Radon (222Rn) is a radioactive gas, from the 238U decay chain, that contributes in large part of the natural radiation dose to which humans are exposed. Radon is the second cause of lung cancer after tobacco. The US-EPA considers a concentration of 148 Bq/m3 for homes and 400 Bq/m3 for workplaces as the reference level. Caves are closed spaces where 222Rn, which emanates from the surrounding minerals and rocks, can accumulate and reaches large concentrations that can represent a health risk for the guides, speleologists and visitors who spend time in these spaces. This work uses the previously recorded radon concentrations in 8 caves in Mexico and calculates the average dose range and the average annual dose for each of them with the “Wise” public domain program (http://www.wise-uranium.org/rdcrn.html) to determine the level of radiological risk with 2,000 1,000 and 500 working hours per year. Karmidas cave had the highest average 222Rn concentration with 27,633.3 Bq/m3 and for 2,000 working hours per year an average annual dose rate of 347.1 mSv/y. Los Riscos cave had the lowest average concentration with 384.7 Bq/m3 and for 2,000 working hours per year an average annual dose rate of 4.832 mSv/y. These results show that all the caves studied present values,with 2,000 working hours per year, that exceed 3 mSv/y for workplaces and must be considered by the people who work in these places. A casual tourist visiting the caves does not present any radiological risk, while guides and speleologists should consider it.
{"title":"Radon Dose Determination and Radiological Risk in Some Mexican Caves with CR-39 Detectors","authors":"A. Chavarria, J. Golzarri, G. Espinosa","doi":"10.15415/JNP.2021.82022","DOIUrl":"https://doi.org/10.15415/JNP.2021.82022","url":null,"abstract":"Radon (222Rn) is a radioactive gas, from the 238U decay chain, that contributes in large part of the natural radiation dose to which humans are exposed. Radon is the second cause of lung cancer after tobacco. The US-EPA considers a concentration of 148 Bq/m3 for homes and 400 Bq/m3 for workplaces as the reference level. Caves are closed spaces where 222Rn, which emanates from the surrounding minerals and rocks, can accumulate and reaches large concentrations that can represent a health risk for the guides, speleologists and visitors who spend time in these spaces. This work uses the previously recorded radon concentrations in 8 caves in Mexico and calculates the average dose range and the average annual dose for each of them with the “Wise” public domain program (http://www.wise-uranium.org/rdcrn.html) to determine the level of radiological risk with 2,000 1,000 and 500 working hours per year. Karmidas cave had the highest average 222Rn concentration with 27,633.3 Bq/m3 and for 2,000 working hours per year an average annual dose rate of 347.1 mSv/y. Los Riscos cave had the lowest average concentration with 384.7 Bq/m3 and for 2,000 working hours per year an average annual dose rate of 4.832 mSv/y. These results show that all the caves studied present values,with 2,000 working hours per year, that exceed 3 mSv/y for workplaces and must be considered by the people who work in these places. A casual tourist visiting the caves does not present any radiological risk, while guides and speleologists should consider it.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"15 1","pages":"169-175"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87498703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Montero-Cabrera María Elena, Caraveo-Castro Carmen del Rocío, Méndez-García Carmen Grisel, Mendieta-Mendoza Aurora, Renteria-Villalobos Marusia, Cabral-Lares Rocío Magaly
1Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Compl. Ind. Chihuahua, Chihuahua CP 31136, Mexico 2CÁTEDRAS-CONACYT Instituto de Física de la UNAM. Circuito de la Investigación Científica, Ciudad Universitaria CP 04510, CDMX, México 3Universidad Autónoma de Chihuahua, Facultad de Zootecnia y Ecología, Chihuahua. Periférico Francisco R. Almada Km.1, Chihuahua, Chih, CP 31453, México 4Tecnológico Nacional de México, Campus Chihuahua II, Ave. de las Industrias #11101, Complejo Industrial Chihuahua, Chih. CP 31130, Mexico
先进材料研究中心(CIMAV)，米格尔·德·塞万提斯120,Compl。奇瓦瓦工业，奇瓦瓦CP 31136，墨西哥2主席- conacyt物理研究所UNAM。科学研究电路，Ciudad Universitaria CP 04510, CDMX, mexico 3Universidad autonoma de Chihuahua, faculty de Zootecnia y ecologia, Chihuahua。Francisco R. Almada Km.1, Chihuahua, Chih, CP 31453, mexico 4tecnologico Nacional de mexico, Campus Chihuahua II, Ave. de las Industrias #11101, Chih Chihuahua Industrial综合体。墨西哥邮政编码31130
{"title":"Determination of 234U and 238U Activities in Soil by Liquid Scintillation and High-Resolution Alpha Spectrometry","authors":"Montero-Cabrera María Elena, Caraveo-Castro Carmen del Rocío, Méndez-García Carmen Grisel, Mendieta-Mendoza Aurora, Renteria-Villalobos Marusia, Cabral-Lares Rocío Magaly","doi":"10.15415/JNP.2021.82014","DOIUrl":"https://doi.org/10.15415/JNP.2021.82014","url":null,"abstract":"1Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Compl. Ind. Chihuahua, Chihuahua CP 31136, Mexico 2CÁTEDRAS-CONACYT Instituto de Física de la UNAM. Circuito de la Investigación Científica, Ciudad Universitaria CP 04510, CDMX, México 3Universidad Autónoma de Chihuahua, Facultad de Zootecnia y Ecología, Chihuahua. Periférico Francisco R. Almada Km.1, Chihuahua, Chih, CP 31453, México 4Tecnológico Nacional de México, Campus Chihuahua II, Ave. de las Industrias #11101, Complejo Industrial Chihuahua, Chih. CP 31130, Mexico","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"84 1","pages":"115-120"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91323828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Osorio-González, V. J. Muñiz-Orozco, C. Gonzalez, M. Fuentes-Acosta, J. Mulia-Rodríguez, L. A. Mandujano-Rosas
Received: September 28, 2020 Accepted: January 27, 2021 Published Online: February 10, 2021 SARS-CoV-2 is responsible for causing the Coronavirus disease 2019 (COVID-19) pandemic, which has so far infected more than thirty million people and caused almost a million deaths. For this reason, it has been a priority to stop the transmission of the outbreak through preventive measures, such as surface disinfection, and to establish bases for the design of an effective disinfection technique without chemical components. In this study, we performed in silico analysis to identify the conformational alterations of the SARS-CoV-2 Spike Receptor Binding Domain (RBD) caused by the effect of a pulsed electric field at two different intensities. We found that both stimuli, especially the one with the highest angular frequency and amplitude, modified the electrical charge distribution in the RBD surface and the number of hydrogen bonds. Moreover, the secondary structure was significantly affected, with a decrease of the structured regions, particularly the regions with residues involved in recognizing and interacting with the receptor ACE2. Since many regions suffered conformational changes, we calculated RMSF and ΔRMSF to identify the regions and residues with larger fluctuations and higher flexibility. We found that regions conformed by 353-372, 453-464, and 470-490 amino acid residues fluctuate the most, where the first is considered a therapeutic target, and the last has already been characterized for its flexibility. Our results indicate that a pulsed electric field can cause loss of stability in the Spike-RBD, and we were able to identify the vulnerable sites to be used as a starting point for the development of viral inhibition or inactivation mechanisms.
{"title":"Receptor Binding Domain (RBD) Structural Susceptibility in the SARS-CoV-2 Virus Spike Protein Exposed to a Pulsed Electric Field","authors":"D. Osorio-González, V. J. Muñiz-Orozco, C. Gonzalez, M. Fuentes-Acosta, J. Mulia-Rodríguez, L. A. Mandujano-Rosas","doi":"10.15415/JNP.2021.82023","DOIUrl":"https://doi.org/10.15415/JNP.2021.82023","url":null,"abstract":"Received: September 28, 2020 Accepted: January 27, 2021 Published Online: February 10, 2021 SARS-CoV-2 is responsible for causing the Coronavirus disease 2019 (COVID-19) pandemic, which has so far infected more than thirty million people and caused almost a million deaths. For this reason, it has been a priority to stop the transmission of the outbreak through preventive measures, such as surface disinfection, and to establish bases for the design of an effective disinfection technique without chemical components. In this study, we performed in silico analysis to identify the conformational alterations of the SARS-CoV-2 Spike Receptor Binding Domain (RBD) caused by the effect of a pulsed electric field at two different intensities. We found that both stimuli, especially the one with the highest angular frequency and amplitude, modified the electrical charge distribution in the RBD surface and the number of hydrogen bonds. Moreover, the secondary structure was significantly affected, with a decrease of the structured regions, particularly the regions with residues involved in recognizing and interacting with the receptor ACE2. Since many regions suffered conformational changes, we calculated RMSF and ΔRMSF to identify the regions and residues with larger fluctuations and higher flexibility. We found that regions conformed by 353-372, 453-464, and 470-490 amino acid residues fluctuate the most, where the first is considered a therapeutic target, and the last has already been characterized for its flexibility. Our results indicate that a pulsed electric field can cause loss of stability in the Spike-RBD, and we were able to identify the vulnerable sites to be used as a starting point for the development of viral inhibition or inactivation mechanisms.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"58 1","pages":"177-182"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84865471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Rodríguez, E. Vázquez‐Vélez, H. Martinez, A. Torres
Received: September 18, 2020 Accepted: January 30, 2021 Published Online: February 10, 2021 Polymers currently represent materials that are cost-effective, while its recycled nature is significant in terms of environmental protection. However, the surface properties of polymers often do not meet the demands of wettability, adhesion, and friction, among others. Atmospheric plasma treatment on the surface of polymers improves its physical-chemistry properties. In this work, a recycled nylon coating was prepared by the spin coating technique and characterized by Fourier transform infrared spectroscopy and X-ray diffraction. This coating was treated by atmospheric plasma, and Raman spectroscopy was performed to analyze the signals related to different functional groups present in the coating surface after plasma treatment. The action of plasma on the surface morphology was observed by scanning electron microscopy. The contact angle results showed an improvement in surface wettability.
{"title":"Superficial Surface Treatment using Atmospheric Plasma on Recycled Nylon 6,6","authors":"M. Rodríguez, E. Vázquez‐Vélez, H. Martinez, A. Torres","doi":"10.15415/JNP.2021.82025","DOIUrl":"https://doi.org/10.15415/JNP.2021.82025","url":null,"abstract":"Received: September 18, 2020 Accepted: January 30, 2021 Published Online: February 10, 2021 Polymers currently represent materials that are cost-effective, while its recycled nature is significant in terms of environmental protection. However, the surface properties of polymers often do not meet the demands of wettability, adhesion, and friction, among others. Atmospheric plasma treatment on the surface of polymers improves its physical-chemistry properties. In this work, a recycled nylon coating was prepared by the spin coating technique and characterized by Fourier transform infrared spectroscopy and X-ray diffraction. This coating was treated by atmospheric plasma, and Raman spectroscopy was performed to analyze the signals related to different functional groups present in the coating surface after plasma treatment. The action of plasma on the surface morphology was observed by scanning electron microscopy. The contact angle results showed an improvement in surface wettability.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"2 1","pages":"191-196"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87846629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. P. Carreón-Castro, M. Caldera-Villalobos, B. Leal-Acevedo, A. Herrera-González
Chitosan is a bio-based polyelectrolyte with high potential for wastewater treatment. Chitosan can remove anionic dyes by adsorption but it has low performance in the removal of cationic dyes. In this work, we report the synthesis of chitosan-based graft-copolymers using gamma radiation. Acrylic acid and poly(ethylene glycol) were grafted successfully onto chitosan applying a radiation dose of 12 kGy at a dose rate of 8 kGyh-1. The grafted-copolymers have improved adsorptive properties for the removal of basic dyes reaching a maximum adsorption capacity higher than 300 mgg-1. The Lanmguir’s isotherm model described satisfactorily the interaction between the grafted copolymers and basic dyes. Freundlich’s isotherm model described the adsorption of anionic dye acid orange 52. The grafted copolymers removed successfully textile dyes from wastewater of the dyeing process. The best results were obtained in the removal of direct and basic dyes. Further, poly(ethylene glycol) grafted on the copolymer conferred better swelling behavior making easy the separation of the adsorbent after dye removal. The results showed that the adsorbent materials synthesized by radiochemical graftcopolymerization are more efficient than the beads, composite materials, and blends of chitosan.
{"title":"Simultaneous Grafting of Poly(Acrylic Acid) and Poly(Ethylene Glycol) onto Chitosan using Gamma Radiation: Polymer Networks for Removal of Textile Dyes","authors":"M. P. Carreón-Castro, M. Caldera-Villalobos, B. Leal-Acevedo, A. Herrera-González","doi":"10.15415/JNP.2021.82017","DOIUrl":"https://doi.org/10.15415/JNP.2021.82017","url":null,"abstract":"Chitosan is a bio-based polyelectrolyte with high potential for wastewater treatment. Chitosan can remove anionic dyes by adsorption but it has low performance in the removal of cationic dyes. In this work, we report the synthesis of chitosan-based graft-copolymers using gamma radiation. Acrylic acid and poly(ethylene glycol) were grafted successfully onto chitosan applying a radiation dose of 12 kGy at a dose rate of 8 kGyh-1. The grafted-copolymers have improved adsorptive properties for the removal of basic dyes reaching a maximum adsorption capacity higher than 300 mgg-1. The Lanmguir’s isotherm model described satisfactorily the interaction between the grafted copolymers and basic dyes. Freundlich’s isotherm model described the adsorption of anionic dye acid orange 52. The grafted copolymers removed successfully textile dyes from wastewater of the dyeing process. The best results were obtained in the removal of direct and basic dyes. Further, poly(ethylene glycol) grafted on the copolymer conferred better swelling behavior making easy the separation of the adsorbent after dye removal. The results showed that the adsorbent materials synthesized by radiochemical graftcopolymerization are more efficient than the beads, composite materials, and blends of chitosan.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"17 1","pages":"135-142"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87443416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Rodil, B. Campillo, I. Domínguez, J. González-Rodríguez, H. Martínez
1Center of Research in Engineering and Applied Science, FCQeI UAEM., Av Univ. 1001 Col., Chamilpa 62209, Cuernavaca Mor., Mexico 2Institute of Material Research, Autonomous National University of Mexico. Circuito Exterior s/n CU, Mexico City 04510, Mexico 3Faculty of Chemestry, National Autonomous University of Mexico (UNAM), Circuito de la Investigación Científica S/N, Ciudad Universitaria, C.P. 04510, Mexico City, Mexico 4Research Center for Applied Science and Advanced Technology, National Polytechnic Institute.Cerro Blanco No. 141 Col. Colinas del Cimatario, C.P. 76090 Querétaro, Querétaro. Mexico 5Institute of Physical Sciences, Autonomous National University of Mexico, P.O. Box 48-3, Av. Universidad s/n, Col. Chamilpa 62210, Cuernavaca Mor., México
{"title":"Wear Behavior of a Ni/Co Bilayer Coating by Physical Vapor Deposition on AISI 1045 Steel","authors":"S. Rodil, B. Campillo, I. Domínguez, J. González-Rodríguez, H. Martínez","doi":"10.15415/JNP.2021.82027","DOIUrl":"https://doi.org/10.15415/JNP.2021.82027","url":null,"abstract":"1Center of Research in Engineering and Applied Science, FCQeI UAEM., Av Univ. 1001 Col., Chamilpa 62209, Cuernavaca Mor., Mexico 2Institute of Material Research, Autonomous National University of Mexico. Circuito Exterior s/n CU, Mexico City 04510, Mexico 3Faculty of Chemestry, National Autonomous University of Mexico (UNAM), Circuito de la Investigación Científica S/N, Ciudad Universitaria, C.P. 04510, Mexico City, Mexico 4Research Center for Applied Science and Advanced Technology, National Polytechnic Institute.Cerro Blanco No. 141 Col. Colinas del Cimatario, C.P. 76090 Querétaro, Querétaro. Mexico 5Institute of Physical Sciences, Autonomous National University of Mexico, P.O. Box 48-3, Av. Universidad s/n, Col. Chamilpa 62210, Cuernavaca Mor., México","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"1 1","pages":"203-209"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82973775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adverse effects of long-term exposure to galactic cosmic radiation (GCR) pose a non negligible obstacle for future space exploration programs; the high-LET-particle-rich environment has an adverse effect on human health. Concomitant to GCR we have as well solar particle radiation. Long term space exploration will rely on adequate and highly efficient shielding materials that will reduce exposure of both biosystems and electronic equipment to GCR and solar particles. The shield must attenuate efficiently heavy GCR ions, by breaking them up into less-damaging fragments and secondary radiation: biologically damaging energetic neutrons and highly charged and energetic HZE- particles. An approach to this problem is the development of shielding compounds. Shielding materials should address the conditions of different aspects of a given mission, e.g. time duration and travel path. The Monte Carlo method (GEANT4) is here employed to estimate the effects of a shielding material based on the recently developed Bi2O3-based compound (Cao et al., 2020). In the present study GEANT4 code is used to make estimations of attenuation of solar protons. The objective is to provide some insight about the effect of the new composite shield that has an intrinsic capability for dose reduction.
{"title":"Simulation of Dose Estimations from Solar Protons: A PMMA-Bi2O3 Shielding Model for Space Exploration","authors":"L. Sajo-Bohus, J. A. López, M. Castro-colin","doi":"10.15415/JNP.2021.82020","DOIUrl":"https://doi.org/10.15415/JNP.2021.82020","url":null,"abstract":"Adverse effects of long-term exposure to galactic cosmic radiation (GCR) pose a non negligible obstacle for future space exploration programs; the high-LET-particle-rich environment has an adverse effect on human health. Concomitant to GCR we have as well solar particle radiation. Long term space exploration will rely on adequate and highly efficient shielding materials that will reduce exposure of both biosystems and electronic equipment to GCR and solar particles. The shield must attenuate efficiently heavy GCR ions, by breaking them up into less-damaging fragments and secondary radiation: biologically damaging energetic neutrons and highly charged and energetic HZE- particles. An approach to this problem is the development of shielding compounds. Shielding materials should address the conditions of different aspects of a given mission, e.g. time duration and travel path. The Monte Carlo method (GEANT4) is here employed to estimate the effects of a shielding material based on the recently developed Bi2O3-based compound (Cao et al., 2020). In the present study GEANT4 code is used to make estimations of attenuation of solar protons. The objective is to provide some insight about the effect of the new composite shield that has an intrinsic capability for dose reduction.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"19 1","pages":"155-160"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86687346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Vázquez-López, O. D. Ángel-Gómez, R. Raya-Arredondo, S. Cruz-Galindo, J. I. Golzarri-Moreno, Guillermo Espinosa
The neutron flux of the Triga Mark III research reactor was studied using nuclear track detectors. The facility of the National Institute for Nuclear Research (ININ), operates with a new core load of 85 LEU 30/20 (Low Enriched Uranium) fuel elements. The reactor provides a neutron flux around 2 × 1012 n cm-2s-1 at the irradiation channel. In this channel, CR-39 (allyl diglycol policarbonate) Landauer® detectors were exposed to neutrons; the detectors were covered with a 3 mm acrylic sheet for (n, p) reaction. Results show a linear response between the reactor power in the range 0.1 - 7 kW, and the average nuclear track density with data reproducibility and relatively low uncertainty (±5%). The method is a simple technique, fast and reliable procedure to monitor the research reactor operating power levels.
利用核径迹探测器对Triga Mark III型研究堆的中子通量进行了研究。国家核研究所(ININ)的设施使用85 LEU 30/20(低浓缩铀)燃料元件的新堆芯负荷运行。该反应堆在辐照通道处提供约2 × 1012 n cm-2s-1的中子通量。在该通道中，CR-39(聚碳酸二烯丙基)兰道尔探测器暴露于中子中;探测器被3毫米的亚克力片覆盖，用于(n, p)反应。结果表明，在0.1 ~ 7kw范围内，反应堆功率与平均核径迹密度呈线性关系，数据重现性好，不确定度相对较低(±5%)。该方法是一种技术简单、快速、可靠的研究堆运行功率水平监测方法。
{"title":"Changes of the Neutron Flux of the Nuclear Reactor Triga Mark III Since the Conversion from High to Low 235U Enrichment","authors":"C. Vázquez-López, O. D. Ángel-Gómez, R. Raya-Arredondo, S. Cruz-Galindo, J. I. Golzarri-Moreno, Guillermo Espinosa","doi":"10.15415/JNP.2021.82019","DOIUrl":"https://doi.org/10.15415/JNP.2021.82019","url":null,"abstract":"The neutron flux of the Triga Mark III research reactor was studied using nuclear track detectors. The facility of the National Institute for Nuclear Research (ININ), operates with a new core load of 85 LEU 30/20 (Low Enriched Uranium) fuel elements. The reactor provides a neutron flux around 2 × 1012 n cm-2s-1 at the irradiation channel. In this channel, CR-39 (allyl diglycol policarbonate) Landauer® detectors were exposed to neutrons; the detectors were covered with a 3 mm acrylic sheet for (n, p) reaction. Results show a linear response between the reactor power in the range 0.1 - 7 kW, and the average nuclear track density with data reproducibility and relatively low uncertainty (±5%). The method is a simple technique, fast and reliable procedure to monitor the research reactor operating power levels.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86566566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Yadav, Basilia Quispe Huillcara, Pablo Víctor Cerón Ramírez, M. S. Aquino, Miguel Ángel Vallejo Hernández
Radiation application in medicine offers extraordinary benefits. But radiation is like a double-edged sword, it has both benefits and associated risks on the community in contact. To justify the safety of workers and members of the public, regulated use of radiation is assessed by the radiation protection protocols. The aim of this study is to design a Computed Tomography (CT) facility with a simplified model of CT scanner, whose shielding follows the guidelines of National Council on Radiation Protection and Measurements (NCRP) Report No. 147. To design the study model, Monte Carlo (MC) radiation transport code in MCNPX 2.6.0 was used for the simulation. Furthermore, MCNPX was used to measure the photon flux in a vicinity or the detector cell. To validate the functioning of the X-ray tube, the experimental results were compared with the X-ray Transition Energies Database of National Institute of Standards and Technology, U.S. Department of Commerce. The results obtained were within 0.60% of relative error. To confirm the functioning of shielding design, radiation protection quantity, air kerma was measured at several points outside, and inside of the CT room and they were under the radiation dose recommended by NCRP, which demonstrates that the shielding design wassuccessful in blocking the radiation. The study can be used for an easy evaluation of any CT room within the framework of the model of the study.
{"title":"Structural Shielding Design of CT Facility using Monte Carlo Simulation","authors":"A. Yadav, Basilia Quispe Huillcara, Pablo Víctor Cerón Ramírez, M. S. Aquino, Miguel Ángel Vallejo Hernández","doi":"10.15415/JNP.2021.82018","DOIUrl":"https://doi.org/10.15415/JNP.2021.82018","url":null,"abstract":"Radiation application in medicine offers extraordinary benefits. But radiation is like a double-edged sword, it has both benefits and associated risks on the community in contact. To justify the safety of workers and members of the public, regulated use of radiation is assessed by the radiation protection protocols. The aim of this study is to design a Computed Tomography (CT) facility with a simplified model of CT scanner, whose shielding follows the guidelines of National Council on Radiation Protection and Measurements (NCRP) Report No. 147. To design the study model, Monte Carlo (MC) radiation transport code in MCNPX 2.6.0 was used for the simulation. Furthermore, MCNPX was used to measure the photon flux in a vicinity or the detector cell. To validate the functioning of the X-ray tube, the experimental results were compared with the X-ray Transition Energies Database of National Institute of Standards and Technology, U.S. Department of Commerce. The results obtained were within 0.60% of relative error. To confirm the functioning of shielding design, radiation protection quantity, air kerma was measured at several points outside, and inside of the CT room and they were under the radiation dose recommended by NCRP, which demonstrates that the shielding design wassuccessful in blocking the radiation. The study can be used for an easy evaluation of any CT room within the framework of the model of the study.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"2013 1","pages":"143-147"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73971251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. A. López, S. González, O. Rodriguez, J. Holmes, R. Alarcon
Received: September 18, 2020 Accepted: January 09, 2021 Published Online: February 10, 2021 Proton therapy uses a beam of protons to destroy cancer cells. A problem of the method is the determination of what part of the body the protons are hitting during the irradiation. In a previous study we determine that by capturing the gamma rays produced during the irradiation one can determine the location of the proton-body interaction, in this work we investigate if by examining the gamma rays produced it is possible to determine the body part that produced the gamma rays by the proton collision. This study uses GEANT4 computer simulations of interactions of proton-tissue, protonbrain, proton-bone, etc., which produce gamma rays, to determine the characteristics of the gamma rays produced. We then analyze the characteristics of the gamma rays to find signatures that could be used to determine the source of the rays. In particular, we study the distribution of gamma ray energies, their full-width half-maximum, energy resolution, maximum height, and total number of counts. This study concludes that it is possible to use the gamma ray spectra to determine what body part produced it.
{"title":"GEANT4 Study of Proton–Body Interactions","authors":"J. A. López, S. González, O. Rodriguez, J. Holmes, R. Alarcon","doi":"10.15415/JNP.2021.82015","DOIUrl":"https://doi.org/10.15415/JNP.2021.82015","url":null,"abstract":"Received: September 18, 2020 Accepted: January 09, 2021 Published Online: February 10, 2021 Proton therapy uses a beam of protons to destroy cancer cells. A problem of the method is the determination of what part of the body the protons are hitting during the irradiation. In a previous study we determine that by capturing the gamma rays produced during the irradiation one can determine the location of the proton-body interaction, in this work we investigate if by examining the gamma rays produced it is possible to determine the body part that produced the gamma rays by the proton collision. This study uses GEANT4 computer simulations of interactions of proton-tissue, protonbrain, proton-bone, etc., which produce gamma rays, to determine the characteristics of the gamma rays produced. We then analyze the characteristics of the gamma rays to find signatures that could be used to determine the source of the rays. In particular, we study the distribution of gamma ray energies, their full-width half-maximum, energy resolution, maximum height, and total number of counts. This study concludes that it is possible to use the gamma ray spectra to determine what body part produced it.","PeriodicalId":16534,"journal":{"name":"Journal of Nuclear Physics, Material Sciences, Radiation and Applications","volume":"8 1","pages":"121-127"},"PeriodicalIF":0.0,"publicationDate":"2021-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81544393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：