Determining Free-Flow Speed on Different Classes of Rural Two-Lane Highways

Current analytical free-flow speed models consider all rural two-lane highways as the same road type despite their different functional significance in the network. The aim of this paper is to develop a prediction model for free-flow speed as a function of speed limit and road geometric characteristics for different classes of rural two-lane highways. The research was conducted on 50 representative sections of the two rural classes of two-lane highways equipped with automatic traffic counters in Serbia. In order to develop the appropriate models, it was necessary to determine the threshold values of vehicle time headway in the free-flow for both classes of rural two-lane highways, based on the total number of 191,720 vehicles. The obtained results show that there are differences in the threshold values of free-flow time headway for different road classes. Namely, it was determined that the values of free-flow time headway for Class I amounted to 6.3 s, and for Class II to 8.4 s. The free-flow speed prediction model for different road classes showed that speed limit had the highest impact on free-flow speed for Class I and II highways, followed by horizontal curve radius and shoulder width

Cruise Port Passenger Flow Analysis: a Cruise Port Governance Perspective

Cruise tourism as one of the most dynamic and fastest growing segments of tourism industry is shaping tourism activities. The growth rate of global cruise tourism has constantly increased over the last years and the number of cruise passengers is expected to grow worldwide. Cruising as form of leisure tourism is the most expressed in the Caribbean, followed by the Mediterranean as cruising region with increasing cruise passenger rates. The demand for cruise tourism continues to grow and cruise ports will continue to develop an interest in advancing their cruise activities. The paper elaborates on the pattern of cruise port industry with regard to cruise port model of operation governance, two basic types of port operation, namely ports without private entry in port operation and ports with private entry in port operation. Research sample are cruise ports in the Mediterranean and adjoining seas. The main indicators of passenger flows are analysed and the intensity, structure and dynamics is identified. Descriptive statistics is used to describe the basic features of the data in the study together with summaries about the sample and the measures. Along with graphics analysis, quantitative analysis of data is performed. Port governance including private entry, especially port operators, is seen as key response to global cruise industry growth, having advantage over public port governance in diverse fields of port operation. Research results indicate that cruise ports with private entry in port operation are not geographically concentrated. Cruise ports with private entry in port operation are dominating the market, but cruise ports without private entry are catching up as their growth rate is higher. At the same time cruise ports with private entry in port operation are turning to bigger sized cruise ships increasing overall efficiency per call. Findings contribute to cruising tourism theory and practice. In practical terms the contribution of this paper is the understanding of current market position of cruise ports with regard to their model of port governance, more precisely the position of ports with private entry in cruise port operation versus cruise ports without private entry in cruise port operation

Role of destination management in strengthening the competitiveness of Croatian tourism

Tourism today is marked by various social-economic trends. Croatia as a tourist destination is present on the networked international tourism market, which imposes daily adjustments to varying conditions on the market, primarily through improvement of the competitiveness of its own tourism offer. An important precondition for forming such an offer is an effective system for managing a tourist destination or destination management. With its accession to the European Union, Croatia has become a part of the European tourist market, which is a boost for tourism but also challenging, as it needs to stay true to its identity and maintain its uniqueness. Due to Croatia’s new macroenvironment, conditions and rapidly changing consumer requirements on the global tourism market, as well as global economic and political instability, which has not left the European Union unscathed, strategic operational planning and clear guidance for the future development of tourism in Croatia are essential. Thus, the goal of this paper is to emphasize the importance and functionality of destination management for the development of competitiveness of Croatian tourism, with emphasis on strategic managing of its development and review the challenges and adaptations to the conditions on the European tourism market

Green infrastructure planning for climate smart and "green" cities

The aim of the paper is to present green infrastructure planning within the concept of climate-smart cities. In this context the use of Geographic Information Systems (GIS), as part of green infrastructure planning, is stressed in the establishment of climate-smart cities. In addition to presenting international examples of good practice, such as using GIS data, maps and tools for support in the USA, or designing a tool for water management and water infrastructure planning in Chicago, the paper provides an insight into the current status of green infrastructure planning in Serbia. The "Green regulation of Belgrade" project is presented as a representative example. The conclusions emphasise that the main preconditions for achieving climate-smart and green cities include legal and planning frameworks, as well as appropriate strategic and other programs that will further encourage the creation of GIS for green areas and create the conditions for climate-smart green infrastructure planning

Role of destination management in strengthening the competitiveness of Croatian tourism

Tourism today is marked by various social-economic trends. Croatia as a tourist destination is present on the networked international tourism market, which imposes daily adjustments to varying conditions on the market, primarily through improvement of the competitiveness of its own tourism offer. An important precondition for forming such an offer is an effective system for managing a tourist destination or destination management. With its accession to the European Union, Croatia has become a part of the European tourist market, which is a boost for tourism but also challenging, as it needs to stay true to its identity and maintain its uniqueness. Due to Croatia’s new macroenvironment, conditions and rapidly changing consumer requirements on the global tourism market, as well as global economic and political instability, which has not left the European Union unscathed, strategic operational planning and clear guidance for the future development of tourism in Croatia are essential. Thus, the goal of this paper is to emphasize the importance and functionality of destination management for the development of competitiveness of Croatian tourism, with emphasis on strategic managing of its development and review the challenges and adaptations to the conditions on the European tourism market

Effect of ozone, ozone/hydrogen peroxide and hypoclorite on natural organic matter and oxidation by-products content in water after coagulation, floculation and adsorption procesess

Cilj ovog rada je bio da se ispita uticaj ozona i ozon/vodonik-peroksida na efikasnost uklanjanja POM i prekursora oksidacionih nusproizvoda, procesima koagulacije, flokulacije i adsorpcije. Posebna pažnja posvećena je ispitivanju uticaja navedenih procesa na sadržaj prekursora oksidacionih nusproizvoda hlora (trihalometana i halosirćetnih kiselina), kao i na uticaj hipohlorita na formiranje ovih jedinjenja u tretiranoj vodi. Analiza hemijskih karakteristika sirove podzemne vode korišćene u ispitivanjima pokazuje da sadrži visok nivo POM pretežno hidrofobnog karaktera (PB = 37,7±0,60 mg KMnO4/l; DOC = 9,27±0,92 mg C/l; UV254 = 0,497± 0,015 cm-1; SUVA = 5,36±0,49 1 mg-1 m-1; PFTHM = 555±128 µg/l; PFHAA = 245±54,9 µg/l), kao i visoku koncentraciju arsena (51,7±16,4 µg/l). Poređenjem uticaja dve ispitivane vrste koagulanata (FeCl3 i FeCl3/PACl) utvrđeno je da imaju različite mehanizme uklanjanja POM i prekursora oksidacionih nusproizvoda. FeCl3/PACl omogućava smanjenje sadržaja POM izraženih preko vrednosti DOC, PB, UV254 apsorbancije i SUVA za 54%, 71%, 88% i 74%, u odnosu na sirovu vodu respektivno, dok se koagulacijom sa FeCl3 postiže smanjenje DOC, PB, UV254 apsorbancije i SUVA za 51%, 48%, 61% i 21%, respektivno. U vodi nakon koagulacije sa FeCl3 zaostaju POM hidrofobnog karaktera (SUVA = 5,12 l m-1 mg-1), dok se POM u koagulisanoj vodi sa FeCl3/PACl, mogu okarakterisati kao hidrofilne (SUVA = 1,70 l m-1 mg-1). Koagulacija sa FeCl3 i FeCl3/PACl omogućila je smanjenje sadržaja arsena u vodi za preko 95%, pri čemu su koncentracije As u koagulisanoj vodi bile niže od 10 µg/l. Ozon i O3/H2O2 proces pokazuju sličnu efikasnost u smanjenju sadržaja POM i prekursora oksidacionih nusproizvoda. Poređenjem kombinovanih tretmana koji obuhvataju oksidacioni predtretman i koagulaciju, utvrđeno je da efikasnost koagulacije sa FeCl3 i FeCl3/PACl u smanjenju vrednosti DOC, PB, UV254, SUVA, PFTHM i aldehida, uglavnom zavisi od mehanizma delovanja samih koagulanata, dok ozon i O3/H2O2 proces doprinose smanjenju vrednosti ovih parametara kroz oksidaciju i izdvajanje lako isparljivih komponenti iz vode stripingom gasa. Sa aspekta promene sadržaja prekursora HAA, ozon i O3/H2O2 proces omogućavaju povećanje efikasnosti procesa koagulacije sa FeCl3 i FeCl3/PACl, u odnosu na koagulaciju bez oksidacionog predtretmana. Kada se uzmu u obzir vrednosti svih navedenih parametara, kao i primenjenje doze oksidacionih sredstava i koagulanata, najbolji rezultati u uklanjanju POM i prekursora oksidacionih nusproizvoda (smanjenje vrednosti DOC za 55%, UV254 i SUVA za više od 90%, u odnosu na sirovu vodu; PB = 7,70 mg KMnO4/l;  PFTHM =158-188 µg/l; PFHAA = 33,0-53,8 µg/l i sadržaj aldehida 16,7-17,9 µg/l) postižu se primenom tretmana koji obuhvataju oksidacioni predtretman ozonom (3,0 g O3/m3), odnosno O3/H2O2  (3,3 g O3/m3; H2O2:O3 =1:1), koagulaciju (30 g FeCl3/m3 / 30 g Al/m3) uz recirkulaciju flokulacionog mulja i adsorpciju na zeolitu, flokulaciju, sedimentaciju i filtraciju na peščano/antracitnom filtru. Za završnu obradu vode GAU filtracijom pre procesa dezinfekcije, na osnovu svih ispitivanih parametara, kao najefikasniji u uklanjanju POM i prekursora oksidacionih nusproizvoda (THM, HAA i aldehida) pokazao se GAU Norit Row 0,8 Supra. Hlorisanjem u simuliranim uslovima dezinfekcije, utvrđeno je da voda dobijena nakon GAU filtracije u ispitivanim tretmanima, ima zadovoljavajući kvalitet sa aspekta sadržaja THM i HAA (sadržaj THM je 69,7-77,4 µg/l; koncentracija DCAA je < MDL) čije su maksimalno dozvoljene koncentracije regulisane u vodi za piće (100 µg/l za THM i 50 µg/l za DCAA). Statističkom obradom podataka iz laboratorijskih i pilot ispitivanja utvrđene su empirijske zavisnosti koje se mogu primenjivati za predviđanje koncentracije THM i HAA u tretiranoj vodi nakon tretmana ispitivanih na pilot postrojenju. Da bi se mogle primeniti za druge vrste vode i drugačije dizajnirane tetmane, neophodno je izvršiti validaciju primenom nezavisnog seta podataka.         Svi rezultati dobijeni u toku istraživanja ukazuju na neophodnost primene oksidacionih sredstava u tretmanu ispitivane podzemne vode. Zbog različitog mehanizma delovanja, neophodno je izvršiti odabir odgovarajuće vrste i doze oksidacionog sredstva, kao i koagulanta u tretmanu vode za piće, uzimajući u obzir karakteristika sirove vode i efikasnost koja se želi postići. Primena optimalnih doza ozona i O3/H2O2 omogućava povećanje efikasnosti uklanjanja POM i prekursora oksidacionih nusporizvoda, procesima koagulacije, flokulacije i adsorpcije. Odabirom odgovarajućih uslova tretmana postiže se da i nakon hlorisanja u postupku dezinfekcije, voda zadovoljava kriterijume kvaliteta vode za piće, sa aspekta sadržaja trihalometana i halosirćetnih kiselina.The aim of this work was to investigate influence of ozone and ozone/hydrogen peroxide on efficiency of coagulation, flocculation and adsorption on natural organic matter and oxidation by-products removal. Special attention was dedicated to investigation of these processes on chlorine oxidation by-products (trihalomethanes and haloacetic acids) as well as on hypochlorite influence on formation of these compounds in treated water. The analysis of chemical characteristics of raw ground water used in this investigation show that it contains high amount of NOM, mainly of hydrophobic nature (PB = 37,7±0,60 mg KMnO4/l; DOC = 9,27±0,92 mg C/l; UV254 = 0,497± 0,015 cm-1; SUVA = 5,36±0,49 1 mg-1 m-1; PFTHM = 555±128 μg/l; PFHAA = 245±54,9 μg/l) as well as high arsenic concentration (51,7±16,4 μg/l). Comparing the influences of two investigated coagulants (FeCl3 and FeCl3/PACl) it was observed that they have different mechanisms of NOM and oxidation by-products precursors’ removal. FeCl3/PACl enables reduction of DOC, PB, UV254 absorbance and SUVA value for 54%, 71%, 88% i 74%, respectively, relative to raw water. Coagulation with FeCl3 provides reduction of DOC, PB, UV254 absorbance and SUVA for 51%, 48%, 61% i 21%, respectively. In water coagulated with FeCl3 remains NOM of hydrophobic nature (SUVA = 5,12 l m-1 mg-1) while NOM in coagulated water with FeCl3/PACl can be characterized as hydrophilic (SUVA = 1,70 l m-1 mg-1). Coagulation with FeCl3 and FeCl3/PACl enables arsenic content reduction for over 95% relative to raw water, with As concentrations in coagulated water below of 10 μg/l. Ozone and O3/H2O2 process demonstrates similar efficiency in NOM and oxidation by-products precursors content reduction. Comparing combined treatment which includes oxidation pretreatment and coagulation, it was observed that efficiency of coagulation in DOC, PB, UV254, SUVA, PFTHM and aldehydes reduction mainly depends on coagulants activity mechanisms, while ozone and O3/H2O2 process contributes to reduction of these parameters through oxidation and removal of volatile compounds from water by gas stripping. Ozone and O3/H2O2 process enables increase of coagulation efficiency for HAA precursor’s removal, comparing to coagulation without oxidation pretreatment. Taking into account all measured parameters as well as applied doses of oxidation reagents and coagulants, it can be concluded that the best results in NOM and oxidation by-products precursors content reduction (decrease of DOC for 55%, UV254 i SUVA for more then 90%, related to raw water; PB = 7,70 mg KMnO4/l; PFTHM =158-188 μg/l; PFHAA = 33,0-53,8 μg/l and content of aldehydes 16,7-17,9 μg/l) can be obtained by treatments which include oxidation pretreatment with ozone (3,0 g O3/m3), as well as with O3/H2O2 (3,3 g O3/m3; H2O2:O3 =1:1), coagulation (30 g FeCl3/m3 / 30 g Al/m3), with flocculation sludge recirculation and zeolit adsorption, flocculation, sedimentation and filtration on sand/anthracite filter. For the final water treatment with GAC filtration before disinfection process, based on all parameters, GAC Norit Row 0,8 Supra was the most efficient in NOM and oxidation by-products precursors reduction (THM, HAA and aldehydes). After chlorination in simulated disinfection conditions, it was determined that water after GAC filtration in investigated treatments has satisfactory quality in terms of regulated THM and HAA (content of THM is 69,7-77,4 μg/l; concentration of DCAA is < MDL) which maximal allowable level for drinking water is established (100 μg/l for THM and 50 μg/l for DCAA). By statistical analysis of data obtained in laboratory and pilot scale experiments it was determined empirical relations for THM and HAA concentration predictions in treated water. All obtained results in this research indicate that oxidation reagents need to be applied in treatment of investigated ground water. Because of different action mechanism, it is necessary to select the adequate type and dose of oxidation reagent and coagulant in water treatment, taking into account characteristics of raw water and efficiency that needs to be achieved. Application of optimal doses of ozone and O3/H2O2 enables increase of coagulation, flocculation and adsorption efficiency in NOM and oxidation by-products precursors’ removal. Selection of adequate treatment conditions provides that after chlorination in disinfection process water satisfies drinking water quality criteria, in terms of trihalomethanes and haloacetic acids

The Story of Judita in the Works of Croatian Authors

U radu je riječ o dopreporodnim obradama biblijske priče o Juditi: Judita Marka Marulića, anonimno pučko prikazanje Komedija od Juditi, Početaka tragedije imenovane Judit Ignjata Đurđevića, Oslobođenja Betulije Antuna Gleđevića, anonimna drama Judit victrix Holofernis, Tragedija od Judite Ive Roše iz Vrbnika. Utvrdit će se sličnosti i razlike između biblijskog predloška i hrvatskih interpretacija priče o Juditi te sličnosti i razlike između interpretacijâ na tematskoj i motivskoj razini

Influence of medium and temperature on the corrosion behavior and microstructure of copper and brass

U ovom je radu elektrokemijskim mjerenjima ispitana korozijska otpornost bakra i mesinga u vodovodnoj vodi i 3,5 % otopini NaCl pri sobnoj temperaturi i pri 60 °C. Promjene na površini uzoraka praćene su svjetlosnim i pretražnim elektronskim mikroskopom. Rezultati ispitivanja pokazali su da korozijska otpornost i za bakar i za mesing opada porastom temperature i u vodi i u 3,5 % otopini NaCl. Veću brzinu korozije u oba medija i pri obje ispitivane temperature pokazao je mesing, dok se bakar kao plemenitiji metal pokazao otpornijim na koroziju. Metalografskim i mikrostrukturnim ispitivanjima je ustanovljeno da se na površini bakra za vrijeme elektrokemijskog procesa u 3,5 % otopini NaCl stvara sloj bakrovog klorida, koji je nedovoljno postojan da u potpunosti spriječi prodiranje agresivnih iona iz otopine. Iz metalografskih snimaka mesinga nakon elektrokemijskih mjerenja utvrđeno je da dolazi do selektivnog otapanja cinka iz mesinga u kloridnom mediju.In this paper the corrosion resistance of copper and brass in drinking water and 3.5 % NaCl solution at room temperature and 60 °C was examined by electrochemical measurements. Changes in the surface of the samples were followed by light and scanning electron microscope. Investigation results showed that the corrosion resistance of both copper and brass decreases with temperature elevation in water and 3.5 % NaCl solution. Brass showed a higher corrosion rate in both media, while copper as a more noble metal showed more resistance to corrosion. Metallographic and microstructure investigations revealed copper chloride layer formed at copper surface during the electrochemical process in 3.5 % NaCl solution. Copper chloride layer is not stable enough to completely prevent the penetration of aggressive ions from the solution. Results of metallographic investigation of brass proved the process of dezinfication taking place at the metal surface in chloride solution

Mjerenje odstupanja od pravocrtnosti i okomitosti 2D mjernog sustava

U ovom radu utvrđena su odstupanja od pravocrtnosti i okomitosti dviju preciznih vodilica, smještenih na optičkom stolu u Laboratoriju za precizna mjerenja dužina na Fakultetu strojarstva i brodogradnje. U današnje doba, točna i precizna mjerenja vrlo su bitna u svim granama industrije. Zahtjevi industrije sve su veći te su poboljšanja mjernih alata neizbježna. U uvodnom dijelu rada opisane su tolerancije oblika i položaja, s posebnim naglaskom na pravocrtnosti i okomitost te su objašnjeni mjerni alati koji se koriste u radu. U eksperimentalnom dijelu rada, za mjerenjasu upotrijebljena dva različita mjerna alata: autokolimator i laserski mjerni sustav, odnosno interferometar. Mjerenja su ponovljena nekoliko puta, kroz vremenski period od nekoliko mjeseci, kako bi se kvalitetno mogla izraziti preciznost i stabilnost vođenja. Tijekom izvođenja mjerenja, utvrđeno je da pod u laboratoriju nije dovoljno krut, te je zbog toga u radu definiran i koliki utjecaj ta nedovoljna krutost poda ima na rezultate mjerenja

The Significance ofBacillusspp. in Disease Suppression and Growth Promotion of Field and Vegetable Crops

Bacillusspp. produce a variety of compounds involved in the biocontrol of plant pathogens and promotion of plant growth, which makes them potential candidates for most agricultural and biotechnological applications. Bacilli exhibit antagonistic activity by excreting extracellular metabolites such as antibiotics, cell wall hydrolases, and siderophores. Additionally,Bacillusspp. improve plant response to pathogen attack by triggering induced systemic resistance (ISR). Besides being the most promising biocontrol agents,Bacillusspp. promote plant growth via nitrogen fixation, phosphate solubilization, and phytohormone production. Antagonistic and plant growth-promoting strains ofBacillusspp. might be useful in formulating new preparations. Numerous studies of a wide range of plant species revealed a steady increase in the number ofBacillusspp. identified as potential biocontrol agents and plant growth promoters. Among different mechanisms of action, it remains unclear which individual or combined traits could be used as predictors in the selection of the best strains for crop productivity improvement. Due to numerous factors that influence the successful application ofBacillusspp., it is necessary to understand how different strains function in biological control and plant growth promotion, and distinctly define the factors that contribute to their more efficient use in the field