3,145 research outputs found
Representing whose access and allocation interests? Stakeholder perceptions and interests representation in climate governance
This chapter presents a synthesis of findings from quantitative and qualitative investigations of the perspectives of participants involved in international climate governance, conducted over the period 2010-2015. In this study, an established framework of principles, criteria and indicators (PC&I) for institutional governance was applied to two mechanisms under the United Nations Framework Convention on Climate Change (UNFCCC): the initiative referred to as ‘Reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests, and enhancement of forest stocks in developing countries’ (REDD+); and the Clean Development Mechanism (CDM) of the Kyoto Protocol (KP). Assessment focuses on the governance value of interest representation in terms of inclusiveness (access) and resources (allocation). It begins by outlining the historical context of UNFCCC, as well as CDM and REDD+, and continues with a delineation of the methods adopted, and results to reveal a relatively consistent set of results across the elements investigated, with inclusiveness receiving the highest score of all the governance indicators, and resources the lowest. The CDM was the weakest performer
Buckling of very short elastic cylinders with weld imperfections under uniform bending
The length-dependent behaviour domains of thin elastic cylindrical shells under uniform bending have recently received significant research attention. Ovalization is known to affect very long cylinders that undergo significant cross-sectional flattening before failing by local buckling. This effect is restrained by the end boundary conditions in shorter cylinders, which instead fail by local buckling at moments close to the classical analytical prediction. In very short cylinders, however, even this local buckling is restrained by the end boundary, and failure occurs instead through the development of a destabilizing meridional fold on the compressed side. Although this is a limit point instability under bending, ovalization does not play any role at all. This ‘very short’ length domain has only recently been explored for the first time with the aid of finite element modelling. A brief overview of the non-linear buckling behaviour of very short elastic cylinders under uniform bending is presented in this paper. Two types of edge rotational restraint are used to illustrate the influence of a varying support condition on the stability in this short length range. It is shown that short cylinders under bending do not suffer at all from local short-wave buckling. Additionally, when the meridional dimension of such cylinders becomes particularly short, the resulting numerical models may predict indefinite stiffening without a limit point, even when the shell is modelled using more complete 3D solid continuum finite elements. Idealized weld depressions, which are realistic representations of a systemic manufacturing defect, are used to demonstrate only a very mild sensitivity to geometric imperfections at such short lengths owing to a pre-buckling stress state dominated by local compatibility bending. The topic should be of interest to researchers studying shell problems dominated by local bending with computational tools and designers of multi-segment shells with very close segment spacing
Optimization of Convolutional Neural Network ensemble classifiers by Genetic Algorithms
Breast cancer exhibits a high mortality rate and it is the most invasive cancer in women. An analysis from histopathological images could predict this disease. In this way, computational image processing might support this task. In this work a proposal which employes deep learning convolutional neural networks is presented. Then, an ensemble of networks is considered in order to obtain an enhanced recognition performance of the system by the consensus of the networks of the ensemble. Finally, a genetic algorithm is also considered to choose the networks that belong to the ensemble. The proposal has been tested by carrying out several experiments with a set of benchmark images.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Cylindrical shells under uniform bending in the framework of Reference Resistance Design
The resistance of cylindrical shells and tubes under uniform bending has received significant research attention in recent times, with a number of major projects aiming to characterise their strength through both experimental and numerical studies. However, the investigated cross-section slenderness ranges have mostly addressed low radius to thickness ratios where buckling occurs after significant plasticity and the influence of geometric imperfections is relatively minor. The behaviour under uniform bending of thinner imperfection-sensitive cylinders that fail by elastic buckling was largely omitted, as was the influence of finite length effects. The value of such resistance models that are only useful for thicker cylinders is therefore somewhat limited. This paper offers the most comprehensive known characterisation of the buckling and collapse resistance of isotropic cylindrical shells and tubes under uniform bending. Expressed within the modern framework of Reference Resistance Design (RRD), it holistically incorporates the effects of material plasticity, geometric nonlinearity and sensitivity to realistic and damaging weld depression imperfections. The characterisation was made possible by the authors' recently-developed novel methodology for mass automation of nonlinear shell buckling finite element analyses. A modification of the RRD formulation is proposed which facilitates its application to systems of low slenderness, and offers a compact algebraic characterisation of all potential imperfection amplitudes for this common shell structural condition. A reliability analysis is also performed
Mesure des activités de l'uranium ( 238U, 234U) et du rapport isotopique 234U/238U dans des échantillons d’eau naturelle au Maroc à l'aide de la spectrométrie alpha
Measurement of the activities of uranium (238U, 234U) and of Isotopic ratio 234U 238U in natural water samples in Morocco using spectrometry alphaIn this work, specific activities of     234U and 238U and isotopic activity ratios have been measured for 68 natural water samples collected from 5 principal sources of water in Morocco: Wells (18 samples), springs (17 hot spring water samples and 7 cold spring water samples), rivers (13 samples), lakes (5 samples) and tap water (8 samples). These samples have been collected in Moroccan regions characterized by various geology, different socio-economical activities. The obtained results have allow us to establish general tendencies of measured parameters repartition in sources of the analysed waters. This tendency is clear for hot springs where activities of uranium are relatively low and 234&U/238&U activities ratios are important. This is due to temperature and oxydoreduction conditions of waters that are favourable in particularly to 234U solubility. The results so-obtained are comparable to those habitually found in natural waters in different regions of world and show that there is no radioactive pollution in these water
Energy Efficiency-Spectral Efficiency Trade-Off of Transmit Antenna Selection
We investigate the energy efficiency-spectral efficiency (EE-SE) trade-off of transmit antenna selection/maximum ratio combining (TAS) scheme. A realistic power consumption model (PCM) is considered, and it is shown that using TAS can provide significant energy savings when compared to multiple-input multiple-output (MIMO) in the low to medium SE region, regardless the number of antennas, as well as outperform transmit beamforming scheme (MRT) for the entire SE range. For a fixed number of receive antennas, our results also show that the EE gain of TAS over MIMO becomes even greater as the number of transmit antennas increases. The optimal value of SE that maximizes the EE is obtained analytically, and confirmed by numerical results. Moreover, the influence of receiver correlation is also evaluated and it is shown that considering a non-realistic PCM can lead to mistakes when comparing TAS and MIMO
Sebaceous Hyperplasia of the Scrotum and Penile Shaft
Sebaceous hyperplasia (SH) is a proliferative abnormality of sebaceous glands, most often seen in elderly individuals. It consists of single or multiple, asymptomatic, small yellow papules with a central depression. The face is most commonly affected, but there have been reports of SH on the chest or genitalia. A lobular array of well-differentiated mature sebaceous lobules is noted on histological preparations. In this report, we describe a patient with SH on the penile shaft and parts of the scrotum
Governance values in the climate change regime: stakeholder perceptions of REDD+ legitimacy at the national level
This paper presents the results of two national-level studies of REDD+ governance values in Nepal and Papua New Guinea (PNG), using a hierarchical framework of principles, criteria, and indicators (PC&I), with evaluation at the indicator level. The research was conducted by means of an online survey to determine general perspectives on the governance quality of REDD+, as well as stakeholder workshops, in which participants were asked to rank indicators on the basis of perceived national significance. In the online survey, respondents in both countries identified inclusiveness and resources as the highest and lowest scoring governance values, while inclusiveness, resources, accountability, and transparency, were given priority, although their relative importance differed
between countries given national circumstances. The reasons for the commonalities and differences of perceptions between these countries are discussed. The findings suggest that while a generic set of governance values may be usefully applied for determining the institutional legitimacy of REDD+, their relative importance is different. This leads to the conclusion that it may not be appropriate to use a simplified approach to REDD+ governance, focusing for example on safeguards, given different national priorities and contexts
Intraspecfic variation in cold-temperature metabolic phenotypes of Arabidopsis lyrata ssp petraea
Atmospheric temperature is a key factor in determining the distribution of a plant species. Alongside this, plant populations growing at the margin of their range may exhibit traits that indicate genetic differentiation and adaptation to their local abiotic environment. We investigated whether geographically separated marginal populations of Arabidopsis lyrata ssp. petraea have distinct metabolic phenotypes associated with exposure to cold temperatures. Seeds of A. petraea were obtained from populations along a latitudinal gradient, namely Wales, Sweden and Iceland and grown in a controlled cabinet environment. Mannose, glucose, fructose, sucrose and raffinose concentrations were different between cold treatments and populations, especially in the Welsh population, but polyhydric alcohol concentrations were not. The free amino acid compositions were population specific, with fold differences in most amino acids, especially in the Icelandic populations, with gross changes in amino acids, particularly those associated with glutamine metabolism. Metabolic fingerprints and profiles were obtained. Principal component analysis (PCA) of metabolite fingerprints revealed metabolic characteristic phenotypes for each population and temperature. It is suggested that amino acids and carbohydrates were responsible for discriminating populations within the PCA. Metabolite fingerprinting and profiling has proved to be sufficiently sensitive to identify metabolic differences between plant populations at different atmospheric temperatures. These findings show that there is significant natural variation in cold metabolism among populations of A. l. petraea which may signify plant adaptation to local climates
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