Improvements in the two-dimensional nuclear magnetic resonance spectroscopy of humic substances

Understanding pollutant sorption, bioremediation of these pollutants, and their interactions with humic substances requires knowledge of molecular-level processes. New developments with nuclear magnetic resonance (NMR) experiments and labeled compounds have improved the overall understanding of these mechanisms. The advancements made with two-dimensional NMR show great promise, as structural information and hydrogen-carbon bond connectivity can be discerned. This communication presents the application of improved two-dimensional NMR methods, the double quantum filtered (DQF) correlation spectroscopy (COSY) and echo/anti-echo heteronuclear single quantum coherence (HSQC) experiments, for use in structural studies of humic substances. Both experiments were found to produce significant improvements over the conventional COSY and heteronuclear multiple quantum coherence (HMQC) experiments that have been previously employed in similar studies. The more sensitive echo/anti-echo HSQC experiment produced more cross-peaks with higher resolution when compared with the HMQC spectra. The DQF-COSY significantly suppressed the diagonal signals and allowed numerous signals previously hidden in the standard COSY experiment to be observed. These improvements will aid current characterization strategies of humic substances from soils, sediments, and water and their subsequent reactions with pollutants and microorganisms.     

University of Benin water supply system: Microbiological and physico-chemical assessments

The microbiological and physico-chemical characteristics of the drinking water supplied by the Central Borehole at the University of Benin, Ugbowo Campus were investigated. The investigation entailed assessment of the pH, turbidity, total suspended solids, total dissolved solids, dissolved oxygen, temperature, salinity, conductivity, nitrate, nitrite, phosphate, sulphate, chloride, N-nitroso compounds, cadmium, chromium, nickel, lead, zinc, manganese, iron, coliform count, BOD₅ and COD of the water at the Central Borehole and at ten residential quarters. The assessment indicated that the water was fit for drinking and other domestic applications. Results were also compared with WHO, EU and Nigeria FEPA standards. The results showed that the pH values of the water (5.01–5.86) and total coliform count (1–2/100 ml) expressed as MPN were outside the limits set by the WHO, EU and FEPA. The data also showed that the other water quality parameters assessed were within WHO, EU and FEPA permissible limits. The results of ANOVA showed that significant changes occurred during distribution.     

OWNERSHIP AND WATER SYSTEM OPERATION1

ABSTRACT: Two types of organizational systems provide most of the water service in the United States. The investor-owned firm operates on a profit basis generally subject to state commission regulation. The government-owned firm is generally confronted by local control. The comparative efficiency of private versus government firm provision of water services is essentially an empirical issue. Unit costs and other operating statistics are examined for water firms of each ownership form. The analysis shows that private firms tend to have higher operation costs than do government firms, possibly attributable to wage-salary differentials. The analysis also indicates that capital investment in large government firms may result in diseconomies. The analysis creates serious doubt as to whether efficient provision of water services can be better facilitated by large mergers of either ownership form.     

POLITICAL PARTICIPATION AND WATER RATES: A REPLY1

ABSTRACT: Mercer and Morgan provide several valid criticisms of a previous analysis on political influence and water rates. More sophisticated statistical analyses may be justified given the high degree of interdependence among regulated firm variables. Theoretically, there are numerous measures of political activity superior to the one employed in the original analysis; however, data unavailability precludes their use. A better (and yet practical) measure of consumer leverage may be relative dominance by a specific political party. Until relatively easy access is obtained to municipal election data, the possible political variables that can be employed in more elegant analyses are few in number, and each has theoretical limitations.     

Case study of landfill reclamation at a Florida landfill site

A landfill reclamation project was considered to recover landfill airspace and soil, reduce future groundwater impacts by removing the waste buried in the unlined area, and optimize airspace use at the site. A phased approach was utilized to evaluate the technical and economic feasibility of the reclamation project; based on the results of these evaluations, approximately 6.8 ha of the unlined cells were reclaimed. Approximately 371,000 in-place cubic meters of waste was mined from 6.8 ha in this project. Approximately 230,600 cubic meters of net airspace was recovered due to beneficial use of the recovered final cover soil and reclaimed soil as intermediate and daily cover soil, respectively, for the current landfill operations. This paper presents the researchers’ landfill reclamation project experience, including a summary of activities pertaining to reclamation operations, an estimation of reclamation rates achieved during the project, project costs and benefits, and estimated composition of the reclaimed materials.     

A time‐lagged investigation of the impact of coworker behavior on the effects of demographic dissimilarity

Although it is clear that coworker absenteeism, tardiness, and turnover can influence an employee's actions, scholars have yet to consider the impact of relational demography on the adoption of these behavioral norms. Inspired by social identity, situational strength, and attraction‐selection‐attrition theories, we proposed that individuals who differ from their coworkers in age, sex, or racioethnicity would feel threatened by their outnumbered status and subsequently motivated to be absent, tardy, or more likely to turnover. However, we expected coworker withdrawal behavior to moderate whether or not dissimilar personnel act on these desires. Results from hierarchical multilevel modeling analyses of data from 470 U.S. call center workers nested in 51 work groups revealed that racioethnic dissimilarity was positively related to time‐lagged changes in absenteeism and tardiness as well as heightened turnover likelihood. These effects emerged only among employees whose coworkers engaged in greater withdrawal behavior. Importantly, racioethnically dissimilar employees working in more permissive climates (i.e., those with high levels of coworker absenteeism, tardiness, or turnover) exhibited the greatest increases in absenteeism and tardiness over three months and had the highest supervisor‐rated turnover likelihood. Implications for diversity management are discussed. Copyright © 2015 John Wiley & Sons, Ltd.