Dielectric relaxation of polysiloxanes and kerr effect of p-phenylene vinylene oligomers

The dielectric relaxation behaviour of a series of cyclic and linear poly(dimethylsiloxanes) with overline nn in the range 28 to 99 has been studied, as a function of temperature (142.0K-157.5K) and frequency (12-105Hz). Activation energies for the -relaxation process, Davidson-Cole empirical distribution factors, , and mean-square dipole moments per repeat unit, < 2> , have been calculated. Differences in values of H_act reflected restricted dipolar rotation for the cyclic structures, compared to the linear structures, over the range of molecular weights studied. The dielectric relaxation behaviour of a series of linear oligomers of methyl phenyl siloxane, with n in the range 4 to 10, a series of linear fractions of poly(methyl phenyl siloxane), with overline n_n in the range 31 to 1370, and a cyclic oligomer of mehyl phenyl siloxane, with n = 10, has been studied as a function of temperature (155.5K-264.0K) and frequency (12-105Hz). Activation energies for the -relaxation process, Davidson-Cole and Cole-Cole empirical distribution factors, and , respectively, and mean-square dipole moments per repeat unit have been calculated. The reduced flexibility of short methyl phenyl siloxane chains, compared to dimethyl siloxane chains, was apparent from a comparison of dipole moment ratios. The dilectric relaxation behaviour of poly(methyl hydrogen siloxane) and poly(n-hexyl methyl siloxane) has been studied as a function of temperature and frequency. A polysiloxane liquid crystal has been synthesised and its dielectric relaxation behaviour has been studied, as a function of temperature and frequency, in the liquid crystalline phase and below T_g. Poly(p-phenylene vinylene) and related oligomers have been synthesised and characterised by a variety of experimental techniques. The Kerr effect of two oligomeric fractions, in solution in PPG 2025, has been measured. The electrical conductivities of the undoped and I_2-doped polymer and oligomers have been measured.

Association between sciatica and Propionibacterium acnes

We hypothesised that the inflammation seen around the nerve root in patients with sciatica may be caused by microbial infection. We used a newly developed serological test to diagnose deep-seated infections caused by low virulent gram-positive microorganisms. 43 of 140 (31%) patients with sciatica tested positive. Intervertebral disc material from a further 36 patients with severe sciatica who had undergone microdiscectomy was cultured for the presence of microorganisms. 19 of these patients (53%) had positive cultures after long-term incubation. Propionibacterium acnes was isolated from 16 of the 19 (84%) positive samples. Low virulent microorganisms, in particular P acnes, might be causing a chronic low-grade infection in the lower intervertebral discs of patients with severe sciatica. These microorganisms could have gained access to the spinal disc after previous minor trauma.

Organised for inward investment? Development agencies, local government, and firms in the inward investment process

Inward investment promotion and aftercare remain central aspects of local economic development for English Regional Development Agencies, Scottish and Welsh development bodies, and local authorities in Britain. In many cases, partnership and consultation mechanisms have become integral to attracting inward investment and providing aftercare. Inward investment is thus an important area in which to explore interinstitutional relations between agents operating along diverse spatial boundaries and with different responsibilities. In this paper we analyse the local and regional institutional structures and relations characterising the inward investment process in Britain using new survey data from local authorities, regional bodies, and inward investors. We find that promotional activities have clearly defined structures which are chiefly led by the regional level. Aftercare is characterised by more collaborative arrangements involving both regional bodies and local government. However, many bodies are little used, with competition and tension between partners remaining frequent within English regions, regardless of recent institutional changes designed to reduce such problems. In Scotland and Wales, however, their national institutions are not only widely used, but they create high levels of satisfaction from firms. Hence, England has yet to respond to the effective challenges of Scotland and Wales. The analysis also highlights the limited importance of all national, regional, and local public institutions in attracting inward investors and their subsequent aftercare. The critical inputs to business decisions appear to be driven chiefly by more general supply-side conditions (for example, general skills versus local public packages) and the general attractions of a particular location.

A multi-modular second life hybrid battery energy storage system for utility grid applications

The modern grid system or the smart grid is likely to be populated with multiple distributed energy sources, e.g. wind power, PV power, Plug-in Electric Vehicle (PEV). It will also include a variety of linear and nonlinear loads. The intermittent nature of renewable energies like PV, wind turbine and increased penetration of Electric Vehicle (EV) makes the stable operation of utility grid system challenging. In order to ensure a stable operation of the utility grid system and to support smart grid functionalities such as, fault ride-through, frequency response, reactive power support, and mitigation of power quality issues, an energy storage system (ESS) could play an important role. A fast acting bidirectional energy storage system which can rapidly provide and absorb power and/or VARs for a sufficient time is a potentially valuable tool to support this functionality. Battery energy storage systems (BESS) are one of a range suitable energy storage system because it can provide and absorb power for sufficient time as well as able to respond reasonably fast. Conventional BESS already exist on the grid system are made up primarily of new batteries. The cost of these batteries can be high which makes most BESS an expensive solution. In order to assist moving towards a low carbon economy and to reduce battery cost this work aims to research the opportunities for the re-use of batteries after their primary use in low and ultra-low carbon vehicles (EV/HEV) on the electricity grid system. This research aims to develop a new generation of second life battery energy storage systems (SLBESS) which could interface to the low/medium voltage network to provide necessary grid support in a reliable and in cost-effective manner. The reliability/performance of these batteries is not clear, but is almost certainly worse than a new battery. Manufacturers indicate that a mixture of gradual degradation and sudden failure are both possible and failure mechanisms are likely to be related to how hard the batteries were driven inside the vehicle. There are several figures from a number of sources including the DECC (Department of Energy and Climate Control) and Arup and Cenex reports indicate anything from 70,000 to 2.6 million electric and hybrid vehicles on the road by 2020. Once the vehicle battery has degraded to around 70-80% of its capacity it is considered to be at the end of its first life application. This leaves capacity available for a second life at a much cheaper cost than a new BESS Assuming a battery capability of around 5-18kWhr (MHEV 5kWh - BEV 18kWh battery) and approximate 10 year life span, this equates to a projection of battery storage capability available for second life of >1GWhrs by 2025. Moreover, each vehicle manufacturer has different specifications for battery chemistry, number and arrangement of battery cells, capacity, voltage, size etc. To enable research and investment in this area and to maximize the remaining life of these batteries, one of the design challenges is to combine these hybrid batteries into a grid-tie converter where their different performance characteristics, and parameter variation can be catered for and a hot swapping mechanism is available so that as a battery ends it second life, it can be replaced without affecting the overall system operation. This integration of either single types of batteries with vastly different performance capability or a hybrid battery system to a grid-tie 3 energy storage system is different to currently existing work on battery energy storage systems (BESS) which deals with a single type of battery with common characteristics. This thesis addresses and solves the power electronic design challenges in integrating second life hybrid batteries into a grid-tie energy storage unit for the first time. This study details a suitable multi-modular power electronic converter and its various switching strategies which can integrate widely different batteries to a grid-tie inverter irrespective of their characteristics, voltage levels and reliability. The proposed converter provides a high efficiency, enhanced control flexibility and has the capability to operate in different operational modes from the input to output. Designing an appropriate control system for this kind of hybrid battery storage system is also important because of the variation of battery types, differences in characteristics and different levels of degradations. This thesis proposes a generalised distributed power sharing strategy based on weighting function aims to optimally use a set of hybrid batteries according to their relative characteristics while providing the necessary grid support by distributing the power between the batteries. The strategy is adaptive in nature and varies as the individual battery characteristics change in real time as a result of degradation for example. A suitable bidirectional distributed control strategy or a module independent control technique has been developed corresponding to each mode of operation of the proposed modular converter. Stability is an important consideration in control of all power converters and as such this thesis investigates the control stability of the multi-modular converter in detailed. Many controllers use PI/PID based techniques with fixed control parameters. However, this is not found to be suitable from a stability point-of-view. Issues of control stability using this controller type under one of the operating modes has led to the development of an alternative adaptive and nonlinear Lyapunov based control for the modular power converter. Finally, a detailed simulation and experimental validation of the proposed power converter operation, power sharing strategy, proposed control structures and control stability issue have been undertaken using a grid connected laboratory based multi-modular hybrid battery energy storage system prototype. The experimental validation has demonstrated the feasibility of this new energy storage system operation for use in future grid applications.

Information Technologies for Presentation of Bulgarian-Indian Cooperation in a Virtual Museum

We investigate digitalization and security of the Bulgarian and Indian cultural artifacts in multimedia archive. In the paper we describe project implementation and methods for intellectual property protection that are result of bilateral cultural and scientific cooperation between research-workers in India and Bulgaria.

A banki hitelfelvevők rejtett gazdaságból származó jövedelme. Marketingmegközelítés és empirikus kísérlet a kockázatkezelés szolgálatában

A rejtett gazdaság kiemelkedő makrogazdasági problémának tekinthető a kelet-közép- európai társadalmakban; a széles terjedelemben ingadozó kutatási eredmények Magyarországon a GDP 20–25%-ára becsülik az informális szektor méretét. A nem megfi gyelt gazdaságból származó jövedelmek ugyanakkor potenciális üzleti lehetőségként is értelmezhetők a visszafogott hitelkihelyezési magatartással jellemezhető hitelintézetek számára. Tanulmányunkban a banki kockázatmenedzsment gyakorlati működését – a hitelképesség becslésének nem konvencionális, fogyasztói magatartás alapú megközelítésével – szándékoztuk támogatni. 1) Proxyváltozókat azonosítottunk, amelyek valószínűsítik a banki ügyfelek rejtett gazdasági érintettségét. 2) Felállítottunk egy „a priori” fontossági sorrendet e változók között. 3) Megbecsültük az ügyfelek informális kifi zetéseinek mértékét. 4) Javaslatokat fogalmaztunk meg a proxyváltozók értékének, valóságtartalmának igazolására, dokumentálhatóságára. Célkitűzéseink realizálásához interdiszciplináris szakirodalmi forrásfeldolgozást, valamint primer szakértői mélyinterjúkat és személyes megkérdezést alkalmaztunk. Pilottanulmányunk tapasztalatai szerint a rejtett gazdasági érintettséget valószínűsítő változók közül kiemelkedik a rendszeres kifizetési kötelezettséget jelentő tételek aránya a háztartás rendelkezésére álló jövedelemében, továbbá az informális kifizetések mintegy 20–33%-kal növelhetik meg az ügyfelek hitelfelvételi korlátját. Az ügyfelek rejtett gazdaságból származó jövedelmének megbecsléséhez mindenképpen szükséges a banki ügyfélreferensek megfelelő képzése és motiválása.

Magyarország jövője szakértői előrejelzésekre és nem szakértői véleményekre építve

A tanulmány a Magyar Tudományos Akadémia felkérésére 2007-2008. között készített, „Magyarország 2025” című kutatás eredményeit tárja az olvasó elé. A modern jövőkutatás három módszertani elvét – komplexitás, participativitás és alternativitás – alkalmazza. Bemutatja a társadalom néhány jövő-érzékeny területén várható szakértői reményeket és félelmeket, valamint a millenniumi generáció jövő-vélekedésére alapozott négy forgatókönyvet. A szakértői előrejelzések és a nem-szakértői vélemények közötti kölcsönkapcsolat szilárd alapot nyújt jövőalternatívák és stratégiák kimunkálásához.

Potential urban distribution of Phlebotomus mascittii Grassi and Phlebotomus neglectus Tonn. (Diptera: Psychodidae) in 2021–50 in Budapest, Hungary

Background & Objective: The most northern populations of two sand fly species (Phlebotomus mascittii and Phlebotomus neclectus) in the Carpathian Basin are known from Central Hungary. The most important limiting factor of the distribution of Phlebotomus species in the region is the annual minimum temperature which may be positively affected by the urban heat island and the climate change in the future. Method: Based on the latest case reports of the species, Climate Envelope Model was done for the period 1961-1990 and 2025-2050 to project the potential urban distribution of the species. The climatic data were obtained from RegCM regional climate model and MODIS satellite images. Results: The recent occurrence of the species in Central Hungary indicates that Phlebotomus species can overwinter in non-heated shelters in the built environment. Interpretation & Conclusion: Jointly heat island and future climate change seem to be able to provide suitable environment for the studied species in urban areas in a great extent.

12022011_wolf_0027.tif

Photo from the Wolfsonian ArtBasel event on 12/2/2025

Properties of seawater from a Sea-Bird TSG temperature and conductivity sensor mounted on the continuous surface water sampling system during campaign TARA_20100523Z of the Tara Oceans expedition 2009-2013

The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data publication contains measurements from the Continuous Surface Sampling System [CSSS] made during one campaign of the Tara Oceans Expedition. Water was pumped at the front of the vessel from ~2m depth, then de-bubbled and circulated to a Sea-Bird TSG temperature and conductivity sensor. System maintenance (instrument cleaning, flushing) was done approximately once a week and in port between successive legs. All data were stamped with a GPS.

Prospecção tecnológica de células fotovoltaicas para energia solar

Solar energy presents itself as an excellent alternative for the generation of clean, renewable energy. This work aims to identify technological trends of photovoltaic cells for solar energy. The research is characterized, in relation to nature, to be applied; regarding the approach is qualitative and quantitative; with respect to the objectives, it is exploratory and descriptive; concerning the methodological procedure is considered a bibliographic research with a case study in the case of solar photovoltaic sector. The development of this research began with a literature review on photovoltaic solar energy and technology foresight. Then it led to the technology mapping of photovoltaic solar cells through the analysis of articles and patents. It was later performed the technological prospecting of photovoltaic cells for solar energy through the Delphi method, as well as the construction of the current plan and future technology of photovoltaic cells for the current scenario, 2020 and 2025. The results of this research show that the considered mature technologies (silicon mono and multicrystalline) will continue to be commercially viable within the prospected period (2020-2025). Other technologies that are currently viable (amorphous silicon, cadmium telluride and copper indium selenide / Copper indium gallium diselenide-), may not submit the same condition in 2025. Since the cells of silicon nanowires, dye-sensitized and based on carbon nanostructure, which nowadays are not commercially viable, may be part of the future map of photovoltaic technologies for solar energy.

(Table 2) Radiocarbon ages of selected southern Baja California sediment cores

Piston, gravity, and multicores as well as hydrographic data were collected along the Pacific margin of Baja California to reconstruct past variations in the intensity of the oxygen-minimum zone (OMZ). Gravity cores collected from within the OMZ north of 24°N did not contain laminated surface sediments even though bottom water oxygen (BWO) concentrations were close to 5 µmol/kg. However, many of the cores collected south of 24°N did contain millimeter- to centimeter-scale, brown to black laminations in Holocene and older sediments but not in sediments deposited during the Last Glacial Maximum. In addition to the dark laminations, Holocene sediments in Soledad Basin, silled at 290 m, also contain white coccolith laminae that probably represent individual blooms. Two open margin cores from 430 and 700 m depth that were selected for detailed radiocarbon dating show distinct transitions from bioturbated glacial sediment to laminated Holocene sediment occurring at 12.9 and 11.5 ka, respectively. The transition is delayed and more gradual (11.3-10.0 ka) in another dated core from Soledad Basin. The observations indicate that bottom-water oxygen concentrations dropped below a threshold for the preservation of laminations at different times or that a synchronous hydrographic change left an asynchronous sedimentary imprint due to local factors. With the caveat that laminated sections should therefore not be correlated without independent age control, the pattern of older sequences of laminations along the North American western margin reported by this and previous studies suggests that multiple patterns of regional productivity and ventilation prevailed over the past 60 kyr.

Efeitos induzidos por treino complementar de força em basquetebolistas adolescentes

O estudo teve por objetivo analisar os efeitos induzidos por sessões adicionais de treino de força em adolescentes praticantes de basquetebol. Mais especificamente, pretendeu-se comparar dois programas de treino (um baseado na teoria do treino integrado e outro no treino integrado com um trabalho complementar de treino de força recorrendo ao peso do próprio corpo) ao nível da aptidão física em praticantes de basquetebol sub-14. A amostra foi constituída por 12 jogadores que se voluntariaram para participar no estudo. Após uma avaliação inicial, a amostra foi dividida em 2 grupos homogéneos. Um dos grupos, grupo experimental (GE) realizou 8 semanas de treino integrado, mais um trabalho complementar de treino de força valendo-se do peso do próprio corpo, ao mesmo tempo que o grupo de controlo (GC) apenas realizou o treino integrado. Após 8 semanas houve lugar a nova avaliação (avaliação final). As avaliações foram realizadas sempre no mesmo local, com os mesmos membros da equipa de investigação a proceder às recolhas, e no mesmo período do dia. Após um aquecimento mio-articular de 10 min as avaliações consistiram nos seguintes testes: (i) lançamento da bola medicinal 2kg; (ii) salto vertical com contramovimento sem mobilização dos membros superiores; (iii) com mobilização dos membros superiores; (iv) sprint de 22 m; (v) agilidade sem bola; (vi) e com bola. Os resultados finais indicaram que o GE melhorou significativamente a força nos membros superiores medida através do lançamento da bola medicinal. Tendo-se verificado que a utilização dos 6 exercícios selecionados, através do incremento de volume de duas em duas semanas, promoveu em apenas oito semanas de trabalho, melhorias significativas de desempenho que rondaram os 10% relativamente ao teste inicial. Foi também possível verificar que, ao nível da agilidade com bola, as 8 semanas de aplicação do trabalho complementar não foram suficientes para promover incrementos significativos. No entanto, ao nível da agilidade sem bola, os jogadores do GE conseguiram ver esta capacidade melhorada, demonstrando uma maior facilidade na mudança de direção e deslocamento lateral e a retaguarda em comparação à avaliação inicial. Ao nível da força inferior, verificou-se que fazendo comparação entre os dois momentos de avaliação, ao nível do salto sem uso dos membros superiores, nenhum dos grupos obteve diferenças estatisticamente significativas na melhoria desta componente, nos dois momentos. Já quando foi permitido o uso dos membros superiores para balancear o corpo, foram observadas melhorias de rendimento no GE. Ao nível da velocidade, por se tratar de velocidade pura, i.e. todos os esforços foram abaixo dos 5s na totalidade dos jogadores, além disso foi possível verificar que, as oito semanas de aplicação do trabalho complementar, não foram suficientes para promover diferenças significativas em ambos os grupos nos dois momentos. Assim, as diferenças obtidas entre os grupos reforçam a importância que um trabalho de força complementar tem para praticantes de basquetebol adolescentes. Pelo que, os treinadores desta faixa etária deverão procurar incluir trabalho multifuncional na prescrição de treino, de forma a visar uma aptidão física adequada para a prática da modalidade.

Análise custo/benefício do processo da dessalinização da água do mar

As previsões mais recentes, e em relação à “crise” da água, apontam para que até ao ano de 2025 quase dois terços da humanidade possa vir a sofrer com a escassez de água potável, afetando praticamente todos os países do mundo, incluindo os países desenvolvidos, a menos que haja uma redução da procura e/ou o desenvolvimento de novas fontes de água potável. Face ao atual panorama mundial de escassez de água potável, devido às alterações climáticas, deficiente gestão e exploração dos recursos hídricos e crescente procura de água para a agricultura, consumo doméstico e industrial, a dessalinização da água do mar apresenta-se como uma solução segura e confiável para fazer face a este problema. Nesta dissertação são descritas as várias técnicas de dessalinização da água do mar em uso corrente, assim como as novas tecnologias e aplicações futuras. De todas as técnicas, a Reverse Osmosis (RO) foi tratada com mais detalhe neste estudo, por ser das técnicas mais utilizadas em todo mundo e porque é a mais promissora em termos de custo/benefício, mesmo em regiões onde antes a sua aplicação era impensável. Esta dissertação foca aspetos importantes relacionados com o processo da dessalinização, nomeadamente, os impactes ambientais e relação custo/benefício associados ao processo, e as perspetivas futuras. Finalmente procedeu-se a uma análise do processo de dessalinização aplicado à situação de Cabo Verde, onde os recursos hídricos de água potável são escassos, e a dessalinização apresenta-se como a principal fonte de água potável para abastecimento público.

Public-Private Partnership Design for Inclusive Cocoa Global Value Chains in Ghana

Within 10 years, there could be a severe global shortage in the supply of cocoa, according to industry practitioners and other experts. Due to global population growth and the emergence of a growing global middle class, by 2025 the cocoa crop would need to increase by nearly 50 per cent to keep up with projected demand. A potential shortage of supply is a direct threat to the business model of lead firms – including cocoa grinders and processors, chocolate confectioners, and retail distributors. But these international firms – the ones that will suffer the most if there is a shortage of cocoa supply – are helping create the market failure that is stifling sustainability. Functioning as a two-tiered consolidated oligopoly with a combined market share of approximately 89%, these firms enjoy the largest portion of value capture in the cocoa-chocolate global value chain (GVC). The smallholder cocoa producers, conversely, are trapped in low value-add segments of the GVC. In fact, most smallholder farmers survive on less than $1.00 per day per capita, on average in many cocoa exporting countries. In Ghana - the second largest producer of cocoa in the world - the government has accomplished little to help these smallholders upgrade and make cocoa an attractive sector for the next generation to inherit. The result – both in Ghana and around the world – is a lack of sustainability of the supply of cocoa. Demand is already beginning to outstrip supply. As a result of these underlying circumstances, the United States Agency for International Development (USAID) has posed the following policy question: "Under what conditions could USAID, as a development agency, support and enhance potential public-private partnerships in order to improve the bargaining power (and financial wherewithal) of smallholder organizations and farmers in the context of the global value chain for cocoa in Ghana?"