The effect of dissolved oxygen on autotrophic nitrification

U ovom radu istražen je učinak koncentracije otopljenog kisika (DO) na brzinu autotrofne nitrifikacije u ovisnosti o pH, koncentraciji mikrobne biomase i opterećenja s NH₄-N. Provedeni su diskontinuirani pokusi, pri DO 2 mg/L, DO2 mg/L, pri pH 7,3-7,4 i pH 7,9-8,0, te uz 1 g MLSS/L, 2,8 g MLSS/L i 3,8 g MLSS/L. Provedena je autotrofna nitrifikacija 30 mg NH₄-N/L, 50 mg NH₄-N/L i 80 mg NH₄-N/L. U nitrifikaciji 50 mg NH₄-N/L najveća brzina autotrofne nitrifikacije od 19 mg NH₄-N/Lh je postignuta pri DO 2 mg/L i pri pH 7,9-8,0 i s 2,8 g MLSS/L i s 3,8 g MLSS/L. Brzina autotrofne nitrifikacije raste s porastom opterećenja s NH₄-N i pri pH 7,3-7,4 i pri pH 7,9-8,0 za istraženih 30-80 mg NH₄-N/L. Veće brzine autotrofne nitrifikacije se postižu pri pH 7,9-8,0 u usporedbi s pH 7,3-7,4 neovisno o DO.In this paper, the effect of dissolved oxygen concentration (DO) on the autotrophic nitrification velocity, depending on the pH, the concentration of microbial biomass (MLSS) and the load with NH₄-N, was studied. Discontinuous experiments were performed at DO 2 mg/L, DO2 mg/L at pH 7.3-7.4 and pH 7.9-8.0 and with 1 g MLSS /L, 2.8 g MLSS/L and 3.8 g MLSS/L. Autotrophic nitrification of 30 mg NH₄-N/L, 50 mg NH₄-N/L and 80 mg NH₄-N/L was performed. In the nitrification of 50 mg NH₄-N/L, the maximum autotrophic nitrification rate of 19 mg NH₄-N/Lh was reached at DO 2 mg/L and at pH 7.9-8.0 and 2.8 g MLSS/L and with 3.8 g MLSS/L. The rate of autotrophic nitrification increases with the increase in loading with NH₄-N and at pH 7.3-7.4 and at pH 7.9-8.0 for the investigated 30-80 mg NH₄-N/L. Greater autotrophic nitrification rates are achieved at pH 7.9-8.0 compared to the pH 7.3-7.4 irrespective of DO

Društveno poduzetništvo u odabranim zemljama Europske unije

Social entrepreneurs create value. Global problems such as poverty have been heightened by the economic crisis lately and continue to affect the lives of many people all over the world and bring a great deal of interest to the social economy. Social entrepreneurship is an important determinant of the social economy and describes a set of exceptional behaviors. This paper analyzes the notion, perception, and degree of social-economic development with an emphasis on social entrepreneurship in the selected countries of the European Union and Croatia. The analysis encompasses the concept and development of selected older members of the European Union and relies on post-socialist countries at the same time as the newest members of the European Union. By analyzing the facts it is trying to prove that the social economy and social entrepreneurship are more developed and more fragmented in the older and more developed countries of the European Union. Further evidence of this fact is the level of employment in the social economy in the European Union, where the post-socialist countries lag behind the more developed countries of the European Union.Društveni poduzetnici stvaraju vrijednost. Globalni problemi poput siromaštva u posljednje su vrijeme intenzivirani uslijed gospodarske krize te i dalje imaju velik utjecaj na život mnogih ljudi diljem svijeta i predstavljaju velik interes društvenoj ekonomiji. Društveno poduzetništvo je važna odrednica društvene ekonomije i opisuje skup iznimnih ponašanja. Ovaj rad analizira pojam, percepciju i stupanj društveno-gospodarskog razvoja s naglaskom na društveno poduzetništvo u odabranim zemljama Europske unije i u Hrvatskoj. Analiza obuhvaća koncept i razvoj odabranih starijih članica Europske unije i oslanja se na postsocijalističke zemlje, kao najmlađe članice Europske unije. Analiziranjem činjenica članak pokušava dokazati da su društvena ekonomija i društveno poduzetništvo razvijeniji i rascjepkaniji u starijim i razvijenijim zemljama članicama Europske unije. Dodatni dokaz tome je razina zaposlenosti u društvenom gospodarstvu u Europskoj uniji, gdje postsocijalističke zemlje zaostaju za razvijenijim zemljama Europske unije

Komplikacije endodontskog liječenja

Neuspjesi u endodontskoj terapiji zuba mogu biti posljedica komplikacija koje se događaju tijekom endodontskog liječenja ili onih nakon endodontskog liječenja. Tijekom endodontskog liječenja može doći do: - pogrešaka u dijagnozi - pogrešaka u trepanaciji - pogrešaka u instrumentaciji - pogrešaka u punjenju korijenskog kanala. Postendodontske komplikacije su: - postendodntska bol - promjena boje zuba - resorpcije - parestezije - periapikalni parodontitisi (granulom, ciste) - uzduţna fraktura korijena - upala maksilarnog sinusa. Većinu komplikacija moguće je izbjeći pravilnim i savjesnim radom, ali nažalost, postoji određeni postotak neuspjeha i u tom slučaju.Complications of endodontic treatment Failures in endodontic treatment of teeth may be a result of complications that occur during or after endodontic treatment. Errors that may occur during endodontic treatment: - Errors in diagnosis - Errors in trepanation - Errors in the instrumentation - Errors in filling the root canal. Postendodontic complications are: - Postendodontic pain - Changes in the color of teeth - Resorption - Paraesthesia - Periapical periodontitis (granuloma, cyst) - Longitudinal root fracture - Inflammation of the maxillary sinus. Most complications can be avoided by proper and conscientious work, but unfortunately, there is a certain percentage of failure in that case as well

Bioactive potential of wild stinging NETTLE (Urtica dioica L.)

U ovom radu ispitan je utjecaj lokacije i klimatskih uvjeta na udio bioaktivnih spojeva u listu i stabljici samonikle koprive ubrane s 14 lokacija u RH s područja Ozlja i okolice, Zagreba, Žumberka, Ogulina, Like i Istre. Liofilizirani uzorci ekstrahirani su ubrzanom ekstrakcijom otapalima pri povišenom tlakom (ASE) pri prethodno definiranim optimalnim uvjetima ekstrakcije: a) za uzorke lista - temperatura 110 °C, statičko vrijeme ekstrakcije 10 minuta i 4 ciklusa ekstrakcije, i b) za uzorke stabljike - temperatura 80 °C te statičko vrijeme ekstrakcije 5 minuta i 4 ciklusa ekstrakcije. U dobivenim ekstraktima spektrofotometrijski je određen udio ukupnih fenola, klorofila a, klorofila b, ukupnih klorofila i ukupnih karotenoida. Prema dobivenim rezultatima, list koprive sadržavao je znatno više udjele analiziranih spojeva u odnosu na stabljiku. Najviši udio ukupnih fenola u listu određen je u uzorku s područja Ozlja i okolice (1162,95±36,33 mg GAE 100 gˉ¹), dok je najviši udio ukupnih fenola u stabljici određen u uzorku s područja Istre (245,39±3,33 mg GAE 100 gˉ¹). Najviši udjeli ukupnih klorofila u listu i stabljici određeni su u uzorcima s područja Istre (list 1110,24±11,15 mg 100 gˉ¹; stabljika 72,34±2,39 mg 100 gˉ¹), kao i najviši udio ukupnih karotenoida (list 148,59±5,53 mg 100 gˉ¹; stabljika 17,50±0,59 mg 100 gˉ¹).In this work, the influence of location and climatic conditions on the content of bioactive compounds in the leaf and stem of wild nettle harvested from 14 locations in the Republic of Croatia from Ozalj area, Zagreb, Žumberak, Ogulin, Lika and Istria was examined. Lyophilized samples were extracted using accelerated solvent extraction (ASE) under the previously optimized extraction conditions: a) for leaf samples - temperature 110°C, static extraction time 10 minutes and 4 extraction cycles, and b) for stem samples - temperature 80°C, static extraction time 5 minutes and 4 extraction cycles. In obtained extracts, content of total phenols, chlorophyll a, chlorophyll b, total chlorophylls and total carotenoids was determined spectrophotometrically. According to the obtained results, nettle leaf contained considerably higher content of analyzed compounds when compared to the stem. The highest content of total phenols in the leaf was determined in the sample from the Ozalj area (1162.95±36.33 mg GAE 100 gˉ¹), while the highest total phenols in the stem were determined in the sample from Istria (245.39±3.33 mg GAE 100 gˉ¹). The highest total chlorophylls in leaf and stem were determined in samples from Istria (leaf 1110.24±11.15 mg 100 gˉ¹; stem 72.34±2.39 mg 100 gˉ¹), as well as the highest content of total carotenoids (leaf 148,59±5.53 mg 100 gˉ¹, stem 17.50±0.59 mg 100 gˉ¹)

Bioactive potential of wild stinging NETTLE (Urtica dioica L.)

U ovom radu ispitan je utjecaj lokacije i klimatskih uvjeta na udio bioaktivnih spojeva u listu i stabljici samonikle koprive ubrane s 14 lokacija u RH s područja Ozlja i okolice, Zagreba, Žumberka, Ogulina, Like i Istre. Liofilizirani uzorci ekstrahirani su ubrzanom ekstrakcijom otapalima pri povišenom tlakom (ASE) pri prethodno definiranim optimalnim uvjetima ekstrakcije: a) za uzorke lista - temperatura 110 °C, statičko vrijeme ekstrakcije 10 minuta i 4 ciklusa ekstrakcije, i b) za uzorke stabljike - temperatura 80 °C te statičko vrijeme ekstrakcije 5 minuta i 4 ciklusa ekstrakcije. U dobivenim ekstraktima spektrofotometrijski je određen udio ukupnih fenola, klorofila a, klorofila b, ukupnih klorofila i ukupnih karotenoida. Prema dobivenim rezultatima, list koprive sadržavao je znatno više udjele analiziranih spojeva u odnosu na stabljiku. Najviši udio ukupnih fenola u listu određen je u uzorku s područja Ozlja i okolice (1162,95±36,33 mg GAE 100 gˉ¹), dok je najviši udio ukupnih fenola u stabljici određen u uzorku s područja Istre (245,39±3,33 mg GAE 100 gˉ¹). Najviši udjeli ukupnih klorofila u listu i stabljici određeni su u uzorcima s područja Istre (list 1110,24±11,15 mg 100 gˉ¹; stabljika 72,34±2,39 mg 100 gˉ¹), kao i najviši udio ukupnih karotenoida (list 148,59±5,53 mg 100 gˉ¹; stabljika 17,50±0,59 mg 100 gˉ¹).In this work, the influence of location and climatic conditions on the content of bioactive compounds in the leaf and stem of wild nettle harvested from 14 locations in the Republic of Croatia from Ozalj area, Zagreb, Žumberak, Ogulin, Lika and Istria was examined. Lyophilized samples were extracted using accelerated solvent extraction (ASE) under the previously optimized extraction conditions: a) for leaf samples - temperature 110°C, static extraction time 10 minutes and 4 extraction cycles, and b) for stem samples - temperature 80°C, static extraction time 5 minutes and 4 extraction cycles. In obtained extracts, content of total phenols, chlorophyll a, chlorophyll b, total chlorophylls and total carotenoids was determined spectrophotometrically. According to the obtained results, nettle leaf contained considerably higher content of analyzed compounds when compared to the stem. The highest content of total phenols in the leaf was determined in the sample from the Ozalj area (1162.95±36.33 mg GAE 100 gˉ¹), while the highest total phenols in the stem were determined in the sample from Istria (245.39±3.33 mg GAE 100 gˉ¹). The highest total chlorophylls in leaf and stem were determined in samples from Istria (leaf 1110.24±11.15 mg 100 gˉ¹; stem 72.34±2.39 mg 100 gˉ¹), as well as the highest content of total carotenoids (leaf 148,59±5.53 mg 100 gˉ¹, stem 17.50±0.59 mg 100 gˉ¹)

The effect of dissolved oxygen on autotrophic nitrification

U ovom radu istražen je učinak koncentracije otopljenog kisika (DO) na brzinu autotrofne nitrifikacije u ovisnosti o pH, koncentraciji mikrobne biomase i opterećenja s NH₄-N. Provedeni su diskontinuirani pokusi, pri DO 2 mg/L, DO2 mg/L, pri pH 7,3-7,4 i pH 7,9-8,0, te uz 1 g MLSS/L, 2,8 g MLSS/L i 3,8 g MLSS/L. Provedena je autotrofna nitrifikacija 30 mg NH₄-N/L, 50 mg NH₄-N/L i 80 mg NH₄-N/L. U nitrifikaciji 50 mg NH₄-N/L najveća brzina autotrofne nitrifikacije od 19 mg NH₄-N/Lh je postignuta pri DO 2 mg/L i pri pH 7,9-8,0 i s 2,8 g MLSS/L i s 3,8 g MLSS/L. Brzina autotrofne nitrifikacije raste s porastom opterećenja s NH₄-N i pri pH 7,3-7,4 i pri pH 7,9-8,0 za istraženih 30-80 mg NH₄-N/L. Veće brzine autotrofne nitrifikacije se postižu pri pH 7,9-8,0 u usporedbi s pH 7,3-7,4 neovisno o DO.In this paper, the effect of dissolved oxygen concentration (DO) on the autotrophic nitrification velocity, depending on the pH, the concentration of microbial biomass (MLSS) and the load with NH₄-N, was studied. Discontinuous experiments were performed at DO 2 mg/L, DO2 mg/L at pH 7.3-7.4 and pH 7.9-8.0 and with 1 g MLSS /L, 2.8 g MLSS/L and 3.8 g MLSS/L. Autotrophic nitrification of 30 mg NH₄-N/L, 50 mg NH₄-N/L and 80 mg NH₄-N/L was performed. In the nitrification of 50 mg NH₄-N/L, the maximum autotrophic nitrification rate of 19 mg NH₄-N/Lh was reached at DO 2 mg/L and at pH 7.9-8.0 and 2.8 g MLSS/L and with 3.8 g MLSS/L. The rate of autotrophic nitrification increases with the increase in loading with NH₄-N and at pH 7.3-7.4 and at pH 7.9-8.0 for the investigated 30-80 mg NH₄-N/L. Greater autotrophic nitrification rates are achieved at pH 7.9-8.0 compared to the pH 7.3-7.4 irrespective of DO

Ružička days : International conference 17th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

In front of you are the Proceedings of the International Conference 17th Ružička days: „Today Science – Tomorrow Industry“ that was held in Vukovar, Croatia at September 19-21, 2018. The main goal of this interdisciplinary conference is to promote excellence in science and engineering as well as application of up-to-date research results and technological achievements in industry. In its fifth issue (2011, 2013, 2015, 2017, 2019) the Proceedings continues with publishing of quality scientific and professional full papers in sections Chemical Analysis and Synthesis (2), Chemical and Biochemical Engineering (3), Food Technology and Biotechnology (4), Medical Chemistry and Pharmacy (2), Environmental Protection (9) and Meeting of Young Chemists (4). All the papers were thoroughly reviewed from respectable evaluators, to whom we express our gratitude. We are also thankful to all the authors and participants of the Ružička days, and to all that support and contribute in its organization; especially our international coorganizers EuCheMS, EFFoST and EHEDG, the members of organizing and scientific committee, plenary and invited lecturers, sponsors, and of course our highly skilled and committed associates, which put a lot of effort in preparation of this book