Papers by Keyword: Solid

Abstract: Warp knitting is appointed as a manufacturing method for high-performance and high-quality textiles due to its versatility and production speed. To ensure a continuous and error-free manufacturing process under highly dynamic production conditions, a high level of knowledge of the yarn and machine interaction is required. Mechanical stresses from the machine are transferred to the yarn via friction points, as well as during the stitching process from one yarn to another, where the yarn is subjected to high stresses.Therefore, the focus of this research is the investigation of the friction between the yarn and yarn guiding elements and the friction between the yarns themselves during the stitch formation. For this reason, all contact points between yarn and yarn guiding elements as well as between the yarns themselves are examined and classified. A test rig is set up to determine all occurring frictions as a function of various machine parameters.The knowledge gained and the derived analytical expressions between machine settings and occurring friction can thus become the basis for modeling the friction points of the warp knitting machine, which is also presented. Furthermore, based on the findings a design improvement of the machine can be achieved and the friction model can serve as part of a simulation model of the entire warp knitting machine, which will be the focus of further publications.

Abstract: The actuality of the topic chosen by us lies in the fact that the effect of oxygen on the properties of semiconductors has not been studied sufficiently well, mainly because of the imperfections of methods for controlling the oxygen content in semiconductor materials. Almost in all such materials, oxygen is present either as an uncontrolled impurity or as a doping additive, or, in the case of oxide semiconductors, as in our case with a semiconductor film of vanadium dioxide, is part of the compound. The oxygen contained in the semiconductor film significantly affects the property of the material: in the first two cases, this influence is determined by the amount and state of the impurity, in the third - by the composition, or by the stoichiometry of the oxide compound. We set a goal to develop a technique for obtaining a semiconductor film of vanadium dioxide in a controlled atmosphere of oxygen. The semiconductor film thus obtained is used in holography to record and store optical information. For the production of VO₂ films by oxidation in a controlled atmosphere, an apparatus including an oxygen pump based on stabilized zirconia dioxide has been developed. The principle of operation and the main characteristics of such an oxygen pump is the unique application of the property of the superionics - to carry through itself exclusively oxygen ions under the influence of a constant current field and a high temperature. The technique developed by us for obtaining a semiconductor film of vanadium dioxide in a controlled atmosphere of oxygen has no analog.

Abstract: This paper examines the free energy potentials of damaged solids for the construction of damage mechanics constitutive models. The physical meaning of free energy in solid mechanics is analyzed in contrast with that in traditional fields of thermodynamics; 1D stress-strain curves are used to show the relationships between various thermodynamic state functions in isothermal loading processes; and the role of plastic free energy in damage evolution is discussed both macroscopically and microscopically. It is concluded that plastic free energy, which is a macroscopic representation of some additional microscopic elastic energy, cannot do work during unloading but get released when damage takes place, constituting part of the driving force for damage evolution.

Abstract: Size plays an important role in sizing. The sort of size is various, and its various performance indicators are not comprehensive, so it brings very great difficulty to sizing workers. Through a large number of experiments, LX-6, PAM, SFB, LM, FY five kinds of solid poly-acrylic acid size of various performances had been tested, contrasted and analyzed. Meanwhile, the film-forming ability, and the adhesion of pure cotton roving and polyester-cotton roving were tested. Moreover, we did experiments on polyester cotton yarns, which were sized with these five kinds of size, and the sized yarn hairiness reduction rate, moisture regain, enhancement rate, reduction rate and other performance indicators had been tested, contrasted and analyzed. Results provide reference for the use of these five kinds of size.

Abstract: Hyperbranched polymer was prepared by the polycondensation reaction via the A₂+B₄ route. The polymer was obtained by the reaction of 1,3-tetramethyl-1,3-bis (methyl-dicholorosilyl) ethyl disiloxane and di-tert-butyl adipate. The obtained polymer was soft solid. The polymer was characterized by ¹HNMR and IR spectroscopies. The¹H NMR and IR analysis proved the existence of the branched structures in the polymer.

Abstract: A bottleneck problem in mechanical productions design is presented in this paper. The fundamental conceptions and problems of relation design should be resolved at present. A method of relation design, which using mate relation constraint and align relation constraint and dimensions equation relation constraint, is putted forward. This way is implemented to mechanical productions relation design.

Abstract: Mud solid phase is an important factor of formation damage, the effect of mud solid phase on plugging and flowing back is a vital parameter of the drilling fluid compatibility. This paper introduced drilling fluid solids type and feature, analyzed the experimental data, reached the conclusion that mud solid phase made more evident influence on flowing back than plugging.

Abstract: The complex parts, like block engine or inside panel door, represent a real challenge for 3D modeling with modern parametric 3D CAD systems if we intend to reuse the modeling for future modifications. The complexity of the part generates a large number of parameters and parametrical dependencies that is difficult to manage and even difficult to change for modifying the part, often, for big changes, making it easier to remodeling the part from the beginning. In this paper is presented a new method of parametric and hierarchical 3D modeling that allows easy future modifications of the part. This paper also presents the implementation of this new method in Catia V5 and the validation for a number of CAD models.

Abstract: The gas-solid flow is widely used in the enterprises. The real-time solid mass flowrate measurement is an important role to the enterprise production. Based on the gas flowrate measurement principle of the Elbow, the new Double-Elbow real-time solid mass flowrate measurement method in the gas-solid flow is brought out in this paper. The new method can finger out the mass flowrate directly and need not measure the mixture density in advance. The instrument on measuring the solid mass flowrate is developed based on the new method; the instrument is using the 8031 as the MCU; the measurement result can be displayed on the LED. The experiment on measuring the solid mass flowrate is carried out in the pneumatic conveying system. The experimental results prove that the instrument can be real-time on-line measuring the solid mass flowrate.

Abstract: The aim of this study was to optimize the variables which affect the protein content of fermented soybean meal (FSBM) with multi-strain in solid state condition. Response surface methodology (Box-behnken design) was used to design the experiments. Also, the effects of each factor and their interactions on protein content were analyzed. Regression equation between the influencing factors (moisture content, inoculation ratio and fermentation period) and the response value (protein content) was established and the results revealed that the optimal conditions were 56% moisture content, 9.5% inoculation ratio and fermentation periods was 43.5 h. Under these conditions, the actual protein content of FSBM reached 56.96%, which was very close to the predicted value (57.08%). The good correlation between predicted and actual values proved the validity of the response model.