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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).