Engineering Challenges in Karst

Anisotropy and heterogeneity of karstified rocks make them the most problematic media for various interventions which are needed in engineering practice. The long history of attempts to adapt karstic nature to human needs started with the utilization of karstic aquifers: tapping large springs, transferring their waters to the long distances, improving minimal flows or capturing fresh water in coastal areas. During the 20th century the number of other challenges such as building dam and reservoirs, and constructing roads and railways, bridges, tunnels, new settlements open a new era in engineering works but also in collecting new knowledge and experience for the karstology and hydrogeology sciences. Today, almost no engineering projects can be implemented without a proper environmental impact assessment, which establishes a better balance between human and ecological needs.Inženirski izzivi v KrasuAnizotropija in heterogenost zakraselih kamnin sta lastnosti, ki povzročata, da so te najbolj problematičen medij za različne posege, ki so potrebni v inženirski praksi. Dolga zgodovina poskusov, da bi prilagodili kraško naravo človekovim potrebam se je začela z izrabo kraških vodonosnikov: izkoriščanje velikih izvirov, prenos vode na dolge razdalje, poviševanje minimalnih pretokov ali zajemanje vode na obalnih območjih. V 20. stoletju je število drugih izzivov, kot so gradnja jezov in rezervoarjev, cest in železnic, mostov, predorov, novih naselij odprla novo obdobje v inženirstvu. Poleg tega je botrovala zbiranju novih krasoslovnih in hidrogeoloških znanj in izkušenj. Danes skoraj noben inženirski projekt ne more biti izveden brez ustrezne presoje vplivov na okolje, kar vzpostavlja boljše ravnotežje med človekovimi in ekološkimi potrebami

Supportive methods for assessing effective porosity and regulating karst aquifers

Regulation of a karst aquifer implies engineering interventions designed to control its flow and manage its water reserves. One of the most important prerequisites for the feasibility and suc­cess of regulation projects is proper assessment of aquifer ef­fective porosity (storativity) and accumulated groundwater reserves. This paper is focused on several specific methods whichcan contribute to a reliable assessment of the size and volume of effective storage in karst: cave diving survey, camera logging of cavities, stochastic analysis of discharge regime and 3D modelling of karst interior. The application of these meth­ods on selected test sites in Montenegro, Algeria and Serbia are described. These methods were applied as part of the researchprogramme conducted in the catchment of Mlava Spring, the largest spring in the Carpathian karst of Serbia. The results ob­tained by the stochastic analyses of the spring’s discharge re­gime, as well as siphon diving of the spring and 3D modelling for reconstruction of conduits networks in karst interior are particularly important

Five minutes with Zoran Milanović, Prime Minister of Croatia: “A referendum against minority rights is not going to happen – we shall oppose it by all legal means”

Croatia joined the European Union in July 2013, becoming the 28th member state. Following the referendum on EU membership, however, a number of other referendums have been initiated by grassroots movements under the country’s Referendum Law, including an amendment to the Croatian constitution banning same-sex marriage (which passed in December 2013), and a referendum against the official use of Cyrillic script. In an interview with EUROPP’s Managing Editor Stuart Brown and LSEE’s Tena Prelec, Croatian Prime Minister Zoran Milanović discusses Croatia’s policy on EU reform, how the country has strengthened the rights of same-sex couples, and why his government will ensure the referendum on Cyrillic script will not take place

Usporedba kapaciteta anaerobne izdržljivosti vrhunskih nogometaša, rukometaša i košarkaša

The aim of the study was to determine whether there was a difference in anaerobic endurance between soccer, handball and basketball players. One hundred fifty players (mean age: 22.35±4.31 years), 50 from each sport (mean age: soccer, handball and basketball players 23.54±4.19, 20.42±4.48, 23.10±3.63 years, respectively), were members of the highest level of their sport in Croatia; some were members of respective national teams. Participants undertook a 300 yard shuttle run test (300Y) and a maximal blood lactate test (BL). Results showed that there were significant differences in both 300Y and BL scores between the soccer, handball and basketball players. Basketball players (57.04±3.41s) achieved the best results in the 300Y test, followed by soccer (57.06±2.27s) and then handball players (59.53±2.65snl). Post-hoc tests indicated that the soccer players (14.70±2.07) had significantly (p< .05) higher maximal lactate values (BL) than the handball players (13.70±1.83). It is not possible to say that these three sports require equal levels of anaerobic endurance, but it is certainly an important component of performance in each and every one of them. We have concluded that the required anaerobic abilities are different, in all the three investigated sports, which means that the sport-specific demands could influence athletes anaerobic capacity.Cilj istraživanja bio je utvrditi postoji li razlika u anaerobnoj izdržljivosti između nogometaša, rukometaša i košarkaša. Stotinu i pedeset igrača (srednja dob: 22,35±4,31 godina ), po 50 iz svakog sporta (srednja dob nogometaša 23,54±4,19, rukometaša 20,42±4,48 i košarkaša 23,10±3,63 godina), najkvalitetniji su u svom sportu u Hrvatskoj, a neki su bili članovi nacionalnih izabranih vrsta. Sudionici su izveli test 300 yard shuttle run (300Y) i izmjerene su im maksimalne vrijednosti laktata u krvi (BL). Rezultati su pokazali da postoje značajne razlike u rezultatima oba testa (300Y i BL) između nogometaša, rukometaša i košarkaša. Košarkaši (57,04±3,41s) su ostvarili najbolje rezultate u testu 300Y, nakon čega slijede nogometaši (57,06±2,27s), a zatim rukometaši (59,53±2,.65s). Post-hoc testovi pokazali su da su nogometaši (14,70±2,07) imali značajno (p<0,05) veće maksimalne vrijednosti laktata (BL) od rukometaša (13,70±1,83). Ne može se reći da ta tri sporta zahtijevaju jednake razine anaerobne izdržljivosti, ali je ona svakako važna komponenta uspješnosti u svakom od sportova. Zaključili smo da su potrebne anaerobne sposobnosti različite u sva tri istraživana sporta, što znači da zahtjevi specifičnog sporta mogu utjecati na anaerobni kapacitet sportaša

Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C) (soil water regime in pots was maintained at the level of field water capacity) and treated (water-stressed, WS) (soil water regime was maintained in the range of wilting point and lentocapillary capacity). The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively), which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively). Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½). Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering

Improved Method for Calibration and Nonlinearity Correction of Microwave Power Sensor

Power sensor nonlinearity contributes significantly to the increase of the microwave power measurement uncertainty. Current methods for sensor calibration do not provide correction of the results, due to the sensor nonlinearity. The paper describes an improved method and an automated measuring system based on it for power sensor calibration that enables the correction of the results, taking into account amplitude and frequency dependent nonlinearity. The novel calibration method is based on the application of high-linearity thermistor power transfer standard. The power sensor calibration process is fully automated and improved by applying the automated measuring system, PC and VEEpro software. Performed calculation of the calibration measurement uncertainty and the analysis of power measurement uncertainty budget indicate that the new calibration method allows the correction of sensor nonlinearity and contributes to significant reduction of the microwave power measurement uncertainty, ranging from 15,8% to 40,5%. Experimental results and validation confirm the applicability of the improved calibration method and prove the existence of significant dependence of sensor nonlinearity on the power level, but also on the frequency of the measured microwave power

Informaciono-bezbednosna kultura - imperativ savremenog društva

The importance of building information-security culture of each society has become a well-established idea. The aim of such a culture is the impact on different human behaviors that may affect the overall results of protection of information assets. The authors believe that culture is the 'key' of the information security. Extensive review and analysis of the information security literature have come to the conclusion that the collective consciousness about the use and protection in the field of contemporary forms of crime is very low. In this sense, the goal of this paper is that the examination of information security culture from the standpoint of best practices, support the view that knowledge and education play an important role in building a secure environment with a special emphasis on raising awareness of end-users about the need and importance of data protection, information and knowledge.Značaj izgradnje informaciono-bezbednosne kulture svakog društva postala je dobro utemeljena ideja. Cilj takve kulture je uticaj na različita ljudska ponašanja koja se mogu odraziti na ukupne rezultate zaštite informacione imovine. Autori rada smatraju da je kultura 'ključ' informacione bezbednosti. Obimnim pregledom i analizom literature o informacionoj bezbednosti došlo se do zaključka da je kolektivna svest o upotrebi informacionih tehnologija i zaštiti u domenu savremenih oblika kriminaliteta na veoma niskom nivou. U tom smislu, cilj rada je da se, razmatranjem informaciono- bezbednosne kulture sa stanovišta najbolje prakse, podrži stav da znanje i obrazovanje igraju važnu ulogu u izgradnji bezbednog ambijenta sa posebnim akcentom na podizanju svesti krajnjih korisnika o potrebi i važnosti zaštite podataka, informacija i znanja

Digitalna forenzika u kontekstu zaštite informacionih sistema

Although a lot has been said and written about the protection of information systems and users of the Internet, only a small number of managers and users of information technologies are aware of the significance of this problem. This can lead to occurrence of risky situations in which business information systems may be threatened. Their inadequate protection may have disastrous effects on the business process itself. The purpose of the paper is to clearly and transparently establish relations between methods and techniques of information system protection and digital forensic investigation, as well as to raise the security awareness and promote security culture as essential elements of the cycle of risk management and protection.Iako se o zaštiti informacionih sistema i korisnika interneta često govori i piše, mali broj menadžera i korisnika informacionih tehnologija su svesni značaja ovog problema. To može dovesti do pojave rizičnih incidentnih situacija u kojima su ugroženi poslovni informacioni sistemi. Njihova neadekvatna zaštita može imati katastrofalne posledice na sam poslovni proces. Cilj rada je da se na jasan i transparentan način uspostave i dovedu u vezu metode i tehnike zaštite informacionih sistema sa digitalnom forenzičkom istragom, kao i da se skrene pažnja na bezbednosnu svest i kulturu kao esencijalne elemente ciklusa upravljanja rizikom i zaštitom

Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C) (soil water regime in pots was maintained at the level of field water capacity) and treated (water-stressed, WS) (soil water regime was maintained in the range of wilting point and lentocapillary capacity). The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively), which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively). Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½). Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.U radu je analizirana fotosintetička efikasnost sadnica Quercus robur, izloženih kratkotrajnom vodnom stresu u laboratorijskim uslovima, metodom indukovane fluorimetrije. Kao supstrat za gajenje sadnica korišćena je glinovita ilovača, čiju je dominantnu teksturnu frakciju činio prah, zatim glina pa sitan pesak; totalne poroznosti 68,2%. Sadnice su bile podeljene u dve grupe: S (kontrolna grupa, kod kojih je vodni režim supstrata u saksijama održavan na nivou poljskog vodnog kapaciteta) i WS (grupa izložena vodnom stresu, kod kojih je vodni režim supstrata održavan između tačke venjenja i lentokapilarnog kapaciteta). Fotosintetička efikasnost iznosila je 0,642±0,258 kod kontrolnih sadnica, odnosno 0,522±0,0243 kod izloženih vodnom stresu, što je uglavnom bilo uzrokovano poremećajima izazvanim presađivanjem kao i pojavi hloroze na listovima. Tokom eksperimenta, vrednost Fv/Fm se smanjila u obe grupe sadnica (0,551±0,0100 kod C, odnosno 0,427±0,018 kod WS). U oba merenja utvrđene su statistički značajne razlike između stresirane i kontrolne grupe sadnica u pogledu ispitivanih parametara. Izlaganje sadnica hrasta lužnjaka kratkotrajnom vodnom stresu imalo je značajan uticaj na smanjenje fotosintetičke efikasnosti sadnica, ali u manjoj meri nego izlaganje sadnica obilnom zalivanju.Projekat ministarstva br. TD2005