Innovative SMC with low iron loss was made from iron powders with evaporated MgO insulation coating. The coating had greater heat-resistance than conventional phosphatic insulation coating, which enabled stress relieving annealing at higher temperature. Magnetic properties of toroidal samples (OD35mm,ID25mm, t5) were examined. The iron loss at 50Hz for Bm = 1.5T was lower 50% of conventional SMC and was almost the same with silicon iron laminations(t0.35). It became clear that MgO insulation coating has enough heat resistance and adhesiveness to powdersurface to obtain innovative SMC with low iron loss.

Influences of machining on magnetic properties of soft magnetic composites (SMC's) with addition of two kinds of binder, i.e., organic binder and inorganic one, were investigated. Machining does not affect DC magnetic properties of the SMC compacts. This can be ascribed to their particular structure in which the ironpowder particles are highly isolated by the binder. On the other hand, decrease in resistivity and resultant increase in eddy current loss was confirmed in the machined compacts containing inorganic binder. It is supposed that the brittleadditive binder existing between the iron particles is partly broken, and iron-to-iron contact is formed on the machined surface.

Improvement of the strength is one of the most important subjects on soft magnetic composite (SMC) to increase the applica ble items. In this study, lubricants for inner lubricating SMC, which can be produced in lower cost than die wall-lubricatin g SMC, varied to investigate their effect on the strength. The newly developed SMC with self-lubricating resin shows high st rength equivalent to that of SMC obtained by die wall lubrication.

We have observed dense core around young stellar objects, DR21, S140, Orion-KL, and L1551 using four millimeter-wave transitions of H C 3 N J =4-3, J=5-4, J=10-9, and J=12-11. The spatial distribution of H C 3 N emission closely resembles the morphology of the previous CS observations that trace high density gas. These observations reveal the existence of H C 3 N dense cores around central IR source, elliptical in shape and almost perpendicular to the CO bipolar outflow axis. Small differences can be explained by that H C 3 N molecular line is more optically thin and is seen to be more detailed structure in the neighborhood of central IR sources. In S140 and Orion-KL, massive( ∼ 10 M ⊙ ), slowly rotating dense cores lie near at the central IR sources of bipolar outflows. The velocity channel maps of DR21 show that the bipolar outflow gas may have a correlation with the dense core of DR21. We analyzed intensities of the four lines to derive physical conditions in dense core from two methods, LTE and LVG. The column density of H C 3 N , N ( H C 3 N ) , between LTE and LVG calculations agree well with each other. The abundances of H C 3 N in each observing source have been estimated using the average values of n ( H 2 ) and N ( H C 3 N ) and assuming the size of dense core. The fractional H C 3 N abundances in massive dense cores of DR21, S140, and Orion-KL have a range of ( 2 − 7 ) × 10 − 10 , while that of low mass dense core, L1551, has one order of magnitude greater value of 2 × 10 − 9 . This should be considered good agreement with the result by Morris et al.(1976). It may be considered that dense cores of DR21, S140, and Orion-KL may have almost same stage of chemical evolution, and their abundances have a small values relative to that of L1551. The column density N ( H C 3 N ) decreases with increasing distance from the densest part of the cloud, the central infrared source, and have the relation of N ( H C 3 N ) ∝ R α , where a has a range of 0.65 to 0.89. The values of n ( H 2 ) are not varied with increasing distance from the dense core, and have almost same values. Therefore, it is considered that the dense cores in these regions probably consist of dense clumps in diffuse molecular gas medium, and n ( H 2 ) of each clump is ∼ 10 5 c m − 3 . Levels in the T e x increases with n ( H 2 ) . It is considered that the H C 3 N dense cores are not completely thermalized. We examine the relationships between the luminosity of central infrared sources versus mass of the dense cores, and the luminosity of central infrared sources versus molecular hydrogen column density. Luminosities of the central IR sources show good correlation with mass and hydrogen column density of the dense core. Same has been found from CS observations. However, mass and size derived from H C 3 N observations are one order of magnitude smaller than those from CS. It can be interpreted that we see more central part of the cloud cores in N C 3 N lines than CS lines.