A Comparison of Action of Chlorine and Ozone on Malodorous Organic Products

The study covers a comparison of actions of chlorine and of ozoneon maladorous products– amines and mercaptans. Oxygen requirements and , rates of consumption of reagents are examined. These products of ozonization are shown to do little harm to bacteria ; chloiamines are stable and have a certain degree of toxicity.

On–site tests with two units confirm the relatively high rateof oxidation of mercaptans when compared with amines.     

Removal Of Residual Organics From Drinking Water By Ozonation And Activated Carbon Filtration: A Pilot Plant Study

The effects of ozonation, granular (GAC) and biological activated carbon (BAC) in the removal of natural organic matter and precursors of disinfection byproducts from drinking water were studied on pilot scale. Ozonation was determined to be the best method to reduce concentrations of the precursors of AOX, chloroform and mutagenicity, whereas BAC removed organic matter the most effectively. Reductions in TA100 mutagenicity were an average 40%, 4%, 26% in ozonated, GAC and BAC filtered water, respectively. Average reductions of AOX levels were similar at 48%, 7% and 35%, respectively. The chloroform formation potential always increased after GAC filtration.     

Channel estimation with ISFLA based pilot pattern optimization for MIMO OFDM system

In multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems, the channel state information should be known by the receiver for obtaining transmitted data. Channel estimation algorithms are used to examine the multipath effects of frequency selective Rayleigh fading channels. In this paper, Compressed Sensing (CS) based channel estimation technique is considered for reconstructing the signal with improved spectral efficiency. It requires transmitting the known pilot data to the receiver for estimating channel information. The optimum pilot patterns are selected through reducing the mutual coherence of measurement matrix. In order to maximize the accuracy of sparse channel estimation and to reduce the computational complexity, an optimization algorithm Improved Shuffled Frog Leaping (ISFL) is proposed. When compared with the traditional estimation methods like least squares (LS), and minimal mean square error (MMSE), 4.7% of spectral efficiency is increased with ISFLA based channel estimation. Implementation results show that, by using the proposed algorithm, the bit error rate (BER) and Mean Square Error (MER) performance of the system is increased with 1.5 dB and 2 dB respectively.     

Reproducibility of indoor environment characteristics obtained in a walk through questionnaire. A pilot study

Walk through questionnaires may be feasible tools to obtain data on the indoor environment in community studies. However, limited information is available regarding the reproducibility of the data obtained through these questionnaires. In this pilot study, two construction engineering students inspected ten dwellings twice by means of a standardized walk through questionnaire. The two engineering students inspected the dwellings independent of each other within two months. Time between the two visits varied between 14 and 40 days. The variables presented were based on information from the residents and inspection. The continuous variables recorded included number of rooms in the dwellings, room volume, length of filled shelves and textile area. The inter- and intra-observed variabilities were poorer for number of rooms and shelf factor than for the other variables. For the 3 of the 9 categorical variables based on inspection, the inter-observer comparison showed complete agreement with a kappa statistics of 1.0, these variables being condition of the window frames and construction of outside walls and roof. One of the categorical variables showed a kappa statistics of < 0.5, these variables being presence of basement and presence of condensation at windows. This study indicates a wide variation in observer variability between various items of a walk through questionnaire. Clear definitions of all the parts of the questionnaire are needed, as well as thorough training of observers.     

Photocatalytic Oxidation of Organic Micro-Pollutants: Pilot Plant Investigation and Mechanistic Aspects of the Degradation Reaction

An innovative pilot plant based on UVB and TiO₂ (Anatase) allowed for photocatalytic degradation of organic micro-pollutants. The catalyst was immobilized onto a channel through which the solution containing a target molecule (methylene blue, MB) was re-circulated. Due to the cationic nature of the MB substrate, the adsorption reaction onto the catalyst surface provided a significant contribution to the overall degradation mechanism due to the negatively charged surface at neutral pH (TiO₂ pH_zpc = 6.8). The influence of the initial MB concentration was investigated in the range 0.3–2.0 mg L^?1 with the Langmuir–Hinshelwood (LH) model showing good data correlations at concentrations up to 0.7 mg L^?1, whereas at higher concentrations a pure zero-order (catalytic) kinetic trend was observed. Flow rate of the re-circulating solution sensibly influenced kinetics after the larger volumes of liquid exposed to UVB/TiO₂ and to the better oxygen saturation in the liquid phase. UV?vis and HPLC-MS/MS experimental determinations allowed for identification of MB residual concentration and by-products.     

In situ stabilisation/solidification: project lifecycle

The successful application of any remedial technology, including stabilisation/solidification, begins with the site investigation. Following a review of the data collected during the site investigation, a treatability study (TS) and pilot study (PS) are prerequisites to full-scale implementation as they show the effects and delivery of binders to the soils, the geochemistry of the soils, and binder dosages necessary for the existing geology. Further, evaluating the data gathered during the TS and PS can help in accurately estimating and executing full-scale operations. Invariably, deviations from the TS and PS regarding soil characteristics and soil chemistry may exist, but the experience gained via the TS and PS aids in making decisions when faced with new and unexpected conditions in the field. This paper will discuss the execution of typical TS and PS applications and their implementation for full-scale treatment. Because the long-term performance durability of design mixes and technology applications are not generally addressed in remediation, post-remediation monitoring and sampling data must be made available to the public to advance the science and art of stabilisation/solidification. As a first step in advancing this technology, this paper follows the lifecycle of stabilisation/ solidification projects from the site investigation through the completion of full-scale work. A 10-year post-remediation sampling event also evidences the long-term viability of the technology.     

Simulation of pervaporation process for ethanol dehydration by using pilot test results

This paper focuses on providing a pervaporation simulation method for ethanol dehydration from a practical point of view. The simulation procedure is performed by setting up simulation equations which describe the pervaporation process, obtaining the necessary data from pervaporation batch mode pilot tests, verifying the simulation tool through simulations of continuous mode pilot tests, and comparing the simulation results with the real pilot test results. We considered the mass and energy balances that describe separating an ethanol/water mixture by a pervaporation membrane. The simulation equations were mathematically expressed into simultaneous non-linear differential equations based on these balances. The necessary data for simulation consist of the thermophysical properties for the ethanol-water mixture and the characteristic data of a PVA composite membrane. The membrane characteristic data are permeation flux and membrane selectivity, which are functions of feed composition and operating conditions. These data were experimentally determined by a batch mode pilot test. The continuous mode pilot tests were simulated and the simulation results were compared to the real test results. The resulte were fairly good.     

基于卷积神经网络的大规模MIMO-D2 D的导频复用

大规模MIMO-D2D异构网络中,可以通过在蜂窝用户和D2D用户之间使用相同的频谱资源来提高频谱效率,但是在信道估计中,共享相同导频序列的用户之间会产生严重干扰.为了解决该问题,利用卷积神经网络,通过学习最优的导频分配来推断导频分配结果以减轻导频污染的影响.将用户在小区中的位置和相应的导频分配作为输入和输出标签,通过穷...     

WCDMA中一种利用查表LMS算法的自适应阵

本文针对WCDMA中上行链路存在导频信道的特点,并结合变步长LMS算法的优点,提出了一种查表LMS波束形成算法。该算法利用导频信号作为空间波束形成的参考信号,把误差范围和相应的步长存储到列表中,在进行波束形成时所要采用的迭代步长直接在列表中查取。该算法的实现复杂度低,收敛速度快,运算量小。     

Biohydrogen production by Rhodobacter capsulatus Hup mutant in pilot solar tubular photobioreactor

In this study, a pilot solar tubular photobioreactor was successfully implemented for fed batch operation in outdoor conditions for photofermentative hydrogen production with Rhodobacter capsulatus (Hup⁻) mutant. The bacteria had a rapid growth with a specific growth rate of 0.052 h⁻¹ in the batch exponential phase and cell dry weight remained in the range of 1–1.5 g/L throughout the fed batch operation. The feeding strategy was to keep acetic acid concentration in the photobioreactor at the range of 20 mM by adjusting feed acetate concentration. The maximum molar productivity obtained was 0.40 mol H₂/(m³ h) and the yield obtained was 0.35 mol H₂ per mole of acetic acid fed. Evolved gas contained 95–99% hydrogen and the rest was carbon dioxide by volume.