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91.
Emmanuel K. Ackom Warren E. Mabee John N. Saddler 《Applied biochemistry and biotechnology》2010,162(8):2259-2272
The amount of sawmill residue available in Canada to support the emerging cellulosic ethanol industry was examined. A material
flow analysis technique was employed to determine the amount of sawmill residue that could possibly be available to the ethanol
industry per annum. A combination of two key trends—improved efficiency of lumber recovery and increased uptake of sawmill
residues for self-generation and for wood pellet production—have contributed to a declining trend of sawmill residue availability.
Approximately 2.3 × 106 bone-dry tonnes per year of sawmill residue was estimated to be potentially available to the cellulosic ethanol industry
in Canada, yielding 350 million liters per year of cellulosic ethanol using best practices. An additional 2.7 billion liters
of cellulosic ethanol might be generated from sawmill residue that is currently used for competing wood energy purposes, including
wood pellet generation. Continued competition between bioenergy options will reduce the industrial sustainability of the forest
industry. Recommendations for policy reforms towards improved industrial sustainability practices are provided. 相似文献
92.
Curtis P. Rinsland Linda Chiou Chris Boone Peter Bernath Emmanuel Mahieu 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(18):2127-2134
The first measurement of the HCFC-142b (CH3CClF2) trend near the tropopause has been derived from volume mixing ratio (VMR) measurements at northern and southern hemisphere mid-latitudes for the 2004–2008 time period from spaceborne solar occultation observations recorded at 0.02 cm−1 resolution with the ACE (atmospheric chemistry experiment) Fourier transform spectrometer. The HCFC-142b molecule is currently the third most abundant HCFC (hydrochlorofluorocarbon) in the atmosphere and ACE measurements over this time span show a continuous rise in its volume mixing ratio. Monthly average measurements at northern and southern hemisphere mid-latitudes have similar increase rates that are consistent with surface trend measurements for a similar time span. A mean northern hemisphere profile for the time span shows a near constant VMR at 8–20 km altitude range, consistent on average for the same time span with in situ results. The nearly constant vertical VMR profile also agrees with model predictions of a long lifetime in the lower atmosphere. 相似文献
93.
Castaings M Le Clezio E Hosten B 《The Journal of the Acoustical Society of America》2002,112(6):2567-2582
The interaction of the low-order antisymmetric (a0) and symmetric (s0) Lamb waves with vertical cracks in aluminum plates is studied. Two types of slots are considered: (a) internal crack symmetrical with respect to the middle plane of the plate and (b) opening crack. The modal decomposition method is used to predict the reflection and transmission coefficients and also the through-thickness displacement fields on both sides of slots of various heights. The model assumes strip plates and cracks, thus considering two-dimensional plane strain conditions. However, mode conversion (a0 into s0 and vice versa) that occurs for single opening cracks is considered. The energy balance is always calculated from the reflection and transmission coefficients, in order to check the validity of the results. These coefficients together with the through-thickness displacement fields are also compared to those predicted using a finite element code widely used in the past for modeling Lamb mode diffraction problems. Experiments are also made for measuring the reflection and transmission coefficients for incident a0 or s0 lamb modes on opening cracks, and compared to the numerical predictions. 相似文献
94.
95.
Emmanuel Chasseigne Juan Luis Vazquez 《Archive for Rational Mechanics and Analysis》2002,164(2):133-187
This paper is devoted to constructing a general theory of nonnegative solutions for the equation called “the fast-diffusion equation” in the literature. We consider the Cauchy problem taking initial data in the set ?+ of all nonnegative Borel measures, which forces us to work with singular solutions which are not locally bounded, not even locally integrable. A satisfactory theory can be formulated in this generality in the range 1 > m > m c = max {(N? 2)/N,0}, in which the limits of classical solutions are also continuous in ? N as extended functions with values in ?+∪{∞}. We introduce a precise class of extended continuous solutions ? c and prove (i) that the initial-value problem is well posed in this class, (ii) that every solution u(x,t) in ? c has an initial trace in ?+, and (iii) that the solutions in ? c are limits of classical solutions. Our results settle the well-posedness of two other related problems. On the one hand, they solve the initial-and-boundary-value problem in ?× (0,∞) in the class of large solutions which take the value u=∞ on the lateral boundary x∈??, t>0. Well-posedness is established for this problem for m c < m > 1 when ? is any open subset of ? N and the restriction of the initial data to ? is any locally finite nonnegative measure in ?. On the other hand, by using the special solutions which have the separate-variables form, our results apply to the elliptic problem Δf=f q posed in any open set ?. For 1 > q > N/(N? 2)+ this problem is well posed in the class of large solutions which tend to infinity on the boundary in a strong sense. As is well known, initial data with such a generality are not allowed for m≧ 1. On the other hand, the present theory fails in several aspects in the subcritical range 0> m≦m c , where the limits of smooth solutions need not be extended-continuously. 相似文献
96.
We revisit the notion of renormalized charge, which is a concept of central importance in the field of highly charged colloidal or polyelectrolyte solutions. Working at the level of a linear Debye-Hückel-like theory only, we propose a versatile method to predict the saturated amount of charge renormalization, which is, however, a nonlinear effect arising at strong electrostatic coupling. The results are successfully tested against nonlinear Poisson-Boltzmann theory for polyions of various shapes (planar, cylindrical, and spherical), both in the infinite dilution limit or in confined geometry, with or without added electrolyte. Our approach, accurate for monovalent microions in solvents such as water, is finally confronted against experimental results on charged colloids and B-DNA solutions. 相似文献
97.
Insight is gained into about the processes governing cavitational activity and acoustic streaming induced by high frequency (500 kHz) ultrasound by the use of microelectrodes with short time resolution electrochemical equipment to allow monitoring of the activity of single cavitating bubbles. Current transients are interpreted as showing the flux of solution towards the electrode surface due to microstreaming. In order to explain the current amplitude, a simplified model is produced. Important parameters such as bubble size and shape on the surface as well as the boundary layer thickness for microstreaming are taken into account. This model leads to the amplitude of the oscillations of the cavitating bubble. Introducing realistic bubble sizes, this amplitude is found to be in the order of 1 micron. The conclusions arising from this work allow a further interpretation of previous observations at millimeter scale electrodes. 相似文献
98.
Jacques-Emile Dubois Georges Axiotis Emmanuel Bertounesque 《Tetrahedron letters》1985,26(36):4371-4372
The proposed cross aldolization of α-bromoketones with aldehydes in presence of Chromium (II) chloride is an excellent stereospecific reaction. One exception to the stereospecific orientation is reported. 相似文献
99.
Acousto-optic sensing (AOS) is a dual-wave sensing technique based on the ultrasound modulation of diffuse light in a turbid medium. We experimentally demonstrate the feasibility of combining AOS and conventional ultrasound imaging by use of a commercially available pulsed-ultrasound scanner coupled with a photorefractive crystal-based optical interferometry system. Optically absorbing targets embedded in highly diffusive phantoms (mus'= 10 cm(-1)) are imaged through a thickness of 27 mm with millimeter resolution. The acousto-optic images are intrinsically coregistered with the ultrasound images. 相似文献
100.
Phase-sensitive optical low-coherence reflectometry technique applied to the characterization of photonic crystal fiber properties 总被引:3,自引:0,他引:3
Palavicini C Jaouën Y Debarge G Kerrinckx E Quiquempois Y Douay M Lepers C Obaton AF Melin G 《Optics letters》2005,30(4):361-363
Localized measurements of group-velocity dispersion and birefringence of photonic crystal fibers are achieved with a phase-sensitive optical low-coherence reflectometry technique. This technique is efficient for fiber samples no longer than 1 m. Theoretical simulations are in good agreement with experimental results. As a result, the stress-induced birefringence proves to be at most 1 order of magnitude below the geometrical-shape birefringence. 相似文献