The purpose of this investigation was to quantify the acute pressor response to caffeine at rest and during exercise, and to compare responses for different reportings of caffeine consumption and sensitivity. Eight young men with high use (HU) consumption patterns (<600 mg/day) and eight with low use (LU) patterns (<90 mg/day) participated. Caffeine (C) (4.5 mg/kg fat free mass) and placebo (P) were administered, double-blind and counterbalanced. Systolic (SBP), diastolic blood pressure (DBP) and heart rate (HR) were monitored during baseline, 40 minutes of absorption and graded treadmill walking. Oxygen consumption (V02) and rating of perceived exertion (RPE) were monitored during exercise. No significant differences were found for the responses to C between HU and LU nor between sensitive and not sensitive groups. Following a 12 hour abstinence, caffeine significantly increase SBP and DBP at absorption compared to P (11/9 mm Hg). The increase was additive with exercise for SBP but not DBP. Caffeine significantly increased VO2 compared to P. No significant differences were found for HR nor RPE between C and P trials. The present data indicate chronic caffeine consumption does not build tolerance to the acute pressor response to caffeine ingestion, the resting pressor response is additive with the pressor response to exercise for SBP, and individual perceptions of caffeine sensitivity are not accurate predictors of pressor responses. / School of Physical Education

We studied the pressure effect of polycrystal BiMnO3 (type-I multiferroic) and single crystal Co3TeO6 (type-II multiferroic) with different magnetic fields and pressures. With the primary objective of understanding the pressure effect on BiMnO3, complex multiple magnetic transitions (kink I, II and III) are observed under the maximum applied pressure of 15.94 kbar (~1.6 GPa). Kink I, a long-range soft ferromagnetic transition at TcI ~ 100 K under ambient pressure, is suppressed completely at 11.74 kbar. Kink II emerges at 8.66 kbar along with TcII ~ 93 K. Kink II is a long-range soft ferromagnetic the same as kink I but canted in nature. Kink III, a canted antiferromagnetic transition at TcIII ~ 72.5 K appears along with kink II also at 8.66 kbar. These results indicate the complicated correlation between the lattice distortion and the spin configuration under pressures and magnetic fields in multiferroic system. Whereas, two distinct anomalies (T1 ~ 26 K and T2 ~ 18 K) are observed on single crystal Co3TeO6 in magnetic susceptibility, specific heat, and neutron diffraction measurements. Interestingly, the strong anisotropic magnetic variations are also noticed in high-magnetic-field hysteresis measurements with applied magnetic field parallel to a- and c- axes. Dielectric studies were also carried out in different magnetic fields at the temperature range 5 ¡V 300 K. Concomitantly, frequency-independent step-like dielectric anomaly is observed around 18 K, coinciding with the transition of magnetic susceptibility, specific heat, and neutron diffraction. The dielectric constant is also modified by external magnetic fields. These experimental results strongly suggest the multiferroicity of Co3TeO6. From temperature-dependent X-ray diffraction studies, it is evident that a structural distortion appears around 18 K, responsible of dielectric and/or magnetic ordering. The transition at 18 K is disappeared under pressure above 9.82 kbar, indicative of suppressing structural distortion. Similarly, the lattice distortion and the spin configuration under pressures are important factors for multiferroic property. Through the specific heat and pressure-dependent susceptibility, the structural distortion probably results from the magnetic ordering, indication the dielectric anomaly at 18 K.

The effect of caffeine consumption on blood pressure has been widely studied. Robertson et al. (J Clin Invest 67: 1111-1117, 1981) cited findings of tolerance to humoral and hemodynamic effects from caffeine within four days when caffeine is consumed with each meal. These findings of tolerance have not been verified. The purpose of this study was to determine the effect of caffeine intake pattern on the development of tolerance to hemodynamic effects of caffeine. Fourteen volunteers were randomly assigned to two groups of seven. One group received 250 mg of caffeine in the morning only (MO), the other group received 250 mg of caffeine in the morning, afternoon, and evening (All Day-AD). Subjects underwent a seven day trial during which blood pressure (BP) and heart rate (HR) were assessed; morning beverage (250 mg of caffeine) was ingested and BP and HR assessments were obtained every 10 minutes for 50 minutes at rest, and after 10 minutes of cycling at 100 Watts. Afternoon and evening beverages were consumed which contained 250 mg caffeine each or placebo. No significant change in SBP, DBP, or HR from rest to 40 minutes post-caffeine absorption or between caffeine dosing pattern across trial days was found. A main effect was found for SBP post caffeine consumption (MO=5.4 vs. AD= 1.3). Mean values for DBP were stable across days 3-7 (M0=3.14-4.7 mmHg) but decreased from (3.86-.14 mmHg) from days 3 to 7 (AD). SBP revealed a significant interaction during exercise and across trial days. SBP and HR for the morning only group was higher than the all day caffeine consumption group across days. However DBP was lower across days for the morning only vs. the all day intake pattern. Therefore, caffeine dosing pattern does not appear to have an effect on tolerance to the hemodynamic effects of caffeine at rest or during exercise. / School of Physical Education

Bi2Rh3Se2 have been known as a charge-density-wave (CDW) superconductor, where the superconducting critical temperature Tc and the CDW phase transition are about 0.7 K and 250 K, respectively. Since there has no definite proof that the anomaly at around 250 K comes from charge-density-wave, we wished to provide another evidence to study whether the superconductor had the properties of CDW by electric resistivity measurements applied different pressures. Bi2Rh3Se2 was prepared by using the solid state reaction method and heating in the quartz tube. After the sample was synthesized, the quality was identified by XRD, MPMS, and specific heat probe. With the confirmation of the above-mentioned measurements, we can determine the sample¡¦s quality is good. Furthermore, temperature-dependent resistivity (2-340 K) under pressure (up to 22.23 kbar) on the ternary superconductor Bi2Rh3Se2 are performed to study the possible coexistence of CDW and superconductivity. Interestingly, the resistive anomaly occurred at Ts~250 K, is shifted to higher temperature with increasing pressure. This experimental finding is not consistent with a traditional CDW transition. Moreover, the temperature-dependent Transmission Electron Microscopy (TEM) electron diffraction is evident a structural phase transition from space group ¡§C1 2/m 1¡¨ (Ts > 250 K) to ¡§P1 2/m 1¡¨ (Ts < 250 K). Finally, We do the Co doping to make sure the effects of chemical pressure on this phase transition. The results are opposite to imposed by physical pressure that the transition is shift to lower temperature with more Co inside the sample.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21554号 / 理博第4461号 / 新制||理||1640(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 石田 憲二, 教授 前野 悦輝, 教授 松田 祐司 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

In spite of the large number of research works on carbon capture and sequestration (CCS), the migration and behaviour of CO2 in the subsurface (i. e. strata below the earth's surface) still needs further understanding and investigations with the aim of encouraging the governmental policy makers to adopt CCS technology as one of the most viable means to tackle the global warming threats. In this research work, a series of numerical simulations has been carried out using STOMP-CO2 simulation code to determine the flow behaviour and ultimate fate of the injected supercritical carbon dioxide (scCO2) into saline aquifers in medium terms of storage (i. e. few thousand years). The characteristics of the employed simulator, including the mathematical algorithm, governing equations, equations of states and phase equilibria calculations are explained in details.

Es wurden verschiedene NMR-spektrokopische Messungen an flexiblen und chiralen MOFs durchgeführt. Zur Untersuchung der Porensysteme kamen 129Xe-NMR und 13C-NMR an adsorbiertem CO2 zum Einsatz, während die MOF-Gitter und ihre Wechselwirkungen mit adsorbierten Gastmolekülen mittels 13C- und 1H-MAS-NMR-Spektroskopie studiert wurden. Während DUT-8(Ni) Flexibilität zeigt, weist DUT-8(Cu) ein starres Gitter auf. Die Flexibilität der sogenannten Solid-Solutions hängt in ausgeprägter Weise vom Verhältnis der funktionalisierten bdc-Linker 2,5-bme-bdc und db-bdc ab. Dieses Verhältnis hat zudem einen großen Einfluss auf die Orientierung der adsorbierten CO2-Moleküle. Es wurde erstmals eine Methode vorgestellt, die den Festkörper-NMR-spektroskopischen Nachweis chiraler Seitengruppen in chiralen MOFs erlaubt, wie anhand des chiral modifizierten UMCM-1 (ChirUMCM-1) demonstriert wurde. Die Chiralität kann einen NMR-spektroskopisch messbaren Einfluss auf die intrinsische Dynamik des MOF-Gitters ausüben, wie am chiral modifizierten DUT-32 deutlich wurde, dessen chirale Seitengruppe selektiv 15N- und 13C-isotopenmarkiert wurde.

Es wurden verschiedene NMR-spektrokopische Messungen an flexiblen und chiralen MOFs durchgeführt. Zur Untersuchung der Porensysteme kamen 129Xe-NMR und 13C-NMR an adsorbiertem CO2 zum Einsatz, während die MOF-Gitter und ihre Wechselwirkungen mit adsorbierten Gastmolekülen mittels 13C- und 1H-MAS-NMR-Spektroskopie studiert wurden. Während DUT-8(Ni) Flexibilität zeigt, weist DUT-8(Cu) ein starres Gitter auf. Die Flexibilität der sogenannten Solid-Solutions hängt in ausgeprägter Weise vom Verhältnis der funktionalisierten bdc-Linker 2,5-bme-bdc und db-bdc ab. Dieses Verhältnis hat zudem einen großen Einfluss auf die Orientierung der adsorbierten CO2-Moleküle. Es wurde erstmals eine Methode vorgestellt, die den Festkörper-NMR-spektroskopischen Nachweis chiraler Seitengruppen in chiralen MOFs erlaubt, wie anhand des chiral modifizierten UMCM-1 (ChirUMCM-1) demonstriert wurde. Die Chiralität kann einen NMR-spektroskopisch messbaren Einfluss auf die intrinsische Dynamik des MOF-Gitters ausüben, wie am chiral modifizierten DUT-32 deutlich wurde, dessen chirale Seitengruppe selektiv 15N- und 13C-isotopenmarkiert wurde.

Two-phase flow in porous media is an important subsurface process that has significant impacts on the global economy and environments. To study two-phase system in porous media, capillary pressure (Pc ), relative permeability (Kr), bulk electrical conductivity (σb) and bulk relative permittivity (εb) are often employed as characterization parameters. Interestingly, all of these parameters are functions of water saturation (S). However, the non-uniqueness in the Pc -S, Kr-S,σb-S and εb-S relationships pose considerable challenges in employing them for effective monitoring and control of the two-phase flow processes. In this work, laboratory scale experiments and numerical simulations were conducted to investigate the factors and conditions contributing to the non-uniqueness in the above relationships for silicone oil-water and supercritical CO2-water flow in porous media, with a special emphasis on geological carbon sequestration. Specifically, the dynamic capillary pressure effect, which indicates the dependence of the Pc - S relationship on the rate of change of saturation (αS/αt) during two-phase flow in porous media was investigated. Using a silicone oil-water system, the dynamic capillary pressure effect was quantified in term of the parameter named the dynamic coefficient, τ , and it was found to be dependent on the domain scale and the viscosity ratio of the two fluids. It was found that τ increases with the domain scale and the viscosity ratio. It is inversely affected by αS αt , which is related to the degree of resistance to the fluid motion, namely, viscosity. In almost all cases, τ was found to decrease monotonically with an increase in water saturation, S. An order increase in magnitude of τ was observed as the domain scale increases from 4cm scale to 8cm in height. A similar order of increase in τ was observed in the 12cm high domain scale. There is an order increase in the value of τ for the silicone oilwater system as the viscosity ratio increases from 200 to 500. For the supercritical CO2 (scCO2) and water system in porous media, the experiments and numerical simulations showed that τ increases with rising system temperature and decreasing porous media permeability. Dimensionless analysis of the silicone oil-water experimental results showed that by constructing non-dimensional groups of quantities expressing a relationship among different variables on which τ depends, it is possible to summarise the experimental results and determine their functional relationship. A generalised scaling relationship for τ was derived from the dimensionless analysis which was then validated against independent literature data. The exercise showed that the τ-S relationship obtained from the literature and the ii scaling relationship match reasonably well. This work also demonstrated the applicability of an artificial neural network (ANN) as an alternative computational platform for the prediction of the domain scale dependence of τ . The dependence of the Kr-S relationship on αS/αt was also investigated. The results showed that the Kr-S curve under dynamic flow condition is different from that under the quasi-static condition. Kr for water (Krw) increases with increasing water saturation and decreases with the increase in viscosity ratio while Kr for silicone oil (Krnw) increases with decreasing water saturation as well as with the increase in viscosity ratio. Also, Krw decreases while Krnw increases with the increasing boundary pressure. However, the εb-S and σb-S relationships were found to be independent of αS/αt for the scCO2-water system in carbonate and silicate porous media. Nevertheless, the εb and σb values decrease as the water saturation decreases in the two porous media samples. While εb decreases with increase in temperature in silica sand, the trend in the limestone showed a slight increase with temperature, especially at high water saturation. Also, the εb-S relationship is shown to be affected by pressure in silica sand increasing with the pressure of the domain. On the contrary, the σb-S relationship increases as the temperature increases with more significance at higher water saturation in the silica sand sample. This work further demonstrated the application of a membrane in the monitoring of the CO2 in geological sites used for carbon sequestration. Commercial silicone rubber coupled with a pressure transducer showed potential in the detection of CO2 leakage from geological sites. The response of the device in terms of the mass of permeated gas, permeability and gas flux were investigated for both CO2 and N2. In addition, the monitoring of potable water contamination in a shallow aquifer by the migrating or leaking of CO2 is demonstrated with the combination of the pH analysis, geoelectrical measurement techniques and the membrane-sensor system. Overall, the work in this PhD research demonstrated robust applications of two-phase systems'characterization parameters under different scenarios in the porous media. Implications of the findings in this work to the monitoring and control of two-phase systems in porous media are expatiated.