64 research outputs found
Product Selection and Supply Chain Optimization for Fast Pyrolysis and Biorefinery System
This study determines the optimal
plant sizes, locations, and product
distributions for an integrated fast pyrolysis biorefinery supply
chain using a mixed-integer nonlinear programming (MINLP) model. Hydrogen,
liquid fuels, commodity chemicals, and lignin are considered as the
potential biorefinery products. The proposed approach is illustrated
through a case study of Minnesota, where forest residue is selected
as the biomass feedstock. The decisions about biomass supply (roadside
chipped forest residue and raw forest residue), facility selection,
and product distribution are explored in this case study. The total
converted bio-oil is 1.1 million metric tons per year and the total
cost is $330 million for the base case. Impacts of marketing prices
on product selections are investigated. Compared to upgrading of phase
separated bio-oil, whole bio-oil upgrading is preferable in terms
of economics. Hydrogen and liquid fuel prices have greater influence
on the annualized profit than the commodity chemical price
Dimensional index structure of colleges and universities.
Dimensional index structure of colleges and universities.</p
Structure of regional dimension indicators.
Structure of regional dimension indicators.</p
Expression and purification of L-asparaginase from <i>Escherichia coli</i> and the inhibitory effects of cyclic dipeptides
<p>L-asparaginase, a key enzyme involved in nitrogen metabolism, is an effective anti-tumour agent. Cyclic dipeptides, a group of compounds, contain several important biological functions. In this paper, we proposed a novel method for L-asparaginase expression and purification from <i>Echerichia coli</i> and determined the effect of cyclic dipeptides on the enzymatic activity of recombinant L-asparaginase. The gene <i>ansB</i> encoding L-asparaginase was amplified from the genome of <i>E. coli</i> BL21 (DE3) by polymerase chain reaction and sub-cloned into pET-15b vector to construct expressing plasmid pET-15b-ansB. The expression of recombinant protein was purified by affinity chromatography using a nickel resin followed by anion exchange chromatography. The purity and quality of the recombinant L-asparaginase were optimised. The results indicated that km for the recombinant L-asparaginase was 3.02 × 10<sup>−4</sup> mol/L. Both cyclo-(Pro-Tyr) and cyclo-(Pro-Phe) could inhibit the activity of recombinant L-asparaginase at the level of 10<sup>−5</sup> mol/L.</p
Factor analysis item screening results.
Factor analysis item screening results.</p
Judgment matrix of four dimensions affecting the employment of college Students in Xiangtan City.
Judgment matrix of four dimensions affecting the employment of college Students in Xiangtan City.</p
KMO value and Bartlett sphericity test value of college students’ employment and entrepreneurial intention.
KMO value and Bartlett sphericity test value of college students’ employment and entrepreneurial intention.</p
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