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1.
Bioresour Technol ; 155: 300-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24462881

RESUMO

The aim of this study was to compare gaseous and particulate matter (PM) emissions from the combustion of agricultural (switchgrass, fast-growing willow and the dried solid fraction of pig manure) and forest (wood mixture of Black Spruce and Jack Pine) biomasses in a small-scale unit (17.58kW). Concentrations of CO2, CO, CH4, NO2, NH3, N2O, SO2, HCl, and H2O were measured by Fourier transform infrared spectroscopy and converted into emission rates. Opacity was also evaluated and particulates were sampled. Results showed significantly higher emissions of SO2, NO2 and PM with the combustion of agricultural biomass compared to the forest biomass. However, further studies should be carried out so regulations can be adapted in order to permit the combustion of agricultural biomass in small-scale combustion units.


Assuntos
Agricultura , Poluição do Ar/análise , Biomassa , Florestas , Temperatura Alta , Material Particulado/análise , Poluição do Ar/legislação & jurisprudência , Animais , Esterco/análise , Modelos Químicos , Dióxido de Nitrogênio/análise , Panicum/química , Quebeque , Salix/química , Dióxido de Enxofre/análise , Suínos , Fatores de Tempo
2.
Chemistry ; 19(19): 6021-6, 2013 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-23512352

RESUMO

The effectiveness of amine-borane as reducing agent for the synthesis of iron nanoparticles has been investigated. Large (2-4 nm) Fe nanoparticles were obtained from [Fe{N(SiMe3)2}2]. Inclusion of boron in the nanoparticles is clearly evidenced by extended X-ray absorption fine structure spectroscopy and Mössbauer spectrometry. Furthermore, the reactivity of amine-borane and amino-borane complexes in the presence of pure Fe nanoparticles has been investigated. Dihydrogen evolution was observed in both cases, which suggests the potential of Fe nanoparticles to promote the release of dihydrogen from amine-borane and amino-borane moieties.


Assuntos
Boranos/química , Compostos de Boro/química , Ferro/química , Nanopartículas Metálicas/química , Nanopartículas/química , Espectroscopia de Mossbauer , Espectroscopia por Absorção de Raios X
3.
Animals (Basel) ; 2(1): 1-15, 2011 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-26486772

RESUMO

Agriculture accounts for 10 to 12% of the World's total greenhouse gas (GHG) emissions. Manure management alone is responsible for 13% of GHG emissions from the agricultural sector. During the last decade, Québec's egg production systems have shifted from deep-pit housing systems to manure belt housing systems. The objective of this study was to measure and compare carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions from three different cage layer housing systems: a deep liquid manure pit and a manure belt with natural or forced air drying. Deep liquid manure pit housing systems consist of "A" frame layer cages located over a closed pit containing the hens' droppings to which water is added to facilitate removal by pumping. Manure belt techniques imply that manure drops on a belt beneath each row of battery cages where it is either dried naturally or by forced air until it is removed. The experiment was replicated with 360 hens reared into twelve independent bench-scale rooms during eight weeks (19-27 weeks of age). The natural and forced air manure belt systems reduced CO2 (28.2 and 28.7 kg yr(-1) hen(-1), respectively), CH4 (25.3 and 27.7 g yr(-1) hen(-1), respectively) and N2O (2.60 and 2.48 g yr(-1) hen(-1), respectively) emissions by about 21, 16 and 9% in comparison with the deep-pit technique (36.0 kg CO2 yr(-1) hen(-1), 31.6 g CH4 yr(-1) hen(-1) and 2.78 g N2O yr(-1) hen(-1)). The shift to manure belt systems needs to be encouraged since this housing system significantly decreases the production of GHG.

4.
J Med Chem ; 53(19): 6923-33, 2010 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-20822096

RESUMO

A series of bimetallic titanium-ruthenium complexes of general formula [(η(5)-C(5)H(5))(µ-η(5):κ(1)-C(5)H(4)(CR(2))(n)PR'R'')TiCl(2)](η(6)-p-cymene)RuCl(2) (n = 0, 1, 2 or 4; R = H or Me; R' = H, Ph, or Cy; R'' = Ph or Cy) have been synthesized, including two novel compounds as well as two cationic derivatives of formula [(η(5)-C(5)H(5))(µ-η(5):κ(1)-C(5)H(4)(CH(2))(n)PPh(2))TiCl(2)] [(η(6)-p-cymene)RuCl](BF(4)) (n = 0 or 2). The solid state structure of two of these compounds was also established by X-ray crystallography. The complexes showed a cytotoxic effect on human ovarian cancer cells and were markedly more active than their Ti or Ru monometallic analogues titanocene dichloride and RAPTA-C, respectively. Studies of cathepsin B inhibition, an enzyme involved in cancer progression, showed that enzyme inhibition by the bimetallic complexes is influenced by the length of the alkyl chain in between the metal centers. Complementary ESI-MS studies provided evidence for binding of a Ru(II) fragment to proteins.


Assuntos
Antineoplásicos/síntese química , Complexos de Coordenação/síntese química , Rutênio , Titânio , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Catepsina B/antagonistas & inibidores , Bovinos , Linhagem Celular Tumoral , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Cristalografia por Raios X , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Ligação Proteica , Relação Estrutura-Atividade
5.
J Agromedicine ; 14(3): 291-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19657878

RESUMO

Numerous residents in agricultural areas are concerned about the impact that the swine industry may have on the ambient air quality. They assume there is a risk because there is limited information on the airborne contaminant that may originate from these facilities. The objective of the project was to assess the impact of swine production on ambient air quality related to public health in farming communities. Of the six chosen communities, three were considered not to be in a swine production area, whereas the three others were considered to be within a swine production area. Data were collected during three periods in spring and summer 2006. Ammonia and hydrogen sulfide concentrations were monitored on a continuous basis whereas odor concentrations and intensities were monitored twice a week. Odor concentrations were measured by dynamic olfactometry and odor intensities were determined by trained odor assessors. Public health was evaluated by survey questionnaires sent to a sample of residents in each of the six communities. Average NH(3) concentrations ranged from 6.9 to 12.6 ppb for nonexposed communities and from 8.9 to 18.3 ppb for exposed communities. Average H(2)S concentrations ranged from 1.1 to 1.5 ppb for nonexposed communities and from 1.1 to 1.6 ppb for exposed communities. For a community in a swine production area, ambient NH(3) and H(2)S concentrations were found to be higher than those communities not in a swine production area; however, that difference was not significant and they were within air quality standards for public health and safety. Odor concentrations showed no significant difference between the nonexposed and exposed communities and between evening and morning periods. Odor intensities were found to be significantly higher in the communities within swine production areas. More research will be required to fully understand the correlation between specific physical symptoms from residents and the presence of odors from swine production.


Assuntos
Poluentes Atmosféricos/análise , Amônia/análise , Exposição Ambiental/análise , Sulfeto de Hidrogênio/análise , Odorantes/análise , Suínos , Agricultura , Poluentes Atmosféricos/efeitos adversos , Animais , Eletroforese em Gel de Ágar , Exposição Ambiental/efeitos adversos , Humanos , Quebeque , População Rural , Inquéritos e Questionários
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