Jiri Kucerik | Universität Koblenz (original) (raw)

Papers by Jiri Kucerik

Research paper thumbnail of Characterization of lignin monomers in low rank coal humic acids using the derivatization/reductive cleavage method

Organic Geochemistry, 2010

Traditional CuO oxidation and thermochemolysis with tetramethylammonium hydroxide are the two mai... more Traditional CuO oxidation and thermochemolysis with tetramethylammonium hydroxide are the two main methods for lignin characterization in gymnosperm wood, and in soils and sediments formed from degraded gymnosperm wood, or for assessing the supply of terrestrial organic matter to marine sediments. In some cases, the overall lignin yield and the compound ratios used as plant source proxies have been found

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Research paper thumbnail of Structure and properties of humic and fulvic acids. I. Properties and reactivity of humic acids and fulvic acids

Journal of Polymer Materials

The aim of this part is to characterize of HA and FA on the basis of their ability to form comple... more The aim of this part is to characterize of HA and FA on the basis of their ability to form complexes with inorganic and organic molecules capable to cause the effect of crosslinking. The characterization and properties of HA and FA and differences between these two groups of compounds were summarized. Their reactivity with transition elements was investigated by EPR spectroscopy. The properties of HA and FA in more details were studied by FTIR spectroscopy. With aid of semiempirical version of INDO method parameterized for compounds of transition elements the interaction energies were calculated. Obtained results were discussed and compared.

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Research paper thumbnail of Practical application of thermogravimetry in soil science

Journal of Thermal Analysis and Calorimetry, 2013

ABSTRACT Soil samples collected in South America, North America and West Siberia were measured by... more ABSTRACT Soil samples collected in South America, North America and West Siberia were measured by thermogravimetry to verify the connection between mass losses and soil respiration represented by the rate and amount of carbon dioxide measured under laboratory conditions. It was demonstrated that linear correlation between those parameters is a common feature for soils originating from different climatic and geographic regions. Significant coefficients of determination were observed in temperature areas corresponding to the moisture evaporation and degradation of soil organic matter (SOM). It was concluded that the correlations are the consequences of soil-forming processes mediated by microorganisms over a long time period. The comparison of experimental data with earlier results showed that disturbance of those processes causes the decrease in observed correlations. The subtraction of thermal mass losses of incubated and non-incubated soils revealed the change in water holding character in all samples, which was ascribed to the transformation of SOM and its water-holding properties during the incubation. In contrast, the changes in thermal mass losses above 200 °C showed that this area reflects the specificity of biological transformation of each soil sample. Further, applied approach and obtained results indicate the necessity of very gentle soil sample preparation and especially gentle air drying to get comparable results about intrinsic soils’ features in different regions.

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Research paper thumbnail of Land use effects on carbon quality and soil biological properties in Eutric Cambisol

Acta Agriculturae Scandinavica, Section B - Soil & Plant Science, 2011

The choice of prospective type of farming requires knowledge about the specific relationships tha... more The choice of prospective type of farming requires knowledge about the specific relationships that exist between farm management practices and base environmental conditions. Nowadays the protection of soil organic carbon is one of the main tasks, because organic carbon in addition to soil fertility can act in elimination of soil contamination and carbon sequestration. Field experiments were focused on the

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Research paper thumbnail of The kinetics of thermo-oxidative humic acids degradation studied by isoconversional methods

Journal of Thermal Analysis and Calorimetry, 2007

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Research paper thumbnail of Stability evaluation of n-alkyl hyaluronic acid derivates by DSC and TG measurement

Journal of Thermal Analysis and Calorimetry, 2006

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Research paper thumbnail of The role of various compounds in humic acids stability studied by TG and DTA

Journal of Thermal Analysis and Calorimetry, 2006

Simultaneous DTA/TG technique has been used to study the influence of various model compounds (ar... more Simultaneous DTA/TG technique has been used to study the influence of various model compounds (aromatics, organic acids, alkanes, ketone, heterocyclic and sterole) on the thermo-oxidative behavior of lignite humic acids. As a measure of stability the shift of the onset temperature of the exothermic degradation peak has been used. Further, the ratio of mass loss recorded in the high and

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Research paper thumbnail of Correlation of humic substances chemical properties and their thermo-oxidative degradation kinetics

Journal of Thermal Analysis and Calorimetry, 2009

Application of the Arrhenius equation as the temperature function in modeling of the degradation ... more Application of the Arrhenius equation as the temperature function in modeling of the degradation kinetics of humic substances brought a high positive Pearson correlation coefficient with the carbon content and a reasonable negative correlation with the oxygen content. Ratio C/H indicating the aromaticity degree of humic samples did not show any significant correlation. Relatively high value of correlation coefficients provided also O + N and ratios C/(O + N) and C/O, respectively. In contrast, H, N content and natural and heat generated free radical content and their ratio gave substantially lower correlation coefficients. The latter indicates that free radicals are probably not the main reason of the collapse of the secondary structure of humic substances leading to their degradation.

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Research paper thumbnail of Thermoanalytical investigation of lignite humic acids fractions

Journal of Thermal Analysis and Calorimetry, 2000

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Research paper thumbnail of Effect of Heating Time and Temperature on the Chemical Characteristics of Biochar from Poultry Manure

Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical−ph... more Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical−physical
characterization of the different PM chars was conducted by cross-polarization magic angle spinning (CPMAS) 13C NMR
spectroscopy and thermal analysis. CPMAS 13C NMR spectra showed that the chemical composition of PM char is dependent on
production temperature rather than on production duration. Aromatic and alkyl domains in the PM chars obtained at the lowest
temperatures remained unchanged at all heating times applied for their production. The PM char obtained at the highest
temperature consisted only of aromatic structures having chemical nature that also appeared invariant with heating time.
Thermogravimetry revealed differences in the thermo-oxidative stability of the aromatic domains in the different PM chars. The
PM char produced at the highest temperature appeared less stable than those produced at the lowest temperatures. This
difference was explained by a protective effect of the alkyl groups, which are still present in chars formed at lower temperature.
The analysis of the chemical and physicochemical character of poultry manure chars produced at different temperatures can
increase understanding of the role of these materials in the properties and behavior of char-amended soils.

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Research paper thumbnail of Cation-mediated cross-linking in natural organic matter: a review

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Research paper thumbnail of Solid state nuclear magnetic resonance spectroscopy in the evaluation of soil organic matter changes following thermal variations

Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation... more Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation of plant tissues and animal bodies. It is the major indicator of soil quality since it is directly involved in the maintenance of soil fertility, prevention of erosion and desert encroachment and provision of suitable environment for biological activity. Organic matter is an important driving

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Research paper thumbnail of Solid state NMR spectroscopy in the evaluation of the conformational changes of humic substances as affected by thermal variations

Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation... more Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation of plant tissues and animal bodies. It is the major indicator of soil quality since it is directly involved in the maintenance of soil fertility, prevention of erosion and desert encroachment and provision of suitable environment for biological activity. Organic matter is an important driving

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Research paper thumbnail of SURFACE AND SOLUTION BEHAVIOR OF SURFACTANTS PRODUCED FROM LIGNITE HUMIC ACIDS

Fresenius Environmental Bulletin

Analytical and physical-chemical techniques, such as elemental analysis, FTIR, surface tension (S... more Analytical and physical-chemical techniques, such as elemental analysis, FTIR, surface tension (ST) measurement, high performance size exclusion chromatography (HPSEC) and high resolution ultrasonic spectroscopy (HRUS) were combined in order to assess the surface activity of lignite sodium humic acids salts (humates). Humates were obtained from parental and modified South Moravian lignite pre-treated either by oxidation or by small organic acids. It was shown that unlike common surfactants, humates dissolved in water do not exhibit the critical micelle concentration and form micelle-like aggregates also in diluted solutions. As revealed by HRUS, the aggregation and/or reconformation of humic aggregates in solution takes up to ten minutes; in contrast, the ST measurements showed long-term stabilization associated with a slow decrease in ST of the solution. Correlation with results of HPSEC indicated that the surface activity of lignite humates is caused predominantly by aggregates wi...

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Research paper thumbnail of The physico-chemical properties and biostimulative activities of humic substances regenerated from lignite

SpringerPlus, 2014

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Research paper thumbnail of Dynamics of water solutions of natural polysaccharides by fast field cycling nmr relaxometry

Cryobiology studies the effect of low temperatures on living systems such as microorganisms and p... more Cryobiology studies the effect of low temperatures on living systems such as microorganisms and plants. In particular, plants growing in cold or frozen environments can survive such extreme conditions due to the cold hardening process. Hardening is a three step process during which, first, translocation of polysaccharides to the plant roots affects water structure in the cell-soil surface. For this

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Research paper thumbnail of Paclitaxel isomerisation in polymeric micelles based on hydrophobized hyaluronic acid

International Journal of Pharmaceutics, 2014

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Research paper thumbnail of New insights into aggregation and conformational behaviour of humic substances: Application of high resolution ultrasonic spectroscopy

Organic Geochemistry, 2007

The potential of high resolution ultrasonic analysis (HRUS) in humic acid colloidal properties re... more The potential of high resolution ultrasonic analysis (HRUS) in humic acid colloidal properties research has been demonstrated. Sodium salts of humic acids from soil and lignite showed similar behaviour, supporting the hypothesis that, at both neutral and alkaline pH, they aggregate from very low concentration. The same conclusion can be reached for solutions at high ionic strength. We tried to

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Lignite pre-treatment and its effect on bio-stimulative properties of respective lignite humic acids

Soil Biology & Biochemistry, 2009

Humic acids originating from South-Moravian lignite were subjected to a comparative study with th... more Humic acids originating from South-Moravian lignite were subjected to a comparative study with the aim to assess the alteration of their physico-chemical properties after various lignite pre-treatments. Physical modification was achieved with two organic acids, such as acetic acid and citric acid and chemical modification by nitric acid and hydrogene peroxide in various concentrations. Elemental analysis, solid-state NMR, GC–MS analysis

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Research paper thumbnail of DSC study on hyaluronan drying and hydration

Thermochimica Acta, 2011

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Research paper thumbnail of Characterization of lignin monomers in low rank coal humic acids using the derivatization/reductive cleavage method

Organic Geochemistry, 2010

Traditional CuO oxidation and thermochemolysis with tetramethylammonium hydroxide are the two mai... more Traditional CuO oxidation and thermochemolysis with tetramethylammonium hydroxide are the two main methods for lignin characterization in gymnosperm wood, and in soils and sediments formed from degraded gymnosperm wood, or for assessing the supply of terrestrial organic matter to marine sediments. In some cases, the overall lignin yield and the compound ratios used as plant source proxies have been found

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Structure and properties of humic and fulvic acids. I. Properties and reactivity of humic acids and fulvic acids

Journal of Polymer Materials

The aim of this part is to characterize of HA and FA on the basis of their ability to form comple... more The aim of this part is to characterize of HA and FA on the basis of their ability to form complexes with inorganic and organic molecules capable to cause the effect of crosslinking. The characterization and properties of HA and FA and differences between these two groups of compounds were summarized. Their reactivity with transition elements was investigated by EPR spectroscopy. The properties of HA and FA in more details were studied by FTIR spectroscopy. With aid of semiempirical version of INDO method parameterized for compounds of transition elements the interaction energies were calculated. Obtained results were discussed and compared.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Practical application of thermogravimetry in soil science

Journal of Thermal Analysis and Calorimetry, 2013

ABSTRACT Soil samples collected in South America, North America and West Siberia were measured by... more ABSTRACT Soil samples collected in South America, North America and West Siberia were measured by thermogravimetry to verify the connection between mass losses and soil respiration represented by the rate and amount of carbon dioxide measured under laboratory conditions. It was demonstrated that linear correlation between those parameters is a common feature for soils originating from different climatic and geographic regions. Significant coefficients of determination were observed in temperature areas corresponding to the moisture evaporation and degradation of soil organic matter (SOM). It was concluded that the correlations are the consequences of soil-forming processes mediated by microorganisms over a long time period. The comparison of experimental data with earlier results showed that disturbance of those processes causes the decrease in observed correlations. The subtraction of thermal mass losses of incubated and non-incubated soils revealed the change in water holding character in all samples, which was ascribed to the transformation of SOM and its water-holding properties during the incubation. In contrast, the changes in thermal mass losses above 200 °C showed that this area reflects the specificity of biological transformation of each soil sample. Further, applied approach and obtained results indicate the necessity of very gentle soil sample preparation and especially gentle air drying to get comparable results about intrinsic soils’ features in different regions.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Land use effects on carbon quality and soil biological properties in Eutric Cambisol

Acta Agriculturae Scandinavica, Section B - Soil & Plant Science, 2011

The choice of prospective type of farming requires knowledge about the specific relationships tha... more The choice of prospective type of farming requires knowledge about the specific relationships that exist between farm management practices and base environmental conditions. Nowadays the protection of soil organic carbon is one of the main tasks, because organic carbon in addition to soil fertility can act in elimination of soil contamination and carbon sequestration. Field experiments were focused on the

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The kinetics of thermo-oxidative humic acids degradation studied by isoconversional methods

Journal of Thermal Analysis and Calorimetry, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Stability evaluation of n-alkyl hyaluronic acid derivates by DSC and TG measurement

Journal of Thermal Analysis and Calorimetry, 2006

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The role of various compounds in humic acids stability studied by TG and DTA

Journal of Thermal Analysis and Calorimetry, 2006

Simultaneous DTA/TG technique has been used to study the influence of various model compounds (ar... more Simultaneous DTA/TG technique has been used to study the influence of various model compounds (aromatics, organic acids, alkanes, ketone, heterocyclic and sterole) on the thermo-oxidative behavior of lignite humic acids. As a measure of stability the shift of the onset temperature of the exothermic degradation peak has been used. Further, the ratio of mass loss recorded in the high and

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Correlation of humic substances chemical properties and their thermo-oxidative degradation kinetics

Journal of Thermal Analysis and Calorimetry, 2009

Application of the Arrhenius equation as the temperature function in modeling of the degradation ... more Application of the Arrhenius equation as the temperature function in modeling of the degradation kinetics of humic substances brought a high positive Pearson correlation coefficient with the carbon content and a reasonable negative correlation with the oxygen content. Ratio C/H indicating the aromaticity degree of humic samples did not show any significant correlation. Relatively high value of correlation coefficients provided also O + N and ratios C/(O + N) and C/O, respectively. In contrast, H, N content and natural and heat generated free radical content and their ratio gave substantially lower correlation coefficients. The latter indicates that free radicals are probably not the main reason of the collapse of the secondary structure of humic substances leading to their degradation.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Thermoanalytical investigation of lignite humic acids fractions

Journal of Thermal Analysis and Calorimetry, 2000

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Effect of Heating Time and Temperature on the Chemical Characteristics of Biochar from Poultry Manure

Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical−ph... more Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical−physical
characterization of the different PM chars was conducted by cross-polarization magic angle spinning (CPMAS) 13C NMR
spectroscopy and thermal analysis. CPMAS 13C NMR spectra showed that the chemical composition of PM char is dependent on
production temperature rather than on production duration. Aromatic and alkyl domains in the PM chars obtained at the lowest
temperatures remained unchanged at all heating times applied for their production. The PM char obtained at the highest
temperature consisted only of aromatic structures having chemical nature that also appeared invariant with heating time.
Thermogravimetry revealed differences in the thermo-oxidative stability of the aromatic domains in the different PM chars. The
PM char produced at the highest temperature appeared less stable than those produced at the lowest temperatures. This
difference was explained by a protective effect of the alkyl groups, which are still present in chars formed at lower temperature.
The analysis of the chemical and physicochemical character of poultry manure chars produced at different temperatures can
increase understanding of the role of these materials in the properties and behavior of char-amended soils.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Cation-mediated cross-linking in natural organic matter: a review

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Solid state nuclear magnetic resonance spectroscopy in the evaluation of soil organic matter changes following thermal variations

Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation... more Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation of plant tissues and animal bodies. It is the major indicator of soil quality since it is directly involved in the maintenance of soil fertility, prevention of erosion and desert encroachment and provision of suitable environment for biological activity. Organic matter is an important driving

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Solid state NMR spectroscopy in the evaluation of the conformational changes of humic substances as affected by thermal variations

Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation... more Soil organic matter (SOM) is an ubiquitous, complex material which is produced by the degradation of plant tissues and animal bodies. It is the major indicator of soil quality since it is directly involved in the maintenance of soil fertility, prevention of erosion and desert encroachment and provision of suitable environment for biological activity. Organic matter is an important driving

Bookmarks Related papers MentionsView impact

Research paper thumbnail of SURFACE AND SOLUTION BEHAVIOR OF SURFACTANTS PRODUCED FROM LIGNITE HUMIC ACIDS

Fresenius Environmental Bulletin

Analytical and physical-chemical techniques, such as elemental analysis, FTIR, surface tension (S... more Analytical and physical-chemical techniques, such as elemental analysis, FTIR, surface tension (ST) measurement, high performance size exclusion chromatography (HPSEC) and high resolution ultrasonic spectroscopy (HRUS) were combined in order to assess the surface activity of lignite sodium humic acids salts (humates). Humates were obtained from parental and modified South Moravian lignite pre-treated either by oxidation or by small organic acids. It was shown that unlike common surfactants, humates dissolved in water do not exhibit the critical micelle concentration and form micelle-like aggregates also in diluted solutions. As revealed by HRUS, the aggregation and/or reconformation of humic aggregates in solution takes up to ten minutes; in contrast, the ST measurements showed long-term stabilization associated with a slow decrease in ST of the solution. Correlation with results of HPSEC indicated that the surface activity of lignite humates is caused predominantly by aggregates wi...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The physico-chemical properties and biostimulative activities of humic substances regenerated from lignite

SpringerPlus, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Dynamics of water solutions of natural polysaccharides by fast field cycling nmr relaxometry

Cryobiology studies the effect of low temperatures on living systems such as microorganisms and p... more Cryobiology studies the effect of low temperatures on living systems such as microorganisms and plants. In particular, plants growing in cold or frozen environments can survive such extreme conditions due to the cold hardening process. Hardening is a three step process during which, first, translocation of polysaccharides to the plant roots affects water structure in the cell-soil surface. For this

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Paclitaxel isomerisation in polymeric micelles based on hydrophobized hyaluronic acid

International Journal of Pharmaceutics, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of New insights into aggregation and conformational behaviour of humic substances: Application of high resolution ultrasonic spectroscopy

Organic Geochemistry, 2007

The potential of high resolution ultrasonic analysis (HRUS) in humic acid colloidal properties re... more The potential of high resolution ultrasonic analysis (HRUS) in humic acid colloidal properties research has been demonstrated. Sodium salts of humic acids from soil and lignite showed similar behaviour, supporting the hypothesis that, at both neutral and alkaline pH, they aggregate from very low concentration. The same conclusion can be reached for solutions at high ionic strength. We tried to

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Lignite pre-treatment and its effect on bio-stimulative properties of respective lignite humic acids

Soil Biology & Biochemistry, 2009

Humic acids originating from South-Moravian lignite were subjected to a comparative study with th... more Humic acids originating from South-Moravian lignite were subjected to a comparative study with the aim to assess the alteration of their physico-chemical properties after various lignite pre-treatments. Physical modification was achieved with two organic acids, such as acetic acid and citric acid and chemical modification by nitric acid and hydrogene peroxide in various concentrations. Elemental analysis, solid-state NMR, GC–MS analysis

Bookmarks Related papers MentionsView impact

Research paper thumbnail of DSC study on hyaluronan drying and hydration

Thermochimica Acta, 2011

Bookmarks Related papers MentionsView impact