TY  - CONF
AU  - Bošnjaković, Jovana
AU  - Đuričković, Ivan
AU  - Milanovic, Jovana
AU  - Grujić, Dragana
AU  - Marinković, Aleksandar
AU  - Manasijević, Srećko
AU  - Milošević, Milena
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7056
AB  - In the last decades, the rapid development of industrial and agricultural activity caused the release of different organic/or nonorganic pollutants in water, earth, and air which lead to a threat to human health and the ecological environment. These pollutants contain toxic heavy metals, organic dyes, pesticides, pharmaceutics, and others (Aboua et al., 2015). Organic dyes are visible pollutants used as coloring agents in, textiles, plastics, paper, food industries, etc. For their removal from wastewater, eco-friendly treatment is needed. Among many process purification, the process of adsorption proved to be an effective method for removing pollutants that are present in water, such as pesticides, dyes, and heavy metal ions. Due to the specific properties of polluting substances, the goal is to develop a cheap, efficient, environmentally friendly material. Among them, cotton-based materials can be obtained from various natural sources and can be employed as inexpensive adsorbents. Their adsorption capacities for pollutants can be related to chemical treatment. In general, chemically modified cellulose exhibits higher adsorption capacities for various aquatic pollutants than their unmodified forms. In this aim, oxidized cotton fabric was used in this work, which was chemically modified with citric acid and ethyl lysinate, respectively. In order to activate the surface of the fabric for chemical modification and increase absorption ability, carboxyl and aldehyde functional groups were introduced using hydrogen peroxide. Then the oxidized cotton fabric was cross-linked with citric acid and ethyl lysinate (Co-CA-Et-Lys) using diisopropylcarboimide to promote ester and amide groups formation. The structure of obtained material was analyzed by using the ATR-FTIR technique. The resulting modified fabric proved to be a good adsorbent for the removal of cationic dyes malachite green (MG) and methylene blue (MB). Its adsorption behavior with respect to the pH, adsorption time, and initial concentration was investigated. Based on the obtained results, it was concluded that the adsorption equilibrium was reached after 1 h for both Malachite Green (MG) and Methylene Blue (MB). Adsorption kinetics data were satisfactorily fitted with the pseudo-second-order rate model (PSO), and adsorption data were best fitted using Langmuir model. The Langmuir maximum adsorption capacities for Co-CA-Et-Lys cross-linked fabric showed a maximum of 168.4 mg/g and 124.9 mg/g for MG and MB, respectively. Compared to other adsorbents based on natural materials, oxidized cotton fabric showed much better sorption properties.
PB  - Zvornik : Faculty of Technology
C3  - Proceedings - 8th International Congress “Engineering, Environment and Materials in Process Industry“ – EEM2023, 20-23 March 2023, Jahorina, Republic of Srpska, Bosnia and Herzegovina
T1  - Oxidized cotton fabric cross-linked with citric acid and ethyl lysinate for cationic dyes adsorption
SP  - 310
EP  - 316
UR  - https://hdl.handle.net/21.15107/rcub_cer_7056
ER  - 

@conference{
author = "Bošnjaković, Jovana and Đuričković, Ivan and Milanovic, Jovana and Grujić, Dragana and Marinković, Aleksandar and Manasijević, Srećko and Milošević, Milena",
year = "2023",
abstract = "In the last decades, the rapid development of industrial and agricultural activity caused the release of different organic/or nonorganic pollutants in water, earth, and air which lead to a threat to human health and the ecological environment. These pollutants contain toxic heavy metals, organic dyes, pesticides, pharmaceutics, and others (Aboua et al., 2015). Organic dyes are visible pollutants used as coloring agents in, textiles, plastics, paper, food industries, etc. For their removal from wastewater, eco-friendly treatment is needed. Among many process purification, the process of adsorption proved to be an effective method for removing pollutants that are present in water, such as pesticides, dyes, and heavy metal ions. Due to the specific properties of polluting substances, the goal is to develop a cheap, efficient, environmentally friendly material. Among them, cotton-based materials can be obtained from various natural sources and can be employed as inexpensive adsorbents. Their adsorption capacities for pollutants can be related to chemical treatment. In general, chemically modified cellulose exhibits higher adsorption capacities for various aquatic pollutants than their unmodified forms. In this aim, oxidized cotton fabric was used in this work, which was chemically modified with citric acid and ethyl lysinate, respectively. In order to activate the surface of the fabric for chemical modification and increase absorption ability, carboxyl and aldehyde functional groups were introduced using hydrogen peroxide. Then the oxidized cotton fabric was cross-linked with citric acid and ethyl lysinate (Co-CA-Et-Lys) using diisopropylcarboimide to promote ester and amide groups formation. The structure of obtained material was analyzed by using the ATR-FTIR technique. The resulting modified fabric proved to be a good adsorbent for the removal of cationic dyes malachite green (MG) and methylene blue (MB). Its adsorption behavior with respect to the pH, adsorption time, and initial concentration was investigated. Based on the obtained results, it was concluded that the adsorption equilibrium was reached after 1 h for both Malachite Green (MG) and Methylene Blue (MB). Adsorption kinetics data were satisfactorily fitted with the pseudo-second-order rate model (PSO), and adsorption data were best fitted using Langmuir model. The Langmuir maximum adsorption capacities for Co-CA-Et-Lys cross-linked fabric showed a maximum of 168.4 mg/g and 124.9 mg/g for MG and MB, respectively. Compared to other adsorbents based on natural materials, oxidized cotton fabric showed much better sorption properties.",
publisher = "Zvornik : Faculty of Technology",
journal = "Proceedings - 8th International Congress “Engineering, Environment and Materials in Process Industry“ – EEM2023, 20-23 March 2023, Jahorina, Republic of Srpska, Bosnia and Herzegovina",
title = "Oxidized cotton fabric cross-linked with citric acid and ethyl lysinate for cationic dyes adsorption",
pages = "310-316",
url = "https://hdl.handle.net/21.15107/rcub_cer_7056"
}

Bošnjaković, J., Đuričković, I., Milanovic, J., Grujić, D., Marinković, A., Manasijević, S.,& Milošević, M.. (2023). Oxidized cotton fabric cross-linked with citric acid and ethyl lysinate for cationic dyes adsorption. in Proceedings - 8th International Congress “Engineering, Environment and Materials in Process Industry“ – EEM2023, 20-23 March 2023, Jahorina, Republic of Srpska, Bosnia and Herzegovina
Zvornik : Faculty of Technology., 310-316.
https://hdl.handle.net/21.15107/rcub_cer_7056

Bošnjaković J, Đuričković I, Milanovic J, Grujić D, Marinković A, Manasijević S, Milošević M. Oxidized cotton fabric cross-linked with citric acid and ethyl lysinate for cationic dyes adsorption. in Proceedings - 8th International Congress “Engineering, Environment and Materials in Process Industry“ – EEM2023, 20-23 March 2023, Jahorina, Republic of Srpska, Bosnia and Herzegovina. 2023;:310-316.
https://hdl.handle.net/21.15107/rcub_cer_7056 .

Bošnjaković, Jovana, Đuričković, Ivan, Milanovic, Jovana, Grujić, Dragana, Marinković, Aleksandar, Manasijević, Srećko, Milošević, Milena, "Oxidized cotton fabric cross-linked with citric acid and ethyl lysinate for cationic dyes adsorption" in Proceedings - 8th International Congress “Engineering, Environment and Materials in Process Industry“ – EEM2023, 20-23 March 2023, Jahorina, Republic of Srpska, Bosnia and Herzegovina (2023):310-316,
https://hdl.handle.net/21.15107/rcub_cer_7056 .

TY  - CONF
AU  - Milošević, Milena
AU  - Marinković, Aleksandar
AU  - Batinić, Petar M.
AU  - Đuričković, Ivan
AU  - Jovanović, Aleksandra A.
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7336
AB  - Thymus serpyllum L. (wild thyme) extracts were prepared using 1 g of plant material and three natural deep eutectic solvents (30 mL, malic acid+maltose, lactic acid+menthol, or citric acid+glycerol with 50% of water) in maceration (90 min). The extracts were characterized in terms of total polyphenol content (TPC), total protein content, extraction yield, zeta potential, conductivity, pH, density, surface tension, and viscosity. TPC was the highest in citric acid+glycerol extract (35.06±1.13 mg gallic acid equivalents (GAE)/g of plant material), whereas malic acid+maltose and lactic acid+menthol extracts possessed similar TPC (29.62±1.11 and 28.94±1.15 mg GAE/g, respectively). Total protein content amounted to 5.55±0.20 mg/g in citric acid+glycerol extract, while significantly lower values were determined in malic acid+maltose and lactic acid+menthol extracts (1.22±0.30 and 1.73±0.18 mg/g, respectively). The extraction yield was the highest for citric acid+glycerol extract, 1.57±0.11%, followed by malic acid+maltose and lactic acid+menthol extracts, 1.28±0.10 and 1.27±0.13%, respectively. Zeta potential (absolute value, as a predictor of potential application in water treatment) was low in all extracts (0.86±0.06 mV for citric acid+glycerol, -0.35±0.09 mV for lactic acid+menthol, and -0.17±0.05 mV for malic acid+maltose extract). The conductivity (as a predictor of antioxidant capacity) was in the range of 2.35±0.21 and 2.71±0.29 mS/cm (citric acid+glycerol and malic acid+maltose extracts) to 5.70±0.23 mS/cm (lactic acid+menthol extract). pH ranged from 1.44 in citric acid+glycerol extract to 1.78 and 1.85 in malic acid+maltose and lactic acid+menthol extracts. Density varied from 1.067±0.003 g/mL for lactic acid+menthol extract to 1.169±0.002 and 1.195±0.005 g/mL for citric acid+glycerol and malic acid+maltose extracts. Surface tension was the highest in citric acid+glycerol extract (38.0±0.4 mN/m), followed by malic acid+maltose and lactic acid+menthol extracts (31.5±0.4 and 25.9±0.1 mN/m, respectively). The viscosity of lactic acid+menthol extract was significantly lower (1.83±0.30 mPa•s) in comparison to malic acid+maltose and citric acid+glycerol extracts (6.64±0.15 and 7.84±0.10 mPa•s, respectively). The highest TPC, total proteins, and extraction yield were measured in citric acid+glycerol extract, while lactic acid+menthol extract possessed the highest conductivity and the lowest density, surface tension, and viscosity. Therefore, the constitution of natural deep eutectic solvent should be optimized depending on the future application of T. serpyllum extract.
PB  - Zvornik : University of East Sarajevo, Faculty of Technology
C3  - Proceedings - VIII International Congress "Engineering, Environment and Materials in Process Industry", EEM 2023, March 20-23 2023, Jahorina
T1  - Physicochemical characterisation of Thymus serpyllum extracts prepared using natural deep eutectic solvents
SP  - 258
EP  - 266
UR  - https://hdl.handle.net/21.15107/rcub_cer_7336
ER  - 

@conference{
author = "Milošević, Milena and Marinković, Aleksandar and Batinić, Petar M. and Đuričković, Ivan and Jovanović, Aleksandra A.",
year = "2023",
abstract = "Thymus serpyllum L. (wild thyme) extracts were prepared using 1 g of plant material and three natural deep eutectic solvents (30 mL, malic acid+maltose, lactic acid+menthol, or citric acid+glycerol with 50% of water) in maceration (90 min). The extracts were characterized in terms of total polyphenol content (TPC), total protein content, extraction yield, zeta potential, conductivity, pH, density, surface tension, and viscosity. TPC was the highest in citric acid+glycerol extract (35.06±1.13 mg gallic acid equivalents (GAE)/g of plant material), whereas malic acid+maltose and lactic acid+menthol extracts possessed similar TPC (29.62±1.11 and 28.94±1.15 mg GAE/g, respectively). Total protein content amounted to 5.55±0.20 mg/g in citric acid+glycerol extract, while significantly lower values were determined in malic acid+maltose and lactic acid+menthol extracts (1.22±0.30 and 1.73±0.18 mg/g, respectively). The extraction yield was the highest for citric acid+glycerol extract, 1.57±0.11%, followed by malic acid+maltose and lactic acid+menthol extracts, 1.28±0.10 and 1.27±0.13%, respectively. Zeta potential (absolute value, as a predictor of potential application in water treatment) was low in all extracts (0.86±0.06 mV for citric acid+glycerol, -0.35±0.09 mV for lactic acid+menthol, and -0.17±0.05 mV for malic acid+maltose extract). The conductivity (as a predictor of antioxidant capacity) was in the range of 2.35±0.21 and 2.71±0.29 mS/cm (citric acid+glycerol and malic acid+maltose extracts) to 5.70±0.23 mS/cm (lactic acid+menthol extract). pH ranged from 1.44 in citric acid+glycerol extract to 1.78 and 1.85 in malic acid+maltose and lactic acid+menthol extracts. Density varied from 1.067±0.003 g/mL for lactic acid+menthol extract to 1.169±0.002 and 1.195±0.005 g/mL for citric acid+glycerol and malic acid+maltose extracts. Surface tension was the highest in citric acid+glycerol extract (38.0±0.4 mN/m), followed by malic acid+maltose and lactic acid+menthol extracts (31.5±0.4 and 25.9±0.1 mN/m, respectively). The viscosity of lactic acid+menthol extract was significantly lower (1.83±0.30 mPa•s) in comparison to malic acid+maltose and citric acid+glycerol extracts (6.64±0.15 and 7.84±0.10 mPa•s, respectively). The highest TPC, total proteins, and extraction yield were measured in citric acid+glycerol extract, while lactic acid+menthol extract possessed the highest conductivity and the lowest density, surface tension, and viscosity. Therefore, the constitution of natural deep eutectic solvent should be optimized depending on the future application of T. serpyllum extract.",
publisher = "Zvornik : University of East Sarajevo, Faculty of Technology",
journal = "Proceedings - VIII International Congress "Engineering, Environment and Materials in Process Industry", EEM 2023, March 20-23 2023, Jahorina",
title = "Physicochemical characterisation of Thymus serpyllum extracts prepared using natural deep eutectic solvents",
pages = "258-266",
url = "https://hdl.handle.net/21.15107/rcub_cer_7336"
}

Milošević, M., Marinković, A., Batinić, P. M., Đuričković, I.,& Jovanović, A. A.. (2023). Physicochemical characterisation of Thymus serpyllum extracts prepared using natural deep eutectic solvents. in Proceedings - VIII International Congress "Engineering, Environment and Materials in Process Industry", EEM 2023, March 20-23 2023, Jahorina
Zvornik : University of East Sarajevo, Faculty of Technology., 258-266.
https://hdl.handle.net/21.15107/rcub_cer_7336

Milošević M, Marinković A, Batinić PM, Đuričković I, Jovanović AA. Physicochemical characterisation of Thymus serpyllum extracts prepared using natural deep eutectic solvents. in Proceedings - VIII International Congress "Engineering, Environment and Materials in Process Industry", EEM 2023, March 20-23 2023, Jahorina. 2023;:258-266.
https://hdl.handle.net/21.15107/rcub_cer_7336 .

Milošević, Milena, Marinković, Aleksandar, Batinić, Petar M., Đuričković, Ivan, Jovanović, Aleksandra A., "Physicochemical characterisation of Thymus serpyllum extracts prepared using natural deep eutectic solvents" in Proceedings - VIII International Congress "Engineering, Environment and Materials in Process Industry", EEM 2023, March 20-23 2023, Jahorina (2023):258-266,
https://hdl.handle.net/21.15107/rcub_cer_7336 .

TY  - CONF
AU  - Milentijević, Goran
AU  - Marinković, Tijana
AU  - Rančić, Milica
AU  - Milošević, Milena
AU  - Đuričković, Ivan
AU  - Marinković, Aleksandar D.
AU  - Milosavljević, Milutin M.
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/6936
AB  - This work presents an optimized laboratory procedure for the synthesis of zinc dimethyldithiocarbamate (Ziram) by the reaction of the sodium salt of dimethyl dithiocarbamic acid and zinc sulfate. The reaction of synthesis of the sodium salt of dimethyl-dithiocarbamic acid takes place starting from dimethylamine, carbon disulfide and sodium hydroxide solution. To the prepared acidified aqueous solution of zinc sulphate, a solution of the sodium salt of dimethyl dithiocarbamic acid was added, whereby zinc dimethyldithiocarbamate is formed in the form of a suspension. The suspension is filtered, the filter cake is washed with water to remove the sulfate ion and dried. The structure of the obtained Ziram was confirmed by IR, 1H and 13C NMR and MS instrumental methods, and the purity was determined by the classical analytical method. The obtained product zinc dimethyldithiocarbamate was ground, formulated and used in pomiculture as fungicide under the trade name Ziram.
PB  - University of Belgrade, Technical Faculty in Bor
C3  - 29th International Conference Ecological Truth and Environmental Research - EcoTER'22, 21-24 June 2022, Sokobanja, Serbia
T1  - Optimization of zinc dimethyldithiocarbamate synthesis process (ziram)
SP  - 343
EP  - 349
UR  - https://hdl.handle.net/21.15107/rcub_cer_6936
ER  - 

@conference{
author = "Milentijević, Goran and Marinković, Tijana and Rančić, Milica and Milošević, Milena and Đuričković, Ivan and Marinković, Aleksandar D. and Milosavljević, Milutin M.",
year = "2022",
abstract = "This work presents an optimized laboratory procedure for the synthesis of zinc dimethyldithiocarbamate (Ziram) by the reaction of the sodium salt of dimethyl dithiocarbamic acid and zinc sulfate. The reaction of synthesis of the sodium salt of dimethyl-dithiocarbamic acid takes place starting from dimethylamine, carbon disulfide and sodium hydroxide solution. To the prepared acidified aqueous solution of zinc sulphate, a solution of the sodium salt of dimethyl dithiocarbamic acid was added, whereby zinc dimethyldithiocarbamate is formed in the form of a suspension. The suspension is filtered, the filter cake is washed with water to remove the sulfate ion and dried. The structure of the obtained Ziram was confirmed by IR, 1H and 13C NMR and MS instrumental methods, and the purity was determined by the classical analytical method. The obtained product zinc dimethyldithiocarbamate was ground, formulated and used in pomiculture as fungicide under the trade name Ziram.",
publisher = "University of Belgrade, Technical Faculty in Bor",
journal = "29th International Conference Ecological Truth and Environmental Research - EcoTER'22, 21-24 June 2022, Sokobanja, Serbia",
title = "Optimization of zinc dimethyldithiocarbamate synthesis process (ziram)",
pages = "343-349",
url = "https://hdl.handle.net/21.15107/rcub_cer_6936"
}

Milentijević, G., Marinković, T., Rančić, M., Milošević, M., Đuričković, I., Marinković, A. D.,& Milosavljević, M. M.. (2022). Optimization of zinc dimethyldithiocarbamate synthesis process (ziram). in 29th International Conference Ecological Truth and Environmental Research - EcoTER'22, 21-24 June 2022, Sokobanja, Serbia
University of Belgrade, Technical Faculty in Bor., 343-349.
https://hdl.handle.net/21.15107/rcub_cer_6936

Milentijević G, Marinković T, Rančić M, Milošević M, Đuričković I, Marinković AD, Milosavljević MM. Optimization of zinc dimethyldithiocarbamate synthesis process (ziram). in 29th International Conference Ecological Truth and Environmental Research - EcoTER'22, 21-24 June 2022, Sokobanja, Serbia. 2022;:343-349.
https://hdl.handle.net/21.15107/rcub_cer_6936 .

Milentijević, Goran, Marinković, Tijana, Rančić, Milica, Milošević, Milena, Đuričković, Ivan, Marinković, Aleksandar D., Milosavljević, Milutin M., "Optimization of zinc dimethyldithiocarbamate synthesis process (ziram)" in 29th International Conference Ecological Truth and Environmental Research - EcoTER'22, 21-24 June 2022, Sokobanja, Serbia (2022):343-349,
https://hdl.handle.net/21.15107/rcub_cer_6936 .

TY  - CONF
AU  - Milošević, Milena
AU  - Kovačina, Jovanka
AU  - Marunkić, Dunja
AU  - Đuričković, Ivan
AU  - Perendija, Jovana
AU  - Milošević, Dragana
AU  - Cvijetić, Ilija
AU  - Marinković, Aleksandar
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7069
AB  - In this study, the corrosion inhibitory activity of symmetrical bis(imino)pyridine (BIP-16) was tested by the Linear Polarization Resistance (LPR) and Electrochemical Impendence Spectroscopy (EIS) methods on zinc and iron. The investigation was carried out in a neutral and acidic medium of 0.5 M NaCI solution. The temperature-dependent (25-45 °C) inhibitory efficacy of BIP-16 on iron and zinc was tested in an acidic medium (pH 3). Under the same conditions, the time dependence of BIP-16 up to 72 h was examined . Moreover, a synergistic effect of BIP-16 with cerium acetate was also examined in time and temperature (25-45 °C) dependence on zinc (pH 7) and iron (pH 3) in 0.5 M NaCI solution at optimal concentrations. The inhibition efficiency of BIP-16 declined with time on both zinc and iron indicating physisorption. Also, kinetic and thermodynamic parameters of this process were calculated. To gain deeper insights into the inhibitory mechanism of tested compounds, DFT calculations were performed.
PB  - Leskovac : Faculty of Technology
C3  - Book of abstracts - 14th symposium "Novel technologies and economic development", October 22-23 2021, Leskovac
T1  - Eco-friendly bis(imino)pyridine as corrosion inhibitor for iron and zinc in NaCl solution
SP  - 95
EP  - 95
UR  - https://hdl.handle.net/21.15107/rcub_cer_7069
ER  - 

@conference{
author = "Milošević, Milena and Kovačina, Jovanka and Marunkić, Dunja and Đuričković, Ivan and Perendija, Jovana and Milošević, Dragana and Cvijetić, Ilija and Marinković, Aleksandar",
year = "2021",
abstract = "In this study, the corrosion inhibitory activity of symmetrical bis(imino)pyridine (BIP-16) was tested by the Linear Polarization Resistance (LPR) and Electrochemical Impendence Spectroscopy (EIS) methods on zinc and iron. The investigation was carried out in a neutral and acidic medium of 0.5 M NaCI solution. The temperature-dependent (25-45 °C) inhibitory efficacy of BIP-16 on iron and zinc was tested in an acidic medium (pH 3). Under the same conditions, the time dependence of BIP-16 up to 72 h was examined . Moreover, a synergistic effect of BIP-16 with cerium acetate was also examined in time and temperature (25-45 °C) dependence on zinc (pH 7) and iron (pH 3) in 0.5 M NaCI solution at optimal concentrations. The inhibition efficiency of BIP-16 declined with time on both zinc and iron indicating physisorption. Also, kinetic and thermodynamic parameters of this process were calculated. To gain deeper insights into the inhibitory mechanism of tested compounds, DFT calculations were performed.",
publisher = "Leskovac : Faculty of Technology",
journal = "Book of abstracts - 14th symposium "Novel technologies and economic development", October 22-23 2021, Leskovac",
title = "Eco-friendly bis(imino)pyridine as corrosion inhibitor for iron and zinc in NaCl solution",
pages = "95-95",
url = "https://hdl.handle.net/21.15107/rcub_cer_7069"
}

Milošević, M., Kovačina, J., Marunkić, D., Đuričković, I., Perendija, J., Milošević, D., Cvijetić, I.,& Marinković, A.. (2021). Eco-friendly bis(imino)pyridine as corrosion inhibitor for iron and zinc in NaCl solution. in Book of abstracts - 14th symposium "Novel technologies and economic development", October 22-23 2021, Leskovac
Leskovac : Faculty of Technology., 95-95.
https://hdl.handle.net/21.15107/rcub_cer_7069

Milošević M, Kovačina J, Marunkić D, Đuričković I, Perendija J, Milošević D, Cvijetić I, Marinković A. Eco-friendly bis(imino)pyridine as corrosion inhibitor for iron and zinc in NaCl solution. in Book of abstracts - 14th symposium "Novel technologies and economic development", October 22-23 2021, Leskovac. 2021;:95-95.
https://hdl.handle.net/21.15107/rcub_cer_7069 .

Milošević, Milena, Kovačina, Jovanka, Marunkić, Dunja, Đuričković, Ivan, Perendija, Jovana, Milošević, Dragana, Cvijetić, Ilija, Marinković, Aleksandar, "Eco-friendly bis(imino)pyridine as corrosion inhibitor for iron and zinc in NaCl solution" in Book of abstracts - 14th symposium "Novel technologies and economic development", October 22-23 2021, Leskovac (2021):95-95,
https://hdl.handle.net/21.15107/rcub_cer_7069 .