bluuebunny/crossref_metadata_2025 huggingface dataset:
Desempenho acústico de conjuntos de portas e paredes separadas pelo hall de entrada
Authors: Scherer Claudio Trindade , Oliveira Maria Fernanda de , Medeiros Daniel Reis , Tutikian Bernardo Fonseca
Published: June 2019

Resumo O conjunto de paredes e portas separadas pela circulação de uso comum em edifícios residenciais passou a ter seu desempenho acústico avaliado, a partir da entrada em vigor da norma brasileira NBR 15575. Nesse contexto, este trabalho propõe determinar a influência das características dos elementos construtivos - portas e circulações entre unidades habitacionais - no isolamento ao ruído aéreo do conjunto de paredes e portas separadas pelo hall de entrada. Foram escolhidos três prédios e realizada uma série de ensaios de desempenho acústico em campo, abrangendo diversas situações. Também foram usados artifícios para a vedação das frestas das portas, a fim de verificar a melhora do desempenho do sistema. Os resultados obtidos apontam para a perda de desempenho acústico com o aumento das frestas entre a folha da porta e o piso. Ainda, foram encontradas relações entre o tempo de reverberação dos ambientes de circulação e a distância entre as portas de entrada das unidades habitacionais. Pode-se concluir que o alinhamento frontal de portas de entrada das unidades habitacionais distintas e halls com elevado tempo de reverberação reduzem a eficiência do isolamento acústico do conjunto de portas e parede voltadas para circulações de uso comum em edifícios habitacionais, assim como frestas mal vedadas.
CFD simulation and measurement of the thermal behavior inside a room of the institutional library: a comparative study
Authors: Silva Efrén Vázquez , Muñoz Franco David Cajas , Deleg Marcelo Xavier Asitimbay , Jara Paúl Bolívar Torres , Farfán Gabriela Abad
Published: June 2019

Abstract This article presents the results of the comparison between the CFD simulation and temperature measurements, both in the time domain, at a certain point of interest within a specific closed space (cubicle) of the institutional library of the Salesian Polytechnic University (UPS), at its headquarters in the city of Cuenca, Republic of Ecuador. In this specific case, solar radiation is considered as the main heat transfer mechanism, which is why it was considered in the applied simulation method. An acceptable relative error was obtained between the simulated and measured temperature values. During the summer period, the thermal conditions inside the cubicle are not suitable for the comfort of the users. The study developed can constitute a basic tool for possible future research related to the implementation of climate conditioning for the cubicle, the library in general and any other site with similar constructive and operational characteristics.
Tipos e eficiência de unidades de tratamento para água pluvial: revisão de literatura
Authors: Dalpaz Leticia , Borgert Aline Eloize , Vendrami Júlia May , Ghisi Enedir
Published: June 2019

Resumo O aproveitamento de água pluvial em edificações representa uma alternativa atraente como fonte de água. No entanto, para possibilitar sua utilização, a água pluvial deve ser tratada para atingir a qualidade necessária. Os filtros são bastante utilizados e aparecem em diversos modelos. Com o intuito de avaliar diferentes sistemas de filtragem, foi feita uma comparação entre os parâmetros obtidos com cada unidade de tratamento levantada e os valores recomendados pela ABNT (2007). Também foram comparadas as eficiências dos sistemas entre si. Para isso, uma revisão bibliográfica foi desenvolvida com base em pesquisa na literatura existente. Visou-se organizar informações a respeito do estado da arte de unidades de tratamento de água pluvial no mundo e contribuir para a consolidação do uso desses sistemas. Identificou-se falta de padronização nos métodos e parâmetros, o que prejudica a análise precisa acerca de quais modelos seriam mais adequados para os possíveis cenários de utilização. Também foi constatado que o padrão de qualidade de água exigido na norma brasileira não foi atingido para nenhum caso. Entretanto, os modelos estudados mostraram resultados promissores, atingindo elevados percentuais de remoção, variando em sua maioria de 60% a 100%.
Vazão de projeto na microdrenagem em locais sem dados de precipitação: estudo para o Rio Grande do Sul
Authors: Basso Raviel Eurico , Allasia Daniel Gustavo , Tassi Rutinéia
Published: June 2019

Resumo O dimensionamento de estruturas da drenagem pluvial urbana é realizado, normalmente, a partir de dados de chuvas intensas. Essas informações comumente são obtidas por meio das relações intensidade-duração-frequência (IDF), ou na indisponibilidade destas, mediante metodologias simplificadas, tais como as relações entre durações, isozonas de chuvas, ou métodos sintéticos tais como os propostos por Bell (1969) e Chen (1983). Neste artigo é apresentada uma análise da aplicabilidade do método sugerido por Bell, com uma modificação (BACK, 2009), para estimativa de chuvas intensas no Estado do Rio Grande do Sul a partir de informações de chuva diárias, e o uso destas para a determinação de vazões utilizadas no dimensionamento de obras de microdrenagem. Os resultados mostraram que a metodologia de Bell e a modificada segundo Back (2009) estimaram corretamente as chuvas intensas e as vazões de microdrenagem (por sua vez estimadas a partir do método racional) para durações inferiores a 2 horas, quando comparada com informações obtidas diretamente de equações IDFs, em que as variações médias ficaram próximas a 10%. As exceções foram em Espumoso e em Santa Vitória do Palmar, onde superaram os 15% de variação, o que a torna uma opção adequada para o dimensionamento de estruturas da microdrenagem pluvial, quando as relações IDF não estiverem disponíveis.
Avaliação de desempenho dos sistemas de abastecimento de água do Agreste brasileiro
Authors: Bezerra Saulo de Tarso Marques , Pertel Monica , Macêdo José Eloim Silva de
Published: June 2019

Resumo De acordo com os dados do Sistema Nacional de Informações sobre Saneamento (SNIS) do Brasil, do total da água produzida pelas companhias de saneamento em 2016, cerca de 38% foram perdidos na distribuição, entre perdas reais e aparentes. Além das perdas de água, perdem-se outros insumos, recursos financeiros e mão de obra que poderiam ser investidos na melhoria e na reabilitação de ativos das empresas. A presente pesquisa objetiva avaliar o abastecimento de água de municípios do Agreste brasileiro com base em indicadores do SNIS relacionados às perdas de água. A metodologia fundamentou-se em estatística descritiva, de modo que os valores dos indicadores operacionais adotados de cada munícipio foram comparados com valores de referência, a fim de analisar a eficiência dos sistemas de abastecimento de água e estabelecer um benchmarking da região. Os melhores resultados foram da Embasa (Bahia), enquanto o estado com pior desempenho foi o de Sergipe. O estudo fornece subsídios aos gestores de companhias estaduais para a priorização de investimentos em sistemas ineficientes.
Escritórios de planta livre: o impacto de diferentes soluções de fachada na eficiência energética
Authors: Brugnera Rosilene Regolão , Mateus Ricardo , Rossignolo João Adriano , Chvatal Karin Maria Soares
Published: June 2019

Resumo No Brasil, os edifícios de escritórios de planta livre têm se destacado pela utilização de fachadas totalmente envidraçadas, aspecto que pode impactar diretamente o consumo de energia do ar condicionado. O objetivo deste estudo é classificar e caracterizar o desempenho energético de edifícios de escritório de planta livre em três climas brasileiros. Simulações computacionais foram realizadas no programa EnergyPlus, a fim de verificar o impacto de vários parâmetros (clima, tipo de fachada, PAF, tipo de vidro, dispositivo de sombreamento e temperatura de setpoint) no consumo de energia do ar condicionado. Os resultados, classificados em faixas de desempenho energético, mostraram que alterar de uma fachada tradicional (alvenaria) para uma fachada cortina (totalmente envidraçada) elevou o consumo de energia do ar condicionado em média 25% para Curitiba e São Paulo e 15% para Manaus; que o PAF foi o parâmetro que mais impactou esse consumo, e o tipo de vidro teve mais impacto nas maiores aberturas; que utilizar um dispositivo de sombreamento sempre gerou economia e a elevação em 1 ºC do setpoint de resfriamento reduziu o consumo, em média, até 16,4%. Tais resultados geraram as melhores combinações desses parâmetros para cada clima, podendo servir de suporte aos projetistas, no sentido de se criar edifícios energeticamente mais eficientes.
Predicting the Structure of Grain Boundaries in Fluorite-Structured Materials
Authors: Lucid Aoife K. , Plunkett Aoife C. , Watson Graeme W.
Published: June 2019

Interfaces are a type of extended defect which govern the properties of materials. As the nanostructuring of materials becomes more prevalent the impact of interfaces such as grain boundaries (GBs) becomes more important. Computational modelling of GBs is vital to the improvement of our understanding of these defects as it allows us to isolate specific structures and understand resulting properties. The first step to accurately modelling GBs is to generate accurate descriptions of the structures. In this paper, we present low angle mirror tilt GB structures for fluorite structured materials (calcium fluoride and ceria). We compare specific GB structures which are generated computationally to experimentally known structures, wherein we see excellent agreement. The high accuracy of the method which we present for predicting these structures can be used in the future to predict interfaces which have not already been experimentally identified and can also be applied to heterointerfaces.
Geometric Morphometrics Dismiss the Polymorphic Hydrocotyle quinqueloba (Araliaceae) from the Neotropics
Authors: Nery Eduardo Koerich , Fiaschi Pedro
Published: June 2019

Abstract—Hydrocotyle taxonomy is poorly resolved due the traditional assessment of leaf morphology that has imposed difficulties to species delimitation and prompted the recognition of several infraspecific taxa. Hydrocotyle quinqueloba comprises ten infraspecific
taxa that differ mainly by the shape of their leaf blade. The species complex occurs in montane forests of the Andes and eastern Brazil, along the Atlantic Forest and Cerrado domains. However, the geographic distribution of the taxa under H. quinqueloba is poorly known, and their supposedly
continuous morphological variation remains unverified. Here we analyze the morphological variation and documented correlated differences in geographic distribution of H. quinqueloba to assess whether they support the delimitation of distinct species or the recognition of infraspecific
taxa. For this task, we applied landmark-based geometric morphometrics (GM) to leaves and traditional morphometrics to other structures of specimens of H. quinqueloba. Procrustes analysis of variance (Procrustes ANOVA) indicated that variation of leaf blade shape was weakly associated
with geography and was mainly explained by taxa themselves. In contrast, variation of leaf blade size was significantly (p < 0.001) associated with geography, but variation at the specimen level could account for it. Principal component analysis (PCA) of leaf blade shape indicated
that taxa differed mainly by the angle and relative size between median and lateral primary veins, by the space between the petiole insertion and middle lobe’s sinuses, and by the width of the middle lobe’s base. Canonical variate analysis (CVA) indicated significant (p
< 0.01) differences among seven infraspecific taxa that formed groups defined by leaf blade shape. Linear discriminant analysis (LDA) of 11 morphological characters separated five groups of taxa, which displayed significant (p < 0.001) differences among each other. Based on that,
we propose an updated taxonomic treatment that restricts the circumscription of H. quinqueloba to plants from the Andes and accepts four species from eastern Brazil.
Mycetia suedixieana (Rubiaceae), a New Species of Argostemmateae Endemic to the Philippines
Authors: Tandang Danilo N. , Ordas Jorge Anton D. , Tadiosa Edwin R. , Banag-Moran Cecilia I. , Alejandro Grecebio Jonathan D.
Published: June 2019

Abstract—A new species, Mycetia suedixieana, from Samar, Philippines, is described and illustrated. It is an unusual, heavily-branched shrub thriving on moist limestone that is easily distinguishable from other Mycetia species in multiple aspects
of its morphology. A key to the known species of Philippine Mycetia is also provided in this study.
A Curious New Species of Xenostegia (Convolvulaceae) from Central Africa, with Remarks on the Phylogeny of the Genus
Authors: Sosef Marc S. M. , Gereau Roy E. , Janssens Steven B. , Kompanyi Modestine , Simões Ana R.
Published: June 2019

Abstract—The polymorphic genus Merremia has been shown to be polyphyletic. In 1980, Xenostegia was separated from the first, based on its longitudinally dehiscing anthers, stigmas with long tapering papillae, and non-spiny, pantoporate pollen, and accommodated
two species in the Old World tropics. A recent molecular study and subsequent review of the tribe Merremieae resulted in the distinction of seven genera and corroborated the delimitation of Xenostegia at genus level, with three more species added to it. During fieldwork carried out
in 2015 and 2016 in Lomami National Park, Democratic Republic of the Congo, material was collected of a Convolvulaceae species with pinnatifid leaves that was morphologically very close to Xenostegia sapinii, but deviated notably in sepal shape and corolla length. Closer examination
revealed additional distinctive characters leading to the conclusion that it represents a distinct taxon new to science. Its pantoporate pollen, longitudinally dehiscing anthers, and stigmas with long papillae seem to confine its placement in Xenostegia. However, its most striking feature
is the presence of two free styles, a character otherwise not present in the subfamily Convolvuloideae. The results of our molecular phylogenetic analyses confirmed our hypothesis on our new taxon being a member of Xenostegia. The observed incongruence between the nuclear and plastid-based
trees might indicate that the new taxon has a hybrid origin. Based on all evidence, it is recognized at species level, Xenostegia lomamiensis, and it is formally published, along with a full morphological description, illustration, habitat data, and an informal IUCN Red List
assessment. A key to the species of Xenostegia in central Africa is provided.
Artemisia baxoiensis (Asteraceae: Anthemideae), a Distinctive New Species from Xizang, China
Authors: Jiao Bohan , Zhang Guojin , Zheng Jiye , Nie Bao , Niu Guohao , Shen Jiahao , Wei Meng , Gao Tiangang
Published: June 2019

Abstract—A new species of Artemisia (Asteraceae: Antemideae) from Xizang, China, A. baxoiensis, is described, illustrated, and discussed based on morphological, micromorphological, and molecular phylogenetic evidence. It grows in the Nu Jiang dry-hot
valley and is narrowly distributed. This plant is similar to Neopallasia pectinata, but different in capitula and indumentum. Artemisia baxoiensis has a distinctive morphology with a pectinately pinnatisect leaf blade and unusually dense glandular hairs.
New and Reassessed Species of Griffinia (Amaryllidaceae) from the Brazilian Atlantic Forest
Authors: Campos-Rocha Antonio , Meerow Alan William , Menezes Lopes Edimar Faria , Semir João , Sampaio Mayer Juliana Lischka , Antoinette Dutilh Julie Henriette
Published: June 2019

Abstract—In the context of the revision of Amaryllidaceae tribe Griffinieae that we are preparing, we describe and illustrate a new species, Griffinia albolineata, known from a single fragment of the Atlantic Forest in the Brazilian State of Minas Gerais.
It is distinguished by the foliar blade with a whitish longitudinal stripe and long-acuminate apex, unique features among the large-sized species of the genus. Additionally, we present a taxonomic reassessment of G. intermedia, described two centuries ago and historically of very uncertain
identity. We provide a description and detailed distribution data, previously unpublished records, and photographs of the species in its natural habitat. We also compare the foliar anatomy and surface micromorphology of the two species. The conservation status of the two species is informally
evaluated, and both are tentatively considered endangered. An identification key to the large-sized species of the genus is presented.
Description of a New Species of Spiny Solanum (Solanaceae) from Rocky Outcrops of Northeastern Brazil, with Modeling of Its Environmental Suitability
Authors: da Silva Sampaio Valéria , Gouvêa Yuri Fernandes , Bezerra de Souza Elnatan , José-Silva Leandro , Eisenlohr Pedro V. , Bezerra Loiola Maria Iracema
Published: June 2019

Abstract—Rocky outcrops surrounded by vegetation in northeastern Brazil form special ecosystems of high species richness and endemism and represent priority areas for biodiversity studies and conservation measures. Floristic surveys of rocky outcrops in the State of
Ceará resulted in the identification of a new species of Solanum from the Thomasiifolium clade. Its morphological description, geographic distribution, habitat, ecology, informal conservation status, and environmental suitability models are provided and discussed.
Aspidosperma huberianum (Apocynaceae), a New Species from the Brazilian Amazon
Authors: Stephanie de Souza Pereira Andreza , Devides Castello Ana Carolina , Freitas da Silva Edilson , Felix Guimarães José Tasso , Simões André Olmos , Koch Ingrid
Published: June 2019

Abstract—We describe Aspidosperma huberianum, a new species from the Brazilian Amazon. The new taxon is morphologically similar to A. darienense, but can be distinguished readily by characters of the leaf (including venation), flower (including
calyx lobe number and indument of the corolla and ovary), pollen, fruit, and seed. We provide a taxonomic description, pollen characterization, illustration, photographs, and a distribution map for the new taxon, as well as information on its conservation status, habitat, and phenology.
The Kenyan IPP experience
Authors: Eberhard A , Gratwick K , Gratwick K
Published: June 2019

Public and concessionary finance for the expansion of power systems in Kenya dwindled in the 1990s. Meanwhile, demand for electricity services was on the rise. Private investment emerged to fill the gap with four Independent Power Producers (IPPs) established in the country by the second half of the decade. From 2000, the private market appears to have collapsed. Expansion of the power sector is once again led by the incumbent state-owned utility. This paper examines the investment and development outcomes of the four IPP projects, and highlights a number of interesting features of this experience. Firstly, the regulator matters. Established after the first wave of IPP developments, the regulator helped to bring tariffs of the second wave down. Secondly, the tendering process (i.e. an international competitive bid) does not ensure competition for a country that has significant political risk. Bidders self select well before the tender begins, a process which led one Kenyan tender to attract only two bidders (one of which was non-compliant). Thirdly, local partners matter. Half of the projects had local partners, and those that did faired better in the long run. The impact of project financing, public perception and currency devaluation is also evaluated to glean lessons learned of past projects and help pave the way for a more sustainable future for the Kenyan power sector—which presently serves only 15% of the population.
Energy efficiency in South African industry
Authors: Fawkes H
Published: June 2019

Energy efficiency in South African industry has only recently started receiving attention due to the low cost of South Africa’s electricity, and a not too distant history of isolation leading up to democratic elections in 1994.This study shows that strong incentives exist for energy efficiency improvement in South African industry, in particular, the potential for increasing profit, the need to reduce greenhouse gas (GHG) emissions, the need to maintain economic competitiveness, and the need to delay the cost of new peak-load electricity generation facilities. Barriers to the implementation of energy efficiency projects need to be anticipated and addressed by managers, policy makers and energy efficiency practitioners. In particular, the lesson from the case study in this paper showed how organisation structure, financial controls and culture, can be barriers to the implementation of energy projects. By ensuring the support of top management, and by the initiation of an energy management program early on, these barriers can be avoided and results and recommendations from an energy assessment can feed into a receptive management system.
Technologies for recovery of energy from wastewaters: Applicability and potential in South Africa
Authors: Stafford William , Cohen Brett , Pather-Elias Simisha , Von Blottnitz Harro , Van Hille Robert , Harrison Sue T.L. , Burton Stephanie G.
Published: June 2019

This study explored technologies for recovering energy from wastewater through production of biomass, combustion and gasification, generation of biogas, production of bioethanol, heat recovery and microbial fuel cells. A first order desktop analysis of the potential for applying these solutions to wastewaters in South Africa revealed that 3 200 to 9 000 MWth of energy has potential for recovery, equating to at most 7% of South Africa’s current electrical power supply. Formal and informal animal husbandry, fruit and beverage industries and domestic blackwater were identified as wastewaters with the greatest potential for energy recovery. Of the reviewed technologies, anaerobic digestion shows applicability to the widest range of feedstocks. Net energy generated, reduction in pollution, and water reclamation are identified as the main benefits, but additional benefits such as certified emission reductions, fertiliser production and the production of secondary products may dictate the economic feasibility.
Evaluation of feed-in tariff-schemes in African countries
Authors: Meyer-Renschhausen M.
Published: June 2019

Almost all African countries are planning to increase their power supply capacities and to diversify the resource base of the electricity sector. In sharp contrast to the ambitious objectives, grid connected power plants, based on renewable energies, are very rare except large scale hydropower in African countries. The small number of renewable energy (RE)-plants in Africa shows that a quick diffusion of these technologies cannot be expected from the dynamic of market forces alone. Political support is necessary. By now, feed-in tariffs (FIT) is the most prominent economic instrument promoting renewable energy technologies in the power sector. They are applied in more than 50 countries, among them several African countries like Algeria, Kenya, Uganda, Ghana and Tanzania. The objective of the paper is to investigate the outcome and effectiveness of African FIT-schemes. It is assumed that most of the FIT-schemes in Africa are poorly working because of unfavourable institutional design, insufficient level of FIT rates or obstacles in the process of implementation. Deficiencies in the design of FIT-schemes and the implementation process can be explained by conflicting policy targets like affordable power prices and grid stability but also with an unclear allocation of property rights that can lead to time-consuming negotiations of Power Purchase Agreements.
Efficiency and costs of different concentrated solar power plant configurations for sites in Gauteng and the Northern Cape, South Africa
Authors: Telsnig Thomas , Eltrop Ludger , Winkler Hartmut , Fahl Ulrich
Published: June 2019

Concentrated solar power (CSP) plants can play a major role in the future South African electricity mix. Today the Independent Power Producer (IPP) Procurement Programme aims to facilitate renewable energy projects to access the South African energy market. In spite of this incentive programme, the future role of CSP plants in South Africa has yet to be defined. Using hourly irradiance data, we present a new method to calculate the expected yield of different parabolic trough plant configurations at a site in each of Gauteng and the Northern Cape, South Africa. We also provide cost estimates of the main plant components and an economic assessment that can be used to demonstrate the feasibility of solar thermal power projects at different sites. We show that the technical configurations, as well as the resulting cost of electricity, are heavily dependent on the location of the plant and how the electricity so generated satisfies demand. Today, levelised electricity costs for a CSP plant without storage were found to be between 101 and 1.52 ZAR2010/kWhel, assuming a flexible electricity demand structure. A CSP configuration with Limited Storage produces electricity at costs between 1.39 and 1.90 ZAR2010/kWhel, whereas that with Extended Storage costs between 1.86 and 2.27 ZAR2010/kWhel. We found that until 2040 a decrease in investment costs results in generating costs between 0.73 ZAR2010/kWhel for a CSP plant without storage in Upington and 1.16 ZAR2010/ kWhel for a configuration with Extended Storage in Pretoria. These costs cannot compete, however, with the actual costs of the traditional South African electricity mix. Nevertheless, a more sustainable energy system will require dispatchable power which can be offered by CSP including storage. Our results show that the choice of plant configuration and the electricity demand structure have a significant effect on costs. These results can help policymakers and utilities to benchmark plant performance as a basis for planning.
Potential and future of concentrating solar power in Namibia
Authors: Le Fol Y. , Ndhlukula K.
Published: June 2019

The Namibian electricity sector has mainly relied on electricity imports from the Southern African Power Pool (SAPP) over the last decade. However, a growth in electricity demand and scarce import options could cause energy shortages. Therefore, new power plants ought to be commissioned in the near future to avoid the forecasted energy crisis. In this context, Concentrating Solar Power (CSP) generation is regarded as an appropriate alternative to conventional energy technologies, particularly for the excellent solar regime available in Namibia. The study presents a GIS analysis that identifies suitable areas for CSP establishment. A broad range of geographical parameters such as solar radiation, topography, hydrology or land use are examined. The calculations show that the CSP ceiling generation in Namibia is equivalent to 70% of the worldwide electricity production. Moreover, the study offers a scenario analysis where concrete CSP alternatives are compared to coal-fired plant projects developed by the national power utility. Meteonorm and System Advisor Model (SAM) are used to design CSP alternatives located in the area offering the best combination between high solar irradiation and short distances to the infrastructures. Despite the affordability concern which has to be addressed with sound financial instruments, CSP represents a seminal opportunity for the energy sector in
Policy options for the sustainable development of Zambia’s electricity sector
Authors: Tembo Bernard , Merven Bruno
Published: June 2019

This paper aims at understanding how Zambia’s electricity system would be affected by droughts (due to a dry year) and how the system’s adaptive capacity could be improved. Hydropower currently supplies 99% of the total electricity in Zambia, and concerns have been raised because many climate change studies project increased occurrences of dry years in the Southern Africa region. Different economic and climatic scenarios were explored to understand their impact on the development of Zambia’s power generation system, and what policies and strategies could be adopted to mitigate these impacts on security of supply and average generation costs, which directly affect the electricity price. The results show that a dry year has significant impact on the average generating cost since hydropower continues to dominate the system. Diversifying the system does not improve the adaptive capacity of the system but only increases the average cost of generating electricity in an average year. The most cost effective way of increasing the system’s adaptive capacity is by importing electricity and gradually increasing share of renewable and coal technologies in the system. Further research on how electricity trade in Southern Africa could be enhanced, should be done.
Simulation of a syngas from a coal production plant coupled to a high temperature nuclear reactor
Authors: Botha Frikkie , Dobson Robert , Harms Thomas
Published: June 2019

In light of the rapid depletion of the world’s oil reserves, concerns about energy security prompted the exploration of alternative sources of liquid fuels for transportation. One such alternative is the production of synthetic fuel using an indirect coal liquefaction process or coal-to-liquids (CTL) process. In this process, coal is gasified in a gasifier in the presence of steam and oxygen to produce a synthesis gas or syngas consisting mainly of hydrogen and carbon monoxide. The syngas is then converted to liquid fuels and a variety of useful chemicals in a Fischer Tropsch-type synthesis reactor. However, the traditional process for syngas production also produces substantial amounts of carbon dioxide. In fact, only about one third of the carbon in the coal feedstock ends up in the liquid fuel product using traditional CTL technology. If more hydrogen was available than the hydrogen produced during the gasification step, the carbon utilisation of the process could be improved significantly. The high temperature reactor (HTR) is a gas cooled Generation IV nuclear reactor ideally suited to provide power and high temperature heat for carbon neutral production of hydrogen via high temperature electrolysis. The integration of an HTR into a CTL process therefore provides an opportunity to improve the thermal and carbon efficiency of the CTL process significantly. This paper presents a possible process flow scheme for a nuclear assisted CTL process. The system is evaluated in terms of its thermal or syngas production efficiency (defined as the ratio of the heating value of the produced syngas to the sum of the heating value of the coal plus the HTR heat input) as well as its carbon utilisation. If the hydrogen production plant is sized to produce only enough associated oxygen to supply the needs of the gasification plant, syngas is produced at about 63% thermal efficiency, while 71.5% of the carbon is utilised in this process. It was found that the optimum HTR outlet temperature to produce hydrogen with a high temperature steam electrolysis process is 850°C. If enough process heat and power are available and process equipment capacities are sufficient, the carbon utilisation of the process could be improved even further to values in excess of 90%.
Human and physical energy cycles in a subsistence village in South Africa
Authors: Chikava Winnie , Annegarn Harold J.
Published: June 2019

A rural, self-contained village in Africa relies mainly on draft animals, energy provided by humans and energy from natural resources, especially firewood, for survival. The human metabolic energy cycle in a rural self-sufficient village in Venda in the Limpopo Province of South Africa is investigated, concentrating on selected activities that make up the routine livelihoods in the wet season. The selected village depended on only a slight extent on external ‘modern’ energy inputs such as electricity, paraffin and diesel in relation to overall energy consumption. Forty-three interviews were conducted in order to identify patterns of labour, sources of food, and foods consumed, while electronic pedometers were employed to quantify energy expended for weeding, firewood and water collection carried out in the wet season in February. A conceptual energy model showing flows of energy from one activity to another within the village was developed. An energy balance model, for an average adult male and female village resident, was developed quantitatively from the conceptual model, taking into account energy intake and energy expenditure. Energy expenditure for males was 1 991 kcal/d; females were 1 965 kcal/d, energy intake for males was 1 953 kcal/d and females was 2 007 kcal/d .This study is significant for future development of rural dwellers. It provides a baseline case for future developments in which modern energy carriers are introduced into remote areas. These may include conventional energy such as electricity, or renewable energies such as low energy devices powered off solar photovoltaic panels or off grid solar/wind systems.
Considerations for a sustainable hybrid mini-grid system: A case for Wanale village, Uganda
Authors: Kimera Raymond , Okou Richard , Sebitosi Adoniya Ben , Awodele Kehinde O.
Published: June 2019

The extension of modern energy services to rural sub-Saharan Africa has continuously provided a challenge to energy utilities. The continued reliance on diesel generators for rural electrification is increasingly becoming unsustainable, due to a number of factors, among which includes their high fuel dependency, and the uncertainty surrounding the price and availability of fossil fuels. While the influx of renewable energy technologies has provided a means for providing off-grid electrification services, the intermittent nature of renewable resources poses a challenge, as energy generation does not always coincide with usage. Through a combination of renewable energy technologies, energy storage, and conventional diesel generation, a hybrid mini-grid system is able to achieve synergy in operation, hence providing a reliable means of extending electricity services to rural consumers. In this paper, a hybrid mini-grid system is proposed for the supply of electricity to a remote village in Uganda. Renewable energy resources are identified, an estimation of the projected village short-term electricity demand is modelled, and using HOMER software, a hybrid mini-grid system is designed, components sized, and the system optimized for efficient and reliable operation to meet the village demand at an affordable cost. A well designed and operated hybrid mini-grid system offers a viable tool for the electrification of even the remotest of areas.
umerical simulation of atmospheric boundary layer and wakes of horizontal-axis wind turbines
Authors: AbdelSalam Ali M. , Velraj Ramalingam
Published: June 2019

Simulations of wind turbine wakes are presented in this paper using the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations employing the k-e turbulence model appropriately modified for the atmospheric flows. The actuator disk approach is used to model the action of the turbine rotor. Modified formulations of the inlet conditions and the wall functions are used to allow consistency between the fully developed atmospheric boundary layer (ABL) inlet profiles and the wall function formulation. Results are presented and compared with three wind turbines running under neutral atmospheric conditions. The results demonstrate that the accurate simulation of the atmospheric boundary layer applying enhanced inlet conditions and wall function formulation consistent with the k-e model can give very useful information about the wakes, directly contributing to the accurate estimation of the power of the downstream turbines.
A 2MW direct drive wind turbine; vector control and direct torque control techniques comparison
Authors: Allagui Mehdi , Hasnaoui Othman B.k. , Belhadj Jamel
Published: June 2019

This paper presents a comparative study on the most popular control strategies used to control high power, Direct Drive Wind Turbines. The studied wind turbine is equipped with a supervision scheme in order to fulfil Grid connection requirements (GCR). For the generator-side converter, performances of the Field Oriented Control (FOC) and Direct Torque Control (DTC) are compared. Concerning the grid-side converter, Voltage Oriented Control (VOC) and Direct Power Control (DPC) are examined. The comparison is based on various criteria mainly, steady-state and transient performances. In addition, performances are evaluated in terms of low voltage ride through capabilities (LVRT), power limitation and reactive power control. It has been shown that best power quality features are given by vector control techniques. On the other hand, direct control offers the better dynamic response and power cross-coupling is substantially lower. Furthermore, during fault, the wind turbine does not trip for both techniques. However, vector control is better since it gives low power oscillations
Islas Senkaku o Diaoyu: los intereses geopolíticos de dos estados en tensión
Authors: Cardona Ruiz Daniel Elifonso
Published: June 2019

La disputa fronteriza entre Japón y China sobre las islas Diaoyu o Senkaku ha estado presente por más de cuarenta años. Este conflicto está caracterizado por ser cíclico, pues por varios años se puede dejar de hablar del asunto, y de un momento a otro, acciones por parte de uno de los dos países generan inmediato descontento en el otro, que va desde simples protestas callejeras a xenofobia y amenazas de limitación comercial. Con el fin de entender mejor la situación, el presente artículo presenta los hechos históricos más importantes a lo largo de la disputa, al igual que analiza las acciones tomadas por ambas partes en los últimos meses.
Filosofías espirituales en China
Authors: Gómez Gómez Laura
Published: June 2019

El Confucionismo, Budismo y Taoísmo son conceptos muy importantes para la cultura china. Por lo general, se presentan confusiones con respecto a su definición, bien sea como religión o como filosofía. En este artículo se clasifican como filosofías espirituales, puesto que comprenden conceptos tanto religiosos como filosóficos.
Seúl, ciudad de contrastes: masculinidad y capital mundial del maquillaje para hombres
Authors: Osorio Gómez Laura , Soler Vélez Cristina
Published: June 2019

El rol del hombre en la sociedad ha cambiado en los últimos tiempos. Este cambio se evidencia en Corea del Sur, un país en el que la cultura ha sido tradicionalmente machista, pero que en la modernidad ha acogido nuevos valores y se ha convertido en un escenario de competencia, donde el más fuerte sobrevive. Allí, el éxito no sólo se mide por las cualidades y capacidades, sino también por la apariencia. Este cambio cultural ha transformado a Seúl, que es hoy la capital mundial del maquillaje masculino.
De reino ermitaño a tigre asiático. El modelo de desarollo de Corea del Sur
Authors: Posada Suárez Camilo
Published: June 2019

La República de Corea es un caso especialmente llamativo dentro del selecto grupo de los cuatro tigres asiáticos. A pesar de sus anteriores condiciones hostiles y adversas para su crecimiento, actualmente se ubica dentro de las 15 economías más grandes del planeta. En este artículo se estudian y analizan las particulares condiciones políticas, económicas, geográficas, demográficas y corporativas, que han guiado al país por la senda del progreso.
Singapur: El pequeño gigante del Sureste Asiático
Authors: Franco Herrera David
Published: June 2019

En este artículo se pretende mostrar un panorama general de Singapur, país que hoy por hoy es reconocido mundialmente como centro financiero y de negocios por la estabilidad de su gobierno y la fortaleza de su economía. Además, se busca exponer algunos de los logros alcanzados por esta economía y el tipo de políticas implementadas para alcanzar el estatus del que goza hoy en día. Posteriormente, se presentan los avances en materia de relaciones bilaterales entre Colombia y Singapur, para finalmente concluir con una opinión sobre lo que Colombia debería aprender de Singapur para alcanzar un desarrollo económico que permita elevar el nivel de vida de sus habitantes, siendo clave para este proceso la educación de su población y el beneficio que trae la Inversión Extranjera Directa (IED) a los países que saben aprovecharla, desde el punto de vista de la absorción de conocimiento.
¿Es posible una reunificación en la península coreana?
Authors: Osorio Gómez Laura
Published: June 2019

Desde 1948, las relaciones intercoreanas han fluctuado. En un principio se buscaba la reunificación por medio de la fuerza y la absorción, posteriormente la recuperación de la confianza dominaba el proceso. Corea del Norte se encuentra cada vez más aislado y en decadencia. Sucesos como el desmoronamiento del sistema de la Unión Soviética, la muerte del fundador del Juche, las fuertes hambrunas y el cambio de curso de sus aliados históricos, han debilitado profundamente al régimen que terminará colapsando en algún momento. Dada la situación actual en Corea del Norte y el cambio en la actitud del gobierno de Corea del Sur hacia una mejoría en las relaciones, es posible pensar en que se acerca una reunificación.
Educación universitaria en Japón: políticas para la atracción de estudiantes extranjeros.
Authors: Rodríguez-Ríos Juan David
Published: June 2019

Desde el año 1983 Japón ha venido implementado políticas encaminadas a hacer atractivo su sistema de educación superior para los estudiantes internacionales. El presente artículo expone el desarrollo de dichas políticas y analiza la situación actual de Japón en materia de estudiantes extranjeros con miras al cumplimiento de las metas establecidas por el gobierno para el año 2020.
Publication Trends in Drug Delivery and Magnetic Nanoparticles v1
Authors: Ale Ebrahim Saba , Ashtari Amirhossein , Zamani Pedram Maysam , Ale Ebrahim Nader
Published: June 2019

This bibliometric study investigated the public trends in the fields of nanoparticles which is limited to drug delivery and magnetic nanoparticles’ literature published from 1980 to October 2017. The data were collected from the Web of Science Core Collections, and a network analysis of research outputs was carried out to analyse the research trends in the nanoparticles literature. Nanoparticles and its applications are progressing in recent years. The results show that documents in the field of nanoparticles in chemistry and material science have improved in citation rate, as the authors were researching in multidisciplinary zones. Top-cited documents are mainly focusing on drug delivery, magnetic nanoparticles and iron oxide nanoparticles which are also the top research keywords in all papers published. Top-cited papers are mostly published in Biomaterials journal which so far has published 12% of top-cited articles. Although research areas such as contrast agents, quantum dots, and nanocrystals are not considered as the top-ranked keywords in all documents, these keywords received noticeable citations. The trends of publications on drug delivery and magnetic nanoparticles give a general view on future research and identify potential opportunities and challenges.
Introduction to this Special Issue on Multimedia, Mobility and the Digital Southeast Asian Family’s Polymedia Experiences
Authors: Winarnita Monika
Published: June 2019

Southeast Asia is home to the largest number of social media users in the world. It is also a region known for its mobile population, with high numbers of overseas workers, international students, refugees/asylum seekers, and migrants seeking permanent residency or citizenship in other countries. Digital technology is shaping the way Southeast Asians express themselves, interact, maintain contact, and sustain their family relationships. Online multimedia content is one way that migrants and mobile Southeast Asians express their sense of belonging, their multiple and varied identities, their cultural backgrounds, and their sense of connectedness to family members. This special issue aims to provide a contemporary understanding of online multimedia expressions of identity, belonging, and intergenerational family relationships of migrants and mobile Southeast Asians. Six peer- reviewed journal articles and three creative commentaries explore how online multimedia productions and stories enable a deeper understanding of the effects of migration and mobility on intergenerational family relationships. By focusing on the online multimedia expressions of Southeast Asian people, this issue aims to comprehend social and cultural change in this region and the nuances of how it is being shaped by digital technologies. Moving beyond connectedness, the articles address a wide range of issues, such as power, con ict, and kinship relations. Themes such as educational mobility, the transnational family’s online communication, and the hopes and af rmations shared through digital diasporic communities are explored. By focusing on multimedia, mobility, and the digital Southeast Asian family’s polymedia experiences, this special issue contributes to the literature on digital networked societies.
Facebook, Polymedia, Social Capital, and a Digital Family of Indonesian Migrant Domestic Workers: A Case Study of The Voice of Singapore’s Invisible Hands
Authors: Rahajeng Mintarsih Adriana
Published: June 2019

Rarely do female migrant domestic workers (MDWs) get a chance to narrate their own migration experience. Voice of Singapore’s Invisible Hands (or The Voice), which started as a literary community on Facebook, aims to reshape the dominant—negative—discourse on migrant workers, especially Indonesian MDWs, by providing access to their literary work. In a transnational migration setting, Facebook has been used as a tool to maintain people’s relations with their families and friends back home, as well as for making new friends. Connections gained between individuals become a form of social capital where people build social networks and establish norms of reciprocity and a sense of trustworthiness. In the early establishment of The Voice, Facebook helped its initiator gain social capital. Ultimately, this social capital benefts the community and its members. Over the course of The Voice’s development, other social media platforms, namely WhatsApp, Skype, and email, have been used in addition to Facebook because they offer a different set of features and affordances of privacy and frequency. This practice of switching from one media to another is an illustration of polymedia, in which all media operate as an integrated structure and each is defned in relation to other media. This study, which focused on the relation of Facebook, polymedia, and social capital in the context of The Voice, used integrated online and offine qualitative data-gathering methodologies. The study found that Facebook initially helped both the community, which began as a learning space for Indonesian MDWs who wanted to narrate their stories about their home and family, and its members in their efforts to reshape the negative dominant discourse on migrant workers. It was the affordances of polymedia, however, that paved the way for the formation later on of a digital family in which the members provide emotional support for each other, similar to what family and close friends do.
Super-Homem e a Busca do Caminho Aristotélico: Contribuições para a Educação
Authors: Weschenfelder Gelson Vanderlei
Published: June 2019

Um dos mais notáveis fenômenos da cultura popular da atualidade é o ressurgimento vigoroso das histórias em quadrinhos de Super – Heróis, que, no entanto, não são tão inocentes como parecem.  Elas não trazem só o divertimento ao leitor. Elas introduzem e abordam de forma vívida questões de suma importância enfrentadas pelos seres humanos, referentes à ética, à responsabilidade pessoal e social, direitos e cidadania.  Super-Homem, um dos super-heróis mais conhecidos no mundo dos quadrinhos e, um dos primeiros a surgir, traz estas questões em suas histórias. A atitude deste super-herói aborda de forma vivenciada, questões éticas referendadas pelo filósofo grego Aristóteles.