Removal of E. coli and helminth eggs in UASB: Polishing pond systems in Brazil.

Ponds following anaerobic reactors, such as Upflow Anaerobic Sludge Blanket (UASB) reactors, have been termed polishing ponds in the literature. The present paper analyses the removal of E. coli and helminth eggs in five UASB-polishing pond systems in Brazil. Since there were ponds in series, the total number of ponds was 10. The ponds had average retention times varying from 2 to 21 days, and depths ranging from 0.40 to 2.00 m. The shallow ponds in series, even with low retention times, were able to produce effluents complying with the coliform WHO guidelines for unrestricted irrigation (< or = 1000 MPN/100 ml). An equation for the coliform decay coefficient was proposed: Kb (dispersed flow) = 0.710H(-0955) (20 degrees C). The equation highlights the inverse relationship between the pond depth and the decay coefficient. All polishing pond systems were able to produce effluents with helminth eggs concentrations predominantly equal to zero, and satisfying the WHO guidelines for unrestricted and restricted irrigation (< or = 1 egg/L, arithmetic mean). The approximate range of helminth eggs removal efficiency was predicted satisfactorily.     

Value of Multinationality: Internalization, Managerial Self-interest, and Managerial Compensation

In this paper, we examine the impact of managerial self-interest on the value of multinationality. Since agency theory also suggests that a divergence between the interests of managers and shareholders can be aligned by effective managerial incentive, we also examine the effect of managerial compensation on the value of multinationality. Our results show that for high- Q (Tobin's Q > 1 ) firms, investors do not associate the spending of free cash flow on multinationality with the problem of overinvestments. For high- Q firms, it is also found that the value of multinationality can be enhanced by effective managerial incentives. For low- Q firms (Tobin's Q < 1 ), it is found that the concern of managerial self-interest overwhelms the benefits of internalization, making multinationality a value-decreasing event. For low- Q firms, managerial compensation is also ineffective in promoting value-enhancing foreign direct investments.     

Influence of influent tributaries on water quality changes in Lake Mogan, Turkey

Lake Mogan, located in the steppes of central Anatolia, is a vital Turkish ecological system, in terms of its water resources, flora and fauna. The lake also is a unique recreational area for Ankara, the capital of Turkey. However, the lake is currently threatened by severe pollution, being under the risk of serious degradation because of (i) uncontrolled urbanization; (ii) point and non‐point source pollution; (iii) inefficient sewerage systems; (iv) sediment transportation and pollution via influent creeks to the lake; (v) uncontrolled soil erosion in its drainage basin; (vi) inappropriate flood control measures; and (vii) severe degradation of the natural wetlands within its drainage basin. This study evaluates the influence of its influent creeks on the water quality of Lake Mogan, mainly because the creeks are believed to be responsible for the major pollutant load reaching the lake, and because the extensive database documenting this situation has not previously been critically evaluated. Accordingly, this study reviews (i) change in the water quality of Lake Mogan between 1993 and 2002; (ii) the water quality classification of the major influent creeks feeding Lake Mogan; and (iii) the influence of the influent creeks on the water quality of the lake between 1993 and 2004.     

Effect of reliability of grounding of the shaft of a turboset on the operation of devices for control and protection of exciting circuits

Disturbance of the grounding of the shaft of a turboset or its absence for technical reasons can result in failure, misoperation, limitation of the operating zone, errors or limitation of the sensitivity of devices for control and protection of exciting circuits from single-point leakage, and electroerosion of elements of the turboset structure. Measures for increasing the reliability of the grounding of the shaft are discussed. __________ Translated from élektricheskie Stantsii, No. 3, March 2006, pp. 61–66.     

Efficient Liability Rules: Complete Characterization

Received May, 18, 2000; revised version received March, 19, 2001     

A Conceptual Model of the Household's Housing Decision–Making Process: The Economic Perspective

At some stage in every household's family life cycle, the household is likely to make certain decisions with regard to its housing environment. Although the household's housing decisions essentially comprise the decision to move, and the selection of a new residence, the process from which these decisions are derived is very complex because varying circumstances could produce a multitude of different housing decisions. Due to the sheer complexity of the household's housing decision–making process, researchers have generally focused on individual decision–making stages rather than on the process as a whole. This paper therefore attempts to conceptualize the entire household housing decision–making process using theoretical concepts from the economic perspective, and then tests the conceptual model with empirical evidence drawn from the moving population within the multi–racial society in Singapore.     

Rapid and comprehensive indicator for evaluation of performance of treatment processes and of river waters.

Naturally occurring UV active compounds, commonly present in almost all source waters, can be rapidly monitored by their ultraviolet absorbance at 260 nm (E260). Herein, the extent of correlation between the E260 and the removal efficiency of the hazardous contaminants, endocrine disrupters and dioxins, were investigated using various treatment and river source waters. The detection of various types of hazardous contaminants using sophisticated analytical methods, such as high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC)/inductively coupled plasma (ICP)/mass spectrometry (MS), as well as various short-term bioassays, can require hours or even days for results to be obtained. The removal of the E260 correlated well with those of individual contaminants, such as endocrine disruptor chemicals and dioxins, with the various treatment processes employed. In the plots of the endocrine disrupters against the DOC/E260, a correlation was found with the endocrine activity of the Korean/Japanese river waters employed in this study.     

Organochlorine and Mercury Residues in Young-of-the-Year Spottail Shiners from the Detroit River,Lake St. Clair,and Lake Erie

Young-of-the-year spottail shiners (Notropis hudsonius) were used as biomonitors to determine the spatial distribution (1982/83) and assess trend data for organochlorine and mercury residues. Significantly (p < 0.01) higher PCB residues were found in Detroit River spottail shiners than in collections from southwestern Lake St. Clair and northwestern Lake Erie. The highest PCB residues were found in the west bank collections from Michigan waters (912–2,997ng/g) compared to the mid-stream (96–290 ng/g) and east bank collections (153–316 ng/g). Chlordane residues were found to be elevated in all spottail shiner samples from urbanized areas. Octachlorostyrene and ∑ DDT residues were distributed uniformly within the study area, whereas mercury concentrations were found to be lower in spottail shiners from northwestern Lake Erie than in comparable samples from the Detroit River and southwestern Lake St. Clair. Residues for BHC, heptachlor, aldrin, and chlorinated benzenes were near their detection limits; mirex and chlorinated phenols were not detectable. Recent (1982/83) PCB residue levels in spottail shiners exceeded the IJC aquatic life objective (Great Lakes Water Quality Agreement of 1978) at all the sites sampled, except at Pike Creek in Lake St. Clair. PCB residues in spottail shiners from Pike Creek, Big Creek, and Leamington have declined significantly (p < 0.01) since the mid-seventies. Mercury and chlordane residues have decreased in spottail shiner samples from Leamington, but have remained virtually unchanged at Big Creek and Pike Creek.     

Explaining the Cross‐Section of Stock Returns in Japan: Factors or Characteristics?

Japanese stock returns are even more closely related to their book-to-market ratios than are their U.S. counterparts, and thus provide a good setting for testing whether the return premia associated with these characteristics arise because the characteristics are proxies for covariance with priced factors. Our tests, which replicate the Daniel and Titman (1997) tests on a Japanese sample, reject the Fama and French (1993) three-factor model, but fail to reject the characteristic model.