The hottest middle school student invented a gutte

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Middle school students invented a gutter oil recognition instrument. The hand-held gutter oil recognition instrument invented by Wang Yile is a major public hazard in society. Can we invent a simple instrument to "pull" gutter oil from real or fake edible oil? At the recently held Intel Shanghai Youth Science and technology innovation competition, the invention project of Wang Yile, a student of Shixi middle school, won the second prize. This project puts forward a new idea: using the physical characteristics of different freezing points of animal oil and vegetable oil to identify gutter oil. This invention has also attracted widespread social attention

the report aroused interest in scientific research

according to Wang Yile, she learned from the report last year that "difficult detection" is a big problem in the supervision of gutter oil: at present, there is no authoritative detection method in China that can identify all gutter oil from edible oil. This gives illegal traders an opportunity to take advantage of it

these reports aroused Xiao Wang's interest in scientific research. Under the guidance of teacher Huang Zengxin, Xiao Wang decided to develop a simple method to identify gutter oil. An accidental opportunity, which is expected to occupy the largest market share, made her notice that lard coagulates at room temperature and should be fixed in line with the rules of relevant experimental specifications and methods, while vegetable oils such as soybean oil, rapeseed oil, peanut oil and so on did not coagulate. This gave Wang Yile the inspiration for Innovation: can we identify gutter oil through the different freezing points of animal oil and vegetable oil

through investigation, Xiao Wang learned that gutter oil can be divided into three categories: first, gutter oil in a narrow sense, that is, the oil extracted from greasy floating objects in sewers after simple processing; Second, inferior pork, pig viscera, pig skin processing and refined oil; Third, the oil used for fried food is reused after being used for more than a certain number of times. "Most of the oil people use when cooking is vegetable oil. Because the gutter oil is left after cooking and frying, it is usually a mixture of vegetable oil and animal oil. Or insulating parts, chemical instruments, optical instruments and other parts may use the characteristics of different freezing points of animal and vegetable oil to distinguish food oil from most gutter oil." Xiao Wang told me

gutter oil is fully solidified above -15 ℃

following this idea, Wang Yile started the experiment. She found that animal oils such as lard, butter and chicken oil will "knot" at room temperature below 30 ℃, and the freezing point temperature is very high, while vegetable oils such as soybean oil, rapeseed oil, sesame oil and peanut oil all have freezing points below -15 ℃. Then, Xiao Wang mixed lard into vegetable oil in different proportions. The results showed that when the power system oil of pig zl201110006271.41 large servo injection molding machine accounted for 10% of the "mixed oil", the freezing point of the "mixed oil" was 0 ℃; When lard accounts for 5%, the freezing point of "mixed oil" is -5 ℃; When lard accounts for 2%, the freezing point of "mixed oil" reaches -10 ℃. This shows that the smaller the proportion of lard contained in "mixed oil", the lower its freezing point temperature, but the freezing point temperature of "mixed oil" is always higher than that of pure vegetable oil. According to Wang Yile, this experimental result proves that through freezing point detection, we can distinguish between gutter oil mixed with animal oil and pure vegetable oil

with the support of tens of thousands of yuan from Jing'an District Youth Activity Center, she tried repeatedly and finally developed a hand-held gutter oil recognition instrument. This instrument is rectangular and has a handle. Its shell is equipped with semiconductor refrigeration fins and heat sinks, which can be cooled quickly after being powered on; The upper part of the instrument is equipped with a red copper sheet. During detection, the measured oil can be dropped onto the red copper sheet. The front end of the handle is a thermometer to display the refrigeration temperature

After the invention came out, Xiao Wang contacted a gutter oil recycling enterprise and tested the gutter oil provided by the company. The results showed that all kinds of gutter oil solidified above -15 ℃, forming a sharp contrast with the liquid state of pure vegetable oil

students' spirit of exploration is worthy of recognition.

about this invention, we interviewed relevant experts from the Municipal Food and drug administration. Experts said that Xiao Wang's spirit of being able to explore social hot issues with scientific methods is worthy of affirmation, but she considered the problem too simply. In fact, not all vegetable oils have freezing point temperatures below zero. Palm oil and margarine can solidify at room temperature

in addition, the components of gutter oil are very complex, so it is not comprehensive to regard gutter oil as "the mixture of animal oil and vegetable oil". At present, the Ministry of science and technology has approved this project. The experts of the project team try to establish a "fingerprint" for different oils through the detection of conductivity, cholesterol, trans fatty acids, biotoxins and other indicators, so as to formulate the detection standard of gutter oil

after hearing the experts' views, Wang Yile said that she would not lose heart, but would continue to study. "In addition to the freezing point, I also intend to use viscosity, refractive index and other characteristics to distinguish between gutter oil and vegetable oil. I have prepared experimental equipment such as viscometer and illuminometer, and strive to formulate a set of physical standards for testing gutter oil." Xiao Wang said

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