URBAN RUNOFF IMPACT ON COMPOSITION AND CONCENTRATION OF HYDROCARBONS IN RIVER SEINE SUSPENDED SOLIDS

International audienceIt is now well established that hydrocarbons are recognised like hazardous compounds, especially polynuclear aromatic hydrocarbon (PAH) [Bomboi and Hernandez, 1991; Hermann R, 1981], Urban runoff is a non negligible source of hydrocarbon that may damage the quality of receiving river. In this report, we present the first results of a study of the impact of combined sewer overflows (CSOs), during summer 1995, on the distribution of n-alkanes (C11-C37 ) in theSeine river. Figure 1 shows the site of Chatou, where suspended solids (SS) were sampled just before and during a week period following the moderate CSO event of September 7, 1995

Mobile sink based fault diagnosis scheme for wireless sensor networks

Network diagnosis in Wireless Sensor Networks (WSNs) is a difficult task due to their improvisational nature, invisibility of internal running status, and particularly since the network structure can frequently change due to link failure. To solve this problem, we propose a Mobile Sink (MS) based distributed fault diagnosis algorithm for WSNs. An MS, or mobile fault detector is usually a mobile robot or vehicle equipped with a wireless transceiver that performs the task of a mobile base station while also diagnosing the hardware and software status of deployed network sensors. Our MS mobile fault detector moves through the network area polling each static sensor node to diagnose the hardware and software status of nearby sensor nodes using only single hop communication. Therefore, the fault detection accuracy and functionality of the network is significantly increased. In order to maintain an excellent Quality of Service (QoS), we employ an optimal fault diagnosis tour planning algorithm. In addition to saving energy and time, the tour planning algorithm excludes faulty sensor nodes from the next diagnosis tour. We demonstrate the effectiveness of the proposed algorithms through simulation and real life experimental results

Experiment to Characterize Aircraft Volatile Aerosol and Trace-Species Emissions (EXCAVATE)

The Experiment to Characterize Aircraft Volatile and Trace Species Emissions (EXCAVATE) was conducted at Langley Research Center (LaRC) in January 2002 and focused upon assaying the production of aerosols and aerosol precursors by a modern commercial aircraft, the Langley B757, during ground-based operation. Remaining uncertainty in the postcombustion fate of jet fuel sulfur contaminants, the need for data to test new theories of particle formation and growth within engine exhaust plumes, and the need for observations to develop air quality models for predicting pollution levels in airport terminal areas were the primary factors motivating the experiment. NASA's Atmospheric Effects of Aviation Project (AEAP) and the Ultra Effect Engine Technology (UEET) Program sponsored the experiment which had the specific objectives of determining ion densities; the fraction of fuel S converted from S(IV) to S(VI); the concentration and speciation of volatile aerosols and black carbon; and gas-phase concentrations of long-chain hydrocarbon and PAH species, all as functions of engine power, fuel composition, and plume age

Genetic variability among sorghum accessions for seed starch and stalk total sugar content

Sorghum (Sorghum bicolor (L.) Moench) is a staple food grain in many semi-arid and tropical areas of the world, notably in sub-Saharan Africa because of its adaptation to harsh environments. Among important biochemical components for sorghum for processors are the levels of starch (amylose and amylopectin) and total sugar contents. The aim of this study was to determine the genetic variation for total starch in the seed, its components and total sugar in the stalks of the sorghum accessions from Ethiopia and South Africa. Samples of 22 sorghum accessions were evaluated. Significant variations were observed in total starch (31.01 to 64.88 %), amylose (14.05 to 18.91 %), the amylose/amylopectin ratio (0.31 to 0.73) and total stalk sugar content (9.36 to 16.84 %). Multivariate analysis showed a wide genetic variation within and among germplasm accessions which could be used in the selection of parental lines for the improvement of traits of interest through breeding. The variation found among the sorghum accessions shows that an improved total starch and starch components and stalk sugar contents can be achieved through crossing these selected genotypes

Chemical characterisation and the anti-inflammatory, anti-angiogenic and antibacterial properties of date fruit (Phoenix dactylifera L.)

Ethnopharmacological relevance: Date fruit, Phoenix dactylifera L. has traditionally been used as a medicine in many cultures for the treatment of a range of ailments such as stomach and intestinal disorders, fever, oedema, bronchitis and wound healing. Aim of the review: The present review aims to summarise the traditional use and application of Phoenix dactylifera date fruit in different ethnomedical systems, additionally the botany and phytochemistry are identified. Critical evaluation of in vitro and in vitro studies examining date fruit in relation to anti-inflammatory, anti-angiogenic and antimicrobial activities are outlined. Key Findings: The ethnomedical use of Phoenix dactylifera in the treatment of inflammatory disease has been previously identified and reported. Furthermore, date fruit and date fruit co-products such as date syrup are rich sources of polyphenols, anthocyanins, sterols and carotenoids. In vitro studies have demonstrated that date fruit exhibits antibacterial, anti-inflammatory and anti-angiogenic activity. The recent interest in the identification of the numerous health benefits of dates using in vitro and in vivo studies have confirmed that date fruit and date syrup have beneficial health effects that can be attributed to the presence of natural bioactive compounds. Conclusions: Date fruit and date syrup have therapeutic properties, which have the potential to be beneficial to health. However, more investigations are needed to quantify and validate these effects

Seasonal variability and trends of volatile organic compounds in the lower polar troposphere

Measurements of the atmospheric mixing ratios of 10 nonmethane hydrocarbons (NMHC) and four halocarbons (methyl chloride, dichloromethane, trichloroethene, and tetrachloroethene) were conducted between January 1989 and July 1996 at Alert (Canadian Arctic, 82°27′N, 62°31′W). About 270 canister samples were analyzed covering the 7-year period with an average frequency of about one sample every 9 days. The mixing ratios of these volatile organic compounds (VOC) exhibit considerable variability, which can partly be described by systematic seasonal dependencies. The highest mixing ratios were always observed during winter. During spring, the mixing ratios decrease for some compounds to values near the detection limit. The amplitudes of the seasonal variability, the time of the occurrence of the maxima, and the relative steepness of the temporal gradients show a systematic dependence on OH reactivity. The steepest relative decrease is less than 1% d−1 for methyl chloride, increasing to about 4% d−1 for highly reactive VOC. Similarly, the highest relative increase rates vary between 0.5% d−1 for VOC with low reactivity to 4% d−1 for reactive VOC. With the exception of ethyne, toluene, and methyl chloride the concentrations of all measured VOC decrease during the studied period, although this decrease is not always statistically significant. In general, the largest changes were found for the most reactive VOC, although the seemingly random overall variability observed for these compounds results in substantial uncertainties. For the less reactive VOC (ethane, benzene, and propane) the average relative annual decrease rate is in the range of a few percent per year. Dichloromethane and tetrachloroethene showed a decrease of 4 and 14% yr−1, respectively. The average decrease rate for the other alkanes is in the range of some 10% yr−1, indicating a substantial change of emission rates during this period. A likely explanation is a reduction in VOC emissions in the area of the former Soviet Union, most likely Siberia, as a consequence of the recent major economic changes in this region. The measurements were compared with the results of chemical transport models' simulations using the Emission Database for Global Atmospheric Research NMHC emission inventory. Although the model captures most of the main features of the shapes of the seasonal cycles of the NMHC, the results clearly show that model estimates are consistently too low compared to the observations. Most likely this is the consequence of an underestimate of the NMHC emission rates in the emission inventory