91 research outputs found
Estudio comparativo de las características físicas del semen de ovino en el laboratorio de reproducción asistida de la Diputación de Córdoba
En el presente trabajo se ha realizado un estudio comparativo
de las caracteristicas físicas (volumen y concentración)
de semen procedente de las extracciones realizadas
en el laboratorio de Reproducción Asistida de
Pequeños Rumiantes (código comunitario ES-04-02-0C),
ubicado en el Centro Agropecuario Provincial de la
Diputación de Córdoba, durante los años 2003, 2004 y 2005. Estos trabajos se vienen desarrollando en el seno de los convenios de colaboración suscritos entre la institución cordobesa y las Asociaciones de Criadores de
Ovinos Precoces, Merino y Lacaune, para la mejora genética
de los rebaños de la provincia mediante el empleo de técnicas de inseminación artificial como medida de apoyo al desarrollo de los esquemas de selección de estas
razas. Se realizó un análisis de varianza para la evaluación
de la influencia de los efectos del año de extracción,
la raza, la época de extracción y la interacción entre la
raza y la época de extracción sobre el volumen y la concentración
seminal
Iron substitution in Na4VMn(PO4)3 as a strategy for improving the electrochemical performance of sodium-ion batteries
Six NASICON type samples with Na4-xVFexMn1-x(PO4)3 (0 ≤ x ≤ 1) stoichiometry are examined as positive electrodes for sodium-ion batteries. The structural, morphological, and chemical state of elements in raw samples is unveiled by XRD diffraction, electron microscopy, and Raman and XPS spectroscopies. The effect of the dual Fe/Mn substitution is examined by electrochemical tests using both voltammetric and galvanostatic methods. The results reveal the beneficial effect of the iron substitution, justified by an improvement of the kinetic response, and supported by the calculation of the apparent diffusion coefficients and internal cell resistance
Two qubits of a W state violate Bell's inequality beyond Cirel'son's bound
It is shown that the correlations between two qubits selected from a trio
prepared in a W state violate the Clauser-Horne-Shimony-Holt inequality more
than the correlations between two qubits in any quantum state. Such a violation
beyond Cirel'son's bound is smaller than the one achieved by two qubits
selected from a trio in a Greenberger-Horne-Zeilinger state [A. Cabello, Phys.
Rev. Lett. 88, 060403 (2002)]. However, it has the advantage that all local
observers can know from their own measurements whether their qubits belongs or
not to the selected pair.Comment: REVTeX4, 5 page
The biomass based electricity generation potential of the Province of Cienfuegos, Cuba
By 2013, the province of Cienfuegos in Cuba consumed about 5165 GWh of primary energy, of which an estimated 60 % was used to produce 767 GWh of electricity. 29 % of the primary energy was obtained from renewable fuel, and only less than 5 % of the biomass energy, was used to produce about 27 GWh of biomass based electricity. This study proposes and assesses opportunities to produce electricity from biomass in the sugar industry of the province. The scenarios considered include: upgrading the agricultural yield of sugarcane, producing energy cane and combusting it after the sugarcane milling season, combusting the filter cake, combusting marabu (Dichrostachys cinerea, a bush tree considered a plague in Cuba) after the sugarcane milling season, and updating the electricity generation technology. Results are given for the different scenarios and it is shown that a combined scenario, including upgrading agricultural yield of sugarcane, upgrading electricity generation technology, combusting filter cake, and producing energy cane to generate electricity after the sugarcane milling season, thus allowing to use the generation units in sugar factories during 8000 h per year affords a potential production of 1150 GWh of electricity, 50 % more than consumed in Cienfuegos province in 2013. © 2016, Springer Science+Business Media Dordrecht
Water footprint from growing potato crops in Cuba
This article determines the water footprint from the potato crop in Cuba between the years 2009 and 2012 using the CROPWAT model. Climate, yields and fertilization data are specific to each of the areas where the crops were grown. The results are compared with previous works in other countries in Latin America and the Caribbean. In the case of Cuba, the results show a difference of 25% with respect to international reports developed with data related to climate and average crops in the country. Other countries in the region have similar levels, although with a smaller gray component and a larger green component. The water footprint from potato crops is also compared with other crops in Cuba, finding that potatoes represent the fourth largest water demand.En el artículo se determina la huella hídrica de la cosecha de la papa
en Cuba entre los años 2009 y 2012 utilizando el modelo CROPWAT.
Los datos climáticos, de rendimiento y de fertilización son específicos
de cada una de las áreas donde se realiza la cosecha y los resultados
obtenidos se comparan con los de trabajos anteriores realizados en
otros países de América Latina y el Caribe. En el caso de Cuba los
resultados muestran diferencias de un 25% respecto a los obtenidos
en reportes internacionales elaborados a partir de datos climáticos y
de la cosecha promedios del país. Respecto a otros países de la región
tienen niveles similares aunque con menor componente gris y mayor
componente verde. También se compara la Huella Hídrica de la
cosecha de la papa con la de otros cultivos en Cuba estableciéndose
que la papa ocupa el cuarto lugar en demanda de agua
Electricity management in the production of leadaAcid batteries: the industrial case of a production plant in Colombia
Electricity stands as the main energy used for lead-acid battery (LAB) manufacturing. This study introduces an energy management methodology to address the electricity consumption in lead-acid battery plants, improving efficiency standards. The “equivalent battery production” is introduced to define the energy performance criteria to be met in the different production sections of the battery plant. The methodology combines the guidelines of the ISO 50001 standard with the energy management framework for manufacturing plants. The result is a structured approach for detecting inefficiencies and pinpointing their sources. The management methodology was implemented during 2016. In the formation area 222 MWh were saved during 2016. This saving accounts for 3.9% less electricity than forecasted by the energy baseline of the area. Additionally, the emission of some 40 tCO2.eq. associated with the generation of the electricity production were saved. Moreover, at plant level 424 MWh were saved, which account for 3.6% less electricity than forecasted by the energy baseline of the plant. In total, around 76 tCO2.eq. were saved as a result of the electricity savings in the plant
Kinetic transcriptomic approach revealed metabolic pathways and genotoxic-related changes implied in the Arabidopsis response to ionising radiations
Plants exposed to ionising radiation (IR) have to face direct and indirect (oxidative stress) deleterious effects whose intensity depends on the dose applied and led to differential genome regulation. Transcriptomic analyses were conducted with CATMA microarray technology on Arabidopsis thaliana plantlets, 2 and 26 h after exposure to the IR doses 10 Gy and 40 Gy. 10 Gy treatment seemed to enhance antioxidative compound biosynthetic pathways whereas the 40 Gy dose up-regulated ROS-scavenging enzyme genes. Transcriptomic data also highlighted a differential regulation of chloroplast constituent genes depending on the IR dose, 10 Gy stimulating and 40 Gy down-regulating. This probable 40 Gy decrease of photosynthesis could help for the limitation of ROS production and may be coupled with programmed cell death (PCD)/senescence phenomena. Comparisons with previous transcriptomic studies on plants exposed to a 100 Gy dose revealed 60 dose-dependent up-regulated genes, including notably cell cycle checkpoints to allow DNA repairing phenomena. Furthermore, the alteration of some cellular structure related gene expression corroborated a probable mitotic arrest after 40 Gy. Finally, numerous heat-shock protein and chaperonin genes, known to protect proteins against stress-dependent dysfunction, were up-regulated after IR exposure
Cu-Doped Extremely Small Iron Oxide Nanoparticles with Large Longitudinal Relaxivity: One-Pot Synthesis and in Vivo Targeted Molecular Imaging
Synthesizing iron oxide nanoparticles for positive contrast in magnetic resonance imaging is the most promising approach to bring this nanomaterial back to the clinical field. The success of this approach depends on several aspects: the longitudinal relaxivity values, the complexity of the synthetic protocol, and the reproducibility of the synthesis. Here, we show our latest results on this goal. We have studied the effect of Cu doping on the physicochemical, magnetic, and relaxometric properties of iron oxide nanoparticles designed to provide positive contrast in magnetic resonance imaging. We have used a one-step, 10 min synthesis to produce nanoparticles with excellent colloidal stability. We have synthesized three different Cu-doped iron oxide nanoparticles showing modest to very large longitudinal relaxivity values. Finally, we have demonstrated the in vivo use of these kinds of nanoparticles both in angiography and targeted molecular imaging
On the evolution of “cleaner production” as a concept and a practice
“Cleaner Production“(CP) is about less and more efficient energy and materials use and the substitution of more harmful products (for the environment and health) by less dangerous ones. CP was the reply of the industry to the call for sustainable development as launched by the WCED (1987) and further elaborated in Rio's Agenda 21 (UN, 1992). During the past 25 years, the concept was put in practice. During this period it changed in scope, methods, and application area. This provided a deeper socio-economic impact to an idea that was originally launched to awaken industry on its environmental responsibilities. This paper provides a review of essentials that contributed to the fundamental changes in CP during the most recent quarter of a century. It takes off with a review of CP definitions illustrating the changes of the content. Changes in scope are exemplified with the increasing importance of “Corporate Social Responsibility” (CSR). This includes that post-modern companies have not only responsibilities on their economic performance and the environment, but should also act on issues including human rights and resources, business ethics, and community involvement. The links between CP and green and circular economy are indicated. The CP approach is increasingly applied outside the industry. CP for sustainable tourism is discussed in more detail but is only an example of the wider application in e.g. agriculture or health services
- …