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Nacu S.,National Administration Romanian Waters
Revista de Chimie | Year: 2011

Polytetrafluorethylene PTFE is used in flare pyrotechnical compositions, together with a metallic fuel, usually magnesium or aluminum plus a binder. This paper presents new research on the flare pyrotechnical compositions for thermal decoys, obtained from polytetrafluorethylene (PTFE), carburants like aluminum or magnesium, phenol-formaldehyde resine and graphite. DTA differential thermal analysis is used to determine the thermal behaviour of energetic material and the auto-inflammation temperature. For performance characteristic of pyrotechnic compositions, the combustion velocity has been determined. Source


Nacu S.,National Administration Romanian Waters
Revista de Chimie | Year: 2011

Polyvinyl chloride (PVC) is used in colored pyrotechnic compositions by substituting hexachloroethane and hexachlorobenzene. Research carried out for obtaining the red signaling pyrotechnic compositions (using strontium nitrate, magnesium, PVC and phenol-formaldehyde resin) respectively, green signalling (using barium nitrate, magnesium, PVC and phenol-formaldehyde resin) are treated in this article. The author determined the temperature sensitivity or thermal behaviour of pyrotechnic compositions using Differential Thermal Analysis (DTA) and also the linear velocity of combustion. Source


Hamchevici C.,National Administration Romanian Waters | Udrea I.,University of Bucharest
Handbook of Environmental Chemistry | Year: 2015

The assessment of pollution by nutrients in the Danube River has a long-term history at the basin-wide level, especially for estimating the influx of these substances to the Black Sea. The main aim of this chapter is to provide a general overview of the nutrient levels in the Danube Basin based on the data collected in the frame of long-term Trans-National Monitoring Network (TNMN) of the International Commission for the Protection of the Danube River (ICPDR) during 2001-2009. For selected monitoring sections, the dependence of the nutrient concentrations on corresponding daily discharges is also investigated. A comparative view of the surveillance TNMN data and investigative data obtained during the two monitoring programs known as Joint Danube Surveys 1 and 2 (JDS1 and JDS2) is presented. In order to get a general overview of the nutrient levels over the studied period, the temporal trends were analyzed using nonparametric Spearman correlation coefficient before and after removing the impact of the daily discharge on the measured concentration. © 2015 Springer-Verlag Berlin Heidelberg. Source


Vasilache V.,Stefan Cel Mare University of Suceava | Filote C.,Stefan Cel Mare University of Suceava | Cretu M.A.,Al. I. Cuza University | Sandu I.,Al. I. Cuza University | And 3 more authors.
Environmental Engineering and Management Journal | Year: 2012

This paper emphasizes a groundwater quality assessment using thirty-seven hydro-geological drillings, located in vulnerable and non-vulnerable areas in Botosani County as regarding nitrate and nitrites based pollutants and also phosphates and ammonium, during 2001-2008. The groundwater quality from vulnerable areas is within allowed limits. It was observed a decrease of nitrates and nitrites concentration in four locations designated as vulnerable zones regarding nitrates. In non-vulnerable areas, the groundwater quality deteriorated between 2006-2008, in terms of ammonium, nitrites and nitrates content. In some hydrogeological drillings, like Sadoveni and Stefanesti, the nitrites concentration (1.54 mg/L, 1.37 mg/L respectively) exceeded the legal accepted limit. The ammonium concentration in non-vulnerable areas also exceeded the limit of 0.5 mg/L. By token of the results of this monitoring activity the risk of groundwater pollution with nitrates was reassessed. MMDD Order 1552/743/2008 approved a new list of localities where sources of nitrates exist from agricultural activities; in Botosani County seventy-seven new localities were designated as vulnerable areas regarding nitrates pollutants. Source


Mihoc M.,Banat University of Agricultural Sciences and Veterinary Medicine, Timisoara | Pop G.,Banat University of Agricultural Sciences and Veterinary Medicine, Timisoara | Alexa E.,Banat University of Agricultural Sciences and Veterinary Medicine, Timisoara | Dem D.,National Administration Romanian Waters | Militaru A.,Victor Babes University of Medicine and Pharmacy Timisoara
Revista de Chimie | Year: 2013

This study's aim is to be a continuation of the research conducted by Mihoc et al, 2012 to deternine the heavy metal content for the hemp seeds of Five romanian varieties by following the distribution of Fe, Mn, In, Cu and Ni in the two fractions: hulled hemp seeds and shell as opposed to whole hemp seeds. Microelements content in hemp seeds are: Fe (130-164 mg/kg), Mn (89-108 mg/kg), In (42-57 mg/kg), Cu (10-12 mg/kg), Ni (1.6-6.1 mg/kg), Cr (598-877μ/kg) and Mo (265-652μg/kg). The Pb analysis shows a high dispersion of the results with many values under the quantification limit. Therefore the Pb concentration in hemp seeeds belongs to the range of 217-626 fig/kg excepting the Armanca variety. Iron is concentrated in shell, zinc and nickel in hemp heart, while manganese and copper are equally balanced in both the core and the shell. Source

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