Radovan Karkalic - Academia.edu (original) (raw)

Papers by Radovan Karkalic

FME Transactions, 2019

Defining the Ideality of the Protective Masks by the Mathematical Modeling Method Technical contr... more Defining the Ideality of the Protective Masks by the Mathematical Modeling Method Technical contradiction occurs when the system improves one parameter, which automatically causes the deterioration of some of its other parameters. In such a situation, instead of usual acceptance of the optimization of the solution to the problem, in inventology-the process of idealization is carried out for finding the ideal final solution for the given problem. It is achieved if the physical contradictions that exist within the technical contradiction are solved. The paper deals with the procedure of mathematical modeling in determining the level of ideality as a criterion for the effectiveness of the Serbian military protective masks model M3 (mark ZM M3) in relation to the Serbian protective mask of the previous generation of the M2FV label (phonic with the drinking water subsystem). The presented mathematical model for the protective mask can be used as a standard for determining the idealness of any engineering system.

Vojnotehnički Glasnik, 2008

Jedno od najznačajnijih sredstava za hemijsku zaštitu u uslovima visokotoksične kontaminacije pre... more Jedno od najznačajnijih sredstava za hemijsku zaštitu u uslovima visokotoksične kontaminacije predstavlja zaštitno filtrirajuće odelo koje svojom konstrukcijom omogućava bolju fiziološku podobnost od izolirajućih zaštitnih sredstava. U radu su prikazane metode i rezultati ispitivanja fiziološke podobnosti nekoliko različitih modela filtrirajućih zaštitnih odela kojima je predviđeno opremanje Vojske Srbije i jedinica civilne zaštite. Ispitivana je tolerancija na nekompenzovani toplotni stres ispitanika pri korišćenju četiri modela ovog odela, a u toku simulacije vršenja osnovnih namenskih zadataka u toploj sredini, koje je obuhvatilo ispitivanje u klimatskoj komori i terenskim uslovima pri realizaciji namenskih zadataka. Upoređeni su parametri tolerancije na toplotni stres i donet zaključak o uticaju nošenja određenog odela na intenzitet toplotnog stresa i neuropsihološke funkcije.

Research on Chemical Intermediates, May 29, 2013

The pseudo-equilibrium concentrations of the H+, IO3−, and H2OI+ ions, kinetically very important... more The pseudo-equilibrium concentrations of the H+, IO3−, and H2OI+ ions, kinetically very important species in the disproportionation reaction of iodous acid, have been determined from the equilibrium dissociation reactions of sulfuric and iodous acids in the quasi-stationary state. The values observed were higher than the concentration of the protonated ion of hypoiodous acid.

Scientific-technical Review, 2019

Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pest... more Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pesticides, drugs or chemical warfare agents. Their acute toxicity is ascribed to the inhibition of acetylcholinesterase (AChE), a key enzyme in the transmission of nerve impulses in mammals. Their toxic effects are manifested by the accumulation of acetylcholine and can lead to the paralysis or death. OPs poisoning therapy is based on the application of specific antidotes as well as non-specific and symptomatic procedures. In this contribution, recent achievements concerning the protection from OPs activity and an overview of the methods for their removal from the environment and decontamination of contaminated persons were presented

Challenges to national defence in contemporary geopolitical situation, Oct 31, 2022

The pandemic situation associated with the occurrence of COVID-19 has necessitated the initiation... more The pandemic situation associated with the occurrence of COVID-19 has necessitated the initiation or renewal of research activities aimed at the possibility of using materials that will have very good post-accident properties. One of the materials that have been developed, tested and applied in the past has been materials based on the spherical fullerene C 60 molecule. A microstructure using REM and SEM and sorptive properties of fullerene C 60 for gases of toluene with the employment of a QCM detector has been studied. Obtained micrographs are discussed in relation to a possible spatial arrangement at the molecular level. The envisaged solution aims to develop a sensor that, due to its surface properties, would be useful for the detection of gas and liquid phases of chemical warfare agents and industrial chemicals. It is envisaged that the surface layer consisting of fullerene C 60 will be universally applicable, reusable and low cost and low maintenance.

Vojnosanitetski Pregled, 2014

Background/Aim. In military services, emergency situations when soldiers are exposed to a combina... more Background/Aim. In military services, emergency situations when soldiers are exposed to a combination of nuclear, biological and chemical (NBC) contamination combined with heat stress, are frequent and complex. In these specific conditions, usage of personal body cooling systems may be effective in reducing heat stress. The present study was conducted in order to evaluate the efficiency of four various types of contemporary personal body cooling systems based on the "Phase Change Material" (PCM), and its effects on soldiers' subjective comfort and physiological performance during exertional heat stress in hot environments. Methods. Ten male soldiers were voluntarily subjected to exertional heat stress tests (EHSTs) consisted of walking on a treadmill (5.5 km/h) in hot conditions (40ºC) in climatic chamber, wearing NBC isolating impermeable protective suits. One of the tests was performed without any additional cooling solution (NOCOOL), and four tests were performed while using different types of cooling systems: three in a form of vests and one as underwear. Physiological strain was determined by the mean skin temperature (Tsk), tympanic temperature (Tty), and heart rate values (HR), while sweat rates (SwR) indicated changes in hydration status. Results. In all the cases EHST induced physiological response manifested through increasing Tty, HR and SwR. Compared to NOCOOL tests, when using cooling vests, Tty and Tsk were significantly lower (on 35th min, for 0.44 ± 0.03 and 0.49 ± 0.05ºC, respectively; p < 0.05), as well as the average SwR (0.17 ± 0.03 L/m 2 /h). When using underwear, the values of given parameters were not significantly different compared to NOCOOL tests. Conclusions. Using a body cooling system based on PCM in the form of vest under NBC protective clothes during physical activity in hot conditions, reduces sweating and alleviates heat stress manifested by increased core and skin temperatures and heart rate values. These effects directly improve heat tolerance, hydration state, decrease in the risk of heat illness, and extends the duration of soldiers' exposure to extreme conditions.

Scientific-technical Review, 2019

Vojnotehnički Glasnik, 2017

This paper presents the characteristics of the materials used in footwear industry, with a partic... more This paper presents the characteristics of the materials used in footwear industry, with a particular emphasis on polyurethane materials for making soles. The role, purpose and design of soles are also discussed, as well as the requirements this part of the shoe should satisfy. The manufacturing of polyurethane soles by liquid injection molding technology (LIM technology) is described, namely its two procedures. In the first one, the sole is obtained by pouring polyurethane into an open tool, and the second one is direct injection of polyurethane on the shoe upper in a closed tool, thus completing the production of finished footwear.

Materials, methods & technologies, Jul 1, 2016

The paper presents a new type of modified glassy carbon paste electrode with different Co-ferrite... more The paper presents a new type of modified glassy carbon paste electrode with different Co-ferrites. First part of this work was the preparation of ferrites by five different methods such as hydrothermal, ultrasound and microwave-assisted hydrothermal, mechanochemical and sol-gel synthesis. Ferrite nanoparticles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). They were used for preparation new modified glassy carbon paste electrode (CoFeMGCPE). The electrode was used for determination of nanomolar level of copper ions in waste waters using electrochemical methods such as differential pulse anodic stripping voltammetry, DPASV. A significant increase in current was achieved at the modified electrode in comparison with the bare glassy carbon paste electrode. Detection limit for the proposed electrode was 30nM Cu when percentage of modifier was 3%, pH 4.5, deposition potential-0.3 V and deposition time 4min. This electrode was successfully applied for determination of copper ions in waste water without any pretreatment.

International Journal of Electrochemical Science

Materials, methods & technologies, 2018

A novel, low cost adsorbent, a cerium supported on high porous carbon from fish scales carp (Cypr... more A novel, low cost adsorbent, a cerium supported on high porous carbon from fish scales carp (Cyprinus carpio), has been synthesized to remove As(V) ions from water. The synthesis consisted of chemical and thermal treatment for converting the fish scales into the porous carbon decorated by cerium nanoparticles. By changing the reaction conditions, the porosity and the content of the CeO2 nanoparticles may be controlled in synthesized porous carbon. By optimizing the reaction parameters, using the response surface methodology (RSM) where the output is the result of the adsorbent capacity, a highly efficient material (CeO2-HPC) with a capacity of 81.664 mg g -1 (Langmuir isothermal model) was obtained to remove As (V) ions from the drinking water. The adsorption studies were conducted as a function of pH, contact time, mass of adsorbent and temperature. The best sorption of arsenate ions was achieved for pH between 4.0 and 6.0. The adsorption data for arsenate at 25, 35 and 45 °C are f...

Materials, methods & technologies, 2016

The paper presents a new type of modified glassy carbon paste electrode with different Coferrites... more The paper presents a new type of modified glassy carbon paste electrode with different Coferrites. First part of this work was the preparation of ferrites by five different methods such as hydrothermal, ultrasound and microwave-assisted hydrothermal, mechanochemical and sol-gel synthesis. Ferrite nanoparticles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). They were used for preparation new modified glassy carbon paste electrode (CoFeMGCPE). The electrode was used for determination of nanomolar level of copper ions in waste waters using electrochemical methods such as differential pulse anodic stripping voltammetry, DPASV. A significant increase in current was achieved at the modified electrode in comparison with the bare glassy carbon paste electrode. Detection limit for the proposed electrode was 30nM Cu when percentage of modifier was 3%, pH 4.5, deposition potential -0.3 V and deposition time 4min. This electrode was successfully applied...

Materials, methods & technologies, 2015

This paper presents results related to thermo-physiological efficiency of special underwear where... more This paper presents results related to thermo-physiological efficiency of special underwear where organic PCM integrated in textile through microencapsulation process. The efficiency of PCM underwear was tested through physiological examinations in simulated hot conditions (climate chamber, 40 oC, max. 45 min), where test-subjects voluntarily exposed to heat stress tests wearing NBC protective suit without underwear (option "NoTHERM") and with PCM underwear (option "THERM"). Physiological strain level was determined by measuring volunteer’s heat stress indicators: mean skin temperature (Tsk), body core temperature (Tty), hart rate (HR) and sweat rate (SwR). In climate chamber, compared to "NoTHERM" tests, when using thermoregulation clothes based on PCM (option "THERM"), parameters Tty, Tsk and HR were significantly lower, as well as average SwR. It can be concluded that wearing a textile clothes for body thermoregulation based on integrated o...

DESALINATION AND WATER TREATMENT, 2020

The synthesis and adsorption potential of Cy-npAg, obtained by modification of raw montmorillonit... more The synthesis and adsorption potential of Cy-npAg, obtained by modification of raw montmorillonite clay (raw-Cy) with silver nanoparticle (npAg), was studied in this work. Optimization procedure, with respect to time, temperature and amount of deposit npAg, obtained either by reductive precipitation or ultraviolet irradiation, was performed using response surface methodology (RSM). The most efficient adsorbent, obtained by chemical reduction of silver ion with sodium borohydride, named Cy-npAg, was characterized in detail using Brunauer-Emmett-Teller, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques, and point of zero charge determination. The Cy-npAg showed good adsorption capacity with respect to non-systemic organophosphate insecticide (diazinon) as well as of heavy metals ions (Cd 2+ and Ni 2+ ions), that is, 74.26, 62.33, and 35.49 mg g-1 , respectively, obtained from Langmuir model fitting. Temperature dependent kinetic study allowed determination of pseudo-second rate constant (10 3 g mg-1 min-1)/activation energies (kJ mol-1): 1.45/14.48 for diazinon, and 1.27/6.59 and 0.7/7.35 kJ mol-1 for Cd 2+ and Ni 2+ ions, respectively. Thermodynamic parameters indicated feasible and spontaneous adsorption with main participation of physisorption. Antibacterial potential of npAg deposit for water disinfection was confirmed by the moderate reduction of bacterial growth of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, by 64%, 39%, and 70%, respectively. Thus, two synergistic effects contribute to water purification processes using Cy-npAg: pollutants removal with a simultaneous decrease of the microbial contamination contributing to overall water quality improvement.

Scientific Technical Review, 2019

Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pest... more Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pesticides, drugs or chemical warfare agents. Their acute toxicity is ascribed to the inhibition of acetylcholinesterase (AChE), a key enzyme in the transmission of nerve impulses in mammals. Their toxic effects are manifested by the accumulation of acetylcholine and can lead to the paralysis or death. OPs poisoning therapy is based on the application of specific antidotes as well as non-specific and symptomatic procedures. In this contribution, recent achievements concerning the protection from OPs activity and an overview of the methods for their removal from the environment and decontamination of contaminated persons were presented

Scientific Technical Review, 2015

Simultaneous influence of corrosion, static and dynamic loads on the elements of aircraft structu... more Simultaneous influence of corrosion, static and dynamic loads on the elements of aircraft structures influence to a large extent their mechanical properties and the foreseen length of their service. The paper presents the influence of corrosion on physical and mechanical properties of the test bars made from materials for a wide range of applications which are used in aircraft structural elements manufacturing. Study comprises laboratory testing of bars for the simultaneous influence of corrosive environment, static and dynamic load. The problems are pinpointed regarding the use of strain gauges for continuous monitoring of the condition in real time. In addition, this paper deals with a modern non-destructive testing and evaluation system (NDT&E), whose operation is based on thermal image processing. Thermographic method has been used to detect a hidden corrosion in the aircraft structure in real life. The study results have shown the possibility of NDT application in simple and quick detection of areas affected by corrosion that are visually invisible

International conference KNOWLEDGE-BASED ORGANIZATION, 2017

Study of barrier material resistance against permeation of toxic compounds belongs to a category ... more Study of barrier material resistance against permeation of toxic compounds belongs to a category of chemical warfare agents and toxic industrial chemicals are permanently insufficiently solved problems. This work deals with changes in approaches to testing barrier materials against toxic compounds permeation in static and dynamic conditions. An aim of this information is to describe specifications of cancelled norms of ČSN EN ISO 6529 (2002) a ČSN EN 374-3 (2004) with newly established norms ČSN EN 16523-1 a 16523-2 (2015). Authors focused on specification and comments of changes in such parts of norms concerning their scope, terms and definitions. A selected problem was solved with the help of analyse of newly established norms in a form of comments. Conditions for specification of understanding of mentioned problems in a context of established or occasionally prepared methods of testing resistance barrier materials against toxic compounds permeation have been formed with elaborate...

The efficiency of a thin layered activated charcoal material used in chemical protective overgarm... more The efficiency of a thin layered activated charcoal material used in chemical protective overgarments has been evaluated. The study has been conducted with the aim to obtain protective materials with best characteristics considering resistance to benzene effect under dynamic conditions and to create a new filtration protection device. In order to evaluate dynamic adsorption characteristics of thin layered sorption materials, sophisticated dynamic gas chromatography method is used. The curves of benzene penetration are determined for sandwich materials, and sorption layers used in filtrating protective clothing shows that thin layered carbon sorption materials (type M00) have good protective properties as compared to other similar materials. The findings will help to create conditions for developing a functional model for producing a new protective overgarment in the near future.

FME Transactions, 2019

Defining the Ideality of the Protective Masks by the Mathematical Modeling Method Technical contr... more Defining the Ideality of the Protective Masks by the Mathematical Modeling Method Technical contradiction occurs when the system improves one parameter, which automatically causes the deterioration of some of its other parameters. In such a situation, instead of usual acceptance of the optimization of the solution to the problem, in inventology-the process of idealization is carried out for finding the ideal final solution for the given problem. It is achieved if the physical contradictions that exist within the technical contradiction are solved. The paper deals with the procedure of mathematical modeling in determining the level of ideality as a criterion for the effectiveness of the Serbian military protective masks model M3 (mark ZM M3) in relation to the Serbian protective mask of the previous generation of the M2FV label (phonic with the drinking water subsystem). The presented mathematical model for the protective mask can be used as a standard for determining the idealness of any engineering system.

Vojnotehnički Glasnik, 2008

Jedno od najznačajnijih sredstava za hemijsku zaštitu u uslovima visokotoksične kontaminacije pre... more Jedno od najznačajnijih sredstava za hemijsku zaštitu u uslovima visokotoksične kontaminacije predstavlja zaštitno filtrirajuće odelo koje svojom konstrukcijom omogućava bolju fiziološku podobnost od izolirajućih zaštitnih sredstava. U radu su prikazane metode i rezultati ispitivanja fiziološke podobnosti nekoliko različitih modela filtrirajućih zaštitnih odela kojima je predviđeno opremanje Vojske Srbije i jedinica civilne zaštite. Ispitivana je tolerancija na nekompenzovani toplotni stres ispitanika pri korišćenju četiri modela ovog odela, a u toku simulacije vršenja osnovnih namenskih zadataka u toploj sredini, koje je obuhvatilo ispitivanje u klimatskoj komori i terenskim uslovima pri realizaciji namenskih zadataka. Upoređeni su parametri tolerancije na toplotni stres i donet zaključak o uticaju nošenja određenog odela na intenzitet toplotnog stresa i neuropsihološke funkcije.

Research on Chemical Intermediates, May 29, 2013

The pseudo-equilibrium concentrations of the H+, IO3−, and H2OI+ ions, kinetically very important... more The pseudo-equilibrium concentrations of the H+, IO3−, and H2OI+ ions, kinetically very important species in the disproportionation reaction of iodous acid, have been determined from the equilibrium dissociation reactions of sulfuric and iodous acids in the quasi-stationary state. The values observed were higher than the concentration of the protonated ion of hypoiodous acid.

Scientific-technical Review, 2019

Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pest... more Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pesticides, drugs or chemical warfare agents. Their acute toxicity is ascribed to the inhibition of acetylcholinesterase (AChE), a key enzyme in the transmission of nerve impulses in mammals. Their toxic effects are manifested by the accumulation of acetylcholine and can lead to the paralysis or death. OPs poisoning therapy is based on the application of specific antidotes as well as non-specific and symptomatic procedures. In this contribution, recent achievements concerning the protection from OPs activity and an overview of the methods for their removal from the environment and decontamination of contaminated persons were presented

Challenges to national defence in contemporary geopolitical situation, Oct 31, 2022

The pandemic situation associated with the occurrence of COVID-19 has necessitated the initiation... more The pandemic situation associated with the occurrence of COVID-19 has necessitated the initiation or renewal of research activities aimed at the possibility of using materials that will have very good post-accident properties. One of the materials that have been developed, tested and applied in the past has been materials based on the spherical fullerene C 60 molecule. A microstructure using REM and SEM and sorptive properties of fullerene C 60 for gases of toluene with the employment of a QCM detector has been studied. Obtained micrographs are discussed in relation to a possible spatial arrangement at the molecular level. The envisaged solution aims to develop a sensor that, due to its surface properties, would be useful for the detection of gas and liquid phases of chemical warfare agents and industrial chemicals. It is envisaged that the surface layer consisting of fullerene C 60 will be universally applicable, reusable and low cost and low maintenance.

Vojnosanitetski Pregled, 2014

Background/Aim. In military services, emergency situations when soldiers are exposed to a combina... more Background/Aim. In military services, emergency situations when soldiers are exposed to a combination of nuclear, biological and chemical (NBC) contamination combined with heat stress, are frequent and complex. In these specific conditions, usage of personal body cooling systems may be effective in reducing heat stress. The present study was conducted in order to evaluate the efficiency of four various types of contemporary personal body cooling systems based on the "Phase Change Material" (PCM), and its effects on soldiers' subjective comfort and physiological performance during exertional heat stress in hot environments. Methods. Ten male soldiers were voluntarily subjected to exertional heat stress tests (EHSTs) consisted of walking on a treadmill (5.5 km/h) in hot conditions (40ºC) in climatic chamber, wearing NBC isolating impermeable protective suits. One of the tests was performed without any additional cooling solution (NOCOOL), and four tests were performed while using different types of cooling systems: three in a form of vests and one as underwear. Physiological strain was determined by the mean skin temperature (Tsk), tympanic temperature (Tty), and heart rate values (HR), while sweat rates (SwR) indicated changes in hydration status. Results. In all the cases EHST induced physiological response manifested through increasing Tty, HR and SwR. Compared to NOCOOL tests, when using cooling vests, Tty and Tsk were significantly lower (on 35th min, for 0.44 ± 0.03 and 0.49 ± 0.05ºC, respectively; p < 0.05), as well as the average SwR (0.17 ± 0.03 L/m 2 /h). When using underwear, the values of given parameters were not significantly different compared to NOCOOL tests. Conclusions. Using a body cooling system based on PCM in the form of vest under NBC protective clothes during physical activity in hot conditions, reduces sweating and alleviates heat stress manifested by increased core and skin temperatures and heart rate values. These effects directly improve heat tolerance, hydration state, decrease in the risk of heat illness, and extends the duration of soldiers' exposure to extreme conditions.

Scientific-technical Review, 2019

Vojnotehnički Glasnik, 2017

This paper presents the characteristics of the materials used in footwear industry, with a partic... more This paper presents the characteristics of the materials used in footwear industry, with a particular emphasis on polyurethane materials for making soles. The role, purpose and design of soles are also discussed, as well as the requirements this part of the shoe should satisfy. The manufacturing of polyurethane soles by liquid injection molding technology (LIM technology) is described, namely its two procedures. In the first one, the sole is obtained by pouring polyurethane into an open tool, and the second one is direct injection of polyurethane on the shoe upper in a closed tool, thus completing the production of finished footwear.

Materials, methods & technologies, Jul 1, 2016

The paper presents a new type of modified glassy carbon paste electrode with different Co-ferrite... more The paper presents a new type of modified glassy carbon paste electrode with different Co-ferrites. First part of this work was the preparation of ferrites by five different methods such as hydrothermal, ultrasound and microwave-assisted hydrothermal, mechanochemical and sol-gel synthesis. Ferrite nanoparticles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). They were used for preparation new modified glassy carbon paste electrode (CoFeMGCPE). The electrode was used for determination of nanomolar level of copper ions in waste waters using electrochemical methods such as differential pulse anodic stripping voltammetry, DPASV. A significant increase in current was achieved at the modified electrode in comparison with the bare glassy carbon paste electrode. Detection limit for the proposed electrode was 30nM Cu when percentage of modifier was 3%, pH 4.5, deposition potential-0.3 V and deposition time 4min. This electrode was successfully applied for determination of copper ions in waste water without any pretreatment.

International Journal of Electrochemical Science

Materials, methods & technologies, 2018

A novel, low cost adsorbent, a cerium supported on high porous carbon from fish scales carp (Cypr... more A novel, low cost adsorbent, a cerium supported on high porous carbon from fish scales carp (Cyprinus carpio), has been synthesized to remove As(V) ions from water. The synthesis consisted of chemical and thermal treatment for converting the fish scales into the porous carbon decorated by cerium nanoparticles. By changing the reaction conditions, the porosity and the content of the CeO2 nanoparticles may be controlled in synthesized porous carbon. By optimizing the reaction parameters, using the response surface methodology (RSM) where the output is the result of the adsorbent capacity, a highly efficient material (CeO2-HPC) with a capacity of 81.664 mg g -1 (Langmuir isothermal model) was obtained to remove As (V) ions from the drinking water. The adsorption studies were conducted as a function of pH, contact time, mass of adsorbent and temperature. The best sorption of arsenate ions was achieved for pH between 4.0 and 6.0. The adsorption data for arsenate at 25, 35 and 45 °C are f...

Materials, methods & technologies, 2016

The paper presents a new type of modified glassy carbon paste electrode with different Coferrites... more The paper presents a new type of modified glassy carbon paste electrode with different Coferrites. First part of this work was the preparation of ferrites by five different methods such as hydrothermal, ultrasound and microwave-assisted hydrothermal, mechanochemical and sol-gel synthesis. Ferrite nanoparticles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). They were used for preparation new modified glassy carbon paste electrode (CoFeMGCPE). The electrode was used for determination of nanomolar level of copper ions in waste waters using electrochemical methods such as differential pulse anodic stripping voltammetry, DPASV. A significant increase in current was achieved at the modified electrode in comparison with the bare glassy carbon paste electrode. Detection limit for the proposed electrode was 30nM Cu when percentage of modifier was 3%, pH 4.5, deposition potential -0.3 V and deposition time 4min. This electrode was successfully applied...

Materials, methods & technologies, 2015

This paper presents results related to thermo-physiological efficiency of special underwear where... more This paper presents results related to thermo-physiological efficiency of special underwear where organic PCM integrated in textile through microencapsulation process. The efficiency of PCM underwear was tested through physiological examinations in simulated hot conditions (climate chamber, 40 oC, max. 45 min), where test-subjects voluntarily exposed to heat stress tests wearing NBC protective suit without underwear (option "NoTHERM") and with PCM underwear (option "THERM"). Physiological strain level was determined by measuring volunteer’s heat stress indicators: mean skin temperature (Tsk), body core temperature (Tty), hart rate (HR) and sweat rate (SwR). In climate chamber, compared to "NoTHERM" tests, when using thermoregulation clothes based on PCM (option "THERM"), parameters Tty, Tsk and HR were significantly lower, as well as average SwR. It can be concluded that wearing a textile clothes for body thermoregulation based on integrated o...

DESALINATION AND WATER TREATMENT, 2020

The synthesis and adsorption potential of Cy-npAg, obtained by modification of raw montmorillonit... more The synthesis and adsorption potential of Cy-npAg, obtained by modification of raw montmorillonite clay (raw-Cy) with silver nanoparticle (npAg), was studied in this work. Optimization procedure, with respect to time, temperature and amount of deposit npAg, obtained either by reductive precipitation or ultraviolet irradiation, was performed using response surface methodology (RSM). The most efficient adsorbent, obtained by chemical reduction of silver ion with sodium borohydride, named Cy-npAg, was characterized in detail using Brunauer-Emmett-Teller, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques, and point of zero charge determination. The Cy-npAg showed good adsorption capacity with respect to non-systemic organophosphate insecticide (diazinon) as well as of heavy metals ions (Cd 2+ and Ni 2+ ions), that is, 74.26, 62.33, and 35.49 mg g-1 , respectively, obtained from Langmuir model fitting. Temperature dependent kinetic study allowed determination of pseudo-second rate constant (10 3 g mg-1 min-1)/activation energies (kJ mol-1): 1.45/14.48 for diazinon, and 1.27/6.59 and 0.7/7.35 kJ mol-1 for Cd 2+ and Ni 2+ ions, respectively. Thermodynamic parameters indicated feasible and spontaneous adsorption with main participation of physisorption. Antibacterial potential of npAg deposit for water disinfection was confirmed by the moderate reduction of bacterial growth of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, by 64%, 39%, and 70%, respectively. Thus, two synergistic effects contribute to water purification processes using Cy-npAg: pollutants removal with a simultaneous decrease of the microbial contamination contributing to overall water quality improvement.

Scientific Technical Review, 2019

Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pest... more Esters of organophosphorus acids (OPs) are widely used nowadays. They have an application as pesticides, drugs or chemical warfare agents. Their acute toxicity is ascribed to the inhibition of acetylcholinesterase (AChE), a key enzyme in the transmission of nerve impulses in mammals. Their toxic effects are manifested by the accumulation of acetylcholine and can lead to the paralysis or death. OPs poisoning therapy is based on the application of specific antidotes as well as non-specific and symptomatic procedures. In this contribution, recent achievements concerning the protection from OPs activity and an overview of the methods for their removal from the environment and decontamination of contaminated persons were presented

Scientific Technical Review, 2015

Simultaneous influence of corrosion, static and dynamic loads on the elements of aircraft structu... more Simultaneous influence of corrosion, static and dynamic loads on the elements of aircraft structures influence to a large extent their mechanical properties and the foreseen length of their service. The paper presents the influence of corrosion on physical and mechanical properties of the test bars made from materials for a wide range of applications which are used in aircraft structural elements manufacturing. Study comprises laboratory testing of bars for the simultaneous influence of corrosive environment, static and dynamic load. The problems are pinpointed regarding the use of strain gauges for continuous monitoring of the condition in real time. In addition, this paper deals with a modern non-destructive testing and evaluation system (NDT&E), whose operation is based on thermal image processing. Thermographic method has been used to detect a hidden corrosion in the aircraft structure in real life. The study results have shown the possibility of NDT application in simple and quick detection of areas affected by corrosion that are visually invisible

International conference KNOWLEDGE-BASED ORGANIZATION, 2017

Study of barrier material resistance against permeation of toxic compounds belongs to a category ... more Study of barrier material resistance against permeation of toxic compounds belongs to a category of chemical warfare agents and toxic industrial chemicals are permanently insufficiently solved problems. This work deals with changes in approaches to testing barrier materials against toxic compounds permeation in static and dynamic conditions. An aim of this information is to describe specifications of cancelled norms of ČSN EN ISO 6529 (2002) a ČSN EN 374-3 (2004) with newly established norms ČSN EN 16523-1 a 16523-2 (2015). Authors focused on specification and comments of changes in such parts of norms concerning their scope, terms and definitions. A selected problem was solved with the help of analyse of newly established norms in a form of comments. Conditions for specification of understanding of mentioned problems in a context of established or occasionally prepared methods of testing resistance barrier materials against toxic compounds permeation have been formed with elaborate...

The efficiency of a thin layered activated charcoal material used in chemical protective overgarm... more The efficiency of a thin layered activated charcoal material used in chemical protective overgarments has been evaluated. The study has been conducted with the aim to obtain protective materials with best characteristics considering resistance to benzene effect under dynamic conditions and to create a new filtration protection device. In order to evaluate dynamic adsorption characteristics of thin layered sorption materials, sophisticated dynamic gas chromatography method is used. The curves of benzene penetration are determined for sandwich materials, and sorption layers used in filtrating protective clothing shows that thin layered carbon sorption materials (type M00) have good protective properties as compared to other similar materials. The findings will help to create conditions for developing a functional model for producing a new protective overgarment in the near future.