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The purpose of this paper is to evaluate the effect that polymer coat has on the impact behavior of grinding sphere and to find possible subsection of parameter space in which grinding sphere wear could be reduced.

Numerical analysis is based on axisymmetric finite elements that were developed using symbolic tool AceGen. Comparing stress response of elastic and visco‐elastic material revealed that for high strain rates observed in impacts both behave the same and that is why elastic elements were used in simulations.

Impact velocity, coat thickness and polymer material properties were varied in a parametric case study of polymer‐coated sphere impact. Decrease of the pressure on the surface of grinding sphere indicates that polymer layer can be effective in reducing grinding media wear, but in order to maintain adequate impact pressure to do the grinding the impact velocity has to be increased. Both upper and lower limit for impact velocity were determined for some arbitrary pressure threshold values. This shows that combining measured threshold values of specific material with results from presented numerical tool could provide valuable guides for finding optimum stirred media milling operation parameters.

In this work, the authors develop numerical tools with the aim of supporting experimental development of polymer coat capable of reducing grinding media wear.

Efficient particle size reduction or dispersions and wetting form a vital stage in an extensive range of production processes and, because it is frequently related to the quality of the final product, the consistency of performance of the machine over very long periods of continuous operation is of considerable importance.

Generally the physical properties of the vehicle have a greater influence on the physical nature of a dispersion than those of the pigment, and in practice the choice of binder solids and thinning solvent are important.

This paper covers some of the work undertaken in our Product Applications Laboratories over a period of several years in connection with universal tinter acceptance into alkyd gloss paints. Our work has covered a very wide range in the past ten years and we have developed some guiding principles to improve tinter acceptance. Purists could argue that the term ‘universal tinter’ is a misnomer and I would accept that argument. However, the term has a general acceptance, within the paint industry, to mean a range of strength controlled coloured tinters intended for decorative/architectural paints such as gloss, semi‐gloss, flat systems based on both alkyd and emulsion polymer resins. The tinting of strength controlled base paints with these universal tinters is done at point of sale, to produce commercially acceptable colour matches to a large number of colours offered, say 1,000 or more.

During the dispersion of a pigment in a given application medium, two main processes are taking place side by side. These are the wetting of the pigment surface by the binder components, and the actual dispersion process, i.e. the separation of agglomerates into primary particles or at least into smaller agglomerates by the application of mechanical energy.

This paper aims to present a friction stir molding (FSM) method for the rapid manufacturing of metal tooling. The method uses additive and subtractive techniques to sequentially friction stir bond and then mill slabs of metal. Mold tooling is grown in a bottom-up fashion, overcoming machining accessibility problems typically associated with deep cavity tooling.

To test the feasibility of FSM in building functional molds, a layer addition procedure that combines friction stir spot welding (FSSW) with an initial glue application and clamping for slabs of AA6061-T651 was investigated. Additionally, FSSW parameters and the mechanical behavior of test mold materials, including shear strength and hardness, were studied. Further, scanning electron microscopy (SEM)/elemental map analysis (EDS) of the spot weld zones was carried out to understand the effect of FSSW on the glue materials and to study potential mixing of glue with the plate materials in the welded zone.

The results indicate that FSM provides good layer stacking without gaps when slabs are pre-processed through sand blasting, moistening, uniform clamping and FSSW using a tapered pin tool. The tensile shear strength results revealed that the welded spots were able to withstand cutting forces during machining stages; however, FSSW was found to cause hardness reduction among spot zones because of over-aging. The SEM/EDS results showed that glue was not mixed with slab materials in spot zones. The proposed process was able to build a test tooling sample successfully using AA6061-T651 plates welded and machined on a three-axis computer numerical control (CNC) mill.

The proposed FSM process is a new process presented by the authors, developed for the rapid manufacturing of metal tooling. The method uses additive and subtractive techniques to sequentially friction stir bond and then mill slabs of metal. The use of FSSW process for materials addition is an original contribution that enables automatic process planning for this new process.

The General Industries Division will be featuring a number of new products recently added to its Surcol range of acrylic polymers.

It is a well known fact that bacteria play a large part in the success or failure of the satisfactory production of dairy products, but the role of yeasts and moulds should not be overlooked. These living organisms, commonly known as fungi, are the next higher form of life in the vegetable world after the bacteria stage. Their form of growth resembles the growth of plants in that they reproduce by budding, and their spores, analogous to the seeds of plants, are the means whereby many species propagate further generations. The yeast cell is much larger than the ordinary bacterium, so that it is possible to study them with the aid of much lower magnifications. When grown on solid media the yeasts give colonies not unlike those of bacteria except that the edges of the colonies are less defined, the colonies themselves project well above the surface of the media, and their surfaces are usually of a rough appearance. A good example of mould growth is that of the ordinary “green mould.”—Yeasts usually prefer to grow on the surface of liquids, and moulds are found to grow most vigourously on solid or semi‐solid media, such as meat, cheese, butter, etc. The growth of bacteria in the media hinders the simultaneous growth of the fungi, so that it is only after the media has become too acid for the growth of bacteria that yeasts and moulds are able to grow. In support of this theory it has been found that fungi will grow on the surface of sterile milk, but ordinary fresh milk containing bacteria is not a suitable media as the fungi cannot compete with the bacteria. It is found, therefore, that only bacteria proliferate in fresh milk. However, when milk has become sour bacterial growth is arrested, and it is then that mould growth becomes perceptible. The fungi tolerate a relatively large amount of acid. Media used for their cultivation is generally standardised to a ph of about 4.5. The optimum temperature for their growth is in the region of 75°–90° F. Some species will grow at 32° F., others even below this temperature. Low temperatures are not lethal to the fungi, so that when infected products are removed from cold storage growth may occur. The temperatures required to kill them and their spores generally falls between 130°–180° F. Most yeasts are killed at temperatures above 120° F., while their spores may have to be exposed to higher temperatures.

This paper aims to enrich the scope of the influence of media reports on the stock risk, and it also provides a path to support the research on the relationship between media reports and idiosyncratic risks in the stock market.

The authors select financial restatement samples of listed companies in China from Jan 2015 to Dec 2017 to explore the impact of the financial restatement on the idiosyncratic risk of stocks. Further, the financial restatement that has more media attention may play a more significant role in promoting the idiosyncratic risk.

The authors found that the financial restatement of listed companies has a significant positive effect on the idiosyncratic risk of stocks. Specifically, the idiosyncratic risk changed five months before the restatement. After the restatement, the idiosyncratic risk increased by 83.47 in five days then decreased slowly, which lasted about one year. The restatement caused by sensitive issues and legal issues has a greater impact on the idiosyncratic risk. Both current restatement and delayed restatements will increase the idiosyncratic risk of stocks, but the impact of the latter is higher than the former.

Possible deficiencies in the paper are that the number of restatements caused by major accounting errors is low. Therefore, no regular conclusions were drawn on the impact of the financial restatement caused by major accounting errors.

The conclusions provide a basis for targeted supervisory measures on the restatements of listed companies. The increase in financial restatements is closely related to the lack of governance mechanisms in the stock market. For investors, although the mystery of idiosyncratic volatility exists significantly in the market, the company's valuation level will affect the relationship between the idiosyncratic risk and expected return. Investors should pay attention to the intrinsic value of the company and should not blindly pursue stocks with a low idiosyncratic risk.

These conclusions may enrich the scope of the influence of media reports on the stock risk and also provide a path to support the research on the relationship between media reports and idiosyncratic risks in the capital market.

Material recirculation is the idea behind a small wet‐grinding system used to reduce comparatively large process batches down to size.