2,015 research outputs found
Negotiated Contracts - Two-Step Procurement, Cost and Pricing Data Requirements and Protests to the Comptroller General
state of charge estimation of thermal storages for distributed generation systems
Abstract The aim of this work is the development of three different models to calculate the enthalpy content of a stratified water thermal storage tank from discrete temperature measurements. The difficulty related to enthalpy value evaluation comes from the discrete temperature measurement along the storage (often only 2 to 4 temperatures along the volume height are known): the actual temperature distribution between two subsequent probes is unknown. Three different models based on three different approaches were developed and compared, basing on experimental data. A first model calculates the enthalpy value considering the measured temperatures and the thermal power difference between generation and consumption. The second model uses a mathematical pre-defined temperature shape fitted considering real-time experimental data. The latter model is based on a 1-D physical approach using a multi-nodal method. All the models were validated against the experimental data obtained from the distributed generation laboratory installed in Savona, Italy
Gas turbine size optimization in a hybrid system considering SOFC degradation
The coupling of a pressurized solid oxide fuel cell (SOFC) and a gas turbine has been proven to result in extremely high efficiency and reduced emissions. The presence of the gas turbine can improve system durability compared to a standalone SOFC, because the turbomachinery can supply additional power as the fuel cell degrades to meet the power request. Since performance degradation is an obstacles to SOFC systems commercialization, the optimization of the hybrid system to mitigate SOFC degradation effects is of great interest. In this work, an optimization approach was used to innovatively study the effect of gas turbine size on system durability for a 400 kW fuel cell stack. A larger turbine allowed a bigger reduction in SOFC power before replacing the stack, but increased the initial capital investment and decreased the initial turbine efficiency. Thus, the power ratio between SOFC and gas turbine significantly influenced system economic results
del(13q) in chronic lymphoproliferative diseases
Review on del(13q) in chronic lymphoproliferative diseases, with data on clinics, and the genes involved
del(13q) in non-Hodgkin's lymphoma
Review on del(13q) in non-Hodgkin's lymphoma, with data on clinics, and the genes involved
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