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For the accurate measurement of small masses and forces, a voltage balance that uses electrostatic force between electrodes has been developed at the National Metrology Institute of Japan (NMIJ). This voltage balance enables traceable mass and force measurements based on the revised definition of the kilogram, as per electric standards. To confirm the reliability of the developed balance apparatus, the mass of a 2 mg wire weight was determined. The first complete uncertainty analyses were performed, following which the relative standard uncertainty of the mass measurement was estimated to be $5.3 \times 10^{-4}$ . The mass of the weight was measured via the submultiple method in a traceable manner with respect to the mass standard at NMIJ. The results obtained from the two different methods were observed to be in agreement within their uncertainties.

The new definition of the kilogram was implemented on May 20, 2019. The kilogram is presently defined by a fixed value of the Planck constant. On the basis of the new definition, the kilogram will be realized at the National Metrology Institute of Japan by the X-ray crystal density method using 28Si-enriched spheres. For the realization, the volume of 28Si-enriched spheres is measured by optical interferometry. The sphere surface characterization by X-ray photoelectron spectroscopy and ellipsometry is also performed. The relative standard uncertainty of the realization is estimated to be 2.4 × 10−8. Details of the realization and future dissemination of mass standards in Japan based on the 28Si-enriched spheres are described.

The new definition of the kilogram based on the Planck constant was implemented in May 2019. The National Metrology Institute of Japan (NMIJ) will realize the new kilogram by the X-ray crystal density method using a 28Si-enriched sphere. An international comparison of the realizations of the new kilogram by national metrology institutes was organized. As a participant in the comparison, the NMIJ realized the kilogram by the volume measurement and surface characterization of a 28Si-enriched sphere. Details of the measurement results and the uncertainty evaluation of the realization are described. The comparison of the realization results with previous realization results in 2016 is also provided.

The precision measurement of radiation pressure force, especially in a manner traceable to the International System of Units (SI) is of importance. For the precision measurement of radiation pressure of optical laser, a voltage balance which uses electrostatic force between electrodes has been developed at the National Metrology Institute of Japan (NMIJ). The voltage balance enables mass and force measurements traceable to the new definition of the kilogram. To confirm the reliability of the balance, the mass of a 2 mg wire weight was determined. The relative standard uncertainty of the mass measurement was estimated to be $8.4\times 10^{-4}$ . The mass of the weight was also measured by a commercially available electronic balance. The masses determined by the two different methods were in agreement within their uncertainties. Details on the measurement system and result are presented.

A 70-year-old woman has been followed up for chronic hepatitis C and hepatocellular carcinoma which had been successfully controlled by several sessions of radiofrequency ablation. A small cystic lesion in segment IV associated with adjacent intrahepatic duct dilatation was firstly noted 4 years before on MR imaging, which showed gradual increase in size and significant interval change in the MRI signal intensity of the cystic content on the follow-up examinations. The mass finally reached 4 cm in its largest dimension, associated with slightly enhancing thickened wall, suggesting its neoplastic nature. The mass was surgically resected and a final diagnosis of mucinous cystic neoplasm (MCN) of the liver was made. MCN is usually considered to have no communication with intrahepatic duct, but in this particular case, the communication with the biliary duct was suggested from its early stage of the lesion, which would be the cause of peculiar chronological change in MR appearance.

For the accurate measurement of small masses and forces in a traceable manner to the new definition of the kilogram, a voltage balance apparatus that uses electrostatic force between coaxial electrodes has been developed at the National Metrology Institute of Japan (NMIJ). In the voltage balance measurements, the coaxial electrodes of the apparatus are mechanically aligned by measuring the capacitance to achieve accurate small mass measurements. In this work, we investigated the effect of surface roughness on mechanical alignment of coaxial electrodes for voltage balance measurements using the finite element method (FEM). The results indicate that misalignments caused by surface roughness alter the capacitance gradient but do not significantly increase unwanted lateral forces in the mass measurement compared to that in the ideal condition.

To determine the Avogadro constant N A by the x-ray crystal density method, the density of a 28Si-enriched crystal was determined by absolute measurements of the mass and volume of a 1 kg sphere manufactured from the crystal. The mass and volume were determined by an optical interferometer and a vacuum mass comparator, respectively. The sphere surface was characterized by x-ray photoelectron spectroscopy and spectroscopic ellipsometry to derive the mass and volume of the Si core of the sphere excluding the surface layers. From the mass and volume, the density of the Si core was determined with a relative standard uncertainty of 2.3 × 10−8. By combining the Si core density with the lattice constant and the molar mass of the sphere reported by the International Avogadro Coordination (IAC) project in 2015, a new value of 6.022 140 84(15) × 1023 mol−1 was obtained for N A with a relative standard uncertainty of 2.4 × 10−8. To make the N A value determined in this work usable for a future adjustment of the fundamental constants by the CODATA Task Group on Fundamental Constants, the correlation of the new N A value with the N A values determined in our previous works was examined. The correlation coefficients with the values of N A determined by IAC in 2011 and 2015 were estimated to be 0.07 and 0.28, respectively. The correlation of the new N A value with the N A value determined by IAC in 2017 using a different 28Si-enriched crystal was also examined, and the correlation coefficient was estimated to be 0.21.

The redefinition of the kilogram is scheduled for 2018. This will be achieved by fixing the numerical value of the Planck constant with relation to the current unit of mass, as realized by the International Prototype Kilogram (IPK). The Consultative Committee for Mass and Related Quantities (CCM) has requested that, as one of the essential steps before the redefinition, a comparison of realizations based on watt balance and X-ray crystal density experiments be carried out, since these will become the primary realization experiments in the new SI. This comparison will be undertaken as a 'Pilot Study' and will be carried out during 2016. The aim of the study is to compare the future primary realizations to check their equivalence with each other and with the IPK and to develop and evaluate the protocol which will be used for future comparisons of the realization experiments after the redefinition. This will ensure the continuity of the mass unit across the redefinition and the validity of its dissemination following the redefinition. This paper outlines the basis for the comparison protocol taking into account the results of previous work evaluating transfer methods for primary mass standards. Possible future traceability routes for the kilogram from watt balance or XRCD experiments to end user requirements are also presented.

For establishing a new calibration method for small mass and force based on a new definition of the kilogram, the SI traceable measurement method which uses the electrostatic force balance was developed. Small mass was measured by comparing the gravity force acting on the small object and the electrostatic force which can be calibrated by using the electrical standards. New technical approaches such as monolithic flexure hinge for balance mechanism and double equal capacitor system for electrical control were applied. Weighing of a 2 mg stainless steel weight was performed. In the measurement, there was deviation from the nominal value of the weight, which was caused by the thermal drift and surface charge. Details on the measurement apparatus and the experiment results are presented.

To determine the Avogadro constant by the International Avogadro Coordination using the x-ray crystal density method, the volume of a28Si-enriched sphere, named Si28kgOla, was measured at NMIJ. The volume was determined from the diameter measurement in 2175 directions by an optical interferometer. Taking into account the results of the surface characterization of the sphere by x-ray photoelectron spectroscopy and spectroscopic ellipsometry, the volume of the Si core excluding the surface layers was determined with a relative uncertainty of $\pmb{2\ \times\ 10^{-8}}$ . Details of the interferometer and the uncertainty analysis of the volume measurement are presented.

For the determination of the Avogadro constant using the x-ray crystal density method, surface analysis of Si spheres is essential. The difference of the surface layer thickness in vacuum and in air conditions was investigated by ellipsometry. In order to estimate the effect of vapor adsorption on the determination of the thickness of the surface layer of Si spheres, an ellipsometer with vacuum chamber and vapor controlling system is proposed.

This report describes the first CCM key comparison of realizations of the kilogram definition based on the fixed numerical value of the Planck constant, which came into force on 20 May 2019. The objectives were to determine the level of agreement between realizations of the kilogram using Kibble and joule balances and the X-ray crystal density (XRCD) method and to provide input for the calculation of the first "consensus value" of the kilogram. The consensus value will serve as the basis for an internationally coordinated dissemination of the kilogram which will continue until sufficient agreement between realization experiments has been achieved. The comparison was organized by the BIPM and had seven participants. The BIPM, KRISS, NIST and NRC operated Kibble balances, the NIM used a joule balance and the NMIJ and the PTB participated using 28Si spheres, the masses of which were determined with the XRCD method. These realization methods were used to calibrate 1 kg mass standards under vacuum. The standards were sent (in air) to the BIPM where they were compared under vacuum with each other and with BIPM Pt-Ir working standards. The latter were calibrated (in air) traceable to the International Prototype of the Kilogram (IPK), the mass of which served as the definition of the kilogram until 20 May 2019. The results of the weighings at the BIPM together with the measurement results communicated by the participants allowed comparison of the values attributed to mass standards of 1 kg using the participating realization experiments. The level of agreement between mass determinations with the realization experiments and the BIPM as-maintained mass unit, traceable to the Planck constant through the mass of the International Prototype of the Kilogram can also be deduced. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

In the present study, the corrosion behavior of AM magnesium alloys (AM50 and AM60) in 5% NaCl solution was examined. The corrosion rate was found to depend on the impurity concentration in the alloy, and increased with Fe/Mn ratio. Inclusions were present within the alloys, with compositions of 40–80% Al, 20–60% Mn, and 0–10% Fe. It was determined that these inclusions acted as initiation points for corrosion. In addition, corrosion preferentially occurred at inclusions with a high Fe content, and the Fe content of inclusions was found to be proportional to that in the alloy itself.

For the new definition of the kilogram, surface analysis of Si spheres is essential to determine the Avogadro constant by using the x-ray crystal density method. In this work, to investigate surface characteristics of Si spheres both in vacuum and in air, a new ellipsometer having a vacuum chamber was developed. This ellipsometer enables accurate determination of the density of 28Si-enriched spheres.

A change in the definition of the kilogram has been proposed. The new definition will be based on the Planck constant. After the change, the National Metrology Institute of Japan (NMIJ) will realize the kilogram using the X-ray crystal density method with a 28Si-enriched sphere. A pilot study to confirm the international equivalence of the ability to realize the kilogram from the new definition is ongoing, where the volume measurement of a 28Si-enriched sphere by optical interferometry and the sphere surface characterization by spectroscopic ellipsometry and X-ray photoelectron spectroscopy required for the realization were performed by NMIJ independently. The mass of the sphere was determined with a relative standard uncertainty of $2.4\times 10^{\mathrm {\mathbf {-8}}}$ based on the new definition. This paper provides details of the measurements, the data analysis, and the uncertainty evaluation.

Background and Objectives : Hypothermia is likely to develop faster during spinal anesthesia than epidural anesthesia. A natural consequence of the rapid temperature decrease during spinal anesthesia is that the shivering threshold will be reached sooner and that more shivering will be required to prevent further hypothermia. We tested the hypotheses that the onset of hypothermia is more rapid and the onset and intensity of shivering earlier during spinal than epidural anesthesia. Methods : Patients undergoing cesarean delivery were randomly assigned to spinal anesthesia or epidural anesthesia. Spinal anesthesia was induced by injecting 2 mL 0.5% dibucaine into the L4–L5 interspace. Epidural anesthesia was induced with 20 mL 2% mepivacaine injected into the L2–L3 interspace. Thermal comfort and shivering were scored by a blinded observer. Results : Fifteen patients given each type of anesthesia had upper sensory levels ≥T4 dermatome. Sensation was entirely absent from the leg during spinal anesthesia, but lower block levels were near S5 during epidural anesthesia. Tympanic membrane temperatures initially decreased faster during spinal anesthesia, but subsequently decreased at a rate of 0.5°C/h in both groups. The onset and incidence of shivering (detected qualitatively) did not differ significantly between the two groups, but shivering intensity was significantly reduced during spinal anesthesia. Furthermore, the shivering thresholds were 36.4 ± 0.3°C (mean ± SD) during spinal anesthesia versus 37.1 ± 0.4°C in those given epidural anesthesia ( P = .006). There were no clinically important differences in thermal comfort with the two kinds of neuraxial anesthesia. Conclusions : We failed to confirm our hypothesis, but for an unexpected reason: Thermoregulation was impaired more by spinal anesthesia than epidural anesthesia. It seems likely that in our patients spinal anesthesia inhibited thermoregulatory control more than epidural anesthesia because it better blocked sensory input from the legs.

Many medical students are interested in basic medical researches. However, to make a decision to get into the research position throughout the life is not easy. In Kurume University, although shortage of clinicians, partly due to the atmosphere that senior doctors consider experiences of basic research is favorable as well as a re-evaluation of PhD degree, staffs and PhD students with MD or DDS are not very rare in the departments of basic medical sciences including the anatomy department. Some, not many though, MDs once lead clinical experience return to basic research in order to solve problems they encountered at clinical scenes or for enthusiasms for spirit of further inquiry for life sciences. Those might be lead by the push of senior doctors or through "admission course for medical sciences" and "laboratory experience training" in the initial curriculum of the medical course. Open spaces where students and researchers can enjoy free scientific talking are hopefully expected to facilitate establishing students' incentive to participate in basic studies.

Requirements engineering has been extensively developed as a discipline. Many statistics on the software development indicate requirements process is the most influential to both success and failure of software development. However, practitioners are still difficult to learn and apply requirements engineering. As a guideline for practitioners to learn and apply requirements engineering, we developed REBOK (Requirements Engineering Body Of Knowledge). In the development, we found there is no common model of BOKs in software engineering. This article proposes the model and architecture of the body of knowledge of REBOK and its proof of the concept.

冷水を満たした円筒水槽内の上部に垂直円管から温水を流入させ, 液温度の過渡応答を測定することにより, 円筒水槽の蓄熱性能に及ぼす流入部水平円形邪魔板設置の効果に関する実験的研究を行った.実験では流入用円管径, 邪魔板径, 邪魔板設置位置, 温・冷水温度差, 流量, および水位を変えた.実験結果ならびに理論的考察に基づいて, 温水領域への混合冷水量および円筒水槽の蓄熱効率を予測する無次元半経験式を, 流入部基準のアルキメデス数, ペクレ数, および3個の槽幾何形状無次元パラメータの関数として導いた.邪魔板設置によって温・冷水の混合が抑制されるので.比較的低いアルキメデス数の領域において, 邪魔板設置は蓄熱効率をかなり向上させるという結論を得た.