1,447 research outputs found
The CCD and readout electronics for the OMC instrument on Integral
The Optical Monitoring Camera (OMC) on ESA's Integral gamma-ray astronomy satellite is devoted to optical wavelength observations simultaneously covering the same field-of-view as the gamma-ray and X-ray instruments. The OMC consists of a refracting telescope with a CCD as the imaging device in the focal plane. Here we describe the CCD and its associated readout electronics, in particular pointing out features of interest to users of the OMC instrument and its data
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Applicability of an 'uptake wave' energy transition concept in Indian households
Abstract
Reliable, secure, and affordable energy services are essential to ensuring sustainable economic and social development in the rapidly growing cities of the Global South, yet in India over 30 percent of urban households are still reliant on traditional fuels such as biomass and kerosene for some portion of their energy needs. Understanding the factors that influence energy transitions at a household level, is essential for successful strategies to promote the uptake of cleaner fuels and deliver associated socio-economic benefits. Such fast-growing cities often display intra-urban inequalities of considerable magnitude which can condition individual access to resources and impact the effectiveness of energy provision strategies for individual city districts. In this paper we will use the results of a survey of 500 households in Bangalore, India and explore how this data compares with the ‘wave concept’ model of energy transition. This ‘wave concept’ view of energy transitions focuses on appliance ownership as a proxy for energy services and conceptualises the uptake of appliances as a wave with early and late adopters rather than an income-based step change, and as a result better accounts for the role of non-income factors. The wards targeted by the survey cover a range of low-income ward typologies characterised by factors including income, livelihoods, building construction, socio-cultural factors, access to fuels, and reliability of supply. Validating an appropriate model for the uptake of new energy technologies and fuels in households, can better inform policy makers, entrepreneurs, and engineers on the influence of non-income barriers to energy transition across different districts of a city. By understanding how households use energy, and what limits the adoption of more efficient technologies at a local level, city planners and engineers can develop targeted sustainable strategies for adoption of cleaner more efficient fuels and appliances in households.</jats:p
Slipping through the net: Can data science approaches help target clean cooking policy interventions?
Reliance on solid biomass cooking fuels in India has negative health and socio-economic consequences for households, yet policies aimed at promoting uptake of LPG for cooking have not always been effective at promoting sustained transition to cleaner cooking amongst intended beneficiaries. This paper uses a two-step approach combining predictive and descriptive analyses of the IHDS panel dataset to identify different groups of households that switched stove between 2004/5 and 2011/12. A tree-based ensemble machine learning predictive analysis identifies key determinants of a switch from biomass to non-biomass stoves. A descriptive clustering analysis is used to identify groups of stove-switching households that follow different transition pathways. There are three key findings of this study: firstly non-income determinants of stove switching do not have a linear effect on stove switching, in particular variables on time of use and appliance ownership which offer a proxy for household energy practices; secondly location specific factors including region, infrastructure availability, and dwelling quality are found to be key determinants and as a result policies must be tailored to take into account local variations; thirdly some groups of households that adopt non-biomass stoves continue using biomass and interventions should be targeted to reduce their biomass use
Nucleation mechanism for the direct graphite-to-diamond phase transition
Graphite and diamond have comparable free energies, yet forming diamond from
graphite is far from easy. In the absence of a catalyst, pressures that are
significantly higher than the equilibrium coexistence pressures are required to
induce the graphite-to-diamond transition. Furthermore, the formation of the
metastable hexagonal polymorph of diamond instead of the more stable cubic
diamond is favored at lower temperatures. The concerted mechanism suggested in
previous theoretical studies cannot explain these phenomena. Using an ab initio
quality neural-network potential we performed a large-scale study of the
graphite-to-diamond transition assuming that it occurs via nucleation. The
nucleation mechanism accounts for the observed phenomenology and reveals its
microscopic origins. We demonstrated that the large lattice distortions that
accompany the formation of the diamond nuclei inhibit the phase transition at
low pressure and direct it towards the hexagonal diamond phase at higher
pressure. The nucleation mechanism proposed in this work is an important step
towards a better understanding of structural transformations in a wide range of
complex systems such as amorphous carbon and carbon nanomaterials
The Dynamics of Nestedness Predicts the Evolution of Industrial Ecosystems
In economic systems, the mix of products that countries make or export has
been shown to be a strong leading indicator of economic growth. Hence, methods
to characterize and predict the structure of the network connecting countries
to the products that they export are relevant for understanding the dynamics of
economic development. Here we study the presence and absence of industries at
the global and national levels and show that these networks are significantly
nested. This means that the less filled rows and columns of these networks'
adjacency matrices tend to be subsets of the fuller rows and columns. Moreover,
we show that nestedness remains relatively stable as the matrices become more
filled over time and that this occurs because of a bias for industries that
deviate from the networks' nestedness to disappear, and a bias for the missing
industries that reduce nestedness to appear. This makes the appearance and
disappearance of individual industries in each location predictable. We
interpret the high level of nestedness observed in these networks in the
context of the neutral model of development introduced by Hidalgo and Hausmann
(2009). We show that, for the observed fills, the model can reproduce the high
level of nestedness observed in these networks only when we assume a high level
of heterogeneity in the distribution of capabilities available in countries and
required by products. In the context of the neutral model, this implies that
the high level of nestedness observed in these economic networks emerges as a
combination of both, the complementarity of inputs and heterogeneity in the
number of capabilities available in countries and required by products. The
stability of nestedness in industrial ecosystems, and the predictability
implied by it, demonstrates the importance of the study of network properties
in the evolution of economic networks.Comment: 26 page
Determinants of Acceptance of Cervical Cancer Screening in Dar es Salaam, Tanzania.
To describe how demographic characteristics and knowledge of cervical cancer influence screening acceptance among women living in Dar es Salaam, Tanzania. Multistage cluster sampling was carried out in 45 randomly selected streets in Dar es Salaam. Women between the ages of 25-59 who lived in the sampled streets were invited to a cervical cancer screening; 804 women accepted and 313 rejected the invitation. Information on demographic characteristics and knowledge of cervical cancer were obtained through structured questionnaire interviews. Women aged 35-44 and women aged 45-59 had increased ORs of 3.52 and 7.09, respectively, for accepting screening. Increased accepting rates were also found among single women (OR 2.43) and among women who had attended primary or secondary school (ORs of 1.81 and 1.94). Women who had 0-2 children were also more prone to accept screening in comparison with women who had five or more children (OR 3.21). Finally, knowledge of cervical cancer and awareness of the existing screening program were also associated with increased acceptance rates (ORs of 5.90 and 4.20). There are identifiable subgroups where cervical cancer screening can be increased in Dar es Salaam. Special attention should be paid to women of low education and women of high parity. In addition, knowledge and awareness raising campaigns that goes hand in hand with culturally acceptable screening services will likely lead to an increased uptake of cervical cancer screening
The adaptation of the Affective Norms for English Words (ANEW) for European Portuguese
This study presents the adaptation of the Affective Norms for English Words (ANEW; Bradley & Lang, 1999a) for European Portuguese (EP). The EP adaptation of the ANEW was based on the affective ratings made by 958 college students who were EP native speakers. Participants assessed about 60 words by considering the affective dimensions of valence, arousal, and dominance, using the Self-Assessment Manikin (SAM) in either a paper-and-pencil and a web survey procedures. Results of the adaptation of the ANEW for EP are presented. Furthermore, the differences between EP, American (Bradley & Lang, 1999a), and Spanish (Redondo, Fraga, Padrón, & Comesaña, 2007) standardizations were explored. Results showed that the ANEW words were understood in a similar way by EP, American, and Spanish subjects, although some sex and cross-cultural differences were observed. The EP adaptation of the ANEW is shown to be a valid and useful tool that will allow researchers to control and/or manipulate the affective properties of stimuli as well as to develop cross-linguistic studies. The normative values of EP adaptation of the ANEW can be downloaded at http://brm.psychonomic-journals.org/content/supplemental.COMPETE - Programa Operacional Factores de CompetitividadeFundo Europeu de Desenvolvimento Regional - FEDERQuadro de Referência Estratégico Nacional - QRENFundação para a Ciência e a Tecnologia (FCT) - research project “Procura Palavras (P-Pal ): A software program for deriving objective and subjective psycholinguistic indices for European Portuguese words
Measuring player’s behaviour change over time in public goods game
An important issue in public goods game is whether player's behaviour changes over time, and if so, how significant it is. In this game players can be classified into different groups according to the level of their participation in the public good. This problem can be considered as a concept drift problem by asking the amount of change that happens to the clusters of players over a sequence of game rounds. In this study we present a method for measuring changes in clusters with the same items over discrete time points using external clustering validation indices and area under the curve. External clustering indices were originally used to measure the difference between suggested clusters in terms of clustering algorithms and ground truth labels for items provided by experts. Instead of different cluster label comparison, we use these indices to compare between clusters of any two consecutive time points or between the first time point and the remaining time points to measure the difference between clusters through time points. In theory, any external clustering indices can be used to measure changes for any traditional (non-temporal) clustering algorithm, due to the fact that any time point alone is not carrying any temporal information. For the public goods game, our results indicate that the players are changing over time but the change is smooth and relatively constant between any two time points
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