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Estudio detallado del sismo de Pino Solo, Baja California, México, del 8 de mayo de 1985

Mario González Escobar (1987)

Se determinaron los epicentros y el mecanismo focal para el sismo del 8 de mayo de 1985 (ML = 5.1) y sus réplicas, ocurrido en el área de Pino Solo, Baja California, México. Para esto, se analizaron los datos proporcionados por estaciones de las redes sísmicas permanentes del norte de Baja California, U.S.A. (CALTECH/USGS) y de una red temporal de sismógrafos analógicos y digitales instalada después del evento principal.

El epicentro del sismo principal se localizó a alrededor de 10 km al norte del epicentro calculado por Nava y Brune (1983) para un temblor de igual magnitud ocurrido en julio de 1975. La zona de réplicas no muestra una tendencia definida en su distribución epicentral, mientras que los hipocentros fueron localizados a profundidades de entre 1.5 y 10km.

Tanto el sismo principal como la zona de réplicas se encuentran entre las fallas de San Miguel y Sierra Juárez, donde no se tiene mapeada falla alguna. Invluyendo lo reportado por Nava y Brune (1983), la ocurrencia de los sismos que se reportan en este artículo indican la existencia de una falla geológica que no se manifiesta superficialmente.

Los mecanismos focales obtenidos para el evento principal y sus réplicas reflejan el patrón tectónico dominante que rige los sistemas de fallas en la región, el cual consiste en fallas del rumbo con dirección noroeste-suroeste (dextro).

Para algunas de las réplicas principales, registradas de forma digital, se calculó la magnitud local mediante la generación de sismogramas Wood-Anderson equivalentes, para lo cual se empleó la metodología de Kanamorl y Jennins (1978).

Para algunas réplicas fue posible determinar también su momento sísmico. Estos resultados son consistentes por los resultados obtenidos por Vidal (1987), y permitieron obtener una relación empírica de momento sísmico-magnitud local para la región del macizo rocoso peninsular. De la comparación de los sismogramas de estaciones de la red mundial (WWSSN) que se registraron los eventos de Pino. Solo de 1975 y 1985, se observó una gran similitud entre ambos eventos, lo cual sugiere que los procesos de ruptura de estos sismos fueron muy similares (hipocentro y tensor de momentos).

El momento sísmico para el evento principal de Pino solo de 1985 se obtuvo mediante la síntesis de ondas superficiales en cinco estaciones de la red mundial, ubicada en el suroeste de Estados Unidos. Estos sismogramas sintéticos fueron comparados directamente con los sismogramas observados en las estaciones.

Master thesis

Sismo Pino Solo Baja California Sismogramas Wood-Anderson Metodología de Kanamorl y Jennins CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO

Diversity and deadwood-based interaction networks of saproxylic beetles in remnants of riparian cloud forest

ALFREDO RAMIREZ HERNANDEZ ANA PAOLA MARTINEZ FALCON Estefanía Micó Sandra Almendarez Pedro Reyes Castillo FEDERICO ESCOBAR SARRIA (2019)

"We studied the saproxylic beetle community inhabiting deadwood in remnants of riparian cloud forests in "La Antigua" basin, in central Veracruz (Mexico). We assessed the influence of deadwood features (tree species, trunk position, trunk diameter, trunk volume and decomposition stages) on saproxylic beetle diversity. In order to assess the stability of beetle species-deadwood interactions, we also analyzed the ecological networks structure. A total of 63 deadwood trunks, belonging to four tree species, were sampled by standardized hand-collection throughout well-preserved remnants of riparian cloud forest. We found that tree species and deadwood decay stage are the main drivers that determine the diversity and stability of saproxylic beetle species interactions. Our results indicate that Quercus corrugata is the main tree species in terms of maintaining the significantly highest saproxylic beetle diversity, but with no stable interactions (saproxylic beetle-deadwood). A nested network structure was detected for Clethra mexicana and Liquidambar styraciflua, with a pool of core (generalist) saproxylic beetle species. We observed that beetle diversity from the early and late deadwood stages comprises distinct assemblages and the four stages of decomposition showed a nested network structure. During deadwood succession, community composition and guilds changed among networks; the early successional stage had more specialized xylophagous beetles, while other guilds (mycophagous, saprophagous and zoophagous) arrive later and become the core species in the advanced stages of decomposition networks. Heliscus tropicus (Passalidae) is a key species constituting the core of all of the networks and could be considered an ecosystem engineer in cloud forests. By exploring links between saproxylic beetles and deadwood characteristics, we can further our understanding of species interaction in order to develop management strategies oriented towards the protection of species and their habitats in this threatened ecosystem."

Article

Beetles Species interactions Cloud forests Wood Trees Decomposition Forests Species diversity INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS CIENCIAS TECNOLÓGICAS

Variaciones morfo-anatómicas de seis especies a lo largo de un gradiente altitudinal en el Cerro Tláloc, Estado de México

MAYTE STEFANY JIMENEZ NORIEGA (2014)

Tesis (Maestría en Ciencias, especialista en Botánica).- Colegio de Postgraduados, 2014.

Las condiciones ambientales asociadas a gradientes altitudinales inducen modificaciones de las características morfo-anatómicas de las especies que ahí se encuentran. Las variaciones morfo-anatómicas en regiones intertropicales han sido poco documentadas. Se espera que los patrones relacionados con estos gradientes altitudinales serán similares a aquellos registrados en regiones fuera de la zona intertropical. Se estudiaron seis especies (Acaena elongata, Alchemilla procumbens, Geranium seemannii, Lupinus montanus, Ribes ciliatum y Symphoricarpos microphyllus) que se distribuyen en el gradiente altitudinal del Cerro Tláloc, Estado de México con el objetivo de reconocer y evaluar las modificaciones morfo-anatómicas asociadas al gradiente. Se recolectaron tres plantas/especie/sitio y se prepararon con la microtecnia convencional. Los caracteres cuantitativos se sometieron a análisis de varianza y de regresión múltiple. Los resultados indican que las especies tienen tres formas de vida (criptófita, hemicriptófita y fanerófita). Las hemicriptófitas y fanerófitas redujeron su talla a mayor altitud. A nivel de anatomía foliar únicamente R. ciliatum disminuyó en el mesofilo como ha sido registrado por otros autores. La epidermis adaxial presentó diferencias significativas entre los sitios, pero con tendencias opuestas en las especies, además de disminuir o aumentar, en los extremos del gradiente dependiendo de la especie. Para el área foliar y el peso seco de la hoja hubo diferencias significativas, pero tampoco había tendencias claras con respecto al gradiente. La altitud explicó parte de la variación para el ancho del mesofilo en A. procumbens, G. seemannii, L. montanus y R. ciliatum. En la madera el diámetro de los vasos disminuyó en los sitios de mayor altitud a excepción de A. elongata, en la que aumento. La densidad de vasos fue la variable más sensible al gradiente altitudinal. La altitud explicó los cambios anatómicos en la madera de S. microphyllus, mientras que en las otras cinco especies fueron la cobertura, la materia orgánica y la altitud. Se concluye que cada especie tiene modificaciones propias, pero que algunos caracteres de la hoja y la madera presentan una respuesta similar al gradiente altitudinal de otras especies fuera de los subtrópicos. A diferencia de otras investigaciones, los caracteres anatómicos de las especies analizadas tienden a disminuir en tamaño, pero no lo hacen gradualmente, sino hacia los extremos del gradiente, o sea, tienen un comportamiento bimodal, posiblemente relacionado con cambios en la vegetación del dosel. _______________ ABSTRACT: Environmental conditions associated with altitudinal gradients induce morpho-anatomical changes in species distributed along these gradients. However, the morpho-anatomical variation in species distributed along altitudinal gradients in the inter-tropical regions is poorly documented. We expect that the patterns associated to altitudinal gradients to be similar to those recorded in regions outside the intertropics. Six species (Acaena elongata, Alchemilla procumbens, Geranium seemannii, Lupinus montanus, Ribes ciliatum, and Symphoricarpos microphyllus) distributed along the altitudinal gradient at Cerro Tlaloc in Sierra Nevada, State of Mexico, Mexico, were studied with the aim to recognize and evaluate the morpho- anatomical changes associated to the altitudinal gradient. Three plants per species per site were collected and prepared with conventional microtechniques. Quantitative characters were subjected to analysis of variance and multiple regressions. The results showed that the species studied belonged to three life forms (cryptophyte, hemicryptophyte and phanerophyte). The hemicryptophytes and phanerophytes reduced their size at higher altitudes. In terms of leaf anatomy only R. ciliatum decreased in its mesophyll size as it has been recorded by other authors. The adaxial epidermis showed significant differences (P < 0.05) between sites, but with opposite tendencies in the species as well as decreasing or increasing. Leaf area and leaf dry weight also showed significant differences, but without a clear trend in relation with the gradient. Altitude predicted part of the variation in the mesophyll width of A. procumbens, G. seemannii, L. montanus, and R. ciliatum . For wood, vessel diameter decreased towards higher altitudes except for A. elongata, in which it increased. Vessel densitywas the most sensitive character to the altitudinal gradient. The altitude explained most of the anatomical changes in the wood of S. microphyllus, while in the other five species vegetation cover and soil organic matter also contributed to explain wood variation. In conclusion, each species has its own modifications, but some leaf and wood characters showed a similarresponse to altitude as other species outside the subtropics region. Unlike other studies, the anatomical characters of most species studied tend to decrease in size, but not gradually, instead they decreased towards the lowest or highest sites of the gradient; that is, they have a bimodal behavior, possibly related to changes in the canopy vegetation.

Master thesis

Anatomía Morfología Variación Gradientes altitudinales Madera Anatomy Morphology Altitude Variation Altitudinal gradients Wood Botánica Maestría CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Study of critical disordered systems coupled to the continuum

NAHUM CALDERON CHAVEZ (2020)

“In this thesis, we study paradigmatic quantum systems coupled to external environments which can be unbounded or bounded. An unbounded external environment can be characterized by few decay channels, where the excitation can be lost. Due to the competition of the states of the system to decay in few channels of the external environment, cooperative eects such as superradiance and subradiance can be induced. Together with the coupling to an unbounded environment, we also consider a bounded external environment. Such coupling will induce a transition to a gapped regime, where the ground state is separated from the other excited states. In order to study the eect of the coupling to external environments on quantum transport, we intend to analyze three dierent models. e rst model that we consider is the Power-law Banded Random Matrix (PBRM) model. E PBRM represents 1D tight-binding chains with long-range random hopping.”

Doctoral thesis

Fenómeno crítico (Física) Superradiancia Teoría cuántica Mecánica cuántica Modelo de Anderson CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Study of critical disordered systems coupled to the continuum

NAHUM CALDERON CHAVEZ (2020)

"In this thesis, we study paradigmatic quantum systems coupled to external environments which can be unbounded or bounded. An unbounded external environment can be characterized by few decay channels, where the excitation can be lost. Due to the competition of the states of the system to decay infew channels of the external environment, cooperative eects such as superradiance and subradiance can be induced. Together with the coupling to an unbounded environment, we also consider a bounded external environment. Such coupling will induce a transition to a gapped regime, where the ground state is separated from the other excited states."

Doctoral thesis

Matrices aleatorias Sistemas cuánticos Modelo de Anderson CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Structural characterization of lignin in four cacti wood: Implications of lignification in the growth form and succulence

Jorge Reyes Rivera Ramón Marcos Soto Hernández GONZALO CANCHE ESCAMILLA Teresa Terrazas (2018)

Wood lignin composition strongly depends on anatomical features and it has been used as a marker for characterizing major plant groups. Wood heterogeneity in Cactaceae is involved in evolutionary and adaptive processes within this group; moreover, it is highly correlated to the species growth form. Here we studied the lignin structure from different types of woods in four Cactaceae species with different stem morphologies (Pereskia lychnidiflora, tree/fibrous wood; Opuntia streptacantha and Pilosocereus chrysacanthus, tree/succulent fibrous wood; Ferocactus hamatacanthus, cylindrical stem/dimorphic wood) in order to determine their relationship with the wood anatomy in an evolutionary-adaptive context. Dioxane lignin was isolated and analyzed by pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS), two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The main linkages are the β-O−4′ ether (67–85%), the β-β′ resinol (10–26%) and the β-5′ and α-O−4′ linkages of the phenylcoumaran structures (≤7%). Spirodienone structures have a considerable abundance (5%) in the dimorphic wood of F. hamatacanthus. In addition, low contents (≤3%) of α,β-diaryl ether, α-oxidized β-O−4′ ether and dibenzodioxocin structures were found. The sinapyl- and coniferyl acetates are not part of the wood lignin in any of the studied species. The low (≤5%) γ-acetylation in the F. hamatacanthus and P. chrysacanthus wood lignin is here interpreted as an evidence of a high specialization of the wood elements in the conduction/storage of water. The lignin of the studied Cactaceae is composed predominantly of guaiacyl and syringyl units (S/G: 0.9–16.4). High abundance of syringyl units (62–94%) in three of the four species is considered as a defense mechanism against oxidative agents, it is a very conspicuous trait in the most succulent species with dimorphic wood. Furthermore, it is also associated with ferulates and the herein called γ-acetylated guaiacyl-syringaresinol complexes acting as nucleation sites for lignification and as cross-links between lignin and carbohydrates at the wide-band tracheid-fiber junctions.

Article

CACTACEAE DIMORPHIC WOOD EVOLUTIONARY-ADAPTIVE PROCESSES S-RICH LIGNIN STRUCTURAL PROTECTION SUCCULENCE BIOLOGÍA Y QUÍMICA BIOLOGÍA Y QUÍMICA

Retención y absorción de solución de sales de boro de diez maderas mexicanas

Retention and absorption of boron salts solution of ten mexican woods

JAVIER RAMON SOTOMAYOR CASTELLANOS JOSE MARIA VILLASEÑOR AGUILAR (2016)

Las sales de boro son un agente protector para la madera con un amplio espectro en su acción fungicida e insecticida, de poca toxicidad, inodoras, incoloras e incombustibles, y su aplicación es una de las estrategias más efectivas de preservación. La presente investigación tuvo por objetivo determinar la densidad de la madera, la absorción y la retención de sales de boro de diez maderas mexicanas. Se propuso como hipótesis de trabajo que la capacidad de retención de sales de boro de la madera depende, principalmente, de la especie, y es independiente de la densidad y de la porosidad. Se prepararon 30 litros de solución de sales de boro con una concentración al 3%. Las probetas se impregnaron con el método baño caliente-frío. Se diseñó un experimento de análisis de varianza para comparar los valores medios de la densidad de la madera, de la absorción y de la retención, como las variables de respuesta, evaluadas para cada una de las diez especies de madera. La especie de madera fue considerada el factor de variación. La absorción de sales de boro varió entre 136 kg/m3 y 476 kg/m3. Los valores promedio de retención de sales de boro para todas las especies fueron mayores que el límite inferior tóxico de retención comprendido en el intervalo de retención que va de 0.2 kg/m3 a 4.7 kg/m3, reportado en trabajos anteriores. Se concluye que cada especie tiene una retención de sales de boro diferente, y la capacidad de absorción es particular a cada una de ellas y no está relacionada con su densidad.

Boron salts are a wood protector agent with a wide spectrum in their fungicidal and insecticide action and of low toxicity, odorless, colorless and nonflammable, and their application is one of the most effective preservation strategies. This research aims to determine the density of wood, absorption and retention of the boron salts of ten Mexican woods. The working hypothesis proposed in this investigation is that wood retention capacity of boron salts depends mainly on the species and is independent of its density and porosity. Thirty liters of boron salts solution with a concentration of 3 % were prepared, the wood specimens were impregnated by following the “hot-cold bath” method. It was designed an experiment that compared means of the density of wood, the absorption and the retention, as the response variables, assessed for each one of the ten wood species. Wood species was considered as the variation factor. Absorption of Boron salts varied between 136 kg/m3 and 476 kg/m3. Average values of the boron salts retention for all species were higher than lower retention toxicity limit reported in previous researches (0.2 kg/m3 to 4.7 kg/m3). It was concluded that each species has different boron salts retention. Absorption capacity is specific to each species and it is not related to the wood density.

Article

BIOLOGÍA Y QUÍMICA Densidad Preservación de la madera Baño caliente-frío Porosidad. Density Wood preservation Hot-cold bath Porosity

Pellets from forest waste: A viable alternative fuel in Mexico

IGNACIO MARTIN MONICA MORENO LOPEZ MARIA TERESA ALARCON HERRERA (2011)

The search for non-fossil fuels is a task of global interest. In the case of Mexican forest waste (sawdust,

splinters, and woodchips), it is estimated that 45% of this biomass is discarded as garbage rather than used industrially.

The production of wood pellets is a viable alternative for the recovery of wooden waste from wood processing, forestry,

and other industrial uses (such as the wooden pallets used with forklifts for the transport and storage of manufactured

goods). Wood pellets are compressed cylinders between 6 and 10mm in diameter, used for generating thermal energy.

The increase in European pellet consumption has promoted the construction of many pelletizing plants in that continent,

and this trend has extended to Africa, North America, and South America. In Mexico, however, this industry does not yet

exist despite the fact that 72% of the national territory is dedicated to various forestry uses. The State of Chihuahua,

located in northern Mexico, has the second largest timber production in the country. This research project encompassed

the 10 most significant sawmills in the region of Ciudad Madera, Chihuahua. Their timber resources and their generation

rates were analyzed and quantified. The purpose of this project was to determine the technical feasibility of developing a

pelletizing industry in the state of Chihuahua, Mexico.

Article

Wood pellets Biofuel BIOLOGÍA Y QUÍMICA QUÍMICA BIOQUÍMICA TECNOLOGÍA DE LA CONSERVACIÓN

La madera auxiliar en la construcción y su huella ecológica: caso de la superficie de contacto de la tarima

MARIA SUSANA BIANCONI BAILEZ (2012)

Se diseña una tarima de cimbra alternativa, con material reciclado, para contrarrestar el uso indiscriminado de madera en la construcción del concreto armado. Se presenta esta problemática en el estado de México y se relaciona con el consumo de madera talada clandestinamente. Se grafica el ciclo de vida de la tarima para cimbra de construcción y se comparan parámetros y desempeños de nuestra propuesta, a la que llamamos tarima híbrida y la tarima convencional. Se sugiere contrarrestar el mal uso del recurso madera asociado a la factura in situ del concreto armado mediante el uso de este nuevo diseño.

An alternative framework is designed, based on recycled material, to tend to diminish the irrational use of wood. Wood related problems in concrete construction in the State of Mexico are presented, and this issue is related to the illegal harvest of timber. The wood framework life cycle assessment is graphed and several parameters are compared between our proposed hybrid frame and the conventional one. This new design is proposed to mitigate the irrational use of timer in the making of daily concrete building in situ

.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA Madera Tala Cimbra Ciclo de vida Tarima híbrida Timber Prune Wood framework Life cycle assessment Hybrid frame

Efecto del genotipo sobre características de la curva de lactación de ovinos en una unidad de producción en el altiplano

JUAN CARLOS ANGELES HERNANDEZ ARACELI DE JESUS GUERRERO LOREDO DIANA ARELY SOLIS GUZMAN AURORA HILDA RAMIREZ PEREZ SERGIO CARLOS ANGELES CAMPOS Manuel González Ronquillo (2018)

The aim of this study was to analyze the milk production and characteristics of the lactation curve of six sheep genetic groups. Were analyzed 863 weekly milk production records of 70 lactations of six genetic groups: East Friesian (EF), Criollo (Cr), EF ½ Cr ½ (EF50Cr50), EF ¾ Cr ¼ (EF75Cr25), Suffolk ½ Cr ½ (Suffolk50Cr50), and Corriedale (C). The function of Wood (WD) was used to estimate the actual total milk yield (PLTobs) and estimated total milk yield at day 180 (PLT180), peak lactation (PL), time at peak lactation (tPL) and persistence (Per). The genetic group influenced significantly (P < 0.05) on PLTobs, PLT180, PL and parameter b of WD model, with highest values of EF50Cr50 sheep. The observed differences in productive performance in relation with the genetic group could be associated with deficiencies in the adaptability of EF sheep to local agro-climatic conditions.

Al proyecto PAPIME 204411, Asuntos de Personal Académico General de la UNAM. Al Consejo Nacional de Ciencia y Tecnología (CONACYT) por las becas otorgadas a Diana Arely Solís, Juan Carlos Ángeles y Araceli Guerrero. A Arturo Arellano su apoyo y a la Srta. Liz Hopper, de la Universidad del Norte de Texas por la revisión crítica del presente manuscrito.

Article

pico de lactancia ovejas lecheras modelo de Wood East Friesian CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA