Organic matter release in low temperature thermal treatment of biological sludge for reduction of excess sludge production.

Thermal treatment applied in association with a biological system allows for a significant reduction in excess sludge production (approximately 50%). In general, heat treatment is described as a sludge disintegration technique. This paper offers a thorough study on the impact of heat treatment, at temperatures below 100 degrees C, on the solubilisation of the sludge COD and its biodegradability. Discontinuous heating experiments were performed on activated and digested sludge. At all temperatures tested the released COD for digested sludge was systematically higher than that for activated sludge (15 and 40%, respectively, at 95 degrees C for 40 min of contact time). For the first 30 min, a 1st order kinetic, with respect to the residual COD, was systematically found. In the range of 40-95 degrees C, digested sludge had a lower activation energy than activated sludge (26 kcal/mol compared to 70-160 kcal/mol). COD solubilisation is thus more positively influenced by temperature in the case of activated sludge. This may be due to the significant difference in the ratio of protein/carbohydrate in digested and activated sludge (1-5 and 0.2-0.7, respectively). The increase in the COD/TKN ratio in the solubilised fraction after thermal treatment of activated sludge suggests a preferential solubilisation of proteins over carbohydrates. Respirometric tests performed on the solubilised COD showed that whatever the sludge origin, only 40-50% of released COD is biodegradable at a conventional hydraulic retention time (i.e., 24 h). Hence, heat treatment would act more through organic matter solubilisation rather than by a biodegradability increase.     

The economic performance of the Russian economy in 2006 and a forecast for 2008–2010

This article examines the economic outcome of 2006 and builds a forecast for 2007–2010. The medium-term development risks of the Russian economy are analyzed.     

Use of electrochemical oxidation process as post-treatment for the effluents of a UASB reactor treating cellulose pulp mill wastewater.

The main purpose of this study was to evaluate the performance of the electrochemical oxidation process as a post-treatment for the effluents of a bench-scale UASB reactor treating simulated wastewater from an unbleached pulp plant. The oxidation process was performed using a single compartment cell with two plates as electrodes. The anode was made of Ti/Ru0.3Ti0.7O2 and the cathode of stainless steel. The following variables were evaluated: current density (75, 150 and 225 mA cm(-2)) and recirculation flow rate in the electrochemical cell (0.22, 0.45 and 0.90 L h(-1)). The increase in current density from 75 to 225 mA cm(-2) did not increased the color removal efficiency for the tested flow rates, 0.22, 0.45 and 0.90 L h(-1), however the energy consumption increased significantly. The results indicated the technical feasibility of the electrochemical treatment as post-treatment for UASB reactors treating wastewaters from pulp and paper plants.     

Disc filtration for separation of flocs from a moving bed bio-film reactor.

A Discfilter with 10 and 18 microm filter openings, respectively, was placed in parallel to a flotation plant for separation of biological flocs from a post-denitrifying Kaldnes Moving Bed Process, the last treatment step at the municipal wastewater treatment plant at Sj?unda, Malm?, Sweden. The effluent concentrations from the 10 and 18 microm filter were 2-5 and 2-8 mg SS L(-1), respectively, which is comparable to, or better than, the flotation plant. Comparison with experiences from activated sludge plants shows that the Discfilter works especially well after the Kaldnes process. Particle size distribution (PSD) studies show that particles larger than the filter openings of 10 and 18 microm are separated with approximately 90% efficiency, whereas most of the smaller particles pass the filter. This fact indicates that the major particle separation mechanism is physical blocking. These findings point to the possibility of improving the prediction of the separation efficiency by combining measurements of turbidity and suspended solids with particle size analysis.     

Efficiency in agricultural production: the case of peasant farmers in eastern Paraguay

This paper contributes to the productivity literature in developing country agriculture by quantifying the level of efficiency for a sample of peasant farmers from Eastern Paraguay. A stochastic efficiency decomposition methodology is used to derive technical, allocative and economic efficiency measures separately for cotton and cassava. An average economic efficiency of 40.1% for cotton and of 52.3% for cassava is found, which suggests considerable room for productivity gains for the farms in the sample through better use of available resources given the state of technology. Gains in output through productivity growth have become increasingly important to Paraguay as the opportunities to bring additional virgin lands into cultivation have significantly diminished in recent years. No clear strategy to improve farm productivity could be gleaned from an examination of the relationship between efficiency and various socioeconomic variables. One possible explanation for this finding is the existence of a stage of development threshold below which there is no consistent relationship between socioeconomic variables and productivity. If this is the case, then our results suggest that this sample of Paraguayan peasants are yet to reach such a threshold. Hence, improvements in educational and extension services, for example, would be needed to go beyond this threshold. Once this is accomplished, additional productivity gains would be obtained by further investments in human capital and related factors.     

Are the elderly really machiavellian? A reinterpretation of an unexpected finding

In an article published recently in theJournal of Business Ethics, Vitellet al. (1991) found that elderly respondents scored surprisingly high on a measure of Machiavellianism. This paper offers an alternative explanation for this unexpected result — it may be an artifact of the survey format employed — and recommends additional research to help clarify the issues raised by Vitell and his colleagues.Peter E. Mudrack is an Assistant Professor in the Department of Management and Organization Sciences at Wayne State University's School of Business Administration. His publications have appeared inHuman Relations, Journal of Business Ethics, andJournal of Organizational Behavior.     

Educating business schools about safety & health is no accident

This paper summarizes the consequences of safety and health inattentiveness, and reviews four primary dangers in the workplace. In addition, perspectives of employee health and safety are presented from industry and academia which provide the basis for a strong recommendation to include safety and health issues in business school curricula. Wayne H. Stewart's areas of research and teaching interest include Social Responsibility in Management, Entrepreneurship, and International Business. Wayne is currently on the editorial board of the International Journal of Case Studies, and has published in the Journal of Management Learning, as well as participating in several academic conferences. Donna E. Ledgerwood is currently the Secretary for the Southern Management Association. Donna was President of the Southwest Academy of Management in 1993 and served as the Academy of Management's Director of Exhibits/Publisher Relations and Director of Advertising from 1983–1991. Having written one of the first articles on sexual harassment in 1980, Donna serves on the Editorial Review Board for the Journal of Business Strategies and has published in the Labor Law Journal, the Monthly Labor Review, and the Personnel Administrator. Ruth C. May's areas of expertise are International Business, Business Policy and Strategy and International Human Resource Management. Specializing in the transfer of Western management practices to the former Soviet Union, Ruth is currently involved in the development of training programs and privatization processes in central Russia. She has published in the Academy of Management Executive, Multinational Business Review, and Socialist Labor (Russia).     

R&D–Marketing Integration Mechanisms, Communication Flows, and Innovation Success

Rudy Moenaert, William Souder, Arnoud De Meyer, and Dirk Deschoolmeester report the results of their study of forty technologically innovative Belgian companies to examine the interaction between marketing and R&D. They studied one commercially successful and one commercially unsuccessful technological product innovation project in each participating company and collected data from one marketing and one R&D respondent per project. Communication flows between marketing and R&D are increased under conditions involving formalization of projects, decentralization, positive interfunctional climate, and role flexibility.     

ORGANIZATIONAL CONTEXT AND THE INTERPRETATION OF STRATEGIC ISSUES: A NOTE ON CEOS’ INTERPRETATIONS OF FOREIGN INVESTMENT*

This paper explores the relationship between organizational context and the interpretation of strategic issues by examining the hypothesis that CEOs' interpretations of foreign investment in the USA are influenced by the organizational context in which they are embedded. Three aspects of organizational context - the global business experience of the firm; the firm's level of organizational inertia (as represented by firm age and size); and the resources available for responding - are examined as predictors of CEOs' perceptions of foreign investment as a threat or an opportunity. Analysis of data from 320 organizations, controlled by industry, shows that global business experience, firm size, and perceived capability are significant predictors of the perception of threat and opportunity. the discussion addresses the implications of these findings for future research on issue interpretation and organizational context.