459 research outputs found
Cap a la síntesi total del (−)-Curcumè i la (−)-Curcuquinona
Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2022, Tutors: Antoni Riera Escalé, Marina Bellido MuñozThe synthesis of chiral natural products has long been the focal point in the field of asymmetric catalysis since both stereoisomers usually have different bioactivity. Within all the catalytic asymmetric methodologies, homogeneous transition-metal catalyzed hydrogenation plays a pivotal role.
Our group has been working in the Ir-catalyzed asymmetric hydrogenation reactions of several substrates such as sulfones, which are versatile building blocks in synthetic chemistry. In this respect, the group recently developed a methodology to synthesize homoallylic sulfones through a highly selective process which has set the stage for the synthesis of different natural products.
The previously mentioned methodologies have established the framework for the synthesis and the Ir-catalyzed asymmetric hydrogenation of homoallylic sulfones. In the present work, the applicability of these methodologies has been demonstrated through the synthesis of (+)-⍺-curcumene 1 and an advanced intermediate of (−)-curcuquinone 2
A Scrum-based approach to CMMI maturity level 2 in Web Development environments
Scrum has become one of the most popular agile methodologies, either alone or combined with other agile practices. Besides, CMMI (Capability Maturity Model Integration) is accepted as a suitable model to measure the maturity of the organizations when developing or acquiring software. Although these two approaches are often considered antagonist, the use of an agile approach to reach certain CMMI maturity levels may result beneficial to organizations that develop Web systems, since they would take the advantages of both approaches. In Web community, this union may be very interesting, because agile approaches fits with the special needs of Web development, and they could be a useful tool for companies getting a certain grade of maturity. This work analyzes the goals of CMMI maturity level 2 and the feasibility of achieving them using the practices proposed by Scrum, trying to assess whether the use of this methodology is suitable for meeting the CMMI generic and specific goals or not. Finally, and based on this analysis, this paper raises a possible extension of Scrum, based on agile techniques, to accommodate the CMMI maturity level 2.Ministerio de Educación y Ciencia TIN2010-20057-C03-02Junta de Andalucía TIC-578
Agile in Public Administration: Oxymoron or reality? An experience report
In the last 10 years, Agile methods and practices have emerged as an
alternative for software development. Different "flavors" of Agile have
appeared ranging from project management to tests organization. These
approaches have being gaining popularity and involve now a solid option for
organizations developing software, but what about Public Administrations? Is
Agile a suitable option for developing software in Public Administrations?
Even if Public Administrations have been traditionally regarded as changeresistant,
Agile approach can also provide them with the benefits of quick
adaptation and frequent value delivery.
This paper presents the results of two different projects, which use an Agile
framework based on Scrum, developed by a Spanish Public Administration.
Additionally, after considering the obtained results, it takes out some relevant
learned lessons on the suitability of applying Agile approaches to Public
Administration environments.Ministerio de Ciencia e Innovación TIN2010-20057-C03-02Junta de Andalucía TIC-578
The Ejulve cave speleothemic record:from monitoring control to abrupt climate changes during the Pleistocene in the Eastern Iberian Range (Teruel)
La presente tesis engloba un completo estudio en la Cueva de El Recuenco (Ejulve, Cordillera Ibérica, NE Península Ibérica) sobre la espeleogénesis de la cueva, la dinámica espeleotémica actual y la reconstrucción de cambios climáticos abruptos durante el Pleistoceno a partir de sus registros espeleotémicos. La cueva de Ejulve, situada a 1240 m.s.n.m., es una cueva relativamente pequeña en el sector suroriental de la Cordillera Ibérica. Se encuentra desarrollada en calizas dolomíticas y dolomías de la formación Mosqueruela, del Cretácico Superior, y está afectada por el arco de cabalgamientos de Portalrubio-Vandellós, estructurado durante el Oligoceno y Mioceno Inferior. El paisaje está dominado por amplias y deformadas superficies de erosión situadas a gran altitud (Superficie de Erosión Fundamental de la Cordillera Ibérica), que terminó de formarse en el Plioceno. El origen de la cueva debería situarse antes de la fase final de desarrollo de la Superficie de Erosión Fundamental. La identificación de ciertas morfologías de la cueva, muy características, como son el boxwork, los tubos con cúpulas ascendentes en el techo, pendants y cups, spongework y rasgos de micro-corrosión, sugieren un origen hipógeno de la misma. Por lo tanto, la karstificación hipógena ocurriría tentativamente durante el Mio-Plioceno, y se explicaría por al ascenso de agua subterránea debido a gradientes hidráulicos en un acuífero confinado, generando así las galerías en forma de laberinto y las morfologías características mencionadas previamente. Adicionalmente, el análisis del boxwork sugiere una fase previa, probablemente durante el Mioceno Superior, en la que calcita y dolomita rellenaron las discontinuidades existentes en el epikarst, todo ello bajo condiciones freáticas. Después de la karstificación, la cueva tuvo una transición a condiciones epigénicas sin confinamiento, debido a la reactivación de los procesos regionales de levantamiento y doming. Después de la tectónica extensional durante el Plioceno-Cuaternario, se produciría la fase de la incisión fluvial. Así, una vez el karst queda exhumado y se da paso a la fase vadosa, comienza la precipitación de espeleotemas, al menos desde hace 650.000 años antes del presente. El estudio de la dinámica actual de la cueva, incluyendo el muestreo de lluvia, goteo y carbonato precipitado, fue llevado a cabo durante cuatro años (2013-2016). El principal factor que controla el d18O de la lluvia es la temperatura (r2 = 0.82, p-value > 0.001), mostrando un patrón estacional con valores más bajos en invierno y más altos en verano. Tanto el área de origen de la precipitación (junto al componente de la lluvia) y la cantidad de lluvia, actúan como controles secundarios. El uso de la infiltración neta resulta crucial para evaluar la recarga del epikarst en las condiciones semi-áridas propias del área de estudio. De hecho, el uso de la infiltración neta revela que el efecto de cantidad de lluvia ejerce escasa influencia en la variabilidad isotópica del agua de goteo, en contraste con la influencia moderada que ejercía sobre el d18O de la lluvia anual. El muestreo de 12 goteos a lo largo de la cueva evidenció que tanto los goteos estacionales como los no estacionales muestran similares valores de d18O en el agua de goteo. La estacionalidad vista en el d18O del agua de lluvia, es también observada en el agua de goteo, aunque atenuada y con cierto retardo, por lo tanto, no hay un proceso completo de homogeneización de las aguas en el epikarst. La respuesta hidrológica de la cueva a la lluvia externa es rápida, con un incremento en las tasas de goteo en pocas semanas en ambos grupos de goteos durante las lluvias estacionales de otoño. No obstante, el retardo visto en el d18O de las lluvias de otoño-invierno asciende hasta un máximo de 21 semanas. Estos resultados sugieren la existencia del ‘efecto pistón’, según el cual el agua ‘nueva’ presiona en sentido descendente el agua ‘antigua’ pre-existente en el epikarst, a través de la red de fracturas existentes.El carbonato precipitado muestra una escasa variación total de un 0.11 ‰ en el d18O, con una variabilidad similar entre los goteos estacionales y los no estacionales. El d18O del carbonato depende del d18O del agua de goteo, con una escasa influencia de la tasa de goteo. La variación del d13C es de un 0.22 ‰, y muestra estacionalidad con valores más altos en verano y otoño, y más bajos en invierno y primavera. El d13C es más positivo en los goteos no estacionales, los cuales, debido a una mayor desgasificación, registran una variabilidad que asciende hasta el 0.42 ‰, comparado con el 0.29 ‰ de los goteos estacionales. Estas diferencias entre diferentes tipos de goteo están explicadas por la alta correlación entre el d13C y la tasa de goteo. Por lo tanto, los valores altos de d13C en el carbonato precipitado en la cueva de Ejulve se explican por la mayor desgasificación y menor disponibilidad hídrica, mientras que los valores bajos de d13C se registrarían cuando hay más actividad microbiana, mayor productividad vegetal y más disponibilidad hídrica. La ventilación de la cueva desde finales del otoño hasta la primavera, favorece una mayor precipitación de carbonato. De esta manera, tanto la hidroquímica de las aguas de goteo como la tasa de goteo quedan como controles secundarios de la tasa de precipitación de carbonato actual.La reconstrucción de los cambios climáticos en el pasado utilizado registros espeleotémicos de la cueva de Ejulve se ha centrado en dos períodos: (1) durante la transición de MIS 8 a MIS 7 a través de la estalagmita ARTEMISA, y (2) durante los períodos MIS 5, 4 y 3 a través de la estalagmita ANDROMEDA. Los indicadores usados han sido d18O, d13C y Mg/Ca.La estalagmita ‘ARTEMISA’ creció durante el período 262.7 - 217.9 ka, incluyendo la respuesta climática a la Terminación Glacial III (T-III), una transición glacial-interglacial escasamente conocida, en contraposición a las Terminaciones II y I. La respuesta del d13C y Mg/Ca a los eventos abruptos áridos en el desarrollo de la T-III es realmente pronunciada. Por lo tanto, se han identificado dos eventos de escala milenial (S8.1 y S8.2) que estarían explicados por debilitamientos de la AMOC durante MIS 8. La sensibilidad de la Península Ibérica a los cambios en la AMOC, debido a su posición latitudinal y geográfica, ya ha sido demostrada previamente durante la Terminación I y MIS 3. La variabilidad en d18O del registro marca el último evento (S8.1) con un cambio en el d18O del agua en el área fuente de la precipitación, probablemente asociado a la llegada de agua dulce en el Atlántico norte. Tras una comparación entre la T-III, T-II y T-I, los dos eventos estadiales que han sido propuestos tienen semejanzas con los eventos Heinrich (HS) 1 y 2. Estas similitudes se basan en las intensas descargas de IRD, la dominancia de taxones semidesérticos durante los eventos áridos, y la similar señal del d18O de los foraminíferos bentónicos marinos. No obstante, los cambios en el nivel del mar y en la insolación durante S8.1, lo hacen más similar al YD que a HS-1, impidiendo por lo tanto concluir que el YD es un evento único de la última terminación.La estalagmita ‘ANDROMEDA’ crece de manera continua durante el intervalo de 118.9 a 36.9 ka. Durante MIS 5, los valores de d18O estaban regidos por control orbital, con picos de baja precisión que dan paso a condiciones húmedas. En contraste, durante MIS 4 y 3, los valores de d18O se desacoplan de la precesión, y covarían con el d13C, sugiriendo así un control común en ambos isótopos, debido a una mayor desgasificación del agua de goteo durante los períodos áridos. En general, el d13C exhibe una clara respuesta a los eventos fríos marinos desde el C26 hasta el C23, así como a las oscilaciones Dansgaard-Oeschger (D-O) y a los eventos Heinrich. Este registro apoya los resultados de estudios previos que mostraban un final tardío del Eemiense en el sur de Europa, y ofrece nuevas fechas para dicha finalización, desde 108.6 ± 0.3 a 108.3 ± 0.3 ka para esta área. La respuesta a los eventos Heinrich se establece en dos períodos distintivos en forma de ‘W’ en el patrón de variabilidad del d13C. Esos períodos se caracterizan por la respuesta del d13C a los débiles eventos D-O 15 y 18. La variabilidad en el d13C es similar en ambos eventos, no así su desarrollo, siendo más largo el primer evento, contemporáneo a HS-6. En el evento W más antiguo (~67-60 ka) han sido identificadas dos fases, la primera caracterizada por un patrón frío-árido antes de 63 ka, y una segunda de patrón húmedo-frío de 63 ka en adelante. El evento W más moderno (~57-53 ka) está en concordancia con un refuerzo de los vientos alisios en el NE (fase NAO+), provocando así unas condiciones de clima árido en el sur de Europa. Por otro lado, la correlación positiva entre el d13C y Mg/Ca en los períodos estudiados (Terminación III y MIS 5, 4 y 3) está en concordancia con mayor disponibilidad hídrica, más productividad vegetal y actividad microbiana sobre la cueva, como sugieren los resultados de la monitorización expuestos anteriormente.En resumen, la presente tesis muestra un modelo inusual de espeleogénesis en la Cordillera Ibérica propuesto para la cueva de Ejulve, un completo y detallado conjunto de datos procedentes de la monitorización de la dinámica espeleotémica actual, y la reconstrucción de interesantes cambios climáticos pasados. Esas características la convierten en la primera compilación de datos de este tipo en una cueva de la Cordillera Ibérica. Asimismo, conviene recalcar el gran interés de los resultados paleoclimáticos procedentes de estalagmitas de esta cueva, especialmente en cambios climáticos abruptos. La clara respuesta que exhibe durante el final de los períodos glaciares (Terminaciones), durante las oscilaciones D-O o los eventos Heinrich, y la clara vinculación con otros registros clave como las estalagmitas procedentes de cuevas de China, hacen a la cueva de Ejulve un lugar extraordinario para realizar estudios paleoclimáticos. The present dissertation addresses a complete study of Ejulve cave (Iberian Range, NE Spain) related to the speleogenesis of the cave, the current speleothemic dynamics and the reconstruction of past Pleistocene abrupt climate changes based on its speleothem record. Ejulve cave, located at 1240 m.a.s.l., is a relatively small cave in the southeastern sector of the Iberian Range. The cave is developed in dolomitic limestones and dolostones of the Mosqueruela Fm., Upper Cretaceous in age, affected by the thrust fronts of Portalrubio-Vandellós system, structured during Oligocene and Low Miocene. The landscape is dominated by extensive high-altitude deformed planation surfaces (Main Planation Surface of the Iberian Chain), finally shaped during the Pliocene. The origin of the cave is expected to have occurred before the final phase of the Main Planation Surface development. The identification of some characteristic cave morphologies such as boxwork, tubes with rising ceiling cupolas, pendants and cusps, spongework and micro-corrosion features, suggests a hypogene karst setting during this time. Hence, the hypogene karstification, tentatively occurred during the Mio-Pliocene, could be explained by ascending water flows driven by hydraulic gradients in a confined aquifer, generating a maze network and the characteristic cave morphologies listed above. Additionally, the analysis of the boxwork suggests an earlier stage, probably during the Upper Miocene, of calcite and dolomite infills hosted in discontinuities of the bedrock, formed under phreatic conditions. After the karstification, the cave underwent a transition to epigenic unconfined conditions, driven by the regional uplift and doming mechanisms. After the extensional tectonics during Pliocene-Quaternary, there was the subsequent fluvial incision. Once the exhumation of the karst leads to the vadose phase, it is the starting point for the precipitation of carbonate speleothems, at least from 650 kyr BP. The study of the cave speleothemic dynamics, including sampling of rainfall, drip waters and farmed calcite, was conducted during four years (2013-2016). The main factor that controls the d18O of the rainfall are the temperature effect (r2 = 0.82, p-value > 0.001), showing a seasonal pattern of lower values in winter and higher in summer. Both source effect (together with the rainfall component) and amount effect act as secondary controls. The use of the effective infiltration is crucial to evaluate the recharge of the epikarst, in the semi-arid conditions of the study area. In fact, the use of the effective infiltration reveal that the amount effect exerts a scarce influence on the isotopic variability of the drip waters, in contrast with the moderate influence that it exerts on the annual d18O in rainfall. The sampling of 12 drips throughout the cave indicated that seepage and seasonal drips featured similar d18O in dripwaters. The d18O seasonality seen in rainfall was also observed in dripwater d18O, albeit attenuated and lagged, so the homogeneisation process of the waters in the epikarst was not complete. The hydrological response of the cave to the external rainfall is fast, with an increase of drip rates within few weeks in both seasonal and seepage drips during the seasonal rainfall in autumn. However, the lag seen in the d18O of autumn-winter rainfall is as long as 21 weeks. These results suggest the existence of a ‘piston effect’, in which the ‘new’ water pushed down the ‘old’ pre-existent water in the epikarst through the fracture network. The farmed calcite shows a small variation of 0.11 ‰ in d18O, with similar variability between seasonal and seepage sites. The d18O of the calcite showed dependence on the d18O of the dripwaters, with a weak influence of drip rate. The variation in d13C is of 0.22 ‰, and exhibit seasonality with higher values during summer and autumn, and lower in winter and spring. The d13C was more positive in seepage sites, enhanced by degassing kinetics, up to 0.42 ‰ compared to the 0.29 ‰ observed in the seasonal sites. These differences between drip sites are explained by the high correlation of the d13C with the drip rate. Therefore, the high d13C in the farmed calcite of Ejulve cave was explained by enhanced degassing and low water availability, while low d13C values were in concordance with more microbial activity, vegetation productivity, and greater water availability. The ventilation of the cave during late autumn through spring favored the higher calcite deposition rates found during that time. Dripwater chemistry and drip rate exerts as secondary controls on carbonate growth rate. The reconstruction of past climate changes using stalagmites from Ejulve cave was focused in two main periods: (1) during the transition MIS 8 - MIS 7 using the stalagmite ARTEMISA, and (2) during the periods MIS 5, 4 and 3, using the stalagmite ANDROMEDA. The proxies used were d18O, d13C and Mg/Ca. The stalagmite ‘ARTEMISA’ covered the interval 262.7 to 217.9 kyr BP, including the response to the Termination III (T-III), a poorly known glacial-interglacial transition, in contrast to Terminations II and I. The response of the d13C and Mg/Ca to the abrupt arid events in the timing of the T-III was clear. Hence, we identify two millennial-scale events (S8.1 and S8.2) that are related to AMOC slowdowns during MIS 8. The sensitivity of the Iberian Peninsula to AMOC changes, due to its latitudinal and geographical location, has been demonstrated previously during Termination I and MIS 3. The variability in d18O in the record also marks the latest event (S8.1) with a change in the d18O composition of the sea water in the source of moisture, probably associated with the entrance of freshwater in north Atlantic. After a comparison between T-III, T-II and T-I, the two stadial events we propose have some similarities with Heinrich stadial (HS) 1 and 2. These similarities are supported by intense IRD discharges, the dominance of semidesert taxa in the arid intervals, and the similar phasing of the benthic d18O. However, the changes in sea level and insolation during S8.1, makes it more similar to the YD than HS-1, precluding the identification of the YD as a unique feature of the most recent termination. The stalagmite ‘ANDROMEDA’ covers continuously the interval from 118.9 to 36.9 kyr. During MIS 5, the d18O were controlled by orbital pacing, with low precession peaks leading wet conditions. In contrast, during MIS 4 and 3, the d18O fluctuations were decoupled from precession, and co-varies with d13C, suggesting a common control of both isotopes by enhanced degassing of drip waters during dry periods. In general, d13C exhibit a clear response to the cold marine events C26 to C23, as well as Dansgaard-Oeschger (D-O) oscillations and Heinrich events. This record supports previous studies showing a late demise of the Eemian forest stage in southern Europe, and offer new dates from 108.6 ± 0.3 to 108.3 ± 0.3 in this area. The response to Heinrich events were identified by two periods with a marked ‘W-shape’ pattern in the d13C. These periods were characterized by the response of the d13C to the weak D-O cycles 15 and 18. The variability in the d13C is similar between both events, but a different timing is seen, longer in the first event contemporary with HS-6. Two phases were identified within the older W-event (~ 67-60 kyr), a first one with dry-cold conditions before 63 kyr BP, and a second one with wet-cold conditions afterwards. The younger W-event (~ 57-53 kyr) is in concordance with the reinforcement of the northeasterly trade winds (NAO+ phase) giving rise to a dry climate in Southern Europe at that time. On the other hand, the positive correlation seen between d13C and Mg/Ca, in both periods (Termination III and MIS 5, 4 and 3), is expected to reflect water availability, vegetation productivity and microbial activity over the cave, such as was suggested by the monitoring results above. In summary, the present dissertation shows an unusual speleogenesis model in the Iberian Range proposed for Ejulve cave, a complete and careful detailed dataset related to the monitoring of present-day speleothem dynamics, and the reconstruction of interesting past climate changes. Those features make it the first compilation of such outstanding new brand data in a cave from the Iberian Range. Likewise, it is worth noting the high interest of the paleoclimatic results using speleothems from this cave, especially in the abrupt climate changes. The clear response exhibited during the end of Glacial periods (Terminations), to D-O oscillations and Heinrich events, and the clear link with other key records such as the speleothems from caves in China, makes Ejulve cave an outstanding site for paleoclimatic studies. <br /
Agile, Web Engineering and Capability Maturity ModelI ntegration : A systematic literature review
Context
Agile approaches are an alternative for organizations developing software, particularly for those who develop Web applications. Besides, CMMI (Capability Maturity Model Integration) models are well-established approaches focused on assessing the maturity of an organization that develops software. Web Engineering is the field of Software Engineering responsible for analyzing and studying the specific characteristics of the Web. The suitability of an Agile approach to help organizations reach a certain CMMI maturity level in Web environments will be very interesting, as they will be able to keep the ability to quickly react and adapt to changes as long as their development processes get mature.
Objective
This paper responds to whether it is feasible or not, for an organization developing Web systems, to achieve a certain maturity level of the CMMI-DEV model using Agile methods.
Method
The proposal is analyzed by means of a systematic literature review of the relevant approaches in the field, defining a characterization schema in order to compare them to introduce the current state-of-the-art.
Results
The results achieved after the systematic literature review are presented, analyzed and compared against the defined schema, extracting relevant conclusions for the different dimensions of the problem: compatibility, compliance, experience, maturity and Web.
Conclusion
It is concluded that although the definition of an Agile approach to meet the different CMMI maturity levels goals could be possible for an organization developing Web systems, there is still a lack of detailed studies and analysis on the field
Estimating, planning and managing Agile Web development projects under a value-based perspective
Context: The processes of estimating, planning and managing are crucial for software development projects,
since the results must be related to several business strategies. The broad expansion of the Internet
and the global and interconnected economy make Web development projects be often characterized by
expressions like delivering as soon as possible, reducing time to market and adapting to undefined
requirements. In this kind of environment, traditional methodologies based on predictive techniques
sometimes do not offer very satisfactory results. The rise of Agile methodologies and practices has
provided some useful tools that, combined with Web Engineering techniques, can help to establish a
framework to estimate, manage and plan Web development projects.
Objective: This paper presents a proposal for estimating, planning and managing Web projects, by
combining some existing Agile techniques with Web Engineering principles, presenting them as an
unified framework which uses the business value to guide the delivery of features.
Method: The proposal is analyzed by means of a case study, including a real-life project, in order to obtain
relevant conclusions.
Results: The results achieved after using the framework in a development project are presented, including
interesting results on project planning and estimation, as well as on team productivity throughout the
project.
Conclusion: It is concluded that the framework can be useful in order to better manage Web-based
projects, through a continuous value-based estimation and management process.Ministerio de Economía y Competitividad TIN2013-46928-C3-3-
An Approach to Transform Public Administration into SOA-based Organizations
Nowadays, Service-Oriented Architectures (SOA) is widely spread in private organizations. However, when transferring this knowledge to Public Administration, it is realized that it has not been transformed in terms
of its legal nature into organizations capable to operate under the SOA paradigm. This fact prevents public
administration bodies from offering the efficient services they have been provided by different boards of
governments. A high-level framework to perform this transformation is proposed. Taking it as starting
point, an instance of a SOA Target Meta-Model can be obtained by means of an iterative and incremental
process based on the analysis of imperatives and focused on the particular business context of each local public administration. This paper briefly presents a practical experience consisting in applying this process
to a Spanish regional public administration.Junta de Andalucía TIC-578
Exploratory Evaluation of Retranslocation and Bioconcentration of Heavy Metals in Three Species of Mangrove at Las Cucharillas Marsh, Puerto Rico
Heavy metal contamination in the coastal area of Cataño, Puerto Rico accountable to anthropogenic sources is of great concern due to the risk posed over the surrounding communities and adjacent ecosystems. Estuarine ecosystems are widely recognized for the presence of mangroves. This type of flora is recognized for their many beneficial properties for example, the ability to purge aquatic ecosystems where they stand. Exploratory analyses on the phytoaccumulative capacity of three mangrove species for ten metals (Hg, Al, As, Cd, Cr, Cu, Fe, Pb, Mg, Zn) were performed in this research. Random soil samples and both green and senescent leaves of Rhizophora mangle, Laguncularia racemosa and Avicennia germinans from three different sites of Peninsula La Esperanza were analyzed in order to apply the retranslocation efficiency (RT%) and bioconcentration factor (BCF) concepts. After calculating the RT% and the BCF, comparison analyses among the three mangrove species were performed. In general, the results showed low RT% values for Avicennia in comparison with Rhizophora and Laguncularia. BCF values confirmed RT% results for Avicennia, showing higher heavy metal concentrations in its senescent leaves in contrast with the other species. Therefore, these preliminary results suggest that Rhizophora and Laguncularia act better as phytoremediators for heavy metals in polluted areas due to their ability to accumulate lower concentrations in senescent leaves; preventing further contamination in surrounding ecosystems by encapsulating the pollutants instead of exporting them
Inquiring some megaliths at the province of Sevilla
Hemos seleccionado una serie de necrópolis en la provincia de Sevilla en áreas distintas y distantes
con la intención de captar diferencias de entidades sociales y aproximarnos a entender el cambio cultual de
los enterramientos colectivos a los individuales.From series of necropolis at the province of Sevilla we have chosen some, located in different and
distant places, with the aim of spotting the dissimilarities between social classes and trying to explain the cult
evolution from communal graves to individual burials
Simulador en Python de métodos de predicción de punto a zona para servicios terrenales en la gama de frecuencias de 30 a 3000 MHz
Este proyecto está basado en la Recomendación de la ITU-R P.1546-5. En esta Recomendación se describe un método de predicción de propagación radioeléctrica punto a zona para servicios terrenales en la gama de frecuencias de 30 a 3000 MHz. El método será utilizado en los circuitos radioeléctricos troposféricos en trayectos terrestres y marítimos entre 1-1000 km de longitud para alturas de antena de transmisión efectivas menores de 3000 m y está basado en la interpolación/extrapolación de curvas de intensidad de campo deducidas empíricamente en función de: la distancia, la altura de la antena, la frecuencia y el porcentaje de tiempo. El procedimiento de cálculo incluye además correcciones de los resultados a fin de reflejar diferentes casuísticas.
A partir, de este método se elaborará un simulador en Python que implementará lo explicado anteriormente. Este programa partirá de una serie de parámetros introducidos por el usuario y se encargará de desarrollar el método descrito en la recomendación. Utilizando la API Open-Elevation (open-source), se obtienen otros datos relevantes para la aplicación y se muestran por pantalla ciertas gráficas del terreno estudiado. Finalmente, se realizan una serie de correcciones sobre los valores obtenidos.
Para comprobar la correcta implementación de nuestro código, se han realizado una serie de pruebas que permiten verificar su funcionamiento.This Project is based on the Recommendation of ITU-R P.1546-5. This Recommendation describes a point-to-area radio propagation method for terrestrial services in the frequency range from 30 to 3000 MHz. The method will be used in tropospheric radio circuits on land sea routes between 1-1000 km length for effective transmisision antennas smaller tan 3000 m and is based in the interpolation/extrapolation of field strength curves deduced empirically as a function of: the distance, the height of the antenna, the frequency and the percentage of time. The calculation procedure also includes corrections of the results in order to reflect different casuistry.
From this method a Python simulator will be developed that will implement what was explained above. This program is available in a series of parameters entered by the user and will be responsable for developing the method described in the Recommendation. Using Open-Elevation API (open-source), other relevant data to the application is displayed and certain graphs on the studied terrain are displayed on the screen. Finally, a serie f corrections is made on the nominal values.
A serie of test has been carried out to verify its operation.Universidad de Sevilla. Grado en Tecnologías de Telecomunicació
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