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In this paper, numerical simulations were used to study the decomposition and combustion processes inside the 0.2 N-class ADN-based thruster, and the effects of two geometrical parameters (length and diameter) of the combustion chamber on the combustion performance were evaluated. The decomposition and combustion processes of the thruster were simulated using a reduced chemical reaction mechanism with 22 components and 20 reactions steps. According to the distribution of the basic physical fields, the variation patterns of the pressure field, velocity field, temperature field, and key component parameters caused by different combustion chamber geometrical parameters were observed and analyzed. The results show that the specific impulse and thrust of the thruster increased and then decreased with the increase of the combustion chamber diameter. When the combustion chamber diameter is 7.9 mm, the specific impulse reaches the maximum value of 206.6 s. Additionally, the specific impulse increased from 186 s to 206 s when the combustion chamber length was changed from 7 mm to 11 mm; the specific impulse increased gradually but not significantly, and the growth trend started to flatten out. The results from the paper can serve as a reference for the design and vacuum testing of an ADN-based thruster.
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http://dx.doi.org/10.3390/mi13040605 | DOI Listing |
STAR Protoc
September 2025
UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital, Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; UCLA Environmental and Molecular Toxicology Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA
Exposure systems to study the effects of environmental exposures can be costly to purchase and difficult to use. Here, we present an accessible and cost-effective approach to building an exposure chamber in the lab. We describe steps for constructing the exposure system and writing the code to run it and simple instructions for experiments using the system.
View Article and Find Full Text PDFArch Environ Contam Toxicol
September 2025
Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering, 1015, Lausanne, Switzerland.
Pollution from past industrial activities can remain unnoticed for years or even decades because the pollutant has only recently gained attention or been identified by measurements. Modeling the emission history of pollution is essential for estimating population exposure and apportioning potential liability among stakeholders. This paper proposes a novel approach for reconstructing the history of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) pollution from municipal solid waste incinerators (MSWIs) with unknown past emissions.
View Article and Find Full Text PDFJ Hazard Mater
August 2025
College of Mechanical Engineering, Guangxi University, Nanning 530004, China. Electronic address:
This research addresses the soot emission challenges of conventional internal combustion engines by incorporating Fe-based metal-organic frameworks (Fe-MOFs) into alcohol-based fuel. In a constant volume combustion chamber, optical diagnostic methods were employed to examine the spray properties, combustion dynamics, and emission profiles of fuel mixtures with Fe-MOFs concentrations of 20 ppm, 40 ppm, and 60 ppm. Additionally, a BO-GPR algorithm was employed to predict emission outcomes.
View Article and Find Full Text PDFSci Rep
August 2025
College of Mechanical and Electrical Engineering, Changchun University of Science and Technology, Changchun, 130022, China.
This article focuses on optimizing the evaporation and atomization performance of the evaporator tube in the combustion chamber of a microturbine engine, and examines its impact on engine thrust. Given that the evaporator tube design is crucial for enhancing combustion efficiency as a key component of the combustion chamber, this study introduces an innovative evaporator tube structure that incorporates biomimetic design principles through theoretical exploration. The proposed structure adds specifically sized grooves to the inner wall of traditional evaporation tubes to improve the evaporation and atomization processes of fuel droplets.
View Article and Find Full Text PDFBMJ Open
August 2025
Division of Genetic, Environmental and Inhalational Disease, Department of Internal Medicine, The University of Kansas Medical Center, Kansas City, Kansas, USA.
Introduction: Reliable detection of cigarette smoking is necessary for just-in-time adaptive smoking cessation support. Smoking detection typically relies on intervention recipients to self-report smoking behaviours and their antecedents, which is burdensome and subject to reporting biases, or on specialised sensors and wearables to detect smoking gestures, which may not be feasible for real-world implementation. Here, we describe an observational laboratory-based study protocol designed to identify signature biomarkers and hand-mouth gestures associated with presmoking, smoking and postsmoking using off-the-shelf wearable devices.
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