Enzymatic synthesis of Mycoplasma fermentans specific glycoglycerophospholipid from 1,2-dipalmitoylglycerol

A gene, mf3, encoding glycosyltransferase in glycoglycerophospholipid (GGPL; GGPL-I and GGPL-III) biosynthesis in Mycoplasma fermentans PG18 was identified by genomic analysis, cloned, modified codon usage, and expressed in Escherichia coli. The mf3 gene consists of an open reading frame of 1221 bp encoding 406 amino acids. The mf3 gene product, Mf3, has 27% amino acid homology with glycosyltransferase of Borrelia burgdorferi but no homology to genes of other Mycoplasma species in the GenBank database. The reaction product of Mf3 using 1,2-dipalmitoilglycerol and UDP-glucose as substrates showed a specific sodium adducted ion at m/z 753, which corresponded to glucopyranosyl dipalmitoilglycerol as determined by MALDI-TOF mass spectrometry. Furthermore, in the reaction product by Mf3 and Mf1 which was a cholinephosphotransferase and previously cloned from M. fermentans PG18, an ion at m/z 896 corresponding to GGPL-I was detected by mass spectrometry. The product ions of choline, phosphocholine, and hexose-bound phosphocholine were detected by tandem MS analysis of protonated molecules at m/z 896. From these results, mf3 was identified as a glycosyltransferase. It was suggested that glucose transfer and phosphocholine transfer to 1,2-dipalmitoylglycerol are involved in the GGPL biosynthesis pathway of M. fermentans PG18.     

Influence of Composition on the Morphology of Primary Cu6Sn5 in Sn-4Cu Alloys

Alloys from the composition range Sn-(0.7 wt.% to 7.6 wt.%)Cu consist of primary Cu₆Sn₅ surrounded by a eutectic Sn-Cu₆Sn₅ mixture. The primary Cu₆Sn₅ intermetallics commonly adopt a coarse elongated morphology, which is not optimal for the mechanical properties of the soldered joint. This paper investigates the effect of trace elemental additions on the size and morphology of the primary Cu₆Sn₅ in Sn-4 wt.%Cu alloy with and without Ni additions. Elements investigated include ppm additions of Al, Ag, Ge, and Pb. It is shown that Al has a marked effect on the solder microstructure and refines the size of the primary Cu₆Sn₅, even at very low addition levels, in both binary Sn-Cu alloys and those containing additional Ni. The effect of Al is confirmed using real-time x-radiographic synchrotron observations of solidification.     

Optimal control of a job-shop production system: Periodic versus dynamic type

Following recent work of Matsui, Yang and Miya, the authors assume that jobshop production systems consist of the sales centre - with order-selection - and the production centre - with switch-over. This paper studies on the control problem of a job-shop Production system of periodic versus dynamic type. First, a stochastic model of semi-dynamic type is proposed, and the two sub-objective functions: the mean accepted price and the mean operating cost, are given. Next, a cooperative versus non-cooperative problem of sales and production centres is discussed, and the non-monotonicity of optimal selection criteria is again found. Finally, a comparison of the alternative periodic, dynamic and semi-dynamic types is given, and the optimal structure is found.     

Anionic polymerization of <Emphasis Type="Italic">N</Emphasis>-substituted maleimide with achiral and chiral amines as an initiator

We have investigated anionic polymerization ability of N-substituted maleimides (RMI) with various amines as anionic initiator. As a result, anionic polymerizations of RMI proceed successfully in high polar solvents such as DMF and DMSO. The basicity and structure of amines influenced yields and number average molecular weights of polymers. Furthermore, using various chiral amines as an initiator, polymerizations of RMI were performed to obtain optically active polymers.     

An experimental study on the high frequency oscillatory combustion in tubular flame burners

In this study, high frequency oscillatory combustion in tubular flame burner was experimentally investigated using large scale 8- and 12-in. diameter tubular flame burners. The conditions for the high frequency oscillatory combustion were determined, and the pressure fluctuations were measured, on which spectral analyses were made. The results showed that a smooth laminar tubular flame could be established, however, high frequency combustion sound was emitted from the 8- and 12-in. burners when the air flow rates exceeded 650 and 1200 m³/h, respectively. Pressure fluctuation measurements and spectral analyses showed that high frequency pressure fluctuations occurred simultaneously during the high frequency oscillation. The flame images were also obtained with a high speed video camera. The flame surface was found to be notably corrugated and the symmetry was broken during the oscillation. By assuming that the tubular flame burner is a simple tube, the natural frequencies of the burners were determined using the fundamental theory of the acoustic resonance in a cylindrical cavity, and the experimental peak frequencies in the spectra were compared with the natural frequencies. As a result, it was found that the high frequency oscillations in both the burners were identified as the tangential/radial mode acoustic resonant oscillations. It was further found that the tangential first mode of oscillation, which had an asymmetric structure, preceded the higher modes of oscillation which indicated that the mode dominated the occurrence of the high frequency oscillation. To verify the occurrence of the tangential first mode oscillation, the pressure fluctuations were measured with two pressure sensors installed at opposed locations. The results showed that the phase of the oscillation was 180° difference, and the asymmetric structure confirmed the occurrence of the tangential first mode of oscillation.     

EFFECT OF CCA AND CHARGING BEHAVIOR ON PRINT QUALITY

ABSTRACT

Fourteen test toners and two types of toner of irregular shape and spherical shape were studied for charging behavior. There are three types of CCA of various concentrations. They were mixed by rotation roller, developing roller, and hand shaking. Charging properties of the toners were measured by E-SPART analyzer and blow off measurement unit. Evaluations of print quality in terms of solid density, background density and percentage of dot gain were carried out to obtain correlation with charging properties. The charge of the toners with CCA increased to an equilibrium state within a shorter time. The toners without CCA have the lowest density. The higher the CCA amount, the higher the print density, but the background density of the toners without CCA were higher than the toners with CCA In addition, the presence of CCA and silica affects the toner charge when the humidity is varied. This article describes the effects of CCA type/its concentration and charging behavior on the extent of q/m values which controls the print quality.     

Position Dependence of SS304 and Iron Phases in Welded Specimen by Neutron Diffraction and Bragg-Edge Transmission Method

We investigated the nondestructive examination method by neutron scattering. A welded plate of SS304 (fcc) and iron (bcc) was investigated using neutron diffraction and the Bragg-edge transmission method. We tried to clear the positions of the welded area, SS304 phase, and iron phase and to determine the lattice spacing. The determined value of d ₁₁₁ for SS304 is 2.07471(8) Å using neutron diffraction. With Bragg-edge transmission, it is possible to collect the information of a specimen as two-dimensional (2-D) images using a 2-D position sensitive detector at a pulse neutron source. The determined d ₁₁₁ of SS304 phase indicates between 2.0745(8) and 2.0752(9) Å depending on the measurement points using Bragg-edge transmission. The same tendency was also seen in iron phase. The determined d ₁₁₀ of the iron phase is 2.02802(1) Å using neutron diffraction. The determined d ₁₁₀ of iron phase indicates between 2.0266(7) and 2.0321(13) Å using Bragg-edge transmission. The determined d using diffraction exists within that of Bragg-edge transmission. In order to clarify the position dependency of the phase and lattice spacing, the combined diffraction and Bragg-edge transmission is effective.     

KINETICS OF ABSORPTION OF OXYGEN IN ALKALINE SOLUTIONS CONTAINING A QUINONE-TYPE COMPOUND

The rates of absorption of pure oxygen in alkaline aqueous solutions containing sodium salt of 1,4-naphthoquinone 2-sulfonic acid (NQS) as a catalyzer for the Takahax desulfurization process were measured at 25°C using a liquid jet column.

The kinetics of the absorption was examined based on the theory for gas absorption accompanied by an irreversible second order chemical reaction. The pH of the solution, that is, the concentration of hydroxyl ion plays an important role in a reaction of first order with respect to oxygen and to NQS. The reaction rate constant is directly proportional to pH in the range 9.8-11.5, for more alkaline solutions being found to be 4.5 × l0⁶L/mole ? s.     

Immobilization of flame-retardant onto silica nanoparticle surface and properties of epoxy resin filled with the flame-retardant-immobilized silica (2)

To prepare silica nanoparticle having flame-retardant activity, immobilization of flame-retardant onto the surface was investigated. The immobilization of phosphorous flame-retardant was achieved by two-step reactions: (1) introduction of cyclotriphosphazene (PH) groups onto silica nanoparticle by the reaction of terminal amino groups of the surface with hexachlorocyclotriphosphazene and (2) immobilization of bis(4-aminophenoxy)phenyl phosphine oxide (BAPPO) onto silica having PH groups by the reaction of PH groups on the surface with BAPPO. The immobilization of BAPPO was confirmed by FT-IR and thermal decomposition GC–MS. The composite of epoxy resin filled with BAPPO-immobilized silica (Silica–PH–BAPPO) was successfully prepared by heating in the presence of curing agents. Thermal decomposition temperature and glass transition temperature of the epoxy resin filled with Silica–PH–BAPPO was higher than that of epoxy resin filled with untreated silica, free HCTP and BAPPO. Moreover, flame-retardant property of epoxy resin filled with Silica–PH–BAPPO was estimated by limiting oxygen index (LOI). The LOI value of epoxy resin filled with Silica–PH–BAPPO was higher than that of epoxy resin filled with untreated silica, free HCTP and BAPPO. This may be due the fact that char yield of the epoxy resin filled with Silica–PH–BAPPO was higher than that filled with free flame-retardant.