Debido a la crisis ambiental que atraviesa la humanidad, actualmente se vienen realizando diversas investigaciones encaminadas a encontrar alternativas sustentables para diferentes procesos industriales. En este sentido, en la actualidad las fibras naturales se han convertido en un recurso atractivo para diferentes industrias, dentro de la que se puede destacar la de los materiales compuestos. Las fibras naturales son recursos renovables que pueden ser obtenidos de animales o vegetales, que presentan múltiples ventajas como son su bajo costo y peso, biodegradabilidad y altas propiedades específicas. Este documento constituye una revisión de algunos aspectos relevantes a tener en cuenta para el empleo de fibras naturales en la industria de los compuestos, como son su origen, composición química, metodologías de extracción, propiedades físicas y mecánicas, y algunos tratamientos necesarios para mejorar la adherencia cuando se emplean como refuerzo de matrices poliméricas. Además, se destacan algunos de los resultados obtenidos en una investigación enfocada a proporcionar aspectos técnicos para el empleo de fibras de bambú Guadua angustifolia como material de refuerzo. Cabe resaltar que la revisión presentada en este documento se centra en fibras de origen vegetal.
{"title":"FIBRAS NATURALES COMO REFUERZO EN MATERIALES COMPUESTOS DE MATRIZ POLIMÉRICA","authors":"Patricia Luna, Juan M. Lizarazo-Marriaga","doi":"10.15446/mo.n65.103151","DOIUrl":"https://doi.org/10.15446/mo.n65.103151","url":null,"abstract":"\u0000Debido a la crisis ambiental que atraviesa la humanidad, actualmente se vienen realizando diversas investigaciones encaminadas a encontrar alternativas sustentables para diferentes procesos industriales. En este sentido, en la actualidad las fibras naturales se han convertido en un recurso atractivo para diferentes industrias, dentro de la que se puede destacar la de los materiales compuestos. Las fibras naturales son recursos renovables que pueden ser obtenidos de animales o vegetales, que presentan múltiples ventajas como son su bajo costo y peso, biodegradabilidad y altas propiedades específicas. Este documento constituye una revisión de algunos aspectos relevantes a tener en cuenta para el empleo de fibras naturales en la industria de los compuestos, como son su origen, composición química, metodologías de extracción, propiedades físicas y mecánicas, y algunos tratamientos necesarios para mejorar la adherencia cuando se emplean como refuerzo de matrices poliméricas. Además, se destacan algunos de los resultados obtenidos en una investigación enfocada a proporcionar aspectos técnicos para el empleo de fibras de bambú Guadua angustifolia como material de refuerzo. Cabe resaltar que la revisión presentada en este documento se centra en fibras de origen vegetal. \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48387507","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}
E. A. S. Filho, C. Luna, A. L. Silva, E. S. B. Ferreira, E. Araújo, A. C. F. Costa
The heat treatment effect on kaolin waste from mining was evaluated on the structural and thermal behavior of poly(ε-caprolactone) (PCL). The PCL/KW (kaolin waste) and PCL/HTKW (heat-treated kaolin waste) composites were processed in an internal mixer and subsequently characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The kaolin waste showed kaolinite and quartz in its composition, while the heat treatment at 1200°C modified it to mullite, quartz and silica-rich amorphous phase. By XRD, there was an increase in the intensity of the peak 2θ = 23.9° of the PCL/KW composites compared to neat PCL. In contrast, PCL/HTKW composites tended to reduce the intensity of the peak 2θ = 23.9°, especially at 5% HTKW. The crystalline melting temperature and the degree of crystallinity of PCL/KW and PCL/HTKW composites were practically unchanged, compared to PCL. However, the crystallization process was more effective with the kaolin waste (KW) without heat treatment, indicating that the HTKW amorphous phase inhibited crystallization. The PCL/KW development promoted an increase in crystallization temperature, relative crystallinity, and crystallization rate, surpassing PCL and the PCL/HTKW system. In view of this, kaolin waste has the potential to accelerate the PCL crystallization process, contributing to add value to a material that would otherwise be discarded and minimizing environmental impacts.
{"title":"Effect of kaolin waste annealing on the structural and thermal behavior of poly(ε−caprolactone)","authors":"E. A. S. Filho, C. Luna, A. L. Silva, E. S. B. Ferreira, E. Araújo, A. C. F. Costa","doi":"10.15446/mo.n64.99725","DOIUrl":"https://doi.org/10.15446/mo.n64.99725","url":null,"abstract":"The heat treatment effect on kaolin waste from mining was evaluated on the structural and thermal behavior of poly(ε-caprolactone) (PCL). The PCL/KW (kaolin waste) and PCL/HTKW (heat-treated kaolin waste) composites were processed in an internal mixer and subsequently characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The kaolin waste showed kaolinite and quartz in its composition, while the heat treatment at 1200°C modified it to mullite, quartz and silica-rich amorphous phase. By XRD, there was an increase in the intensity of the peak 2θ = 23.9° of the PCL/KW composites compared to neat PCL. In contrast, PCL/HTKW composites tended to reduce the intensity of the peak 2θ = 23.9°, especially at 5% HTKW. The crystalline melting temperature and the degree of crystallinity of PCL/KW and PCL/HTKW composites were practically unchanged, compared to PCL. However, the crystallization process was more effective with the kaolin waste (KW) without heat treatment, indicating that the HTKW amorphous phase inhibited crystallization. The PCL/KW development promoted an increase in crystallization temperature, relative crystallinity, and crystallization rate, surpassing PCL and the PCL/HTKW system. In view of this, kaolin waste has the potential to accelerate the PCL crystallization process, contributing to add value to a material that would otherwise be discarded and minimizing environmental impacts.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41435761","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. J. Jattin Balcázar, Javier Rodríquez Velásquez, S. P. Prieto Bohórquez, S. C. Correa Herrera, César A. Valdés Cadena
La ley de Zipf/Mandelbrot ha permitido caracterizar fenómenos con una organización hiperbólica en las ciencias biomédicas y los lenguajes naturales, entre otros; sin embargo, su aplicación podría extenderse a estudiar características planetarias. Por tanto, el objetivo de esta investigación consiste en aplicar la ley de Zipf/Mandelbrot para caracterizar el grado de complejidad del período orbital, la velocidad orbital media planetaria y la distancia media al sol de los planetas del sistema solar. Para ello, se tomaron los valores del período orbital, la velocidad orbital media y la distancia media al sol de los planetas del sistema solar para evaluar su distribución hiperbólica. Posteriormente, se aplicó la ley de Zipf/Mandelbrot para calcular la dimensión fractal de ambas variables. Se comprobó que los valores del período orbital, la velocidad orbital y la distancia media planetaria se distribuyen jerárquicamente, lo cual permitió calcular los valores de dimensión fractal, que fueron 0.28, 0.88 y 0.42, con coeficientes R2 de 0.92, 0.87 y 0.92, respectivamente. Lo anterior sugiere que la aplicación de la ley de Zipf/Mandelbrot revela la existencia de órdenes matemáticos no descritos en la cinemática celeste al encontrar un mayor grado de complejidad de la velocidad media orbital con respecto a la distancia media planetaria al sol y el período orbital, de donde se puede inferir que los parámetros de análisis de los sistemas planetarios podrían complementarse con este enfoque.
{"title":"Caracterización del grado de complejidad del sistema solar mediante la ley de Zipf/Mandelbrot","authors":"J. J. Jattin Balcázar, Javier Rodríquez Velásquez, S. P. Prieto Bohórquez, S. C. Correa Herrera, César A. Valdés Cadena","doi":"10.15446/mo.n64.97365","DOIUrl":"https://doi.org/10.15446/mo.n64.97365","url":null,"abstract":"La ley de Zipf/Mandelbrot ha permitido caracterizar fenómenos con una organización hiperbólica en las ciencias biomédicas y los lenguajes naturales, entre otros; sin embargo, su aplicación podría extenderse a estudiar características planetarias. Por tanto, el objetivo de esta investigación consiste en aplicar la ley de Zipf/Mandelbrot para caracterizar el grado de complejidad del período orbital, la velocidad orbital media planetaria y la distancia media al sol de los planetas del sistema solar. Para ello, se tomaron los valores del período orbital, la velocidad orbital media y la distancia media al sol de los planetas del sistema solar para evaluar su distribución hiperbólica. Posteriormente, se aplicó la ley de Zipf/Mandelbrot para calcular la dimensión fractal de ambas variables. Se comprobó que los valores del período orbital, la velocidad orbital y la distancia media planetaria se distribuyen jerárquicamente, lo cual permitió calcular los valores de dimensión fractal, que fueron 0.28, 0.88 y 0.42, con coeficientes R2 de 0.92, 0.87 y 0.92, respectivamente. Lo anterior sugiere que la aplicación de la ley de Zipf/Mandelbrot revela la existencia de órdenes matemáticos no descritos en la cinemática celeste al encontrar un mayor grado de complejidad de la velocidad media orbital con respecto a la distancia media planetaria al sol y el período orbital, de donde se puede inferir que los parámetros de análisis de los sistemas planetarios podrían complementarse con este enfoque.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45430325","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}
For automatic temperature measuring and logging purposes in solar thermal experiments, a single board computer - Raspberry Pi based and sensor system is proposed. Different data sets are observed for sensors, thermometers, and thermocouples and they are compared. The consistency of the automated temperature measurement system is also verified.
{"title":"Raspberry Pi based automatic temperature measurement and logging system for solar thermal purposes","authors":"Natarajan Shriethar, Pournan Letchoumanane, Saravanakumar Solai","doi":"10.15446/mo.n64.97787","DOIUrl":"https://doi.org/10.15446/mo.n64.97787","url":null,"abstract":"For automatic temperature measuring and logging purposes in solar thermal experiments, a single board computer - Raspberry Pi based and sensor system is proposed. Different data sets are observed for sensors, thermometers, and thermocouples and they are compared. The consistency of the automated temperature measurement system is also verified.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67019306","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. Valverde-Alva, Jhenry F. Agreda-Delgado, W. Aldama-Reyna, L. Angelats-Silva, Guillermo Gayoso-Bazán, H. León-León, Fredy Pérez-Azahuanche, Santiago A. Vásquez-García
In this work we studied the microfibers of a textile (T-shirt) of the Chimú culture. This culture developed on the northern coast of Peru. To determine the raw material and structural quality of the microfibers, the results of the Chimú textile were compared with the corresponding results for the microfibers of cotton from the northern coast of Peru (native cotton). Scanning electron microscopy images revealed that the Chimú textile yarns are composed of a set of interwoven microfibers. Energy dispersive X-ray spectroscopy and pulsed laser-induced plasma spectroscopy techniques allowed the identification of characteristic cellulose atoms in the microfibers of Chimú textile and native cotton. Only for the Chimú textile, these spectroscopic techniques allowed the identification of atoms corresponding to natural dyes and powder residues. Attenuated total reflection Fourier transform infrared spectroscopy identified the same molecular bonds for the microfibers of Chimú textile and native cotton. For the microfibers of Chimú textile and native cotton, the X-ray diffractograms showed peaks characteristic of the cellulose Iβ polymorphism of of monoclinic P21 structure. The raw material of the Chimú textile is cotton and the microfibers of this material show significant structural stability.
{"title":"Morphology, composition and structure of the fibers of a Chimu culture textile","authors":"M. Valverde-Alva, Jhenry F. Agreda-Delgado, W. Aldama-Reyna, L. Angelats-Silva, Guillermo Gayoso-Bazán, H. León-León, Fredy Pérez-Azahuanche, Santiago A. Vásquez-García","doi":"10.15446/mo.n64.97681","DOIUrl":"https://doi.org/10.15446/mo.n64.97681","url":null,"abstract":"In this work we studied the microfibers of a textile (T-shirt) of the Chimú culture. This culture developed on the northern coast of Peru. To determine the raw material and structural quality of the microfibers, the results of the Chimú textile were compared with the corresponding results for the microfibers of cotton from the northern coast of Peru (native cotton). Scanning electron microscopy images revealed that the Chimú textile yarns are composed of a set of interwoven microfibers. Energy dispersive X-ray spectroscopy and pulsed laser-induced plasma spectroscopy techniques allowed the identification of characteristic cellulose atoms in the microfibers of Chimú textile and native cotton. Only for the Chimú textile, these spectroscopic techniques allowed the identification of atoms corresponding to natural dyes and powder residues. Attenuated total reflection Fourier transform infrared spectroscopy identified the same molecular bonds for the microfibers of Chimú textile and native cotton. For the microfibers of Chimú textile and native cotton, the X-ray diffractograms showed peaks characteristic of the cellulose Iβ polymorphism of of monoclinic P21 structure. The raw material of the Chimú textile is cotton and the microfibers of this material show significant structural stability.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43504239","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}
Kelvin Ramos, Carlos A. Morgan, J. E. Cieza Montalvo, Antonio Rivasplata, Guillermo Ramírez, Carlos E. Rodríguez Benites
The total decay widths of the charged Higgs (H±2) and gauge bosons (V±) have been calculated in the version of the 3-3-1 Model with heavy leptons. In each case, we analyze the decay rates and determine the most likely channels to occur in order to identify the most relevant final events.
{"title":"Decay Width of 3-3-1 Model Charged Higgs and Gauge Bosons","authors":"Kelvin Ramos, Carlos A. Morgan, J. E. Cieza Montalvo, Antonio Rivasplata, Guillermo Ramírez, Carlos E. Rodríguez Benites","doi":"10.15446/mo.n64.97711","DOIUrl":"https://doi.org/10.15446/mo.n64.97711","url":null,"abstract":"The total decay widths of the charged Higgs (H±2) and gauge bosons (V±) have been calculated in the version of the 3-3-1 Model with heavy leptons. In each case, we analyze the decay rates and determine the most likely channels to occur in order to identify the most relevant final events.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47320182","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}
The 2021 Physics Nobel Prize was awarded to Syukuro Manabe, Klaus Hasselmann, and Giorgio Parisi for their “groundbreaking contributions to our understanding of complex physical systems.” Here we review some of the ideas and results which served as the scientific basis to the award. We also comment on the works by our research group on the complex systems properties of random lasers and random fiber lasers.
{"title":"Letter to the editor: The 2021 Physics Nobel Prize and the understanding of complex physical systems","authors":"E. Raposo, A. Gomes, C. B. de Araújo","doi":"10.15446/mo.n64.100335","DOIUrl":"https://doi.org/10.15446/mo.n64.100335","url":null,"abstract":"The 2021 Physics Nobel Prize was awarded to Syukuro Manabe, Klaus Hasselmann, and Giorgio Parisi for their “groundbreaking contributions to our understanding of complex physical systems.” Here we review some of the ideas and results which served as the scientific basis to the award. We also comment on the works by our research group on the complex systems properties of random lasers and random fiber lasers. ","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49433661","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}
Marcial Vasquez-Arteaga, H. Vega-Carrillo, Gustavo Montalvo-Soberon, Juan Rivera-Vásquez, Pedro Jaramillo-Arica, Marcela Vasquez-Silva, Carlos Cabrera-Salvatierra, Roberto Rojas-Alegŕıa
Using the Cristy-Eckerman (C-E) / Segars anatomical representations and the MIRD formalism, the Absorbed doses in lungs of newborn patients scanned with radiopharmaceuticals 133Xe (ventilation) and 99mTc (MAA) (perfusion) are estimated. These representations are phantoms used in Monte Carlo calculations to determine specific absorbed fractions, which, associated with the pharmaceutical residence time, determine the absorbed dose. Concerns about the dosimetric impact of using these ventilation / perfusion agents, as well as the use of different phantoms, were explored in newborn patients. When the lungs were scanned with 99mTc (MAA), the relative difference in total dose between the C-E / Segars anatomical representations was 1.0%. When the lungs were scanned with 133Xe, the relative difference in total dose between the anthropomorphic representations of C-E / Segars was 0.5%. Regardless of the radiopharmaceutical used for the pulmonary studies of a newborn patient, the substitution of the C-E representation for that of Segars does not reflect very significant changes in the calculation of the absorbed dose in the lungs, where the greatest dosimetric contribution is its self-dose, which is supplied mainly by the electrons produced during the 99mTc and 133Xe decay.
{"title":"Dosymmetric estimates of 99mTc (MAA) and 133Xe in newborn lungs using Cristy-Eckerman / Segars representations","authors":"Marcial Vasquez-Arteaga, H. Vega-Carrillo, Gustavo Montalvo-Soberon, Juan Rivera-Vásquez, Pedro Jaramillo-Arica, Marcela Vasquez-Silva, Carlos Cabrera-Salvatierra, Roberto Rojas-Alegŕıa","doi":"10.15446/mo.n64.99290","DOIUrl":"https://doi.org/10.15446/mo.n64.99290","url":null,"abstract":"Using the Cristy-Eckerman (C-E) / Segars anatomical representations and the MIRD formalism, the Absorbed doses in lungs of newborn patients scanned with radiopharmaceuticals 133Xe (ventilation) and 99mTc (MAA) (perfusion) are estimated. These representations are phantoms used in Monte Carlo calculations to determine specific absorbed fractions, which, associated with the pharmaceutical residence time, determine the absorbed dose. Concerns about the dosimetric impact of using these ventilation / perfusion agents, as well as the use of different phantoms, were explored in newborn patients. When the lungs were scanned with 99mTc (MAA), the relative difference in total dose between the C-E / Segars anatomical representations was 1.0%. When the lungs were scanned with 133Xe, the relative difference in total dose between the anthropomorphic representations of C-E / Segars was 0.5%. Regardless of the radiopharmaceutical used for the pulmonary studies of a newborn patient, the substitution of the C-E representation for that of Segars does not reflect very significant changes in the calculation of the absorbed dose in the lungs, where the greatest dosimetric contribution is its self-dose, which is supplied mainly by the electrons produced during the 99mTc and 133Xe decay.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45298845","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. Valverde-Alva, Jhenry F. Agreda-Delgado, J. A. Vega-Gonzalez, J. C. Rodriguez-Soto, Julio C. Idrogo-Córdova, L. Angelats-Silva, C. W. Aldama-Reyna
The effect of magnetic field of 0.3 T on the concentration, distribution of sizes in suspension and zeta potential of colloidal gold and colloidal silver nanoparticles, obtained by considering the pulsed laser ablation in double distilled water was studied. The magnetic field was transverse to the direction of incidence of the laser radiation and parallel to the surface of a submerged target. An Nd: YAG laser was used (1064 nm in wavelength, 10 ns in duration, repetition rate of 10 Hz and 37 mJ of energy) to ablate targets. The colloids were characterized by inductively coupled plasma optical emission spectroscopy, ultraviolet-visible spectroscopy, dynamic light scattering and zeta potential. Concentration analysis suggested that applying magnetic field of 0.3 T during nanoparticle synthesis leads to higher concentration. Applying magnetic field led to an eleven percent increase in the concentration of the colloid with gold nanoparticles and a five percent increase in the concentration of the colloidal silver nanoparticles. The absorption spectra suggested the presence of spherical nanoparticles. When analyzing the effect of the magnetic field on the hydrodynamic size distribution of the nanoparticles and the zeta potential of the colloids, no significant changes were evidenced. The magnetic confinement of the plasma induced by laser ablation caused changes in the characteristics of the colloids.
{"title":"Effect of the magnetic field on the synthesis of colloidal silver and gold nanoparticles by laser ablation in bidestilated water","authors":"M. Valverde-Alva, Jhenry F. Agreda-Delgado, J. A. Vega-Gonzalez, J. C. Rodriguez-Soto, Julio C. Idrogo-Córdova, L. Angelats-Silva, C. W. Aldama-Reyna","doi":"10.15446/MO.N63.91515","DOIUrl":"https://doi.org/10.15446/MO.N63.91515","url":null,"abstract":"The effect of magnetic field of 0.3 T on the concentration, distribution of sizes in suspension and zeta potential of colloidal gold and colloidal silver nanoparticles, obtained by considering the pulsed laser ablation in double distilled water was studied. The magnetic field was transverse to the direction of incidence of the laser radiation and parallel to the surface of a submerged target. An Nd: YAG laser was used (1064 nm in wavelength, 10 ns in duration, repetition rate of 10 Hz and 37 mJ of energy) to ablate targets. The colloids were characterized by inductively coupled plasma optical emission spectroscopy, ultraviolet-visible spectroscopy, dynamic light scattering and zeta potential. Concentration analysis suggested that applying magnetic field of 0.3 T during nanoparticle synthesis leads to higher concentration. Applying magnetic field led to an eleven percent increase in the concentration of the colloid with gold nanoparticles and a five percent increase in the concentration of the colloidal silver nanoparticles. The absorption spectra suggested the presence of spherical nanoparticles. When analyzing the effect of the magnetic field on the hydrodynamic size distribution of the nanoparticles and the zeta potential of the colloids, no significant changes were evidenced. The magnetic confinement of the plasma induced by laser ablation caused changes in the characteristics of the colloids.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48269121","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}
In order to increase the contrast and to improve the imaging capabilities of a Gamma-ray Backscattering device some changes are proposed with the aim of achieving a reduction of the intrinsic noise of the device. Simulated results suggest that the shielding system proposed, in addition to the use of a 68 Ge -γ ray source, produce a considerable reduction of the intrinsic noise of the device.
为了提高伽玛射线后向散射器件的对比度和成像能力，提出了一些改进措施，以达到降低器件固有噪声的目的。仿真结果表明，所提出的屏蔽系统除了使用68 Ge γ射线源外，还能显著降低器件的本征噪声。
{"title":"Intrinsic noise reduction of a Gamma-ray Backscattering imaging device","authors":"D. Flechas, Fernando Cristancho","doi":"10.15446/mo.n63.93837","DOIUrl":"https://doi.org/10.15446/mo.n63.93837","url":null,"abstract":"In order to increase the contrast and to improve the imaging capabilities of a Gamma-ray Backscattering device some changes are proposed with the aim of achieving a reduction of the intrinsic noise of the device. Simulated results suggest that the shielding system proposed, in addition to the use of a 68 Ge -γ ray source, produce a considerable reduction of the intrinsic noise of the device.","PeriodicalId":42463,"journal":{"name":"MOMENTO-Revista de Fisica","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48899555","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}
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