物理探査データと岩石物理学の統合による資源評価技術の開発

京都大学新制・課程博士博士(工学)甲第23175号工博第4819号新制||工||1753(附属図書館)京都大学大学院工学研究科都市社会工学専攻(主査)教授 小池 克明, 教授 林 為人, 准教授 柏谷 公希学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA

Water transport model during CAPD: Determination of parameters

Water transport model during CAPD: Determination of parameters. To minimize the total amount of glucose required for removing the same volume of water as a bolus, a continuous infusion of glucose during CAPD was proposed and studied. Both a computer simulation of water transport through the peritoneal membrane and in vivo assessment with rats were carried out to evaluate the feasibility of the newly proposed mathematical model in which lymphatic drainage of dialysate from the peritoneal cavity to lymphatic system was considered in addition to conventional water transport. Mass transport area coefficients (KA) of 0.041 to 0.063 ml/min/100 g body wt and 0.045 to 0.066 ml/min/100 g body wt were measured for glucose and urea during CAPD with male Wistar rats. Hydraulic conductivity of peritoneal membrane (Lc) was 7.9 × 10-5 to 1.5 × 10-4 ml/min/mm Hg/100 g body wt, which was calculated by a linear relationship between volume and osmotic pressure. Simulated water transport model using determined parameters indicated that the ratio of lymphatic transport to convective transport would be changeable in CAPD with glucose infusion at varying infusion rates, while up to 16% of the glucose uptake could be reduced compared with that of the common CAPD at the same dwell time

Statistical Study of the Star Formation Efficiency in Bars: Is Star Formation Suppressed in Gas-Rich Bars?

The dependence of star formation efficiency (SFE) on galactic structures, especially whether the SFE in the bar region is lower than those in the other regions, has recently been debated. We report the SFEs of 18 nearby gas-rich massive star-forming barred galaxies with a large apparent bar major axis ($\geqq 75^{\prime\prime}$). We statistically measure the SFE by distinguishing the center, bar-end, and bar regions for the first time. The molecular gas surface density is derived from archival CO(1-0) and/or CO(2-1) data by assuming a constant CO-to-H$_2$ conversion factor ($\alpha_{\rm CO}$), and the star formation rate surface density is derived from a linear combination of far-ultraviolet and mid-infrared intensities. The angular resolution is $15^{\prime\prime}$, which corresponds to $0.3 - 1.8~\rm kpc$. We find that the ratio of the SFE in the bar to that in the disk was systematically lower than unity (typically $0.6-0.8$), which means that the star formation in the bar is systematically suppressed. Our results are inconsistent with similar recent statistical studies that reported that SFE tends to be independent of galactic structures. This inconsistency can be attributed to the differences in the definition of the bar region, spatial resolution, $\alpha_{\rm CO}$, and sample galaxies. Furthermore, we find a negative correlation between SFE and velocity width of the CO spectrum, which is consistent with the idea that the large dynamical effects, such as strong shocks, large shear, and fast cloud-cloud collisions caused by the noncircular motion of the bar, result in a low SFE.Comment: 27 pages, 11 figures, accepted for publication in Ap

How to Construct Cryptosystems and Hash Functions in Weakened Random Oracle Models

In this paper, we discuss how to construct secure cryptosystems and secure hash functions in weakened random oracle models. ~~~~The weakened random oracle model (\wrom), which was introduced by Numayama et al. at PKC 2008, is a random oracle with several weaknesses. Though the security of cryptosystems in the random oracle model, \rom, has been discussed sufficiently, the same is not true for \wrom. A few cryptosystems have been proven secure in \wrom. In this paper, we will propose a new conversion that can convert \emph{any} cryptosystem secure in \rom to a new cryptosystem that is secure in the first preimage tractable random oracle model \fptrom \emph{without re-proof}. \fptrom is \rom without preimage resistance and so is the weakest of the \wrom models. Since there are many secure cryptosystems in \rom, our conversion can yield many cryptosystems secure in \fptrom. ~~~~The fixed input length weakened random oracle model, \filwrom, introduced by Liskov at SAC 2006, reflects the known weakness of compression functions. We will propose new hash functions that are indifferentiable from \ro when the underlying compression function is modeled by a two-way partially-specified preimage-tractable fixed input length random oracle model (\wfilrom). \wfilrom is \filrom without two types of preimage resistance and is the weakest of the \filwrom models. The proposed hash functions are more efficient than the existing hash functions which are indifferentiable from \ro when the underlying compression function is modeled by \wfilrom

Mechanism of oxygen release from Li-rich cathode material for lithium ion batteries

For further wide spread of high energy density batteries, one of the most important technological challenges is preventing thermal runaway. For that, a key phenomenon is the oxygen release from cathode active materials, because released oxygen may react with the organic solvent and generate heat. Therefore, it is important to understand the mechanism of oxygen release to ensure safe battery operation. While the reaction of charged cathode material and organic solvent was investigated well [1], the mechanism of oxygen release from cathode material is not understood so far [2]. In this study, oxygen release behavior of Li-rich cathode material Li1.2Mn0.6Ni0.2O2-d was investigated, and the mechanism of oxygen release was discussed based on defect chemistry and thermodynamics. Please click Additional Files below to see the full abstract

Surgical Punctal Occlusion; Combined Lacrimal Canaliculi Cauterization and Punctal Suturing for Severe Dry Eye

Purpose: To evaluate the treatment outcome of surgical punctal occlusion with combined canaliculi ablation and punctal suturing in patients with severe dry eye. Methods: Eleven eyes of seven patients were diagnosed with severe dry eye with decreased lacrimal secretion and were refractory to treatment with various eye drops and/or had repeatedly experienced loss of punctal plugs, and continued to experience subjective symptoms received surgical punctal occlusion. In 20 puncta, lacrimal canaliculi ablation was performed along the entire length of the lacrimal canaliculus where a diathermy needle could be inserted. After resection of the annulus fibrosus in the peri-punctal area, tight cross-stitch suturing of the puncta was performed with 8-0 absorbent thread. Visual acuity, corneal staining score according to the area (A) and density (D) classification, and Schirmer tear test (STT); tear break up time (tBUT); and subjective symptoms assessed by the University of North Carolina (UNC) and Dry Eye Management Scale were compared before and one year after surgery. Results: Recanalization occurred in 1/20 puncta (5.0% at month 5) in 1/11 eyes. Student’s t-test showed significant improvement at one year compared with preoperative values for LogMAR value (P = 0.019), corneal staining score A (P = 0.00003) and D (P = 0.0003), STT (P = 0.004), and subjective symptoms (P = 0.015). No change was shown in tBUT and no serious adverse event occurred. Conclusion: This improved, minimally invasive surgical procedure has a low recanalization rate and achieves both objective and subjective improvements at one year. Keywords: Cauterization; Dry Eye; Lacrimal Canaliculi; Lacrimal Puncta; Punctal Occlusio

Brain Abscess as a Rare Complication of Primary Extranodal Nasal-type Natural Killer/T-cell Lymphoma

We present the case of a 58-year-old Japanese woman with a natural killer T (NK/T)-cell lymphoma complicated by brain abscess. NK/T-cell lymphomas represent a rare type of lymphoma derived from either activated NK cells or, rarely, cytotoxic T cells. They are aggressive Epstein-Barr virus (EBV)-associated lymphomas that involve mainly the nasal cavity. Brain abscess associated with primary extranodal nasal-type NK/T-cell lymphoma is extremely uncommon: to our knowledge, this is the first reported case of this lymphoma with brain abscess as the initial clinical manifestation. Endoscopic surgery was performed for definitive diagnosis under intraoperative navigation system. Chemotherapy followed by radiotherapy was performed and was effective: 72 months later the tumor has not recurred. Recommendations of endoscopic management for diagnosis and treatment of this rare neoplasm are discussed