Hard copy Journal

Hard copy Journal

Yeah...Since the concept of online journals was new to me, and I wanted to work in school but didn't have a laptop, well most of my initial brainstorming and lists of variables and whatnot are on paper. Very messy paper. So, here (clicking will enlarge the scans):

This is the preliminary brainstorming, when I haven't even settled what to cook. It started with dumplings (which then led to questions about consistency and factors involved), but then Ms Tan suggested fish balls...The format of my results were xy graphs pretty much from the start though, and this was also when the infamous Image-J debuted.

Variables/constants/likely relationships between them hashed out during science block, note the top with hastily scrawled ideas from discussing with others.

The difference between a theoretical experiment (and tables) with square tangyuan (in pencil) dreamt up during class and the actual trial with round tangyuan (in pen) developed after actually trying it. Who knows, there is a reason why generations of Asian women make balls instead of blocks. Also, see how the measurements ended up being halfway across the page because there wasn't enough space.

Cleaned up version of the table, still with random bits of data everywhere they're not supposed to be of course, plus reflections for the trials below.

Number crunching time after trials 1 and 2. The top part is feedback from friends who took a look at my blog so far, bottom is the data for density used while discussing the results with Ms Tan.

Working for the new shape of tangyuan (same surface area, different volume), and finally getting it.

Trial 0 and the actual experiment...

(p.s. If you're wondering why there're strange bulges all over the paper, why yes, I did spill water on it while cooking tangyuan.)

LB: Trial 2 Results

LB: Trial 2 Results

Date: 30 June 2012

Time: 3pm-7pm

Room temperature: 27°C

Weather: Sunny

Trial 2 was conducted immediately after Trial 1 to check the repeatability of the results. From figure 3, the volume of the two 40g GRB was greater than their mass, but the opposite is true for the 20g GRB. Out of all the variables I identified initially, mass, volume, surface area or density do not predict the trend in time taken and only surface area to volume ratio is left.

Director's Cut: Trial 2

Director's Cut: Trial 2

The first two trials were done on the same day (last Wednesday in fact), before analysing the data collected, so the changes dealt with physical problems. After analysing, other flaws were revealed in some of the methodology as well.

• Even with an attempt at squeezing out air, placing uncooked GRB inside waterproof bags to keep them from dissolving in the displacement can still allowed for too much air. The plastic bag was too stiff to be compressed by the water. In retrospect, using a large enough sheet of cling wrap such that the opening could be kept above water would be more accurate.
• A preliminary look at the data indicates that the surface area calculations are going to be problematic. There's no way to make (and preserve) perfectly round spheres or circles (which have an added complication of depth) with according to exact measurements. Have thought of something to try for the flat GRB, but have no idea what to do for the round ones.

Edit: Will not make any more round GRB, instead focusing on investigating surface area:volume with less-curved shapes whose surface areas are easier to measure

I'll post this data after I've polished them 

• I overlooked procuring an apron, or at least a portable dry cloth to wipe off residues of dough. Now my tables are very clean, but my pants look like this:

Water and flour.

In other news, I've (finally) had to learn excel. Yay.

Questions after the two trials:

1. Does the temperature of the water affect its density, and therefore whether the GRBs will float in it?
2. Does the ratio of flour:water affect how the GRBs float? (e.g. density)
3. Since GRBs are water soluble, what does this mean for their cooking in water?
4. Does the amount of water in the pot affect how GRBs float?
5. Prelim points at GRBs shrinking, not expanding. How?

Edit: 1: Yes it does. 
Temp (°C)     Density (kg/m3)
+100    958.4
+80     971.8
+60     983.2
+40     992.2
+30     995.6502
+25     997.0479
+22     997.7735
+20     998.2071
+15     999.1026
+10     999.7026
+4     999.9720
0       999.8395
−10     998.117
−20    993.547
−30     983.85

LB: Trial 2

LB: Trial 2 Procedure

Research Question: Does the process of gelatinisation cause the GBR to float?
Hypothesis: The higher the surface area to volume ratio, the faster the GBR floats in water.

Steps

   1. Measure out 50g each of rice flour and water using a weighing scale, add a drop of blue food colouring and mix until evenly distributed.

Dough after mixing

   2.  Divide the dough into 3 parts, 2 parts of 40g each using the scale and 1 part of 20g using a spring balance.

3.  Roll all parts into balls. Then, evenly flatten 1 of the 40g balls until about 1 cm thick, leaving the rest untouched. Dust the GRB with cornflour.

4.  Lay all GRB on black paper covered with plastic, with a ruler in sight, and then take a photo from directly above.

This photo will be used for measuring surface area 

5. Wrap the 20g ball in cling wrap and place it inside a plastic bag. Squeeze out remaining air before twisting the bag closed.
6. Fill a displacement can with water, and slowly submerge the plastic bag while using the 100ml measuring cylinder to catch the displaced water. Record the volume and repeat steps 5-6 for the other two GRB.
7. Using a 250ml cylinder, pour 750ml of water  into a pot. Put the pot on a hotplate set to 120°C and start the stopwatch. When the water has begun to boil, slowly drop all GRB into the water by hand.
 8. Stir continuously with the strainer and record the time it took for each GRB to float. Turn off the hotplate when all GRBs are floating.

At 5.04 minutes, just dropped in GRB

At 8.30 minutes, with 40g flat floating

At 9.52 minutes, with 40g flat and 20g ball floating

    9. Using the strainer, transfer all GRB into a plate while making sure they are not sticking and leave them to cool for 30 minutes.

GRBs from both trials

10. Repeat step 4. 

11. Repeat steps 5-6, but directly slipping the GRBs into the displacement can without wrapping them. 

Displacement can measuring 40g flat, with 100 cylinder catching the displaced water

12. Weigh each GRB with the spring balance again.