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721.
Abhijeet P. Borole K. Thomas Klasson Whitney Ridenour Justin Holland Khursheed Karim Muthanna H. Al-Dahhan 《Applied biochemistry and biotechnology》1996,131(1-3):887-896
Manure waste from dairy farms has been used for methane production for decades, however, problems such as digester failure
are routine. The problem has been investigated in small scale (1–2 L) digesters in the laboratory; however, very little scale-up
to intermediate scales are available. We report production of methane in a 100-L digester and the results of an investigation
into the effect of partial mixing induced by gas upflow/recirculation in the digester. The digester was operated for a period
of about 70 d (with 16-d hydraulic retention time) with and without the mixing induced by gas recirculation through an internal
draft tube. The results show a clear effect of mixing on digester operation. Without any mixing, the digester performance
deteriorated within 30–50 d, whereas with mixing continuous production of methane was observed. This study demonstrates the
importance of mixing and its critical role in design of large scale anaerobic digesters. 相似文献
722.
Juliano Chaker Karim Dahmouche Valérie Briois Celso V. Santilli Sandra H. Pulcinelli Patrick Judeinstein 《Journal of Sol-Gel Science and Technology》2003,26(1-3):1075-1080
The structure and the ionic conduction properties of siloxane-poly(oxypropylene) (PPO) hybrids doped with different potassium salts (KCF3SO3, KI, KClO4 and KNO2) are reported for two polymer molecular weights (300 and 4000 g/mol), labelled PPO300 and PPO4000, respectively. The doping concentration, related to the concentration of the ether type oxygen of the PPO chain, is the same whatever the salt and verifies [O]/[K] = 20. Ionic room temperature conductivity shows the highest value for the KCF3SO3 doped PPO4000 hybrid (4 × 10–7 –1 cm–1). The structure of these hybrids was investigated by X-ray powder diffraction (XRPD) and X-ray absorption spectroscopy (EXAFS and XANES) at the potassium K-edge (3607 eV). XRPD results show that the hybrid matrix is always amorphous and the formation of secondary potassium phases is observed for all the samples, except for the KCF3SO3 doped PPO4000 hybrid. EXAFS results evidence a good correlation between the ionic conductivity and the presence of oxygen atoms as first neighbours around potassium. 相似文献
723.
M. A. Wittenauer J. A. Nyenhuis A. I. Schindler H. Sato F. J. Friedlaender J. Truedson R. Karim C. E. Patton 《Journal of Crystal Growth》1993,130(3-4):533-542
High purity single crystals of barium ferrite have been grown with the use of a BaO flux. The detected residual impurities have a total concentration of 130 ppm (wt), of which 100ppm is due to platinum. While the crystals exhibit occassional inclusions of a barium rich phase, the predominant microstructural defects are voids, which exhibit two geometries; one spherical and one hexagonal. Magnetic and resistivity measurements have yielded values which are comparable to those reported in the literature. Room temperature effective linewidth measurements at 10 GHz indicate that eddy current losses are dominant for disk shaped samples thicker than ≈0.3 mm. Room temperature FMR linewidth measurementson a sample 0.04 mm thick exhibit a linear frequency response between 55 and 90 GHz, which is consistent with a Landau-Lifshitz damping mechanism. 相似文献
724.
725.
726.
An efficient technique for the design of multiple-valued logic circuits using polarization-encoded optical shadow-casting is presented. As an illustration, a trinary full subtracter is designed using this technique. The resulting logic unit is compared with those obtained by using other algorithms. 相似文献
727.
G.W. van Apeldoorn D. Harting D.J. Holthuizen B.J. Pijlgroms M.M.H.M. Rijssenbeek D. Visser J.M. Warmerdam-de Leeuw V. Karimäki R. Kinnunen M. Korkea-Aho J. Tuominiemi W.H. Evans P. Johnson P. Mason H. Muirhead G.D. Patel G. Blomquist G. Ekspong N. Yamdagni 《Physics letters. [Part B]》1978,72(4):487-488
In a study of 12 GeV/cp interactions in the CERN 2 m HBC, we have searched for a narrow K3π state. Contrary to an investigation of 12 GeV/cp interactions in the CERN BEBC, we find no support for such a state. 相似文献
728.
Karim Zahidi 《Proceedings of the American Mathematical Society》2000,128(3):877-884
We prove that the recursively enumerable relations over a polynomial ring , where is the ring of integers in a totally real number field, are exactly the Diophantine relations over .
729.
730.
We prove the undecidability of the positive existential theories of: (a) the field C(t), in the language of rings augmented by a constant t and a symbol for the set of derivatives D, D = {x':x ? C(t)};(b)any polynomial ring over an integral domain of constants, in the lansruage of rings augmented by a symbol for the nonconstant polynomials. 相似文献