Substance Flow Research Articles

Candidate Molecular Biomarkers of Traumatic Brain Injury: A Systematic Review.

Traumatic brain injury (TBI) is one of the leading causes of mortality and disability among young and middle-aged individuals. Adequate and timely diagnosis of primary brain injuries, as well as the prompt prevention and treatment of secondary injury mechanisms, significantly determine the potential for reducing mortality and severe disabling consequences. Therefore, it is crucial to have objective markers that indicate the severity of the injury. A number of molecular factors-proteins and metabolites-detected in the blood immediately after trauma and associated with the development and severity of TBI can serve in this role. TBI is a heterogeneous condition with respect to its etiology, clinical form, and genesis, being accompanied by brain cell damage and disruption of blood-brain barrier permeability. Two oppositely directed flows of substances and signals are observed: one is the flow of metabolites, proteins, and nucleic acids from damaged brain cells into the bloodstream through the damaged blood-brain barrier; the other is the infiltration of immune cells (neutrophils and macrophages) and serological proteins. Both flows aggravate brain tissue damage after TBI. Therefore, it is extremely important to study the key signaling events that regulate these flows and repair the damaged tissues, as well as to enhance the effectiveness of treatments for patients after TBI.

The environmental costs of clean cycles: Quantitative analysis for the case of PVC window profile recycling in Germany

AbstractRecycling schemes for long‐lived products are challenged by the presence of “legacy substances,” which have been used in production in the past, but are nowadays classified as substances of concern. This study quantitatively evaluates the trade‐offs between phasing out legacy substances, increasing circularity levels, and reducing life cycle impacts of polyvinylchloride (PVC) window profiles recycling in Germany based on a comprehensive dynamic material and substance flow analysis coupled with a prospective life cycle assessment. Scenario results indicate that although lead had been phased out in virgin PVC by 2015, lead concentrations in end‐of‐life PVC window profiles will remain above 0.3% until the end of the century without a restriction of lead in recycled PVC and will be by factor 3–5 higher compared to a restriction as stipulated by EU 2023/923. However, the latter is associated with lower recycling rates and higher life cycle environmental impacts of PVC window frame waste management, which cannot be fully compensated by the introduction of new waste treatment pathways using currently available technologies. The study serves to introduce a new comprehensive modeling framework, which allows for the consideration of trade‐offs between substance, material, and environmental impact dimensions as a basis for discussing and developing sustainable waste management strategies.

Managing phosphorus input pressures for improving water quality at the catchment scale

Phosphorus (P) pollution of freshwater is an endemic threat to water quality and aquatic biodiversity. To better define the contributions of the two main food system sectors (agriculture and wastewater) responsible for freshwater P pollution, we investigated how the magnitude and distribution of sector P input pressures calculated using Substance Flow Analysis (SFA) linked to the P pollution threat across four distinct physiographic regions of the River Stour catchment (1260 km2) in Dorset, England. Agricultural P input pressures (−1 to 7 kg ha−1 yr−1) were dependent on the amount of livestock feed imports and resulting manure loadings to land, whilst food imports and population densities were the main driver of the human net P inputs of up to 13 kg ha−1 yr−1. Total P input pressures (i.e. Net Anthropogenic P Inputs (NAPI)) were positively correlated (r2 0.8–0.9) to riverine P flux of up to 6 kg ha−1 yr−1 across the catchment. Using measured river P concentration (C) and flow discharge (Q) analysis to distinguish monitoring stations capturing mainly diffuse P sources (termed diffuse stations), estimated riverine P fluxes attributable to agriculture varied up to 0.92 kg ha−1 yr−1 depending on the surplus P inputs applied to land. A combination of enhanced wastewater P removal and reduced surplus agricultural P inputs was required to improve water quality. For example, the P pressure-river P flux relationship at diffuse stations suggested that in the catchment area dominated by livestock production, removing the agricultural P surplus of 7 kg ha−1 yr−1 would reduce annual average river SRP concentrations in this area by a third to 0.23 mg L−1, but still well above the target concentration for eutrophication control (0.08 mg L−1). Our approach of linking SFA outputs to measured river P data provides a potential complimentary and internationally relevant methodology to evidence effective sector mitigation targets and policies in catchments, and its further testing in other catchments is recommended.

Increasing the Recycling of PVC Flooring Requires Phthalate Removal for Ensuring Consumers' Safety: A Cross-Checked Substance Flow Analysis of Plasticizers for Switzerland.

As our planet grapples with the severe repercussions of plastic pollution, mechanical recycling has been proposed as a potential remedy. However, increasing mechanical recycling may have unintended negative consequences. For example, recycling of PVC flooring containing hazardous plasticizers that were used in the past may lead to continued exposure. Here we propose measures to increase recycling while circumventing adverse health impacts caused by legacy additives. For this, we conduct a dynamic substance flow analysis for Switzerland and the time period from 1950 to 2100, focusing on three plasticizers: di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DiNP), and di(2-ethylhexyl) terephthalate (DEHT). We quantify the uncertainty of results, check their plausibility against measured concentrations in samples representative for the Swiss market, and compare them with modeled substance flows in Germany. Based on the cross-checked model, future average concentrations of DEHP in PVC flooring on the Swiss market are expected to be above the legal limit of 0.1 wt % for several decades if increased recycling rates are implemented without additional measures. Phasing out the potentially concerning DiNP, too, and preventing phthalates from entering recycling would lower their average market concentrations to values below 0.1 wt % and enable increasing recycling rates without compromising product safety. Analogous measures could help achieve this goal across other European countries and product groups.

Reaching China’s fertilizer reduction goals through nitrogen and phosphorus recovery: a substance flow analysis case study

Linear agricultural nutrient regimes are the principal cause for perturbation of the geochemical cycles for nitrogen (N) and phosphorus (P) and other planetary boundaries. Nutrient cycles are characterized by high spatial disparity and China is a hotspot due to high fertilizer application rates. Using substance flow analysis, this study identified and quantified nutrient flows from agricultural production to residue management of Huangyan tangerines (Citrus reticulata) and water bamboo (Zizania latifolia) in a case study of Huangyan district (Taizhou City, Zhejiang province). About 754 Mg/a of N and 105 Mg/a of P can theoretically be recovered in the tangerines and water bamboo systems from currently untapped material flows. This could replace 59% of the N and 15% of the P currently applied as chemical fertilizer, reducing environmental impacts. Combining the nutrient recovery of both systems and upscaling the results to Taizhou City, the goal from the 14th Five-Year Plan for Agricultural and Rural Modernization to save 1182 Mg of nutrients per year could be exceeded by almost 12 times. This study’s data have varying degrees of uncertainty. The analysis of data representativeness shows potential for improvements, especially in the agricultural production of water bamboo and the nutrient contents of material flows.

Identifying leverage points using material flow analysis to circularise resources from urban wastewater and organic waste

Anthropogenic systems are synonymous with linear economies that cause widespread resource waste and environmental degradation. Urban areas are hotspots for this behaviour due to their high population density and resource consumption. Changing this situation is limited by the lack of a holistic but sufficiently detailed understanding of system units where resource waste occurs. The objectives of this study were: (1) to develop and apply a model of the material and substance (nitrogen, phosphorus, and carbon) flows of organic waste and wastewater systems at a local scale, taking Christchurch, New Zealand, as a study case, and (2) to identify leverage points within the system to achieve resource circularisation. Results show that groundwater, infiltrated water, and industrial wastewater are the predominant material flows into the system. Nitrogen and phosphorus inputs predominantly come from food products, detergents, green waste, and industrial wastewater. The Christchurch wastewater system is a prime example of a linear economy, where ∼66 % of the nitrogen and ∼63 % of the phosphorus entering the wastewater system is discharged to the ocean. Leakage from the water supply system reduces water resource efficiency, while water infiltration into the wastewater network inflates the quantity of wastewater treated at the centralised treatment plant, limiting nutrient recovery. In the compost facility, 86 % of the waste is composted, with 33% of the nitrogen and all the phosphorus exiting as compost, while ∼66 % of the nitrogen treated exits through volatilisation. The remaining 14 % of the organic waste entering the treatment plant is deemed unsuitable for composting and is landfilled. The material and substance flow analysis allowed the identification of flows with leverage points in the system where there are opportunities to reduce, reuse, or recover materials and substances to encourage circularisation. These flows include food products, detergents, unsuitable materials for composting, domestic water supply leakages, wastewater network infiltration, and wastewater treatment plant's nutrient recovery.

Phosphorus recovery potential revealed by substance flow analysis of the Indian food, agricultural and sanitation system

Phosphorus is a finite resource that is in high demand due to its essential role as a fertiliser. We undertook a substance flow analysis of phosphorus for India's agri-food system to identify where the biggest losses of phosphorus occur and which flows could be targeted to move phosphorus from a linear use and waste approach to a circular approach encompassing recovery and re-use. A novel aspect of the analysis was the inclusion of sanitation systems in India. National phosphorus flows were calculated annually for the five years 2015–2019, and the mean was then used to provide a representative annual flow. The analysis showed that India is dependent on imports for 95% of applied mineral phosphorus fertiliser and has a low phosphorus-use efficiency of 32%. The largest recoverable flow is human excreta (urine and faeces), equivalent to 21% of the current phosphorus applied in mineral fertiliser in India. Phosphorus recovery from septic tanks, the most prevalent sanitation system in India, could alone replace 8% of phosphorus applied in mineral fertiliser in India. Alongside the ongoing development of sanitation systems in India this provides an opportunity to ensure that nutrient recovery is included in sanitation developments.

Mapping chromium flows in China's stainless-steel product chain: A product-level substance flow analysis

Chromium (Cr) is a critical metal that supports the development of China's emerging industries. Approximately 82% of China's Cr is used to manufacture stainless steel. However, the stainless-steel product chain has often been referred to as a “black box” in Cr substance flow analysis, leading to limited guidance for Cr management. This study aims to fill this gap by analysing Cr flows and in-use stock patterns in China's stainless-steel product chain from 2012 to 2022. During this period, China's Cr consumption experienced significant growth, increasing by over 10% annually, with 90.4% being imported. The Energy Infrastructure sector emerged as the dominant consumer of Cr (8,099 kt) and in-use stock (7,702 kt), Heavy Machinery products accounting for the highest Cr consumption (3,269 kt). Conducting product-level SFA is crucial for sustainable Cr resource management and environmental policy-making.

Scenario Analysis of Food Phosphorus Footprint in Kisumu, a Lakeside East African City in Lake Victoria (Kenya).

Increased food production and consumption patterns have resulted in higher urban food phosphorus footprints, leading to a series of resource and environmental problems worldwide. We quantified the food phosphorus footprint of the African city of Kisumu using substance flow analysis. Our aim was to develop Kisumu's sustainable phosphorus management framework so that the city would reduce phosphorus losses into the food system. Our results show that in the year 2023, the import and export of food phosphorus in the Kisumu food system was 2730.26 ± 2.7% t P yr-1 and 3297.05 ± 2.4% t P yr-1, respectively. There was -566.79 ± -18% t P yr-1 food phosphorus deficit in the Kisumu food system. Crop planting subsystem runoff/leaching/erosion loss, household consumption subsystem waste loss, and pit latrine subsystem blackwater loss are the major pathways of phosphorus losses into the environment and the main contributors to the food phosphorus footprint in the city. The 2030 scenario analysis shows that implementing a comprehensive scenario scheme throughout the entire lifecycle process from phosphorus input to waste disposal is the best choice for reducing phosphorus losses and suppressing the growth of food phosphorus footprint in the future. Our study shows that the food phosphorus footprint in the Kisumu food system was 0.67 kg P cap-1yr-1 in 2023, which is still at a low level but may enter a continuous upward trend with the improvement of socio-economic development of the city. In our framework, we have proposed a few essential measures that include urine separation, installation of septic tank, adjustment of dietary structure, flexible layout of sanitary disposal facilities, and separation of organic waste streams to reduce food phosphorus footprints in Kisumu. Given the similarity of cities along the shores of Lake Victoria, our calculation methods and management strategies can be applied to other cities in the region.

Phosphorus Flow Analysis in Lithuania

Substance flow analysis was used to analyze phosphorus (P) flows, accumulations and losses in Lithuania. P and phosphate rock are included in the list of EU critical raw materials, showing their importance for the EU economy, especially agriculture, and supply risks. It is important to minimize P losses as much as possible, avoid inefficient use, and maximize the potential of secondary P. The analysis showed Lithuania’s huge dependence on P imports, which occurred because one of the largest P fertilizer factories operates in the country, and the country also grows and exports a significant amount of cereals. In total, 69% of P addition to soil is from mineral fertilizers. The potential of secondary P is only partially used, mainly via manure, which constitutes 83% of the recycled P and adds 26% of P to agricultural soil. In total, 58% of P “waste” is either lost or accumulated, largely in phosphogypsum stacks. If this P was fully utilized, the country could reduce the current usage of mineral fertilizers by 71%; without P in phosphogypsum, the reduction would be just 7.2%. The P balance in Lithuanian soil is close to neutral. Agricultural leaching and erosion are the main reasons for P entering water bodies (78% of P) and, therefore, should be further reduced.

Impact of hypertension and arterial wall expansion on transport properties and atherosclerosis progression

This study explored the impact of hypertension on atheroma plaque formation through a mechanobiological model. The model incorporates blood flow via the Navier–Stokes equation. Plasma flow through the endothelium is determined by Darcy’s law and the Kedem–Katchalsky equations, which consider the three-pore model utilized for substance flow across the endothelium. The behaviour of these substances within the arterial wall is described by convection–diffusion–reaction equations, while the arterial wall itself is modelled as a hyperelastic material using Yeoh’s model. To accurately evaluate hypertension’s influence, adjustments were made to incorporate wall compression-induced wall compaction by radial compression. This compaction impacts three key variables of the transport phenomena: diffusion, porosity, and permeability. Based on the obtained findings, we can conclude that hypertension significantly augments plaque growth, leading to an over 400% increase in plaque thickness. This effect persists regardless of whether wall mechanics are considered. Tortuosity, arterial wall permeability, and porosity have minimal impact on atheroma plaque growth under normal arterial pressure. However, the atheroma plaque growth changes dramatically in hypertensive cases. In such scenarios, the collective influence of all factors—tortuosity, permeability, and porosity—results in nearly a 20% increase in plaque growth. This emphasizes the importance of considering wall compression due to hypertension in patient studies, where elevated blood pressure and high cholesterol levels commonly coexist.

Non-negligible environmental risks of typical hazardous trace elements in wastes from Chinese coal-fired industrial boilers

Coal-fired industrial boilers (CFIBs) that provide heat for industrial production operate to produce large quantities of wastes containing hazardous trace elements (HTEs), threatening the quality of the environment. Based on the established facility-level material flow inventory of five typical HTEs (Hg, As, Cd, Cr, and Pb) of Chinese CFIBs in 2020, we explored the enrichment characteristics and environmental risks of HTEs in wastes at the regional scale from the perspective of substance flow and enrichment levels. Results showed that the shares of HTEs entering the waste stream were 2.2–16.8 % higher in the focus regions of continuous improvement of air quality compared to the non-focus regions, explained by the higher synergistic control efficiencies of their air pollution control facilities (ACPFs), at 86.6–90.4 % (Hg), 98.6–99.1 % (As), 95.1–95.9 % (Cd), 93.2–94.8 % (Cr), and 97.1–98.0 % (Pb), respectively. In addition, the national averages of HTEs in slag, fly ash, and flue gas desulphurisation (FGD) were simulated to be 0.15–0.87 g/t, 3.25–18.44 g/t, 0.30–0.96 g/t, 19.76–70.11 g/t, and 15.85–73.74 for Hg, As, Cd, Cr, and Pb, respectively. Nationally, the integrated environmental risks of the five HTEs in slag, fly ash, and FGD residue exhibited Considerable, Very High, and Very High level of environmental risk, with the cumulative environmental risk indexes of 171, 317, and 281, respectively. Hg and Cd were the major contributors to the environmental risks of slag, fly ash, and FGD residue, with environmental risk contributions ranging from 23.8 to 82.3 % and 16.0 to 66.1 %, respectively. Results can provide data support for modelling the environmental release of HTEs from wastes and formulating control strategies for environmental management agencies.

Water-Energy Nexus Flow Analysis of a Wastewater Treatment Plant in Thailand

Abstract The Wastewater Treatment Plant in Thailand plays a vital role in treating raw domestic wastewater. As the demand for treating wastewater grows, the energy requirements associated with treatment processes become essential. This study aims to identify energy-intensive areas in wastewater treatment plants and provide inventory data for the indirect environmental impact. It also determines the suitable opportunities to recover energy from wastewater treatment plants. The water-energy nexus was examined through Material Flow Analysis (MFA) using Substance Flow Analysis (STAN) Software. The wastewater treatment plant is extended to produce water for reuse. System allocation is adopted to separate the treated wastewater and reuse water products. In Thailand, the aeration tank unit is the most energy-intensive. This condition can be explained by operating the aeration tank, which accounts for 33.87% of the total energy demand. The research found that around 0.155 kWh/m3 is needed for treating raw domestic wastewater to meet the effluent standard. The extended treatment for converting the raw wastewater into reuse water requires 0.3286 kWh/m3. Reuse water is beneficial for providing sustainable water resources but requires a 112% energy increase. The plant relies on Thailand’s EGAT Energy Mix (58.09% Natural Gas, 29.01% Lignite, 10.21% Hydropower, 2.52% Diesel, 0.16% Fuel Oil, 0.002% Geothermal Energy and 0.008% remain unidentified). Rather than fully relying on Thailand EGAT, the research suggests renewable energy installations and nutrient recovery options. Solar panels and micro-hydro power generation are promising ideas to install. Moreover, recovering the nutrients from wastewater can address environmental problems and offer valuable resources simultaneously. The findings of this Study provide profound benefits for developing sustainability in wastewater treatment plants.

Patching sustainability loopholes within the lead-acid battery industry of Bangladesh: An environmental and occupational health risk perspective

Despite global efforts to phase out lead (Pb) products, their widespread use persists, notably in the lead-acid battery (LAB) industry. This trend is also evident in Bangladesh, where sustainability concerns surrounding the largely unexplored, yet highly vibrant informal sector remain unaddressed. It is imperative to unravel a comprehensive picture to implement targeted formalization strategies effectively at a meso level. This study aims to achieve this by using a substance flow analysis (SFA), life cycle assessment (LCA), and human health risk assessment (HHRA) approach, to highlight the environmental impacts and health risks associated with the industry's thriving informal sector. This sector emerges as a towering colossus of Pb pollution in the country, with a striking 86 % of the total Pb loss occurring from informal recycling alone. Informal electric vehicle (EV) LAB manufacturing is identified as a major contributor to land use, global warming, fine particulate matter formation, and terrestrial acidification impacts, with global warming and fine particulate matter contributing about 40 % each to the total human health impacts. Workers in the informal sector, the most overlooked victims of this industry, face alarming risks of non-carcinogenic and carcinogenic toxicity-related diseases, with oral exposure route making up 90.8 % of the total non-carcinogenic risks. As developing nations grapple with similar waste management challenges, often exacerbated by their socio-economic and political contexts, these findings underscore the urgent need for a robust national action plan. Collaboration among governmental entities and international stakeholders is imperative to execute targeted cleanup initiatives and uphold compliance with international environmental and public health standards.

Conjoint analysis of nitrogen and phosphorus metabolism in urban system: A case study of Dar es Salaam, Tanzania

AbstractNitrogen (N) and phosphorus (P) metabolism is becoming an increasingly complex process during urbanization due to increasing rates of consumption and emission worldwide. Understanding the urban N and P metabolism helps identifying production capacity, consumption demand, and the impact of N and P emissions on the environment, providing a scientific basis for decision‐making in sustainable utilization of N and P resources. Quantifying and mapping the source, path, and sinks of N and P in an urban system is the premise of controlling emissions. In this paper, we used the substance flow analysis (SFA) method to describe the N and P metabolism processes in the urban system of Dar es Salaam (Tanzania) in 2017, and used the scenario‐based analysis method to understand the impact of different N and P metabolisms on potentially recoverable N and P sources by 2030. The results showed that the urban system of Dar es Salaam receives a total input flow of 28,101.8 tN/year and 3,379 tP/year, with a total output flow of 18,859.6 tN/year and 1,849.3 tP/year with net stock changes of 9,242.2 t/year for N and 1,529.7 t/year for P, respectively. We noticed that increased human activities largely represented the city's waste released after the household consumption, and would become the main causes of N and P emissions. In addition to this, 59.38%, 31.25%, and 9.38% of N flow quantification quality were at high, medium, and low levels, respectively, while 74.07%, 11.11%, and 14.81% of P flow quantification quality were at high, medium, and low levels, respectively. Our results suggest that implementing integrated nutrient management measures, such as changes in people's diets and the use of washing products, and improved management and technologies of manure, sewage, and landfill leachate treatment, would be the most effective approach to resolve the urban nutrient emissions in Dar es Salaam.

Security evaluation of China's indium industrial chain: Perspective on substance flow throughout the whole life cycle

As the world's largest supplier of primary indium, China's indium industrial chain structure and demand change affect global supply. It is necessary to evaluate the security of China's indium industrial chain and determine the reasons that affect security. The past substance flow analysis (SFA) of indium and mineral industrial chain security evaluation has problems such as a lack of timeliness, a single dimension mainly focusing on the upstream, and simple evaluation methods. In this paper, based on the SFA, an integrated evaluation system for the whole life cycle is constructed from 2000 to 2022 according to mineral industrial chain security characteristics. The results show that since introducing liquid crystal in 2003, China's indium industrial chain security level has been low despite a slight increase. Although China has gradually broken through the production technology of high-purity indium and indium tin oxide (ITO) targets, the large consumption and export of refined indium has reduced China's indium metal stock to 2214 t, while the resource reserves advantage is also diminishing. Mass consumption has also led China to import more ores, while China still imports high-end products from other countries with high import source concentrations. The pollutants emitted by the large production and the declining environmental governance level pose a significant environmental threat. Finally, suggestions for strengthening international cooperation, increasing technological research, establishing a reserve system, risk monitoring mechanisms, and strict emission standards can improve China's indium industrial chain security.

Smoothing the Phosphorus Resource Stress under the Socioeconomic Development in China.

Phosphorus (P) is the key in maintaining food security and ecosystem functions. Population growth and economic development have increased the demand for phosphate rocks. China has gradually developed from zero phosphate mining to the world's leading P miner, fertilizer, and agricultural producer since 1949. China released policies, such as designating phosphate rock as a strategic resource, promoting eco-agricultural policies, and encouraging the use of solid wastes produced in mining and the phosphorus chemical industry as construction materials. However, methodological and data gaps remain in the mapping of the long-term effects of policies on P resource efficiency. Here, P resource efficiency can be represented by the potential of the P cycle to concentrate or dilute P as assessed by substance flow analysis (SFA) complemented by statistical entropy analysis (SEA). P-flow quantification over the past 70 years in China revealed that both resource utilization and waste generation peaked around 2015, with 20 and 11 Mt of mined and wasted P, respectively. Additionally, rapidly increasing aquaculture wastewater has exacerbated pollution. The resource efficiency of the Chinese P cycle showed a U-shaped change with an overall improvement of 22.7%, except for a temporary trough in 1975. The driving force behind the efficiency decline was the roaring phosphate fertilizer industry, as confirmed by the sharp increase in P flows for both resource utilization and waste generation from the mid-1960s to 1975. The positive driving forces behind the 30.7% efficiency increase from 1975 to 2018 were the implementation of the resource conservation policy, downstream pollution control, and, especially, the circular agro-food system strategy. However, not all current management practices improve the P resource efficiency. Mixing P industry waste with construction materials and the development of aquaculture to complement offshore fisheries erode P resource efficiency by 2.12% and 9.19%, respectively. With the promotion of a zero-waste society in China, effective P-cycle management is expected.

ITrendRNN: An Interpretable Trend-Aware RNN for Meteorological Spatiotemporal Prediction

Accurate prediction of meteorological elements, such as temperature and relative humidity, is important to human livelihood, early warning of extreme weather, and urban governance. Recently, neural network-based methods have shown impressive performance in this field. However, most of them are overcomplicated and impenetrable. In this paper, we propose a straightforward and interpretable differential framework, where the key lies in explicitly estimating the evolutionary trends. Specifically, three types of trends are exploited. (1) The proximity trend simply uses the most recent changes. It works well for approximately linear evolution. (2) The sequential trend explores the global information, aiming to capture the nonlinear dynamics. Here, we develop an attention-based trend unit to help memorize long-term features. (3) The flow trend is motivated by the nature of evolution, i.e., the heat or substance flows from one region to another. Here, we design a flow-aware attention unit. It can reflect the interactions via performing spatial attention over flow maps. Finally, we develop a trend fusion module to adaptively fuse the above three trends. Extensive experiments on two datasets demonstrate the effectiveness of our method.

Wireless flow-powered miniature robot capable of traversing tubular structures.

Wireless millimeter-scale robots capable of navigating through fluid-flowing tubular structures hold substantial potential for inspection, maintenance, or repair use in nuclear, industrial, and medical applications. However, prevalent reliance on external powering constrains these robots' operational range and applicable environments. Alternatives with onboard powering must trade off size, functionality, and operation duration. Here, we propose a wireless millimeter-scale wheeled robot capable of using environmental flows to power and actuate its long-distance locomotion through complex pipelines. The flow-powering module can convert flow energy into mechanical energy, achieving an impeller speed of up to 9595 revolutions per minute, accompanied by an output power density of 11.7 watts per cubic meter and an efficiency of 33.7%. A miniature gearbox module can further transmit the converted mechanical energy into the robot's locomotion system, allowing the robot to move against water flow at an average rate of up to 1.05 meters per second. The robot's motion status (moving against/with flow or pausing) can be switched using an external magnetic field or an onboard mechanical regulator, contingent on different proposed control designs. In addition, we designed kirigami-based soft wheels for adaptive locomotion. The robot can move against flows of various substances within pipes featuring complex geometries and diverse materials. Solely powered by flow, the robot can transport cylindrical payloads with a diameter of up to 55% of the pipe's diameter and carry devices such as an endoscopic camera for pipeline inspection, a wireless temperature sensor for environmental temperature monitoring, and a leak-stopper shell for infrastructure maintenance.

Substance-flow analysis and emission-reduction strategies for thallium in the steel industry process

Thallium, which is a highly toxic and sparsely distributed element, is often found in various mineral compounds. Its release into the environment primarily occurs through the mining of metals, metallurgical processes, and the combustion of fossil fuels. These activities release thallium from minerals, concentrating it in ash, wastewater, and exhaust gases, thus contributing to thallium pollution. With over 600 active steelworks in China continuously producing steel, the risk of thallium pollution is significant and thus presents a major challenge. This research focuses on understanding the mechanisms of the physical phase evolution, migration pathways, and emission characteristics of thallium in steelworks. For the first time, a thallium flow network in steelworks is developed using substance flow analysis. This involves examining the input, output, waste discharge characteristics, and potential for reduction of thallium. The findings reveal that iron concentrate is the primary source of thallium in steelworks, with dust being the main form of thallium output. The quantities of thallium input, output, and circulation are found to be 425.44, 365.49, and 49.66 mg/t-CS, respectively. Implementing source control, endpoint governance, or a combination of both can reduce pollutant emissions in steelworks by 41.47%, 43.35%, and 65.63%, respectively. This study enhances our understanding of thallium pollution in steelworks.