Effect Of Condensation Research Articles

An assessment of scaling methods for ECC behavior in downcomer of UPTF with RELAP5 code

Various experimental investigations in scaled-down test facilities have been conducted to observe the ECC behaviors during a Large-Break Loss of Coolant Accident (LBLOCA). The ability of the scaling method to describe the similarity between the prototype and the scaled models required validation. In this paper, a series of simulations were performed to investigate the characteristics of ECC penetration in UPTF and the models scaled by four scaling methods including three-level scaling method, linear method, modified linear method and Hierarchical Two-tiered Scaling (H2TS) method. The ECC behaviors, such as the inventory and pressure in lower plenum, steam mass flow at the break, have been analyzed. And the applicability of the scaling method has been evaluated based on the analysis of the ECC behaviors in both of the prototype and scaled models. The results showed that the transient process in the model scaled by H2TS method with aspect ratio of 1.87 and modified linear was in good agreement with the prototype during ECC injection. Moreover, in order to investigate the effect of the aspect ratio, different aspect ratio in H2TS method was applied to scale the model and the inventory in the lower plenum between the UPTF and the model has been compared. In addition, the modified Wallis correlation for CCFL accounting for the condensation effect has been performed.

Performance Study of a Supersonic Swirl Separator

At present, as a new separation technology, supersonic separators have great potential in the separation of natural gases. However, their system performance is still low. In this paper, a supersonic swirl separator design is proposed with an integration approach of the discrete phase model (DPM), bi-coupling, and the random walk model, and it is used to predict the flow process of liquid droplets within the device. Such a numerical method is further employed to study the influence of key parameters on system performance. The results show that with an increase in the inlet port number and the ratio of the gas-liquid area, the separation performance decreases. As a result, the expansion, condensation effect, and economy of the separation system are greatly improved. When the deflection angle exceeds 20°, the separation temperature increases greatly. Consequently, this may ruin the condensing environment. The working pressure ranges are: (1) the boost ratio (the dry outlet pressure/total inlet pressure) is less than 0.76; (2) the wet pressure ratio (the wet outlet pressure/total inlet pressure)is less than 0.46. The increase in droplet diameter can improve the separation performance, and the droplets are completely separated as the diameter reaches 1.75 μm.

Condenser performance in a cylindrical humidification and dehumidification (HDH) system

AbstractIn recent years, humidification and dehumidification (HDH) systems have garnered significant attention due to their enhanced effectiveness with packed beds, particularly for high‐salinity waters. The direct‐contact packed beds HDH system offers a more convenient and efficient installation compared with conventional HDH systems. This paper introduces a novel, compact cylindrical crossflow HDH system design that is easily constructed and scalable for industrial and residential applications. The compact crossflow‐packed bed condenser employs perforated air tubes to distribute humidified air radially while cooling water drips vertically through the packed bed, coming into direct contact with the humidified air. To evaluate the system's performance, two‐dimensional steady‐state energy, and mass conservation equations were developed solving enthalpies instead of temperatures as dependents. The coupled partial differential equations were numerically solved to predict water temperature, air/vapor temperature, humidity ratio, and condenser effectiveness. Multiple designs were proposed, demonstrating that the proposed configuration can achieve effectiveness above 0.80 and a water production rate of 3.85 g/s under ideal operating conditions.

Experimental study of the unconstrained melting of a phase change material for air-conditioning applications

This study analyzed the RT8HC melting in a spherical vessel employing air as a heat transfer fluid. The phase change process was followed both visually and by thermal measurements. Photographs and thermographs allow the following phases' evolution and melting mechanisms. We observed that the melting process was not symmetric around the vertical axis; implications of non-symmetric conditions on the melting mechanisms and heat transfer are discussed and analyzed. This work also includes the effects of outer water vapor condensation on heat transfer in the analyses. We proposed a mathematical model to quantify the heat flux that only requires humidity and temperature measurements and considers both heat convection and condensation effects. Results show that condensation significantly affects heat transfer during the initial stage of the melting process. Beside, these effects extend beyond the condensation time due to the liquid film draining from the spherical vessel surface. Regarding thermography, this technique may be a valuable tool for analyzing and following melting processes inside vessels; however, the presence of liquid film over the sphere affects the temperature measurements obtained from the thermograph analysis. This investigation provides relevant information about using phase change materials in cold thermal energy storage applications, latent thermal loads, and humidity control, which are essential aspects of air-conditioning system designs.

Numerical modelling of the evaporative cooling effect on solid walls in steam sterilisers

Steam sterilisation is based on high heat transfer rates which occur during the condensation of steam on medical devices or the steriliser walls themselves. To ensure these high heat transfer rates, non-condensable gases (NCGs) such as air must be removed from the chamber. One method is to extract the NCGs by using vacuum pumps. Due to the reduction in pressure, the saturation temperature drops as well, causing water droplets to evaporate; thus, the walls and loads cool down. This mechanism was investigated using a three-phase CFD model. A highly time-efficient heat transfer model for the evaporation process was developed as a result of this investigation. Evaporative cooling effects on the steriliser walls could be achieved by using a mass source term which varied in terms of time and space. Our results indicate that the model can be used to predict the temperatures of the fluid as well as the solids in a numerically inexpensive manner. In addition, this model allows the user to predict whether surfaces can be completely dried, an aspect which is crucial for ensuring the quality of a sterilisation process. The model created allows researches to simulate the entire sterilisation cycle, addressing a previously existing knowledge gap. Furthermore, the presented methods are also suitable for use in other industrial applications where condensation and evaporation effects on solids need to be effectively and inexpensively determined.

Effects of condensates from volcanic fumaroles and cigarette smoke extracts on airway epithelial cells

The impact of volcanic airborne products on airway epithelium homeostasis is largely unknown. This study assessed the effects of volcanic Fumarole Condensates (FC) alone or combined with Cigarette Smoke Extracts (CSE) on airway epithelial cells (16HBE and A549). Chemical composition of FC was analyzed by gas chromatography and HPLC. Cells were exposed to FC and IL-33 and IL-8 were assessed. The effects of FC and CSE on cell injury were evaluated assessing cell metabolism/cell viability, mitochondrial stress, cell apoptosis/cell necrosis, and cell proliferation. FC contained: water vapor (70–97%), CO2 (3–30%), acid gases (H2S, SO2, HCl, HF) around 1%. FC increased the intracellular IL-33 but differently modulated IL-33 and IL-8 gene expression and IL-8 release in the tested cell lines. FC without/with CSE: (a) increased cell metabolism/cell viability in 16HBE, while decreased it in A549; (b) increased mitochondrial stress in both cell types. FC with CSE increased cell necrosis in A549 in comparison to CSE alone. CSE reduced cell proliferation in 16HB,E while increased it in A549 and FC counteracted these effects in both cell types. Overall, FC induce a pro-inflammatory profile associated to a metabolic reprogramming without a relevant toxicity also in presence of CSE in airway epithelial cells.

A two-phase density-based solver for simulating wet steam flows with non-equilibrium condensation. II. Effects of 3D surface topography through nozzles

In Paper I, we developed a new two-phase flow solver and assessed its reliability and effectiveness through a series of numerical simulations. In Paper II, we utilized this solver to study the steam flow through nozzles characterized by three-dimensional surface topography. To generate random rough surfaces, we employed a multivariate Weierstrass–Mandelbrot function. Our numerical simulation results exhibited good agreement with the reported experimental data for pressure distribution. Moreover, we examined the changes in pressure, temperature, humidity, Mach number, average Nusselt number, and thrust as the wall surface morphology varied. We observed that the pressure field was prone to fluctuations, the boundary layer structure thickened and changed, the degree of condensation decreased with reduced humidity, three-dimensional Mach waves occurred, and the averaged Nusselt number decreased while thrust deviation increased. These findings contribute to a better understanding of the effects of fractal dimensions and condensation on random roughness in steam flow through nozzles and highlight the significance of incorporating surface topography into numerical simulations to improve accuracy and predictability in engineering applications.

MENINGKATKAN EFEKTIVITAS KONDENSOR VERTIKAL PIPA HELIKAL KOIL UNTUK DESTILASI MINYAK ATSIRI SEREH

The main focus of this research is to modify the straight pipe of the Citronella essential oil distillation condenser using a helical coil pipe to shorten the distillation time. This study aims to obtain an effective shell-side fluid volumetric rate to shorten the distillation time. The volumetric rate of the shell side fluid varies from 0.72 to 3.66 LPM at a constant pitch ratio of 2.10. Recording of data in the form of temperature, volumetric rate of shell side water, and tube side steam after steady state is reached. The experimental results show that the effectiveness increases with the increase in the volumetric flow rate of the shell side fluid, where the maximum effectiveness at the volumetric flow rate of 3.66 LPM is 69.99%, while the minimum effectiveness at the volumetric flow rate of 0.72 LPM is 44.39%. The results of the validation of the effectiveness of the condenser show a trend curve that is identical to the previous research, with an average deviation of 5.67%. The maximum volumetric flow rate with a minimum distillation time of 120 minutes with a condensate volume of 8 ml or 240 minutes is smaller than the result of straight-pipe condenser distillation by UKM. The maximum effectiveness is due to an increase in the Reynolds number on the shell side, which results in an increase in the actual heat transfer. It can be concluded that the maximum condenser effectiveness at a maximum volumetric rate of 3.66 LPM could be used for refining Citronella essential oil by SMEs.

Three condensation paths of exhaust and its five effects on exhaust gas recirculation (EGR) cooler fouling and thermal performance: A review

Fouling has limited the evolution of compact heat exchangers (represented by EGR cooler) to smaller and more efficient sizes, an important reason is the unclear mechanism of the effect of exhaust gas condensation on fouling and thermal performance. This paper reviews the effects of hydrocarbon vapor, water vapor and acid vapor condensation on EGR cooler fouling and thermal performance from 1998 to 2023. Three paths of vapors condensation can occurr: interaction with particles, homogeneous nucleation and interaction with fouling. Beneficial effect (3) and harmful effects (2) to EGR cooler thermal performance have identified: filling, removal and chemical are beneficial effects whereas adhesion and nucleation are harmful effects. Three pathways and five effects play a key role on the composition, the mass, the thickness, density, the morphology and thermal resistance of fouling layer. The involvement level of sub-paths and contribution degree of sub-effects of vapor condensation under different boundary conditions, standard database, holistic model and the effect of renewable synthetic fuels on fouling and thermal performance can be further explored. The results will help researchers to understand the logical relationship between exhaust vapor condensation and fouling and thermal performance from the new perspective of condensation.

Applying Copolymerization Kinetics to Understand and Optimize Swelling Responses in Superabsorbent Hydrogels

While acrylic acid (AA)-based superabsorbent hydrogels (SAHs) have been widely used in multiple applications, the effects of counterion condensation and the polyelectrolyte effect at suppressing the effective degree of ionization in such systems limit their superabsorbency. Herein we describe the use, and investigate the mechanism, of sulfate comonomers containing different types of polymerizable functional groups for increasing the superabsorbency of acrylic acid-based SAHs. Specifically, acrylamido-2-methylpropanesulfonic acid (AMPS), 3-sulfopropyl acrylate (SPAK), and 3-sulfopropyl methacrylate (SPMK) sulfated monomers featuring similar distances between the polymer backbone and the sulfate group but different polymerizable groups were copolymerized with acrylic acid to fabricate SAHs. Measurements of the effective homopolymerization rate constants and copolymerization ratios associated with each copolymerization enabled the prediction of the relative chain distributions of monomers in each copolymer, as quantified by the blockiness parameter (i.e., the instantaneous or average number of consecutive monomers of each type polymerized). While all sulfated comonomers significantly enhanced swelling relative to an acrylic acid control, copolymers in which longer AA blocks are produced (AA-AMPS) resulted in lower swelling than copolymers in which shorter AA blocks are produced (AA-SPAK, AA-SPMK), a result attributed to the suppressed polyelectrolyte effect in copolymers with shorter AA blocks. The formation of limited length blocks of the sulfated monomer SPMK showed additional benefits for enhancing swelling, consistent with enhanced direct charge–charge repulsion between fixed charges in such copolymer systems. We anticipate this linkage between copolymerization kinetics and swelling properties offers the potential to enable improved rational design of superabsorbent hydrogels with higher sorbency.

CFD modeling of double-partition divided-wall column for mass transfer characteristics

In this study, a coupled two-fluid computational fluid dynamics (CFD)–component transfer (CT) model was constructed to investigate the mass transfer behavior and distribution of component concentration fields on trays within the two-staggered wall regions of a double-partition divided-wall column (DPDWC). By comparing the simulation results of the coupled CFD-CT model with the height-dependent calculation of the clear-liquid layer, this study validated the model, and then proceeded to analyse its effect on mass transfer in multiple zones of the tower under varying gas velocity conditions. The results showed that the mass-transfer efficiency increased initially, but then decreased with an increase in gas velocity within the studied gas velocity range. In addition, the evaporative condensation effect of the component mass transfer cause temperature variations across different regions of the tower.

Oxidized Kinetic Normal Distribution Models for Sophisticated Electrochemical Windows

The electrochemical window (EW) of electrolytes is considered the essential bottleneck of the voltage range for lithium batteries, which is theoretically overestimated previously. In this work, we present an innovative strategy to quantify the EW without experiential parameters accurately. This strategy encompasses energy states and statistical distribution from both thermodynamic and oxidized kinetic aspects. Verified by linear sweep voltammetry, which specializes in intrinsic redox kinetics of reactants and excludes the influences of products, the most restrictive factor among the effects of condensation, thermal motion, solvent, electric field, and catalysis determines the practical EW. For polyethylene oxide (PEO) and ethylene carbonate (EC)-dimethyl carbonate (DMC) with glassy carbon, the solvent effect is the restriction, while for EC-DMC with LixCoO2, the catalysis effect of the LixCoO2 surface is the restriction. This work provides an effective criterion for accurate prediction, guiding the electrolyte system design to satisfy the expected EW.

Experimental study of direct contact condensation of spent vapor in a cocurrent flow packed tower under negative pressure

AbstractCondensers are often required in power generation systems to condense the exhaust steam generated at the end of the turbine. This paper will investigate the enhanced condensation process of spent steam in a parallel flow type. The operating parameters of steam temperature (Tcond), steam flow rate (Gin), cooling water temperature (Tin), and cooling water flow rate (Lw) will affect the condensation effect by changing the gas–liquid arrangement in the tower. In this experiment, an orthogonal test was designed in the Raschig ring to investigate the significance of these four operating parameters on the experimental results. Different types of packings have different condensation effects due to different accumulation methods. The same type of packing has a different surface area, resulting in different contact areas between the gas and liquid phases during condensation. In this experiment, four different packings will be investigated to find their condensation performance. This paper uses the size of subcooling (ΔT) as an indicator to evaluate the effectiveness of condensation, and the values of condensation rate (R), number of liquid phase heat transfer units (NTUL), and total volume heat transfer coefficient (Kv) are used as a reference for the effectiveness of condensation. The results show that the overall condensation effect of regular packing is better than that of random packing, The average condensation rate of regular packing is 95%, the average condensation rate of random packing is 90%, the subcooling of regular packing is about three to five smaller than that of random packing, the heat transfer coefficient of regular packing is about 1.5 times of that of random packing. And by fitting the Kv data for different packings, an empirical formula was obtained that can be used to predict the Kv size of other packings.

Gap equations of background field invariant refined Gribov-Zwanziger action proposals and the deconfinement transition

In earlier work, we set up an effective potential approach at zero temperature for the Gribov-Zwanziger model that takes into account not only the restriction to the first Gribov region as a way to deal with the gauge fixing ambiguity, but also the effect of dynamical dimension-two vacuum condensates. Here, we investigate the model at finite temperature in presence of a background gauge field that allows access to the Polyakov loop expectation value and the Yang-Mills (de)confinement phase structure. This necessitates paying attention to Becchi-Rouet-Stora-Tyutin and background gauge invariance of the whole construct. We employ two such methods as proposed elsewhere in literature: one based on using an appropriate dressed, Becchi-Rouet-Stora-Tyutin invariant, gluon field by the authors and one based on a Wilson-loop dressed Gribov-Zwanziger auxiliary field sector by Kroff and Reinosa. The latter approach outperforms the former in estimating the critical temperature for $N=2$, 3 as well as correctly predicting the order of the transition for both cases.

A novel calculation strategy for optimized prediction of the reduction of electrochemical window at anode

The reduction of the electrochemical window (EW) of electrolytes plays a significant role in assessing their compatibility with the anode in lithium-ion batteries. However, the accurate calculation of the reduction of EW is still challenging due to missing the solvation effects, condensation effects, kinetic factors, and the passivation on anodes. The theoretical prediction of the intrinsic and apparent EW is confirmed by a comprehensive experimental analysis of ethylene carbonate-dimethyl carbonate (EC-DMC) electrolytes, combining linear sweep voltammetry (LSV) and gas chromatography-mass spectrometry (GC-MS). The proposed novel kinetic normal distribution theory model can quantitatively explain the current density from LSV and affirm acetaldehyde (MeCHO) as one of the primary reduction products of EC. The solvent effect restricts the intrinsic EW of EC-DMC without lithium salt to 2.6 V (vs. Li+/Li) arising from the Marcus–Gerischer theory and the passivation of MeCHO on the anode broadens the apparent EW to 0.3 V (vs. Li+/Li) arising from the normal distribution of the lowest unoccupied molecular orbital (LUMO) for MeCHO produced by thermal motion. In addition, the passivation on the anode depends intensively on the lithium salt, resulting in more complicated influences on the apparent EW.

Effects of cigarette smoke condensate on reproduction in mice in vivo

Smoking has dangerous and sometimes irreversible effects on various body tissues, including the reproductive system. We conducted this research to determine the in vivo effects of cigarette smoke condensate (CSC) on reproduction in mice. In this experimental in vivo study, 32 male and female NMRI mice were divided into four groups. The mice were injected with CSC (CSC-1R3F) for 28 days. The mice were mated 1 day after the last injection and observed daily for 1 week for the presence of a vaginal plug to track mating. We evaluated mating success rate, and sperm and oocyte quality, pregnancy outcome, childbearing status, and in vitro fertilization (IVF). The results showed a decrease in successful mating in female mice that received the CSC injections. CSC significantly influenced the number of offspring born to males. When the CSC was injected into male mice, there was a significant increase in the number of offspring compared with the group in which only the females received CSC injections. According to the results, there was a negative effect of CSC on morphological parameters in male and female mice. Also, successful IVF after exposure to CSC was significantly decreased in the female mice treated group. The results indicated that CSC significantly affected the number of offspring and fecundity success in females.

Kaon condensation in skyrmion matter and compact stars

We address the possibility of the appearance of a charged kaon condensate in neutron star cores described within a generalized Skyrme model. Our treatment of strange degrees of freedom is based on the Bound State Approach by Callan and Klebanov, which allows to obtain an in-medium effective potential for the $s$-wave kaon condensate. We predict the onset of kaon condensation at a certain threshold density - whose value depends on the parameters of the model, and ranges between 1.5 and 2.5 times saturation density -, and obtain both the particle fractions and equation of state for dense matter in the kaon condensed phase. Finally, we discuss the effect of such condensates on the mass-radius curves and other observable properties of neutron stars with kaon condensed cores.

Effect of cannabis smoke condensate on human nasal epithelial cell adhesion, growth, and migration

ObjectiveWhen inhaled, cannabis smoke interacts with airway tissues, including the nasal mucosa, which may lead to nasal pathologies. We examined the effect of cannabis smoke condensate (CSC) on nasal epithelial cell and tissue behaviors. MethodsHuman nasal epithelial cells were exposed or not to CSC at different concentrations (1, 5, 10, and 20 %) and for different durations. Cell adhesion and viability were assessed, as well as post-wound cell migration and lactate dehydrogenase (LDH) release. ResultsThe nasal epithelial cells showed a larger cell size and a faint nucleus following exposure to CSC, compared to that observed in that control. This was supported by fewer adherent cells present after exposure for either 1 or 24 h to 5, 15, and 20 % CSC. CSC also had a significant toxic effect by reducing cell viability after both 1 and 24 h of exposure. This toxic effect was significant even at a low concentration (1 %) of CSC. The effects on nasal epithelial cell viability were confirmed by the decrease in cell migration. After the scratch and subsequent exposure to CSC for either 6 or 24 h, a complete inhibition of nasal epithelial cell migration was observed, compared to that found in the controls. CSC was toxic to the nasal epithelial cells, as the level of LDH significantly increased following cell exposure all CSC concentrations. ConclusionCannabis smoke condensate had a negative effect on several nasal epithelial cell behaviors. These findings indicate that cannabis smoke could be a threat to nasal tissues and ultimately lead to nasal and sinus disorders.

Gluon condensation signature in the GeV gamma-ray spectra of pulsars

The accumulation of gluons inside nucleons, i.e., the gluon condensation, may lead to a characteristic broken power-law gamma-ray spectrum in high-energy nucleon collisions. Here we show that the observed spectra of at least 25 sources in the second Fermi Large Area Telescope Catalog of Gamma-ray Pulsars can be well fitted by such a broken power-law function that has only four free parameters. It strongly indicates that the gamma-ray emission from these pulsars is of hadronic origin, but with gluon condensation inside hadrons. It is well known that the quark-gluon distribution in a free nucleon is different from that in a bound nucleon. This work exposes the nuclear $A$ dependence of the gluon condensation effect, where $A$ refers to the baryon number. Our study reveals the gluon condensation under the condition of $A\ensuremath{\rightarrow}\ensuremath{\infty}$, which may open a new window for eavesdropping on the structure of compact stars on the subnuclear level.

E-Cigarette Aerosol Condensate Leads to Impaired Coronary Endothelial Cell Health and Restricted Angiogenesis

Cardiovascular disease (CVD) is a leading cause of mortality worldwide, with cigarette smoking being a major preventable risk factor. Smoking cessation can be difficult due to the addictive nature of nicotine and the withdrawal symptoms following cessation. Electronic cigarettes (e-Cigs) have emerged as an alternative smoking cessation device, which has been increasingly used by non-smokers; however, the cardiovascular effects surrounding the use of e-Cigs remains unclear. This study aimed to investigate the effects of e-Cig aerosol condensate (EAC) (0 mg and 18 mg nicotine) in vitro on human coronary artery endothelial cells (HCAEC) and in vivo on the cardiovascular system using a mouse model of 'e-vaping'. In vitro results show a decrease in cell viability of HCAEC when exposed to EAC either directly or after exposure to conditioned lung cell media (p < 0.05 vs. control). Reactive oxygen species were increased in HCAEC when exposed to EAC directly or after exposure to conditioned lung cell media (p < 0.0001 vs. control). ICAM-1 protein expression levels were increased after exposure to conditioned lung cell media (18 mg vs. control, p < 0.01). Ex vivo results show an increase in the mRNA levels of anti-angiogenic marker, FKBPL (p < 0.05 vs. sham), and endothelial cell adhesion molecule involved in barrier function, ICAM-1 (p < 0.05 vs. sham) in murine hearts following exposure to electronic cigarette aerosol treatment containing a higher amount of nicotine. Immunohistochemistry also revealed an upregulation of FKBPL and ICAM-1 protein expression levels. This study showed that despite e-Cigs being widely used for tobacco smoking cessation, these can negatively impact endothelial cell health with a potential to lead to the development of cardiovascular disease.