Signature of carrier-induced ferromagnetism in Ti(1-x)Co(x)O(2-delta): exchange interaction between high-spin Co2+ and the Ti 3d conduction band

X-ray photoemission spectroscopy measurements were performed on thin-film samples of rutile Ti(1-x)Co(x)O(2-delta) to reveal the electronic structure. The Co 2p core-level spectra indicate that the Co ions take the high-spin Co2+ configuration, consistent with substitution on the Ti site. The high-spin state and the shift due to the exchange splitting of the conduction band suggest strong hybridization between carriers in the Ti 3d t(2g) band and the t(2g) states of the high-spin Co+2 . These observations support the argument that room temperature ferromagnetism in Ti(1-x)Co(x)O(2-delta) is intrinsic.     

Content analysis of OR job advertisements to infer required skills

The paper presents an empirical method to infer employers' requirements ofoperational research (OR) skills by analysing the text of online job ads usingcontent analysis. The method entailed collecting more than a thousand job adsfrom online sources, creating a hierarchy of sets of OR-related words andphrases, and then analysing the job ads using content analysis software to countthe numbers of ads using the hierarchy of words and phrases. The method isparticularly well suited for the periodic analysis of job ads to understandchanges and trends, and is replicable in that, when carried out using ourproposed keywords, it would yield the same results for any set of OR jobads.     

Robust stability of a class of positive quasi-polynomials in Banach spaces

In this paper, we study the stability radii of positive quasipolynomials associated with linear functional difference equations in infinite-dimensional spaces. It is shown that the positive, real and complex stability radii coincide. Moreover, explicit formulas are derived for these stability radii and illustrated by a simple example.     

Production and Characterization of Cellulose by <Emphasis Type="Italic">Acetobacter</Emphasis> sp. V6 Using a Cost-Effective Molasses–Corn Steep Liquor Medium

In order to reduce of the manufacturing cost of bacterial cellulose (BC), BC production by Acetobacter sp. V6 was investigated in shaking culture using molasses and corn steep liquor (CSL) as the sole carbon and nitrogen sources, respectively. The highest BC production was obtained with Ca₃(PO₄)₂-treated molasses. Maximum BC yield (2.21 ± 0.04 g/l) was obtained at 5% (w/v) total sugar in molasses. In improved medium containing molasses and CSL, BC production was observed in the medium after 1 day of incubation and increased rapidly thereafter with maximum yield (3.12 ± 0.03 g/l) at 8 days. This value was approximately twofold higher than the yield in the complex medium. Physical properties of BC from the complex and molasses media were studied using Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffractometer. By FT-IR, all the BC were found to be of cellulose type І, the same as typical native cellulose. The relative crystallinity of BC produced in the complex and molasses media were 83.02 and 67.27%, respectively. These results suggest that molasses and CSL can be useful low-cost substrates for BC production by Acetobacter sp. V6 without supplementation with expensive nitrogen complexes such as yeast extract and polypeptone, leading to the reduction in the production costs.     

Comparison of the decomposition characteristics of aromatic VOCs using an electron beam hybrid system

We applied a hybrid technique to assess the decomposition characteristics of ethylbenzene and toluene that annexed the catalyst technique with existing electron beam (EB) technology. The removal efficiency of ethylbenzene in the EB–catalyst hybrid turned out to be 30% greater than that of EB-only treatment. We concluded that ethylbenzene was decomposed more easily than toluene by EB irradiation. We compared the independent effects of the EB–catalyst hybrid and catalyst-only methods, and observed that the efficiency of the EB–catalyst hybrid demonstrated approximately 6% improvement for decomposing toluene and 20% improvement for decomposing ethylbenzene. The G-values for ethylbenzene increased with initial concentration and reactor type: for example, the G-values by reactor type at 2800 ppmC were 7.5–10.9 (EB-only) and 12.9–25.7 (EB–catalyst hybrid). We also observed a significant decrease in by-products as well as in the removal efficiencies associated with the EB–catalyst hybrid technique.     

Control factors and by-products during decomposition of butane in electron beam irradiation

This research was conducted to determine the removal characteristics of butane, using an electron beam. Influential factors, such as an initial concentration, background gases (nitrogen, air, and helium), and absorbed doses (kGy) were investigated. The decomposition efficiencies of background gases showed that oxidation caused by radicals formed from gases, such as N₂ and O₂, had a greater influence on results than oxidation from primary electrons for butane removal. Removal efficiencies were 40% at 2.5 kGy and 66% at 10 kGy, when the initial concentration of butane was 60 ppmC. When the initial concentration was lower, the energy efficiency of butane removal by electron beam was higher. By-products, including CO₂, CO, acetaldehyde, and acetone, formed after electron beam irradiation. Concentrations of CO₂ and CO tended to increase when absorbed doses increased as butane was decomposed by the electron beam through an advanced oxidation.     

Characterizations of optimal solution sets of convex infinite programs

In this paper, several Lagrange multiplier characterizations of the solution set of a convex infinite programming problem are given. Characterizations of solution sets of cone-constrained convex programs are derived as well. The procedure is then adopted to a semi-convex problem with convex constraints. For this problem, we present firstly a necessary and sufficient condition for optimality and secondly a characterization of its optimal solution set, based on a Lagrange multiplier associated with a given solution and on directional derivatives of the objective function.      

An Efficient Synthesis of 2,8-Diazabicyclo[4.3.0]-nonane Derivatives via Intramolecular Cyclization Reaction

Novel 5-functionalized-2,8-diazabicyclo[4.3.0]nonane derivatives 5 were synthesized from epoxide 1 through 4 steps in 46.7～52.6% yield.