A Numerical Simulation of the Reconnection Layer in 2D Resistive MHD

In this paper we present a two-dimensional, time dependent, numerical simulation of a reconnection current layer in incompressible resistive magnetohydrodynamics with uniform resistivity in the limit of very large Lundquist numbers. We use realistic boundary conditions derived consistently from the outside magnetic field, and we also take into account the effect of the back pressure from flow into the the separatrix region. We find that within a few Alfven times the system evolves from an arbitrary initial state to a steady state consistent with the Sweet--Parker model, even if the initial state is Petschek-like.Comment: 33 pages, 17 figure

Comparison of data on Mutation Frequencies of Mice Caused by Radiation - Low Dose Model -

We propose LD(Low Dose) model, the extension of LDM model which was proposed in the previous paper [Y. Manabe et al.: J. Phys. Soc. Jpn. 81 (2012) 104004] to estimate biological damage caused by irradiation. LD model takes account of all the considerable effects including cell death effect as well as proliferation, apoptosis, repair. As a typical example of estimation, we apply LD model to the experiment of mutation frequency on the responses induced by the exposure to low levels of ionizing radiation. The most famous and extensive experiments are those summarized by Russell and Kelly [Russell, W. L. & Kelly, E. M: Proc. Natl Acad. Sci. USA 79 (1982) 539-541], which are known as 'Mega-mouse project'. This provides us with important information of the frequencies of transmitted specific-locus mutations induced in mouse spermatogonia stem-cells. It is found that the numerical results of the mutation frequency of mice are in reasonable agreement with the experimental data: the LD model reproduces the total dose and dose rate dependence of data reasonably. In order to see such dose-rate dependence more explicitly, we introduce the dose-rate effectiveness factor (DREF). This represents a sort of preventable effects such as repair, apoptosis and death of broken cells, which are to be competitive with proliferation effect of broken cells induced by irradiation.Comment: subimitting to J. Phys. Soc. Jpn, 32 pages, 8 figure

LDR structural experiment definition

A study was performed to develop the definition of a structural flight experiment for a large precision segmented reflector that would utilize the Space Station. The objective of the study was to use the Large Deployable Reflector (LDR) baseline configuration for focusing on experiment definition activity which would identify the Space Station accommodation requirements and interface constraints. Results of the study defined three Space Station based experiments to demonstrate the technologies needed for an LDR type structure. The basic experiment configurations are the same as the JPL baseline except that the primary mirror truss is 10 meters in diameter instead of 20. The primary objectives of the first experiment are to construct the primary mirror support truss and to determine its structural and thermal characteristics. Addition of the optical bench, thermal shield and primary mirror segments and alignment of the optical components occur on the second experiment. The structure will then be moved to the payload pointing system for pointing, optical control and scientific optical measurement for the third experiment

Economic freedom and employment growth in U.S. states

The authors extend earlier models of economic growth and development by exploring the effect of economic freedom on U.S. state employment growth. They find that states with greater economic freedom—defined as the protection of private property and private markets operating with minimal government interference—experienced greater rates of employment growth. In addition, they find that less-restrictive state and national government labor market policies have the greatest impact on employment growth in U.S. states. Beyond labor market policies, state employment growth is influenced by state and local government policies, but not the policies of all levels of government, including the national government. Their results suggest that policymakers concerned with employment should seriously consider the degree to which their own labor market policies and those of the national government may be limiting economic growth and development in their respective states.Economic development ; Employment

On the size and growth of government

The size of the U.S. federal government, as well as state and local governments, increased dramatically during the 20th century. This paper reviews several theories of government size and growth that are dominant in the public choice and political science literature. The theories are divided into two categories: citizen-over-state theories and state-over-citizen theories. The relationship between the 16th Amendment to the U.S. Constitution and the timing of government growth is also presented. It is likely that portions of each theory can explain government size and growth, but the challenge facing economists is to develop a single unifying theory of government growth.Economic development ; Expenditures, Public ; Local government ; Federal government

Social security versus private retirement accounts: a historical analysis

This paper compares Social Security benefits relative to those paid from private investments: specifically, whether 2003 retirees would gain more retirement income if they had invested their payroll taxes in private accounts during their working years. Three different retirement ages and four possible earnings levels are considered for two private investments-6-month CDs or the S&P 500. On average, the results suggest less than 5 percent of current retirees would receive a higher monthly benefit with Social Security. Several Social Security reform proposals are described.Social security ; Pensions ; Individual retirement accounts

High-resolution liquid-crystal heat-transfer measurements on the end wall of a turbine passage with variations in Reynolds number

Local heat-transfer coefficients were experimentally mapped on the end-wall surface of a three-times turbine vane passage in a static, single-row cascade operated with room-temperature inlet air over a range of Reynolds numbers. The test surface was a composite of commercially available materials: a Mylar sheet with a layer of cholesteric liquid crystals, which change color with temperature, and a heater made of a polyester sheet coated with vapor-deposited gold, which produces uniform heat flux. After the initial selection and calibration of the composite sheet, accurate, quantitative, and continuous heat-transfer coefficients were mapped over the end-wall surface. The local heat-transfer coefficients (expressed as nondimensional Stanton number) are presented for inlet Reynolds numbers (based on vane axial chord) from 0.83 x 10(5) to 3.97 x 10(5)

Visualization techniques to experimentally model flow and heat transfer in turbine and aircraft flow passages

Increased attention to fuel economy and increased thrust requirements have increased the demand for higher aircraft gas turbine engine efficiency through the use of higher turbine inlet temperatures. These higher temperatures increase the importance of understanding the heat transfer patterns which occur throughout the turbine passages. It is often necessary to use a special coating or some form of cooling to maintain metal temperatures at a level which the metal can withstand for long periods of time. Effective cooling schemes can result in significant fuel savings through higher allowable turbine inlet temperatures and can increase engine life. Before proceeding with the development of any new turbine it is economically desirable to create both mathematical and experimental models to study and predict flow characteristics and temperature distributions. Some of the methods are described used to physically model heat transfer patterns, cooling schemes, and other complex flow patterns associated with turbine and aircraft passages