A new synthesis of 2-pyrazolin-5-ones from the condensation of C(α),N-dilithiophenylhydrazones with diethyl carbonate

C(α),N-Dilithiophenylhydrazones were prepared from phenylhydrazones in an excess of lithium diisopropylamide and condensed with diethyl carbonate followed by an acid cyclization to give 2-pyrazolin-5-ones.     

Ru complexes bearing bidentate carbenes: from innocent curiosity to uniquely effective catalysts for olefin metathesis

The discovery and development of a new class of Ru-based catalysts for olefin metathesis is described. These catalysts, particularly those that do not bear a phosphine ligand, have been demonstrated to promote unique levels of reactivity in a variety of olefin metathesis reactions. The design and development of supported and chiral optically pure variants of this class of Ru catalysts for use in enantioselective metathesis are discussed as well. All catalysts are air stable, reusable, and can be employed with unpurified solvents.     

Enzyme production, growth, and adaptation of T. reesei strains QM9414, L-27, RL-P37, and rut C-30 to conditioned yellow poplar sawdust hydrolysate

National Renewable Energy Laboratory (NREL) has developed a conditioning process that decreases acetic acid levels in pretreated yellow poplar hydrolysate. Trichoderma reesei is sensitive to acetic acid and this conditioning method has enabled applied cellulase production with hardwoods. T. reesei strains QM9414, L-27, RL-P37, and Rut C-30 were screened for growth on conditioned hydrolysate liquor. Tolerance to hydrolysate was found to be strain-dependent. Strain QM9414 was adapted to grow in 80% (v/v) conditioned hydrolysate (40 g/L of soluble sugars and 1.6 g/L acetic acid from pretreated poplar). However, enzyme production was highest at 20% (v/v) hydrolysateusing strain L-27. Cellulasetiters of 2–3 International Filter Paper Units (IFPU)/mL were achieved using pretreated yellow poplar liquors and solids as the sole carbon sources.     

Finding the optimal solution to the Huff based competitive location model

In this paper we solve the gravity (Huff) model for the competitive facility location problem. We show that the generalized Weiszfeld procedure converges to a local maximum or a saddle point. We also devise a global optimization procedure that finds the optimal solution within a given accuracy. This procedure is very efficient and finds the optimal solution for 10,000 demand points in less than six minutes of computer time. We also experimented with the generalized Weiszfeld algorithm on the same set of randomly generated problems. We repeated the algorithm from 1,000 different starting solutions and the optimum was obtained at least 17 times for all problems.     

Nuclearg-factors of the 328 keV state in194Pt,the 240 keV state in195Pt,and the 356 keV state in196Pt determined by recoil-implantation into iron and cobalt hosts

The iron-implantation-perturbed-angular-correlation technique (IMPACT) has been used to measure the Larmor precessions of the 328, 240, and 356 keV states of¹⁹⁴Pt,¹⁹⁵Pt, and¹⁹⁶Pt nuclei, respectively, in ferromagnetic iron and cobalt hosts. The observed angular precessions in iron, corrected for the transient field effect, wereω τ ₁₉₄(328)=0.103±0.006 rad,ω τ ₁₉₅ (240)=0.142±0.012, andω τ ₁₉₆(356)=0.084±0.010. For cobalt hosts, the observed Larmor precessions were ω τ₁₉₄(328)=0.068±0.006, ω τ₁₉₅(240)=0.096±0.012, andω τ ₁₉₆(356)=0.057±0.013. Agreement between theg-factors obtained from the measurements in iron hosts and the measurements in cobalt hosts is very good, and a weighted average of the two measurements givesg ₁₉₄(328)=0.349±0.031,g ₁₉₅ (240)=0.136±0.013, andg ₁₉₆(356)=0.329±0.039.     

The connexion of duality and causal properties for generalized free fields

It is shown that the time-slice axiom and the diamond property are equivalent for the generalized free field. If, in addition, there is a mass gap, duality is equivalent to either causality requirement. It is further shown that the local rings associated with certain space-time regions are factors in the case of causal generalized free fields with mass gap. Necessary and sufficient conditions for causality and duality and some examples for causal and acausal generalized free fields are also given.     

Improvements in titer,productivity, and yield using solka-floc for cellulase production

Researchers studying cellulase enzymes for the economical production of fuel ethanol envision cellulose as the carbon source. However, submerged Trichoderma reesei cultures grown on cellulose exhibit high run-to-run variability. Thus, an investigation of 30 batch cellulase production experiments was instrumental in determining fermentation conditions that improved enzyme titers, yields, and productivities. Eighteen of the 30 batch experiments experienced minimal process upsets and were classified into eight groups based on agitation rate, gas sparge rate, and the use of oxygen supplementation. Comparing corn steep liquor with yeast extract/peptone also tested the effect of different sources of nitrogen in the media. Average 7-d enzyme titers were doubled from 4 to 8 FPU/mL primarily by increasing aeration.