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Search Results (254)

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Keywords = liquid deposition modelling

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23 pages, 10386 KiB  
Article
Hair Metabolomic Profiling of Diseased Forest Musk Deer (Moschus berezovskii) Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry (UHPLC-MS/MS)
by Lina Yi, Han Jiang, Yajun Li, Zongtao Xu, Haolin Zhang and Defu Hu
Animals 2025, 15(14), 2155; https://doi.org/10.3390/ani15142155 - 21 Jul 2025
Viewed by 186
Abstract
Hair, as a non-invasive biospecimen, retains metabolic deposits from sebaceous glands and capillaries, reflecting substances from the peripheral circulation, and provides valuable biochemical information linked to phenotypes, yet its application in animal disease research remains limited. This work applied ultra-high-performance liquid chromatography–tandem mass [...] Read more.
Hair, as a non-invasive biospecimen, retains metabolic deposits from sebaceous glands and capillaries, reflecting substances from the peripheral circulation, and provides valuable biochemical information linked to phenotypes, yet its application in animal disease research remains limited. This work applied ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) to compare the hair metabolomic characteristics of healthy forest musk deer (FMD, Moschus berezovskii) and those diagnosed with hemorrhagic pneumonia (HP), phytobezoar disease (PD), and abscess disease (AD). A total of 2119 metabolites were identified in the FMD hair samples, comprising 1084 metabolites in positive ion mode and 1035 metabolites in negative ion mode. Differential compounds analysis was conducted utilizing the orthogonal partial least squares–discriminant analysis (OPLS-DA) model. In comparison to the healthy control group, the HP group displayed 85 upregulated and 92 downregulated metabolites, the PD group presented 124 upregulated and 106 downregulated metabolites, and the AD group exhibited 63 upregulated and 62 downregulated metabolites. Functional annotation using the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the differential metabolites exhibited significant enrichment in pathways associated with cancer, parasitism, energy metabolism, and stress. Receiver operating characteristic (ROC) analysis revealed that both the individual and combined panels of differential metabolites exhibited area under the curve (AUC) values exceeding 0.7, demonstrating good sample discrimination capability. This research indicates that hair metabolomics can yield diverse biochemical insights and facilitate the development of non-invasive early diagnostic techniques for diseases in captive FMD. Full article
(This article belongs to the Section Animal Physiology)
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17 pages, 6527 KiB  
Article
Mechanical Properties of Bio-Printed Mortars with Bio-Additives for Green and Sustainable Construction
by Sotirios Pemas, Dimitrios Baliakas, Eleftheria Maria Pechlivani and Maria Stefanidou
Materials 2025, 18(14), 3375; https://doi.org/10.3390/ma18143375 - 18 Jul 2025
Viewed by 285
Abstract
Additive manufacturing (AM) has brought significant breakthroughs to the construction sector, such as the ability to fabricate complex geometries, enhance efficiency, and reduce both material usage and construction waste. However, several challenges must still be addressed to fully transition from conventional construction practices [...] Read more.
Additive manufacturing (AM) has brought significant breakthroughs to the construction sector, such as the ability to fabricate complex geometries, enhance efficiency, and reduce both material usage and construction waste. However, several challenges must still be addressed to fully transition from conventional construction practices to innovative and sustainable green alternatives. This study investigates the use of non-cementitious traditional mixtures for green construction applications through 3D printing using Liquid Deposition Modeling (LDM) technology. To explore the development of mixtures with enhanced physical and mechanical properties, natural pine and cypress wood shavings were added in varying proportions (1%, 3%, and 5%) as sustainable additives. The aim of this study is twofold: first, to demonstrate the printability of these eco-friendly mortars that can be used for conservation purposes and overcome the challenges of incorporating bio-products in 3D printing; and second, to develop sustainable composites that align with the objectives of the European Green Deal, offering low-emission construction solutions. The proposed mortars use hydrated lime and natural pozzolan as binders, river sand as an aggregate, and a polycarboxylate superplasticizer. While most studies with bio-products focus on traditional methods, this research provides proof of concept for their use in 3D printing. The study results indicate that, at low percentages, both additives had minimal effect on the physical and mechanical properties of the tested mortars, whereas higher percentages led to progressively more significant deterioration. Additionally, compared to molded specimens, the 3D-printed mortars exhibited slightly reduced mechanical strength and increased porosity, attributable to insufficient compaction during the printing process. Full article
(This article belongs to the Special Issue Eco-Friendly Materials for Sustainable Buildings)
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23 pages, 7045 KiB  
Article
Deposition: A DPM and PBM Approach for Particles in a Two-Phase Turbulent Pipe Flow
by Alkhatab Bani Saad, Edward Obianagha and Lande Liu
Powders 2025, 4(3), 20; https://doi.org/10.3390/powders4030020 - 4 Jul 2025
Viewed by 229
Abstract
Particle deposition is a phenomenon that occurs in many natural and industrial systems. Nevertheless, the modelling and understanding of such processes are still quite a big challenge. This study uses a discrete phase model (DPM) to determine the deposition constant for the particles [...] Read more.
Particle deposition is a phenomenon that occurs in many natural and industrial systems. Nevertheless, the modelling and understanding of such processes are still quite a big challenge. This study uses a discrete phase model (DPM) to determine the deposition constant for the particles in a liquid phase flowing in a horizontal pipe. This study also develops a steady-state population balance equation (PBE) for the particles in the flow involving deposition and aggregation and an unsteady-state PBE for particles depositing on the wall. This establishes a mathematical relationship between the deposition constant and velocity. An industrial setting of a 1000 m long pipe of 0.5 m in diameter was used for the population balance modelling (PBM). Based on the extracted deposition constant from the DPM, it was found that the particle deposition velocity increases with the continuous flow velocity. However, the number and volume of the deposit particles on the wall reduce with the increase of the continuous flow velocity. The deposition was found mainly taking place in the inlet region and reduces significantly towards the pipe outlet. The deposition was also found driven by advection of particles. Calculated deposit thickness showed that increasing the continuous flow velocity from 1 m s−1 to 5 m s−1, the thickness at the inlet would reduce to nearly 1/40th. With a 10 m s−1 flow, this would be 1/80th. Full article
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15 pages, 2767 KiB  
Article
Solid-to-Solid Manufacturing Processes for High-Performance Li-Ion Solid-State Batteries
by David Orisekeh, Byeong-Min Roh and Xinyi Xiao
Polymers 2025, 17(13), 1788; https://doi.org/10.3390/polym17131788 - 27 Jun 2025
Viewed by 557
Abstract
Batteries are used as energy storage devices in various equipment. Today, research is focused on solid-state batteries (SSBs), replacing the liquid electrolyte with a solid separator. The solid separators provide electrolyte stability, no leakage, and provide mechanical strength to the battery. Separators are [...] Read more.
Batteries are used as energy storage devices in various equipment. Today, research is focused on solid-state batteries (SSBs), replacing the liquid electrolyte with a solid separator. The solid separators provide electrolyte stability, no leakage, and provide mechanical strength to the battery. Separators are mostly manufactured by either traditional processes or 3D printing technologies. These processes involve making a slurry of plastic, active and conductive material and usually adding a plasticizer when making thin films or filaments for 3D printing. This study investigates the additive manufacturing of solid-state electrolytes (SSEs) by employing fused deposition modeling (FDM) with recyclable, bio-derived polylactic acid (PLA) filaments. Precise control of macro-porosity is achieved by systematically varying key process parameters, including raster orientation, infill percentage, and interlayer adhesion conditions, thereby enabling the formation of tunable, interconnected pore networks within the polymer matrix. Following 3D printing, these engineered porous frameworks are infiltrated with lithium hexafluorophosphate (LiPF6), which functions as the active ionic conductor. A tailored thermal sintering protocol is then applied to promote solid-phase fusion of the embedded salt throughout the macro-porous PLA scaffold, resulting in a mechanically robust and ionically conductive composite separator. The electrochemical ionic conductivity and structural integrity of the sintered SSEs are characterized through electrochemical impedance spectroscopy (EIS) and standardized mechanical testing to assess their suitability for integration into advanced solid-state battery architectures. The solid-state separator achieved an average ionic conductivity of 2.529 × 10−5 S·cm−1. The integrated FDM-sintering process enhances ion exchange at the electrode–electrolyte interface, minimizes material waste, and supports cost-efficient, fully recyclable component fabrication. Full article
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20 pages, 9033 KiB  
Article
Design and Evaluation of a Novel Efficient Air-Assisted Hollow-Cone Electrostatic Nozzle
by Li Zhang, Zhi Li, Huaxing Chu, Qiaolin Chen, Yang Li and Xinghua Liu
Agriculture 2025, 15(12), 1293; https://doi.org/10.3390/agriculture15121293 - 16 Jun 2025
Viewed by 448
Abstract
For crop protection, electrostatic spraying technology significantly improves deposition uniformity and pesticide utilization through the “wraparound-adsorption” effect of charged droplets. However, existing electrostatic nozzles using hydraulic atomization suffer from low charge-to-mass ratios due to unclear principles for optimizing electrode parameters. To this end, [...] Read more.
For crop protection, electrostatic spraying technology significantly improves deposition uniformity and pesticide utilization through the “wraparound-adsorption” effect of charged droplets. However, existing electrostatic nozzles using hydraulic atomization suffer from low charge-to-mass ratios due to unclear principles for optimizing electrode parameters. To this end, this study designs and evaluates a novel air-assisted hydraulic-atomization hollow-cone electrostatic nozzle. First, the air-assisted hollow-cone nozzle was designed. High-speed imaging was then employed to obtain morphological parameters of the liquid film (length: 2.14 mm; width: 1.96 mm; and spray angle: 49.25°). Based on these parameters, an electric field simulation model of the electrostatic nozzle was established to analyze the influence of electrode parameters on the charging performance and identify the optimal parameter combination. Finally, feasibility and efficiency evaluation experiments were conducted on the designed electrostatic nozzle. The experimental results demonstrate that cross-sectional dimensions of the electrode exhibit a positive correlation with the surface charge density of the pesticide liquid film. In addition, optimal charging performance is obtained when the electrode plane coincides with the tangent plane of the liquid film leading edge. Based on these charging laws, the optimal electrode parameters were determined as follows: 2.0 × 2.0 mm cross-section with an electrode-to-nozzle tip distance of 3.8 mm. With these parameters, the nozzle achieved a droplet charge-to-mass ratio of 4.9 mC/kg at a charging voltage of 3.0 kV. These charged droplets achieved deposition coverages of 12.19%, 5.72%, and 5.91% on abaxial leaf surfaces in the upper, middle, and lower soybean canopies, respectively, which is a significant improvement in deposition uniformity. This study designed a novel air-assisted hollow-cone electrostatic nozzle, elucidated the optimization principles for annular induction electrodes, and achieved improved spraying performance. The findings contribute to enhanced pesticide application efficiency in crops, providing valuable theoretical guidance and technical references for electrostatic nozzle design and application. Full article
(This article belongs to the Section Agricultural Technology)
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24 pages, 10324 KiB  
Article
A Versatile Platform for Designing and Fabricating Multi-Material Perfusable 3D Microvasculatures
by Nathaniel Harris, Charles Miller and Min Zou
Micromachines 2025, 16(6), 691; https://doi.org/10.3390/mi16060691 - 8 Jun 2025
Viewed by 1267
Abstract
Perfusable microvasculature is critical for advancing in vitro tissue models, particularly for neural applications where limited diffusion impairs organoid growth and fails to replicate neurovascular function. This study presents a versatile fabrication platform that integrates mesh-driven design, two-photon lithography (TPL), and modular interfacing [...] Read more.
Perfusable microvasculature is critical for advancing in vitro tissue models, particularly for neural applications where limited diffusion impairs organoid growth and fails to replicate neurovascular function. This study presents a versatile fabrication platform that integrates mesh-driven design, two-photon lithography (TPL), and modular interfacing to create multi-material, perfusable 3D microvasculatures. Various 2D and 3D capillary paths were test-printed using both polygonal and lattice support strategies. A double-layered capillary scaffold based on the Hilbert curve was used for comparative materials testing. Methods for printing rigid (OrmoComp), moderately stiff hydrogel (polyethylene glycol diacrylate, PEGDA 700), and soft elastomeric (photocurable polydimethylsiloxane, PDMS) materials were developed and evaluated. Cone support structures enabled high-fidelity printing of the softer materials. A compact heat-shrink tubing interface provided leak-free perfusion without bulky fittings. Physiologically relevant flow velocities and Dextran diffusion through the scaffold were successfully demonstrated. Cytocompatibility assays confirmed that all TPL-printed scaffold materials supported human neural stem cell viability. Among peripheral components, lids fabricated via fused deposition modeling designed to hold microfluidic needle adapters exhibited good biocompatibility, while those made using liquid crystal display-based photopolymerization showed significant cytotoxicity despite indirect exposure. Overall, this platform enables creation of multi-material microvascular systems facilitated by TPL technology for complex, 3D neurovascular modeling, blood–brain barrier studies, and integration into vascularized organ-on-chip applications. Full article
(This article belongs to the Special Issue Microfluidic Chips for Biomedical Applications)
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15 pages, 5879 KiB  
Article
The Mineralization Mechanism of the Axi Gold Deposit in West Tianshan, NW China: Insights from Fluid Inclusion and Multi-Isotope Analyses
by Fang Xia, Chuan Chen and Weidong Sun
Minerals 2025, 15(5), 536; https://doi.org/10.3390/min15050536 - 18 May 2025
Viewed by 440
Abstract
The Axi gold deposit, which is located in the Tulasu Basin of the West Tianshan orogenic belt in Northwest China, features vein-type ore bodies hosted in radial structural fractures formed due to volcanic activity. The deposit experienced three distinct mineralization stages: Stage I, [...] Read more.
The Axi gold deposit, which is located in the Tulasu Basin of the West Tianshan orogenic belt in Northwest China, features vein-type ore bodies hosted in radial structural fractures formed due to volcanic activity. The deposit experienced three distinct mineralization stages: Stage I, characterized by the microcrystalline quartz–pyrite crust; Stage II, characterized by quartz–sulfide–native gold veins; and Stage III, characterized by quartz–carbonate veins. Fluid inclusion studies have identified four types of inclusions: pure vapor, vapor-rich, liquid-rich, and pure liquid. The number of vapor-rich inclusions decreases when moving from Stage I to Stage III, whereas the number of liquid-rich inclusions increases. The fluid temperature gradually decreases from 178–225 °C in Stage I to 151–193 °C in Stage II and further to 123–161 °C in Stage III, whereas the fluid salinity decreases slightly from 2.1%–5.1% wt.% NaCl eqv to 1.4%–4.6% wt.% NaCl eqv and finally to 0.5%–3.7% wt.% NaCl eqv. As suggested by the results of the oxygen, hydrogen, and carbon isotope analyses, the ore-forming fluids were primarily meteoric water. Sulfur isotopic compositions indicate a single deep mantle source. The lead isotopic compositions closely resemble those of Dahalajunshan Formation volcanic rocks, indicating that these rocks were the primary source of the ore-forming material. In addition, gold mineralization formed in a Devonian–Early Carboniferous volcanic arc environment. Element enrichment was mainly caused by the circulation of heated meteoric water through the volcanic strata, while fluid boiling and water–rock interactions were the main mechanisms driving element precipitation. The integrated model developed in this study underscores the intricate interplay between volcanic processes and meteoric fluids during the formation of the Axi gold deposit, offering a robust framework for an understanding of the formation processes and enhancing the predictive exploration models in analogous geological settings. Full article
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19 pages, 2340 KiB  
Article
Study on Coal Particle Properties and Critical Velocity Model in Coalbed Methane Horizontal Wells
by Ruili Zhou, Tian He, Yuxiang Liu, Peidong Mai and Guoqing Han
Processes 2025, 13(5), 1550; https://doi.org/10.3390/pr13051550 - 17 May 2025
Viewed by 411
Abstract
During the drainage process of coalbed methane (CBM) horizontal wells, wellbore fluctuations exert a significant influence on gas–liquid–solid three-phase flow behavior and coal particle migration. This study investigates the effects of wellbore inclination, gas–liquid flow rates, and coal particle sizes on migration characteristics [...] Read more.
During the drainage process of coalbed methane (CBM) horizontal wells, wellbore fluctuations exert a significant influence on gas–liquid–solid three-phase flow behavior and coal particle migration. This study investigates the effects of wellbore inclination, gas–liquid flow rates, and coal particle sizes on migration characteristics through laboratory-scale experiments, based on an initial analysis of coal particle physical properties. A critical velocity model accounting for wellbore fluctuations is developed and refined. The migration states of coal particles under various operational conditions are examined, and the corresponding critical velocities and movement patterns are analyzed. The results show that coal particle migration is predominantly governed by the liquid phase, while the presence of particles has limited impact on the overall gas–liquid flow regime. Under different wellbore inclinations, the critical velocity increases with particle size; however, the influence of inclination is more pronounced than that of particle size. Coal particle entrainment follows three distinct stages: hopping, rolling, and suspension. The velocity during the rolling stage is identified as the critical velocity. At steeper inclination angles, particles are more easily entrained by the flow, and the associated critical velocity is higher. Based on the fitted experimental data, the model is revised to improve its predictive capability for coal particle transport in CBM wells. Finally, the model is validated using field data from a CBM well in the Ordos Basin. The results confirm the model’s ability to predict coal particle accumulation trends within the wellbore. This study provides new insights into coal particle migration mechanisms under fluctuating wellbore conditions, offering both experimental and theoretical support for understanding gas–liquid–solid flow behavior. It also presents technical guidance for optimizing drainage performance, controlling particle deposition, and formulating wellbore cleaning strategies. Full article
(This article belongs to the Special Issue Coalbed Methane Development Process)
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19 pages, 9507 KiB  
Article
Mechanical Strength of Waste Materials: A Cone Penetration Testing-Based Geotechnical Assessment for the Reclamation of Landfills
by Marek Bajda, Mariusz Lech, Katarzyna Markowska-Lech, Piotr Osiński and Eugeniusz Koda
Materials 2025, 18(9), 2130; https://doi.org/10.3390/ma18092130 - 6 May 2025
Viewed by 470
Abstract
The stability and mechanical properties of municipal solid waste (MSW) deposits in closed landfills are critical for safe land reclamation and infrastructure development. This study employs Cone Penetration Testing (CPT) to evaluate the geotechnical parameters of aged waste at three closed landfill sites [...] Read more.
The stability and mechanical properties of municipal solid waste (MSW) deposits in closed landfills are critical for safe land reclamation and infrastructure development. This study employs Cone Penetration Testing (CPT) to evaluate the geotechnical parameters of aged waste at three closed landfill sites in central Poland. Key parameters, including shear strength, internal friction angle, density, and liquidity index, were assessed to determine slope stability and bearing capacity for future redevelopment. Due to the heterogeneous nature of MSW, CPT results were analyzed in conjunction with empirical correlations and nomograms to improve accuracy, so the parameters can be used for future numerical modeling and proposing new computational approaches for landfill body elastic and mechanical behavior predictions. The findings indicate significant variability in landfill waste mechanical properties, influenced by waste composition, decomposition stage, and compaction history. The study highlights CPT’s reliable detremination of geotechnical parameters for landfill restoration projects, particularly for infrastructure, creating the potential for green energy and sustainable development. The results contribute to improving engineering practices in landfill restoration and ensuring the long-term stability of post-closure land use. This study also contributes to obtaining reliable results on anthropogenic waste material mechanical parameters at both the material point and at the overall structural scale, benefiting future computational methods and modeling approaches for analyzing structural and geotechnical safety of such complex and demanding structures as landfills. Full article
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22 pages, 7582 KiB  
Article
Computational and Experimental Research on Dense Medium Separation of Low-Grade Spodumene
by Shuli Wang, Jun Wang, Guanzhou Qiu, Li Shen, Rui Liao and Lianjun Wu
Minerals 2025, 15(5), 434; https://doi.org/10.3390/min15050434 - 22 Apr 2025
Viewed by 509
Abstract
Due to the increasing demand for lithium resources, the efficient exploitation and utilization of low-grade hard-rock deposits has become an inevitable trend. This study conducted comprehensive heavy liquid separation (HLS), numerical simulation, and dense medium separation (DMS) tests using a laboratory dense medium [...] Read more.
Due to the increasing demand for lithium resources, the efficient exploitation and utilization of low-grade hard-rock deposits has become an inevitable trend. This study conducted comprehensive heavy liquid separation (HLS), numerical simulation, and dense medium separation (DMS) tests using a laboratory dense medium cyclone (DMC) on a low-grade spodumene ore to demonstrate the potential role of DMS technology in this task. HLS tests verified the feasibility of directly producing qualified concentrate and rejecting waste under different separation densities. A two-stage DMS circuit was then proposed, with the influence of key parameters investigated by numerical simulations using the two-fluid model and dispersed model. The optimized set of structural and operational parameters was finally identified by DMS tests. A continuously operated test conducted on −8 + 0.5 mm ore produced a spodumene concentrate grading 5.68% Li2O with over 80% lithium recovery while rejecting 0.13% Li2O waste to tailings with ~70% disposal rate but only 7.44% lithium losses. The middling with a yield of 12.66% can be further subjected to a traditional grinding-flotation process. The findings underscore the importance of parameter matching in the DMS and demonstrate the application potential of DMS in the development of low-grade spodumene from other hard-rock occurrences. Full article
(This article belongs to the Special Issue Recent Advances in Ore Comminution)
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23 pages, 2587 KiB  
Article
Enhancing Physiological Realism in Nasal Spray Deposition Studies: Synthetic Mucus Properties and Interactions with Saline Solutions and Stereolithography Resin
by Amr Seifelnasr, Farhad Zare, Xiuhua Si and Jinxiang Xi
Liquids 2025, 5(2), 11; https://doi.org/10.3390/liquids5020011 - 7 Apr 2025
Cited by 1 | Viewed by 1337
Abstract
This study investigated the role of synthetic mucus coatings in enhancing the physiological relevance of in vitro nasal spray deposition assessments using 3D-printed nasal cavity models. Synthetic mucus solutions, representing normal (0.25% w/v xanthan gum) and diseased (1% w/v [...] Read more.
This study investigated the role of synthetic mucus coatings in enhancing the physiological relevance of in vitro nasal spray deposition assessments using 3D-printed nasal cavity models. Synthetic mucus solutions, representing normal (0.25% w/v xanthan gum) and diseased (1% w/v xanthan gum) nasal conditions, were developed to mimic the viscoelastic properties of human nasal mucus. Their physical properties, including viscosity, surface tension, contact angle, and adhesivity on dry and synthetic mucus-coated stereolithography (SLA) surfaces, were systematically characterized. Comparative experiments evaluated the behavior of saline drops and liquid films on dry versus synthetic mucus-coated SLA surfaces at inclinations of 30°, 45°, and 60°. Observational deposition experiments using anatomically accurate nasal models were conducted under a 45° backward-tilted head position with gentle sniff airflow across uncoated, 0.25% w/v mucus-coated, and 1% w/v mucus-coated surfaces. Synthetic mucus coatings significantly influenced saline spray deposition patterns. On uncoated surfaces, deposition consisted of scattered droplets and limited film formation, mainly in the anterior and turbinate regions. In contrast, synthetic mucus coatings facilitated broader and more uniform liquid distribution due to diffusion and lubrication effects. These findings highlight the value of synthetic mucus coatings for better simulating nasal environments, offering insights to optimize nasal spray formulations and delivery devices. Full article
(This article belongs to the Section Physics of Liquids)
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22 pages, 522 KiB  
Article
Non-Maturing Deposits: Predictive Modelling and Risk Management
by Anton van Dyk
J. Risk Financial Manag. 2025, 18(2), 84; https://doi.org/10.3390/jrfm18020084 - 5 Feb 2025
Viewed by 2300
Abstract
Non-maturing deposits (NMDs) are a significant source of liquidity for banks, making research into their modelling and forecasting invaluable. However, NMDs have no explicit expiration date, posing liquidity risks and complicating management. This research develops models and a framework to explain, predict, and [...] Read more.
Non-maturing deposits (NMDs) are a significant source of liquidity for banks, making research into their modelling and forecasting invaluable. However, NMDs have no explicit expiration date, posing liquidity risks and complicating management. This research develops models and a framework to explain, predict, and manage variations in non-maturing deposits. Aggregate savings and transaction deposit data from an African bank were analysed to test the methodologies. The Trend-Fourier model, leveraging historical trends and Fourier analysis, forecasted 90-day deposit volumes. The model revealed prominent cyclicalities and monthly trends in deposit account volumes. Benchmarking showed high accuracy for savings deposit volumes, while transaction deposit volumes were less accurate, suggesting simpler models might be suitable. Additionally, a risk metric called LVaR (Liquidity Value at Risk) was proposed. Two approaches for calculating the LVaR were tested. An exceedance test demonstrated notable accuracy for savings deposit volumes but struggled with transaction deposits. Results indicated savings deposit volumes were more predictable than transaction deposits. These findings could enhance banks’ balance sheet management by improving non-maturing deposit forecasting. The proposed methodologies could be utilized for internal and regulatory purposes, such as calculating the liquidity coverage ratio under Basel regulations. Full article
(This article belongs to the Section Mathematics and Finance)
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17 pages, 6532 KiB  
Article
GravelSens: A Smart Gravel Sensor for High-Resolution, Non-Destructive Monitoring of Clogging Dynamics
by Kaan Koca, Eckhard Schleicher, André Bieberle, Stefan Haun, Silke Wieprecht and Markus Noack
Sensors 2025, 25(2), 536; https://doi.org/10.3390/s25020536 - 17 Jan 2025
Viewed by 955
Abstract
Engineers, geomorphologists, and ecologists acknowledge the need for temporally and spatially resolved measurements of sediment clogging (also known as colmation) in permeable gravel-bed rivers due to its adverse impacts on water and habitat quality. In this paper, we present a novel method for [...] Read more.
Engineers, geomorphologists, and ecologists acknowledge the need for temporally and spatially resolved measurements of sediment clogging (also known as colmation) in permeable gravel-bed rivers due to its adverse impacts on water and habitat quality. In this paper, we present a novel method for non-destructive, real-time measurements of pore-scale sediment deposition and monitoring of clogging by using wire-mesh sensors (WMSs) embedded in spheres, forming a smart gravel bed (GravelSens). The measuring principle is based on one-by-one voltage excitation of transmitter electrodes, followed by simultaneous measurements of the resulting current by receiver electrodes at each crossing measuring pores. The currents are then linked to the conductive component of fluid impedance. The measurement performance of the developed sensor is validated by applying the Maxwell Garnett and parallel models to sensor data and comparing the results to data obtained by gamma ray computed tomography (CT). GravelSens is tested and validated under varying filling conditions of different particle sizes ranging from sand to fine gravel. The close agreement between GravelSens and CT measurements indicates the technology’s applicability in sediment–water research while also suggesting its potential for other solid–liquid two-phase flows. This pore-scale measurement and visualization system offers the capability to monitor clogging and de-clogging dynamics within pore spaces up to 10,000 Hz, making it the first laboratory equipment capable of performing such in situ measurements without radiation. Thus, GravelSens is a major improvement over existing methods and holds promise for advancing the understanding of flow–sediment–ecology interactions. Full article
(This article belongs to the Section Environmental Sensing)
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23 pages, 955 KiB  
Article
A Proof-of-Concept for Safety Evaluation of Inhalation Exposure to Known Respiratory Irritants Using In Vitro and In Silico Methods
by Nikaeta Sadekar, Holger Peter Behrsing, Tanja Hansen, Vivek Patel, Hazel Paulo, Alex Rae, Detlef Ritter, Katharina Schwarz and Anne Marie Api
Toxics 2025, 13(1), 35; https://doi.org/10.3390/toxics13010035 - 4 Jan 2025
Cited by 3 | Viewed by 1911
Abstract
There is increased interest in developing non-animal test systems for inhalation exposure safety assessments. However, defined methodologies are absent for predicting local respiratory effects from inhalation exposure to irritants. The current study introduces a concept for applying in vitro and in silico methods [...] Read more.
There is increased interest in developing non-animal test systems for inhalation exposure safety assessments. However, defined methodologies are absent for predicting local respiratory effects from inhalation exposure to irritants. The current study introduces a concept for applying in vitro and in silico methods for inhalation exposure safety assessment. Three in vitro systems, representing the upper (MucilAir™—nasal epithelial tissue) and lower (A549 cells and human precision-cut lung slices) human respiratory regions, were exposed to six respiratory irritants. These irritant exposures were conducted as liquid droplets, aerosol, or vapors, and samples were collected over 24 h. Cytotoxicity, cytokine release, epithelial resistance, oxidative stress, and mitochondrial membrane potential were measured. To determine the human relevance of in vitro exposures, airway surface depositions were predicted by simulating airborne concentrations equivalent to the Cramer class III inhalation threshold of toxicological concern limit of 0.47 mg/person/day using an in silico model. A > 100-fold margin of exposure was calculated comparing lowest concentrations showing in vitro effects to in silico simulated values. While further studies are needed, this manuscript presents a basic requirement for employing non-animal methods to inform inhalation exposure safety assessments by combining in vitro and in silico assays. Full article
(This article belongs to the Special Issue Feature Papers in the Novel Methods in Toxicology Research)
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15 pages, 4450 KiB  
Article
Enhancing the Proportion of Sub-5 μm Atomized Droplet Size in Medical Air-Compression Nebulizer
by Kun Xu, Zhongyou Lu, Li Wang and Yunqing Tang
Symmetry 2025, 17(1), 6; https://doi.org/10.3390/sym17010006 - 24 Dec 2024
Cited by 1 | Viewed by 4671
Abstract
Medical air-compression nebulizers deliver atomized medication to the lungs, providing rapid and painless treatment for respiratory diseases. However, the size of most atomized droplets is around 10 μm, limiting drug deposition in the lower airways and alveoli, with increasing the proportion of sub-5 [...] Read more.
Medical air-compression nebulizers deliver atomized medication to the lungs, providing rapid and painless treatment for respiratory diseases. However, the size of most atomized droplets is around 10 μm, limiting drug deposition in the lower airways and alveoli, with increasing the proportion of sub-5 μm droplets remaining challenging. In this work, finite element analysis was employed to model the effects of gas flow rate, liquid channel width, and broken baffle structure on droplet size distribution, aiming to optimize structure symmetrical parameters and operating conditions. A novel compression atomizer was developed and experimentally evaluated, incorporating an improved symmetrical structure for the crushing baffle. Following this modification, the proportion of sub-5 μm droplets increased from 54.6% to 59.25%, representing a 4.65% enhancement in the generation of sub-5 μm droplets. The effects of gas flow rate and liquid concentration on droplet size distribution were systematically investigated to further optimize the atomization performance. The results demonstrated a significant increase in the proportion of sub-5 μm droplets, thereby enhancing drug delivery efficiency to the lower respiratory tract and improving treatment efficacy for respiratory diseases. Full article
(This article belongs to the Special Issue Symmetry in Mechanical Engineering: Properties and Applications)
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