53,323 research outputs found
A Preliminary Check-List of the Marine Algae of the Moss Landing Jetty: An Annotated Floristic Compilation. Annual Report, Part 7, 1973
(PDF contains 55 pages
1/z-renormalization of the mean-field behavior of the dipole-coupled singlet-singlet system HoF_3
The two main characteristics of the holmium ions in HoF_3 are that their
local electronic properties are dominated by two singlet states lying well
below the remaining 4f-levels, and that the classical dipole-coupling is an
order of magnitude larger than any other two-ion interactions between the
Ho-moments. This combination makes the system particularly suitable for testing
refinements of the mean-field theory. There are four Ho-ions per unit cell and
the hyperfine coupled electronic and nuclear moments on the Ho-ions order in a
ferrimagnetic structure at T_C=0.53 K. The corrections to the mean-field
behavior of holmium triflouride, both in the paramagnetic and ferrimagnetic
phase, have been calculated to first order in the high-density 1/z-expansion.
The effective medium theory, which includes the effects of the single-site
fluctuations, leads to a substantially improved description of the magnetic
properties of HoF_3, in comparison with that based on the mean-field
approximation.Comment: 26pp, plain-TeX, JJ
The Deaths of Manufacturing Plants
This paper examines the causes of manufacturing plant deaths within and across industries in the U.S. from 1977-1997. The effects of international competition from low wage countries, exporting, ownership structure, product diversity, productivity, geography, and plant characteristics are considered. The probability of shutdowns is higher in industries that face increased competition from low-income countries, especially for low-wage, labor-intensive plants within those industries. Conditional on industry and plant characteristics, closures occur more often at plants that are part of a multi-plant firm and at plants that have recently experienced a change in ownership. Plants owned by U.S. multinationals are more likely to close than similar plants at non-multinational firms. Exits occur less frequently at multi-product plants, at exporters, at plants that pay above average wages, and at large, older, more productive and more capital-intensive plants.
Firm Structure, Multinationals, and Manufacturing Plant Deaths
Plant shutdowns shape industry productivity, the dynamics of employment, and industrial restructuring. Plant closures account for more than half of gross job destruction in US manufacturing. This paper examines the effects of firm structure on US manufacturing plant closures. Plants belonging to multi-plant firms and those owned by US multinationals are less likely to exit. However, the superior survival chances are due to the characteristics of the plants rather than the nature of the firms. Controlling for plant and industry attributes, we find that plants owned by multi-unit firms and US multinationals are much more likely to close.Exit, shutdown, closure, multi-plant firms, multinational firms, takeovers, entry costs, agglomeration, specialization
Understanding the U.S. Export Boom
U.S. exports grew at a rate of 8.2% per year from 1987-1994, far faster than the economy as a whole or even the manufacturing sector. This paper examines the source of this export boom and argues that the boom itself has been less remarkable for the rate of growth of exports than for the striking increase in export intensity. This increase in export intensity has occurred both in the aggregate and for individual plants across a wide range of industries. Competing explanations for the rise in exports are tested with a comprehensive plant level data set. Changes in exchange rates and rises in foreign income are the dominant sources for the export increase, while productivity increases in U.S. plants play a relatively small role. The results suggest that slower growth rates of U.S. trading partners and an appreciation of the dollar will have strong negative effects on the growth rate of U.S. manufacturing exports.
Polyimides with pendant alkyl groups
The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed
Who Dies? International Trade, Market Structure, and Industrial Restructuring
This paper examines the role of changing factor endowments in the growth and decline of industries and regions. The implications of an endowment-based Heckscher-Ohlin trade model for plant entry and exit are tested on 20 years of data for the entire US manufacturing sector. The trade model provides predictions for which industries will see growth through the positive net entry of plants. A multi-region version of the same model has predictions for which regions will see high turnover and net entry of plants. In a country such as the U.S. that is augmenting both its physical and human capital, the least capital-intensive, least skill-intensive industries are correctly predicted to have the lowest rate of net entry. In addition, increases in regional capital and skill intensity are associated with higher probabilities of shutdown, especially for plants in industries with low initial capital and skill intensities.
- …