14,046 research outputs found
Papel de la biblioteca y del bibliotecario en las Humanidades Digitales
As the Digital Humanities (HD) evolves, the role of libraries and librarians working in the field continues to develop. In this context, specialists in the field of university libraries, also known as links, are responsible for working with different disciplines, such as English or philosophy. In general, their work requires communicating with departments, providing bibliographic references and assisting in the development of research in a variety of formats, offering novelties, trends and collection management. Thus, these new functions may require the learning of new skills; thus, subject matter specialists working in the humanities are led to assume new roles as a result of interest in the digital humanities
Radio-frequency ring resonators for self-referencing fiber-optic intensity sensors
A theoretical and experimental study of radiofrequency ring resonators (RR) for referencing and improving the sensitivity of fiber-optic intensity sensors (FOS) is
reported. The separation between lead and transducer losses in the FOS is solved by converting the light intensity fluctuations to be measured into RR losses that produce
high amplitude variations in the proximity of the RR resonance frequencies. Two different self-referencing techniques are developed. Via the definition of the measurement parameter RM , sensor linearity and sensitivity are analyzed. A calibration
using an optical attenuator is reported to validate the model.Publicad
Ring Resonators with Sagnac Loops for Photonic Processing in DWDM Backbone Networks
In this paper, optical configurations based on ring resonators (RR) with an internal Sagnac (SG) loop in the feedback path, are analyzed in terms of their amplitude response and dispersive properties for filtering and chromatic dispersion managing in digital transmission systems over amplified single- mode fiber (SMF) spans in DWDM backbone networks. Design issues for the architecture as regards quadratic dispersion and magnitude distortion are provided. The RR+SG compound filter provides frequency tunability of the amplitude and dispersion peaks by adjusting a coupling coefficient of an optical coupler, with no need for using integrated thermo-optic nor current- injection based phase shifters. The configuration can be employed as an additional structure for a general RR-based design and synthesis architecture, allowing bandwidth increase of dispersion compensators and flexibility. The performance of a compound filter consisting of a two RR in series stage and a RR+SG filter are reported as a more compact and effective solution for existing multi-channel SMF backbone links operating at high bit rates. Design guidelines of an integrated ring resonator based on polymer technology for showing feasibility of the proposal is reported.This work was partially supported by Spanish CICYT (TEC2006-13273-C03-03-MIC), European project NoE
EPhoton/One+, CAM (FACTOTEM-CM:S-0505/ESP/000417), FENIS-CCG06-UC3MITIC-0619.Publicad
CWDM self-referencing sensor network based on ring resonators in reflective configuration
A new scalable self-referencing sensor network with low insertion losses implemented in Coarse Wavelength Division Multiplexing (CWDM) technology is reported. It allows obtaining remote self-referenced
measurements with a full-duplex fibre downlead up to 35 km long, with no need for optical amplification. Fibre Bragg gratings (FBG) are used in order to achieve a reflective configuration, thus increasing the sensitivity of the optical transducers. Low-cost off-the-shelf devices in CWDM technology can be used to implement and scale the network. Ring resonator (RR) based
incoherent interferometers at the measuring points are used as selfreferencing
technique. A theoretical analysis of power budget of the topology is reported, with a comparison between the proposed network and a conventional star topology. Finally, the new configuration has been experimentally demonstrated.This work has been supported by CICYT:TIC2003-03783, UC3M:FAVICOBIS and CAM:FACTOTEM-CM (S-0505/ESP/000417).Publicad
Estereoisomería
Titulación: Grao en Enxeñería de Procesos Químicos Industriais -- Materia: Química OrgánicaA planificación da materia fíxose mediante unha ordenación segundo os distintos grupos funcionais. Isto permite subministrar os coñecementos básicos sobre a estrutura das moléculas orgánicas ao mesmo tempo que posibilita a introdución progresiva dos
distintos tipos de reaccións (substitución, eliminación, adición,…). Esta ordenación é aconsellable, dende o punto de vista pedagóxico, para o alumnado que se inicia no estudo da química orgánica, pero non impide que se vaian introducindo ao longo do curso as relacións existentes entre funcións que dan reaccións similares. Trátase de evitar un programa con contidos excesivamente enciclopédicos e de carácter demasiado descritivo. O obxectivo é que o estudante comprenda a química orgánica dunha maneira lóxica e consiga un bo afianzamento da súa metodoloxía. Xa que é necesario a compresión e o coñecemento dos temas anteriores para o seguimento dos posteriores. Estes coñecementos dirixiranse a súa utilidade na industria química.
Esta unidade didáctica encádrase no bloque I sobre a estrutura dos compostos orgánicos, abordando os isómeros configuracionais aos
que se lles soe dar o nome de estereoisómeros. Na unidade didáctica anterior xa se estudaron outro tipo de isómeros (confórmeros ou rotámeros) que, a diferenza dos que se abordan nesta, son interconvertibles por rotación de enlaces sinxelos. A comprensión dos isómeros conformacionais facilitará o estudo dos estereoisómeros, que se ben presentan o mesmo patrón de enlaces no son interconvertibles por rotación (enantiómeros e diastereoisómeros). O seu entendemento vai ser imprescindible e, ao mesmo tempo, facilitar o estudo do bloque 2. Por outra parte, vai permitir a comprensión de moitos procesos que teñen lugar nos seres vivos e a súa utilidade na industria, xa que a actividade de certos pesticidas, fármacos e axentes mutáxenos pódense explicar por medio das interaccións cos centros activos dos enzimas.Universidade de Santiago de Compostela. Servizo de Normalización Lingüístic
Haluros de Alquilo
Titulación: Grao en Enxeñería de Procesos Químicos Industriais -- Materia: Química OrgánicaA planificación para un curso de química orgánica xeral no que se encadra esta unidade didáctica fíxose mediante unha ordenación segundo os distintos grupos funcionais. Isto permite subministrar os coñecementos básicos sobre a estrutura das moléculas orgánicas ao mesmo tempo que posibilita a introdución progresiva dos distintos tipos de reaccións(substitución, eliminación, adición, etc.). Esta ordenación é aconsellable, dende o punto de vista pedagóxico, para o alumnado que se inicia no estudo da química orgánica, pero non impide que se vaian introducindo ao longo do curso as relacións existentes entre funcións que dan reaccións similares. Deste xeito, evitarase un programa con contidos excesivamente enciclopédicos e de carácter demasiado descritivo. Tendo por obxecto que o estudante comprenda a química orgánica dunha maneira lóxica e entenda o seu carácter encadeado. Por iso, é necesario a compresión e o coñecemento dos temas anteriores para o seguimento dos posteriores.
Finalmente, os coñecementos adquiridos aplícanse ao deseño de sínteses sinxelas de compostos orgánicos.
Esta unidade didáctica encádrase no bloque II sobre a reactividade dos compostos orgánicos. Aínda que na unidade didáctica anterior se estuda a reactividade dos alcanos é realmente nesta onde se inicia o estudo dos mecanismos e da reactividade dos compostos orgánicos, xa que se estuda por primeira vez un composto orgánico que contén un grupo funcional. Introdúcense as reaccións de substitución nucleófila e de eliminación, cuxo entendemento vai ser imprescindible e, ao mesmo tempo, facilitar o estudo dos contidos posteriores. De feito, practicamente en todos os temas que seguen vaise facer referencia á similitude doutras
reaccións con estas. Por outra parte, a súa comprensión vai permitir o entendemento de moitos procesos que teñen lugar na industria e mesmo nos seres vivos, xa que moitas reaccións que ocorren na natureza, así como a actividade de certos pesticidas, fármacos, axentes mutáxenos, etc. pódense explicar por medio destes mecanismos.Universidade de Santiago de Compostela. Servizo de Normalización Lingüístic
Multi-sensor system using plastic optical fibers for intrinsically safe level measurements
A system for measuring liquid level in multiple tanks using optical fibe technology has been developed. Oil fiel service industry or any sector requiring liquid level measurements in flammabl atmospheres can be benefite from this intrinsically safe technology. The device used a single lens for the emitting and receiving fibe and it is based on amplitude variations as a function of the liquid distance and not in time of fligh or phase detection. Being the firs fiber-opti liquid level sensor with those characteristics for long ranges (>200 cm). A simple model to describe their behavior has been derived and tested on two prototypes. A Monte-Carlo method is used to fi the experimental data and obtain the model parameters. High accuracy between experimental data and fitte curve is obtained. The prototypes have a good linearity, better than 1.5% FS (full scale). Sensor heads are made of plastic optical fiber (POF) that are easy to handle, flexible and economical. They are excited by 650 nm lasers, housed in ST-connectors to obtain compact and rough prototypes. Optical multiplexing is used to increase the measuring safety area. Frequency division multiplexing is used to address each sensor head. A discussion about the influenc of tilts and aberrations is also included.Publicad
Dinuclear Fluoride Single-Bridged Lanthanoid Complexes as Molecule Magnets: Unprecedented Coupling Constant in a Fluoride- Bridged Gadolinium Compound
The authors thank the Spanish Ministerio de Ciencia e Innovacion projects (PGC2018-102052-B-C21, PGC2018093863-B-C21, MCIN/AEI/10.13039/501100011033/FEDER "Una manera de hacer Europa") for financial support. E.C. acknowledges Junta de Andalucia for the FEDER Andalucia project A-FQM-172-UGR18. J.C.-V. also thanks Xunta de Galicia for his Ph.D. fellowship (ED481A-2018/136). The authors acknowledge computer resources, technical expertise, and assistance provided by the CSUC.The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.inorgchem.2c00773. Figures S1−S9 and Tables S1−S9 (PDF)
https://pubs.acs.org/doi/suppl/10.1021/acs.inorgchem.2c00773/suppl_file/ic2c00773_si_001.pdfA new synthetic method allows isolating fluoride-bridged complexes Bu4N{[M(3NO(2),5Br-H3L1,1,4)](2)(mu-F)} (M = Dy, 1; M = Ho, 2; M = Gd, 3) and Bu4N{[Dy(3Br,5Cl-H3L1,2,4)](2)(mu-F)}center dot 2H(2)O, 4 center dot 2H(2)O. The crystal structures of 1 center dot 5CH(3)C(6)H(5),center dot 2 center dot 2H(2)O center dot 0.75THF, 3, and 4 center dot 2H(2)O center dot 2THF show that all of them are dinuclear compounds with linear single fluoride bridges and octacoordinated metal centers. Magnetic susceptibility measurements in the temperature range of 2-300 K reveal that the Gd-III ions in 3 are weakly antiferromagnetically coupled, and this constitutes the first crystallographically and magnetically analyzed gadolinium complex with a fluoride bridge. Variabletemperature magnetization demonstrates a poor magnetocaloric effect for 3. Alternating current magnetic measurements for 1, 2, and 4 center dot 2H(2)O bring to light that 4 center dot 2H(2)O is an SMM, 1 shows an SMM-like behavior under a magnetic field of 600 Oe, while 2 does not show relaxation of the magnetization even under an applied magnetic field. In spite of this, 2 is the first fluoride-bridged holmium complex magnetically analyzed. DFT and ab initio calculations support the experimental magnetic results and show that apparently small structural differences between 1 and 4 center dot 2H(2)O introduce important changes in the dipolar interactions, from antiferromagnetic in 1 to ferromagnetic in 4 center dot 2H(2)O.Spanish Ministerio de Ciencia e Innovacion projects
PGC2018-102052-B-C21,
PGC2018093863-B-C21Junta de Andalucia
A-FQM-172-UGR18Xunta de Galicia
ED481A-2018/13
Self-Referencing Fiber-Optic Intensity Sensors Using Ring Resonators and Fiber Bragg Gratings
An improved ring resonator self-referencing technique in a new reflection configuration for remote fiber-optic intensity sensors is demonstrated using fiber Bragg gratings. Sensor sensitivity doubles and a single fiber lead is used. The sensor is interrogated at two subcarrier frequencies having a high rejection of interference from laser source intensity fluctuations and loss in the fiber lead. We experimentally demonstrate the efficiency of the new reflection configuration, the usefulness of the theoretical model proposed, and discuss design parameters for optimum insertion lossesThis work was supported in part by CICYT (TIC2003-03783 and TEC2006-13273-C03-03-MIC), in part by UC3M (FAVICOBIS), in part by CAM (FACTOTEM-CM:S-0505/ESP/000417), and in part by COST 299.Publicad
Social networks applied to training
Abordamos en este artículo la importancia que las redes sociales presentan para su uso como recurso educativo. Relevancia que radica en la posibilidad de implementar nuevos recursos de aprendizaje o aumentar el nivel de conectividad de los participantes, así como el fomento de comunidades de aprendizaje. Igualmente se exponen los riesgos que su empleo entraña, sobre todo para los alumnos con una baja formación tecnológica o excesiva confianza en los medios. Es importante reseñar que el empleo educativo de las redes sociales, no es una simple extensión o traslación del uso para fines lúdicos que generalmente le dan los alumnos, sino que implica un importante cambio en los roles desempeñados tanto por docentes como discentes; de situaciones de aprendizaje acomodaticias y que fomentan la memorización a otras en las que se exige una actitud activa, reflexiva, colaborativa y proactiva, que además precisa del desarrollo/adquisición de habilidades, aptitudes y valores tanto tecnológicos como sociales. Y es destacable como con una implementación y uso adecuados se fomenta no solo el aprendizaje formal, sino también el informal y el no formal.In this article, we address the importance and relevance that social networks exhibit in their use as an educational resource. This relevance relies in the possibility of implementing new learning resources or increasing the level of the participant's connectivity, as well as developing learning communities. Also, the risk entailed from their use is discussed, especially for the students that have a low technological education or those having excessive confidence on the media. It is important to highlight that the educational use of social networks is not a simple extension or translation of the student's habitual, recreational use, but that it implies an important change in the roles given to teachers as well as learners; from accommodative learning environments that only encourage memorization to other environments that demand an active, reflective, collaborative and proactive attitude, that require the development/acquisition of technological as well as social abilities, aptitudes and values. It is also important to highlight that a correct implementation and adequate use will not only foment formal learning, but also informal and non-formal learning
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