Flexible and Scalable Automation Solutions For Scoring Single Nucleotide Polymorphisms Using Rolling Circle Amplification

A single nucleotide polymorphism (SNP) scoring assay that uses ligation-dependent Rolling Circle Amplification (RCA)† was transferred to a series of automated protocols addressing a range of throughput levels. The systems utilised various automation modules consisting of custom-made and offthe-shelf devices. Several system parameters were evaluated to ensure assay integrity and homogeneity. These included reagent carry over, liquid evaporation rates, thermal regulation of reactions and fluorescence reading capabilities.Data analysis software was developed in order to rapidly allocate SNP calls from data generated by the automated system. A modified fuzzy c -means clustering algorithm was employed to separate data points into groups associated with specific genotypes. Data were then presented graphically and within a summary table, which allowed easy and rapid organization and interpretation of data.     

Comparative experimental study on effects of conventional and ultrasonic deep cold rolling processes on Ti–6Al–4V

Abstract

The present paper presents the experimental studies on the treatment of Ti–6Al–4V using conventional and ultrasonic deep cold rolling (CDCR and UDCR) processes. The UDCR process is a novel technique in which the ultrasonic technology was incorporated into the concept of the CDCR process, which enables use of superimposed dynamic forces onto considerably reduced static forces applied on a part surface during treatments by UDCR. Considerable improvements in surface topography and near surface characteristics of treated material were achieved in the present study. Both processes exhibited comparable results in surface finish and induced compressive residual stresses, while the UDCR process produced superior results than the CDCR process in work hardening. The investigations suggest that the UDCR process could provide technological benefits for the treatment of thin walled aerospace components to be carried out without geometry distortion, which would lead to improved fatigue life and resistance to failure mechanisms.     

Numerical determination of heat transfer coefficient for boiling phenomenon at runout table of hot strip mill

Abstract

The heat transfer coefficient during film boiling at the runout table of the hot strip mill is usually determined by experimental methods. Described in the present paper is a finite difference based model for analysis of the thermal behaviour of the strip during cooling at the runout table of the hot strip mill at Tata Steel, India. The model, developed for the prediction of strip temperature, is used to determine the heat transfer coefficient at the water/strip interface while water cooling occurs. A simple form of polynomial as a function of the strip surface temperature is proposed to describe the heat transfer coefficient at the water/strip interface. Good correlation has been found between model predicted temperatures considering the polynomial type heat transfer coefficient and the actual coiling temperature.     

Finite Element Analysis of Axial Feed Bar Rolling

A flexible technique of hot working of bars by axial feed rolling was introduced . The process deformation, strain field, stress field, and temperature field of the parts are analyzed by finite element method (FEM)-simulation software DEFORM-3D. The material flow rule and tool load have been investigated.     

Thermal cracking of multicomponent white cast iron

Abstract

The effect of the volume fraction of eutectic carbides on the thermal fatigue resistance of multicomponent white cast iron has been investigated. Thermal fatigue tests were carried out for 100 and 500 cycles. Nucleation of thermal fatigue cracks took place mostly at the specimen surface, induced by mechanical and metallurgical stress raisers. The crack nucleated in the matrix as well as at the carbide/matrix interface or at the carbide itself. The surface crack density increased slightly for increasing volume fraction of eutectic carbides from 9 to 14%, approximately. Crack propagation took place mostly at the carbide/matrix interface or through the carbide. The propagation rate was affected by the carbide distribution: the higher was the 'carbide continuity/mean free path between carbides' ratio, the higher was the propagation rate. The propagation rate decreased with increasing test time, regardless of the volume fraction of eutectic carbides.     

Thermophysical properties of slags for process control

Abstract

Thermophysical properties have been shown to be important in a number of industrial processes. Unfortunately, for a number of properties there are scant data available and/or the data that are available are of dubious quality. In the Thermo-Physical Property Group at the National Physical Laboratory (NPL) the aim has been to develop measurement techniques capable of working in the difficult environments that are typical of industrial processes. This paper presents current developments at NPL in techniques to measure the thermal diffusivity of liquid slags using a laser flash and insights into the copper smelting process using interfacial tension techniques.     

Influence of force variations in skin pass rolling on texture and surface reactivity of hot dip galvanised low carbon steel sheets

Abstract

In this research work, the skin pass rolling force was changed in the range of 50 to 200 kN in steps of 30 kN. The crystallographic orientation of the coatings was determined using X-ray diffraction, and texture parameters were calculated. Corrosion behaviour was assessed employing the Tafel polarisation test. It was concluded that by increasing the force the texture coefficient of the basal planes component in the coating would be decreased and conversely, other components such as prismatic planes components would be strengthened. Increasing skin pass force would also cause an increase in surface roughness and microcracks in the coating. Such increasing in prismatic component texture coefficient, roughness and microcracks of the coating would result in the decreasing of coating corrosion resistance.     

Thermomechanical processing of 42CrMoS4 steel

Abstract

Billets of 42CrMoS4 steel were subjected to a programme including forging and rolling to different reduction ratios, followed by quenching and tempering to simulate online thermomechanical treatment (TMT) during rolling. The mechanical properties obtained were compared with those obtained by conventional heat treatment (CHT) (quenching from 860°C and tempering). It was found that increasing the hot reduction ratio from 18 to 60%, accompanied by a decrease in the finish rolling temperature from 900 to 750°C, enhances strength only at the expense of elongation, while rapid quenching instead of air cooling from the same finish rolling temperature yields improvements in both strength and ductility. It was also found that CHT provides higher hardness, whereas TMT provides higher impact toughness. TMT will confer major economic savings since the heat treatment is achieved online.     

Rolling to control residual stress and distortion in friction stir welds

Abstract

Considerable residual stress and distortion can be produced by friction stir welding, impeding industrial implementation. Finite element analysis has been used to develop three innovative rolling methods that reduce residual stress and distortion in friction stir welds. Of the three methods, post-weld direct rolling where a single roller is applied to roll the top surface of the weld after the weld metal has cooled to room temperature proved the most effective. The residual stress predictions from the model compared favourably with residual stress measurements reported in an accompanying paper. Finally, the effectiveness of using post-weld direct rolling is illustrated with an industrial example of a large integrally stiffened panel, where the distortion was virtually eliminated.     

GTA welding of AISI 316L metal injection moulded components

Abstract

The thin sections and residual porosity typical of metal injection moulded (MIM) components pose challenges when using welding as a joining technology, but if welding can be successfully applied the potential commercial benefits are considerable. Process development of gas tungsten arc (GTA) welding for MIM parts to tubing and wrought components are described and the suitability of MIM 316L products in welded applications, particularly fluid system components, is discussed.