High-efficiency liquid chromatographic separation utilizing long monolithic silica capillary columns

Long monolithic silica-C18 capillary columns of 100 microm i.d. were prepared, and the efficiency was examined using reversed-phase HPLC under a pressure of up to 47 MPa. At linear velocities of 1-2 mm/s, 100,000-500,000 theoretical plates could be generated with a single column (90-440 cm in length) using an acetonitrile-water (80/20) mobile phase with a column dead time (t0) of 5-40 min. It was possible to prepare columns with a minimum plate height of 8.5 +/- 0.5 microm and permeability of (1.45 +/- 0.09) x 10(-13) m(2). The chromatographic performance of a long octadecylsilylated monolithic silica capillary column was demonstrated by the high-efficiency separations of aromatic hydrocarbons, benzene derivatives, and a protein digest. The efficiency for a peptide was maintained for an injection of up to 0.5-2 ng. When three 100 microm i.d. columns were connected to form a 1130-1240 cm column system, 1,000,000 theoretical plates were generated for aromatic hydrocarbons with retention factors of up to 2.4 with a t0 of 150 min. The fact that very high efficiencies were obtained for the retained solutes suggests the practical utility of these long monolithic silica capillary columns.     

Polymerization of propylene with TiCl3–AlEt2Cl–trilauryltrithiophosphite catalyst

AlEt₃Cl was modified with TLTTP (trilauryltrithiophosphite) in the catalyst system consisting of TiCl₃ and AlEt₂Cl. The effects of TLTTP on the polymerization of propylene were studied in comparison with those of alkyl homologues of TLTTP. The catalytic behavior of the TiCl₃–AlEt₂Cl-TLTTP catalyst system in the polymerization of propylene was also studied in comparison with that of the TiCl₃–AlEt₂Cl catalyst system. In the study of the effect of various alkylthiophosphites added, it is found that the bulkiness of the alkyl group affects the rate of propylene polymerization and the stereoregularity of the resultant polymers. The TiCl₃–AlEt₂Cl–TLTTP catalyst system gave different catalytic behavior in the propylene polymerization from that of the unmodified conventional catalyst system (TiCl₃–AlEt₂Cl). These effects of TLTTP were considered to be due to the bulkiness of the alkyl groups attached to the phosphorous atom and the higher reactivity to TiCl₃ of the modified AlEt₂Cl than of the unmodified AlEt₂Cl.     

Electrochromic devices using Fe(II)‐based metallo‐supramolecular polymer: Introduction of ionic liquid as electrolyte to enhance the thermal stability

We fabricated electrochromic (EC) devices with Fe(II)‐based metallo‐supramolecular polymer (polyFe), 1‐butyl‐1‐methyl‐pyrrolidinium bis(trifluoromethanesulfonyl)imide (BMPyr(NTf)₂) ionic liquid ( IL ), and Prussian blue (PB) as electrochromic layer, electrolyte layer, and counter layer, respectively. Thermal stability and ionic conductivity of BMPyr(NTf)₂ IL was measured by thermogravimetric analysis (TGA) and impedance analysis to be 380°C and approximately 7.8 × 10^?4 S/cm, respectively. The fabricated device showed reversible electrochromism between bluish‐violet and colorless by applying +3.0/?1.5 V alternately. The 65% of the original EC contrast remained in the device after the repeated changes for 100 cycles at 100°C.     

Flow control valve for pneumatic actuators using particle excitation by PZT vibrator

This paper reports a new flow control valve for pneumatic actuators that has a lightweight and simple structure and uses particle excitation by PZT vibrator. The flow control valve in this report consists of an orifice plate which has plural orifices, PZT vibrator which is adhered on the orifice plate and iron particles. The valve is normally closed, because air flow carries the particles on to the orifice and particles seal the air flow. Because the orifice plate excitation by the PZT vibrator works to make the particles away from the orifice plate, the air flows through the orifices. It is driven at resonance mode and can be used as a variable speed controller for pneumatic actuators. The new flow control valve avoids the stopping shock of pneumatic actuators at the stroke ends while retaining the advantages of pneumatic actuators.     

Testing Method for the Johnson–Mehl–Avrami Equation in Kinetic Analysis of Crystallization Processes

The kinetics of crystallization processes in solids are usually described by the Johnson–Mehl–Avrami equation. One of the most popular methods to test the applicability of this equation is based on a double logarithmic plot of fraction crystallized (α). However, such plot is not very sensitive to small changes in α, and its reliability is rather limited. A simple and convenient testing method based on rate data (dα/d t ) is proposed. The method can be applied to virtually any type of kinetic data obtained under isothermal or nonisothermal conditions.     

Fabrication of bioceramic scaffolds with ordered pore structure by inverse replication of assembled particles

β-Tricalcium phosphate (β-TCP) scaffolds with an ordered pore structure were fabricated by ceramic slip casting using a particle-assembled template. An ordered pore structure is expected to enable uniform and accurate improvement in the topology of the porous structure of scaffolds. Monosized spherical polyethylene particles were self-assembled into an fcc lattice by close-packing with a pyramidal indentation and heat-treated for interparticle necking. β-TCP slurry was cast with this particle array, followed by heat treatments to burn out the particles and sinter the β-TCP frame. The sintered scaffold showed not only an ordered arrangement of uniform pores but also pore interconnection pathways, which faithfully replicated the particle-assembled structure. High porosity, high pore interconnectivity, and structural controllability, as well as high accessibility, were achieved by this process.     

Nondestructive analysis of uneven paint coatings by dynamic heat conduction following flash heating

A method of assessing uneven paint coatings is described, wherein a painted surface is rapidly heated by a light flash and the subsequent surface temperature changes are monitored using thermography. This method exploits the differences in dynamic heat transport caused by variations in paint thickness, using thermographic observation to track differences in temperature related to thickness. During trials with intentionally uneven test specimens spray coated with blackbody paint or red, blue, and green acrylic lacquers, we determined that surfaces with thinner paint coatings exhibited lower temperatures. Based on our findings, this article also discusses the theoretical basis of the detection method. While this technique can detect uneven painting, it is difficult to determine a quantitative relationship between temperature variations in the coated surfaces and paint thickness, since the relationship is dependent not only on the particular substrate and paint, but also on the optical reflectance of the paint. We consider that the proposed method is currently capable of detecting uneven paint coatings with variations in thickness of approximately 20 μm, although improvements in detection resolution are possible. Although detection sensitivity is somewhat low, this technique allows rapid analysis of coatings to assess evenness through visual examination.     

Study on Changes in the Rheologic Properties of EHL Film Using Fluorescence Measurements

This article describes a fundamental study using the fluorescence measurement method to understand the rheologic properties (such as viscosity and solidification) of elasto-hydrodynamic lubrication (EHL) film. The measurement principle is based upon the excimer emission of a pyrene fluorescence agent, which depends on the viscosity. To investigate the relationship between the excimer emission and viscosity, the measurements were taken under low temperature, with the results showing that the excimer emission decreased with decreasing temperature because of increasing of viscosity. No remarkable peak was observed below the temperature at which the state changed from liquid into a viscoelastic or elastic–plastic solid. The fluorescence was clearly observed in EHL film, and its spectrum revealed that the intensity of excimer emission decreases along the flow direction, with a contact area having the same behavior as that of the elastic–plastic solid at 243 K. These results suggest that the viscosity increased at the inlet of contact because of increasing hydrodynamic pressure under the wedge action and that the state in the contact region changes to solid because of high contact pressure. This study also proposes that this measurement method can be used to understand the viscosity change and solidification in the lubrication film.     

Molecular biological analysis of microflora in a garbage treatment process under thermoacidophilic conditions

In our efforts to solve problems associated with the treatment of garbage wastes, a novel, efficient process utilizing a small bioreactor equipped with a heating and an agitating apparatus was developed. The use of this process, which reduces and stabilizes garbage wastes, can be distinguished from other similar treatment processes that utilize similar equipment by its highly stable operation. This advantage led us to consider a characteristic microflora that would play an important role in the process. Thus, we analyzed the structure of the microflora in the process using molecular biological methods. The major microorganisms inhabiting the treatment environment were usually maintained for several weeks although garbage waste was added to the system each weekday. Moreover, surprisingly, lactic acid bacteria constituted a large majority in the microflorae in spite of the thermoacidophilic conditions in the reactor. These analyses permitted a better understanding of the mechanism of the process, especially of its stability.     

Quantitative analyses of the behavior of exogenously added bacteria during an acidulocomposting process

Poly[3-hydroxybutyrate-co-3-hydroxyvalerate(3HV)] was produced in recombinant Escherichia coli LS5218 from ruthenium-catalyzed cellulose hydrolysate and propionate. The strain was found to be resistant to 5-hydroxymethylfurfural (5-HMF), which is a major inhibitory byproduct generated in the cellulose hydrolysis reaction. The 3HV fraction was successfully regulated in the range of 5.6-40 mol%.