Structure and physical properties of biaxially stretched polyethylene terephthalate sheet after heat-setting

The consumption of hot-fillable poly(ethylene terephthalate) bottles is extremely large and is still increasing in Japan. This type of bottle is generally manufactured by the heat-set method using hot molds after stretch-blow molding. In this study, the method is simulated using a setting application in which sheets can be stretched constraining their sizes on a hot aluminum block. The crystallinities of the sheets are found to depend on the thermal history, i.e., the duration and temperature of the heat-set cycle. Heat-setting mitigates thermal-shrinkage of the sheets which is due to the increase in crystallinity or in the tense segments in the amorphous region. The structure of the heat-set sheet varies depending on the original stretched sheet. For a sample of low draw ratio, the crystallinity does not increase because of the heat-set. For a sample of medium draw ratio, the crystallinity increases greatly and the tense segments in the amorphous region also increase because of heat-set. For a sample of high draw ratio, the crystallinity increases a little but the numbers of the crystallite and tense segments in the amorphous region do not change with the heat-set.     

Preparation and characterization of dicesium tetravalent plutonium hexanitrate

In experiments on U crystallization in a dissolver solution containing Cs, there is concern that Cs and Pu(IV) nitrate complex are deposited on the UNH crystal in the dissolver solution at the time of the U crystallization. The characteristics of generation of Cs and Pu(IV) nitrate complex with dissolver solution of MOX fuel were examined. This complex was obtained as a precipitate by mixing dissolver solution of MOX fuel and CsNO₃ solution, and was identified as dicesium tetravalent plutonium hexanitrate, Cs₂Pu(NO₃)₆ by concentration analysis and XRD. The precipitate has a tendency to be generated at high HNO₃ concentrations. Thermal analysis shows that the precipitate is stable below 245 °C, and a weight loss of 10.29 ± 0.23% is observed between 245 and 297 °C. This result indicates the decomposition of Cs₂Pu(NO₃)₆ to Cs₂PuO₂(NO₃)₄. With these properties, the UNH crystal should melt at the condition between 60 and 100 °C and be separable from the Cs complex by filtration. This suggests a new method of crystal purification allowing higher decontamination of UNH crystal in the U crystallization process.     

A study on cooperative tap control method for voltage profile maintenance in distribution networks with distributed generators

The introduction of distributed generators (DGs) that can utilize renewable energy is of prime importance to solve the energy and environmental issues. When a distribution network has a large number of DGs, voltage maintenance becomes a serious problem. To solve this problem, we had proposed the ‘voltage profile control method’ using reactive power control of DGs. However, the control is limited to continuous reactive power control so far, and tap control has not been considered. It is important that the conventional voltage control equipment such as the load ratio tap changer (LRT) or step voltage regulator (SVR) is utilized in order to enhance the control efficiency of the voltage profile control method. Therefore, in this paper, we develop a new method that can realize a cooperative work between inverters and tap control of LRT and SVR. The proposed method is tested in 8‐ and 24‐node model systems and its effectiveness is shown. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Conduction-corrected modified effective temperature as the indices of combined and separate effect of environmental factors on sensational temperature

In living spaces, people sit or lie on the floor and adopt a posture in which much of the surface of the body is in contact with the floor. When the temperature of the spatial structure or the surface temperature of an object in contact with the human body is not equivalent to the air temperature, these effects are non-negligible. Most research examining the physiological and psychological responses of the human body has involved subjects sitting in chairs. Research that takes into account body heat balance and assessments of thermal conduction into the environment is uncommon. Thus, in this study, conduction-corrected modified effective temperature (ETF), which is a new thermal environmental index incorporating heat conduction, is defined in order to make possible the evaluation of thermal environments that take into account different postures. This sensational temperature index converts the effects of the following parameters into a temperature equivalent: air velocity, thermal radiation, contact material surface temperature and humidity. This index has the features of a summation formula. Through the use of these parameters, it is possible to represent and quantify their composite influence on bodily sensation and the effects of discrete meteorological elements through an evaluation on an identical axis.     

Reliability of parameters of associated base straight line in step height samples: Uncertainty evaluation in step height measurements using nanometrological AFM

Step height is widely used as one of the important nanometrological standards for the calibration of nanometrological instruments. In the calculation of step height, a method of determining a base straight line as a reference line is very important. In nanometrology, which is a field of dimensional metrology, an associated feature (Gaussian associated feature), such as a base straight line, is normally calculated from a measured dataset of a metrological instrument on a real feature using the least squares method. The reliability of a base straight line varies depending on the position and number of measured points for the line and the uncertainty in step height calibration also varies depending on the reliability of the base straight line. In this study, we carried the out step height measurement of micropatterned thin films (10, 7, 5, and 3 nm) using an atomic force microscope (AFM) equipped with a three-axis laser interferometer (nanometrological AFM) and evaluated the uncertainty in these measurements. From the uncertainty evaluation results, the uncertainty derived from the reliability of the parameters of the base straight line was one of the major sources of uncertainty when the measured points for the base straight line were varied. An expanded uncertainty (k = 2) of less than 0.4 nm was obtained. Furthermore, the reliable range of an associated base straight line in a single step height, such as that in an atomic step sample, was calculated and in importance of the calculation of the reliable range was shown in the uncertainty evaluation and in determining the measurement strategy.     

Site-specific mutagenesis of the N-(deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine DNA adduct in mammalian cells

 Site-specifically modified oligodeoxynucleotides were used to explore the mutagenic properties of a cooked food mutagen-derived DNA adduct, N-(deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (dG-C8-PhIP). A dG-C8-PhIP-modified oligodeoxynucleotide was prepared post-synthetically by reacting an oligodeoxynucleotide containing a single dG (^5′-TCC TCC TCG CCT CTC T) with N-acetoxy-PhIP. The unmodified and dG-C8-PhIP-modified oligomers were inserted into single-strand (ss) phagemid vectors. These ss vectors were transfected into simian kidney (COS-7) cells. The progeny plasmid obtained was used to transform Escherichia coli DH10B. The transformants were analyzed by oligodeoxynucleotide hybridization and sequencing to determine the mutation frequency and spectrum. Preferential incorporation of dCMP, the correct base, was observed opposite dG-C8-PhIP. Targeted mutants showing G→T transversions were detected, along with a small number of G→A transitions and G→C transversions. Significant amounts of non-targeted mutations representing C→T transitions also were detected 5′ to the dG-C8-PhIP lesion. Thus, dG-C8-PhIP, a major DNA adduct induced by PhIP, is mutagenic in mammalian cells and may be involved in the initiation of human cancer. Received: 23 April 1998     

Effective utilization of N2-ethyl-2'-deoxyguanosine triphosphate during DNA synthesis catalyzed by mammalian replicative DNA polymerases

Acetaldehyde is produced by metabolic oxidation of ethanol after drinking alcoholic beverages. This agent reacts with nucleosides and nucleotides, resulting in the formation of N2-ethyl-guanine residues. N2-ethyl-2'-deoxyguanosine (N2-ethyl-dG) adduct has been detected in the lymphocyte DNA of alcoholic patients [Fang, J. L., and Vaca, C. E. (1997) Carcinogenesis 18, 627-632]. Thus, the nucleotide pool is also expected to be modified by acetaldehyde. N2-Ethyl-2'-deoxyguanosine triphosphate (N2-ethyl-dGTP) was chemically synthesized. The utilization of N2-ethyl-dGTP during DNA synthesis was determined by steady-state kinetic studies. N2-Ethyl-dGTP was efficiently incorporated opposite template dC in reactions catalyzed by mammalian DNA polymerase alpha and delta. When pol alpha was used, the insertion frequency of N2-ethyl-dGTP was 400 times less than that of dGTP, but 320 times higher than that of 7,8-dihydro-8-oxo-2'-deoxyguanosine triphosphate (8-oxo-dGTP), an oxidative damaged nucleotide. Using pol delta, the insertion frequency of N2-ethyl-dGTP was only 37 times less than that of dGTP. The chain extension from dC:N2-ethyl-dG pair occurred much more rapidly: the extension frequencies for pol alpha and pol delta were only 3.8 times and 6.3 times, respectively, lower than that of dC:dG pair. We also found that N2-ethyl-dG can be detected in urine samples obtained from healthy volunteers who had abstained from drinking alcohol for 1 week before urine collection. This indicates that humans are exposed constantly to acetaldehyde even without drinking alcoholic beverages. Incorporation of N2-ethyl-dG adducts into DNA may cause mutations and may be related to the development of alcohol- and acetaldehyde-induced human cancers.     

Study of Electron Beam Misalignment in a Submillimeter Wave Gyrotron

Electron beam misalignment in a submillimeter-wave gyrotron strongly affects its total efficiency as well as excitation of rotating and counterrotating modes. Some of misalignment phenomena were studied theoretically and experimentally.