Experimental Investigation of Air Relative Humidity (RH) Cycling Tests on MEA/Cell Aging in PEMFC Part I: Study of High RH Cycling Test With air RH at 62%/100%

Fuel Cells ◽  
2012 ◽  
Vol 12 (3) ◽  
pp. 335-346 ◽  
Author(s):  
B. T. Huang ◽  
Y. Chatillon ◽  
C. Bonnet ◽  
F. Lapicque ◽  
S. Leclerc ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Relative Humidity ◽  
Cell Aging ◽  
Cycling Test

Experimental Investigation of Air Relative Humidity (RH) Cycling Tests on MEA/Cell Aging in PEMFC Part II: Study of Low RH Cycling Test with Air RH at 62%/0%

Fuel Cells ◽  
2012 ◽  
Vol 12 (3) ◽  
pp. 347-355 ◽  
Author(s):  
B. T. Huang ◽  
Y. Chatillon ◽  
C. Bonnet ◽  
F. Lapicque ◽  
S. Leclerc ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Relative Humidity ◽  
Cell Aging ◽  
Cycling Test

On the Use of Monolayers to Reduce Evaporation From Stationary Water Pools

1993 ◽  
Vol 115 (1) ◽  
pp. 209-214 ◽  
Author(s):  
T. D. Tang ◽  
M. T. Pauken ◽  
S. M. Jeter ◽  
S. I. Abdel-Khalik
Keyword(s):  
Experimental Investigation ◽  
Relative Humidity ◽  
Water Surface ◽  
Surface Film ◽  
Free Water ◽  
Vapor Concentration ◽  
Controlled Environment ◽  
Stearyl Alcohol ◽  
Water Pool ◽  
Evaporation Suppression

An experimental investigation has been conducted to quantify the extent by which monolayers of fatty alcohols can reduce evaporation from a deep stationary water pool within a controlled environment. Octadecanol (stearyl alcohol), C17H35–CH2–OH, was chosen as the surface film and ethanol was selected to be the spreading agent. Evaporation suppression of 60 percent was achieved at a water temperature of 25°C with an air temperature of 20°C and a relative humidity of 70 percent. The experimental techniques and data have been validated by comparing the measured evaporation rates for film-free water with earlier data published by other investigators. Data for the evaporation rates of water covered by octadecanol films were correlated as a function of vapor concentration differences between the water surface and air.

scholarly journals Experimental Investigation of Workers Physiology under Tropical Climate in Construction Industries

2020 ◽  
Vol 78 (1) ◽  
pp. 35-47
Author(s):  
Ahmad Rasdan Ismail ◽  
Norfadzilah Jusoh ◽  
Mohd Amin Mahd Asri ◽  
Raemy Md Zein ◽  
Ismail Abdul Rahman
Keyword(s):  
Heart Rate ◽  
Experimental Investigation ◽  
High Risk ◽  
Relative Humidity ◽  
Construction Industry ◽  
Air Temperature ◽  
Thermal Environment ◽  
Construction Workers ◽  
Activity Levels ◽  
Vo2 Max

Construction workers are particularly susceptible to heat-related illnesses, for the weather is very hot and humid. The objective of this study is to investigate the interaction between the temperature and relative humidity to the physiological parameters such as heart rate (HR) and volume oxygen uptake (VO2 max) of the workers in the construction industry. The experiment was conducted in an environmental chamber which simulates the environment of the construction industry with three conditions combining air temperature and relative humidity (34 °C/74 %, 34 °C/92 %, 38 °C/83 %). The HR and the VO2 max of three subjects were monitored, and all the data were continuously recorded every 15 minutes. For each condition, the activity levels such as lifting the heavy sand (10 kg) were conducted for subjects. In the VO2 case, a significant correlation was observed between air temperature (p=0.043) and the relative humidity (p=0.000). Meanwhile, in HR case, a significant correlation was also observed between air temperature (p=0.004) and the relative humidity (p=0.028). The high-risk thermal environment (38 °C/83 %) and subject were identified. In conclusion, it can be empirically proved that environmental factor such as temperature and relative humidity have a significant impact on workers’ performance.

Experimental Investigation of the Effect of Materials and Their Surface Colours on Nocturnal Cooling

2013 ◽  
Author(s):  
Nnamdi V. Ogueke ◽  
Kevin N. Nwaigwe ◽  
Chidiebere Nwaiwu ◽  
Emmanuel E. Anyanwu
Keyword(s):  
Experimental Investigation ◽  
Relative Humidity ◽  
Temperature Difference ◽  
The Other ◽  
Galvanized Steel ◽  
Ambient Temperatures ◽  
Clear Night ◽  
The Third ◽  
Night Sky

The experimental investigation of the effects of materials and their surface colours on nocturnal cooling is presented. Two materials, galvanized steel and aluminium, were considered. Three plates of each material were used. One was painted black, the other white, while the third was left unpainted. Each of the plates (0.5 × 0.5 m) was used to cover a wooden box of dimension 0.5 × 0.5 × 0.24 m, made of 0.02 m thick plywood, thus producing an air tight arrangement. Six of such boxes were formed in all; three from galvanized steel and three from aluminium. Ambient temperatures, temperatures of the air inside the box and on the outside surface of the plates were measured between 19:00 hours and 06:00 hours for 6 months. Also measured was the relative humidity. Results obtained reveal that the plates’ performances greatly depended on how clear the night was. For very clear night, the black painted aluminium gave the best result, maintaining a temperature difference of 3–8°C with the ambient. For a partly overcast night, the best result of 1–5°C difference between the inside air and the ambient was recorded by the unpainted galvanized steel while on heavily overcast night the best performance came from the unpainted aluminium with a temperature difference of 1–4°C. Thus unpainted galvanized steel and aluminium are considered best in region where the night sky is hardly clear.

Experimental Investigation of Linear Cumulative Damage Theory With Power Cycling Test

2019 ◽  
Vol 34 (5) ◽  
pp. 4722-4728 ◽  
Author(s):  
Guang Zeng ◽  
Christian Herold ◽  
Torsten Methfessel ◽  
Marc Schafer ◽  
Oliver Schilling ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Cumulative Damage ◽  
Cycling Test ◽  
Power Cycling ◽  
Damage Theory

Experimental investigation of pinhole effect on MEA/cell aging in PEMFC

2013 ◽  
Vol 38 (1) ◽  
pp. 543-550 ◽  
Author(s):  
B.T. Huang ◽  
Y. Chatillon ◽  
C. Bonnet ◽  
F. Lapicque ◽  
S. Leclerc ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Cell Aging

scholarly journals Experimental Investigation of Thermal Performance of Aluminum Foil Coated with Polyester in a Direct Evaporative Cooling System

2021 ◽  
Vol 27 (4) ◽  
pp. 1-15
Author(s):  
Abbas Magid Taleb ◽  
Mohammed Abdulraouf Nima
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Relative Humidity ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Aluminum Foil ◽  
Adiabatic Process ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Positive Impression

An experimental study was carried out for an evaporative cooling system in order to investigate the effect of using an aluminum pad coated with fabric polyester. In the present work, it was considered to use a new different type of cooling medium and test its performance during the change in the wet-bulb temperature and dry-bulb temperature of the supply air outside of the pad, the relative humidity of the supply air, the amount of air supplied (300-600) CFM and also the change of the amount of circulated water (1.75, 2.5, 4.5) liter per minute. A decrease in the WBT of the air was obtained, whereas the WBT of the air entering the pad was 26.5 . In contrast, the WBT of the outside air had reached 23  even though evaporative cooling is an adiabatic process which makes the WBT of the air that comes out of the pad is equal to the entering air WBT. The decrease in DBT is by changing the amount of air and water passing through the aluminum pad, whereas the DBT of the air entering the pad was 45 , while the DBT of the outside air had reached 29 . Also, an essential thing was obtained as this rise in the relative humidity of the air is very small 57%RH compared to the conventional pads, and this gives a positive impression as the air supplied from this pad has less moisture and its ability to carry moisture is much higher than that of air supplied from other pads. This gives a positive impression because the air supplied from this pad has lower humidity and its ability to hold moisture much higher than the air supplied from other traditional pads.

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