Design of sensor electronics for electrical capacitance tomography

The design of the sensor electronics for a tomographic imaging system based on electrical capacitance sensors is described. The performance of the sensor electronics is crucial to the performance of the imaging system. The problems associated with such a measurement process are discussed and solutions to these are described. Test results show that the present design has a resolution of 0.3 femtofarad. (For a 12-electrode system imaging an oil/gas flow, this represents a 2% gas void fraction change at the centre of the pipe) with a low noise level of 0.08 fF (RMS value), a large dynamic range of 76 dB and a data acquisition speed of 6600 measurements per second. This enables sensors with up to 12 electrodes to be used in a system with a maximum imaging rate of 100 frames per second, and thus provides an improved image resolution over the earlier 8-electrode system and an adequate electrode area to give sufficient measurement sensitivit

Gender and water security in Burkina Faso: lessons for adaptation (SEI Policy brief)

In many countries, traditional divisions of labour mean that women conduct the majority of unpaid work related to the collection, transport, and management of water supplies for drinking and other domestic uses. Women’s work on water limits time for other activities, including paid work, education or leisure, which can impact the wellbeing of the entire household. Women and girls also face different sanitation needs than men, due to social taboos and stigmas, as well as biological factors. In addition, social norms within households and communities can lead to women having less of a voice in decisions over the use of water, or the management of facilities. These gender and power relations result in differing water security for individuals, even when they live in the same household or community. This brief explores gender-differentiated water security risks in Burkina Faso, with the aim of informing the development of adaptation strategies in the water, sanitation and hygiene (WASH) sector

A Micro Financing Framework for Rural Water and Sanitation Provisioning in Sub-Saharan Africa

This paper investigates potential issues with regard to water and sanitation. It argues that technological fixes alone are not enough and need to be complemented by other forms of innovation such as local community organization and financial innovation. It provides a micro financing framework that is founded on the Rotating Savings and Credit Associations (RoSCA) arrangements at the village level

The effect of movement velocity and eccentric contractions on the bilateral deficit

This study was performed to examine the effects of movement velocity and eccentric contractions on the bilateral deficit. To accomplish this, 18 participants performed bilateral and unilateral contractions eccentrically and concentrically across 6 movement velocities (30, 60, 90, 120, 150, and 180{dollar}\sp\circ{dollar}/s). Repeated measures ANOVA\u27s revealed that for both eccentric and concentric contractions, significant differences existed between bilateral and summed unilateral contractions; and at each of the six tested velocities. Further analyses revealed that the degree of the bilateral deficit increased as movement velocity increased. It is believed that the decreased tension developed during bilateral eccentric and concentric contractions, is attributed to incomplete activation of fast twitch muscle fibers recruited during unilateral contractions

Clean and Green: A New Implementation Framework for Rural Sustainable Sanitation

There is a growing recognition that many of the things we commonly discard are, simply, too good to waste. This is particularly true in the setting of poor rural villages facing water scarcity and low crop productivity and energy access – and where these waste streams actually pose a risk to health and ecosystem services.Clean and Green is the first rural sanitation implementation framework that explicitly addresses efficient local resource management, including waste reuse, in parallel with sanitation and hygiene promotion. The framework centres on certifications to reward progress along parallel Clean (risk management) and Green (resource management) tracks.Clean and Green is being developed under the SEI Initiative on Sustainable Sanitation (SISS), with pilot projects now lined up. This discussion brief sets out the main concepts

Empowerment in WASH Index (SEI Discussion brief)

This brief presents a new Empowerment in WASH Index (EWI) that is designed to measure empowerment in the WASH sector. The Empowerment in WASH Index (EWI) is a new survey-based tool to measure women’s empowerment and gender outcomes in the WASH sector. EWI can help to fill key gender data gaps in the sector. EWI can be used to inform better design of WASH interventions, and to monitor and evaluate WASH-related gender outcomes. We describe how the EWI tool is constructed using a series of indicators, and a case study applying the EWI in Burkina Faso

Concept mapping: Engaging stakeholders to identify factors that contribute to empowerment in the water and sanitation sector in West Africa

Research has shown that inadequate access to water, sanitation, and hygiene (WASH) affects women and girls in several ways, including lowering their participation in the labour market and community activities and contributing to psychosocial stress and poor educational outcomes. There is growing awareness that addressing the gender inequalities related to WASH that many women and girls face on a daily basis must go beyond focusing on delivery of infrastructure and facilities alone and include attention to issues of empowerment. Yet there is limited exploration of how the concept of empowerment is defined and applied in the WASH sector and thus limited information on how it could be measured. This study used concept mapping to uncover the meaning and key dimensions of empowerment in WASH among 34 and 24 stakeholders in Asutifi North District, Ghana, and Banfora Commune, Burkina Faso, respectively. The study was part of initial steps toward choosing indicators for developing an Empowerment in WASH Index. In Ghana and Burkina Faso, 42 and 29 items were generated, respectively. These items were thought to empower men and women in WASH at the household and community levels. In both case studies, 7 clusters were generated and named by participants, and themes related to sharing of information, sociocultural norms, participation, and accessibility of WASH services were associated with empowerment. Some themes were unique to each case study site. Participants also showed a multidimensional and multilevel understanding of empowerment. Concept mapping created an effective balance between individual and group contributions and facilitated accessible, rapid, and contextually relevant data collection. The findings can be used to generate domains of empowerment in future quantitative research as well as inform the design of the Empowerment in WASH Index

Pre-arc basement complex and overlying early island arc strata, Southwestern Puerto Rico : overview, geologic evolution, and revised data bases

The pre-arc basement complex in southwestern Puerto Rico consists of rocks exposed in the Bermeja complex. The oldest rocks are highly serpentinized peridotites that occur in three belts (Monte del Estado, Río Guanajibo, and Sierra Bermeja). These serpentinites were emplaced into a sequence of Jurassic to mid-Cretaceous pelagic chert (Mariquita chert) that contains abundant rafts and blocks of N-MORB-type amphibolites (Las Palmas amphibolite) and tholeiite and associated trondhjemite fractionates (Lower Cajul MORB) also of N-MORB affinity. The rocks are apparently overlain by a younger sequence of pre-arc plateau basaltic and andesitic lava flows (Upper Cajul Formation) that occur in two distinct geographic sequences, one having E-MORB and the other OIB geochemical characteristics. Overlying these pre-arc rocks in western Puerto Rico are northwest-trending Late Cretaceous to Eocene (85 to 45Ma) island arc strata that chronologically overlap later volcanic phases in central Puerto Rico. These western Puerto Rico arc rocks have elevated incompatible element concentrations together with conspicuously shallow negative Nb-anomalies, slightly positive Zr-Hf anomalies, and exceedingly high OIB-like Nb/Zr, all indicative of enriched source compositions. Trace element patterns are reproduced by multiple component mixing models involving highly depleted spinel peridotite (RMM15 to 20) overprinted by small OIB-type (up to ~2%) and pelagic sediment components. Trace element abundances are too high to qualify Atlantic Cretaceous pelagic sediment as a potential contaminant, but mantle-melting models (f=0.25) are consistent with the incorporation of variable proportions of Caribbean Cretaceous pelagic sediment through northdipping subduction of the Caribbean basin. Anomalous two-pyroxene-bearing andesites with extraordinarily high SiO2/MgO compared with normal mantle basaltic compositions, also indicate the incorporation of Jurassic to Early Cretaceous pelagic chert from the Caribbean. The high degree of source enrichment in western Puerto Rico is inconsistent with regional within-plate plume tectonics. Instead, it is inferred that the younger north-dipping western Puerto Rico arc (dating from ~85Ma) sampled an upper mantle enrichment zone generated in the backarc region of the older (125 to ~85Ma) south-dipping arc system in central Puerto Rico