Effects of Different Feed Additives on Methane Emissions from Beef Cattle

The rate of accumulation of methane in the atmosphere from enteric fermentation in cattle has an important impact on the greenhouse effect and contributing to global warming. Additionally, methane emission reduces the energy efficiency of substrate fermention in the rumen. Under-standing the effect of the diet on enteric methane emissions could help to identify strategies to reduce emissions of this greenhouse gas. Therefore, the main objective of the present investigation was to determine the effect of nutritional additives such as monensin, fumaric acid, tannins of Acacia decurrens, and glycerol on methane production and other measures of fermentation characteristics using the in vitro rumen fermentation technique and ruminal fluid obtained from cattle fed with a base diet of Pennisetum clandestinum

Fermentation Parameters of Kikuyu Grass (\u3cem\u3ePennisetum clandestinum\u3c/em\u3e) by \u3cem\u3ein Vitro\u3c/em\u3e Gas Production Technique (IVGPT)

Methane (CH4) is a byproduct of ruminal fermentation whose production is directly related to forage quality, which in turn is affected by a myriad of environmental factors. In general the quality of pastures in the tropics range from medium to poor due to a high content of lignocellulosic material of low digestibility and a low content of other components, such as soluble carbohydrates and protein (Correa et al, 2008). CH4 produced by enteric fermentation from cattle rumen represents a major source of greenhouse gases (GHG). By measuring these emissions the impact of dairy production systems on the climate change can be determine. In Colombia and in specifically in the Department of Antioquia, dairy herds are characterized by using diets based on kikuyu grass (Pennisetum clandestinum) supplemented with concentrates. Once in the rumen the forage /concentrate combination are used as substrate for ruminal fermentation to generate usable energy but also unusable one represented by methane production. The energy losses due to diets based on kikuyu are unknown. Thus, the measurement of its fermentation products has become an important necessity in order to achieve greater efficiencyin the livestock production systems which are also environmentally friendly and economically competitive. Despite some important progress in Colombia, the potential impact of livestock on global warming is still unknown so that measuring of CH4 emissions is a crucial imperative. In the dairy zone located in the northern part of Antioquia, where daily two millions liters of milk are produced, there are around 185,000 ha in kikuyu pasture. The overall objective of this research was to measure the parameters of fermentation and CH4 production of kikuyu pastures from dairy systems of Antioquia, using the in vitro gas production technique (IVGPT)

Las ontologías en la ingeniería de software: un acercamiento de dos grandes áreas del conocimiento

Los conceptos ontológicos se suelen acercar más a la ingeniería del conocimiento, por lo que los ingenieros del software no los suelen aplicar para resolver problemas de su área. Es necesario que los ingenieros de software se apropien de las ontologías, pues éstas proporcionan un vocabulario común, que podría contribuir en la solución de problemas recurrentes en ingeniería del software, tales como la dificultad de la comunicación entre analista e interesado para definir los requisitos de un sistema, la baja reutilización de componentes y la escasa generación automática de código, entre otros. En este artículo se presenta un primer enlace entre las ontologías y la ingeniería de software mediante la recopilación y análisis de la literatura relativa a la utilización de las ontologías en las diferentes fases del ciclo de vida de un producto de software

Análisis de señales de audio utilizando la transformada de Gabor

La transformada de Gabor es una caso especial de la transformada en tiempo corto de furier (STFT por sus siglas en inglés) la cual permite estimar las frecuencias de una señal en un determinando intervalo de tiempo. Para poder acotar la señal en estos intervalos, se utilizan funciones conocidas como funciones ventanas las cuales están determinadas en el dominio temporal y posibilitan el cálculo del espectrograma el cual es la gráfica de la densidad de energía de una señal definida en un plano tiempo-frecuencia. Cuando la ventana usada es una función Gaussiana, esta se conoce como la transformada de Gabor. El problema con este espectrograma es que dependiendo de la ventana escogida, los resultados podrían no ser claros y las conclusiones tomadas dependiendo de esta gráfica podrían ser erróneas. El interés de este trabajo es comparar algunas ventas de tiempo con la intención de determinar las características que hacen buena o no a las ventas. Además, se aplicará este espectrograma a una señal de audio con el objetivo de analizar las características que se pueden extraer de esta

Brachial plexus injury mimicking a spinal-cord injury.

Objective High-energy impact to the head, neck, and shoulder can result in cervical spine as well as brachial plexus injuries. Because cervical spine injuries are more common, this tends to be the initial focus for management. We present a case in which the initial magnetic resonance imaging (MRI) was somewhat misleading and a detailed neurological exam lead to the correct diagnosis.Clinical presentation A 19-year-old man presented to the hospital following a shoulder injury during football practice. The patient immediately complained of significant pain in his neck, shoulder, and right arm and the inability to move his right arm. He was stabilized in the field for a presumed cervical-spine injury and transported to the emergency department.Intervention Initial radiographic assessment (C-spine CT, right shoulder x-ray) showed no bony abnormality. MRI of the cervical-spine showed T2 signal change and cord swelling thought to be consistent with a cord contusion. With adequate pain control, a detailed neurological examination was possible and was consistent with an upper brachial plexus avulsion injury that was confirmed by CT myelogram. The patient failed to make significant neurological recovery and he underwent spinal accessory nerve grafting to the suprascapular nerve to restore shoulder abduction and external rotation, while the phrenic nerve was grafted to the musculocutaneous nerve to restore elbow flexion.Conclusion Cervical spinal-cord injuries and brachial plexus injuries can occur by the same high energy mechanisms and can occur simultaneously. As in this case, MRI findings can be misleading and a detailed physical examination is the key to diagnosis. However, this can be difficult in polytrauma patients with upper extremity injuries, head injuries or concomitant spinal-cord injury. Finally, prompt diagnosis and early surgical renerveration have been associated with better long-term recovery with certain types of injury

Colombian Energy Market: Optimal Portfolio

This paper focuses on the study of an optimal portfolio in the Colombian Energy Market using the Artificial Intelligence techniques specifically, Fuzzy Modeling and Neural Networks. The methodology at first, is implemented using the Matlab Fuzzy Logic Toolbox and with the help of a script the process is automatized. Secondly, a Neural Network is implemented in Matlab and its results are compared with the ones obtained in the Matlab Neural Network Toolbox. The results of the Fuzzy model and the Neural Network are presented and conclusions of both techniques are discussed. Finally possible future work are proposed

Adsorción de compuestos fenólicos sobre carbones activados modificados químicamente: efecto del sustituyente en el anillo aromático en las interacciones carbón activado-adsorbato

Se estudió la adsorción de Acetaminofén (4-Hidroxiacetanilida) y Ácido Salicílico (Ácido 2- Hidroxibenzoico) desde solución acuosa en tres carbones activados con diferente química superficial, se llevó acabo la adsorción de Fenol en los mismos adsorbentes con el objetivo de comparar el efecto del sustituyente en el proceso de adsorción. Se emplearon tres carbones activados que presentan distinto contenido de grupos oxigenados; un carbónactivado oxidado con HNO3 (CAO), un carbón activado granular (CAG) y un carbón reducido (CAR)a 1173 K, con el objetivo de evaluar el efecto de los grupos funcionales oxigenados en la adsorción de los compuestos de estudio, se determinó que el aumento en el grado de oxidación superficial en el carbón activado desfavorece el proceso de adsorción de los tres compuestos. Debido a la relación que existe entre la adsorción y las interacciones adsorbato-adsorbente se realizó un estudio calorimétrico para estudiar los cambios energéticos entre los solutos y el carbón activado CAR, que corresponde al carbón activado con mayor capacidad de adsorción para el Acetaminofén, Ácido Salicílico y Fenol

Adsorción de dióxido de carbono a diferentes presiones sobre carbones activados obtenidos por activación química

Se preparan carbones activados de tipo granular, obtenidosmediante la activación química pericarpio de palma africana, Elaeis Guineensis, con soluciones de 32 y 48 % de H3PO4, 32 % de ZnCl2 y 3 % de CaCl2 para obtener diferentes estructuras porosas. Se estudió la capacidad de adsorción de dióxido de carbono a presiones de saturación a 273 K y presiones hasta 45 bar y a una temperatura de 298 K, en equipos volumétricos de adsorción, con resultados, para las cantidades máximas de adsorción de CO2, de 180 mg CO2 g-1 a 1 bar y 273 K y de 720 mg CO2 g-1 para 45 bar y 298K. Se establecieron correlaciones entre las característicastexturales de los materiales y la capacidad de adsorción de CO2, obteniéndose una relación proporcional directa para entre los valores de capacidad de adsorción y de área superficial cuando los carbones activados se someten a presión. Los resultados experimentales indicaron que la capacidad de adsorción de CO2 incrementa con el área superficial, volumen total de poro y volumen de microporo.Se determinan las entalpías de inmersión de los carbonesactivados en benceno con valores entre -45 y -78 Jg-1 y alrelacionarlos con la capacidad de adsorción de CO2 presentanun comportamiento similar al que se observa con respecto al área superficial

Contribution enthalpic in the interaction of activated carbon with polar and apolar solvents

AbstractA method is presented for calculating the contribution that enthalpies make for every component of mixtures of activated carbon–water and activated carbon–hexane to the immersion enthalpy using the concepts that are used in the solution enthalpies. The immersion enthalpies of microporous activated carbon in water and in hexane have values from −18.97 to −27.21 and −25.23 to −47.89Jg−1, respectively. From the immersion enthalpies and mass relation of the activated carbon in each of the solvents, the differential enthalpies are calculated for the activated carbon in water, HwDIFac, with values between −15.95 and −26.81Jg−1, as are the differential enthalpies for the activated carbon in hexane, ΔHhDIFac, with values between −6.86 and −46.97Jg−1. For a low mass relation of the mixture components the contributions to the immersion enthalpy of the activated carbon and water differ by 3.20Jg−1, while the difference between the contributions of the activated carbon and hexane is 19.41Jg−1

Flags in zero dimensional complete intersections and indices of real vector fields

We introduce bilinear forms in a flag in a complete intersection local $\mathbb R$-algebra of dimension 0, related to the Eisenbud-Levine, Khimshiashvili bilinear form. We give a variational interpretation of these forms in terms of Jantzen's filtration and bilinear forms. We use the signatures of these forms to compute in the real case the constant relating the GSV-index with the signature function of vector fields tangent to an even dimensional hypersurface singularity, one being topologically defined and the other computable by finite dimensional commutative algebra methods.Comment: 17 pages. v2: Some changes in the introduction. A few typos corrected. To appear in Mathematische Zeitschrif