Performance of a non‐load‐bearing steel stud gypsum board wall assembly: Experiments and modelling

A gypsum wall assembly was exposed to an intense real‐scale compartment fire. For the wall assembly, temperatures were measured at the exposed face, within the stud cavity, and at the unexposed face during the fire exposure. Total heat flux gauges were used to measure the temporal variation of the energy incident on the walls, and cameras, both visual and infrared, were used to image the unexposed face of the wall assembly during the fire exposure. The behaviour of the wall assembly under the fire load is discussed as are current model results for a simulation of the fire test. Copyright © 2006 John Wiley & Sons, Ltd.     

Finite Element Analysis of a Moving Boundary Value Problem

A finite element formulation and the solution of a set of nonlinear coupled heat and mass transfer equations for a two-phase system with a moving evaporation interface is presented. The interface condition takes into account the moisture transfer balance at the moving boundary. The finite element results were compared with existing results for a single phase system for model validation. In the two-phase system, the movement of evaporation front has an appreciable effect on the temperature and moisture distribution inside the porous medium during drying. The effect of the nondimensional heat of vapourization parameter γ on the evaporation front, temperature and moisture distribution in porous medium was studied. The higher the value of γ, the slower is the movement of the evaporation front. The temperature decreased and the moisture content increased as the nondimensional vapourization parameter γ increased. This model has potential applications in studying the heat and mass transfer characteristics in food and biomaterials.     

Thermodynamic Analysis of Various Dehumidifying Dryers for Wood

Typical methods of dehumidification of air circulating in the dehumidifying driers (indirect and direct cooler and partial exchange of the air) were analysed. Energy aspect of cooler operation was evaluated. The method for minimization of unit thermal energy consumption in a dehumidifying drier by the optimal selection of the cooler point was also given. Methods of the heat recovery of heat conveyed in a cooler lending to save energy (heat regeneration. expansion and compression of the air, a dehumidifier) were analysed. It was indicated that introduction of dehumidifiers into contemporary wood driers caused significant improvement of energy aspects of their operation     

管外上升R－113流体的沸腾换热试验

详细介绍了Ｒ－１１３流体管外上升流动的沸腾换热试验，包括试验台架、流量计和温度测量的修正，以及试验数据。拟合的换热关系式为ｑ＝５２８（Ｔｗ─Ｔｓ）１．３３。     

A method to estimate entropies and heat capacities applied to alkali oxides

We present a method that is useful in the estimate and assessment of heat capacity data. The approach is based on an analysis of the logarithmic average of the phonon frequencies. In this quantity, that may be easily derived from experimental data on the vibrational entropy, the influence of atomic masses can be exactly accounted for even in polyatomic solids. Our method is applied to Li₂O, Na₂O, K₂O, Rb₂O, and Cs₂O. In particular, literature data for K₂O are critically examined.     

淀粉液化液灭酶方法的研究

某些情况下淀粉液化液需要严格控制液化的程度 ,因此需要及时终止残余淀粉酶的活性。实验用降低液化液 pH值、升高温度、以及两者并用等 3种方法结束液化反应过程 ,实验结果可作为工业生产过程参考。     

Optimization of metal-based multilayers for transparent heat mirrors

Multilayer calculations by conventional matrix methods for dielectricum/noble metal/dielectricum systems on glass have been performed. The aim has been to maximize the integrated parameters for solar transmission, T_sol, and transmission of visible light, T_eye We have found that Ag is superior for maximizing the transmittance over the narrow visible wavelength range owing to the low internal absorptance. When solar energy transmission is considered multilayers based on Au are the best choice for metal film thicknesses above 15 nm. For thinner films, Ag is still to be preferred.     

A study on time schemes for DRBEM analysis of elastic impact wave

 The precise integration and differential quadrature methods are two new unconditionally stable numerical schemes to approximate time derivative with more than the second order accuracy. Recent studies showed that compared with the Houbolt and Newmark methods, they produced more accurate solutions with large time step for the problems where response is primarily dominated by low and intermediate frequency modes. This paper aims to investigate these time schemes in the context of the dual reciprocity BEM (DRBEM) formulation of various shock-excited scalar elastic wave problems, where high modes have important affect on traction response. The Houbolt method was widely recommended in many literatures for such DRBEM dynamic formulations. However, this study found that the damped Newmark algorithm was the most efficient and accurate for impact traction analysis in conjunction with the DRBEM. The precise integration and differential quadrature methods are shown inapplicable for such shock-excited problems due to the absence of numerical damping. On the other hand, we also found that to achieve the same order of accuracy, the differential quadrature method required much less computing effort than the precise integration method due to the use of the Bartels–Stewart algorithm solving the resulting Lyapunov matrix analogization equation. Received 6 November 2000     

Open‐cycle OTEC systems with freshwater product: Effects of noncondensable gases on performance of condenser

An open‐cycle ocean thermal energy conversion (OC‐OTEC) system is one of the energy conversion methods used to generate electricity from ocean thermal energy. For the OC‐OTEC system, steam evaporated from the surface seawater due to flash evaporation drives the turbine. At that time, dissolved gas such as air is introduced into the low‐pressure system (OC‐OTEC system) as the noncondensable gas, which degrades the performance of condensation heat transfer. In this paper, a small‐scale OC‐OTEC experimental unit experimentally investigates the effect of noncondensable gas on the heat transfer performance in a condenser. The experimental results are discussed in comparison with theoretical estimation by the Sparrow–in method. It is shown that the condensation is occupied by heat and mass transfer near a condensation surface and that the condensation efficiency is affected by exhaust quantity of noncondensable gas at a relatively high concentration ratio of condensable gas. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(1): 29–35, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20179