Impacts of reduced water flow on the riverside intakes

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Ahmed Awaad ◽  
Fahmy Abdelhaleem ◽  
Tarek Nasralla ◽  
Basma abdelrhman
Keyword(s):  
Water Flow ◽  
Reduced Water

Modeling of Reduced Water Flow through Concrete Caused by Crystallization Technology

2006 ◽  
Vol 9 (8) ◽  
pp. 723-730
Author(s):  
Abdelaziz Al-Khlaifat ◽  
Awni Al-Otoom
Keyword(s):  
Water Flow ◽  
Flow Through ◽  
Reduced Water

scholarly journals Effects of canopy-mediated abrasion and water flow on the early colonisation of turf-forming algae

2007 ◽  
Vol 58 (7) ◽  
pp. 657 ◽  
Author(s):  
Bayden D. Russell
Keyword(s):  
Water Flow ◽  
Interactive Effects ◽  
Light Penetration ◽  
Physical Processes ◽  
Percentage Cover ◽  
Negative Effect ◽  
Flow Through ◽  
Per Se ◽  
Reduced Light ◽  
Reduced Water

Algal canopies form predictable associations with the benthic understorey, and canopy-mediated processes may maintain these associations. Three canopy-mediated processes that are inherently linked are water flow through a canopy, abrasion of the substrate by the canopy, and light penetration. These processes were experimentally reduced to test the hypotheses that turf-forming algae would be: (1) positively affected by reduced abrasion by kelp canopies; (2) positively affected by reduced water flow; and (3) negatively affected by shading (reduced light). Biomass of turf-forming algae was greater when abrasion was reduced, but less when light was reduced. In contrast to predictions, reduced water flow had a negative effect on the percentage cover and biomass of turf-forming algae, rejecting the second hypothesis. It seems, however, that this negative effect was caused by an increase in shading associated with reduced canopy movement, not a reduction of water flow per se. None of the factors accounted for all of the change seen in understorey algae, indicating that it is important to study the interactive effects of physical processes.

Residential Flashover Prevention with Reduced Water Flow: Phase 2

2021 ◽  
Author(s):  
Nicholas Dow ◽  
◽  
Daniel Madrzykowski
Keyword(s):  
Water Flow ◽  
Fire Suppression ◽  
Water Flux ◽  
Sprinkler System ◽  
Low Flow ◽  
Fire Growth ◽  
Solid Cone ◽  
Prevention System ◽  
Discharge Density ◽  
Reduced Water

The purpose of this study was to investigate the feasibility of a residential flashover prevention system with reduced water flow requirements relative to a residential sprinkler system designed to meet NFPA~13D requirements. The flashover prevention system would be designed for retrofit applications where water supplies are limited. In addition to examining the water spray's impact on fire growth, this study utilized thermal tenability criteria as defined in UL 199, Standard for Automatic Sprinklers for Fire-Protection Service. The strategy investigated was to use full cone spray nozzles that would discharge water low in the fire room and directly onto burning surfaces of the contents in the room. Where as current sprinkler design discharges water in a manner that cools the hot gas layer, wets the walls and wets the surface of the contents in the fire room. A series of eight full-scale, compartment fire experiments with residential furnishings were conducted with low flow nozzles. While the 23~lpm (6~gpm) of water was the same between experiments, the discharge density or water flux around the area of ignition varied between 0.3~mm/min (0.008~gpm/ft**2) and 1.8~mm/min (0.044~gpm/ft**2). Three of the experiments prevented flashover. Five of the experiments resulted in the regrowth of the fire while the water was flowing. Regrowth of the fire led to untenable conditions, per UL 199 criteria, in the fire room. At approximately the same time as the untenability criteria were reached, the second sprinkler in the hallway activated. In a completed system, the activation of the second sprinkler would reduce the water flow to the fire room, which would potentially lead to flashover. The variations in the burning behavior of the sofa resulted in shielded fires which led to the loss of effectiveness of the reduced flow solid cone water sprays. As a result of these variations, a correlation between discharge density at the area of ignition and fire suppression performance could not be determined given the limited number of experiments. An additional experiment using an NFPA~13D sprinkler system, flowing 30~lpm (8 gpm), demonstrated more effective suppression than any of the experiments with a nozzle. The success of the sprinkler compared with the unreliable suppression performance of the lower flow nozzles supports the minimum discharge density requirements of 2~mm/min (0.05~gpm/ft**2) from NFPA~13D. The low flow nozzle system tested in this study reliably delayed fire growth, but would not reliably prevent flashover.

https://fsri.org/research-update/fsri-releases-report-residential-flashover-prevention-reduced-water-flow-phase-1

2020 ◽  
Author(s):  
Daniel Madrzykowski ◽  
◽  
Nick Down
Keyword(s):  
Water Flow ◽  
Test Structure ◽  
Low Flow ◽  
Flowing Water ◽  
Water Spray ◽  
Water Supplies ◽  
Flow Rates ◽  
Prevention System ◽  
Reduced Water ◽  
Fire Experiments

This study was designed to be an initial step to investigate the potential of low flow nozzles as part of a retrofit flashover prevention system in residential homes with limited water supplies. Not all homes have water supplies that can meet the needs of a residential sprinkler system. Current alter- natives, such as including a supplemental tank and pump, increase the cost of the system. These homes could benefit from an effective fire safety system with lower water supply requirements. The experiments in this study were conducted in a steel test structure which consisted of a fire room attached to a hallway in an L-shaped configuration. Three types of experiments were conducted to evaluate nozzles at different flow rates and under different fire conditions. The performance of the nozzles was compared to the performance of a commercially available residential sprinkler. The first set of experiments measured the distribution of the water spray from each of the nozzles and the sprinkler. The water spray measurements were made without the presence of a fire. The other two sets of experiments were fire experiments. The first set of fire experiments were designed to measure the ability of a water spray to cool a hot gas layer generated by a gas burner fire. The fire source was a propane burner which provided a steady and repeatable flow of heat into the test structure. Two water spray locations were examined, in the fire room and in the middle of the hallway. In each position, the burner was shielded from the water spray. The results showed that for equivalent conditions, the nozzle provided greater gas cooling than the sprinkler. The tests were conducted with a fire size of approximately 110 kW, and water flow rates in the range of 11 lpm (3 gpm) and 19 lpm (5 gpm). The second set of fire experiments used an upholstered sofa as the initial source of the fire with the water spray located in the same room. As a result of the compartment size and water spray distribution, the nozzle flowing water at 23 lpm (6 gpm) provided more effective suppression of the fire than the sprinkler flowing 34 lpm (9 gpm) did. The nozzle was similarly effective with the ignition location moved 1.0 m (3.2 ft) further away. However, the nozzle failed to suppress the fire with a reduced water flow rate of 11 lpm (3 gpm). The results of this limited study demonstrate the potential of low flow nozzles, directly flowing water on to the fuel surface, with the goal of preventing flashover. Additional research is needed to examine larger room sizes, fully furnished rooms, and shielded fires to determine the feasibility of a reduced water flow flashover prevention system.

scholarly journals CRACK HEALING UTILISING BACTERIAL SPORES IN CONCRETE

2017 ◽  
Vol 12 (3) ◽  
pp. 103-114
Author(s):  
Alan Richardson ◽  
Leon Amess ◽  
Simon Neville ◽  
Christopher Walton
Keyword(s):  
Water Flow ◽  
Bacterial Spores ◽  
Life Cycle Costs ◽  
Repair System ◽  
Self Healing ◽  
Flow Test ◽  
Reproduction Process ◽  
Healing Agent ◽  
Scale Test ◽  
Reduced Water

This self repair system is based upon harmless ground borne bacteria as the self-healing agent. The bacteria are activated after the concrete is cracked and the bacterial spores are exposed to moisture and air. The bacterial reproduction process creates a calcite by-product which fills the cracks in the concrete. By sealing the cracks in concrete, an effective barrier to air or liquid borne deleterious materials are formed and as a consequence of this, enhanced durability is achieved in the structure, resulting in lower life cycle costs. The concrete/mortar prisms were cracked and tested for water flow. They were then left for 56 days to heal and were subject to a test for water tightness. Healing was observed and a reduced water flow (74% and 32% healed) measured with the healed samples when compared to the specimens that were cracked and subjected to a water flow test without any healing agent. The number of samples were limited and a larger scale test is recommended for further work; however, this is a proof of concept of the process of healing and testing.

China looms large over South-east Asia’s Mekong states

2021 ◽  
Keyword(s):  
Climate Change ◽  
East Asia ◽  
Water Flow ◽  
East Asian ◽  
Mekong River ◽  
South East Asia ◽  
Content Type ◽  
Mekong River Commission ◽  
Economic Ties ◽  
Reduced Water

Significance The Mekong flows through China and the five mainland South-east Asian states -- Myanmar, Thailand, Cambodia, Laos and Vietnam. Earlier this month, China belatedly informed the downstream Mekong countries of reduced water flow because of power-line maintenance at one of its dams on the river. Impacts US partners India and Japan will look to strengthen economic ties with the South-east Asian Mekong states. Climate change and low rainfall will exacerbate droughts in mainland South-east Asia. The China-led Lancang-Mekong Cooperation initiative will dominate management of the Mekong, overshadowing the Mekong River Commission.

scholarly journals Present Status of Ganges River DolphinsPlatanista gangetica gangetica(Roxburgh, 1801) in the Turag River, Dhaka, Bangladesh

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Abdul Baki ◽  
Naser Ahmed Bhouiyan ◽  
Md. Saiful Islam ◽  
Shayer Mahmood Ibney Alam ◽  
Shibananda Shil ◽  
...  
Keyword(s):  
Water Flow ◽  
Land Development ◽  
Encounter Rate ◽  
Freshwater Ecosystem ◽  
Ganges River ◽  
Brick Kilns ◽  
Toxic Emissions ◽  
Dolphin Population ◽  
Reduced Water

Freshwater ecosystem degradation in the Turag River basin is increasing due to rising human settlement, reduced water flow during the dry season, new large land development projects, and toxic emissions caused by brick kilns. The population of river dolphins was estimated through surveys carried out from December 2012 to November 2013. Surveys were conducted on a fortnightly basis. The dolphins were counted within an 18.4 km stretch (known to be the most polluted stretch) of the 75 km long river. A total of 62 dolphin sightings were recorded, both as individual sightings and as groups. The highest monthly count was in August. The best-high-low estimates of 9-11-7 individuals were recorded in August 2013 in river ecology. Seasonal changes in spatial distribution were observed. The survey revealed that rising floodwater stimulated an increase in the dolphin population in the study area from July to October. The maximum encounter rate was also 0.49 sightings km−1for the month of August. The sightings and encounter rates of dolphins were lower from December to July (dry and premonsoon period) likely due to reduced water flow and adverse water quality of this river.

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