5,033 research outputs found
Distribution of heavy metals in vegetative biofiltration columns
This study investigated the distribution of heavy metals in vegetative biofiltration columns irrigated by synthetic greywater. Twelve species of ornamental plants (three plants from each species) were planted in the same designed 36 biofiltration columns. Samples of effluent water, soils, roots, shoots and leaves were collected and analyzed. It was observed that before irrigation, the distribution of copper was in soils (0%), roots (42%), leaves (37%) and shoots (21%). After irrigation, this distribution changed to soils (29%), roots (39%), leaves (17%) and shoots (15%). It was found that lead concentrations decreased in soils from (84% to 7%), but increased in plants (from 16% to 93%) following irrigation with greywater. In contrast, the distribution of zinc changed from leaves (46%), roots (22%) and soils (16%) before irrigation to 89% in leaves and soils and 11% in shoots following irrigation. The chromium distribution before and after irrigation was found to be almost unchanged in soils, shoots and effluent water, but it increased in roots (19.4% to 26.9%) and decreased in leaves (11.4% to 5.8%). The outcomes of this study demonstrated that heavy metals mostly accumulate in soils and roots, and it is necessary to investigate their potential detrimental effects on the receiving environment
Automatic Classification of Bright Retinal Lesions via Deep Network Features
The diabetic retinopathy is timely diagonalized through color eye fundus
images by experienced ophthalmologists, in order to recognize potential retinal
features and identify early-blindness cases. In this paper, it is proposed to
extract deep features from the last fully-connected layer of, four different,
pre-trained convolutional neural networks. These features are then feeded into
a non-linear classifier to discriminate three-class diabetic cases, i.e.,
normal, exudates, and drusen. Averaged across 1113 color retinal images
collected from six publicly available annotated datasets, the deep features
approach perform better than the classical bag-of-words approach. The proposed
approaches have an average accuracy between 91.23% and 92.00% with more than
13% improvement over the traditional state of art methods.Comment: Preprint submitted to Journal of Medical Imaging | SPIE (Tue, Jul 28,
2017
Rapid hydropyrolysis of coals for production of liquid hydrocarbons
Production of fuels and chemicals from coal is becoming attractive due to potential high cost and uncertain supply of crude petroleum oil. Conventional techniques of coal liquefaction, though technically feasible, have been expensive due to hydrogen requirements, high pressure equipment, and high cost of commercial supported catalysts.
In this study, a novel technique for rapid hydropyrolysis of bituminous, subbituminous, and lignite coals has been investigated. Rapid hydropyrolysis is the process of heating at a fast rate to high temperature in a hydrogen environment. A coal sample in hydrogen atmosphere is targeted, in the absence of a catalyst, with a high intensity xenon light beam. A shuttering mechanism is incorporated to expose the coal sample only for a few seconds at a time. This technique provides the best of several processes: high heating rate of the coal sample to achieve a high carbon conversion, and control of secondary reactions via low ambient hydrogen gas temperature to potentially achieve high yields of liquid hydrocarbons. This technique also provides an effective economic alternative to the use of expensive commercial catalysts for the conventional coal liquefaction process. The operating parameters studied were exposure time, peak temperature, particle size, gaseous atmosphere, and coal rank.
The most suitable conditions for the rapid hydropyrolysis of coals were found to be 30 seconds exposure time, 900\sp\circC peak temperature, 63 to 74 micrometer particle size, and in hydrogen atmosphere (1 atm). The total amount of coal converted to liquid and gaseous products for bituminous coal was found to be 38.5% and decreased to 33.6% for subbituminous coal and to 32.2% for lignite. The amount of liquid hydrocarbons produced were 16.3%, 8.8%, and 3.5% for bituminous, subbituminous, and lignite coal, respectively.
In this process, a radiative heat source is used. The rapid hydropyrolysis method used in this study has several advantages over the coal liquefaction processes. It is conducted at atmospheric pressure, at a relatively shorter exposure time (less than one minute), and in the absence of a catalyst
Role of environment policy and community participation on air pollution control in Malaysia:lessons from Japan.
Air pollution is defined as the presence of pollutant in the air, in quantities large enough to produce harmful effect towards human health, vegetation, human property and water ground cycle
Ottoman Mosques in Sana\u27a, Yemen Archeological and Architectural Study
The Ottoman presence in Yemen is divided into two periods, first period from 945 AH until 1045 AH, and then the second from 1289 AH until 1336 AH, Ottomans interested during their presence in Yemen to establish different types of charitable buildings especially, religious buildings, which include mosques, madrassas, and shrines. The aim of interest of Ottomans governors to make significant civilized and architectural renaissance in Yemen, especially Sana\u27a, with emphasis on establishment mosques to get closer to God and to gain sympathy and love of the people of Yemen. Most of these mosques do the role of the madrassas as documents indicate like mosque of Özdemir, Al-Muradiyya and Al-Bakiriyya therefore, Ottomans are Hanifite Sunni and want by these mosques to facing shite and spread Sunni.In this paper researcher will discuss styles of Ottoman mosques in Sana\u27a. There are eight mosques, seven dates to the first period of Ottomans in Yemen and only one date to the second period of Ottomans in Yemen
The potential for using remote sensing to quantify stress in and predict yield of sugarcane (Saccharum spp. hybrid)
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010
Analysis of Cannabinoids in Post-mortem Blood Samples
This thesis is concerned with the analysis of cannabinoids, delta-9-tetrahydrocannabinol (THC) and its major metabolite, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THCCOOH), in post-mortem blood samples. It concentrates on sample preparation procedures and end-step detection techniques by High Pressure Liquid Chromatography (HPLC) and Gas Chromatography-Mass Spectrometry (GC-MS). A comparative evaluation was made of solid-phase (diatomaceous earth, Extrelut) and solvent extraction procedures. When extracted with hexane, mixtures of hexane and more polar solvents, or acetonitrile, the former gave low extraction yields, for example, with acetonitrile the recoveries were 70.4% for THC and 43.9% for THCCOOH. It was observed that clogging of the extrelut columns by precipitated blood proteins might have resulted in the poor results obtained. On the other hand, solvent extraction procedures using acetonitrile gave better results. Recoveries obtained for THC and THCCOOH were 82.1% and 82.7% respectively. These values were found to be higher when deionised water was added to dilute the blood samples (83.2% for THC and 86.9% for THCCOOH). However, addition of buffers at pH 5.0 and 7.4 did not improve the recoveries obtained by addition of water. Calibration curves of the solvent extraction procedure produced linear plots within the 0-80ng/ml range for both THC and THCCOOH. The solid-phase extraction material Bond Elut Certify II was developed recently for the extraction and purification of cannabinoids from biological matrices. It was incorporated into this study as a clean-up procedure for HPLC analysis of the solvent extracts. Therefore, extraction procedure selected for further analysis involved deproteinization and extraction with acetonitrile, supernatant clean-up using the Bond Elut Certify II columns, evaporation to dryness and either reconstitution of the residue in mobile phase for HPLC analysis or derivatization of the residue prior to GC-MS analysis. For HPLC analysis, acetonitrile-methanol-0. 02N sulphuric acid (65:15:50, v:v:v) was chosen from four mobile phases examined. Detection of analytes was carried out using ultra-violet (UV) and electro-chemical (ECD) detectors at wavelengths 212nm, 220nm and at an applied potential of +1.10V respectively, after detector optimisation procedures. The clean-up procedure separated the cannabinoids into THC and THCCOOH fractions. Thus, two internal standards were needed for quantitation purposes. N-octyl p-hydroxy benzoate and phenylbutazone were found to be the most suitable choices for the two fractions, respectively. It was also observed that the THC fraction gave clean chromatograms while the THCCOOH fraction contained co-extracted interferences which eluted closed to the metabolite. Average recoveries for THC, cannabidiol (CBD), cannabinol (CBN) and THCCOOH by this HPLC system were 91.1%, 93.6%, 90.1% and 91.4% detected by UV 212nm; 88.9%, 93.5%, 88.9% and 90.7% by UV 220nm and 93.4%, 94.7%, 98.7% and 89.1% by ECD +1.10V, respectively. Calibration curves were linear from 0-100ng/ml for both UV detection wavelengths, and within the range 0-200ng/ml for ECD detection. When eight test samples were analysed, which were positive when screened for cannabinoids by radioimmunoassay, none of the samples gave positive results for THC and CBN. Electrochemical detection but not UV detection gave five samples positive for CBD, while THCCOOH was found to be present in all of the test samples. GC-MS analysis was performed under full scan, selected ion recording (SIR), multiple reaction monitoring (MRM) and negative ion chemical ionisation (NICI) modes. Extracted samples were not cleaned up with Bond Elut Certify II in order to evaluate the sensitivity and selectivity of the different GC-MS modes. Full scan mass spectra of THC, THCCOOH and their derivatives were compared. They were found to produce parallel series of ion fragments through similar fragmentation mechanisms. Analyses by SIR-MS were performed to confirm the identity of the analytes in blood extracts. Calibration curves for THC and THCCOOH were linear from 0-100ng/ml. When the same eight test samples were analysed, three of them were found to be positive for THCCOOH, but only two of the samples gave positive results for THC. In the MRM mode, the transitions to the most prominent daughter fragments [M-15]+ formed by the parent analytes, THC and THCCOOH, were monitored. Linear calibration curves were obtained within the range 0-100ng/ml. In conclusion, the optimum method established in this study was acetonitrile extraction of blood samples followed by GC-MS in El(+) selected ion recording mode used as the end-step analysis. Sample clean-up is not essential but would help in prolonging the column life
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