Molecular/cluster statistical thermodynamics methods to simulate quasi-static deformations at finite temperature

AbstractThe rapid evolution of nanotechnology appeals for the understanding of global response of nanoscale systems based on atomic interactions, hence necessitates novel, sophisticated, and physically based approaches to bridge the gaps between various length and time scales. In this paper, we propose a group of statistical thermodynamics methods for the simulations of nanoscale systems under quasi-static loading at finite temperature, that is, molecular statistical thermodynamics (MST) method, cluster statistical thermodynamics (CST) method, and the hybrid molecular/cluster statistical thermodynamics (HMCST) method. These methods, by treating atoms as oscillators and particles simultaneously, as well as clusters, comprise different spatial and temporal scales in a unified framework. One appealing feature of these methods is their “seamlessness” or consistency in the same underlying atomistic model in all regions consisting of atoms and clusters, and hence can avoid the ghost force in the simulation. On the other hand, compared with conventional MD simulations, their high computational efficiency appears very attractive, as manifested by the simulations of uniaxial compression and nanoindenation

Hanakatsura: The Works of Famous Literary Women in Japan

Originally published in Tokyo in 1903, Hanakatsura (literally “garland of flowers”) features a biographical sketch of the activist and author Kishida Toshiko (Baroness Nakajima) plus four short stories by Japanese women writers of the Meiji era: Akebonozome: A Cloth Dyed in Rainbow Colors, by Kaho Miyake Ōtsugomori: The Last Day of the Year, by Ichiyo Higuchi Onisenbiki: The Thousand Devils, by Usurai Kitada (Mrs. Kajita) Shinobine, by Otsuka Kusuo Compiled and translated by Tei Fujiu, four memorable and affecting stories depict women experiencing the frustrations of traditional family roles within an emergent commercial society at the turn of the century. The men seem preoccupied with buying and selling votes, fighting foreign wars, ignoring their families, or going out on the town; and they are fully capable of rejecting a bride for her looks or just letting a new wife walk away. Meanwhile, young female characters cope with overall shabbiness, lost samurai dignity, orphanhood, servitude, poverty, indebtedness, jealous sisters, stepmothers, and mothersin- law, and the combined challenges of being blind, ugly, alone, and empathetic. doi: 10.32873/unl.dc.zea.1337https://digitalcommons.unl.edu/zeabook/1133/thumbnail.jp

Prediction of deterioration of sewage facilities based on statistical analysis for asset management

日本の全国下水道普及率は近年約1.2ポイントずつの上昇を続け、2007年度末で71.7%に達し、浄化槽などの区域を除いた最終想定普及率88%まで残すところ十数年の段階となっている。また、全国下水道管渠総延長も40万kmを超えている。このように日本の蓄積された下水道資産は膨大な量であり、かつ、下水道管渠損傷を原因とする道路陥没数が2007年度約4,700件となるなど、施設の老朽化が進んでいるおり、加えて下水道事業体である地方自治体の財政難や少子高齢化の進展などの事情や状況もある。したがって、資産管理を効率的に行うアセットマネジメント手法の開発導入が下水道事業の喫緊の課題となっている。本研究は,アセットマネジメントのうち、統計解析に適する程度の大きさの施設群について関与・管理する国又は大規模事業体統括部局が施設,財務,組織等の管理計画策定などに利用できるマクロマネジメント手法の開発を主たる研究方針とし,個別施設の管理を直接担う現場事務所や小規模事業体でも利用できるようミクロマネジメントへの応用にも配慮しつつ行った。本研究の成果をまとめると以下のようになる。(1) 下水道事業が会社や他の地方公営企業に比べ残存耐用年数も償却資産回転期間も格段に大きな,いわば経営的に非常に重い償却性固定資産を有していることを明らかにした。このことから,下水道事業では償却性固定資産の効率的管理の成否が,すなわちアセットマネジメントの巧拙が経営に重大な影響を与えるものと推察される。(2) 全国の管渠の同一年度の管齢別の供用延長及び改築延長のデータにワイブル分布を適用して耐用年数確率分布(ワイブル係数m=2.87, η=104, 平均μ=93年, 標準偏差σ=35年)を算出した。得られた分布を基に全国年間改築延長の将来予測を行い,ピークを2093年,年間4,653km,6,400億円と推計した。これら手順をマクロマネジメント手法として提案した。(3) 全国の下水道起因の道路陥没について前章で得られた分布を基に年間陥没数の過去データを良好に再現できる管齢別陥没発生率を推計した。さらに将来陥没数を推計し,ピークを2061年,年間45,222件と算出した。これら手順をマクロマネジメント手法として提案した。また,陥没による損失額が得られる場合に陥没数削減を目的とする早期改築の効率性を検討する手法を提案した。(4) 処理場コンクリートの腐食改修履歴データにワイブル分布を適用し,腐食環境分類に応じた耐用年数確率分布(I類:ワイブル係数m=3.2, η=42, 平均μ=38年, 標準偏差σ=13年, II類:ワイブル係数m=1.9, η=68, 平均μ=60年, 標準偏差σ=33年)を算出した。また,硫化水素ないし硫酸によるコンクリート腐食進行の研究調査文献データを整理・解析した結果,下水道現場での腐食深さは平均的に時間の0.88乗で進行すると考えられる。これらの手順をそれぞれマクロマネジメント手法,ミクロマネジメント手法として提案した。(5) 全国機電設置事業費の過去データにワイブル分布を適用し,耐用年数確率分布(ワイブル係数m=4.34, η=29.2, 平均μ=26.6年, 標準偏差σ=6.9年)を算出した。ただし別分布もありうるので,上記分布による将来改築事業費推計にあたっては,当該現場の過去及び新規データへの適合性を十分に検討する必要がある。同分布を用いて全国の将来改築事業費を推計し,長期的には年間約6,800億円で推移すると算出した。(6) 費用効果分析やLCC,LCA検討に大きな影響を与える割引率について適正値を検討した。併せて管渠工事を例とし,割引率のうち利子率について,その値に応じて経済効率的となる耐用年数と管材コスト比の関係を試算した。また,人口減少と高齢化による財源難に備え,耐用年数増加及び管材コスト比抑制となる管材開発により2030年に管渠工事の年当たり費用を78.8%に低減させることは,利子率4%では難しいが,2%でなら管材企業努力による実現の可能性があると考えられる。(7) 事業へのアセットマネジメントの効果的適用方法について検討した。まず,ミクロマネジメント結果のマクロマネジメントへの反映手法としてベイズ推定の利用可能性を指摘した。次に,マクロマネジメント結果のミクロマネジメントへの反映手法として,既報のスクリーニング手法の利用可能性を指摘し,確率密度関数又は信頼度関数による劣化予測手法を提案した。さらに,全国や類似施設のデータを利用してデータのない高齢域を補外する手法を提案した。最後に本研究の各種手法の効果的適用に必要なデータ項目一覧を示した。学位の種別: 論文博士審査委員会委員（主査） : 東京大学教授花木 啓祐, 東京大学教授小澤 一雅, 東京大学教授古米 弘明, 東京大学教授滝沢 智, 東京大学講師栗栖 聖University of Tokyo(東京大学

Thermoelectric Performance of p-Type Mg 2 Si 0:25 Sn 0:75 with Li and Ag Double Doping

The single-phase of p-type Mg 2 Si 0:25 Sn 0:75 with Li and Ag double doping were prepared by the liquid-solid reaction and hot-pressing methods. All samples thus obtained were identified by XRD as single-phase solid solutions with an anti-fluorite structure. The effects of Li and Ag double doping on thermoelectric performance were investigated at temperature differences (ÁT) of 0 to 500 K. The thermoelectromotive force (E) of the Li-25000 ppm single-doped sample was determined to be 88 mV at ÁT ¼ 500 K. For the Li-20000 ppm and Ag-5000 ppm double-doped sample, the E value became larger (92 mV) after Ag substitution. A maximum E value of 97 mV was obtained for the Ag-25000 ppm single-doped sample and the Li-5000 ppm and Ag-20000 ppm double-doped sample. Mean resistivity (r m ) at ÁT ¼ 500 K decreased by double doping and showed a minimum value of 2:94 Â 10 À5 m for the Li-5000 ppm and Ag-20000 ppm double-doped sample. The maximum effective power (P ¼ E 2 =4r m ) increased with ÁT. The P values of single-doped samples at ÁT ¼ 500 K were 38 Wm À1 for Li singledoped and 72 Wm À1 for Ag single-doped samples. P for the Li-20000 ppm and Ag-5000 ppm double-doped sample was 64 Wm À1 , which was an improvement of about 90% compared with the Li single-doped sample. The maximum value of P at ÁT ¼ 500 K was 80 Wm À1 for the Li-5000 ppm and Ag-20000 ppm double-doped sample, which was an improvement of about 10% compared with the Ag single-doped sample

Association of Cardiovascular Health Metrics With Risk of Transition to Hypertension in Non-Hypertensive Young Adults

BACKGROUND The risk of developing hypertension in young adults and its relationship to modifiable lifestyle factors are unclear. We aimed to examine the association of cardiovascular health (CVH) metrics with the risk of hypertension. METHODS We analyzed 66,876 participants aged 20-39 years, with available blood pressure (BP) data for 5 consecutive years, who had normal or elevated BP at the initial health check-up, enrolled in the JMDC Claims Database. Ideal CVH metrics included nonsmoking, body mass inde

Establishment of a reborn MMV-microarray technology: realization of microbiome analysis and other hitherto inaccessible technologies

BACKGROUND: With the accelerating development of bioscience, the problem of research cost has become important. We previously devised and developed a novel concept microarray with manageable volumes (MMV) using a soft gel. It demonstrated the great potential of the MMV technology with the examples of 1024-parallel-cell culture and PCR experiments. However, its full potential failed to be expressed, owing to the nature of the material used for the MMV chip. RESULTS: In the present study, by developing plastic-based MMVs and associated technologies, we introduced novel technologies such as C2D2P (in which the cells in each well are converted from DNA to protein in 1024-parallel), NGS-non-dependent microbiome analysis, and other powerful applications. CONCLUSIONS: The reborn MMV-microarray technology has proven to be highly efficient and cost-effective (with approximately 100-fold cost reduction) and enables us to realize hitherto unattainable technologies

Age-Dependent Association Between Modifiable Risk Factors and Incident Cardiovascular Disease

BACKGROUND: There have been limited data examining the age-dependent relationship of wide-range risk factors with the incidence of each subtype of cardiovascular disease (CVD) event. We assessed age-related associations between modifiable risk factors and the incidence of CVD. METHODS AND RESULTS: We analyzed 3 027 839 participants without a CVD history enrolled in the JMDC Claims Database (mean age, 44.8±11.0 years; 57.6% men). Each participant was categorized as aged 20 to 49 years (n=2 008 559), 50 to 59 years (n=712 273), and 60 to 75 years (n=307 007). Using Cox proportional hazards models and the relative risk reduction, we identified associations between risk factors and incident CVD, consisting of myocardial infarction, angina pectoris, stroke, and heart failure (HF). We assessed whether the association of risk factors for developing CVD would be modified by age cat-egory. Over a mean follow-up of 1133 days, 6315 myocardial infarction, 56 447 angina pectoris, 28 079 stroke, and 56 369 HF events were recorded. The incidence of myocardial infarction, angina pectoris, stroke, and HF increased with age category. Hazard ratios of obesity, hypertension, and diabetes in the multivariable Cox regression analyses for myocardial infarction, angina pectoris, stroke, and HF decreased with age category. The relative risk reduction of obesity, hypertension, and diabetes for CVD events decreased with age category. For example, the relative risk reduction of hypertension for HF decreased from 59.2% in participants aged 20 to 49 years to 38.1% in those aged 60 to 75 years. CONCLUSIONS: The contribution of modifiable risk factor to the development of CVD is greater in younger compared with older individuals. Preventive efforts for risk factor modification may be more effective in younger people.</p