scholarly journals Sensitivity of a large flow-through lake to meteorological condition and anthropogenic stress (hydromorphological assessment)

2017 ◽  
Vol 90 (4) ◽  
pp. 401-415
Author(s):  
Barbara Nowicka ◽  
Marta Bałandin ◽  
Anna Nadolna
Keyword(s):  
Meteorological Condition ◽  
Anthropogenic Stress ◽  
Hydromorphological Assessment ◽  
Flow Through ◽  
Large Flow

scholarly journals Control Method of Slipstream Gas Source System of a Propeller

2019 ◽  
Vol 267 ◽  
pp. 01001
Author(s):  
Jinchun Shi
Keyword(s):  
Control Method ◽  
Low Flow ◽  
Source Control ◽  
Whole Process ◽  
Gas Source ◽  
Compressed Gas ◽  
Flow Through ◽  
Great Energy ◽  
Large Flow ◽  
Stable Control

For the slipstream gas source control system of propeller, there is no mature application in China. The traditional slipstream gas source system manually realizes the stable control of gas and flow through the self-operated pressure reducing device. But this mode can only be used in the condition of small pressure and low flow, cannot meet the actual need of high pressure and large flow, and cannot monitor and automatically control the energy consumption of compressed gas and heating equipment, resulting in great energy waste. Based on the actual engineering conditions, and according to the characteristics, user requirements and work flow of the slipstream gas source system, this paper describes a new control method for the slipstream gas source system of a propeller in detail, which solves the issue of automatic control in the whole process and realizes the key technical point, rapid stabilizing of airflow pressure and temperature.

scholarly journals Modeling nutrient consumptions in large flow-through bioreactors for tissue engineering

2009 ◽  
Vol 103 (5) ◽  
pp. 1003-1015 ◽  
Author(s):  
Mamatha Devarapalli ◽  
Benjamin J. Lawrence ◽  
Sundararajan V. Madihally
Keyword(s):  
Tissue Engineering ◽  
Flow Through ◽  
Large Flow

Air-Vapor Dynamics in Large-Scale Atmospheric Spray Cooling Systems

1978 ◽  
Vol 100 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Sushil Chaturvedi ◽  
R. W. Porter
Keyword(s):  
Reasonable Agreement ◽  
Large Scale ◽  
Spray Cooling ◽  
Cooling Towers ◽  
Cooling Systems ◽  
Flow Through ◽  
Spray Field ◽  
Large Flow ◽  
Essential Problem ◽  
Theory And Experiments

Atmospheric spray cooling systems are alternatives to cooling towers and cooling ponds. A quantity NTU containing the spray drop-wise parameters allows prediction of cooling range if local wet-bulb temperature is known. The essential problem is predicting local wet-bulb proceeding windward through the spray field. Theory was developed for this purpose involving wind attenuation and turbulent diffusion. Experiments were performed on a large flow-through spray canal involving segments with two types of floating spray modules. Previous experimental data are available for a fixed manifolded spray pond. A comparison of theory and experiments shows reasonable agreement.

scholarly journals Importance of Runoff and Winter Anoxia to the P and N Dynamics of a Beaver Pond

1993 ◽  
Vol 50 (10) ◽  
pp. 2222-2234 ◽  
Author(s):  
Kevin J. Devito ◽  
Peter J. Dillon
Keyword(s):  
Pond Water ◽  
Organic N ◽  
Beaver Pond ◽  
Average Water Temperature ◽  
N Dynamics ◽  
Average Water ◽  
Flow Through ◽  
Large Flow ◽  
Net Release

Annual retentions of total phosphorus (TP) (−11%) and total nitrogen (TN) (−5%) of a headwater beaver pond in central Ontario were low during 1987–88. Annually, inputs exceeded outputs of total reactive P (71%) and NO3–N (35%), and outputs exceeded inputs of total unreactive P (−33%) and total organic N (−26%), and inputs approximated outputs of NH4–N (−8%). Seasonal trends in P and N retention were inversely correlated with runoff. Monthly retention was weakly positively related to average water temperature and redox potential (ORP). Positive monthly retention coincided with low runoff and high biotic assimilation during the growing season. Winter ice cover was associated with undetectable dissolved oxygen and low ORP and increased levels of P and N, particularly NH4–N. High levels of P and N in the surface water during winter were coupled with increased runoff and potentially low biotic assimilation resulting in a net release of TP and TN. Large flow-through of waterborne inputs and flushing of regenerated P and N occurred during peak snowmelt resulting in low annual retention. Initial accumulation of flooded forest material and input of organic matter by beaver may be very important to P and N dynamics, representing a long-term source of nutrients to the pond water and outflow.

Research on the performance of electro-hydraulic proportional flow valve controlled by active pilot pump

2016 ◽  
Vol 231 (4) ◽  
pp. 720-731 ◽  
Author(s):  
Yunxiao Hao ◽  
Long Quan ◽  
Jiahai Huang
Keyword(s):  
Pressure Differential ◽  
Small Displacement ◽  
Flow Pulsation ◽  
Pump Speed ◽  
Pump Flow ◽  
Flow Capacity ◽  
Flow Through ◽  
Large Flow ◽  
Proportional Flow ◽  
Flow Valve

The cartridge flow valves, used in heavy machine and equipment, have the advantages of low leakage, large flow capacity, simple structure, and ease of modulation. However, in order to reduce the influence of load variety on the flow through valve, a pressure differential compensator or a cartridge type flow sensor should be added to the proportional throttle valve. These methods have disadvantages of reducing the flow capacity of valve and increasing the throttling loss. To overcome these disadvantages, a low energy consumption, high controllable electro-hydraulic proportional flow valve which consists of a hydraulic transistor (Valvistor) and a small displacement hydraulic pump driven by a servo motor is proposed firstly in the world. As the pump flow is basically proportional to the pump speed and little influenced by load variety, the flow through main valve is proportional to pilot pump speed. In the research, it’s known that feedback throttle slot pre-opening will cause the decrease of the main valve flow as pressure drop increases. So, small orifices are used instead of the pre-opening of feedback throttle slot to reduce the influence of load variety on the flow through valve. Furthermore, a method of pressure differential changing with pilot pump rotational speed calibration is introduced to further mitigate the influence of pressure difference. In this paper, the mathematical dynamic model of the valve is also established and the stability criterion of valve is derived. The influence of valve parameters and the flow pulsation of pilot pump on valve flow performance is analyzed and simulated. In view of the pilot pump flow pulsation frequency being much higher than the valve natural frequency, the research shows that the influence of flow pulsation of pilot pump on valve flow performance is very little. The research work provides a new method for the large flow electro-hydraulic proportional control system.

Dehalococcoides abundance and alternate electron acceptor effects on large, flow-through trichloroethene dechlorinating columns

2015 ◽  
Vol 100 (5) ◽  
pp. 2367-2379 ◽  
Author(s):  
Babur S. Mirza ◽  
Darwin L. Sorensen ◽  
R. Ryan Dupont ◽  
Joan E. McLean
Keyword(s):  
Electron Acceptor ◽  
Flow Through ◽  
Large Flow

Development of apical pits in chloride cells of the gills of Pimephales promelas after chronic exposure to acid water

1983 ◽  
Vol 41 ◽  
pp. 462-463
Author(s):  
Richard L. Leino ◽  
Jon G. Anderson ◽  
J. Howard McCormick
Keyword(s):  
Confidence Interval ◽  
Chronic Exposure ◽  
Lake Superior ◽  
Pimephales Promelas ◽  
Chloride Cells ◽  
Fathead Minnows ◽  
Secondary Lamellae ◽  
Untreated Water ◽  
Water Ph ◽  
Flow Through

Groups of 12 fathead minnows were exposed for 129 days to Lake Superior water acidified (pH 5.0, 5.5, 6.0 or 6.5) with reagent grade H2SO4 by means of a multichannel toxicant system for flow-through bioassays. Untreated water (pH 7.5) had the following properties: hardness 45.3 ± 0.3 (95% confidence interval) mg/1 as CaCO3; alkalinity 42.6 ± 0.2 mg/1; Cl- 0.03 meq/1; Na+ 0.05 meq/1; K+ 0.01 meq/1; Ca2+ 0.68 meq/1; Mg2+ 0.26 meq/1; dissolved O2 5.8 ± 0.3 mg/1; free CO2 3.2 ± 0.4 mg/1; T= 24.3 ± 0.1°C. The 1st, 2nd and 3rd gills were subsequently processed for LM (methacrylate), TEM and SEM respectively.Three changes involving chloride cells were correlated with increasing acidity: 1) the appearance of apical pits (figs. 2,5 as compared to figs. 1, 3,4) in chloride cells (about 22% of the chloride cells had pits at pH 5.0); 2) increases in their numbers and 3) increases in the % of these cells in the epithelium of the secondary lamellae.

Flow Through Heterogeneous Geologic Media

2015 ◽  
Author(s):  
Tian-Chyi Yeh ◽  
Raziuddin Khaleel ◽  
Kenneth C. Carroll
Keyword(s):  
Flow Through ◽  
Geologic Media
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