平坦化CMPにおけるパッドドレッシングに関する基礎的研究

Fundamental investigation for pad conditioning was studied on CMP (Chemical Mechanical Polishing). In particular, pad surface roughness was focused on various pad surface conditions. Pad conditioning under wet condition makes pad surface roughness finer than pad conditioning under dry condition. The pad surface with fine roughness contributes to rapid pad break-in and removal rate　stabilization. In this study, various factors of pad conditioning were verified to clarify the difference of pad conditioning between under wet condition and dry condition. One of major differences of pad conditioning under dry condition against wet condition was the magnitude of friction force between pad and conditioner, which generates stick-slip motion of pad conditioner on a pad. The other was removal efficiency of pad fragment to be scraped away on conditioning pad. Pad fragments disturbs a stable contact between pad and conditioner. Consequently, it will be possible to realize pad pre-conditioning without pasting pad on a platen by taking appropriate measures against the two.textapplication/pdfdepartmental bulletin pape

High-pressure synthesis of highly oxidized Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ cubic perovskite

application/pdfMaterials Chemistry Frontiers. 2019, 3 (6), P.1209-1217journal articl

Observation of B̅0→DsJ*(2317)+K- Decay

journal articl

Solar neutrino measurements in Super-Kamiokande-II

The results of the second phase of the Super-Kamiokande solar neutrino measurement are presented and compared to the first phase. The solar neutrino flux spectrum and time variation as well as oscillation results are statistically consistent with the first phase and do not show spectral distortion. The timedependent flux measurement of the combined first and second phases coincides with the full period of solar cycle 23 and shows no correlation with solar activity. The measured 8B total flux is (2:38± 0.05(stat.)/begin+0.16 // -0.15/end (sys.)) × 10^6 cm^{-2} s^{-1} and the day-night difference is found to be (-6.3 ±4.2(stat.)±3.7(sys.))%.There is no evidence of systematic tendencies between the first and second phases.journal articl

Photocreated metastable states in polysilanes

Photocreated metastable states in organopolysilane (PSi) solids are observed using the electron-spin-resonance (ESR) technique. Two types of light-induced ESR (LESR) spectra are found depending on the excitation photon energy. These two types of LESR centers are annihilated by thermal annealing. Based on a first-principle electronic calculation, the origins of these LESR centers have been discussed. The lowest photoexcitation (～3.5 eV) in PSi induces the Si skeleton stretching forces, which creates a weak bond (WB) in several places of the Si skeleton. Electronically, this WB acts as a self-trapping center for the photoexcited σ electron. The other higher photoexcitation (over 4.8 eV) causes side-pendant dissociation, which creates a dangling bond (DB) and causes the localized midgap state. The four lines found in the higher-energy excitation are considered to arise from hyperfine interaction between this DB electron and a sodium impurity nucleus.journal articl

Respiratory hospitalizations in association with fine PM and its components in New York State

<div><p>Despite observed geographic and temporal variation in particulate matter (PM)-related health morbidities, only a small number of epidemiologic studies have evaluated the relation between PM_2.5 chemical constituents and respiratory disease. Most assessments are limited by inadequate spatial and temporal resolution of ambient PM measurements and/or by their approaches to examine the role of specific PM components on health outcomes. In a case-crossover analysis using daily average ambient PM_2.5 total mass and species estimates derived from the Community Multiscale Air Quality (CMAQ) model and available observations, we examined the association between the chemical components of PM (including elemental and organic carbon, sulfate, nitrate, ammonium, and other remaining) and respiratory hospitalizations in New York State. We evaluated relationships between levels (low, medium, high) of PM constituent mass fractions, and assessed modification of the PM_2.5–hospitalization association via models stratified by mass fractions of both primary and secondary PM components. In our results, average daily PM_2.5 concentrations in New York State were generally lower than the 24-hr average National Ambient Air Quality Standard (NAAQS). Year-round analyses showed statistically significant positive associations between respiratory hospitalizations and PM_2.5 total mass, sulfate, nitrate, and ammonium concentrations at multiple exposure lags (0.5–2.0% per interquartile range [IQR] increase). Primarily in the summer months, the greatest associations with respiratory hospitalizations were observed per IQR increase in the secondary species sulfate and ammonium concentrations at lags of 1–4 days (1.0–2.0%). Although there were subtle differences in associations observed between mass fraction tertiles, there was no strong evidence to support modification of the PM_2.5-respiratory disease association by a particular constituent. We conclude that ambient concentrations of PM_2.5 and secondary aerosols including sulfate, ammonium, and nitrate were positively associated with respiratory hospitalizations, although patterns varied by season. Exposure to specific fine PM constituents is a plausible risk factor for respiratory hospitalization in New York State.</p><p>Implications: <i>The association between ambient concentrations of PM_2.5 components has been evaluated in only a small number of epidemiologic studies with refined spatial and temporal scale data. In New York State, fine PM and several of its constituents, including sulfate, ammonium, and nitrate, were positively associated with respiratory hospitalizations. Results suggest that PM species relationships and their influence on respiratory endpoints are complex and season dependent. Additional work is needed to better understand the relative toxicity of PM species, and to further explore the role of co-pollutant relationships and exposure prediction error on observed PM–respiratory disease associations.</i></p></div

The World Trade Center Residents’ Respiratory Health Study: New-Onset Respiratory Symptoms and Pulmonary Function-0

<p><b>Copyright information:</b></p><p>Taken from "The World Trade Center Residents’ Respiratory Health Study: New-Onset Respiratory Symptoms and Pulmonary Function"</p><p>Environmental Health Perspectives 2004;113(4):406-411.</p><p>Published online 20 Dec 2004</p><p>PMCID:PMC1278479.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Adjusted odds ratios between occupational exposure to ultraviolet radiation (UVR) and non-melanoma skin cancer (NMSC) stratified by anatomical site.

a<p>Total number of participants varies due to missing data for some covariates;</p>b<p>Adjusted odds ratios (95% CI) for sex, age, county of residence, family history of cancer, skin complexion, and lifetime average arsenic concentration in drinking water;</p>c<p>Any UVR consists of natural UV, artificial UV, and both (results omitted due to scarce data); associations were estimated in two separate multivariable logistic regression models.</p

Adjusted odds ratios between occupational exposure to ultraviolet radiation (UVR) and non-melanoma skin cancer (NMSC).

a<p>Total number of participants varies due to missing data for some covariates;</p>b<p>Adjusted odds ratios (95% CI) for sex, age, county of residence, family history of cancer, skin complexion, and lifetime average arsenic concentration in drinking water;</p>c<p>Any UVR consists of natural UV, artificial UV, and both (results omitted due to scarce data); associations were estimated in two separate multivariable logistic regression models.</p

Adjusted odds ratios between occupational exposure to ultraviolet radiation (UVR) and basal cell carcinoma (BCC), and modifying effects by skin complexion.

a<p>Total number of participants varies due to missing data for some covariates;</p>b<p>Adjusted odds ratios (95% CI) for sex, age, county of residence, family history of cancer, skin complexion, and lifetime average arsenic concentration in drinking water;</p>c<p>Any UVR consists of natural UV, artificial UV, and both (results omitted due to scarce data); associations were estimated in two separate multivariable logistic regression models;</p>d<p>Cumulative lifetime exposure is not showed for artificial UVR because of small numbers per strata;</p>*<p>Significance of the Wald Chi-Square test for interaction at p<0.10.</p