bluuebunny/crossref_metadata_2025 huggingface dataset:
The Least Squares Stochastic Finite Element Method in Structural Stability Analysis of Steel Skeletal Structures
Authors: Kamiński M. , Szafran J.
Published: May 2015

The main purpose of this work is to verify the influence of the weighting procedure in the Least Squares Method on the probabilistic moments resulting from the stability analysis of steel skeletal structures. We discuss this issue also in the context of the geometrical nonlinearity appearing in the Stochastic Finite Element Method equations for the stability analysis and preservation of the Gaussian probability density function employed to model the Young modulus of a structural steel in this problem. The weighting procedure itself (with both triangular and Dirac-type) shows rather marginal influence on all probabilistic coefficients under consideration. This hybrid stochastic computational technique consisting of the FEM and computer algebra systems (ROBOT and MAPLE packages) may be used for analogous nonlinear analyses in structural reliability assessment.
Evaluating the Effect of Cutting Parameters on Machinability Issues in Hard Turning of AISI M2 Steel
Authors: Rahul Varma K. , Kaladhar M.
Published: May 2015

Off-line process control improves the efficiency of the manufacturing process through the manipulation of process variables. The present study uses a combination of Taguchi orthogonal array and analysis of variance to experimentally investigate the effect of cutting parameters on profile roughness parameters, tool flank wear and power consumption during hard and dry turning of AISI M2 steel with cubic boron nitrite cutting insert. The results reveal that the surface roughness and flank wear are significantly affected by speed and feed. The power consumption of the machine is substantially affected by the feed and the depth of cut. Thereafter, optimum values of performance characteristics are predicted.
Further Frontiers in GIS: Extending Spatial Analysis to Textual Sources in Archaeology
Authors: Murrieta-Flores Patricia , Gregory Ian
Published: May 2015

Although the use of Geographic Information Systems (GIS) has a long history in archaeology,
spatial technologies have been rarely used to analyse the content of textual collections. A newly
developed approach termed Geographic Text Analysis (GTA) is now allowing the semi-automated
exploration of large corpora incorporating a combination of Natural Language Processing techniques,
Corpus Linguistics, and GIS. In this article we explain the development of GTA, propose possible uses
of this methodology in the field of archaeology, and give a summary of the challenges that emerge from
this type of analysis.
Talking About Task Progress: Towards Integrating Task Planning and Dialog for Assistive Robotic Services
Authors: Broz Frank , Di Nuovo Alessandro , Belpaeme Tony , Cangelosi Angelo
Published: May 2015

The use of service robots to assist ageing people in their own homes has the potential to allow people to maintain their independence, increasing their health and quality of life. In many assistive applications, robots perform tasks on people’s behalf that they are unable or unwilling to monitor directly. It is important that users be given useful and appropriate information about task progress. People being assisted in homes and other realworld environments are likely be engaged in other activities while they wait for a service, so information should also be presented in an appropriate, nonintrusive manner. This paper presents a human-robot interaction experiment investigatingwhat type of feedback people prefer in verbal updates by a service robot about distributed assistive services. People found feedback about time until task completion more useful than feedback about events in task progress or no feedback. We also discuss future research directions that involve giving non-expert users more input into the task planning process when delays or failures occur that necessitate replanning or modifying goals.
Catalytic growth of multi-walled carbon nanotubes using NiFe2O4 nanoparticles and incorporation into epoxy matrix for enhanced mechanical properties
Authors: Javed Hassan , Islam Mohammad , Mahmood Nasir , Achour Amine , Hameed Asad , Khatri Nasrullah
Published: May 2015

Mechanical properties of multi-walled carbon nanotubes (CNT) reinforced epoxy nanocomposites, with and without any structural defect, were investigated using different weight percent values of pristine and covalently functionalized CNT. First, nickel ferrite (NiFe2O4) catalyst nanoparticles were prepared using the co-precipitate method followed by CNT growth via chemical vapor deposition, using acetylene as carbon feedstock. Through a combination of magnetic stirring and ultrasound vibration treatments in acetone, pristine, COOH-, or NH2-functionalized CNTs at 0.15, 0.60, 1.10 and 1.50 wt% were added to the Epon 828 epoxy. During each stage, extensive materials characterization was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA)/differential thermal analysis (DTA) techniques. Tensile testing of the specimens revealed an increase in the elastic modulus and tensile strength values with maximum increase registered in the case of nanocomposites made from 1.1 wt% CNT-NH2 (+73%) or CNT-COOH (67%) addition. The energy absorbed during impact testing also increased by 86% upon addition of 1.50 wt% CNT-NH2. The presence of a small notch in the nanocomposite specimens yielded superior mechanical properties to those of the neat epoxy. Such enhancement in the mechanical properties can be attributed to better CNT dispersion in the nanocomposites and good interfacial bonding, as confirmed from microstructural examination of the fractured surfaces.
Stereoisomers of platinum dimeric and oligomeric coordination complexes
Authors: Melník Milan , Mikuš Peter
Published: May 2015

The coordination chemistry of platinum covers a huge field as shown by a recent survey covering the structural parameter of almost 460 dimeric to oligomeric examples. Approximately 10% of these complexes exist as isomers and are summarized in this review. Included are distortion (87%) and cis-trans (13%) isomers. These are discussed in terms of the coordination about the platinum atom, and correlations are drawn among donor atom, bond distance, and interbond angles. Distortion isomers, differing by a degree of distortion in Pt-L and Pt-Pt distances and L-Pt-L angles, and some also by crystal classes, are the most common. Distortion isomers are also spread over a wider range of oxidation states of platinum [0, +1, +2 (most common), +3, +4, and even nonintegral (+2.14 and +2.375)] than cis-trans isomers (+2 and +3 only). Surprisingly, distortion isomerism is more common than the better-known cis-trans isomerism in the chemistry of platinum.
Dirac Bound States of the Killingbeck Potential Under External Magnetic Fields
Authors: Sharifi Zahra , Tajic Fateme , Hamzavi Majid , Ikhdair Sameer M.
Published: May 2015

The Killingbeck potential model is used to study the influence of the external magnetic and Aharanov–Bohm (AB) flux fields on the splitting of the Dirac energy levels in a 2+1 dimensions. The ground state energy eigenvalue and its corresponding two spinor components wave functions are investigated in the presence of the spin and pseudo-spin symmetric limit as well as external fields using the wave function ansatz method.
Optimized Ultrasharp Silicon Nanowire Geometries for Enhanced Field Ionization Properties
Authors: Polat Kazim Gurkan , Zhou Chen , Umar Ahmad , Islam M. Saif
Published: May 2015

Silicon (Si) nanowires offer great potential for field ionization (FI) applications due to well-established Si microfabrication methods combined with favorable ionizing properties of Si. Band bending of semiconductors under applied electric fields increases the FI probability, which is not possible with metal-based counterparts. While it has been demonstrated that scaling down the active material geometry can increase the FI efficiency, maximum electric field at the tip of a single nanowire decreases by quenching effect of nearby nanowires. In this work, optimization of Si nanowire geometries for improved FI efficiencies is explored.
Génesis y consecuencias erosivas de las lluvias de alta intensidad en la región mediterránea
Authors: López Bermúdez F. , Romero Díaz M. A.
Published: May 2015

Desde siempre, los procesos de erosión de los suelos por el agua han presentado serios problemas, sobre todo, en aquellos territorios como los mediterráneos, en donde el vigor del relieve, frecuente escasa resistencia de los materiales, débil o nulo recubrimiento vegetal, lluvias de alta energía y deficiente gestión humana de los recursos, crean condiciones favorables a la degradación del suelo. En la Región Mediterránea española, la erosión de las tierras agrícolas y forestales, constituye uno de Los más graves problemas ambientales. La erosividad de las lluvias mediterráneas depende esencialmente de la intensidad y del volumen precipitado. El régimen pluviométrico que registran las lluvias en la Región Mediterránea, está caracterizado por su aleatoriedad y concentración en unos pocos días, particularmente en otoño. Lluvias de 100, 200 y hasta 300 mm., registradas en los pluviógrafos en pocas horas, liberan enormes cantidades de energía, cuyas consecuencias se hacen visibles por todas partes: elevadas pérdidas de suelo, abarrancamientos, socavamientos, desprendimientos, tubificaciones, abultadas sedimentaciones, inundaciones ... La evaluación de los índices de erosión de los aguaceros, que constituye la base para la determinación del factor R de la U.S.L.E., presenta dificultades, sin embargo, los resultados de la eficacia erosiva de los violentos chaparrones, están omnipresentes por toda la Región Mediterránea.
Uranium contamination of fluvial systems. Mechanisms and processes. Part II : dynamics of groundwater, stream interaction. A case study from Koekemoerspruit (South Africa)
Authors: Winde F. , Walt J. van der
Published: May 2015

Dissolved uranium from tailings-deposits of various goldmines in South Africa was found to migrate via seepage and groundwater into adjacent fluvial systems. The extent of the associated non-point pollution depends not only on the concentration of uranium in the water but also on the volumes of polluted groundwater seeping into the stream channel. While the uranium concentration in the groundwater is rather constant and therefore comparably easy to determine, the same is not true for the water exchange at the groundwater-stream interface. In order to track the relevant hydraulic processes, in-situ data-logger controlled probes were placed within the system measuring gauging heights and electric conductivity (EC) in 10-minute intervals. As a result of a steep hydraulic gradient between water-saturated tailing-deposits and the receiving watercourse, exfiltration (baseflow) of contaminated groundwater generally dominates. However, short-term inversions of the direction of flow (infiltration of stream water into the groundwater) were also observed. They are attributed the artificial flow-regime of the Koekemoer Spruit, which results from a pumping scheme that discharges dolomitic groundwater into the stream. Electricity costs-related differences of pumping rates lead to pronounced diurnal fluctuations of gauging heights in the stream, which in turn cause even higher fluctuations of the associated groundwater table (up to 90cm a day). The consequences and mechanisms of these man-made stream fluctuations for the hydraulic stream-groundwater interaction.
Localización y caracterización morfométrica de los glaciares rocosos relictos de la Sierra de Gistredo (Montaña Cantábrica, León)
Authors: Redondo Vega J. M. , Gómez Villar A. , González Gutierrez R. B.
Published: May 2015

En la Sierra de Gistredo se han seleccionado 43 glaciares rocosos con el fin de estudiar los factores geoambientales (litología, exposición y altitud) que explican su distribución y diversos rasgos morfométricos significativos en función de su morfología (de lengua, lobulados y complejos). Los resultados confirman el rígido control que ejercen los factores geoambientales en su localización y en su forma. La aplicación de análisis estadísticos permite discriminar y caracterizar los tres tipos de glaciares rocosos atendiendo a su geometría y observar la escasa relación que existe entre su tamaño y pendiente y determinadas variables morfométricas referidos a su área fuente, como es la altitud, pendiente y desnivel.
Influencia de la radiación solar en el proceso de degradación y fragmentación post-pequeña Edad del Hielo del glaciar de la Madaleta (Pirineo Central Español)
Authors: Chueca Cía J. , Julián Andrés A.
Published: May 2015

El objetivo de este trabajo es analizar el papel de la radiación solar incidente de onda corta en el proceso de degradación y fragmentación observado en el glaciar de la Maladeta desde el último Máximo de la Pequeña Edad del Hielo (PEH) hasta la actualidad. La reconstrucción de la evolución post-PEH del glaciar se efectuó partiendo de la documentación gráfica disponible (iconografía, cartografía topográfica, fotogramas aéreos y fotografías) que ilustraba su estado en distintos momentos de su historia reciente. Los valores de radiación solar han sido estimados a partir de la utilización del programa informático Solar Analyst (ejecutable como una extensión del Sistema de Información Geográfica ArcView), que ofrece la posibilidad de obtener, para cada celda de un Modelo Digital de Elevaciones, valores puntuales de radiación solar directa, difusa y global, así como estimaciones acumuladas de la radiación para períodos de tiempo determinados. Los resultados confirman la fuerte influencia de la radiación solar en la evolución de detalle del glaciar de la Maladeta al propiciar, en función de su intensidad (relacionada con la topografía y el albedo), el desarrollo de áreas con mayor o menor repercusión de los procesos de ablación
Efectos del fuego en el comportamiento hidrológico de dos cuencas en el Prepirineo aragonés (España)
Authors: Echeverría Arnedo M. T. , Ibarra Benlloch P. , Sebastián López M. , Pérez Cabello F.
Published: May 2015

The hydrological behaviour of two basins affected by a forest fire. The different percentage of burnt surface in both areas is translated in a different hydrological behaviour, analysed through the discharge hydrograms and a comparative statistical analysis. In the burnt catchment area, the hydrological response to the precipitation is bigger and faster than in the other basin, in relation to a greater superficial runoff and a smaller infiltration rate (mean runoff coefficients: 10% compared to the 4.8% obtained at the non-burnt catchment).
Diferencias estacionales en la generación de escorrentía en una pequeña cuenca de campos abandonados en el Pirineo Central
Authors: Lana-Renault N. , Latron J. , Regüés D. , Serrano P. , Nadal E.
Published: May 2015

This study shows that the relationships between rainfall and runoff at the event scale in a small farmland abandoned catchment are not linear and that the hydrological response is linked to the antecedent wetness conditions. Rainfall and baseflow discharge have a pronounce influence on the value of the runoff coefficient, while rainfall intensity affects the maximum discharge increment. Watertable data show high seasonal dynamics, with a dry period during summer, a wet period during winter and spring, and a transition period characterised by a high spatial variability. The analysis of the hydrological information at the event scale allows the distinction of three types of event, and reveals the occurrence of different runoff generation processes within the catchment. During dry conditions, the hydrological response is very low and infiltration excess over localised areas is ikely to be the main runoff process. As the catchment gets wetter, saturated excess runoff (and probably subsurface flow) becomes the dominant runoff process.
Cold and heat impact on human comfort in the Bahía Blanca Estuary Harbours (Argentina)
Authors: Píccolo M. C. , Díez P. G.
Published: May 2015

The aim of the present work was to study the human comfort at working hours related to the number of persons attended in the main hospital wards in two harbours located on the north coast of the Bahía Blanca estuary. For this purpose, the wind chill and humidex indexes were calculated and compared. Ingeniero White harbour is situated at the head of the estuary while Rosales port is located at its mouth. Meteorological data from both harbours was measured during the period 1999-2001. The results show that wind chill index is an average 2.9º C below the actual mean temperature in winter (9.5ºC). The humidex is 3º C above the actual mean temperature in summer (23.9ºC). The greatest discomfort is experienced from noon to night during this season. No significant thermal differences were observed between the inner and outer region of the Bahía Blanca estuary. However, enough evidence has been found to prove that the winter and summer indexes may be related to workers' health.
Escorrentía y pérdida de suelo en cárcavas : modelización en un agrosistema del Prepirineo oscense
Authors: López-Vicente M. , Navas A.
Published: May 2015

Erosive dynamic of gullies in Mediterranean environments represents one the main causes of land degradation and sediment yield in productive agrosystems. In this work the semi-physics enhanced RMMF model is applied into a GIS to elaborate spatially distributed maps of potential and effective cumulative runoff and soil erosion at the La Coloma Gully catchment (Spanish Central Pre-Pyrenees). The gully reaches a maximum length of 523 m and is divided into four different sectors according to its physiographic properties. The map of soil detachment by splash highlights the key role of vegetation properties to explain the different estimated rates. Processes of runoff accumulation and infiltration and slope values mainly control the estimated values of soil detachment by runoff. The average value of soil erosion at catchment scale is 33.9 Mg ha-1 yr-1 being runoff transport capacity the limiting factor in 88% of the surface and total soil loss adds up to 411.4 Mg yr-1. The average value of estimated soil erosion in the gully is 176.5 Mg ha-1 yr-1 with values that range between 0.1 and 502.6 Mg ha-1 yr-1 for the different sectors and the total volume of runoff is 779 mm yr-1. Crops, paths and areas with low vegetation cover and high slope are the main source areas of sediment to the main channel of the gully and present high values of soil erosion (higher than 30 Mg ha-1 yr-1).Information gained with the enhanced RMMF model is of interest to implement soil and water conservation practices and develop sustainable economic and environmental strategies.
Cobertura nival y distribución de las temperaturas en el suelo en las cumbres de la Sierra de Guadarrama
Authors: Andrés de Pablo N. , Palacios Estremera D.
Published: May 2015

Air and ground temperatures were monitored from 2002 - 2007 at the summit area of Alto de las Guarramillas (2258 m; 40º 47' 10'' N and 3º 58' 46'' W) in the central sector of Sierra de Guadarrama, a mountain range located 50 km from Madrid. Air temperature was recorded at the summit while ground temperature was monitored at 3 locations, differentiated by the permanence of snow cover: the summit, inside a snow hollow, known as Ventisquero de la Condesa, located on the east side of the summit and the pronival sector of this hollow. During the summer, ground temperatures were uniform for all three control points, and showed symmetrical changes with the air temperature. During the period of snow cover, ground temperature varied widely among the sample sites as influenced by snow thickness and, particularly, snow cover duration. It is uncertain as to whether these variations could be related to variations in air temperature. Snow thickness and snow cover duration are factors that directly affect phase changes in ground water content, which subsequently influences geomorphologic processes and plant cover. Snow cover duration is a crucial factor, because it can markedly alter ground temperature in a distance of only a few meters
El turismo de nieve como estrategia de desarrollo en el Pirineo aragonés
Authors: Lasanta T.
Published: May 2015

Five alpine ski resorts were built in the Pyrenees between 1965 and 1976: Candanchú (with a previous history dating back to 1920), Formigal, Cerler, Panticosa and Astún. The aim was to develop tourist activities and improve a regressive socio-economical situation, in which the population abandoned progressively the area that had suffered a severe crisis in the Primary Productive Sector since the beginning of the XXth Century. In this paper two factors have been analyzed: i) the influence that ski resorts have had in the evolution of the human population, in demographic structure and in employment, and ii) the impact of the tourist sector on the Primary Productivity farms, and on the livestock census. The results obtained permit the conclusion that in the municipalities affected by the ski resorts, the population has grown 60.4 % between 1970 and 2008, showing a fairly balanced demographic structure and a concentration of employment in the sectors of Services (82.26 %) and building construction (13.1 %) whereas the primary sector only occupies 2.6 % of active population. The municipalities without ski resorts have lost 26.6 % of their population between 1970 and 2008, show an aged demographic structure and a high dependency level rate (55.7%) although the employment distribution is more balanced, with 19.5 % of workers in the primary sector. The evolution of the number of farms shows a greater decline in the municipalities with ski resorts (48 % between 1970 and 2008), than in those without ski resorts (22 % during the same period of time). Similar behaviour can be observed in the evolution of livestock census, where the municipalities with ski resorts have lost 43 % of their livestock while, on the contrary, the municipalities without ski resorts increased their census by 31.8 % during the same period.
Evaluación de la producción de sedimentos y calidad de las aguas en cuencas agrarias de Navarra
Authors: Giménez R. , Casalí J. , Díez J.
Published: May 2015

The Government of Navarre (Spain) established a series of experimental watersheds on different sites of its territory in order to assess the impact of the agricultural activities on the environment. Hydrological/meteorological and water quality data are continuously monitored. In this paper, data recorded –precipitation, runoff, sediment, nitrate and phosphate– in two grain-sown watersheds (La Tejería and Latxaga) and in a third one (Oskotz) covered with forest and pasture (cattle-breeding) with a sub-watershed almost entirely under forest, are analyzed; the information covers a period of ca. 15 years. The inter/intra annual variability of the involved processes are studied as well as their impact on the water quality and on the ecosystem. The majority of the sediments yielded in the watersheds are registered during winter, though most of the erosive rainfalls occurred in summer. This is because of the easy-prone runoff that prevailed during winter due to the (much) higher water content of the soils in this period. The grain-sown watersheds –roughly similar at first view– present however important differences regarding sediment yield: 1800 kg/ha year at La Tejería and only 450 kg/ha year at Latxaga. This could be mainly due to differences in morphology, topography, and amount of stream channel vegetation between both sites. At Oskotz this figures are as a whole lower than those registered in the cultivated watersheds but eventually larger than those at Latxaga; this depending on the forest management (logging). Water quality is seriously affected at La Tejería with nitrate concentration constantly over critical threshold. By contrast, nitrate values are much lower in Latxaga watershed. However, phosphate concentrations were similar in both grain-sown watersheds corresponding to water with a significant risk of eutrophication. The cattle-breeding activity at Oskotz generated unexpected levels of phosphate much higher than those registered in the cultivated wathersheds.
Efectos de las rodadas de tractores en la escorrentía y erosión de suelos en laderas cultivadas con viñedos
Authors: Arnáez J. , Ruiz-Flaño P. , Lasanta T. , Ortigosa L. , Llorente J. A. , Pascual N. , Lana-Renault N.
Published: May 2015

Mechanization characterizes the vineyards of La Rioja, one of the most important wine regions in Spain. Farming operations (plowing, soil removal, herbicide and pesticide application, harvesting of grapes and its transportation, etc.) are carried out with tractors that usually move in the direction of maximum slope, generating wheel tracks approximately 50 cm wide and 5-7 cm deep. The displacement of tractors on plots leads to the compaction of the topsoil and the subsoil. On the other hand, the location of vineyard parcels on steep slopes favours the erosive impact of surface runoff. This paper provides information on the role played by wheel tracks on soil loss by runoff in vineyards. To obtain this information, rainfall simulations with different intensities were carried out. The results confirm that, with moderate and high rainfall intensity, the runoff starts earlier and reach higher values in wheel tracks, due to compaction of the topsoil. Differences between wheel tracks and interrills are less pronounced on sediment yield. These differences are minimal in high intensity storms, having the tractor tracks lesser importance in erosion. By contrast, the drainage micro-network of hillslopes, eliminated by tillage and reactivated by heavy rainfall, seems to have more impact on runoff and erosion. The results obtained with the rainfall simulation experiments shed light on the relationships between runoff, raindrop impact and suspended sediment transport.
Repelencia al agua en suelos forestales afectados por incendios y en suelos agrícolas bajo distintos manejos y abandono
Authors: Bodí M. B. , Cerdà A. , Mataix-Solera J. , Doerr S. H.
Published: May 2015

Soil water repellency determines the water available in the soil system, the runoff generation and the geomorphologic processes. This study examines the soil wettability during the summer of 2008 and 2009 in forest soils with different fire history, and in agricultural soils with different managements. Water repellency was assessed using the Water Drop Penetration Time test (WDPT). Results indicate that water repellency is more frequent and persistent in forest soils than in agricultural ones. In the former, water repellency is reduced a year after a fire and is not recovered during at least 12 years. In agricultural soils, it is found under no till treatment, whereas sites treated with herbicides or tillage were virtually unaffected. Water repellency is exhibited because of the increment of aboveground biomass and organic matter content as the vegetation is recovered following a wildfire or after abandoned crop fields, and after adding reaping or with green manure. In any case, water repellency levels are not either high or continuous enough to produce important runoff and erosion rates in the agricultural soils, although this can occur after forest fires if the soil it is not still protected by the vegetation recovery. Land abandonment trigger the water repellency on soils, and in our case fire reduce it for some years.
Estudio sedimentológico de la Rambla de Chiva
Authors: Sanjaume E. , Segura F. , Meyer M. J.
Published: May 2015

Este artículo pretende estudiar los procesos actuales que se producen en la Rambla de Chiva (Valencia), mediante el análisis de sus sedimentos. Los datos obtenidos han permitido reconstruir la circulación del agua en la última crecida. Asimismo, se ha intentado caracterizar las diferencias existentes entre las barras y los canales de la sección analizada, así como de las microformas que en ella se establecen
El área metropolitana de Barcelona : una región desequilibrada
Authors: Plana Castellví José A.
Published: May 2015

El Area Metropolitana de Barcelona (A.M. B.) carece hasta la fecha de marco legal. Comprende las comarcas del Barcelonés, Baix Llobregat, Val!és Occidental, Val!és Oriental, Maresme, Garra! y Alt Penedés de acuerdo con la división administrativa realizada, en el año 1932, por la Generalitat de Catalunya, (Institución de Autogobierno de origen Medieval. Comprende 162 municipios, con una superficie igual al 10,2 % del total del Principado (Catalunya 31.895,29 km2). En ella, se asienta el 70% de la población catalana (6.078.154 en 1983). En el conjunto, sobresale Barcelona con el 31% de la población de Cataluña y el 45% de la del A.M. La comarca del Barcelonés se muestra como la más favorecida en cuanto a servicios y es la que presenta una mayor densidad, con 16.213 h/km2.
Incisiones (cárcavas) en el nivel supraforestal de la Sierra de la Demanda (Sistema Ibérico) : Morfología y significación
Authors: Arnáez-Vadillo José
Published: May 2015

En este articulo se estudian un conjunto de incisiones que surgen en el nivel supraforestal de la Sierra de la Demanda (Sistema Ibérico). Estas se presentan en las cabeceras de los barrancos y vertientes deforma aislada, conectando con la red principal. Manifiestan, junto con otros procesos, el importante grado de denudación que soportan los sectores elevados de la Si~ra. Las incisiones parecen ser consecuencia de la evolución y reajuste de la red fluvial: dimandina, como consecuencia de la conjunción de una serie de factores (existencia de fallas, un manto de derrubios muy erosionable, deforestación).
Organización espacial de sedimentos en las barras del cauce trenzado del río Oja
Authors: Gómez Villar Amelia , Martínez Castroviejo Ricardo
Published: May 2015

En este artículo se definen diferentes ambientes deposicionales atendiendo al eje mayor de los sedimentos en tres puntos del cauce trenzado del río Oja: dos en el sector de la Sierra de la Demanda y un tercero en el tramo de los conglomerados de borde de cuenca, cerca de Santurde. Los resultados muestran que el tamaño medio de los sedimentos sobre las barras y canales decrecen aguas abajo y las irregularidades están definidas por los procesos locales de transporte de sedimentos.
Formas y procesos kársticos en los conglomerados de la cabecera del río Oca (Cuenca del Ebro, Burgos)
Authors: Ugarte Félix
Published: May 2015

Se expone en esta nota un fenómeno de convergencia de formas y procesos, describiéndose una morfología típica de zonas kársticas desarrollada sobre conglomerados del Plioceno.
Pendiente, sinuosidad y tipo de canal en el Ebro medio
Authors: Ollero Ojeda Alfredo
Published: May 2015

Se han calculado los valores de pendiente y sinuosidad del cauce del río Ebro en su curso medio, a lo largo de 338 km. de meandros libres entre Logroño y Alfarque. Ambos parámetros se han calculado igualmente para los 22 sectores en que se ha dividido longitudinalmente el río, buscando una relación causa-efecto entre pendiente y sinuosidad que no es clara en todos los casos. Tras definir los tipos de canal del Ebro medio, se completa el trabajo comparando los resultados obtenidos con los valores registrados en los ríos Po y Garona.
La vegetación de ribera y su dinámica en relación con el factor antrópico : El ejemplo de los tramos finales de los cauces del SE de Málaga
Authors: Bejarano Palma Rosalía
Published: May 2015

La vegetación asociada a las riberas de los cauces fluviales tiene un interés particular en biogeografía, dado que son medios originales -la humedad edáfica favorece la presencia de especies asociadas en particular a estos medios y que se escapan del control climático regional-, muy dinámicos y también de una gran fragilidad. El caso concreto de los cauces estudiados reviste aún mayor complejidad, pues se trata de cauces no permanentes o ramblas.
Tras la conceptualización y unas notas metodológicas, se aborda en este artículo una breve descripción fisiográfica de la zona estudiada. Seguidamente, se aportan unos primeros datos sobre la distribución actual de la vegetación en los cauces de los ríos Vélez, Seco II y Chillar. En la última parte se compara esa situación actual con la que debió ser la vegetación potencial. en un intento de aproximación a la dinámica de la vegetación en los cauces citados.
Potential for attenuation of a stream in a subtropical region - Rio Grande do Sul - Brazil
Authors: Peresin Denise , Vieceli Nathalia Cristine , Bortolin Taison Anderson , Bavaresco Gabriela , Schneider Vania Elisabete
Published: May 2015

The study and knowledge of the depuration capacity of the water resources, is necessary to preserve them. This study was objective identify the attenuation capacity of the Belo stream - Caxias do Sul - RS / Brazil, through the evaluation of physicochemical parameters, distance and slope between 4 points located along the stream. Were collected five samplings, bimonthly. The data were analyzed through descriptive statistics, one-way Analysis of Variance (ANOVA "one way"), Tukey’s test e Pearson’s correlation. The results showed that there is an improvement in the quality of water resources from upstream to downstream of the stream. However, despite the stream have a high attenuation potential, is necessary the development of control actions to input of industrial and domestic effluents, to prevent the ecological impairment of the same. http://dx.doi.org/10.18226/23185279.v3iss1p1
Designing an effective mark–recapture study of Antarctic blue whales
Authors: Peel David , Bravington Mark , Kelly Natalie , Double Michael C.
Published: May 2015

To properly conserve and manage wild populations, it is important to have information on abundance and population dynamics. In the case of rare and cryptic species, especially in remote locations, surveys can be difficult and expensive, and run the risk of not producing sample sizes large enough to produce precise estimates. Therefore, it is crucial to conduct preliminary analysis to determine if the study will produce useable estimates. The focus of this paper is a proposed mark–recapture study of Antarctic blue whales (Balaenoptera musculus intermedia). Antarctic blue whales were hunted to near extinction up until the mid‐1960s, when commercial exploitation of this species ended. Current abundance estimates are a decade old. Furthermore, at present, there are no formal circumpolar‐level cetacean surveys operating in Antarctic waters and, specifically, there is no strategy to monitor the potential recovery of Antarctic blue whales. Hence the work in this paper was motivated by the need to inform decisions on strategies for future monitoring of Antarctic blue whale population. The paper describes a model to predict the precision and bias of estimates from a proposed survey program. The analysis showed that mark–recapture is indeed a suitable method to provide a circumpolar abundance estimate of Antarctic blue whales, with precision of the abundance, at the midpoint of the program, predicted to be between 0.2 and 0.3. However, this was only if passive acoustic tracking was utilized to increase the encounter rate. The analysis also provided guidance on general design for an Antarctic blue whale program, showing that it requires a 12‐year duration; although surveys do not necessarily need to be run every year if multiple vessels are available to clump effort. Mark–recapture is based on a number of assumptions; it was evident from the analysis that ongoing analysis and monitoring of the data would be required to check such assumptions hold (e.g., test for heterogeneity), with the modeling adjusted as needed.
Sheep farming and large carnivores: What are the factors influencing claimed losses?
Authors: Mabille Géraldine , Stien Audun , Tveraa Torkild , Mysterud Atle , Brøseth Henrik , Linnell John D. C.
Published: May 2015

Large carnivore populations are recovering in many parts of the world and this generates conflicts with humans, notably in terms of livestock depredation. Governmental programs of mitigation measures and compensation for losses are often implemented to reduce conflicts, but the factors affecting losses are poorly understood. We used 11 years of data on domestic sheep (Ovis aries) claimed, and confirmed, to have been killed by predators in Norway to evaluate how predator density, flock management, and other environmental or habitat‐related variables are related to losses. The percentage of animals claimed as lost that was found and confirmed to have been killed by large predators (i.e., the detection rate) was low, especially for sheep claimed as killed by Eurasian lynx (Lynx lynx), wolverine (Gulo gulo) and golden eagle (Aquila chrysaetos). Still, we generally found that similar factors predicted the number of claims and number of carcasses found across predator species. Predator density was strongly associated with losses, especially for sheep claimed as killed by brown bears (Ursus arctos), lynx and wolverines. Percentage of forest in the pastures, average slaughter weight of the lambs (an indicator of the forage conditions during summer) and vegetation characteristics in the spring also predicted the number of sheep claimed and found killed by lynx, wolverines and eagles. Factors related to losses due to wolves (Canis lupus) were harder to ascertain, possibly because of the severity of mitigation measures (e.g., electric fences) taken to protect sheep in wolf territories, a factor we were not able to include in our large scale analyses. Patrolling of the grazing area and early gathering of sheep in the autumn were not associated with a substantial reduction in losses. However, our dataset was not well suited to evaluate the efficiency of those mitigation strategies. Our findings could help develop new mitigation strategies as alternatives to predator removal where large carnivore conservation is a concern.
Synthesis of new derivatives of hydrazinecarbothioamides and 1,2,4-triazoles and evaluation of their antimicrobial activities
Authors: Socea Laura , Saramet Gabriel , Draghici Constantin , Socea Bogdan , Constantin Vlad , Radu-Popescu Manuela
Published: May 2015

A new series of hydrazinecarbothioamides 6-9 bearing
5H-dibenzo[a,d][7]annulene moiety were synthesized. Cyclization of 6-9 in
NaOH solution produced the corresponding 1,2,4-triazoles-3(4H)-thiol 10-13,
which proved to be axial isomers. The thioethers 14-17 were prepared by
alkylation of 10-13 with methyl iodide. All new compounds were characterized
by elemental analysis, IR-, UV-, 1H-NMR and 13C-NMR spectroscopy. The
evaluation for antimicrobial activity against Staphylococcus aureus ATCC
25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922,
Bacillus subtilis ATCC 6663, Salmonella tiphimurium ATCC 14028, Shigella
flexneri ATCC 12022, Candida albicans ATCC 90028 was performed.
The use in grass production of clinoptilolite as an ammonia adsorbent and a nitrogen carrier
Authors: Milovanovic Jelena , Eich-Greatorex Susanne , Krogstad Tore , Rakic Vesna , Rajic Nevenka
Published: May 2015

The clinoptilolite-rich tuff (NZ) from Zlatokop deposit (Vranjska Banja,
Serbia) has been studied as a nitrogen carrier for grass production.
Mechanism of binding ammonium cations present in water solutions by NZ has
been examined as well as possibility of adsorption of ammonia released in
fresh cattle manure during its fermentation. The NH4+ binding from solutions
proceeds via an ion-exchange process which follows the pseudo-second-order
kinetics. Adsorption isotherms studied at 298-318 K follow the Freundlich
isotherm equation. The NZ readily adsorbs ammonia liberated from manure and
an addition of 10 wt.% of NZ to manure can preserve up to 90% of ammonia.
The potential benefit of this effect has been examined in greenhouse pot
experiments with the Italian ryegrass (Lolium multiflorum, var. Macho) using
three different types of soil (silty, clayey and sandy). The zeta potential
measurements show that stability of their colloidal dispersions differs
mutually and that addition of the NZ differently affects the stability and
nitrogen cycling. All results indicate that NZ can be applied in grass
production.
Enhancement of amylase production by Aspergillus sp. using carbohydrates mixtures from triticale
Authors: Dojnov Biljana , Grujic Marica , Percevic Bojana , Vujcic Zoran
Published: May 2015

For the purpose of finding a suitable available inducer in combination with
starvation, carbohydrate mixtures from triticale was used as inducers and
compared with well-known amylase inducers in fungi. Carbohydrate mixtures
from triticale induced production of amylase cocktail (?-amylase and
glucoamylase) in Aspergillus niger, unlike induction with well-known
inducers which induce only glucoamylase, showed by zymogram and TLC analysis
of carbohydrates mixtures before and after fermentations. Glucoamylase
production by A. niger was highest in the presence of extract obtained after
autohydrolysis of starch from triticale (95.88 U/mL). Carbohydrate mixtures
from triticale induced production of ?-amylase in A. oryzae. More ?-amylase
isoforms were detected upon using complex carbohydrate mixture, compared to
induction with maltose or starch. The 48 h induction was the most efficient
by using triticale extract (101.35 U/mL). Carbohydrates from triticale
extracts can be used as very good cheap amylase inducers. Triticale, still
not fully utilized, could be taken into consideration as the inducer in
amylase production by Aspergillus sp, such a way it could be used as sole
substrate in fermentation.
Preliminary results on performance of new ultra-fast static positioning module – POZGEO-2 in areas outside the ASG-EUPOS network
Authors: Paziewski Jacek , Krukowska Marta , Wielgosz Paweł
Published: May 2015

The presented preliminary research concerns the accuracy and reliability of new ultra-fast static positioning module - POZGEO-2 - in case of processing GPS data collected outside the ASG-EUPOS network. Such a case requires extrapolation of the network-derived atmospheric corrections which limits correction accuracy and, therefore, has adverse effect on the carrier phase ambiguity resolution. The presented processing tests are based on processing 5-minute long observing sessions and show that precise positioning can be supported up to 35 km from the ASG-EUPOS borders. This means that precise positioning with POZGEO-2 module can be assured for the most of the border areas of Poland.
Seeking realistic upper-bounds for internal reliability of systems with uncorrelated observations
Authors: Prószyński Witold
Published: May 2015

From the theory of reliability it follows that the greater the observational redundancy in a network, the higher is its level of internal reliability. However, taking into account physical nature of the measurement process one may notice that the planned additional observations may increase the number of potential gross errors in a network, not raising the internal reliability to the theoretically expected degree. Hence, it is necessary to set realistic limits for a sufficient number of observations in a network. An attempt to provide principles for finding such limits is undertaken in the present paper. An empirically obtained formula (Adamczewski 2003) called there the law of gross errors, determining the chances that a certain number of gross errors may occur in a network, was taken as a starting point in the analysis. With the aid of an auxiliary formula derived on the basis of the Gaussian law, the Adamczewski formula was modified to become an explicit function of the number of observations in a network. This made it possible to construct tools necessary for the analysis and finally, to formulate the guidelines for determining the upper-bounds for internal reliability indices. Since the Adamczewski formula was obtained for classical networks, the guidelines should be considered as an introductory proposal requiring verification with reference to modern measuring techniques.
Usefulness of Nonlinear Interpolation and Particle Filter in Zigbee Indoor Positioning
Authors: Zhang Xiang , Wu Helei , Uradziński Marcin
Published: May 2015

The key to fingerprint positioning algorithm is establishing effective fingerprint information database based on different reference nodes of received signal strength indicator (RSSI). Traditional method is to set the location area calibration multiple information sampling points, and collection of a large number sample data what is very time consuming. With Zigbee sensor networks as platform, considering the influence of positioning signal interference, we proposed an improved algorithm of getting virtual database based on polynomial interpolation, while the pre-estimated result was disposed by particle filter. Experimental result shows that this method can generate a quick, simple fine-grained localization information database, and improve the positioning accuracy at the same time.
Long-Term Degradation of Composites Exposed to Liquid Environments in Agriculture
Authors: Valášek P.
Published: May 2015

Polymeric particles composites with hard inorganic particles are abrasion resistant materials which can be used in the sphere of agriculture - e.g. for functional areas in renovation or as resistant layers. Silicon carbide waste particles were used in the present experiment, replacing the primary filler with waste without significant changes in the mechanical properties. The present paper describes the effect of immersion of polymeric particles composites with epoxy matrix in liquids on selected mechanical properties. Overall, it explains the change of hardness and resistance of abrasive wear, a typical kind of wear in the sphere of agriculture.
Means of Staff Number Reduction and Outplacement
Authors: Urbancová H.
Published: May 2015

The paper focuses on staff number reducing in Czech organizations because it is an important issue due to adaptation to changing economic conditions and ongoing financial crisis. The number of organizations reducing their staff number goes up in all sectors of economy including agriculture and the problem is associated with financial costs. The objective is to present the ways of staff number reduction in Czech organizations and outplacement for the laid-off workers and a partial objective is to compare the results with those in the Slovak Republic. Moreover, the paper discusses the recommendation in the sphere of knowledge continuity for organizations and it also examines the cost level of employees’ turnover. The results were obtained by implementing quantitative research with the help of questionnaire data collection (n = 109) which were analyzed by the tools of descriptive statistics. Results show that 52.3% of organizations have reduced their staff number. However, outplacement was used by only 10.1% of the addressed Czech organizations, out of which 28.6% were agricultural.
The Missionary Dilemma
Authors: McLoughlin William G.
Published: May 2015

The dilemma of the missionary is not unlike that which Edmund S. Morgan defined as "the Puritan dilemma." Moreover, as Morgan also noted, "The central problem of Puritanism is the problem of every age," "It was the question of what responsibility a righteous man owes to society. If society follows a course that he considers morally wrong, should he withdraw and keep his principles intact, or should he stay....Henry Thoreau did not hesitate to reject a society that made war with Mexico. William Lloyd Garrison called on the North to leave the Union in order to escape com- plicity with the sin of slaveholding. John Winthrop had another answer... Winthrop's answer to the dilemma was to struggle to the best of his ability to live as a responsible citizen in a world full of sin, corruption and confusion. For Morgan, Winthrop was a model of responsible Christian citizenship.