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101.
Folarin B. Oyebolu Jeroen van Lidth de Jeude Cyrus Siganporia Suzanne S. Farid Richard Allmendinger Juergen Branke 《Journal of Heuristics》2017,23(4):231-256
Biopharmaceutical manufacturing requires high investments and long-term production planning. For large biopharmaceutical companies, planning typically involves multiple products and several production facilities. Production is usually done in batches with a substantial set-up cost and time for switching between products. The goal is to satisfy demand while minimising manufacturing, set-up and inventory costs. The resulting production planning problem is thus a variant of the capacitated lot-sizing and scheduling problem, and a complex combinatorial optimisation problem. Inspired by genetic algorithm approaches to job shop scheduling, this paper proposes a tailored construction heuristic that schedules demands of multiple products sequentially across several facilities to build a multi-year production plan (solution). The sequence in which the construction heuristic schedules the different demands is optimised by a genetic algorithm. We demonstrate the effectiveness of the approach on a biopharmaceutical lot sizing problem and compare it with a mathematical programming model from the literature. We show that the genetic algorithm can outperform the mathematical programming model for certain scenarios because the discretisation of time in mathematical programming artificially restricts the solution space. 相似文献
102.
103.
Summary The unsteady, compressible Navier-Stokes equations in Reynolds-averaged variables are solved for a shock wave turbulent boundary layer interaction. For the free stream Mach number 3.7 and Reynolds number 8.202×106 computation is performed using MacCormack's explicit-implicit finite difference scheme with 42×42 grid points. It is found that the peak heating amplification correlation agrees well with computational results.
Numerische Untersuchung des Auftreffens einer schiefen Stoßwelle auf eine ebene Platte
Zusammenfassung Die Navier-Stokes-Gleichungen in instationärer, kompressibler Form mit Reynolds-gemittelten Variablen werden für die gegenseitige Beeinflussing einer Stoßwelle mit einer turbulenten Grenzschicht gelöst. Die Berechnung wird anhand des MacCormack's explizit-impliziten Finite-Differenzen-Verfahrens mit 42×42 Gitterpunkten für eine Freistrahl-Machzahl von 3,7 und einer Reynoldszahl von 8,202·106 durchgeführt. Die Rechenergebnisse stimmen mit den Experimenten gut überein.相似文献
104.
A reliable Pd-catalyzed amination protocol is described for the synthesis of N-alkyltacrines and analogs. The Josiphos ligand CyPFtBu was found to provide optimum yields: 16 examples are given. Compared to the typical high-temperature nucleophilic aromatic substitution (NAS) routes, Pd-catalyzed aminations proceed at significantly lower reaction temperatures, and enable the synthesis of otherwise inaccessible products. 相似文献
105.
Anil Kumar Sharma Abhilasha Singh R. K. Mehta Sudhanshu Sharma S. P. Bansal K. S. Gupta 《国际化学动力学杂志》2011,43(7):379-392
To understand the chemistry of Cu(II)–NH3–S(IV)–O2 system, the kinetics of the oxidation of sulfur(IV) catalyzed by amminecopper(II) complexes has been studied in the ammonia‐buffered solutions. Sulfur(IV) is oxidized to sulfate. The complexes, Cu(NH3)2+, Cu(NH3)22+, and Cu(NH3)2+3 appear to be equally reactive and Cu(NH3)42+ appears to be unreactive. The kinetics obey the rate law: where α1 and γ1 are the rate constants for O2‐dependent and O2‐independent pathways, respectively, for Cu(NH3)2+, Cu(NH3)2+2, and Cu(N H3)32+ complexes, which appear to be equally reactive. The values of α1 and γ1 were found to be (1.32 ± 0.21) × 106 L2 mol?2 s?1 (1.74 ± 0.40) × 109 L3 mol?3 s?1respectively at 30°C. The reaction rate is not influenced by the presence of ethanol—a free radical scavenger, so a nonradical mechanism has been proposed. The results of this study are useful in understanding the atmospheric chemistry of aqueous phase autoxidation of dissolved sulfur dioxide in copper(II)–ammonia–sulfur(IV)–oxygen system at high pH. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 379–392, 2011 相似文献
106.
Goverdhan Mehta Raja MohanraoSreenivas Katukojvala Yannick LandaisSaikat Sen 《Tetrahedron letters》2011,52(22):2893-2897
A stereocontrolled synthesis of nine-membered aminocarbasugar analogs (amino-cyclononanoses) from a rigid bicyclo[4.3.1]deca-2,4-dien-10-one platform, harboring a latent functionalized cyclononane ring, is described. 相似文献
107.
Monodispersed PEG-coated ZnS (P-ZnS) nanoparticles (NPs) were synthesized by facile microwave process and utilized as efficient electron mediators for the fabrication of highly sensitive hydrazine chemical sensor. The detailed morphological and structural properties revealed the monodispersity and good crystallinity for synthesized P-ZnS NPs. A high-sensitivity of ∼89.3 μA cm−2 μM and low limit of detection of 1.07 μM, based on S/N ratio, were obtained for the fabrication of hydrazine chemical sensor based on P-ZnS NPs. To the best of our knowledge, this is the first report which demonstrates the utilization of P-ZnS NPs for the fabrication of efficient hydrazine chemical sensor. By this work, it could be concluded that simply synthesized ZnS NPs can be used as efficient electron mediators for the fabrication of effective hydrazine chemical sensors. 相似文献
108.
Bouxsein NF Leal C McAllister CS Ewert KK Li Y Samuel CE Safinya CR 《Journal of the American Chemical Society》2011,133(19):7585-7595
We report the formation of liquid crystalline (LC) phases of short double-stranded DNA with nonpairing (nonsticky) overhangs, confined between two-dimensional (2D) lipid bilayers of cationic liposome-DNA complexes. In a landmark study (Science2007, 318, 1276), Nakata et al. reported on the discovery of strong end-to-end stacking interactions between short DNAs (sDNAs) with blunt ends, leading to the formation of 3D nematic (N) and columnar LC phases. Employing synchrotron small-angle X-ray scattering, we have studied the interplay between shape anisotropy-induced and DNA end-to-end interaction-induced N ordering for 11, 24, and 48 bp sDNA rods with single-stranded oligo-thymine (T) overhangs modulating the end-to-end interactions. For suppressed stacking interactions with 10-T overhangs, the volume fraction of sDNA at which the 2D isotropic (I)-to-N transition occurs for 24 and 48 bp sDNA rods depended on their length-to-width (L/D) shape anisotropy, qualitatively consistent with Onsager's theory for the entropic alignment of rigid rods. As the overhang length is reduced from 10 to 5 and 2 T for 24 and 48 bp sDNA, the N-to-I transition occurs at lower volume fractions, indicating the onset of some degree of end-to-end stacking interactions. The 11 bp sDNA rods with 5- and 10-T overhangs remain in the I phase, consistent with their small shape anisotropy (L/D ≈ 1.9) below the limit for Onsager LC ordering. Unexpectedly, in contrast to the behavior of 24 and 48 bp sDNA, the end-to-end interactions between 11 bp sDNA rods with 2-T overhangs set in dramatically, and a novel 2D columnar N phase (N(C)) with finite-length columns formed. The building blocks of this phase are comprised of 1D stacks of (on average) four 11 bp DNA-2T rods with an effective L(stacked)/D ≈ 8.2. Our findings have implications for the DNA-directed assembly of nanoparticles on 2D platforms via end-to-end interactions and in designing optimally packed LC phases of short anisotropic biomolecules (such as peptides and short-interfering RNAs) on nanoparticle membranes, which are used in gene silencing and chemical delivery. 相似文献
109.
Mehta VP Sharma Ak Modha SG Sharma S Meganathan T Parmar VS Van der Eycken E 《The Journal of organic chemistry》2011,76(8):2920-2925
The N-heterocyclic carbene catalyzed chemoselective C3-aroylation of 3,5-dichloro-2(1H)-pyrazinones with various aldehydes is reported. We herein describe results of this remarkable mild and efficient procedure. 相似文献
110.