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El objetivo de la presente investigación consiste en determinar los motivos en la práctica de ejercicio físico y relación con la condición física -agilidad, flexibilidad, fuerza explosiva- en deportistas marciales adolescentes en la nueva normalidad. La muestra está constituida por 56 deportistas de taekwondo y 18 de kárate. Se utilizó el Autoinforme de Motivos para la Práctica de Ejercicio Físico (AMPEF) y los test de: Illinois, sit and reach y salto vertical cuantificaron la agilidad, flexibilidad de musculatura isquiotibial y fuerza explosiva de tren inferior. Se cumplió análisis estadístico -coeficiente de correlación de Pearson- entre motivaciones y condición física. Los principales factores motivacionales de los adolescentes marciales fueron: Prevención y salud positiva (M=8,9; DE=1,69), desafío (M=8,9; DE=1,8), diversión y bienestar (M=8,6; DE=1,9). Los test físicos evidencian excelentes resultados en agilidad y flexibilidad, la fuerza explosiva está por debajo de la media. Existen correlaciones positivas entre las capacidades de agilidad (0.86 en hombres y 0.80 en mujeres), fuerza (0.90 en hombres y 0.84 en mujeres) y sus correspondientes factores motivacionales, y una correlación negativa entre la flexibilidad (-0.88 en hombres y -0.90 en mujeres) y su motivación respectiva. Se concluye que los resultados del cuestionario AMPEF y niveles de agilidad, flexibilidad y fuerza explosiva se correlacionan ya sea positiva o negativamente, con valores altos en el coeficiente de Pearson, significa que los adolescentes marciales están conscientes de sus capacidades físicas y mostraron motivación para mejorar sus habilidades.

Ecuador es uno de los países con mayor probabilidad de ocurrencia de desastres naturales, tanto por las condiciones vulnerables como por las frecuentes manifestaciones de fenómenos intensos de origen geológico, geomorfológico e hidrometeorológicos. El objetivo del estudio es diseño de un video con animación sobre las acciones a seguir en caso de ocurrir un deslave de tierra en la comunidad de Gatazo Chico de la provincia de Chimborazo. Proyecto factible desarrollado bajo una metodología positivista, con una perspectiva mixta, bajo un diseño no experimental, siendo una investigación de campo con un nivel descriptivo. La población objeto de estudio estuvo conformada por estudiantes desde segundo grado hasta séptimo grado de la Unidad Educativa Fiscal 15 de agosto de la ciudad de Riobamba, quedando conformada la muestra por 20 alumnos de dicha institución. Siendo la técnica de recolección de datos la entrevista y la encuesta y su instrumento el cuestionario. Como técnica de análisis de datos, se usó el análisis estadístico. En conclusión, debido a la ubicación de la escuela en zona montañosa, se hace necesario elaborar un material audiovisual como apoyo y refuerzo para el objetivo del estudio

The stellar occultation technique is a very powerful tool to obtain the size and shape of Solar System bodies with high accuracy [6]. Size determination allows to obtain geometric albedos and, in the case of binary/multiple objects, even the mass density can be derived [3]. Satellites, atmospheres, and rings can also be detected and characterized [1,2,3]. The observation of stellar occultations produced by Kuiper Belt Objects (KBOs) and Centaurs with the James Webb Space Telescope (JWST) offers a unique possibility to extend our knowledge of these bodies [4] by providing key information on the body's ability to retain volatiles, surface thermal properties, roughness, porosity, etc.We will present our Target of Opportunity (ToO) program [5] accepted within Heidi Hammel's JWST Guaranteed Time Observations (GTO), dedicated to observing stellar occultations by trans-Neptunian objects (TNO) and distant dwarf planets or particularly interesting centaurs (such as the ringed centaurs Chariklo [1] or Chiron [2]). Predictions of such events visible from JWST are challenging due to the chaotic motion of the space telescope around the Lagrange 2 (L2) point. Statistically, we expect there to be approximately a 50% chance of such an occultation of a star brighter than K=19 by a numbered TNO observable from JWST in Cycle 1. We will discuss the possible candidates for Cycle 1 occultations that we have identified so far. As JWST station-keeping maneuvers are executed, the list of possible occultations and their uncertainties will be revised. Very accurate relative astrometry will be performed using the latest releases of the Gaia catalog for particularly promising occultation events through established ground-based programs. Suppose a stellar occultation event is confirmed through such an astrometric revision to have a predicted impact parameter less than 3 times the estimated target radius and to have a 1 sigma uncertainty in prediction less than 2 times the target radius. In that case, the ToO observation will be triggered. JWST station-keeping and trajectory-prediction operations have been studied in the context of stellar occultations by solar system bodies [4]. The accuracy of the trajectory predictions is adequate to support this triggering mechanism up to roughly 30 days before an occultation event: the ToO response time is set to 14 days, the minimum value for a non-disruptive ToO.The observations will be made with NIRCam and the F070W and F277W filters. These filters were chosen to maximize the flux from the star while minimizing the reflected flux from the TNO or Centaur. This filter combination could change based on the properties of the occulted star and the occulting TNO/Centaur. Other technical aspects and updates on this project will be provided during the presentation.Acknowledgments. We acknowledge financial support from the Spanish grant AYA-RTI2018-098657-J-I00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE) and from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). Funding from Spanish projects PID2020-112789GB-I00 from AEI and Proyecto de Excelencia de la Junta de Andalucía PY20-01309 is also acknowledged. Part of this work has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ERC Grant Agreement no. 669416 “LUCKY STAR”). M.V-L. acknowledges funding from Spanish project AYA2017-89637-R (FEDER/MICINN).References[1] Braga-Ribas et al., Nature 508, 72 (2014)[2] Ortiz et al., A&A 576, id.A18 (2015)[3] Ortiz, Santos-Sanz et al., Nature 550, 219 (2017)[4] Santos-Sanz et al., PASP 128, 959 (2016)[5] Santos-Sanz, JWST Proposal. Cycle 1, ID. #1271[6] Sicardy et al., Nature 439, 52 (2006)

In our field of work, a wide variety of large databases are being generated from data obtained by different instruments, in different formats, on similar objects at different times or thousands of different objects over a number of years. In recent years only, catalogues of CCD optical observations from ground-based telescopes are published. Well known examples are the catalogues of moving objects from SLOAN, Gaia-DR2, K2 and several others. In this paper we present a set of software tools that can process images from any telescope, any filter and any FITS header content. The source code of the tools is open to the scientific community using a public repository. Those tools (OM, M2 and HENOSIS) are executed locally (no internet access required), does not include any dependence with traditional software packages (IDL, Python), store the results in a database and has been designed in Scala programming language, allowing to run them in computation clusters (with Spark Hadoop and Yarn) for massive data processing and also enabling the use of latest machine learning algorithms. The OM tool, automatically detects relevant information of an image (telescope, filter, observing date, etc.), including the image type (i.e. science, bias, flat-field, dark). Then it performs the calibration of science images using the master flat, bias and dark previously generated. Finally, it solves the images astrometry using the Gaia-EDR3 catalogue. The M2 tool has a set of capabilities using as input the calibrated images generated by OM: 1) Astrometrya) It fits the image WCS to increase the accuracyb) Manages an astrometry database with 100K images calibrated by OM 2) Photometrya) Calculates the absolute and relative photometry of an asteroid/TNOb) Calculates the light curve and rotational phase of an asteroid/TNOc) Locates all Gaia-EDR3 sources present in an image and calculates its absolute and relativephotometryd) Locates all images that contains a specific asteroid/TNO, by requeste) Locates all known asteroids/TNOs in a sequence of imagesf) Using an input sequence of images, locates the groups of them with the biggest common fieldof view Finally, the HENOSIS tool, allows to cross match different catalogues (Gaia-DR2 MOC, SDSS MOC,MPC...) including the database generated by M2, obtaining as result a unique extended catalogue merging all disperse data. Note that with point 2.c) of M2, for the Gaia stars, the G, Bp and Rp magnitudes are extracted and with them it is possible to calculate the V and R magnitudes. We then calculate and fit to a cubic polynomial and obtain the parameters from which we can obtain the asteroid/TNO magnitude in V and R filters. In this way, data from different telescopes, in different filters and with years of difference, can be compared, assuming a known V-R color for the object. We have tested the system on images from our database of observations over 21 years, at different telescopes and observing filters and present the first results in the poster "Absolute photometry of the transneptunian dwarf planets in a long time span" done by Nicolas Morales at this same meeting.

We have analyzed our database with thousands of images including trans-Neptunian dwarf planets. This images have been obtained since 2005 within our own observing programs to derive absolute photometry at different wavelength bands. We have used specifically designed tools that take into account color terms to derive accurate photometric transformations by taking advantage of the latest Gaia EDR3 photometry [1] for the reference stars in our images. With this remarkable 16-year time span we derive accurate absolute magnitudes and phase slopes in order to analyse trends along the years. Our observing program has mainly used the 1.5-m telescope at Sierra Nevada Observatory in Spain and the 1.23-m telescope at Calar Alto Observatory in Spain but also includes other telescopes such us the TNG or the WHT at La Palma Observatory, Spain. Using some archive images we have also been able to extend the available time span. We will present our preliminary analysis and results of the long term evolution of some of the physical properties for the dwarf planets Haumea, Makemake and Eris. We acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709).Funding from Spanish projects PID2020-112789GB-I00 from AEI and Proyecto de Excelencia de la Junta de Andalucía PY20-01309 is acknowledged. Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ERC Grant Agreement no. 669416 “LUCKY STAR”). M.V-L. acknowledges funding from Spanish project AYA2017-89637-R (FEDER/MICINN). P.S-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 “LEO-SBNAF”. [1] M. Riello , F. De Angeli , D. W. Evans et al. A&A 649, A3 (2021)

Eris is currently the most massive known dwarf planet in the Solar system, it has one known satellite, Dysnomia (Brown & Schaller 2007; Holler et al. 2020). There have been several attempts trying to identify the rotation period of Eris from visible ground based measurements which resulted in a wide range of possible values (Duffard et al., 2008). Here we present some new light curve data of Eris, taken with ∼1m-class ground based telescopes, with the GROND instrument at the 2.2m MPG/ESO telescope La Silla, and also with the Transiting Exoplanet Survey Satellite (TESS). Observations of Eris with GROND were made in 3 nights in August 2010. Auxiliary ground based photometry data of Eris from five telescopes were obtained in irregular intervals between 2005 and 2020 (see table 1.) TESS observed Eris in Sector 30 with its Camera 1 and CCD 3. A significant portion of the light curve data had to be excluded due to Eris’ encounter with nearby background sources which left a dominant feature in the background-subtracted image. We note that due to the limited length of the TESS light blocks (2.3 d and 6.6 d) it was not possible to detect light curve periods in to order or close to the orbital period (15.78 d). For most of the ground-based measurements we used our night-averaged values for the 1.5m, La Hita and CA2.2m data), except for the GROND measurements, for which we used the all the individual data points. In addition, we also considered previously published data, including ground-based data from Carraro et al., 2006 and Duffard et al., 2008, and the SWIFT satellite data from Roe et al., 2008. We assumed that i) the light curve amplitude is the same in any of the photometric bands used and ii) the light curve can be described by a simple sinusoidal variation. With these assumptions each model light curve can be described by four parameters: a light curve amplitude, period, phase-shift, and an offset from the photometric zero point. We allowed a different offset for each measurement block even if the data were taken by the same instrument and filter combination (1.5m measurements) due to the year-long gaps between the measurement blocks. We chose an amplitude A and period P, and determined the best fitting light curve phase using a Levenberg–Marquardt minimization algorithm. We expect that the best-fitting period-amplitude values provide the lowest C(P,A) values. We searched the period range P ∈ [1d, 15.88 d], where 15.88 d is the orbital period of Dysnomia, and it would correspond to a synchronised rotation. The C(P,A) contour map shows two minima, one at P ≈ 8 h, and A ≈ 0.05, and another at P ≈ 11.5 h, and A ≈ 0.08. To check the robustness of this result, we repeated the process by modifying the photometric data points by adding a random value with normal distribution and repeating the fitting process several times for the whole data set. The same two minima popped up in all cases. TESS data favours a rotation period of 59.420±0.527 h (See Figure 1.), while ground based data is more compatible with a synchronous or nearly synchronous rotation (See Figure 2.). We inspected the colours calculated from the GROND photometry and compared our results to previous values from the literature (Table 2). The optical colours (B-V, V-R, R-I) are in good agreement with previous colours, but the J-H colour from GROND is different from the ones in the literature. Also, we can see a big scatter in those. (See Table 2.) One possible explanation can be, that there is a big CH4 feature on the surface of Eris, which has strong absorption lines in H band, and it can change the NIR colour, but not the optical ones. To confirm this, more long-term optical and NIR measurements are needed. Finally, we use the simple tidal evolution code by Hastings et al. (2016) to calculate the evolution of the satellite orbit (only the semi-major axis in this approximation) and the spin evolution of Eris and Dysnomia. Although the spin period of Eris is not well defined yet, it is an interesting question whether the possible rotation periods of Eris – ranging from a few hours to the orbit-synchronous state – are feasible in terms of tidal evolution, using the current knowledge on the system components.

We have carried out a long term photometric analysis of time series images of the trans-Neptunian object (TNO) 2008 OG19 with which we have refined its physical properties from its long-term variability. Photometric Analysis The first detailed analysis of 2008 OG19 was carried out by [1] using rotational light-curves from 2014 and 2016 from which a volume-equivalent diameter, a rotation period (P), a triaxial ellispoidal shape model, and a density were estimated. We have used 1,314 images covering a time-span of six years (2014-2021), obtained with the Sierra Nevada 1.5-m telescope and the Calar Alto 1.2-m telescope, both in Spain, in order to build yearly rotational light-curves for 2008 OG19. To refine the rotation period estimation of 2008 OG19, we have combined the whole set of data and applyed the lomb periodogram [2] and the Phase Dispersion Minimization techniques [3] resulting in P = 8.72565 +/- 0.0008 hr. The resulting rotational light-curve can be seen in Figure 1. Long-term variability By folding the light-curves with the refined period, we have been able to see an increase of the amplitude of the rotational light-curve. This increase is due to a change in the aspect angle, that allows to estimate the orientation of 2008 OG19 rotational axis as seen in Figure 2. Using the largest rotational light-curve amplitude and assuming hydrostatic equilibrium we have updated its triaxial ellispoid model and its density. Figure 1: 2008 OG19 rotational light-curves folded to P = 8.72565 h. Observational data are represented by color points with each color indicating a different observational night. The black dashed line represent the Fourier series fit. Figure 2: Model of the amplitude given by the fit to the observational data using b/a = 0.643 in blue (best fit). Other pole solutions are possible with different values of the b/a such as the red model. The gray line represents 2008 OG19 aspect angle given by the best fit. The magenta points with error bars are the observational data from this work. References[1] E. d. M. Fernández-Valenzuela, Physical properties of transneptunian objects and centaurs; Ph.D. thesis, University of Granada, Spain, 2017.[2] N. R. Lomb, Least-squares frequency analysis of unequally spaced data, Astrophysics and Space Science 39 (1976) 447–462. doi:10.1007/BF00648343.[3] R. F. Stellingwerf, Period determination using phase dispersion minimization, ApJ 224 (1978) 953–960. doi:10.1086/156444.2

Hi’iaka is the largest satellite of the dwarf planet Haumea, with an estimated area-equivalent diameter of 300 km (Fernández-Valenzuela et al., 2021). It is the best studied satellite in the trans-Neptunian region. Its rotational light-curve was observed with Hubble, for which an approximate rotation period of 9.8 h was obtained (Hastings et al. 2016). The system is very peculiar because it stands out from all other TNO-binary systems. While all other known satellites are thought to be synchronous, Hi’iaka’s rotation period is fast compared to the 49 days that takes to complete an orbit around Haumea. Therefore, the study of Haumea-Hi’iaka system yields important information about the formation processes of the whole Haumea’s system, which includes another moon (Brown et al. 2006), a ring (Ortiz et al. 2017) and a family of objects (Brown et al. 2007). Our group has been observing Haumea since its discovery, compiling a large database of images since around 20 years ago. Using this set of images we have obtained high accuracy astrometric measurements of the photocenter of the Haumea-Hi’iaka system. We have applied a similar procedure as in Ortiz et al. (2017) to disentangle the position of Haumea from the contribution of Hi'iaka, but for a much larger time span as mentioned above. Therefore, we have been able to determine more accurate orbits for Haumea and Hi'iaka. Additionally, we have carried out two specific observational runs of several days in order to obtain the rotational phase of Hi’iaka at that moment of the two stellar occultations that occurred last year (in April 2021). We used the 1.23-m telescope at Calar Alto Observatory, the Artemis telescope at Teide Observatory and the 1.5-m telescope at Sierra Nevada Observatory to acquire images of the unresolved system. The resulting photometry of these images give rise two rotational light-curves of Haumea in 2021 and 2022. We fitted a fourth-order Fourier function, which represents Haumea’s body-shape contribution to the rotational light-curves. From this fit, we took the residuals of the observational data and searched for periodicities within them. We obtained a rotation period in agreement with the estimations in Hastings et al. (2016), but much more accurate. These residuals, when folded to the resulting period, provide Hi’iaka’s rotational light-curve. The amplitude obtained for Hi’iaka’s rotational light-curve is 0.015 mag, which agrees with the expected signal induced in Haumea’s rotational light-curve when accounting for a variable source as that produced by Hi’iaka, i.e., considering the rotational light-curve obtained in Hastings et al. (2016). We have not detected a change in the amplitude of Hi’iaka’s rotational light-curve when comparing our data, taken in 2021 and 2022, with those from Hastings et al. (2016), taken in 2010. This means that the obliquity of Hi’iaka must be close to 90º in its orbit around Haumea. Brown et al. (2006), The Astrophysical Journal, Volume 639, Issue 1, pp. L43-L46. Brown et al. (2007), Nature, Volume 446, Issue 7133, pp. 294-296. Fernández-Valenzuela et al. (2021), AAS Division of Planetary Science meeting #53, id. 503.05. Bulletin of the American Astronomical Society, Vol. 53, No. 7 e-id 2021n7i503p05. Hastings et al. (2016), The Astronomical Journal, Volume 152, Issue 6, article id. 195, 12 pp. Ortiz et al. (2017), Nature, Volume 550, Issue 7675, pp. 219-223.

The following article presents the process to obtain the kinematic and dynamic model of a Cartesian robot with 3 degrees of freedom. The robot that is used was designed for educational purposes, it allows two linear movements and one angular. The kinematic model has two forms, direct and inverse, the first provides the final position of the robot if desired values are given to each of the robot's joints, the second provides the values of the joints if there are desired values for the effector final. On the other hand, the obtaining of the dynamic model is presented in detail, which obtains the torques and forces necessary for the robot to be able to move to a specific point. The procedure includes kinematic analysis using Denavit-Hartenberg parameters and dynamic analysis using Jacobeans. As a result, responses obtained from a Simulink model are presented that show the behavior of the developed models.

A correct assessment of the academic level of students with attention deficits is essential for any teacher and parent who is interested in integrating the student into a conventional education school. Centros de Atención Multiple (CAM) that care children with Autism Spectrum Disorder (ASD) do not always have the right way to evaluate a student with these characteristics. This work presents the design of a protocol for evaluating students presenting ASD by using simultaneously a mechanical pedaling system as an aid element to focus the student's attention on assigned tasks.

The article presents the analysis of a robot with three degrees of freedom to follow trajectories through a partitioned control. Which is made up of two revolute and one prismatic joint where the end effector is located, that allows it to move correctly in its work area. This robot has a different structure from those most studied and analyzed by current literature, therefore it presents an opportunity to be used as a didactic resource, due to the structure, the degrees of freedom and the affinity of the models used by the students. The analysis consists of the use of the DH rule for the assignment of frames and referential axes, centers of mass, dynamic model by Jacobian and Christoffel symbols, inverse kinematic model, variables such as friction, gravitational and friction compensation, ending in a model in "Simulink" capable of following trajectories from the partitioned control law.

Recently Ni–Co mixed oxide nanoparticles have received tremendous attention for their application potential in electrochemical devices, biosensing, and biomedical treatments. However, the biomedica...

The cognitive abilities of children with Autism Spectrum Disorder (ASD) are different from those of children who do not have this characteristic. Parents, teachers, scientists, and therapists strive to develop neuropsychological systems, ludic software, and others systems that help children with ASD improve their attention to learn faster. According to the experience of experts from the Multiple Attention Center 51, a mechanical system that forces them to use their two cerebral hemispheres, as allowed by a pedaling system and with a specific protocol of tasks, will help them to focus their attention allowing them to learn basic tasks that allow them to integrate into conventional schools. There are not many Educational organizations focused on treating children with ASD so they need to improve and develop different learning conditions for infants with ASD to accelerate their integration into conventional schools. This article presents the evolution of a dynamic pedaling system that is used as a parallel complement to the education of a child with ASD, which we believe will accelerate the development of their abilities and the possibility of integrating more quickly into their social environment.

This article presents the results of tests performed on the mechanical system of wheeled robots, so they can be implemented as therapy instruments for people with different capacities (ASD). The results displayed show the robot's behavior following a trajectory and its dependence on operator handling. In this way, results can be extrapolated about the importance of design for the development of mechanical systems that can be reliable to be implemented as therapy tools.

The article shows the needed procedure to obtain the dynamic model of a robot, with the purpose of being able to follow a planned path using the control law “CTC” Computed Torque Control. The robot was designed in a simple way for didactic reasons, this robot has three degrees of freedom, four links and three joints to move around in the work place. Two out of these joints are rotatory joints meanwhile the third one is a prismatic joint. The dynamic model of the robot is obtained using the Jacobians and Christoffel symbols of the center of mas of each link. Also including the Gravitational vector and the frictions of each joint. The objective of the dynamic model is to be able to simulate the robot in “Simulink” and test different paths using the computed torque control in which the gains of the control will be manipulated until a value that satisfies the desired path is found

Main text The CCQM-K173 Assay of Sodium Carbonate key comparison was jointly organized by the Inorganic Analysis (IAWG) and Electrochemical Analysis and Classical Chemical Methods (EAWG) working groups of CCQM to test the abilities of the national metrology institutes (NMIs) to measure the purity or amount content of solid bases. They are important challenges for reference material producers, providers of other measurement services, such as proficiency testing schemes. Evidence of successful participation in formal, relevant international comparisons are needed to support calibration and measurement capability claims (CMCs) made by NMIs and designated institutes (DIs). Nine NMIs participated in this key comparison CCQM-K173. National Institute of Metrology P. R. China (NIM) and Ural Research Institute for Metrology - Affiliated Branch of the D.I. Mendeleyev Institute for Metrology (VNIIM-UNIIM), Russian Federation, acted as the coordinating laboratories of the comparison. The measurement methods used by the participants for measuring the amount content of bases expressed as sodium carbonate were coulometry and titrimetry. In general, good overlap of results was observed, the suitability of coulometry and titrimetry for assay of high purity materials was demonstrated. The majority of results were split in two groups differing from each. This bias was however covered by the stated uncertainty estimates. Various effects have been evaluated that may cause it. However, the reason for the bias has not been identified clearly. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

El presente ensayo se enfoca en realizar una reflexión acerca del papel que cumple la interinstltucionalidad en el Ordenamiento Territorial Marino Costero y de los Espacios Oceánicos en Colombia, a través de una revisión de las funciones que las instituciones ejecutan y la jurisdicción que posee cada una de estas; se resaltan algunos casos específicos del traslape de funciones e ineficiencia en la ejecución de estas, igualmente, se dan a conocer las acciones relacionadas con el Ordenamiento Territorial Marino Costero y de los Espacios Oceánicos a lo largo de los años, donde se analizan las diferentes perspectivas con las que se han estudiado estas zonas, así como las diferentes estrategias que se han empleado en distintas escalas espaciales, lo que evidencia la inadecuada gestión realizada en estos territorios tan importantes para Colombia, donde la opinión de la población no se ha tenido en cuenta para construir estrategias y lincamientos de ordenamiento territorial con miras a lograr un desarrollo sostenible. Se finaliza con unas recomendaciones para fortalecer la interinstltucionalidad en Colombia y la construcción de herramientas poderosas para lograr una interconectividad entre instituciones.

The bandwidth, low cost, great storage capacity and performance are characteristics of the random Access Memories (RAM).Some kinds of RAM include ferro-random access memory (FRAM) and magnetoresistive random access memory (MRAM), the latter being of great interest to the scientific community since storage is achieved via magnetic orientation rather than electric orientation. In this paper, we analyze the effect of the application of an external magnetic field on the current-voltage (I-V) characteristics of Schottky barriers made of silicon-gold, to show the effects of magnetoresistance in dispositive semiconductors suited for use as memory storage.

Surface activation of catalysts is known to be an efficient process to enhance their activity in catalytic processes. The activation process includes the generation of oxygen vacancies, changing the nature of the catalyst surface from acidic to basic and vice versa, and the reduction of catalyst surface by H2. On the other hand, magnetically separable catalysts are highly beneficial for their utilization in water or biological fluid-based catalytic processes, as they can be easily guided to the target site and recovered. Here, we present the fabrication of CoFe2O4 and composites of Co3O4/CoFe2O4/α-Fe2O3 and Co/CoFe2O4/α-Fe2O3 through solution combustion process to utilize them as catalysts for 4-nitrophenol (4-NP) reduction. Although none of the as-prepared CoFe2O4 and Co3O4/CoFe2O4 was seen to be active in 4-NP reduction reaction, the surface of the composite gets activated by borohydride (NaBH4) treatment to act as a highly active catalyst for 4-NP reduction. X-ray photoelectron spectroscopy of the composite revealed the formation of metal-hydroxide (M–O–H) species of both Co and Fe at its surface due to borohydride treatment. The mechanism of the surface activation and the dynamics of 4-NP reduction of the surface-activated composite have been studied, proposing a possible pathway for the reduction of 4-NP.

Language is a fundamental tool for human interaction. Through communication an individual may obtain and transmit information, emotions and wishes. However, language is an acquired skill that requires a development process, in which the critical phase of development occurs during childhood an individual may encounter social, cognitive and emotional problems during the aforementioned and later stages of life if this skill has not fully matured. This impact may be reduced or eliminated through therapy, with the aid of tools such as Augmentative and Alternative Communication (AAC) systems, along with techniques such as music therapy and articulation therapy. These techniques are employed to aid the patient fully develop their linguistic abilities. A platform which incorporates the aforementioned therapeutic elements with current technological advances is proposed in this research paper, which combines them with a label system readable by machine. The results of experimental therapeutic sessions are be addressed in this research paper.

This article examines the history of survey and communication research in Latin America. Aiming to contribute to a more robust transnational history of communication research in the American contin...

Here, we present the low-temperature (∼600 °C) solution combustion method for the fabrication of CoFe2O4, NiFe2O4, and Co0.5Ni0.5Fe2O4 nanoparticles (NPs) of 12–64 nm range in pure cubic spinel structure, by adjusting the oxidant (nitrate ions)/reductant (glycine) ratio in the reaction mixture. Although nitrate ions/glycine (N/G) ratios of 3 and 6 were used for the synthesis, phase-pure NPs could be obtained only for the N/G ratio of 6. For the N/G ratio 3, certain amount of Ni2+ cations was reduced to metallic nickel. The NH3 gas generated during the thermal decomposition of the amino acid (glycine, H2NCH2COOH) induced the reduction reaction. X-ray diffraction (XRD), Raman spectroscopy, vibrating sample magnetometry, and X-ray photoelectron spectroscopy techniques were utilized to characterize the synthesized materials. XRD analyses of the samples indicate that the Co0.5Ni0.5Fe2O4 NPs have lattice parameter larger than that of NiFe2O4, but smaller than that of CoFe2O4 NPs. Although the saturation magnetization (Ms) of Co0.5Ni0.5Fe2O4 NPs lies in between the saturation magnetization values of CoFe2O4 and NiFe2O4 NPs, high coercivity (Hc, 875 Oe) of the NPs indicate their hard ferromagnetic behavior. Catalytic behavior of the fabricated spinel NPs revealed that the samples containing metallic Ni are active catalysts for the degradation of 4-nitrophenol in aqueous medium.

The present work describes and discusses some novel aqueous colloidal generation of Bi, (BiO)2CO3, and (BiO)4(OH)2CO3 nanoparticles (NPs) and their structural characterization. These Bi NPs are transformed into (BiO)2CO3 NPs by capturing atmospheric CO2 at room temperature. This transformation is highly dependent on pH, temperature, and the presence of halloysite nanotubes (HNTs) in the solution. When halloysite was present, small (7 nm) nanospheres were obtained. A substantial change in the relative intensity of the peaks in the X-ray patterns for (BiO)2CO3 was observed. In some cases, that change was due to water molecules within the (BiO)2CO3 powder. The crystallite sizes associated with the crystallographic planes parallel to the (040) plane were smaller than for the remaining planes. This difference was more appreciable for (BiO)2CO3 nanoplates and nanorods that have the ability to float on water. β-Bi2O3 NPs, suspended in water and exposed to the light from a xenon arc lamp for 16 h, produced a mixt...

Fabrication of phase-pure well-crystalline BiFeO3 submicroparticles in large scale is of great importance for the utilization of this rhombohedrally distorted perovskite material in applications such as memory storage and spintronic devices and visible photocatalyst for the degradation of organic pollutants. In fact, because of the narrow temperature range of phase stabilization, the fabrication of phase-pure BiFeO3 in large scale remained elusive. We present the synthesis of phase-pure BiFeO3 particles of submicrometric dimensions (246-330 nm average size) through the adjustment of oxidizing/reducing agent ratio in solution combustion process utilizing glycine as reducing agent and nitrate precursors as oxidizing agent. Utilizing X-ray diffraction and Raman spectroscopy, we demonstrate that the BiFeO3 submicroparticles synthesized at equivalence ratio (Φe) close to 0.5 do not contain undesired impurities such as Bi2Fe4O9 and Bi24Fe2O39. Moreover, the submicroparticles are highly crystalline, possessing high room temperature magnetic moment and stable antiferromagnetic behavior across a wide temperature range. The superparamagnetic behavior at low magnetic field manifested by impurities attached to the BiFeO3 submicroparticles might lead to their use as effective magnetically separable photocatalysts.

Spinel NixMn3-xO4 nanostructures have attracted a huge research interest due to their applications in catalysis, electrocatalysis , high-performance supercapacitors, lithium-ion batteries, among others. However, those applications strongly depend on the Ni:Mn ratio, valence states and spatial distribution of cations in the spinel lattice. Using a low-temperature sol-gel process, we synthesized Ni xMn3-xO4 nanoparticles of 14–26 nm average sizes with different Ni contents. Effects of Ni incorporation on the morphology, structure and magnetic properties of the nanostructures were studied by SEM, XRD , XPS, Raman spectroscopy and VSM. While a high Ni content in the spinel nanostructures causes lattice shrinkage, lattice expansion at lower Ni content occurs due to higher occupancy of Mn 2+ ions in tetrahedral sites. Structural and magnetic behaviors of the nanostructures were explained by considering the crystal field stabilization energies of the cations. We demonstrate that superparamagnetic behavior can be induced in the NixMn3-xO4 nanostructures by incorporating Ni at x>1.0.

Interest in nanostructured partially substituted bismuth oxides has been increasing over the last years. Research on new synthesis methods, properties, and possible uses for these oxides is needed. The objective of this paper is to synthesize β-Bi2O3, β-Bi2O3:Eu3+, β-Bi2O3:Mn4+, Bi12Bi0.8O19.2, Bi12Bi0.8O19.2/Li+, Bi12MnO20, and Bi12SiO20 nanoparticles and to investigate their structural, spectroscopic, and optical changes. Some of the causes that generated their properties are also discussed. These materials are important because the doping or partial substitution of bismuth oxide with these cations (Eu3+, Mn4+, and Si4+) modifies some properties such as optical absorption, reactivity toward CO2, among others. X-ray diffraction (in powders), high-resolution transmission electron microscopy, Fourier transform infrared (FTIR), resonance Raman scattering, diffuse reflectance, and solid-state magic-angle-spinning 29Si NMR were used for the characterization of the synthesized materials. We found that partial ...

Main text The CCQM-K152 key comparison in parallel with CCQM-P192 pilot comparison were organised jointly by the Inorganic Analysis (IAWG) and Electrochemical Analysis and Classical Chemical methods (EAWG) working groups of CCQM to test the abilities of the metrology institutes to measure the amount content of the non-metallic elements in high purity salts as well as assaying high purity salts to be used as primary standards. Eight NMIs participated in the key comparison CCQM-K152. Ural Research Institute for Metrology (UNIIM) (since 2020 it has been called Affiliated Branch of D.I.Mendeleev Institute for Metrology (VNIIM-UNIIM)), Russian Federation, acted as the coordinating laboratory of the comparison. There were two measurands: the amount content of oxidants expressed as potassium iodate, mol/kg, and the mass fraction of iodine, kg/kg. The measurement methods used by participants for the amount content of oxidants expressed as potassium iodate were constant current coulometry and titrimetry. For the mass fraction of iodine results were provided by 5 NMIs, 3 of them used the direct approach (recalculation from coulometric or titrimetric results) and 2 NMIs implemented the indirect approach based on impurities assessment using combination of the instrumental methods (ion chromatography, ICP OES, ICP MS). In general, good overlap of results was observed for both measurands. Direct and indirect approaches for purity determination of pure salt provide overlapping results when impurities are summarized in ionic form. The suitability of coulometry for assay of high purity materials was demonstrated again, and some possible technical problems were highlighted. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text This key comparison is being performed to evaluate the degree of equivalence of measurement procedures to support the participants' claims of Calibration and Measurement Capabilities (CMCs) and to evaluate the capabilities of participants for the determination of the pH of carbonate buffer solutions. This is the fourth APMP key comparison on pH measurement following APMP.QM-K9/P16 (phosphate), APMP.QM-K19/P25 (borate) and APMP.QM-K91/P29 (phthalate). The results have the linkage to CCQM-K18.2016 (carbonate buffer) and were evaluated by comparing the results of the Physikalisch-Technische Bundesanstalt (PTB) and the National Metrology Institute of Japan (NMIJ) performing Harned cell method. The results of PTB and NMIJ were used for the definition of the Key Comparison Reference Value (KCRV). The ensuing pH value was calculated based on the Bates-Guggenheim convention to compare the results of primary and secondary methods. In this comparison measurements of pH were performed only at the temperature of 25 °C. The results demonstrated by most participants are in better agreement than those in CCQM-K18.2016. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text The CCQM-K34.2016.1 was organized as a subsequent key comparison of CCQM-K34.2016 assay of potassium hydrogen phthalate to demonstrate the improved capability of the laboratories which did not perform well in the original CCQM-K34.2016. The key comparisons were organized jointly by the working groups of inorganic analysis and electrochemistry analysis. National Institute of Metrology P. R. China (NIM) acted as the coordinating laboratory, and NIM and SMU (Slovak Institute of Metrology) served as linking laboratories to link to the CCQM-K34.2016 key comparison reference value (KCRV). CENAM, NIST and VNIIFTRI registered in K34.2016.1, however, VNIIFTRI gave up participating in the comparison due to failure to get the samples through the customs clearance in Russia. All participants used constant current coulometry for measurement, and improved capabilities were demonstrated. The scope is same as in CCQM-K34.2016. The comparison tested the capabilities and methods used for assay of high purity materials. Good result indicates good performance in assaying the purity （amount content）of solid weak acids. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

This key comparison (KC), CCQM-K73, was performed to demonstrate the capability of the participating National Metrology Institutes (NMIs) to measure the amount content of H + , νH + , in an HCl solution with a nominal νH + of 0.1 mol·kg -1 . A parallel Pilot Study, CCQM-P19.2, was performed for NMIs that did not desire to participate in the KC. The comparison was a joint activity of the Electrochemical Working Group (EAWG) and Inorganic Analysis Working Group (IAWG) of the CCQM and was coordinated by NIST (USA) and CENAM (Mexico). The method of determination of νH + was left to the individual participant. All participants used either coulometry or titrimetry with potentiometric determination of the endpoint. The agreement of the results was not commensurate with the claimed uncertainties of the subset of participants that claimed small uncertainties for this determination. A workshop on technical issues relating to the CCQM-K73 measurements was conducted at the joint IAWGEAWG meeting at the Bureau International des Poids et Mesures (BIPM), Paris (Sevres) in April 2010. Several possible sources of bias were investigated, but none could explain the observed dispersion among the participants’ results. In the absence of a specific cause for the dispersion, the IAWG and EAWG decided to assign a Key Comparison Reference Value, KCRV, and standard uncertainty of the KCRV, uKCRV, based on the DerSimonian-Laird statistical estimator. The uKCRV is dominated by the between-laboratory scatter of results in CCQM-K73. The uncertainty estimates from the participants with the lowest reported uncertainties remain unsupported by this KC.

La1-xSrxMnO3 perovskites are of enormous current interest due to their superior magnetoresistance and application as cathode material for solid oxide fuel cells. However, practical applications of these perovskites critically depend on size, composition, and concentration of La3+ vacancies at their surfaces. Here we present the fabrication of size controlled (90–255 nm average size), highly crystalline La1-xSrxMnO3 (x = 0, 0.3, 0.5, and 1) nanoparticles, simply by ball-milling of metal acetylacetonate precursors in NaCl and subsequent air-annealing. The size of the nanoparticles increased in the order LaMnO3+ δ

Key comparison (KC) CCQM-K18.2016 was performed to evaluate the degree of equivalence between pH measurement results on an unknown carbonate buffer reported by participating National Metrology Institutes and Designated Institutes (NMI/DIs). The participants used the highest metrological method existing at their institution. The nominal buffer pH was 10.0 and was determined only at 25 °C. Good agreement of the results is demonstrated by most participants. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Fabrication of phase-pure well-crystalline BiFeO

In the present work, the nonresonance and resonance Raman scattering by Bi2S3 quantum dots, with an average size of 2.3 nm and standard deviation of 0.4 nm, is studied. The Raman spectra of a bulk sample, used as reference, also helped to identify recurrent misleading interpretations present in the literature. A blue-shift of 0.58 eV was observed in the band gap of the quantum dots with respect to the bulk value. In nonresonance conditions, the Raman bands of the Bi2S3 quantum dots (those at 186, 236, and 259 cm–1) are asymmetrically broadened, and the intensity of the peak at 259 cm–1 is enhanced, when compared to the bulk reference. In resonance condition, the Raman spectrum intensity of the Bi2S3 nanostructures is enhanced by a factor of ∼26 at 237 cm–1 with respect to the nonresonance case and ∼18 times with respect to that corresponding to its bulk counterpart. The observed results are qualitatively explained in the framework of the microscopic Raman scattering theory of spherical quantum dots.

Interest in nanostructured partially substituted bismuth oxides has been increasing over the last years. Research on new synthesis methods, properties, and possible uses for these oxides is needed. The objective of this paper is to synthesize β-Bi

Resumen La biblioteca académica por sus funciones de apoyo a la docencia, investigación y difusión de la cultura, son un nodo fundamental de información que más allá del lugar que ocupan en la estructura organizacional de la universidad o centro de investigación al que pertenecen, tiene un amplio radio de acción, el cual repercute de manera significativa en actividades relacionadas con la formación de los estudiantes y en el desarrollo de las investigaciones y la difusión de la cultura. El presente trabajo brinda algunas herramientas metodológicas relacionadas con la gestión de información que permiten abordar el estudio de los usuarios de la información de la biblioteca académica del Centro Interdisciplinario de Ciencias Marinas, dependiente del Instituto Politécnico Nacional en México, desde un enfoque de la planeación estratégica empresarial, que consiste en representar un sistema de gestión de información que oriente al bibliotecario en la toma de decisiones sobre las necesidades de los usuarios de la información. El método utilizado en el estudio de usuarios y sus necesidades, fue el método integral para la determinación y la satisfacción dinámica de las necesidades de formación e información (AMIGA) y los principios de la planificación de TI/SI integrados a la planificación estratégica de negocios, a partir del análisis relacionado con las ideas rectoras de la organización, con los usuarios de la información, los servicios, los canales de distribución, los proveedores, la cadena de valor de los sistemas de información y muchas otras más que le amplíen el conocimiento sobre las necesidades de información de los usuarios y a su vez sea el facilitador en el uso productivo de la información. Es decir, la biblioteca como un sistema de información fundamental de apoyo, que le permite al Centro alcanzar su misión y objetivos, por lo tanto los bibliotecarios y profesionales de la información consideran como prioritaria la planeación estratégica para conocer más a sus usuarios y saber atender sus requerimientos de información. Abstract The academic library for their supporting roles in teaching , research and dissemination of culture, are a key node for information beyond their place in the organizational structure of the university or research center to which they belong , have a wide range , which significantly impacts related to the training of students and the development of research and dissemination of cultural activities. This paper provides some methodological tools related to information management that tackle the study of information users of academic library of the Interdisciplinary Center of Marine Sciences , under the National Polytechnic Institute in Mexico , from a strategic planning approach business , which is to represent an information management system to guide the librarian in making decisions about the needs of information users . The method used in the study of users and their needs , was the comprehensive method for the determination and satisfaction dynamics of the training and information needs ( Amiga ) and early planning of IT / IS strategic planning integrated business from the leading ideas related to the organization , with users of information analysis, services , distribution channels , suppliers, the value chain of information systems and many more that will broaden the knowledge of the information needs of the users and in turn be the facilitator in the productive use of information. That is, the library as a system of fundamental supporting information, which allows the center to achieve its mission and objectives , so librarians and information professionals consider as a priority strategic planning to better understand their users and find address their information requirements .

The CCQM-K34.2016 key comparison for determination of the purity of potassium hydrogen phthalate was organized jointly by the inorganic analysis and electrochemical analysis working groups of CCQM to repeat CCQM-K34 for supporting CMC claims of participating metrology institutes in assaying the amount content of monoprotic weak acid. National Institute of Metrology P.R.China (NIM) acted as the coordinating laboratory of this comparison. Twelve NMIs participated in this key comparison. With the exception of one laboratory that used NaOH-titration, all participants used coulometry. In general a good overlap of results was observed, the suitability of coulometry for assay of high purity materials was demonstrated again, and some possible technical problems were highlighted. The comparison tested the capabilities and methods used for assay of high purity materials. Good result indicates good performance in assaying the purity (amount content) of solid weak acids. KEY WORDS FOR SEARCH CCQM-K34.2016; potassium hydrogen phthalate; coulometry Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

International audience; This work reports the effects of four organic compounds (referred to as levelers) on the electrodeposition of Zn on steel from alkaline free-cyanide electrolytes. The additives tested included polyvinylalcohol (PVA) and the condensation products of epichlorhydrin with amines, called polyamines (PAs), that were synthesized using an aliphatic amine (PA-I, from diethylamine and PA-II from diethylamine-triethylamine), and a heterocyclic quaternary imidazolium molecule (PA-Imid, from imidazole). These compounds were evaluated in the absence and in addition to a quaternary ammonium brightener, N-benzyl-3-carboxylpyridinium chloride (3NCP). The imidazole derivative-based polyamine (PA-Imid) causes greater inhibition of the zinc reduction process than the aliphatic polyamine, and more cathodic overpotential is necessary to promote massive metal deposition. The morphology of the deposits is modified when polyamines are added to the bath; more compact and smaller crystals are obtained with PVA as well as with polyamine PA-I. The addition of PA-II as well as PA-Imid yields crystals growing perpendicular to the substrate. The addition of 3NCP with PVA, PA, or PA-Imid increased the deposition overpotential and modified the morphology by diminishing the grain size. In the absence of additives, crystallographic orientation favored the basal Zn(002) with high atomic packing. The addition of the levelers favored the high-angle pyramidal Zn(101) with low atomic packing. The combination of the levelers with (3NCP) favored the prismatic Zn(100) crystallographic orientation. Additives decrease the size of zinc crystals and tend to increase the energy of lattice favoring the growth of pyramidal and prismatic planes.

La informacion sobre la estructura cromosomica es basica dentro del conocimiento biologico de cualquier especie y fundamental para la comprension de fenomenos citogeneticos que subyacen a procesos fisiologicos, ontogenicos y evolutivos. En este ultimo ambito, el conocimiento del grado de similitud de los cromosomas de especies filogeneticamente cercanas complementa la informacion necesaria para plantear hipotesis causales sobre procesos de divergencia evolutiva. El objetivo del presente estudio fue determinar la similitud citogenetica entre Paralabrax maculatofasciatus y P. nebulifer , especies filogeneticamente cercanas que se distribuyen en el Pacifico oriental, mediante la comparacion del numero, tipo y tamano de los cromosomas. El examen de celulas mitoticas de eleuteroembriones en ambas especies mostro un cariotipo constituido por 48 cromosomas acrocentricos (2n = 48A; numero fundamental = 48), sin la presencia de cromosomas heteromorficos. No se detectaron diferencias significativas entre especies, tanto en el tamano promedio, como en la longitud relativa (LR) de los pares cromosomicos homeologos que presentaron un valor maximo de 4 μm (LR = 5.5 %; par 1) y un minimo de 1.7 μm (LR = 2.3 %; par 24). Este cariotipo es considerado ancestral dentro del Orden Perciformes y esta presente en la mayoria de las especies de la Familia Serranidae. Con base en estos resultados se sustenta la hipotesis de que la divergencia evolutiva entre P. maculatofasciatus y P. nebulifer se origino a traves del establecimiento de barreras reproductivas precopulatorias sin alteracion cariotipica ni formacion de barreras postcopulatorias, tanto precigoticas como postcigoticas. Evidencen of karyotypic stasis during the evolutionary divergence between Paralabrax maculatofasciatus and P. nebulifer (Perciformes: Serranidae) Information on chromosome structure is basic within the biological knowledge of any species and fundamental to the understanding of the cytogenetic phenomena underlying physiological, ontogenic and evolutionary processes. Knowledge on the degree of similarity of chromosomes in phylogenetically close species supplements the necessary information to raise causal hypotheses on the processes of evolutionary divergence. The objective of this study was to determine the cytogenetic similarity between Paralabrax maculatofasciatus and P. nebulifer , closely (phylogenetically) related species distributed in the Eastern Pacific, by comparing number, type and size of chromosomes of these taxa. The examination of mitotic cells from eleutheroembryos of both species showed a karyotype consisting of 48 acrocentric chromosomes (2n = 48A; fundamental number = 48), without the presence of heteromorphic chromosomes. No significant differences between species were observed in size and relative length (RL) of homeologous chromosome pairs which showed maximum and minimum values of 4 μm (RL = 5.5 %; pair 1) and 1.7 μm (RL = 2.3 %; pair 24), respectively. This karyotype is considered ancestral within the Order Perciformes and is present in most of the species of the Family Serranidae. The results found in this study supported the hypothesis that evolutionary divergence between P. maculatofasciatus and P. nebulifer occurred through the establishment of pre-mating reproductive barriers, without karyotype modification or formation of post-mating barriers, either pre-zygotic or post-zygotic.

Embryos, larvae, and juveniles of the streaked mojarra Eugerres lineatus are described and illustrated from a series of laboratory specimens. The description was based on morphometry, pigmentation pattern, squamation sequence, and osteological development. The eggs were obtained by stripping ripe adults captured in Bahía de La Paz, Baja California Sur, México. Eggs (cleavage egg and embryo phases) had a mean diameter of 0.69 mm with an oil globule of 0.19 mm mean diameter. Eleutheroembryos were 1.05 mm mean notochordal length (NL) at hatching. The yolk sac was absorbed by 2.10 mm mean NL, underwent notochord flexion at 3.16 mm NL-3.86 mm standard length (SL), and transformed to juveniles at 10.0 mm SL. Juveniles were completely scaled by 14.0 mm SL. Osteological development of the neurocranium, jaws and suspensorium, opercular series, hyoid and branchial arches, vertebral column and ribs, and the paired and unpaired fins and the supports were studied. The identification of the earliest stages of development of E. lineatus compared to the other gerreids and allied taxonomic groups present along the northwestern Mexican coast is possible only in the juvenile period (24.1 mm SL), based on anal fin ray count (II, 9-III, 8), the presence of papilliform teeth, and the number of gillrakers on the lower first pharyngeal arch (15–20).ResumenA partir de especímenes de una serie de laboratorio, se describieron e ilustraron los embriones, las larvas y los juveniles de la mojarra Eugerres lineatus. La descripción estuvo basada en la morfometría, el patrón de pigmentación, la secuencia de escamación y el desarrollo osteológico. Los huevos fueron obtenidos por desove de adultos capturados en la Bahía de La Paz, Baja California Sur, México. Los huevos (fases de segmentación de huevo y embrión), tuvieron un diámetro promedio de 0.69 mm con un glóbulo de aceite de 0.19 mm de diámetro promedio. Al eclosionar los eleuteroembriones tuvieron una longitud notocordal (LN) promedio de 1.05 mm. El saco vitelino fue absorbido a un valor promedio de 2.10 mm LN, experimentan la flexión del notocordio entre los 3.16 mm de longitud notocordal-3.86 mm de longitud patrón (LP) y se transforman a juveniles a los 10.0 mm LP. Los juveniles estuvieron completamente escamados a los 14.0 mm LP. La identificación de las primeras fases

International audience; The influence of cobalt on the electrodeposition of zinc onto AISI 1018 steel was studied in weakly alkaline glycine solutions. Thermodynamic calculations were performed to construct predominance-zone diagrams to identify the stability of the zinc and cobalt glycine complexes, and experimental studies of electrochemical behavior and deposit properties were conducted. When zinc is present, cobalt deposition shifts to more negative potentials, producing ZnCo alloys. Two main reduction steps were observed for electrodeposition from the ZnCo bath: the first at low potentials was due to ZnCo electrodeposition. In the second, at more negative potentials, cobalt content in the deposit increased forming a range of intermediate phases, and the hydrogen-evolution reaction became significant. The presence of Co(II) in the bath modified the morphology of the deposits as well as reducing the faradaic metal-deposition efficiency. ZnCo-deposit morphology was modified by the applied current density as well as the metal composition of the coating. X-ray diffraction studies revealed that cobalt oxide or hydroxide is formed during ZnCo electrodeposition, indicating that an elevation of the interfacial pH plays a role in the alloy deposition process.

Phosphate esters are employed in some agrochemical formulations and have long life time in the Environment. They are neurotoxic to mammals and it is very difficult to hydrolyze them. It is easy to find papers in the literature dealing with transition metal complexes used in the hydrolysis processes of organophosphorous compounds. However, there are few reports related with degradation of phosphate esters with inorganic nanoparticles. In this work bis-4-nitrophenyl phosphate (BNPP) was used as an agrochemical agent model. The BNPP interaction with zero-valent iron nanoparticles (ZVI NPs), in aqueous media, was searched. The concentration of BNPP was 1000 times higher than the ZVI NPs concentration. The average size of the used iron nanoparticles was 10.2 ± 3.2 nm. The BNPP degradation process was monitored by means of UV-visible method. Initially, the BNPP hydrolysis happens through the P-O bonds breaking-off under the action of the ZVI NPs. Subsequently, the nitro groups were reduced to amine groups. The overall process takes place in 10 minutes. The reaction products were identified employing standard substances in adequate concentrations. The iron by-products were isolated and characterized by X-RD. These iron derivatives were identified as magnetite (Fe3O4) and/or maghemite (γ-Fe2O3) and lepidocrocite (γ-FeOOH). A suggested BNPP degradation mechanism will be discussed.

Key Comparison CCQM-K36.2016 was a follow-up comparison for K36 and provided updated support for the corresponding calibration and measurement capability (CMC) entries in the BIPM CMC database. It aimed to demonstrate the capabilities of the participating NMIs to measure electrolytic conductivity of aqueous electrolyte solutions in the conductivity range 0.15 S m−1 to 1.5 S m−1 and in the conductivity range 1.5 mS m−1 to 15 mS m−1. To this end electrolytic conductivity of a potassium chloride solution (nominal conductivity 0.5 S m−1) and of a HCl solution (nominal conductivity 5 mS m−1) had to be measured. 17 NMIs participated in the comparison. The key comparison reference value (KCRV) of the KCl solution was (0.50999 +/-0.00032) S m−1 and the KCRV of the HCl solution was (4.9877 +/-0.012) mS m−1. Both values were estimated from the medians of the results considered eligible for KCRV calculation. They were given with their expanded uncertainties (95% coverage). The majority of the 0.5 S m-1 results were consistent with the KCRV. Two institutes showed a small inconsistency, one outlier was observed. The conductivity of the HCl solution showed a small, but steady linear drift of 0.00006843 mS m−1 per day during the measurement period and was corrected for KCRV calculation. Some institutes reported unstable measurement conditions for this solution. The results of seven participants have been inconsistent with the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

— The effect on growth and survival of the initial stocking density (50, 100, 150, and 200 larvae/ L) in larval rearing of spotted sand bass was evaluated over 30 d in a closed recirculating system. Larvae were fed with rotifers, copepods, nauplii and adult Artemia, and spotted sand bass yolk-sac larvae. Water quality was monitored daily. The notochordal or standard length of sampled larvae was measured by image analysis. Specific growth rates at each density were compared by covariance analysis. Survival was estimated from day 15 to the end of the experiment, when a resistance test was used to evaluate the juvenile quality among densities. At the end of the experiment, mean standard length of larvae at lower densities was significantly larger (P < 0.05) than at higher densities. Higher specific growth rates were found at lower densities. Significantly higher survival (P < 0.05) was recorded for the lowest density, but the highest number of harvested fish was obtained with the highest densities (150 and 200 larvae/L). The lowest density also showed the significantly (P < 0.05) higher survival after using a resistance test. We conclude the highest density can be used in larval rearing of spotted sand bass. However, better survival, growth, and seed quality are obtained at the lowest density. To recommend an optimal density for this specie, it is necessary to improve the water quality in the culture system and to make a cost-benefit study.