Stack Sampling Research Articles

Noise analysis and optical response of microwave kinetic inductance detectors with an optical stack

We report on the experimental investigation of optical coupling for superconducting microresonators known as microwave kinetic inductance detectors (MKIDs) in the visible and near-infrared bands. MKIDs are photon-counting, time and energy-resolving detectors that still suffer from a poor quantum efficiency. To improve this efficiency, we propose to add a superconducting reflective layer below the absorbing part of the detector separated by a transparent Al2O3 layer with a quarter-wavelength thickness optimized around a single wavelength λ = 405 nm. We have first fabricated samples patterned from stoichiometric TiN ( Tc∼4 K), one with the full optical stack, one without for reference and one with a partial optical stack in order to characterize the noise influence of each layer individually. We observe that the full optical stack geometry has the most impact on the resonator’s noise and quality factors. A second design was fabricated to characterize the optical response to short pulses of the optical stack and we show from both the frequential noise and optical response that a strong signature of TLS is still present in the optical stack sample. We have finally obtained single-photon response with the optical stack using a more sensitive tri-layer TiN/Ti/TiN absorber ( Tc∼1.3 K) for which a maximum energy resolving power of R=E/ΔE∼ 1.3 was achieved using 405 nm laser pulses at 225 mK. The quality factors of both the reference and optical stack samples are similar but the frequency noise is still a tenfold higher for the optical stack sample which degrades the energy-resolving power of the detector.

Bendable, lamellar MXene membrane electrodes with diverse diffusion pathways for potential application in miniaturized capacitive deionization devices

Flexible devices have shown great application potential in portable and miniaturized devices. However, work on flexible electrodes for capacitive deionization (CDI) has not been well developed due to the issues of desalination property, processability, and availability under actual bending conditions. Herein, we constructed a kind of flexible lamellar MXene membrane by assembling Ti3C2Tx sheets with both crumpled and perforated structures and studied their desalination performance in conventional planar and bent configurations. The crumpled and perforated features in Ti3C2Tx (C-P-TC) nanosheets could optimize the in-plane and out-of-plane diffusion channels of the stacked samples, respectively, effectively improving the accessibility of membranes. As a result, the desalination performance of such C-P-TC electrodes was superior to that of those assembled from crumpled or perforated sheets alone. Significantly, this flexible C-P-TC electrode still showed excellent performance at real bend deformation, which possessed not only almost the same CDI capacity as the traditional planar configuration but also good cycling stability. This work not merely proposes an alternative strategy to improve the CDI performance of lamellar MXene electrodes by regulating the nanostructures of channels but also confirms their effective deionization ability under real bent state, greatly facilitating the potential use of flexible electrodes in miniaturized CDI devices.

Identification of exhaust stack sampling location of a research reactor considering ANSI/HPS N13.1-2011 mixing criteria using computational fluid dynamics

ABSTRACT Research Reactors have exhaust stacks that emit filtered radioactive gaseous waste into the atmosphere. In this research work, to check whether the radioactive gaseous waste met the requirements of ANSI/HPS N13.1–2011 mixing criteria, computational fluid dynamics (CFD) analysis was performed. According to ANSI criteria, Coefficient of Variance (COV) of velocity uniformity, flow angle, tracer gas, and aerosol particles concentration should be less than 20%. Therefore, the COV of the four parameters at different sampling positions along the stack height, with eight tracer gas and eight particles injection cases, were analyzed. The COV of velocity at 6 m height is 17.5% and flow cyclone is 9.8 degree. The results indicated that the 6 m height of the stack is enough for cyclone angle and COV of velocity to fulfill the ANSI mixing criteria. The COV of tracer gas concentration in one to eight injection cases is 10%, 4.8%, 7.5%, 17%, 2.5%, 6%, 13%, and 5% at 14 m stack height so the tracer gas also satisfied the standard mixing criteria in a concise length of 14 m because of the minimal difference in densities of tracer gas and air. However, due to their much higher density, aerosol particles took much longer to mix into the air. At 60 m stack height, the COV of aerosol particle concentration in one to eight injection cases is 14.8%, 18%, 8%, 12%, 11%, 15%, 15.5%, and 2%, respectively. As a result, when the stack height is set to 60 m, the COV of velocity, cyclone flow angle, tracer gas concentration, and aerosol particle concentration are found to meet the ANSI mixing criteria. Therefore, the minimum recommended height of the stack is proposed to be 60 m for the case under consideration.

Face Positioned Driver Drowsiness Detection Using Multistage Adaptive 3D Convolutional Neural Network

Accidents due to driver drowsiness are observed to be increasing at an alarming rate across all countries and it becomes necessary to identify driver drowsiness to reduce accident rates. Researchers handled many machine learning and deep learning techniques especially many CNN variants created for drowsiness detection, but it is dangerous to use in real time, as the design fails due to high computational complexity, low evaluation accuracies and low reliability. In this article, we introduce a multistage adaptive 3D-CNN model with multi-expressive features for Driver Drowsiness Detection (DDD) with special attention to system complexity and performance. The proposed architecture is divided into five cascaded stages: (1) A three level Convolutional Neural Network (CNN) for driver face positioning (2) 3D-CNN based Spatio-Temporal (ST) Learning to extract 3D features from face positioned stacked samples. (3) State Understanding (SU) to train 3D-CNN based drowsiness models (4) Feature fusion using ST and SU stages (5) Drowsiness Detection stage. The Proposed system extract ST values from the face positioned images and then merges it with SU results from each state understanding sub models to create conditional driver facial features for final Drowsiness Detection (DD) model. Final DD Model is trained offline and implemented in online, results show the developed model performs well when compared to others and additionally capable of handling Indian conditions. This method is applied (Trained and Evaluated) using two different datasets, Kongu Engineering College Driver Drowsiness Detection (KEC-DDD) own dataset and National Tsing Hua University Driver Drowsiness Detection (NTHU-DDD) Benchmark Dataset. The proposed system trained with KEC-DDD dataset produces accuracy of 77.45% and 75.91% using evaluation set of KEC-DDD and NTHU-DDD dataset and capable to detect driver drowsiness from 256×256 resolution images at 39.6 fps at an average of 400 execution seconds.

Tunable quasi-supercontinuum generation in a 1.7 µm spectral band for spectral domain optical coherence tomography

We present a system for generating a 1.7 µm quasi-supercontinuum (SC) as what we believe to be a new broadband light source for spectral domain (SD) optical coherence tomography (OCT). The quasi-SC source, whose spectral range and spectral shape can be arbitrarily changed, is based on wavelength-tunable soliton pulse generation and high-speed intensity modulation. A Gaussian-shaped quasi-SC was introduced into an SD-OCT system. A maximum axial resolution of 14 µm in air (corresponding to 10 µm in tissue) and an imaging sensitivity of 94 dB was obtained. We also demonstrated high-resolution imaging for tape stack, human nail and pig thyroid gland samples using a quasi-SC. From these results, we confirmed the usefulness of a quasi-SC for SD-OCT imaging.

Optimisation of stacked, bulk high temperature superconductors for trapped-field magnet applications

It is necessary to fabricate (RE)BCO bulk high temperature superconductors in the form of individual single grains in order to maximise the length scale over which current flows, and hence the trapped magnetic field. However, inherent difficulties in the grain growth process place limitations on the diameter and height of the single grain that may be achieved by existing melt processes. A practical approach to increase the height of the sample and the trapped field at its surface is by assembling individual single grains in a stack formation with their ab planes aligned parallel, primarily to avoid the expensive process of fabricating large, individual monoliths. The trapped fields observed at the top and bottom surfaces of a single grain sample are frequently different since both the superconducting and physical properties of single grain (RE)BCO samples are generally non-uniform. This leads to challenges in determining how to spatially arrange stacks of single grain samples to generate the largest and most uniform trapped field overall. In this study, we report the optimisation of two-stack configurations involving a total of 8 individual GdBCO/Ag single grains. The samples were arranged in four pairs and configured with different surfaces in contact in the assembly of the stack. The primary superconducting properties for trapped field and total flux distributions were measured at 77 K and compared for each stack arrangement. The initial results indicate that surfaces with inferior flux trapping properties (measured in terms of the overall trapped field value) of a two-sample stack should be positioned at the middle of the assembly to achieve the best overall trapped field and higher total flux at the external, and therefore, usable surface of the stack sample. A numerical modelling method that incorporates different Jc-B characteristics for the top and bottom layers of a single grain to take account of the variability in physical properties and spatial non-uniformity confirmed the optimised experimental arrangement of the stacked bulk samples. Furthermore, the optimisation of single grains of ring geometry to achieve a longer and wider uniform magnetic field zone inside the bore was also performed.

Prediction of inhalation health risk of mercury emissions from stacks of cement plant employing coal as an alternative fuel

Due to the Egyptian shortage of energy sources, especially for energy-intensive industries, the Egyptian President decree No 105-2015, and the Egyptian Prime Minister’s Decisions No. 964 - 2015, No 544-2017, and No 618-2017 setting standards for the exportation, using, handling, and storage of coal as an alternative fuel in mega industries within the Arab Republic of Egypt. Fossil fuels, with their different types, are materials that produce different amounts of air pollutants, especially coal, which, when burned, produces quantities of sulfur oxides, carbon oxides, and some heavy metals that have environmental and health effects in the short and long term alike. The objective of the present study is to identify the distance from each stack of approximately zero mercury concentration as compared to the distance of the external plant fences to ensure that the community air is free from mercury of the cement production source by using an air pollutants dispersion model. This study was a descriptive cross-sectional survey that was conducted in Cement Production plant in the Helwan area that use coal as an energy source. Stack sampling of both vapor and particulates' Hg was conducted according to the standard isokinetic method.

Reduction of pollutant emissions from a heat treatment furnace.

This paper addresses a preliminary study on the emission control of pollutants from an industrial furnace. The stack sampling technique was implemented in this study, and the quantity of pollutants released from the furnace smoke was monitored. The transverse points required to collect the data were selected based on the upstream and downstream disturbances. At first, the investigation was made with the furnace oil. A 15.28% and 5.1% of CO2 and O2 were observed in the flue gas from of regular furnace oil. Hence, by considering the emission level observed, the analysis was repeated with the low sulphur-low stack and the coal tar fuel. The emission of SO2 and N2 was reduced with coal-tar fuel compared with the regular furnace fuel. Thus, the proposed operational adjustment attenuates the pollutant emission, which also helps to reduce the unfavorable impact on the environment. In the future, the authors intend to include a design change in the furnace burner, which would help to increase fuel efficiency and reduce pollution.

Modeling steganocontent extraction attempts with different lengths stack sampling series of images blocks

The results obtained by using different lengths of sample stacks of runs in simulating the attempts of unauthorized extraction (attack) of steganocontent "protected" by implementing the mechanism of inter-block multiplexing of the parameters of the run lengths of image blocks have been considered in the article. The relationship between the parameters of processing the content (namely, halftone images) and the number of series, as well as the combinatorics of the component elements of the obtained pairs of series parameters, which are the objects of inter-block multiplexing has been demonstrated. It is concluded that the simultaneous use of 2-level data multiplexing significantly extends the capabilities to withstand content attack attempts. It has been found that the use of blocks of higher dimensionality, significantly reduces the role current parameters of the series reliance (base) blocks, in breaking the structure of the original images (those. original content). It is noted that use of two levels of multiplexing of output data at once significantly increases the resistance of the content to attempts at its unauthorized extraction, leading to large distortions in the attacked image, in case of incorrect selection of the active processing parameters.

Feasibility of Using Isokinetic Sampling Techniques to Extract a Representative Sample from Processes in the United Kingdom

The requirement to monitor and control particulate emissions from industrial processes using continuous emission monitoring systems (CEMS) has significantly increased over recent years. Under current legislation, CEMS equipment requires calibration against the standard reference method (SRM) using isokinetic sampling and gravimetric analysis under controlled conditions as detailed through BS EN 13284-1 “Stationary source emissions–Determination of low range mass concentration of dust. Manual gravimetric method”. This process includes pumping a known volume of gas through a filter, which is weighed before and after sampling, and the total mass of dust per m3 can then be calculated to output results in mg/m3. As tougher legislation is introduced and stringent emission limit values (ELVs) are imposed on emissions processes in the United Kingdom (UK), the calibration of CEMS is increasingly more difficult due to the reliability of the SRM at low concentrations. The accuracy of results from the SRM and therefore CEMS equipment must be questioned when the uncertainty of measurement is higher than process ELVs. This research analyses data taken from an industrial survey and 21 UK processes where the standard reference method, in accordance with the procedure in BS EN 13284-1 has been used for particulate measurement. Investigating the reliability of isokinetic sampling when used as a method to extract a representative sample from a stack process when used in conjunction with innovative, alternative methods of sample analysis. In processes with particulate emissions <5 mg/m3, 80.7% of the total sample was collected in the rinse, and for processes >5 mg/m3, 56.4% of the sample was collected in the rinse. The data does not suggest any correlation between any of the measured parameters and the percentage of particulate in the rinse, including the stack velocity, isokinetic percentage, sample volume, and total mass concentration.

Changes in trace metal concentrations throughout the phosphogypsum lifecycle

Phosphogypsum (PG) samples from four distinct sources in the Southeastern US were analyzed to explore the variation in total metal content between newly generated (fresh) PG and PG disposed of in phosphogypsum stacks for different lengths of time (stack). Fresh PG exhibited greater total metal concentrations relative to stack PG, including those identified in the literature as important from a risk assessment perspective (As, Cd, Co, Cr, Cu, Pb, and Zn). The pH varied between fresh and stack PG, with some stack samples exhibiting lower pH than fresh samples, however the relationship between pH and age of sample was not linear. Stack samples with pH values similar to fresh samples possessed lower concentrations of total inorganic metals than fresh samples suggesting that process water drainage and stack location play an important role in the reusability of PG as they can affect the pH of stack PG and total inorganic metal concentrations. Overall observations show that stacking PG for three or more years prior to beneficial reuse provides a construction material with lower total metal concentrations than fresh PG.

'Cloudbuster': a Python-based open source application for three-dimensional reconstruction and quantification of stacked biological imaging samples.

Three-dimensional (3D) spheroid cultures are generating increasing interest in cancer research, e.g. for the evaluation of pharmacological effects of novel small molecule inhibitors. This is mainly due to the fact that such 3D structures reflect physiological characteristics of tumours and the cellular microenvironments they reside in more faithfully than two-dimensional (2D) cell cultures; in addition, they allow the reduction of animal experiments while providing significantly relevant human-based models. Quantification of such organoid structures as well as the mainly slice-based acquisition and thus forced 2D representation of 3D spheroids provide a challenge for the interpretation of the associated generated data. Here, we provide a novel open-source workflow to reconstruct a 3D entity from slice-recorded microscopical images with or without treatment with anti-migratory small molecule inhibitors. This reconstruction produces distinct point clouds as basis for subsequent comparison of basic readout parameters using average computer processor, memory and graphics resources within an acceptable time frame. We were able to validate the usefulness of this workflow using 3D data generated by various imaging techniques, including z-stacks from confocal microscopy and histochemically labelled spheroid sectioning, and demonstrate the possibility to accurately characterize inhibitor effects in great detail.

Non-destructive depth profile evaluation of multi-layer thin film stack using simultaneous analysis of data from multiple X-ray photoelectron spectroscopy instruments

Non-destructive depth profile evaluation of multi-layer thin film stacks using simultaneous analysis of angle-resolved X-ray photoelectron spectroscopy data from multiple instruments is demonstrated. The data analysis algorithm, called the maximum smoothness method, was originally designed to handle data from a single XPS instrument with a single X-ray energy; in this work, the algorithm is extended to provide a simultaneous analysis tool which can handle data from multiple instruments with multiple X-ray energies. The analysis provides depth profiles for multilayer stacks that cannot be obtained by conventional data analysis methods. In this paper, metal multi-layer stack samples with total thickness greater than 10 nm are analyzed with the maximum smoothness method to non-destructively obtain depth profiles, with precise information on the chemical states of atoms in the surface layer (<2 nm) and the overall layer stack structure, which can only be obtained by analyzing the data from multiple instruments.

A Self-calibrating Halo-based Galaxy Group Finder: Algorithm and Tests

Abstract We describe an extension of the halo-based galaxy group-finding algorithm. We add freedom to the algorithm in order to more accurately determine which galaxies are central and which are satellites, and to provide unbiased estimates of halo masses. We focus on determination of the galaxy-halo relations for star-forming and quiescent galaxies. The added freedom in the group-finding algorithm is self-calibrated using observations of color-dependent galaxy clustering, as well as measurements of the total satellite luminosity in deep imaging data around stacked samples of spectroscopic central galaxies, L sat. We test this approach on a series of mocks that vary the galaxy-halo connection, including one mock constructed from Universe Machine results. Our self-calibrated algorithm shows marked improvement over previous methods in estimating the color-dependent satellite fraction of galaxies. It reduces the error in log M h for central galaxies by over a factor of two, to ≲0.2 dex. Through the L sat data, it can quantify differences in the luminosity-to-halo mass relations for star-forming and quiescent galaxies, even for groups with only one spectroscopic member. Thus, whereas previous algorithms cannot constrain the scatter in L gal at fixed M h , the self-calibration technique can provide a robust lower limit to this scatter.

Meta-Study of Particulate Detection Losses on Radioactive Air Sample Filters

Several mathematical relationships between air sample filter mass loading and the correlated analytical self-absorption factor were developed using data from other published research in this meta-study. Gross-alpha and -beta applications are addressed for this research. As filter media becomes loaded with particulate matter, there is potential for measurement losses due to self-absorption by mass loading. Components contributing to absorption include particulate dust, radioactive particulates, and filter material. Standards indicate a correction factor should be used when the penetration of radioactive material into the collection media or self-absorption of radiation by the material collected would reduce the detection rate by more than 5%. Previously, losses due to self-absorption have been reported up to 100% over a range up to ~10 mg⋅cm-2 mass loading. These absorption losses then can be used to determine a correction factor for sample results. For low mass loadings (e.g., ≤0.1 mg⋅cm-2) corrections factors in the 0.85 - 1 range have been recommended and used, while at higher mass loadings nearer to 10 mg⋅cm-2 correction factors closer to 0 (representing near 100% losses) are used. Based on data from published studies, the different methods for relating percent loss due to self-absorption to mass loading include linear, exponential, quadratic, and trinomial derived functions. Where applicable, both forced zero and non-forced zero results were evaluated. From the derived functions evaluated, the trinomial function provided the best fit. Once the sample filter mass loading is known, the trinomial function can be applied to estimate losses and the corresponding self-absorption factor. When applied to routine operating conditions for radiological facility stacks monitored at the Pacific Northwest National Laboratory for an average sample filter mass loading of 0.09 ± 0.12 (2σ) mg⋅cm-2 (excluding negative values and outliers) and a range from 0 - 0.24 mg⋅cm-2, the estimated trinomial function nominal self-absorption losses are less than 5% at 0.09 mg⋅cm-2 and less than 10% at 0.24 mg⋅cm-2. The trinomial function is one method that may be used to adjust the activity results of an air sample when the sample-specific mass loading is determined. The application of no correction factor when the ANSI/HPS N13.1-2021 guidance of a 5% threshold for loss is not reached with typical stack sample mass loadings may be reasonable in high-efficiency particulate air filtered systems. For simplicity, it would be conservative in assigning the self-absorption correction factor at the 5% threshold (i.e., 0.95) for general uses but in cases of heavy mass loading to calculate the factor.

Emission characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans from industrial combustion of biomass fuels

Although biomass fuel has always been regarded as a source of sustainable energy, it potentially emits polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated PCDD/F emissions from industrial boilers fired with three types of biomass fuel (i.e., bagasse, coffee residue, and biomass pellets) via stack sampling and laboratory analysis. The measured mass concentrations of PCDD/Fs varied among the boilers from 0.0491 to 12.7 ng Nm−3 (11% O2), with the calculated average international toxic equivalent quantity (I-TEQ) from 0.00195 to 1.71 ng I-TEQ Nm−3 (11% O2). Some of them were beyond the limit value for municipal waste incineration. 2,3,4,7,8-PeCDF could be used as a good indicator of dioxin-induced toxicity of stack flue gases from biomass-fired boilers. The PCDFs/PCDDs ratios were more than 1, likely indicating the formation of dioxins in the boilers favored by de novo synthesis. The emission factor (EF) of total PCDD/Fs averaged 5.35 ng I-TEQ kg−1 air-dry biomass (equivalent to 39.0 ng kg−1 air-dry biomass). Specifically, the mean EF was 6.94 ng I-TEQ kg−1 (52.6 ng kg−1) for biomass-pellet-fired boiler, 11.8 ng I-TEQ kg−1 (74.6 ng kg−1) for coffee-residue -fired boiler, and 0.0277 ng I-TEQ kg−1 (0.489 ng kg−1) for bagasse-fired boilers. The annual PCDD/F emission was estimated to be 208 g I-TEQ in 2020 in China, accounting for approximately 2% of the total national annual emission of PCDD/Fs. The results can be used to develop PCDD/Fs emission inventories and offer valuable insights to authorities regarding utilizing biomass in industry in the future.

Experimental investigation of removal of flue gas emissions exhaust from municipal solid waste incinerator using photovoltaic-based electrostatic precipitator.

For the past decades, the flue gas emitted from municipal solid waste incinerator, power plant, and various industries is a permanent problem for the environment and has been affecting human life. Many flue gas filtration devices have been emerging out over the years. Although the electrostatic precipitator was an appropriate device due to high filtration efficiency and little pressure drop and energy efficiency, the cost and design of the electrostatic precipitator is a major restriction for manufacturers and end-users. With recent advances in technology, designing a cost-effective and less complex electrostatic precipitator has become mandatory. This article aims to design and develop a solar-powered cost-effective needle-plate type electrostatic precipitator which includes a static power converters and high-voltage transformer-rectifier (T-R) set with an input voltage as 230V AC, output voltage as 80-kV direct current (DC), and output current of 40mA for mitigation of flue gas emissions exhaust from municipal solid waste incinerator. The analysis of flue gas at ESP inlet and outlet has been performed using Ecotech stack sampler and flue gas analyzer. The obtained experimental results are validated with emission standards provided in the Solid Waste Management rules book, India, 2016.

Depth resolution of transmission ERDA for H in Al under nuclear-elastically enhanced recoiling of H by 8 MeV He

Using stacked samples of Al foil and H-containing resin film, we have carried out elastic recoil detection analysis with transmission layout (T-ERDA) to investigate the depth resolution in the measurements of H distribution in Al. For narrow and wide acceptance conditions of the detector, the depth resolutions of 1.5–4.9 μm at several depths in Al of 50 and 80 μm thicknesses have been determined for incidence of 8 MeV 4He. While the main factor to degrade the depth resolution is the energy straggling of recoil H for narrow acceptance conditions, it is the extended low-energy side of the H spectrum for wide acceptance conditions. The knowledge obtained in this work is useful for analysis of 3D images of H distribution measured by T-ERDA, for example, future analysis of minerals or natural glass samples to determine abundances and distributions of water or OH in the samples.

TEM Characterization of Long Term Aged Interconnect Oxide Layers from Real Stack

Steel interconnect robustness under SOFC conditions for extended operation remains a challenge. The observation and analysis of the interconnect microstructure aged in real conditions for long periods provides analysis data to help to understand degradation and potentially to design accelerated testing.In this study, TEM observations of the cross section of interconnects aged in real conditions (9000h and 20000h stacks) are presented. The interconnects are Crofer22APU with the air side coated with manganese cobalt oxide (MCO) to prevent chromium evaporation and increase oxidation resistance. FIB-prepared lamella from the inlet and outlet air side are analysed by TEM imaging and EDX. A major difference between inlet and outlet is the position of Mn-rich grains in the chromia scale: at the inlet, Mn-rich grains are located at the metal/chromia interface (figure 1(a)) while at the outlet, Mn-rich crystals are located close but not directly adjacent to the metallic bulk (figure 1(b)). The inlet microstructure has been observed in the literature in an oxidation study of MCO coated steel [1]. However, the outlet case which was observed for both the 9000h and 20000h aged stack samples was not yet reported in the literature, to the best of our knowledge. The difference between the inlet and outlet position was observed as well on a 15000h aged sample by SEM, and may be explained by differences between the inlet and outlet conditions: higher temperature at the outlet, as well as lower oxygen content. In addition to this particular Mn position, Fe particles are also observed in the chromia scale, confirming results previously described in the literature[2]. The analysis of the MCO coating also shows an inner denser layer, as expected after ageing at high temperature[3]. Analysis of the segregation of cobalt oxide at the MCO grain boundaries is also presented.More investigations are necessary to explain the complete oxidation mechanisms of the MCO-coated Crofer interconnect. However, the important role of the coating in interconnect oxidation is shown. The understanding of all reactions and the analysis of interconnects aged in real conditions, on different locations, should help designing more reliable combinations, better predictive models and possibly accelerated tests.[1] S. Molin et al., « Microstructural and electrical characterization of Mn-Co spinel protective coatings for solid oxide cell interconnects », J. Eur. Ceram. Soc., vol. 37, no 15, p. 4781-4791, déc. 2017, doi: 10.1016/j.jeurceramsoc.2017.07.011.[2] L. V. Gambino, N. J. Magdefrau, et M. Aindow, « Microstructural effects of the reduction step in reactive consolidation of manganese cobaltite coatings on Crofer 22 APU », Mater. High Temp., vol. 32, no 1-2, p. 142-147, janv. 2015, doi: 10.1179/0960340914Z.00000000090.[3] B. Talic, V. Venkatachalam, P. V. Hendriksen, et R. Kiebach, « Comparison of MnCo2O4 coated Crofer 22 H, 441, 430 as interconnects for intermediate-temperature solid oxide fuel cell stacks », J. Alloys Compd., vol. 821, p. 153229, avr. 2020, doi: 10.1016/j.jallcom.2019.153229. Figure 1

Emissions of PAHs, PCDD/Fs, dl-PCBs, chlorophenols and chlorobenzenes from municipal waste incinerator cofiring industrial waste

Concentrations and distributions of PAHs and chlorinated aromatic compounds including PCDD/Fs, dl-PCBs, chlorophenols (CPs), and chlorobenzenes (CBz) in the municipal waste incinerator are investigated to characterize their formation and emission via intensive stack sampling. In addition, the toxicity of fly ash contribution by PCDD/Fs and dl-PCBs is evaluated in this study. The results reveal that concentrations of PCDD/Fs and dl-PCBs in flue gas are significantly lower than those of CPs, CBz, and PAHs. Additionally, the removal efficiencies of PAHs and chlorinated aromatic compounds achieved with existing air pollution control devices are evaluated, indicating that the removal efficiencies achieved with activated carbon injection + baghouse (95–99%) are higher than those with semi-dry scrubber (SDS). Besides, PCDD/Fs and PCBs TEQ concentrations in SDS and BH ashes are within 1.61–2.66 WHO-TEQ/g and 0.09–0.19 WHO-TEQ/g, respectively. Furthermore, the calculated mass flow rates suggest that the input rate of PCDD/Fs and dl-PCBs of SDS are 60.24 mg/h and 59.74 mg/h, respectively. The mass flow rates of PCDD/Fs and dl-PCBs after SDS in flue gas are 32.47 mg/h and 49.73 mg/h, respectively. However, the discharge rates of PCDD/Fs and dl-PCBs from SDS are 120.60 mg/h and 27.05 mg/h, respectively, indicating that PCDD/Fs are significantly formed within the SDS. PCDD/Fs formation is attributed to the operating temperature of SDS (240 ± 11.5 °C), which is within the temperature window for de novo synthesis. Thus, operating parameters of the APCDs should be optimized to reduce the formation of PAHs and chlorinated aromatic pollutants from MWI.