351 research outputs found
Biotechnological potential of metagenomic libraries from microbial mats from carbonate caves
No full textANALYSIS OF BUSINESS STRATEGIES ON THE BOCAH JAJAN ANGKRINGAN (BOJAN) IN KOJA, NORTH JAKARTA
No full text This study was made based on observations for three months at Angkringan Bojan, the purpose of the observation was to find out the marketing strategies carried out by Angkringan Bojan to achieve its sales targets. From the observations, Angkringan Bojan has never reached the target set. This is because in the implementation of the Angkringan Bojan strategy, the SWOT (Strength, Weakness, Opportunity, Threat) analysis has not been carried out by comparing the strengths, weaknesses, opportunities, threats with existing theories. Angkringan Bojan needs to find a more strategic sales location than the previous location which is close to the market waste disposal. In its development, the author also recommends Angkringan Bojan to improve the quality, design, promotion and bonus of culinary products available on the menu, strengthen the security system with complex passwords and back up data to minimize the possibility of hackers.Key words: Marketing Strategy, Sales Target, SWOT Analysis, Culinary Products
Ep098 Croatian Tales of Long Ago
No full textIvana Brlić-Mažuranić might not be the first name you think of when you think of fairy tales, unless, of course, you had a magical Croatian childhood like photographer and researcher Bojan Fürst. Bojan is the Manager of Knowledge Mobilization at the Leslie Harris Centre of Regional Policy and Development, Memorial University of Newfoundland. Bojan leads the Harris Centre's knowledge brokering team, connecting community needs with the resources available at the university. Recently, Bojan has been working to translate some of the literary fairy tales of Croatian author, poet, and essayist Ivana Brlić-Mažuranić, who has been praised as one of Croatia’s best writers for children, and whose work utilizing traditional Slavic names and motifs been compared to Hans Christian Andersen and JRR Tolkien, though her work is not widely known by English-speaking audiences. Today, we’re working to fix that, and delving into the enchanting fairytales of Bojan’s childhood. Recorded 23 January 201
Development of advanced photocatalytic processes for degradation of aromatic pollutants in water
No full textNajčešće korišteni poluvodič kao fotokatalizator za fotooksidaciju, u heterogenom fotokatalitičkom sustavu za razgradnju onečišćivala u vodi, koristi se titanijev dioksid
TiO2-P25. Razlog njegovog korištenja ogleda se u velikoj moći fotogeneriranja parova elektrona i šupljina, niskoj cijeni, velikoj aktivnosti i slično. Međutim, problem koji ograničava primjenu TiO2 fotokatalizatora je apsorpcija zračenja valnih duljina većih od 400 nm, kao i problem uklanjanja suspenzije fotokatalizatora nakon završenog procesa fotokatalitičke oksidacije i njegova ponovna upotreba. Osim navedenoga, ne postoji jednostavan matematički model, koji opisuje heterogeni fotokatalitički proces, a da posjeduje konstantu brzine razgradnje organske tvari neovisnu o geometriji fotoreaktora. Navedeni model mogao bi se koristiti za uvećanje procesa. Prema navedenom, u ovom radu istražen je heterogeni fotokatalitički proces u cilju pronalaženja rješenja za navedene probleme koji ograničavaju primjenu TiO2 fotokatalizatora. Kao modelno onečišćivalo korištena je salicilna kiselina. Istraživanje je pokazalo da se metodom redukcije srebra uz kitozan može sintetizirati srebrom dopirani fotokatalizator koji pri zračenju valnih duljina > 400 nm pokazuje fotokatalitičku aktivnost (kvis = 0,0037 min^-1), dok pri umjetnom sunčevom zračenju pokazuje 1,4 puta veću aktivnost od nedopiranog suspendiranog TiO2-P25 pri istim uvjetima. Primjenom željezove soli moguće je poboljšati proces fotokatalize i provesti separaciju suspenzije fotokatalizatora koagulacijom (nakon 60 min uklonjeno 89,55 % TiO2-P25), ako se željezova sol dodaje samo u svrhu koagulacije tada je separacija izraženija (nakon 60 min uklonjeno 95,05 % TiO2-P25). Kitozan kao koagulanta također pokazuje zadovoljavajuće rezultate uklanjanja suspenzije TiO2-P25 (nakon 60 min uklonjeno > 95 % TiO2-P25). Istraživanje je pokazalo kada je separacija TiO2-P25 fotokatalizatora temeljena na koagulaciji, bilo željezovom soli ili kitozanom, nije moguće upotrijebiti istaloženi fotokatalizator u novom fotokatalitičkom ciklusu. Međutim, istraživanje je pokazalo da se imobilizacijom fotokatalizatora može riješiti problem ponovne upotrebe fotokatalizatora u novom ciklusu. Rezultati su pokazali da ne dolazi do pada aktivnosti kada se TiO2 imobilizira na stijenku reaktora i primijeni u više ciklusa zargradnje salicilne kiseline. Istraživanje je provedeno na
6 ciklusa fotokatalize (1 ciklus trajao je 60 min). Konstanta brzine imobiliziranog fotokatalizatora na stijenci reaktora koja uzima u obzir masu fotokatalizatora ima 6,3 puta veću vrijednost od procesa s suspendiranim TiO2- P25. Osim na staklenoj stjenci imobilizacija TiO2 provedena je i na nosaču hidroksiapatita. Iako je aktivnost navedenog imobiliziranog fotokatalizatora pokazala jednaku aktivnost kao i suspendirani TiO2-P25, zbog raspadanja nosača tijekom miješanja, pokazao se kao neučinkovit. Razvijen je matematički model za sustav s imobiliziranim TiO2 na stijenci reaktora. Kinetički model uključuje model emisije zračenja, te konstantu brzine neovisnu o geometriji reaktora koja opisuje razgradnju salicilne kiseline, 2,5-dihidroksibezojeve kiseline, 2,3-dihidroksibenzojeve kiseline i grupu spojeva koju čine katehol, resorcinol, hidrokinon, alifatske kiseline kao i ostali organski spojevi kuji su, kao grupa organski nusprodukti, praćeni metodom ukupnog organskog ugljika.Titanium dioxide TiO2-P25 is the most commonly used semiconductor as photocatalyst for photooxidation, in the heterogeneous photocatalytic system for the degradation of pollutants in water. The reason for its use is reflected in the great power of photogeneration of pairs of electrons and cavities, low cost, high activity and similar. However, the problem limiting the application of TiO2 photocatalyst is the absorption of radiation of wavelengths exceeding
400 nm, as well as the problem of removing the photocatalyst suspension after the photocatalytic oxidation process has been completed and its re-use. Apart from the above, there is no simple mathematical model describing a heterogeneous photocatalytic process which also possesses a rate constant of degradation of organic matter independent of the geometry of the photoreactor. The mentioned model could be used for scaling up process. Accordingly, in this paper, a heterogeneous photocatalytic process was investigated in order to find a solution to the stated problems which limit the application of TiO2 photocatalyst. Salicylic acid was used as a model pollutant. The research showed that with the method of reduction of silver with chitosan the silver-doped photocatalyst can be synthesized, which exhibits photocatalytic activity (kvis = 0.0037 min^-1) under the radiation of wavelengths
> 400 nm, while it exhibits 1.4 times higher activity under artificial solar radiation than undoped suspended TiO2-P25 under the same conditions. By using iron salt it is possible to improve the photocatalysis process and to carry out the separation of the photocatalyst suspension by coagulation (after 60 min 89.55% TiO2-P25 is removed), and if the iron salt is added for coagulation purposes only then the separation is more pronounced (after 95 min 95.05% TiO2-P25 is removed). Chitosan as a coagulant also showed satisfactory results of the TiO2-P25 suspension removal (after 60 min is removed> 95% TiO2-P25). The research showed that when the separation of TiO2-P25 photocatalyst is based on coagulation, whether iron salt or chitosan, it is not possible to use a precipitated photocatalyst in a new photocatalytic cycle. However, the research has shown that by photocatalyst immobilization can be solved the problem of reusing photocatalysts in a new cycle. The results showed that no decrease in activity occurs when TiO2 is immobilized on the reactor wall and applied to multiple salicylic acid degradation cycles. The research was conducted on 6 cycles of photocatalysis (1 cycle lasted 60 min). The rate constant of the immobilized photocatalyst on the reactor wall considering the mass of the photocatalyst is 6.3 times higher than the process with suspended TiO2-P25. In addition to the glass wall, TiO2 immobilization was also carried out on a hydroxyapatite carrier. Although the activity of said immobilized photocatalyst showed the same activity as suspended TiO2-P25, due to carrier decomposition during mixing, it proved to be ineffective. A mathematical model for a system with immobilized TiO2 on a reactor wall has been developed. The kinetic model includes a radiation emission model and a rate constant independent of the reactor geometry describing the degradation of salicylic acid, 2,5-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid and a group of compounds consisting of catechol, resorcinol, hydroquinone, aliphatic acids and other organic compounds which are, as a group organic by-products, followed by the total organic carbon method
Characterization and epidemiological investigation of Listeria monocytogenes isolates using next-generation sequencing
No full textListerioza je resno obolenje ljudi in živali, ki ga povzroča bakterija Listeria monocytogenes. Sekvenciranje celotnih genomov (angl. whole-genome sequencing, WGS) postaja metoda izbora za epidemiološki nadzor listerioze, vključno s preiskavami izbruhov. Tipizacija izolatov ni sestavni del rutinskih preiskav izbruhov listerioze pri živalih, zato genotipi bakterije L. monocytogenes, ki so udeleženi pri tovrstnih izbruhih, niso dobro raziskani. V prvem sklopu naloge smo metodo WGS uporabili za podrobno genetsko opredelitev domnevno epidemiološko in mikrobiološko povezanih izolatov. Retrospektivno smo analizirali sedem izbruhov listerioze pri drobnici, ki so jih povzročili kloni ST1 (CC1), ST18 (CC18), ST21 (CC21) in ST184. Z več analitičnimi pristopi, ki temeljijo na metodi WGS, smo potrdili monoklonalno naravo izbruhovmikrobiološko povezani izolati so se razlikovali v največ 13 polimorfizmih posameznih nukleotidov v celotnem genomu (angl. whole-genome single nucleotide polymorphism, wgSNP), sedmih alelih osrednjega genoma (angl. core-genome multilocus sequence typing, cgMLST) in 12 alelih celotnega genoma (angl. whole-genome multilocus sequence typing, wgMLST). V primeru izbruha, povzročenega s sevom ST184, smo mikrobiološko povezan sev ugotovili tudi v vodi iz napajalnika in silaži, ki sta bila najverjetnejši vir okužbe za obolele živali. Metoda WGS je imela večjo moč razlikovanja od elektroforeze v pulzirajočem električnem polju (angl. pulsed-field gel electrophoresis, PFGE), ki dveh izbruhov, povzročenih s sevoma CC1, ni uspela razlikovati. Retrospektivno smo preiskali tudi izbruh listerioze pri ljudeh, ki ga je povzročil sev ST8 (CC8). Potrdili smo, da je bil izbruh monoklonalne narave, in ovrgli domnevo, da je bil vir okužbe preiskovano živilo oz. z živilom povezano okolje. Nadalje smo metodo WGS uporabili za podrobno preučitev genetske raznolikosti in poti širjenja izolatov bakterije L. monocytogenes v kmetijskem okolju. Na kmetiji s primerom živčne oblike listerioze smo hipervirulentni klon CC4 ugotovili tudi pri kravah s subkliničnim mastitisom. Z metodo WGS smo potrdili mikrobiološko povezavo med dvema izolatoma CC5 iz kmetijskega okolja z različnim profilom PFGE. Naši rezultati kažejo, da bi metoda WGS morala nadomestiti metodo PFGE za epidemiološki nadzor bakterije L. monocytogenes. V drugem sklopu naloge smo analizirali populacijsko strukturo izolatov živalskega kliničnega izvora in iz naravnega okolja, ki je slabo poznana. Za opis populacijske strukture izolatov živalskega kliničnega izvora in iz naravnega okolja smo uporabili tipizacijo na osnovi zaporedij več lokusov (angl. multilocus sequence typing, MLST). Klon CC1 je bil značilno povezan s kliničnim izvorom in z živčno obliko listerioze. Na novo smo opisali značilno povezavo klonov CC6 in CC37 z abortivno obliko bolezni. Kloni CC9, CC14 in CC29 so bili značilno povezani z naravnim okoljem. Zbrani rezultati predstavljajo pomemben doprinos k razumevanju genetske raznolikosti bakterije L. monocytogenes v kmetijskem okolju na nacionalni in mednarodni ravni.Listeriosis is a serious disease of humans and animals caused by Listeria monocytogenes. Whole-genome sequencing (WGS) is becoming the method of choice for the epidemiological surveillance of listeriosis, including outbreak investigations. Bacterial typing is not an integral part of routine investigations of animal listeriosis outbreakstherefore, L. monocytogenes genotypes involved in these outbreaks remain poorly known. In the first part of the dissertation, WGS was used for detailed genetic characterization of presumably epidemiologically and microbiologically related isolates. Seven listeriosis outbreaks in small ruminants caused by the ST1 (CC1), ST18 (CC18), ST21 (CC21) and ST184 clones were retrospectively analyzed. Several WGS-based analytical approaches confirmed the monoclonal nature of the investigated outbreaksmicrobiologically related isolates differed in up to 13 polymorphisms by whole-genome single nucleotide polymorphism (wgSNP) typing, seven alleles in core-genome multilocus sequence typing (cgMLST) and 12 alleles in whole-genome multilocus sequence typing (wgMLST). In the case of an outbreak caused by the ST184 strain, a microbiologically related strain was also found in the drinking water and silage, which were the most likely source(s) of infection of the diseased animals. WGS showed a greater dicriminatory power compared with pulsed-field gel electrophoresis (PFGE), which failed to distinguish between two outbreaks caused by the CC1 strains. We retrospectively investigated the human listeriosis outbreak caused by the ST8 (CC8) strain. We confirmed the monoclonal nature of the outbreak and rejected the hypothesis that the analyzed food or food-associated isolates caused the outbreak. Furthermore, WGS was used for a comprehensive genetic characterization and elucidation of L. monocytogenes transmission pathways in the farm environment. On a farm with a neurolisteriosis case, the hypervirulent CC4 clone was also found in cows with subclinical mastitis. The microbiological link between two CC5 isolates from the farm environment with different PFGE profiles was confirmed by WGS. The results of this study suggest that WGS should replace PFGE in epidemiological surveillance of L. monocytogenes. In the second part of the dissertation, we analyzed the population structure of L. monocytogenes isolates of animal clinical origin and from the natural environment, which are poorly understood. Multilocus sequence typing (MLST) was used to describe the population structure of isolates of animal clinical origin and from the natural environment. The CC1 clone was significantly associated with a clinical origin and with neurolisteriosis. We described a novel and significant association of CC6 and CC37 with abortion. CC9, CC14 and CC29 were significantly associated with the natural environment. The results presented herein represent an important contribution to the understanding of the genetic diversity of L. monocytogenes in the farm environment at regional and international levels
Development of advanced photocatalytic processes for degradation of aromatic pollutants in water
No full textNajčešće korišteni poluvodič kao fotokatalizator za fotooksidaciju, u heterogenom fotokatalitičkom sustavu za razgradnju onečišćivala u vodi, koristi se titanijev dioksid
TiO2-P25. Razlog njegovog korištenja ogleda se u velikoj moći fotogeneriranja parova elektrona i šupljina, niskoj cijeni, velikoj aktivnosti i slično. Međutim, problem koji ograničava primjenu TiO2 fotokatalizatora je apsorpcija zračenja valnih duljina većih od 400 nm, kao i problem uklanjanja suspenzije fotokatalizatora nakon završenog procesa fotokatalitičke oksidacije i njegova ponovna upotreba. Osim navedenoga, ne postoji jednostavan matematički model, koji opisuje heterogeni fotokatalitički proces, a da posjeduje konstantu brzine razgradnje organske tvari neovisnu o geometriji fotoreaktora. Navedeni model mogao bi se koristiti za uvećanje procesa. Prema navedenom, u ovom radu istražen je heterogeni fotokatalitički proces u cilju pronalaženja rješenja za navedene probleme koji ograničavaju primjenu TiO2 fotokatalizatora. Kao modelno onečišćivalo korištena je salicilna kiselina. Istraživanje je pokazalo da se metodom redukcije srebra uz kitozan može sintetizirati srebrom dopirani fotokatalizator koji pri zračenju valnih duljina > 400 nm pokazuje fotokatalitičku aktivnost (kvis = 0,0037 min^-1), dok pri umjetnom sunčevom zračenju pokazuje 1,4 puta veću aktivnost od nedopiranog suspendiranog TiO2-P25 pri istim uvjetima. Primjenom željezove soli moguće je poboljšati proces fotokatalize i provesti separaciju suspenzije fotokatalizatora koagulacijom (nakon 60 min uklonjeno 89,55 % TiO2-P25), ako se željezova sol dodaje samo u svrhu koagulacije tada je separacija izraženija (nakon 60 min uklonjeno 95,05 % TiO2-P25). Kitozan kao koagulanta također pokazuje zadovoljavajuće rezultate uklanjanja suspenzije TiO2-P25 (nakon 60 min uklonjeno > 95 % TiO2-P25). Istraživanje je pokazalo kada je separacija TiO2-P25 fotokatalizatora temeljena na koagulaciji, bilo željezovom soli ili kitozanom, nije moguće upotrijebiti istaloženi fotokatalizator u novom fotokatalitičkom ciklusu. Međutim, istraživanje je pokazalo da se imobilizacijom fotokatalizatora može riješiti problem ponovne upotrebe fotokatalizatora u novom ciklusu. Rezultati su pokazali da ne dolazi do pada aktivnosti kada se TiO2 imobilizira na stijenku reaktora i primijeni u više ciklusa zargradnje salicilne kiseline. Istraživanje je provedeno na
6 ciklusa fotokatalize (1 ciklus trajao je 60 min). Konstanta brzine imobiliziranog fotokatalizatora na stijenci reaktora koja uzima u obzir masu fotokatalizatora ima 6,3 puta veću vrijednost od procesa s suspendiranim TiO2- P25. Osim na staklenoj stjenci imobilizacija TiO2 provedena je i na nosaču hidroksiapatita. Iako je aktivnost navedenog imobiliziranog fotokatalizatora pokazala jednaku aktivnost kao i suspendirani TiO2-P25, zbog raspadanja nosača tijekom miješanja, pokazao se kao neučinkovit. Razvijen je matematički model za sustav s imobiliziranim TiO2 na stijenci reaktora. Kinetički model uključuje model emisije zračenja, te konstantu brzine neovisnu o geometriji reaktora koja opisuje razgradnju salicilne kiseline, 2,5-dihidroksibezojeve kiseline, 2,3-dihidroksibenzojeve kiseline i grupu spojeva koju čine katehol, resorcinol, hidrokinon, alifatske kiseline kao i ostali organski spojevi kuji su, kao grupa organski nusprodukti, praćeni metodom ukupnog organskog ugljika.Titanium dioxide TiO2-P25 is the most commonly used semiconductor as photocatalyst for photooxidation, in the heterogeneous photocatalytic system for the degradation of pollutants in water. The reason for its use is reflected in the great power of photogeneration of pairs of electrons and cavities, low cost, high activity and similar. However, the problem limiting the application of TiO2 photocatalyst is the absorption of radiation of wavelengths exceeding
400 nm, as well as the problem of removing the photocatalyst suspension after the photocatalytic oxidation process has been completed and its re-use. Apart from the above, there is no simple mathematical model describing a heterogeneous photocatalytic process which also possesses a rate constant of degradation of organic matter independent of the geometry of the photoreactor. The mentioned model could be used for scaling up process. Accordingly, in this paper, a heterogeneous photocatalytic process was investigated in order to find a solution to the stated problems which limit the application of TiO2 photocatalyst. Salicylic acid was used as a model pollutant. The research showed that with the method of reduction of silver with chitosan the silver-doped photocatalyst can be synthesized, which exhibits photocatalytic activity (kvis = 0.0037 min^-1) under the radiation of wavelengths
> 400 nm, while it exhibits 1.4 times higher activity under artificial solar radiation than undoped suspended TiO2-P25 under the same conditions. By using iron salt it is possible to improve the photocatalysis process and to carry out the separation of the photocatalyst suspension by coagulation (after 60 min 89.55% TiO2-P25 is removed), and if the iron salt is added for coagulation purposes only then the separation is more pronounced (after 95 min 95.05% TiO2-P25 is removed). Chitosan as a coagulant also showed satisfactory results of the TiO2-P25 suspension removal (after 60 min is removed> 95% TiO2-P25). The research showed that when the separation of TiO2-P25 photocatalyst is based on coagulation, whether iron salt or chitosan, it is not possible to use a precipitated photocatalyst in a new photocatalytic cycle. However, the research has shown that by photocatalyst immobilization can be solved the problem of reusing photocatalysts in a new cycle. The results showed that no decrease in activity occurs when TiO2 is immobilized on the reactor wall and applied to multiple salicylic acid degradation cycles. The research was conducted on 6 cycles of photocatalysis (1 cycle lasted 60 min). The rate constant of the immobilized photocatalyst on the reactor wall considering the mass of the photocatalyst is 6.3 times higher than the process with suspended TiO2-P25. In addition to the glass wall, TiO2 immobilization was also carried out on a hydroxyapatite carrier. Although the activity of said immobilized photocatalyst showed the same activity as suspended TiO2-P25, due to carrier decomposition during mixing, it proved to be ineffective. A mathematical model for a system with immobilized TiO2 on a reactor wall has been developed. The kinetic model includes a radiation emission model and a rate constant independent of the reactor geometry describing the degradation of salicylic acid, 2,5-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid and a group of compounds consisting of catechol, resorcinol, hydroquinone, aliphatic acids and other organic compounds which are, as a group organic by-products, followed by the total organic carbon method
Corrigendum to “The effect of process parameters and catalyst support preparation methods on the catalytic efficiency in transesterification of sunflower oil over heterogeneous KI/Al2O3-based catalysts for biodiesel production” [Fuel 315 (2022) 123246]
No full textThe authors regret to inform about an error in the affiliation of the corresponding author in the published version of this article. The correct affiliation of Dr. Bojan Janković should be: University of Belgrade, Department of Physical Chemistry, “Vinča” Institute of Nuclear Sciences – National Institute of the Republic of Serbia, Mike Petrovića Alasa 12–14, P.O. Box 522, 11001 Belgrade, Serbia. The authors would like to apologise for any inconvenience caused.Link to the corrected article: [https://vinar.vin.bg.ac.rs/handle/123456789/10134
Development of advanced photocatalytic processes for degradation of aromatic pollutants in water
No full textNajčešće korišteni poluvodič kao fotokatalizator za fotooksidaciju, u heterogenom fotokatalitičkom sustavu za razgradnju onečišćivala u vodi, koristi se titanijev dioksid
TiO2-P25. Razlog njegovog korištenja ogleda se u velikoj moći fotogeneriranja parova elektrona i šupljina, niskoj cijeni, velikoj aktivnosti i slično. Međutim, problem koji ograničava primjenu TiO2 fotokatalizatora je apsorpcija zračenja valnih duljina većih od 400 nm, kao i problem uklanjanja suspenzije fotokatalizatora nakon završenog procesa fotokatalitičke oksidacije i njegova ponovna upotreba. Osim navedenoga, ne postoji jednostavan matematički model, koji opisuje heterogeni fotokatalitički proces, a da posjeduje konstantu brzine razgradnje organske tvari neovisnu o geometriji fotoreaktora. Navedeni model mogao bi se koristiti za uvećanje procesa. Prema navedenom, u ovom radu istražen je heterogeni fotokatalitički proces u cilju pronalaženja rješenja za navedene probleme koji ograničavaju primjenu TiO2 fotokatalizatora. Kao modelno onečišćivalo korištena je salicilna kiselina. Istraživanje je pokazalo da se metodom redukcije srebra uz kitozan može sintetizirati srebrom dopirani fotokatalizator koji pri zračenju valnih duljina > 400 nm pokazuje fotokatalitičku aktivnost (kvis = 0,0037 min^-1), dok pri umjetnom sunčevom zračenju pokazuje 1,4 puta veću aktivnost od nedopiranog suspendiranog TiO2-P25 pri istim uvjetima. Primjenom željezove soli moguće je poboljšati proces fotokatalize i provesti separaciju suspenzije fotokatalizatora koagulacijom (nakon 60 min uklonjeno 89,55 % TiO2-P25), ako se željezova sol dodaje samo u svrhu koagulacije tada je separacija izraženija (nakon 60 min uklonjeno 95,05 % TiO2-P25). Kitozan kao koagulanta također pokazuje zadovoljavajuće rezultate uklanjanja suspenzije TiO2-P25 (nakon 60 min uklonjeno > 95 % TiO2-P25). Istraživanje je pokazalo kada je separacija TiO2-P25 fotokatalizatora temeljena na koagulaciji, bilo željezovom soli ili kitozanom, nije moguće upotrijebiti istaloženi fotokatalizator u novom fotokatalitičkom ciklusu. Međutim, istraživanje je pokazalo da se imobilizacijom fotokatalizatora može riješiti problem ponovne upotrebe fotokatalizatora u novom ciklusu. Rezultati su pokazali da ne dolazi do pada aktivnosti kada se TiO2 imobilizira na stijenku reaktora i primijeni u više ciklusa zargradnje salicilne kiseline. Istraživanje je provedeno na
6 ciklusa fotokatalize (1 ciklus trajao je 60 min). Konstanta brzine imobiliziranog fotokatalizatora na stijenci reaktora koja uzima u obzir masu fotokatalizatora ima 6,3 puta veću vrijednost od procesa s suspendiranim TiO2- P25. Osim na staklenoj stjenci imobilizacija TiO2 provedena je i na nosaču hidroksiapatita. Iako je aktivnost navedenog imobiliziranog fotokatalizatora pokazala jednaku aktivnost kao i suspendirani TiO2-P25, zbog raspadanja nosača tijekom miješanja, pokazao se kao neučinkovit. Razvijen je matematički model za sustav s imobiliziranim TiO2 na stijenci reaktora. Kinetički model uključuje model emisije zračenja, te konstantu brzine neovisnu o geometriji reaktora koja opisuje razgradnju salicilne kiseline, 2,5-dihidroksibezojeve kiseline, 2,3-dihidroksibenzojeve kiseline i grupu spojeva koju čine katehol, resorcinol, hidrokinon, alifatske kiseline kao i ostali organski spojevi kuji su, kao grupa organski nusprodukti, praćeni metodom ukupnog organskog ugljika.Titanium dioxide TiO2-P25 is the most commonly used semiconductor as photocatalyst for photooxidation, in the heterogeneous photocatalytic system for the degradation of pollutants in water. The reason for its use is reflected in the great power of photogeneration of pairs of electrons and cavities, low cost, high activity and similar. However, the problem limiting the application of TiO2 photocatalyst is the absorption of radiation of wavelengths exceeding
400 nm, as well as the problem of removing the photocatalyst suspension after the photocatalytic oxidation process has been completed and its re-use. Apart from the above, there is no simple mathematical model describing a heterogeneous photocatalytic process which also possesses a rate constant of degradation of organic matter independent of the geometry of the photoreactor. The mentioned model could be used for scaling up process. Accordingly, in this paper, a heterogeneous photocatalytic process was investigated in order to find a solution to the stated problems which limit the application of TiO2 photocatalyst. Salicylic acid was used as a model pollutant. The research showed that with the method of reduction of silver with chitosan the silver-doped photocatalyst can be synthesized, which exhibits photocatalytic activity (kvis = 0.0037 min^-1) under the radiation of wavelengths
> 400 nm, while it exhibits 1.4 times higher activity under artificial solar radiation than undoped suspended TiO2-P25 under the same conditions. By using iron salt it is possible to improve the photocatalysis process and to carry out the separation of the photocatalyst suspension by coagulation (after 60 min 89.55% TiO2-P25 is removed), and if the iron salt is added for coagulation purposes only then the separation is more pronounced (after 95 min 95.05% TiO2-P25 is removed). Chitosan as a coagulant also showed satisfactory results of the TiO2-P25 suspension removal (after 60 min is removed> 95% TiO2-P25). The research showed that when the separation of TiO2-P25 photocatalyst is based on coagulation, whether iron salt or chitosan, it is not possible to use a precipitated photocatalyst in a new photocatalytic cycle. However, the research has shown that by photocatalyst immobilization can be solved the problem of reusing photocatalysts in a new cycle. The results showed that no decrease in activity occurs when TiO2 is immobilized on the reactor wall and applied to multiple salicylic acid degradation cycles. The research was conducted on 6 cycles of photocatalysis (1 cycle lasted 60 min). The rate constant of the immobilized photocatalyst on the reactor wall considering the mass of the photocatalyst is 6.3 times higher than the process with suspended TiO2-P25. In addition to the glass wall, TiO2 immobilization was also carried out on a hydroxyapatite carrier. Although the activity of said immobilized photocatalyst showed the same activity as suspended TiO2-P25, due to carrier decomposition during mixing, it proved to be ineffective. A mathematical model for a system with immobilized TiO2 on a reactor wall has been developed. The kinetic model includes a radiation emission model and a rate constant independent of the reactor geometry describing the degradation of salicylic acid, 2,5-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid and a group of compounds consisting of catechol, resorcinol, hydroquinone, aliphatic acids and other organic compounds which are, as a group organic by-products, followed by the total organic carbon method
Analysis of the possibility of starting and profitability of an agritourism entrepreneurship based on the example of “Stari dud d.o.o.”,
No full textU ovom završnom radu analizirana je mogućnost otvaranja i isplativosti agroturističkoga
gospodarstva. Autor, ujedno i poduzetnik investitor je Bojan Mraović, a
investicija je planirana kroz poduzeće Stari Dud d.o.o. Analiza je rađena
metodologijom izrade poslovnog plana, što uključuje razradu po ključnim poglavljima
kako bi se dobio jezgrovit uvid u detalje planiranoga poslovanja. Korištene procedure
za izradu poslovnog plana osigurale su sustavnu obradu podataka te strukturiranu
prezentaciju informacija. Završni rad stoga uključuje opis ruralnog turizma kao
turističke djelatnosti, razradu planiranih usluga i proizvoda iz ponude, analizu tržišta
na kojima je planiran plasman te strategije za maksimizaciju prodaje, SWOT analizu,
temeljne logističke zahtjeve za nesmetano provođenje djelatnosti te detaljne
financijske podatke i izračune koji upućuju na isplativost poslovanja. Ovakva obrada
podataka poslužila je za bolje razumijevanje isplativosti ulaganja i u konačnici
donošenje kvalitetnije odluke o potencijalnom pokretanju poslovanja. Visina ulaganja
iznosi 1.709.697,36 kn, a izvori financiranja su u omjeru 60:40 u korist vanjskih izvora
u obliku bankovnoga kredita. Analiza je pokazala isplativost pokretanja navedenog
poslovanja.This final paper, the Analysis of the possibility of starting and profitability of a
agritourism entrepreneurship based on the example of “Stari dud d.o.o.”, analyses the
possibility of starting a rural tourism estate and its profitability. The author and investor
entrepreneur is Bojan Mraović, while the investment itself is planned to be realized
through the Stari Dud d.o.o. company. The analysis was conducted using the
methodology for creating business plans which includes a breakdown of key chapters
in order to get a concise insight into the details of the planned entrepreneurial venture.
The implementation of procedures used to make business plans has ensured a
systematic processing of data and a structured presentation of the obtained results.
Therefore, this final paper includes a definition of rural tourism as a tourist activity, a
breakdown of planned services and products to be offered, an analysis of the markets
in which participation is planned, strategies for sales maximization, a SWOT analysis,
fundamental logistical requirements for an undisrupted flow of business activities and
detailed financial data and calculations which point to the profitability of the business.
This kind of data analysis helped to understand better the profitability of the investment
and, in turn, helped to make a more informed decision about starting the business.
The investment amount is set at 1.709.697,36 HRK, while the sources of funding are
set at a ratio of 60:40 in favor of the external source in the form of a bank loan. The
analysis has shown that the business is profitable
Work on the play "The End of an Idyll"
No full textPredstava „Kraj jedne idile” autorska je predstava Bojana Dronjka i Anabele Sulić, studenata druge godine diplomskoga studija Kazališna umjetnost, smjer Neverbalni teatar. Predstava je nastala pod mentorstvom doc. art. Nenada Pavlovića i asistenta Marijana Josipovića. S obzirom na to da je u pitanju autorska predstava, u ovom sam radu nastojao obrazložiti izbor teme, samu ideju za predstavu kao i izbor scenskih izražajnih sredstava prilikom njenoga kreiranja. Povrh toga htio sam pokazati na koji smo način postdramske izvedbene forme iskoristili unutar određene dramaturške strukture proistekle iz likova. Rad se referira na literaturu navedenu na njegovom kraju.The play "The End of an Idyll" is the author project of the students Bojan Dronjak and Anabela Sulić, second year of the graduate study of Theater Arts, non-verbal theater. The performance was created under the mentorship of doc. art. Nenad Pavlović and assistant Marijan Josipović. Given that it is an authors project, in this work I tried to explain the choice of theme, the very idea for the play, as well as the choice of scenic means of expression during its creation. On top of that, I wanted to show how we used post-dramatic performance forms within a certain dramaturgical structure which is derived from the characters. The paper refers to the literature listed at the end
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