An ingenious technique for functional palatal reservoir construction in complete dentures

The retention, stability and comfort of wearing denture is greatly influenced by the flow, quantity and consistency of saliva. Insufficient salivary output results especially in old-aged edentulous patients may result in denture sores because of lack of lubrication by saliva, thus, reducing patient’s ability to retain the prosthesis. Various approaches have been concernes with the use of reservoir with holes have been described in the literature. However the flow of salivary substitute is very difficult to control. Moreover the frequent cleaning of the denture required to maintain the patency of the reservoir holes poses various challenges to the patient. This article explains a novel technique for the incorporation of a reservoir with controlled salivary flow in complete denture to enhance the retention of the prosthesis and thus, improving the comfort of wearing denture and the speech of patient.

The Impact of the Construction of Large Reservoirs on the Cultural Landscape: A Case Study of the Shimen Reservoir, Taiwan

Reservoirs are large-scale water facilities with multiple functions, such as water supply, power generation, and tourism. This paper introduces the new community and cultural landscape formed by the indigenous people, engineers, workers who left their homes, and many migrating families at the Shimen Reservoir in Taoyuan, Taiwan, as an example. We analyzed how the community value of reservoir construction contributed to the development of the landscape through fieldwork, document review, and in-depth interviews. First, the new communities created to meet the needs of the immigrants influenced the surrounding environment and shaped a particular lifestyle. Secondly, new immigrants have formed a community consensus, and changes in the diet and natural landscape have promoted local tourism and affected the function of the reservoir. This study concludes that promoting local values through autonomous community action is a sustainable approach to community development. Tourism development with its symbiotic relationship with the reservoir can meet the needs of local socio-economic and cultural development. For sustainable development, a vulnerability study based on the Shimen Reservoir tourism is necessary.

Evaluation of Greenhouse Gas Emissions from Reservoirs: A Review

In order to evaluate the greenhouse gas (GHG) emissions from a reservoir or from several reservoirs in a country or a climatic zone, simpler or more complex models based on measurements and analyses of emissions presented in the literature were developed, which take into account one or more reservoir-specific parameters. The application of the models in the assessment of GHG emissions from a multipurpose reservoir gave values that are more or less close to the average values reported in the literature for the temperate zone reservoirs. This is explained by the fact that some models only consider emissions caused by impoundment and not degassing, spillway emissions, and downstream emissions, or those that use different calculation periods. The only model that calculates GHG emissions over the life cycle that occur pre-impoundment, post-impoundment, from unrelated anthropogenic sources and due to the reservoir construction is the model used by the G-res tool. In addition, this tool is best suited for multipurpose reservoirs because it allocates GHG emissions for each use, thus facilitating the correct reporting of emissions. The G-res tool used to calculate GHG emissions from the Stânca-Costești Multipurpose Reservoir shows that this is a sink of GHG with a net emission of −5 g CO2eq/m2/yr (without taking into account the emissions due to dam construction).

Desiccation of the Transboundary Hamun Lakes: Natural or Anthropogenic?

This paper investigates the hydrologic and water management reasons behind the desiccation of the Hamun Lakes in the Iran-Afghanistan border region. We analysed changes in Hirmand (or Helmand) River flow, the main tributary providing 70% of the lakes’ total inflow, and precipitation during 1960-2016 by calculating standardized indices for precipitation (SPI) and discharge (SDI). Also, we applied Normalized Difference Spectral Indices (NDSIs) using satellite images from 1987 to present to observe monthly areal change of the lakes. The transboundary water body is responding to changes in regional water management, which has severely reduced the lakes’ inflow. Upstream water regulation in Afghanistan coupled with reservoir construction on the Iranian side has caused nearly full desiccation of major parts of the lake system. There is a discernible shift in the relation between the Hirmand River flow at the international border and upstream precipitation over the lakes’ basin before and after 2004. From 1960 to 2003, high river flows were expected to feed the lakes due to high precipitation over the basin. However, the Hirmand River flow at the border declined after 2004 despite large amounts of upstream precipitation, including the largest recorded amounts, especially in the Hindu Kush mountains. Further, environmental water stress caused by anthropocentric water management in Iran by reservoir construction has impacted the area of the lakes. Although a long period of drought from 1998-2004, i.e. climatic driver, decreased the lakes’ area, the lake system is primarily falling victim to anthropogenic flow alterations in the transboundary river basin. The lakes’ shrinkage places socio-economic stress on an already-vulnerable region with important public health implications as the exposed lake beds turn into major sources of sand and dust storms.

Accuracy vs Realism: Does including reservoirs improve hydrological models?

Brazil has invested considerably in the reservoir construction during the past decades, mainly for irrigation and hydro-power generation. Despite their large impact on catchment hydrology, reservoir dynamics are often not included in hydrological models due to their complexity. In this study, we investigated the effect of including reservoir dynamics (realism) in hydrological models on the model performance (accuracy). Combined, realism and accuracy form the model fidelity. We used the HBV-EC and GR4J models to simulate hydrological processes and daily streamflow of 403 catchments across Brazil in two scenarios, with and without reservoirs. The model performances were assessed with the Kling Gupta Efficiency (KGE) and its components, and were compared between the models and scenarios. We found a significant increase in the HBV-EC model performance when the reservoirs were taken into account, although the overall performance was relatively poor. The average KGE increased from 0.21 without the reservoirs to 0.40 with the reservoirs. The GR4J model, on the other hand, showed better overall performance, but without the improvement when including the reservoirs; the average KGE slightly decreased from 0.57 to 0.56. In the catchments with the largest reservoir capacity, HBV-EC in the scenario with reservoirs outperformed GR4J in both scenarios. We note that better model performance can still be obtained with a smaller spatial scale or other methods of including reservoirs, which require more data and detailed studies. With this paper, we demonstrate that model performance can improve when including reservoir dynamics, but this depends on model structure and does not always increase model fidelity.

The Influence of Cascade Reservoir Construction on Labile Phosphorus in the Sediment of Lancang River

The influence of cascade reservoirs construction on labile phosphorus (P) is an important scientific problem in the Lancang River. The concentration of labile P in cascade deep-water reservoirs were determined, and the influence of cascade reservoirs construction on the DGT-labile P was analyzed. The construction of cascade reservoirs led to significant differences in concentrations of DGT-labile P, which in the upstream of Xiaowan (XW) Reservoir were differences from that in the downstream Nuozhadu (NZD) Reservoir. The P diffusion fluxes in XW Reservoir were − 8.59–250.50 ng·cm− 2·d− 1, and that in NZD Reservoir were 3.82–24.80 ng·cm− 2·d− 1. The P pollution of XW Reservoir was higher, highlighting the importance of controlling P pollution of XW Reservoir. The construction of cascade reservoirs had made the release of DGT-labile P more dependent on the reductive dissolution of Mn oxides. The early diagenesis transformed bio-availability P (BAP) remobilization into DGT-labile P that made the increase of DGT-labile P/BAP with depth. However, the DGT-labile P/BAP of upstream XW Reservoir was 7.8 times larger than that of downstream NZD Reservoir, which indicated that the construction of cascade reservoirs weakened the remobilization of P in sediment.

Impact of Climate Variability on Reservoir Based Hydro-Power Generation in Jebba Dam, Niger State, Nigeria

This study examined impact of climate variability on reservoir-based hydro-power-generation in Jebba dam, Niger State of Nigeria. Data of rainfall, temperature, evaporation, reservoir inflow and outflow and power output for thirty-one years were obtained from Jebba Hydropower Station [JHP]. The Man-Kendall and Pearson’s Product Moment Correlation Coefficient (PPMCC) were used to establish the influence of weather parameters on the reservoir inflow and outflow. Findings showed increased electricity generation during dry season than wet season. The highest annual mean amount of the electricity generated was in 2016 having mean of 689.12mwh, dry season (352.26mwh) and wet season (336.86mwh). Reservoir inflow showed negative trend with severe fluctuations in 1998 (1436.42M3/Sec), 1999 (1581.08M3/Sec) and 2010 (1641.08M3/Sec) with steady increase in 2016 (1556.0042M3/Sec), 2017 (1556.4242M3/Sec) and 2018 (1635.7542M3/Sec). The reservoir outflow pattern showed tremendous and negative trend in fluctuation with increase in 1998 (1421.75M3/Sec) 1999 (1581.58M3/Sec) and 2010 (1641.16M3/Sec) and a steady increase in 2016 (1535.00M3/Sec), 2017 1558.83M3/Sec and 2018 (1632.00M3/Sec). Thus, rainfall and reservoir inflow had strong relationships with the amount of power generated than temperature and evaporation. Therefore, the government should increase the water carrying capacity of the reservoir construction by storing water to be used during dry periods.

Ex Ante Impact Assessment of Reservoir Construction Projects for Different Stakeholders Using Agent-Based Modeling

Reservoir construction projects are frequently met with fierce opposition. Consequently, to mitigate any potential negative impacts, environmental and social impact assessments are usually mandatory. Stakeholder perspectives are often only implicit in such assessments, and the medium-term effects of mitigating actions are assessed at the aggregate level, which fails to take into account unequal disaggregated impacts. In this paper, we design and apply an agent-based model (ABM) built on stakeholder information to conduct an ex ante assessment of the impact of a reservoir construction project in southern Thailand over a 30-year period for individual agents. We incorporate stakeholders’ knowledge into the ABM on the basis of primary data collected during the 2016–2018 period, including workshops with affected farmers to assess their interests and concerns, in-depth interviews with farmers in nearby districts to assess farming behaviors, and the expert opinions of policymakers to assess the relevant regulations and processes. In a case study for which the model was established, the results predict that, overall, farmers will have more farm income if the dam is built. We find that affected people require a standard of living similar to that provided by their previous livelihood as soon as possible after resettlement. By simulating the impacts on individual agents, we conclude that the compensation for relocation offered to affected farmers is not sufficient for sustainable resettlements. Facilitating compensation may increase the speed of project implementation and lead to better outcomes for everyone, including affected communities, whereas failure to reshape the current compensation policy leaves everyone more disadvantaged.