TY  - JOUR
AU  - Salević, Ana
AU  - Stojanović, Dušica
AU  - Lević, Steva
AU  - Pantić, Milena
AU  - Đorđević, Verica
AU  - Pešić, Radojica
AU  - Bugarski, Branko
AU  - Pavlović, Vladimir
AU  - Uskoković, Petar
AU  - Nedović, Viktor
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5008
AB  - In this study, in order to develop zein-based, edible, functional food-contact materials in different forms incorporating sage extract (10, 20, and 30%), solvent casting and electrospinning were employed. The study aimed to assess the effects of the applied techniques and the extract's incorporation on the materials' properties. The solvent casting generated continuous and compact films, where the extract's incorporation provided more homogenous surfaces. The electrospinning resulted in non-woven mats composed of ribbon-like fibers in the range of 1.275-1.829 mu m, while the extract's incorporation provided thinner and branched fibers. The results indicated the compatibility between the materials' constituents, and efficient and homogenous extract incorporation within the zein matrices, with more probable interactions occurring during the solvent casting. All of the formulations had a high dry matter content, whereas the mats and the formulations incorporating the extract had higher solubility and swelling in water. The films and mats presented similar DPPH center dot and ABTS(center dot+) radical scavenging abilities, while the influence on Staphylococcus aureus and Salmonella enterica subsp. enterica serovar Typhimurium bacteria, and the growth inhibition, were complex. The antioxidant and antibacterial activity of the materials were more potent after the extract's incorporation. Overall, the results highlight the potential of the developed edible materials for use as food-contact materials with active/bioactive functionality.
PB  - MDPI
T2  - Foods
T1  - The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning
IS  - 3
SP  - 390
VL  - 11
DO  - 10.3390/foods11030390
ER  - 

@article{
author = "Salević, Ana and Stojanović, Dušica and Lević, Steva and Pantić, Milena and Đorđević, Verica and Pešić, Radojica and Bugarski, Branko and Pavlović, Vladimir and Uskoković, Petar and Nedović, Viktor",
year = "2022",
abstract = "In this study, in order to develop zein-based, edible, functional food-contact materials in different forms incorporating sage extract (10, 20, and 30%), solvent casting and electrospinning were employed. The study aimed to assess the effects of the applied techniques and the extract's incorporation on the materials' properties. The solvent casting generated continuous and compact films, where the extract's incorporation provided more homogenous surfaces. The electrospinning resulted in non-woven mats composed of ribbon-like fibers in the range of 1.275-1.829 mu m, while the extract's incorporation provided thinner and branched fibers. The results indicated the compatibility between the materials' constituents, and efficient and homogenous extract incorporation within the zein matrices, with more probable interactions occurring during the solvent casting. All of the formulations had a high dry matter content, whereas the mats and the formulations incorporating the extract had higher solubility and swelling in water. The films and mats presented similar DPPH center dot and ABTS(center dot+) radical scavenging abilities, while the influence on Staphylococcus aureus and Salmonella enterica subsp. enterica serovar Typhimurium bacteria, and the growth inhibition, were complex. The antioxidant and antibacterial activity of the materials were more potent after the extract's incorporation. Overall, the results highlight the potential of the developed edible materials for use as food-contact materials with active/bioactive functionality.",
publisher = "MDPI",
journal = "Foods",
title = "The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning",
number = "3",
pages = "390",
volume = "11",
doi = "10.3390/foods11030390"
}

Salević, A., Stojanović, D., Lević, S., Pantić, M., Đorđević, V., Pešić, R., Bugarski, B., Pavlović, V., Uskoković, P.,& Nedović, V.. (2022). The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning. in Foods
MDPI., 11(3), 390.
https://doi.org/10.3390/foods11030390

Salević A, Stojanović D, Lević S, Pantić M, Đorđević V, Pešić R, Bugarski B, Pavlović V, Uskoković P, Nedović V. The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning. in Foods. 2022;11(3):390.
doi:10.3390/foods11030390 .

Salević, Ana, Stojanović, Dušica, Lević, Steva, Pantić, Milena, Đorđević, Verica, Pešić, Radojica, Bugarski, Branko, Pavlović, Vladimir, Uskoković, Petar, Nedović, Viktor, "The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning" in Foods, 11, no. 3 (2022):390,
https://doi.org/10.3390/foods11030390 . .

TY  - JOUR
AU  - Volić, Mina
AU  - Pećinar, Ilinka
AU  - Micić, Darko
AU  - Đorđević, Verica
AU  - Pešić, Radojica
AU  - Nedović, Viktor
AU  - Obradović, Nataša
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5067
AB  - Innovative coating powders, based on whey protein concentrate (10–15 wt%) as native (WPC) or denatured protein (D-WPC), solely or in combination with alginate (0.75 wt%, AL), containing thyme essential oil, were produced using the freeze-drying technique. The impact of individual components (protein, alginate and oil) as well as the effect of heat-induced protein denaturation, was resolved regarding physicochemical, thermal and morphological properties of powders. High product yield (∼100%), particle size (223–257 nm), low moisture content (0.10–0.13%) and zeta potential (−19 to −25.6 mV) were determined for all samples. Strong antimicrobial activity of thyme oil nanocarriers against foodborne pathogens was demonstrated. Thermogravimetric analysis (TGA) indicated enhanced thermal stability of encapsulated oil. The most specific bands of structural compounds were identified in Raman spectra of the tested formulations, but principal component analysis (PCA) on recorded spectra was necessary to show the differences between carriers of different wall materials.
PB  - Elsevier
T2  - Food Chemistry
T1  - Design and characterization of whey protein nanocarriers for thyme essential oil encapsulation obtained by freeze-drying
SP  - 132749
VL  - 386
DO  - 10.1016/j.foodchem.2022.132749
ER  - 

@article{
author = "Volić, Mina and Pećinar, Ilinka and Micić, Darko and Đorđević, Verica and Pešić, Radojica and Nedović, Viktor and Obradović, Nataša",
year = "2022",
abstract = "Innovative coating powders, based on whey protein concentrate (10–15 wt%) as native (WPC) or denatured protein (D-WPC), solely or in combination with alginate (0.75 wt%, AL), containing thyme essential oil, were produced using the freeze-drying technique. The impact of individual components (protein, alginate and oil) as well as the effect of heat-induced protein denaturation, was resolved regarding physicochemical, thermal and morphological properties of powders. High product yield (∼100%), particle size (223–257 nm), low moisture content (0.10–0.13%) and zeta potential (−19 to −25.6 mV) were determined for all samples. Strong antimicrobial activity of thyme oil nanocarriers against foodborne pathogens was demonstrated. Thermogravimetric analysis (TGA) indicated enhanced thermal stability of encapsulated oil. The most specific bands of structural compounds were identified in Raman spectra of the tested formulations, but principal component analysis (PCA) on recorded spectra was necessary to show the differences between carriers of different wall materials.",
publisher = "Elsevier",
journal = "Food Chemistry",
title = "Design and characterization of whey protein nanocarriers for thyme essential oil encapsulation obtained by freeze-drying",
pages = "132749",
volume = "386",
doi = "10.1016/j.foodchem.2022.132749"
}

Volić, M., Pećinar, I., Micić, D., Đorđević, V., Pešić, R., Nedović, V.,& Obradović, N.. (2022). Design and characterization of whey protein nanocarriers for thyme essential oil encapsulation obtained by freeze-drying. in Food Chemistry
Elsevier., 386, 132749.
https://doi.org/10.1016/j.foodchem.2022.132749

Volić M, Pećinar I, Micić D, Đorđević V, Pešić R, Nedović V, Obradović N. Design and characterization of whey protein nanocarriers for thyme essential oil encapsulation obtained by freeze-drying. in Food Chemistry. 2022;386:132749.
doi:10.1016/j.foodchem.2022.132749 .

Volić, Mina, Pećinar, Ilinka, Micić, Darko, Đorđević, Verica, Pešić, Radojica, Nedović, Viktor, Obradović, Nataša, "Design and characterization of whey protein nanocarriers for thyme essential oil encapsulation obtained by freeze-drying" in Food Chemistry, 386 (2022):132749,
https://doi.org/10.1016/j.foodchem.2022.132749 . .

TY  - JOUR
AU  - Brzić, Danica
AU  - Pešić, Radojica
AU  - Arsenijević, Zorana
AU  - Đuriš, Mihal
AU  - Bošković-Vragolović, Nevenka
AU  - Kaluđerović-Radoičić, Tatjana
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5052
AB  - The present work concerns an experimental study on heat transfer in gas-solid fluidized bed of coarse (Geldart D) particles to a larger immersed sphere at high superficial velocities from 2 to 5.5 Umf. The heat transfer coefficient was determined by measuring the temperature of the test sphere during its heating in a fluidized bed in the temperature range of 65–175 °C. The test spheres of different sizes and different materials were utilized. For the given gas-particles system the flow regime changes from rapidly growing bubbles to turbulent fluidization at superficial velocity Uc ≈ 3Umf. It has been found that in rapidly growing bubbles regime, the heat transfer coefficient is higher for smaller test spheres while it is almost independent of the superficial gas velocity. In turbulent regime, the heat transfer coefficient increases with increase of gas velocity while the size of the test sphere exhibits less influence. In the rapidly growing bubbles regime, experimental data for heat transfer coefficient can be predicted adequately with correlation of Scott et al.. For the turbulent flow regime a new correlation for prediction of the heat transfer coefficient has been proposed.
PB  - Taylor & Francis Online
T2  - Particulate Science and Technology
T1  - Heat transfer to a sphere immersed in a fluidized bed of coarse particles with transition from bubbling to turbulent flow regime
EP  - 83
IS  - 1
SP  - 75
VL  - 41
DO  - https://doi.org/10.1080/02726351.2022.2053015
ER  - 

@article{
author = "Brzić, Danica and Pešić, Radojica and Arsenijević, Zorana and Đuriš, Mihal and Bošković-Vragolović, Nevenka and Kaluđerović-Radoičić, Tatjana",
year = "2022",
abstract = "The present work concerns an experimental study on heat transfer in gas-solid fluidized bed of coarse (Geldart D) particles to a larger immersed sphere at high superficial velocities from 2 to 5.5 Umf. The heat transfer coefficient was determined by measuring the temperature of the test sphere during its heating in a fluidized bed in the temperature range of 65–175 °C. The test spheres of different sizes and different materials were utilized. For the given gas-particles system the flow regime changes from rapidly growing bubbles to turbulent fluidization at superficial velocity Uc ≈ 3Umf. It has been found that in rapidly growing bubbles regime, the heat transfer coefficient is higher for smaller test spheres while it is almost independent of the superficial gas velocity. In turbulent regime, the heat transfer coefficient increases with increase of gas velocity while the size of the test sphere exhibits less influence. In the rapidly growing bubbles regime, experimental data for heat transfer coefficient can be predicted adequately with correlation of Scott et al.. For the turbulent flow regime a new correlation for prediction of the heat transfer coefficient has been proposed.",
publisher = "Taylor & Francis Online",
journal = "Particulate Science and Technology",
title = "Heat transfer to a sphere immersed in a fluidized bed of coarse particles with transition from bubbling to turbulent flow regime",
pages = "83-75",
number = "1",
volume = "41",
doi = "https://doi.org/10.1080/02726351.2022.2053015"
}

Brzić, D., Pešić, R., Arsenijević, Z., Đuriš, M., Bošković-Vragolović, N.,& Kaluđerović-Radoičić, T.. (2022). Heat transfer to a sphere immersed in a fluidized bed of coarse particles with transition from bubbling to turbulent flow regime. in Particulate Science and Technology
Taylor & Francis Online., 41(1), 75-83.
https://doi.org/https://doi.org/10.1080/02726351.2022.2053015

Brzić D, Pešić R, Arsenijević Z, Đuriš M, Bošković-Vragolović N, Kaluđerović-Radoičić T. Heat transfer to a sphere immersed in a fluidized bed of coarse particles with transition from bubbling to turbulent flow regime. in Particulate Science and Technology. 2022;41(1):75-83.
doi:https://doi.org/10.1080/02726351.2022.2053015 .

Brzić, Danica, Pešić, Radojica, Arsenijević, Zorana, Đuriš, Mihal, Bošković-Vragolović, Nevenka, Kaluđerović-Radoičić, Tatjana, "Heat transfer to a sphere immersed in a fluidized bed of coarse particles with transition from bubbling to turbulent flow regime" in Particulate Science and Technology, 41, no. 1 (2022):75-83,
https://doi.org/https://doi.org/10.1080/02726351.2022.2053015 . .

TY  - JOUR
AU  - Prokić-Vidojević, Dragana
AU  - Glišić, Sandra B.
AU  - Pešić, Radojica
AU  - Orlović, Aleksandar M.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5184
AB  - Re/Pd-TiO2/SiO2 aerogel catalysts were synthesized by using a sol-gel method and supercritical drying in excess solvent and investigated in the reaction of hydrodesulphurisation (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). Both Re/Pd catalysts, obtained with and without the use of mesitylene in the synthesis step, have shown increased conversions of up to 70 % in the desulphurization of 4,6-DMDBT, when compared to conventional Co/Mo hydroprocessing catalysts. This observation is of importance for conversion of highly refractory 4,6-DMDBT and hydroprocessing to produce ultra-low sulphur diesel fuels, ULSD. In order to quantify the extent of desulphurisation, which proceeds via a hydrogenation route, conversions of DBT and 4,6-DMDBT along with evolution of reaction products characteristic for the direct desulphurisation route and the hydrogenation route were monitored by using a gas chromatography–mass spectrometry (GC-MS) analytical technique. The reaction was performed at 630 K and 6 MPa in a batch catalytic reactor. The experimental results were used in the Hougen-Watson kinetic model describing DBT and 4,6-DMDBT desulphurisation on σ and τ active sites. Kinetic parameters of this complex catalytic kinetics were determined by using a Genetic Algorithm method and minimum deviation function. Values of calculated kinetic parameters and values of the ratio of 3-methylcyclohexyltoluene (MCHT and dimethyl biphenyl (DMBPH) expressed as the MCHT/(MCHT+DMBPH) ratio ranging between 0.66 and 0.94, have confirmed that the hydrogenation route is the dominant route for desulphurisation of 4,6-DMDBT.
PB  - Association of the Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Desulphurisation of dibenzothiophene and 4,6 – dimethyl dibenzothio-phene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: Kinetic parameters estimation and modelling
T1  - Desulfurizacija dibenzotiofena i 4,6 – dimetildibenzotiofena procesom hidrogenovanja uz korišćenje RePd–TiO2/SiO2 aerogel katalizatora: proračun kinetičkih parametara i simulacijaprocesa
EP  - 145
IS  - 3
SP  - 135
VL  - 76
DO  - 10.2298/HEMIND220114008P
ER  - 

@article{
author = "Prokić-Vidojević, Dragana and Glišić, Sandra B. and Pešić, Radojica and Orlović, Aleksandar M.",
year = "2022",
abstract = "Re/Pd-TiO2/SiO2 aerogel catalysts were synthesized by using a sol-gel method and supercritical drying in excess solvent and investigated in the reaction of hydrodesulphurisation (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). Both Re/Pd catalysts, obtained with and without the use of mesitylene in the synthesis step, have shown increased conversions of up to 70 % in the desulphurization of 4,6-DMDBT, when compared to conventional Co/Mo hydroprocessing catalysts. This observation is of importance for conversion of highly refractory 4,6-DMDBT and hydroprocessing to produce ultra-low sulphur diesel fuels, ULSD. In order to quantify the extent of desulphurisation, which proceeds via a hydrogenation route, conversions of DBT and 4,6-DMDBT along with evolution of reaction products characteristic for the direct desulphurisation route and the hydrogenation route were monitored by using a gas chromatography–mass spectrometry (GC-MS) analytical technique. The reaction was performed at 630 K and 6 MPa in a batch catalytic reactor. The experimental results were used in the Hougen-Watson kinetic model describing DBT and 4,6-DMDBT desulphurisation on σ and τ active sites. Kinetic parameters of this complex catalytic kinetics were determined by using a Genetic Algorithm method and minimum deviation function. Values of calculated kinetic parameters and values of the ratio of 3-methylcyclohexyltoluene (MCHT and dimethyl biphenyl (DMBPH) expressed as the MCHT/(MCHT+DMBPH) ratio ranging between 0.66 and 0.94, have confirmed that the hydrogenation route is the dominant route for desulphurisation of 4,6-DMDBT.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Desulphurisation of dibenzothiophene and 4,6 – dimethyl dibenzothio-phene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: Kinetic parameters estimation and modelling, Desulfurizacija dibenzotiofena i 4,6 – dimetildibenzotiofena procesom hidrogenovanja uz korišćenje RePd–TiO2/SiO2 aerogel katalizatora: proračun kinetičkih parametara i simulacijaprocesa",
pages = "145-135",
number = "3",
volume = "76",
doi = "10.2298/HEMIND220114008P"
}

Prokić-Vidojević, D., Glišić, S. B., Pešić, R.,& Orlović, A. M.. (2022). Desulphurisation of dibenzothiophene and 4,6 – dimethyl dibenzothio-phene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: Kinetic parameters estimation and modelling. in Hemijska industrija
Association of the Chemical Engineers of Serbia., 76(3), 135-145.
https://doi.org/10.2298/HEMIND220114008P

Prokić-Vidojević D, Glišić SB, Pešić R, Orlović AM. Desulphurisation of dibenzothiophene and 4,6 – dimethyl dibenzothio-phene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: Kinetic parameters estimation and modelling. in Hemijska industrija. 2022;76(3):135-145.
doi:10.2298/HEMIND220114008P .

Prokić-Vidojević, Dragana, Glišić, Sandra B., Pešić, Radojica, Orlović, Aleksandar M., "Desulphurisation of dibenzothiophene and 4,6 – dimethyl dibenzothio-phene via enhanced hydrogenation reaction route using RePd–TiO2/SiO2 aerogel catalysts: Kinetic parameters estimation and modelling" in Hemijska industrija, 76, no. 3 (2022):135-145,
https://doi.org/10.2298/HEMIND220114008P . .

TY  - JOUR
AU  - Pešić, Radojica
AU  - Kaluđerović-Radoičić, Tatjana
AU  - Bošković-Vragolović, Nevenka
AU  - Arsenijević, Zorana
AU  - Grbavčić, Željko
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2926
AB  - The aim of this work was the experimental investigation of the particle friction factor for air flow through a packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20 to 350°C and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using the Ergun equation, with mean absolute deviation of 10.90%. Ergun's equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, the Ergun equation is proposed for friction factor calculation both at ambient and at elevated temperatures.
AB  - Cilj ovog rada je bio eksperimentalno ispitivanje koeficijenta trenja fluid-čestice prilikom strujanja vazduha kroz pakovani sloj čestica, na sobnoj i povišenim temperaturama. Izvršeno je eksperimentalno merenje pada pritiska u pakovanim slojevima različitih temperatura zagrejanih korišćenjem vrelog vazduha. Kao materijal za pakovanje korišćene su sferične staklene kuglice 7 različitih prečnika. Temperaturni interval u kom su vršeni eksperimenti bio je od 20 do 350°C, dok su poroznosti sloja iznosile od 0,3574 do 0,4303. Dobijeni rezultati korelisani su korišćenjem većeg broja literaturnih korelacija. Najbolje slaganje sa eksperimentalnim podacima pokazala je Ergunova jednačina [1], sa srednjim procentnim odstupanjem od 10,90%. Ergunova jednačina je dala bolje rezultate prilikom korelisanja podataka na sobnoj temperaturi (srednja procentna greška 9,77%), dok je korelisanje podataka na povišenim temperaturama izvršeno sa greškom od 12,38%. Većina testiranih literaturnih korelacija je dala bolje rezultate pri korelisanju podataka dobijenih na sobnoj temperaturi u odnosu na podatke dobijene na povišenim temperaturama. Na osnovu dobijenih rezultata, predlaže se korišćenje Ergunove jednačine za izračunavanje koeficijenta trenja fluid-čestice kako na sobnoj, tako i na povišenim temperaturama.
PB  - Association of the Chemical Engineers of Serbia
T2  - Chemical Industry & Chemical Engineering Quarterly
T1  - Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures
T1  - Pad pritiska u pakovanom sloju sferičnih čestica na sobnoj i povišenim temperaturama
EP  - 427
IS  - 3
SP  - 419
VL  - 21
DO  - 10.2298/CICEQ140618044P
ER  - 

@article{
author = "Pešić, Radojica and Kaluđerović-Radoičić, Tatjana and Bošković-Vragolović, Nevenka and Arsenijević, Zorana and Grbavčić, Željko",
year = "2015",
abstract = "The aim of this work was the experimental investigation of the particle friction factor for air flow through a packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20 to 350°C and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using the Ergun equation, with mean absolute deviation of 10.90%. Ergun's equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, the Ergun equation is proposed for friction factor calculation both at ambient and at elevated temperatures., Cilj ovog rada je bio eksperimentalno ispitivanje koeficijenta trenja fluid-čestice prilikom strujanja vazduha kroz pakovani sloj čestica, na sobnoj i povišenim temperaturama. Izvršeno je eksperimentalno merenje pada pritiska u pakovanim slojevima različitih temperatura zagrejanih korišćenjem vrelog vazduha. Kao materijal za pakovanje korišćene su sferične staklene kuglice 7 različitih prečnika. Temperaturni interval u kom su vršeni eksperimenti bio je od 20 do 350°C, dok su poroznosti sloja iznosile od 0,3574 do 0,4303. Dobijeni rezultati korelisani su korišćenjem većeg broja literaturnih korelacija. Najbolje slaganje sa eksperimentalnim podacima pokazala je Ergunova jednačina [1], sa srednjim procentnim odstupanjem od 10,90%. Ergunova jednačina je dala bolje rezultate prilikom korelisanja podataka na sobnoj temperaturi (srednja procentna greška 9,77%), dok je korelisanje podataka na povišenim temperaturama izvršeno sa greškom od 12,38%. Većina testiranih literaturnih korelacija je dala bolje rezultate pri korelisanju podataka dobijenih na sobnoj temperaturi u odnosu na podatke dobijene na povišenim temperaturama. Na osnovu dobijenih rezultata, predlaže se korišćenje Ergunove jednačine za izračunavanje koeficijenta trenja fluid-čestice kako na sobnoj, tako i na povišenim temperaturama.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry & Chemical Engineering Quarterly",
title = "Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures, Pad pritiska u pakovanom sloju sferičnih čestica na sobnoj i povišenim temperaturama",
pages = "427-419",
number = "3",
volume = "21",
doi = "10.2298/CICEQ140618044P"
}

Pešić, R., Kaluđerović-Radoičić, T., Bošković-Vragolović, N., Arsenijević, Z.,& Grbavčić, Ž.. (2015). Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures. in Chemical Industry & Chemical Engineering Quarterly
Association of the Chemical Engineers of Serbia., 21(3), 419-427.
https://doi.org/10.2298/CICEQ140618044P

Pešić R, Kaluđerović-Radoičić T, Bošković-Vragolović N, Arsenijević Z, Grbavčić Ž. Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures. in Chemical Industry & Chemical Engineering Quarterly. 2015;21(3):419-427.
doi:10.2298/CICEQ140618044P .

Pešić, Radojica, Kaluđerović-Radoičić, Tatjana, Bošković-Vragolović, Nevenka, Arsenijević, Zorana, Grbavčić, Željko, "Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures" in Chemical Industry & Chemical Engineering Quarterly, 21, no. 3 (2015):419-427,
https://doi.org/10.2298/CICEQ140618044P . .

TY  - JOUR
AU  - Pešić, Radojica
AU  - Kaluđerović-Radoičić, Tatjana
AU  - Bošković-Vragolović, Nevenka
AU  - Arsenijević, Zorana
AU  - Grbavčić, Željko
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2727
AB  - In this paper, heat transfer coefficients between the hot packed beds of particles and the larger cold immersed sphere were experimentally determined. The packed beds consisted of mono-sized spherical glass particles of d(p), = 1.2, 1.94 and 2.98 mm. The aluminum test spheres of D-p = 6, 12 and 20 mm with K-type (Ni/A1) thermocouples inserted in them were immersed into the bed. The temperatures of the test spheres were recorded until the thermal equilibrium was reached. From these recordings, heat transfer coefficients were determined. The experiments were performed in the range of gas superficial velocity of similar to 0.3-0.8 m/s and the bed temperature from 90 to 320 degrees C. It was found that the measured heat transfer coefficients increased with the increase in gas superficial velocity, while only a slight increase with temperature was observed for test spheres D-p = 6 and 12 mm in the investigated temperature interval. The heat transfer coefficients were generally larger for smaller test spheres, while they did not show significant dependence on the size of the bed particles. The literature correlations for heat transfer coefficients in packed beds in form of Nusselt number and heat transfer factor j(H) were compared to experimental data from this work. The correlations proposed by Collier et al. (2004) [18] and Handley and Heggs (1968) [2] fit our experimental data best. The mean error between the experimentally determined heat transfer coefficients and the ones calculated from Collier et al. (2004) [18] correlation was 12.7%.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - International Journal of Heat and Mass Transfer
T1  - Heat transfer between a packed bed and a larger immersed spherical particle
EP  - 136
SP  - 130
VL  - 78
DO  - 10.1016/j.ijheatmasstransfer.2014.06.040
ER  - 

@article{
author = "Pešić, Radojica and Kaluđerović-Radoičić, Tatjana and Bošković-Vragolović, Nevenka and Arsenijević, Zorana and Grbavčić, Željko",
year = "2014",
abstract = "In this paper, heat transfer coefficients between the hot packed beds of particles and the larger cold immersed sphere were experimentally determined. The packed beds consisted of mono-sized spherical glass particles of d(p), = 1.2, 1.94 and 2.98 mm. The aluminum test spheres of D-p = 6, 12 and 20 mm with K-type (Ni/A1) thermocouples inserted in them were immersed into the bed. The temperatures of the test spheres were recorded until the thermal equilibrium was reached. From these recordings, heat transfer coefficients were determined. The experiments were performed in the range of gas superficial velocity of similar to 0.3-0.8 m/s and the bed temperature from 90 to 320 degrees C. It was found that the measured heat transfer coefficients increased with the increase in gas superficial velocity, while only a slight increase with temperature was observed for test spheres D-p = 6 and 12 mm in the investigated temperature interval. The heat transfer coefficients were generally larger for smaller test spheres, while they did not show significant dependence on the size of the bed particles. The literature correlations for heat transfer coefficients in packed beds in form of Nusselt number and heat transfer factor j(H) were compared to experimental data from this work. The correlations proposed by Collier et al. (2004) [18] and Handley and Heggs (1968) [2] fit our experimental data best. The mean error between the experimentally determined heat transfer coefficients and the ones calculated from Collier et al. (2004) [18] correlation was 12.7%.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "International Journal of Heat and Mass Transfer",
title = "Heat transfer between a packed bed and a larger immersed spherical particle",
pages = "136-130",
volume = "78",
doi = "10.1016/j.ijheatmasstransfer.2014.06.040"
}

Pešić, R., Kaluđerović-Radoičić, T., Bošković-Vragolović, N., Arsenijević, Z.,& Grbavčić, Ž.. (2014). Heat transfer between a packed bed and a larger immersed spherical particle. in International Journal of Heat and Mass Transfer
Pergamon-Elsevier Science Ltd, Oxford., 78, 130-136.
https://doi.org/10.1016/j.ijheatmasstransfer.2014.06.040

Pešić R, Kaluđerović-Radoičić T, Bošković-Vragolović N, Arsenijević Z, Grbavčić Ž. Heat transfer between a packed bed and a larger immersed spherical particle. in International Journal of Heat and Mass Transfer. 2014;78:130-136.
doi:10.1016/j.ijheatmasstransfer.2014.06.040 .

Pešić, Radojica, Kaluđerović-Radoičić, Tatjana, Bošković-Vragolović, Nevenka, Arsenijević, Zorana, Grbavčić, Željko, "Heat transfer between a packed bed and a larger immersed spherical particle" in International Journal of Heat and Mass Transfer, 78 (2014):130-136,
https://doi.org/10.1016/j.ijheatmasstransfer.2014.06.040 . .

TY  - JOUR
AU  - Nedović, Viktor
AU  - Leskošek-Čukalović, Ida
AU  - Trifunović, Olivera
AU  - Pešić, Radojica
AU  - Bugarski, Branko
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/329
AB  - In beer brewing with immobilized yeast cells it is very important to minimize the mass transfer resistance, problem associated with large diameter beads, because the mass transfer limitations may force the cells to alter their metabolic states and thus, impact the efficiency of fermentation process and quality of final beer. Internal mass transfer can be optimized by adjusting the immobilization matrix size, texture and porosity. The classical dripping method, that is commonly used to produce gel beads, has a limitation in the large diameter of the produced beads, which is typically 2 to 3 mm. In recent time other techniques have been developed to produce smaller particles of equal size. The major objective of this study was to optimize the bead size by using the new technique, electrostatic droplet generation. We have obtained promising results since in this way it was possible to produce very small uniform microbeads (in the diameter range of several hundreds of micrometers to 2 mm) under stable conditions. The size of beads was strongly influenced by applied potential, needle size and electrode distance.
AB  - Pri primeni imobilisanih ćelija kvasca u fermentaciji piva važno je, kako sa aspekta produktivnosti sistema, tako i sa aspekta hemijskog sastava piva, da se otpori prenosu mase supstrata i proizvoda metabolizma ćelija unutar matrice nosača svedu na najmanju moguću meru. Ovo se može postići podešavanjem veličine, teksture i poroznosti matrice nosača. Obzirom da klasična tehnika imobilizacije kvasca u matrici Ca-alginata daje čestice većih dimenzija (prečnika od 2 do 3 mm), danas je razvijeno vise različitih tehnika koje pružaju mogućnost dobijanja čestica malih dimenzija. Jedna od novih tehnika, čije su mogućnosti primene u cilju optimizacije veličine alginatnih čestica ispitivane u sklopu ovog istraživanja, je postupak elektrostatičke ekstruzije. Dobijeni rezultati su pokazali daje primenom ove tehnike moguće dobiti kontrolisanu i stabilnu proizvodnju mikro čestica uniformne veličine, čiji se prečnik kretao u rasponu od nekoliko stotina mikrometara do 2 mm, u zavisnosti od primenjene razlike potencijala, prečnika igle i rastojanja između elektroda.
PB  - Faculty of Technology, Novi Sad
T2  - Acta periodica technologica
T1  - Immobilization of yeast cells in small alginate beads using electrostatic droplet generation
T1  - Primena postupka elektrostatičke ekstruzije pri dobijanju alginatnih čestica malih dimenzija sa imobilisanim ćelijama pivskog kvasca
EP  - 597
IS  - 31
SP  - 591
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_172
ER  - 

@article{
author = "Nedović, Viktor and Leskošek-Čukalović, Ida and Trifunović, Olivera and Pešić, Radojica and Bugarski, Branko",
year = "2000",
abstract = "In beer brewing with immobilized yeast cells it is very important to minimize the mass transfer resistance, problem associated with large diameter beads, because the mass transfer limitations may force the cells to alter their metabolic states and thus, impact the efficiency of fermentation process and quality of final beer. Internal mass transfer can be optimized by adjusting the immobilization matrix size, texture and porosity. The classical dripping method, that is commonly used to produce gel beads, has a limitation in the large diameter of the produced beads, which is typically 2 to 3 mm. In recent time other techniques have been developed to produce smaller particles of equal size. The major objective of this study was to optimize the bead size by using the new technique, electrostatic droplet generation. We have obtained promising results since in this way it was possible to produce very small uniform microbeads (in the diameter range of several hundreds of micrometers to 2 mm) under stable conditions. The size of beads was strongly influenced by applied potential, needle size and electrode distance., Pri primeni imobilisanih ćelija kvasca u fermentaciji piva važno je, kako sa aspekta produktivnosti sistema, tako i sa aspekta hemijskog sastava piva, da se otpori prenosu mase supstrata i proizvoda metabolizma ćelija unutar matrice nosača svedu na najmanju moguću meru. Ovo se može postići podešavanjem veličine, teksture i poroznosti matrice nosača. Obzirom da klasična tehnika imobilizacije kvasca u matrici Ca-alginata daje čestice većih dimenzija (prečnika od 2 do 3 mm), danas je razvijeno vise različitih tehnika koje pružaju mogućnost dobijanja čestica malih dimenzija. Jedna od novih tehnika, čije su mogućnosti primene u cilju optimizacije veličine alginatnih čestica ispitivane u sklopu ovog istraživanja, je postupak elektrostatičke ekstruzije. Dobijeni rezultati su pokazali daje primenom ove tehnike moguće dobiti kontrolisanu i stabilnu proizvodnju mikro čestica uniformne veličine, čiji se prečnik kretao u rasponu od nekoliko stotina mikrometara do 2 mm, u zavisnosti od primenjene razlike potencijala, prečnika igle i rastojanja između elektroda.",
publisher = "Faculty of Technology, Novi Sad",
journal = "Acta periodica technologica",
title = "Immobilization of yeast cells in small alginate beads using electrostatic droplet generation, Primena postupka elektrostatičke ekstruzije pri dobijanju alginatnih čestica malih dimenzija sa imobilisanim ćelijama pivskog kvasca",
pages = "597-591",
number = "31",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_172"
}

Nedović, V., Leskošek-Čukalović, I., Trifunović, O., Pešić, R.,& Bugarski, B.. (2000). Immobilization of yeast cells in small alginate beads using electrostatic droplet generation. in Acta periodica technologica
Faculty of Technology, Novi Sad.(31), 591-597.
https://hdl.handle.net/21.15107/rcub_agrospace_172

Nedović V, Leskošek-Čukalović I, Trifunović O, Pešić R, Bugarski B. Immobilization of yeast cells in small alginate beads using electrostatic droplet generation. in Acta periodica technologica. 2000;(31):591-597.
https://hdl.handle.net/21.15107/rcub_agrospace_172 .

Nedović, Viktor, Leskošek-Čukalović, Ida, Trifunović, Olivera, Pešić, Radojica, Bugarski, Branko, "Immobilization of yeast cells in small alginate beads using electrostatic droplet generation" in Acta periodica technologica, no. 31 (2000):591-597,
https://hdl.handle.net/21.15107/rcub_agrospace_172 .