Hybrid electric vehicle regenerative-braking using ultracapacitors

The concept and application of ultracapacitors for electric load leveling and regenerative braking is presented. Proposed sizing of an ultracapacitor system is presented and discussed based on the available energy and the nominal operating voltage from a hybrid electric vehicle transit bus; A control scheme is required to effectively control the charge and discharge of the ultracapacitor system. This system is required to provide for electric load leveling, effective control and maximization of the regenerative-braking system. In order to optimally control the ultracapacitor system a DC/DC converter is required. Alternatively, direct connection of the ultracapacitor system across the battery bank does not allow for control of energy flow but does assist the battery system by altering the charge and discharge rate thereby reducing the stress on the battery system. Both connections of the ultracapacitor system were investigated. System integration using optimal power dispatch from the battery packs and generator was investigated with the aid of PSPICE and the Advanced Vehicle Simulator (ADVISOR) developed by the National Renewable Energy Laboratory (NREL)

All work and no pay: consequences of unpaid work experience in the creative industries

This research note evaluates the benefits and pitfalls of unpaid work as an entry route into employment in the creative industries and investigates the consequences of this practice for those who already work in the sector. Based on a qualitative study of perspectives of stakeholders in unpaid work, this article argues that the social capital thesis, often used as a rationale for unpaid work, inadequately explains the practice of unpaid work experience, primarily because it does not take cognisance of the consequences of this practice for other people working in the sector. The study also highlights methodological issues that need to be considered in the future. As well as the importance of a plurality of stakeholder perspectives, the study emphasizes the need to consider the perspectives of those who are excluded from unpaid work and those who are potentially displaced by it

Effects of Dynamic Variable - Value Ordering Heuristics on the Search Space of Sudoku Modeled as a Constraint Satisfaction Problem

We carry out a detailed analysis of the effects of different dynamic variable and value ordering heuristics on the search space of Sudoku when the encoding method and the filtering algorithm are fixed. Our study starts by examining lexicographical variable and value ordering and evaluates different combinations of dynamic variable and value ordering heuristics. We eventually build up to a dynamic variable ordering heuristic that has two rounds of tie-breakers, where the second tie-breaker is a dynamic value ordering heuristic. We show that our method that uses this interlinked heuristic outperforms the previously studied ones with the same experimental setup. Overall, we conclude that constructing insightful dynamic variable ordering heuristics that also utilize a dynamic value ordering heuristic in their decision making process could drastically improve the search effort for some constraint satisfaction problems

Deep silicon maxima in the stratified oligotrophic Mediterranean Sea

The silicon biogeochemical cycle has been studied in the Mediterranean Sea during late summer/early autumn 1999 and summer 2008. The distribution of nutrients, particulate carbon and silicon, fucoxanthin (Fuco), and total chlorophyll-<i>a</i> (TChl-<i>a</i>) were investigated along an eastward gradient of oligotrophy during two cruises (PROSOPE and BOUM) encompassing the entire Mediterranean Sea during the stratified period. At both seasons, surface waters were depleted in nutrients and the nutriclines gradually deepened towards the East, the phosphacline being the deepest in the easternmost Levantine basin. Following the nutriclines, parallel deep maxima of biogenic silica (DSM), fucoxanthin (DFM) and TChl-<i>a</i> (DCM) were evidenced during both seasons with maximal concentrations of 0.45 μmol L<sup>−1</sup> for BSi, 0.26 μg L<sup>−1</sup> for Fuco, and 1.70 μg L<sup>−1</sup> for TChl-<i>a</i>, all measured during summer. Contrary to the DCM which was a persistent feature in the Mediterranean Sea, the DSM and DFMs were observed in discrete areas of the Alboran Sea, the Algero-Provencal basin, the Ionian sea and the Levantine basin, indicating that diatoms were able to grow at depth and dominate the DCM under specific conditions. Diatom assemblages were dominated by <i>Chaetoceros</i> spp., <i>Leptocylindrus</i> spp., <i>Pseudonitzschia</i> spp. and the association between large centric diatoms (<i>Hemiaulus hauckii</i> and <i>Rhizosolenia styliformis</i>) and the cyanobacterium <i>Richelia intracellularis</i> was observed at nearly all sites. The diatom's ability to grow at depth is commonly observed in other oligotrophic regions and could play a major role in ecosystem productivity and carbon export to depth. Contrary to the common view that Si and siliceous phytoplankton are not major components of the Mediterranean biogeochemistry, we suggest here that diatoms, by persisting at depth during the stratified period, could contribute to a large part of the marine primary production as observed in other oligotrophic areas

Inferring phytoplankton carbon and eco-physiological rates from diel cycles of spectral particulate beam-attenuation coefficient

The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (<i>c</i><sub>p</sub>) measured at multiple wavelengths. The method is based on fitting observations with a size-structured population model coupled to an optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in <i>c</i><sub>p</sub>. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the diel variability in <i>c</i><sub>p</sub>. Application of this method to spectral <i>c</i><sub>p</sub> measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in <i>c</i><sub>p</sub> can be ascribed to a synchronized population of cells with an equivalent spherical diameter around 4.6±1.5 μm. The inferred carbon biomass of these cells was about 5.2–6.0 mg m<sup>−3</sup> and accounted for approximately 10% of the total particulate organic carbon. If successfully validated, this method may improve our in situ estimates of primary productivity

Los aportes de aerosoles afectan las propiedades ópticas de la materia orgánica disuelta en las aguas costeras del Mediterráneo Noroccidental

10 pages, 6 figures, 1 table[EN] Aeolian inputs of organic and inorganic nutrients to the ocean are important as they can enhance biological production in surface waters, especially in oligotrophic areas like the Mediterranean. The Mediterranean littoral is particularly exposed to both anthropogenic and Saharan aerosol depositions on a more or less regular basis. During the last few decades experimental studies have been devoted to examining the effect of inorganic nutrient inputs from dust on microbial activity. In this study, we performed experiments at two different locations of the NW Mediterranean, where we evaluated the changes in the quality and quantity of dissolved organic matter due to atmospheric inputs of different origin (Saharan and anthropogenic) and its subsequent transformations mediated by microbial activities. In both experiments the humic-like and protein-like substances, and the fluorescence quantum yield increased after addition. In general, these changes in the quality of dissolved organic matter did not significantly affect the prokaryotes. The recalcitrant character of the fluorescent dissolved organic matter (FDOM) associated with aerosols was confirmed, as we found negligible utilization of chromophoric compounds over the experimental period. We framed these experiments within a two-year time series data set of atmospheric deposition and coastal surface water analyses. These observations showed that both Saharan and anthropogenic inputs induced changes in the quality of organic matter, increasing the proportion of FDOM substances. This increase was larger during Saharan dust events than in the absence of Saharan influence[ES] Los aportes atmosféricos de nutrientes orgánicos e inorgánicos al océano son importantes ya que pueden aumentar la producción biológica en aguas superficiales, especialmente en las zonas oligotróficas como el Mediterráneo. El litoral del Mediterráneo está particularmente expuesto a aportes de origen antropogénico y a deposiciones de polvo sahariano de forma más o menos regular. Durante las últimas décadas los estudios experimentales se han dedicado, sobre todo, a examinar el efecto de la entrada de nutrientes inorgánicos atmosféricos sobre la actividad microbiana. En este estudio, se realizaron experimentos con comunidades microbianas procedentes de dos zonas del Mediterráneo noroccidental. Se evaluaron los cambios en la calidad y cantidad de la materia orgánica disuelta debido a aportes atmosféricos de distinto origen y sus posteriores transformaciones mediadas por actividades microbianas. En ambos experimentos las sustancias orgánicas fluorescentes y el rendimiento cuántico de fluorescencia aumentaron después de la adición de material atmosférico. En general, estos cambios en la calidad de la materia orgánica no afectaron significativamente a los organismos procariotas. El carácter recalcitrante de la materia orgánica disuelta fluorescente (FDOM) contenida en los aerosoles se confirmó ya que la utilización de compuestos cromóforos durante el período experimental fue insignificante. Los resultados obtenidos se contextualizan en relación con una serie temporal de dos años de datos adquiridos de deposición atmosférica y análisis de agua superficial costera. La variabilidad temporal de estas dos variables mostró que tanto los aportes saharianos como antropogénicos provocaron cambios en la calidad de la materia orgánica disuelta en aguas superficiales, incrementando la fracción fluorescente. Éste aumento resultó ser mayor durante eventos de polvo sahariano que en ausencia de ellosThis study was supported by the projects 1179-1198. ADEPT (CTM2011-23458), DOREMI (CTM2012-342949) and ANIMA (CTM2015-65720-R MINECO/FEDER, UE). E.D. Sánchez-Pérez would like to thank the Consejo Nacional de Ciencia y Tecnologia (CONACyT) for their financial support through a PhD fellowship. I. Marín thanks the FPI Spanish scholarship programme for its support (BES 2012-052976)Peer Reviewe

Success Factors of Small and Medium-Sized International Enterprises in the Chinese Market from the Perspective of Polish Direct Investment (Cultural Approach)

Globalization has resulted in increasing transfer of firms operations, regardless of their size, to other countries. The recent dynamic emergence of China in the global economy, connecting with the vast inflows of foreign direct investment in their territory and common adjustments problems of many Western companies, has resulted in growing interest for best suitable business practices to this culturally and socially different environment. In this article, the key factors critical to the success of international companies in this region are introduced, with particular consideration to indigenous cultural elements and specific operation requirements of small and medium-sized enterprises in Business-to-Business sectors. The presented information are based on the broad literature review, five years of direct observation and thirty eight interviews conducted with Polish managers directly residing in China. In addition, some practical recommendations for managers and further research are given.Globalizacja wymusza na firmach, niezależnie od ich wielkości, coraz częstsze przenoszenie operacji do innych krajów. Dynamiczne pojawienie się Chin w światowej gospodarce i szeroki napł;yw zagranicznych inwestycji bezpośrednich na ich teren oraz problemy adaptacyjne wielu zachodnich przedsiębiorstw, spowodował;y zainteresowanie najlepszymi praktykami biznesowymi dostosowanymi do tego odmiennego kulturowo i społ;ecznie otocznia. W artykule zaprezentowane został;y najważniejsze czynnik mające wpł;yw na osiągnięcie sukcesu przez firmy międzynarodowe na tym obszarze, ze szczególnym uwzględnieniem aspektów kulturowych i specyfiki dział;ania mał;ych i średnich podmiotów na rynkach B2B. Prezentowane informacje są oparte na przeglądzie literatury, pięcioletnich obserwacjach bezpośrednich oraz trzydziestu ośmiu wywiadach przeprowadzonych z menadżerami polskich przedsiębiorstw odpowiedzialnymi za operacje w Chinach. Dodatkowo wskazano kilka praktycznych rekomendacji menadżerskich oraz możliwości dalszych badań

Los aportes de aerosoles afectan las propiedades ópticas de la materia orgánica disuelta en las aguas costeras del Mediterráneo Noroccidental

Aeolian inputs of organic and inorganic nutrients to the ocean are important as they can enhance biological production in surface waters, especially in oligotrophic areas like the Mediterranean. The Mediterranean littoral is particularly exposed to both anthropogenic and Saharan aerosol depositions on a more or less regular basis. During the last few decades experimental studies have been devoted to examining the effect of inorganic nutrient inputs from dust on microbial activity. In this study, we performed experiments at two different locations of the NW Mediterranean, where we evaluated the changes in the quality and quantity of dissolved organic matter due to atmospheric inputs of different origin (Saharan and anthropogenic) and its subsequent transformations mediated by microbial activities. In both experiments the humic-like and protein-like substances, and the fluorescence quantum yield increased after addition. In general, these changes in the quality of dissolved organic matter did not significantly affect the prokaryotes. The recalcitrant character of the fluorescent dissolved organic matter (FDOM) associated with aerosols was confirmed, as we found negligible utilization of chromophoric compounds over the experimental period. We framed these experiments within a two-year time series data set of atmospheric deposition and coastal surface water analyses. These observations showed that both Saharan and anthropogenic inputs induced changes in the quality of organic matter, increasing the proportion of FDOM substances. This increase was larger during Saharan dust events than in the absence of Saharan influence.Los aportes atmosféricos de nutrientes orgánicos e inorgánicos al océano son importantes ya que pueden aumentar la producción biológica en aguas superficiales, especialmente en las zonas oligotróficas como el Mediterráneo. El litoral del Mediterráneo está particularmente expuesto a aportes de origen antropogénico y a deposiciones de polvo sahariano de forma más o menos regular. Durante las últimas décadas los estudios experimentales se han dedicado, sobre todo, a examinar el efecto de la entrada de nutrientes inorgánicos atmosféricos sobre la actividad microbiana. En este estudio, se realizaron experimentos con comunidades microbianas procedentes de dos zonas del Mediterráneo noroccidental. Se evaluaron los cambios en la calidad y cantidad de la materia orgánica disuelta debido a aportes atmosféricos de distinto origen y sus posteriores transformaciones mediadas por actividades microbianas. En ambos experimentos las sustancias orgánicas fluorescentes y el rendimiento cuántico de fluorescencia aumentaron después de la adición de material atmosférico. En general, estos cambios en la calidad de la materia orgánica no afectaron significativamente a los organismos procariotas. El carácter recalcitrante de la materia orgánica disuelta fluorescente (FDOM) contenida en los aerosoles se confirmó ya que la utilización de compuestos cromóforos durante el período experimental fue insignificante. Los resultados obtenidos se contextualizan en relación con una serie temporal de dos años de datos adquiridos de deposición atmosférica y análisis de agua superficial costera. La variabilidad temporal de estas dos variables mostró que tanto los aportes saharianos como antropogénicos provocaron cambios en la calidad de la materia orgánica disuelta en aguas superficiales, incrementando la fracción fluorescente. Éste aumento resultó ser mayor durante eventos de polvo sahariano que en ausencia de ellos

Inferring phytoplankton carbon and eco-physiological rates from diel cycles of spectral particulate beam-attenuation coefficient

The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (cp) measured at multiple wavelengths. The method is based on fitting observations with a size-structured population model coupled to an optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in cp. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the diel variability in cp. Application of this method to spectral cp measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in cp can be ascribed to a synchronized population of cells with an equivalent spherical diameter around 4.6-1.5 1/4μm. The inferred carbon biomass of these cells was about 5.2-6.0 mg mg -\u273 and accounted for approximately 10% of the total particulate organic carbon. If successfully validated, this method may improve our in situ estimates of primary productivity