A novel synthesis of reactive polyethers with pendant chloromethyl group by polyaddition of bis(epoxide)s with aromatic dichlorides

New polyethers with pendant chloromethyl groups were successfully synthesized by a polyaddition of bisepoxides with 4,4′-dichloro-3,3′-dinitrodiphenyl sulfone (DCNS) using quaternary onium salts or crown ether complexes as catalysts. The polyaddition of DCNS with diglycidyl ether of bisphenol A (DGEBA) was enhanced efficiently by the addition of tetrabutylammonium chloride (TBAC), tetrabutylammonium bromide (TBAB), or tetrabutylphosphonium chloride (TBPC) as catalysts. It was also found that the reaction proceeded smoothly in amide-type polar solvents such as N,N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP) to give a high molecular weight polyether P-1. The polyaddition of DCNS with diglycidyl ether of ethylene glycol (DGEEG) using TBAB in DMAc also proceeded to give the polyether P-2 in good yield. The resulting polyethers contain reactive chloromethyl groups in a side chain, which was introduced during main chain formation.     

Quantitative derivatization of sialic acids for the detection of sialoglycans by MALDI MS

Recently, glycans have been recognized as valuable biomarkers for various disease states. In particular, sialoglycans, which have sialic acids at their terminal end, are likely to have relevance to diseases such as cancer and inflammation. Mass spectrometry (MS) has become an indispensable tool for biomarker discovery. However, matrix-assisted laser desorption ionization (MALDI) MS of sialoglycans normally causes loss of sialic acid. Methylesterification or amidation of carboxyl functionality in sialic acid has been reported to suppress the loss of sialic acids. We found that the modifications of alpha2,3-linked sialic acids proceed less efficiently than those at alpha2,6-linkages. Furthermore, the modifications of the alpha2,3-linked sialic acids are incomplete. This variability in the extent of derivatization presents a major problem in terms of glycan biomarker discovery using MALDI MS. In this study, we developed a novel amidation using acetohydrazide which can completely modify both types of linkages of sialoglycans. With the use of this method, we demonstrate MS profiling of N-linked glycans released from a bovine fetuin which is rich in alpha2,3-linked sialic acids.     

Reactor design for the UT-3 thermochemical hydrogen production process

The UT-3 thermochemical cycle for hydrogen production previously proposed consists of four reactions given by:

(1)$\text{CaBr}{}_2\text{+H}{}_2\text{O→CaO +2HBr}$

(2)$\text{CaO+Br}{}_2\text{→CaBr}{}_2\text{+}\text{1}\text{2}\text{O}{}_2$

(3)$\text{Fe}{}_3\text{O}{}_4\text{+8HBr→3FeBr}{}_2\text{+4H}{}_2\text{O+Br}{}_2$

(4)$\text{3FeBr}{}_2\text{+4H}{}_2\text{O→Fe}{}_3\text{O}{}_4\text{+6HBr+H}{}_2$

.At present, a series of both theoretical and experimental studies aiming at the industrialization of this process have been conducted. In this paper the measurements of the kinetic study for reaction (3) were first described. Based on experimental data and conceptual design of the whole process, then the simulation of the performance for the reactor using a honeycomb-shaped solid reactant was conducted. The result gives information on the reactor design.     

Sensorless sinusoidal wave drive for control of power factor of PM motor by detection of inverter bus current

Permanent‐magnet synchronous motors (PMSMs) with sinusoidal back EMF are widely used in domestic appliances for the reduction of acoustic noise and energy consumption. PMSMs are generally controlled with a sinusoidal waveform current. Typically, PMSMs are controlled by vector‐controlled sinusoidal drives, which require substantial computational resources. Hence, simpler sinusoidal wave drives such as V/f drives, which control the phase difference between the voltage and the current (the power factor of the PM motor), have been proposed for controlling PMSMs, This paper presents a new method that does not require current sensors but can be used to estimate the phase difference by sampling the voltage of the shunt resistor, which is used to detect the overcurrent supplied to the inverter. This method allows for detection of the current and accurate estimation and appropriate control of the phase difference. Using this method, we were able to control the phase difference and achieve high efficiency, cost reduction, and high reliability. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(4): 57–65, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21201     

Simulation of dispersion of agglomerates in gas phase – acceleration field and impact on cylindrical obstacle

The dispersion of agglomerates by acceleration field and impact onto cylindrical obstacles in gas phase was successfully simulated by the three-dimensional modified discrete element method qualitatively. In case of gas-phase acceleration fields, agglomerates are dispersed into much smaller fragments comparing to the dispersion in liquid-phase shear or elongation flows. The microscopic structure of agglomerates much affects the dispersibility of agglomerates and the agglomerates containing particle of single-point contact with other particles are extremely easy to be dispersed. The impact onto obstacles is more effective dispersion mechanism than acceleration fields, since rigid agglomerates, which cannot be dispersed by acceleration fields, can be dispersed at rather low gas velocity. Although when the gas velocity is very low, agglomerates are only deformed and stuck to the obstacle surface. Then the dispersion becomes significant and size of fragments decreases with the increase in gas velocity.     

Simulation of dispersion and collection process of agglomerated particles in collision with fibers using discrete element method

The behavior of agglomerates in collision with fibers was simulated using the three-dimensional modified discrete element method and the influences of several factors on the fraction of collected particles were examined. Furthermore the single fiber collection efficiency for agglomerated particles was also investigated. In the case where gas velocity is quite low, agglomerates are only deformed but barely dispersed and thus collected as a single deformable particle. By contrast above some critical gas velocity, constituent particles are dispersed and at the same time partly collected on fibers. The fraction of collected particles first increases then decreases as the van der Waals attractive force between particle and fiber increases. The reason for the decrease in fraction of collected particles in strong adhesion region is that the smooth deformation of agglomerates along the fiber surface is inhibited by too strong adhesion. It was also suggested that there exists an optimum size ratio between the agglomerate size and fiber radius for the collection fraction. This is also closely related to the deformation of agglomerate along the fiber surface. In case of non-agglomerated particle collision, all the particles entering within the collision region are collected by fiber. By contrast in case of agglomerate collision, the dispersion of agglomerates as well as collection occurs in the same process and all the particles colliding with the fiber are not necessarily collected. Consequently the single fiber collection efficiency considerably decreases comparing to that for non-agglomerated particle collision.     

Temperature programmed desorption/surface-reaction study of an anodic alumina supported Ag catalyst for selective catalytic reduction of nitric oxide with propene

On an anodic alumina supported silver catalyst with a low Ag loading (1.68 wt.%), NO_x (NO/He, NO/O₂/He, NO₂/He) adsorption measurements and NO_x-temperature programmed decomposition (TPD)/temperature programmed surface-reaction (TPSR) measurements in different gas streams (He, C₃H₆/He, C₃H₆/O₂/He) were conducted to investigate the formation, consumption and reactivity of surface adsorbed NO_x species.

During NO adsorption, no noticeable uptake of NO was detected. Introducing oxygen greatly improved the formation of ads-NO_x species. A greater quantity of surface nitrate species was found after NO₂ adsorption, accompanied with gaseous NO release. The result of TPSR demonstrates the surface nitrate species can be effectively and preferentially reduced by propene. When introducing oxygen into the propene gas stream of TPSR test, the significantly increased amount of reacted nitrate undoubtedly shows the importance of oxygen in activating propene. The pathway for the selective reduction of NO_x in the presence of excess oxygen is proposed to pass through the selective reduction of the adsorbed nitrate species with the activated propene.

The enhanced NO_x conversion when replacing NO with NO₂ was attributed to the stronger NO_x adsorption capacity and oxidation ability of NO₂, than those for NO. With increasing oxygen concentration, the difference between NO and NO₂ would gradually decrease, and finally disappear in a high excess of oxygen.