Air Bubbles Research Articles

Novel sparging strategies to enhance dissolved carbon dioxide stripping in industrial scale stirred tank reactors

Aerated stirred tank reactors are widely used in bio-process engineering and pharmaceutical industries. To supply the organisms with oxygen and control the pH value, oxygen is transferred from air bubbles into the liquid phase, and, at the same time, carbon dioxide is stripped from the liquid phase with the same gas bubbles. The volumetric mass transfer coefficients for oxygen and carbon dioxide are, therefore, of crucial importance for the design and scale-up of aerated stirred tank reactors. In this experimental work, the volumetric mass transfer coefficients for oxygen and carbon dioxide are investigated simultaneously to study their mutual influence. The mass transfer performance for oxygen and carbon dioxide is conducted in stirred tank reactors on the 3 L laboratory scale, 30 L pilot scale, and 15,000 L production scale. First, the influence of dissolved carbon dioxide on the oxygen mass transfer performance is investigated in a 30 L pilot scale stirred tank reactor. The results show that the volumetric mass transfer coefficient of oxygen is not affected by the concentration of dissolved carbon dioxide, but the total mass flux of oxygen decreases with increasing carbon dioxide concentration due to the decreasing partial pressure difference. With rising gassing rate and volumetric power input, both mass transfer coefficients for oxygen and carbon dioxide show the same increasing trend. Although this trend can also be observed when scaling down to the 3 L laboratory scale reactor, a significantly different effect must be considered for the scale-up to the 15,000 L industrial scale reactor. The limited absorption capacity for carbon dioxide of the gas bubbles during the long residence time in the industrial scale reactor is noticeable here, which is why the specific interfacial area is of negligible importance. This effect is used to develop a method for independent control of oxygen and carbon dioxide mass transfer performance on an industrial scale and to increase the mass transfer performance for carbon dioxide by up to 25%.

Towards Sustainable Construction: Evaluating Thermal Conductivity in Advanced Foam Concrete Mixtures

Traditional concrete structures are frequently linked to poor energy efficiency and substantial heat loss, which pose significant environmental issues. To enhance thermal insulation and reduce heat loss, the use of precast insulated walls is suggested. This research introduces a new energy-efficient precast concrete panel (PCP). We explored various material combinations, including air bubbles, nano microsilica compound (NMC), nano microsilica powder (NMP), and latex, to determine the most effective formulation. A total of 99 tests were performed to assess the compressive strength of the samples, with 28 tests selected for thermal conductivity evaluations at temperatures of 300 °C and 400 °C based on satisfactory compressive strength results. The results indicated that the optimal mix of 4% air bubbles and 13% NMC achieved the lowest thermal conductivities of 1.31 W/m·K and 1.20 W/m·K at 300 °C and 400 °C, respectively, showing improvement ratios of 7% and 15.5% compared to the baseline tests. Additionally, the tests that included latex did not meet the thermal conductivity standards. The optimal combinations identified in this research can be effectively utilized in PCPs, resulting in significant energy savings. It is expected that stakeholders in the green building sector will recognize these proposed PCPs as a practical energy-efficient solution to advance sustainable and environmentally friendly construction practices.

Bubble defect detection for tire shearography images with transfer learning based deep CNN models

Abstract Safety of drivers and passengers is an important quality assurance aim of the tire manufacturers. Tires that have air bubbles in them are a frequent cause of accidents. Recently, manufacturers have placed a high value on employing laborers with tire diagnostic experience. Along with the expenditure of time and money, this process also necessitates a sizable workforce of experienced laborers. The detection of tire defects can be automated utilizing a number of different ways, greatly reducing the margin for human error. One such method is digital shearography, which can be used to detect air bubbles in images. In this study, transfer learning-based models are proposed to classify air bubble defects in tire shearography images. Proposed method employed in transfer learning with several deep learning CNN-based models, including VGG16, VGG19, ResNet50, Xception, MobileNetV2 and DenseNet201. Owing to the assistance of the experts at the Pirelli Automobile Tires Izmit factory, we were able to collect and label the dataset used in this study. The dataset contains 1392 tire shearography images. 811 of these images belong to the “good” class, while the remaining 581 images belong to the “bad” class. The proposed method in this study achieves remarkable bubble detection results over 95% in terms of accuracy and other metrics with the DenseNet201 model. The results indicate that the proposed model has comparable accuracy and recall with the existing studies. This study is valuable for the tire industry, as the existing literature offers limited research on the classification of tire bubble defects, the differentiation between defective and defect-free tires, and the categorization of various defect types. In addition, the proposed model offers several advantages over existing studies, including higher robustness against overfitting, suitability for real-time industrial applications, and improved efficiency in processing, making a practical solution for defect detection in industrial settings.

Mechanical Analysis of the Critical Conditions for Trapping and Detachment of Microscale Air Bubbles on the Pure Water Freezing Front.

Icing is a widespread phase change phenomenon with implications for daily life and industrial production. Air bubbles form on the freezing front of pure water with dissolved air during the icing, which may affect the physical properties of ice. Controlling the behavior of air bubbles will be one method to change the physical properties of ice. To analyze the critical conditions for trapping and detachment of microscale air bubbles on a pure water freezing front, a mathematical model describing the forces on air bubble is developed on the basis of the principle of force equilibrium. Results show that the average accuracy of the present model in predicting the average air bubble detachment radius is about 62%, which is 30% higher than the model with the best prediction accuracy in the literature. Buoyant, temperature gradients, and hydrodynamic forces push air bubbles to detach from the freezing fronts, while adhesion force and gravity impede their detachment. Temperature gradient and adhesion forces are the main factors affecting the detachment of air bubbles from freezing fronts. The temperature gradient has the greatest effect on the air bubble detachment radius, while the tilt angle and liquid density have a lesser effect. When the temperature gradient is increased from 1000 to 10 000 K/m, the air bubble detachment radius decreases by 37.78%. Studying the forces acting on the air bubbles on the pure water freezing front is an important reference for the production of special ice bodies, phase change cold storage, and de-icing technology.

Parameters of Collision and Adhesion Process Between a Rising Bubble and Quartz in Long-Chain Amine Solution and Their Correlation with Flotation

The successful adhesion of air bubbles to mineral particles is the crucial to flotation technology. This paper systematically investigates the parameters variation in the dynamic interaction process between a rising bubble and a quartz plate in long-chain amine solutions (dodecylamine, tedecylamine, and octadecylamine). The results show that the type and concentration of long-chain amine affected the collision and adhesion process between bubbles and quartz plates remarkably. The maximum rebound distance (rebound distance after the first collision) of bubbles and the stable-state liquid film thickness gradually decreases with the increase of reagent concentration. Additionally, the collision-rebound duration and induction time shorten accordingly, the surface tension of the solution decreases, the surface hydrophobicity of quartz increases, and the deformation degree and average movement velocity of bubbles decrease. With the increase in carbon chain length, the adsorption form of the amine collector and quartz surface becomes closer to vertical, and the density of water molecules decreases. The recovery of quartz particles is highest with octadecylamine systems, corresponding well with the changing trend in steady-state liquid film thickness. This research provides an effective method for in-depth analysis of the microscopic interaction mechanism between bubbles and mineral surfaces and the prediction of flotation results.

Effect of sonication time on physical and foaming properties of pasteurized milk

This study investigates the impact of ultrasonication duration on the properties of milk foam. Milk samples were subjected to ultrasonication for varying durations (1, 3, 5, 7, and 10 min), resulting in different sizes of native fat globules (249.5, 221.5, 222.6, 207.5, and 244.8 nm, respectively). The results indicate that viscosity increases as fat globule size decreases, with slight effect on zeta potential. NanoFoamer was identified as the optimal method providing the highest between foamability and stability (p < 0.05). Notably, foaming performance decreases after 7 min of sonication, highlighting the importance of selecting an appropriate frothing method to achieve the desired foam characteristics. Comparisons with non-ultrasonicated milk suggest that ultrasonication duration not only influences foamability by reducing fat globule size but also enhances foam stability through alterations in the fat globule sizes. Analysis of the foam structure revealed that smaller fat globules initially produce smaller, more numerous air bubbles with polyhedral shapes and well-defined lamellae. However, excessive reduction in fat globule size destabilizes the foam due to competitive protein adsorption and altered membrane composition, resulting in larger, less stable bubbles over time. Exploring ultrasonication times to enhances quality of milk and foam properties, offering significant benefits for dairy processing, product innovation and customer satisfaction.

Pilot-scale process development for recombinant adeno-associated virus (rAAV) production based on high-density Sf9 cell culture

BackgroundIn recent years, gene therapy drugs have been widely marketed, and their effectiveness and potential have been confirmed. Thus, increasing their production on an industrial scale is critical. Recombinant adeno-associated viruses (rAAVs) are optimal vectors for gene therapy applications, and the baculovirus expression vector system (BEVS), which is based on Sf9 cell culture, is a common tool for rAAV production.MethodsIn this work, an Sf9 cell fed-batch process was developed using shake flasks. In the laboratory-scale bioreactor, four processes were selected as the key factors when carrying out the orthogonal experiment. On the basis of the equal P/V principle and considering the problem posed by air bubbles, a pilot-scale level bioreactor process was established.ResultsHere, we describe a method in which a BEVS was used to produce rAAV vectors, with the cell density increasing to 22.8 × 106 cells/mL and the rAAV titre increasing to 20 × 1011 VG/mL upon adding feed material. By resolving the problems associated with high-density cell culture and air bubbles, this process was successfully scaled to a 50 L pilot-scale level.ConclusionsThis successful experiment not only provides a technological basis for further scale-up but also guarantees product capacity. We hope that this development process can provide reference data for studying cell culture-based drug production.

Effects of Environmental Temperature and Trapped Air Bubbles on the Mechanical Properties of Ice Cubes.

Ice is a widespread material in natural and industrial fields. Trapped air bubbles form in ice cubes due to the differences in the solubility of air in ice and water, which directly affects the mechanical strength of the ice cubes. To investigate the effects of environmental temperature and trapped air bubbles on the mechanical properties of ice cubes, a series of experiments are designed and carried out. A mathematical model that predicts the mechanical strength of ice cubes with an accuracy over 80% is developed and validated. The results show that even a volume content of trapped air bubbles in an ice cube as low as 1.98% can greatly impact the mechanical properties. This model reveals the mechanisms and principles governing the influences of environmental temperature and bubble volume content on the mechanical strength of ice cubes. As the environmental temperature decreases from 0 to -20 °C, the compressive strength of clear ice cubes increases from 1.71 to 2.10 MPa, while that of bubble ice cubes increases from 1.58 to 1.95 MPa. This study has implications for utilizing trapped air bubbles to regulate the mechanical properties of ice and for optimizing various mechanical deicing techniques.

Emphysematous Pancreatitis: A Rare and Serious Complication

Emphysematous pancreatitis is a severe and rare form of acute pancreatitis that can be life threatening. The diagnosis is based on imaging. CT is the examination of choice, highlighting intraparenchymal air bubbles or bubbles in the pancreatic compartment. It also helps to guide therapeutic management and identify other complications.

A Ritornello Pedagogy: Troubling School Art Orthodoxies

AbstractIn the studio, there are routines and rituals to be observed. One of those is making gesso. The quantities change each time and the ingredients vary, but the mechanical process remains the same: soak rabbit skin glue for 3 hours, double burner melt the glue, sieve in champagne chalk whiting, stir slowly, and tap the sides to remove air bubbles. Brush on first layer. Dry. Sand. Repeat × 10. Out of repetition each new territory is unique with its own lumps, drips and curves on a straight edge board. Making gesso is a kind of ritornello. Drawing on Deleuze and Guattari, a ritornello is a repetition leading to a transformation; it is a methodical kind of time that is rhythmic, local and spatiotemporal. It contravenes the idea of a universal, overarching time to consider heterogeneous, plural experiences of time in the art classroom. Ritornellos exist in both the studio and the art classroom, but in the art classroom, they often sediment into endless repetitions without rupture: tonal scales, colour wheels, drawing grids and pastiche. We apply the concept of ritornello to pedagogy in Secondary Art and Design education to think about school art orthodoxies and how they can be reterritorialised.

Application of Nano Bubble Aeration Technology in Domestic Wastewater Treatment: Optimization of Gas Flow and Reaction Time

Nano bubble aeration is an emerging technology with significant potential in wastewater treatment, particularly for removing suspended solids and organic matter. This study investigates the application of nano bubble aeration in the treatment of domestic wastewater, focusing on the reduction of chemical oxygen demand (COD) and total suspended solids (TSS). Nano bubbles, with diameters ranging from tens of nanometers to a few micrometers, exhibit slower rising velocities and prolonged stability in water due to their negatively charged surfaces. Various nano bubble air flow rates were tested over 90-minute intervals to determine the optimal treatment conditions. The results indicate that a flow rate of 2 liters per minute achieves the highest treatment efficiency, reducing COD by 84.73% and TSS by 77.51%. Increasing the flow rate beyond this level showed minimal improvement, demonstrating that 2 liters per minute is the optimal flow rate for efficient wastewater treatment using nano bubble aeration. This research highlights the advantages of nano bubble technology in enhancing the treatment efficiency of suspended solids and organic matter in wastewater.

Electrohydrodynamic effect within CFRP laminates by bipolar nsPDC electric field during the curing process

In this paper, a new method based on bipolar nanosecond pulsed superimposed direct current (nsPDC) electric field assisted curing technique was developed to fabricate modified fiber-reinforced composites to enhance their mechanical properties. It was found that the mode I interlaminar fracture toughness of the electric field-modified CFRP laminates reached 1014.2 MPa, which increased by 80.4 %. The average tensile strength and tensile modulus were 2180 MPa and 100780 MPa, respectively, which were 20.7 % and 3.5 % higher than the blank control group. The enhancement mechanism was explored by COMSOL simulation, curing temperature inspection, and microscopic characterization by electron microscopy. The results show that the presence of electric field and electric field force inside the laminate, which affects the flow of resin and the weak migration of fibers, enables the elimination of larger air bubbles present in the material, the reduction of resin-rich zones in the interlayer as well as the improvement of the fiber-resin wettability without significantly altering the curing temperature. The proposed simple, convenient, and environmentally friendly strategy can effectively regulate some of the deficiencies in the conventional manufacturing methods and thus is suitable for the optimal design of fiber-reinforced composites.

Possible differences in the performances of vibration-reducing gloves when used with hammers of different sizes

Protection provided by vibration-reducing gloves (VR) when used with impact tools can be considerably different from that measured following the ISO 10819 Standard. This paper investigates the transmissibility, at the palm level, of three different types of vibration-reducing gloves (air bubbles; gel; neoprene) and a working leather glove, while using 8 different models of electro-pneumatic hammers for chiseling rock in a limestone quarry plant. The capability to reduce the triaxial vibration as the average of all the tested hammers results limited: 12 % for both the gloves in gel and neoprene, and 7 % for the glove in air. The working leather glove shows a tri-axial transmissibility (Tc(T)) quite equal to the unit. Anyway, the capability to reduce vibrations is tool-dependent. Among the used hammers, the glove in air showed a Tc(T) variable from 0.71 to 1.02, the glove in gel from 0.76 to 1.01, and the glove in neoprene from 0.74 to 1.05, while for the glove in leather the transmissibility remains quite always close to the unit. Grouping the hammers in two different categories in terms of average weight and average impact energy: small-size (4.4 kg; 4 J) and middle-size (10.6 kg; 18.5 J), the average transmissibility results different: Tc(T) = 0.94 for middle-size hammers, and Tc(T) = 0.86 for small-size hammers (p-value <0.00001). This mean that VR gloves could be around 10 % more efficient when used with lightweight and small impact energy hammers. Anyway, mainly because of the relatively small number of hammers investigated, further studies are needed for confirming this result.

Hybrid FSO/RF and UWOC system for enabling terrestrial-underwater communication: Performance analysis

This work examines the performance of the terrestrial-underwater communication system utilizing hybrid free space optics (FSO)/radio-frequency (RF) and underwater wireless optical communication (UWOC) links. Here, the base station communicates with the underwater vehicle via a decode-and-forward (DF) based relay (buoy) in two phases. In the first phase, a hybrid FSO/RF link is used to transmit signal to the buoy, where the RF link acts as an alternative link to increase the reliability of the system, and in the next phase, the buoy forwards signal to the underwater vehicle through the UWOC link. To enhance the reliability of the RF link, the buoy is deployed with multiple antennas, and it exploits a maximal ratio combining scheme on the received RF signals. The analysis takes into consideration some primary variables that influence the system’s performance, such as atmospheric turbulence, attenuation, temperature gradient, air bubbles, water salinity variations, pointing errors, and detection techniques. Closed-form expressions for the outage probability, system throughput, and average channel capacity in terms of the Meijer-G and bivariate Fox-H functions are derived. Simulation results are presented to validate the analytical expressions and disclose valuable findings.

Investigations on the near-wall bubble dynamic behaviors in a diverging channel

This study investigates the movement characteristics and causes of the dramatic deceleration of individual bubbles as they enter a diverging channel near the wall, an important phenomenon for understanding fluid dynamics in the Venturi-type bubble generator. The use of a modified volume of fluid model with a user defined source method based on van der Geld’s drag theory improves the accuracy of bubble velocity predictions. Visualization experiments were conducted to observe air bubble motion in water, focusing on deceleration near the wall, while numerical simulations were employed to complement these observations. The results reveal the identification of forces governing bubble deceleration, such as pressure gradient, drag, added mass, and lateral force (lift and wall lubrication). Pressure gradient and added mass forces of magnitudes of 106 N/m3 were found to dominate the deceleration process, with drag and lift forces contributing to bubble acceleration and lateral motion in low-speed liquid flow, respectively. In addition, simulations revealed the formation of a faster-moving liquid region downstream of the bubble during rapid deceleration, highlighting the critical role of added mass on the bubble dramatic deceleration process.

High-temperature behaviour of geopolymer composites containing carbon fibre and nano-silica: Mechanical, microstructure, and air-void characteristics

The fly ash–ground granulated blast-furnace slag-based geopolymer (FSG) represents a groundbreaking material, offering a sustainable and environmentally friendly alternative to conventional construction materials. This paper presents a systematic experimental study on FSG reinforced with carbon fibre (CF, 0%–1.0%) and nano-silica (NS, 1%–3%) at high temperatures (20, 200, 400, 600, 800, and 900 °C). Various tests concerning appearance, residual strength, uniaxial tension, XRD, FTIR, TGA, SEM, and air-void characteristics were conducted to analyse thermal effects. The findings show that as temperature increases, the colour of the geopolymer transitions from dark grey to yellow grey. Enhanced geopolymerisation during thermal solidification from 20 to 400 °C significantly increases the compressive, flexural, and tensile strengths of the geopolymer. The addition of CF and NS improves the residual strength of geopolymers at high temperatures, with optimal concentrations found to be 0.6% for CF and 2% for NS. CF maintains its bridging effect at high temperatures, enhancing fibre–matrix bonding, while NS promotes the formation of additional hydration products on CF surfaces, thereby strengthening the material further. After exposure to 800 °C, despite a weakening of the fibre–matrix interface, the modified geopolymers (FSGC0.6 and FSGC0.6N2) exhibit finer air bubble chord lengths and superior air-void characteristics than the control group. This supports the theory that the synergistic action of CF and NS not only enhances geopolymerisation but also fills pores, thus limiting crack propagation and densifying the pore structure.

Transient resonant triads: An examination of turbulent patches injected into finite-width internal wave fields

This article presents an experimental investigation into the interaction of a freely evolving turbulent structure with a steadily forced, finite-width internal gravity wave beam. Specifically, a vortex ring is used as the simplified prototype for a propagating turbulent structure and we present an exploration into how it's passage affects the linear stability of the imposed (or forced) wave field. We use the term "vortex ring" to describe an initially axisymmetric, toroidal fluid structure with azimuthal vorticity. We first examine both the vortex ring and the imposed internal gravity wave beam separately and present how they develop in a quiescent, stratified environment. In the absence of any vortex ring, we find—in agreement with many previous studies—there is an amplitude threshold that the wave beam must surpass before it becomes linearly unstable by a process known as triadic resonance instability (TRI). In the absence of an imposed wave field, we present the propagation and collapse of a coherent vortex ring into a turbulent patch, and measure the transient spectrum of internal waves produced. We then combine these two phenomena and investigate how each impacts the other. While we find that the preexisting internal wave beam has no significant influence on the evolution of the incident vortex ring, we do find that the propagation and subsequent collapse of the ring provokes a response from the internal wave beam. This response allows us to demonstrate two key findings relating to the internal wave beams pathway to triadic resonance. First, the passage of a vortex ring propagating through a forced wave field can provide a nonlinear trigger for the transition to a triadic state when the amplitude of the imposed wave field is itself too small for the spontaneous growth of such a triadic state through TRI. Second, we find that in some cases the triadic states induced by this interaction are not self-sustaining and eventually decay, prompting the terminology "transient triads." These surprising findings are further confirmed by the unintentional release of trapped air arising from under our "magic carpet" wavemaker. These air bubbles turbulently propagate vertically through the imposed beam and, in some cases, induce similar triadic state transitions to those of the vortex ring. Our analysis leads to a discussion on the beam's pathway to instability and to question the structure of the underlying dynamical system arising from the distribution of spectral power in a finite-width beam. Published by the American Physical Society 2024

Delayed-Onset Arterial Gas Embolism After Underwater Egress Training

BACKGROUND: Arterial gas embolism (AGE) may occur while breathing compressed air and failing to exhale during ascent to compensate for gas expansion as pressure decreases. Trauma to the lungs from over-pressurization may result in air bubbles entering the pulmonary veins and subsequently the systemic circulation, causing obstructed blood flow and inflammatory cascades. AGEs are known to always manifest within 10 min of surfacing from depth. In underwater egress training (UET), which is mandatory for U.S. Marines, service members learn to escape from a tilt-wing or rotor aircraft after it submerges and inverts in water. CASE REPORT: We report a case of cerebral AGE in which the victim experienced neurological symptoms more than 1 h after completing UET at a depth between only 3.28–6.56 ft (1–2 m). The patient was treated with a U.S. Navy Treatment Table 6 and experienced complete resolution of symptoms. DISCUSSION: This case is one of only two AGEs reported with symptom onset occurring after 10 min of surfacing from depth to be published. AGE at depths between 1–2 m has only been reported on three other occasions, and dysbarism injuries during UET are also exceedingly rare. This case demonstrates a situation in which all three events occurred, highlighting the need for increased awareness and clinical consideration of delayed AGE in similar scenarios despite the commonly held belief that AGEs do not occur outside of 10 min of surfacing. Harvey SE, Reynolds RP, Fisher JF. Delayed-onset arterial gas embolism after underwater egress training. Aerosp Med Hum Perform. 2024; 95(11):867–870.

Impact of early-age vibration on the permeability and microstructure of mature-age concrete

Dynamic excitation in early-age significantly impacts the performances of mature concrete in underground structures, such as tunnels beneath railways supported by cast-in-place concrete. This study explores the impact of early dynamic excitation on properties of mature concrete. Vibration tests at a fundamental frequency of 114Hz, with peak acceleration levels ranging from 0.1g to 0.4g, were conducted using shaking table. Specimens underwent 33seconds of dynamic excitation every 15minutes over the initial 48hours, excluding a night break from 0-6am, totaling 114 vibration cycles. Various lab tests were employed to assess the properties and microstructure of mature concrete post-vibration, including water penetration resistance, capillary water absorption, Coulomb electric flux, scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and Nitrogen adsorption-desorption measurement (NAM). The results proves that vibration causes water secretion and air bubbles discharge before the initial setting of concrete, thereby enhancing the hydration reaction. The relationship between vibration loads with varying peak accelerations and the cohesion resulting from hydration reaction influences the microstructural evolution of concrete, leading to the weakening and strengthening of permeability of mature concrete. Under the vibration spectrum and test conditions described in this paper, vibration loads with peak values less than 0.234g decrease the total volume of large and middle pores (>20nm) by up to 50% and increase the total volume of small pores (<20nm) by up to 200%. Due to these changes in pore structure, the permeability coefficient (Sk), cumulative capillary water height (i) and Coulomb electric flux decrease by up to 47.84%, 39.5% and 31.6%, respectively. However, when the amplitudes of vibration loads exceed 0.234g, the total volume of large and medium pores (>20nm) increases, and that of small pores (<20nm) decreases, leading to a reduction of the impermeability of mature concrete. Additionally, the SEM analysis corroborates these microstructural variations.

Unraveling the causation of flatulence on silver pomfret after starvation aquaculture involved in intestinal microbiota structure, enzyme, and histology

During periods of starvation aquaculture, silver pomfret often suffer from flatulence and lateral flapping, which prevents them from refeeding and dying. Despite existing research on this phenomenon, the understanding of the associated changes in the intestine remains limited. This study aimed to investigate flatulence in silver pomfret during starvation. We conducted a comprehensive analysis of the enzymatic activity, histology, and microbial communities in the gut. Through the examination of 28 samples, we found that the trigger for flatulence under starvation does not appear to be enzyme activity but rather gut microbes. During periods of food deprivation, the fish often ingest air bubbles, leading to an increased proportion of aerobic bacteria. We observed a notable shift in the β - diversity of the intestinal microbial community in flatulent fish, accompanied by a significant decrease in network stability. A marked enrichment in functional microbes was noted, which contributed to increased activities related to CO2 production. In conclusion, this study provides novel insights into the mechanism of flatulence in silver pomfret during starvation stress, highlighting the role of microbial composition. These findings have significant implications for improving aquaculture practices by addressing microbial management.