Optimization of Reaction Typed Water Turbine in Very Low Head Water Resources for Pico Hydro

The purpose of this research is to investigate the dominant parameters that influence the optimum performance of reaction typed turbine at very low water head. The concepts of conservation of mass, momentum and energy are utilised to explore performance characteristics using a graphical technique. Parametric analysis of the governing equation and experimental results were performed to show that the turbine diameter and nozzle exit area has a dynamic response to mass flow rate, angular speed, output power and efficiency. Depending on the nozzle diameter of (0.01 m, 0.006 m, and 0.008 m) and turbine pipe size with (diameter of 0.025 m and 0.015 m), six versions of prototype turbine Z-blade turbine were produced. All the turbines have been tested at 100 kPa static water pressures and below. According to a variety of experimental data for all types of turbines, the turbine diameter and nozzle exit area have a substantial impact on turbine performance, especially at high water heads. Despite differences in turbine length and nozzle exit area, more than 90 % of the pattern curves for rotational speed, water flow rate, and mechanical power were identical. Overall, the Z-blade turbine Type B outperforms, resulting in higher turbine efficiency at low head and low flow water condition.

Investigative Study on the Bacteriological, Physical and Chemical Profiles of Aquaculture Waters: Insights Into Health Hazards for Fish and Human

Bacteriological and physic-chemical analysis of fish pond water is very important in aquaculture as this gives insights into likely threats to aquaculture and associated personnels. Bacteriological and physico-chemical profiles of selected fish ponds in the Ilorin West area of Kwara State, Nigeria were investigated to evaluate the water quality of rearing enclosures. Physico-chemical analyses revealed quality parameters were within the recommended range for aquaculture. Following bacteriological analyses of static water pond culture, the TVC and TCC showed temporal variations with concentration increasing with sampling time. However, the FCC showed fluctuation. Totally, 8 bacteria groups were isolated from both rearing enclosures. Of these, Gram negative bacteria showed dominance. In which 5 Gram negative (Escherichia coli, Proteus spp, Serratia spp, Enterobacter spp and Pseudomonas spp) and 3 Gram positive (Staphylococcus spp, Streptococcus spp, and Bacillus spp) were encountered. Estimates of bacteria occurrence in both rearing facilities respectively gave: Staphylococcus spp (20%), Streptococcus spp (12%) Proteus spp (8%) Enterobacter spp (20%) Serratia spp (16%), Bacillus spp (9%), Escherichia coli (8%), Pseudomonas spp (7%) from earthen pond water sampled. While Staphylococcus spp (18%), Streptococcus spp (16%), Proteus spp (8%), Enterobacter spp (22%), Serratia spp (8%), Bacillus spp (15%), Escherichia coli (8%), Pseudomonas spp (6%) from concrete water sampled. Conclusively, although there is the presence of bacteria groups of public health concern, the static water exchange provides benefits of natural processing of wastes and restoration of the pond ecosystem. Notably, the presence of Escherichia coli gives indication of presence of pathogenic organisms of enteric origin. The presence of these organisms has been associated with a lack of tentative pond management and effective biosecurity procedures. One recommendation to this culture system (static water aquaculture) is the consideration of adaptation of concepts in biomimicry or biofloc technology which operates on similar principles.

Numerical Study on the Rising Motion of Bubbles near the Wall

Based on the volume of fluid method (VOF), the rising characteristics of bubbles in near-wall static water are studied. In this study, the influence of the wall on the rising motion of the bubble was studied by changing the distance of the bubble wall, the diameter of the bubble, the arrangement of the bubble and the size ratio, etc. The influence is expressed as the average swing amplitude of the “Z”-shaped motion when the bubble rises. The study found that in the case of a single bubble, the wall surface has a certain influence on the rise of the bubble, and its degree is affected by the bubble wall distance and the bubble diameter. The influence of bubble wall distance is more obvious. The greater the bubble wall distance, the less the bubble is affected by the wall; in the case of double bubbles, the influence of the interaction force between the bubbles is significantly greater than the wall surface.

The kapok petal: superhydrophobic surface induced by microscale trichomes

The Kapok petal is reported for the first time that it shows a superhydrophobic characteristic with a static water contact angle higher than 150°. Intriguingly, there exist single-scale micro-trichomes and no more nanocrystals on a kapok petal in contrast to most natural superhydrophobic surfaces with hierarchical morphologies, such as lotus leaf and rose petal. Experiment results show that kapok petal has an excellent self-cleaning ability either in air or oil. Further scanning electron microscope characterization demonstrates that the superhydrophobic state is induced by densely-distributed microscale trichomes with an average diameter of 10.2 μm and a high aspect ratio of 17.5. A mechanical model is built to illustrate that the trichomes re-entrant curvature should be a key factor to induce the superhydrophobic state of the kapok petal. To support the proposed mechanism, gold-wire trichomes with a re-entrant curvature are fabricated and the results show that a superhydrophobic state can be induced by microstructures with a re-entrant curvature surface. Taking the scalability and cost-efficiency of microstructure fabrication into account, we believe the biomimetic structures inspired by the superhydrophobic kapok petal can find numerous applications that require a superhydrophobic state.

Botulinum toxin – Know the product before injecting

Botulinum toxin for injection is a purified and diluted protein which is isolated from the bacterium Clostridium botulinum. It is one of the most potent toxins known to humankind. C. botulinum is an anaerobic Gram-positive, spore-forming bacterium which is present naturally in soil, plants, static water bodies, and the gastrointestinal tract of mammals and aquatic life. Different formulations of botulinum toxins are available. FDA approval for these formulations varies. This article reviews these factors and the molecule, its mechanism of action, and other pharmacological aspects including dilutions for various indications.

Numerical Investigation of Shallow Liquid Sloshing in a Baffled Tank and the Associated Damping Effect by BM-MPS Method

Understanding the damping mechanism of baffles is helpful to make more reasonable use of them in suppressing liquid sloshing. In this study, the damping effect and mechanism of vertical baffles in shallow liquid sloshing under a rotational excitation are investigated by an improved particle method. By incorporation of a background mesh scheme and a modified pressure gradient model, the accuracy of impact pressure during sloshing is significantly enhanced. Combined with the advantages of the particle method, the present numerical method is a wonderful tool for the investigation of liquid sloshing issues. Through the analysis of impact pressure, the influences of baffle height and baffle position on the damping mechanism are discussed. The results show that the damping effect of vertical baffles increases with the increase of the elevation of baffle top and decreases with the increase of the elevation of the baffle bottom. Moreover, the resonance characteristics of sloshing are altered when static water is divided into two parts by the vertical baffle. The dominant damping mechanism of vertical baffles depends on the configurations.

A comprehensive approach of hydrological issues related to ground water using GIS in the Hindu holy city of Gaya, India

Purpose Gaya, the holy city of Hindus, Buddhists and Jains, is facing an acute shortage of potable water. Although the city is blessed with some static and dynamic water bodies all around the region, they do not fulfill the requirement of millions of public either inhabitants of the area or tourists or pilgrims flocking every day. Countless crowds, congested roads, swarming pedestrians, innumerable vehicles moving throughout the day and night have made the city into a non-livable one. The present status of surface water is a mere nightmare to the requirements of the people. Due to which, massive ground water pumping mostly illegally has added a grid in addition to the other socio-economic issues. Design/methodology/approach To focus on such problem, the ground water of the region was studied thoroughly by calculating the depth of water level, discharge, pre-and post-monsoon water table and specifically the storativity in ten different locations. Some data were acquired, others were assessed, and few are calculated to provide an overall view of the ground water scenario. Findings After a long and tedious field study, it was finally established from that static water level ranges from 2.45 to 26.59 m, below ground level (bgl), discharge varies from 3.21 m3/day to 109.32 m3/day. Post pumping drawdown falls between 0.93 m and 16.59 m, whereas the specific capacity lies in between 0.96 and 7.78 m3/hr/m. Transmissivity, which is a key objective to assess ground water potential ranges from 109.8 to 168.86 m2/day. Originality/value This research work is original.

Implications of the Engineering Geological Properties of Soils in the Implementation of the Greater Jos Master Plan, North Central Nigeria

A study of the engineering properties of the subsurface soil in the Greater Jos Master Plan development area has been carried out to address the paucity of engineering data in the area. The study became necessary because the rapid urbanization has led to limited construction land with more ground prone to instability due to reworking by mining and related activities. The study area is located within Latitudes 09º 48' 20'' to 09º 53'20''N and Longitudes 08º 53' 54'' to 08º 57 '00'' E and extending over 54km2 on Naraguta Sheet 168NE. Surface geological mapping was carried out to confirm the existing geology. Geotechnical properties of soils were determined by analysis of soil samples for 38 locations. While 94 static water level measurements provided additional information on groundwater conditions. The area is underlain by the Jos-Bukuru Complex rocks predominantly biotite granites differentiated on the basis of mode of formation, mineralogy and texture. Soils derived from weathering of the rocks revealed gradual decomposition from gravel, sand, and silt-sized particles to lateritic clays. The soils are considered to have low to medium plasticity/compressibility, expansiveness, and swelling potential across all rock types. The static water table depicts fluctuation in the water table varying between 2.9 and 3.9m. These findings are expected to serve as guide in the choice of design and construction and as a baseline subsurface soil compendium for planning and urban development in the Greater Jos Master plan and for further studies.