Spread Of Particles Research Articles

Perforated plate ventilation system and dynamics of infectious respiratory particle transmission

AbstractWith the removal of indoor pollutants and the assurance of air quality emerging as critical research topics, the optimization of the internal environment in offices, where people stay for extended periods, is essential for controlling the spread of infectious respiratory particles. Frequent movements of personnel and the operation of doors and windows within offices significantly impact the mechanisms of droplet transmission, warranting further investigation. This study employs computational fluid dynamics simulations to explore the droplet dispersion characteristics and pollutant removal efficiency of the simplified model of perforated plate ventilation system (PPVS) (the diameter of the air supply openings has been reasonably simplified and uniformly set to 0.02 m) in office settings, as well as the impact of dynamic door operation scenarios on droplet spread and concentrations in breathing zones. To optimize the ventilation system's pollutant removal efficiency, airflow velocities (2.86, 3.18, and 5.00 m/s) are varied, with simulations conducted at the optimal velocity of 3.18 m/s. The effects of continuous door operations, door‐opening directions (towards the office and towards the isolation room), and opening speeds (π/4, π/6, π/8, and π/10 rad/s) are also examined, revealing significant impacts on droplet spread. Results indicate that PPVS effectively reduces indoor pollutant concentrations at all tested airflow velocities, with the optimal speed identified as 3.18 m/s. Additionally, door‐opening direction and speed can significantly influence droplet spread. Opening doors towards isolation rooms at smaller angles (less than 30°) effectively reduces droplet concentrations in personnel breathing zones, thereby mitigating the risk of droplet transmission. Faster door‐opening speeds also contribute to lower droplet concentrations in these zones. This innovative study explores the impacts of PPVS and dynamic door operation dynamics on droplet transmission during respiratory disease outbreaks, providing valuable theoretical insights and technical support for disease prevention and indoor air quality improvement.

Impact of Horizontal Model Resolution on Mixing and Dispersion in the Northeastern Gulf of Mexico

AbstractIn this paper, the importance of model horizontal resolution in mixing and dispersion is investigated by comparing two data‐assimilative high‐resolution simulations (4 and 1 km), one of which is submesoscale‐permitting. By employing both Eulerian and Lagrangian metrics, upper‐ocean differences between the mesoscale‐resolving and submesoscale‐permitting simulations are examined in the northeastern Gulf of Mexico, a region of high mesoscale and submesoscale activity. Mixing in both simulations is explored by conducting Lagrangian experiments to track the generation of Lagrangian coherent structures (LCSs) and their associated transport barriers. Finite‐time Lyapunov exponent (FTLE) fields show higher separation rates of fluid particles in the submesoscale‐permitting case, which indicate more vigorous mixing with differences being more pronounced in the shelf regions (depths ≤ 500 m). The extent of the mixing homogeneity is examined using probability density functions (PDFs) of FTLEs with results suggesting that mixing is heterogeneous in both simulations, but some homogeneity is exhibited in the submesoscale‐permitting case. The FTLE fields also indicate that chaotic advection dominates turbulent mixing in both simulations regardless of the horizontal resolution. In the submesoscale‐permitting experiment, however, smaller scale LCSs emerge as noise‐like filaments that suggest a larger turbulent mixing component than in the mesoscale‐resolving experiment. The impact of resolution is then explored by investigating the spread of oil particles at the location of the Deepwater Horizon oil spill.

Effect of water hardness and surfactant on the particle coverage and distribution of plant protection products granules

The paper presents a study done to determine how particles of different plant protection products (fungicides) are distributed onto treated surfaces when their solutions are prepared with water of different hardness and addition of surfactant. A total of fifteen plant protection products were studied, all in the same concentration of 0.3% with four type of solutions: only distilled water, distilled water plus a wetting agent – the organosilicone surfactant – Silwet L-77, very hard tap water (hardness = 196.9 ррm СаСО3, 11 °dH) and very hard tap water plus wetting agent. The observations and images were made via light microscope with magnification 200X and 3MP digital camera. The images were analyzed for a percent distribution, and spreading of particles by ImageJ software. The results showed that the distribution, and coverage of particles onto treated surfaces can be different even at application of similar plant protection products. The variations in the properties were observed when the solutions were made with waters with different hardness and a wetting agent was added to the solutions. Contrary to the common perception that hard water can reduce the effectiveness of pesticides towards pests, according to the distribution and coverage of particles onto treated surfaces, in some cases hard water can even enhance these properties of the pesticide solutions. Keywords: plant protection products, distribution, coverage, wetting agent, water hardness

Mitochondrial Network Branching Enables Rapid Protein Spread with Slower Mitochondrial Dynamics

Mitochondrial network structure is controlled by the dynamical processes of fusion and fission, which merge and split mitochondrial tubes into structures including branches and loops. To investigate the impact of mitochondrial network dynamics and structure on the spread of proteins and other molecules through mitochondrial networks, we used stochastic simulations of two distinct quantitative models that each included mitochondrial fusion and fission, and particle diffusion via the network. Better-connected mitochondrial networks and networks with faster dynamics exhibit more rapid particle spread on the network, with little further improvement once a network has become well connected. As fragmented networks gradually become better connected, particle spread either steadily improves until the networks become well connected for slow-diffusing particles or plateaus for fast-diffusing particles. We compared model mitochondrial networks with both end-to-end and end-to-side fusion, which form branches, to nonbranching model networks that lack end-to-side fusion. To achieve the optimum (most rapid) spread that occurs on well-connected branching networks, nonbranching networks require much faster fusion and fission dynamics. Thus, the process of end-to-side fusion, which creates branches in mitochondrial networks, enables rapid spread of particles on the network with relatively slow fusion and fission dynamics. This modeling of protein spread on mitochondrial networks builds toward mechanistic understanding of how mitochondrial structure and dynamics regulate mitochondrial function. Published by the American Physical Society 2024

Asymmetric vertical transport in weakly forced shallow flows

In this paper, we report on an investigation of the vertical transport of tracer particles released within a shallow, continuously-forced flow by means of numerical simulations. The investigation is motivated by the shallow flows encountered in many environmental situations and inspired by the laboratory experiments conducted in electromagnetically forced shallow fluid layers. The flow is confined to a thin fluid layer by stress-free top and no-slip bottom walls. The dynamics and the transport properties of the shallow flow are investigated under various flow conditions characterized by a Reynolds number related to the forcing, ReF, and the aspect ratio of vertical and horizontal length scales δ. The forcing generates an array of vortices that becomes unsteady when ReFδ2≳10. These vortices are accompanied by upwellings in their cores which are surrounded by narrower, stronger downwellings. Hence, upwellings occur where the horizontal flow is vorticity-dominated, while downwellings where it is strain-dominated. The magnitude of the asymmetry in strength and size of the vertical flows and their correlation with horizontal structures depends on the flow conditions and significantly influences the vertical spreading of particles within the fluid volume. Under conditions leading to a large asymmetry, particles within updrafts are transported slowly upwards, while particles within downdrafts rapidly move downwards. In addition, particles are trapped for longer within the updrafts than downdrafts because of their correlation with vorticity-dominated regions. However, when the flow becomes fully three-dimensional and highly unsteady for large ReFδ2 values, this transport asymmetry subsides because the updrafts and downdrafts exhibit similar strength and size in such flow conditions. Consequently, similar amounts of particles are transported upwards and downwards at similar rates.

A randomised, double blinded control study to compare the efficacy of intraperitoneal nebulization and instillation of ropivacaine for postoperative pain relief in patients undergoing laparoscopic appendicectomy

: Patients scheduled for laparoscopic appendicectomy encounter moderate to severe shoulder pain on the first postoperative day. Intraperitoneal nebulization of local anaesthetics is a new technique which provides uniform spread of local anaesthetic drug particles all through the peritoneum thus providing enhanced analgesic efficacy when compared to intraperitoneal instillation which provides non uniform distribution of the drug. : Fifty participants posted for laparoscopic appendicectomy under general anesthesia were randomized into Group A (Intraperitoneal nebulization of 8ml ropivacaine 0.75%) and Group B (intraperitoneal instillation of 8ml ropivacaine 0.75%). Our primary aim was to evaluate analgesic efficacy in both the groups postoperatively. Our secondary objectives were to compare the incidence of shoulder pain post operatively, total 48 hours fentanyl consumption and postoperative complications like nausea & vomiting and paralytic ileus. : There was statistically significance in the pain scores at 24 hours (static pain p=0.003 and dynamic pain p=0.005) & at 48 hours after surgery (static pain p=0.00 and dynamic pain p=0.015). Significant difference was seen in the incidence of shoulder pain. In Group A, no patients complained pain in shoulders while in Group B a maximum of 6 patients complained shoulder pain postoperatively (p=0.022). The total fentanyl consumption over 48 hours was 0.20 ± 0.005 in Group A and 0.80 ± 0.957 in Group B (p = 0.008). Occurrence of postoperative Nausea & Vomiting were similar in both groups. None of the patients complained paralytic ileus in both groups as systemic absorption of the ropivacaine is also considerably less in comparison to other local anaesthetic drugs . : Intraperitoneal nebulized ropivacaine provides greater reduction in postop pain, lesser consumption of opioids, reduction in referred shoulder pain in laparoscopic appendicectomy patients.

Energy-efficient ventilation strategies at hospital front desks for minimizing infectious particle dispersion: Considering patient postures and airflow optimization

This research presents a novel examination of infectious particle dispersion at hospital front desks, analysing the impact of different patient postures on particle dynamics. It evaluates the efficacy of various ventilation strategies in mitigating particle spread within this high-risk area. Specifically, this study innovatively assesses particle dispersion associated with three common patient postures: upright standing, sitting in a wheelchair, and lying on a mobile bed. Results showed the baseline ventilation that considers the upright standing patient has the highest particles (34) adhered on the nurse. Particle adherence decreases with the sitting (29 particles) and lying postures (20 particles), underscoring the significant influence of human posture on particle distribution. The key contribution of this study is the identification of an optimized ventilation strategy which installs low-level wall-mounted air supply diffusers and ceiling-mounted exhaust grilles, as demonstrated in Case 3. This strategy effectively reduces particle deposition on the nurses and visitors by 52.9 % and 40 %, respectively. These findings advocate for practical infection control measures, like barriers between nurses and patients, to better protect healthcare workers. The study also suggests that future research should account for more crowded environments and occupant movement to better reflect real-world conditions at hospital front desks.

Innovative Nanoscale Ceramic Separators to Boost Cycle Life and Cycle Efficiency of Lithium Metal Batteries

In the pursuit of advancing energy storage, the extraordinary theoretical specific capacity of lithium metal at 3,860 mAh/g significantly outperforms traditional graphite anodes, which offer a capacity of around 372 mAh/g. This disparity underscores the potential of lithium metal batteries to facilitate a leap in energy density, heralding a new age of high-performance batteries. Yet, the evolution of lithium metal batteries is hindered by the formation of dendritic structures during repetitive cycling, posing serious risks, including the likelihood of short circuits that underscore severe safety concerns. To mitigate these risks and enhance the longevity of lithium metal anodes, extensive research has been dedicated to various strategies, including surface modifications of lithium metal and the application of innovative coatings on separators. These strategies, however, often compromise energy density and ionic conductivity due to the addition of ceramic materials and binders. Our study introduces a groundbreaking approach that utilizes nanoscale ceramic-coated separators, created via electron beam deposition. This method achieves a consistent nanoscale spread of metal oxide particles on conventional polyethylene (PE) separators. Crucially, this technique ensures even lithium-ion flow and greatly reduces dendrite growth. The effectiveness of this innovative approach was confirmed in comprehensive LiFePO4-Li cell tests, where cells with these ceramic-coated separators showed notable improvements in both cycle life and Coulombic efficiency, representing a significant advancement over traditional methods.

Influence of a Solid Surface on PNIPAM Microgel Films.

Stimuli-responsive microgels have attracted great interest in recent years as building blocks for fabricating smart surfaces with many technological applications. In particular, PNIPAM microgels are promising candidates for creating thermo-responsive scaffolds to control cell growth and detachment via temperature stimuli. In this framework, understanding the influence of the solid substrate is critical for tailoring microgel coatings to specific applications. The surface modification of the substrate is a winning strategy used to manage microgel-substrate interactions. To control the spreading of microgel particles on a solid surface, glass substrates are coated with a PEI or an APTES layer to improve surface hydrophobicity and add positive charges on the interface. A systematic investigation of PNIPAM microgels spin-coated through a double-step deposition protocol on pristine glass and on functionalised glasses was performed by combining wettability measurements and Atomic Force Microscopy. The greater flattening of microgel particles on less hydrophilic substrates can be explained as a consequence of the reduced shielding of the water-substrate interactions that favors electrostatic interactions between microgels and the substrate. This approach allows the yielding of effective control on microgel coatings that will help to unlock new possibilities for their application in biomedical devices, sensors, or responsive surfaces.

Numerical simulation of solidification of molten slag impacting inclined wall in boiler based on smoothed particle hydrodynamics method

In order to study the process of high temperature liquid slag impinging on the wall, the slagging phase change is produced by combustion of high alkali coal in a boiler chamber. In this paper, based on the smoothed particle hydrodynamics (SPH) method, the flow spreading and solidification model of slag particles hitting the inclined wall are established, and the dynamic process of flow spreading and the phase change of slag particles hitting the wall are analyzed by simulating the deposition process of the phase change of slag particles hitting the wall. The effects of different inclination angles of the wall on its deformation and solidification heat transfer are further discussed. It is shown that the change of inclination angle during the impact of single slag on the wall has a greater influence on the spreading flow process. During the impact of single/double slag on the wall with different inclination angles, the time taken by the double slag to reach the final spreading length and complete phase transition is nearly five times longer than that of the single slag. The direction of slag impact also has an effect on the spreading and phase transition. This SPH method provides a novel numerical simulation idea to study the kinetic behavior of molten slag hitting the wall and the problems related to phase change deposition in boilers.

Identification of dust sources inside and outside of Iran affecting air quality in the Tehran region

Introduction: Recent climate changes and droughts have exacerbated the impact of dust sources globally, necessitating a thorough understanding of their influence on air quality. In Tehran, the interaction between internal dust sources from Iran and external sources from neighboring countries significantly affects air quality. Materials and methods: This study spans a 20-year period (2003-2022), utilizing satellite data and advanced algorithms to analyze dust event trends and patterns. The material and methods section outlines the use of Aqua satellite MODIS sensor data alongside two algorithms to identify dust sources, focusing on Aerosol Optical Depth (AOD) data during peak dust event seasons. Statistical analysis of dust events in 2022 supplements the investigation. Results: The analysis reveals distinct patterns in dust particle origin and transport, highlighting the predominant contribution of internal dust sources from Iran's southern Semnan province and significant input from external sources in Iraq and northern Saudi Arabia. Examining meteorological conditions during severe dust events highlights the role of synoptic conditions, particularly the presence of a tropospheric trough, in facilitating dust transport. Increased convective motions and downburst occurrences in specific regions further exacerbate the spread of dust particles, particularly those originating from external countries and provinces. Conclusion: The conclusion emphasizes the complex interplay between internal and external dust sources and the necessity of understanding dust emission dynamics for effective mitigation strategies. It calls for proactive measures involving local and regional cooperation to mitigate dust pollution's adverse effects on air quality in Tehran and similar urban centers.

Compact Expansion of a Repulsive Suspension.

Short-range repulsion governs the dynamics of matter from atoms to animals. Using theory, simulations, and experiments, we find that an ensemble of repulsive particles spreads compactly with a sharp boundary, in contrast to the diffusive spreading of Brownian particles. Starting from the pair interactions, at high densities, the many-body dynamics follow nonlinear diffusion with a self-similar expansion, growing as t^{1/4}; At longer times, thermal motion dominates with the classic t^{1/2} expansion. A logarithmic growth controlled by nearest-neighbor interactions connects the two self-similar regimes.

Numerical study of particle dispersion in the wake of a static and rotating cylinder at Re = 140 000

In this study, the particle-laden flow in the wake of a static and a rotating cylinder at Reynolds number of 140 000 was investigated using the Reynolds Averaged Navier–Stokes numerical approach. Three turbulence models such as k–ω shear stress transport, Reynolds stress model, and local-correlation transition model (LCTM) were selected to predict the flow topology. Lagrangian approach with one-way coupling was used to track solid spherical particles of different sizes (0.01, 0.1, 2.5, 10, and 50 μm). The study reveals that LCTM is the most accurate to predict the flow topology in both cases. Cylinder's rotation generates different effects on flow structure. It breaks the wake's symmetry and reduces its width, and increases the frequency of vortex shedding and the size of the recirculation zone. Particle transport analysis has revealed that particles' response to the flow depends on their Stokes number and wake flow topology. Particles of 0.01, 0.1, and 2.5 μm distribute in and around vortex cores, while particles of 10 and 50 μm do not penetrate vortex cores. Instead, 10 μm particles accumulate mainly around the periphery of vortices, while 50 μm particles skip the vortex street to the thin shear flow region between vortices to be transported by the mainstream flow. Finally, cylinder rotation reduces the particle spread in the vertical direction and shifts all particle distributions in the cylinder's rotation direction. Analysis of particle dispersion functions showed that cylinder's rotation reduces differences in dispersion extent depending on particle size.

Optimizing Synergistic Silica–Zinc Oxide Coating for Enhanced Flammability Resistance in Cotton Protective Clothing

This study reports process optimization studies of silica and zinc oxide-based flame-retardant (FR) coatings on cotton fabric for protective clothing and enhanced flammability properties. The experiments were designed by central composite design (CCD) using response surface methodology (RSM) to assess the synergistic protective effects of silica and zinc oxide FR coating. These prepared sols were coated on cotton fabrics by a simple dip dry cure process. The resulting FR-finished fabrics were characterized by SEM, mechanical properties, flame retardancy, and air permeability. SEM results confirmed the homogenous spreading of particles on cotton fabrics. From TGA results, it was noticed that the incorporation of silica and ZnO in the prepared nano-sols results in improved thermal stability of the FR-finished fabrics. These sol–gel-treated FR cotton fabrics showed excellent comfort properties, which shows their suitability for fire-retardant protective clothing. RSM analysis proved that the predicted values are in good agreement with the experimental values since R2 values for time to ignite, flame spread time, and air permeability were greater than 0.90. The optimized concentration of silica and ZnO in FR-finished fabrics was found to be 0.302% and 0.353%, respectively, which was further confirmed by confirmatory experiments. The optimization analysis successfully optimized the process for synergistic coating of silica and zinc oxide nanoparticles for enhanced flammability properties of FR cotton fabric for protective clothing.

On the efficacy of facial masks to suppress the spreading of pathogen-carrying saliva particles during human respiratory events: Insights gained via high-fidelity numerical modeling.

Respiratory fluid dynamics is integral to comprehending the transmission of infectious diseases and the effectiveness of interventions such as face masks and social distancing. In this research, we present our recent studies that investigate respiratory particle transport via high-fidelity large eddy simulation coupled with the Lagrangian particle tracking method. Based on our numerical simulation results for human respiratory events with and without face masks, we demonstrate that facial masks could significantly suppress particle spreading. The studied respiratory events include coughing and normal breathing through mouth and nose. Using the Lagrangian particle tracking simulation results, we elucidated the transport pathways of saliva particles during inhalation and exhalation of breathing cycles, contributing to our understanding of respiratory physiology and potential disease transmission routes. Our findings underscore the importance of respiratory fluid dynamics research in informing public health strategies to reduce the spread of respiratory infections. Combining advanced mathematical modeling techniques with experimental data will help future research on airborne disease transmission dynamics and the effectiveness of preventive measures such as face masks.

Neural networks for separation of cosmic gamma rays and hadronic cosmic rays in air shower observation with a large area surface detector array

The Tibet ASγ experiment has been observing cosmic gamma rays and cosmic rays in the energy range from teraelectron volts to several tens of petaelectron volts with a surface detector array since 1990. The derivation of cosmic gamma-ray flux is made by finding the excess distribution of the arrival direction of air showers above background cosmic rays. In 2014, the underground water Cherenkov muon detector (MD) was added to separate cosmic gamma rays from the background on the basis of the muon-less feature of the air showers of gamma-ray origin; hybrid observations using these two detectors were started at this time. In the present study, we developed methods to separate gamma-ray-induced air showers and hadronic cosmic-ray-induced ones using the measured particle number density distribution to improve the sensitivity of cosmic gamma-ray measurements using the Tibet air shower array data alone before the installation of the MD. We tested two approaches based on neural networks. The first method used feature values representing the lateral spread of the secondary particles, and the second method used the shower image data. To compare the separation performance of each method, we analyzed Monte Carlo air shower events in the vertically incident direction with mono-initial-energy gamma rays and protons. When discriminated by a single feature, the feature with the highest separation performance has an area under the curve (AUC) value of 0.701 for a gamma-ray energy of 10 TeV and 0.808 for 100 TeV. A separation method with a multilayer perceptron (MLP) based on multiple features has AUC values of 0.761 for a gamma-ray energy of 10 TeV and 0.854 for 100 TeV, which represents an improvement of approximately 5% in the AUC value compared with the single-feature case. We also found that the feature values that effectively contribute to the separation vary depending on the energy. A separation method with a convolutional neural network (CNN) using the shower image data has AUC values of 0.781 for a gamma-ray energy of 10 TeV and 0.901 for 100 TeV, which are approximately 5% higher than those of the MLP method. We applied the CNN separation method to Monte Carlo gamma-ray and cosmic-ray events from the Crab Nebula in the energy range 10–100 TeV. The AUC values range from 0.753 to 0.879, and the significance of the observed gamma-ray excess is improved by 1.3 to 1.8 times compared with the case without the separation procedure.

Spatiotemporal Analysis of Particle Spread to Assess the Hybrid Particle-Flow CFD Model of Radioembolization of HCC Tumors.

Computational fluid dynamics (CFD) models can potentially aid in pre-operative planning of transarterial radioactive microparticle injections to treat hepatocellular carcinoma, but these models are computationally very costly. Previously, we introduced the hybrid particle-flow model as a surrogate, less costly modelling approach for the full particle distribution in truncated hepatic arterial trees. We hypothesized that higher cross-sectional particle spread could increase the match between flow and particle distribution. Here, we investigate whether truncation is still reliable for selective injection scenarios, and if spread is an important factor to consider for reliable truncation. Moderate and severe up- and downstream truncation for selective injection served as input for the hybrid model to compare downstream particle distributions with non-truncated models. In each simulation, particle cross-sectional spread was quantified for 5-6 planes. Severe truncation gave maximum differences in particle distribution of ∼4-11% and ∼8-9% for down- and upstream truncation, respectively. For moderate truncation, these differences were only ∼1-1.5% and ∼0.5-2%. Considering all particles, spread increased downstream of the tip to 80-90%. However, spread was found to be much lower at specific timepoints, indicating high time-dependency. Combining domain truncation with hybrid particle-flow modelling is an effective method to reduce computational complexity, but moderate truncation is more reliable than severe truncation. Time-dependent spread measures show where differences might arise between flow and particle modelling. The hybrid particle-flow model cuts down computational time significantly by reducing the physical domain, paving the way towards future clinical applications.

An Individual Barrier Enclosure Actively Removing Aerosols for Airborne Isolation: A Vacuum Tent.

Aerosol barrier enclosure systems have been designed to prevent airborne contamination, but their safety has been questioned. A vacuum tent was designed with active continuous suctioning to minimize risks of aerosol dispersion. We tested its efficacy, risk of rebreathing, and usability on a bench, in healthy volunteers, and in an ergonomic clinical assessment study. First, a manikin with airway connected to a breathing simulator was placed inside the vacuum tent to generate active breathing, cough, and CO2 production; high-flow nasal cannula (HFNC) was applied in the manikin's nares. Negative pressure was applied in the vacuum tent's apex port using wall suction. Fluorescent microparticles were aerosolized in the vacuum tent for qualitative assessment. To quantify particles inside and around vacuum tent (aerosol retention), an airtight aerosol chamber with aerosolized latex microparticles was used. The vacuum tent was tested on healthy volunteers breathing with and without HFNC. Last, its usability was assessed in 5 subjects by 5 different anesthesiologists for delivery of full anesthesia, including intubation and extubation. The vacuum tent was adjusted until no leak was visualized using fluorescent particles. The efficacy in retaining microparticles was confirmed quantitatively. CO2 accumulation inside the vacuum tent showed an inverse correlation with the suction flow in all conditions (normal breathing and HFNC 30 or 60 L/min) in bench and healthy volunteers. Particle removal efficacy and safe breathing conditions (CO2, temperature) were reached when suctioning was at least 60 L/min or 20 L/min > HFNC flow. Five subjects were successfully intubated and anesthetized without ergonomic difficulties and with minimal interference with workflow and an excellent overall assessment by the anesthesiologists. The vacuum tent effectively minimized aerosol dispersion. Its continuous suction system set at a high suction flow was crucial to avoid the spread of aerosol particles and CO2 rebreathing.

Effects of deposited microstructure on wear behaviors of detonation sprayed Fe-based amorphous coatings

Fe-based amorphous coatings (AMCs) were deposited using the detonation spray at varying spraying distances. The study aimed to characterize the deposition morphologies and elemental composition of splats for single shots under different spraying distances. Additionally, the relationship between spraying distance, particle deposition behavior, spreading morphology, and wear behavior of the coatings was comprehensively discussed. The results indicate that modifying the spraying distance affects the melting state of spray particles, thereby influencing the morphology of deposition and determining the coating's microstructure. Larger spraying distances result in reduced deposition efficiency and lead to particles depositing in a manner similar to cold spraying, resulting in an uneven coating structure with higher porosity. Consequently, the coating becomes more susceptible to fatiguedelamination wear. Conversely, a moderate spraying distance leads to full melting and acceleration of powders, results in good spreading and the formation of a uniform and dense laminar structure.

Dampak Perubahan Iklim Terhadap Kualitas Udara Pada Peternakan Unggas: Systematic Literature Review

The Impact of climate change in poultry farming through increased ambient temperatures. Poor air quality also has serious consequences related to the spread of dust particles and toxic chemicals from poultry waste. The aims this study, based on the description above is to see the relationship between increased ambient temperature and air quality in poultry farms. This study used a systematic literature review method with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. The results obtained from 12 articles related to climate change on air quality in poultry farms. Literature results show that air quality monitoring involves parameters such as NH3, CO2, SO2, NOx, CH4, PM2.5, and PM10 with various measurement methods. The temperature and humidity of the poultry environment are critical to achieving optimal conditions for livestock welfare and growth.
 
 Keywords: Air Quality, Climate Change, Poultry, Temperature,