The effect of environmental parameters on contaminant uptake by a passive sampler device

A passive sampling device previously developed was used to assess environmental contamination. It consists of a polymeric bag filled with an organic solvent in which contaminants are preconcentrated after passively diffusing from the water column. The contents of the device were subjected to analysis without further cleanup. The effect of temperature, turbulence, ionic strength, pH, and the presence of dissolved organic material on the partioning process were examined. The results showed that increase in temperature supply the molecules with greater energy and enables them to pass through the membrane and into the solvent. Turbulence was found to disrupt the boundary layer formed around the device as a result of concentration polarization causing irregular fluctuations in the concentration of contaminants in equilibrium with the membrane. There was no discernable correlation between the concentration of contaminants accumulated by the devices and the ionic strength of the incubation solution. There was also no discernable relationship between pH and contaminants uptake by the sampling devices as was expected with non polar, non-ioniseable solutes. The uptake of compounds with lower molar volumes was most susceptible to the presence oh humic materials. Journal of Applied Sciences and Environmental Management Vol. 10(1) 2006: 15-2

Cross-border Banking, Spillover Effects and International Business Cycles

This paper studies the link between cross-border banking activities and the international propagation of real and financial shocks. We develop a two-country DSGE model with a bank capital channel and a financial accelerator, in which banks grant loans to domestic as well as to foreign firms. The model economy is calibrated to data from the U.S. and Canada. Our results suggest that following a positive technology shock and a tightening of home monetary policy, the existence of cross-border banking activities tends to amplify the transmission channel in both the domestic and the foreign country. However, cross-border banking activities tend to weaken the impact of shocks on foreign and home consumption because of the cross-border saving possibility between the two countries. Finally, our simulations suggest that under cross-border banking, correlations between macroeconomic variables of both countries become greater than in the absence of international banking activities. Overall, our results show sizable spillover effects of cross-border banking on macroeconomic dynamics and suggest cross border banking is an important source of the synchronization of business cycles between the U.S. and Canada

Cross-border Banking, Spillover Effects and International Business Cycles

This paper studies the link between cross-border banking activities and the international propagation of real and financial shocks. We develop a two-country DSGE model with a bank capital channel and a financial accelerator, in which banks grant loans to domestic as well as to foreign firms. The model economy is calibrated to data from the U.S. and Canada. Our results suggest that following a positive technology shock and a tightening of home monetary policy, the existence of cross-border banking activities tends to amplify the transmission channel in both the domestic and the foreign country. However, cross-border banking activities tend to weaken the impact of shocks on foreign and home consumption because of the cross-border saving possibility between the two countries. Finally, our simulations suggest that under cross-border banking, correlations between macroeconomic variables of both countries become greater than in the absence of international banking activities. Overall, our results show sizable spillover effects of cross-border banking on macroeconomic dynamics and suggest cross border banking is an important source of the synchronization of business cycles between the U.S. and Canada

Diversité et Éthologie des Mammifères sur Deux Îles du Nord du Parc National de Taï, Sud-Ouest, Côte d’Ivoire

Les nombreux travaux de recherche sur les mammifères du parc national de Taï se sont intéressés à sa grande partie sud. L’extrême nord du parc constitué d’un ensemble de 11 îles a rarement été investigué. Le présent travail essai de combler ce manque d’informations en étudiant la diversité des mammifères, leur période d’activité ainsi que quelques aspects de leur comportement sur Nakolo et Dafidougou, deux des 11 îles qui n’ont jamais fait l’objet d’aucune recherche. A cet effet, 20 pièges photographiques a été installé de façon systématique sur ces deux îles pour conduire la présente étude. Un total de neuf (09) espèces de mammifères a été identifié dont huit (08) espèces sur l’île Nakolo et cinq (05) sur Dafidougou. Cependant, l’indice de Shannon indique que la richesse en biodiversité de Dafidougou (H’=1,297) est légèrement supérieure à celle de Nakolo (H’=1,209) du fait de la grande dominance de la civette d’Afrique (Civettictis civetta) sur l’île de Nakolo. Parmi les huit (08) espèces de mammifères détectées sur l’île Nakolo, quatre (04) espèces sont nocturnes, trois (03) sont cathémérales et une (01) seule est diurne. Quant à l’île Dafidougou, des cinq (05) espèces rencontrées, trois (03) sont nocturnes, une (01) cathémérale et une (01) autre diurne. Sur le plan comportemental, les mammifères rencontrés se déplacent beaucoup, se nourrissent fréquemment et sont très peu vigilants surtout sur l’île Dafidougou. Nous en déduisons l’existence désormais d’une quiétude et d’une tranquillité sur ces îles très anthropisées dans un passé récent. Many research studies on mammals in Taï National Park have focused on its large southern part. The extreme north of the park, made up of a set of 11 islands, has rarely been investigated. The present work tries to fill this lack of information by studying the diversity of mammals, their period of activity as well as some aspects of their behaviour on Nakolo and Dafidougou, two of the 11 islands which have never been the subject of no research. For this purpose, 20 camera traps were systematically installed on these two islands to conduct this study. A total of nine (09) species of mammals have been identified including eight (08) species on Nakolo Island and five (05) on Dafidougou. However, the Shannon index indicates that the biodiversity richness of Dafidougou (H'=1.297) is slightly higher than that of Nakolo (H'=1.209) due to the great dominance of the African civet (Civettictis civetta) on the island of Nakolo. Among the eight (08) species of mammals detected on Nakolo Island, four (04) species are nocturnal, three (03) are cathemeral and only one (01) is diurnal. As for Dafidougou Island, of the five (05) species encountered, three (03) are nocturnal, one (01) cathedral and another (01) diurnal. Behaviourally, the mammals encountered move around a lot, feed frequently and are not very vigilant, especially on Dafidougou Island. We deduce from this the existence now of peace and tranquillity on these islands which were very anthropized in the recent past

Périodes D’activités et Quelques Aspects du Comportement des Moyens et Grands Mammifères sur Deux îles (Dafidougou et Nakolo) au Nord du Parc National de Taï, Sud-ouest de la Côte d’Ivoire

Les nombreux travaux de recherche sur les mammifères du parc national de Taï se sont intéressés à sa grande partie sud. L’extrême nord du parc constitué d’un ensemble d’îles a rarement été investigué. Le présent travail essai de combler ce manque d’informations en étudiant la diversité des mammifères, leur période d’activité ainsi que quelques aspects de leur comportement sur Nakolo et Dafidougou, deux des 11 îles que constitue cette portion du parc. A cet effet, un total de 20 pièges photographiques a été installé de façon systématique sur ces deux îles. Un total de neuf espèces de mammifères a été identifié dont huit espèces sur l’île Nakolo et cinq sur Dafidougou. Cependant, l’indice de Shannon indique que la richesse en biodiversité de Dafidougou est légèrement supérieure à celle de Nakolo du fait de la grande dominance de la civette d’Afrique (Civettictis civetta) sur l’île Nakolo. Parmi les neuf espèces de mammifères détectées sur ces îles, la majorité est nocturnes, certaines sont diurnes et d’autres cathémérales. Sur le plan comportemental, les mammifères rencontrés se déplacent beaucoup, se nourrissent fréquemment et sont trè peu vigilants surtout sur l’île Dafidougou. Nous en déduisons l’existence désormais d’une quiétude et d’une tranquillité sur ces îles très anthropisées dans un passé récent.   Many research studies on mammals in Taï National Park have focused on its large southern part. The extreme north of the park, made up of a group of islands, has rarely been investigated. This work tries to fill this lack of information by studying the diversity of mammals, their period of activity as well as some aspects of their behavior on Nakolo and Dafidougou, two of the 11 islands that make up this portion of the park. To this end, a total of 20 camera traps have been systematically installed on these two islands. A total of nine species of mammals have been identified, including eight species on Nakolo Island and five on Dafidougou. However, the Shannon index indicates that the biodiversity richness of Dafidougou is slightly higher than that of Nakolo due to the great dominance of the African civet (Civettictis civetta) on Nakolo Island. Among the nine species of mammals detected on these islands, the majority are nocturnal, some are diurnal and others cathemeral. Behaviourally, the mammals encountered move around a lot, feed frequently and are not very vigilant, especially on Dafidougou Island. We deduce from this the existence now of peace and tranquility on these islands which were very anthropized in the recent past

Simultaneous phosphates and nitrates removal from waste-waters by electrochemical process: Techno-economical assessment through response surface methodology

In this study, a new multiobjective optimization of the simultaneous removal of phosphates and nitrates by electrocoagulation was studied using the Box-Behnken design. Ten aluminium electrodes, connected in a monopolar configuration in a batch reactor, were immersed in synthetic wastewater and then in real wastewater. The optimal conditions and the effects of parameters (current intensity, electrolysis time and initial pH) on phosphate and nitrate removal, the formation of by-products, and the operating cost were assessed in the case of synthetic wastewater. This optimization allowed to eliminate 89.21 % of phos­phates, 69.06 % of nitrates with an operating cost of 3.44 USD m-3 against 13.67 mg L-1 of ammonium generated. Optimal conditions applied to real domestic wastewater made it possible to remove 93 % of phosphates and 90.3 % of nitrates with an ammonium residual of 30.9 mg L-1. The addition of sodium chloride reduced the residual ammonium content to 2.95 mg L-1. Further, XRD analysis of the sludge showed poor crystal structure and the FTIR spectrum suggested that the phosphate is removed by adsorption and co-precipitation

Bank Capital, Credit Market Frictions and International Shocks Transmission

Recent empirical evidence suggests that the state of banks’ balance sheets plays an important role in the transmission of monetary policy and other shocks. This paper presents an open-economy DSGE framework with credit market frictions and an active bank capital channel to assess issues regarding the transmission of domestic and foreign shocks. The theoretical framework includes the financial accelerator mechanism developed by Bernanke et al. (1999), the bank capital channel and the exchange rate channel. Our simulations show that the exchange rate channel plays an amplification role in the propagation of shocks. Furthermore, with these three channels present, domestic and foreign shocks have an important quantitative role in explaining domestic aggregates like output, consumption, inflation and total bank’s lending. In addition, results suggest that economies whose banks remain well-capitalized when affected by adverse shock experience less severe downturns. Our results highlight the importance of bank capital in an international framework and can be used to inform the worldwide debate over banking regulation

Lead concentrations in sediments and mollusc gastropod from Vridi Canal, Côte d’Ivoire

Lead (Pb) is one of the most frequent and toxic contaminant in the environment. It can be bioaccumulated by marine organisms through contaminated sediments as well as their food chains. The current study aimed at investigating Pb occurrence in the sediments and gastropod P. haemastostoma from Vridi Canal. Sediment samples were taken using a Van Veen steel grab of 0.02 m2 area, sealed in plastic bags and transported to the laboratory at 4 °C. Gastropod P. haemastostoma species were collected manually using gloves, and then placed in polyethylene plastic bags. The different concentrations were determined using atomic absorption spectrometer Varian AA 20. The results showed seasonal variability of Pb concentrations in sediments and P. haemastostoma. In the both matrices, Pb exhibited the same trend in the distribution between the seasons. This study also mentioned that sediments were highly  contaminated by Pb (54.27-134.71 mg/kg). Vridi Canal was found to be one of the most contaminated seaport area. Pb levels  (49.55-104.19 mg/kg) in P. haemastostoma exceeding the maximum permitted levels according to the United Nations Food and Agriculture Organization (FAO). This research demonstrated that sediments having lower ecological risk may be resulting in lower tissue Pb of P. haemastostoma. Keywords: Metal Pb, sediment, P. haemastostoma, seasonal variatio

Périodes D’activités et Quelques Aspects du Comportement des Moyens et Grands Mammifères sur Deux îles (Dafidougou et Nakolo) au Nord du Parc National de Taï, Sud-ouest de la Côte d’Ivoire

Les nombreux travaux de recherche sur les mammifères du parc national de Taï se sont intéressés à sa grande partie sud. L’extrême nord du parc constitué d’un ensemble d’îles a rarement été investigué. Le présent travail essai de combler ce manque d’informations en étudiant la diversité des mammifères, leur période d’activité ainsi que quelques aspects de leur comportement sur Nakolo et Dafidougou, deux des 11 îles que constitue cette portion du parc. A cet effet, un total de 20 pièges photographiques a été installé de façon systématique sur ces deux îles. Un total de neuf espèces de mammifères a été identifié dont huit espèces sur l’île Nakolo et cinq sur Dafidougou. Cependant, l’indice de Shannon indique que la richesse en biodiversité de Dafidougou est légèrement supérieure à celle de Nakolo du fait de la grande dominance de la civette d’Afrique (Civettictis civetta) sur l’île Nakolo. Parmi les neuf espèces de mammifères détectées sur ces îles, la majorité est nocturnes, certaines sont diurnes et d’autres cathémérales. Sur le plan comportemental, les mammifères rencontrés se déplacent beaucoup, se nourrissent fréquemment et sont trè peu vigilants surtout sur l’île Dafidougou. Nous en déduisons l’existence désormais d’une quiétude et d’une tranquillité sur ces îles très anthropisées dans un passé récent.   Many research studies on mammals in Taï National Park have focused on its large southern part. The extreme north of the park, made up of a group of islands, has rarely been investigated. This work tries to fill this lack of information by studying the diversity of mammals, their period of activity as well as some aspects of their behavior on Nakolo and Dafidougou, two of the 11 islands that make up this portion of the park. To this end, a total of 20 camera traps have been systematically installed on these two islands. A total of nine species of mammals have been identified, including eight species on Nakolo Island and five on Dafidougou. However, the Shannon index indicates that the biodiversity richness of Dafidougou is slightly higher than that of Nakolo due to the great dominance of the African civet (Civettictis civetta) on Nakolo Island. Among the nine species of mammals detected on these islands, the majority are nocturnal, some are diurnal and others cathemeral. Behaviourally, the mammals encountered move around a lot, feed frequently and are not very vigilant, especially on Dafidougou Island. We deduce from this the existence now of peace and tranquility on these islands which were very anthropized in the recent past