Analysis of Reusability using ‘Marginal Reuse Rate’

While reuse is an effective lifecycle option in terms of reduction of environmental loads and value of reutilization, reuse has inherent difficulties. Our naive question is why component reuse of home appliances seems impossible while that of photocopiers succeeded. This paper clarifies an essential factor for successful reuse; that is, the balance between supply and demand of reusables, and proposes an index named ‘marginal reuse rate,’ which indicates upper limit of reusability. By using this index, reusability of several products is analyzed. The marginal reuse rate indicates that design of lifecycle, in addition to product design, is indispensable for successful reuse.     

Site-specific functionalization of proteins by organopalladium reactions

A new carbon-carbon bond has been regioselectively introduced into a target position (position 32 or 174) of the Ras protein by two types of organopalladium reactions (Mizoroki-Heck and Sonogashira reactions). Reaction conditions were screened by using a model peptide, and the stability of the Ras protein under the reaction conditions was examined by using the wild-type Ras protein. Finally, the iF-Ras proteins containing a 4-iodo-L-phenylalanine residue were subjected to organopalladium reactions with vinylated or propargylated biotin. Site-specific biotinylations of the Ras protein were confirmed by Western blot and LC-MS/MS.     

Si-C-O glass-like compound/exfoliated graphite composites for negative electrode of lithium ion battery

Two low molecular weight silicone compounds, a cyclic type having vinyl groups and a chain-type having Si-H bonds, a catalyst for curing, and a catalyst regulator were mixed. The mixture was impregnated into exfoliated graphite (EG) by sorption, and cured in air at 200 °C. By this process cross-linked silicone coatings were formed on graphite flakes. The composites of Si-C-O glass-like compounds and EG were synthesized by heat treatment of this precursor at 1000-1400 °C for 1 h in argon. The composites formed at 1000-1300 °C were amorphous by XRD and had practically the same chemical composition: Si 44-45, C 27-29, O 25-26, H < 0.5, all in mass%. The ²⁹Si MAS-NMR spectra indicated that the compound formed at 1000 °C was mainly composed of siloxane bonds and amorphous silica, whereas in the compound formed at 1300°C, Si-C bonds and amorphous silica were predominant. The insertion/extraction characteristics of lithium ions for the electrode prepared with composite:poly(vinylidene fluoride) = 90:10 mass% were examined in 1 mol L⁻¹ LiClO₄ solution of ethylene carbonate:diethyl carbonate = 50:50 vol%. High, 650-700 mA h g⁻¹, capacities and steady cycle performance at 50 mA g⁻¹ were achieved with the composites formed at 1250-1300 °C. Capacities of the composites formed at 1200 °C and lower were initially higher but decreased with increasing number of cycles. The composites formed at 1350 °C showed good cycle performance but the capacity was about 500 mA h g⁻¹ due to the formation of β-SiC. Except for the first cycle, the capacity-potential characteristics were similar to those of hard carbons and the coulomb efficiency was 95-100%. For all the composites the capacity was larger than that of graphite (372 mA h g⁻¹) in the range of 50-200 mA g⁻¹. Due to the large insertion capacity of the first cycle, the efficiency was low (60-70%) at first. By short-circuiting the working electrode to the lithium foil counter electrode for a certain period, the irreversible capacity of the first cycle was almost eliminated. It indicates that direct doping of lithium ions into composites is a promising way to increase the efficiency of the first cycle.     

Synthesis of diameter-controlled carbon nanotubes using centrifugally classified nanoparticle catalysts

Iron-based nanoparticles, centrifugally classified by size, with variation of subnanometer order, have been used for the growth of diameter-controlled carbon nanotubes (CNTs) for the first time via catalytic chemical vapor deposition. The centrifugal classification of nanoparticles is facilitated by fractional precipitations through the sequential addition of ethanol to a hexane solution containing the nanoparticles. Three different nanoparticle sizes were obtained, which have average diameters and standard deviations of 3.9 ± 0.8 nm, 3.3 ± 0.6 nm, and 2.8 ± 0.4 nm. By the classification process of nanoparticles, the standard deviation of the average diameter of the fractionated nanoparticles decreased by around one half of that of the as-synthesized nanoparticles. In addition, we demonstrate a technique for estimating the average diameter of each classified nanoparticle using conventional low-angle X-ray diffraction, without the need for time-consuming TEM observation and analysis. From the three classified nanoparticle sizes, with average diameters of 2.8, 3.3, and 3.9 nm, CNTs with average diameters of 3.1, 3.6, and 4.5 nm were obtained by changing growth temperatures, respectively. Therefore, centrifugally classified nanoparticles are one of the most promising ‘seeds’ for use in the diameter-selective growth of CNTs.     

Intramolecular hydrogen bonding (proton transfer) of 1-phenyl-1,3-butanedione

Through the (1)H and (13)C NMR measurements for the symmetrical beta-diketones such as 2,4-pentanedione and 1,3-diphenyl-1,3-propanedione and unsymmetrical one such as 1-phenyl-1,3-butanedione at various concentrations and temperatures, we confirmed that 1-phenyl-1,3-butanedione in CDCl(3) exists as monomers in its relatively low concentration. In addition, the 1-phenyl-1,3-butanedione in CDCl(3) exists not as a keto-form but as two kinds of cis-enol forms. The proton transfer between the two kinds of cis-enols for 1-phenyl-1,3-butanedione was discussed thermodynamically; it is concluded that the OH proton of enol of 1-phenyl-1,3-butanedione is considerably located near the oxygen atom attached to the carbon atom linking to a phenyl group.     

Convenient preparative method for lactones from 3-hydroxy propanoic acids using iodine under solvent-free conditions

Intramolecular cyclization of 3-hydroxy acids was investigated using iodine as a catalyst under solvent-free conditions. The reaction proceeded to completion in the heterogeneous system. Lactones were obtained by intramolecular cyclization of 3-hydroxy acids. Propella lactone (11-oxatricyclo[4.4.3.0(1,6)]tridecan-12-one) was conveniently synthesized from 3-hydroxy acid ((6-hydroxyspiro[4.5]dec-6-yl)acetic acid) in 88% yield with carbon skeleton rearrangement. Spiro lactones and bicyclic lactones were also obtained from the corresponding 3-hydroxy acids in yields of over 75%. The most suitable reaction conditions were a temperature of 80 degrees C, a molar ratio of 3-hydroxy acid:iodine = 1:0.1, and a time period of 6 h. In addition, terpenic lactones were efficiently synthesized from the corresponding 3-hydroxy acids, derived from (+)-camphor, (-)-fencone, and (-)-pulegone, with skeleton rearrangement. The yield of the solvent-free reaction was as high as that of the corresponding reaction in solution.     

Effect of crystallization temperature of palm oil on its crystallization. IV. The influence of tripalmitoylglycerol (PPP) on the crystallization of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 1,2-dioleoyl-3-palmitoyl-glycerol (POO)

Triacylglycerin in Palm Oil contains POP (1,3-dipalmitoyl-2-oleoyl-glycerol) at 30%, POO (1,2-dioleoyl-3-palmitoyl-glycerol) at 20% and PPP (tripalmitoylglycerol) at 5%. The crystallization temperature of PPP is high and the rates of crystal nuclear formation and growth are fast. It is thus considered that PPP may have some effect on the manner or mode of Palm Oil. Examination was thus made to clarify how PPP may affect the crystallization of POP and POO by differential scanning calorimetry (DSC) and X ray diffractometry (XRD) conducted on PPP/POP and PPP/POO mixtures. High and low temperature peaks were noted to appear on the DSC crystallization curve for either of these mixtures. The high temperature peak was considered possibly due to PPP, and the low temperature peak, to POP or POO. DSC isothermal analysis indicated the rate of crystal growth of either mixture to exceed that of pure of POP or POO. Crystal mixture structure was also seen to be complicated than either compound in pure form. The present findings thus clearly indicate that clarification should be made of the effects of high melting point triacylglycerin, such as PPP, on the crystallization of Palm Oil.     

High luminance YAG:Ce nanoparticles fabricated from urea added aqueous precursor by flame process

High luminance Y₃Al₅O₁₂:Ce³⁺ (YAG:Ce) nanoparticles were prepared from urea-added nitrate aqueous precursor by flame-assisted spray pyrolysis (FASP). The addition of urea into nitrate precursor plays an important role in YAG:Ce nanoparticle formation and in improving its optical performance. The decomposition and combustion of urea in the flame zone provides additional heat to the particles, which coupled with the evolution of large volumes of gasses, contributes to nanoparticle formation. The as-prepared nanoparticles are hexagonal YAlO₃, that are nearly spherical, rough on the surface and dense—and they can be converted to YAG:Ce after being annealed at 1200 °C for 4 h. The heat-treated particles are single crystalline, smooth in surface and dense with an average size around 50 nm. The optimum cerium-doping concentration of YAG:Ce nanoparticles is 4.0 at.%, which exhibits quantum efficiency of 45.0%. This quantum efficiency is comparable with that of YAG:Ce nanoparticles produced from other processes. The efficient emission of YAG:Ce nanoparticles also originates from a relatively good distribution of Ce ions incorporated into the host material of YAG as evidenced from the elemental mapping analysis.     

Elimination of Voids at Interface of <Emphasis Type="Italic">β</Emphasis>-SiC Films and Si Substrate by Laser CVD

Void-free β-SiC films were deposited on Si(001) substrates by laser chemical vapor deposition using hexamethyldisilane (HMDS) as the precursor. The effect of the time of introducing HMDS, i e, the substrate temperature when HMDS introduced (T_in), on the preferred orientation, surface microstructure and void was investigated. The orientation of the deposited SiC films changed from <001> to random to <111> with increasing T_in. The surface showed a layer-by-layer microstructure with voids above T_in ? 773 K, and then transformed into mosaic structure without voids at T_in= 298 K. The mechanism of the elimination of voids was discussed. At T_in =298 K, Si surface can be covered by an ultrathin SiC film, which inhibits the out-diffusion of Si atoms from substrate and prohibites the formation of the voids.     

日本表面处理技术近期动向第四部分金属钌电镀

分别介绍了金属钌的物理特性和亚硝基氯化钌镀钌、钌酸钾镀钌、硫酸钌镀白色钌和镀黑色钌的工艺规范,氨基磺酸镀白色钌和氨基磺酸镀黑色钌的工艺规范及各种应用实例。指出了氨基磺酸的加入对镀液的稳定性及涂层性能的提高所起的作用。比较了钌、铑和钯镀层的性能,并介绍了钌镀层性能的测试方法。说明了钌电镀的工业用途。