Supercritical CO2 impregnation of Radiata pine with organic fungicides: Effect of operating conditions and two-parameters modeling

Supercritical impregnation of Radiata pine with ethyl acetate and decanal using CO₂ as carrier solvent has been studied at pilot plant scale. Radiata pine is one of the most common wood species that is originally from Australia and is widely grown in Spain and Portugal and ethyl acetate and decanal were selected as organic compounds.Some experiences were carried out to obtain the optimal operating conditions for the supercritical impregnation process. Experiments were conducted at pressures of 7–15 MPa, temperatures of 35–50 °C and solvent flow rate between 1.5 and 3.5 kg/h. The results of this study have indicated that the treatment gives much better preservative penetration and retention operating with low pressures (7.5 MPa), low temperatures (close to 35 °C) and moderate CO₂ flow rate (3.5 kg/h) in the selected operating range. Moreover, a simple mathematical model of two adjustable parameters (external mass transfer coefficient and partition coefficient) has demonstrated to fit the experimental impregnation curves with reasonable accuracy (average absolute deviation, 3–10%).     

Synthesis of Super-Microporous Aluminosilicate Having Excellent Water Vapor Adsorption Property as an Adsorbent for an Adsorption Heat-Pump

The synthesis of super-microporous aluminosilicate with a pore diameter of 14.6 Å has been achieved, by means of synthesis under specified conditions with a skeletal material comprising TMOS and a small quantity of sodium aluminate, and a conventional alkyl-trimethylammonium halide (C₁₀TMABr) as a template. This super-microporous aluminosilicate has an adsorption capacity of 0.2 ml/g at a relative water vapor pressure of 0.2, and thus is promising as an adsorbent for an adsorption heat-pump.     

Experiments of a prototype wind-driven reverse osmosis desalination system with feedback control

A prototype wind-powered reverse osmosis desalination system was constructed and tested on Coconut Island off the northern coast of Oahu, Hawaii, for brackish water desalination. The system has four major subsystems: a multi-vaned windmill/pump, a flow/pressure stabilizer, a reverse osmosis module, and a control mechanism. The feedback control mechanism, developed by this study, allowed this prototype system to be operated satisfactorily under mild ambient wind of 5 m/s or less. No auxiliary power source was needed. The system operational data showed that at an average wind speed of 5 m/s, brackish feedwater at a total dissolved solids concentration of 3000 mg/1 and at a flow rate of 13 1/min could be processed by this system. The average rejection rate of this prototype system was 97% and the average recovery ratio was 20%. The energy efficiency of the system was measured at 3 5%, which is comparable to the typical energy efficiency of well-operated multi-vaned windmills. Generally, the system's energy efficiency decreases as wind speed increases.     

筏板基础在自贡地区高层建筑设计中的应用研究

文章结合工程设计经验对自贡地区的高层建筑在选用天然筏板基础的设计过程中,对高层建筑基础设计中涉及到的重要的地基沉降计算、结构设计和地下水等有关问题的处理进行了具体分析,对在一般高层建筑中采用天然筏板基础的实用性和可行性从设计和施工两个方面进行了相关的工程探讨。     

工业酚水稀释的RBF神经网络预测控制

针对酚水稀释过程中酚水流量不便测量的工程情况,提出了一种基于RBF（径向基）神经网络的预测控制方法.在酚水罐每个液位变化周期内使用计算机定时测量液位高度,并将这些高度值作为目标输出,在每个循环结束时训练RBF网络,利用RBF网络的逼近能力来实时预测酚水流量,从而控制清水的配比,实现酚水质量浓度的稳定.该方法可避免测量误差带来的干扰,提高控制精度.     

4－氨基安替比林比色法测定水中苯胺类

基于苯胺与４－氨基安替比林的显色反应提出一种新的苯胺测定方法。本方法可以测定浓度为０．０２～４０ｍｇ／ｌ的苯胺水样，方法的回收率为９５．９％～１０２％，相对标准偏差为０．６３％～１．９７％。     

“双储”模式下的节能控制在小区供水系统中的应用

根据城市居民对供水的可靠性、稳定性、经济节能性的需求,课题组提出了一种基于"双储"模式的供水系统,并按照本市德胜住宅小区的供水要求,设计了一套由储水池、气压罐、变频器、多台水泵机组等主要设备构成的全自动变频恒压供水系统.经过近半年的运行测试,系统有效地解决了传统供水方式中存在的问题,增强了系统的总体性能,有明显的节能效果.     

水平切片解释方法在焦作井田构造复杂区的应用

河南焦作某矿地处焦作煤田东部,该矿东三盘区地质构造复杂,主采的2号煤层底板与L_8灰岩平均间距仅20m,与奥灰顶界面平均间距约100m,因此断层的存在极易导通奥灰水,形成较大的水患事故。故查明区内构造分布情况十分必要。本文重点介绍了用三维地震常规解释方法结合偏移及方差数据体水平切片解释方法在构造复杂区的应用情况,具有一定的推广意义。     

Microstructural Investigation of Protective and Non-Protective Oxides on 11% Chromium Steel

FIB, SEM and STEM/EDX were used to investigate X20 stainless-steel samples exposed to dry O₂, or O₂ containing 40% H₂O, with a flow velocity of 0.5 cm/s or 5 cm/s, for 168 hr or 336 hr at 600°C. Thin protective Cr-rich (Cr,Fe)₂O₃ was maintained on the samples exposed to dry O₂, even after 336 hr, and on the sample exposed to O₂/H₂O mixture with the low-flow velocity (0.5 cm/s) for 168 hr. The oxide scale formed in the latter environment contained less Cr, due to Cr loss through CrO₂(OH)₂ evaporation. Breakaway oxidation occurred on the samples exposed in high-gas-flow velocity for shorter time (168 hr) or in low-gas-flow velocity (0.5 cm/s) for longer time (336 hr). The breakaway scales featured a two-layered structure: an outward-growing oxide “island” consisting of almost pure hematite (α-Fe₂O₃), and an inward-growing oxide “crater” consisting of (Cr,Fe)₃O₄. The transition from a thin protective (Cr,Fe)₂O₃ scale to a non-protective thick scale on this martensitic/ferritic steel originated locally and was followed by rapid oxide growth, resulting in a thick scale that covered the whole sample surface.