2018 EMF-Med 1st World Conference on Biomedical Applications of Electromagnetic Fields (EMF-Med), 2018
A water-based suspension of biogenic magnetite nanocrystals extracted from cultured magnetotactic... more A water-based suspension of biogenic magnetite nanocrystals extracted from cultured magnetotactic bacteria was exposed to a set of electromagnetic stimuli in the range (0.1-3) GHz. Controlled exposure was provided and the heating rate of the suspension was measured in each case, providing a comparison between the thermal response of this suspension and pure water, in order to quantify the role of biogenic magnetite in absorbing the electromagnetic field.
2018 International Conference and Exposition on Electrical And Power Engineering (EPE), 2018
Water-based suspensions of magnetotactic bacteria (MTB) containing magnetite (Fe3O4) nanocrystals... more Water-based suspensions of magnetotactic bacteria (MTB) containing magnetite (Fe3O4) nanocrystals in the form of magnetosomes (MS) chained inside the bacteria cells have been exposed to radiofrequency fields with the aim of observing how the electromagnetic energy is converted and expressed as thermal or non-thermal effects. A wide frequency band was tested, (0.1-2.9) GHz, by applying continuous wave stimuli. Significant field strength components were provided and characterized, by using a GTEM cell and adequate expo-dosimetric instruments. The heating rates of the suspensions were measured. Because the recorded values were very low, non-thermal expression of energetic conversion was further investigated by scanning-transmission electron microscopy methods, by various spectroscopic means and by electrical conductivity determinations. Clear non-thermal effects were revealed, which need further research.
A dual band mobile phone model was used to check the shielding properties of an amorphous ferroma... more A dual band mobile phone model was used to check the shielding properties of an amorphous ferromagnetic textile against the radiation emitted by the handset. Two frequencies belonging to the 2nd and 3rd generation of mobile emission technologies were used, 897 MHz and 1950 MHz. The specific absorption rate (SAR) of energy deposition in a human head phantom was measured in standardized conditions. The textile contained micrometric-diameter wires of a ferromagnetic mixture embedded in a thin glass coat and weaved in a specific way. A set of fabric orientations and configurations (layering) were provided in the experiment in order to achieve a better shielding to the phone’s radiation. Compared with the non-shielded handset, SAR deposited in the head while using the fabric-covered phone could be decreased up to 30 % of its initial value – in case of 2G technology and up to 24 % – in case of 3G technology. This type of material shows one of the highest shielding efficiencies of the elec...
International conference KNOWLEDGE-BASED ORGANIZATION, 2019
The paper presents a synthesis of the research performed on the electromagnetic properties and ch... more The paper presents a synthesis of the research performed on the electromagnetic properties and characterization of textile and non-textile materials with applications in shielding and protection from the electromagnetic field. The composite structures of functional textiles intended for protective clothing or general applications for electromagnetic immunity are presented and characterized. There are analyzed composite textiles with amorphous, ferrous or non-ferromagnetic metallic threads manufactured by means of woven and knitting classical technologies as well as materials using non-metallic, electrically conductive powders. The properties of the plain jersey, rib jersey, full and half cardigan fabric, Milano rib, are presented, too. Besides textiles, there are also characterized some composite and non-composite structures using metallic yarns and carbon powder. Another direction of interest relates to the use of textile materials with amorphous metal structure with the scope of a...
2016 International Conference and Exposition on Electrical and Power Engineering (EPE), 2016
Woven fabrics with metallic yarns were produced and tested for their electromagnetic shielding pr... more Woven fabrics with metallic yarns were produced and tested for their electromagnetic shielding properties in the ultra high frequency band. After shielding effectiveness was measured in a dual transverse electromagnetic cell, seven types of woven fabrics containing Bekinox, copper and silver yarns were further tested for their capabilities to reduce the mobile phone radiation. Results indicate that shielding effectiveness itself should not be used as a unique indicator of the protective characteristic when it comes to mobile phone radiation. We have proved that the use of such woven fabrics as cover of the handset may result in both reducing and increasing the absorbed energy in the head.
2016 International Conference on Communications (COMM), 2016
Experimental checking of the specific absorption rate (SAR) level modifications when using conduc... more Experimental checking of the specific absorption rate (SAR) level modifications when using conductive textiles attached to mobile phone handsets was applied by using the COMOSAR system in both 2G and 3G communication standards. Based on measured data, SAR reduction effectiveness was calculated. Results indicated either shielded or amplified absorbed radiation in the head, depending on the communication technology and on the fabric position to the handset. A discussion based on SAR hotspot position variation with respect to different experimental scenarios is also provided.
International conference KNOWLEDGE-BASED ORGANIZATION, 2016
An analysis of the shielding effectiveness by the method of dual transversal electromagnetic cell... more An analysis of the shielding effectiveness by the method of dual transversal electromagnetic cell is proposed for a set of conductive materials of the type wire-inserted textiles. Based on the experimental results, some of the materials are further on used to test their capability to effectively reduce the specific absorption rate of energy deposition in the head due to mobile phone, when they are covering the surface of the handset. It is demonstrated that both reducing and increasing the radiation that penetrates the head may appear, and this depends on both the material structure, its position and orientation relative to the device and to the frequency band the phone is emitting.
2018 EMF-Med 1st World Conference on Biomedical Applications of Electromagnetic Fields (EMF-Med), 2018
A water-based suspension of biogenic magnetite nanocrystals extracted from cultured magnetotactic... more A water-based suspension of biogenic magnetite nanocrystals extracted from cultured magnetotactic bacteria was exposed to a set of electromagnetic stimuli in the range (0.1-3) GHz. Controlled exposure was provided and the heating rate of the suspension was measured in each case, providing a comparison between the thermal response of this suspension and pure water, in order to quantify the role of biogenic magnetite in absorbing the electromagnetic field.
2018 International Conference and Exposition on Electrical And Power Engineering (EPE), 2018
Water-based suspensions of magnetotactic bacteria (MTB) containing magnetite (Fe3O4) nanocrystals... more Water-based suspensions of magnetotactic bacteria (MTB) containing magnetite (Fe3O4) nanocrystals in the form of magnetosomes (MS) chained inside the bacteria cells have been exposed to radiofrequency fields with the aim of observing how the electromagnetic energy is converted and expressed as thermal or non-thermal effects. A wide frequency band was tested, (0.1-2.9) GHz, by applying continuous wave stimuli. Significant field strength components were provided and characterized, by using a GTEM cell and adequate expo-dosimetric instruments. The heating rates of the suspensions were measured. Because the recorded values were very low, non-thermal expression of energetic conversion was further investigated by scanning-transmission electron microscopy methods, by various spectroscopic means and by electrical conductivity determinations. Clear non-thermal effects were revealed, which need further research.
A dual band mobile phone model was used to check the shielding properties of an amorphous ferroma... more A dual band mobile phone model was used to check the shielding properties of an amorphous ferromagnetic textile against the radiation emitted by the handset. Two frequencies belonging to the 2nd and 3rd generation of mobile emission technologies were used, 897 MHz and 1950 MHz. The specific absorption rate (SAR) of energy deposition in a human head phantom was measured in standardized conditions. The textile contained micrometric-diameter wires of a ferromagnetic mixture embedded in a thin glass coat and weaved in a specific way. A set of fabric orientations and configurations (layering) were provided in the experiment in order to achieve a better shielding to the phone’s radiation. Compared with the non-shielded handset, SAR deposited in the head while using the fabric-covered phone could be decreased up to 30 % of its initial value – in case of 2G technology and up to 24 % – in case of 3G technology. This type of material shows one of the highest shielding efficiencies of the elec...
International conference KNOWLEDGE-BASED ORGANIZATION, 2019
The paper presents a synthesis of the research performed on the electromagnetic properties and ch... more The paper presents a synthesis of the research performed on the electromagnetic properties and characterization of textile and non-textile materials with applications in shielding and protection from the electromagnetic field. The composite structures of functional textiles intended for protective clothing or general applications for electromagnetic immunity are presented and characterized. There are analyzed composite textiles with amorphous, ferrous or non-ferromagnetic metallic threads manufactured by means of woven and knitting classical technologies as well as materials using non-metallic, electrically conductive powders. The properties of the plain jersey, rib jersey, full and half cardigan fabric, Milano rib, are presented, too. Besides textiles, there are also characterized some composite and non-composite structures using metallic yarns and carbon powder. Another direction of interest relates to the use of textile materials with amorphous metal structure with the scope of a...
2016 International Conference and Exposition on Electrical and Power Engineering (EPE), 2016
Woven fabrics with metallic yarns were produced and tested for their electromagnetic shielding pr... more Woven fabrics with metallic yarns were produced and tested for their electromagnetic shielding properties in the ultra high frequency band. After shielding effectiveness was measured in a dual transverse electromagnetic cell, seven types of woven fabrics containing Bekinox, copper and silver yarns were further tested for their capabilities to reduce the mobile phone radiation. Results indicate that shielding effectiveness itself should not be used as a unique indicator of the protective characteristic when it comes to mobile phone radiation. We have proved that the use of such woven fabrics as cover of the handset may result in both reducing and increasing the absorbed energy in the head.
2016 International Conference on Communications (COMM), 2016
Experimental checking of the specific absorption rate (SAR) level modifications when using conduc... more Experimental checking of the specific absorption rate (SAR) level modifications when using conductive textiles attached to mobile phone handsets was applied by using the COMOSAR system in both 2G and 3G communication standards. Based on measured data, SAR reduction effectiveness was calculated. Results indicated either shielded or amplified absorbed radiation in the head, depending on the communication technology and on the fabric position to the handset. A discussion based on SAR hotspot position variation with respect to different experimental scenarios is also provided.
International conference KNOWLEDGE-BASED ORGANIZATION, 2016
An analysis of the shielding effectiveness by the method of dual transversal electromagnetic cell... more An analysis of the shielding effectiveness by the method of dual transversal electromagnetic cell is proposed for a set of conductive materials of the type wire-inserted textiles. Based on the experimental results, some of the materials are further on used to test their capability to effectively reduce the specific absorption rate of energy deposition in the head due to mobile phone, when they are covering the surface of the handset. It is demonstrated that both reducing and increasing the radiation that penetrates the head may appear, and this depends on both the material structure, its position and orientation relative to the device and to the frequency band the phone is emitting.
Uploads
Papers by George Mihai