Effect of starch substitution with crude glycerol on growing rabbit and lactating doe performance

The aim of this work was to study the effect of dietary inclusion of 2.5 or 5.0% of glycerol in substitution for starch on performance of lactating does and fattening rabbits. Over four consecutive reproductive cycles, a total of 81 New Zealand ´ Californian rabbit does and 813 young rabbits weaned at 25 (fattening trial 1) or 35 (fattening trial 2) days of age were allocated at random to the experimental treatments. Inclusion of glycerol in the diet up to 5% did not influence total feed consumption of does and suckling rabbits, body weight and bioelectrical impedance of does at parturition or at day 21 of lactation and litter weight at weaning, or reproductive efficiency. Substitution of starch with glycerol did not affect feed intake, weight gain or mortality during fattening. The results of the current study indicate that crude glycerol from the biofuel industry can be used at levels up to 5% in rabbit diets without any detrimental or beneficial effect on performance

Ship manoeuvrability: full scale trials of colombian navy riverine support patrol vessel

Methodology and results of full scale maneuvering trials for Riverine Support Patrol Vessel “RSPV”, built by COTECMAR for the Colombian Navy are presented. !is ship is equipped with a “Pump – Jet” propulsion system and the hull corresponds to a wide-hull with a high Beam – Draft ratio (B/T=9.5). Tests were based on the results of simulation of turning diameters obtained from TRIBON M3© design software, applying techniques of Design of Experiments “DOE”, to rationalize the number of runs in di"erent conditions of water depth, ship speed, and rudder angle. Results validate the excellent performance of this class of ship and show that turning diameter and other maneuvering characteristics improve with decreasing water depth.

Relación entre la composición química corporal, la fertilidad y la prolificidad en conejas primíparas.

En este trabajo se ha estudiado el efecto de la composición química corporal, estimada mediante el método de impedancia bioeléctrica (BIA) en la primera y segunda inseminación artificial (IA), sobre la fertilidad y la prolificidad de conejas primíparas. Se utilizaron los datos de 137 conejas procedentes de dos granjas que utilizaban dos genéticas distintas (UPV e Hyplus) y tres ritmos reproductivos (R4: inseminación a los 4 días tras el parto y destete a los 28 días, R11: inseminación a los 11 días postparto y destete a 35 días y R14: inseminación a los 14 días tras el parto y destete a los 42 días). La fertilidad media observada en el segundo parto fue de un 56,2% y el porcentaje de nacidos vivos, sobre los nacidos totales, fue de un 87,5%, no encontrándose diferencias entre los ritmos utilizados. El aumento de la proporción de proteína corporal, grasa y energía en la primera IA tuvieron un efecto positivo (P=0,007; P=0,03 y P<0,001, respectivamente) sobre la fertilidad del segundo parto. Igualmente, un mayor contenido en grasa (P<0,001) y energía (P<0,001) en la segunda IA también incrementaron la fertilidad del segundo parto. El incremento del ratio proteína/energía corporal de las conejas, determinado en las dos IA, tuvo un efecto negativo sobre la fertilidad en el segundo parto (P<0,001), observándose mejores resultados en conejas con 12 g proteína/MJ respecto a otras con valores superiores. El porcentaje de nacidos vivos (P<0,001), sobre los nacidos totales, aumentó con la proporción de proteína de las conejas en el momento de la segunda IA, pero esta última no tuvo efecto sobre la fertilidad. This study evaluated the effect of chemical body composition at first and second artificial inseminations (AI), determined by bioelectric impedance technique (BIA), on fertility and prolificacy of primiparous rabbit does. Data of 137 does from two farms using two different genetics (UPV and Hyplus) and three breeding systems were analyzed. Fertility was 56.2 % and the percentage of kits born alive over total born was 87.5 %. Breeding system had no effect on fertility or the percentage of kits born alive. Higher body protein, fat and energy of the rabbit doe at first artificial insemination (AI) increased the fertility in the second parity (P=0.007, P=0.03 and P<0.001 respectively). Fat and energy content of the doe at the second AI affected positively fertility in the second parity (P<0.001 and P<0.001 respectively), while protein influenced positively only prolificacy (P<0.001). The increase of the ratio protein/energy in both AI moments had a negative influence on fertility in the second parity (P<0.001), rabbit does with 12 g protein/MJ showed a higher fertility than those with higher values

Clean Coal Technologies Scenario and Evaluation of Present CO2 Dwindling Initiatives to Approach Zero Emission Power Stations By Coal Combustion. Deployment Situation and Evaluation Study

In the present uncertain global context of reaching an equal social stability and steady thriving economy, power demand expected to grow and global electricity generation could nearly double from 2005 to 2030. Fossil fuels will remain a significant contribution on this energy mix up to 2050, with an expected part of around 70% of global and ca. 60% of European electricity generation. Coal will remain a key player. Hence, a direct effect on the considered CO2 emissions business-as-usual scenario is expected, forecasting three times the present CO2 concentration values up to 1,200ppm by the end of this century. Kyoto protocol was the first approach to take global responsibility onto CO2 emissions monitoring and cap targets by 2012 with reference to 1990. Some of principal CO2emitters did not ratify the reduction targets. Although USA and China spur are taking its own actions and parallel reduction measures. More efficient combustion processes comprising less fuel consuming, a significant contribution from the electricity generation sector to a CO2 dwindling concentration levels, might not be sufficient. Carbon Capture and Storage (CCS) technologies have started to gain more importance from the beginning of the decade, with research and funds coming out to drive its come in useful. After first researching projects and initial scale testing, three principal capture processes came out available today with first figures showing up to 90% CO2 removal by its standard applications in coal fired power stations. Regarding last part of CO2 reduction chain, two options could be considered worthy, reusing (EOR & EGR) and storage. The study evaluates the state of the CO2 capture technology development, availability and investment cost of the different technologies, with few operation cost analysis possible at the time. Main findings and the abatement potential for coal applications are presented. DOE, NETL, MIT, European universities and research institutions, key technology enterprises and utilities, and key technology suppliers are the main sources of this study. A vision of the technology deployment is presented.

Simulación de maniobras de buques con sistemas de propulsión no convencional en aguas poco profundas

Los requisitos cada vez más exigentes en cuanto a misiones, limitaciones operacionales y ambientales así como nuevas tecnologías, imponen permanentemente retos a los arquitectos navales para generar alternativas de buques y valorar su bondad en las primeras etapas del proyecto. Este es el caso de los Buques Patrulleros de Apoyo Fluvial Pesados PAF-P, que por requerimiento de la Armada Nacional de Colombia ha diseñado y construido COTECMAR. Los PAF-P, son buques fluviales cuya relación Manga-Calado excede la mayoría de los buques existentes (B/T=9,5), debido principalmente a las restricciones en el calado a consecuencia de la escasa profundidad de los ríos. Estos buques están equipados con sistemas de propulsión acimutales tipo “Pum-Jet”. Las particularidades del buque y del ambiente operacional, caracterizado por ríos tropicales con una variabilidad de profundidad dependiente del régimen de lluvias y sequía, así como la falta de canalización y la corriente, hacen que la maniobrabilidad y controlabilidad sean fundamentales para el cumplimiento de su misión; adicionalmente, no existen modelos matemáticos validados que permitan predecir en las primeras etapas del diseño la maniobrabilidad de este tipo de buques con los efectos asociados por profundidad. La presente tesis doctoral aborda el desarrollo de un modelo matemático para simulación de maniobrabilidad en aguas poco profundas de buques con relación manga-calado alta y con propulsores acimutales tipo “Pump-Jet”, cuyo chorro además de entregar el empuje necesario para el avance del buque, genera la fuerza de gobierno en función del ángulo de orientación del mismo, eliminando la necesidad de timones. El modelo matemático ha sido validado mediante los resultados obtenidos en las pruebas de maniobrabilidad a escala real del PAF-P, a través de la comparación de trayectorias, series temporales de las variables de estado más significativas y parámetros del círculo evolutivo como son diámetro de giro, diámetro táctico, avance y transferencia. El plan de pruebas se basó en técnicas de Diseño de Experimentos “DOE” para racionalizar el número de corridas en diferentes condiciones de profundidad, velocidad y orientación del chorro (ángulo de timón). En el marco de la presente investigación y para minimizar los errores por efectos ambientales y por inexactitud en los instrumentos de medición, se desarrolló un sistema de adquisición y procesamiento de datos de acuerdo con los lineamientos de ITTC. La literatura existente describe los efectos negativos de la profundidad en los parámetros de maniobrabilidad de buques convencionales (Efecto tipo S), principalmente las trayectorias descritas en los círculos evolutivos aumentan en la medida que disminuye la profundidad; no obstante, en buques de alta relación manga-calado, B/T=7,51 (Yoshimura, y otros, 1.988) y B/T=6,38 (Yasukawa, y otros, 1.995) ha sido reportado el efecto contrario (Efecto tipo NS Non Standart). Este último efecto sin embargo, ha sido observado mediante experimentación con modelos a escala pero no ha sido validado en pruebas de buques a escala real. El efecto tipo NS en buques dotados con hélice y timones, se atribuye al mayor incremento de la fuerza del timón comparativamente con las fuerzas del casco en la medida que disminuye la profundidad; en el caso de estudio, el fenómeno está asociado a la mejor eficiencia de la bomba de agua “Pump-Jet”, debido a la resistencia añadida en el casco por efecto de la disminución de la profundidad. Los resultados de las pruebas con buque a escala real validan el excelente desempeño de esta clase de buques, cumpliendo en exceso los criterios de maniobrabilidad existentes y muestran que el diámetro de giro y otras características de maniobrabilidad mejoran con la disminución de la profundidad en buques con alta relación manga-calado. ABSTRACT The increasingly demanding requirements in terms of missions, operational and environmental constraints as well as new technologies, constantly impose challenges to naval architects to generate alternatives and asses their performance in the early stages of design. That is the case of Riverine Support Patrol Vessel (RSPV), designed and built by COTECMAR for the Colombian Navy. RSPV are riverine ships with a Beam-Draft ratio exceeding most of existing ships (B/T=9,5), mainly due to the restrictions in draft as a result of shallow water environment. The ships are equipped with azimuthal propulsion system of the “Pump-Jet” type. The peculiarities of the ship and the operational environment, characterized by tropical rivers of variable depth depending on the rain and dry seasons, as well as the lack channels and the effect of water current, make manoeuvrability and controllability fundamental to fulfill its mission; on the other hand, there are not validated mathematical models available to predict the manoeuvrability of such ships with the associated water depth effects in the early stages of design. This dissertation addresses the development of a mathematical model for shallow waters’ manoeuvrability simulation of ships with high Beam-Draft ratio and azimuthal propulsion systems type “Pump-Jet”, whose stream generates the thrust required by the ship to advance and also the steering force depending on the orientation angle, eliminating the need of rudders. The mathematical model has been validated with the results of RSPV’s full scale manoeuvring tests, through a comparison of paths, time series of state variables and other parameters taken from turning tests, such as turning diameter, tactical diameter, advance and transfer. The test plan was developed applying techniques of Design of Experiments “DOE”, in order to rationalize the number of runs in different conditions of water depth, ship speed and jet stream orientation (rudder angle). A data acquisition and processing system was developed, following the guidelines of ITTC, as part of this research effort, in order to minimize errors by environmental effects and inaccuracy in measurement instruments, The negative effects of depth on manoeuvrability parameters for conventional ships (Effect Type S: the path described by the ship during turning test increase with decrease of water depth), has been documented in the open literature; however for wide-beam ships, B/T=7,51 (Yoshimura, y otros, 1.988) and B/T=6,38 (Yasukawa, y otros, 1.995) has been reported the opposite effect (Type NS). The latter effect has been observed thru model testing but until now had not been validated with full-scale results. In ships with propellers and rudders, type NS effect is due to the fact that increment of rudder force becomes larger than hull force with decrease of water depth; in the study case, the phenomenon is associated with better efficiency of the Pump-Jet once the vessel speed becomes lower, due to hull added resistance by the effect of the decrease of water depth. The results of full scale tests validates the excellent performance of this class of ships, fulfilling the manoeuvrability criteria in excess and showing that turning diameter and other parameters in high beam-draft ratio vessels do improve with the decrease of depth.

Optimizing rabbit production under heat stress: cage density and cage size during fattening, and breeding system and water quality on rabbit does

The aim of this work was to evaluate different management strategies to optimize rabbit production under chronic heat stress. To achieve it, three trials were conducted. In the first trial, to find the optimal cage density in tropical very dry forest condition, were measured growth performance, mortality rate, injured animals and carcass performance over an initial population of 300 cross-breed rabbits of New Zealand, California, Butterfly, Dutch and Satin, weaned at 30 days (535 ± 8 g, standard error). Treatments evaluated were: 6, 12, 18 and 24 rabbits/m2 (3, 6, 9 and 12 rabbits/cage, respectively, each cage of 0.5 m2). The maximal temperature-humidity index indicated a severe heat stress from weaning to 2.2 kg body weight (experimental time). At the end of experimental period 10, 20, 30 and 30 rabbits from the treatments of 6, 12, 18 and 24 rabbits/m2, respectively, were slaughtered and carcass performance recorded. Average daily gain and feed intake decreased by 0.31 ± 0.070 and 1.20 ± 0.25 g, respectively, per each unit that the density increased at the beginning of the experiment (P = 0.001). It increased the length of the fattening period by 0.91 ± 0.16 d (P = 0.001) per each unit of increment of density. However, rabbit production (kg/m2) increased linear and quadratically with the density (P < 0.008). Animals housed at the highest density compared to the lower one tended to show a higher incidence of ringworm (68.9 vs 39.4%; P = 0.075), injured animals (16.8 vs 3.03%; P = 0.12) and mortality (20.5 vs 9.63%; P = 0.043). The proportion of scapular fat (P = 0.042) increased linearly with increasing levels of density. Increasing density reduced linearly dorsal length (P = 0.001), and reduced linear and quadratically drip loss percentage (P = 0.097 and 0.018, respectively). In the second trial, 46 nulliparous rabbit does (23 clipped and 23 unclipped) with a BW of 3.67 ± 0.05 kg (s.e.) were used to evaluate heat stress and circadian rhythms comparing unclipped and clipped rabbit does, and to study if a more extensive breeding system increase litters performance at weaning without impairing rabbit doe performance,. Rectal temperature, feed and water 4 intake were recorded for 24 h. Rabbit does were mated 7 d after circadian measurements, and randomly assigned to two breeding systems. Control (C): mated at 14 d after parturition + litter weaned at 35 d of age. Extensive (E): mate at 21 after parturition + litter weaned at 42 d of age. The first three cycles were evaluated concerning to rabbit doe and litter performance. Two hundred twenty eight weaned rabbits, were divided into two cage sizes: 0.5 and 0.25 m2 with same density (16 rabbit/m2) and growing performance was recorded. Farm and rectal temperatures were minimal and feed and water intake maximal during the night (P < 0.001). Unclipped rabbit does showed higher rectal temperature (P = 0.045) and lower feed intake respect to clipped does (P = 0.019) which suggest a lower heat stress in the latter. Kits weaned per litter was reduced by 33% (P=0.038) in C group. This reduction was more important in the 2nd and 3rd cycles compared to the first (P ≤ 0.054). Rabbit doe feed efficiency tended to decrease in E respect C group (P = 0.093), whereas it was impaired from the first to the third cycle by 48% (P = 0.014). Growing rabbits from the E group were heavier at weaning (by 38%. P < 0.001), showed a higher feed intake (+7.4%) and lower feed efficiency (-8.4%) throughout the fattening period (P ≤ 0.056) respect to C group. Cage size had minor influence in growing performance. In the third trial, forty five non pregnant and non lactating rabbit does (21 nulliparous and 24 multiparous) were assigned randomly to farm water and to potable water to study if a water quality improvement can affect positively rabbit doe response to heat stress during pregnancy and lactation. A transponder was implanted in each animal to record subcutaneous temperature at 07:30 and 14:30 h. Experimental period extended from pregnancy (with no lactation) to the next lactation (until day 28). Body temperature and milk production were recorded daily, and body condition, feed and water intake weekly. Water quality did not affect any trait (P ≥ 0.15). Pregnant rabbit does were classified as does that weaned (W: 47%), not weaned (NW: 44%) or those pregnant that did not deliver (NB: 9%). Body temperature and feed intake decreased during pregnancy (P ≤ 0.031), but water intake remained constant. In this period body temperature decreased with metabolic weight (P ≤ 0.009). In W and NW does, 5 from mating to birth energy and protein balance impaired (P≤0.011). Body temperature of W does tended to be the lowest (P ≤ 0.090). Pregnancy length and total number of kits born tended to be longer and higher in NW than in W does (P = 0.10 and 0.053, respectively). Kit mortality at birth and from birth to 14 d of lactation was high, being worse for NW than for W does (97 vs. 40%; P<0.001). Body temperature during lactation was maximal at day 12, and milk production increased it (P ≤ 0.025). . In conclusion, in our heat stress conditions densities higher than 18 rabbits/m2 (34 kg/m2) at the end of fattening, are not recommended despite cage size, gestation and lactation productivity impaired not only when lactation is extended and along successive reproductive cycles but also due to a reduced embryo/kit survival and finally water quality improvement did not attenuate negative effect of heat stress. RESUMEN El propósito de éste trabajo fue evaluar diferentes estrategias de manejo para optimizar la producción de conejos bajo estrés térmico. Para lo cual se desarrollaron tres experimentos. En el primer experimento, para encontrar el número óptimo de gazapos por m2 de jaula durante el cebo en condiciones de bosque muy seco tropical, se estudiaron los rendimientos durante el cebo, mortalidad, animales lesionados y rendimiento de la canal sobre una población inicial de 300 conejos mestizos de Nueva Zelanda, California, Mariposa, Holandés y Satin, destetados a los 30 días de edad (535 ± 8g, error estándar). Los tratamientos evaluados fueron: 6, 12, 18 y 24 conejos/m2 (3, 6, 9 y 12 conejos/jaula, respectivamente, en jaulas de 0.5 m2). Durante el período experimental (destete a 2.2 kg de peso vivo), se observaron valores de THI correspondientes con un estrés térmico severo (THI max. De 31 a 35). Al final del período experimental, 10, 20, 30, y 30 conejos de los tratamientos con densidades de 6, 12, 18 y 24 conejos/m2, respectivamente, fueron sacrificados y su canal fue valorada. El promedio de la ganancia diaria y el consumo de alimento disminuyeron en 0.31 ± 0.070 y 1.20 ± 0.25 g, respectivamente, por cada unidad de incremento en la densidad al inicio del experimento (P=0.001). Esto alargó el período de engorde en 0.91 ± 0.16 d (P=0.001) por cada unidad de incremento de la densidad. Sin embargo, la producción de conejos (kg/m2) aumentó lineal y cuadráticamente con la densidad (P<0.008). Los animales alojados en las mayores densidades en comparación con el resto tendieron a mostrar una mayore incidencia de tiña (68.9 vs 39.4%; P=0.075), de cantidad de animales heridos (16.8 vs 3.03%; P=0.12), así como de mortalidad (20.5 vs 9.63%; P=0.043). El aumento en la densidad aumentó linealmente la proporción de grasa escapular (P=0.042) y redujo linealmente la longitud dorsal (P=0.001), y lineal y cuadráticamente el porcentaje de pérdida por goteo (P=0.018). En el segundo experimento, 46 conejas nulliparas (23 rasuradas y 23 no rasuradas) con un peso vivo de 3.67 ± 0.05 kg (e.e.) fueron usadas para evaluar el estrés 8 térmico y los ritmos circadianos comparando conejas rasuradas o no, y estudiar si un sistema de crianza más extensivo mejora el desempeño de la camada al destete sin perjudicar la productividad de la coneja. Durante 24 h se midió la temperatura rectal, consumo de alimento y de agua. Las conejas fueron montadas 7 días después, y distribuidas en dos sistemas de crianza. El control (C): monta a 14 días posparto y destete a 35 d de edad. El extensivo (E): monta a 21 días posparto y destete a 42 d de edad. Se controló la productividad de la coneja y la camada durante los tres primeros ciclos. Doscientos veintiocho gazapos fueron distribuidos en dos tamaños de jaulas (0.5 y 0.25 m2) con la misma densidad (16 conejos/m2) y se controlaron sus rendimientos productivos. Durante la noche se observaron los valores mínimos para la temperatura ambiental y rectal, y los máximos para consumo de alimento y agua (P< 0.001). Las conejas no rasuradas mostraron mayor temperatura rectal (P=0.045) y menores valores de consumo de alimento con respecto a las conejas rasuradas (P=0.019), lo que sugiere un menor estrés térmico en las últimas. El número de gazapos destetados por camada se redujo en 33% (P=0.038) en el grupo C. Este comportamiento se acentuó en el 2do y 3er ciclo en comparación con el primero (P≤0.054). La eficiencia alimenticia de las conejas tendió a disminuir en el grupo E con respecto al grupo C (P=0.093), dicha tendencia se acentúa del primer al tercer ciclo en un 48% (P=0.014). Los gazapos en fase de crecimiento provenientes del grupo E fueron más pesados al momento del destete (en 38% P<0.001), mostrando un mayor consumo de alimento (+7.4%) y menor eficiencia alimenticia (-8.4%) a lo largo del engorde (P≤0.056) con respecto al grupo C. El tamaño de la jaula tuvo una mínima influencia en el comportamiento durante el crecimiento de éstos gazapos. En el tercer experimento, cuarenta y cinco conejas no gestantes ni lactantes (21 nulíparas y 24 multíparas) se les asignó al azar agua dos tipos de agua: común de la granja y agua potable, con el fin de estudiar si una mejora en la calidad del agua puede afectar positivamente la respuesta de la coneja al estrés térmico durante la gestación y la lactancia. Se les implantó un transponder para registrar la temperatura subcutánea a las 7:30 y a las 14:30 h. El período experimental se extendió desde la gestación (sin 9 lactancia) hasta la lactanción consecutiva (hasta los 28 días). La temperatura corporal y la producción de leche se controlaron diariamente, y la condición corporal, consumo de agua y alimento, semanalmente. La calidad del agua no afectó a ninguna variable (P≥0.15). Las conejas preñadas fueron clasificadas como conejas que destetaron (W: 47%), que no destetaron (NW:44%) o aquellas que no parieron (NB: 9%). La temperatura corporal y consumo de alimento disminuyeron durante la gestación (P≤0.031), mientras que el consumo de agua se mantuvo constante. La temperatura corporal descendió con el peso metabólico durante la gestación (P≤0.009). El balance de energía y proteína disminuyó desde la monta al parto para las conejas W y NW (P≤0.011). Durante la gestación la temperatura corporal tendió a ser menor en las conejas W (P≤0.090). La longitud de la gestación y el número total de gazapos nacidos tendieron a ser mayores en conejas NW que en conejas W (P=0.10 y 0.053, respectivamente). La mortalidad de los gazapos al parto y del parto a los 14 días de lactancia fue alta, siendo peor para las conejas NW que para las W (97 vs 40%; P<0.001). Durante la lactancia la temperatura corporal alcanzó su valor máximo para el día 12, y la producción de leche indujo un incremento en la misma (P≤0.025). En conclusión, en nuestras condiciones de estrés térmico y sin importar el tamaño de la jaula, no se recomiendan densidades mayores a 18 conejos/m2 (34 kg/m2) al final del engorde. La productividad de la gestación y la lactancia disminuyen cuando la lactancia es mayor y se suceden varios ciclos reproductivos seguidos. Esto se debe al efecto negativo del estrés térmico sobre la vitalidad y supervivencia del embrión/gazapo. La mejora de la calidad del agua atenuó el efecto negativo del estrés térmico. Las conejas más productoras parece que son aquéllas que consiguen manejar mejor el estrés térmico.

Biostimulation methods associated with early weaning and reproductive rhythms in primiparous rabbit does

El objetivo general de esta Tesis Doctoral ha sido tratar de mejorar los parámetros reproductivos de las conejas primíparas lactantes, empleando dos métodos de manejo (destete temprano y extensificación del ritmo reproductivo), que están directamente relacionados con su balance energético. Para ello, se diseñaron 2 experimentos en este tipo de hembras. En el primero, se estudió el efecto del destete a 25 días post-parto (dpp) sobre la actividad ovárica y el metabolismo energético de las conejas una semana más tarde (32 dpp). Un total de 34 primíparas lactantes con 8 gazapos fueron distribuidas en tres grupos: 10 conejas se sacrificaron a los 25 dpp (grupo L25), 13 fueron destetadas a los 25 dpp y sacrificadas a los 32 dpp (grupo NL32), y 11 conejas no se destetaron y fueron sacrificadas a los 32 dpp (grupo L32). No se observaron diferencias significativas entre grupos en el peso corporal, el peso del ovario, ni en las concentraciones séricas de ácidos grasos no esterificados y de proteínas totales. A pesar de que el grupo NL32 presentó un bajo consumo de alimento (122 ± 23,5 g / día, p <0,001), su contenido corporal estimado de lípidos (16,9 ± 1,09%, P <0,008), proteínas (19,7 ± 0,07%, P <0,0001), y energía (1147 ± 42,7 MJ / kg, p <0,006) fueron más elevados y las concentraciones séricas de glucosa (158 ± 24,5 mg/dl, p <0,04) más bajas que en los grupos L25 (11,9 ± 1,3%, 18,5 ± 0,08%, 942 ± 51,3 MJ/kg y 212 ± 27,9 mg/dl) y L32 (13,4 ± 1,03%, 18,5 ± 0,1%, 993 ± 40,4 MJ/kg y 259 ± 29,5 mg/dl), respectivamente. En el grupo L25 se observó un menor número medio de folículos ≥ 1 mm en la superficie ovárica en comparación con los grupos NL32 y L32 (12,7 ± 1,5 vs. 18,0 ± 1,45 y 17,6 ± 1,67, p <0,05). La población folicular ovárica en las secciones histológicas y la inmunolocalización de los receptores de prolactina fueron similares en todos los grupos. En el grupo L25, tanto la maduración nuclear de oocitos, medida en términos de tasas alcanzadas de Metafase II (67,0 vs. 79,7 y 78,3%, P <0.05) y la maduración citoplasmática, medida por el porcentaje de gránulos corticales (GC) total o parcialmente migrados en los oocitos, fueron significativamente menores que en los grupos NL32 y L32 (16,0 vs 38,3 y 60,0%, P <0.05). En conclusión, a pesar de que el destete precoz a 25 dpp pareció mejorar las reservas de energía de las conejas primíparas, este hecho no se reflejó claramente a nivel ovárico a los 32 dpp y fue similar independientemente del destete, por lo que éste último podría llevarse a cabo más tarde. En el segundo experimento, se compararon dos ritmos reproductivos. Se utilizaron un total de 48 conejas primíparas lactantes con 8 gazapos que se asignaron al azar en dos grupos experimentales: a) lactantes sacrificadas a comienzos del post-parto (11 dpp) de acuerdo a un ritmo semi-intensivo (n = 24), y b) lactantes sacrificadas al final del período post-parto (25 dpp) de acuerdo con un ritmo más extensivo (n = 24). En ellas, se estudió el peso vivo, la composición corporal estimada, parámetros metabólicos y endocrinos (estradiol y progesterona) y características ováricas como la población folicular y la tasa de atresia, así como la maduración nuclear y citoplásmica de los oocitos. En este estudio, el peso vivo, el contenido de energía corporal, los depósitos grasos y los ácidos grasos no esterificados disminuyeron a lo largo del post-parto con respecto al momento del parto (P <0,05). Las concentraciones séricas de proteínas y glucosa aumentaron en el mismo periodo post-parto (P <0,05). Se observaron similares niveles de estradiol y progesterona en ambos ritmos, así como una población folicular, tasas de maduración nuclear (tasa de oocitos en metafase II) y citoplasmática (porcentaje de oocitos con gránulos corticales migrados), similares en ambos momentos del post-parto. Sin embargo, el número de folículos preovulatorios en la superficie ovárica fue menor (P <0,05) y la tasa de atresia tendió a ser mayor con un porcentaje también menor de folículos sanos (P <0,1) en los ovarios de las hembras sometidas al ritmo extensivo. En conclusión, al final del post-parto (25 días), las conejas primíparas sin destetar muestran un deterioro de sus reservas corporales, de sus parámetros metabólicos séricos y de la calidad de sus oocitos; incluso se ha observado una ligera influencia negativa en el desarrollo de sus folículos ováricos. Por esta razón, se considera que en las conejas primíparas lactantes el manejo reproductivo extensivo (25 dpp) no presenta ninguna ventaja en comparación con el semi-intensivo (11 dpp). A la vista de los resultados de estos dos experimentos, podemos decir que ni el destete temprano, ni la extensificación del ritmo reproductivo han conseguido una mejora en los parámetros reproductivos de una hembra primípara. Por ello, son necesarios más estudios sobre el estado metabólico de la coneja primípara lactante para conseguir métodos o estrategias que lo mejoren y tengan consecuencias directas sobre la actividad reproductiva y sobre su éxito productivo. The general aim of this Thesis was to study two management methods (early weaning and extensive reproductive rhythm) linked to the energy balance of the primiparous rabbit does to improve their reproductive performance. In this sense, 2 experiments were conducted using this kind of females. In the first experiment, the effect of weaning at 25 days post-partum (dpp) on ovarian activity and energetic metabolism one week later (32 dpp) was studied. A total of 34 primiparous lactating rabbit does were used and distributed among three groups: 10 does euthanized at 25 dpp (group L25), 13 does weaned at 25 dpp and euthanized at 32 dpp (group NL32), and 11 non weaned does euthanized at 32 dpp (group L32). No significant differences were observed in live body weight, ovary weight, serum non esterified fatty acids (NEFA) and total protein concentration among groups. Although NL32 does had a low feed intake (122±23.5 g/Day; P < 0.001), their estimated lipids (16.9±1.09%, P < 0.008), protein (19.7±0.07%, P < 0.0001), and energy (1147±42.7 MJ/kg, P < 0.006) body contents were higher and their serum glucose concentrations (158±24.5 mg/dl, P < 0.04) were lower compared to L25 does (11.9±1.3%, 18.5±0.08%, 942±51.3 MJ/kg and 212±27.9 mg/dl) and L32 does (13.4±1.03%, 18.5±0.1%, 993±40.4 MJ/kg and 259±29.5 mg/dl, respectively). A lower number of follicles ≥1mm was observed compared to NL32 and L32 groups (12.7±1.5 vs. 18.0±1.45 and 17.6 ±1.67; P < 0.05) in the ovarian surface of L25 does. Follicular population in the histological ovarian sections and immunolocalization of prolactin receptor were similar in all groups. In group L25, both nuclear maturation of oocytes in terms of Metaphase II rate (67.0 vs. 79.7 and 78.3%; P < 0.05) and cytoplasmic maturation measured by percentage of cortical granules (CG), totally or partially migrated in oocytes were significantly lower than in groups NL32 and L32 (16.0 vs. 38.3 and 60.0%; P < 0.05). Consequently, a higher rate of oocytes with non-migrated CGs was found in group L25 than in groups NL32 and L32 (76.0 vs. 46.8 and 33.3%; P < 0.05). In conclusion, even though early weaning at 25 dpp seemed to improve body energy stored in primiparous does, this fact was not well reflected on the ovarian status at 32 dpp, which was similar regardless of weaning time. In the second experiment, two reproductive rhythms were compared. A total of 48 primiparous Californian x New Zealand White rabbit does suckling 8 kits were randomly allocated in two experimental groups: a) lactating does euthanized at early post-partum period (11 dpp) according to a semi-intensive rhythm (n = 24), and b) lactating does euthanized on later post-partum period (25 dpp) according to a more extensive rhythm (n = 24). Live weight, estimated body composition, serum metabolic and endocrine parameters (oestradiol and progesterone concentrations) and ovarian features like follicle population and atresia rate, and oocyte maturation were studied. Live weight, body energy content, lipid depots and serum non esterified fatty acids (NEFA) concentrations diminished from parturition time to post-partum period (P < 0.05). In addition, serum protein and glucose concentrations increased along postpartum time (P < 0.05). Similar oestradiol and progesterone levels were shown in rhythms as well as similar follicle population and nuclear and cytoplasmic maturation rates measured as metaphase II and cortical granule migration, respectively in both postpartum times. However, number of preovulatory follicles on the ovarian surface was lower (P < 0.05) and atresia rate tended to be higher with also lower percentage of healthy follicles (P < 0.1) in ovaries of females of extensive group. In conclusion, primiparous non-weaned rabbits does at late post-partum time (25 days), Did no show any improvement regarding body reserves, serum metabolic parameters and oocyte quality; even a slight negative influence has been observed in the development of their ovarian follicles. Thus this reproductive management does not present any advantage compared to earlier post-partum (11 days) reproductive rhythm. In summary, according to the obtained results from these two experiments, we can say that the application of early weaning and the extensive rhythms did not achieve an improvement in the reproductive performance of primiparous does. Thus, it is necessary to conduct more studies about the metabolic status of the primiparous lactating doe to achieve strategies in order to improve it and consequently, to improve the reproductive activity and their productive success.

Análisis técnico-económico y de las herramientas de caracterización en la búsqueda de almacenes de Co2 en la cuenca alta del Guadalquivir

El presente documento evalúa la Cuenca Alta del Guadalquivir en busca de posibles estructuras viables como almacenes de CO2, tanto técnica como económicamente. Se lleva a cabo la selección de seis posibles estructuras, de las cuales solo tres han resultado viables atendiendo a criterios técnicos y socio-económicos. De estas tres, se evalúa la viabilidad económica de la de mayor capacidad, obteniendo como resultado que la capacidad estimada es demasiado baja para que sea rentable su uso como almacén de CO2 a nivel comercial en una industria tipo de la Unión Europea. Para ello nos basamos principalmente en la Ley 40/2010 que regula el almacenamiento geológico en nuestro país, el informe GeoCapacity elaborado por el IGME, atlas elaborados por el Departamento de Energía de los Estados Unidos (DOE), y en diversos documentos de carácter económico publicados a nivel Europeo. Este proyecto, está incluido dentro de la Cátedra TecFutura, y forma parte del proyecto AVANZACO2. Por tanto, ha contado con la colaboración de las empresas implicadas en dicho proyecto, Sacyr Vallehermoso y Gessal así como con investigadores de la UPM. En relación con dicho proyecto, se procesaron los datos obtenidos mediante la herramienta informática CO2SITEASSES. ABSTRACT This paper evaluates the Upper basin of the Guadalquivir in the search of viable structures for CO2 storage, both technically and economically. The selection of six possible structures has been made, of which only three have proved to be viable attending to technical an socio-economic criteria. Of these three, we evaluate the economic viability of the larger capacity. In result, the estimated capacity is too low to make it profitable for a commercial use. In order to do this, we rely primarily on the Law 40/2010, which regulate the geological storage in our country, the report GeoCapacity, prepared by the IGME, atlas prepared by de Department of Energy of the United States (DOE) and various economic papers published in Europe. This project is included in the “Cátedra TecFutura” and is part of AVANZACO2 project. Therefore it has enjoyed the cooperation of the companies involved in the project, Sacyr Vallehermoso and Gessal, as well as UPM researchers. Related to this project, the obtained data were processed using the software CO2SITEASSES

Thermal effects and other interesting issues with CPV lenses

The Photovoltaic (PV) Module Reliability Workshop was held in Golden, Colorado, on Feb. 28?March 1, 2012. The objective was to share information to improve PV module reliability because such improvements reduce the cost of solar electricity and give investors confidence in the technology. NREL led the workshop, which was sponsored by the U.S. Department of Energy (DOE) Solar Energy Technologies Program (Solar Program).

Escenario de potenciales tecnologías limpias de carbón y evaluación de las iniciativas dereducción de CO2 en su aproximación a centrales de generación eléctrica de emisiones cero

Dentro del objetivo común que persigue alcanzar una estabilidad social y una economía de éxito sostenible en el actual e incierto contexto mundial, el pronóstico es que la demanda de energía siga aumentando y que la generación mundial de electricidad se duplique entre los años 2005 y 2030. En este escenario, los combustibles fósiles podrían mantener una contribución muy significativa al mix energético posiblemente hasta el año 2050, participando del mercado de generación de energía eléctrica mundial en aproximadamente un 70% y siendo base de la generación de energía eléctrica europea en un 60%. El carbón sin duda seguirá teniendo una contribución clave. Este incremento en la demanda energética y energía eléctrica, en el consumo de carbón y de combustibles fósiles en general, sin duda tendrá impacto sobre los niveles de concentración de CO2 a nivel global en los diferentes escenarios evaluados, con un fatal pronóstico de triplicar, si no se contiene de alguna manera su emisión, los niveles actuales de concentración de CO2 hasta valores próximos a 1.200 ppm para finales de este siglo XXI. El Protocolo de Kyoto, adoptado en 1997, fue el primer tratado de responsabilidad a nivel mundial para el monitoreo y limitación de las emisiones de CO2, realizando una primera aproximación hasta el año 2012 y tomando como valores de referencia los referidos a los niveles de concentración de gases de efecto invernadero registrados en 1990. Algunos de los principales países emisores de CO2 como USA y China no ratificaron los objetivos de límite de emisión y niveles de reducción de CO2, y sin embargo están tomando sus propias acciones y medidas en paralelo para reducir sus emisiones. Los procesos de combustión más eficientes y con menor consumo de combustible, proporcionan una significativa contribución del sector de generación eléctrica a la reducción de los niveles de concentración de CO2, pero podría no ser suficiente. Tecnologías de captura y almacenamiento de carbono (CCS, del inglés Carbon Capture and Storage) han comenzado a ganar más importancia desde principios de esta década, se ha intensificado la investigación y proliferado la creación de fondos que impulsen su desarrollo y estimulen su despliegue. Tras los primeros proyectos de investigación básica y ensayos a pequeña escala, casi embrionaria, tres procesos de captura se posicionan como los más viables actualmente, con potencial para alcanzar niveles de reducción de CO2 del 90%, mediante su aplicación en centrales de carbón para generación eléctrica. En referencia al último paso del esquema CCS en el proceso de reducción de las ingentes cantidades de CO2 que habría que eliminar de la atmósfera, dos opciones deberían ser consideradas: la reutilización (EOR y EGR) y el almacenamiento. El presente artículo evalúa el estado de las diferentes tecnologías de captura de CO2, su disponibilidad, su desarrollo y su coste de instalación estimado. Se incorpora un pequeño análisis de los costes de operación y varias extrapolaciones, dado que solo están disponibles algunos de estos datos hasta la fecha. Además este artículo muestra los principales hallazgos y los potenciales de reducción de emisiones de CO2 en la utilización del carbón para generar electricidad y proporciona una visión del desarrollo y despliegue actual de la tecnología. Se realiza una revisión de las iniciativas existentes a nivel mundial mediante proyectos de demostración orientados a la viabilidad comercial del esquema CCS para el período 2020 ? 2030. Se evalúan los diferentes programas en curso y sus avances, como el programa de UK, el EEPR (European Energy Program for Recovery), etc. Las principales fuentes empleadas en la elaboración de este artículo son el DOE, NETL, MIT, EPRI, Centros e Institutos de Investigación, Universidades Europeas, Administraciones Públicas y Agencias Internacionales, suministradores de tecnología crítica, compañías eléctricas (utilities) y empresas tecnológicas.

Electricity price forecasting accounting for renewable energies: optimal combined forecasts

Electricity price forecasting is an interesting problem for all the agents involved in electricity market operation. For instance, every profit maximisation strategy is based on the computation of accurate one-day-ahead forecasts, which is why electricity price forecasting has been a growing field of research in recent years. In addition, the increasing concern about environmental issues has led to a high penetration of renewable energies, particularly wind. In some European countries such as Spain, Germany and Denmark, renewable energy is having a deep impact on the local power markets. In this paper, we propose an optimal model from the perspective of forecasting accuracy, and it consists of a combination of several univariate and multivariate time series methods that account for the amount of energy produced with clean energies, particularly wind and hydro, which are the most relevant renewable energy sources in the Iberian Market. This market is used to illustrate the proposed methodology, as it is one of those markets in which wind power production is more relevant in terms of its percentage of the total demand, but of course our method can be applied to any other liberalised power market. As far as our contribution is concerned, first, the methodology proposed by García-Martos et al(2007 and 2012) is generalised twofold: we allow the incorporation of wind power production and hydro reservoirs, and we do not impose the restriction of using the same model for 24h. A computational experiment and a Design of Experiments (DOE) are performed for this purpose. Then, for those hours in which there are two or more models without statistically significant differences in terms of their forecasting accuracy, a combination of forecasts is proposed by weighting the best models(according to the DOE) and minimising the Mean Absolute Percentage Error (MAPE). The MAPE is the most popular accuracy metric for comparing electricity price forecasting models. We construct the combi nation of forecasts by solving several nonlinear optimisation problems that allow computation of the optimal weights for building the combination of forecasts. The results are obtained by a large computational experiment that entails calculating out-of-sample forecasts for every hour in every day in the period from January 2007 to Decem ber 2009. In addition, to reinforce the value of our methodology, we compare our results with those that appear in recent published works in the field. This comparison shows the superiority of our methodology in terms of forecasting accuracy.

Effect of cage type on the behaviour pattern of rabbit does at different physiological stages

Interest in commercially farmed rabbit welfare has increased in recent years. As a result, new alternative housing systems have been developed, although they require evaluation in order to demonstrate their potential for improving welfare. The aim of this trial was to study the behavioural traits of rabbit does housed in 2 different types of cage (TC): conventional vs. alternative with an elevated platform, at different physiological stages (PS); lactation and gestation. Behavioural observations were carried out on 12 rabbit commercial does using continuous 24 h video recording. Independently of PS and TC, rabbit does spent most of their time on foot mats (on av. 57.7%). However, due to the use of platforms (on av. 23.0% of time), lactating does spent 36.6% less time on foot mats (P<0.001) and gestating does spent 27.0% less time on wire mesh (P<0.001) in alternative cages than in conventional cages. Alternative cages allowed for standing posture, but this behaviour was only observed in gestating does (on av. 4.6 times a day). Frequency of drinking was higher in conventional than in alternative cages (24.6 vs. 19.1 times a day; P<0.05). Gestating does housed in conventional cages reached the highest duration and frequency of interacting with neighbours (276 s/d and 4.6 times/d; P<0.05). The frequency of interacting with kits was lower in alternative than in conventional cages (2.4 vs. 8.6 times a day; P<0.01). Doe behaviour was influenced by the time of day, with less activity during the midday hours. During dark hours, rabbit does more frequently performed restless behaviour such as hyperactivity or nursing, matching the time at which rabbit does spent more time on the platform. The platform was frequently used by rabbit does, regardless of their physiological stage, and during late lactation phase, when mothers were not receptive to nursing, does housed in alternative cages used the platform as a mean to flee from kits trying to suckle. Use of the platform might lead to hygienic problems due to retained faeces on the platform and faeces and urine falling onto animals located in the lower part of the cage. The absence of stereotypies in rabbit does of this trial, suggested that animal welfare was not compromised by the type of housing (conventional or alternative cages).

Effect of late weaning and use of alternative cages on performance of does, suckling and fattening rabbits under extensive reproductive management

The effects of the combined use of long lactation periods (46 days) with alternative cages on the reproductive and growth performance of 104 rabbit does and their litters during five consecutive reproductive cycles were studied. Half of does were housed in conventional polyvalent cages (39 cm×100 cm×30 cm) and the other half in alternative polyvalent cages (39 cm×100 cm×60 cm), with a raised platform. Half of the rabbit does in each type of cage were weaned at 32 and the other half at 46 days after parturition. Longer lactation negatively affected the body weight (P<0.001), fat and energy content (P<0.05) of rabbit does at the end of the lactation period, but this effect decreased with the number of parturitions. Fertility, prolificacy and doe mortality were not affected by lactation length. Late weaning led to higher litter size (by 8.9%) and litter weight (by 11.3%) at the end of growing period (P<0.001) and lower feed conversion ratio per cage during the experimental period (13.5%) than weaning at 32 day (P<0.001). These results were paralleled by lower mortality (12.6 vs. 17.6%; P<0.01) of young rabbits weaned later during the overall experimental period. Differences in performance as a result of different weaning ages were only observed during cycles with worst health status (third and fifth cycles) in which late weaning decreased mortality. Type of cage did not affect doe body weight and body condition, mortality, fertility, prolificacy and litter size during the five reproductive cycles. Nevertheless, at day 21 litter weight and feed conversion ratio between 3 and 21 day were 4.2% higher (P<0.01) and 5.0% lower (P<0.05), respectively, in animals housed in alternative rather than in conventional cages. Alternative cages also led to heavier litters at 59 days (P<0.01). It was concluded that the combined use of longer lactations and cages with higher available surface with a raised platform could be alternatives to improve animal welfare in farmed rabbit.

Effect of late weaning and use of alternative cages on performance of does, suckling and fattening rabbits under extensive reproductive management

The effects of the combined use of long lactation periods (46 days) with alternative cages on the reproductive and growth performance of 104 rabbit does and their litters during five consecutive reproductive cycles were studied. Half of does were housed in conven- tional polyvalent cages (39 cm x 100 cm x 30 cm) and the other half in alternative polyvalent cages (39 cm x 100 cm x 60 cm), with a raised platform. Half of the rabbit does in each type of cage were weaned at 32 and the other half at 46 days after parturition. Longer lactation negatively affected the body weight ( P o 0.001), fat and energy content ( P o 0.05) of rabbit does at the end of the lactation period, but this effect decreased with the number of parturitions. Fertility, prolificacy and doe mortality were not affected by lactation length. Late weaning led to higher litter size (by 8.9%) and litter weight (by 11.3%) at the end of growing period ( P o 0.001) and lower feed conversion ratio per cage during the experimental period (13.5%) than weaning at 32 day ( P o 0.001). These results were paralleled by lower mortality (12.6 vs. 17.6%; P o 0.01) of young rabbits weaned later during the overall experimental period. Differences in performance as a result of different weaning ages were only observed during cycles with worst health status (third and fifth cycles) in which late weaning decreased mortality. Type of cage did not affect doe body weight and body condition, mortality, fertility, prolificacy and litter size during the five reproductive cycles. Nevertheless, at day 21 litter weight and feed conversion ratio between 3 and 21 day were 4.2% higher ( P o 0.01) and 5.0% lower ( P o 0.05), respectively, in animals housed in alternative rather than in conventional cages. Alternative cages also led to heavier litters at 59 days ( P o 0.01). It was concluded that the combined use of longer lactations and cages with higher available surface with a raised platform could be alternatives to improve animal welfare in farmed rabbit.

Reproductive and nutritional management on ovarian response and embryo quality on rabbit does

Rabbit does in modern rabbitries are under intensive reproductive rhythms. Females are high milk producers with high energetic expenses due to the extensive overlap between lactation and gestation. This situation leads to a negative energy balance with a mobilization of body fat especially in primiparous rabbit does. Poor body condition and poor health status severely affect the reproductive features (fertility rate and lifespan of the doe as well as ovarian physiology). This paper reviews some reproductive and nutritional approaches used in the last years to improve the reproductive performance of rabbit females, mainly focusing on the influence on ovarian response and embryo quality and with emphasis on epigenetic modifications in pre-implantation embryos and offspring consequences.