Quantification of hydrochloric acid and particulate deposition resulting from space shuttle launches at John F. Kennedy space center,Florida, USA

Observations of damage to vegetation, acute reductions in surface water pH, and kills of small fish prompted the Biomedical Operations and Research Office at the John F. Kennedy Space Center to initiate intensive environmental evaluations of possible acute and long-term chronic impacts that may be produced by repeated launches of the space shuttle. An important step in this evaluation was the identification of deposition patterns and the quantification of ecosystem loading rates of exhaust constituents from the solid rocket motors (SRMs) in the area of the launch pad. These constituents are primarily aluminum oxide (Al₂O₃) and hydrochloric acid (HCl). During three launches of the space transportation system (STS-11, 13, and 14) up to 100 bulk deposition collectors, 83 mm in diameter containing 100 ml of deionized water, were deployed in a grid pattern covering 12.6 ha north of launch pad 39-A. Estimates of HCl and particulate deposition levels were made based on laboratory measurements of items entrained in the collectors. Captured particulates consisted of a variety of items including Al₂O₃, sand grains, sea shell fragments, paint chips, and other debris ablated from the launch pad surface by the initial thrust of the SRMs. Estimated ranges of HCl and particulate deposition in the study area were 0–127 g/m² and 0–246 g/m², respectively. Deposition patterns were highly influenced by wind speed and direction. These measurements indicate that, under certain meteorological conditions, up to 7.1 × 10³ kg of particulates and 3.4 × 10³ kg of HCl can be deposited to the near-field environment beyond the launch pad perimeter fence.     

Environmental impact of electromagnetic radiation from the 10 kW medium wave transmitter of Weihai Broadcasting Station

The attenuation of electrical field intensity , E , from an electromagnetic source , with the reciprocalof distance, 1/r, was studied using a theoretical calculation method and field simulation measurements. For a10 kW medium wave length transmitter , the electrical field E near the ground (2m above the ground) is lessthan 25 V/m for r>75m from the transmitter , which is lower than the ″Second Class Standard″ of the StateStandard, GB 9175-88. For r>150m, the electrical field E near the ground is less than 10 V/m, which islower than the ″First Class Standard″ . However, at places such as the platform on top of the buildings within200m from the transmitter, the field intensity is so strong that it exceeds the state standard value and that in-jures to human bodies can be caused by metal structures poorly earthed due to induced charge and secondaryradiation.     

文安5.1级地震前十三陵台电磁辐射观测的异常特征

通过对文安5.1级地震前十三陵台电磁辐射观测资料异常的分析,详细说明了地震前电磁辐射观测的异常特征,充分肯定了其在短临预报中所发挥的作用,为电磁辐射台站开展地震分析预报工作提供了一个震例依据.     

室内电磁辐射污染与防护

基于电磁辐射污染对环境和人体健康的影响 ,探讨了目前室内电磁辐射污染的现状和室内潜在的电磁辐射污染源 ,并就室内电磁辐射污染的防护措施提出了几点建议     

新一代天气雷达系统电磁辐射环境影响分析一例

对我国第一部新一代多普勒气候雷达的电磁辐射进行了实地监测,结合所在位置地势,高差等因素,评价了其辐射对环境产生的影响,为分析其搬迁后可能对环境产生的环境影响提供参考.     

三硬条件下孤岛区域大直径钻孔防冲方案优化

忻州窑矿是典型的冲击地压矿井,为确保忻州窑矿8939三硬条件孤岛工作面安全高效回采,采用理论计算的方法,得出在该地质条件下卸压钻孔参数的合理范围,并采用数值模拟方法对理论计算得出的参数范围进行深入研究,得出适合该地质条件下的大直径卸压钻孔优化方案。采用KBD5电磁辐射仪对卸压效果进行了检验,结果表明,经过优化,煤体内电磁辐射强度较原卸压方案降低了15.7%,累计脉冲数降低了16.6%。方案优化后不但提升了卸压效果,而且节省了约690个钻孔和30%的工作量。     

基于现场的电磁干扰工程分析方法

目的探讨机载平台的通信设备电磁干扰故障分析方法。方法以某型机载平台的电子通信设备电磁干扰故障为对象,在满足GJB 151或DO-160等电磁兼容要求和测试标准基础上,分析安装条件、系统架构及工作原理,通过计算和必要的测试建立故障分析数据表单,对被干扰设备非正常工作条件进行解析和仿真测试,得出解决方案。结果总结出基于现场的电磁干扰工程分析方法。结论外场条件下测试手段有限,通过该方法,可结合平台实际安装情况,给出针对性的有效解决方案。     

2450MHz电磁波污泥脱水过程中的温度效应

采用2450MHz电磁波进行污泥脱水,研究电磁波加载过程中污泥温度变化对于剩余污泥性质和溶出效应的影响.研究发现,经电磁波加载后,污泥的容积指数（SVI）随着温度的升高而降低,在温度为80℃时由原泥的130.73mL/g降至最低值95.25mL/g,污泥沉降性能得到改善;经电磁波加载后,污泥离心含水率也随着温度的升高持续降低,最低降到80℃时的93.52%;污泥的毛细吸水时间（CST）在60℃时由原泥的29.4s降至最低值23.2s,污泥比阻（SRF）始终高于初始值,说明电磁波的加载一定程度上可以改善剩余污泥的离心脱水和板框压滤脱水效果,但不利于剩余污泥的真空抽滤.在电磁波加载过程中,检测污泥胞外聚合物（EPS）及上清液中可溶性化学需氧量（SCOD）的含量,发现污泥温度升高有利于污泥胞内物质的溶出.在80℃时,污泥上清液中SCOD含量由初始的124.1mg/L增大到883.4mg/L;同时也发现,温度高于60℃后,污泥中微生物细胞破壁更明显,污泥EPS含量随之发生变化,对污泥脱水性能的影响更加显著.     

基于电磁混响技术的电磁环境与自然环境综合试验技术

目的研究电磁环境与自然环境综合试验方法。方法针对装备电磁环境与温度、湿度环境的多物理场综合试验需求,基于电磁混响技术,解决不同环境模拟相容性问题,对关键部件进行分析和设计,并依据相关标准进行了性能测试。依据IEC61000-4-21,分别测试电磁环境与自然环境综合箱在常温、高温和低温条件下的场均匀性。结果综合场均匀性偏差最大值小于3 d B,性能满足标准要求。结论基于电磁混响技术的综合试验方法,为装备在多重环境应力综合作用下效应机理研究和适应性考核提供了手段。     

厦门市电磁环境解析

为了掌握厦门市电磁环境状况,于2014—2015年对厦门市进行网格分区季度监测,由监测数据发现厦门市区的电磁辐射强度较低,其整体电磁环境监测值符合《电磁环境控制限值》(GB 8702—2014)标准的要求。不同区域低频磁感应强度呈现工业区商业区文教居住区旅游风景区的特点,其中商业区、文教居住区比总体平均水平(0.181μT)略低;射频电磁辐射呈现工业区商业区旅游风景区文教居住区的特点,商业区、旅游风景区的平均辐射强度比较接近,接近平均水平(0.73 V/m);运用主成分法分析电场和磁场分布的综合特征,分布表现为4个主成分;还发现了4代不同代际移动通信信号的分布规律,一代、二代手机代表通讯频段信号强度更高,强信号覆盖的范围也更大;三代手机代表通讯频段信号在中心城区、商业区和个别旅游风景区较强;四代手机代表通讯频段信号在中心城区和商业区较强。