Photoreactivation of Escherichia coli following medium-pressure ultraviolet disinfection and its control using chloramination.

Ultraviolet (UV) disinfection is becoming increasingly popular as an alternative disinfection technology to chlorination in recent years. In this study, we investigated the photoreactivation of Escherichia coli following medium-pressure (MP) UV disinfection of synthetic water by a bench-scale collimated beam apparatus. The UV doses ranged from 1.6 -19.7 mWs/cm2 and photoreactivation was investigated for 6 hours under fluorescent light. In addition, chloramination was applied after UV disinfection to investigate its ability to control photoreactivation. It was found that photoreactivation occurred for all UV doses tested and the increase in bacteria numbers ranged from 0.04 to 1.35 log10. However, the degree of photoreactivation decreased with increased UV doses. Chloramination experiments revealed that the addition of 0.5 mg/l of monochloramine resulted in suppression of photoreactivation for 1 hour only. An increased monochloramine dose of 1 mg/l was found to prevent photoreactivation for the entire duration of the experiment. The results of this study have shown that photoreactivation occurs even after MP UV disinfection, although it is of a lesser extent at higher UV doses. This study has also established that secondary chloramination can effectively suppress and eliminate photoreactivation with a chloramine dose of 1 mg/l.     

Dividend Omissions and Intraindustry Information Transfers

We examine potential information transfers from companies that announce dividend omissions to their industry rivals. Specifically, we examine the abnormal stock returns and abnormal earnings forecast revisions of rivals after a company makes a dividend‐omission announcement. Our results show negative and significant abnormal stock returns and negative and significant abnormal forecast revisions for rival companies in response to the announcement, and a significant and positive relation between the two. We conclude that a dividend‐omission announcement transmits unfavorable information across the announcing company's industry that affects cash flow expectations and ultimately stock prices.     

Service Competitiveness – An Anglo-US Study

This article reports on the latest in a series of international comparisons of management practices and performance outcomes of industries in various countries. Here, it is the service industries in the UK and the US which come under the microscope. Among the companies surveyed, there were more world-class performers in the US than the UK, but also more low performers. The concluding part of the article is diagnostic – the authors also suggest measures which could improve performance.     

The divide-and-conquer and employer/ employee models of discrimination: Neoclassical competition as a familial defect

This article is an examination of the similarities between Michael Reich’s divide-and-conquer model of discrimination and the Becker-Arrow taste model of discrimination. It shows that Reich’s model of discrimination is analytically identical to Arrow’s employer discrimination model when employer utility is a function of total profits and the racial employment ratio. It also shows that the Becker-Arrow distinction between employer and employee discrimination is invalid. Finally, the author argues that neoclassical competition is the major defect of both models. After discussing the implications of these results the article points to new directions in the literature on the economics of discrimination.     

A note on incentive incompatibility under franchising

This note provides a formal demonstration of the incentive incompatibility problem that exists in franchisor — franchisee relationships. It is shown that incentive incompatibility exists with respect to both price and quality. Several contractual mechanisms designed to mitigate the incompatibility problem are examined.