Influence of a stormwater sediment deposit on microbial and biogeochemical processes in infiltration porous media

The purpose of this study was to test the relative influence of organic matter quantity and quality and the pollutant content of a stormwater sediment deposit on mineralization processes, microbial characteristics, and the release of solutes in infiltration sediment systems. In microcosm experiments, two other natural sediment deposits (one low and one rich particulate organic matter deposits) were studied to compare their effects with those of the stormwater deposit. The results showed that the biogeochemical processes (aerobic respiration, denitrification, fermentative processes), the microbial metabolism (enzymatic activities), and the releases of several solutes (NH(4)(+) and DOC) were stimulated in presence of the stormwater deposit and the natural particulate organic matter (POM)-rich deposit because of the quantity of the POM in these deposits. In the stormwater deposit, the high availability of the POM (indicated by its low C/N ratio and its high P content) produced a higher stimulation of the microbial metabolism than in presence of the POM-rich deposit (with a high C/N ratio). Pollutant (hydrocarbon and heavy metal) contents of the stormwater deposit did not have a significant effect on microbial processes. Thus, main effects of the stormwater sedimentary deposit on infiltration system were due to its organic matter characteristics (quantity and quality). Such organic matter characteristics need to be considered in future studies to determine the contamination potential of stormwater management practices.     

Hysteresis current control technique of VSI for compensation of grid-connected unbalanced loads

The global trends nowadays in the power generation industry are to supplement the electricity production using distributed generation (DG) technologies based on renewable energy resources such as photovoltaic, wind power, etc. However, failure to properly control the operation of distributed energy resources as they connect to the exiting power grid could provoke many power quality problems on the grid side. For this reason, due considerations must be given to power generation and safe running before DG units is actually integrated into the power grid. The main aim of this paper is to address the grid interconnection issues that usually arise as DG units connect to the electric grid. The proposed strategy, implemented in Matlab/Simulink environment in different operating scenarios, provides compensation for active, reactive, unbalanced, and harmonic current components of grid-connected nonlinear unbalanced loads. The simulation results obtained in this study demonstrate the level of accuracy of the proposed technique, which ensure a balance in the overall grid phase currents, injection of maximum available power from DG resources to the grid, improvement of the utility grid power factor, and a reduction in the total harmonic distortion of grid currents.     

Using ontology-based clustering to understand the push and pull factors for British tourists visiting a Mediterranean coastal destination

This paper studies why British tourists decide to travel to a particular destination in a Catalan region. The analysis is based on a survey that includes open-ended questions. First, we propose the operationalization of the concepts of motivation and meaning as push–pull factors when choosing a destination. Second, an ontology-based clustering method is presented, which makes it possible to analyse these qualitative factors from a semantic perspective to obtain tourist segments. A benchmark confirms that the segmentation obtained is better than that generated using classic clustering methods The results show that different meanings can be associated with any single place.     

Using convolutional neural networks for classification of malware represented as images

Journal of Computer Virology and Hacking Techniques - The number of malicious files detected every year are counted by millions. One of the main reasons for these high volumes of different files is...     

High throughput screening of CO2 solubility in aqueous monoamine solutions

Post-combustion Carbon Capture and Storage technology (CCS) is viewed as an efficient solution to reduce CO(2) emissions of coal-fired power stations. In CCS, an aqueous amine solution is commonly used as a solvent to selectively capture CO(2) from the flue gas. However, this process generates additional costs, mostly from the reboiler heat duty required to release the carbon dioxide from the loaded solvent solution. In this work, we present thermodynamic results of CO(2) solubility in aqueous amine solutions from a 6-reactor High Throughput Screening (HTS) experimental device. This device is fully automated and designed to perform sequential injections of CO(2) within stirred-cell reactors containing the solvent solutions. The gas pressure within each reactor is monitored as a function of time, and the resulting transient pressure curves are transformed into CO(2) absorption isotherms. Solubility measurements are first performed on monoethanolamine, diethanolamine, and methyldiethanolamine aqueous solutions at T = 313.15 K. Experimental results are compared with existing data in the literature to validate the HTS device. In addition, a comprehensive thermodynamic model is used to represent CO(2) solubility variations in different classes of amine structures upon a wide range of thermodynamic conditions. This model is used to fit the experimental data and to calculate the cyclic capacity, which is a key parameter for CO(2) process design. Solubility measurements are then performed on a set of 50 monoamines and cyclic capacities are extracted using the thermodynamic model, to asses the potential of these molecules for CO(2) capture.     

Side-line tunable laser transmitter for differential absorption lidar measurements of CO2: design and application to atmospheric measurements

A 2 microm wavelength, 90 mJ, 5 Hz pulsed Ho laser is described with wavelength control to precisely tune and lock the wavelength at a desired offset up to 2.9 GHz from the center of a CO(2) absorption line. Once detuned from the line center the laser wavelength is actively locked to keep the wavelength within 1.9 MHz standard deviation about the setpoint. This wavelength control allows optimization of the optical depth for a differential absorption lidar (DIAL) measuring atmospheric CO(2) concentrations. The laser transmitter has been coupled with a coherent heterodyne receiver for measurements of CO(2) concentration using aerosol backscatter; wind and aerosols are also measured with the same lidar and provide useful additional information on atmospheric structure. Range-resolved CO(2) measurements were made with <2.4% standard deviation using 500 m range bins and 6.7 min? (1000 pulse pairs) integration time. Measurement of a horizontal column showed a precision of the CO(2) concentration to <0.7% standard deviation using a 30 min? (4500 pulse pairs) integration time, and comparison with a collocated in situ sensor showed the DIAL to measure the same trend of a diurnal variation and to detect shorter time scale CO(2) perturbations. For vertical column measurements the lidar was setup at the WLEF tall tower site in Wisconsin to provide meteorological profiles and to compare the DIAL measurements with the in situ sensors distributed on the tower up to 396 m height. Assuming the DIAL column measurement extending from 153 m altitude to 1353 m altitude should agree with the tower in situ sensor at 396 m altitude, there was a 7.9 ppm rms difference between the DIAL and the in situ sensor using a 30 min? rolling average on the DIAL measurement.     

Self health care when faced with acute pathology in childhood

OBJECTIVE: To quantify and describe the self-care practices for children up to 14 seeking care because of an acute pathology. DESIGN: An observation study carried out by means of a questionnaire administered to the person accompanying the patient. SETTING: Primary Care: an urban Health Centre. PATIENTS AND OTHER PARTICIPANTS: The total number of cases of acute pathology treated during April and May 1993 in the Centre's paediatric clinics. MEASUREMENTS AND MAIN RESULTS: 248 cases were studied (53% boys and 47% girls, with an average age of 5.3 +/- 3.85). Self-care (self-medication, 84.6%; non-pharmacological measures, 11.5%; both of these, 3.9%) was practised in 61.3% of cases (CI 95%: 55.2-67.4). The most common drugs were: antipyretics-analgesics (60%), antitussives (9.6%) and antibiotics (8.1%). Self-care was practised most often on patients presenting respiratory symptoms (69.6%) (p < 0.001), with self-medication predominant (91.2%) (p < 0.001). The number of days occurring between the appearance of symptoms and the medical consultation was greater among those who did not practise self-care (4.5 +/- 5.2 as against 2.1 +/- 1.8) (p < 0.001). CONCLUSIONS: Self-care is a very common practice among people seeking paediatric treatment. Self-medication, especially for respiratory trouble, is the most common form. Patients who practise self-care tend to be earlier in seeking a medical consultation.