164 research outputs found
Seguridad, estado y sociedad en México
Este trabajo pretende abordar la problemática de la seguridad en el México contemporáneo, en donde el nivel de violencia derivado de la estrategia de lucha contra la delincuencia del gobierno de Felipe Calderón cobró miles de vidas de mexicanos. El trabajo se estructura en tres grandes capítulos. En el primero, se presentan las consideraciones teóricas fundamentales sobre las tareas del estado moderno y de los gobiernos en particular; en el segundo, se plantea el contexto histórico particular de México en materia de seguridad, con los datos fundamentales sobre lo acontecido en el sexenio de Felipe Calderón; y en el tercero, se ofrece una propuesta específica de política pública en materia de seguridad
Establishing arthropod community composition using metabarcoding : Surprising inconsistencies between soil samples and preservative ethanol and homogenate from Malaise trap catches
DNA metabarcoding allows the analysis of insect communities faster and more efficiently than ever before. However, metabarcoding can be conducted through several approaches, and the consistency of results across methods has rarely been studied. We compare the results obtained by DNA metabarcoding of the same communities using two different markers - COI and 16S - and three different sampling methods: (a) homogenized Malaise trap samples (homogenate), (b) preservative ethanol from the same samples, and (c) soil samples. Our results indicate that COI and 16S offer partly complementary information on Malaise trap samples, with each marker detecting a significant number of species not detected by the other. Different sampling methods offer highly divergent estimates of community composition. The community recovered from preservative ethanol of Malaise trap samples is significantly different from that recovered from homogenate. Small and weakly sclerotized insects tend to be overrepresented in ethanol while strong and large taxa are overrepresented in homogenate. For soil samples, highly degenerate COI primers pick up large amounts of nontarget DNA and only 16S provides adequate analyses of insect diversity. However, even with 16S, very little overlap in molecular operational taxonomic unit (MOTU) content was found between the trap and the soil samples. Our results demonstrate that none of the tested sampling approaches is satisfactory on its own. For instance, DNA extraction from preservative ethanol is not a valid replacement for destructive bulk extraction but a complement. In future metabarcoding studies, both should ideally be used together to achieve comprehensive representation of the target community.Peer reviewe
Medidas multi-influencia como medio para caracterizar la firma global de un buque y proteger el entorno marino
The overall signature of a vessel comprises acoustic, magnetic, electric-field, pressure, and seismic radiations. Over the past years, the international community’s efforts have mainly centered on reducing the acoustic influence with the dual aim of decreasing the vessel’s detectability and reducing the levels of acoustic pollution generated in the marine environment. Nowadays, the need to act not only on the acoustic radiation but against the overall set of the vessel’s radiations is becoming increasingly clear, both in the military and the civilian fields, based on aspects like vessel stealthiness, security of harbor and critical infrastructures, and environmental protection. As a key element to achieve this goal, it is greatly important to have at our disposal highly modular and adaptable measurement systems covering the overall set of the vessel’s radiations, with a high capacity of data transmission to base centers to have the capacity to make measurements in all kinds of marine environments.La firma global de un buque está compuesta por radiaciones: acústica, magnética, de campo eléctrico, de presión y sísmica. A lo largo de los últimos años, los esfuerzos de la comunidad internacional se han centrado principalmente en reducir la influencia acústica, con el doble objetivo de disminuir la detectabilidad del buque y reducir el nivel de contaminación acústica generada en el entorno marino. En la actualidad, se está constatando con claridad la necesidad de actuar no sólo sobre la radiación acústica, sino sobre el conjunto global de las radiaciones del buque, tanto en el ámbito militar como en el ámbito civil, basado en aspectos como: la discreción de los buques, la seguridad en puertos e infraestructuras críticas y la protección ambiental. Como elemento clave para alcanzar esta meta, es de gran importancia tener a nuestra disposición sistemas de medida adaptables y altamente modulares que cubran el conjunto total de las radiaciones de los buques, con alta capacidad de transmisión de datos a centros base, con el objeto de tener la capacidad de realizar medidas en toda clase de entornos marinos
Insights into the structure of MoS2/WS2 nanomaterial catalysts as revealed by aberration corrected STEM
Molybdenum disulfide/Tungsten disulphide (MoS2/WS2) is a compound very useful for its properties; it is used as lubricant, catalyst in hydrodesulfuration, in hydrogen fuel storage, etc. As part of the 2nd Joint Congress of the Portuguese and Spanish Microscopy Societies the present work reports about the different types of MoS2/WS2 nanomaterials which have been investigated by using aberration corrected STEM namely: (1) MoS2 nanotubes (2) MoS2 hexagonal nanoplates, (3) rippled or helical MoS2 nanowires, (4) Co-doped MoS2/WS2 nanowires and (5) fullerene-like WS2 nanoparticle
NIA 701- EXPERIENCIAS EN ESPAÑA Y REINO UNIDO: DESAFÍOS PARA LOS AUDITORES INDEPENDIENTES EN CHILE
This research analyzes the experience of disclosure of key audit issues (hereinafter ACA) under the International Standard on Auditing ISA (701) approved in Europe on January 1, 2015 by the International Auditing and Assurance Standards Board (IAASB). The methodology is descriptive of the content of a sample for convenience of 94 ACA in Spain and 160 ACA in the United Kingdom for the periods 2017 and 2018. The exploratory character is due to the fact that it is a phenomenon that has not been studied much in Chile, and it is longitudinal because it considers the analysis of information from two consecutive periods. The result of this research shows a trend in both countries of greater communication of ACA in the manufacturing industry. In Spain, for example, the ACA “Impairment” is mostly reported in the manufacturing industry, while in the United Kingdom the ACA was “Provisions, contingentliabilities and other accounting provisions”, for the Retail (first place) and Transportation industries (second place). Given this study, it is foreseeable that independent auditors in Chile will tend to report the same concepts of significant ACA risks in similar and/or equal industry structures, as has been the experience in Europe.La presente investigación analiza la experiencia de divulgación de asuntos claves de auditoría (en adelante, ACA) bajo la norma internacional de auditoría NIA (701) aprobada en Europa el 1° de enero 2015 por el Consejo Internacional de Normas de Auditoría y Aseguramiento (IAASB). La metodología es descriptiva sobre el contenido de una muestra por conveniencia de 94 ACA en España y 160 ACA en Reino Unido para los períodos 2017 y 2018. El carácter exploratorio se debe a que es un fenómeno poco estudiado en Chile, y es longitudinal porqueconsidera el análisis de información de dos períodos consecutivos. El resultado de esta investigación muestra una tendencia en ambos países de mayor comunicación de ACA en la industria de manufactura. En España por ejemplo, el ACA “Deterioro de Valor” es divulgado mayoritariamente en la industria de manufactura, mientras que en Reino Unido el ACA fue “Provisiones, pasivos contingentes y otras provisiones contables”, para las industrias de Retail (primer lugar) y de Transporte (segundo lugar). Dado este estudio, es previsible quelos auditores independientes en Chile tenderán a informar los mismos conceptos de riesgos significativos ACA en estructuras de industrias similares y/o iguales, conforme ha sido la experiencia en Europa
Estudio de viabilidad para la utilización de gas metano generado a partir de residuos orgánicos en la comunidad de Coper-Boyacá
Definir la viabilidad para la utilización de gas metano generado a partir de residuos orgánicos en la comunidad de Coper-Boyacá.Actualmente el sector ganadero y agrícola han tenido un gran desarrollo tecnológico, el cual ha permitido aprovechar los residuos generados por estos, como fuente de energía en zonas rurales de difícil acceso.
El biodigestor es un tanque herméticamente sellado, que permite la fermentación anaeróbica de residuos orgánicos, generando en un tiempo determinado biogás rico en metano y bioabono, cuyo mercado objetivo es el municipio de Coper-Boyacá.
Para el desarrollo del proyecto fue necesario un estudio de mercados a través de encuestas, para poder desarrollar el estudio técnico, la propuesta administrativa, organizacional y legal y el estudio financiero, con el fin de demostrar la viabilidad del proyecto.TITLE: FEASIBILITY STUDY FOR THE USE OF METHANE GAS GENERATED
FROM ORGANIC WASTE IN THE COPER-BOYACÁ COMMUNITY*
AUTHORS:
Álvarez Niño Rita Paola, Buitrago Esparza José Rodrigo, López Palacio Carolina**
KEY WORDS: Digester, Biogas, Biofertilizer, Feasibility, Organic waste.
DESCRIPTION
Currently the livestock and agricultural sector have had a great technological development,
which has allowed to take advantage of the waste generated by these, as an energy source in rural
areas of difficult access.
The digester is a hermetically sealed tank, which allows the anaerobic fermentation of organic
waste, generating in a certain time biogas rich in methane and biofertilizer, whose target market
is the municipality of Coper-Boyacá.
For the development of the project it was necessary to study markets through surveys, to develop
the technical study, the administrative, organizational and legal proposal and the financial study,
in order to demonstrate the viability of the project
Preparation and Characterization of Natural Zeolite Modified with Iron Nanoparticles
This study is aimed at investigating the structural and morphological characterization of natural and modified zeolite obtained from the state of Oaxaca (Mexico). Iron nanoparticles were used for the zeolite modification. The iron nanoparticles were loaded on the zeolite surface by homogeneous nucleation. Adsorption kinetic models of pseudo first and second order were surveyed. The characterization of pristine and modified zeolite was performed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). From the results, three main phases were identified: clinoptilolite, mordenite, and feldspar. We could also determine the adsorption capacity of the zeolites by means of adsorption kinetic models
Pb(core)/ZnO(shell) nanowires obtained by microwave-assisted method
In this study, Pb-filled ZnO nanowires [Pb(core)/ZnO(shell)] were synthesized by a simple and novel one-step vapor transport and condensation method by microwave-assisted decomposition of zinc ferrite. The synthesis was performed using a conventional oven at 1000 W and 5 min of treatment. After synthesis, a spongy white cottonlike material was obtained in the condensation zone of the reaction system. HRTEM analysis revealed that product consists of a Pb-(core) with (fcc) cubic structure that preferentially grows in the [111] direction and a hexagonal wurtzite ZnO-(Shell) that grows in the [001] direction. Nanowire length was more than 5 μm and a statistical analysis determined that the shell and core diameters were 21.00 ± 3.00 and 4.00 ± 1.00 nm, respectively. Experimental, structural details, and synthesis mechanism are discussed in this stud
Estudio de viabilidad para la utilización de gas metano generado a partir de residuos orgánicos en la comunidad de Coper-Boyacá
Definir la viabilidad para la utilización de gas metano generado a partir de residuos orgánicos en la comunidad de Coper-Boyacá.Actualmente el sector ganadero y agrícola han tenido un gran desarrollo tecnológico, el cual ha permitido aprovechar los residuos generados por estos, como fuente de energía en zonas rurales de difícil acceso.
El biodigestor es un tanque herméticamente sellado, que permite la fermentación anaeróbica de residuos orgánicos, generando en un tiempo determinado biogás rico en metano y bioabono, cuyo mercado objetivo es el municipio de Coper-Boyacá.
Para el desarrollo del proyecto fue necesario un estudio de mercados a través de encuestas, para poder desarrollar el estudio técnico, la propuesta administrativa, organizacional y legal y el estudio financiero, con el fin de demostrar la viabilidad del proyecto.TITLE: FEASIBILITY STUDY FOR THE USE OF METHANE GAS GENERATED
FROM ORGANIC WASTE IN THE COPER-BOYACÁ COMMUNITY*
AUTHORS:
Álvarez Niño Rita Paola, Buitrago Esparza José Rodrigo, López Palacio Carolina**
KEY WORDS: Digester, Biogas, Biofertilizer, Feasibility, Organic waste.
DESCRIPTION
Currently the livestock and agricultural sector have had a great technological development,
which has allowed to take advantage of the waste generated by these, as an energy source in rural
areas of difficult access.
The digester is a hermetically sealed tank, which allows the anaerobic fermentation of organic
waste, generating in a certain time biogas rich in methane and biofertilizer, whose target market
is the municipality of Coper-Boyacá.
For the development of the project it was necessary to study markets through surveys, to develop
the technical study, the administrative, organizational and legal proposal and the financial study,
in order to demonstrate the viability of the project
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