{"id":173,"date":"2015-07-30T15:06:11","date_gmt":"2015-07-30T20:06:11","guid":{"rendered":"http:\/\/www.nano-blog.com\/?p=173"},"modified":"2022-09-02T13:24:57","modified_gmt":"2022-09-02T18:24:57","slug":"sorting-wheat-from-chafe","status":"publish","type":"post","link":"http:\/\/www.nano-blog.com\/?p=173","title":{"rendered":"Sorting Wheat from Chafe"},"content":{"rendered":"

There is considerable activity in the world to develop regulations on nanomaterials. The questions that need to be asked is on what basis are these specifications being developed. The fact that materials change \u201cphysical characteristics\u201d as they get smaller raises the question of how small a range of sizes would be appropriate to be able to fully classify a specific nanomaterial. If we can\u2019t answer that question, how can we establish regulations? How well documented is the underlying information?<\/p>\n

This raises the question of where does the information come from? If it is true data obtained by a scientific method then others can duplicate the experiments and reproduce the results. Sometimes there is a change of the resulting hypothesis over time. This can be due to: 1) improved experimentation with enhanced or new instrumentation; 2) different variations in the actual experimental process (more purified materials and\/or larger sampling sizes); 3) additional knowledge about outside influencing factors; or. 4) bias in presenting the results.\u00a0 Some examples follow.<\/p>\n

1) Nano Materials<\/strong><\/p>\n

It is accepted that the ability to closely classify sizes\/distributions of large nanomaterial quantities is both difficult and time consuming. I am unaware of any process available today that is able to evaluate a nanometer distribution of a large quantity of material \u2013 many hundreds or thousands of kilograms. Most measurements in the low nanometer range are time consuming due to sample preparation for the measuring process. Some scatterometry has been used, but does not give the resolution required. Basically, this is understandable due to being able to measure accurately to at least one and preferably two orders of magnitude smaller than the objects\/material being manufactured. Tools have greatly improved over the last twenty years, but there is still a way to go.<\/p>\n

2) Coffee<\/strong><\/p>\n

Is it good for you? It depends. An article in the New York Times indicates that there are a number of benefits and some other possible ones that are still unproven. [1] However, another article warms that caffeine can kill you \u2013 if you drink 118 cups a day (body weight of 75Kg with 50% probability of fatality).[2] Early work indicated that there were issues with coffee; however the sample size was extremely small.<\/p>\n

3) Global Warming<\/strong><\/p>\n

There is significant disagreements about global warming. One side indicates that we are in a period of severe warming due to mankind causes. The other side disagrees with the conclusions and implies the results are based on selective data. There has been a recent report [3] that the earth could be entering into a mini-ice age! This hypothesis is based on the fact that the sun is going through a stage that earth has not seen since the late 1600s. Sunspots on the northern and southern hemispheres will cancel each other out giving rise to a low activity period. Increasing warmth can raise water levels. Decreasing temperatures can devastate farming and food production. Has anyone evaluated the impact of these two different events together? Professor Bob Shannon of Texas A&M was known to make the comment that \u201cAll models are wrong, but some are useful.\u201d If factors are excluded in an evaluation, the potential for faulty conclusions increases.<\/p>\n

4) Fracking and Groundwater<\/strong><\/p>\n

An interesting report released by the EPA concluded \u201cWe did not find evidence that these mechanisms (hydraulic fracturing) have led to widespread, systematic impacts on drinking water resources in the United States.\u201d There were some qualifications they found some possible interaction but stated the number was small with respect to the total wells. How did the press report these findings? [from Ref. 4]<\/p>\n