目に見えない粒子がもたらす先入観。Preconception caused by invisible particles


English follows Japanese.

掲載予定雑誌:日本エネルギー学会誌 (2010) This article was prepared for Journal of the Japan Institute of Energy (2010)


人間の目に見える波長は300から800 nmまでとされ、0.3μm以下の物質は肉眼で見えない。省エネ型照明素子の白色LEDに使用される蛍光体粒子の場合、工業的にbreak-down型の粉砕法で製造された数μmの粒子(粉)が使われている。理論的には0.3μm以下の蛍光体粒子を使えば、光の散乱が減り、LED素子のエネルギー効率が高まると考えられる。しかし、粉砕を用いた物質の微細化には高いエネルギーが必要なうえ、0.3μm以下のLED用蛍光体の開発は今でもホットな課題である。




” Selective information and safe living “

This article was prepared for Journal of the Japan Institute of Energy (2010). Originally written in Japanese

The visible wavelengths range from 300 to 800 nm, and substances below 300 nm (0.3 μm) are invisible to the naked eye. In the case of phosphor particles used in white LEDs for energy-saving lighting devices, particles (powder) of several micrometers manufactured by an industrial break-down type pulverization (milling) method are used. Theoretically, the use of phosphor particles smaller than 0.3 μm would reduce light scattering and enhance the energy efficiency of LED devices. However, high energy is necessary for the size-reduction of materials using milling method, and the development of phosphors for LED of 0.3 μm or less is still a hot issue.

The size of particulate matter “bad material” suspended in the atmosphere by combustion processes at mobile sources (vehicles, etc.) and stationary sources (power stations, etc.) also varies. The artificially produced particles are mainly produced by a bottom-up (gas-particle conversion) process, and the number concentration in the environment is high. Using the five senses (especially the nose and eyes) that function as sensors, human-being live with a certain amount of “bad” particulate matter such as dust and soot in addition to organic and biological particles such as odors and pollen. So, when someone feel discomfort or uneasiness with this particulate matter, whether it is visible or not, that is, 0.3 μm is the size of the boundary. Again, 0.3 μm is an important value. A standard particle size of 0.3 μm is generally used to measure the dust removal rate (e.g. in mask filter) because 0.3 μm is the size of the particle that is least likely to be trapped by the filter.

Hit products that contribute to reducing CO2 emissions are being produced one after another, but information on where the raw materials for the device come from is rarely disclosed under confidentiality agreements between materials manufacturers. With the increasing desire to contribute to the global environment, a great deal of information about immediate effects is flowing. In reality, people tend to lead safe lives and reduce CO2 emissions (and saving) without obtaining information on “For the Earth”. Unless journalists and the mass media provide information on environmental issues, including material cycles and degradation of the ecosystem in the resource collection area, which are associated with advanced, energy-saving products that are being replaced, many consumers will not be able to obtain such information.

A display panel that shows at a glance the amount of CO2 reduction installed in energy-related products is good, but from now on it will be important to introduce educational programs on energy and the environment, such as the transfer of energy such as heat and material circulation, at the elementary and junior high school level. Otherwise, an increasing number of adults will make wrong decisions about their future, relying solely on information and their senses.

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