•REs recovery process was improved by solid-state chlorination and organic leaching.•The process addresses lamps waste valorization and critical RE circular economy.•2,4 pentanedione/ethanol mixture ...was employed as a selective lixiviant for REs.•High RE extractions were achieved reaching 96.8% of Yyield and 91.9% of Euyield.
Processing of end-of-life products (EoL) containing rare earth elements (REE) has gained increasing importance in recent years with the aim of avoiding supply risks. In addition, circular economy renders complete recirculation of technology metals mandatory. Fluorescent lamp wastes are an important source for REE recovery since they contain significant amounts, up to 55 wt%, of Y and Eu in red phosphors. For these purposes, solid-state chlorination (SSC) is an economically attractive alternative to wet acid leaching treatment, which profits from a considerable reduction of chemicals consumption and process costs. Chlorination takes place with dry HCl(g) produced from thermal decomposition of NH4Cl(s), not only converting the REE content of the Hg-free phosphor waste into water soluble REE metal chlorides, but also avoiding the implications of aqueous complex chemistry of REE. To establish an industrial process viable on a commercial scale, the SSC process has been optimized by (i) using a design of experiment (DOE) varying temperature, residence time, and gNH4Cl/gsolid ratio and (ii) improved leaching of the chlorinated metals with an organic mixture selective for REE. As a result, 95.7% of the Y and 92.2% of the Eu were selectively recovered at 295.9 °C, 67 min and a ratio of 1.27 gNH4Cl/gsolid, followed by quantitative selective leaching of the REE. Owed to its low chemicals consumption and operation costs, the current process allows for valorizing lamp waste even when raw material prices are low.
In recent years, there have been several solutions to medical image segmentation, such as U-shaped structure, transformer-based network, and multi-scale feature learning method. However, their ...network parameters and real-time performance are often neglected and cannot segment boundary regions well. The main reason is that such networks have deep encoders, a large number of channels, and excessive attention to local information rather than global information, which is crucial to the accuracy of image segmentation. Therefore, we propose a novel multi-branch medical image segmentation network MBSNet. We first design two branches using a parallel residual mixer (PRM) module and dilate convolution block to capture the local and global information of the image. At the same time, a SE-Block and a new spatial attention module enhance the output features. Considering the different output features of the two branches, we adopt a cross-fusion method to effectively combine and complement the features between different layers. MBSNet was tested on five datasets ISIC2018, Kvasir, BUSI, COVID-19, and LGG. The combined results show that MBSNet is lighter, faster, and more accurate. Specifically, for a Formula: see text input, MBSNet's FLOPs is 10.68G, with an F1-Score of Formula: see text on the Kvasir test dataset, well above Formula: see text for UNet++ with FLOPs of 216.55G. We also use the multi-criteria decision making method TOPSIS based on F1-Score, IOU and Geometric-Mean (G-mean) for overall analysis. The proposed MBSNet model performs better than other competitive methods. Code is available at https://github.com/YuLionel/MBSNet .
Displacing the use of polluting and inefficient cookstoves in developing countries is necessary to achieve the potential health and environmental benefits sought through clean cooking solutions. Yet ...little quantitative context has been provided on how much displacement of traditional technologies is needed to achieve targets for household air pollutant concentrations or fuel savings.
This paper provides instructive guidance on the usage of cooking technologies required to achieve health and environmental improvements.
We evaluated different scenarios of displacement of traditional stoves with use of higher performing technologies. The air quality and fuel consumption impacts were estimated for these scenarios using a single-zone box model of indoor air quality and ratios of thermal efficiency.
Stove performance and usage should be considered together, as lower performing stoves can result in similar or greater benefits than a higher performing stove if the lower performing stove has considerably higher displacement of the baseline stove. Based on the indoor air quality model, there are multiple performance-usage scenarios for achieving modest indoor air quality improvements. To meet World Health Organization guidance levels, however, three-stone fire and basic charcoal stove usage must be nearly eliminated to achieve the particulate matter target (< 1-3 hr/week), and substantially limited to meet the carbon monoxide guideline (< 7-9 hr/week).
Moderate health gains may be achieved with various performance-usage scenarios. The greatest benefits are estimated to be achieved by near-complete displacement of traditional stoves with clean technologies, emphasizing the need to shift in the long term to near exclusive use of clean fuels and stoves. The performance-usage scenarios are also provided as a tool to guide technology selection and prioritize behavior change opportunities to maximize impact.
To investigate whether a specific tooth or teeth provide the most accurate estimation of chronological age (CA), and determine which of the three staging systems studied represents dental development ...for an individual tooth.
Data were collected from 400 digital panoramic radiographs of healthy Saudi children aged 6.00-15.99 years. Each permanent tooth on the left side was evaluated to determine its developmental stage and dental age using the methods by Moorrees, Fanning, and Hunt (MFH) (1963), as adapted by Smith (1991), Gleiser and Hunt (1955), and Nicodemo et al. (1974). The accuracy (bias) of each tooth type and stage was assessed in relation to the CA, the teeth and the methods were compared, and the accuracy of age estimation using all teeth and the most accurate tooth in each method were compared.
Regarding staging systems, comparatively, Gleiser and Hunt's method had the lowest bias for the lower first molar (-0.50 ± 1.05 years). Nicodemo et al.'s method had a lower bias for all other mandibular teeth compared to the MFH method. For individual teeth using the MFH method, the most and least accurate teeth for the combined sexes were the lower central incisor (-0.59 ± 0.77 years) and the lower first molar (-1.54 ± 0.93 years), respectively. No significant difference was found between the biases when using the lower central incisor alone and when using all teeth for the combined sexes. For individual teeth using Nicodemo et al.'s method, the most and least accurate teeth for combined sexes were the upper central incisor (-0.03 ± 1.01 years) and the lower first molar (-1.08 ± 1.59 years), respectively. A significant difference was found between the biases using the upper central incisor alone and all teeth for the combined sexes, with the upper central incisor exhibiting the lowest bias (P=0.028).
Comparatively, Nicodemo et al.'s method had the lowest bias for all teeth except for the lower first molar, where Gleiser and Hunt's method had the lowest bias. This, however, should not be confused with precision. MFH's staging system was more representative of dental development for an individual tooth. For combined sexes, the lower central and lateral incisors were the most accurate teeth using the MFH method. The upper central incisor and lower first premolar were the most accurate teeth using Nicodemo et al.'s method. The lower first molar was the least accurate tooth using both methods.
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a large group of important chemical compounds with unique and useful physico-chemical properties, widely produced and used in many ...applications. However, due to the toxicity, bioaccumulation and long-range transport potential of certain PFASs, they are of significant concern to scientists and policy makers. To assess human exposure to PFASs, it is necessary to understand the concentrations of these emerging contaminants in our environment, and particularly environments where urban population spend most of their time, i.e. buildings and vehicles.
A total of 126 samples of building materials, consumer products, car interior materials and wastes were therefore analyzed for their content of key PFASs - 15 perfluoroalkyl acids (PFAAs). At least one of the target PFAAs was detected in 88% of all samples. The highest concentration of Σ15PFAAs was found in textile materials (77.61 μg kg−1), as expected, since specific PFAAs are known to be used for textile treatment during processing. Surprisingly, PFAAs were also detected in all analyzed composite wood building materials, which were dominated by perfluoroalkyl carboxylic acids with 5–8 carbons in the chain (Σ4PFCAs up to 32.9 μg kg−1). These materials are currently widely used for building refurbishment, and this is the first study to find evidence of the presence of specific PFASs in composite wood materials. Thus, in addition to consumer products treated with PFASs, materials used in the construction of houses, schools and office buildings may also play an important role in human exposure to PFASs.
•15 target PFAAs were analyzed in 126 samples of consumer products and building materials.•In 88% of samples at least one PFAA was detected; dominated by PFOS.•The highest Σ15PFAA concentration (77.61 μg kg−1) was found in a textile.•Several materials contained high levels of unregulated short-chain PFAAs.•C5-C8-chain PFCAs in wood-based building materials were identified for the first time.
Clean fuels are urgently needed to reduce household cooking emissions. The thermal efficiencies (η
) and pollutant emission factors (EFs) of biocoal briquettes (made from a mixture of biomass and ...coal powder) burned in a typical cooking stove were investigated and compared with those of coal briquettes and biomass briquettes. Biocoal briquette samples were obtained by molding blends of anthracite with 10-30 wt % crop straw of various types (maize straw, wheat straw, or rice straw). The optimum proportions for energy savings and PM
EF reduction were found to be 15-20 wt %. Compared with the η
of coal briquettes and biomass briquettes, the η
of biocoal briquettes increased by 81-127% and 88-179%, respectively, with the optimum addition ratios of crop straw, while the delivered energy-based PM
EFs of the biocoal briquettes were reduced by 61-67% and 99.0-99.5%, respectively. Delivered energy-based EFs of NO
, SO
, and toxic elements (As, Se, and Pb) also showed a significant reduction. These results indicated that biocoal briquettes can serve as a promising substitute for domestic solid fuel to reduce pollutant emissions and save energy.
•Develop an internal heat re-circulation and self-atomization burner was developed.•Direct combustion of three waste oils in a self-atomized turbulence burning stove.•Quantify the emission factors, ...thermal efficiency and improved combustion efficiency.•Compare the performances of waste oils with traditional fuel/stove combinations.•Rate the emission of stove fueled with waste oil by current available standards.
Direct use of waste oil as fuel to meet the residential energy demands, is very attractive due to its potentials to decrease fossil fuel consumption, reduce pollution and increase sustainability. This paper uses a domestic stove with an internal heat re-circulation and self-atomization technology to burn yellow waste cooking oil (WCO-1), brown waste cooking oil (WCO-2) and waste lubricant oil (WLO). Emission factors (EFs), energy efficiency and modified combustion efficiency (MCE) of this combined fuel/stove system were determined under space-heating and cooking modes. The results showed that EFs of CO, PM2.5, total 16 PAHs and corresponding toxic equivalent quantity (TEQ) values ranged from 2.18 × 103 to 4.90 × 103 mg/MJnet, 16.36–69.40 mg/MJnet, 2.39–12.93 μg/MJnet and 0.16–0.92 μg of TEQ/MJnet. WCO-1 was verified to be the cleanest fuel with the highest energy efficiency (85.3 ± 3.3% and 90.4 ± 2.2%) and lowest emission levels, such as NO (53.75 ± 2.62 and 37.09 ± 5.41 mg/MJnet), NO2 (82.40 ± 3.96 and 56.87 ± 8.29 mg/MJnet) and PM2.5 (20.94 ± 6.55 and 16.35 ± 5.06 mg/MJnet) compared to WCO-2 and WLO. The estimated total cost of using waste oil for each household in winter was much cheaper than some current available clean energy means, including only USD$ 400 of stove price and USD$ 250/ton of fuel per year. It is a promising candidate choice for replacing low-quality solid fuels in rural China and 2.62 million rural households would achieve environmental and economic benefits if promoting direct combustion of waste oil for daily heating and cooking.
Over 40% of the world's population relies on solid fuels for heating and cooking. Use of improved biomass cookstoves (ICS) has the potential to reduce household air pollution (HAP).
As part of an ...evaluation to identify ICS for use in Kenya, we collected indoor air and personal air samples to assess differences between traditional cookstoves (TCS) and ICS.
We conducted a cross-over study in 2012 in two Kenyan villages; up to six different ICS were installed in 45 households during six two-week periods. Forty-eight hour kitchen measurements of fine particulate matter (PM2.5) and carbon monoxide (CO) were collected for the TCS and ICS. Concurrent personal CO measurements were conducted on the mother and one child in each household. We performed descriptive analysis and compared paired measurements between baseline (TCS only) and each ICS.
The geometric mean of 48-hour baseline PM2.5 and CO concentrations in the kitchen was 586μg/m3 (95% CI: 460, 747) and 4.9ppm (95% CI: 4.3, 5.5), respectively. For each ICS, the geometric mean kitchen air pollutant concentration was lower than the TCS: median reductions were 38.8% (95% CI: 29.5, 45.2) for PM2.5 and 27.1% (95% CI: 17.4, 40.3) for CO, with statistically significant relationships for four ICS. We also observed a reduction in personal exposures to CO with ICS use.
We observed a reduction in mean 48-hour PM2.5 and CO concentrations compared to the TCS; however, concentrations for both pollutants were still consistently higher than WHO air quality guidelines. Our findings illustrate that ICS tested in real-world settings can reduce exposures to HAP, but implementation of cleaner fuels and related stove technologies may also be necessary to optimize public health benefits.
Assessment of Traditional and Improved Stove Use on Household Air Pollution and Personal Exposures in Rural Western Kenya•We examined kitchen and personal concentrations of fine particulate matter (PM2.5) and carbon monoxide (CO) for six different improved cookstoves (ICS).•Mean 48-hour PM2.5 and CO concentrations for ICS were reduced compared to TCS, but still exceeded WHO air quality guidelines.•Multiple factors (e.g., kerosene use, stove stacking, fuel moisture, acceptability) contributed to heterogeneity in our results.
Intelligent detection of athlete behavior is beneficial for guiding sports instruction. Existing mature target detection algorithms provide significant support for this task. However, large-scale ...target detection algorithms often encounter more challenges in practical application scenarios. We propose SCB-YOLOv5, to detect standardized movements of gymnasts. First, the movements of aerobics athletes were captured, labeled using the labelImg software, and utilized to establish the athlete normative behavior dataset, which was then enhanced by the dataset augmentation using Mosaic9. Then, we improved the YOLOv5 by (1) incorporating the structures of ShuffleNet V2 and convolutional block attention module to reconstruct the Backbone, effectively reducing the parameter size while maintaining network feature extraction capability; (2) adding a weighted bidirectional feature pyramid network into the multiscale feature fusion, to acquire precise channel and positional information through the global receptive field of feature maps. Finally, SCB-YOLOv5 was lighter by 56.9% than YOLOv5. The detection precision is 93.7%, with a recall of 99% and mAP value of 94.23%. This represents a 3.53% improvement compared to the original algorithm. Extensive experiments have verified that our method. SCB-YOLOv5 can meet the requirements for on-site athlete action detection. Our code and models are available at https://github.com/qingDu1/SCB-YOLOv5 .
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