Isolation and partial purification of carthamine: an instrumentation manual

Summary Crude carthamine was obtainable through alkaline extraction, acidification, and cellulose adsorption. It was purified by column chromatography on Avicel cellulose and Toyo Pearl HW-40f. Using these techniques, the dye was purified up to about 3.5-fold at a final yield of 28.4% (mg carthamine·g dry flower^–1: 5.221.48). On the basis of the experimental model data, an instruction manual for isolation and purification of carthamine is presented in order to standarize the bio-dye preparation at an economically pertinent cost.

---

Isolierung und teilweise Reinigung des Carthamin durch manuellen Betrieb

Zusammenfassung Rohes Carthamin kann durch alkalische Extraktion, Säuerung und Adsorption an Cellulose gewonnen werden. Der Farbstoff wird durch Säulenchromatographie auf Avicel-Cellulose und Toyo Pearl HW-40f gereinigt. Mit dieser Technik wird der Farbstoff 3,5fach konzentriert (auf rund 28,4%). Auf der Basis dieser experimentellen Daten ist die Isolierung und Reinigung des Carthamin zu standardisieren, und die Farbstoffgewinnung zu einem wirtschaftlichen Preis möglich.

     

Sintering conditions of cordierite for microwave/millimeterwave dielectrics

With the advent of ubiquitous age, the high-quality, dielectric materials have been required for the applications of wireless communications available to millimeterwave as well as microwave frequencies such as ultra-high speed local area network (LAN), electronic toll collection (ETS), and car anticollision systems on the intelligent transport system (ITS), and so on. Cordierite (Mg(2)Al(4)Si(5)O(18)), which is one of the silicates, is a good candidate for microwave/ millimeterwave dielectrics due to low dielectric constant epsilon(r) and low loss. This study is focused on optimization of the sintering condition of cordierite. A single phase of cordierite could be obtained from the powders calcined from 1355 degrees C to 1375 degrees C for 3 hours, and the samples sintered from 1375 degrees C to 1440 degrees C for 2 hours. The highest relative density of 98.7% was obtained for the samples sintered at 1440 degrees C for 2 hours. The dielectric constant and the quality factor of cordierite depend on the sintering temperatures. The density also was improved to 2.51 g/cm(3) by a slower heating and cooling rate of 3 degrees C/minute. The microwave dielectric properties are as follows: epsilon(r) = 6.14, Q . f = 59682 GHz, and tau(f) = -26.1 ppm/ degrees C.     

Mechanistic Aspects of Catalytic Steam Reforming of Biomass-related Oxygenates

Catalytic steam reforming of acetic acid, as a model oxygenate derived from biomass, was studied over supported Pt catalysts. It is suggested that both Pt and the support are involved in the activation of acetic acid and water, respectively. This manifests in different intrinsic activity for Pt when anchored on different supports. Accordingly, the reforming proceeds most likely at the boundary between the Pt and the support and the number of Pt sites that are in the close proximity of the support determine hydrogen formation rates.     

Megahertz operation of voltage-fed inverter for HID lamps usingdistributed constant line

A novel type of solid-state ballast, which operates in the megahertz-range frequency, is presented in this paper. A circuit composed of a voltage-fed half-bridge inverter, a distributed constant line, and a parallel LC resonant circuit has been developed for this purpose. The high-intensity discharge (HID) lamp is connected to the output terminal of the inverter through the distributed constant line. Here, since the length of the line is adjusted to 1/4 of the propagation wavelength λ, the output voltage of the voltage-fed inverter can be converted to a current source on the load side. Based on the experiment results, the ballast appears to be able to supply not only high voltage, but also constant current for ignition of the HID lamp. The experimental results from a prototype system are used to verify the theoretical procedure     

Mechanism of puffing and the role of puffing inhibitors in the graphitization of electrodes from needle cokes

A mechanism of puffing that occurs during graphitization of needle coke in the electrode is proposed based on the experimental results in the literature. Gases may evolve from within needle coke grains via porosity, causing pore walls to expand irreversibly when they are softened during graphitization. Hence, extents of puffing are influenced by rate and temperature range of gas evolution, the nature of evolved gases, location of the evolved heteroatoms such as sulfur and nitrogen in the coke, and the structure (especially grain size), porosity (pores and cracks), and preferred orientation of the coke, because these factors are related to the pressure induced by the evolved gas, timing for the softening of the coke and gas evolution and the resistivity of the wall against the pressure. Porosity within a coke grain can be modified by the coke derived from binder and impregnation pitches that can diffuse into the porosity of filler coke in the electrode. The graphitization also leads to shrinkage of the carbon. Hence, the size of the electrode is influenced by both puffing and shrinkage, these having opposing effects. The extent of puffing can be described semi-quantitatively in terms of influential factors described above. Thus, it is understandable that the puffing increased the porosity in a certain range (0.1–1 μm) and that puffing is suppressed by the increased porosity of 1–100μm. Based on the mechanism, procedures for puffing inhibition are suggested including:

1. 1. moderate acceleration of graphitization

2. 2. capture of heteroatoms to be liberated

3. 3. controled gasification to increase porosity of the filler cokes

4. 4. removal of heteroatoms from the needle coke or its starting feedstock The roles of puffing inhibitors are discussed based on the mechanism of puffing.

Preparation of new hydrophilic and durable porous polymer particles

A preparation method for new highly durable hydrophilic porous polymer particles consisting of acrylic monomers and copolymerizable cross-linking agents was studied. In the case of using only a two-functional acrylic monomer as the cross-linking agents, the obtained particles had a relatively low mechanical strength, but by the addition of a multifunctional acrylic monomer into the above system, it was found that the porous particles obtained became highly durable and showed excellent mechanical strength of more than 500 kg/cm². The effect of preparation conditions on the specific surface area of these particles consisting of three components was investigated from the following viewpoints: The first was aimed at the stabilized phase of droplets consisting of monomer/cross-linkers/porogen under various conditions of aqueous poly(vinyl alcohol) (PVA) media, and the second was the effect of composition changes of the monomer and cross-linkers on the inner porous structure of the particles obtained. Thus, the specific surface area of the particles was found to be significantly affected both by the degree of saponification (DS) of PVA and by the change of composition. On the other hand, the average pore radius of typical particles obtained in this way can be controlled in the range from 40 to 120 Å by the weight ratio of chlorobenzene as the porogen. Furthermore, the mechanical stability and durability of the column packed with the porous particles obtained were discussed. © 1993 John Wiley & Sons, Inc.     

In situ multipurpose time-resolved spectrometer for monitoring nanoparticle generation in a high-pressure fluid

We developed a multipurpose time-resolved spectrometer for studying the dynamics of nanoparticles generated by pulsed-laser ablation (PLA) in a high-pressure fluid. The apparatus consists of a high-pressure optical cell and three spectrometers for in situ measurements. The optical cell was designed for experiments at temperatures up to 400 K and pressures up to 30 MPa with fluctuations within ±0.1% h(-1). The three spectrometers were used for the following in situ measurements at high pressures: (i) transient absorption spectrum measurements from 350 to 850 nm to investigate the dynamics of nanoparticle generation from nanoseconds to milliseconds after laser irradiation, (ii) absorption spectrum measurements from 220 to 900 nm to observe the time evolution of nanoparticles from seconds to hours after laser ablation, and (iii) dynamic light scattering measurements to track nanoparticles with sizes from 10 nm to 10 μm in the time range from seconds to hours after laser ablation. By combining these three spectrometers, we demonstrate in situ measurements of gold nanoparticles generated by PLA in supercritical fluids. This is the first report of in situ time-resolved measurements of the dynamics of nanoparticles generated in a supercritical fluid.     

Behavior of graft and host cells in underlying subchondral bone after transplantation of osteochondral autograft

Transplantation of osteochondral autograft is widely used as a therapeutic strategy for the defect of articular cartilage. In the repair process, although underlying subchondral bone becomes necrotic and then is followed by bone reconstruction, the fate of graft and host cells during remodeling of underlying subchondral bone has not been elucidated. The objectives of this study were to establish a method to follow graft and host cells after transplantation of osteochondral autograft, and to elucidate the fate of both graft and host cells during remodeling of underlying subchondral bone. For these purposes, autologous transplantation models employing transgenic rats and wild-type rats, which were genetically identical to each other except for transgenes, were used. Two transplantation models were designed so that either the graft or the host cells had transgenes. Model I: transgenic rats were the donor, and wild-type rats were the recipient; model II: conversely, wild-type rats were the donor, and transgenic rats were the recipient. The grafted bone marrow cells and osteocytes in the trabeculae survived in the graft at 3 weeks after transplantation. Invasion of the host bone marrow cells into the graft was also found. Thus, bone marrow cells in the host as well as both bone marrow cells and osteocytes in the graft could potentially participate in the remodeling of underlying subchondral bone. Furthermore, the interface between graft and host was consisted with both graft and host derived cells. Since new bone formation was found in this space, both graft and host cells could have the potential to contribute to remodeling of underlying subchondral bone. The two models of the transplantations using the transgenic rats were found to be beneficial in following graft cells as well as host cells and in understanding their function on healing after autologous transplantation.     

High-resolution electron microscopy of solution-grown crystals of poly (p-phenylene sulphide)

Crystals of poly (p-phenylene sulphide) were obtained from an-chloronaphthalene solution. The chain axis (the crystalc-axis) was usually normal to the support-film. For these crystals, high-resolution electron microscopic images were taken as the projection of the molecular chains on theab plane along the chain axis. Occasionally it was observed that crystals took different orientations on the support-film for undefined reasons. From such orientations, the high-resolution image of a crystal rotated by 28.7° around thea-axis from the usual orientation, was also obtained.