Energy Integration of High and Low Temperature Solid Sorbents for CO2 Capture

It is crucial to reduce the energy penalties related to CO2 capture processes if CCS is to be implemented at industrial scale. In this context, gas-solid sorption has become a relevant technology. The absence of large amounts of water when using dry solid sorbents and their high heat capacity reduce the energy requirements in the gas-solid sorption CO2 capture process. Depending on the sorbent composition, the gas-solid sorption process carries out at high or low temperatures. High temperature sorbents allow the utilization of waste energy while energy requirements in low temperature processes will be less demanding. This study is focused on the assessment and comparison of the final energy penalty of low-temperature (amine impregnated alumina-based solid particles) and high-temperature solid sorbents capture process (calcium oxide)

Discrete breathers in dc biased Josephson-junction arrays

We propose a method to excite and detect a rotor localized mode (rotobreather) in a Josephson-junction array biased by dc currents. In our numerical studies of the dynamics we have used experimentally realizable parameters and included self-inductances. We have uncovered two families of rotobreathers. Both types are stable under thermal fluctuations and exist for a broad range of array parameters and sizes including arrays as small as a single plaquette. We suggest a single Josephson-junction plaquette as an ideal system to experimentally investigate these solutions.Comment: 5 pages, 5 figure, to appear June 1, 1999 in PR

Adaptive minimax estimation in classes of smooth functions

In this thesis we study adaptive methods of estimation for two particular types of statistical problems: regression and density estimation. For all these problems the classes of probabilities are parameterized by real-valued functions. In each model, the underlying function is assumed to belong to some class of smooth functions. In practice the `true' smoothness of the function is unknown and so the actual class is also unknown. We study different regression problems with fixed discrete designs: regression on the real line and regression on a bounded interval. Formally, the distinction here lies just in the definition of the underlying functional classes. The construction of optimal adaptive procedures however is quite different in these cases. This is underlined by the essential difference between these two models; namely, in the case of regression models on bounded observation intervals, the presence of the boundary -- the so called boundary effect -- has to be incorporated in the study of optimal statistical procedures. For each of the three problems: regression on the real line, regression on bounded intervals and density estimation, we introduce corresponding scales of functional classes for which exact -- up to constants -- rates of convergence are obtained, under the classical minimax non-parametric framework, i.e. in the case when the classes are known. We proceed then by constructing adaptive estimators and prove them to be asymptotically optimal, for the corresponding functional scales

Bio-inspired broad-class phonetic labelling

Recent studies have shown that the correct labeling of phonetic classes may help current Automatic Speech Recognition (ASR) when combined with classical parsing automata based on Hidden Markov Models (HMM).Through the present paper a method for Phonetic Class Labeling (PCL) based on bio-inspired speech processing is described. The methodology is based in the automatic detection of formants and formant trajectories after a careful separation of the vocal and glottal components of speech and in the operation of CF (Characteristic Frequency) neurons in the cochlear nucleus and cortical complex of the human auditory apparatus. Examples of phonetic class labeling are given and the applicability of the method to Speech Processing is discussed

Infrared Spectroscopy in the Analysis of Building and Construction Materials

Preprin

The Calcium-Looping technology for CO2 capture: On the important roles of energy integration and sorbent behavior

The Calcium Looping (CaL) technology, based on the multicyclic carbonation/calcination of CaO in gas-solid fluidized bed reactors at high temperature, has emerged in the last years as a potentially low cost technology for CO2 capture. In this manuscript a critical review is made on the important roles of energy integration and sorbent behavior in the process efficiency. Firstly, the strategies proposed to reduce the energy demand by internal integration are discussed as well as process modifications aimed at optimizing the overall efficiency by means of external integration. The most important benefit of the high temperature CaL cycles is the possibility of using high temperature streams that could reduce significantly the energy penalty associated to CO2 capture. The application of the CaL technology in precombustion capture systems and energy integration, and the coupling of the CaL technology with other industrial processes are also described. In particular, the CaL technology has a significant potential to be a feasible CO2 capture system for cement plants. A precise knowledge of the multicyclic CO2 capture behavior of the sorbent at the CaL conditions to be expected in practice is of great relevance in order to predict a realistic capture efficiency and energy penalty from process simulations. The second part of this manuscript will be devoted to this issue. Particular emphasis is put on the behavior of natural limestone and dolomite, which would be the only practical choices for the technology to meet its main goal of reducing CO2 capture costs. Under CaL calcination conditions for CO2 capture (necessarily implying high CO2 concentration in the calciner), dolomite seems to be a better alternative to limestone as CaO precursor. The proposed techniques of recarbonation and thermal/mechanical pretreatments to reactivate the sorbent and accelerate calcination will be the final subjects of this review

Burnout en médicos de atención primaria de la provincia de Cáceres

ObjetivosAnalizar el grado de desgaste profesional en médicos de atención primaria de nuestra provincia y la influencia de diversos factores.DiseñoEstudio transversal, descriptivo y analítico.EmplazamientoProvincial, atención primaria.SujetosTodos los médicos de primaria de la provincia de Cáceres (n = 255).MedicionesCuestionario autoadministrado y anónimo, Maslach Burnout Inventory, que valora: despersonalización (DP), autoestima (PA) y agotamiento emocional (AE); variables sociodemográficas, sociolaborales, preguntas personales y medidas adoptadas si hay estrés laboral. Análisis mediante t de Student y Anova (medias) y ji-cuadrado o Fisher (porcentajes).Resultados principalesUn total de 157 cuestionarios válidos (tasa de respuesta, 62%). La edad media es 41,5 ± 7,2 años; 75% varones, 80,2% casados, 73,2% propietarios, 48,9% ejercen en núcleos urbanos, presión asistencial media de 40,5 ± 16,5 pacientes/día.Los valores medios obtenidos fueron: DP, 8,3 ± 5,8; PA, 35,2 ± 8,4; AE, 22 ± 11,3; un 65,8% presentó elevadas puntuaciones en alguna de las tres.Para AE las medias fueron significativamente superiores en varón, propietario, de centro urbano, más de 10 años de antigüedad o atendía a más de 40 pacientes/día.Un 50% presentaba alteraciones psicofísicas en los 3 meses previos; el 33% soporta mucha burocracia; ambos grupos muestran medias < PA y > AE. Dedicar < 2 h/día al ocio asocia > AE y ser tutor un nivel significativamente superior de burnout. Alteraciones en la esfera familiar o sociolaboral asocian niveles elevados de DP y AE (p < 0,001).ConclusionesCoincidiendo con otros estudios, encontramos un nivel moderado de desgaste profesional en nuestros encuestados. La antigüedad, conflictividad sociolaboral y familiar, y ciertas características personales y laborales se asocian con niveles altos de desgaste.ObjectivesTo analyse the degree of professional burnout in primary care doctors from our province and the effect of various factors.DesignDescriptive and analytic cross-sectional study.SettingPrimary care (PC) in the provinceParticipantsAll the PC doctors in the province of Cáceres (n=255).Main measurements and resultsSelf-administered anonymous questionnaire: the Maslach Burnout Inventory that evaluates Depersonalisation (DP), Self-esteem (SE), and Emotional Exhaustion (EE); social and personal variables, work data, personal questions and measures taken if there was work stress. Student´s t test, ANOVA (means), and Chi-square or Fisher test (percentages) were used. 157 valid questionnaires were returned (62% response rate). Mean age was 41.5 years old±7.2; 75% were male, 80.2% married, 73.2% had tenure, 48.9% worked in towns, and their mean case-load was 40.5±16.5 patients/day. Mean values found were: DP, 8.3±5.8; SE, 35.2±8.4; EE, 22±11.3; 65.8% scored high on one of the three. For EE mean scores were significantly higher in men, doctors with tenure, in towns, those with >10 years seniority or who saw >40 patients a day. 50% had had psycho-physical disorders in the previous 3 months; 33% withstood a lot of bureaucracy; both groups had <SE and >EE averages. Dedicating <2 hours a day to leisure was associated with >EE; and being a tutor with a significantly higher level of burnout. Disorders in the family or social/work sphere were associated with high levels of DP and EE (P<.001).ConclusionsLike other studies, we found a moderate level of burnout in our sample. Seniority, social/labour or family conflict, and certain personal and job characteristics were associated with high burnout

Effect of feed evaluation system on the cost of rations for dairy cows

El objetivo del presente trabajo fue comparar la valoración de las necesidades y los aportes de energía calculados según sistemas históricos y modernos de alimentación para vacas lecheras -unidades alimenticias escandinavas (UA), energía neta grasa (ROSTOCK), energía metabolizable (MAFF), energía neta de lactación (NRC) y unidades forrajeras leche (INRA)- con el fin de investigar la repercusión de aquella en el coste de la ración diaria. Las necesidades energéticas se expresaron como energía neta de lactación (ENL) y se calcularon a intervalos de 30 días en leche (DEL) para una vaca Holstein adulta de 680 kg de peso vivo con una producción de 10000 kg de leche en 305 días y un intervalo entre partos de un año. El aporte de ENL según cada sistema se calculó a partir de diez raciones optimizadas con el programa CPMDairy 1.0 para satisfacer las necesidades nutritivas de la vaca modelo cada 30 DEL. Exceptuando los valores obtenidos con el sistema de unidades alimenticias y el comienzo inmediato de la lactación, las diferencias entre las necesidades de ENL calculadas según los distintos sistemas fueron relativamente bajas (entre 1,1 y 7,5%) y achacables fundamentalmente a la valoración energética del cambio de peso. El aporte calculado de energía mostró diferencias importantes entre los sistemas, oscilando de 19,1 a 25,2%. A lo largo de la lactación, los aportes calculados fueron inferiores a las necesidades en todos los sistemas, con la excepción de NRC y MAFF a 30 y 270 DEL, respectivamente, y UA desde 90 DEL. La diferencia promedio estuvo comprendida entre -1,4 ± 1,1 Mcal d-1 (4,5 ± 2,9%; MAFF) y -5,5 ± 1,7 Mcal d-1 (15,6 ± 4,5%; INRA). El coste unitario de la Mcal varió notablemente entre sistemas (de 18,7 a 25,5%) al igual que el coste de satisfacer los requerimientos diarios de energía (de 13,5 a 50,2%). Se concluyó que, independientemente de cual sea la precisión real, el sistema de valoración de energía empleado en la formulación tiene una importante repercusión sobre el coste de las raciones para vacas lecherasThe objective of the present work was to compare energy requirements and supply calculated according to old and modern feed evaluation systems for dairy cattle - Scandinavian feed units (UA), net energy fat (ROSTOCK), metabolizable energy (MAFF), net energy of lactation (NRC) and milk fodder units (INRA) - to assess the differences in the cost of the ration. The energy requirements were expressed as net energy of lactation (NEL) and were calculated every 30 days in milk (DIM) for a mature Holstein cow weighing 680 kg, producing 10000 kg of milk in 305 days, and calving every year. Ten rations optimized with CPM-Dairy 1.0 to satisfy the nutritional requirements of the model cow every 30 DIM were used to compare the calculated NEL supply according to the systems being evaluated. Except for the values obtained according to the feed units system and the onset of lactation, the differences between the systems in the calculated energy requirements were relatively low (from 1.1% to 7.5%) and mainly attributable to the energy value assigned to the live weight change. The differences between the systems in the NEL supply of the rations were high and oscillated between 19.1% and 25.2%. The calculated supplies were smaller than the requirements in all the systems throughout lactation, except for UA from 90 DIM and NRC and MAFF at 30 and 270 DIM, respectively. The average differences were in the range from -1.4 ± 1.1 Mcal d-1 (4.5 ± 2.9%; MAFF) to -5.5 ± 1.7 Mcal d-1 (15.6 ± 4.5%; INRA). The cost of the Mcal differed between the systems (from 18.7% to 25.5%) and the same was true for the cost of satisfying the daily energy requirements (from 13.5% to 50.2%). It was concluded that, without taking into account the real accuracy, the energy evaluation system used in the formulation affects considerably the cost of rations for lactating dairy cattle

La Responsabilidad Social Corporativa en las instituciones educativas

El concepto de Responsabilidad Social Corporativa (RSC) surge como una forma de hacer de las organizaciones dedicadas a los negocios con repercusión en la forma de ser de las personas implicadas en esas operaciones (stakeholders o grupos de interés). Desde diversos organismos internacionales se propone hacer extensible esta perspectiva a todo tipo de organizaciones entre las que se encuentran las instituciones educativas. El trasplante de la noción a las instituciones educativas requiere una aclaración conceptual previa y una adecuada transmisión, teniendo en cuenta la fuerte inercia en la trasmisión de valores sociales propia de estas organizaciones. En este artículo aportamos nuestra definición de Responsabilidad Social Educativa, diferenciándola de conceptos semejantes y que podría llevar a equívocos y ofrecemos su- gerencias con las que hacer una adecuada comunicación institucional para que las instituciones educativas adopten con mayor intencionalidad y eficiencia esta forma de ser.The concept of Corporate Social Responsibility (CSR) emerges as a specific business organization’s work life that enhances the stakeholders and interest groups lifestyles. Various international organizations aim at promoting this dimension to all types of institutions including educational organizations. In this context, a conceptual clarification and communication is needed because of the strong inertia in the transmission of social values in academic institutions. In this paper, we propose a definition of Education Social Responsibility, covering aspects on how to establish measures to ensure effective educational institutional communication, allowing them to adopt this dimension more efficiently

Emergence, survival, and segregation of competing gangs

In this paper, we approach the phenomenon of criminal activity from an infectious perspective by using tailored compartmental agent-based models that include the social flavor of the mechanisms governing the evolution of crime in society. Specifically, we focus on addressing how the existence of competing gangs shapes the penetration of crime. The mean-field analysis of the model proves that the introduction of dynamical rules favoring the simultaneous survival of both gangs reduces the overall number of criminals across the population as a result of the competition between them. The implementation of the model in networked populations with homogeneous contact patterns reveals that the evolution of crime substantially differs from that predicted by the mean-field equations. We prove that the system evolves toward a segregated configuration where, depending on the features of the underlying network, both gangs can form spatially separated clusters. In this scenario, we show that the beneficial effect of the coexistence of two gangs is hindered, resulting in a higher penetration of crime in the population