1,294 research outputs found

    Some Notes on Theories of Technology, Society and Innovation Systems for S&T Policy Studies

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    This paper is an examination of technological determinism – the shaping of society by technology – and the influence of society on the evolution of technology

    Caracterização físico-química de diferentes cultivares de romã colhidas em Espanha

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    O presente estudo teve como objetívo caracterizar em termos físico-químicos romãs de nove cultivares colhidas em Espanha no estado de maturação adequado à colheita. Os resultados mostraram que as cultivares estudadas apresentam diferenças entre si, designadamente ao nível dos pesos dos frutos e dos seus componentes (casca, película, arilos e sementes), tendo-se destacado a Mollar de Elche pelo maior peso médio dos frutos (478,64 g), ao contrário da White, que apresentou os menores frutos (175,95 g). Esta última cultivar foi aquela que apresentou os menores valores de massa para os quatro componentes da roma. A Mollar de Elche foi a cultivar que forneceu o maior rendimento de sumo, o que está relacionado com a massa elevada dos arilos e baixa percentagem de sementes, mostrando ser a mais apropriada para o consumo em fresco e para a indústria dos sumos. Além disso, os sumos das diferentes cultivares apresentaram diferenças significativas entre si, variando o pH entre 2,56 e 4,31, e o teor de sólidos solúveis totais (TSS) entre 14,87 e 18,04 °Brix. Em relação ao índice TSS/Acidez Titulável Total, verificou-se que as nove cultivares apresentaram índices diferentes, o que se reflete na doçura e acidez dos sumos. As diferenças observadas indicam utilizações diferentes de acordo com a cultivar. Verificou-se também que a cultivar Katirbasi se distinguiu das demais, uma vez que apresentou um teor superior de flavonóides, antocianinas monoméricas, taninos e vitamina C, o que sugere uma boa composição em compostos bioativos que estão associados a efeitos benéficos para a saúde dos consumidores. Em suma, o presente trabalho permitiu fornecer informação útil aos produtores deste fruto de modo a poderem escolher as variedades consoante o seu fim.Os autores agradecem ao POCTEP - Programa Cooperação Transfi-onteiriça Espanha-Portugal pelo apoio financeiro através do Projeto "RED/AGROTEC - Red transfronteriza Espana Portugal de experimentación y transferencia para el desarrollo dei sector agropecuario y agromdustíal".info:eu-repo/semantics/publishedVersio

    Caracterização físico-química e atividade antioxidante da casca de diferentes cultivares de romã produzidas em Espanha

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    A casca de romã é um subproduto importante da indústria de bebidas elaboradas à base deste fruto. Até ao momento, geralmente a casca não é utilizada para outros fins, sendo desperdiçada. Nesse sentido, de forma a valorizar este subproduto, o presente estudo teve como objetivo proceder à determinação da presença de taninos hidrolisáveis, flavonóides e atividade antioxidante da casca de nove cultivares produzidas em Espanha. Os resultados demonstraram que as cultivares estudadas apresentaram diferenças nas percentagens de casca (36,2 a 57,7% para a Parfianka e Cis 127, respetivamente), bem como na sua cor. A cultivar White foi aquela que apresentou os valores mais baixos de luminosidade (L*) e das coordenadas a* (-verde-vermelho+) e b* (-azul-amarelo+). Em relação à atividade antioxidante, a cultivar Valenciana destacou-se face às restantes, apresentando os valores mais elevados de flavonóides (546 mg QE g-1 extrato), taninos hidrolisáveis (2109 mg TAE g-1 extrato), Capacidade Redutora Total (1510 mg GAE g- 1extrato), Efeito Bloqueador dos Radicais Livres de DPPH (menor valor de EC50 e igual a 6,93 mg L-1) e Poder Redutor (menor valor de EC50 e igual a 41,8 mg L-1), sendo a casca com a maior quantidade em compostos bioativos. Além disso, outras cultivares, tais como a Cis 127, Mollar de Elche e Wonderful 1, apresentaram características importantes, como sejam, elevado teor em flavonóides, taninos e Capacidade Redutora Total. Pelo contrário, de um modo geral, a casca da cultivar Katirbasi foi a que apresentou os valores inferiores nessas propriedades. Em suma, o presente trabalho demonstrou que as cascas de cultivares de romã podem ser reutilizadas e os seus extratos incorporados em outros produtos alimentares, tendo em conta os compostos detetados que são referidos na literatura como tendo efeitos positivos na saúde humana

    An expeditious low-cost method for the acoustic characterization of seabeds in a Mediterranean coastal protected area

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGPosidonia oceanica meadows are ecosystem engineers which, despite their ecological relevance, are experiencing habitat fragmentation and area decrease. Cartography and information on the ecological status of these habitats is key to an effective maritime spatial planning and management for habitat conservation. In this work we apply an acoustic methodology to map benthic habitats (substrate and vegetation) in an archipelago of the Natura 2000 Network close to the coast of Murcia (SE Spain) where dense and sparse areas of P. oceanica, and patches of Cymodocea nodosa appear over a sandy and had bottom. The methodology uses dual frequency information (200 kHz and 38 kHz) acquired with a single-beam echosounder to develop a bathymetry, and performs sea bottom and vegetation supervised classifications, using video and scuba diver observations as groundtruthing data. Sea bottom was classified from acoustic features of the first and second 200 kHz echoes into 5 substrate classes using a random forest classifier: sand, fine sand, coarse sand, hard bottoms and hard bottoms with sandy patches. The vegetation was classified from features extracted from the "above-bottom" part of the echo (height and backscattering intensity) in both frequencies, resulting also in a 5 class classification: C. nodosa meadows, dense P. oceanica meadows, dispersed P. oceanica meadows, dense P. oceanica with sand patches, and no-vegetation; according to the random-forest Gini index, 38 kHz features were the most informational variables for this classification. The validation accuracies of both classifications were 85% (substrates) and 70% (vegetation), close to accuracies reported in the literature when using a similar number of classes. The results of this article (including bathymetric, and substrate and vegetation thematic maps), together with the acoustic methodology described and used, are contributions that can improve the continuous monitoring of Mediterranean seagrasses

    New insights on the seismogenic potential of the Eastern Betic Shear Zone (SE Iberia): Quaternary activity and paleoseismicity of the SW segment of the Carrascoy Fault Zone

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    The Carrascoy Fault (CAF) is one of the main active faults that form part of the Eastern Betic Shear Zone, a 450 km fault system that accommodates most of the convergence between the Eurasian (Iberia) and Nubian plates in the Betic Cordillera, south Spain. Although the CAF represents a major earthquake threat to the nearby City of Murcia, studies on its Quaternary tectonics and seismogenic potential are scarce to date. We present evidence that supports the division of the CAF into two overlapping segments with contrasting tectonic structure, Quaternary activity, and landform control: a SW segment, characterized by a broad fold-and-thrust zone similar to the forebergs defined in the Gobi-Altai region, and a NE segment, characterized by a sharp mountain front controlled by strike-slip tectonics. We attribute the differentiation into these two segments to the stresses associated with topography, which in turn is a consequence of the shortening component, at the middle Pleistocene, after circa 217.4 ka. For the SW segment we infer the occurrence of 9 to 11, Mw 6.7 paleoearthquakes in the last 30.2 kyr, and a slip rate of 0.37 ± 0.08 m/kyr. We date the occurrence of the last surface rupture event after 2750 B.P., and we estimate an average recurrence period of major events of 3.3 ± 0.7 kyrThis work was supported by SISMOGEN (IGME, 2279) and FASEGEO (CGL2009-09726) research projects and a technical assistance of the Civil Protection Service of Murci

    Paleoseismological evidence of holocene activity of the Los Tollos fault (Murcia, se Spain): a lately formed quaternary tectonic feature of the eastern betic shear zone

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    The Los Tollos Fault is a recent and important feature of the Eastern Betic Shear Zone, one of the major tectonic structures in South Iberia accommodating the convergence between Nubian and Eurasian plates in the western Mediterranean. The Los Tollos Fault became active by the end of Middle Pleistocene introducing some paleogeographical modifications. Previously mapped as a secondary normal fault related to the Carrascoy Fault, recent research evidences that the Los Tollos Fault is an independent Holocene active left-lateral reverse fault extending for at least 15 km. Data analysis from 4 trenches dug across the fault has revealed the occurrence of at least two paleo-earthquake events during the Holocene. The most recent event is dated between 2,740 and 2,140 yr BP (8th to 2nd centuries BC). The size of the paleoevents is calculated to be Mw 6.3 – 6.6 following empirical regressions on surface rupture length. The recurrence interval is estimated to be between 2,200-6,860 years, fitting a slip rate for the fault between 0.12 and 0.17 mm/yr. Such parameters highlight the Los Tollos Fault as a tectonic structure with a considerable activity located relatively close to densely populated areas. These seismogenic parameters should be considered in future reassessments of the seismic hazard of the regionThis work forms part of the research activities carried out in the FASEGEO Project (CGL2009-09726) funded by the Spanish Ministry of Science and Innovatio

    Correlating material-specific layers and magnetic distributions within onion-like Fe 3 O 4 /MnO/ γ- Mn2 O3 core/shell nanoparticles

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    This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.The magnetic responses of two nanoparticle systems comprised of Fe3 O 4/γ−Mn2O3 (soft ferrimagnetic, FM/hard FM) and Fe3O4/MnO/γ−Mn2 O3 (soft FM / antiferromagnetic, AFM/hard FM) are compared, where the MnO serves to physically decouple the FM layers. Variation in the temperature and applied field allows for Small Angle Neutron Scattering (SANS) measurements of the magnetic moments both parallel and perpendicular to an applied field. Data for the bilayer particle indicate that the graded ferrimagnetic layers are coupled and respond to the field as a single unit. For the trilayer nanoparticles, magnetometry suggests a Curie temperature (TC)≈ 40 K for the outer γ−Mn2O3 component, yet SANS reveals an increase in the magnetization associated with outer layer that is perpendicular to the applied field above TC during magnetic reversal. This result suggests that the γ−Mn2O3 magnetically reorients relative to the applied field as the temperature is increased above 40 K

    Biosorción de Cd (II) y Pb (II) de soluciones acousas en residuos agrícolas de Phaseolus vulgaris L.: optimización, cinética, isotermas y desorción

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    Industrial activities are the most common cause of water contamination by heavy metals, which endanger the quality of water resources and human health, due to their bioaccumulation capacity and consequent biomagnification. For this reason, the removal of metals from e uents before their discharge into the receiving water bodies is of crucial importance. This is why, in the present investigation, the biosorption processes of Cd (II) and Pb (II) in Phaseolus vulgaris L. (bean) agricultural residues (stems, leaves and leaf sheaths) were optimized. The influence of pH, biosorbent doses and initial concentration levels of metallic ions was evaluated using the response surface methodology (RSM). Quadratic models were developed for the percent removal of Cd (II) and Pb (II). Optimal biosorption conditions were attained at pH = 4.3, a 7.4 g/L biosorbent dose and an initial 9.14 mg/L concentration of each metal, achieving percent removals of 87.70 and 95.58% for Cd (II) and Pb (II), respectively. The FT-IR characterization showed that the functional groups involved in adsorption would be in the range of 2300 to 2400 cm-1. The biosorption kinetics were described by the pseudo first order model and the equilibrium data was adjusted to the Freundlich isotherm. An approximate desorption of 98% of Cd (II) and Pb (II) was achieved. The Phaseolus vulgaris L. residue showed a great biosorption capacity of Cd (II) and Pb (II) simultaneously.Las actividades industriales son la fuente más común de contaminación del agua por metales pesados que resultan ser un peligro para la calidad de los recursos hídricos y la salud humana, debido a su capacidad de bioacumulación y consecuente biomagnificación, por tal motivo, la remoción de metales de efluentes antes de ser vertidos a los cuerpos receptores es de crucial importancia. Razón por la cual, en la presente investigación se optimizó el proceso de biosorción de Cd (II) y Pb (II) en residuos agrícolas de Phaseolus vulgaris L. (frejol) que constó de tallos, hojas y vainas. Se evaluó la influencia del pH, dosis de biosorbente y concentración inicial del ion metálico mediante la metodología de superficie de respuesta (RSM). Se desarrollaron modelos cuadráticos para las remociones porcentuales de Cd (II) y Pb (II). Las condiciones óptimas de biosorción fueron pH=4.3, dosis de biosorbente 7.4 g/L y una concentración inicial de cada metal de 9.14 mg/L logrando remociones de 87.70 y 95.58% para Cd (II) y Pb (II), respectivamente. La caracterización por FT-IR mostró que, los grupos funcionales involucrados en la adsorción estarían en el rango de 2300 a 2400 cm-1. La cinética de biosorción fue descrita por el modelo de pseudo primer orden y los datos en equilibrio se ajustaron a la isoterma de Freundlich. Se logró una desorción aproximada de 98% de Cd (II) y Pb (II). El residuo de Phaseolus vulgaris L. mostró gran capacidad de biosorción de Cd (II) y Pb (II) simultáneamente.Campus Arequip
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