1,721,130 research outputs found
NUMERICAL COMPUTATION OF CORONA SPACE-CHARGE AND V-I CHARACTERISTIC IN DC ELECTROSTATIC PRECIPITATORS
No full textA procedure is presented for the numerical computation of the corona space-charge density and V-I characteristic in dc electrostatic precipitators in the absence of fly ash. An iterative numerical procedure, based on the finite element method, is implemented for solving Poisson's and continuity equations satisfying Kaptzov's assumption on the coronating conductors. The mathematical model is applied to a duct of an electrostatic precipitator; the ion charge density, electric potential, and electric field distributions are computed. The V-I characteristic, obtained by means of the proposed procedure, is compared with the experimental one measured by the Italian Electricity Authority (Enel) in a pilot precipitator put in the slipstream of the flue gas duct of a 35-MWe coal boiler. The agreement between computed and experimental values shows the efficiency of the numerical procedure
A configurable hardware word re-ordering block for multi-lane communication protocols: Design and use case
Full text linkData rate requirements, from consumer application to automotive and aerospace grew rapidly in the last years. This led to the development of a series of communication protocols (i.e. Ethernet, PCI-Express, RapidIO and SpaceFibre), which use more than one communication lane, both to speed up data rate and to increase link reliability. Some of these protocols, such as SpaceFibre, are able to detect real-time changes in the number of active lanes and to adapt the data flow appropriately, providing a flexible solution, robust to lane failures. This results in a real time varying data path in the lower layers of the data handling system. The aim of this paper is to propose the architecture of a hardware block capable of reading a fixed number of words from a host FIFO and shaping them on a real time variable number of words equal to the number of active lanes
Degradation and side effects of three sulfonylurea herbicides in soil
No full textSoil degradation and side effects of triasulfuron [3-(6-methoxy-4-methyl-1,3,5-triazin-2-yl)-1-(2-(2-chloroethoxy) phenylsulfonyl)-urea], primisulfuron methyl [2-(4,6-bis(difluoromethoxy)-pyrimidin-2-ylcarbamoylsulfamoyl)benzoic acid], and rimsulfuron [1-(4,6-dimethoxypyrimidin-2-yl)-3-(3-ethylsulfonyl-2-pyridylsulfonyl)- urea] were investigated under laboratory conditions in a pH 6.5 sandy loam soil. In microbially active and sterile soil, the degradation of the three sulfonylureas followed first-order kinetics and was independent of the herbicide soil concentration up to 5 mg a.i. kg-1 of soil. In microbially active soil the mean half-lives of triasulfuron (26.2 d), primisulfuron methyl (30.2 d) and rimsulfuron (7.5 d) were, respectively, 4.0, 3.7, and 1.9 times lower than those in sterile soil, thus confirming the decisive contribution of biological processes in soil degradation of the three sulfonylureas. At the concentrations of 0.2 and 5 mg a.i. kg-1 of soil, no detrimental effects of the three sulfonylureas on soil respiration and dehydrogenase activity were detected. Indeed, soil amended with the three sulfonylureas at 5 mg a.i. kg-1 of soil showed a transient increase of both respiration and dehydrogenase activity. Results showed that triasulfuron, primisulfuron methyl, and rimsulfuron have probably no effects on soil microbial activities at the concentrations used in agricultural practice, which are approximately 1/10 of the lowest concentration tested in the present study
DETECTION AND QUANTITATION OF SULFONYLUREA HERBICIDES IN SOIL AT THE PPB LEVEL BY CAPILLARY ELECTROPHORESIS
No full textA multi-residue analytical method based on solid-phase extraction enrichment combined with capillary electrophoresis (CE), using micellar electrokinetic capillary chromatography, was developed to isolate, recover and quantitate three sulfonylurea herbicides (chlorsulfuron, chlorimuron and metasulfuron) from soil samples. Optimization for CE separation was achieved using an overlapping resolution map scheme. The recovery of each herbicide was >80% and the limit of detection was 10 ppb. The capability of CE in providing quantitative analysis of sulfonylureas in soil samples at the ppb level has been demonstrated. © 1995
SN1-XFEXOY - A NEW MATERIAL WITH HIGH-CARBON MONOXIDE SENSITIVITY
No full textThe preparation method and the sensing properties (sensitivity and selectivity to interfering gases) towards carbon monoxide of the new ternary compound Sn1-xFexOy, deposited in the form of thin films, are presented in this paper. The metal of the VIIIB group is introduced with concentrations in the range 0<x<25 at. %. Thin films are sputtered using the RGTO (rheotaxial growth and thermal oxidation) technique. This technique consists of metal deposition onto a substrate maintained at a temperature higher than the metal melting point and metal oxidation by means of an annealing cycle in pure oxygen. Particular emphasis is given to the relations between some preparation parameters of the material, namely the atomic percentage of iron or the annealing cycle, and to the sensor sensitivity towards CO and other interfering gases like C2H5OH, H-2 and NOx diluted in dry air. A sensitivity S=(C-gas-G(air))/G(air)=3.5 towards 10 ppm of CO has been measured: the kinetic characteristics of the sensors are also presented, together with the working mechanism
Editorial: Ancient crop varieties based food intake: impact on nutritional quality, human health and environmental sustainability
Full text linkWound Healing Potential of a Novel Sedum Species: S. album Murales
Full text linkNatural wound healing products are in increased demand. The potential for unexplored Sedum species in wound healing was discovered based on benefits of the genus reported in traditional medicine. The objectives were to screen ten Sedum species for wound healing, to ascertain the optimal harvest period using the five best, and finally to investigate effects of extraction protocols on wound healing using the most promising species. Different protocols were used to extract leaf polyphenol and mucilage content. Wound healing was assessed from L929 fibroblast migration. April was the optimal harvest month for wound healing efficacy, whereas the highest polyphenol content and antioxidant activity were evident in September and November. S. album Murales (ALBU), the best candidate, was then compared with S. telephium (TELE), which is well recognized in skin care. The mucilage-containing aqueous extract of ALBU was shown for the first time to induce the highest fibroblast migration after 24 h, not evident in TELE. Moreover, functional constituents contained within the absolute acetone- and isopropanol-containing polyphenol pools from ALBU induced significantly higher migration compared to TELE. A prototype cream, containing the water- and solvent-extracted bioactive compounds was effective at inducing fibroblast migration at 24 h in ALBU. The potential of ALBU in wound healing was evidenced and warrants further investigation
MEM-OPT: A Scheduling and Data Re-Use System to Optimize On-Chip Memory Usage for CNNs On-Board FPGAs
No full textIn the last years, Convolutional Neural networks (CNNs) found applications in many fields from computer vision to speech recognition, showing outstanding results in terms of accuracy. Field Programmable Gate Arrays (FPGAs) proved to be a promising platform for running CNN algorithms because they offer a remarkable trade-off between power consumption and computational power. However, an efficient implementation of CNN models on-board an FPGA represents a complex task since CNN massive parallel processing is often limited by FPGA storage capabilities and design congestion. This article introduces MEM-OPT, a scheduling algorithm and data re-use system that aims to optimize on-chip memory usage on-board FPGAs for what concerns input feature maps storage and Processing Elements multiply and accumulation process. The work presents MEM-OPT implementations results on a Xilinx XC7Z020, including hardware resources, maximum clock frequency and power consumption. MEM-OPT memory requirements are analyzed for LeNet-5, MobileNet, VGG-16 and other state-of-the-art CNNs, showing, a reduction up to 80% of the overall on-chip memory necessary for storing input feature maps and accumulating output results with respect to alternative solutions available in the literature
Short-time effects of pure and formulated herbicides on soil microbial activity and biomass
No full textThe short-time of six pure herbicides (atrazine, terbuthylazine, rimsulfuron, primisulfuron-methyl, glyphosate and gluphosinate-ammonium) with respect to the corresponding commercial formulations on microbial activity and biomass of sandy loam soil were investigated. Application rates were: agricultural rate, 20 and 200 μg a.i. g-1 soil. Application at normal agricultural rates did not lead to significant effects on soil microbial activity, whereas soil microbial activity was markedly stimulated when pure and commercial formulations of the six herbicides were applied at 20 μg a.i. g-1 soil. The addition of 200 μg a.i. g-1 soil of four pure herbicides (atrazine, terbuthylazine, rimsulfuron, primisulfuron-methjyl) led to a significant decrease of soil microbial activity. Commercial formulations characterized by a higher relative a.i. concentration (atrazine and primisulfuron-methyl) approximately determined the same decreasing effect of the pure compound, whereas herbicide formulations with a lower relative a.i. concentration (terbuthylazine and rimsulfuron) produced a significant increase in soil microbial activity
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