A model that describes hydration and heat-mass transport in Portland cement mortar during steam curing was developed. The hydration reactions are described by a maturity function that uses the equivalent age concept, coupled to a heat and mass balance. The thermal conductivity and specific heat of mortar with water-to-cement mass ratio of 0.30 was measured during hydration, using the Transient ...

As the important signal of once-through boiler's water-fuel ratio control, intermediate point temperature of supercritical boiler plays a key role in the decision of steam and water’s boundary, the match of fuel and water, the control of main steam temperature. The condition of its control directly impacts the once-through boiler’s safety and economy running. For an uncertainty model, a good co...

Softwood bark contains a large amounts of extractives-i.e., soluble lipophilic (such as resin acids) and hydrophilic components (phenolic compounds, stilbenes). The effects of the partial removal of water-soluble extractives before acid-catalyzed steam pretreatment on enzymatic digestibility were assessed for two softwood barks-Norway spruce and Scots pine. A simple hot water extraction step re...

*Correspondence: J. N. Chung, Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA e-mail: [email protected] Two concept systems that are based on the thermochemical process of high temperature steam gasification of lignocellulosic biomass and municipal solid waste are introduced.The primary objectives of the concept systems are (1) to develop the ...

An adiabatic dry saturated steam compression process with inner evaporative spray cooling in screw compressors for steam heat pump systems is studied. Thermodynamic model and simulation of this variable-mass compression process are devised. Differential equations are formulated and used to calculate the amount of liquid injected and the work to drive the compressor on the basis of simplificatio...

In this paper a neuro-predictive method is proposed in order to control the water level in the steam drum boiler system being in use at a Power Plant of Iaşi, Romania. The steam boiler provides thermal and electrical power and it works under complex technology in order to satisfy numerous technical, security and economical requirements. A nonlinear dynamic simulator for the proposed steam drum ...

The essential oils are frequently used in food processing industry, perfumery, cosmetics and pharmaceuticals. Most of the oils obtained by steam distillation and water distillation. It is necessary to specify the best conditions of essential oils production to get much more major compound(s) and higher yield oil. So, fennel oil was selected in this study. The objective of this work was to ident...

2,7-Dichlorodibenzo-p-dioxin (DCDD) was found to evaporate easily with water vapor from a heated solution. Steam distillation was also effective for the removal of DCDD from DCDD-applied soil; its concentration (250 microg/50g soil) in the original soil decreased to less than 5% after steam distillation for only 20 min. Actual dioxin-polluted soil in Tokorozawa City was partially decontaminated...

The solubility of cupric and cuprous oxides was measured in water over the range 25 to 350 °C in the presence of various chemical agents (NaOH, NH3, B(OH)3, H3PO4, (OHCH2)3CNH2, (OHCH2)3CN(OHCH2CH3)2, HF3CSO3, HNO3 and mixtures thereof), and in steam to 400 °C as a function of pressure. Large discrepancies exist between the various experimental studies, especially at high temperatures for cupro...