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This study aims to investigate the effects of different surface-to-jet velocity ratios (Rsj) on the flow structure and the heat transfer of the floatation nozzle under different ratios (h/w) of the separation distance (h) to the slot width (w) and the differences of the flow structure and the heat transfer between the floatation nozzle and the slot nozzle.

The Nusselt number (Nu) and the pressure distribution of the floatation nozzle with a stationary wall are measured. Then the experimental results are used to validate the numerical model. Finally, a series of numerical simulations is carried out to achieve the purpose of this study.

The flow structure and heat transfer differences between the floatation nozzle and the slot nozzle are clarified. The floatation nozzle has more than 18 times the floatation ability of the unconfined slot nozzle. The Nu and pressure distributions of the floatation nozzle are experimentally measured. The effects of wall motion on the Nu and pressure distributions are identified.

The effects of the wall motion on the flow structure and the heat transfer of the floatation nozzle, and the differences between the floatation nozzle and the slot nozzle are first obtained. Therefore, it is valuable for engineers in engineering design of the floatation nozzle.

This empirical research paper draws evidence from a database of UK independent private companies (n=250) and reports on the financial aspirations of owner‐managers of family firms with respect to the flotation route. Following a brief review of the literature, the paper proceeds with an introduction of the UK survey into the financial development of private SMEs. Then evidence is presented on the perceived factors that influence the decision of owner/directors of family companies to consider the flotation option. Phase A employs univariate statistical analysis to contrast financial philosophies of the owner‐managing directors (OMDs) of family firms against those of their mainstream private counterparts. Phase B employs cluster analysis to categorise sample family companies into four generic groups that evidently highlight that the PLC route is not always tailored to financial issues. The empirical results demonstrate that the financial strategies of family companies are more or less in line with the behavioural issues shaping all private companies irrespective of family control. Finally, the paper concludes with a set of tentative policy implications. To encourage the public equity development of smaller privately held companies, particularly family firms, there is scope for more policy initiatives that are tuned to the “socio‐behavioural‐cultural” ethos of private‐OMDs as they master their corporate and entrepreneurial odyssey.

The purpose of this paper is to investigate the relationships of news media coverage and the performance of initial public offerings (IPOs) in Germany. The aim is to find out how media attention, media sentiment, corporate information, and recency of news are related to the flotation performance of firms that go public.

50 IPOs that went public in Germany between January 2011 and December 2015 were investigated. In total, 3,644 German speaking articles dealing with the IPOs were manually analyzed. Hierarchical OLS regressions were performed to find out how news media variables relate with the flotation performance of German IPOs (cf. underpricing, share price percentage gain after second day of trading). It was furthermore distinguished between news media coverage six days prior to the IPO and coverage on the day of the IPO itself.

While more media attention devoted to the IPOs on the day of their flotation might lead to a share price percentage gain after the second day of trading, negativity in the news media and information about new products and products of the IPO firm might be negatively related with their flotation performance. However, information about the strategy change of the IPO firms seems to be positively related with the underpricing of IPOs. Furthermore, news media coverage on the day of the IPO itself seems to be more influential for the flotation performance with regard to negative sentiment and information about new products.

Financial communication professionals should manage media representations of IPO firms before and on the day of the IPO itself. In this vein, negative media coverage should be prevented and information about new products and products of the IPO firm should be considered with caution. Instead, talking about the strategy of the IPO firm might be advantageous for the flotation performance.

This study evolved from a lack of empirical research on the interrelationships between news media and stock market prices in communication science, particularly with regard to IPOs. The study contributes to previous research in paying attention to corporate information and the recency of news when trying to explain IPO performances. The findings of this study provide implications for strategic financial communication and the role of managing news media of firms that go public.

This study examines the distortive effects of the states’ regulatory climate on the underwriting costs of new equity issues of public utilities. Each state has its own public utility commission (or public service commission) to regulate the natural monopolies of public utilities. The wealth‐maximizing behavior of utilities is constrained by the rate‐making process monitored by the commissions. The policies of a state’s commission collectively establish the ’regulatory climate’ in that state. Using a sample of new equity securities issued, during the period from January 1973 through September 1980, by utilities listed on the New York Stock Exchange and the American Stock Exchange, we investigate the effect of the regulatory climate on underwriting costs. Our findings are that,in general, the direct costs of flotation, namely, underwriting commissions and out‐of‐pocket expenses,are positively related to regulatory climate where as the indirect cost of flotation, namely, underpricing of the new issue, is negatively related to regulatory climate. These results are counter intuitive since they imply that as the regulatory climate becomes more unfavorable the direct costs of flotation increase and the indirect cost of flotation decreases. This is clearly a distortive effect of the regulation and we offer some explanations for it.

Private companies go public for a variety of reasons. Whatever the motive, shareholders and directors should have a clear understanding of the implications and responsibilities arising from this change of status. The author examines every aspect of public company status and presents an analysis of the feasibility of a stock market flotation by his company. This article provides valuable insight for companies considering a stock market flotation.

Froth flotation is a process whereby valuable minerals are separated from waste by exploiting natural differences or by chemically inducing differences in hydrophobicity. Flotation processes are difficult to model because of the stochastic nature of the froth structures and the ill‐defined chemorheology of these systems. In this paper a hierarchical configuration hybrid neural network has been used to interpret froth images in a copper flotation process. This hierarchical neural network uses two Pulse‐Coupled Neural Networks (PCNNs) as preprocessors that ‘convert’ the froth images into corresponding binary barcodes. Our technique demonstrates the effectiveness of the hybrid neural network for process vision, and hence, its potential for use for real time automated interpretation of froth images and for flotation process control in the mining industry. The system is simple, inexpensive and is very reliable.

Tailings generated by sulphide ore processing at Chaabet El Hamra mine contain a variety of sulphide minerals such as pyrite, marcasite, sphalerite, galena and chalcopyrite with carbonated and siliceous gangue. It is well known that the presence of pyrite can cause environmental threats, in particular the acid mine drainage risk (AMD), if there is not enough neutralizing potential. Waste chemical analyses show that the content of total sulphur (S) is more than 9 per cent, which could be possible to separate the pyrite from other heavy minerals based on interfacial property of these minerals, because the pyrite contain the sulphur-rich fraction.

In this study, the possibility of waste reprocessing using froth flotation of sulphuric bulk and depression-heavy minerals. It is environmental desulphurization that removes much of the high S fraction.

The results obtained in terms of S recovery and residual S content are interesting after merely 12 min of flotation by addition of potassium amyl xanthate collector (140 g/t), pine oil frother (10 g/t) and activation with copper sulphate (CuSO4+; 60 g/t) and at optimum pH of 5.

It can be shown from waste treatment by flotation of pyrite depression sphalerite collects significant desulphurization in sulphur content is 19 per cent against 8 per cent in the initial release.

Main idea to prevent the ground contamination by heavy metals is to extract them maximally with minimum consumption of chemical reagents. So, a perfect studying of pulp ionic structure, an adjustment of the sulphuric ores flotation parameters and modelling of minerals selectivity variables, by using the thermodynamic method of analysis, the behavior of lead xanthenes surface state in solution and experimental investigation results, allow obtaining quantitative physico-chemical models of minimum necessary xanthenes concentration of lead sulphide complete flotation.

The optimal pH values, ensuring a complete flotation of galena agree with the potential of zero or minimum charge of its surface, and the optimal composition of the collector sorption layer consisting both of chemisorbed xanthenes and physically adsorbed dixanthenes.

In additional, it was obtained quantitative models for the necessary xanthenes concentration of lead sulphide complete flotation in the case of different oxidation products from the galena surface in pH values from 7,0 up to 12,0.

The models derived can be used as the criteria for functional units of automation systems to control and regulate the flotation process in mineral processing plants. All these should conduct to increasing of metals extraction degree with minimum chemical reagents consumption and providing good environmental protection.

Public relations is a management process. When an organisation decides to “go public”, the process becomes an essential aspect in influencing the success of the flotation. Views from a large number of PR consultancies, financial advisers, brokers and other related bodies have been used to devise a strategic framework that would govern the direction of the PR campaign leading to UniChem′s introduction to the Stock Exchange. Target audiences have been identified and specific attention has been given to positioning, financial and defence strategies. Within these strategies, relevant tactics have been developed and scheduled for implementation. A full survey of existing shareholders, the primary target audience for the campaign, has provided evidence of attitudes towards the planned flotation.

The British Unlisted Securities Market (USM) was created in 1980. The study looks at the financial characteristics of small firms which achieved flotation on the USM and makes some comparisons, with small firms that remained private and with similar firms that were floated on the conventional stock market during the early 1970s.