4,978 research outputs found

    Characterization of 60 GHz Shadowing by Human Bodies and Simple Phantoms

    Get PDF
    The 60 GHz band is very prominsing for high data rate (>1 Gb/s) wireless systems operating at short ranges. However, due to the short wavelengths in this frequency band, the shadowing effects cuased by human bodies and furniture are severe and needs to be modeled properly. In this paper, we present an experimental, measurementbased characterization of the reflection and shadowing effects in the 60 GHz band caused by human bodies and various phantoms, in order to find simple phantoms suitable for use in human shadowing measurements. It is shown that a water-filled human phantom serves as a good choice for this purpose

    New shield for gamma-ray spectrometry

    Get PDF
    Gamma-ray shield that can be evacuated, refilled with a clean gas, and pressurized for exclusion of airborne radioactive contaminants effectively lowers background noise. Under working conditions, repeated evacuation and filling procedures have not adversely affected the sensitivity and resolution of the crystal detector

    ECONOMIC FEASIBILITY OF BIODIESEL PRODUCTION IN NORTH DAKOTA

    Get PDF
    The U. S. biodiesel industry is rapidly expanding due to energy production concerns, environmental concerns, and recent legislation. The most common type of biodiesel in the United States is derived from soybean oil. Soybeans are a major crop in North Dakota and could easily supply a 5 million gallon per year biodiesel facility. Potential market segments of a biodiesel facility in North Dakota include agriculture, construction, and state fleet sectors based on current diesel use. However, with existing technology and no subsidy, biodiesel operation and investment costs for a North Dakota facility are not competitive with petroleum diesel. Using soybean oil prices of 17 cents to 25 cents per pound, the per gallon cost of producing diesel in southeastern North Dakota ranges between 2.02and2.02 and 2.64, while the wholesale price for regular diesel is $0.91. The cost of producing biodiesel is highly dependent on the price and availability of soybean oil. While biodiesel production technology is feasible and fairly simple, producing biodiesel in North Dakota is not economically feasible at least in the foreseeable future.biodiesel, soybeans, economic feasibility, Resource /Energy Economics and Policy,

    ECONOMIC FEASIBILITY OF BIODIESEL PRODUCTION IN NORTH DAKOTA

    Get PDF
    The U. S. biodiesel industry is rapidly expanding due to energy production concerns, environmental concerns, and recent legislation. The most common type of biodiesel in the United States is derived from soybean oil. Soybeans are a major crop in North Dakota and could easily supply a 5 million gallon per year biodiesel facility. Potential market segments of a biodiesel facility in North Dakota include agriculture, construction, and state fleet sectors based on current diesel use. However, with existing technology and no subsidy, biodiesel operation and investment costs for a North Dakota facility are not competitive with petroleum diesel. Using soybean oil prices of 17 cents to 25 cents per pound, the per gallon cost of producing diesel in southeastern North Dakota ranges between 2.02and2.02 and 2.64, while the wholesale price for regular diesel is $0.91. The cost of producing biodiesel is highly dependent on the price and availability of soybean oil. While biodiesel production technology is feasible and fairly simple, producing biodiesel in North Dakota is not economically feasible at least in the foreseeable future.biodiesel, soybeans, economic feasibility, Resource /Energy Economics and Policy,

    Color separate singlets in e+e−e^+e^- annihilation

    Get PDF
    We use the method of color effective Hamiltonian to study the properties of states in which a gluonic subsystem forms a color singlet, and we will study the possibility that such a subsystem hadronizes as a separate unit. A parton system can normally be subdivided into singlet subsystems in many different ways, and one problem arises from the fact that the corresponding states are not orthogonal. We show that if only contributions of order 1/Nc21/N_c^2 are included, the problem is greatly simplified. Only a very limited number of states are possible, and we present an orthogonalization procedure for these states. The result is simple and intuitive and could give an estimate of the possibility to produce color separated gluonic subsystems, if no dynamical effects are important. We also study with a simple MC the possibility that configurations which correspond to "short strings" are dynamically favored. The advantage of our approach over more elaborate models is its simplicity, which makes it easier to estimate color reconnection effects in reactions which are more complicated than the relatively simple e+e−e^+e^- annihilation.Comment: Revtex, 24 pages, 7 figures; Compared to the previous version, 1 new figure is added and Monte-Carlo results are re-analyzed, as suggested by the referee; To appear in Phys. Rev.
    • 

    corecore