On the use of Ajisai and Jason-1 satellites for tests of General Relativity

Here we analyze in detail some aspects of the proposed use of Ajisai and Jason-1, together with the LAGEOS satellites, to measure the general relativistic Lense-Thirring effect in the gravitational field of the Earth. A linear combination of the nodes of such satellites is the proposed observable. The systematic error due to the mismodelling in the uncancelled even zonal harmonics would be \sim 1% according to the latest present-day CHAMP/GRACE-based Earth gravity models. In regard to the non-gravitational perturbations especially affecting Jason-1, only relatively high-frequency harmonic perturbations should occur: neither semisecular nor secular bias of non-gravitational origin should affect the proposed combination: their maximum impact is evaluated to \sim 4% over 2 years. Our estimation of the root-sum-square total error is about 4-5% over at least 3 years of data analysis required to average out the uncancelled tidal perturbations.Comment: Latex, 24 pages, 5 tables, 1 figure. Two references added, minor modifications. To appear in New Astronom

Control of the Polymorphism of Calcium Carbonate Produced by Self-Healing in the Cracked Part of Cementitious Materials

Cracking is an inherent development in reinforced concrete structures and can lead to serious damages during their service period. The repeated occurrence of such damages can enlarge the cracks, thereby allowing other deteriorating elements such as CO2 and Cl− to further infiltrate the concrete, which can seriously compromise the concrete structure. This study focuses on the type of calcium carbonate (CaCO3) crystals generated by the self-healing phenomenon. Owing to polymorphism, CaCO3 has three types of crystal forms—calcite, vaterite, and aragonite—whose formation can be controlled by the temperature and pH. Vaterite has the highest density among these crystals, and it is expected to be capable of self-healing. Therefore, experiments were conducted to establish the conditions required to promote the generation of vaterite. A saturated Ca(OH)2 solution with CO2 nanobubbles (CN) was employed for effective self-healing. The temperature was controlled at 20, 40, and 60 °C, and the pH was controlled at 9.0, 10.5, and 12.0. The results showed that the self-healing of cracks occurred both on the surface and internally, and the main product of the self-healing phenomenon was vaterite in CaCO3 crystals at a pH of 9.0 and a temperature of 40 °C. Furthermore, the addition of a saturated Ca(OH)2 solution with CO2 nanobubbles (CN) resulted in the most effective self-healing of the surface and internal cracks

Strength recovery of concrete exposed to freezing-thawing by self-healing of cementitious materials using synthetic fiber

In this study, it is possible to disperse effectively cracked using synthetic fiber, an examination of the most suitable self-healing conditions was performed on the above crack width 0.1mm. As a result, effective crack dispersion using polyvinyl alcohol(PVA) fibers with polar OH-groups, as well as improved self-healing for cracks that are larger than 0.1 mm in width, posing concerns of CO2 gas and Cl-penetration, were observed. Also, CO3 2-reacts with Ca2+ in the concrete crack, resulting in the precipitation of a carbonate compound, CaCO3. Based on this, it is deemed possible for the recovery of effective water tightness and strength recovery through effective freezing-thawing resistance to be made from cracks that are larger than 0.1mm in width. In addition, it was determined that, as for the most suitable self-healing conditions in the inside and surface of the cracks, calcium hydroxide (Ca(OH)2) solution with CO2 micro-bubble was more effective in promoting the self-healing capability than water with CO2 micro-bubble. Copyright © 2017 VBRI Press

Luminescence properties of ZnS phosphor nanocrystals prepared by the laser-induced gas-evaporation method

Nanocrystalline particles of ZnS:(Ag, Al) semiconductor phosphor, whose sizes are mostly 3–5 nm in diameter, are prepared by the gas-evaporation method with cw CO2 laser heating. The Raman scattering spectrum as well as the transmission electron microscope observation demonstrates that the crystallization of the nanoparticles was caused successfully through the gas-phase condensation. Under irradiation of ultraviolet light, the nanoparticles exhibit blue luminescence, as in the case of the starting material of ZnS:(Ag, Al) bulk powder. The peak of the luminescence spectrum of the nanoparticles shifts to lower energy with increasing delay time and also with decreasing excitation intensity, showing that the luminescence originates from the donor–acceptor pair recombination. However, it is concluded that the luminescence of the nanoparticles is not ascribed to the blue Ag luminescence mechanism responsible for the luminescence of the bulk powder, by taking into account the spatial confinement of an electron trapped at the donor and a hole at the acceptor. It is argued that the luminescence mechanism of the nanoparticles is the so called self-activated luminescence, which involves zinc vacancies

How to reach a few percent level in determining the Lense-Thirring effect?

In this paper we discuss and compare a node-only LAGEOS-LAGEOS II combination and a node-only LAGEOS-LAGEOS II-Ajisai-Jason1 combination for the determination of the Lense-Thirring effect. The new combined EIGEN-CG01C Earth gravity model has been adopted. The second combination cancels the first three even zonal harmonics along with their secular variations but introduces the non-gravitational perturbations of Jason1. The first combination is less sensitive to the non-conservative forces but is sensitive to the secular variations of the uncancelled even zonal harmonics of low degree J4 and J6 whose impact grows linearly in time.Comment: Latex2e, 22 pag. 1 table, 2 figures, 45 references. Changes in the Abstract, Introduction and Conclusions. Discussion on the non-gravitational perturbations on Ajisai and on the impact of the secular rates of the even zonal harmonics added. EIGEN-CG01C CHAMP+GRACE+terrestrial gravimetry/altimetry Earth gravity model used. Reference adde

Molecular Evaluation of Phylogenetic Significances in the Highly Divergent Karyotypes of the Genus Gonocephalus (Reptilia: Agamidae) from Tropical Asia

The Oriental large-bodied crested dragons of the genusGonocephalusare known to includetwo distinct karyomorphs. To evaluate their phylogenetic significances, we conducted phylogenetic analysesof the genus together with other agamid genera on the basis of 862 base positions of mitochondrial12S and 16S rRNA genes. Results suggested the presence of two distinct lineages withinGonocephalus,of which one, represented byG. robinsoniithat has a 2n=32 karyotype, was closer to other Oriental agamidgenera than to the other congeneric lineage. Monophyly of the latter, characterized by unique chromosomalarrangement among agamid genera (2n=42 karyotype), was confirmed. It is thus likely that statesof morphological characters shared between the two lineages are derived through convergence, or representsymplesiomorphy. Our results also suggest that the karyological similarity betweenG. robinsoniiandseveral Australian agamids, pointed out in a previous study, is actually attributable to homoplasy ratherthan their recent common ancestry

日本の高校卒業者の進路と適応状況

調査結果の要約 1-16 // 調査の実施状況 17-30第I部 調査結果の概要 : 第1章 調査結果の要約 第2章調査の実施状況 / 第III部 日本の高校卒業者の進路と適応状況 : 第1章進路希望とその実現プロセス 第2章 進学パターンの規定要

Phylogenetic Relationships of Eublepharid Geckos (Reptilia: Squamata): A Molecular Approach

Phylogenetic analyses were carried out for representatives of all eublepharid genera and afew other gekkonoid taxa using sequence data for 879 base pairs of mitochondrial 12S and 16S ribosomalRNA genes. Neighbor-joining (NJ) distance analysis of the data suggested independent great divergencesof Coleonyx and Aeluroscalabotes, and monophyly of the remainder within Eublepharidae (bootstrap proportion[BP]=76%). Of the latter, the two African genera, Hemitheconyx and Holodactylus, were almost certainlymonophyletic altogether (BP=99%), whereas their sister-group relationship with Eublepharis received a weaker,but still substantial support (BP=68%). Within Goniurosaurus kuroiwae, G. k. splendens first diverged fromthe remainder (BP=100%), followed by G. k. kuroiwae from the northern part of Okinawajima (BP=100%): G.k. kuroiwae from the southern part of Okinawajima and G. k. orientalis, differing from each other at onlyseven bases, diverged finally (BP=99%). Parsimony analysis yielded results consistent with those of NJanalysis with respect to the monophyly of the two African genera and relationships within G. kuroiwae, butretained the other relationships within Eublepharidae unresolved. Our results, while showing no seriousdiscrepancies with the relationships among eublepharid genera hypothesized from morphological data, casta serious doubt to the currently accepted population systematics within G. kuroiwae. Furthermore, results ofboth analyses suggested a closer affinity of Diplodactylinae (as represented by Rhacodactylus trachyrhynchus)with Eublepharidae, rather than with Gekkoninae. Our study lends a robust support to the Laurasian origin ofthe family Eublepharidae