Prolonged excretion of a low-pathogenicity H5N2 avian influenza virus strain in the Pekin duck

José Manuel Carranza-Flores,Luis Padilla-Noriega,Elizabeth Loza-Rubio,Gary García-Espinosa 대한수의학회 2013 Journal of Veterinary Science Vol.14 No.4

H5N2 strains of low-pathogenicity avian influenza virus (LPAIV) have been circulating for at least 17 years in some Mexican chicken farms. We measured the rate and duration of viral excretion from Pekin ducks that were experimentally inoculated with an H5N2 LPAIV that causes death in embryonated chicken eggs (A/chicken/Mexico/2007). Leghorn chickens were used as susceptible host controls. The degree of viral excretion was evaluated with real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) using samples from oropharyngeal and cloacal swabs. We observed prolonged excretion from both species of birds lasting for at least 21 days. Prolonged excretion of LPAIV A/chicken/Mexico/2007 is atypical.

Comparison of physicochemical properties of bio and commercial hydroxyapatite

A.L. Giraldo-Betancur,D.G. Espinosa-Arbelaez,A. del Real-López,B.M. Millan-Malo,E.M. Rivera-Muñoz,E. Gutierrez-Cortez,P. Pineda-Gomez,S. Jimenez-Sandoval,M.E. Rodriguez-García 한국물리학회 2013 Current Applied Physics Vol.13 No.7

This article reports a physicochemical comparison of synthetic and biological Hydroxyapatite (HAp). Eight samples were separated into two groups: bio and commercial hydroxyapatite (bio-HAp and commercial-HAp). The bio-HAp group containing defat, alkaline, and calcined samples taken from bovine bone were obtained by using three different treatments, in order to establish their effect on the final product quality. The commercial-HAp group, from different sources: NIST, sigma, apafill G, coralina, and biograft, were analyzed and compared with the bio-HAp results. Thermogravimetric analysis (TG) was used in order to establish thermal degradation of the samples; structural behavior was then analyzed by X-Ray Diffraction (XRD) to found the crystalline phases, as well as the crystalline quality. Fourier Transform Infrared Spectroscopy (FTIR) was performed in order to identify the corresponding HAp functional groups within the samples. The surface morphology was analyzed by Scanning Electron Microscopy (SEM) and the elemental composition was established by using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). It was found that the calcination process obtains HAp with comparable quality to the commercial samples. A crystallinity greater than 62% after the alkaline process was found. Additionally, the surface of the alkaline sample presents a transition behavior between dense and porous morphology.

Fractional Radioactive Decay Law and Bateman equations

C.-A. Cruz-Lopez,G. Espinosa-Paredes 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.1

The aim of this work is to develop the fractional Bateman equations, which can model memory effects insuccessive isotopes transformations. Such memory effects have been previously reported in the alpha decay,which exhibits a non-Markovian behavior. Since there are radioactive decay series with consecutive alphadecays, it is convenient to include the mentioned memory effects, developing the fractional Bateman Equations,which can reproduce the standard ones when the fractional order is equal to one. The proposed fractionalmodel preserves the mathematical shape and the symmetry of the standard equations, being the onlydifference the presence of the Mittag-Leffler function, instead of the exponential one. This last is a veryimportant result, because allows the implementation of the proposed fractional model in burnup and activationcodes in a straightforwardway.Numerical experiments showthat the proposed equations predict highdecay rates for small timevalues, in comparisonwith the standard equations,which have high decay rates forlarge times. This work represents a novelty approach to the theory of successive transformations, and opensthe possibility to study properties of the Bateman equation from a fractional approach

Energy optimization of a Sulfur-Iodine thermochemical nuclear hydrogen production cycle

Juarez-Martinez, L.C.,Espinosa-Paredes, G.,Vazquez-Rodriguez, A.,Romero-Paredes, H. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6

The use of nuclear reactors is a large studied possible solution for thermochemical water splitting cycles. Nevertheless, there are several problems that have to be solved. One of them is to increase the efficiency of the cycles. Hence, in this paper, a thermal energy optimization of a Sulfur-Iodine nuclear hydrogen production cycle was performed by means a heuristic method with the aim of minimizing the energy targets of the heat exchanger network at different minimum temperature differences. With this method, four different heat exchanger networks are proposed. A reduction of the energy requirements for cooling ranges between 58.9-59.8% and 52.6-53.3% heating, compared to the reference design with no heat exchanger network. With this reduction, the thermal efficiency of the cycle increased in about 10% in average compared to the reference efficiency. This improves the use of thermal energy of the cycle.

Timing of Sexual Behaviors among Female Adolescents of Mexican-Origin: The Role of Cultural Variables

Espinosa-Hernandez, Graciela,Bamaca-Colbert, Mayra Y.,Vasilenko, Sara A.,Mirzoeff, Charlotte A. Korean Association of Child Studies 2013 Child studies in Asia-Pacific context Vol.3 No.2

We examined the associations between Latino cultural variables and four sexual behaviors among female adolescents of Mexican origin. Participants ages 14 to 19 (N = 153; 70% born in the U.S) completed surveys about four sexual behaviors (making out, receiving and performing oral sex, and vaginal sex) and cultural variables (nativity, language use, familism, and importance of female virginity). Findings indicated that participants who were born in the U.S. were less likely to have engaged in making out and vaginal sex than participants born in Mexico. Participants reporting stronger familism were less likely to have engaged in making out and oral sex than participants reporting less familism. For all behaviors, placing a greater value on female virginity was associated with lesser odds of engaging in that behavior. This study expands our understanding of the role of nativity and Latino values in the sexual behaviors of Mexican-origin female adolescents.

Rapid physicochemical characterization of innovative fucoidan/ fructan powders by ATR–FTIR

Gerardo Espinosa-Vela´zquez,Ana Mayela Ramos-de-la-Pen˜a,Julio Montanez,Juan Carlos Contreras-Esquivel 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.2

Functional food has been highly demanded lately because of its benefits in counteracting diseases. Fucoidan and agave fructan are ingredients that enhance the growth of beneficial bacteria in the gut (prebiotics). This mixture has great potential to develop innovative products but it has never been explored before. Because of fucoidan is more expensive than agave fructan, the innovative proposed mixture is vulnerable to adulteration. This research was aimed to assess the accuracy of Fourier transform infrared spectroscopy with attenuated total reflectance (ATR–FTIR) coupled with chemometrics to identify and predict concentration of both polysaccharides in powder mixtures (0–100%). Absorption bands at 1240–1255 and 836–840 cm-1 were attributed to fucoidan and a strong peak at * 936 cm-1 confirmed the fructan presence. Peak areas were best fitted into linear models (R2 adj C 0.92, RMSE B 3.54%). This achievement may be useful to certificate ingredients contained in fucoidan– fructan mixtures, preventing adulteration.

The effect of ionizing radiation on robotic trajectory movement and electronic components

Coloma Sofía,Espinosa Peralta Paul,Redondo Violeta,Moroño Alejandro,Vila Rafael,Ferre Manuel 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.11

Robotics applications are greatly needed in hazardous locations, e.g., fusion and fission reactors, where robots must perform delicate and complex tasks under ionizing radiation conditions. The drawback is that some robotic parts, such as active electronics, are susceptible to radiation. It can lead to unexpected failures and early termination of the robotic operation. This paper analyses the ionizing radiation effect from 0.09 to 1.5 Gy/s in robotic components (microcontrollers, servo motors and temperature sensors). The first experiment compares the performance of various microcontroller types and their actuators and sensors, where different mitigation strategies are applied, such as using Radiation-Hardened (Rad-Hard) microcontrollers or shielding. The second and third experiments analyze the performance of a 3-Degrees of Freedom (DoF) robotic arm, evaluating its components ʼ responses and trajectory. This study enhances our understanding and expands our knowledge regarding radiationʼs impact on robotic arms and components, which is useful for defining the best strategies for extending the robotsʼ operational lifespan, especially when performing maintenance or inspection tasks in radiation environments.

Timing of Sexual Behaviors among Female Adolescents of Mexican-Origin: The Role of Cultural Variables

Graciela Espinosa Hernandez,Mayra Y Bamaca Colbert,Sara A Vasilenko,Charlotte A Mirzoeff 한국아동학회 2013 Child studies in Asia-Pacific context Vol.3 No.2

We examined the associations between Latino cultural variables and four sexual behaviors among female adolescents of Mexican origin. Participants ages 14 to 19 (N = 153; 70% born in the U.S) completed surveys about four sexual behaviors (making out, receiving and performing oral sex, and vaginal sex) and cultural variables (nativity, language use, familism, and importance of female virginity). Findings indicated that participants who were born in the U.S. were less likely to have engaged in making out and vaginal sex than participants born in Mexico. Participants reporting stronger familism were less likely to have engaged in making out and oral sex than participants reporting less familism. For all behaviors, placing a greater value on female virginity was associated with lesser odds of engaging in that behavior. This study expands our understanding of the role of nativity and Latino values in the sexual behaviors of Mexican-origin female adolescents.

Intrinsic Bauschinger Effect and Recoverable Plasticity in Pentatwinned Silver Nanowires Tested in Tension

Bernal, Rodrigo A.,Aghaei, Amin,Lee, Sangjun,Ryu, Seunghwa,Sohn, Kwonnam,Huang, Jiaxing,Cai, Wei,Espinosa, Horacio American Chemical Society 2015 NANO LETTERS Vol.15 No.1

<P>Silver nanowires are promising components of flexible electronics such as interconnects and touch displays. Despite the expected cyclic loading in these applications, characterization of the cyclic mechanical behavior of chemically synthesized high-quality nanowires has not been reported. Here, we combine in situ TEM tensile tests and atomistic simulations to characterize the cyclic stress–strain behavior and plasticity mechanisms of pentatwinned silver nanowires with diameters thinner than 120 nm. The experimental measurements were enabled by a novel system allowing displacement-controlled tensile testing of nanowires, which also affords higher resolution for capturing stress–strain curves. We observe the Bauschinger effect, that is, asymmetric plastic flow, and partial recovery of the plastic deformation upon unloading. TEM observations and atomistic simulations reveal that these processes occur due to the pentatwinned structure and emerge from reversible dislocation activity. While the incipient plastic mechanism through the nucleation of stacking fault decahedrons (SFDs) is fully reversible, plasticity becomes only partially reversible as intersecting SFDs lead to dislocation reactions and entanglements. The observed plastic recovery is expected to have implications to the fatigue life and the application of silver nanowires to flexible electronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-1/nl503237t/production/images/medium/nl-2014-03237t_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl503237t'>ACS Electronic Supporting Info</A></P>

Closed-loop controller design, stability analysis and hardware implementation for fractional neutron point kinetics model

Vyawahare, Vishwesh A.,Datkhile, G.,Kadam, P.,Espinosa-Paredes, G. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.2

The aim of this work is the analysis, design and hardware implementation of the fractional-order point kinetics (FNPK) model along with its closed-loop controller. The stability and closed-loop control of FNPK models are critical issues. The closed-loop stability of the controller-plant structure is established. Further, the designed PI/PD controllers are implemented in real-time on a DSP processor. The simulation and real-time hardware studies confirm that the designed PI/PD controllers result in a damped stable closed-loop response.