The Indian Government's National Biogas and Manure Management Programme (NBMMP) seeks to deliver renewable energy services to households across the country by facilitating the deployment of family-sized (<6 m3) anaerobic (biogas) digesters. NBMMP policy is implemented at three levels, from government and state nodal agency, via private contractors to households, creating multiple institutional arrangements. We analysed the scheme in Assam, north-east India, focusing on how policy was implemented across two districts and interviewing stakeholders in rural households, state and non-state institutions. The top-down, supply-side approach to policy enables government to set targets and require individual states to deploy the scheme, which benefits households who can afford to participate. NBMMP delivered improved energy service outcomes to a majority of households, although the level of knowledge and understanding of the technology amongst users was limited. Training and education of householders, and particularly women, is needed in relation to the maintenance of digesters, feedstock suitability and the environmental and potential livelihood benefits of digestate. A revised bottom-up approach to policy, which highlights the contextual and demand-side issues around adopting the technology, may deliver monetary benefits from market competition and enable development of community-focused microfinance schemes to improve the affordability of biogas systems.
Domestic toilet-linked anaerobic digesters (TLADs) recycle organic waste materials, including human excreta (HE), into a clean gaseous fuel and fertiliser product. Socio-cultural resistance is often used to explain local resistance towards TLADs due to the use of HE as a feedstock. However, through qualitative investigation utilising in-depth semi-structured interviews with potential TLAD users in Assam, India, the use of socio-cultural rejection to describe resistance towards TLADs was found to have homogenised local voices and framed them as resistant to technological change whilst ignoring diversity within groups. The narratives revealed resistance to be diverse and related to an individual's place, personal and social identity. Resistance to TLADs results from both socio-cultural as well as socio-technical concerns and is also potentially negotiable. Adoption of TLADs could be facilitated through opportunities such as technology demonstration, social group adoption and a greater perceived necessity. Inefficiencies in Assam's biogas implementation programme have been potentially overlooked due to too much attention being placed on household decision making and generalising socio-cultural resistance across the state. If TLADs are to be disseminated within Assam, authorities must work with communities and employees of the biogas programme to more widely renegotiate social norms around HE as a resource and not a waste product. More generally Assam's biogas programme is ineffectively identifying households with a need and motivation for domestic biogas and we recommend revaluating the use of local contacts to identify households eligible for the national subsidy as well as the bias towards households with large numbers of cattle.
Mineralogical and petrographical investigation of two loessic brickearth profiles from Ospringe and Peg- well Bay in north Kent, UK have differentiated two types of brickearth fabric that can be correlated with different engineering behaviour. Both sequences comprise meta- stable (collapsing) calcareous brickearth, overlain by non- collapsing 'non-calcareous' brickearth. This study has demonstrated that the two types of brickearth are discretely different sedimentary units, with different primary sedimentary characteristics and an erosional junction be- tween the two units. A palaeosol is developed on the cal- careous brickearth, and is associated with the formation of rhizolithic calcrete indicating an arid or semi-arid envi- ronment. No evidence has been found for decalcification being responsible for the fabric of the upper 'non-cal- careous' brickearth. Optically-stimulated dates lend further support for the calcareous and 'non-calcareous' brickearth horizons being of different age or origins. The calcareous brickearth is metastable in that it undergoes rapid collapse settlement when wetted under applied stresses. It is char- acterised by an open-packed arrangement of clay-coated, silt-sized quartz particles and pelletised aggregate grains (peds) of compacted silt and clay, supported by an inter- ped matrix of loosely packed, silt/fine-grained sand, in which the grains are held in place by a skeletal framework of illuviated clay. The illuviated clay forms bridges and pillars separating and binding the dispersed component silt/ sand grains. There is little direct grain-to-grain contact and the resultant fabric has a very high voids ratio. Any applied load is largely supported by these delicate clay bridge and pillar microfabrics. Collapse of this brickearth fabric can be explained by a sequence of processes involving: (1) dispersion and disruption of the grain-bridging clay on saturation, leading to initial rapid collapse of the loose- packed inter-ped silt/sand; (2) rearrangement and closer stacking of the compact aggregate silt/clay peds; (3) with increasing stress further consolidation may result from deformation and break up of the peds as they collapse into the inter-ped regions. Smectite is a significant component of the clay assemblage and will swell on wetting, further encouraging disruption and breaking of the clay bonds. In contrast, the 'non-calcareous' brickearth already possesses a close-packed and interlocking arrangement of silt/sand grains with only limited scope for further consolidation under load. Minor authigenic calcite and dolomite may also form meniscus cements between silt grains. These have either acted as ''scaffolds'' on which illuviated clay has subsequently been deposited or have encrusted earlier- formed grain-bridging clay. In either case, the carbonate cements may help to reinforce the clay bridge fabrics. However, these carbonate features are a relatively minor
Abstract The main challenge in luminescence dating is to provide accurate ages for sediments derived from hillslope, fluvial and marine environments where grains have been transported and deposited by water. A new methodology has been devised for dating Holocene age sediments from the land-ocean interface. Alkali feldspars are recommended as the ideal dosimeter in these environments as they are: rapidly zeroed, have high sensitivity to dose, have an internal dose rate from the decay of 40 K, have signal intensities that are much higher than for quartz, and the equivalent doses (EDs) determined are not affected by chemical weathering. Studies of the fundamental characteristics of feldspars have been used to optimize the luminescence signal for use in dating applications. A quality assurance technique for discriminating between those samples that will give accurate dates and those that will yield inaccurate dates has been developed and is tested here on coastal-zone sediments from Lincolnshire. Sampling from sediment exposures rather than cores minimizes the uncertainties related to past water content fluctuations.
Holocene forested coastal dunes fringe the Atlantic coast of western Portugal. Mapping of dunes in the field and using air photographs shows a range of forms reflecting dominant northwest and westerly onshore wind regimes. Planting of maritime pine forests in the thirteenth and twentieth centuries was initiated because of sand invasion causing problems for human settlement and agriculture. Early Holocene dunes have a well-developed podsol and date to 9.7 and 8.2 ka, suggesting at least some of these sands may have been emplaced during a global cooling event. Significant transgressive dune accretion at 2.2 and 1.5 ka, implies abundant sand supply and strong onshore winds The most recent dune-building period dates to AD 1770-1905 and coincides with a predominantly negative winter North Atlantic Oscillation index (NAOi). Accretion of dunes along the Portuguese coast appears out of phase with dune development in southwest France, which may reflect different Atlantic storm tracks driven by changes in the dominance and state of the NAOi.
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