Safety+of+Outside+Surfaces+for+Activities

__Group Memebers: Pelix, Wei An, Katie, Anna, Jack, and Chris__

__Background Information:__ On the Taipei American School Campus, outdoor activities such as sports take place on several different surfaces including the track, the Upper Field (AstroTurf), and the Lower Field (AstroTurf). During afternoon practices for fall sports season such as cross country and soccer, these surfaces can reach very high temperatures. In some cases the track and the AstroTurf may become too hot to touch. In soccer, for example, when a tackle is made and a player slides on the ground, it can be quite painful: not only does the friction from the slide cause a turf burn, but the extra heat exuded by the surface itself can make the rubbing against the skin even more painful. This can also apply to athletes practicing on the track, if for whatever reason they fall and come into direct contact with the surface. This presents a health and safety concern for the athletes at Taipei American School. Furthermore, the temperature of the surfaces can cause the rubber on the bottom of an athlete's shoes to soften, particularly on the AstroTurf but also on the track. This increases the friction between the athlete's shoes and the surface, which in turn makes the athlete's movement slower. This also presents a safety concern, but in a less direct sense-- if an athlete is less agile on the field or on the track, he or she may be more likely to get injured because of this decrease in mobility. This is especially a concern in soccer when it is important to be on one's toes in order to avoid dangerous physical contact with other players. Thus, it is clear that the increase in temperature of outside surfaces on the TAS Campus can be a potential health and safety concern for athletes and other participants in outdoor activities. In this experiment, the rate at which the different surfaces heat up will be determined. From this, the safest surface for outdoor activities will be determined. The natural grass surface, where some outdoor activities take place but not sports, will serve as a control in this experiment in order to compare the relative safety of the other surfaces.

__Aim:__ to determine the rate of temperature increase for outside surfaces on the TAS campus __Variables:__ Independent: type of surface (track, upper field AstroTurf, lower field AstroTurf, and natural grass) Dependent: surface temperature Controlled variables: surface area of the surface, volume of water used to cool the surface, temperature of the water used to cool the surface, time span of each trial, time at which the surface is cooled, approximate time of day (for each set of trials)

__Materials:__ - thermometer - meter stick (4) - LoggerPro temperature probe - track (area 1m^2) - lower field AstroTurf (area 1m^2) - upper field AstroTurf (area 1m^2) - natural grass (area 1m^2) - 1L pitcher (2)

__Method:__ 1. Measure an area of 1m squared on the track surface using four meter sticks to mark the perimeter. 2. Establish a baseline temperature reading by recording the temperature of the surface at thirty second intervals for two minutes. 3. At exactly two minutes pour 2 liters of water on the surface to cool it. 4. Measure the temperature change for 1290 seconds. 5. Repeat steps 1~4 for each different surface (lower field AstroTurf, upper field AstroTurf, natural grass, track) Astroturf Natural Grass Track

__Data Processing__ Table 1. The Surface Temperature of Different Surfaces Over Time, Trials 1 & 2 (s) || Temperature of track Trial 1 (°C) || Temperature of upper field AstroTurf Trial 1 (°C) || Temperature of lower field AstroTurf Trial 1 (°C) || Temperature of natural grass Trial 1 (°C) || Temperature of track Trial 2 (°C) || Temperature of upper field AstroTurf Trial 2 (°C) || Temperature of lower field AstroTurf Trial 2 (°C) || Temperature of natural grass Trial 2 (°C) ||
 * Time
 * 0 || 49.8 || 55.6 || 62.6 || 44.7 || 40.8 || 52.3 || 40.5 || 40.7 ||
 * 30 || 50.6 || 55.6 || 63.5 || 45.2 || 41.6 || 55.0 || 44.6 || 45.2 ||
 * 60 || 51.5 || 56.0 || 64.2 || 44.8 || 42.0 || 57.3 || 47.2 || 44.8 ||
 * 90 || 51.4 || 56.7 || 65.4 || 44.6 || 43.6 || 59.2 || 48.7 || 44.6 ||
 * 120 || 51.0 || 58.7 || 66.5 || 45.0 || 45.7 || 60.7 || 49.6 || 45.0 ||
 * 150 || 31.9 || 32.4 || 58.7 || 41.6 || 35.4 || 38.2 || 30.0 || 41.6 ||
 * 180 || 34.8 || 35.7 || 53.5 || 39.9 || 39.5 || 39.9 || 29.9 || 39.9 ||
 * 210 || 36.8 || 35.5 || 51.0 || 38.5 || 40.4 || 40.7 || 31.4 || 38.5 ||
 * 240 || 38.4 || 37.0 || 48.9 || 38.0 || 41.9 || 41.7 || 32.5 || 38.0 ||
 * 270 || 39.6 || 38.0 || 47.1 || 38.3 || 42.3 || 42.3 || 33.5 || 38.3 ||
 * 300 || 40.8 || 37.5 || 44.9 || 38.7 || 42.1 || 42.2 || 34.5 || 38.7 ||
 * 330 || 41.6 || 36.8 || 43.5 || 39.3 || 42.5 || 42.8 || 34.7 || 39.3 ||
 * 360 || 42.1 || 36.5 || 42.4 || 39.7 || 42.3 || 43.5 || 34.8 || 39.7 ||
 * 390 || 42.2 || 36.2 || 41.7 || 40.1 || 41.8 || 42.7 || 34.5 || 40.1 ||
 * 420 || 42.6 || 36.0 || 41.5 || 40.2 || 42.8 || 42.5 || 35.1 || 40.2 ||
 * 450 || 42.7 || 36.0 || 43.3 || 40.1 || 43.1 || 42.6 || 35.7 || 40.1 ||
 * 480 || 42.9 || 35.8 || 45.1 || 40.2 || 41.9 || 43.4 || 36.3 || 40.2 ||
 * 510 || 42.3 || 35.7 || 47.5 || 39.6 || 41.4 || 43.5 || 37.2 || 39.6 ||
 * 540 || 41.9 || 35.6 || 47.9 || 39.4 || 40.3 || 43.2 || 38.0 || 39.4 ||
 * 570 || 42.3 || 35.7 || 47.9 || 39.6 || 40.2 || 42.9 || 39.1 || 39.6 ||
 * 600 || 42.4 || 36.3 || 48.9 || 39.8 || 39.9 || 41.8 || 39.1 || 39.8 ||
 * 630 || 42.0 || 37.1 || 49.5 || 40.4 || 40.8 || 40.6 || 39.0 || 40.4 ||
 * 660 || 41.9 || 38.7 || 50.4 || 40.3 || 40.9 || 40.3 || 38.3 || 40.3 ||
 * 690 || 41.8 || 40.0 || 51.2 || 40.5 || 41.3 || 39.3 || 38.1 || 40.5 ||
 * 720 || 41.7 || 41.1 || 52.3 || 40.4 || 41.2 || 38.6 || 38.3 || 40.4 ||
 * 750 || 42.0 || 42.1 || 53.8 || 40.9 || 41.1 || 39.0 || 38.7 || 40.9 ||
 * 780 || 42.1 || 42.7 || 54.3 || 41.0 || 40.5 || 38.1 || 39.4 || 41.0 ||
 * 810 || 42.2 || 43.5 || 53.9 || 40.9 || 40.5 || 38.2 || 39.1 || 40.9 ||
 * 840 || 42.3 || 44.6 || 54.4 || 40.8 || 41.0 || 37.7 || 39.7 || 40.8 ||
 * 870 || 42.1 || 45.4 || 55.4 || 41.2 || 42.0 || 37.0 || 40.1 || 41.2 ||
 * 900 || 42.4 || 45.3 || 56.5 || 41.8 || 41.7 || 36.5 || 40.3 || 41,8 ||
 * 930 || 42.5 || 46.3 || 57.3 || 41.8 || 41.4 || 36.2 || 40.4 || 41.8 ||
 * 960 || 42.7 || 47.2 || 57.8 || 42.3 || 41.0 || 35.6 || 40.9 || 42.3 ||
 * 990 || 42.3 || 48.3 || 58.3 || 42.9 || 40.6 || 35.8 || 41.3 || 42.9 ||
 * 1020 || 42.7 || 49.0 || 58.9 || 43.1 || 40.2 || 36.4 || 41.4 || 43.1 ||
 * 1050 || 42.3 || 47.7 || 59.2 || 42.9 || 40.3 || 38.3 || 41.7 || 42.9 ||
 * 1080 || 42.0 || 46.8 || 59.1 || 42.9 || 40.6 || 39.5 || 42.0 || 42.9 ||
 * 1110 || 41.8 || 46.7 || 58.7 || 43.0 || 40.8 || 40.2 || 42.6 || 42.9 ||
 * 1140 || 42.0 || 45.9 || 59.4 || 43.1 || 41.4 || 41.3 || 43.2 || 43.1 ||
 * 1170 || 42.2 || 46.4 || 58.3 || 43.8 || 41.8 || 42.0 || 43.8 || 43.8 ||
 * 1200 || 42.0 || 48.4 || 57.3 || 43.6 || 41.5 || 42.8 || 44.2 || 43.6 ||
 * 1230 || 42.1 || 49.2 || 55.9 || 42.8 || 41.0 || 43.06 || 44.9 || 42.8 ||
 * 1260 || 42.1 || 50.2 || 54.3 || 42.4 || 41.0 || 43.0 || 45.4 || 42.4 ||
 * 1290 || 42.2 || 52.9 || 52.5 || 42.3 || 40.9 || 42.6 || 45.3 || 42.3 ||













Formulas- Take the coordinates of the vertex of the point where the temperature drops suddenly. Then take the coordinates of the highest point near the end of the graph (relative maxima) Use the coordinates to calculate the slope (the rate of change), which indiates how fast a specific surface heats up. Then average the rates of change if there are two trials.
 * Data Analysis:**

relative maxima (1200 sec, 43.8 C) Average=(0.006+0.008) / 2= **0.007 degrees Celsius per sec** change in y/ change in x therefore 43.8-38 / 1200-250= 5.8/950= 0.006 degrees Celsius per sec 44-36 / 1200-250= 8 / 950=0.008 degrees Celsius per sec 16 / 750= 0.0213 degrees Celsius per sec Lower field 2 (150 sec, 30 C) (1200 sec, 45 C) 15 / 1050= 0.0143 degrees Celsius per sec 10.5 / 1140= 0.009 degrees Celsius per sec Track 2 (150 sec, 35.5 C) (1290 sec, 42 C) 6.5 / 1140 = 0.006 degrees Celsus per sec 21 / 1350= 0.016 degrees Celsius per sec Upper Field 2 (150 sec, 38 C) (1290 sec, 42 C) 4/ 114 = 0.003 degrees Celsius per sec According to the analyzed data above, the surfaces that heat up faster go in this order (slowest to fastest): Real grass, Track, Upper field astroturf, Lower Field astroturf
 * Example:**
 * Real grass**- vertex point (250 sec, 38C)
 * Real grass 2**- (250sec, 35.2 C) (1200sec, 44 C)
 * Lower field** 1 (400 sec, 42 C) (1150 sec, 58 C) Average rate of heating up: **0.0178 degrees Celsius per sec**
 * Track** 1 (150 sec, 32 C) (1290 sec, 42.5 C) Average rate of heating up: **0.0075 degrees Celsius per sec**
 * Upper Field** 1 (150 sec, 31 C) (1500 sec, 52 C) Average rate of heating up: **0.0095 degrees Celsius per sec**

However, note * that some of the rates might not be accurate because the graphs are very sporadic and not very constant. __Conclusion__

i. Summarize and Interpret Findings === From the results obtained, it's suggested that the real grass field heats slowest while the lower field turf heats fastest. One possible way to explain this finding is that the soil underneath the grass absorbs most of the water and maintains a wet surface, so then the temperature doesn’t increase rapidly. This experiment was based on a research done at Brigham Young University*. The data retrieved and the research done at Brigham University both show that Natural grass fields are significantly cooler than artificial fields (approximately 20°C cooler). Heat strokes occur when one's temperature is greater than 38.3°C and when a person's body absorbs more heat than it can lose. With the surface of the lower field heating up to nearly 70°C on a sunny day, it's suggested to hydrate every 30 minutes in order to prevent any heat-related illness. On the graphs, the small temperature drops and rises after the surface has been cooled can be explained by the factor of wind. Due to the fact that wind was not controlled, the temperature of the wind blown was also collected by the temperature probe. Also, water was blown outside the square meter, resulting in an inaccurate rate of change in temperature. To control this variable, a square meter box was considered, but the square box would change the area of each measurement due to its shadow and it might create a heating effect depending on its material. ===

ii. Sources of Error ===There were several potential sources of error in this experiment. Two trials were conducted on each surface. However, each trial for each surface was not conducted simultaneously. Therefore, changes in air temperature, sun exposure, and wind chill may have affected the temperatures recorded at any given time during any trial for any surface. These occurred randomly and were not consistent for the same surface within the same trial because they were not conducted simultaneously. === ===There was also error from the equipment that was used in this experiment. The thermometer that was used to measure the surface temperature recorded temperatures that were recorded with an error of +/- 0.1 degrees Celsius. === ===The different characteristics of the different surfaces also affected the temperature change that was recorded. The track surface, unlike the AstroTurf and natural grass surfaces, is completely flat. While the AstroTurf and the natural grass would radiate some heat back to the surface, the track would not. Because heat is trapped on the surface by the natural grass and the AstroTurf these surfaces would heat up more quickly than the track. Also, the natural grass surface and also the AstroTurf surface to a degree have the characteristic of absorption. When the water was poured on these surfaces it would be absorbed into the ground. This is not the case for the track. Again, this would cause the natural grass and AstroTurf surfaces to heat up more quickly. Natural grass also has the characteristic of water retention however, which would naturally cool the surface, thereby causing it to heat up more slowly. The small black rubbers on the AstroTurf surfaces may have caused it to absorb more solar radiation as well, thereby heating up faster. ===

iii. Possible Improvements ===Changes in air temperature, sun exposure, and wind chill may have affected individual temperature readings for the surface temperature of any surface during any given trial. However, the day on which the experiment was conducted was mostly clear with very little wind. Therefore, these factors probably did not affect the overall trend of the data. An improvement to the procedure would be to measure the change in surface temperature for all four surfaces within the same trial simultaneously. Therefore, the affect of air temperature, sun exposure, and wind chill would be consistent for the different surfaces. Also, a protective glass shield could have been placed over the thermometer in order to protect it from the wind, which was arguably the most significant source of error in this experiment. This would have still allowed the surface to absorb solar energy. However, this would have produced yet another error because the glass would have radiated some heat back to the surface. The two trials were conducted within the time frame of 10 am and 3 pm for each surface. The second trial should be conducted at the same time of day as the first trial in order to minimize error. Performing different trials at different times of day, however, does provide an avenue for further study: to determine how the time of day affects the temperature increase for different surfaces. === ===The error of the thermometer was very slight and did not affect the overall trend of the data. Multiple trials would further limit the effect of this error on the data. Two trials were performed. More trials would confirm the trends already visible. === ===Finally, the different natures of the different surfaces are an inherent part of the experimental procedure: to determine the rate of temperature increase for different outdoor surfaces, Therefore, these errors should be considered when analyzing the results but should be considered to be a natural part of the 'heating up' process. Multiple trials should be performed to achieve concordant results. ===




 * C. Frank Williams and Gilbert E. Pulley “Synthetic Surface Heat Studies”

