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91.
According to the revised 1996 IPCC guidelines, several emission factors are needed to calculate national inventories of N2O emissions from agriculture. To estimate the direct N2O emissions from mineral soils, an emission factor of 0.0125 kg N2O-N per kg N applied is currently being used. From recent literature data it was clearly shown that real N2O emissions could differ substantially from this value. Based on the IPCC methodology an inventory of N2O emission from agriculture in Europe (EU-15) has been made. In 1996, the N2O emission was estimated at 672 Gg N2O-N. The N2O emission per country varied between 10 and 177 Gg N2O-N. The N2O emission per ha agricultural land in the various countries varied between 1.7 and 14.2 kg N2O-N ha−1. Highest N2O emissions per ha were found in countries with a high agricultural intensity, such as the Netherlands, Belgium-Luxembourg,
Denmark and Germany. Agricultural soils are a sink for atmospheric methane. An oxidation capacity of 2.5 and 1.5 kg CH4 ha−1 yr−1 was put forward for grasslands and arable land, respectively. Based on land use data of 1993, the CH4 sink of agricultural lands in EU-15 was estimated at 303.5 Gg CH4. In general, it could be concluded that N2O emissions from soils (327 Tg CO2 equivalents) are far more important than its sink function for CH4 (6.3 Tg CO2 equivalents).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
92.
Polymerization shrinkage of methacrylate‐based dental composites remains a major concern in restorative dentistry. Cyclic monomers that undergo ring‐opening polymerization are known to exhibit reduced polymerization shrinkage compared to methacrylates. In this article, the synthesis of four crosslinking 1,1‐disubstituted 2‐vinylcyclopropanes bearing rigid spacers is described. These monomers were synthesized by esterification of 1‐ethoxycarbonyl‐2‐vinylcyclopropane‐1‐carboxylic acid with the corresponding diols. The photopolymerization kinetics of these monomers was investigated by photo‐differential scanning calorimeter using bis(4‐methoxybenzoyl)diethylgermane as the photoinitiator. The synthesized vinylcyclopropanes (VCPs) were shown to be more reactive than the frequently used reactive diluent triethylene glycol dimethacrylate. Composites based on these VCPs showed good mechanical properties and exhibited a significantly reduced volumetric shrinkage and shrinkage stress compared to a corresponding dimethacrylate‐based restorative material. This work highlights the excellent potential of VCPs as alternatives to methacrylates in the development of low‐shrinkage dental composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45577. 相似文献
93.
José Antonio Díaz Elżbieta Skrzyńska Soraya Zaid Jean‐Sébastien Girardon Mickaël Capron Franck Dumeignil Pascal Fongarland 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2017,92(9):i-i
The cover image, by José Antonio Díaz et al., is based on the Research Article Kinetic modelling of the glycerol oxidation in the liquid phase: comparison of Pt, Au and Ag AS active phases, DOI: 10.1002/jctb.5296 . Photo Credit: CNRS Photothèque / Cyril FRESILLON.
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95.
Absorption methods for the determination of mass transfer parameters of packing internals: A literature review 下载免费PDF全文
Laszlo Hegely John Roesler Pascal Alix David Rouzineau Michel Meyer 《American Institute of Chemical Engineers》2017,63(8):3246-3275
Methods for the determination of mass‐transfer coefficients and effective interfacial areas in packed absorption columns are reviewed. For each parameter, the methods are grouped into categories on the basis of their physical principle; the chemical systems used, experimental protocol, and the advantages and inconveniences are discussed. The treatment of end effects, the influence of packed bed height, and the recent efforts in standardization of measurement methods are also treated. The aim of the review is to give a broad overview of the methods used in literature in the last eight decades, some of which might be reconsidered in the light of modern measurement techniques and to evaluate them in relation to precision, practicality and hazardousness thereby to facilitate the search for reliable, precise, and convenient experimental practices. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3246–3275, 2017 相似文献
96.
Dr. Mohamed Ettaoussi Dr. Ahmed Sabaouni Dr. Basile Pérès Elodie Landagaray Dr. Olivier Nosjean Dr. Jean A. Boutin Dr. Daniel‐Henri Caignard Dr. Philippe Delagrange Prof. Pascal Berthelot Dr. Saïd Yous 《ChemMedChem》2013,8(11):1830-1845
Agomelatine is a naphthalenic analogue of melatonin that is in clinical use for the treatment of major depressive disorders. Interestingly, while agomelatine exhibits potent affinity for melatonin receptors, it binds with only moderate affinity to the serotonin 5‐HT2C receptor. Optimization of agomelatine toward this target could further potentiate its clinical efficacy. To explore this hypothesis and to access derivatives in which a key point of agomelatine metabolism is blocked, a series of naphthalenic derivatives was designed and synthesized as novel analogues of agomelatine. Most of the prepared compounds exhibited good binding affinity at the melatonin MT1 and MT2 receptor subtypes. Two compounds, an acetamide and an acrylamide derivative, exhibited good binding affinities at both the human melatonin (MT) receptors and the serotonin 5‐HT2C receptor subtype, with pKi values of 7.96 and 7.95 against MT1, 7.86 and 8.68 against MT2, and 6.64 and 6.44 against 5‐HT2C, respectively. 相似文献
97.
Andreas Haase Pascal Hesse Lars Brommer Olaf Jacobs Clarissa Abetz Ulrich A. Handge Adriana Boschetti‐de‐Fierro Volker Abetz 《大分子材料与工程》2013,298(3):292-302
This study presents a nanocomposite manufacturing route starting from non‐functionalized nanosilica and SAN surface modification via “grafting from” ATRP up to processing of transparent polycarbonate and glycol modified poly(ethylene terephthalate) nanocomposites. Synthesis limitations of low molecular weight graft SAN derived from “classical” ATRP are overcome by employment of the emerging ARGET ATRP. Mechanical investigations of polycarbonate and glycol modified poly(ethylene terephthalate) nanocomposites present up to 80% enhancement of creep performance and additionally 70% enhancement against wear abrasion for glycol modified poly(ethylene terephthalate) nanocomposites. Strength and tensile modulus are only moderately influenced by the addition of nanoparticles. Morphological studies confirm that the present modification route is able to create uniform dispersions of single particles and small particle aggregates in polymer matrices.
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Jean‐Marie Ringeard Pascal Griesmar Emmanuel Caplain Magalie Michiel Stéphane Serfaty Jean‐Yves Le Huerou Desislava Marinkova Lyubov Yotova 《应用聚合物科学杂志》2013,130(2):835-841
To incorporate microorganisms and to preserve their integrity, new matrices of poly(N‐acryloylglycine) have been designed under appropriate conditions. To understand the interactions between the microorganisms and the organic part of the matrices, different conetworks of poly(N‐acryloylglycine) have been synthesized and characterized. Copolymerization with two crosslinkers was performed with different compositions. The thermal and swelling properties of conetworks are specifically controlled and compared. These investigations show that the swelling ratio of these materials is compatible with the incorporation of biomolecules in these matrices. They successfully permit Pseudomonasspecies 1625 bacteria incorporation. The biological activity of bacteria is also preserved, allowing the use of these materials for innovative biological applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 835‐841, 2013 相似文献
100.
Hassane Oudadesse Eric Wers Xuang Vuong Bui Claire Roiland Bruno Bureau Imane Akhiyat Amany Mostafa Hassan Chaair Hicham Benhayoune Joel Fauré Pascal Pellen-Mussi 《Korean Journal of Chemical Engineering》2013,30(9):1775-1783
Bioactive glass 46S6 and biodegradable therapeutic polymer (Chitosan: CH) have been elaborated to form 46S6-CH composite by freeze-drying process. The kinetics of chemical reactivity and bioactivity at the surface were investigated by using physicochemical techniques, particularly solid-state MAS-NMR. Immortalized cell line used to construct multicellular spheroids was employed as three-dimensional (3D) cell cultures for in vitro studies. Obtained results showed a novel structure of the composite; the chemical treatment (ultrasound, magnetic stirring, freeze drying process and lyophilization) led the bioactive glass particles to be loaded in the chitosan-based materials. 29Si and 31P MAS-NMR results showed the emergence of two new species, Q Si 3 (OH) and Q Si 4 , which are characteristic of the vitreous network dissolution in simulated body fluid (SBF). MAS-NMR also confirmed the formation of amorphous calcium phosphate (ACP) at the surface of the initial 46S6-CH. Three-dimensional (3D) cell cultures highlighted the effect of chitosan, where the cell viability reached up to 78% in 46S6-CH composite and up to 67% in 46S6. The association of (CH) and bioactive glass (BG) matrix promotes a highly significant bioactivity, demonstrating surface bone formation and satisfactory behavior in biological environment. 相似文献