Dye and its removal from aqueous solution by adsorption: A review

In this review article the authors presented up to-date development on the application of adsorption in the removal of dyes from aqueous solution. This review article provides extensive literature information about dyes, its classification and toxicity, various treatment methods, and dye adsorption characteristics by various adsorbents. One of the objectives of this review article is to organise the scattered available information on various aspects on a wide range of potentially effective adsorbents in the removal of dyes. Therefore, an extensive list of various adsorbents such as natural materials, waste materials from industry, agricultural by-products, and biomass based activated carbon in the removal of various dyes has been compiled here. Dye bearing waste treatment by adsorption using low cost alternative adsorbent is a demanding area as it has double benefits i.e. water treatment and waste management. Further, activated carbon from biomass has the advantage of offering an effected low cost replacement for non-renewable coal based granular activated carbon provided that they have similar or better adsorption on efficiency. The effectiveness of various adsorbents under different physico-chemical process parameters and their comparative adsorption capacity towards dye adsorption has also been presented. This review paper also includes the affective adsorption factors of dye such as solution pH, initial dye concentration, adsorbent dosage, and temperature. The applicability of various adsorption kinetic models and isotherm models for dye removal by wide range of adsorbents is also reported here. Conclusions have been drawn from the literature reviewed and few suggestions for future research are proposed.     

基于图像处理的铝合金薄板激光切割质量研究

为加深激光切割中材料去除机理的认识,利用Imagine-Pro Pluse(IPP)图像处理技术研究了激光切割去除熔化物颗粒形状及其特征尺寸分布。基于气熔比控制的试验方法,对0.85mm厚的1000系铝合金薄板进行了激光切割试验。通过对颗粒图像度量标准的设定,去除熔化物颗粒形貌分为圆形颗粒、类圆形颗粒和蝌蚪形颗粒。图像处理结果表明:随气熔比的增大,去除熔化物颗粒中圆形颗粒所占百分比越来越大,类圆形颗粒和蝌蚪形颗粒所占百分比越来越小,且各形状颗粒平均特征尺寸随气熔比的增大而减小。同时对切口质量进行了测量,得到切口质量随着气熔比的增加而提高。建立了熔化物去除模型,揭示了熔化物去除与切割质量有着直接密切的关系,并最终得到了较高质量切口和缝阵天线薄板样件。     

Ecotoxicity of, and remediation with, engineered inorganic nanoparticles in the environment

This article presents recent developments on the use of inorganic nanoparticles (NPs) for environmental remediation in polluted soil, water and gas. The number of publications on these topics has grown exponentially in recent years, especially those focused on wastewater treatment. Among these topics, removal of metals has become the most popular, although some works relate to the use of nanomaterials for the elimination of nutrients (e.g., nitrogen and some persistent organic pollutants). However, this growth has not been accompanied by knowledge about the behavior of NPs once used and released into the environment. In this article, we also comment upon the current situation with respect to NP toxicology (nanotoxicology). A remarkable number of different toxicology tests has been applied to NPs, often making it very difficult to interpret or to generalize the results. We analyze in detail the bioluminescence, Daphnia magna and other tests, and give some preliminary results obtained in our work.     

介质阻挡放电中OH自由基对甲醛脱除的影响

对管线式介质阻挡放电中的甲醛脱除进行了实验研究, 测量了介质阻挡放电产生的OH (A²Σ→X ²Π, 0-0)自由基发射光谱. 研究了在一个大气压下不同放电峰值电压、放电频率、添加氩气和氧气时甲醛脱除率与OH自由基发射光谱强度的变化关系. 实验结果表明: 在氮气含甲醛体系中, 提高放电峰值电压、放电频率和增大氩气含量时, 甲醛脱除率随OH (A²Σ→X ²Π, 0-0)自由基发射光谱强度的增强而提高; 当在氮气含甲醛体系中增大氧气含量时, 甲醛脱除率随OH (A²Σ→X ²Π, 0-0)自由基发射光谱强度的减弱而降低. 在11.5 kV放电峰值电压和9 kHz放电频率下, 氮气含甲醛体系中甲醛脱除率达93.8%.     

An extremal problem for total domination stable graphs upon edge removal

A connected graph is total domination stable upon edge removal, if the removal of an arbitrary edge does not change the total domination number. We determine the minimum number of edges required for a total domination stable graph in terms of its order and total domination number.     

Fluoride removal from water by chitosan derivatives and composites: A review

Fluoride is an essential element, indispensable for maintenance of dental health. Nevertheless, fluoride concentrations in drinking water above 1.5 mg L⁻¹ may be detrimental to human health. Many methods have been developed for removing excessive fluoride from drinking water, adsorption seems to be an effective, environmentally friendly and economical one. Since the sorption capacity of fluoride below 2 mg L⁻¹ on most conventional adsorbents is not satisfactory, much effort has been devoted to develop new and cost-effective fluoride adsorbents. This review reports the recent developments in the F⁻ removal in water treatment, using chitosan derivatives and composites in order to provide useful information about the different technologies. When possibly the adsorption capacity of chitosan derivatives and composites under different experimental conditions is reported to help to compare the efficacy of the fluoride removal process. A comparison with the adsorption capacity of other low cost adsorbents is also tabled.     

Anisotropic diffusion for noise removal of band pass signals

A noise removal method for band pass signals based on the anisotropic diffusion algorithm originally put forward by Perona and Malik is proposed in this paper. The anisotropic smoothing algorithm proposed here is for band pass signals modulated with a constant carrier frequency. A partial differential equation to smooth band pass noisy signals is derived. The propagator of this differential equation is also analytically calculated in this paper. An appropriate linear operator is then considered here for such band pass signals to form an anisotropic diffusion algorithm. The algorithm proposed here demonstrates better performance for band pass noisy signals containing discontinuities in comparison with the traditional Perona-Malik (PM) algorithm and is robust in the presence of excessive noise with SNR less than unity.     

基于高维空间几何信息学的遥感图像去薄云算法

遥感图像中薄云的存在为遥感图像的判读带来了极大的影响,本文针对遥感图像中的薄云雾提出了一种基于高维空间几何信息学(High-Dimensional Space Geometrical Informatics)(HDSGI)的去云的新算法.基于HDSGI理论,将一副带有薄云的遥感图像作为高维空间中的一点,通过各向同性滤波...     

基于相邻像素灰度改正比的遥感图像拼接缝消除

针对常用的拼接缝消除方法在图像间灰度差较大的情况下适用性差,甚至会导致新灰度突变的问题, 提出一种新的拼接缝消除方法。首先以拼接缝两侧相邻像素的改正比值为基准比值, 再将其分别在改正范围内逐渐过渡得到其他像素的改正比值, 然后沿拼接缝方向对改正比值进行卷积平滑以避免条纹状的改正痕迹现象, 最后与原图像加权融合得到无缝的结果图像。实验结果表明, 算法既实现灰度的平滑过渡又较好地保持了原图像的灰度特征, 与原图像的相似度和吻合度更高, 结果图像具有良好的视觉效果和较高的图像质量, 尤其对灰度差增大的情况仍能得到令人满意的结果。此外, 根据拼接缝两侧平均灰度差值提出一种改正范围与灰度差成正比的自动确定改正宽度的方法, 算法可行、有效, 具有较强的适用性。     

新型碱性精抛液对300mm铜膜全局平坦化的影响

The copper removal rate and uniformity of two types copper slurries were investigated, which was performed on the 300 mm chemical mechanical planarization （CMP） platform. The experiment results illustrate that the removal rate of the two slurries is nearly the same. Slurry A is mainly composed ofa FA/OI1 type chelating agent and the uniformity reaches to 88.32%. While the uniformity of slurry B is 96.68%, which is mainly composed of a FA/OV type chelating agent. This phenomenon demonstrates that under the same process conditions, the uniformity of different slurries is vastly different. The CMP performance was evaluated in terms of the dishing and erosion values. In this paper, the relationship between the uniformity and the planarization was deeply analyzed, which is mainly based on the endpoint detection mechanism. The experiment results reveal that the slurry with good uniformity has low dishing and erosion. The slurry with bad uniformity, by contract, increases Cu dishing significantly and causes copper loss in the recessed region. Therefore, the following conclusions are drawn： slurry B can improve the wafer leveling efficiently and minimize the resistance and current density along the line, which is helpful to improve the device yield and product reliability. This investigation provides a guide to improve the uniformity and achieve the global and local planarization. It is very significant to meet the requirements for 22 nm technology nodes and control the dishing and erosion efficiently.