Intelligent Control System of Internal Expansion over Bending and Calibration (IEOBC) Process for Large Pipe Ends

The flattening and asymmetry of a pipe end section seriously affects the welding quality between pipes, therefore the calibration process for pipe end to improve roundness is essential. Because the calibration for a pipe end involves local elastic-plastic deformation for the end effect, it is still difficult to establish an accurate theoretical model. The reasonable and intelligent control method is nevertheless an effective means to improve the production efficiency. In this paper, an internal expansion over bending and calibration (IEOBC) process is introduced. According to the characteristics of the process, the structure of the mobile intelligent calibration machine for large pipe ends is designed, and the intelligent control hardware system of the machine is built. Based on the LabVIEW software platform, an intelligent control software system for the IEOBC process is developed. A three-step control strategy is combined with pipe size detection and ovality recognition. The intelligent prediction and execution of the calibration process parameters are realized. The experimental results show that the intelligent control system has good stability and accuracy, and the ovality can be controlled within 0.5%.

Research on structural parameter optimization and thermal performance of twin-screw expander

This paper analyzes rotor profile and meshing law of twin-screw expander. Elementary area is calculated by meshing sequence method, and elementary volume is solved by integration. The influence of geometric characteristics such as torsion angle and internal expansion angle of male rotor on the thermal performance of twin-screw expander is studied. The results show the following: reasonably reducing internal expansion angle and positive rotor torsion angle can increase isentropic adiabatic power of twin-screw expander. Taking isentropic adiabatic efficiency as optimization goal, sequential quadratic programming algorithm is used to optimize the structural parameters of twin-screw expander, and the influence of leakage on its functional force is analyzed. Considering leakage effect, actual shaft power of twin-screw expander is 16.7 kW, the isentropic adiabatic power under ideal conditions is 21.3 kW, and the adiabatic efficiency is 78.71%.

Sub-Types of Polysynthesis

The structural heterogeneity of polysynthetic languages is captured by a sublassification of allegedly polysynthetic languages according to their word-formational type (number of roots allowed in a verb form), namely, compositional, transitional, or affixal, and their internal organization (template vs. scope or both). Further parameters show correlations to these independent ones: the number of participants encoded on a verb, the imaginable evolutionary path via which the structure has come about, namely layering (“onion type”), internal expansion (“sandwich type”) or coalescence (“burdock type”), and the characteristic design of a complex verb form: Grammatical category accumulation (integration of non-obligatory, rather grammatical information); ping-pong recategorization (multiple verbalization and nominalization); productive in/excorporation; dependent-head synthesis; multiple packing (integration of rather lexical information); holophrasis (all wordforms being predicates—or particles); composite-stem layout (composite root-like morphemes, unitary concept); and building-block design (multiple classifer-like morphemes make up a wordform). The classification along these parameters reconciles conflicting approaches to polysynthesis.