Electrocoagulation technique in enhancing COD and suspended solids removal to improve wastewater quality.

This paper presents a preliminary study for the removal of COD and suspended solids in wastewater treatment by combining magnetic field and electrocoagulation (EC) technology. The experiments were carried out using batch apparatus and setup in the static method. Batch experiments with two monopolar iron (Fe) plate anodes and cathodes were employed as electrodes. Wastewater samples were prepared from milk powder with an initial COD of 1,140 mgL(-1) and suspended solids of 1,400 mgL(-1) and acidic conditions were employed (pH approximately 3). DC current was varied from 0.5-0.8 A and operating times were between 30 and 50 min. The results show that the effluent wastewater was very clear (turbidity approximately 9 NTU) and its quality exceeded the direct discharge standard. The suspended solids and COD removal efficiencies were as high as 30.6 and 75.5%, respectively. In addition, the experimental results also show that the electrocoagulation could neutralise the pH of wastewater.     

The Northern Ireland Civil Service

Although cursory examination reveals that one must refer to 'British civil services', a lacuna has persisted in the literature since Gladden's (1967) seminal work. Invariably, the tendency is to accord the Northern Ireland Civil Service (NICS) footnote status. This article seeks to remedy this deficiency. It offers a resum of the political context of Northern Ireland before concentrating upon NICS itself—its characteristics and changing nature in terms of public administration and the management of public policy since 1970.     

Monetary union and the Maastricht inflation criterion: The accession countries*

We model an accession country facing a Maastricht‐type inflation criterion that specifies an inflation ceiling. In addition to deciding whether or not to satisfy this criterion, the country must decide how much costly economic reform to undertake. If the country puts enough weight on the future that it can credibly meet the inflation criterion no matter what the ceiling is, then the inflation criterion benefits the country but lowers reform. If the country puts less weight on the future, then a criterion with a properly chosen inflation ceiling can increase reform. We derive the inflation ceilings that maximize the country's welfare and its reform.     

Testing for Unit Roots with Breaks: Evidence on the Great Crash and the Unit Root Hypothesis Reconsidered

Nelson and Plosser (1982), in a classic paper, failed to find strong evidence against the null hypothesis of a generating process with a unit autoregressive root for thirteen US macroeconomic time series. Perron (1989) claimed that such evidence was available for a majority of these series if the alternative hypothesis was of trend stationarity with a break in 1929. Zivot and Andrews (1992) treated the break date as endogenous, then finding strong evidence agcainst the null for a minority of these series. Our own analysis extends theirs by permitting a break under the null as well as the alternative hypothesis, and allowing for the sequential nature of the testing. Our empirical findings complete the circle. We find no strong evidence against the unit root hypothesis for any of the thirteen Nelson–Plosser series.     

The beneficial effects of storage on the quality of wastewater for irrigation: a case study in Sicily.

Although the main function of reservoirs in agriculture is to allow the storage and temporal shifting of large volumes of waters, further benefits emerge from their application in wastewater reuse systems. In fact, as observed in several other studies carried out on such complex natural systems, the storage period, under proper conditions, can lead to a significant improvement of the water quality for irrigation thanks to concurrent physical, chemical and biological processes. In order to investigate the reservoir dynamics, an experimental research was carried out in a farm reservoir (volume of 11,000 m3, maximum depth of 6.3 m and mean depth of about 5 m), receiving treated wastewater and subject to scheduled highly variable input to volume ratios, in order to observe the broadest range of behaviour responses. Specifically, over a monitoring period lasted 4 months, the reservoir was operated as a standard batch reactor in the first and third phases and as a continuous flow reactor in the second one. Based on correlation analysis between the chemical, physical and biological water parameters and operational ones, a new operative index is proposed which integrates the morphological characteristics of the tank and the management ones, and shows a significant correlation with the qualitative characteristics of the stored water.     

GATT,Preferential/Regional Trading Blocs and Agricultural Trade*

Agricultural trade impasses have again frustrated the GATT process. Interest in preferential/regional trading blocs is increasing. the paper probes the theoretical and empirical consequences of preferential arrangements instead of multilateral liberalization. It concludes that in a second-best world preferential arrangements could either improve or decrease global welfare. For agricultural trade, previous experience suggests that in regional groupings such as the EC trade diversion exceeded trade creation. This results from trade distorting domestic policies. Prospects for liberalization of agricultural trade under either GATT or preferential arrangements are limited. the consequences for small agricultural exporters are not positive.     

A Study of Arbitrage Efficiency Between the FTSE‐100 Index Futures and Options Contracts

Despite the importance of the London markets and the significance of the relationship for market makers, little published research is available on arbitrage between the FTSE‐100 Index futures and the FTSE‐100 European index options contracts. This study uses the put–call–futures parity condition to throw light on the relationship between options and futures written against the FTSE Index. The arbitrage methodology adopted in this study avoids many of the problems that have affected prior research on the relationship between options or futures prices and the underlying index. The problems that arise from nonsynchroneity between options and futures prices are reduced by the matching of options and futures prices within narrow time intervals with time‐stamped transaction data. This study allows for realistic trading and market‐impact costs. The feasibility of strategies such as execute‐and‐hold and early unwinding is examined with both ex‐post and ex‐ante simulation tests that take into consideration possible execution time lags for the arbitrage trade. This study reveals that the occurrence of matched put–call–futures trios exhibits a U‐shaped intraday pattern with a concentration at both open and close, although the magnitude of observed mispricings has no discernible intraday pattern. Ex‐post arbitrage profits for traders facing transaction costs are concentrated in at‐the‐money options. As in other major markets, despite important microstructure differences, opportunities are generally rapidly extinguished in less than 3 min. The results suggest that arbitrage opportunities for traders facing transaction costs are small in number and confirm the efficiency of trading on the London International Financial Futures and Options Exchange. © 2002 John Wiley & Sons, Inc. Jrl Fut Mark 22:31–58, 2002