An ActiveX component, QrtzGeotherm, to calculate temperature and vapor fraction in a geothermal reservoir using quartz Solubility geothermometry was written in visual basic 6.0. Four quartz solubility equations along ...
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An ActiveX component, QrtzGeotherm, to calculate temperature and vapor fraction in a geothermal reservoir using quartz Solubility geothermometry was written in visual basic 6.0. Four quartz solubility equations along the liquid-vapor saturation curve: (i) a quadratic equation of 1/T and pressure, (ii) a linear equation relating logSiO(2) to the inverse of absolute temperature (T), (iii) a polynomial of T including logarithmic terms and (iv) temperature as a polynomial of SiO(2) including logarithmic terms are programmed. The QrtzGeotherm has input parameters: (j) HRes-the reservoir enthalpy (kj/kg), (ii) SiO2TD-silica concentration in total discharge (ppm), (iii) GeoEq-number of quartz solubility equation and (iv) TempGuess-a guess value of the reservoir temperature (degrees C). The reservoir enthalpy H(res) is assumed to be the same as the total discharge enthalpy H(R). The output parameters are (i) TempRes-reservoir temperature (degrees C) and (ii) VapRes-reservoir vapor fraction. The first step is to calculate the total discharge concentration of silica SiO2TD from the concentration of silica SiO2Col of separated water, sampled after N-separations of vapor and water. To use QrtzGeotherm in MS-Excel, three functions SiO2TD, GeoResTemp and GeoResVap for an N-stage separation of geothermal reservoir fluid are written in visualbasic for Application (VBA). Similarly, a demonstration program, QrtzGeothrm, is written in visual basic 6.0. (C) 2008 Elsevier Ltd. All rights reserved.
Using the IAPWS-95 formulation, an ActiveX component SteamTablesIIE in visual basic 6.0 is developed to calculate thermodynamic properties of pure water as a function of two independent intensive variables: (1) temper...
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Using the IAPWS-95 formulation, an ActiveX component SteamTablesIIE in visual basic 6.0 is developed to calculate thermodynamic properties of pure water as a function of two independent intensive variables: (1) temperature (T) or pressure (P) and (2) T, P, volume (V), internal energy (U), enthalpy (H), entropy (S) or Gibbs free energy (G). The second variable cannot be the same as variable 1. Additionally, it calculates the properties along the separation boundaries (i.e., sublimation, saturation, critical isochor, ice I melting, ice III to ice IIV melting and minimum volume curves) considering the input parameter as T or P for the variable 1. SteamTablesIIE is an extension of the ActiveX component SteamTables implemented earlier considering T (190 to 2000 K) and P (3.23 x 10(-8) to 10000 MPa) as independent variables. It takes into account the following 27 intensive properties: temperature (T), pressure (P), fraction, state, volume (V), density (Den), compressibility factor (Z(o)), internal energy (U), enthalpy (H), Gibbs free energy (G), Helmholtz free energy (A), entropy (S), heat capacity at constant pressure (C(p)), heat capacity at constant volume (C(v)), coefficient of thermal expansion (CTE), isothermal compressibility (Z(iso)), speed of sound (VelS), partial derivative of P with T at constant V (dPdT), partial derivative of T with V at constant P (dTdV), partial derivative of V with P at constant T (dVdP), Joule-Thomson coefficient (JTC), isothermal throttling coefficient (IJTC), viscosity (Vis), thermal conductivity (ThrmCond), surface tension (SurfTen), Prandtl number (PrdNum) and dielectric constant (DielCons). (C) 2009 Elsevier Ltd. All rights reserved.
One potential practice to reduce nitrate and phosphate transfer from subsurface (tile)-drained farmlands is the use of fixed-bed, in-field subsurface bioreactors. These bioreactors are trenches filled with carbon mate...
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One potential practice to reduce nitrate and phosphate transfer from subsurface (tile)-drained farmlands is the use of fixed-bed, in-field subsurface bioreactors. These bioreactors are trenches filled with carbon material (usually wood chips), which serve as a medium for denitrifying bacteria to grow, thus reducing the amount of nitrate that enters water bodies from tile drains. If a bioreactor is undersized, water will not be detained long enough for denitrification to occur, or much of the water will bypass the system. On the other hand, if it is oversized, extreme reducing conditions can result in the formation of deleterious compounds. In this article, we propose a new protocol for optimizing the size of a bioreactor, describe an interactive routine in which this protocol has been implemented, and present the application of the routine to the design of a bioreactor in southern Minnesota. The routine is available in the online version of the Illinois Drainage Guide.
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