Efficiency of different types of ED-tether thrusters

The efficiencies of electrodynamic-tether (EDT) thrusters made of single bare tethers with different types of cross sections, several parallel bare tethers, or a fully insulated tether with a three-dimensional passive end-collector, are discussed. Current collection, mass, and ohmic resistance considerations are balanced against each other in discussing efficiencies. Use is made of recent results on the validity domain of orbital-motion-limited (OML) collection, the current law beyond that domain, and interference effects between parallel bare tethers; and on current adjustment to variations in electron density encountered in orbit. Comparisons between EDT thrusters and electrical thrusters in terms of the ratio of dedicated mass to the total mission impulse show EDT to be superior for mission times over 50-100 days.

Types of metaphor in civil engineering communication

La metáfora y otros mecanismos imaginativos subyacentes al pensa- miento y lenguaje humanos pueden ser utilizados en el discurso diario y especializado (Lakoff y Johnson 1980; Lakoff y Nuñez 2000). Asimismo pueden aparecer en la comunicación no verbal (Forceville y Urios-Aparisi 2009; Littlemore et al. Este volumen).Partiendo de estudios cognitivos y de la teoría de integración conceptual (Fauconnier 1997; Fauconnier y Turner 2002), este artículo examina la presencia de la metáfora en la ingeniería. Primeramente, se analiza un corpus lingüístico procedente de artículos de investigación de ingeniería civil. Los datos revelan el uso de la metáfora antropomórfica, sobre todo en expresiones relativas a la salud, como “diagnóstico”, “auscultación” o “proceso de curación”. Se exploran además ejemplos de ingeniería cuya fuente son proyecciones conceptuales corporales. Finalmente, abordamos la función de la metáfora visual bajo la teoría de integración conceptual mediante representaciones de ingeniería que evocan la anatomía humana o animal. Metaphor and other imaginative mechanisms that underlie human thought and language such as metonymy are used in everyday and specialised discourse (Lakoff and Johnson 1980; Lakoff and Nuñez 2000) They can also be involved in non- verbal forms of communication (Forceville and Urios-Aparisi 2009; Littlemore et al. this volume). Drawing on metaphor cognitive studies and on conceptual integration theory (Fauconnier 1997; Fauconnier and Turner 2002) this paper examines the occurrence of metaphor in engineering. First, we analyse results from a linguistic corpus formed by research papers from civil engineering journals. These data reveal the use of anthropomorphic metaphor, especially related to health or medical mappings such as “diagnosing”, “auscultation” or “curing”. Then, we explore how engineering notions are instantiated by bodily conceptual mappings according to conceptual integration theory. Finally, the function of visual metaphor is examined with conceptual integration theory by using engineering images evoking parts of human or animal anatomy.

Factors driving the carbon mineralization priming effect in a sandy loam soil amended with different types of biochar

The effect of biochar on the soil carbon mineral- ization priming effect depends on the characteristics of the raw materials, production method and pyrolysis conditions. The goal of the present study is to evaluate the impact of three different types of biochar on physicochemical properties and CO2 emissions of a sandy loam soil. For this purpose, soil was amended with three different biochars (BI, BII and BIII) at a rate of 8 wt % and soil CO2 emissions were measured for 45 days. BI is produced from a mixed wood sieving from wood chip production, BII from a mixture of paper sludge and wheat husks and BIII from sewage sludge. Cumulative CO2 emissions of biochars, soil and amended soil were well fit to a simple first-order kinetic model with correlation coef- ficients (r 2 ) greater than 0.97. Results show a negative prim- ing effect in the soil after addition of BI and a positive prim- ing effect in the case of soil amended with BII and BIII. These results can be related to different biochar properties such as carbon content, carbon aromaticity, volatile matter, fixed carbon, easily oxidized organic carbon or metal and phenolic substance content in addition to surface biochar properties. Three biochars increased the values of soil field capacity and wilting point, while effects over pH and cation exchange capacity were not observed.

Analysis of signal impairment and crosstalk penalty induced by different types of optical filters in 100 Gbps PM-DQPSK based systems

Optical filters are crucial elements in optical communication networks. Their influence toward the optical signal will affect the communication quality seriously. In this paper we will study and simulate the optical signal impairment and crosstalk penalty caused by different kinds of filters, which include Butterworth, Bessel, Fiber Bragg Grating (FBG) and Fabry-Perot (F-P). Signal impairment from filter concatenation effect and crosstalk penalty from out-band and in-band are analyzed from Q-penalty, eye opening penalty (EOP) and optical spectrum. The simulation results show that signal impairment and crosstalk penalty induced by the Butterworth filter is the minimum among these four types of filters. Signal impairment caused by filter concatenation effect shows that when center frequency of all filters is aligned perfectly with the laser's frequency, 12 50-GHz Butterworth filters can be cascaded, with 1-dB EOP. This value is reduced to 9 when the center frequency is misaligned with 5 GHz. In the 50-GHz channel spacing DWDM networks, total Q-penalty induced by a pair of Butterworth filters based demultiplexer and multiplexer is lower than 0.5 dB when the filter bandwidth is in the range of 42-46 GHz.

Relationship among slurry characteristics and gaseous emissions at different types of commercial Spanish pig farms

This study aimed to analyse several factors of variation of slurry composition and to establish prediction equations for potential methane (CH4) and ammonia (NH3) emissions. Seventy-nine feed and slurry samples were collected at two seasons (summer and winter) from commercial pig farms sited at two Spanish regions (Centre and Mediterranean). Nursery, growing-fattening, gestating and lactating facilities were sampled. Feed and slurry composition were determined, and potential CH4 and NH3 emissions measured at laboratory. Feed nutrient contents were used as covariates in the analysis. Near infrared reflectance spectroscopy (NIRS) was evaluated as a predicting tool for slurry composition and potential gaseous emissions. A wide variability was found both in feed and slurry composition. Mediterranean farms had a higher pH (p<0.001) and ash (p=0.02) concentration than those located at the Centre of Spain. Also, type of farm affected ether extract content of the slurry (p=0.02), with highest values obtained for the youngest animal facilities. Results suggested a buffer effect of dietary fibre on slurry pH and a direct relationship (p<0.05) with fibre constituents of manure. Dietary protein content did not affect slurry nitrogen content but decreased (p=0.003) total and volatile solids concentration. Prediction models of potential NH3 emissions (R2=0.89) and CH4 yield (R2=0.61) were obtained from slurry composition. Predictions from NIRS showed a high accuracy for most slurry constituents (R2>0.90) and similar accuracy of prediction of potential NH3 and CH4 emissions (R2=0.84 and 0.68, respectively) to models using slurry characteristics, which can be of interest to estimate emissions from commercial farms and establish mitigation strategies or optimize biogas production.

EPIC (Entorno de Páncreas Artificial con Interfaz Clínica)

La Diabetes Mellitus se define como el trastorno del metabolismo de los carbohidratos, resultante de una producción insuficiente o nula de insulina en las células beta del páncreas, o la manifestación de una sensibilidad reducida a la insulina por parte del sistema metabólico. La diabetes tipo 1 se caracteriza por la nula producción de insulina por la destrucción de las células beta del páncreas. Si no hay insulina en el torrente sanguíneo, la glucosa no puede ser absorbida por las células, produciéndose un estado de hiperglucemia en el paciente, que a medio y largo plazo si no es tratado puede ocasionar severas enfermedades, conocidos como síndromes de la diabetes. La diabetes tipo 1 es una enfermedad incurable pero controlable. La terapia para esta enfermedad consiste en la aplicación exógena de insulina con el objetivo de mantener el nivel de glucosa en sangre dentro de los límites normales. Dentro de las múltiples formas de aplicación de la insulina, en este proyecto se usará una bomba de infusión, que unida a un sensor subcutáneo de glucosa permitirá crear un lazo de control autónomo que regule la cantidad optima de insulina aplicada en cada momento. Cuando el algoritmo de control se utiliza en un sistema digital, junto con el sensor subcutáneo y bomba de infusión subcutánea, se conoce como páncreas artificial endocrino (PAE) de uso ambulatorio, hoy día todavía en fase de investigación. Estos algoritmos de control metabólico deben de ser evaluados en simulación para asegurar la integridad física de los pacientes, por lo que es necesario diseñar un sistema de simulación mediante el cual asegure la fiabilidad del PAE. Este sistema de simulación conecta los algoritmos con modelos metabólicos matemáticos para obtener una visión previa de su funcionamiento. En este escenario se diseñó DIABSIM, una herramienta desarrollada en LabViewTM, que posteriormente se trasladó a MATLABTM, y basada en el modelo matemático compartimental propuesto por Hovorka, con la que poder simular y evaluar distintos tipos de terapias y reguladores en lazo cerrado. Para comprobar que estas terapias y reguladores funcionan, una vez simulados y evaluados, se tiene que pasar a la experimentación real a través de un protocolo de ensayo clínico real, como paso previo al PEA ambulatorio. Para poder gestionar este protocolo de ensayo clínico real para la verificación de los algoritmos de control, se creó una interfaz de usuario a través de una serie de funciones de simulación y evaluación de terapias con insulina realizadas con MATLABTM (GUI: Graphics User Interface), conocido como Entorno de Páncreas artificial con Interfaz Clínica (EPIC). EPIC ha sido ya utilizada en 10 ensayos clínicos de los que se han ido proponiendo posibles mejoras, ampliaciones y/o cambios. Este proyecto propone una versión mejorada de la interfaz de usuario EPIC propuesta en un proyecto anterior para gestionar un protocolo de ensayo clínico real para la verificación de algoritmos de control en un ambiente hospitalario muy controlado, además de estudiar la viabilidad de conectar el GUI con SimulinkTM (entorno gráfico de Matlab de simulación de sistemas) para su conexión con un nuevo simulador de pacientes aprobado por la JDRF (Juvenil Diabetes Research Foundation). SUMMARY The diabetes mellitus is a metabolic disorder of carbohydrates, as result of an insufficient or null production of insulin in the beta cellules of pancreas, or the manifestation of a reduced sensibility to the insulin from the metabolic system. The type 1 diabetes is characterized for a null production of insulin due to destruction of the beta cellules. Without insulin in the bloodstream, glucose can’t be absorbed by the cellules, producing a hyperglycemia state in the patient and if pass a medium or long time and is not treated can cause severe disease like diabetes syndrome. The type 1 diabetes is an incurable disease but controllable one. The therapy for this disease consists on the exogenous insulin administration with the objective to maintain the glucose level in blood within the normal limits. For the insulin administration, in this project is used an infusion pump, that permit with a subcutaneous glucose sensor, create an autonomous control loop that regulate the optimal insulin amount apply in each moment. When the control algorithm is used in a digital system, with the subcutaneous senor and infusion subcutaneous pump, is named as “Artificial Endocrine Pancreas” for ambulatory use, currently under investigate. These metabolic control algorithms should be evaluates in simulation for assure patients’ physical integrity, for this reason is necessary to design a simulation system that assure the reliability of PAE. This simulation system connects algorithms with metabolic mathematics models for get a previous vision of its performance. In this scenario was created DIABSIMTM, a tool developed in LabView, that later was converted to MATLABTM, and based in the compartmental mathematic model proposed by Hovorka that could simulate and evaluate several different types of therapy and regulators in closed loop. To check the performance of these therapies and regulators, when have been simulated and evaluated, will be necessary to pass to real experimentation through a protocol of real clinical test like previous step to ambulatory PEA. To manage this protocol was created an user interface through the simulation and evaluation functions od therapies with insulin realized with MATLABTM (GUI: Graphics User Interface), known as “Entorno de Páncreas artificial con Interfaz Clínica” (EPIC).EPIC have been used in 10 clinical tests which have been proposed improvements, adds and changes. This project proposes a best version of user interface EPIC proposed in another project for manage a real test clinical protocol for checking control algorithms in a controlled hospital environment and besides studying viability to connect the GUI with SimulinkTM (Matlab graphical environment in systems simulation) for its connection with a new patients simulator approved for the JDRF (Juvenil Diabetes Research Foundation).

Fine spatial pattern of an epiphytic lichen species is affected by habitat conditions in two forest types in the Iberian Mediterranean region

Persistence and abundance of species is determined by habitat availability and the ability to disperse and colonize habitats at contrasting spatial scales. Favourable habitat fragments are also heterogeneous in quality, providing differing opportunities for establishment and affecting the population dynamics of a species. Based on these principles, we suggest that the presence and abundance of epiphytes may reflect their dispersal ability, which is primarily determined by the spatial structure of host trees, but also by host quality. To our knowledge there has been no explicit test of the importance of host tree spatial pattern for epiphytes in Mediterranean forests. We hypothesized that performance and host occupancy in a favourable habitat depend on the spatial pattern of host trees, because this pattern affects the dispersal ability of each epiphyte and it also determines the availability of suitable sites for establishment. We tested this hypothesis using new point pattern analysis tools and generalized linear mixed models to investigate the spatial distribution and performance of the epiphytic lichen Lobaria pulmonaria, which inhabits two types of host trees (beeches and Iberian oaks). We tested the effects on L. pulmonaria distribution of tree size, spatial configuration, and host tree identity. We built a model including tree size, stand structure, and several neighbourhood predictors to understand the effect of host tree on L. pulmonaria. We also investigated the relative importance of spatial patterning on the presence and abundance of the species, independently of the host tree configuration. L. pulmonaria distribution was highly dependent on habitat quality for successful establishment, i.e., tree species identity, tree diameter, and several forest stand structure surrogates. For beech trees, tree diameter was the main factor influencing presence and cover of the lichen, although larger lichen-colonized trees were located close to focal trees, i.e., young trees. However, oak diameter was not an important factor, suggesting that bark roughness at all diameters favoured lichen establishment. Our results indicate that L. pulmonaria dispersal is not spatially restricted, but it is dependent on habitat quality. Furthermore, new spatial analysis tools suggested that L. pulmonaria cover exhibits a distinct pattern, although the spatial pattern of tree position and size was random.

Fine spatial pattern of an epiphytic lichen species is affected by habitat conditions in two forest types in the Iberian Mediterranean region

Persistence and abundance of species is determined by habitat availability and the ability to disperse and colonize habitats at contrasting spatial scales. Favourable habitat fragments are also heterogeneous in quality, providing differing opportunities for establishment and affecting the population dynamics of a species. Based on these principles, we suggest that the presence and abundance of epiphytes may reflect their dispersal ability, which is primarily determined by the spatial structure of host trees, but also by host quality. To our knowledge there has been no explicit test of the importance of host tree spatial pattern for epiphytes in Mediterranean forests. We hypothesized that performance and host occupancy in a favourable habitat depend on the spatial pattern of host trees, because this pattern affects the dispersal ability of each epiphyte and it also determines the availability of suitable sites for establishment. We tested this hypothesis using new point pattern analysis tools and generalized linear mixed models to investigate the spatial distribution and performance of the epiphytic lichen Lobaria pulmonaria, which inhabits two types of host trees (beeches and Iberian oaks). We tested the effects on L. pulmonaria distribution of tree size, spatial configuration, and host tree identity. We built a model including tree size, stand structure, and several neighbourhood predictors to understand the effect of host tree on L. pulmonaria. We also investigated the relative importance of spatial patterning on the presence and abundance of the species, independently of the host tree configuration. L. pulmonaria distribution was highly dependent on habitat quality for successful establishment, i.e., tree species identity, tree diameter, and several forest stand structure surrogates. For beech trees, tree diameter was the main factor influencing presence and cover of the lichen, although larger lichen-colonized trees were located close to focal trees, i.e., young trees. However, oak diameter was not an important factor, suggesting that bark roughness at all diameters favoured lichen establishment. Our results indicate that L. pulmonaria dispersal is not spatially restricted, but it is dependent on habitat quality. Furthermore, new spatial analysis tools suggested that L. pulmonaria cover exhibits a distinct pattern, although the spatial pattern of tree position and size was random.

Brain structural and functional recovery following initiation of combination antiretroviral therapy

NeuroAIDS persists in the era of combination antiretroviral therapies. We describe here the recovery of brain structure and function following 6 months of therapy in a treatment-naive patient presenting with HIV-associated dementia. The patient’s neuropsychological test performance improved and his total brain volume increased by more than 5 %. Neuronal functional connectivity measured by magnetoencephalography changed from a pattern identical to that observed in other HIV-infected individuals to one that was indistinguishable from that of uninfected control subjects. These data suggest that at least some of the effects of HIV on the brain can be fully reversed with treatment.