241 research outputs found

    Geochemical Clogging in Fracture and Porous Rock for CO2 Mineral Trapping

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    AbstractGeochemical trapping is regarded as one of the promising geologic sequestration of carbon dioxide (CO2). Also carbonate mineralization takes advantage of permeability reduction to seal formations with decreasing CO2 leakage risk and increasing storage safety. As precipitation rates tend to be faster and the solubility product shows lower value at higher temperature, the calcite- and kaolinite- rich rock produced through CO2-water-rock interaction is expected to form the scale in geothermal reservoirs. Ca2+ released from rocks could be removed as carbonate minerals (CaCO3) during CO2 sequestration into aquifer rocks. However, when, where, and how much calcite deposits at the reservoir. For this reason, flow experiments and numerical calculation of advection-reaction model have been done to predict where and when the mineral deposits and permeability changes.The experimental and numerical results provided that fluid velocity change between fracture and porous media have more than one-order discrepancy at isothermal condition. When the fluid velocity in fracture exceeds the critical velocity, surface erosion allows re-entrainment. Critical velocity in porous media is likely to be larger than that in fracture because internal erosion might interrupt the migration of deposit by re-settlement in pore spaces

    アルツハイマー型認知症患者における前頭葉機能と介護負担の関係

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    AIM: Understanding of the relationship between caregiver burden and the degree of behavioural deficits in patients with Alzheimer's disease (AD) is relatively limited. Therefore, it is worthwhile to examine the correlations between the various relevant factors to improve the efficacy of care for patients with AD. The aim of this study was to investigate the specific contributions of frontal lobe dysfunction in AD patients to caregiver burden, while controlling for other predictor variables. METHODS: Participants included 30 pairs of caregivers and patients with AD. The Zarit Burden Interview and Frontal Assessment Battery were used to measure the caregiver burden and patients' frontal lobe function, respectively. To investigate the effects of frontal lobe dysfunction on caregiver burden, hierarchical regression equations with steps incorporating additional predictor variables were fitted. We also performed a correlation analysis between the individual subdomains of the Zarit Burden Interview and the predictor variables. RESULTS: Our study suggests that the degree of frontal lobe dysfunction in AD patients predicts their caregiver burden, when other factors of daily functional limitations and neuropsychiatric symptoms are controlled. Daily functional limitations and neuropsychiatric symptoms affected caregivers' psychosocial burden, whereas frontal lobe dysfunction affected caregivers' burden due to the increase in the dependency of the patients. CONCLUSION: Our findings indicate that to ameliorate the disabilities of patients and reduce caregiver burden, there is a need for interventions that focus on psychosocial burdens, as shown in previous studies, as well as on excessive dependency due to frontal lobe dysfunction.博士(医学)・甲第661号・平成29年3月15日© 2017 Japanese Psychogeriatric SocietyThis is the pre-peer reviewed version of the following article: http://dx.doi.org/10.1111/psyg.12231, which has been published in final form at http://dx.doi.org/10.1111/psyg.12231. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

    気分状態に依存しない双極性障害と大うつ病性障害における脳梁の白質微細構造の差異

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    OBJECTIVE: It is difficult to distinguish between bipolar disorder and major depressive disorder (MDD) in patients lacking a clear history of mania. There is an urgent need for an objective biomarker for differential diagnosis. Using diffusion tensor imaging, this study investigated the differences in the brain white matter microstructure between patients with bipolar disorder and MDD. METHODS: Participants included 16 patients with bipolar disorder and 23 patients with MDD having depressed or euthymic states based on DSM-IV-TR criteria and 23 healthy volunteers. Whole-brain voxel-based morphometric analysis was used to detect any significant differences in fractional anisotropy between patients with bipolar disorder and MDD. The study was conducted between August 2011 and July 2015. RESULTS: We found a significant decrease in fractional anisotropy values in the anterior part of the corpus callosum in patients with bipolar disorder compared with MDD (P < .001), which did not depend on the patients' affective state. This decrease was associated with increased radial diffusivity values (P < .05), which was also found in patients with bipolar disorder when compared with healthy volunteers (P < .05). We predicted bipolar disorder and MDD in all patients using the fractional anisotropy values, with a correct classification rate of 76.9%. CONCLUSIONS: The present study revealed that patients with bipolar disorder have microstructural abnormalities in the corpus callosum during depressed or euthymic states, which may deteriorate the exchange of emotional information between the cerebral hemispheres, resulting in emotional dysregulation. Our results indicate the possible use of diffusion tensor imaging as a differential diagnostic tool.博士(医学)・甲第662号・平成29年3月15日© Copyright 2017 Physicians Postgraduate Press, Inc.発行元の規定により、本文の登録不可。本文は以下のURLを参照 "http://dx.doi.org/10.4088/JCP.15m09851" (※全文閲覧は学内限定

    Water Soluble Aluminum Paste Using Polyvinyl Alcohol for Silicon Solar Cells

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    Screen-printing aluminum is still dominantly used in the solar cell fabrication process. Ethyl cellulose is one of the main contents of screen-printing pastes that require dichloromethane for its cleaning process, a substance renowned for being extremely toxic and threatening to the human body. Developing environmental friendly aluminum pastes is essential in order to provide an alternative to the commercial pastes. In this work, new, nontoxic polyvinyl alcohol-based aluminum pastes are introduced. Polyvinyl alcohol was used as a soluble polymer that can be synthesized without saponification and that is also soluble in water. Three different pastes were developed using different recipes including many aluminum particle sizes varying from 3.0 to 45 μm, aluminum oxide with particle sizes between 35 and 50 μm, and acetic acid. Evaluation of the pastes was carried out by Scanning Electron Microscope (SEM) image analysis, sheet resistance measurements, and fabricating silicon solar cells using each paste. Solar cells with 15.6% efficiency were fabricated by nonvacuum processing on CZ-Si p-type wafers using developed aluminum pastes on the back side

    Behavior-level Analysis of a Successive Stochastic Approximation Analog-to-Digital Conversion System for Multi-channel Biomedical Data Acquisition

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    In the present paper, we propose a novel high-resolution analog-to-digital converter (ADC) for low-power biomedical analog frontends, which we call the successive stochastic approximation ADC. The proposed ADC uses a stochastic flash ADC (SF-ADC) to realize a digitally controlled variable-threshold comparator in a successive-approximationregister ADC (SAR-ADC), which can correct errors originating from the internal digital-to-analog converter in the SAR-ADC. For the residual error after SAR-ADC operation, which can be smaller than thermal noise, the SF-ADC uses the statistical characteristics of noise to achieve high resolution. The SF-ADC output for the residual signal is combined with the SAR-ADC output to obtain high-precision output data using the supervised machine learning method

    VENTRICULAR ENLARGEMENT AND WATER INTOXICATION IN SCHIZOPHRENIA

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    To determine the extent to which atrophy was related to water intoxication in schizophrenic patients, ventricular enlargement in polydipsic schizophrenic patients with hyponatremia and schizophrenic controls without hyponatremia was measured in a linear way. Ventricular enlargement was found in both schizophrenic patient groups, and larger ventricles were associated with water intoxication. It is suggested that ventricular enlargement may reflect a developmental or degenerative pathological process involving the occurrence of water intoxication in schizophrenia

    せん妄の遷延化に関連する因子についての後方視研究

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    Background: It has been reported that delirium causes various problems. Many researchers have reported the risk factors associated with the onset of delirium; however, there are few reports focused on persistent delirium. This study aimed to identify the risk factors associated with persistent delirium. Methods: A total of 573 patients hospitalised in Nara Prefecture General Medical Centre from October 2014 through September 2017 who were referred to the psychiatry consultation service were included in this study. Persistent delirium was defined as delirium lasting for 14 days or more. A retrospective study was carried out based on the patients' records. The relationship between various background factors and persistent delirium was statistically analysed. Results: Of the 573 hospitalised patients, 295 were diagnosed as having delirium. Forty-six patients with persistent delirium and 181 patients with nonpersistent delirium were included in this study. Multivariable logistic regression analyses revealed that male gender, opioid analgesics use, non-opioid analgesics use, and low serum sodium were significantly and independently associated with persistent delirium. Ramelteon or trazodone was used significantly more in persistent delirium, although each use was not significant. Conclusion: This is the first study to reveal that male gender and use of analgesics were associated with persistent delirium in general hospital. However, as this is a case-control study and may contain bias, future cohort studies and intervention studies are needed. It is also necessary to investigate the relevance of the 'degree of pain' behind the use of analgesics.博士(医学)・乙第1516号・令和3年12月21日© 2021 Japanese Psychogeriatric Society.This is the peer reviewed version of the following article: [https://onlinelibrary.wiley.com/doi/10.1111/psyg.12655], which has been published in final form at [https://doi.org/10.1111/psyg.12655]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited
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