Flash floods

The thesis presents flash floods phenomenon and the differences between flash floods and\ud other types of floods. Flooding is usually caused by intense or long-lasting rainfall event.\ud These kinds of events are more often in the last years and climate changes could cause\ud even more natural disasters.\ud Flash floods are quite known phenomenon in Slovenia which is situated in many upper parts\ud of river basins. Flash floods and erosion are most common in northwestern hilly landscape of\ud Slovenia where is also measured the biggest amount of annual precipitation.\ud Flash floods are often accompanied by landslides, erosion, mud and debris flows. These\ud processes can cause even bigger damage than just flash flood only. Because of a rapid and\ud short-term event of flash flooding is quality forecast very important to reduce the damage.\ud Quality forecast depends on several different factors which all should be considered. In the\ud last years is popular use of remote sensing systems for more accurate flood forecasts.\ud The thesis also presents different types of flood protection which are used to reduce the\ud damage caused by flash flooding. With flood protection such as appropriate statutory\ud regulations for building on zones at high risk of flooding, a higher number of rain-gauges,\ud weather radars, satellite systems and quality structural measures we can achieve faster and\ud more accurate flood forecasts and measures in time

Studies of Corrosion Resistance of Passive Layers on Al-Ni Alloys in the Presence of Chloride Ions

The corrosion resistance of passive layers was studied on cast Al-Ni alloys with an ever-increasing mass content of nickel («;(Ni) = 0.54 - 4.30%). The method of potentiodynamic polarization, measuring to 10 V, the method of measuring the changes of the current at a constant potential of 0 V, and the method of determining the critical concentrations of chloride ion gave identical dependence of the corrosive resistance of the passive layers on the mass content of nickel in the alloy. The method of potentiodynamic polarization at low potentials to 1 V was applied to obtain the dependence of insulating properties of the passive layers on the mass content of nickel in alloy

Organised crime in Serbia

Autor prvo izlaže svoje shvatanje o tome kako je i kada nastao organizovani kriminal u Srbiji i kako se, relativno sporo, formirala društvena svest o izuzetno velikoj opasnosti od te vrste kriminala. On smatra da je organizovani kriminal u toj državi pojava novijeg datuma, da ga u bivšoj autoritarnoj i polupolicijskoj Jugoslaviji nije bilo kao danas, ni po obimu, niti prema pojavnim formama i da je za njegovu pojavu i ekspanziju odgovoran vladajući režim devedesetih godina prošloga veka, te da se svest o neophodnosti efi kasne borbe protiv toga kriminala stvarala teško i sporo i posle smene toga režima u 2000. godini. Kada je posle izvesnog vremena ta svest ipak formirana doneti su materijalnopravni, procesni i organizacioni propisi, koji su omogućili efi kasniju i adekvatniju reakciju države protiv organizovanih kriminalnih grupa. Autor na kraju konstatuje da su na tome planu postignuti izvesni početni rezultati, ali da se i u zakonodavnoj i u pravosudnoj praksi u ovoj oblasti mogu uočiti izvesna zabrinjavajuća lutanja, zablude i promašena rešenja, ali da to nije samo specifi čnost Srbije, već i mnogih drugih država u svetu.Firstly, the author presents his understanding of how organised crime in Serbia came about. Also, he discusses how relatively slowly social awareness has developed of the enormously great danger this type of crime presents. The author holds that organised crime in this country is a more recent occurrence and that it was not present as such in the former authoritarian and partly police state of Yugoslavia, neither in extent nor in form. The author further holds that the governing regime from the nineteen nineties is responsible for its occurrence and expansion. Also, he believes that awareness of the necessity of effectively combating this type of crime has developed slowly and with difficulty and only after the governing regime changed in 2000. When, after a certain period of time, that awareness had nevertheless developed, substantive, procedural and organisational regulations were formulated which enabled more efficient and adequate reactions from the state against organised criminal groups. The author finally concludes that, in this area, indisputable initial results have been achieved. However, in legislative and judicial practice in this region, definitely worrying digressions, misconceptions and erroneous solutions are obvious. However, this not only peculiar to Serbia, but to many other states in the world as well

Organised crime in Serbia

Autor prvo izlaže svoje shvatanje o tome kako je i kada nastao organizovani kriminal u Srbiji i kako se, relativno sporo, formirala društvena svest o izuzetno velikoj opasnosti od te vrste kriminala. On smatra da je organizovani kriminal u toj državi pojava novijeg datuma, da ga u bivšoj autoritarnoj i polupolicijskoj Jugoslaviji nije bilo kao danas, ni po obimu, niti prema pojavnim formama i da je za njegovu pojavu i ekspanziju odgovoran vladajući režim devedesetih godina prošloga veka, te da se svest o neophodnosti efi kasne borbe protiv toga kriminala stvarala teško i sporo i posle smene toga režima u 2000. godini. Kada je posle izvesnog vremena ta svest ipak formirana doneti su materijalnopravni, procesni i organizacioni propisi, koji su omogućili efi kasniju i adekvatniju reakciju države protiv organizovanih kriminalnih grupa. Autor na kraju konstatuje da su na tome planu postignuti izvesni početni rezultati, ali da se i u zakonodavnoj i u pravosudnoj praksi u ovoj oblasti mogu uočiti izvesna zabrinjavajuća lutanja, zablude i promašena rešenja, ali da to nije samo specifi čnost Srbije, već i mnogih drugih država u svetu.Firstly, the author presents his understanding of how organised crime in Serbia came about. Also, he discusses how relatively slowly social awareness has developed of the enormously great danger this type of crime presents. The author holds that organised crime in this country is a more recent occurrence and that it was not present as such in the former authoritarian and partly police state of Yugoslavia, neither in extent nor in form. The author further holds that the governing regime from the nineteen nineties is responsible for its occurrence and expansion. Also, he believes that awareness of the necessity of effectively combating this type of crime has developed slowly and with difficulty and only after the governing regime changed in 2000. When, after a certain period of time, that awareness had nevertheless developed, substantive, procedural and organisational regulations were formulated which enabled more efficient and adequate reactions from the state against organised criminal groups. The author finally concludes that, in this area, indisputable initial results have been achieved. However, in legislative and judicial practice in this region, definitely worrying digressions, misconceptions and erroneous solutions are obvious. However, this not only peculiar to Serbia, but to many other states in the world as well

Effect of gas-lift gas injection on mass and heat transfer

Nakon uvođenja kontinualnog gas-lifta, primećen je porast proizvodnje tečnog naftnog gasa, TNG, u postrojenju za preradu gasa, kao jednog od finalnih proizvoda dobijenog iz fluida gaso kondenzatnih i rastvorenog gasa iz naftnih bušotina. Pretpostavljeno je da se prisustvom gas-lift gasa uspostavlja drugačija ravnoteža faza u odnosu na slučaj bez gaslifta, te da je gas-lift gas stripovao propan i butane iz tečne u parnu fazu, što je dovelo do povećanja prinosa TNG-a. Napravljen je model bušotine koja radi u kontinualnom gas-liftu primenom programskog paketa Aspen HYSYS v8.8. Pri modelovanju bušotine koja radi u kontinualnom gas-liftu uključeni su: tubing, unutrašnja cev, i kezing, spoljašnja cev; fluid proizveden iz bušotine; gas-lift gas; razmena toplote fluida u tubingu i gas-lift gasa, razmena toplote između gaslift gasa i okolne sredine (zemlje). Verifikacija modela urađena je poređenjem sa rezultatima karotažnih merenja, tzv. PLT, preko profila pritiska i temperature u stubu bušotine. Rezultati analize pokazali su da se razlika između merenih i vrednosti pritisaka/temperatura u stubu modelovane bušotine smanjuje povećanjem broja pojedinačnih cevi (cevnih segmenata) koje predstavljaju tubing/kezing. Na osnovu dobijenih rezultata zaključeno je da je porast prinosa TNG-a posledica promenjenih faznih odnosa i uslova prenosa mase i toplote kada se u bušotinu utiskuje gas-lift gas. Ispitan je uticaj gas-lift gasa na taloženje parafina. Rezultati ispitivanja pokazali su da taloženje parafina počinje na većim dubinama i da je količina istaloženog parafina veća u bušotinama sa gas-liftom.More than expected increase of liquified petroleum gas, LPG, yield was observed after continuous gas-lift start up in the gas processing plant as one of the final products obtained from gas condensate and associated gas from oil wells. It was assumed that the presence of gas-lift gas leads to the establishment of a different phase equilibrium in comparison to the case without gas-lift, and that increase of LPG yield is the result of stripping propane and butane by gas-lift-gas from the liquid to the vapor phase. A model of the gas-lift well was prepared in Aspen HYSYS v8.8. This model included pipe in pipe segment, i. e. production tubing inside production casing, countercurrent flow of gas-lift gas and producing fluid, heat exchange between gas-lift gas and the surrounding ambient – ground; and gas-lift gas with the fluid in the tubing. The model verification was done by comparing the results of the PLT measurements, through the pressure and temperature profiles in the gas-lift well. The results showed that the difference between the measured and calculated pressure/temperature profiles is reduced by increasing the number of pipe segments. Based on the obtained results, it was concluded that the increase in LPG yield is a result of the changed phase equilibrium and the mass and heat transfer when the gas-lift gas is injected into the wellbore. Influence of the gas-lift on paraffin deposition was investigated. The results of the research have shown that the precipitation of paraffins begins at greater depths and that the amount of deposit is higher in the gas-lift well

Electrocatalytic Activity of the Ni57.3Co42.7 Alloy for the Hydrogen Evolution

The hydrogen evolution reaction (HER) on Ni57.3Co42.7 alloy and its main components, polycrystalline nickel and cobalt was investigated in 1.0 mol L–1 NaOH solution at 20 °C using cyclic voltammetry, pseudo-steady-state linear polarization and electrochemical impedance spectroscopy methods. The purpose of investigation was to evaluate the effect of cobalt on the intrinsic catalytic activity of nickel. Cyclic voltammetry measurements, performed in a wide potential range from hydrogen to oxygen evolution, clearly showed the potential range of formation and reduction metal oxides / hydroxides. Electrocatalytic activity of the investigated electrodes was derived from pseudo-steady-state linear polarization curves, Tafel plots and electrochemical impedance spectroscopy (EIS). Electrochemical impedance spectra obtained in potential range of hydrogen evolution were modeled with modified Randles electric equivalent circuit. Kinetic parameters (the exchange current density and the cathodic Tafel slope), determined from linear polarization measurements and electrochemical impedance measurements, were compared for all three electrode materials. Ni57.3Co42.7 catalyst has shown better electrocatalytic activity compared with pure Co. The main pathway for the HER at investigated electrode materials is Volmer Heyrovski with Heyrovsky as the rate determining step. This work is licensed under a Creative Commons Attribution 4.0 International License

Sleep disturbances and depression: Directions and mechanisms of interaction

Sleep represents physiological process which effects are crucial to maintain homeostasis. Sleep disturbances are widely spread within the population worldwide. The loss in quantity or quality of sleep is associated with numerous diseases. Also, sleep disturbances are highly connected to depressive disorders, but exact mechanism of this interaction still remains unknown. Understanding the underlying mechanisms could be the key for treatment of both disorders especially in patients with psychosomatic and psychiatric comorbidities. Therefore, in this article, we will summarize the most recent findings on the connection between sleep disturbances and depressive disorders, including the mechanisms of this interaction

The Influence of Sodium Alginate on the Properties of Poly(ethylene oxide) as the Matrix for the Preparation of Solid Polymer Electrolyte

Istraživan je utjecaj natrijeva alginata (NaAlg) na strukturu i svojstva filmova poli(etilen-oksida) (PEO) izlivenih iz vodenih otopina primjenom infracrvene spektroskopije s Fourierovom transformacijom (FT-IR), diferencijalne pretražne kalorimetrije (DSC), neizotermne termogravimetrije (TG) i elektrokemijske impedancijske spektroskopije (EIS). Cilj istraživanja je pronalaženje optimalne mješavine za pripravu filma čvrstog polimernog elektrolita (SPE) za litij-ionske baterije (LIB). U filmovima mješavina PEO/NaAlg stvaraju se vodikove veze između PEO-a i NaAlg-a te nastaju mješljive mješavine s manjim udjelom kristalne faze u odnosu na film čistog PEO-a. Filmovi mješavina toplinski su nestabilniji od filma čistog PEO-a i pokazuju dielektrična svojstva. Zbog najmanjeg udjela kristalne faze PEO-a mješavina 80PEO/20NaAlg može biti polimerna matrica koja bi dodatkom litijeve soli tvorila pogodan SPE. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Investigation of the influence of sodium alginate (NaAlg) on the structure and properties of poly(ethylene oxide) (PEO) films cast from aqueous solutions was performed by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), non-isothermal thermogravimetry (TG), and electrochemical impedance spectroscopy (EIS). The research aimed to find the optimal blend for the preparation of a solid polymer electrolyte (SPE) film for lithium-ion batteries (LIB). In PEO/NaAlg blend films, hydrogen bonds are formed between PEO and NaAlg, the blends are miscible, and have a lower content of crystalline phase compared to pure PEO film. The films of the blends are more thermally unstable than the film of pure PEO, and show dielectric properties, but the blend 80PEO/20NaAlg is suitable for the preparation of SPE by addition of lithium salt due to the lowest content of PEO crystalline phase. This work is licensed under a Creative Commons Attribution 4.0 International License

Scientific Research Activities of the Department of General and Inorganic Chemistry in the Period 2010–2020

Od utemeljenja Zavoda, akademske godine 1961./62., njegova znanstveno-istraživačka djelatnost bila je usmjerena na elektrokemijska istraživanja metala, pojavu pasiviteta i inhibiciju korozije. Kasnije, ponajprije primjenom elektrokemijskih metoda, proučavaju se fenomeni na granici faza metal│anodni sloj│elektrolitna otopina koji su od značaja za kemijske izvore struje i poluvodičke sustave. Tijekom posljednjih deset godina istraživanja se usmjeravaju u dva smjera: i) ispitivanje utjecaja legirajućih elemenata na dizajn otpornih materijala i biofunkcionalizacija površine biorazgradljivih i biokompatibilnih metalnih implantata; ii) modifikaciju elektroda i njihovih površina u svrhu razvoja novih elektroanalitičkih metoda za određivanje teških metala i biomolekula. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Since the establishment of the Department of General and Inorganic Chemistry in 1961, at the Faculty of Chemistry and Technology, University of Split, its scientific interest and investigations were focused toward electrochemical research. Consequently, electrochemistry became the backbone of the scientific research and development of the Department. In the last 10 years, scientific interest has been focused on the influence of alloying elements on design of corrosion resistance materials, as well as biofunctionalisation of biodegradable and biocompatible metal-based implants. In addition, development of various electroanalytical methods based on modified electrodes as sensing part of sensors, have been in focus in the recent period. The developed sensors were used for determination of heavy metals or biomolecules. This work is licensed under a Creative Commons Attribution 4.0 International License