This paper describes the practical compensation method of the output of hot-wire anemometer (constant temperature type) for the variation of gas temperature.
The experiments were made in steady air flow under several conditions of the diameter and length of hot-wire, the mean temperature of hot-wire, the gas temperature and the air stream velocity.
The thermal equilibrium for a hot-wire (electrically heated wire) normal to gas stream was examined; the convective heat transfer to gas and the conductive heat flow to the supports of the wire were investigated, and an empirical relation between Nusselt number and Reynolds number was obtained.
Further, a compensation method with the calibration constants of an anemometer obtained under atmospheric condition was proposed.

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The high-intensity ultrasonic homogenizer equipment, which is composed of high-power ultrasonic transducer and mechanical resonant couplers, is to be noted for the fuel improvement system.
As a power supply for that system, the high-frequency thyristor inverters are more hopeful than power transistor oscillators.
This paper describes the transient-state operating analysis and performance evaluations of a high-frequency inverter for high-intensity ultrasonic power supply. The high-frequency inverter using reverse-conducting thyristors (abbreviated RTh type inverter) is analysed with an R-C load model of the ultrasonic transducer systems.
The transient-state characteristics and circuit operation, in which the overlapping commutationmode is considered, are quantitatively discussed comparing with those of basic series-capacitor-commutated inverter (abbreviated basic type inverter), and the necessary data for circuit design of the power supply are supplemented here.

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The three principal types of replacement policies discussed in the literature are age replacement (ARP), block replacement (BRP), proposed by R. Barlow and F. Proschan, and the non-preventive approach known as failure replacement (FRP) . The former two types are widely used as the preventive replacement policies.
The objective of this paper is to provide a simple rule for choosing the least costly of the three policies for any possible values of the planned replacement cost. As the distribution of the life times of units, we adopt the Weibull probability model with one parameter, i.e., the shape parameter. In particular, we stress on the relations between the three policies and the shape parameter.
In order to obtain the relations, it is necessary to solve the Renewal function, and then we obtain its results on the Weibull model due to the numerical methods. According to the results, the simple rule for choosing is given under the condition of variation of the shape parameter. Finally, the usefulness of the rule is shown by illustrating for the field data of the marine use mechanical units.

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In this paper, separation of water droplets from air including water droplets by wire-mesh demisters is investigated through experiments.
Wire-mesh demisters used here are constructed by galvanized iron wires which are held perpendicular to the air flow direction and which have one layer. Moreover, the demisters have three different specific surface area, 11.06, 14.43 and 39.78 cm² /cm³ respectively. For all of the demisters mentioned above, mean air velocity is varied over the range of 1.0 to 6.0 m/s, with the size of water droplets being varied over the range of 5 to about 200μm.
The values of separation efficiencies of these demisters are larger by those predicted by theoretical analysis which has been presented by A. Bürkholz, et al. or C. Carpenter, et al.
Characteristics of size distribution of water droplets at the inlet and the outlet to the demister, and furthermore resistance coefficients of these demisters are also investigated.

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In the cylinder cover of medium speed diesel engine, cracking often occurs between two adjacent valve ports on its fire side, and the major cause is considered to be thermal fatigue.
So the more exact estimation of thermal stress value is desired to establish the strength design method of the cylinder cover.
However, due to its complexity in construction, stress analysis examples are few.
In order to clarify the thermal stresses working on its fire side, a 4-valve double bottomed cylinder cover was subjected to two- and three-dimensional F.E.M stress analyses.
Through the investigations, the followings were clarified.
(i) By introducing the two-dimendisnal approximated model of the cylinder cover, the influences of the vertical wall, the middle wall and the outer side wall for the stresses working on the fire side of the cylinder cover and those of the positions of valve ports, are qualitatively calculated.
(ii) The largest thermal stress appears in the bridge area between the exhaust valve ports. This matter well explains the phenomena of cracking of the cylinder cover.
(iii) By taking consideration of restriction of the outer side wall, the thermal stress of the cylinder cover can be estimated through a simple equation using the arithmetic mean of the combustion surface T_M and the correction factor K.
(iv) The propriety of the calculated thermal stress values were confirmed by the measurement of residual stresses on the fire side of the cylinder cover.

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The 1973's end world oil crisis and sudden price increase of petroleum products in year 1979 have led all the ship owners to look more closer into the transportation fuel cost reduction by evaluating precisely the influence of their ship's operation condition and selecting the fuel saving engines.
As it establishes that now the thermo-dynamic efficiency of the marine propulsion engines, low speed engines or medium speed engines, increases to 45% what represents a specific consumption lower than 140 gr/ps-h, the writer explains on the base of our experience that the further fuel saving of the medium speed engine which may be realized by reconsidering the fuel consumption reduction of engine itself & propulsion plant and heat recovery of exhaust gas etc., will reach more 15% comparing the fuel expenses in the conventional installation with long stroke low speed engines.
Furthermore, how to burn the future fuel and coal on the medium speed engines are described.

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