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半開放形遠心羽根車のシュラウドすきまに基づく効率減少を入力の減少と圧力損失の両面から検討を加え, 種々の実験データから入力の減少は出口すきま比および羽根出口角の余接に比例すること, またすきま損失はのど部すきま比の0.6乗および相対速度の減速に基づく圧力上昇に比例することを明らかにし, 実験式を提案した. しかもこれらの関係を用いればすきまに基づく効率減少がかなりの精度で予測できることを示した.

Ligand coupling reactions take place not only between benzyl and 2-pyridyl groups and two 2-pyridyl groups in the treatment of benzyl, alkyl and aryl 2-pyridyl sulfoxides with Grignard reagents, but also between such groups as p-benzenesulfonylphenyl, 4-pyridyl, 2-quinolyl and 2-pyrimidyl, and the benzyl group. There are cases in which ligand exchange precedes ligand coupling, especially with 2-heteroaryl groups. In addition, even some alkyl groups were found to couple with the 2-pyridyl group. The ease of coupling seems to be associated with the electronegativity of the coupling carbon atom of the ligand, when one compares the 13C NMR chemical shifts.

The velocity distribution is measured at the exit of two different types of unshrouded centrifugal impellers under four different tip clearance conditions each, one with twenty radial blades and inducers and the other with sixteen backward-leaning blades. The secondary flow induced by the tip leakage is similar in both impellers, and the underturning near the blade tip due to the stationary shroud is reduced significantly with the increase of tip clearance. The local change of angular momentum due to the tip clearance is related to the flow rate ratio of leakage-flow and through-flow, and an almost proportional relationship between them is found. Despite a similar secondary flow in both impellers, the input power is hardly changed in the radial blades impeller and is decreased in the backward-leaning blades impeller by the increase of tip clearance.

The authors have been conducting studies on the reduction of exhaust emissions using a high-speed diesel engine. By applying composite countermeasures consisting of five items: (1) timing retard, (2) optimization of fuel injection system, (3) water-in-oil type emulsified fuel, (4) application of ignition improver, and (5) an increase in airflow quantity, an exhaust NOx level less than half of the original was attained while retaining the original low levels of fuel consumption, smoke density, and engine noise. The authors developed new measuring instruments in order to grasp the true nature of combustion, especially to clarify the delicate change in combustion. By using these instruments, the combustion phenomena were analyzed accurately, speedily, and synthetically on various aspects such as combustion mode, vibration, noise, thermal loading, heat balance, etc. The complicated combustion behavior in the cylinder has been clarified in part by simultaneous measurement of cylinder pressure at several points.

Based on our previous findings that medroxyprogesterone acetate (MPA) significantly suppressed the formation of preneoplastic mammary hyperplastic alveolar nodules in mice, and that this suppression persisted for some time, we studied the effects of different schedules of MPA treatment on spontaneous mammary tumorigenesis and uterine adenomyosis in SHN virgin mice. Mice received a subcutaneous pellet of MPA every 2 months: I) during the limited period of 1-3 months of age; II) throughout the experiment beginning at 6-8 months of age; and III) throughout the experiment beginning at 2-3 months of age. All treatments significantly enhanced mammary tumorigenesis with little difference in the effects among treatments. The progression of uterine adenomyosis was also stimulated in Experiments I and III, but not in Experiment II. These results are in good accord with our previous observations with progesterone, indicating that MPA has progesterone-like effects on mammary and uterine lesions of mice.

Swirl, turbulence and the cyclic fluctuation have been examined using LDV in a motored direct injection diesel engine with a spiral port, a troidal piston cavity and a bore of 102 mm. Measurements were made at a low engine speed of 600 rpm at nine points along a cylinder diameter. The authors have developed a new method to analyze turbulence accurately even under the low data rate condition by introducing a concept of confidence interval. It has been clearly shown that there exists a longitudinal vortex in the piston cavity, the tangential velocity distribution shows a forced vortex pattern, and the swirl ratio increases rapidly in the piston cavity. And turbulence in a compression stroke was not always uniform in the cylinder, but in-cylinder averaged turbulence and the cyclic fluctuation were almost the same between the tangential and axial components.

To find a basic principle of residual fuel combustion, tests were conducted on heavy fuels of 34.4 cSt and 75.9 cSt at 50°C (200 and 500 sec RW No. 1 at 100°F) using small-sized, high speed diesel engines with a cylinder bore of 110 mm, a stroke of 125 mm and speeds of 2500 and 2600 rpm. Using a natural-aspirated engine, the effects of individual factors on engine performance were confirmed by changing the fuel injection mode, the cooling water temperature, the suction air flow quantity and the temperature respectively. Then using a turbocharged engine, the optimum combustion method was established by chiefly improving the fuel injection mode. Fuel combustion was evaluated by means of accurate indicator diagrams obtained by the CB-366 combustion analyzer. The reliability and durability of the engines were confirmed through thermal load analysis based on temperature measurements of the combustion chamber walls.

Wall friction and local heat transfer in an oscillating laminar boundary layer over a flat plate with an unheated starting length are theoretically analyzed. In the analysis, the power series solutions are derived for velocity and temperature distributions in three frequency regions, that is, low frequency (ω*, Bulletin of JSME. 1980, 23(183), p.1467-1474

The airflow was measured by a LDV in a motored four-stroke direct injection diesel engine with a troidal cavity combustion chamber, under three different swirl intensity condition. The turbulence scale was calculated by a random sample data analysis utilizing multicycle velocity data. It has been clearly demonstrated that even though the swirl intensity was varied, the integral time scale increased once at the beginning of the compression stroke and decreased toward compression top dead center. On the other hand, the micro time scale hardly changed in suction and compression strokes. Furthermore, it has been revealed that the axial micro time scale was almost uniform in the cylinder under the high swirl condition, but the integral time scale remained large near the piston cavity center.

A study was undertaken to measure the ability of rats to regulate amino acid intake by means of a self-selection method. Weaning rats were simultaneously offered a choice between a 10% casein diet or a 10% amino acid mixture diet lacking methionine or lysine and a 10% casein diet containing different levels of methionine or lysine over 2 weeks. Weight gain and food consumption of rats allowed a choice between the two diets were much greater than those of animals fed on the fixed diets with high levels of methionine or lysine added, and the self-selecting rats had the ability to take in amounts of methionine or lysine appropriate to meet the requirement. Methionine intakes of self-selecting rats were kept to a relatively narrow range (41--100 mg/day), but lysine intakes of self-selecting rats were wide-ranging (86--300 mg/day). It was demonstrated that methionine or lysine intake is closely regulated in rats given a choice of diets containing varied levels of methionine or lysine.

Cylinder pressure is measured simultaneously at several points in the combustion chamber of a high speed diesel engine with a toroidal piston cavity by means of small-sized piezo pressure transducers and a multichannel combustion analyzer with an accuracy of one fourth degree of crank angle. It has been clearly shown on the cylinder pressure behavior that the farther the distance of measuring point from the cavity center, the latter the rapid pressure rise and the larger the pressure fluctuation amplitude. The time difference of the rapid pressure rise between two measuring points is identical to the propagation time of a pressure wave originated in the piston cavity. The peak frequencies in the cylinder pressure spectrum, which correspond to the two kinds of wavelengths of cylinder bore and two times the root mean square diameter, are due to standing waves in the combustion chamber.

There is controversy about the mechanism of decay of the asymmetric flow in the vaneless diffuser of centrifugal blowers. In order to clearly observe the behavior of asymmetric flow, every other flow passage of a centrifugal impeller is blocked with a punched plate so that a severely asymmetric flow is induced. The flow behavior in the vaneless diffuser is measured with unsteady flow measuring instruments as well as with conventional instruments for steady flow. The experimental results indicate that there are some flow phenomena which cannot be explained by the conception of mixing process. Such flow phenomena can be explained quantitatively as the isentropic energy exchange between relative streamlines due to the circumferential pressure variation. In addition, the wall roughness of the vaneless diffuser is changed, and the influence of the wall friction on the total pressure loss is compared with the predictions based on the two controversial hypothesis. While these data are handled, it is recognized that the time average total pressure is considerably larger than the mass average total pressure for a severely asymmetric flow. Therefore, if instruments for steady flow measurement are used near the impeller exit to measure the total pressure, the impeller efficiency may be overestimated and the diffuser efficiency may be underestimated.

The pressure distribution along the shroud is measured for three types of centrifugal impeller at seven different values of tip clearance each. The change of input power due to a change of tip clearance is related to the effective blockage at the impeller tip. Since the change of input power is little for the test cases, the variation of local pressure gradient along the shroud is mostly attributed to the change of local pressure loss. The local pressure loss is related to the local tip clearance ratio and to the local pressure gradient based on the deceleration of relative velocity in the impeller. Since the local pressure gradient is largest near the throat of the impeller, for many impellers the clearance ratio at the throat is used as the representative value. The tip clearance loss is related to the clearance ratio and the pressure rise based on the deceleration of relative velocity in the impeller. A good correlation is observed in all cases at various flow rate.

イオンビームミキシング装置を用い, ダイナミックミキシング及びスタティックミキシングにより, SUS304の表面にTiN薄膜を生成した結果, 硬さ及び耐摩耗特性は向上することがわかった.特に, ダイナミックミキシングによって硬さは母材の約7倍にもなった.またダイナミックミキシソグにより, SUS304の表面に均一なTiN膜が生成でき, 短時間の処理によってその表面改質ができることがわかった.今後は, 蒸着速度やイオンの加速電圧, 注入量等を変化させ, さらに試料母材やイオンの種類を変えて他の方法との比較をする予定である.

The velocity distribution was measured at the exit of two different types of unshrouded centrifugal impellers under four different tip clearance conditions each; one with twenty radial blades and inducers and the other with sixteen backward-leaning blades. And the effect of tip clearance on input power was also measured. By increasing the tip clearance, the input power was hardly changed in the radial blade impeller and was reduced in the backward-leaning blade impeller. The velocity distribution normalized by the passage width between hub and shroud wall was hardly changed at the exit of the radial blade impeller by varying the tip clearance, on the other hand, the relative flow angle was reduced significantly and monotonously by an increase of tip clearance in the backward-leaning blade impeller. The change in input power due to the tip clearance was clearly related to the change of flow pattern at the exit of impeller due to the secondary flow, which is most likely caused by the component, normal to the blade, of the shear force to support the fluid in the clearance space against the pressure gradient in the meridional plane without blades.Copyright © 1989 by ASME

According to the theory presented by the authors, the tip clearance loss of an unshrouded centrifugal impeller mainly consists of two kinds of loss; one is the drag due to the leakage flow through the blade tip clearance and the other is the pressure loss to support the fluid in the thin annular clearance space between the shroud and the blade tip against the pressure gradient in the meridional plane without blades. The former is proportional to the leakage flow or the contraction coefficient of leakage flow. The authors have conducted performance tests using an impeller with sixteen backward-leaning blades in three configurations of the blade tip: round edge, sharp square edge and edge with an end-plate. The experimental tip clearance effects can be predicted by the theory assuming reasonable contraction coefficients. They are 0.91, 0.73 and 0.53 for the respective tip configurations. The impeller efficiency is improved by about 1.5 point by reducing the contraction coefficient from 0.91 to 0.53 providing that the tip clearance ratio at the exit of impeller is 0.1. More improvement is expected for an impeller with highly loaded blades where the leakage loss shares the major part of the tip clearance loss.Copyright © 1989 by ASME