Evaluation of Deformation-Strength Properties of Volcanic Soils by Laboratory and In-Situ Testings

The present study aims to clarify the deformation-strength properties of natural grounds consisting mainly of volcanic coarse-grained soils. Site investigations using cone penetration test (CPT), standard penetration test (SPT) and seismic cone penetration test (SCT) were performed at three sites in Hokkaido, Japan. In addition to these in-situ tests, a series of cyclic triaxial test on the undisturbed samples taken from their sites were also carried out to obtain the pseudo elastic shear modulus and damping ratio and their dependencies on strain level. From the test data, it was found that; (1) N-values obtained from SPT on crushable volcanic grounds are underestimated with the increase of the number of dynamic penetrations due to the particle breakage, (2) there are the linear relationships among ql from CPT, shear modulus GSC, obtained from SCT and SPT-N value for volcanic soil grounds, and (3) small strain shear modulus obtained from the in-situ and laboratory tests is independent of void ratios of volcanic grounds

Serial default and debt renegotiation

Emerging countries that have defaulted on their debt repayment obligations in the past are more likely to default again in the future than are non-defaulters even with the same debt-to-GDP ratio. This paper explains this stylized fact within a dynamic stochastic general equilibrium framework by explicitly modeling renegotiations between a defaulting country and its creditors. The quantitative analysis of the model reveals that the equilibrium probability of default for a given debt-to-GDP level is weakly increasing with the number of past defaults, consistent with empirical observations. The equilibrium of the model also accords with an additional observed fact: a country for which default terms require less than a 100 percent recovery rate tends to pay a higher rate of return (relative to a risk-free rate) on subsequently issued debt than do defaulting countries that agree to a full recovery rate

Sovereign defaults, external debt and real exchange rate dynamics

Emerging countries experience real exchange rate depreciations around defaults. In this paper, we examine this observed pattern empirically and through the lens of a dynamic stochastic general equilibrium model. The theoretical model explicitly incorporates bond issuances in local and foreign currencies, and endogenous determination of real exchange rate and default risk. Our quantitative analysis, using the case of Argentina�s default in 2001, replicates the link between real exchange rate depreciation and default probability around defaults and moments of the real exchange rate that match the data. Prior to default, interactions of real exchange rate depreciation, originated from a sequence of low tradable goods shocks with the sovereign�s large share of foreign currency debt, trigger defaults. In post-default periods, the resulting output costs and loss of market access due to default lead to further real exchange rate depreciation

The clinical significance of the arterial ketone body ratio as an early indicator of graft viabilityin human liver transplantation

Arterial ketone body ratio (AKBR) was measured sequentially in 84 liver transplantations (OLTx). These transplantation procedures were classified into 3 groups with respect to graft survival and patient condition at the end of the first month (Group A, the grafts survived longer than 1 month with satisfactory patient condition; Group B, the grafts survived longer than 1 month but the patients were ICU-bound; Group C, the grafts were lost and the patients died or underwent re-OLTx). In Group A, the AKBR was elevated to above 1.0 by the second postoperative day. In Group B, the AKBR was elevated to above 0.7 but stayed below 1.0 during this period. In Group C, the AKBR remained below 0.7 longer than 2 days after operation. Although conventional liver function tests showed significant increases in Groups B and C as compared with Group A, they were less specific in predicting ultimate graft survival. © 1991 by Williams & Wilkins

Sovereign defaults, external debt and real exchange rate dynamics

Emerging countries experience real exchange rate depreciations around defaults. In this paper, we examine this observed pattern empirically and through the lens of a dynamic stochastic general equilibrium model. The theoretical model explicitly incorporates bond issuances in local and foreign currencies, and endogenous determination of real exchange rate and default risk. Our quantitative analysis, using the case of Argentina�s default in 2001, replicates the link between real exchange rate depreciation and default probability around defaults and moments of the real exchange rate that match the data. Prior to default, interactions of real exchange rate depreciation, originated from a sequence of low tradable goods shocks with the sovereign�s large share of foreign currency debt, trigger defaults. In post-default periods, the resulting output costs and loss of market access due to default lead to further real exchange rate depreciation

Serial default and debt renegotiation

Emerging countries that have defaulted on their debt repayment obligations in the past are more likely to default again in the future than are non-defaulters even with the same debt-to-GDP ratio. This paper explains this stylized fact within a dynamic stochastic general equilibrium framework by explicitly modeling renegotiations between a defaulting country and its creditors. The quantitative analysis of the model reveals that the equilibrium probability of default for a given debt-to-GDP level is weakly increasing with the number of past defaults, consistent with empirical observations. The equilibrium of the model also accords with an additional observed fact: a country for which default terms require less than a 100 percent recovery rate tends to pay a higher rate of return (relative to a risk-free rate) on subsequently issued debt than do defaulting countries that agree to a full recovery rate

Sovereign Debt Restructurings: Preemptive or Post-Default

Sovereign debt restructurings can be implemented preemptively - prior to a payment default. We code a comprehensive new dataset and find that preemptive restructurings (i) are frequent (38% of all deals 1978-2010), (ii) have lower haircuts, (iii) are quicker to negotiate, and (iv) see lower output losses. To rationalize these stylized facts, we build a quantitative sovereign debt model that incorporates preemptive and post-default renegotiations. The model improves the fit with the data and explains the sovereign’s optimal choice: preemptive restructurings occur when default risk is high ex-ante, while defaults occur after unexpected bad shocks. Empirical evidence supports these predictions

Electrochemical reaction engineering of polymer electrolyte fuel cell

Although fuel cells can be considered as a type of reactor, methods of kinetic analysis and reactor modeling from the viewpoint of chemical reaction engineering have not yet been established. The rate of an electrochemical reaction is a function of concentration, temperature, and interfacial potential difference (or electromotive force). This study examined the cathode reaction in a polymer electrolyte fuel cell, in which oxygen and protons react over platinum in the catalyst layer (CL). The effects of the oxygen partial pressure and the cathode electromotive force on the reaction rate were assessed. Resistance to proton transport increases the electromotive force and reducing the reaction rate. It was established that the effectiveness factor of the cathode CL is determined by competition between the reaction and mass transport of oxygen and protons. Two dimensionless moduli that govern the cathode behavior are proposed as a means of depicting the processes in the cell