Practical Production Process Research Articles

AC-loss properties of Bi-2223 multifilamentary taped wires with a central insulation layer

We have been developing twisted Bi-2223 multifilamentary taped wires to suppress the AC losses in perpendicular-field configuration for industrial-production process. It is confirmed that the hysteretic losses in the filamentary region can be reduced by twisting in a same manner as in situ Nb3Sn multifilamentary ones, while the coupling loss remains in unsatisfactory situation for commercial frequency uses. As one of practical methods for further reduction of the coupling loss, we propose an advanced multifilamentary structure of the taped wires in which an insulation layer is arranged in the central region of the tape to effectively restrict the main part of the coupling current in the perpendicular-field configuration instead of an insulation barrier around each filament that may be not usually suitable to the practical production process. We have designed and fabricated prototype wires with the proposed structure, and measured the AC loss properties in the perpendicular-field configuration. The experimental results suggest that the central insulation barrier has a function to suppress the coupling loss remarkably. We also discuss improvement in the structural design for the further reduction of the AC losses.

Designing of a CCD Sensor for On-Line Non-Touch Monitoring Roller Wear

Basing on the principle of laser-linear array CCD detective technology, a high accuracy non-touch on-line optical fibre CCD sensor for monitoring roller wear is brought forward. The principle and composition of the laser-linear array CCD detecting system and the operation process were expatiated. Aiming at the axes shifting of the roller during the detecting process, compensative steps were adopted from the vertical and the parallel detecting surface. And it enhanced the accuracy of the detecting system effectively. Experiments proved that the accuracy of the system could reach to the demand of practical production process. It provides a new method for the high speed, accurate and automatic on line detection of the roller wear.

Extraordinary ductility in Al-bearing δ-TRIP steel

An iron-based alloy system has been developed that exhibits impressive combinations of tensile strength and elongation that are not available with current steels used in the manufacture of automobiles. Furthermore, the heat treatments required to achieve these properties are consistent with practical production processes. The alloys rely on significant concentrations of ferrite-stabilizing solutes so that δ-ferrite which forms during solidification is retained in the microstructure.

Industrial production of difructose anhydride III (DFA III) from crude inulin extracted from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase.

A practical, economical, and industrial process for the enzymatic production of difructose anhydride III (DFA III) was investigated for crude inulin prepared from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase. A comparable level of DFA III production to that from commercial inulin was obtained using crude inulin, suggesting the feasibility of this production process.

CC-DHCR PLANNING AND SCHEDULING METHOD BASED ON SLAB CLUSTER

Focusing on the limitations of the traditional Continuous Casting-Direct Hot Charge Rolling (CC-DHCR) planning and scheduling methods that rarely consider dynamic scheduling problems, a new method is put forward. The key idea is to make out clusters and integrated plans in the planning layer, and then to adjust the rolling sequences according to the slab cluster-based strategy in the dynamic scheduling layer. Results of the test with data from practical production process show that the method can effectively solve the CC-DHCR planning and scheduling problem and increase the DHCR ratio.

Analysis of Curing Reaction for Epoxy Resin Used for Electrical Insulator

Epoxy has been used widely in electronic devices because of its excellent electrical properties for insulators. In epoxy resin curing reaction process, phenomena such as heat of reaction, reaction progress (degree of cure, physical properties, etc.), cure shrinkage and viscoelastic behavior, are related intricately.It is known that there are serious problems of delamination at the metal- epoxy resin interface and crack failure in epoxy resin due to cure shrinkage when epoxy resin is used as encapsulating medium of insulators in electrical and electronic equipments. It is very difficult to make experimentally clear the mechanism of the delamination and crack failure occurring in electrical and electronic equipments during curing reaction. Though several papers have been reported on the attempts to predict the stress-strain behavior during curing reaction, their simulation model is proposed under the conditions without cure shrinkage, heat of reaction, reaction progress, delamination or crack failure. Therefore, previous works cannot be always applied to the practical production process. In order to solve these problems, the authors have proposed a new simulation model, which can applies to the curing process from potting (liquid state) to gelling (solid state) under a constant curing temperature. In this work, the authors have attempted the simulation with a finite element method for two-stage cure reaction as follows:Epoxy resin was potted between the inner and outer iron cylinders. The potted epoxy resin was cured under a given temperature before gelling and under a higher temperature during gelling (two-stage cure reaction). In order to express the two-stage cure reaction, the equation of cure reaction was corrected. The circumferential strain curves on the surface of outer iron cylinder predicted by the simulation are in good agreement with the experimental results.

Optical Fiber On-Line Detection System for Non-Touch Monitoring Roller Shape

Basing on the principle of reflective displacement fiber-optic sensor, a high accuracy non-touch on-line optical fiber measurement system for roller shape is presented. The principle and composition of the detection system and the operation process are expatiated also. By using a novel probe of three optical fibers in equal transverse space, the effects of fluctuations in the light source, reflective changing of target surface and the intensity losses in the fiber lines are automatically compensated. Meantime, an optical fiber sensor model of correcting static error based on BP artificial neural network (ANN) is set up. Also by using interpolation method and value filtering to process the signals, effectively reduce the influence of random noise and the vibration of the roller bearing. So enhance the accuracy and resolution remarkably. Experiment proves that the accuracy of the system reach to the demand of practical production process, it provides a new method for the high speed, accurate and automatic on line detection of the mill roller shape.

Filtered-beam-search-based algorithm for dynamic rescheduling in FMS

In the practical production process of a flexible manufacturing system (FMS), unexpected disturbances such as rush orders arrival and machine breakdown may inevitably render the existing schedule infeasible. This makes dynamic rescheduling necessary to respond to the disturbances and to improve the efficiency of the disturbed FMS. Compared with the static scheduling, the dynamic rescheduling relies on more effective and robust search approaches for its critical requirement of real-time optimal response. In this paper, a filtered-beam-search (FBS) -based heuristic algorithm is proposed to solve the dynamic rescheduling problem in a large and complicated job shop FMS environment with realistic disturbances. To enhance its performance, the proposed algorithm makes improvement in the local/global evaluation functions and the generation procedure of branches. With respect to a due date-based objective (weighted quadratic tardiness), computational experiments are studied to evaluate the performance of the proposed algorithm in comparison with those of other popular methods. The results show that the proposed FBS-based algorithm performs very well for dynamic rescheduling in terms of computational efficiency and solution quality.

Mechanisms of flux action for growth of ZnS phosphor particles

Mechanisms of flux action for the growth of ZnS phosphor particles have been investigated by using a sealed quartz capsule, instead of an unsealed crucible used in practical production process. No growth of ZnS particles is found in the melted sodium chloride phase. This result is in remarkable contrast to the classical model by Leverentz, in which melted NaCl acts as flux for the ZnS particle growth. It is revealed that the fluxing agent is the vaporized ZnCl2 gas, which is formed as a result of sequential chemical reactions. A growth mechanism of ZnS particles by the chlorine cycle via ZnCl2 and Cl2 gases is proposed, with emphasis on the importance of growing spaces (voids) in the blend-mixture charged in a crucible. On the basis of the present results, it is stressed that further improvement is possible for the production process of ZnS phosphor powder.

Effect of SiO2 and SiC doping on the powder-in-tube processed MgB2 tapes

Effect of SiO2 and SiC nano-powder doping was investigated for the powder-in-tube processed MgB2/Fe tapes. Mg or MgH2 powder was used as the Mg source of starting materials, and heat treatment was carried out at 600 °C for 1 h. These heat treatment conditions of lower temperature and shorter heating time are advantageous from the aspect of practical production processes. MgH2 powder improved the connection of MgB2 grains and prevented oxidation of MgB2. SiC and SiO2 doping greatly enhanced the critical current density (JC) values of the tapes prepared with Mg + B powder. However, only the SiC doping was effective in enhancing JC values for MgH2 + B powder. SiC doping decreased magnetic field sensitivity of JC, while SiO2 doping did not change the field dependence of JC. The SiC doped tape showed transport JC value of about 6 500 A cm−2 at 4.2 K and in the magnetic field of 12 T. The irreversibility field increased from 17 T to 23 T by the SiC doping.

A Multivariate Discriminator for Process Drift

Multivariate Exponentially Weighted Moving Average (MEWMA) chart is a control chart under multivariate process based on the idea of EWMA that rapidly detects small dispersion with a trend. the MEWMA chart was first time discussed by Woodall. However, in his study the correlativity among the multivariate was not considered for the selection of the constant of the diagonal matrix (the smooth parameter λ). In this paper, the EWMA chart with a generalized smooth parameter matrix has been discussed which is believed to have a better fitness for practical production processes than Woodall’s approach.

The total completion time open shop scheduling problem with a given sequence of jobs on one machine

This paper addresses the open shop scheduling problem to minimize the total completion time, provided that one of the machines has to process the jobs in a given sequence. The problem is NP-hard in the strong sense even for the two-machine case. A lower bound is derived based on the optimal solution of a relaxed problem in which the operations on every machine may overlap except for the machine with a given sequence of jobs. This relaxed problem is NP-hard in the ordinary sense, however it can be quickly solved via a decomposition into subset-sum problems. Both heuristic and branch-and-bound algorithm are proposed. Experimental results show that the heuristic is efficient for solving large-scaled problems, and the branch-and-bound algorithm performs well on small-scaled problems. Scope and purpose Shop scheduling problems, widely used in the modeling of industrial production processes, are receiving an increasing amount of attention from researchers. To model practical production processes more closely, additional processing restrictions can be introduced, e.g., the resource constraints, the no-wait in process requirement, the precedence constraints, etc. This paper considers the total completion time open shop scheduling problem with a given sequence of jobs on one machine. This model belongs to a new class of shop scheduling problems under machine-dependent precedence constraints. This problem is NP-hard in the strong sense. A heuristic is proposed to efficiently solve large-scaled problems and a branch-and-bound algorithm is presented to optimally solve small-scaled problems. Computational experience is also reported.

A new method for assessing the mean grain size of polycrystalline materials using ultrasonic NDE

We re-analyze published data on ultrasonic inspection of a number of pure metals and alloys involving a range of mean grain sizes (from 0.0125 mm to 0.3 mm). We show that they may be described by one master curve graph consisting mainly of two distinct but parallel linear segments. This means that our presentation clusters the data under study into two distinct groups, each chracterized by its own generalized material constant. The slope of the segments suggests the predominance of scattering other than Rayleigh's, since it is consistent with the second power law rather than the fourth. We argue that the attenuation is likely to be due to multiple scattering, particularly since our generalized material constants seem to be similar to the published stochastic scattering factors. The master curve graph suggests a new fast and simple method for assessing the mean grain size which may be carried out without recourse to standard specimens or measurements other than those routinely carried out during ultrasonic inspection. As the range of materials and grain sizes are in extensive use in industry the simple schedule proposed should prove of substantial use in practical material evaluation and production process control.

Development of Large-Size Ceramic/Metal Bulk FGM Fabricated by Spark Plasma Sintering

Large-size ceramic/metal bulk FGMs have been fabricated on a recently developed and world's largest Spark Plasma Sintering (SPS) system. According to the development program for practical production processes and machines for FGMs by SPS, the processes, mechanical properties, dimensional size and shape effects, and production machine systems were investigated. A disk-shaped sintered compact with a diameter of 100mm and thickness of approximately 17mm ZrO 2 (3Y)/stainless steel FGM was homogeneously consolidated in a shorter sintering time, while maintaining high quality and repeatability by utilizing temperature gradient sintering method. The SPS heating-up and holding time totalled less than one hour.

Control chart for multivariate attribute processes

Many industrial processes are multivariate in nature since the quality of a product depends on more than one variable. Multivariate control procedures can be used to capture the relationship between the variables and to provide more sensitive control than that provided by the application of univariate control procedures on each variable. Much has been done on the multivariate variable processes, such as embodied in control procedures based on Hotelling's T 2 statistic. However, little work has been done to deal with the control of multivariate attribute processes, which is very important in practical production processes. In this paper, we develop a Shewhart-type control chart to deal with multivariate attribute processes, which is called the multivariate np chart (MNP chart). The control chart uses the weighted sum of the counts of nonconforming units with respect to all the quality characteristics as the plotted statistics. It enhances the efficiency of identifying the critical assignable cause when an out-of-control signal appears. It is also simple to interpret for out-of-control signals. The practical application of the MNP chart is also discussed in this paper with an example presented to demonstrate the approach of the MNP chart and to compare with the univariate np control charts which are commonly used in industry.

D -Lysine production from l -lysine by successive chemical racemization and microbial asymmetric degradation

In order to develop a practical process for D-lysine production from L-lysine, successive chemical racemization and microbial asymmetric degradation were investigated. The racemization of L-lysine proceeded quantitatively at elevated temperatures. A sample of 1000 strains of bacteria, fungi, yeast and actinomyces were screened for the ability to degrade L-lysine asymmetrically. Microorganisms belonging to the Achromobacter, Agrobacterium, Candida, Comamonas, Flavobacterium, Proteus, Providencia, Pseudomonas and Yarrowia genera exhibited a high L-lysine-degrading activity. Comamonas testosteroni IAM 1048 was determined to be the best strain and used as a biocatalyst for eliminating the L isomer. The degradation rate of L-lysine with C. testosteroni IAM 1048 was influenced by pH, temperature and agitation speed. Under the optimal conditions, the L isomer in a 100-g/l mixture of racemic lysine was completely degraded within 72 h, with 47 g D-lysine/l left in the reaction mixture. Crystalline D-lysine, with a chemical purity greater than 99% and optical purity of 99.9% enantiomeric excess, was obtained at a yield of 38% from the reaction mixture by simple purification. An engineering analysis of L-lysine racemization and microbial degradation was carried out to establish the basis of process design for D-lysine production.

D -Methionine preparation from racemic methionines by Proteus vulgaris IAM 12003 with asymmetric degrading activity

The microbial degradation of l-methionine was investigated in order to develop a practical process for d-methionine production from racemic methionines. Among the 1000 culture strains tested, microorganisms belonging to the Achromobacter, Bacillus, Micrococcus, Morganella, Proteus, Providencia, Pseudomonas and Sarcina genera exhibited a high l-methionine-degrading activity. Proteus vulgaris IAM 12003 was determined to be the best strain and was used as a biocatalyst for eliminating the l-isomer. The degradation of l-isomer in this P. vulgaris IAM 12003 cell was assured by the action of l-amino acid oxidase. The maximum rate of l-isomer degradation was obtained at 30 °C and pH 8.0. Under these optimal conditions, the l-isomer in a 100 g/l mixture of racemic methionines was almost degraded within 20 h, with 46.5 g d-methionine/l remaining in the reaction mixture. Crystalline d-methionine, with a chemical purity greater than 99% and optical purity of 99.9% enantiomeric excess, was obtained at a yield of 30% from the reaction mixture by simple purification.

An improvement for mewma in multivariate process control

Multivariate exponentially weighted moving average(MEWMA) chart is a control chart under multivariate process based on the idea of EWMA that rapidly detect small dispersion with a trend. Woodalll [1] first studied the MEWMA, however, the problem existing in his approach is that the selection of constant or diagonal matrix for smooth parameter, because of the correlativity among the multivariate in general case. the smooth parameter should be of general pattern. For this reason, this paper will investigate the MEWMA chart with the generalised smooth paramepter matrix. The background and technique of the MEWMA to be studied in this paper will be much better to fit the practical production process than Woodall's.

Hydrogen Reduction of Complex Ammonium Molybdates

High temperature X-ray diffraction analysis is employed to study the reduction of three commercial complex ammonium molybdates marked as AM-l, AM-2 and AM-3 which are used as the starting material for the production of molybdenum metal. The compositions of AM-l, AM-2 and AM-3 are (MH4;)6Mo7024-4 H20 (small amount) + (NH4)Mo5O+ (NH.)2Mo40(small amount) + (3 -(NH4)Mo4O13(NH4):Mo40, + β -(NH4)Mo40, + (NH4)Mo40,-2 H6 (small amount) and (NH4(2MoO13 + β - (NH4)2Mo4O13+(NH4)2Mo4O13-2 H2O respectively. It is found that the thermal decomposition of ammonium molybdates into MoO3, proceeds prior to the reduction of MoO3 The intermediary products of the thermal decomposition, (NH4)Mo14041 and identified which arc more stable in hydrogen than in air. MoO.80) and Mo40 are also identified as the intermediary products during the reduction of MoO to MoO. The reduction reaction of Mo4Ois infered from the phase development of AM-l, AM-2 and AM-3 during the reduction course. The thermal decomposition of AM-2 and the subsequent reduction of MoO occur almost at the same time while those of AM-l or AM-3 take place at a larger range of temperatures, which is identical with what is observed in the practical production process.

D-Alanine production from dl-alanine by Candida maltosa with asymmetric degrading activity

To develop a practical process for d-alanine production from dl-alanine, we screened 107 yeasts for their asymmetric degrading activity against dl-alanine. Candida maltosa JCM1504 degraded the l-isomer ten times more rapidly than the d-isomer. The cells of this strain were used as a biocatalyst for eliminating the l-isomer. However, when the degradation reaction was conducted in the presence of a high concentration of dl-alanine, the pH of the reaction mixture was rapidly increased by the liberation of ammonia from l-alanine, and consequently the reaction stopped. This hindrance was overcome by controlling the pH value at 6.0 with H2SO4 during the reaction. Additionally, we found that the maximum rate of l-isomer degradation was obtained at 30° C and pH 6.0 under conditions of high aeration (1.0 vvm) and agitation (1200 rpm). Under the optimal conditions, the l-isomer of 200 g dl-alanine/l was completely degraded within 40 h and 90 g d-alanine/l remained in the reaction mixture. d-Alanine was easily isolated from the reaction mixture. The chemical and optical purity of the d-isomer product so obtained was 99.0% and 99.9% enantiomeric excess, respectively.