Search

Ab-initio MO calculations have been carried out for hydrogen-dissociation reactions HCNH, i.e. $\rm HCNH \to H + HCN$(I) and $\rm HCNH \to HNC + H$(II), in order to elucidate the branching ratio of HCN/HNC on the ground state potential energy surface. The calculations showed that the transition state for reaction I is lower in energy than that of reaction II. The “bare” barrier heights for channel I and II were calculated to be 33.5–34.8 kcal/mol and 38.5–40.7 kcal/mol, respectively. The energy difference between transition states I and II was calculated to be 3.7–6.9 kcal/mol, meaning that reaction I preferentially occurs in the threshold energy region. Rice-Ramsperger-Kassel-Marcus (RRKM) theory including the tunneling effect indicated that reaction I is more favorable than reaction II at lower energy region, if tunneling effects are included in the rate calculations. On the other hand, the higher energy region above ca. 50 kcal/mol, channel II became dominant. The branching ratio (HCN/HNC) was calculated to be 0.3 at $E = 4.4$eV, which corresponds to the electron affinity of HCNH+. The mechanism of the reaction is discussed on the basis of theoretical results.

Grinding fluid & cutting oil are contained various chemicals. Waste fluid treatment causes huge disposal cost and heavy environmental load. This investigation proposes the electric rust preventive machining method system that water is used as machining fluid. However, there are various problems for this practical use. In this paper, using and re-using of machining water are considered. Water quality is different in various foreign regions for containing impurity ingredient varying with each area. Correspond to water difference, water purification and deionization is examined in developed machining water refine recycle system experimentally. Synthesized water that is likened to hard water is composed from refined water (pure water which is made by water recycle system). And, it is confirmed that synthesized water is refined to deionize by water recycle system. Moreover, 12.25L/min refined water is achieved. In addition, it is indicated that electric rust prevention is possible by refined water at least 1hour. However, high voltage and device twist is necessary.

For low environmental load and decreasing waste fluid disposal cost, the electric rust preventive machining method that uses only water as machining fluid has been developed. However, there are several problems for this practical use. In this investigation, for using this method in various regions of the world, reset and synthesis of water quality that is different in regions for containing impurity ingredient and water hardness is examined. At first, water is deionized and purified with water refine recycle system. Afterward, synthesized water is reproduced. Hardness and conductivity is adjusted in water by addition of very small amount of natural hardness ingredient CaSO4. Consequently, even if water is different, constant quality of the water can be always secured anywhere in world. Furthermore, electric rust prevention is achieved 3hours with adjusted 100S/cm synthesized water. However, adhesion derived from anode is appeared in workpiece 2hours. It is possible that the electric rust preventive machining can be carried out stability anywhere in world.

No Abstract.