27 resultados para 14902


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Material plastikoen kontsumoak izugarri gora egin du azken mendean. Hori dela eta, material hauek erabiltzearen ondorioz sortutako hondakinak asko handitu dira. Europar Batasuneko herrialdeetan 250 milioi tona baino gehiago hiri - hondaki n solido ( RSU ) sortzen dira urtero, urteko %3ko hazkunt zarekin. K antitate honen %7a plastiko hondakinei dagokie, hots, 17.5 milioi tona. Itsasoko uretan ere aurki daitezke plastikoak, urtero sei milioi tona eta erdi botatzen baitira itsasora, mediterraneo itsasoa izanik munduko plastiko biltegirik handiena. Itsasoan 90 urteraino iraun dezake te eta urte hauetan zehar distantzia handiak egin ditzakete aldatu gabe. Horregatik esaten da plastikoak iraunkorrak direla. Egun, hondakin plastikoen portzentaia txiki bat bakarrik birziklatzen da eta bai biltegiratzea bai erreketa bidezko eliminazioak ingurumen arazoak dituzte . Gainera, plastiko gehienak degradaezi nak dira, urte luzez ingurugiro kalteak eraginez . Hori dela eta, material hauen balorizaziorako teknologia berrien sustapena beharrezkoa da, eskala handian eraginkorrak, ekonomikoki bideragarriak eta ingurugiroa errespetatuko dutenak. Hondakin plastikoetatik abiatuz hidrogenoa lortzeko prozesua interesgarria eta bideragarria da, hidrogenoaren kontsumoaren igoe ra kontuan hartuz. Gaur egun erregai fosilen prozesaketatik lortzen da hidrogenoa, CO 2 - a ren emisio handiak sortzen direlarik. Emisio hauen murrizketa beharrezkotzat hartu da. Hau guztiagatik, Gradu Amaierako Lan honen helburu nagusia plastikoen balorizazio a ikertzea da, konkretuki hiri - hondakin solidoetan aurkitzen diren plast ikoena . Pirolisi eta ur baporearen bidezko erreformatua erabili dira hidrogenoa lortzeko, azken hau balio handiko produktua izanik. Horretarako lehenengo etapa iturri ohantze konikoan, 500 ºC - tan, buruturiko pirolisia izan da eta bigarrenik ohantze fluidizatu batean ur baporearen bidezko erreformatua burutu da , 700 ºC - tan . Helburu nagusi hau betetzeko bestelako helburu zehatzak ezarri dira, hiri - hondakin solidoetan aurkitzen diren HDPE, PP, PS eta PET plastiko nahaste baten bideragarritasuna aztertu delarik aurrez aipatutako bi etapen bidez:  Plastiko nahastearen pirolisian sorturiko konposatu hegazkorren erreformatua era jarraian burutzea.  Zero denboran e rreakzio indizeak (konbertsioa et a etekinak) eta lortutako gasaren konposizioa determinatze a .  Erreformatuan erabilitako katalizatzailearen desaktibatzeak erreakzioa ren konbertsio eta etekina n duen eragina aztertzea.

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Ciguatoxins (CTX) are polyether neurotoxins that target voltage-gated sodium channels and are responsible for ciguatera, the most common fish-borne food poisoning in humans. This study characterizes the global transcriptional response of mouse liver to a symptomatic dose (0.26 ng/g) of the highly potent Pacific ciguatoxin-1 (P-CTX-1). At 1 h post-exposure 2.4% of features on a 44K whole genome array were differentially expressed (p ≤ 0.0001), increasing to 5.2% at 4 h and decreasing to 1.4% by 24 h post-CTX exposure. Data were filtered (|fold change| ≥ 1.5 and p ≤ 0.0001 in at least one time point) and a trend set of 1550 genes were used for further analysis. Early gene expression was likely influenced prominently by an acute 4°C decline in core body temperature by 1 h, which resolved by 8 h following exposure. An initial downregulation of 32 different solute carriers, many involved in sodium transport, was observed. Differential gene expression in pathways involving eicosanoid biosynthesis and cholesterol homeostasis was also noted. Cytochrome P450s (Cyps) were of particular interest due to their role in xenobiotic metabolism. Twenty-seven genes, mostly members of Cyp2 and Cyp4 families, showed significant changes in expression. Many Cyps underwent an initial downregulation at 1 h but were quickly and strongly upregulated at 4 and 24 h post-exposure. In addition to Cyps, increases in several glutathione S-transferases were observed, an indication that both phase I and phase II metabolic reactions are involved in the hepatic response to CTX in mice.

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UANL

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Resumen basado en el de la publicación

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The work reported in this paper is motivated by the need to investigate general methods for pattern transformation. A formal definition for pattern transformation is provided and four special cases namely, elementary and geometric transformation based on repositioning all and some agents in the pattern are introduced. The need for a mathematical tool and simulations for visualizing the behavior of a transformation method is highlighted. A mathematical method based on the Moebius transformation is proposed. The transformation method involves discretization of events for planning paths of individual robots in a pattern. Simulations on a particle physics simulator are used to validate the feasibility of the proposed method.

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This thesis intends to show the level of pollutant emissions in the State of Rio Grande do Norte, generated by the final consumption of energy in the many different sectors of the economy. This information was obtained from the energetic matrix and from the pollutant emissions of the State and the data was taken from the Balanço Energético Estadual and from the Sistema de Informações Energéticas da Olade. The result will permit to identify the energy and most polluting economic sectors in Rio Grande do Norte, contributing to energy planning, giving direction to the public policy development that aim at the change of the energy matrix of the State. Also with the objective of reducing pollutant emissions through rationalization, efficiency and energy substitution, which the main objective is to promote the economic development based on energy consumption of less harmful impact on the environment, contributing to establishment of sustainable development

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Incluye Bibliografía

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)