Hydrogeological relationships on the north-eastern edge of the Zagreb aquifer : master’s thesis

Zadatak ovog diplomskog rada bio je detaljnije opisati hidrogeološke odnose na sjeveroistočnom rubu zagrebačkog vodonosnika. Na istraživanom području izvedena su četiri nova zdenca: IW-1, IW-2, PW-1 i PW-2. Krajem 2014. te početkom 2015. godine izvedena su pokusna crpljenja na spomenuta četiri zdenca. Na temelju rezultata pokusnih crpljenja određeni su hidrogeološki parametri vodonosnika i hidraulički parametri zdenaca. Za istraživano područje utvrđene su sljedeće prosječne vrijednosti hidrogeoloških parametara: transmisivnost T = 3,62x10-2 m2/s, koeficijent uskladištenja S = 3,71x10-5 i hidraulička vodljivost K = 4,47x10-3 m/s. Jednadžbe sniženja u zdencima glase: s = 20,504 Q + 93,501 Q2 (IW-2); s = 25,915 Q + 69,289 Q2 (IW-1); s = 18,803 Q + 462,74 Q2 (PW-1); s = 20,657 Q + 112,1 Q2 (PW-2). Kemijske analize uzoraka vode iz svih zdenaca ukazale su na povišene koncentracije željeza, odnosno u svim uzorcima koncentracija je premašila maksimalnu dozvoljenu koncentraciju (MDK) za pitku vodu. Pretpostavlja se da se radi o prirodno povišenom sadržaju željeza, svojstvenom vodonosnicima taloženim u reduktivnim uvjetima. Visoke koncentracije željeza te smještaj zdenaca na istraživanom području ukazuju da je zahvaćen drugi vodonosni sloj građen od dominantno jezersko–barskih naslaga.Abstract: The aim of this thesis was to provide a detailed description of the hydrogeological relationships on the north-eastern edge of the Zagreb aquifer. Four new wells were drilled in the investigated area: IW-1, IW-2, PW-1 and PW-2. Pumping tests on these four wells were performed at the end of 2014 and the beginning of 2015. Based on the results of the pumping tests, the hydrogeological parameters of the aquifer and the hydraulic parameters of wells were determined. The following average values of hydrogeological parameters were defined for the investigated area: transmissivity T = 3,62x10-2 m2/s, storage coefficient S = 3,71x10-5 and hydraulic conductivity K = 4,47x10-3 m/s. Drawdown equations in the wells are as follows: s = 20,504 Q + 93,501 Q2 (IW-2); s = 25,915 Q + 69,289 Q2 (IW-1); s = 18,803 Q + 462,74 Q2 (PW-1); s = 20,657 Q + 112,1 Q2 (PW-2). The chemical analyses of water samples from all wells have shown the elevated iron concentration, i.e. iron concentration exceeds the maximum permissible concentration (MPC) for drinking water in all samples. It is assumed that the elevated iron content is due to natural causes, which is typical for sediments deposited in reductive conditions. High iron concentration and the location of the wells in the investigated area indicate that these wells were drilled in the second aquifer, with the predominantly lacustrine–marshy deposits

Influence of Substrate and Screen Thread Count on Reproduction of Image Elements in Screen Printing

The printing plate and its characteristics in the conventional printing techniques have a significant impact on print quality and image appearance. In screen printing, a weave of screen mesh i.e. a number of threads per cm, is the most important characteristic of the printing plate, hence the most relevant factor which defines printing quality. Print quality itself is a complex term that includes desired colour reproduction and satisfactory reproduction of image elements. In this paper focus was centred upon the reproduction of text and basic image elements (lines and dot structure) when printing on non-absorbent and absorbent substrates with different screen thread counts. The image element analysis led to the conclusion that using mesh with higher thread count does not significantly improve the reproduction of image elements. However, it is a very important parameter for text reproduction since low thread count may result in poor readability

Colour Reproduction on Tablet Devices

With the advent of Internet and mobile devices client services and other print production are migrating more and more to online platforms. In a recent technology changeover it is obvious that there is growing number of printers as well need from the customers for the print service providers to expand their business to online and mobile platforms. With this technological transition there are some open questions regarding the possibilities of using the tablet devices for colour soft proofing and other colour related operations. As a display devices on a hardware level there are large similarities with the desktop display devices but the operating systems which are driving them are not yet colour smart. There have been some initial attempts to characterize the colour reproduction on this type of devices and find a possibility of using them not just for information content but also for colour managed content. In this study we have tested several tablets (Apple iPad2,Asus Transformer TF101, Samsung Galaxy Tab 1) with different display and OS technology and tested a software which is intended for colour managed viewing of the reproduction. We have measured the colour reproduction of the tablets with the digital version of the GretagMacbeth ColorChecker card and have calculated the colour differences between the colour chart data and the displayed data. We have calibrated the Ipad2 with the only existing colour management tool the Spyder Gallery and we have also tested the chart display with and without the colour correction of the software. We have found that there are differences in the colour reproduction of the display technologies and that the possibilities of a real colour managed workflow has yet to be resolved on the OS level of tablet and mobile device

Current utilization and hydrochemical characteristics of geothermal aquifers in the Bjelovar sub-depression

The Bjelovar sub-depression is situated in the north-western part of Croatia, on the southwestern margin of the Pannonian Basin System where favourable geothermal conditions exist. Thermal waters are used for recreation, balneotherapy, space heating, directly as sanitary water and electricity production. Geophysical, geological and borehole data were used to determine the types of geothermal reservoirs. In addition, several campaigns were conducted to sample geothermal waters from the Daruvar spa, Velika-1 and Krečaves locations for isotope (δ18Ο and δ2H) and physico- chemical (EC, T, pH, DO, Na+, K+, Mg2+, NH4+, Ca2+, SO42-, Cl-, Br-, F-, SiO2 and H2S) analyses to determine their hydrochemical characteristics. Two major types of geothermal reservoirs were determined: (i) ‘basement – BM’ reservoir, (ii) ‘basin fill – BF’ reservoir. The BM reservoir consists of Palaeozoic and Mesozoic sediments composed of: (i) fractured/karstified carbonate sediments and/or (ii) fractured/fissured crystalline/metamorphic rocks. The BF reservoirs are ‘Lower Pannonian’ and ‘Upper Pannonian’ sediments composed of coarse and fine-grained sand, sandstones and marls. The BM geothermal aquifers are the most important ones in the study area. The stable isotope δ2H and δ18O indicate that the monitored thermal waters have a meteoric origin, but without recent replenishment. Monitored waters belong to mixed hydrochemical types, from Na-ClHCO3 to Na-HCO3 types in the deep basin thermal waters and a CaMg-HCO3 type in the thermal waters from shallower parts. The study area has great geothermal potential. The estimated total available thermal power from Križevci, Velika-1 and the Daruvar spa is 70.5 MWt, but only 28 % of this thermal power is used. Since the predominant activity in the study area is agriculture, the geothermal resources available could lead to modern agricultural development and consequently contribute to increasing the standard of living of the local population. However, additional geophysical, geological, hydrogeological and hydrochemical investigations at a number of new potential locations are required to estimate the total available geothermal resources

Analiza hidrauličke veze potoka Plitvice i podzemnih voda varaždinskog aluvijalnog vodonosnika

A combination of different statistical methods and flow duration curves was used to examine hydraulic connection between the Plitvica stream and the surrounding piezometers that capture the groundwater of the Varaždin alluvial aquifer. Also, rainfall quantities over a wider study area were considered to examine the effect of precipitation on Plitvica water levels and groundwater levels. The following statistical methods were used in this paper: the correlation method, the auto- correlation method, and the cross-correlation method. Correlation analysis show that there is generally a significant correlation between the Plitvica water levels and groundwater levels, with positive direction of the correlation. The analysis of auto-correlograms for groundwater and surface water shows that the correlation coefficient value drops below 0.2 after a longer period, which indicates a long-term memory of the system that can be explained by the slow flow and thus slow pressure transfer. Cross-correlation analyses of the time series of the Plitvica water levels and groundwater levels showed a time lag of 1-2 days with a fairly significant cross-correlation coefficient. For precipitation and groundwater levels, the relationship is much weaker, with a lag time of 4-5 days with a weak cross- correlation coefficient. The least time lag, within a day, was established between precipitation and Plitvica water levels. Analyses of the flow duration curves revealed that Plitvica almost completely drains groundwater, except in the vicinity of the piezometer 2178 where Plitvica recharges the aquifer about a quarter of the time.Kombinacija različitih statističkih metoda i krivulja trajanja korištena je za ispitivanje hidrauličke veze potoka Plitvice i okolnih piezometra koji zahvaćaju podzemne vode varaždinskog aluvijalnog vodonosnika. Također, razmatrane su količine oborina sa šireg područja istraživanja kako bi se utvrdio utjecaj oborina na vodostaj Plitvice i razine podzemne vode. U radu su korištene sljedeće statističke metode: korelacija, auto-korelacija i kros-korelacija. Korelacijske analize pokazuju da generalno postoji značajna povezanost između vodostaja Plitvice i razina podzemnih voda, s pozitivnim smjerom korelacije. Analiza auto-korelograma za podzemne i površinske vode pokazuje da vrijednost koeficijenta korelacije pada ispod 0,2 nakon duljeg vremenskog razdoblja, što ukazuje na dugotrajnu memoriju sustava koja se može objasniti sporim tečenjem, odnosno sporim prijenosom tlaka. Kros-korelacijska analiza vremenskih nizova između vodostaja Plitvice i podzemnih voda pokazala je vremensko zaostajanje od 1–2 dana s prilično značajnim koeficijentom korelacije. Između oborina i podzemnih voda veza je mnogo slabija, s vremenskim zaostajanjem od 4–5 dana te slabim koeficijentom korelacije. Najmanje zaostajanje, unutar jednog dana, utvrđeno je između oborina i vodostaja Plitvice. Analizama krivulja trajanja utvrđeno je da Plitvica gotovo u potpunosti drenira podzemne vode, izuzev piezometra 2178 u blizini kojega oko četvrtinu vremena prihranjuje vodonosnik

Differential Diagnostic Performance of Rose Bengal Score Test in Sjøgren’s Syndrome Patients

Aim of the study was to evaluate the diagnostic performance of the Rose Bengal score test for Sjøgren’s syndrome (SS), and to explore differences between other tests and examinations. All participants were examined, including (but not limited to) unstimulated (UWS) and stimulated (SWS) whole saliva, labial gland biopsy (LGB or focus score), ophthalmologic questionnaire (ocular surface disease index OSDI) and objective tests: Schirmer test 1 (Sch.1), Schirmer test 2 (Sch.2), Tear Break-up Time (TBUT) test and Rose Bengal score (RBS). Data were analyzed using Mann Whitney U-test, Receiver Operating Characteristic analysis, with specificity and sensitivity calculations and Spearman’s correlation test. ROC curves showed a poor diagnostic performance of TBUT and OSDI. Sch.1, Sch.2 and LGB all exhibited a high diagnostic performance. RBS exhibited the best performance (sensitivity 100,00; specificity 100,00; AUC 1,000). Study reveals the scarce reliability of TBUT, OSDI and Sch.1, and emphasizes RBS as the test of choice in the SS diagnosis

Data on stable isotopic composition of δ18O and δ15N in nitrate in groundwater, and δ15N in solid matter in the Varaždin area, NW Croatia

The Varaždin aquifer is the only source of drinking water for inhabitants of the Varaždin County. In the last decades, groundwater contamination with nitrate has become an increasing problem. Therefore, there is a need to define the origin of nitrate as the first step in groundwater remediation. The data in this article consist of δ18O and δ15N values in nitrate in groundwater, and δ15N in solid matter. Groundwater was sampled in the period from April 2018 to December 2019 at 10 different sites by pumping the wells, and directly in the gravel pit in Šijanec. Representative solid samples of plants, soil, manure, and synthetic fertilizers were collected from arable land in two field campaigns (July and October 2019). The presented dataset can be used as a baseline for identification of nitrate sources in groundwater and possible nitrate attenuation processes. The data is related to the research article “Tracking the nitrogen cycle in a vulnerable alluvial system using a multi proxy approach: case study Varaždin alluvial aquifer, Croatia.” [1]