Category Archives: Experiments

Crochet Hook Sizes G, H, and I With #4 Cotton Yarn

Crochet, Experiments, , ,

DSC07418 These Coasters were made  using Premier Home 85% cotton, 15% polyester size 4 yarn.   Crochet hooks size G, H, and I, in the first, second and third columns respectively.  Each coaster’s diameter was measured once before washing and once after washing producing two measurements for each hook size.  The average diameter gotten for each hook  before washing was:

  • G  –  3.34 inches
  • H  –  3.47 inches
  • I  –   3.84 inches

And after washing was:

  • G  –  3.32 inches
  • H  –  3.22 inches
  • I  –  3.5 inches

The percent shrinkage in coaster diameter for each hook was:

  • G  –  0.6%
  • H  –  7.20%
  • I  –  8.8 %

Conclusions

  1. The larger the hook, the greater the diameter shrinkage.
  2. Hook I, after shrinkage had the same diameter as hook G before shrinkage.

 

It Is Not Worth It To Pre-shrink Size 4, 85% Cotton Yarn, Part 2

Crochet, Experiments, Proportion, , ,

DSC07418 The top row was made with preshrunk Premier Home,  85% cotton yarn, and the bottom row was made with the same yarn, but  unshrunk.  Hook sizes for the columns were G, H, and I, in order of increasing size.  The coasters were washed  in hot water and dried in a hot dryer.  Before and after this washing, the coasters in each row were weighed in ounces on my kitchen scale, and the average diameter was taken.

  1. The preshunk row before washing weighed 0.60 ounces, and had an average diameter of 3.62 inches.   After washing it weighed 0.55 ounces, and had an average diameter of 3.27 inches.
  2. The unshrunk row  before washing weighed 0.55 ounces, and had an average diameter of 3.31 inches.  After washing it weighed 0.55 ounces,  and had an average diameter of 3.31 inches.

After washing the preshrunk coasters felt a bit softer and thicker.

Thus the weight of the pre-shrunk coasters  may have gone down a little with washing;  this was not noticeable in the unwashed coasters.  The average diameter of the unwashed coasters declined 0.35 inches, as opposed to the decline of 0.17 inches in the unshrunk group.  So the preshrunk coasters had a 2 fold greater shrinkage compared to the unshrunk coasters, according to the diameter.  This was 9.6 % by diameter as opposed to a 4.9% decline in diameter for the coasters made with the unshrunk yarn.

The area of the coasters is proportional to the radius squared, percentage is a proportion as well, and the radius is directly proportional to the diameter in all cases , to compare the change in area associated with washing and drying the different sets of coasters, I squared the respective diameters.

The results came out:

The preshrunk yarn coasters started out with an 8.2% larger area than the unshrunk yarn coasters before washing.

The preshrunk yarn coasters came out to have a 2.4 % smaller area than the unshrunk yarn coasters after washing.

The preshrunk yarn coasters came out to have  an 18.4% smaller area after washing than before washing

The unshrunk yarn coasters had a 9.5 % smaller area after washing than before washing.

It surprised me that the preshrunk yarn shrank with respect to itself  more than the unshrunk yarn shrank with respect to itself after washing and hot drying.

 

Did the preshrunk coasters  actually get thicker after washing?  To test this, I stacked the two rows.

DSC07417 The coasters on the left were unshrunk, and the coasters on the right were preshrunk.  I positioned them on each side of a line in the table parallel to the camera, so I can use the image to measure them on the source photograph.  On two different print outs of this photo, I determined the thickness of each coaster stack at the inner edge, close to the middle near the camera and at the out edge, and I added them up, took the difference and related it to the sum of the unshrunk height.   The results were:

  1. The sum of the six preshrunk yarn coaster height determinations was  7.812 inches
  2. The sum of the six unshrunk yarn coaster height determinations was 7.562 inches

The difference of these sums is 0.25 inches, which means that the preshrunk yarn coasters are about 3.3% thicker than the unshrunk yarn coasters.

Thus, preshrinking the yarn made the washed coasters 2.4 % smaller area, and 3.3% thicker.  These small measures are equal, considering the uncertainties of all these direct and indirect measurements.  Thus the smaller area is probably due to an increase in thickness, caused by the prewashing.   The volume of the yarn is conserved (area times height).  This 85% cotton yarn is quite durable, with little of it washing out.   It makes little difference if we prewash the yarn or not, and it is a lot of extra work.

With harsh washing and drying the unshrunk yarn resulted in coasters that shrank in :

  1. Diameter by about 5%
  2. Area by about 9.5%

These results are internally consistent.

Cilantro Seeds Diameter Measurement

Experiments, Science, Scientific Method, Seeds, Words, , , , ,

Here are the cilantro seeds in the self-fallen off group (left), and the pulled-off group (right).   Because the seed weight experiment, done earlier,  suggested, but did not prove that the seeds in the self-fallen-off group were larger than the seeds in the pulled-off group of seeds, I pursued what I had set up to do earlier, and count the number of seeds in the same length, six inches. Problem.  Do these two groups of seeds have a different diameter, as suggested by live visual examination? Hypothesis.  The  cilantro seeds that fell off of the stems have a larger diameter than the cilantro seeds which were pulled off by hand later. DSC03186 The two groups of seeds with the self-fallen-off seeds on the left, and the pulled off seeds on the right (above). Method.  Place a six inch ruler on top of the single layers of each group, and count the number of seeds touching the line within six inches three independent times, once for each of the three placements. DSC03180 Self-fallen-off seeds in a single layer. DSC03181 Self-fallen off seeds in a single layer with a six inch ruler on top #1 DSC03183 Different alignment of ruler for a new measure of the number of seeds in six inches #2.DSC03182 Same as above, but different ruler alignment, #3. DSC03172 Pulled-off seeds in a single layer.  DSC03179 Pulled-off seeds ruler alignment #1DSC03178 Pulled-off seeds ruler alignment #2DSC03177 Pulled off seeds ruler alignment #3 Results.  As counted on the computer screen, I got the following results not nececarily in the same order posted above.  Algnmnt stands for Alignment.  SD stands for Standard Deviation, a statistical determination of data spread.  The measure is the number of seeds in six inches Algnmnt #1           Algnmnt #2          Algnmnt #3         Average        SD Self-fallen                             49                                51                               48                             49.3               1.52 Pulled-off                              52                                54                               53                              53.0              1.00 The means of these measures are different.  There were 49.3 seeds in 6 inches in the fallen-off group, and there were 53 seeds in 6 inches in the pulled-off group.  The standard deviation, a measure of data spread, was larger in the fallen-off group. These results do suggest that the groups do differ in diameter, because the number of seeds in six inches is smaller on the average in the fallen-off group than in the pulled-off group by 3.7 seeds.  The fewer seeds there are,  the larger the diameter.  The actual diameters are inversely proportional to the number of seeds. Conclusions.  This suggests that if this information stands the test of time, then:

  1. The fallen-off group of seeds has a larger diameter, and the hypothesis is supported.  Yes the fallen-off group of seeds are wider.
  2. There may be more variability in the fallen-off group diameter.
  3. The diameter of the fallen-off group of seeds is 0.123 inches and the diameter of the pulled-off group of seeds is 0.113 inches.

Further work. Confirm and refine the results of this and the weight measurement experiments.

  • Explore the diameter by measuring actual print-outs of the single seed layered photos above.
  • Weigh higher numbers of the above seed groups, such as 1000 seeds and 2000 seeds (a lot of counting).
  • Measure the volumes of the counted seed seed groups above.
  • Determine the density of the seeds in weight per seed.
  • Check to see if there is a flotation in water difference in the largest seed group.

Comments.

  • I  consider neither this experiment nor the seed weight experiment to be very important.  I am just pursuing these for demonstration purposes, and for my own entertainment.
  • It looks as if the density of the two seed groups may actually differ. (A new hypothesis.)