Case Depth Measurement of Induction Hardening Using Image Processing

INDUCTION HARDENING of medium carbon steel iswidely used to produce automotive parts,agriculturalequipment and other machines.Inductor with highfrequency electric current was used as a heater totransform microstructure of steel surface into Austenite.Then water was sprayed on the heated steel.Austenitetransformed into Martensite.Area of microstructuralchange was considered to be case depth that was animportant parameter to be controlled in productionprocess.The standard procedure to de…     

Computing Equilibria in Discounted 2 × 2 Supergames

This article examines the subgame perfect pure strategy equilibrium paths and payoff sets of discounted supergames with perfect monitoring. The main contribution is to provide methods for computing and tools for analyzing the equilibrium paths and payoffs in repeated games. We introduce the concept of a first-action feasible path, which simplifies the computation of equilibria. These paths can be composed into a directed multigraph, which is a useful representation for the equilibrium paths. We examine how the payoffs, discount factors and the properties of the multigraph affect the possible payoffs, their Hausdorff dimension, and the complexity of the equilibrium paths. The computational methods are applied to the 12 symmetric strictly ordinal 2 × 2 games. We find that these games can be classified into three groups based on the complexity of the equilibrium paths.     

Application of computer in hot forging

The research to establish a foundation for metal forging industry was done to gather the data concerning the shape of forging products in domestic factory. The products were classified into three categories with respect to die manufacturing and forging, namely, simple, medium, and complex. Forging process from the initial step of receiving order until final inspection before shipment was studied, Parameters, formula and data were explained along side of each step for the application in actual situation. Furthermore, C-language computer program to calculate forging force was developed. Two types of products were forged and the data collected were used to calculate the multiplication factor C by the formula P=C • σ_m • A. The C values from tested results were in good agreement with the previous research’s work. It can be concluded that the developed program can be used to calculate and estimate forging force in order to select a suitable forging machine in the factory.     

Comparative behavior of in situ silica generation in saturated rubbers: EPDM and hydrogenated natural rubber

Role of carbon‐carbon double (C?C) bonds content and their position in ethylene‐propylene diene ter‐polymer (EPDM), hydrogenated natural rubber (HNR) and natural rubber (NR) on in situ silica formation using tetraethoxysilane (TEOS) as a silica precursor is comparatively investigated. Glass transition temperature (T_g ) reflecting rubber chain flexibility is found as an important factor for in situ silica generation via swelling method. Despite of similar solubility parameters, NR has higher TEOS‐swelling degree resulting in the higher in situ silica content (30.8 phr) than EPDM (3.50 phr) and HNR (10.4–17.6 phr) due to the higher T_g of EPDM and HNR providing the less chain flexibility to be swollen in TEOS solution. The morphological analysis implies that C?C bonds in saturated rubbers may be agglomeration sites for in situ silica particles. For practical applications, saturated rubbers containing in situ silica/NR vulcanizates showed the improvement of mechanical properties and resistance of thermal and ozone degradation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44748.     

Investigation of incurred single- and multi-component model food matrices for determination of food proteins triggering allergy and coeliac disease

For detection and quantification of food proteins triggering hypersensitivity reactions, reliable, validated analytical methods are necessary. At present, the most commonly used methodology for this purpose is ELISA. The lack of incurred reference materials (RM) complicates the fulfilling of method validation. Today, a well identifiable research direction is the development of methods (immunoanalytical, PCR and MS methods) suitable for multi-component analysis. As a consequence of these R+D efforts, the development of multi-component RMs is reasonable. Our work presented here is focusing on the development and investigation of multi-component model food matrices that can be suitable for supporting the validation processes. On the basis of the relative incidence of hypersensitivity reactions, four components—wheat, milk, egg and soy—were selected for our preliminary work. The target proteins were determined in single- and multi-component matrices with different ELISA methods, and the results were compared by statistical evaluation. The main direction of our investigation was to identify the effects of the potential interactions of these proteins on the analytical results, and the influence of food processing was also investigated. The results showed that the presence of multiple allergenic components caused much less uncertainty in the analytical results than analytical and technological steps, such as sample preparation, repetition or even heat treatment. However, probably due to the relatively complex matrices, some discrepancies from the expected outcome could also be observed.     

A determination method of initial camera parameters for coplanar calibration

Most coplanar calibration algorithms determine the initial camera parameters from a single image under the assumption that the principal point is known in advance. However, the camera orientations, the shifted principal point and the noise corrupted on images have an influence on the estimated initial camera parameters under the above assumption. This paper proposes a useful method to determine the initial camera parameters for coplanar calibration. The proposed method can determine the initial camera parameters from the single image, wherein the principal point is considered as a parameter. In our experiments, both synthetic and real images are used. The experimental results show that the proposed method provides both stable initial camera parameters and noise robustness for changes of camera orientations, noise levels and shifts of principal point.     

Comparison of planktonic and reed biofilm bacteria in different riverine water bodies of river Danube

As the submerged shoot parts of common reed (Phragmites australis) can provide large surfaces for biofilm‐forming bacteria, extensive reed stands can effectively contribute to the self‐purification in the littoral zones of freshwaters. However, bacterial biofilm developed on reed surfaces have been studied only in still waters. In the present study, comparative examinations were performed on the planktonic and reed biofilm bacterial communities from two different riverine water bodies. Water and reed biofilm samples were taken at the beginning and end of the vegetation period from (a) a regulated side arm and (b) a separated oxbow of River Danube. Besides measuring physical and chemical environmental variables, planktonic bacterial cell numbers were detected by 4′,6‐diamidino‐2‐phenylindole staining method, and the bacterial communities were compared by denaturing gradient gel electrophoresis. Our results demonstrated that the structure and composition of bacterial communities correlated with different environmental variables and were different regarding both the habitats (planktonic vs. reed biofilm) and the types of riverine water bodies. The seasonal differences in the bacterial community structures were smaller in the river side arm than in the separated oxbow. In the water column, representatives of widespread and typical freshwater planktonic bacteria (“Candidatus Planktophila,” Limnohabitans, and Polynucleobacter), whereas, in the reed biofilm samples, phototrophic and plant associated bacteria were identified.     

Flow pattern, mass flow rate, pressure distribution, and temperature distribution of two-phase flow of HFC-134a inside short-tube orifices

New experimental data on the influence of short-tube orifice configuration, including diameter, length, length-to-diameter ratio (L/D), and orientation on the flow pattern, mass flow rate, and pressure distribution of HFC-134a inside the short-tube orifice are presented. Short-tube orifice diameters ranging between 0.605 and 1.2 mm with L/D ranging between 1.87 and 33 are used in the experiments. Three different forms of the metastable liquid flow, which are metastable liquid core flow, conical metastable liquid core flow, and full metastable liquid flow are visually observed. The short-tube orifice diameter has a significant effect on the increase in the flow rate. Conversely, the change in the orientation of the test section has no significant effect on the flow rate. The choke flow phenomenon disappears inside the short-tube orifice when L/D is less than 2.91. Based on the present data, a correlation for predicting the mass flow rate through short-tube orifices is proposed.     

The Role of CaO in the Ziegler–Natta Catalyst for Propylene Polymerization

A certain amount of CaO enhanced the activity of Ziegler–Natta catalyst during propylene polymerization, but decreased isotacticity. The results indicated that CaO accelerated the initial polymerization rates and improved catalyst against deactivation without effects on melting point, crystallinity and morphology of polypropylene. The electron spin resonance (ESR) results revealed that CaO facilitated the reduction of Ti⁴⁺ species.