Applying real-time control to enhance the performance of nitrogen removal in CAST system

A bench-scale reactor（72 L） red with domestic sewage, was operated more than 3 months with three operation modes： traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operation mode on the system performance and to develop a feasible control strategy. Results obtained from fixed-time control study indicate that the variations of the pH and oxidation-reduction potential（ORP） profiles can represent dynamic characteristics of system and the cycle sequences can be controlled and optimized by the control points on the pH and ORP profiles. A control strategy was, therefore, developed and applied to real-time control mode. Compared with traditional mode, the total nitrogen（TN） removal can be increased by approximately 16% in modified mode and a mean TN removal of 92% was achieved in real-time control mode. Moreover, approximately 12.5% aeration energy was saved in real- time control mode. The result of this study shows that the performance of nitrogen removal was enhanced in modified operation mode. Moreover, the real-time control made it possible to optimize process operation and save aeration energy.

RT-Notification: A Novel Real-Time Notification Protocol for Wireless Control in Fog Computing

Fog computing is an emerging paradigm that has broad applications including storage, measurement and control. In this paper, we propose a novel real-time notification protocol called RT-Notification for wireless control in fog computing. RT-Notification provides low-latency TDMA communication between an access point in Fog and a large number of portable monitoring devices equipped with sensor and actuator. RT-Notification differentiates two types of controls: urgent downlink actuator-oriented control and normal uplink access & scheduling control. Different from existing protocols, RT-Notification has two salient features:(i) support real-time notification of control frames, while not interrupting ongoing other transmissions, and(ii) support on-demand channel allocation for normal uplink access & scheduling control. RT-Notification can be implemented based on the commercial off-the-shelf 802.11 hardware. Our extensive simulations verify that RT-Notification is very effective in supporting the above two features.

Achieving and maintaining biological nitrogen removal via nitrite under normal conditions

The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor（SBR） activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride（NaCI） to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.

Induction of Internal Capacitance Effect in Performance Measurement of OPV （Organic Photovoltaic） Device by RTOSM （Real-Time One-Sweep Method）

The advantages of OPV （organic photovoltaic） are low cost, little pollution and flexible. But challenge for OPV manufacture still is lacking of accurately performance measurement due to capacitance issue. Firstly, characterization of OPV requires considering the slowly temporal response due to capacitance effect, and the relative I-V （current-voltage） curves are strongly dependent on the voltage sweep direction, even for the sweep time only in few seconds or less. Secondly, the IPCE （incident photon-to-electron conversion efficiency） also shows the slowly temporal response due to capacitance effect and is dependent on the wavelength of the incident light. Furthermore, the related features for measuring I-V curves are more sensitive with temperature due to non-linear characteristics issue, but current IPCE spectra of OPV are similar to that happened in conventional crystalline Si or amorphous silicon devices. In this work, we developed a RTOSM （real-time one-sweep method） applied both in I-V and IPCE to analysis different electronic transport materials, and result showed this new approach proposed a good way to slow down testing time and having better accuracy for OPV measurement by eliminating acceptance effect instantly.

Advanced nitrogen removal by pulsed sequencing batch reactors (SBR) with real-time control

The feasibility of pH and oxidation reduction potential(ORP)as on-line control parameters to advance nitrogen removal in pulsed sequencing batch reactors(SBR)was evaluated.The pulsed SBR,a novel operational mode of SBR,was utilized to treat real municipal wastewater accompanied with adding ethanol as external carbon source.It was observed that the bending-point(apex and knee)of pH and ORP profiles can be used to control denitrification process at a low influent C/N ratio while dpH/dt can be used to control the nitrification and denitrification process at a high influent C/N ratio.The experimental results demon-strated that the effluent total nitrogen can be reduced to lower than 2 mg/L,and the average total nitrogen(TN)removal effici ency was higher than 98%by using real-time controll strategy.

斜巷转载点粉尘污染规律及多断面雾幕控尘技术研究

针对斜巷转载点粉尘污染严重的问题,运用COMSOL软件对棋盘井煤矿3号转载点进行了几何建模,并基于计算流体力学(CFD)粒子追踪模型、有限元法和k-ε湍流模型,计算了3号转载点风流流线分布、速度多切面分布以及粉尘粒子运动轨迹,研究了生产工作时3号转载点处风流变化及粉尘运移规律,并针对性地提出了一种多断面雾幕控尘技术。该技术基于螺旋雾幕控尘、超音速隔尘原理,可形成距离长、覆盖范围广的雾幕以最大限度包裹粉尘颗粒,实现粉尘高效净化。最后通过控尘试验及在棋盘井煤矿3号转载点现场应用,验证了该技术的高效降尘特性以及可靠性。研究结果表明:风流分布主要受皮带速度、牵引力和诱导气流的综合作用影响,沿水平和垂直方向分层分布,形成密集且平均速度为0.5 m/s的涡流;粉尘易受涡流影响向四周扩散,主要分布在下风侧,粒径为5~15μm更容易受风流牵引扩散,聚集于工人呼吸带高度,污染严重。将该技术进行控尘试验和现场应用后,全尘和呼尘降尘效率分别高达93.65%、85.59%以上。

基于二进制掩码的单幅图像天空区域识别去雾算法

针对暗通道先验去雾算法处理得到的去雾图片存在颜色失真、偏移等问题,提出了一种基于天空区域识别的改进算法。首先,利用区域窗口自适应最小化滤波器获得暗通道图像,并使用二进制掩模图进行天空区域识别。其次,对天空区域进行透射率和大气光值的设定,同时引入引导滤波器对透射率图进行优化,避免了图像恢复时天空部分色彩失真的问题。最后,利用大气散射模型对原始图像进行复原。实验结果表明,本算法能够有效对图像中天空等明亮区域进行去雾,使处理后的图像具有良好的视觉效果。

转炉湿法除尘系统不粘丝网除雾特性研究

为了研究转炉湿法除尘系统的丝网除雾特性,搭建丝网除雾实验平台,研究了不同气流速度下,含水量、丝网层数、丝网目数对不粘丝网的除雾特性的影响。结果表明:随着气流速度的增加,除雾效率先提高后降低,为避免产生二次夹带现象,转炉湿法除尘系统丝网中的气流速度应控制在3~4 m/s;丝网层数从2层增加至6层,除雾效率先提高后趋于平缓,层数为4层时,除雾效率可达95%;气流速度不变时,除雾效率随着含水量、丝网层数、丝网目数的增加而提高,泛液气速随着含水量的增大而减小。

基于改进暗通道先验去雾的无人机目标检测研究

图像去雾是图像处理领域的一个重要研究热点。为了解决雾霾天气下图像的去雾与增强问题,提出了一种基于改进暗通道的去雾算法。首先为了使雾霾图像更接近无雾图像,提高图像的清晰度,该算法分别减少雾图像的RGB通道值,并结合每个减少的通道和其他两个先前未减少的通道,使用该图像去雾算法后再对三个新图像加权来恢复图像;为了解决图像天空区域出现颜色失真的问题,设置了一个参数K来分别计算天空区域和非天空区域的透射率;为了解决图像中亮度过暗和增加目标对比度,本文引入CLAHE的方法对图像进行增强处理。实验结果表明:本算法在5张图像的对比度值分别是MDCP和RSD算法的2倍多和3倍多,在5张图像中的信息熵均值为7.5589,均明显优于其余2种算法,并且该算法在雾霾天气下目标检测的平均精度可达73%,相比于未经处理图像前提升了15%,具有一定的可行性。

基于雾天交通标志识别算法的研究

针对雾霾天气导致交通标志难以被准确识别的问题,本文提出在雾霾天气下快速实现交通标志检测识别算法的研究。通过全局直方图均衡、局部直方图均衡、单尺度Retinex和多尺度Retinex四种去雾算法实现含雾图像的去雾处理。采用YOLOv1目标检测算法对交通标志目标进行精准定位和检测。通过Alex-Net分类识别模型实现对LISA交通标志数据集中14类交通标志的识别。结果表明,本文的方法能使快速准确地对雾天交通标志进行检测、分类和识别。

低碱无磷高效除油粉的研制及应用

为解决现有除油粉由于强碱的浓度过高导致加温时易产生碱雾、表面活性剂失活影响除油效果等问题,本文研制了一种低碱无磷高效除油粉,其配方组成(质量分数)为3%的异构醇油酸皂DX1639、1%的脂肪醇聚氧乙烯醚、2%的烷基糖苷、48%的Na2CO3、18%的五水偏硅酸钠、4%的葡萄糖酸钠和24%的柠檬酸钠。同时,研究表面活性剂比例、碱性助剂配比、螯合剂配比及工作液浓度对除油粉清洗效率的影响。结果发现:该除油粉的最优清洗用量(质量分数)为1%,pH为10.8,在35℃条件下超声清洗2min,清洗效率超过96%。该除油粉可应用于钢铁件、铝合金、锌合金和铜合金等金属件表面的除油清洗,在金属工业清洗领域具有广阔的应用前景。

夏热冬暖地区垃圾发电厂渣坑通风除雾设计

垃圾发电是一项较为环保的产业,但是随着垃圾焚烧发电科技的全面推广和垃圾焚烧处理发电厂建设中的飞速发展,垃圾焚烧处理后所形成的有机废气、污水、炉渣等衍生物对环境污染问题也日益严重,炉渣排出时,伴随着废气及微尘,渣坑内排风需要处理,减少对环境造成污染。特别是夏热冬冷地区渣坑仅通风解决不了灰渣坑内在冬季、春季节灰尘弥漫、雾气遮眼。

一种图像去薄雾方法

雾是常见的一种自然现象,它将使所拍摄到的图像模糊不清。将雾对景物的退化作用等效成照度变化的结果,根据Retinex理论及有雾图像直方图的特点,分析了MSR算法,采用正态截取拉伸对其输出图像进行处理,取得了较好的图像去薄雾效果。

遥感图像薄云薄雾的去除处理方法

分析云雾对图像的影响,对相关文献进行了分析总结,分别介绍了现有的各种薄云薄雾去除方法的主要原理及研究现状等,包括有基于物理模型和基于图像处理的薄雾去除方法,光谱图像去云、图像融合去云、同态滤波去云方法,并讨论了各处理方法的优势及局限。最后,对云雾去除图像处理方法进行了展望。

基于大气散射模型的单幅图像快速去雾

根据大气散射物理模型及光学反射成像模型,总结并分析了影响单幅图像去雾效果的3大因素,以实现对雾霾图像的快速去雾。基于光学原理,解释了暗影通道现象,从新的角度推导出了大气散射模型中各参数的求法。利用灰度开运算去除白色目标的干扰获得精确的环境光亮度,基于快速联合双边带滤波精确计算了大气散射函数,最后由光学反射模型计算了场景目标的反射率并有效截断至[0,1]区间。本方法可以消除天空及环境光线的影响,能真实复原场景的色彩和清晰度。仿真结果表明,对分辨率为576×768的图像处理时间仅为0.517s,且视觉效果和客观指标比现有算法均有不同程度的提高。与现有图像去雾算法相比,本文提出的参数计算方法提高了运算速度、场景适应能力和复原效果。

基于CLAHE的DSP实时去雾系统

为了解决户外监控系统在雾天视频清晰度较低的问题,设计了一种以DSP TMS320DM642为硬件核心,以限定对比度自适应直方图均衡化(CLAHE)为去雾算法的视频实时去雾系统.算法首先将原始图像分割成若干个大小相同的子区域,然后选取特定值截取每个子区域的直方图,并将截取下的像素均匀分配到每个灰度级,最终得到限定对比度直方图.实验结果表明,该系统能够有效提高雾天视频清晰度.

基于亮度小波变换和颜色改善的彩色图像去雾研究

针对户外薄雾条件下彩色图像对比度降低问题,提出了一种有效的图像去雾方法.先将图像亮度分量进行小波变换;然后对该分量图像的低频部分利用大气散射简化模型进行反锐化掩蔽高通滤波,亮度分量图像的高频部分采用非线性变换提升后,进而将处理过的低频、高频部分进行小波反变换重构出新的亮度图像,再利用HIS反变换出初级去雾图像;最后采用单尺度Ret-inex(SSR)算法、颜色恢复等方法改善初级去雾图像亮度,增强其颜色表现,得到最终的去雾图像.实验结果表明,本文提出的算法有效实用,对于薄雾的去除效果较好.

一种除去遥感影像薄云雾的方法

在借鉴相关研究的基础上提出了一种新的基于Laplacian图像增强和直方图分段线性变换的除去遥感影像薄云雾的方法,并与同态滤波和直方图匹配方法进行了实例对比研究。结果表明该文提出的方法不仅能够有效降低薄云雾覆盖干扰噪音,而且可以很好地保持原始影像真实的光谱特性,并能够增加遥感影像的空间细节信息,是一种有效除去薄云雾覆盖的方法。

金属矿山爆破微细粉尘云雾除尘机理及试验研究

为降低金属矿山爆破微细粉尘浓度,提出了巷道全断面云雾除尘技术,净化回风流中的粉尘。利用自行设计的雾化实验平台,分析了云雾喷嘴的雾化效果及气压、水压对雾化效果的影响,获得气流量、水流量随气压的变化规律,认为当气压为0.5 MPa,水压为0.2 MPa,水流量为35 L/h,气流量为2.65 m^3/h时,云雾雾滴中值粒径D50最小,约6.0μm。基于云雾喷嘴雾化特性及最佳工况条件,以云雾除尘主机和气水源处置为主体,研发了巷道全断面云雾除尘技术,并在梅山铁矿进行了现场试验。结果表明:爆破落矿后,经云雾除尘装置净化后,回风流中全尘、呼吸尘的降尘效率分别为96.89%、96.04%,表明云雾与粉尘粒径匹配效果好,可有效降低沿风流方向的微细粉尘浓度,提高降尘效率,取得较好经济效益和社会效益。

航拍图像暗通道先验去雾算法速度改进

针对暗通道先验去雾算法复杂程度较高,利用引导滤波精细化大气透射率图层时间较长的问题,提出一种用中值滤波精细化透射率图层的算法改进航拍图像去雾速度.改进算法定义了一种算法简单且具有边缘保护效果、与滤波窗口无关、时间复杂度为O(1)的中值滤波器,对云雾均匀的输入图像,用中值滤波较好地模糊了计算暗通道图层而产生的块状处理结果.通过计算机编码并采用无参考的客观图像质量评价方法比较算法改进前后的去雾图像效果,定量分析与实验结果表明,当原始图像云雾分布较均匀时,用中值滤波算法时间复杂度低,相比引导滤波更易实现,既能节约去雾时间,又能实现图像平滑处理.