bluuebunny/crossref_metadata_2025 huggingface dataset:
Diferencias de comportamiento entre estudiantes de dos asignaturas de CC de la Salud
Authors: Angulo Carrere María Teresa , Álvarez - Méndez Ana María , Bravo - Llatas María Carmen , Cristóbal Barrios Jesús , Álvarez Vázquez María Pilar
Published: November 2020

Se ha estudiado la actividad de los estudiantes de dos asignaturas de los grados en Fisioterapia, Anatomía Humana III, y en Podología, Biomecánica, en sus respectivos campus virtuales. Para ello se extrajeron los registros almacenados en la plataforma Moodle y se analizaron con los programas R y SPSS. Los resultados revelan comportamientos muy diferentes. Mientras que entre los estudiantes de Anatomía humana III se observa que el uso del campus virtual incide claramente en el rendimiento académico, de manera que a mayores frecuencias de uso mejores calificaciones, los de Biomecánica presentan un comportamiento errático. Parece claro que además de los recursos y herramientas ofertados en el campus, otros factores como el perfil del alumno, su grado de motivación y compromiso son clave para su rendimiento académico.
Incorporación de la plataforma Kahoot en las clases de matemáticas II y evaluación de su funcionamiento
Authors: Carreño Amanda , Ginestar Damian , Sanabria-Codesal Esther
Published: November 2020

En este trabajo se presenta la experiencia de introducir la herramienta Kahoot en las sesiones de prácticas de informática de la asignatura Matemáticas II de la titulación del grado de Ingeniería Electrónica y Automática como elemento motivador. Así mismo, se hace un análisis de las opiniones de los alumnos recogidas a través de una encuesta realizada en dos grupos de la asignatura, con distintas características, donde se incluyen preguntas relacionadas con la herramienta y su capacidad de motivar al alumnado en la revisión del material de las prácticas antes de la sesión presencial. Del análisis de los resultados obtenidos se puede concluir que, en general, la herramienta Kahoot es un elemento motivador para la clase, principalmente, en la parte de prácticas informáticas.
Proceso de aprendizaje en la fabricación integrada de una plataforma robótica educativa multidisciplinar
Authors: Martí Gil Alejandro , Quevedo Gutiérrez Eduardo , Hernández Castellano Pedro , Zapatera Llinares Alberto , Fabelo Gómez Himar , Ortega Sarmiento Samuel , Marrero Callicó Gustavo
Published: November 2020

Educational robotics has come to the classrooms and is here to stay. STEAM (Science, Technology, Engineering, Arts and Mathematics) learning has put the use of robots in classrooms in vogue, though these are mostly closed products and at a high price. The educational innovation project “Design, implementation and tests of a modular low-cost educational robotics platform” from the University of Las Palmas de Gran Canaria, expects to design an open, modular and low-cost educational robot to make robotics more accessible. One of the challenges which the project hopes to accomplish is for this robot to be able to adapt to any educational level, thanks to its modularity, from pre-school to university levels. This study analyzes the Industrial Design and Product Development Engineering degree students’ level of acceptance. Therefore, an analysis of the currently most used educational robots at any level has been made, comparing them to the project design. Moreover, a survey was passed to a total 78 students from several degrees to compare the level of acceptance, concluding that students show a general interest in the proposal, but not so among those of the study group, probably due to the lack of robotics knowledge.
Organización de la evaluación formativa y sumativa: una experiencia negativa
Authors: Salas Vicente Fidel , Vicente Escuder Angel
Published: November 2020

El diseño de los sistemas de evaluación formativa y sumativa es esencial para guiar a los alumnos hacia la consecución de los objetivos de aprendizaje planteados en la guía docente y evitar, junto con la motivación adecuada, que la meta de los alumnos se quede en la mera superación de la asignatura. Esto no siempre es fácil y precisa conocer cual es el comportamiento, no de los mejores alumnos, sino de los menos motivados. En este trabajo se presenta el efecto que ha tenido seleccionar unos métodos de evaluación formativa y sumativa que por quedar su uso a la voluntad de los alumnos y dejar un tipo de evaluación sumativa para el final del curso no ha dado los resultados esperados, llevando a los alumnos a centrarse en asegurar el aprobado y no en conseguir una buena formación y, en consecuencia, una buena calificación.
Aplicaciones como medio e instrumento de evaluación: implementación de quizziz y kahoot en las evaluaciones de los estudiantes de contaduría pública.
Authors: Gómez Reyes Flor Marleny
Published: November 2020

El mundo del siglo XXI está enmarcado en la globalización, en donde la información fluye a través de las comunicaciones, es inevitable parar el desarrollo tecnológico y las nuevas formas de aprender e interactuar entre seres humanos. Las aplicaciones docentes han empezado a surgir y se han convertido en una motivación para hacer las clases más dinámicas e interactivas para los estudiantes. El aprendizaje requiere de motivación para alcanzar las potencializades del mismo. Por ello, se implementará en 4 cursos, que se componen de un total de 190 estudiantes, evaluaciones a través de aplicaciones móviles denominadas: quizziz y kahoot, con el fin de evidenciar al final del curso si éstas herramientas de evaluación cooperan con las nuevas formas de aprendizaje de cursos teóricos, en los estudiantes de los semestres 1, 5, 6 y 7 del programa de contaduría pública de una universidad privada ubicada en la ciudad de Bogotá, Colombia. Submitted:Mar 22, 23:03 GMT
Estrategia tecnológica para nivelar los presaberes matemáticos en la educación superior
Authors: Rueda-Gómez Karol Lisette , Rodríguez-Muñiz Luis
Published: November 2020

Las Tecnologías de la Información y la Comunicación (TIC) permiten utilizar en el ámbito educativo espacios digitales que poseen metodologías innovadoras y creativas para potenciar el aprendizaje de los estudiantes en diferentes áreas del conocimiento. De otro lado, las altas tasas de deserción y repetición en las asignaturas del área de matemáticas en los primeros semestres académicos de la educación superior evidencian, entre otras posibles causas, el bache formativo en los presaberes matemáticos de los estudiantes de nuevo ingreso. El objetivo de este estudio es implementar una prueba piloto del uso de la plataforma online KHAN ACADEMY en estudiantes de nuevo ingreso de una Institución de Educación Superior (IES) colombiana con el fin de fomentar estrategias de mejora que favorezcan los objetivos académicos de los estudiantes en el área de matemáticas. Se concluye que es posible ofrecer a los estudiantes de nuevo ingreso un entrenamiento virtual en el que pueden reforzar los presaberes matemáticos del bachillerato mediante el uso de KHAN ACADEMY, contando con el apoyo activo de los docentes.
Proyecto reflexivo de co-evaluación y auto-evaluación formativa utilizando la técnica del Puzzle de Aronson dentro del Aprendizaje Cooperativo
Authors: Ahís Adell Maria
Published: November 2020

El presente estudio tiene por objetivo la evaluación del proceso de enseñanza-aprendizaje de EF, mediante la comparación de las percepciones del alumnado de dos cursos de primero de Bachillerato y sus dos respectivos profesores/as. Se trata de un estudio de caso, basado en técnicas de investigación cualitativas: entrevistas semiestructuradas, observación participante y general y una innovación competencial cooperativa basada en el Puzzle de Aronson. Los resultados muestran la existencia de una distancia entre la definición teórica del objetivo de la asignatura y la aplicación de esta en el aula. Este hecho se ve condicionado por limitaciones del contexto educativo, pero también por limitaciones profesionales de las cuáles no siempre se tiene consciencia
DEBATMITAL 2.0: 2ª Edición de los debates sobre mitos en Alimentación
Authors: Olaso-González Gloria , Romá-Mateo Carlos , Piqueras Marta
Published: November 2020

En la segunda edición del DEBATMITAL, se ha vuelto a utilizar el debate como herramienta docente para abordar el tema de los Mitos en la Alimentación, en la asignatura optativa del Grado en Medicina de la UV, “Alimentación y Dietética”. Como novedad respecto a la edición pasada, este curso se ha debatido sobre temas de actualidad entre los que existe controversia real en la comunidad científica. Los alumnos han valorado la actividad aún más positivamente este curso: la vuelven a preferir respecto a la lección magistal y además creen que les ayuda a adquirir varias competencias propias de su grado. En base a esta experiencia, se consolida el uso del debate como herramienta docente en la asignatura.
En Marcha. Propuesta real de un proyecto televisivo. Alumnos/as RAE
Authors: Folgado María Soledad , Valero Luis , Abatilli Antonella
Published: November 2020

The present project consists of the real proposal of a TV program by the students of the 2nd year of the RAE higher training program. It consists of preparing a dossier to present a TV program that deals with information on the different solidarity marches that exist in the city of Valencia and its surroundings. The informative folder of presentation of the program contains the essential data about the creative, artistic, technical, economic and content aspects of the program, that is, the characteristics of the audiovisual dossier that the producers present to potential investors in the real working situation. In addition to the dossier, a first pilot program has been carried out on the work and organization of the AECC with the RunCáncer Valencia solidarity marches circuit. The program covers, not only the information of the day that the different marches that make up the racing circuit are carried out, but also small reports have been made whose protagonists are the people to whom the aid is directed, organizers, researchers, volunteers, participants of the races, etc
El club de lectura como metodología activa para mejorar las competencias profesionales de futuros periodistas
Authors: Iranzo Amador , Fortea Miguel Ángel
Published: November 2020

La presente comunicación tiene como objetivo analizar la experiencia del club de lectura que se desarrolló en el segundo curso del Grado en Periodismo de la Universitat Jaume I (Castelló) durante el curso 2017-18. La actividad, ofrecida a los estudiantes fuera del horario lectivo, tenía como objetivos principales incentivar el hábito de lectura, fomentar la capacidad de reflexión y el espíritu crítico y mejorar la formación de los futuros periodistas. El club de lectura se dividió en dos partes, vinculadas a las dos asignaturas de Géneros Periodísticos del curso, una de primer cuatrimestre y otra del segundo. El club de lectura del primer cuatrimestre debatió sobre obras de autores como Kapuściński y Caparrós, mientras que, en el del segundo, los estudiantes debían redactar piezas periodísticas siguiendo como modelo los textos analizados. En la encuesta posterior, los participantes evaluaron la actividad con una nota muy alta. Además, los resultados mostraron que el club de lectura cumplió con los objetivos que se habían marcado inicialmente.
Respuesta docente frente a la pandemia de la COVID-19: el uso de Blackboard y Flipped Teaching en la asignatura de Metodología Arqueológica
Authors: Gallello Gianni , Machause López Sonia , Diez Castillo Agustin
Published: November 2020

El sistema educativo universitario se basa en gran medida en clases presenciales. Un evento inesperado como la pandemia de la COVID-19, que estalló durante los primeros meses del 2020, llevó a las autoridades a declarar el estado de alerta y a tomar, entre otras medidas, la interrupción de la actividad docente presencial. El profesorado universitario tuvo que adaptar la actividad docente a un sistema, para muchos, novedoso: la docencia en línea. Este trabajo tiene como objetivo mostrar los instrumentos y las estrategias empleadas para dar una rápida respuesta a una situación de emergencia. Nuestro caso se centra en la enseñanza de una asignatura de tercer curso del Grado de Historia en la Universitat de València: metodología Arqueológica, adaptada a un sistema de tutorías y clases por e-learning.El empleo de Blackboard Collaborate ha demostrado ser una herramienta muy positiva que complementa el aula virtual simple y potencia la enseñanza y la tutoría en línea, implementada con cuestionarios en Moodle y Kahoot!. Esta plataforma, en colaboración con el modelo pedagógico de aula inversa como modalidad de aprendizaje, ha sido una estrategia motivadora y efectiva para el estudiantado. Esta adaptación ha permitido mantener la trasmisión de los contenidos con resultados de aprendizaje positivos.
La Biología Sintética; reto biotecnológico y bioético en las Ciencias de la Vida
Authors: Ventura Ignacio , Sanmartín Isaias , Lloret Ana , Revert Francisco , Prieto Jesús Ángel
Published: November 2020

Synthetic biology represents a scientific and bioethical challenge for the future, both at the environmental level, as well as in the human and other species improvement. Therefore, the work will mainly address two aspects. The synthesis in the laboratory of artificial cells for the manufacture of a pharmaceutical active principle and, on the other hand, the bioethical reflection on the potential of these techniques, noting the difference in the limits of the synthesis of life and creation of life. Currently, there are an estimated 1.7 million known species out of the estimated 14 million in the wild. In the last 10 years, more than 3,000 patents have been generated for genetically modified organisms. We have advanced in the fields of bioengineering for the improvement of beer-producing species, bakeries, etc. provide to the advancement of molecular biology.
ECOSISTEMA GRÁFICOS. Un paso más desde el grabado no tóxico para la Agenda 2030 y los Objetivos de Desarrollo Sostenible
Authors: Tomás Miralles Ana , Ansio Martinez Tania , Aguilar Briceño Rosángela
Published: November 2020

Etching as a graphic method is not only a ser of thecniques, it also has the scope of a SYSTEM with all that this implies. And as a system, the education of these subjects is directly linked to the fulfillment of the SDG’s 2030, by focusing on the various objectives that are set from an ECOSYSTEM perspective: A form of art practice resorting to its ease of multiple reproduction as a matter of social approach and by constant experimentation on classical and new techniques. The transmission of our graphic approaches is immersed in public awareness of the importance of planet conservation and sustainability, thus motivating artistic practice in the context of becoming aware of the ecological impact of human activity. We are all called upon to act from the new culture of sustainability that permeates everything and is decisive. In experimentation classrooms, the joint of our team and out students at the UPV, has eased the path to develop our projects BOSQUEARTE and MONTA TUS OBJETIVOS, in order to raise awareness, throughout the workshops and art happenings that surrounds them, with the need to commit ourselved to preserving the environment and natural resources.
Development of the SDG-general skills binomial in university teaching: an integral vision at UPV
Authors: Guillén-Guillamón Ignacio , Moreno-Ramón Héctor , Cabedo-Fabrés Marta , Ferrando-Bataller Miguel , Calvet-Sanz Salvador , Ibánez-Asensiof Sara , Jiménez Belenguer Ana
Published: November 2020

Currently, Spanish Universities are involved in the implementation of the Sustainable Development Goals promulgated by the United Nations as part of the 2030 Agenda. In these Institutions, the implementation of these goals should not be limited to the institution itself, but as citizens' educators, a global and inclusive approach must be transmitted. The innovation project "Integration of the SDGs in the CT UPV through gamification strategies" developed by the UPV GRIPAU teaching innovation group proposes the integration of the development of the SDGs in the teaching of subjects through the activities carried out by the CT UPV. The project involves 7 subjects from different UPV degrees. This work shows the experiences in each subject as a case study. In each case, the specific activities developed to integrate TC work with the SDGs are described. The results obtained indicate that the activities carried out improve the proprioception of the students in the SDGs
Desarrollo de la expresión y la oralidad a través de clubs de lectura en el aula de inglés en Escuelas Oficiales de Idiomas
Authors: Vecino-Ramos Sonia , Ruiz-Bernardo Paola
Published: November 2020

The reading clubs or book clubs are an innovative practice in the foreign language classroom that, apart from the reading comprehension, allow the students to share their individual and personal experience with their classmates, and, thus, improve their speaking by means of the practice of orality, as well as to promote their critical and reflexive thinking throudh the contualization offered by the book. This communication explains the case study of these clubs in English classes at Official School of Languages in Castellón in the B1, B2 and C1 levels. To evaluate the experience a self-designed survey was administered based on their reading development and centered in the students perception related to their improvement in reading comprehension and oral expression. From the results, it can be concluded that the students perception towards the use of reading clubs in the classroom to practise oralitiy and speaking is positive, which makes it advisable to use them in other languages and different educational levels.
Implantación de la Docencia Inversa en las prácticas de la asignatura “Teoría y Diseño de Máquinas”
Authors: Montava-Jorda Sergi , Sánchez Caballero Samuel , Sellés Cantó Miguel Ángel , Martinez Sanz Antonio Vicente , Colomer Romero Vicente
Published: November 2020

En el presente trabajo se presentan tanto la iniciativa como los resultados de la puesta en marcha de la docencia inversa en las prácticas de la asignatura Teoría y Diseño de Máquinas impartida en el 3º curso del Grado de Ingeniería Mecánica. Desde el curso académico 2014-2015 la UPV se está impulsando la implantación de esta metodología con el objetivo de mejorar el aprendizaje por parte de los alumnos y este ha sido la principal finalidad de este trabajo. Este tipo de metodología supone una mayor implicación y compromiso tanto de los profesores como de los alumnos debiendo adoptar estos últimos un rol más activo y participativo. El resultado de la implantación de esta iniciativa ha sido positiva por parte del profesorado dado que a pesar de haber tenido que haber dedicar una dedicación extra para la elaboración del material que la metodología exigía los resultados académicos han mejorado, aunque por parte del alumnado la sensación no ha sido tan buena puesto que la mayoría ha visto una carga de trabajo excesiva además de las dificultades que implican los cambios de metodologías.
La Comarca: un instrumento lúdico para el aprendizaje y un proyecto transversal multiescuela en la Universitat Politècnica de València (UPV)
Authors: Gielen Eric , Sosa Espinosa Asenet , Palencia Jiménez José Sergio , Pérez Alonso Yaiza , Moreno Salome , Temes Córdovez Rafael , Miralles García José Luis , Roldan-Garrote David , García Granada Fernando , Martí Testón Ana , Rodríguez Mattalía Lorena , Rodríguez Valdunciel Sergio , Sanchis Gandia Alvaro , Zarraga Llorens Josefa María
Published: November 2020

Esta comunicación es el resultado de un Proyecto de Innovación y Mejora Educativa (PIME), financiado por el Vicerrectorado de Estudios, Calidad y Acreditación de la Universitat Politècnica de València, y por la Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos. El objetivo del PIME que se presenta en esta comunicación es encontrar un nuevo recurso educativo para resolver problemas de motivación y aprendizaje en la enseñanza universitaria relacionada con la disciplina del Urbanismo y la Ordenación del Territorio. El uso del juego permite motivar y enseñar, y bajo esta premisa, se propone la creación de un juego de estrategia de cooperación-oposición, La Comarca, diseñado como un sencillo tablero representando el territorio, dividido en cuatro municipios, en el que cuatro alcaldías interactúan y trabajan para conseguir un territorio bien organizado. En esta comunicación se describe el proceso de construcción del juego, desde su idea hasta su producción, pasando por el proceso de diseño, fruto de un proyecto transversal entre dos escuelas de la Universitat Politècnica de València (Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos y la Facultad de Bellas Artes) y los principales resultados obtenidos tras dicha experiencia.
Exploring Low-Carbon Bus Options for Urban BRT Systems: The Case of Amman
Authors: Imam Rana , Kang Seong-Cheol , Quezada Diana
Published: November 2020

Being able to provide high-quality, metro-like transit service at a fraction of the cost of other options, bus rapid transit (BRT) has been viewed as one of the most cost-effective public mass transport systems suitable for urban areas. Considering significant amounts of greenhouse gas (GHG) and air pollutant emissions are attributed to the transport sector, deploying low carbon buses for BRT systems should be of high priority. With a view to promoting low carbon buses instead of diesel buses for a BRT system currently being planned in Amman, Jordan, this paper evaluates several low carbon bus options – hybrid, plug-in hybrid, opportunity charging, trolleybus, and battery electric bus options – against the baseline case of diesel buses. While low carbon buses reduce GHG and air pollutant emissions often considerably, they usually require higher upfront capital costs and additional infrastructure investments. On the other hand, they tend to incur lower energy and maintenance costs and have a longer lifetime particularly for battery electric buses. All these advantages and disadvantages are included in the assessment of low carbon bus options relative to diesel buses. For the trunk routes of the Amman BRT, the analysis shows that the opportunity charging bus can be the most appealing option having a positive internal rate of return (IRR) for the incremental investment costs. For the feeder routes, both low carbon bus options considered, hybrid and battery electric, do not result in a positive IRR. Nevertheless, the battery electric bus is found to be a comparatively better option than the hybrid bus. In consideration of variability in several parameters used in the analysis such as capital expenditures, electricity price, and diesel price, a sensitivity analysis is conducted for both trunk and feeder routes. The results show that IRR could increase favorably under certain conditions.
Covhindia: Deep Learning Framework for Sentiment Polarity Detection of Covid-19 Tweets in Hindi
Authors: Singh Purva
Published: November 2020

On 11th March 2020, the World Health Organization (WHO) declared Corona Virus Disease of 2019 (COVID-19) as a pandemic. Over time, the exponential growth of this disease has highlighted a mixture of sentiments expressed by the general population from various parts of the world speaking varied languages. It is, therefore, essential to analyze the public sentiment during this wave of the pandemic. While much work prevails to determine the sentiment polarity for tweets related to COVID-19, expressed in the English language, we still need to work on public sentiments expressed in languages other than English. This paper proposes a framework, Covhindia, a deep-learning framework that performs sentiment polarity detection of tweets related to COVID-19 posted in the Hindi language on the Twitter platform. The proposed framework leverages machine translation on Hindi tweets and passes the translated data as input to a deep learning model which is trained on an English corpus of COVID-19 tweets posted from India [18]. The paper compares nine deep learning models' performances in classifying the sentiment polarity on an English dataset. Performance comparison of these architectures reveals that the BERT model had the best polarity detection accuracy on the English corpus. As part of testing the Covhindia’s accuracy in performing sentiment classification on Hindi tweets, the paper employs a separate dataset developed using a python library called Tweepy to extract Hindi tweets related to COVID-19. Experimental results reveal that Covhindia achieved state-of-the-art accuracy in classifying COVID-19 tweets posted in the Hindi language. The use of open-source machine translation tools paved the way for leveraging Covhindia for performing multilingual sentiment classification on COVID-19 tweets. For the benefit of the research community, the code and Jupyter Notebooks related to this paper are available on Github
Reaction between CH3C(O)OOH (peracetic acid) and OH in the gas phase: a combined experimental and theoretical study of the kinetics and mechanism
Authors: Berasategui Matias , Amedro Damien , Vereecken Luc , Lelieveld Jos , Crowley John N.
Published: November 2020

Abstract. Peracetic acid (CH3C(O)OOH) is one of the most
abundant organic peroxides in the atmosphere; yet the kinetics of its
reaction with OH, believed to be the major sink, have only been studied once
experimentally. In this work we combine a pulsed-laser photolysis kinetic
study of the title reaction with theoretical calculations of the rate
coefficient and mechanism. We demonstrate that the rate coefficient is
orders of magnitude lower than previously determined, with an experimentally
derived upper limit of 4×10-14 cm3 molec.−1 s−1. The relatively low rate coefficient is in good agreement with
the theoretical result of 3×10-14 cm3 molec.−1 s−1 at 298 K, increasing to ∼6×10-14 cm3 molec.−1 s−1 in the cold upper
troposphere but with associated uncertainty of a factor of 2. The reaction
proceeds mainly via abstraction of the peroxidic hydrogen via a relatively
weakly bonded and short-lived prereaction complex, in which H abstraction
occurs only slowly due to a high barrier and low tunnelling probabilities.
Our results imply that the lifetime of CH3C(O)OOH with respect to
OH-initiated degradation in the atmosphere is of the order of 1 year (not
days as previously believed) and that its major sink in the free and upper
troposphere is likely to be photolysis, with deposition important in the
boundary layer.
Heterogeneous nucleation of water vapor on different types of black carbon particles
Authors: Laaksonen Ari , Malila Jussi , Nenes Athanasios
Published: November 2020

Abstract. The heterogeneous nucleation of water vapor on insoluble particles affects cloud formation, precipitation, the hydrological cycle, and
climate. Despite its importance, heterogeneous nucleation remains a poorly
understood phenomenon that relies heavily on empirical information for its
quantitative description. Here, we examine the heterogeneous nucleation of water
vapor on different types of soots as well as cloud drop activation of different types of soots, including both pure
black carbon particles and black carbon particles mixed with secondary
organic matter. We show that the recently developed adsorption nucleation
theory quantitatively predicts the nucleation of water and droplet formation
upon particles of the various soot types. A surprising consequence of this
new understanding is that, with sufficient adsorption site density, soot
particles can activate into cloud droplets – even when completely lacking
any soluble material.
Impacts of atmospheric transport and biomass burning on the inter-annual variation in black carbon aerosols over the Tibetan Plateau
Authors: Han Han , Wu Yue , Liu Jane , Zhao Tianliang , Zhuang Bingliang , Wang Honglei , Li Yichen , Chen Huimin , Zhu Ye , Liu Hongnian , Wang Qin'geng , Li Shu , Wang Tijian , Xie Min , Li Mengmeng
Published: November 2020

Abstract. Atmospheric black carbon (BC) in the Tibetan Plateau (TP) can largely impact
regional and global climate. Still, studies on the inter-annual variation in
atmospheric BC over the TP and associated variation in BC sources and
controlling factors are rather limited. In this study, we characterize the
variations in atmospheric BC over the TP surface layer through analysis of
20-year (1995–2014) simulations from a global chemical transport model,
GEOS-Chem. The results show that surface BC concentrations over the TP vary
largely in space and by season, reflecting complicated interplays of BC
sources from different origins. Of all areas in the TP, surface BC
concentrations are highest over the eastern and southern TP, where surface
BC is susceptible to BC transport from East Asia and South Asia,
respectively. Applying a backward-trajectory method that combines BC
concentrations from GEOS-Chem and trajectories from the Hybrid
Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, we assess
the contributions of worldwide source regions to surface BC in the TP. We
estimate that on the 20-year average, 77 % of surface BC in the TP comes from
South Asia (43 %) and East Asia (35 %). Regarding seasonal variation in
non-local influences, South Asia and East Asia are dominant source regions in
winter and summer, respectively, in terms of the amount of BC imported.
However, in terms of affected areas in the TP, South Asia is the dominant
contributor throughout the year. Inter-annually, surface BC over the TP is
largely modulated by atmospheric transport of BC from non-local regions
year-round and by biomass burning in South Asia, mostly in spring. We find
that the extremely strong biomass burning in South Asia in the spring of
1999 greatly enhanced surface BC concentrations in the TP (31 % relative
to the climatology). We find that the strength of the Asian monsoon
correlates significantly with the inter-annual variation in the amount of BC
transported to the TP from non-local regions. In summer, a stronger East
Asian summer monsoon and a stronger South Asian summer monsoon tend to, respectively,
lead to more BC transport from central China and north-eastern South Asia to
the TP. In winter, BC transport from central China is enhanced in years with
a strong East Asian winter monsoon or a strong Siberian High. A stronger Siberian
High can also bring more BC from northern South Asia to the TP. This study
underscores the impacts of atmospheric transport and biomass burning on the
inter-annual variation in surface BC over the TP. It reveals a close
connection between the Asian monsoon and atmospheric transport of BC from
non-local regions to the TP.
Multifactor colorimetric analysis on pH-indicator papers: an optimized approach for direct determination of ambient aerosol pH
Authors: Li Guo , Su Hang , Ma Nan , Zheng Guangjie , Kuhn Uwe , Li Meng , Klimach Thomas , Pöschl Ulrich , Cheng Yafang
Published: November 2020

Abstract. Direct measurement of the acidity (pH) of ambient aerosol particles/droplets has long been a challenge for atmospheric scientists. A novel and
facile method was introduced recently by Craig et al. (2018), where the pH of size-resolved aerosol droplets was directly measured by two types of
pH-indicator papers (pH ranges: 0–2.5 and 2.5–4.5) combined with RGB-based colorimetric analyses using a model of G−B (G minus B) vs. pH2. Given the wide pH range of ambient aerosols, we optimize the RGB-based colorimetric analysis on pH papers with a wider detection range (pH ∼ 0 to 6). Here, we propose a new model to establish the linear relationship between RGB values and pH: pHpredict = a⋅Rnormal+b⋅Gnormal+c⋅Bnormal. This model shows a wider applicability and higher accuracy than those in previous studies and is thus recommended in future RGB-based colorimetric analyses on pH papers. Moreover, we identify one type of pH paper (Hydrion® Brilliant pH dip stiks, lot no. 3110, Sigma-Aldrich) that is more applicable for ambient aerosols in terms of its wide pH detection range (0 to 6) and strong anti-interference capacity. Custom-made impactors are used to collect lab-generated aerosols on this type of pH paper. Preliminary tests show that, with a collected particle size range of ∼ 0.4–2.2 µm, the pH paper method can be used to predict aerosol pH with an overall uncertainty ≤ 0.5 units. Based on laboratory tests, a relatively short sampling time (∼ 1 to 4 h) is speculated for pH prediction of ambient aerosols. More importantly, our design of the impactors minimizes potential influences of changed environmental conditions during pH paper photographing processes on the predicted aerosol pH. We further show that the routinely adopted way of using pH color charts to predict aerosol pH may be biased by the mismatch between the standard colors on the color charts and the real colors of investigated samples. Thus, instead of using the producer-provided color charts, we suggest an in situ calibration of pH papers with standard pH buffers.
From leaf to soil: n-alkane signal preservation, despite degradation along an environmental gradient in the tropical Andes
Authors: Teunissen van Manen Milan L. , Jansen Boris , Cuesta Francisco , León-Yánez Susana , Gosling William D.
Published: November 2020

Abstract. The relative abundance of n-alkanes of different chain lengths
obtained from ancient soils and sediments have been used to reconstruct past
environmental changes. However, interpretation of ancient n-alkane patterns
relies primarily on modern plant wax n-alkane patterns measured from leaves.
Little is still known about how n-alkane patterns, and environmental
information therein, might be altered during the process of transfer from
leaves into soil. We studied the n-alkane patterns extracted from leaves,
necromass, and soil samples from an altitudinal gradient in the tropical
Andes to clarify if the n-alkane pattern, and the local environmental
information reflected, is altered as the plant source material degrades. We
considered the (dis)similarity between n-alkane patterns in soil, necromass, and
leaves and specifically explored whether a temperature and/or precipitation
signal is reflected in their n-alkane patterns. The n-alkane patterns showed
degradation in soil as reflected by a reduced carbon preference index (CPI).
The lower CPI in soils as compared to leaves and necromass was significantly
correlated with temperature and precipitation along the transect, most
likely because of increased microbial activity under warmer and wetter
conditions. Despite degradation, all sample types showed a systematic shift
in longer vs. shorter n-alkanes when moving up the transect. Further
examination revealed the systematic shift correlated with transect
temperature and precipitation. Since transect vegetation is constant along
the transect, this would appear to indicate the recording of a climatic
signal within the n-alkane patterns that is preserved in the soil, albeit that
the correlation was weaker there. The study results warrant further research
into a possible underlying causal relationship that may lead to the
development of n-alkane patterns as a novel palaeoecological proxy.
Investigating crystal orientation patterns of foraminiferal tests by electron backscatter diffraction analysis
Authors: Pabich Stephanie , Vollmer Christian , Gussone Nikolaus
Published: November 2020

Abstract. We studied the crystallographic orientation of calcite
crystals in benthic foraminifers by electron backscatter diffraction (EBSD).
Individuals of two species, Gyroidinoides soldanii and Cibicidoides grimsdalei, featuring different test structures, were
investigated for a time span covering 43 Myr. The aims of this study are to
visualize test structure differences in foraminifers and to reveal potential
changes in crystal orientation and grain size over time caused by diagenetic
reactions such as recrystallization. Such recrystallization effects over
time may aid in the interpretation of time-resolved geochemical data
obtained on foraminiferal samples for paleo-environmental reconstructions.
The EBSD patterns clearly resolve the different test structures of the two
species. Cibicidoides grimsdalei has the c axes perpendicular to the test surface. An apparent
shift in the preferred crystal orientation can most likely be attributed to
a mismatch between the equatorial plane and cutting plane of the foraminiferal
test, highlighting the importance of reproducible preparation techniques. In
Gyroidinoides soldanii, the c axes of the calcite crystals show a broader distribution of the
crystals with no preferred orientation. The specimens show no change in
crystal sizes over time, with a frequency maximum corresponding to the
spot size of the electron beam. Overall, the differences between the two
species demonstrate that EBSD is a powerful tool to visualize and
differentiate between foraminiferal test structures.
Analysis of the electronic structure of the primary electron donor of photosystem I of Spirodela oligorrhiza by photochemically induced dynamic nuclear polarization (photo-CIDNP) solid-state nuclear magnetic resonance (NMR)
Authors: Janssen Geertje J. , Eschenbach Patrick , Kurle Patrick , Bode Bela E. , Neugebauer Johannes , de Groot Huub J. M. , Matysik Jörg , Alia Alia
Published: November 2020

Abstract. The electron donor in photosystem I (PSI), the chlorophyll dimer P700, is studied by photochemically induced dynamic nuclear polarization (photo-CIDNP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) on selectively 13C and uniformly 15N labeled PSI core preparations (PSI-100) obtained from the aquatic plant duckweed (Spirodela oligorrhiza). Light-induced signals originate from the isotope-labeled nuclei of the cofactors involved in the spin-correlated radical pair forming upon light excitation. Signals are assigned to the two donor cofactors (Chl a and Chl a') and the two acceptor cofactors (both Chl a). Light-induced signals originating from both donor and acceptor cofactors demonstrate that electron transfer occurs through both branches of cofactors in the pseudo-C2 symmetric reaction center (RC). The experimental results supported by quantum chemical calculations indicate that this functional symmetry occurs in PSI despite similarly sized chemical shift differences between the cofactors of PSI and the functionally asymmetric special pair donor of the bacterial RC of Rhodobacter sphaeroides. This contributes to converging evidence that local differences in time-averaged electronic ground-state properties, over the donor are of little importance for the functional symmetry breaking across photosynthetic RC species.
The physics of fault friction: insights from experiments on simulated gouges at low shearing velocities
Authors: Verberne Berend A. , van den Ende Martijn P. A. , Chen Jianye , Niemeijer André R. , Spiers Christopher J.
Published: November 2020

Abstract. The strength properties of fault rocks at shearing rates
spanning the transition from crystal–plastic flow to frictional slip play a
central role in determining the distribution of crustal stress, strain, and
seismicity in tectonically active regions. We review experimental and
microphysical modelling work, which is aimed at elucidating the processes that control
the transition from pervasive ductile flow of fault rock to
rate-and-state-dependent frictional (RSF) slip and to runaway rupture,
carried out at Utrecht University in the past 2 decades or so. We address
shear experiments on simulated gouges composed of calcite,
halite–phyllosilicate mixtures, and phyllosilicate–quartz mixtures
performed under laboratory conditions spanning the brittle–ductile
transition. With increasing shear rate (or decreasing temperature), the
results consistently show transitions from (1) stable
velocity-strengthening (v-strengthening) behaviour, to potentially unstable v-weakening behaviour, and
(2) back to v strengthening. Sample microstructures show that the first
transition seen at low shear rates and/or high temperatures represents a
switch from pervasive, fully ductile deformation to frictional sliding
involving dilatant granular flow in localized shear bands where
intergranular slip is incompletely accommodated by creep of individual
mineral grains. A recent microphysical model, which treats fault rock
deformation as controlled by competition between rate-sensitive
(diffusional or crystal–plastic) deformation of individual grains and
rate-insensitive sliding interactions between grains (granular flow),
predicts both transitions well. Unlike classical RSF approaches, this model
quantitatively reproduces a wide range of (transient) frictional behaviours
using input parameters with direct physical meaning, with the latest
progress focusing on incorporation of dynamic weakening processes
characterizing co-seismic fault rupture. When implemented in numerical codes
for crustal fault slip, the model offers a single unified framework for
understanding slip patch nucleation and growth to critical (seismogenic)
dimensions, as well as for simulating the entire seismic cycle.
Numerical modeling of the dynamics of the Mer de Glace glacier, French Alps: comparison with past observations and forecasting of near-future evolution
Authors: Peyaud Vincent , Bouchayer Coline , Gagliardini Olivier , Vincent Christian , Gillet-Chaulet Fabien , Six Delphine , Laarman Olivier
Published: November 2020

Abstract. Alpine glaciers are shrinking and rapidly loosing mass in a warming
climate. Glacier modeling is required to assess the future
consequences of these retreats on water resources, the hydropower
industry and risk management. However, the performance of such ice
flow modeling is generally difficult to evaluate because of the lack
of long-term glaciological observations. Here, we assess the
performance of the Elmer/Ice full Stokes ice flow model using the long
dataset of mass balance, thickness change, ice flow velocity and snout
fluctuation measurements obtained between 1979 and 2015 on the Mer de
Glace glacier, France. Ice flow modeling results are compared in
detail to comprehensive glaciological observations over 4 decades
including both a period of glacier expansion preceding a long period
of decay. To our knowledge, a comparison to data at this detail is
unprecedented. We found that the model accurately reconstructs the
velocity, elevation and length variations of this glacier despite some
discrepancies that remain unexplained. The calibrated and validated
model was then applied to simulate the future evolution of Mer de
Glace from 2015 to 2050 using 26 different climate
scenarios. Depending on the climate scenarios, the largest glacier in
France, with a length of 20 km, could retreat by 2 to
6 km over the next 3 decades.
Geophysical constraints on the properties of a subglacial lake in
northwest Greenland
Authors: Maguire Ross , Schmerr Nicholas , Pettit Erin , Riverman Kiya , Gardner Christyna , Della-Giustina Daniella , Avenson Brad , Wagner Natalie , Marusiak Angela G. , Habib Namrah , Broadbeck Juliette I. , Bray Veronica J. , Bailey Hop
Published: November 2020

Abstract. We report the first ground-based observations of a subglacial lake in Greenland, confirming previous work base on airborne radar data. Here, we perform an active source seismology and ground penetrating radar survey in northwest Greenland where Palmer et al. (2013) first proposed the presence of a subglacial lake. From reflections of both the lake top and lake bottom, we observe a subglacial lake underlying approximately 845 m of ice, and constrain its depth to be between 10–15 m. Additionally, using previously reported estimates of the lake's lateral extent, we estimate the total volume of liquid water to be 0.15 km3 (0.15 Gt of water). Thermal and hydropotential modeling both suggest that the lake should not exist unless it either sits over a localized geothermal flux high or has high salinity due to significant evaporite source in the bedrock. Our study indicates that this field site in northwestern Greenland is a good candidate for future investigations aimed at understanding lake properties and origins or for direct lake sampling via drilling.
Dockless bike-sharing system: Solving the problem of faulty bikes with simultaneous rebalancing operation
Authors: Usama Muhammad , Zahoor Onaira , Shen Yongjun , Bao Qiong
Published: November 2020

The Free-Floating Bike-Sharing System (FFBS) enables commuters to pick up and drop off a shared bike without going to a docking station before and after the trip. However, the specific sharing features of the FFBS can also be a problem for users because randomly scattered and faulty bikes within the system can result in bike unavailability and maintenance difficulties. This not only negatively impacts the company’s service quality but also causes user safety issues. In this study, a mechanism for the rebalancing of useable bikes and faulty bikes is presented in two steps: 1) gathering each faulty bike at a station determined by the model traversing the shortest path by light service vehicles; and 2) enabling the rebalancing operation to obtain optimal bike inventory levels at all stations and collect faulty bikes at a depot. The destination station from which each faulty bike is taken is considered a decision variable rather than shifting them to a closer station. The mechanism is based on minimizing the total cost of the rebalancing operation by optimizing the formulated problem, supported by time and capacity constraints. Using CPLEX solver, the validity of the model is tested through different numerical experiments.
Solving the one-warehouse N-retailers problem with stochastic demand: An inter-ratio policies approach
Authors: Chavarro Gabriela , Fresen Matthaus , González Esneyder Rafael , Ferro David Barrera , López-Ospina Héctor
Published: November 2020

In this paper, we consider a two-echelon supply chain in which one warehouse provides a single product to N retailers, using integer-ratio policies. Deterministic version of the problem has been widely studied. However, this assumption can lead to inaccurate and ineffective decisions. In this research, we tackle the stochastic version of two-echelon inventory system by designing an extension of a well-known heuristic. This research considers customer demands as following a normal density function. A set of 240 random instances was generated and used in evaluating both the deterministic and stochastic solution approaches. Due to the nature of the objective function, evaluation was carried out via Monte Carlo simulation. For variable demand settings, computational experiments shows that: i) the use of average demand to define the inventory policy implies an underestimation of the total cost and ii) the newly proposed method offers cost savings.
The capacitated maximal covering location problem with heterogeneous facilities and vehicles and different setup costs: An effective heuristic approach
Authors: Gazani Masoud Hatami , Niaki Seyed Armin Akhavan , Niaki Seyed Taghi Akhavan
Published: November 2020

In this research, a maximal covering location problem (MCLP) with real-world constraints such as multiple types of facilities and vehicles with different setup costs is taken into account. An original mixed integer linear programming (MILP) model is constructed in order to find the optimal solution. Since the problem at hand is shown to be NP-hard, a constructive heuristic method and a meta-heuristic approach based on genetic algorithm (GA) are developed to solve the problem. To find the most effective solution technique, a set of problems of different sizes is randomly generated and solved by the proposed solution methods. Computational results demonstrate that the heuristic method is capable of producing optimal or near-optimal solutions in a rational execution time.
Recetario de chontaduro y coco
Authors: Ambrosio Annamaria Filomena , Guerrero Ortiz María Alejandra , Salgado Sánchez Alex Fernando , Sotelo Díaz Luz Indira , Vernot Diana
Published: November 2020

Entradas, platos fuertes, postres, bebidas y cocteles fueron elaborados y estandarizados en veinticuatro recetas inspiradas en la cocina tradicional con la incorporación de chontaduro y leche de coco. En este capítulo, además, se involucraron aspectos culturales, técnicas culinarias, y se integraron conceptos desde la ciencia que aportan a los saberes del profesional en gastronomía.