PM10冲击采样器切割头设计参数对切割粒径的影响

本文从颗粒在气流中的受力情况分析入手 ,得到冲击采样器中喷嘴喷出后颗粒的运动轨迹方程以及运动轨迹与采样器切割头设计参数的关系式。分析了PM10空气采样器的切割原理 ,并利用数值计算研究颗粒在不同的流量、喷嘴尺寸及喷嘴与冲击板的距离下的运动轨迹 ,从而得到切割头设计参数对切割粒径的影响     

用于粉煤灰排放的加湿卸灰设备

针对粉煤灰排放产生二次污染问题，经过分析比较，选用了科学的加湿排放工作原理，设计了用于粉煤灰排放的新型灰料加湿卸灰机。     

流体流速对好氧颗粒污泥快速培养的影响

针对好氧颗粒污泥的快速培养,研究了流体流速对好氧颗粒污泥形成特性的影响机制.由于反应器构型的差异,造成水力剪切力与流体特性的不同,从而对好氧颗粒污泥的形成产生较大影响.研究表明,在圆筒式SBR反应器中接种厌氧活性污泥,在36d时培养得到了成熟的颗粒,与挡板式反应器相比提前了4d左右,且MLSS提高了16.2%,达到5023mg/L;颗粒也更加致密,SVI达到45mL/g,远好于挡板式SBR反应器（序批式反应器）的SVI 63mL/g.原因是与挡板式SBR反应器相比,圆筒式SBR反应器的平均液相流速更高,气泡分布更均匀,水力剪切力更强.因此圆筒式SBR反应器培养好氧颗粒污泥的时间较短,污泥颗粒化的速度提高,得到的颗粒污泥更加紧凑密实.     

辐射污染防治地方立法评析

由于国家立法的缺失,近年来中国的辐射污染防治地方立法十分活跃。将放射性污染防治和电磁辐射污染防治合并,制定综合性的辐射污染防治法已成为地方立法的趋势。两种辐射污染同中有异,在污染特性、危害原理和危害程度上有明显的区别,综合性立法既有必要又具可行性。但现有立法未能反映两种辐射污染防治的根本不同,特别是回避和混淆两种辐射污染的防治原则,确立电磁辐射污染防治适用风险预防原则是当务之亟。     

环境样品有机物分析预处理技术研究进展

在环境污染治理过程中,对环境样品进行预处理以进行分析检测必不可少,尤其针对环境中痕量存在的污染物,需经过预处理,浓缩被测痕量组分,以便提高检测方法的灵敏度,降低最小检测极限,并且可以使样品变得容易保存和运输。文章详细介绍了环境样品中有机物分析的预处理方法,将方法分为传统预处理方法和较新预处理方法,传统预处理方法包括:索氏提取法、超声波提取法、真空升华法、气相色谱法、液相色谱法;较新预处理方法包括:超临界流体萃取技术、固相微量萃取技术和吹扫捕集法。分别就传统和较新预处理方法的原理、优缺点及适用范围进行归纳总结和对比,并以多环芳烃的提取为例列举了各方法的应用步骤,从而为其他环境样品其他有机物分析预处理提供参考。     

应急避难场地“就近布置”规划原则探讨

通过对避难行为、避难需求的相关调查,对现有"就近布置"避难场地的规划原则进行了深入分析和研究,对"近"提出了"时间距离近"和"空间距离近"的两重涵义;在此基础上认为不同类型应急避难场地在布局上对"近"的要求应区别对待;该原则可进一步表述为"服务半径基础之上与人口密度、通达路径相对应,就近布置"。     

废弃钻井液固化处理pH值控制措施

提出了在原有固化处理技术的基础上,根据钻井泥浆原样pH值的高低,在固化材中适量加入酸性盐类混凝剂有效控制pH值的方法。采用此方法后,废弃钻井液的固化处理效果好,能够满足环保标准要求。     

Review of hydrogen safety during storage,transmission, and applications processes

Hydrogen is considered an excellent clean fuel with potential applications in several fields. There are serious safety concerns associated with the hydrogen process. These concerns need to be thoroughly understood and addressed to ensure its safe operation. To better understand the safety challenges of hydrogen use, application, and process, it is essential to undertake a detailed risk analysis. This can be achieved by performing detailed consequence modellings and assessing risk using the computational fluid dynamics (CFD) approach. This study comprehensively reviews and analyses safety challenges related to hydrogen, focusing on hydrogen storage, transmission, and application processes. Range of release and dispersion scenarios are investigated to analyse associated hazards. Approaches to quantitative risk assessment are also briefly discussed.     

Green energy generation through PEHF – a blueprint of alternate energy harvesting

In this work, an attempt has been made to harvest green energy from piezoelectric material using fluid flow in a conduit. Piezoelectric Energy Harvesting using Fluid Flow (PEHF) experimental model has been designed and the outputs obtained are compared with results obtained from simulations using ANSYS (computational fluid dynamics) and also with the mathematical modeling. The PEHF model has been utilized to analyze the effect of flow rate of water with reference to energy extracted. The full wave bridge rectifier and voltage doubler circuits have been used to obtain the direct current (DC) from the PEHF model. It is observed that the output obtained using experiments holds good in agreement with the results retrieved through simulations and mathematical results. The increase in flow rate of fluid leads to initially increase and then decrease in output of PEHF model as the maximum energy generated when flow rates (external force) matches with the frequency of excitation of the systems, i.e., at its resonance. The maximum energy output is generated at its resonance frequencies. It is observed that the full wave bridge rectifier circuit gives greater output as compared to a voltage doubler circuit.     

Dynamic contact angle effects on gas-liquid behaviors in the cathode of proton exchange membrane fuel cell with stirred tank reactor design

Liquid water management is still a critical issue in the improvement of proton exchange membrane fuel cell (PEMFC) performance. In this work, for the first time, the liquid water behavior and transport inside the cathode of a PEMFC with a stirred tank reactor (STR) design, rather than the conventional PEMFC flow channel design, are numerically studied. The dynamic contact angle (DCA) is applied to multiple wall boundaries in the numerical model through a user-defined-function (UDF) code, i.e., STR-DCA model. Another numerical model with the static contact angle (SCA) and same operating conditions, i.e., STR-SCA model, is also developed for comparison. The volume of fluid (VOF) method is employed in the simulation to track the gas-liquid interface. The results show that the liquid water distribution and transport are significantly different between these two models, indicating the remarkable effects of DCA on the simulation results. It is also verified the capability of STR-PEMFC to reduce the liquid water flooding, showing the potential of this channel-less type fuel cell in the further development.