Effects of microstructure on fracture strength and conductivity of sintered NMC333

Sintering of LiNi_0.33Mn_0.33Co_0.33O₂ cathode material was investigated for potential application in all-electric aerospace propulsion systems utilizing new architectural concepts. All-solid-state batteries, while inherently safe, may not reach the high energy density required for next generation propulsion systems. To meet this performance requirement, multifunctionality of sintered active material may achieve systems level weight savings through simultaneous load bearing and electrochemical energy storage performance. The effects of sintering conditions on structural stability, chemistry, densification, grain size, fracture strength and electrical conductivity were quantified for the active cathode material. X-ray diffraction and inductively coupled plasma results indicated the structure and stoichiometry were maintained across the range of processing conditions to facilitate intercalation. Densification was achieved by sintering at 1050°C in ambient atmosphere, but grain coarsening was observed for higher temperatures and longer hold times. Mechanical strength was improved with reduction in porosity, but excessive grain growth decreased strength, providing a maximum of 50 MPa for samples sintered at 1050°C for 10 hours. Electrical conductivity initially improved with densification, but significantly diminished as the microstructure coarsened. The optimal sintering condition of 1050°C maximized mechanical fracture strength and electrical conductivity, with shorter sintering times preferred.     

Combined field integral equation formulation for scattering by dielectrically coated conducting bodies

The combined field integral equation (CFIE) formulation for electromagnetic scattering from perfectly conducting bodies is generalized to treat conductors with layered dielectric coatings. The generalized formulation is proved to provide unique solutions at all frequencies. The method of moments is used to solve the resulting system of integral equations. Solutions in terms of two integral operators are developed for body of revolution configurations. The behavior and properties of the generalized combined field formulation are illustrated with results of calculations for coated spheres, cylinders, and cones.     

Selective detection and sequencing of phosphopeptides at the femtomole level by mass spectrometry

We describe a new procedure that enables selective detection and sequencing of Ser-, Thr-, and Tyr-phosphopeptides at the low femtomole level in protein digests. Radiolabeling with 32P is not required, nor is prior chromatographic separation of the peptide mixture. One to two microliters of the unfractionated protein digest is infused at basic pH into an electrospray mass spectrometer at a flow rate of 20-40 nl/min using an ultra-low flow sprayer. A precursor-ion scan of m/z 79 (PO-3) produces a mass spectrum containing only the molecular ions of the phosphopeptides that are present in the sample. In cases where the protein sequence is known, the peptide molecular weights obtained are often sufficient to identify the specific sequences that are phosphorylated. If the protein sequence is not known, tandem MS with collision-induced dissociation of phosphopeptide precursor-ions may be used to obtain the amino acid sequences including the site(s) of phosphorylation. We demonstrate that phosphopeptides may be selectively detected using as little as 3 fmol of a 10 fmol/microl solution and that sequence information for a phosphopeptide in the mixture may be obtained using as little as 3 femtomole of the same solution. In addition, we show that the stoichiometry of phosphorylation at specific sites may be estimated from the ratio of the ion signals for the respective forms of the peptides observed in the normal full-scan mass spectra of the digest. These procedures are illustrated here to identify and sequence phosphopeptides from alpha-casein, a milk-derived protein possessing up to nine phosphorylation-sites. Numerous MS and tandem MS experiments were carried out on a single, 250 fmol/microl loading of the phosphoprotein digest. Phosphopeptides derived from an unexpected variant of the protein were also observed.     

Natural frequencies and modes of finite open circular cylinders

The natural frequencies and natural modes of open circular cylinders of given aspect ratios are calculated by means of a Galerkin procedure involving entire domain bases. The results are validated by comparison with other calculations of natural frequencies and modes for cylinders and time response current for wires. The usefulness of a previously proposed method based on perturbation theory is examined in this context.     

Reconstruction of a spherical scatterer from its natural frequencies

The reconstruction of the index of refracton of a radially distributed spherical scatterer from its natural frequencies is discussed. The practical realization of the main part of the reconstruction procedure is investigated in detail in a specific case.     

Protein partition between the different phases comprising poly(ethylene glycol)-salt aqueous two-phase systems, hydrophobic interaction chromatography and precipitation: a generic description in terms of salting-out effects

The solution behaviour of selected proteins has been studied under conditions promoting precipitation, binding to mildly hydrophobic adsorbents or partition. Solvophobic theory may be used to describe these forms of protein partition. The tendency of a protein to partition therein is dependent upon surface properties of the protein solute mediated by the concentration and nature of added salts. As applied to partitioning in poly(ethylene glycol) (PEG)-salt systems this implies that linear (Br?nsted) relationships apply only to proteins partitioned close to the critical point. At longer tie-line lengths protein partitioning is increasingly influenced by salting-out forces. This is confirmed by the observed behaviour of the proteins. The point at which this behaviour changes has been unambiguously defined enabling the direct comparison of phase transition of proteins during partition in all systems. The results obtained show that phase transition during adsorption and partition occur at similar concentrations of salt. This is less than that required to promote precipitation. It appears, from these limited studies, that top-phase preferring proteins are partitioned at salt concentrations above those required to cause adsorption. Proteins preferring the lower phase are partitioned at salt concentrations close to or below those required for adsorption. This raises questions regarding the solvated molecular form of the partitioned proteins and the definition of the partition coefficient.     

Ultraviolet spectroscopic analysis for following the biodegradation of hydrotropes

The standard methylene blue colorimetric method for the analysis of ppm concentrations of anionic detergents is sensitive to the chain length of the hydrophobic portion of the molecule. The response to this method is not quantitative among alkylbenzene sulfonates when the alkyl chain is shorter than about eight carbon atoms, and becomes essentially zero with the sulfonates of benzene, toluene and xylene. Although these low molecular weight aromatic sulfonates have few detergency properties, their function and substantial commercial use as solubilizers in detergent formulations lend some importance to a study of their biodegradability. Ultraviolet spectroscopic analysis was successfully applied to the study of the biodegradation of these compounds both in a synthetic medium-sewageinoculated system and in the well-known river die-away procedure. Sensitivity to below 1 ppm was obtained from absorption bands between about 220 and 230 mμ. Bands were also utilized near 260–270 mμ for those compounds having significant absorption in this region. Information concerning changes in functional group substitution and aromatic degradation was obtained from monitoring these two band systems during the biodegradation period. Presented at the AOCS Meeting, Houston, April 1965.     

Evaluation of detergent degradation using activated sludge

Continuous feed activated sludge systems provide excellent facilities for evaluating detergent biodegradability only when the environmental conditions can be rigidly controlled. Degradation is rapid in such a system, and because of the microorganisms and environment used, the rate and extent should closely approximate detergent decomposition in many municipal waste disposal plants. The design and operation of such a continuous feed activated sludge unit are described, and observed detergent degradation patterns are reported.     

Economic Impacts on the United States of Siting Decisions for the International Thermonuclear Experimental Reactor

This paper presents the results of a study that examines and compares the probable short-term economic impacts of the International Thermonuclear Experimental Reactor (ITER) on the United States (U.S.) if (1) ITER were to be sited in the U.S., or (2) ITER were to be sited in one of the other countries that, along with the U.S., is currently participating in the ITER program. Life-cycle costs associated with ITER construction, operation, and decommissioning are analyzed to assess their economic impact. A number of possible U.S. host and U.S. non-host technology and cost-sharing arrangements with the other ITER Parties are examined, although cost-sharing arrangements and the process by which the Parties will select a host country and an ITER site remain open issues. Both national and local/regional economic impacts, as measured by gross domestic product, regional output, employment, net exports, and income, are considered. These impacts represent a portion of the complex, interrelated set of economic considerations that characterize U.S. host and U.S. non-host participation in ITER. A number of other potentially important economic and noneconomic considerations are discussed qualitatively.