Search results for "BT"
showing 10 items of 1498 documents
THE IMPACT OF WARFARE ON THE SOIL ENVIRONMENT
2013
Abstract One of the most dramatic ways humans can affect soil properties is through the performance of military activities. Warfare-induced disturbances to soil are basically of three types – physical, chemical, and biological – and are aimed at causing direct problems to enemies or, more often, are indirect, undesired ramifications. Physical disturbances to soil include sealing due to building of defensive infrastructures, excavation of trenches or tunnels, compaction by traffic of machinery and troops, or cratering by bombs. Chemical disturbances consist of the input of pollutants such as oil, heavy metals, nitroaromatic explosives, organophosphorus nerve agents, dioxins from herbicides, …
Evaluation of the Soil Contamination of Tangier (Morocco) by the Determination of BTEX, PCBs, and PAHs
2009
Benzene, toluene, ethylbenzene, and xylenes (BTEX), twelve polycyclic aromatic hydrocarbons (PAHs) and seven polychlorinated biphenyls (PCBs), were selected as pollutants to evaluate the contamination of soils in the urban and industrial areas of Tangier (Morocco). PAHs and PCBs were determined by gas chromatography-mass spectrometry (GC-MS) after a microwave-assisted extraction (MAE) and gel permeation chromatography (GPC) clean-up. BTEX were directly determined by head-space GC-MS. Results obtained in this study show the presence of high levels of BTEX and PAHs in the soil near the urban waste deposit. However, the analysis of pollutants in the other sampling sites provided comprehensive …
The Seasonality Impact of the BTEX Pollution on the Atmosphere of Arad City, Romania
2021
Benzene, toluene, and total BTEX (benzene, toluene, ethylbenzene, and xylene) concentrations registered for one year (2016) have been determined every month for one high-density traffic area. The assessment was performed in Arad City, Romania, to evaluate these pollutants and their influence on the inhabitants’ health. The contaminants were sampled using a static sampling method and analyzed by gas chromatography coupled with mass spectrometry. Benzene was the most dominant among the BTEX compounds—the average concentrations ranged from 18.00 ± 1.32 µg m−3 in December to 2.47 ± 0.74 µg m−3 in August. The average toluene concentration over the year was 4.36 ± 2.42 µg m−3 (with a maximum of 9…
Determining exhaust fumes exposure in chainsaw operations
2016
Abstract The objective of this study was to investigate the inhalation exposure of forest operators to polycyclic aromatic hydrocarbons (PAHs) and BTEX (benzene, toluene, ethylbenzene and total xylenes) contained in the exhaust fumes released from chainsaws and to suggest possible countermeasures. The study was carried out in four silvicultural treatments (coppice clearcut, conifer thinning, conifer pruning, and sanitary cut), using three types of chainsaw fuel (normal two-stroke petrol mix and two alkylate fuels). Eighty personal air samples were collected; IOM samplers combined with Amberlite XAD-2 sorbent tubes were used for collecting PAHs and Radiello® samplers were used for BTEX. Resu…
Polygalacturonate hydrogels using Fe2+ as cross-linkers : impact of the local association mode on gelation mechanisms, control of the multiscale stru…
2018
This pHD thesis describes the design of polygalacturonate hydrogels (polyGal) cross-linked by the Fe2+ cations, and their experimental characterization from the molecular scales up to the macroscopic scales, by combining EXAFS spectroscopy, Small Angle Neutron Scattering (SANS) and rheological measurements. We designed a robust gelling protocol that allowed to obtain reproducible cylindrical gels with controlled concentration gradients from the lower side to the upper side of the gel. The ratio [Fe]/[Gal] has a constant value all along the gel, which demonstrate that the Fe2+ cations are associated with 4 galacturonate units. The comparison of EXAFS measurements and molecular dynamics simul…
Fixed oil from seeds of narrow-leaved ash (F. angustifolia subsp. angustifolia): Chemical profile, antioxidant and antiproliferative activities.
2019
Fraxinus angustifolia subsp. angustifolia is a plant with an age-old use for the production of manna. However, it is also a valuable source of fixed oil rich-seeds. In the present study we examined the chemical and biological properties of this oil in order to support a possible application in foodstuffs, nutraceuticals and cosmetics. Fatty acid composition, volatile and phenolic substances were evaluated. Oleic and linoleic acid represented 45.5% and 50.0%, respectively, of the total fatty acid composition. Among polar phenolic substances identified (secoiridoids, phenylethanoid glycosides, phenolic acids and alcohols, flavonoids, coumarins) isoverbascoside is for the first time reported i…
What is the best surgical option for the resection of transverse colon cancer?
2019
Transverse colon is an infrequent localization of colon cancer and it is burdened by a poor prognosis. The principle of oncological radicality includes primary tumor resection with adequate lymphadenectomy. To date, there is still no consensus on which type of surgical resection perform in case of transverse colon cancer (TCC). Lymphatic drainage and vascularization of this section of the colon is highly variable presenting with different anatomical variants. Moreover, mobilization of the transverse colon can be particularly challenging in comparison to other colon tracts. Despite a lack of standardized definitions, three main surgical options are proposed: segmental colectomy of the transv…
Emerging Tiger? The Paradoxes of the Philippine Economy
2017
The Republic of the Philippines is an exception in the East and Southeast Asia realm. One of the richest countries of the region at the end of World War II, its rankings have slipped, and its growth rates have been weak for several decades. We examine the main causes of the mediocre economic performance of the country since the 1950s. Many analysts have pointed out an excessive bureaucracy, high levels of corruption and the lack of industrial investment in a country dominated by landed interests. After the high debt incurred during the Marcos administration, Philippine leaders have made every effort to improve the debt situation, choosing to pay back loans, but under investing in infrastruc…
Les nouvelles pratiques de formation dans les entreprises du BTP en Bourgogne
1998
International audience
Teacher Shortages, Teacher Contracts and their Impacton Education in Africa
2007
Primary school enrolment rates are very low in francophone Africa. In order to enhance education supply, manycountries have launched large teacher recruitment programmes in recent years, whereby teachers are no longer engaged on civil servant positions, but on the basis of (fixed-term) contracts typically implying considerably lower salaries and a sharply reduced duration of professional training. While this policy has led to a boost of primary enrolment, there is a concern about a loss in the quality of education. In this paper we analyse the impact on educational quality, by estimating nonparametrically the quantile treatment effects for Niger, Togo and Mali, based on very informative dat…