterized by NMR and IR spectroscopies as well as by gel permeation chromatography. The polymers represent amorphous materials with glass transition temperatures of 71–78 °C and thermal decomposition starting at temperatures >320 °C. The electron photoemission spectra of layers of the synthesized polymers showed ionization potentials close to 5.8 eV. The synthesized materials have been tested as hole transporting layers in simple OLED devices with Alq3 as the emitter/electron transporting layer. The green devices containing hole transporting film of poly[N-(2,3-epoxypropyl)-N-phenyl-1-naphtylamine] exhibited the best overall performance with a driving voltage of 4.5 V, maximum photometric efficiency of 3.6 cd/A and maximum brightness of 2850 cd/m2.

Research paper thumbnail of Experimental study of biogas treatment

Research paper thumbnail of Globalisation As a Challenge or Opportunity for Organic Farming

DARCOFenews, 2006

During one intensive week in October 2005, the authors were gathered to discuss the impact that g... more During one intensive week in October 2005, the authors were gathered to discuss the impact that globalisation has on the Organic Food Systems and the opportunities that globalisation opens up for developing these systems. The meeting took place as a Ph.D. course under the ...

Research paper thumbnail of The influence of land use on soil organic carbon and nitrogen content and redox potential

Zemdirbyste-agriculture, 2010

The aim of this research was to evaluate organic matter status in the soil according to the organ... more The aim of this research was to evaluate organic matter status in the soil according to the organic carbon content, total and mineral nitrogen amounts, carbon to nitrogen (C:N) ratio and redox potential depending on land usage and plant species. Soil samples were taken from the fields under different farming systems (conventional and organic) as well as abandoned lands. We chose the plants of two botanical species (Poaceae and Fabaceae) in organic and conventional farming systems as well as in abandoned lands. Experimental results show that the best soil organic matter status according to the investigated indexes is in the soils of conventional and organic farming systems occupied with mixtures of Poaceae and Fabaceae and the worst – in the soils of abandoned Poaceae meadows. In the abandoned lands, Fabaceae (galega) had better influence on soil organic matter status than Poaceae.

Research paper thumbnail of Biodegalai - atsinaujinantys energijos ištekliai / The agricultural research for development (ARD), Dimension of the European research area (ERA)

Kaunas eBooks, 2010

Vytauto Didžiojo universitetasŽemės ūkio akademij

Research paper thumbnail of Rapsų ankštarėlių sandariklių panaudojimo technologinis-ekonominis vertinimas

Aleksandro Stulginskio universitetas Rapsų sėklų derliaus nuostoliai pirmiausiai atsiranda dėl na... more Aleksandro Stulginskio universitetas Rapsų sėklų derliaus nuostoliai pirmiausiai atsiranda dėl natūralių fiziologinių procesų, vykstančių augaluose. Augalui bręstant natūralų ankštarėlių atsidarymą sąlygoja biocheminių procesų metu susidarančios medţiagos metilenas ir auksinas, kurios, savo ruoţtu, sąlygoja fermentų aktyvumą. Antra ankštarėlių atsidarymo prieţastis siejama su daţna meteorologinių sąlygų kaita prieš pat derliaus nuėmimą. Drėgnio ir temperatūros pokyčiai priverčia ankštarėles atsidaryti anksčiau laiko. Trečia prieţastis-rapsų brendimo netolygumas. Vienas iš būdų rapsų sėklų byrėjimui iš ankštarėlių sumaţinti yra specialių preparatų-ankštarėlių sandariklių išpurškimas 2-3 savaites prieš derliaus nuėmimą. Dabartiniu metu plačiausiai naudojami du preparatai: pinoleno grupės produktai, kurių pagrindasdi-1-p-mentenas ir latekso polimerų produktai. Ankštarėlių sandarikliai toliau kuriami ir tobulinami. Viena iš tobulinimo krypčių yra sandariklio tirpalo paviršiaus įtempio maţinimas ir plonos tamprios plėvelės susidarymo ant ankštarėlių uţtikrinimas. Šiomis savybėmis pasiţymi naujos kartos sandariklis Contact. Šiame darbe atliktas kompleksinis technologinis-ekonominis sandariklių Spodnam, Elastiq, Gripil ir Contact tyrimas įvertinant natūralius (savaiminius) rapsų sėklų nuostolius bei nuostolius patiriamus dėl kombaino lenktuvų poveikio derliaus nuėmimo metu. Tyrimais nustatyta, kad pirmųjų trijų rapsų ankštarėlių sandariklių panaudojimu galima sumaţinti rapsų sėklų nuostolius apie 35%. Įvertinus bendras išlaidas sandariklių panaudojimui nustatyta, kad rapsus nupurškus Elastiq preparatu galima gauti 9,02 € ha-1 papildomų pajamų, o Contactapie 3,5 karto didesnę sumą.

Research paper thumbnail of Application of rape pod sealants to reduce adverse environmental impacts

Journal of the Science of Food and Agriculture, Nov 14, 2017

BACKGROUND Rape (Brassica napus L.) is a major global oilseed crop characterised by its high pote... more BACKGROUND Rape (Brassica napus L.) is a major global oilseed crop characterised by its high potential as an alimentary oil and in biodiesel production. The two most popular pod sealants (PS) used to reduce rape pod shattering are products in the pinolene range (di-1-p-menthene) and latex polymer products. Reports on the effective preservation of seed yield by these products are fairly contradictory. With this in mind, an experimental PS (PS4) that contained the active agents acrylic and trisiloxane was developed. RESULTS Comparative experimental trials of the developed PS4 and three other PS (PS1, PS2 and PS3) containing active agents that are generally used for sealant production were conducted. The studies showed that the static and dynamic surface tension of PS4 was the lowest at the same concentration (2.0 g kg −1), consequently demonstrating the lowest spray drift. The chemical substances from PS had not penetrated the rape seeds in any of the PSs.

Research paper thumbnail of Fractionation of heavy metals in sewage sludge and their removal using low-molecular-weight organic acids

Journal of Environmental Engineering and Landscape Management, Oct 11, 2012

The total concentration and the concentrations of individual chemical species of selected heavy m... more The total concentration and the concentrations of individual chemical species of selected heavy metals were estimated in primary and anaerobically digested sewage sludge. The concentration of Zn (1503 mg/kg) was highest and was followed by Cu (201 mg/kg), Cr (196 mg/kg), Pb (56 mg/kg), Ni (44 mg/kg) and Cd (3.6 mg/kg). The metal was divided into 5 fractions (exchangeable (F1), adsorbed (F2), organically bound (F3), bound to carbonates (F4), and residual (F5)) via sequential extraction. The sludge treatment procedure had no significant effect on the fractionation results. In both the primary and anaerobically digested sewage sludge, the heavy metals were ranked according to their mobilities (fractions F1 and F2) in the following order: Ni Zn Cu Cd Pb Cr. Metal stability in the environment was evaluated by the sulphide and residual fraction F5, and the following ranking order was identified: Cr Pb :Ni Cd Zn :Cu. A leaching experiment with low-molecular-weight organic acids (oxalic, acetic and citric acid) revealed that the metal-removal efficiency varied depending on the number of carboxyl groups in the extracting agent, the chemical speciation of the metal (Ni, Zn or Cu) in the sludge and the concentration and pH change of the extracting solution. Acid solutions with a 0.5 M concentration, ranked according to their Zn-removal efficiency, are ranked as follows: citric acid (100%) acetic acid (78%) oxalic acid (71%). In all of the cases, citric acid showed the best capacity for the removal of metal from the sludge, with an extraction efficiency ranging from 30Á100%, while the Ni and Cu removal efficiencies with the acetic and oxalic acid were less than 40%.

Research paper thumbnail of Possibilities of Using Camelina Sativa Oil for Producing Biodiesel Fuel

Transport, Mar 30, 2012

Biofuels for diesel engines are produced mainly from rapeseed oil in Lithuania and the Member Sta... more Biofuels for diesel engines are produced mainly from rapeseed oil in Lithuania and the Member States of the European Union. In order to minimise an adverse impact of biodiesel fuel on the food sector, it is necessary to look for alternative feedstocks for producing biodiesel fuel including the potential utilisation of the new kinds of oilseed crops and various fatty waste. Camelina (Camelina sativa) could be one of the kinds of such oilseed crops, and therefore the physical and chemical parameters of Camelina sativa oil and biodiesel fuel produced from this oil were determined and the conformity of quality parameters with the requirements of biofuel standard was evaluated. It was found that fatty acid methyl esters made from Camelina sativa oil had a high iodine value (164.6÷169.6 g I 2 / 100 g oil), and therefore could be used as fuel for diesel engines only in the mixtures with methyl esters produced from animal fat or used for frying oil. It has been established that similar mixtures can contain 50÷60% of Camelina sativa oil methyl esters. The possibilities of increasing oxidation stability as well as improving the cold flow properties of ester mixtures were investigated. The most effective antioxidant-Ionol (optimal dosage of 500 ppm) and the most efficient depressants Wintron XC-30 (optimal dosage-1500 ppm) and Infineum R-442 (optimal dosage-1200 ppm) were selected.

Research paper thumbnail of Chemical Immobilisation of Trace Elements Using Industrial By-Products

Rural development, Jun 4, 2020

Alkaline soil additives used in this study, as cement kiln dust and lime mud, resulted in signifi... more Alkaline soil additives used in this study, as cement kiln dust and lime mud, resulted in significant rise of the pH in contaminated soil and sludge mixtures, while buffering capacity of the sludge appeared to be much stronger than that of the soil. Total concentrations of the investigated trace elements in the tested samples in most cases were above limit values given in Lithuanian environmental normative documents HN 60:2015 and LAND 20:2005; Cd, Zn and Pb concentrations exceeding MPCs by 2-10 times. Nickel, cadmium and copper in the sludge appeared to be the most mobile elements, their EDTA-extractable fraction reaching 30-50% from the total. The tested industrial by-products in most cases significantly reduced trace element mobility. Immobilizing effect in the contaminated soil was from low to moderate, while impact on the reduction of Cd, Pb, Zn, Cr, Ni, As, Se, Hg mobility in the sludge was much stronger. Alkaline treatment was not so effective to reduce mobility of Cu and As in the soil, but immobilising effect of lime mud on these elements in the sludge was significant. A multivariate data analysis model with two principle components explained 94% of the data variation. The most distinctive factor, separating samples, was the origin of the two tested metal-rich substrates: contaminated soil and sewage sludge. Contaminated soil could be distinguished by high concentrations of As, Tl, Hg and Pb. Both alkaline treatments on sewage sludge were more effective, thus scores are further from the origin, although, difference between kiln dust and lime mud immobilising effectiveness was not so significant. Application of alkaline amendments: cement kiln dust and lime mud, proved to have strong immobilizing effect on the most of the investigated trace elements, and usage of local by-products for contaminated soil (sludge) remediation purposes could be seen as an environmentally friendly, cost-effective and safe disposal alternative.

Research paper thumbnail of Biodegradable Chelants for Heavy Metal Removal from Sludge and Soil-Sludge Mixtures

Rural development, Jun 4, 2020

Heavy metal extraction study was performed using five chelating agents with different biodegradab... more Heavy metal extraction study was performed using five chelating agents with different biodegradability: EDTA, EDDS, MGDA, SCLC and citric acid. Aminopolycarboxylic acids EDDS and MGDA showed high heavy metal extraction capability from sewage sludge and sludge-soil mixtures. According to heavy metal removal efficiency investigated chelants can be ranked in the following order: EDTA≈ EDDS≈ MGDA> CA> SCLC. Extraction efficiency from sludge mixtures with clay soil was markedly lower than from the mixtures with sandy soil. Biodegradability of EDTA, MGDA, EDDS and CA was evaluated measuring BOD in water environment over 28 day period. According to the results of biodegradability test after 28 days the ranking order of the chelants was following: EDDS (99%)> CA (32.4%)> MGDA (29.2%)> EDTA (14.9%). Results showed that significantly easier than EDTA biodegradable chelating agents, such as EDDS and MGDA, can be successfully used for heavy metal removal from sewage sludge as well as metal-contaminated soil.

Research paper thumbnail of The Effects of the Interaction between Bacterial Inoculants and Mineral Fertilizers on Spring Barley Yield and Soil Properties

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of The Influence of Newly Developed Spray Drift Reduction Agents on Drift Mitigation by Means of Wind Tunnel and Field Evaluation Methods

Agriculture, Jan 31, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Bioavailability of trace metals in lime-mud stabilised anaerobically digested sewage sludge substrate

On-land disposal of waste materials containing trace metals (TM) can give rise to accumulation of... more On-land disposal of waste materials containing trace metals (TM) can give rise to accumulation of these potentially toxic elements in the topsoil, following adverse effects on plant growth and crop quality. Sewage sludge (SS) on-land application poses a great concern because soil acts as a transferor, and due to bioaccumulation TM can appear in a food chain (Castro et al., 2009). As terrestrial plants are the first step of food chain, it is important to have good knowledge about their capacity to accumulate toxic metals and ability to pass them on to animals and humans (Khan et al., 2010). On-site chemical immobilization of TM can be carried out by using specific additives, which tend to form with metal-ions stable, non-mobile, poorly soluble compounds. Such stabilisation techniques help to immobilize TM in the soil, so that they cannot be easily taken up by plants. Hydroxides, oxides, phosphates, carbonates, ferric salts or even industrial by-products can be used in-situ as metal immobilizing agents (Hartley et al., 2004; Paulauskas et al., 2006). Furthermore, industrial waste usage can significantly reduce the cost of the immobilization process (Kumpienė et al., 2007). The objective of the present study – to evaluate bioavailability of the selected TM (Cd, Cu, Pb and Zn) in lime-mud stabilised sewage sludge substrate by carrying out the vegetative pot experiment with romaine lettuce (Lactuca sativa). Seeking to predict mobility as well as potential bioavailability of TM in the sludge, sequential extraction procedure has been applied before/after SS anaerobic treatment.[...]Vytauto Didžiojo universitetasŽemės ūkio akademij

Research paper thumbnail of Bicarbazole-Benzophenone Based Twisted Donor-Acceptor Derivatives as Potential Blue TADF Emitters for OLEDs

Molecules/Molecules online/Molecules annual, Apr 8, 2024

Research paper thumbnail of Carbazole core derivatives and their photophysical and electrochemical investigations supported by the theoretical calculations

Synthetic Metals, Dec 31, 2023

Research paper thumbnail of Distribution and mobility of heavy metals in sewage sludge

Rural development, 2011

This study compares the distribution of the heavy metals into different chemical fractions in sew... more This study compares the distribution of the heavy metals into different chemical fractions in sewage sludge before and after anaerobic processing. The total content of Zn, Cd and Cu in the digested sludge was above the upper permissible limits of standard criteria for on-land sludge application under LAND 20:2005. The following metal fractions were defined using sequential extraction scheme: exchangeable (F1), adsorbed (F2), oxidizable (F3, bound to organic matter), acid soluble (F4, bound to carbonates), and residual (F5, bound to silicates and detrital materials). In terms of their stability in the environment (according to fraction F5) the investigated heavy metals both in primary and digested sludge can be ranked as follows: Cr>>Pb>Ni>Cd.Cu.Zn. Anaerobic sludge treatment had no significant effect on metal mobility row, expressed as sum of fractions F1 and F2: Ni>Zn>Cu>Cd>Pb>Cr. The ranking order of heavy metal potential bioavailability, expressed as (F1-F3)/(F4+F5) ratio, was following: Cu>>Zn.Ni>Cd>>Pb.Cr. Copper, due to its high affinity for organic matter, was the only metal significantly transferred from "stable" fractions to "more mobile" fractions during the sludge digestion processVytauto Didžiojo universitetasŽemės ūkio akademij

Research paper thumbnail of Effect of substituent structure in fluorene based compounds: experimental and theoretical study

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Nov 1, 2023

Research paper thumbnail of Electroactive polymers containing pendant harmane, phenoxazine or carbazole rings as host materials for OLEDs

Dyes and Pigments, Sep 1, 2014

Polystyrenes containing electronically isolated harmane, phenoxazine or carbazole rings were synt... more Polystyrenes containing electronically isolated harmane, phenoxazine or carbazole rings were synthesized and characterized by NMR spectroscopy, elemental analysis and gel permeation chromatography. The new polymers represent amorphous materials of high thermal stability with glass-transition temperatures of 139e179 C. The electron photoemission spectra of layers of the synthesized polymers showed ionization potentials of about 5.6e6.0 eV. The polymers were tested as host materials in phosphorescent green OLEDs with bis(2-phenylpyridine)(acetylacetonato)iridium(III) as the guest. The device based on polymer containing phenoxazine fragments exhibited the best overall performance with a turn-on voltage of 2.8 V, maximum photometric efficiency of about 17 cd/A and maximum brightness of 2920 cd/m 2 .

Research paper thumbnail of New carbazole-indan-1,3-dione- based host materials for phosphorescent organic light emitting diodes

Molecular Crystals and Liquid Crystals, Nov 21, 2016

New carbazole-and indan-1,3-dione-based low molecular weight derivatives were synthesized and cha... more New carbazole-and indan-1,3-dione-based low molecular weight derivatives were synthesized and characterized by mass spectrometry and 1 H NMR spectroscopy. Thermal behaviour of the derivatives was demonstrated by thermo-gravimetric analysis and differential scanning calorimetry. The materials were found to show very high thermal stability having initial thermal degradation temperatures in the range of 398-401°C. Glass transition temperatures of the amorphous molecular materials were in the rage of 80-114°C. The derivatives were tested as host materials in blue phosphorescent organic light emitting diodes with iridium(III)[bis(4,6-difluorophenyl)pyridinato-N,C2 ]picolinate as the guests. One of the blue OLED devices demonstrated rather low turn-on voltage of 5.0 V, a maximum luminance efficiency of 2.73 cd/A and maximum brightness of about 220 cd/m 2 .

Research paper thumbnail of Electro-active polymers containing electronically isolated N-phenyl-N-naphtylamine fragments

Synthetic Metals, 2014

ABSTRACT Monomers and polymers containing electronically isolated N-phenyl-N-naphtylamine fragmen... more ABSTRACT Monomers and polymers containing electronically isolated N-phenyl-N-naphtylamine fragments were synthesized and characterized by NMR and IR spectroscopies as well as by gel permeation chromatography. The polymers represent amorphous materials with glass transition temperatures of 71–78 °C and thermal decomposition starting at temperatures >320 °C. The electron photoemission spectra of layers of the synthesized polymers showed ionization potentials close to 5.8 eV. The synthesized materials have been tested as hole transporting layers in simple OLED devices with Alq3 as the emitter/electron transporting layer. The green devices containing hole transporting film of poly[N-(2,3-epoxypropyl)-N-phenyl-1-naphtylamine] exhibited the best overall performance with a driving voltage of 4.5 V, maximum photometric efficiency of 3.6 cd/A and maximum brightness of 2850 cd/m2.

Research paper thumbnail of Experimental study of biogas treatment

Research paper thumbnail of Globalisation As a Challenge or Opportunity for Organic Farming

DARCOFenews, 2006

During one intensive week in October 2005, the authors were gathered to discuss the impact that g... more During one intensive week in October 2005, the authors were gathered to discuss the impact that globalisation has on the Organic Food Systems and the opportunities that globalisation opens up for developing these systems. The meeting took place as a Ph.D. course under the ...

Research paper thumbnail of The influence of land use on soil organic carbon and nitrogen content and redox potential

Zemdirbyste-agriculture, 2010

The aim of this research was to evaluate organic matter status in the soil according to the organ... more The aim of this research was to evaluate organic matter status in the soil according to the organic carbon content, total and mineral nitrogen amounts, carbon to nitrogen (C:N) ratio and redox potential depending on land usage and plant species. Soil samples were taken from the fields under different farming systems (conventional and organic) as well as abandoned lands. We chose the plants of two botanical species (Poaceae and Fabaceae) in organic and conventional farming systems as well as in abandoned lands. Experimental results show that the best soil organic matter status according to the investigated indexes is in the soils of conventional and organic farming systems occupied with mixtures of Poaceae and Fabaceae and the worst – in the soils of abandoned Poaceae meadows. In the abandoned lands, Fabaceae (galega) had better influence on soil organic matter status than Poaceae.

Research paper thumbnail of Biodegalai - atsinaujinantys energijos ištekliai / The agricultural research for development (ARD), Dimension of the European research area (ERA)

Kaunas eBooks, 2010

Vytauto Didžiojo universitetasŽemės ūkio akademij

Research paper thumbnail of Rapsų ankštarėlių sandariklių panaudojimo technologinis-ekonominis vertinimas

Aleksandro Stulginskio universitetas Rapsų sėklų derliaus nuostoliai pirmiausiai atsiranda dėl na... more Aleksandro Stulginskio universitetas Rapsų sėklų derliaus nuostoliai pirmiausiai atsiranda dėl natūralių fiziologinių procesų, vykstančių augaluose. Augalui bręstant natūralų ankštarėlių atsidarymą sąlygoja biocheminių procesų metu susidarančios medţiagos metilenas ir auksinas, kurios, savo ruoţtu, sąlygoja fermentų aktyvumą. Antra ankštarėlių atsidarymo prieţastis siejama su daţna meteorologinių sąlygų kaita prieš pat derliaus nuėmimą. Drėgnio ir temperatūros pokyčiai priverčia ankštarėles atsidaryti anksčiau laiko. Trečia prieţastis-rapsų brendimo netolygumas. Vienas iš būdų rapsų sėklų byrėjimui iš ankštarėlių sumaţinti yra specialių preparatų-ankštarėlių sandariklių išpurškimas 2-3 savaites prieš derliaus nuėmimą. Dabartiniu metu plačiausiai naudojami du preparatai: pinoleno grupės produktai, kurių pagrindasdi-1-p-mentenas ir latekso polimerų produktai. Ankštarėlių sandarikliai toliau kuriami ir tobulinami. Viena iš tobulinimo krypčių yra sandariklio tirpalo paviršiaus įtempio maţinimas ir plonos tamprios plėvelės susidarymo ant ankštarėlių uţtikrinimas. Šiomis savybėmis pasiţymi naujos kartos sandariklis Contact. Šiame darbe atliktas kompleksinis technologinis-ekonominis sandariklių Spodnam, Elastiq, Gripil ir Contact tyrimas įvertinant natūralius (savaiminius) rapsų sėklų nuostolius bei nuostolius patiriamus dėl kombaino lenktuvų poveikio derliaus nuėmimo metu. Tyrimais nustatyta, kad pirmųjų trijų rapsų ankštarėlių sandariklių panaudojimu galima sumaţinti rapsų sėklų nuostolius apie 35%. Įvertinus bendras išlaidas sandariklių panaudojimui nustatyta, kad rapsus nupurškus Elastiq preparatu galima gauti 9,02 € ha-1 papildomų pajamų, o Contactapie 3,5 karto didesnę sumą.

Research paper thumbnail of Application of rape pod sealants to reduce adverse environmental impacts

Journal of the Science of Food and Agriculture, Nov 14, 2017

BACKGROUND Rape (Brassica napus L.) is a major global oilseed crop characterised by its high pote... more BACKGROUND Rape (Brassica napus L.) is a major global oilseed crop characterised by its high potential as an alimentary oil and in biodiesel production. The two most popular pod sealants (PS) used to reduce rape pod shattering are products in the pinolene range (di-1-p-menthene) and latex polymer products. Reports on the effective preservation of seed yield by these products are fairly contradictory. With this in mind, an experimental PS (PS4) that contained the active agents acrylic and trisiloxane was developed. RESULTS Comparative experimental trials of the developed PS4 and three other PS (PS1, PS2 and PS3) containing active agents that are generally used for sealant production were conducted. The studies showed that the static and dynamic surface tension of PS4 was the lowest at the same concentration (2.0 g kg −1), consequently demonstrating the lowest spray drift. The chemical substances from PS had not penetrated the rape seeds in any of the PSs.

Research paper thumbnail of Fractionation of heavy metals in sewage sludge and their removal using low-molecular-weight organic acids

Journal of Environmental Engineering and Landscape Management, Oct 11, 2012

The total concentration and the concentrations of individual chemical species of selected heavy m... more The total concentration and the concentrations of individual chemical species of selected heavy metals were estimated in primary and anaerobically digested sewage sludge. The concentration of Zn (1503 mg/kg) was highest and was followed by Cu (201 mg/kg), Cr (196 mg/kg), Pb (56 mg/kg), Ni (44 mg/kg) and Cd (3.6 mg/kg). The metal was divided into 5 fractions (exchangeable (F1), adsorbed (F2), organically bound (F3), bound to carbonates (F4), and residual (F5)) via sequential extraction. The sludge treatment procedure had no significant effect on the fractionation results. In both the primary and anaerobically digested sewage sludge, the heavy metals were ranked according to their mobilities (fractions F1 and F2) in the following order: Ni Zn Cu Cd Pb Cr. Metal stability in the environment was evaluated by the sulphide and residual fraction F5, and the following ranking order was identified: Cr Pb :Ni Cd Zn :Cu. A leaching experiment with low-molecular-weight organic acids (oxalic, acetic and citric acid) revealed that the metal-removal efficiency varied depending on the number of carboxyl groups in the extracting agent, the chemical speciation of the metal (Ni, Zn or Cu) in the sludge and the concentration and pH change of the extracting solution. Acid solutions with a 0.5 M concentration, ranked according to their Zn-removal efficiency, are ranked as follows: citric acid (100%) acetic acid (78%) oxalic acid (71%). In all of the cases, citric acid showed the best capacity for the removal of metal from the sludge, with an extraction efficiency ranging from 30Á100%, while the Ni and Cu removal efficiencies with the acetic and oxalic acid were less than 40%.

Research paper thumbnail of Possibilities of Using Camelina Sativa Oil for Producing Biodiesel Fuel

Transport, Mar 30, 2012

Biofuels for diesel engines are produced mainly from rapeseed oil in Lithuania and the Member Sta... more Biofuels for diesel engines are produced mainly from rapeseed oil in Lithuania and the Member States of the European Union. In order to minimise an adverse impact of biodiesel fuel on the food sector, it is necessary to look for alternative feedstocks for producing biodiesel fuel including the potential utilisation of the new kinds of oilseed crops and various fatty waste. Camelina (Camelina sativa) could be one of the kinds of such oilseed crops, and therefore the physical and chemical parameters of Camelina sativa oil and biodiesel fuel produced from this oil were determined and the conformity of quality parameters with the requirements of biofuel standard was evaluated. It was found that fatty acid methyl esters made from Camelina sativa oil had a high iodine value (164.6÷169.6 g I 2 / 100 g oil), and therefore could be used as fuel for diesel engines only in the mixtures with methyl esters produced from animal fat or used for frying oil. It has been established that similar mixtures can contain 50÷60% of Camelina sativa oil methyl esters. The possibilities of increasing oxidation stability as well as improving the cold flow properties of ester mixtures were investigated. The most effective antioxidant-Ionol (optimal dosage of 500 ppm) and the most efficient depressants Wintron XC-30 (optimal dosage-1500 ppm) and Infineum R-442 (optimal dosage-1200 ppm) were selected.

Research paper thumbnail of Chemical Immobilisation of Trace Elements Using Industrial By-Products

Rural development, Jun 4, 2020

Alkaline soil additives used in this study, as cement kiln dust and lime mud, resulted in signifi... more Alkaline soil additives used in this study, as cement kiln dust and lime mud, resulted in significant rise of the pH in contaminated soil and sludge mixtures, while buffering capacity of the sludge appeared to be much stronger than that of the soil. Total concentrations of the investigated trace elements in the tested samples in most cases were above limit values given in Lithuanian environmental normative documents HN 60:2015 and LAND 20:2005; Cd, Zn and Pb concentrations exceeding MPCs by 2-10 times. Nickel, cadmium and copper in the sludge appeared to be the most mobile elements, their EDTA-extractable fraction reaching 30-50% from the total. The tested industrial by-products in most cases significantly reduced trace element mobility. Immobilizing effect in the contaminated soil was from low to moderate, while impact on the reduction of Cd, Pb, Zn, Cr, Ni, As, Se, Hg mobility in the sludge was much stronger. Alkaline treatment was not so effective to reduce mobility of Cu and As in the soil, but immobilising effect of lime mud on these elements in the sludge was significant. A multivariate data analysis model with two principle components explained 94% of the data variation. The most distinctive factor, separating samples, was the origin of the two tested metal-rich substrates: contaminated soil and sewage sludge. Contaminated soil could be distinguished by high concentrations of As, Tl, Hg and Pb. Both alkaline treatments on sewage sludge were more effective, thus scores are further from the origin, although, difference between kiln dust and lime mud immobilising effectiveness was not so significant. Application of alkaline amendments: cement kiln dust and lime mud, proved to have strong immobilizing effect on the most of the investigated trace elements, and usage of local by-products for contaminated soil (sludge) remediation purposes could be seen as an environmentally friendly, cost-effective and safe disposal alternative.

Research paper thumbnail of Biodegradable Chelants for Heavy Metal Removal from Sludge and Soil-Sludge Mixtures

Rural development, Jun 4, 2020

Heavy metal extraction study was performed using five chelating agents with different biodegradab... more Heavy metal extraction study was performed using five chelating agents with different biodegradability: EDTA, EDDS, MGDA, SCLC and citric acid. Aminopolycarboxylic acids EDDS and MGDA showed high heavy metal extraction capability from sewage sludge and sludge-soil mixtures. According to heavy metal removal efficiency investigated chelants can be ranked in the following order: EDTA≈ EDDS≈ MGDA> CA> SCLC. Extraction efficiency from sludge mixtures with clay soil was markedly lower than from the mixtures with sandy soil. Biodegradability of EDTA, MGDA, EDDS and CA was evaluated measuring BOD in water environment over 28 day period. According to the results of biodegradability test after 28 days the ranking order of the chelants was following: EDDS (99%)> CA (32.4%)> MGDA (29.2%)> EDTA (14.9%). Results showed that significantly easier than EDTA biodegradable chelating agents, such as EDDS and MGDA, can be successfully used for heavy metal removal from sewage sludge as well as metal-contaminated soil.

Research paper thumbnail of The Effects of the Interaction between Bacterial Inoculants and Mineral Fertilizers on Spring Barley Yield and Soil Properties

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of The Influence of Newly Developed Spray Drift Reduction Agents on Drift Mitigation by Means of Wind Tunnel and Field Evaluation Methods

Agriculture, Jan 31, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Bioavailability of trace metals in lime-mud stabilised anaerobically digested sewage sludge substrate

On-land disposal of waste materials containing trace metals (TM) can give rise to accumulation of... more On-land disposal of waste materials containing trace metals (TM) can give rise to accumulation of these potentially toxic elements in the topsoil, following adverse effects on plant growth and crop quality. Sewage sludge (SS) on-land application poses a great concern because soil acts as a transferor, and due to bioaccumulation TM can appear in a food chain (Castro et al., 2009). As terrestrial plants are the first step of food chain, it is important to have good knowledge about their capacity to accumulate toxic metals and ability to pass them on to animals and humans (Khan et al., 2010). On-site chemical immobilization of TM can be carried out by using specific additives, which tend to form with metal-ions stable, non-mobile, poorly soluble compounds. Such stabilisation techniques help to immobilize TM in the soil, so that they cannot be easily taken up by plants. Hydroxides, oxides, phosphates, carbonates, ferric salts or even industrial by-products can be used in-situ as metal immobilizing agents (Hartley et al., 2004; Paulauskas et al., 2006). Furthermore, industrial waste usage can significantly reduce the cost of the immobilization process (Kumpienė et al., 2007). The objective of the present study – to evaluate bioavailability of the selected TM (Cd, Cu, Pb and Zn) in lime-mud stabilised sewage sludge substrate by carrying out the vegetative pot experiment with romaine lettuce (Lactuca sativa). Seeking to predict mobility as well as potential bioavailability of TM in the sludge, sequential extraction procedure has been applied before/after SS anaerobic treatment.[...]Vytauto Didžiojo universitetasŽemės ūkio akademij