143 research outputs found
Transport model of potentially toxic elements through unsaturated zone at regional wellfield Kosnica : doctoral thesis
Predmet istraživanja ove doktorske disertacije je nesaturirana zona na području regionalnog
vodocrpilišta Kosnica. Ciljevi ovog doktorskog rada bili su: (i) identificirati dominantne
procese transporta u nesaturiranoj zoni; (ii) odrediti parametre toka vode i transporta
onečišćivala nesaturirane zone; (iii) odrediti geokemijsko ponašanje potencijalno toksičnih
elemenata u nesaturiranoj zoni; (iiii) izraditi prognozni model toka vode i transporta
potencijalno toksičnih elemenata (olovo, kadmij, cink) kroz nesaturiranu zonu. Temeljem
brojnih laboratorijskih analiza svojstava tla i eksperimenata definirani su parametri toka vode
(kapacitet tla za vodu, hidraulička vodljivost) i transporta onečišćivala (sorpcija, disperzija,
volumna gustoća, koncentracija potencijalno toksičnih elemenata). Brojnim kemijskim i
eksperimentalnim analizama uzoraka iz nesaturirane zone određeno je geokemijsko ponašanje
potencijalno toksičnih elemenata. Za primjenu numeričkih simulacija korišten je program
HYDRUS-1D. Kapacitet zadržavanja vode u tlu najveći je u A horizontu i iznosi ~45%. Na
temelju istraživanja hidrauličke vodljivosti utvrđene su najniže vrijednosti za A i IVGso/Gr
horizonte. Veće vrijednosti hidrauličke vodljivosti određene su u donjem dijelu profila u
kojima je zastupljena pjeskovito-šljunkovita i šljunkovita tekstura. U AC-IC horizontu je
određena manja vrijednost disperzivnosti koja iznosi 1 cm, dok je za horizont IIC/Gso
određena veća vrijednost i iznosi 1,7 cm. Utvrđene su male razlike u sorpciji između
pojedinih elemenata. Analizom otopina porušenih uzoraka dobivenih digestijom zlatotopkom
utvrđene su najveće koncentracije elemenata (Cd, Pb i Zn) u najplićem dijelu profila. Na
temelju dobivenih parametara toka vode i transporta potencijalno toksičnih elemenata kreiran
je prognozni model na istražnoj lokaciji. Ukoliko se usporede koncentracije potencijalno
toksičnih elemenata dobivene s prognoznim modelom transporta na dnu profila tla odnosno
na granici s otvorenim vodonosnikom s MDK granicama pravilnika za iste elemente onda se
može zaključiti da postoji velika opasnost od onečišćenja na istražnoj lokaciji. Mehanizmi
sorpcije imaju glavni utjecaj na transport elemenata u saturiranu zonu. Uslijed akcidentnih
situacija izlijevanja koncentracije potencijalno toksičnih elemenata od 1000 mg/l, rizik od
onečišćenja vodonosnika s time i regionalnoga vodocrpilišta Kosnica je visok. Ovim
istraživanjima nesaturirane zone na lokaciji Kosnica definirani su parametri toka i transporta
potencijalno toksičnih elemenata te je napravljen numerički model kao osnova za buduća
istraživanja akcidentnih situacija.The subject of this thesis is the unsaturated zone in the area of the regional water well
Kosnica. The objectives of this thesis were: (i) to identify dominant processes in the
unsaturated zone; (ii) to determine water flow and solute transport parameters in the
unsaturated zone (iii) to determine geochemical behaviour of potentially toxic elements in the
unsaturated zone; (iiii) to build prognostic water flow and the transport model of potentially
toxic elements (lead, cadmium, zinc) through the unsaturated zone.
The research was conducted in the area of the Kosnica water well, dominated by Fluvisol soil
type. In order to better understand the water flow and the transport of the potentially toxic
elements through an unsaturated zone detail field, laboratory analyses and experiments were
made. For numerical simulation HYDRUS-1D program was used. The program models the
water flow using Richard's equation. The transport of potentially toxic elements is described
using the advection and dispersion equation.
Based on the laboratory analyses of soil properties, the parameters of water flow and solute
transport are defined. The bulk density rises with depth while the water holding capacity is the
largest in the A horizon due to particle size distribution. Minimum values of hydraulic
conductivity were determined in the A and IVGso/Gr horizons. The experimental results of
the sorption processes were used for the determination of correlation coefficients for
individual elements. The order of decreasing correlation coefficients was: Pb> Zn> Cd. Small
differences in sorption were found between the individual elements. The soil column
dispersivity was 1 cm for AC-IC horizon, and 1.7 cm for horizon IIC/Gso.
The higher cation exchange capacity, determined in the top of the profile, indicates the
possibility of more pronounced sorption of elements in shallow horizons. The highest element
concentrations, extracted by aqua regia, were found in the A and AC-IC horizons (for Zn 70
mg/kg and for Pb 51 mg/kg). The lead concentration obtained using sequential extraction
analysis is mostly bound to the organic fraction, while zinc is mostly bound to the residual
fraction. Illitic material is the most common mineral phase in the fraction <2 μm and
correlates with the sorption of lead in top horizons (A and AC-IC).
Measured values of water content in the soil using TDR probes for the period from September
1, 2011 to October 31, 2012 were used for the water flow model calibration. The comparison
of water simulations’ results and the measured data was performed using the HYDRUS 1D
software. The simulated water content was less variable than the measured values.
Low correlation (~ 0.40) was revealed between the measured and the simulated values of the
water content. Such a low correlation between the measured and the simulated water content
in the soil could be a consequence of the difference between the meteorological data obtained
from a weather station located 3.5 km from the investigated location. Based on the chloride
tracer experiments on soil columns in the laboratory, the calibration of the solute transport
model was made. The best correlation of the measured and the simulated values of tracer
concentration is 0.43 for AC-IC and 0.74 for IIC/Gso horizon.
Based on the parameters of the water flow and the transport of potentially toxic elements, the
prognostic model was created at the investigation site. If the concentrations of potentially
toxic elements, obtained by the transport prognostic model at the bottom of the soil profile are
compared with the MAC limits ordinance for the same elements, it can be concluded that
there is a high risk of contamination at the investigative site. Sorption mechanisms have a
major impact on the transport of potentially toxic elements in the saturated zone. In case of an
accidental spill of potentially toxic elements with concentrations of 1000 mg/l, the risk of
contamination of the aquifer is high. This research of unsaturated zone at the Kosnica location
defined the water flow and the transport of potentially toxic elements’ parameters and
designed a model for the future research and accident mitigation
Transport model of potentially toxic elements through unsaturated zone at regional wellfield Kosnica : doctoral thesis
Predmet istraživanja ove doktorske disertacije je nesaturirana zona na području regionalnog
vodocrpilišta Kosnica. Ciljevi ovog doktorskog rada bili su: (i) identificirati dominantne
procese transporta u nesaturiranoj zoni; (ii) odrediti parametre toka vode i transporta
onečišćivala nesaturirane zone; (iii) odrediti geokemijsko ponašanje potencijalno toksičnih
elemenata u nesaturiranoj zoni; (iiii) izraditi prognozni model toka vode i transporta
potencijalno toksičnih elemenata (olovo, kadmij, cink) kroz nesaturiranu zonu. Temeljem
brojnih laboratorijskih analiza svojstava tla i eksperimenata definirani su parametri toka vode
(kapacitet tla za vodu, hidraulička vodljivost) i transporta onečišćivala (sorpcija, disperzija,
volumna gustoća, koncentracija potencijalno toksičnih elemenata). Brojnim kemijskim i
eksperimentalnim analizama uzoraka iz nesaturirane zone određeno je geokemijsko ponašanje
potencijalno toksičnih elemenata. Za primjenu numeričkih simulacija korišten je program
HYDRUS-1D. Kapacitet zadržavanja vode u tlu najveći je u A horizontu i iznosi ~45%. Na
temelju istraživanja hidrauličke vodljivosti utvrđene su najniže vrijednosti za A i IVGso/Gr
horizonte. Veće vrijednosti hidrauličke vodljivosti određene su u donjem dijelu profila u
kojima je zastupljena pjeskovito-šljunkovita i šljunkovita tekstura. U AC-IC horizontu je
određena manja vrijednost disperzivnosti koja iznosi 1 cm, dok je za horizont IIC/Gso
određena veća vrijednost i iznosi 1,7 cm. Utvrđene su male razlike u sorpciji između
pojedinih elemenata. Analizom otopina porušenih uzoraka dobivenih digestijom zlatotopkom
utvrđene su najveće koncentracije elemenata (Cd, Pb i Zn) u najplićem dijelu profila. Na
temelju dobivenih parametara toka vode i transporta potencijalno toksičnih elemenata kreiran
je prognozni model na istražnoj lokaciji. Ukoliko se usporede koncentracije potencijalno
toksičnih elemenata dobivene s prognoznim modelom transporta na dnu profila tla odnosno
na granici s otvorenim vodonosnikom s MDK granicama pravilnika za iste elemente onda se
može zaključiti da postoji velika opasnost od onečišćenja na istražnoj lokaciji. Mehanizmi
sorpcije imaju glavni utjecaj na transport elemenata u saturiranu zonu. Uslijed akcidentnih
situacija izlijevanja koncentracije potencijalno toksičnih elemenata od 1000 mg/l, rizik od
onečišćenja vodonosnika s time i regionalnoga vodocrpilišta Kosnica je visok. Ovim
istraživanjima nesaturirane zone na lokaciji Kosnica definirani su parametri toka i transporta
potencijalno toksičnih elemenata te je napravljen numerički model kao osnova za buduća
istraživanja akcidentnih situacija.The subject of this thesis is the unsaturated zone in the area of the regional water well
Kosnica. The objectives of this thesis were: (i) to identify dominant processes in the
unsaturated zone; (ii) to determine water flow and solute transport parameters in the
unsaturated zone (iii) to determine geochemical behaviour of potentially toxic elements in the
unsaturated zone; (iiii) to build prognostic water flow and the transport model of potentially
toxic elements (lead, cadmium, zinc) through the unsaturated zone.
The research was conducted in the area of the Kosnica water well, dominated by Fluvisol soil
type. In order to better understand the water flow and the transport of the potentially toxic
elements through an unsaturated zone detail field, laboratory analyses and experiments were
made. For numerical simulation HYDRUS-1D program was used. The program models the
water flow using Richard's equation. The transport of potentially toxic elements is described
using the advection and dispersion equation.
Based on the laboratory analyses of soil properties, the parameters of water flow and solute
transport are defined. The bulk density rises with depth while the water holding capacity is the
largest in the A horizon due to particle size distribution. Minimum values of hydraulic
conductivity were determined in the A and IVGso/Gr horizons. The experimental results of
the sorption processes were used for the determination of correlation coefficients for
individual elements. The order of decreasing correlation coefficients was: Pb> Zn> Cd. Small
differences in sorption were found between the individual elements. The soil column
dispersivity was 1 cm for AC-IC horizon, and 1.7 cm for horizon IIC/Gso.
The higher cation exchange capacity, determined in the top of the profile, indicates the
possibility of more pronounced sorption of elements in shallow horizons. The highest element
concentrations, extracted by aqua regia, were found in the A and AC-IC horizons (for Zn 70
mg/kg and for Pb 51 mg/kg). The lead concentration obtained using sequential extraction
analysis is mostly bound to the organic fraction, while zinc is mostly bound to the residual
fraction. Illitic material is the most common mineral phase in the fraction <2 μm and
correlates with the sorption of lead in top horizons (A and AC-IC).
Measured values of water content in the soil using TDR probes for the period from September
1, 2011 to October 31, 2012 were used for the water flow model calibration. The comparison
of water simulations’ results and the measured data was performed using the HYDRUS 1D
software. The simulated water content was less variable than the measured values.
Low correlation (~ 0.40) was revealed between the measured and the simulated values of the
water content. Such a low correlation between the measured and the simulated water content
in the soil could be a consequence of the difference between the meteorological data obtained
from a weather station located 3.5 km from the investigated location. Based on the chloride
tracer experiments on soil columns in the laboratory, the calibration of the solute transport
model was made. The best correlation of the measured and the simulated values of tracer
concentration is 0.43 for AC-IC and 0.74 for IIC/Gso horizon.
Based on the parameters of the water flow and the transport of potentially toxic elements, the
prognostic model was created at the investigation site. If the concentrations of potentially
toxic elements, obtained by the transport prognostic model at the bottom of the soil profile are
compared with the MAC limits ordinance for the same elements, it can be concluded that
there is a high risk of contamination at the investigative site. Sorption mechanisms have a
major impact on the transport of potentially toxic elements in the saturated zone. In case of an
accidental spill of potentially toxic elements with concentrations of 1000 mg/l, the risk of
contamination of the aquifer is high. This research of unsaturated zone at the Kosnica location
defined the water flow and the transport of potentially toxic elements’ parameters and
designed a model for the future research and accident mitigation
Admissible singular solutions to gas dynamics systems with non-positive pressure
Karakteristika hiperboličnih sistema zakona odrržanja je da čak i u slučaju glatkog po-četnog uslova rešenja uglavnom razvijaju prekide u konačnom vremena. Zbog toga se posmatraju slaba rešenja koja dati sistem zadovoljavaju u distributivnom smislu i mogu biti čak i neograničena što se ispoljava kroz pojavu Dirakove delta funkcije u rešenju. U ovoj disertaciji se akcenat stavlja na analizu protoka stišljivog neviskoznog fluida koji ne menja pravac prilikom kretanja. Protok je opisan Ojlerovim sistemom iz gasne dinamike koji se sastoji iz zakona održanja mase, količine kretanja i energije, dok su karakteristike fluida određene konstitutivnim relacijama. U slučaju izentropskog ili izotermnog protoka sistem se svodi na zakone održanja mase i količine kretanja. Glatka rešenja takvog sistema automatski zadovoljavaju zakon održanja energije, dok prelaskom na slabu formulaciju dolazi do gubitka energije. Za predstavnike sistema gasne dinamike sa nepozitivnim pritiskom su uzeti sistem gasne dinamike bez pritiska i model za Čapliginov gas i njegova uopštenja. Data su rešenja Rimanovih problema za te sisteme koja se mogu predstaviti kao kombinacija klasičnih elementarnih talasa i senka talasa koji aproksimiraju rešenja u obliku delta udarnih talasa i koji omogućavaju rešavanje početnog problema koji u početnom uslovu sadrži delta funkciju. Na primeru modela za uopšten Čapliginov gas dokazano je da uslov prekompresivnosti nije jači od entropijskog uslova, što je prvi takav rezultat u literaturi. Dalje su korišćena rešenja Rimanovih problema, kao i problema singularne interakcije i dat je algoritam za konstrukciju globalnog dopustivog približnog rešenja početnog problema za sistem gasne dinamike bez pritiska. Algoritam je univerzalan i ideja se može proširiti na veliki broj sistema zakona održanja i veliki broj početnih uslova. Diskutovane su promene energije u približnom rešenju i posle interakcija. Dobijeno približno rešenje slabo konvergira u prostoru Radonovih mera sa predznakom. A solutions to hyperbolic conservation laws systems starting out as smooth often develop singularities in a finite time. As a consequence, we are forced to look for weak solutions that satisfy the system in distributional sense. Those solutions are often unbounded, which is expressed through the appearance of Dirac delta function. In this theses we study a one-dimensional, compressible and inviscid flow of a fluid. The process is described by compressible Euler gas dynamics system which consists of conservation laws of mass, linear momentum and energy, while the characteristics of the fluid are described using constitutive relations. In the case of isentropic or isothermal flow the system reduces to conservation laws of mass and linear momentum. The energy is conserved for smooth solutions to such systems, but while passing to the weak formulation the energy is being dissipated. As representatives, we consider pressureless gas dynamics system, as well as Chaplygin gas model and its generalizations. We give the solutions to Riemann problems which can be represented as a combinations of classical elementary waves and shadow waves that approximate the solutions in the form of delta shock and allow as to solve the problems with initial data containing delta function. We use generalized Chaplygin gas model as demonstration of the fact that overcompressibility condition is not stronger that entropy condition, which is the first result of that kind in the literature. Further, we use solutions to the Riemann problems, as well as singular interaction problems to give the algorithm for construction of global admissible approximate solution to the pressureless gas dynamics initial value problem. The algorithm is universal and idea can be applied to large number of conservation laws systems and large number of initial data. We discuss energy changes in approximate solution and after the interactions. The constructed approximate solution converges in the space of signed Radon measures
Modelling knowledge for development and application of information-expert system
Rezime:
U ovoj doktorskoj disertaciji naslov dosta „govori“ o predmetu istraživanja i okviru očekivanog naučnog doprinosa. Prikazano je istraživanje trendova inoviranja znanja, posebno u infornacionim tehnologijama(IT), u cilju unapređenja kvaliteta integrisanih tehnologija i sistema i razvoja informaciono-ekspertnog sistema (IES). Ostvareni su osnovni ciljevi, od modeliranja izvora znanja(KS), preko ažuriranja baze znanja(KB) i sistema baze znanja (KBS), do rešavanja problrma u standardizovanim oblastima stvaralaštva (ICS). Baza znanja koja vodi kontinuiranom unapređenju procesa i proizvoda podrazumeva inoviranje znanja i njihovu stalnu sistematizaciju, kroz tačno definisane oblasti rada. Standardizacijom se upućuje na povezivanje znanja koje bi dovelo do uočavanja potencijalnih razlika i utvrđivanja mera za unapređenje proizvoda, procesa i usluga. Rezultati istraživanja su sagledani kroz 12 ključnih aspekata i prikazani u fazama PDCA (Plan-Do-Check-Act) koncepta:
1. (Plan) Uključujući polazne ciljeve izvršeno je planiranje resursa za unapređenje modela enanja i perioda uporednih analiza klasterizovanih oblasti stvaralaštva na platformi standardizacije. Informacione tehnologije (ICS1 = 35) su oblast sa najvećim intenzitetom inovativnosti;
2. (Do) Formiran je model za razvoj, unapređenje i primene IES u ICS oblastima, modeliranjem izvrsnosti u više dimenzija kroz 12 ključnih IT aspekata, posmatranih i dokazanih u PDCA konceptu, uz ostvarenje ciljeva:
2.1 (P) mogućnosti određivanja originalnih linija trenda, polazeći od izvora znanja, sa ciljem planiranja resursa za svakodnevno inoviranje znanja u pojedinim oblastima na platformi standardizacije;
2.2 (D) mogućnosti definisanja uporednih pokazatelja za sve oblasti stvaralaštva višekriterijumskom analizom, kako bi se ažurirale baze podataka i baze znanja u ICS1 oblastima, kroz omogućavanje realizacije praćenja trendova inoviranja znanja za unapređenjekvaliteta proizvoda;
2.3 (C) mogućnosti kvantitativnog definisanja indeksa inovativnosti, kao preduslova za formiranje klastera, odgovarajuće buduće pouzdane provere (enanja i trenda) u pojedinim oblastima i preferencijalno inoviranje baze znanja za korisnike;
2.4 (A) mogućnosti inoviranja enanja na platformi standardizacije, unapređenjem baze znanja uz obezbeđenje resursa i rešenje problema, realizcijom IES, odnosno modela izvrsnosti u praksi;
3. (Check) Realizacijom neophodnih pratećih aktivnosti istraživanja definisani su uporedni kriterijumi/ indeksi prvog nivoa klasifikacije oblasti stvaralaštva (ICS1 = 01, 03, ... do 99) – indeksi količine, indeksi vrednosti i indeksi inovativnosti, na osnovu kojih su određeni klasteri prema indeksu intenziteta inovativnosti;
4. (Act) Dokazana je potreba za dnevnim inoviranjem znanja kod studenata/ eksperata dvopredmetnih studija, pokazana na primeru master profesora tehnike i informatike na studijskom programu integrisanih akademskih studija Tehnika i informatika (IAS TI).Abstract:
The title of this doctoral dissertation speaks volumes about the subject of the research and the scientific contribution. The dissertation presents a study of trends in knowledge innovation, especially in Information Technology (IT) and it aims to improve the quality of integrated technologies and systems and the development of Information-Expert System (IES). The main objectives were achieved from modeling Knowledge Sources (KS), through updating the Knowledge Base (KB) and Knowledge Base System (KBS), to brief problem-solving in the standardized areas of creativity (ICS). The knowledge base, that leads to continuous improvement of processes and products, implies innovation of knowledge and its constant systematization through clearly defined areas of work. Standardisation refers to knowledge connecting which may contribute to better recogntion of potential differences and establishment of measures for improvement of products, processes and services.
The research results were analyzed and 12 key aspects were distinguished and presented in different stages of PDCA (Plan-Do-Check-Act) concept:
1. (Plan) Besides initial objectives, resource planning for improving knowledge model was carried out and the periods of comparative analysis of the clusterized areas of creativity on the standardization platform were estimated. Information technology (ICS1 = 35) presents the area with the greatest intensity of innovation;
2. (Do) Model for the development, improvement and application of IES was formed in the standardized fields of creativity by modeling excellence through several dimensions and 12 key aspects of IT, which were observed and proven in the PDCA concept. The objectives were achieved and the following should be provided:
2.1 (P) A possibility to determine the original trend line, starting from the source of knowledge, with the aim of resource planning for daily innovation of knowledge in certain areas on the standardization platform;
2.2 (D) A possibility to define comparative indicators for all areas of creativity using multi-criteria analysis, in order to update the database and knowledge base in ICS1 fields, by enabling the realization of monitoring trends in knowledge innovation for the improvement of product quality;
2.3 (C) A possibility to define a quantitative index of innovation intensity as a precondition for the formation of clusters, the appropriate and reliable future testing (of knowledge and trend) in certain areas and preferential innovation of knowledge base for users;
2.4 (A) A possibility to boost knowledge innovation on the standardization platform through the improvement of the knowledge base and the provision of resources and problem-solving, realization of IES or the model of excellence in practice;
3. (Check) Realizing the required accompanying research activities, the comparative criteria/indices for the first level of classification of fields of creativity (ICS1 = 01, 03, … to 99) were defined: quantity indices, indices and indices of innovation. The innovation intensity clusters were determined based on the index indicators and parameters;
4. (Act) The need for daily knowledge innovation for students/experts completing double-major undergraduate studies was evident and demonstrated on the example of Master students in Techniques and Informatics at the integrated study program of Techniques and informatics (IAS TI)
Transport model of potentially toxic elements through unsaturated zone at regional wellfield Kosnica : doctoral thesis
Predmet istraživanja ove doktorske disertacije je nesaturirana zona na području regionalnog
vodocrpilišta Kosnica. Ciljevi ovog doktorskog rada bili su: (i) identificirati dominantne
procese transporta u nesaturiranoj zoni; (ii) odrediti parametre toka vode i transporta
onečišćivala nesaturirane zone; (iii) odrediti geokemijsko ponašanje potencijalno toksičnih
elemenata u nesaturiranoj zoni; (iiii) izraditi prognozni model toka vode i transporta
potencijalno toksičnih elemenata (olovo, kadmij, cink) kroz nesaturiranu zonu. Temeljem
brojnih laboratorijskih analiza svojstava tla i eksperimenata definirani su parametri toka vode
(kapacitet tla za vodu, hidraulička vodljivost) i transporta onečišćivala (sorpcija, disperzija,
volumna gustoća, koncentracija potencijalno toksičnih elemenata). Brojnim kemijskim i
eksperimentalnim analizama uzoraka iz nesaturirane zone određeno je geokemijsko ponašanje
potencijalno toksičnih elemenata. Za primjenu numeričkih simulacija korišten je program
HYDRUS-1D. Kapacitet zadržavanja vode u tlu najveći je u A horizontu i iznosi ~45%. Na
temelju istraživanja hidrauličke vodljivosti utvrđene su najniže vrijednosti za A i IVGso/Gr
horizonte. Veće vrijednosti hidrauličke vodljivosti određene su u donjem dijelu profila u
kojima je zastupljena pjeskovito-šljunkovita i šljunkovita tekstura. U AC-IC horizontu je
određena manja vrijednost disperzivnosti koja iznosi 1 cm, dok je za horizont IIC/Gso
određena veća vrijednost i iznosi 1,7 cm. Utvrđene su male razlike u sorpciji između
pojedinih elemenata. Analizom otopina porušenih uzoraka dobivenih digestijom zlatotopkom
utvrđene su najveće koncentracije elemenata (Cd, Pb i Zn) u najplićem dijelu profila. Na
temelju dobivenih parametara toka vode i transporta potencijalno toksičnih elemenata kreiran
je prognozni model na istražnoj lokaciji. Ukoliko se usporede koncentracije potencijalno
toksičnih elemenata dobivene s prognoznim modelom transporta na dnu profila tla odnosno
na granici s otvorenim vodonosnikom s MDK granicama pravilnika za iste elemente onda se
može zaključiti da postoji velika opasnost od onečišćenja na istražnoj lokaciji. Mehanizmi
sorpcije imaju glavni utjecaj na transport elemenata u saturiranu zonu. Uslijed akcidentnih
situacija izlijevanja koncentracije potencijalno toksičnih elemenata od 1000 mg/l, rizik od
onečišćenja vodonosnika s time i regionalnoga vodocrpilišta Kosnica je visok. Ovim
istraživanjima nesaturirane zone na lokaciji Kosnica definirani su parametri toka i transporta
potencijalno toksičnih elemenata te je napravljen numerički model kao osnova za buduća
istraživanja akcidentnih situacija.The subject of this thesis is the unsaturated zone in the area of the regional water well
Kosnica. The objectives of this thesis were: (i) to identify dominant processes in the
unsaturated zone; (ii) to determine water flow and solute transport parameters in the
unsaturated zone (iii) to determine geochemical behaviour of potentially toxic elements in the
unsaturated zone; (iiii) to build prognostic water flow and the transport model of potentially
toxic elements (lead, cadmium, zinc) through the unsaturated zone.
The research was conducted in the area of the Kosnica water well, dominated by Fluvisol soil
type. In order to better understand the water flow and the transport of the potentially toxic
elements through an unsaturated zone detail field, laboratory analyses and experiments were
made. For numerical simulation HYDRUS-1D program was used. The program models the
water flow using Richard's equation. The transport of potentially toxic elements is described
using the advection and dispersion equation.
Based on the laboratory analyses of soil properties, the parameters of water flow and solute
transport are defined. The bulk density rises with depth while the water holding capacity is the
largest in the A horizon due to particle size distribution. Minimum values of hydraulic
conductivity were determined in the A and IVGso/Gr horizons. The experimental results of
the sorption processes were used for the determination of correlation coefficients for
individual elements. The order of decreasing correlation coefficients was: Pb> Zn> Cd. Small
differences in sorption were found between the individual elements. The soil column
dispersivity was 1 cm for AC-IC horizon, and 1.7 cm for horizon IIC/Gso.
The higher cation exchange capacity, determined in the top of the profile, indicates the
possibility of more pronounced sorption of elements in shallow horizons. The highest element
concentrations, extracted by aqua regia, were found in the A and AC-IC horizons (for Zn 70
mg/kg and for Pb 51 mg/kg). The lead concentration obtained using sequential extraction
analysis is mostly bound to the organic fraction, while zinc is mostly bound to the residual
fraction. Illitic material is the most common mineral phase in the fraction <2 μm and
correlates with the sorption of lead in top horizons (A and AC-IC).
Measured values of water content in the soil using TDR probes for the period from September
1, 2011 to October 31, 2012 were used for the water flow model calibration. The comparison
of water simulations’ results and the measured data was performed using the HYDRUS 1D
software. The simulated water content was less variable than the measured values.
Low correlation (~ 0.40) was revealed between the measured and the simulated values of the
water content. Such a low correlation between the measured and the simulated water content
in the soil could be a consequence of the difference between the meteorological data obtained
from a weather station located 3.5 km from the investigated location. Based on the chloride
tracer experiments on soil columns in the laboratory, the calibration of the solute transport
model was made. The best correlation of the measured and the simulated values of tracer
concentration is 0.43 for AC-IC and 0.74 for IIC/Gso horizon.
Based on the parameters of the water flow and the transport of potentially toxic elements, the
prognostic model was created at the investigation site. If the concentrations of potentially
toxic elements, obtained by the transport prognostic model at the bottom of the soil profile are
compared with the MAC limits ordinance for the same elements, it can be concluded that
there is a high risk of contamination at the investigative site. Sorption mechanisms have a
major impact on the transport of potentially toxic elements in the saturated zone. In case of an
accidental spill of potentially toxic elements with concentrations of 1000 mg/l, the risk of
contamination of the aquifer is high. This research of unsaturated zone at the Kosnica location
defined the water flow and the transport of potentially toxic elements’ parameters and
designed a model for the future research and accident mitigation
Procjena propusnosti aluvijalnog tla korištenjem varijacije sadržaja vlage
The use of unsaturated hydraulic conductivity can help to define soil permeability, i.e. can contribute to the estimation of water percolation through unsaturated zone. The goal of this paper was the estimation of soil permeability at the location of case study profile Kosnica, situated in the alluvial plain of the Zagreb aquifer, Croatia, based on the variation in soil water content. Zagreb aquifer represents the only source of potable water for inhabitants of the City of Zagreb and Zagreb County. The thickness of unsaturated zone of the Zagreb aquifer varies from 8 meters in NW part to 2 meters in SE part. The unsaturated hydraulic conductivity values were calculated according to the granulometric composition of soil horizons and with optimized soil parameters. Variation in unsaturated hydraulic conductivity showed that the upper part of the soil profile was generally permeable throughout the 2011/2012 hydrologic year. The unsaturated hydraulic conductivity calculated with optimized soil parameters gave the highest values, always greater than 1E-9 m/s. Even though the estimation of soil profile permeability would be more precise with measurements of water content and pressure head in each soil horizon, calculation performed in this manner can give the first insight in general estimation of the unsaturated hydraulic conductivity variability and related soil permeability.Korištenje nesaturirane hidrauličke vodljivosti može pomoći u definiranju propusnosti tla, odnosno procjeđivanju vode kroz nesaturiranu zonu. Cilj ovog rada je procjena propusnosti tla na lokaciji profila Kosnica, koji se nalazi u aluvijalnoj ravnici zagrebačkoga vodonosnika, Republika Hrvatska, na temelju varijacije sadržaja vlage u tlu. Zagrebački vodonosnik predstavlja jedini izvor pitke vode za stanovnike Grada Zagreba i dijela Zagrebačke županije. Debljina nesaturirane zone zagrebačkoga vodonosnika varira od 8 m u sjeverozapadnom dijelu, do 2 m u jugoistočnom dijelu. Vrijednosti nesaturirane hidrauličke vodljivosti izračunate su na temelju granulometrijskog sastava horizonata tla i na temelju optimiziranih parametara tla. Varijacija nesaturirane hidrauličke vodljivosti pokazala je da je gornji dio profila općenito propustan tijekom 2011./2012. hidrološke godine. Nesaturirane hidrauličke vodljivosti proračunate na temelju optimiziranih parametara tla generirale su najviše vrijednosti, uvijek veće od 1E–9 m/s. Iako bi procjena propusnosti profila tla bila preciznija kada bi postojala mjerenja sadržaja vlage i tlaka u svakom horizontu, ovakav način proračuna može dati prvi uvid u okvirne vrijednosti varijacije nesaturirane hidrauličke vodljivosti i povezane propusnosti
Morphological and functional aspects of cardiac adaptation to training and detraining in rats of different sexes
Uvod: Dok su mehanizmi odgovorni za blagotvorno dejstvo aerobnog treninga na
funkciju kardiovaskularnog sistema dobro poznati, uticaj prestanka treninga na
parametre srčane funkcije nisu dovoljno razjašnjeni. Osim toga, uloga oksidativnog
stresa u efektima koje na kardiovaskularni sistem ostavlja trening i prestanak
trenažnog procesa su takođe malo poznati. Na kraju, polne razlike u dobijenim
efektima su dodatna nepoznanica
Cilj: Studija je imala za cilj da utvrdi pojavu i brzinu reverzibilnosti srčane
adaptacije nakon prestanka aerobnog treninga, kao i da otkrije postojanje razlike
među polovima prilikom treninga/prestanka treninga. Uloga oksidacionog stresa u
dobijenim efektima je takođe ispitivana.
Metode: Wistar albino pacovi (ženke i mužjaci) su svrstani u sledeće grupe:
kontrolna, trening i dve detrening grupe. Trenažni proces je podrazumevao
programirani trening plivanja u sepcijalno konstruisanom bazenu za plivanje pacova.
Izolovana srca su perfundovana po Langendorff tehnici pri čemu su praćeni sledeći
kardiodinamski parametri: maksimalna i minimalna stopa razvoja pritiska u levoj
komori (dp/dt max, dp/dt min), sistolni i dijastolni pritisak u levoj komori (SLVP,
DLVP), frekvenca srca (HR) i koronarni protok (CF). U uzorcima krvi i koronarnog
venskog efluenta su određivani markeri oksidacionog stresa: indeks lipidne
peroksidacije meren u formi TBARS, azot monoksid u obliku nitrita - NO2
-
,
superoksid anjon radikal - O2
-
, vodonik peroksid - H2O2, superoksid dizmutaza –
SOD, katalata – CAT, redukovani glutation – GSH.
Rezultati: Ovim istraživanjem smo na modelu izolovanog srca pacova potvrdili
postojanje treningom izazvanih promena srčane funkcije. Prestanak treninga je bio
praćen gubitkom tih adaptacija, koji je bio brži kod mužjaka nego kod ženki.
Primenjeii tip treninga je uzrokovao pozitivne adaptacione promene
antioksidacionog zaštitnog sistema koje su se manifestovale povećanom enzimskom
aktivnošću. Nakon prekida treninga uočen je parcijalni gubitak ovih treningom
izazvanih adaptacija. Povećanje antioksidacionog kapaciteta se duže zadržalo kod
mužjakaIntroduction: While the mechanisms responsible for the beneficial effects of aerobic training on cardiovascular function are well known, the impact of training cessation on cardiac function parameters has not been sufficiently elucidated. In addition, the role of oxidative stress in the effects on the cardiovascular system that training and cessation of the training
process achieve, are also little known. In the end, the gender differences in the obtained
effects are additionally unknown
Objective: The study aimed to determine the occurrence and rate of reversibility of cardiac
adaptation after cessation of aerobic training, as well as to detect the existence of gender
differences during training / cessation of training. The role of oxidative stress in the obtained effects was also investigated.
Methods: Wistar albino rats (females and males) were classified into the following groups: control, training and two detraining groups. The training process involved programmed swimming training in a specially constructed rat swimming pool. Isolated hearts were
perfused according to the Langendorff technique, where the following cardiodynamic
parameters were monitored: maximum and minimum rate of left ventricular pressure
development (dp / dt max, dp / dt min), systolic and diastolic left ventricular pressure (SLVP, DLVP), heart frequency (HR) and coronary flow (CF). Markers of oxidative stress were determined in blood and coronary venous effluent samples: index of lipid peroxidation measured in the form of TBARS, nitric oxide in the form of nitrite - NO2 -, superoxide anion radical - O2-, hydrogen peroxide - H2O2, superoxide disatutase - SOD, catalase CAT, reduced
glutathione - GSH.
Results: In this study, we confirmed the existence of training - induced changes in cardiac
function in a model of an isolated rat heart. Cessation of training was followed by loss of
these adaptations, which was faster in males than in females. The application of this type of training caused positive adaptive changes in the antioxidant defense system, which were manifested by increased enzyme activity. After the interruption of training, a partial loss of these training-induced adaptations was observed. The increase in antioxidant capacity lasted longer in males
The relationship between the geochemical and mineralogical characteristics of Calcocambisol, colluvium and recent marine lake sediment of the narrow seashore intertidal zone: a case study from the Veliko Jezero (Mljet Island, Croatia)
is study investigates the mineral composition, particle size distribution and geochemical characteristics of Calcocambisol, colluvium and recent marine lake sediment in a narrow intertidal seashore zone of the Veliko Jezero on the Island of Mljet (Croatia). The obtained results show that the fractions of Calcocambisol/colluvium less than 2 mm and 2 µm display similar particle size distribution (PSD) curves compared to marine lake sediments containing larger particles in these fractions. The smallest fractions of the investigated materials that are less than 1 µm show identical PSD curves. The bulk and clay mineral composition of the marine lake sediment show that the non-carbonate fraction is derived from weathering of the surrounding soils and colluvium containing quartz, feldspars and phyllosilicates (illitic material, kaolinites, chlorite, and a mixed layer clay mineral, MLCM), as well as the authigenic formation of
early-diagenetic pyrite, while one part is related to the yield of material by aeolian deposition (amphibole). The observed difference between the phyllosilicate mineral phases in the clay fraction of the Calcocambisol/colluvium and the carbonate-free clay fraction of the marine lake sediment is related to 1) the presence of chlorite in the marine lake sediment and 2) the higher content of MLCM in the Calcocambisol/colluvium. The chlorite in the marine lake sediment was inherited from the Calcocambisol/colluvium as a result of soil erosion prior to its complete destabilization in the soil. High Chemical Index of Alteration (CIA) values in the Calcocambisol and colluvium clearly indicate their intense weathering. Based on the Sm/Nd and Ti/Al ratios, it can be concluded that the aluminosilicates in the Calcocambisol, colluvium and marine lake sediment are of the same provenance. The distribution of each analysed element among the sequential fractions is very similar in both the Calcocambisol and colluvium. The highest concentrations for most of trace elements in the Calcocambisol, colluvium and marine lake sediment was determined in their residual fraction. Mn, Co and Pb show a different partitioning between the Calcocambisol/colluvium and marine lake sediment, respectivel
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