Main Technical Indexes Research Articles

A Methodology of Noncontact Automatic Measurement and Development of an Online Measurement Unit on Charge Temperature of a Large Caliber Artillery

Charge temperature is one of the main tactical and technical indices for a large caliber self-propelled gun, and is a critical firing datum affecting the projectile muzzle velocity and gun firing accuracy. In this paper, on the basis of analyzing the heat transfer character of propellant, an unsteady-state heat conduction model describing the variation of the charge temperature is built and the finite-difference implicit schemes are theoretically deduced using the volume equilibrium method for numerical simulation. Comparing simulation curves with experiment results indicates that the physical models used reflect the real-time change process of the charge temperature with the environment temperature. A noncontact automatic online charge temperature measurement unit is developed. This unit can accurately measure the temperature field and real-time average temperature of the charge for all charge zones placed in a combat vehicle and simultaneously transfer the temperature information to the gunner task terminal computer through a controller area network (CAN) bus interface for trajectory calculation and firing data correction, ensuring the weapon system meets the requirements of digitalization and informatization.

Study of features of copper alloy pyrorefining using aegirine concentrate

The possibility is described of using aegirine concentrate, i.e., technogenic waste from OAO Apatit, as a combined flux during copper alloy pyrorefining with the aim of improving the main technical and economic indices of the process. Laboratory tests for the flux are described with the aim of determining its refining capacity.

Assessing technical efficiency of Chios sheep farms with data envelopment analysis

In this study the level of technical efficiency of 58 Chios sheep farms is estimated with the implementation of Data Envelopment Analysis. This level of technical efficiency is used as a classification criterion and the main technical and economic indices of the farms are analyzed in order to investigate their contribution to the improvement of technical efficiency. Next, the structural and economic characteristics of the farms that utilize the existing technology efficiently are described and compared with the average farm. The results show the presence of substantial inefficiencies in the allocation of the existing resources among farms that rear Chios sheep in Greece, which indicates that there is considerable room for development. The estimated mean level of technical efficiency is 0.76, suggesting that the average farm could increase its value of production by 24%, given the level of inputs and the existing production technology. Furthermore, larger farms are associated with higher levels of efficiency. A technical and economic description indicates that the efficient farms, compared to the average Chios breed farm, use less land and labor, rear a smaller number of ewes, utilize less variable and fixed capital and achieve a higher income in order to produce the same level of output.

Multipurpose criteria of selecting the method of regulating the delivery of pumping stations of a water-supply canal

The method of regulatingthe delivery of pumping stations of a water-supply canal, which in the general case represents a cascade of pumping Stations and pressure and open stretches, affects both the capital expenditures for the main structures and the main technical and economic indices during operation. This is more clearly expressed for large canals with pump units characterized by a strict dependence of the head on the flow rate with limited possiblities of regulation. Various methods of regulation are described, for example, in [ 7 ] .