Mare volcanism in the Taurus-Littrow region

The products of mare volcanism at Taurus-Littrow occur in the form of crystalline basalts and volcanic glass beads. Both categories of samples define a compositionally diverse, but petrogenetically unrelated, suite of magmas derived by partial melting of a heterogenous, differentiated mantle beneath the region of the Apollo 17 landing site. This is a brief review of what is known and what is not known about mare volcanism at this location on the Moon

Sustainable External Debt Levels : Estimates for Selected Asian Countries

High ratios of external debt to GDP in selected Asian countries have contributed to the initiation, propagation, and severity of the financial and economic crises in recent years, reflecting runaway fiscal deficits and excessive foreign borrowing by the private sector. Applying the formal framework proposed by Villanueva (2003) to a selected group of Asian countries, the research estimates the external debt thresholds beyond which further debt accumulation will have negative effects on growth and will become unsustainable. The framework is an extension of the standard neoclassical growth model that incorporates global capital markets. Sustainability is measured in terms of the steady-state ratio of the stock of external debt to GDP, as functions of real world interest rates, risk spreads and their responsiveness to external debt burdens and market perceptions of country risk, marginal propensities to save out of national disposable income and foreign borrowing, rates of technical change, and parameters of the production function. The major policy implications are that in the long run, fiscal consolidation and the promotion of private saving are critical, and that reliance on foreign saving in a globalized financial world has limits, particularly when the risk spreads are positively correlated with rising external debt levels.GDP, financial and economic crises, neoclassical growth model

Sustainable External Debt Levels: Estimates for Selected Asian Countries

High ratios of external debt to GDP in selected Asian countries have contributed to the initiation, propagation, and severity of the financial and economic crises in recent years, reflecting runaway fiscal deficits and excessive foreign borrowing by the private sector. Applying the formal framework proposed by Villanueva (2003) to a selected group of Asian countries, the research estimates the external debt thresholds beyond which further debt accumulation will have negative effects on growth and will become unsustainable. The framework is an extension of the standard neoclassical growth model that incorporates global capital markets. ‘Sustainability’ is measured in terms of the steady-state ratio of the stock of external debt to GDP, as functions of real world interest rates, risk spreads and their responsiveness to external debt burdens and market perceptions of country risk, marginal propensities to save out of national disposable income and foreign borrowing, rates of technical change, and parameters of the production function. The major policy implications are that in the long run, fiscal consolidation and the promotion of private saving are critical, and that reliance on foreign saving in a globalized financial world has limits, particularly when the risk spreads are positively correlated with rising external debt levels.

External Debt, Adjustment, and Growth

High ratios of external debt to GDP in selected Asian countries have contributed to the initiation, propagation, and severity of the financial and economic crises in recent years, reflecting runaway fiscal deficits and excessive foreign borrowing by the private sector. More importantly, the servicing of large debt stocks has diverted scarce resources from investment and long-term growth. Applying and calibrating the formal framework proposed by Villanueva (2003) to Philippine data, we explore the joint dynamics of external debt, capital accumulation, and growth. The relative simplicity of the model makes it convenient to analyze the links between domestic adjustment policies, foreign borrowing, and growth. We estimate the optimal domestic saving rate that is consistent with maximum real consumption per unit of effective labor in the long run. As a by-product, we estimate the steady-state ratio of net external debt to GDP that is associated with this optimal outcome. The framework is an extension of the standard neoclassical growth model that incorporates endogenous technical change and global capital markets. The major policy implications are that in the long run, fiscal adjustment and the promotion of private saving are critical; reliance on foreign saving in a globalized financial world has limits; and when risk spreads are highly and positively correlated with rising external debt levels, unabated foreign borrowing depresses long run welfare.

Abundances of sodium, sulfur, and potassium in lunar volcanic glasses: Evidence for volatile loss during eruption

Six varieties of lunar volcanic glass are known to occur within the Apollo 17 sample collection. Investigations have shown that 25 volatile elements are known to be concentrated on the exterior surfaces of individual volcanic glass spheres. Since bulk analyses of volcanic glass provide an integrated abundance of an element on and with the glass spherules, other methods must be relied on to determine the interior abundance of an element. The interior abundance of an element with a volcanic glass sphere establishes the abundance of that element in the melt at the time of quench. The current study is part of a comprehensive attempt to measure the abundance of three volatile elements (Na, S, and K) within representative spheres of the 25 varieties of lunar volcanic glass currently known to exist at the Apollo landing sites. Comparison of the measured abundances of these elements within the interiors of individual glasses with bulk analyses and crystalline mare basalts will furnish new constraints on the geochemical behavior of volatile elements during lunar mare volcanism

CHARACTERISTICS OF HIGHLY EFFICIENT FARMS

A sample of Kansas farms was used to examine the relationship between overall efficiency and farm characteristics. Overall efficiency was significantly related to operator age, farm size, and farm type. Approximately 26.7% of the farms were in the top one-third overall efficiency category for more than half of the sample period.Farm Management,

Foam composite structures

The need to include fire resistant foams into state of the art aircraft interior paneling to increase passenger safety in aircraft fires was studied. Present efforts were directed toward mechanical and fire testing of panels with foam inclusions. Skinned foam filled honeycomb and PBI structural foams were the two constructions investigated with attention being directed toward weight/performance/cost trade-off. All of the new panels demonstrated improved performance in fire and some were lighter weight but not as strong as the presently used paneling. Continued efforts should result in improved paneling for passenger safety. In particular the simple partial filling (fire side) of state-of-the-art honeycomb with fire resistant foams with little sacrifice in weight would result in panels with increased fire resistance. More important may be the retarded rate of toxic gas evolution in the fire due to the protection of the honeycomb by the foam

Proceedings of a workshop on Lunar Volcanic Glasses: Scientific and Resource Potential

This workshop on lunar mare volcanism was the first since 1975 to deal with the major scientific advances that have occurred in this general subject, and the first ever to deal specifically with volcanic glasses. Lunar volcanic glasses are increasingly being recognized as the best geochemical and petrologic probes into the lunar mantle. Lunar volcanic glasses, of which 25 compositional varieties are presently known, appear to represent primary magmas that were produced by partial melting of differentiated mantle source regions at depths of perhaps 400 to 500 km. These high-magnesian picritic magmas were erupted onto the lunar surface in fire fountains associated with the release of indigenous lunar volatiles. The cosmic significance of this volatile component, in an otherwise depleted Moon, remains a lingering puzzle. The resource potential, if any, of the surface-correlated volatile sublimates on the volcanic glass spherules had not been systematically addressed prior to this workshop