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21.
David Sauvanier W. S. Jennifer Li Nadge Ferlin Patrick Lacroix‐Desmazes Bndicte Prelot Peter Hesemann 《Israel journal of chemistry》2019,59(9):843-851
We report a very simple synthesis strategy for the formation of moderately porous ionosilica materials containing ammonium groups. We synthesized an ionosilica xerogel and an ionosilica aerogel, either via conventional or supercritical work‐up. The synthesis scheme of both precursor and ionosilica materials could easily be up‐scaled to a 100 g scale. All syntheses and work‐up procedures are sustainable as no additional agent and very low quantities of solvents were used, and no additional purifications steps were necessary. Although both materials show excellent anion exchange properties for chromate adsorption, noticeable differences were found regarding the thermodynamics of the exchange process. We attribute these differences to different surface chemistries of the materials, induced by the different work‐up procedures. Due to the easy availability of high quantities of material, ionosilicas can be implemented as functional ion exchange materials in larger scale processes, thus opening new fields of applications. 相似文献
22.
Incorporation of process integration into life cycle analysis for the production of biofuels 总被引:1,自引:1,他引:0
Pascale Chouinard-Dussault Laura Bradt José María Ponce-Ortega Mahmoud M. El-Halwagi 《Clean Technologies and Environmental Policy》2011,13(5):673-685
This article presents a new approach for incorporating process-integration tools into life cycle analysis (LCA) for biofuel
production. Process synthesis techniques using mass- and energy-integration tools are employed to generate various scenarios
for reducing mass and energy consumption in the process. The global implications of these changes and the associated trade-offs
are assessed using the LCA tool: GREET. The developed approach enables the consideration of several levels of process integration
while tracking the process economics and the reduction of the net greenhouse gas emissions. Several cases of biofuels with
different processing technologies have been considered in this study, and the results show that when the process-integration
tools are effectively utilized and combined with LCA, better insights are obtained and the net greenhouse gas emissions decrease
drastically for different biofuels. 相似文献
23.
Audrey Roy-Poirier Pascale Champagne Yves Filion 《Canadian Metallurgical Quarterly》2010,136(9):878-889
This paper reviews the evolution of bioretention systems, a promising at-source storm-water best management practice. The introduction of bioretention systems in the 1990s by Prince George’s County, Md. is examined along with the motivations behind the development of the systems. A summary of the research findings on the performance of bioretention systems is provided including proposed design modifications to improve the field performance. Also included is an overview of past and current bioretention design guidelines in North America, as well as a discussion of issues surrounding the public adoption and implementation of bioretention systems. Potential alternative uses for the systems are highlighted and a review of bioretention modeling work is provided. Finally, the paper outlines research needs and anticipated future work necessary to bring about the widespread use of bioretention systems. 相似文献
24.
In this paper, we focus first on the time needed by a node to join a Time Slotted Channel Hopping (TSCH) network, this time is called joining time. Second, we are also interested in the network building time. Since the data generated by a sensor node remain unavailable as long as this node has not yet joined the wireless sensor network, these times are of prime importance for applications having strong latency requirements on data gathering. The joining time depends on the beacon advertising policy that has been left unspecified by the standard. The contribution of this paper is triple. First, we propose an Enhanced Deterministic Beacon Advertising algorithm, called EDBA, that ensures a collision-free advertising of beacons and minimizes the average joining time. Second, we model the behavior of a joining node by a Markov chain, validated by NS3 simulations, and compute the average joining time. Third, we compare the performance of EDBA with this of MBS, considered as the best beacon advertising algorithm in the literature. 相似文献
25.
In the framework of the EU participation to JT-60SA project [1], a dedicated simulation tool named after Thermo-hydraulic EXtended Tool (TEXTO) was developed at CEA between 2006 and 2007 in order to address in a reliable way the calculation of the magnet conductor temperature increase and temperature margins in different operating conditions. The simulation process is based on three different codes, addressing each specific aspects (MCNP for the 3D nuclear heat calculation, TRAPS for magnetic field, ANSYS for 2D transverse thermal contribution of coil casing), which finally stand as input for the well established code GANDALF (with transient helium properties).Both steady-state operating and disruption transient regimes can be studied with this process and a first application is performed on the basis of the design and operating conditions available at this time on JT-60SA TF magnets, i.e. the first version of the different design stages. The complete analysis is shown together with the associated proposals for the TF conductor layout that could be derived from these studies. 相似文献
26.
Pascale Silvestre Jean Vion-Dury Mostafa Kriat Patrick Viout Louis Cara Jean Pierre Ardissone Bernard Vialettes Patrick J. Cozzone 《Magma (New York, N.Y.)》1994,2(4):523-530
The impact of induced lipolysis on the composition of plasma lipids is analyzed by proton magnetic resonance spectroscopy (MRS) in humans. The variations of the methylene and methyl resonances from lipids in lipoproteins are studied under two sets of lipolytic conditions: acute endovascular lipolysis induced by an intravenous injection of heparin and subacute lipolysis induced by short fasting. During acute lipolysis, the degradation of the very low density lipoproteins structures is well correlated to the modifications observed in the areas of CH2 and CH3 MRS signals. The comparison of regular spectra, spectra with water signal suppression, and spectra recorded with a spin-echo sequence provides information on the behavior of the different parts of the lipoproteins, that is, the neutral core, little affected by heparine-induced lipoprotein lipase (LPL) activation, and the surface layer supplying substrates to LPL. During 48 h of fasting, only limited modifications occur on the MR spectra, and lipolysis cannot be documented in details.Address for correspondence: CRMBM-CNRS, Faculté de Médecine, 27, bd Jean Moulin, 13005 Marseille, France. 相似文献
27.
The need for multi-media communication is currently rapidly increasing. This leads to a sharp increase in the number of public and private networks, and they must inter-operate in spite of their being heterogeneous. Mastering those networks is a complex but crucial task. This can only be achieved via good management. Thus, users have been impulsing a heavy thrust in the field of network management and especially its standardization. This paper focusses on the current status of network management standards in the main international bodies, highlighting the main points. It also describes some of France Telecom’s experiments concerning the implementation of the standards. 相似文献
28.
Roger Moret Pascale Launois Sylvain Ravy 《Fullerenes, Nanotubes and Carbon Nanostructures》1996,4(6):1287-1298
Single-crystal X-ray diffraction studies of the orientational ordering in solid C60 are reviewed. The temperature dependence of selected Bragg reflections was carefully examined, allowing to obtain original information on the first-order orientational ordering transition at To = 259K, the unusual behavior of both fundamental and superstructure reflections below To and the freezing in of the C60 reorientations at Tg ≈ 85K. The diffuse intensity due to orientational disorder of the C60 molecules at room temperature is found to be strongly modulated, both radially and azimuthally. showing that the molecular orientations are indeed correlated. The corresponding intensity distribution has been calculated within a mean-field theory for different microscopic models of inter molecular interactions. It should allow a better understanding of these interactions. 相似文献
29.
M Gagner A Pomp BT Heniford D Pharand A Lacroix 《Canadian Metallurgical Quarterly》1997,226(3):238-46; discussion 246-7
One hundred consecutive laparoscopic adrenal procedures for a variety of endocrine disorders were reviewed. There was no mortality, morbidity was 12%, and conversions was 3%. During follow-up, none had recurrence of hormonal excess. Laparoscopic adrenalectomy is the procedure of choice for adrenal removal except in carcinoma or masses > 15 cm. OBJECTIVE: The authors evaluate the effectiveness of laparoscopic adrenalectomy for a variety of endocrine disorders. SUMMARY BACKGROUND DATA: Since the first laparoscopic adrenalectomy was performed in 1992, this approach quickly has been adopted, and increasing numbers are being reported. However, the follow-up period has been too short to evaluate the completeness of these operations. METHODS: One hundred consecutive laparoscopic adrenal procedures from January 1992 until November 1996 were reviewed and followed for adequacy of resection. RESULTS: Eighty-eight patients underwent 97 adrenalectomies and biopsies. The mean age was 46 years (range, 17-84 years). Indications were pheochromocytomas (n = 25), aldosterone-producing adenomas (n = 21), nonfunctional adenomas (n = 20), cortisol-producing adenomas (n = 13), Cushing's disease (n = 8), and others (n = 13). Fifty-five patients had previous abdominal surgery. Mean operative time was 123 minutes (range, 80-360 minutes), and estimated blood loss was 70 mL (range, 20-1300 mL). There was no mortality, and morbidity was encountered in 12% of patients, including three patients in whom venous thrombosis developed with two sustaining pulmonary emboli. During pheochromocytoma removal, hypertension occurred in 56% of patients and hypotension in 52%. There were three conversions to open surgery. The average length of stay has decreased from 3 days (range, 2-19 days) in the first 3 years to 2.4 days (range, 1-6 days) over the past 16 months. During follow-up (range, 1-44 months), two patients had renovascular hypertension and none had recurrence of hormonal excess. CONCLUSION: Laparoscopic adrenalectomy is safe, effective, and decreases hospital stay and wound complications. Prior abdominal surgery is not a contraindication. Pheochromocytomas can be resected safely laparoscopically despite blood pressure variations. Venous thrombosis prophylaxis is mandatory. The laparoscopic approach is the procedure of choice for adrenalectomy except in the case of invasive carcinoma or masses > 15 cm. 相似文献
30.
Tahiri I Desbiens M Benech R Kheadr E Lacroix C Thibault S Ouellet D Fliss I 《International journal of food microbiology》2004,97(2):123-136
Carnobacterium divergens M35, isolated from a commercial sample of frozen smoked mussels, produces a new bacteriocin, divergicin M35, a class IIa bacteriocin. Divergicin M35 is sensitive to pronase-E, alpha-chymotrypsin and proteinase K, but not to trypsin and withstands thermal treatments up to 121 degrees C for 30 min. Divergicin M35 was extracted from the culture supernatant of C. divergens M35 using an SP-Sepharose cation-exchange column, desalted and purified on a C18 Sep-Pack column and further purified by reverse phase-high pressure liquid chromatography. This procedure allowed the recovery of 10% of the bacteriocin present in the culture supernatant with purity higher than 99%. Divergicin M35 had a molecular mass of 4518.75 Da as determined by mass spectrometry, a pI value of 8.3 and positive net charge (+3). The amino acid sequence of divergicin M35 was found to consist of 43 amino acid with four cysteine residues (Cys10, 15, 25, 43) and showed 80.5% homology with divercin V41 (80.5%) and 80.0% with bavaricin MN. Divergicin M35 showed powerful antilisterial activity, especially against Listeria monocytogenes and was also active against carnobacteria but not against strains of Lactococcus, Lactobacillus, Enterococcus, Bifidobacteria and Escherichia. Divergicin M35 production began in late exponential phase and reached a maximum activity of 65,000 AU/ml in early stationary phase. Initial broth pH, Tween 80 and acetate did not affect C. divergens M35 growth or divergicin production. This bacteriocin may be a potential tool for inhibiting L. monocytogenes in seafood products that do not usually undergo an adequate heat treatment. 相似文献