Design and Testing of a Plastic Bubble-Film Covered Shallow Solar Pond

1983 ◽  
Vol 105 (4) ◽  
pp. 382-384 ◽  
Author(s):  
R. E. Forbes
Keyword(s):  
Temperature Rise ◽  
Thick Layer ◽  
Incident Radiation ◽  
Measured Quantity ◽  
Film Material ◽  
Solar Pond ◽  
Plastic Materials ◽  
Maximum Water Temperature ◽  
Program Temperature ◽  
Maximum Water

A shallow solar pond was designed from inexpensive plastic materials and tested during the summer months. The bag containing the water consisted of a black polyethylene bottom (1.5 mil) covered with a clear polyvinylchloride top (4 mil) and a layer of polyethylene bubble-film on the top of the PVC bag. The bubble-film material is of the type commonly used for protection of breakable goods during shipment. The bubble-film material provided an inexpensive and effective upper glazing for the bag assembly. The bag was insulated from bottom losses by placing it on a 2.22-cm (0.875-in.)-thick layer of polystyrene foam. Tests were performed during May, June, and July 1980. These tests were performed by batch-filling the bag in the morning with a measured quantity of water and measuring the temperature rise of the water during the day. Measurement of water quantity, initial temperature, final temperature, and total incident radiation allowed for calculation of a daily efficiency for the pond. Tests were made for water depths of 5.2 and 10.2 cm (2.05 and 4 in.). Maximum daily efficiencies of up to 63 percent were recorded during the testing. Daily efficiency was determined by dividing the total daily heat collection of the pond by the total radiation incident on the pond for the day. Maximum water temperature of 67°C (152°F) was reached during the testing program. Temperature rise in the pond assembly was typically on the order of 33–39°C (60–70°F) during clear days.

scholarly journals Limnological survey of dhaka-narayanganj-demra (dnd) dam area wetlands

2020 ◽  
Vol 48 (1) ◽  
pp. 93-103
Author(s):  
AHM Shafiullah Habib ◽  
Mahiuddin Sarker ◽  
Md Gias Uddin ◽  
Shimu Akter ◽  
M Niamul Naser
Keyword(s):  
Physicochemical Characteristics ◽  
Fish Production ◽  
Water Parameters ◽  
Fresh Fish ◽  
Average Maximum ◽  
Maximum Water Temperature ◽  
Free Carbon Dioxide ◽  
Maximum Water ◽  
Carbon Dioxide Co2 ◽  
Limnological Survey

Present investigation was conducted to assess the physicochemical characteristics of water and its suitability for fish production at Dhaka-Narayanganj-Demra (DND) dam wetlands. Data were collected at eight points of the study area between March 2014and February 2015on temperature, transparency, pH, dissolved oxygen (DO) and free carbon dioxide (CO2) in the water. The average maximum water temperature, transparency, pH, DO, free CO2, hardness were recorded as34.6±0.4°C, 40.3±0.8cm, 7.9±0.06, 7.6±0.4 mgL-1,85.6±6.6 mgL-1 and 491.2±76mgL-1while minimum average were found as26.3±1.0°C,7.1±0.2 cm, 7.4±0.05, 5.9±0.3 mgL-1, 11.9±0.8 mgL-1 and 87.6±11.3 mgL-1respectively.All the water parameters were found in favourable condition for optimum freshwater fish production with some modification. This study can be the baseline data toward fresh fish supply and production prospect in the Dhaka city at wetland of the DND canal area. Bangladesh J. Zool. 48(1): 93-103, 2020

scholarly journals Experimental analysis of Scheffler reflector water heater

2011 ◽  
Vol 15 (3) ◽  
pp. 599-604 ◽  
Author(s):  
Rupesh Patil ◽  
Gajanan Awari ◽  
Mahendra Singh
Keyword(s):  
Storage Tank ◽  
Large Diameter ◽  
Average Power ◽  
Water Heater ◽  
Average Value ◽  
Water Boiling Test ◽  
Maximum Water Temperature ◽  
Maximum Water ◽  
Set Up ◽  
And Storage

The performance of Scheffler reflector has been studied. In this system storage reservoir was installed at Focus point. It has a single large diameter drum which serves the dual purpose of absorber tube and storage tank. The drum is sized to have a storage capacity of 20 liter for experiment. The tests were carried out with this set up and were repeated for several days. Performance analysis of the collector has revealed that the average power and efficiency in terms of water boiling test to be 1.30 kilowatts and 21.61 % respectively against an average value of beam radiations of 742[Wm-2]. The maximum water temperature in the storage tank of 98?C has been achieved on a clear day operation and ambient temperature between 28?C to 31?C.

Confinement And Control Of Oil Pollution On Water With Monomolecular Surface Films

1969 ◽  
Vol 1969 (1) ◽  
pp. 257-261 ◽  
Author(s):  
William D. Garrett
Keyword(s):  
Water Surface ◽  
Oil Pollution ◽  
Surface Film ◽  
Thick Layer ◽  
Surface Films ◽  
Film Material ◽  
Chemical Character ◽  
Favorable Conditions ◽  
And Control ◽  
Reduced Surface

Abstract Under favorable conditions monomolecular surface films can be used to guide, confine and condense petroleum spills on water. Composed of water-insoluable, non-toxic organic material, these films spread rapidly and spontaneously into a one-molecule-thick layer. Consequently, small quantities of piston-film material will clear thin oil layers from large areas of a water surface. The effects of wind, the chemical character of the pollution and its thickness upon the usefulness of the piston film will be discussed. In addition to clearing water surfaces of oil, one of the most useful applications may be the ability of the surface film to confine and condense a small oil spill into layers as thick as one centimeter. Since the petroleum is thickened and compressed into a much reduced surface area, the efficiency of oil retrieval techniques would be enhanced.

scholarly journals What causes cooling water temperature gradients in forested stream reaches?

2014 ◽  
Vol 11 (6) ◽  
pp. 6441-6472 ◽  
Author(s):  
G. Garner ◽  
I. A. Malcolm ◽  
J. P. Sadler ◽  
D. M. Hannah
Keyword(s):  
Water Temperature ◽  
Water Column ◽  
Stream Temperature ◽  
Temperature Gradients ◽  
Daily Maximum ◽  
Net Energy ◽  
Net Radiation ◽  
Maximum Water Temperature ◽  
Maximum Water ◽  
Energy Gains

Abstract. Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperature and provide refugia for temperature sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts, or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts, and in the absence of potentially confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian landuse transitions from open moorland to semi-natural forest. Observations were made along a 1050 m reach using a spatially-distributed network of ten water temperature micro-loggers, three automatic weather stations and >200 hemispherical photographs, which were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model, incorporating flow-routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water column–atmosphere interface. Predominantly net energy gains occurred along the reach during daylight hours, and heat exchange across the bed-water column interface accounted for <1% of the net energy budget. For periods when daytime net radiation gains were high (under clear skies), differences between water temperature observations decreased in the streamwise direction; a maximum difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ≤1°C cooler than at the upstream reach boundary and lagged the occurrence of daily maximum water temperature upstream by >1h. Temperature gradients were not generated by cooling of stream water, but rather by a combination of reduced rates of heating in the woodland reach and advection of cooler (overnight and early morning) water from the upstream moorland catchment. Longitudinal thermal gradients were indistinct at night and on days when net radiation gains were low (under over-cast skies), thus when changes in net energy gains or losses did not vary significantly in space and time, and heat advected into the reach was reasonably consistent. The findings of the study and the modelling approach employed are useful tools for assessing optimal planting strategies for mitigating against ecologically damaging stream temperature maxima.

scholarly journals Hematite (U-Th)/He thermochronometry detects asperity flash heating during laboratory earthquakes

Geology ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 514-518 ◽  
Author(s):  
Gabriele Calzolari ◽  
Alexis K. Ault ◽  
Greg Hirth ◽  
Robert G. McDermott
Keyword(s):  
High Temperatures ◽  
Temperature Rise ◽  
Thick Layer ◽  
Seismogenic Zone ◽  
Experimental Conditions ◽  
Slip Rates ◽  
Seismic Slip ◽  
Slip Surfaces ◽  
Before And After ◽  
Dynamic Weakening

Abstract Evidence for coseismic temperature rise that induces dynamic weakening is challenging to directly observe and quantify in natural and experimental fault rocks. Hematite (U-Th)/He (hematite He) thermochronometry may serve as a fault-slip thermometer, sensitive to transient high temperatures associated with earthquakes. We test this hypothesis with hematite deformation experiments at seismic slip rates, using a rotary-shear geometry with an annular ring of silicon carbide (SiC) sliding against a specular hematite slab. Hematite is characterized before and after sliding via textural and hematite He analyses to quantify He loss over variable experimental conditions. Experiments yield slip surfaces localized in an ∼5–30-µm-thick layer of hematite gouge with &lt;300-µm-diameter fault mirror (FM) zones made of sintered nanoparticles. Hematite He analyses of undeformed starting material are compared with those of FM and gouge run products from high-slip-velocity experiments, showing &gt;71% ± 1% (1σ) and 18% ± 3% He loss, respectively. Documented He loss requires short-duration, high temperatures during slip. The spatial heterogeneity and enhanced He loss from FM zones are consistent with asperity flash heating (AFH). Asperities &gt;200–300 µm in diameter, producing temperatures &gt;900 °C for ∼1 ms, can explain observed He loss. Results provide new empirical evidence describing AFH and the role of coseismic temperature rise in FM formation. Hematite He thermochronometry can detect AFH and thus seismicity on natural FMs and other thin slip surfaces in the upper seismogenic zone of Earth’s crust.

Life History of Redside Shiners, Richardsonius balteatus, with Particular Reference to Movements In and Out of Sixteenmile Lake Streams

1963 ◽  
Vol 20 (4) ◽  
pp. 1001-1030 ◽  
Author(s):  
C. C. Lindsey ◽  
T. G. Northcote
Keyword(s):  
Life History ◽  
Fork Length ◽  
Water Levels ◽  
Daily Maximum ◽  
Egg Deposition ◽  
Maximum Water Temperature ◽  
History Of ◽  
Maximum Water ◽  
Richardsonius Balteatus ◽  
Downstream Movement

Movements of shiners through two-way traps on inlet and outlet streams of a small British Columbia lake were studied from 1956 to 1962. The date on which adults first entered the inlet each spring corresponded to the first rise of daily maximum stream temperature above 10 °C. Days on which increased numbers of shiners ascended the inlet were positively associated with days of rising daily maximum water temperature, and were not associated with water levels. Egg deposition occurred both in daylight and darkness. Downstream movement of shiner fry was greatest during periods of turbidity, and occurred largely during darkness. Shiners first spawned at age III or older; some lived to age V or VI. Number of adult shiners over 79 mm fork length was estimated by Petersen marking experiments to be about 13,000 in the 42-acre lake. A large interchange of adults took place in some years between the lake and parts of the watershed upstream; a small interchange occurred downstream. Many shiners entered a stream more than once each year. Many survived to spawn in two or more successive years. Movement into the streams varied markedly in different years and was small compared with the number of adults in the lake. Homing is suggested as a mechanism which determines the proportion of inlet-, outlet-, and lake-spawning in this species.

scholarly journals Long-term changes in the water temperature of rivers in Latvia

2016 ◽  
Vol 70 (2) ◽  
pp. 78-87 ◽  
Author(s):  
Inese Latkovska ◽  
Elga Apsīte
Keyword(s):  
Water Temperature ◽  
Kendall Test ◽  
Maximum Temperature ◽  
Small Rivers ◽  
Positive Trend ◽  
Annual Maximum ◽  
Monitoring Period ◽  
Time Period ◽  
Maximum Water Temperature ◽  
Maximum Water

Abstract The study describes the trends of monthly mean water temperature (from May to October) and the annual maximum water temperature of the rivers in Latvia during the time period from 1945 to 2000. The results demonstrated that the mean water temperatures during the monitoring period from May to October were higher in the largest rivers (from 13.6 °C to 16.1 °C) compared to those in the smallest rivers (from 11.5 °C to 15.7 °C). Similar patterns were seen for the maximum water temperature: in large rivers from 22.9 °C to 25.7 °C, and in small rivers from 20.8 °C to 25.8 °C. Generally, lower water temperatures occurred in rivers with a high groundwater inflow rate, for example, in rivers of the Gauja basin, in particular, in the Amata River. Mann-Kendall test results demonstrated that during the monitoring period from May to October, mean water temperatures had a positive trend. However, the annual maximum temperature had a negative trend.

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