Multiple Aqueous Events in the Nakhlite Meteorite North West Africa (NWA)

Geological records suggest the past existence of abundant water flowing freely on Mars’ surface. Most of this aqueous activity appears to have been restricted to early Mars and although aqueous alteration by thin films of water or acid fog may still occur today, evidence suggests that liquid water has not existed at the surface for the last 3 Ga [1]. The Nakhlites, which are 1.3 Ga old Martian meteorites, contain mineralogical proof for the existence of liquid water within the shallow Martian crust duting the Amazonian [2]. To understand the nature of the water-rich fluids and conditions responsible for aqueous alteration on Mars, thorough characterization of chemical and mineralogical changes resulting from aqueous processes is essential.<p></p> The Nakhlite meteorite North West Africa (NWA) 817 was discovered in the Saharan desert (Morocco) as a single stone of 104g by meteorite hunters in 2000 [4]. In common with most other Nakhlite meteorites, NWA 817 presents mineralogical evidence of interactions with low temperature water-bearing fluids on Mars [5]. Here, we present a petrological and chemical reinvestigation of the alteration products of NWA 817. Our study reveals evidence for multiple fluid infiltrations in Mars subsurface during the Amazonian.<p></p&gt

Secondary Minerals in the Nakhlite Meteorite Yamato 000593: Distinguishing Martian from Terrestrial Alteration Products

The nakhlites are olivine-bearing clinopyroxenites that formed in a Martian lava flow or shallow intrusion 1.3 Ga ago [1, 2]. They are scientifically extremely valuable because they interacted with water-bearing fluids on Mars [3]. Fluid-rock interactions led to the precipitation of secondary minerals, many of which are hydrous. The secondary minerals consist in a mixture of poorly crystalline smectitic material and Fe-oxide, collectively called “iddingsite”, but also carbonate and sulphate [4]. The proportion, chemistry and habit of the secondary minerals vary between members of the Nakhlite group, which is thought to reflect compositional variation of the fluid within the Martian crust [5]. However, some secondary minerals are quite similar to terrestrial alteration products and thus the chemical and textural variations could also reflect terrestrial contamination (deposition or exchange). Identifying the origin of the secondary minerals is not straightforward but essential to unravel the Martian fluid chemistry and conditions.<p></p> Yamato 000593 (Y-000593) is a nakhlite meteorite that was discovered in Antarctica near the Yamato Mountains by the Japanesse Antarctic Research Expedition in 2000-2001 [6]. Most of the meteorite is covered by a black shiny fusion crust but it also has deep erosion features in its underside that probably formed by freeze- thaw cycles. As in most other Nakhlites, Y 000593 contains iddingsite-like alteration products believed to have been formed on Mars because they have devolatilization features at the vicinity of the fusion crust [7]. Additional evidence of Martian aqueous alteration is the presence of laihunite, a high temperature oxidative alteration product of fayalitic olivine [8].<p></p> The secondary minerals in Y-000593 can provide a powerful insight into the Martian hydrosphere from high to low temperature environments with implications for the origin, cycling, and availability of water on Mars. However, it is highly likely that some secondary minerals have formed on Earth which can biased our understanding of the Martian groundwater chemistry. With this in mind, we are trying to identify all the different secondary minerals and document their spatial and textural relations, their mineralogy and chemistry to better constrain their possible origin and the impact that terrestrial fluids may have had on the Martian alteration products.<p></p&gt

Method and apparatus for producing microshells

A method is described for forming hollow particles, or shells, of extremely small size. The shell material is heated to a molten temperature in the presence of a gas that is at least moderately soluble in the shell material, to form a solution of the molten shell material and the soluble gas. The solution is atomized to form a multiplicity of separate droplets that are cooled while in free fall. Cooling of a droplet from the outside traps the desolved gas and forces it to form a gas bubble at the center of the droplet which now forms a gas filled shell. The shell is reheated and then cooled in free fall, in an environment having a lower pressure than the gas pressure in the shell. This causes expansion of the shell and the formation of a shell having a small wall thickness compared to its diameter

Signatures of unconventional pairing in near-vortex electronic structure of LiFeAs

A major question in Fe-based superconductors remains the structure of the pairing, in particular whether it is of unconventional nature. The electronic structure near vortices can serve as a platform for phase-sensitive measurements to answer this question. By solving Bogoliubov-de Gennes equations for LiFeAs, we calculate the energy-dependent local electronic structure near a vortex for different nodeless gap-structure possibilities. At low energies, the local density of states (LDOS) around a vortex is determined by the normal-state electronic structure. However, at energies closer to the gap value, the LDOS can distinguish an anisotropic from a conventional isotropic s-wave gap. We show within our self-consistent calculation that in addition, the local gap profile differs between a conventional and an unconventional pairing. We explain this through admixing of a secondary order parameter within Ginzburg-Landau theory. In-field scanning tunneling spectroscopy near vortices can therefore be used as a real-space probe of the gap structure

IMPACTS ON U.S. PRICES OF REDUCING ORANGE JUICE TARIFFS IN MAJOR WORLD MARKETS

A demand model is developed to examine the impacts on orange juice prices resulting from elimination or reduction of the tariffs on orange juice imposed by the United States, European Union, and Japan. An empirical analysis suggests that elimination of the U.S. tariff by itself would decrease the U.S. orange juice price by about $0.22 per gallon, while simultaneous elimination of the U.S., European, and Japanese tariffs would decrease the U.S. price by about$0.13 per gallon. Alternatively, reducing these tariffs according to the Swiss 25 formula would decrease the U.S. price by an estimated $0.09 per gallon. The U.S. produces about 1.4 billion gallons of orange juice annually and each penny reduction in the price impact increases U.S. orange juice FOB revenue by$14 million.Demand and Price Analysis,

Canadian import demand for fresh fruits: a differential demand system approach

import demand, Canada, fresh fruit, Demand and Price Analysis, International Relations/Trade,

Demand for Nutrients: The Household Production Approach

This study uses the household production theory to study the demand for nutrients, i.e., households purchase a combination of food items from the market and produce the needed nutrients from these food items. By following the traditional household production approach, shadow prices for nutrients in food consumption are calculated. The cost function that generates the shadow prices appears plausible in terms of its elasticities of substitution and factor demand. After obtaining the calculated shadow prices of nutrients, the nutrient demand functions are estimated. Results show that the own-price elasticity of demand for nutrient is inelastic, whereas the expenditure elasticities indicate that nutrients are normal goods. Crossprice elasticities show that there appears to be complementarity in the demand for nutrients. This seems a logical result.nutrient, household production theory, demand, Demand and Price Analysis,

An Engel Curve Analysis of Household Expenditure in Taiwan: 1996-98

Seven systems of Engel curves for expenditures on ten commodity groups were estimated using Taiwanese household expenditure data for the period from 1996 through 1998. Results show that the estimated expenditure elasticities are insensitive to the choice of functional forms.Engel curve, Taiwan, Consumer/Household Economics,

They Were Meant for Each Other: Professor Edward Cooper and the Rules Enabling Act

This introduction to the essays in this Symposium illuminates Professor Ed Cooper\u27s years as Reporter to the Civil Rules Committee by first briefly describing those who preceded him in the position and his own background. We then describe some of Ed Cooper\u27s many contributions to the Civil Rules Committee, the Federal Rules, rulemaking, and civil procedure by examining the present state of the Rules Committees\u27 work under the Rules Enabling Act. We conclude that after almost eighty years of experience under that Act, it is working well in large part because of the sound leadership provided by Ed Cooper over his twenty years as Reporter. It was during these years that the Committee developed an approach to rulemaking that was at once transparent and empirical, with multiple opportunities for participation by members of the public, the bench, the academy, and the bar; with many informal opportunities for consultation with members of Congress and the Executive Branch; and with an understanding by the Committee of its role in relation to the courts, Congress, and the Executive. Two episodes of recent rulemaking and related activity are described as examples of how well the Rules Enabling Act is working, in large part because of the very flexibility and discretion the Act has provided since 1934. One of those episodes occurred when Judge Anthony Scirica chaired the Standing Committee and then- Judge David Levi chaired the Civil Rules Committee. The other occurred when Judge Lee Rosenthal and Judge Mark Kravitz were the chairs of the Standing and Civil Rules Committees, respectively. Both episodes provide a basis for optimism about the future. And they make clear Ed Cooper\u27s continued steady role in supporting and cultivating the robust good health of the rulemaking process and the institutional values it protects