Kazutaka Makino

Experimental discussion on the effect of carboxylic acid addition on the specific surface area of calcium hydroxide powder generated from calcium oxide.

The dioxin from the arbage incineration is one of the most serious environmental problems in recent years. There is a method using calcium hydroxide [Ca (OH) 2] as one of the dioxin preventive methods, reacting in the present garbage incineration and removing the chlorine in combustion exhaust gas. The formation mechanism of specific surface in the calcium hydroxide powder generated by reaction from quicklime is not sufficiently elucidated up to now.Calcium hydroxide was thought to decrease specific surface area until now in the case where carboxylic acid is used as an addition in calcium hydroxide reaction.In this paper, the applicability of carboxylic acid to calcium hydroxide reaction, and the morphology formation mechanism of the specific surface of calcium hydroxide is experimentally discussed. As a result, a new triple product factors of the alkyl chain length of the added carboxylic acid, the acidity and the interaction between carboxylic acid and water, were successfully introduced to be reasonably described the experimental result between specific surface area and amount of acid.And, the optimum alkyl chain ength was experimentally pointed out to exist at 5 showing the maximum specific surface area of calcium hydroxide. Also, the increment effect to specific surface area by carboxylic acid addition was shown to be maximum at 0.05 of the amount of carboxylic acid.

Materials Culturology Discussions on The Concept of "Light" in Future Materials Civilization. Presentation of The Concept of Electric Candle Accepting "Night and Day" as They are.

In this paper, in order to create a new concept of “light” in future materialscivilization, the light technologies in various pre-modern materials civilizations accepting “night and day” as they are, were taken into notice and discussedfrom a point of materials civiliqation. As the result, “electric candle” was conceptually presented as a new concept “light”accepting “night and day” as they are.And the feasibility was fundamentally discussed from a point of materials engineering and culturology.The following results were obtained.i) In various pre-modern materials civilizations accepting “night and day” as they are, natural regenerable materials can be pointed out to be chosen as lightmaterials and satisfy the condition of the keeping the consumption not to increase enermously.ii) The “electric candle” accepting “night and day” as they are, is operated byuse of water and sun light only as energy sources. And it satisfies thecondtion of i).iii) The “electric candle” accepting “night and day” as they are, is assembledby three of water decomposition by sun light, hydrogen fuel cell, and whitecolor light emitting diode.iv) SiTiO3, Sr0.875 Pb0.125 TiO3, and Sr0.75 Pb0.25 TiO3, are selected as optimum waterdecomposition catalysts and are assembled as the catalyst elements by pinconjunction.v) Thin film of Zr1-y-z Cay Gex O2-y (y=0.2-0.3, z=0.18-0.20) is pointed out tobe able to be used as soild electrolyte operating at normal temperature.vi) White color light emitting diode is realized by the combination of GaAs (red), GaP1-0.25N0.25 (green), and Zn1-0.055Mg0.05Se1-0.05So0.05 (blue).Vii) Necessaryd imensionsofelectric light to emit white color light of 1candle for two hours in night after being irradiated by daylight for seven hours are estimatedas follows; Hydrogen fuelcell, white color light emitting diode and waterdecomposition part are respectively 5cm×2cm×2cm, 1.0cm∅×0.65m, and4.0cm∅×150cm.viii) The concept of “electric candle” can be taken to indicate the “proto type” of white colour light in futue materials civilization.

Structuralism Discussions on the Paradigm of Modern Materials Civilization. Pre-modern times to modern times.

To elucidate the paradigm of modern materials civilization, typical materials civilizations keeping the coexistence of human culture with natural system from pre-modern times and typical technologies characterizing modern materials civilization are taken notice.The paradigms of the typical materials civilizations and the typical technologies are fundamentally discussed by use of structuralism analysis method. And their structuralism structures are respectively and qualitatively elucidated by the analysis mentioned above.The characterizations of these structures are described by structuralism structure diagram.As a result, the following conclusions are obtained.1) The paradigms of typical materials civilizations keeping the coexistence of human culture with natural system are described by the structuralism structure balancing between two mutually contradictory transformation structures.2) The paradigm of pillage between two mutually different civilizations or civilization and natural system forms single irreversible physics or meta-physics transformation structure (natural system to culture, civilization to another one).3) The paradigm of each typical technology characterizing modern materials civilization contains a negative irreversible meta-physics transformation structure introducing negative accumulation into civilization. In particular, technologies such as car, computer, atomic power generation, and genetic engineering produce the paradigm including unstable, austismic, threatening or fearful phase.

Thermophysical Discussions on the Powder Surface Improvement Effect of Initial Powder Packing

The powder materials are used in various field of industry as raw or intermediate materials. And many kinds of powder unit operation handle these powder materials, but various phenomena of powder have not yet been elucidated sufficiently. Fundamental relationship between powder surface properties and behavior is expected to be discussed as one of important subjects.In this paper, calcium carbonate is used as test packing powder and powder packing operation is fundamentally discussed. And the effects of powder surface improvement on initial bulk density distribution are experimentally and thermophsically discussed using X-ray radiograph system. As a results of it, the optimum conditions to generate the most homogeneity of powder density distribution is pointed out to exist.

Thermophysical Discussions on The Homogeneity of Ceramics Thin Powder Layer.

In the ceramics production process composed of unit operations such as weighing, mixing, drying, crushing, granulation, forming, firing and so on, to control the homogeneity of materials is one of the most important problems because the properties of ceramics are strongly effected by the homogeneous degree.In this paper, thin powder layer forming process is selected to be discussed, and doctor blade method is used, which is one of the thin powder layer forming processings. This method will give a thin powder layer. However, the thermophysical mechanism of the forming process has not yet been discussed. Then, the bulk density distributions are observed by its X-ray radiograph using the image processing system, and are thermophysically discussed.The following findings are obtained. When electric field is applied to the powder layer, the homogeneity increases enormously. And the stronger electric field applies, the higher homogeneity of powder layer is obtained. Beacuse the electric field produces the corresponding negative free energy to the field in powder, it results in the increase of the entropy of powder laver.

Study on Evaluation Method of Hierarchy in Ceramics Manufacturing Processes

Fine ceramics manufacturing process is constituted of several processes such as material crushing, preparing, mixing, powder compacting and sintering process. These processes have each peculiar size of basic particle which causes each material behaviors and determine the material properties. In order to elucidate these material behaviors and properties thermophysically, the thermophysical three concepts of particle system, entropy and free energy have to be defined. But before defining these three concepts, we have to know the size of basic particle of each process. Because these thermophysical three concepts can be defined only by obtaining the information of basic particle size. Up to now, the size estimation method of basic particle has not yet been developed. From this point of view, in this paper, the size estimation method of basic particle especially in powder compacting and sintering processes is noticed and discussed thermophysically. As a result of it, a new size estimation method of basic particle in each process is presented by use of the thermophysical concepts of entropy and free energy, and the method is applied to powder compacting and sintering processes by use of three ceramics powder of BaTiO3, PZT and Mn-Ni-CuO powder. And the validity of this method is checked experimentally, obtaining interesting knowledges on the hierarchy problems of fine ceramics manufacturing process.

Measurement of initial porosity distribution in a powder cell by X-ray radiograph.

Homogeneous powder packing into a powder cell is one of the fundamental and also important problems which should be urgently elucidated in powder technology. For example, to get a sufficient mechanical strength of sintered powder chips in fine ceramics or electronics industry, a good homogeneous powder packing method should be developed. However, it has not been sufficiently established up to now.In this paper, from such a point of view, the initial powder packing states in different powder cells with one to five powder feeding points were systematically radiographed by X-ray, and their initial powder porosity (or powder bulk density) distributions were quantitatively analyzed by applying the analysis method presented by the authors. As the result, the following conclusions were obtained.(1) In every type of powder packing, the minimum porosity column was generated just under the powder feeding points.(2) The interference effect between two neighbouring powder feeding points changed remarkably depending upon test powder. That is, the porosity at the central region between two feeding points changed from the minimum value of the porosity distribution to the maximum one with the change of test powder.

Discussions on the Transmission of the Particle Bulk Density Generated in a Powder Layer

Abstract The transmission characteristics of the particle bulk density relating to plastic deformation which is generated in a powder layer in a rupture state due to external forces are qualitatively discussed on the basis of motion. The results show that it satisfies the wave equation and propagates as a kind of dynamic wave in the powder layer. It is pointed out that acoustic emission from a powder is closely related to the transmission of the particle bulk density.

On the Economically Optimal Design of Air Filter

エアフィルタの年間経費式をファンの固定費と動力費, エアフィルタの固定費, およびろ材費から構成した。特に自動交換形で部分交換運転によるろ材寿命の増加を考慮してろ材費を求めた。2～3の典型的なろ材を想定して, それぞれの場合について年間経費を最小にする最適ろ過風速, および最適運転圧損 (パネル形では最終圧損, 自動交換形では標準運転圧損) を毬々の処理風量と粉塵濃度に対して求めた。なお2～3のメーカーやユーザーに間い合わせ, 現在の実用的な定数値を計算に使用した。さらに近似精度のよい最適解を解析的に求めた。それを使って各パラメータの最適解に対する影響を論じた。その結果, 最適操作条件は処理ガス風量には余り影響を受けないが, 粉塵濃度に大きく影響されること, さらに, ろ材の圧損特性によって著しく影響されることなどがわかった。自動交換形での部分交換運転の経済的効果は, たかだか2割程度の年間経費の低減であることがわかった。

On Critical Cut Size of Particle Separator

The particle diameter at 50% partial collection efficiency is usually used as critical cut size to evaluate a particle separator. However, such assumption is not adequate for exact estimation of the overall collection efficiency, because the latter depends on the inlet particle size distribution too.The theoretical correlations between overall collection efficiency and equilibrium (real) cut size are herein derived, assuming the Rosin-Rammler or the logarithmic normal distribution for the inlet particle size. The ratio of the equilibrium and an arbitrary cut size is also calculated for any R-R distribution, assuming an equation of partial collection efficiency. As an example, this calculation method is applied to the measurement of size distribution of monodisperse aerosol by a two-stage cascade impacter.