Статті в журналах з теми "Film bursting"
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1
Bico, J. "Cracks in bursting soap films." Journal of Fluid Mechanics 778 (July 30, 2015): 1–4. http://dx.doi.org/10.1017/jfm.2015.376.
Анотація:
The rupture of soap films is traditionally described by a law accounting for a balance between momentum and surface tension forces, derived independently by Taylor and Culick in the 1960s. This law is highly relevant to the dynamics of thin liquid films of jets when viscous effects are negligible. However, the minute amounts of surfactant molecules present in soap films play a major role in interfacial rheology, and may result in complex behaviour. Petit et al. (J. Fluid Mech., vol. 774, 2015, R3) challenge standard thin film dynamics via intriguing experiments conducted with highly elastic surfactants. Unexpected structures reminiscent of faults are observed.
2
Lhuissier, H., and E. Villermaux. "Bursting bubble aerosols." Journal of Fluid Mechanics 696 (November 18, 2011): 5–44. http://dx.doi.org/10.1017/jfm.2011.418.
Анотація:
AbstractWe depict and analyse the complete evolution of an air bubble formed in a water bulk, from the time it emerges at the liquid surface, up to its fragmentation into dispersed drops. To this end, experiments describing the drainage of the bubble cap film, its puncture and the resulting bursting dynamics determining the aerosol formation are conducted on tapwater bubbles. We discover that the mechanism of marginal pinching at the bubble foot and associated convection motions in the bubble cap, known as marginal regeneration, both drive the bubble cap drainage rate, and are responsible for its puncture. The resulting original film thickness $h$ evolution law in time, supplemented with considerations about the nucleation of holes piercing the film together culminate in a determination of the cap film thickness at bursting ${h}_{b} \propto {R}^{2} / \mathscr{L}$, where $R$ is the bubble cap radius of curvature, and $\mathscr{L}$ a length which we determine. Subsequent to a hole nucleation event, the cap bursting dynamics conditions the resulting spray. The latter depends both on the bubble shape prescribed by $R/ a$, where $a$ is the capillary length based on gravity, and on ${h}_{b} $. The mean drop size $\langle d\rangle \ensuremath{\sim} {R}^{3/ 8} \hspace{0.167em} { h}_{b}^{5/ 8} $, the number of drops generated per bubble $N\ensuremath{\sim} \mathop{ (R/ a)}\nolimits ^{2} \mathop{ (R/ {h}_{b} )}\nolimits ^{7/ 8} $ and the drop size distribution $P(d)$ are derived, comparing well with measurements. Combined with known bubble production rates over the ocean, our findings offer an adjustable parameter-free prediction for the aerosol flux and spray structure caused by bubble bursting in this precise context.
3
Duchemin, Laurent, and Christophe Josserand. "Dimple drainage before the coalescence of a droplet deposited on a smooth substrate." Proceedings of the National Academy of Sciences 117, no. 34 (August 11, 2020): 20416–22. http://dx.doi.org/10.1073/pnas.2007857117.
Анотація:
Thin liquid or gas films are everywhere in nature, from foams to submillimetric bubbles at a free surface, and their rupture leaves a collection of small drops and bubbles. However, the mechanisms at play responsible for the bursting of these films is still in debate. The present study thus aims at understanding the drainage dynamics of the thin air film squeezed by gravity between a millimetric droplet and a smooth solid or a liquid thin film. Solving coupled lubrication equations and analyzing the dominant terms in the solid- and liquid-film cases, we explain why the drainage is much faster in the liquid-film case, leading often to a shorter coalescence time, as observed in recent experiments.
4
Gatapova, Elizaveta Ya, and Kyunney B. Gatapova. "Bubble dynamics in thin liquid films and breakup at drop impact." Soft Matter 16, no. 46 (2020): 10397–404. http://dx.doi.org/10.1039/d0sm01882a.
Анотація:
A bubble layer forms in a thin liquid film at drop impact on a hot surface. Bubble coalescence and instability generated by a wave are the reason for irreversible bubble bursting, leading to film breakup at contact boiling.
5
Resch, François, and George Afeti. "Film drop distributions from bubbles bursting in seawater." Journal of Geophysical Research 96, no. C6 (1991): 10681. http://dx.doi.org/10.1029/91jc00433.
6
Wu, Jin. "Production Functions of Film Drops by Bursting Bubbles." Journal of Physical Oceanography 31, no. 11 (November 2001): 3249–57. http://dx.doi.org/10.1175/1520-0485(2001)031<3249:pfofdb>2.0.co;2.
7
Martin, P., A. Buguin, and F. Brochard-Wyart. "Bursting of a Liquid Film on a Liquid Substrate." Europhysics Letters (EPL) 28, no. 6 (November 20, 1994): 421–26. http://dx.doi.org/10.1209/0295-5075/28/6/008.
8
Reyssat, É., and D. Quéré. "Bursting of a fluid film in a viscous environment." Europhysics Letters (EPL) 76, no. 2 (October 2006): 236–42. http://dx.doi.org/10.1209/epl/i2006-10262-x.
9
Joanny, J. F., and P. G. De Gennes. "Bursting of a soap film in a viscous environment." Physica A: Statistical Mechanics and its Applications 147, no. 1-2 (November 1987): 238–55. http://dx.doi.org/10.1016/0378-4371(87)90108-7.
10
Yu, Xiang, Haifeng Gu, Weikai Yin, and Qingyang Sun. "Bubble Bursting and Drainage Characteristics at the Free Surface of a Liquid Pool with an Aerosol." Science and Technology of Nuclear Installations 2020 (October 16, 2020): 1–13. http://dx.doi.org/10.1155/2020/8829074.
Анотація:
When nuclear reactor accidents such as steam generator pipe ruptures or core melting occur, radioactive aerosols will remain in the liquid pools. Bubbles may be generated by boiling or gas injection. Film droplets produced by bubble bursts may entrain radioactive aerosols from the liquid to the air. This long-lasting behavior can produce a considerable amount of aerosols. To evaluate radioactive source terms, many physical quantities related to bubble bursting need to be determined, such as bubble burst position, bubble lifetime, cap film roll-up velocity, and cap film thickness, which are very important parameters that influence the releasing of radioactive aerosols. In this research, the phenomenon of bubble bursting was investigated by visualization. The above parameters were measured. We obtained the lifetime distribution of bubbles under different conditions, and we found that the addition of an aerosol increased the lifetime of the bubbles. By comparing the bubble lifetime to the roll-up velocity and cap thickness, we showed that the increase of the liquid temperature thickened the cap at rupture and the increase of the air temperature thinned the cap. The addition of an aerosol increased the film roll-up velocity.
11
Wang, Xiaofei, Grant B. Deane, Kathryn A. Moore, Olivia S. Ryder, M. Dale Stokes, Charlotte M. Beall, Douglas B. Collins, et al. "The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles." Proceedings of the National Academy of Sciences 114, no. 27 (June 19, 2017): 6978–83. http://dx.doi.org/10.1073/pnas.1702420114.
Анотація:
The oceans represent a significant global source of atmospheric aerosols. Sea spray aerosol (SSA) particles comprise sea salts and organic species in varying proportions. In addition to size, the overall composition of SSA particles determines how effectively they can form cloud droplets and ice crystals. Thus, understanding the factors controlling SSA composition is critical to predicting aerosol impacts on clouds and climate. It is often assumed that submicrometer SSAs are mainly formed by film drops produced from bursting bubble-cap films, which become enriched with hydrophobic organic species contained within the sea surface microlayer. In contrast, jet drops formed from the base of bursting bubbles are postulated to mainly produce larger supermicrometer particles from bulk seawater, which comprises largely salts and water-soluble organic species. However, here we demonstrate that jet drops produce up to 43% of total submicrometer SSA number concentrations, and that the fraction of SSA produced by jet drops can be modulated by marine biological activity. We show that the chemical composition, organic volume fraction, and ice nucleating ability of submicrometer particles from jet drops differ from those formed from film drops. Thus, the chemical composition of a substantial fraction of submicrometer particles will not be controlled by the composition of the sea surface microlayer, a major assumption in previous studies. This finding has significant ramifications for understanding the factors controlling the mixing state of submicrometer SSA particles and must be taken into consideration when predicting SSA impacts on clouds and climate.
12
Bittolo Bon, Silvia, Michele Rapi, Riccardo Coletta, Antonino Morabito, and Luca Valentini. "Plasticised Regenerated Silk/Gold Nanorods Hybrids as Sealant and Bio-Piezoelectric Materials." Nanomaterials 10, no. 1 (January 20, 2020): 179. http://dx.doi.org/10.3390/nano10010179.
Анотація:
Manual and mechanical suturing are currently the gold standard for bowel anastomosis. If tissue approximation fails, anastomotic leaks occur. Anastomotic leaks may have catastrophic consequences. The development of a fully absorbable, biocompatible sealant material based on a bio-ink silk fibroin can reduce the chance of anastomotic leaks. We have produced a Ca-modified plasticised regenerated silk (RS) with gold nanorods sealant. This sealant was applied to anastomosed porcine intestine. Water absorption from wet tissue substrate applied compressive strains on hybrid RS films. This compression results in a sealant effect on anastomosis. The increased toughness of the hybrid plasticised RS resulted in the designing of a bio-film with superior elongation at break (i.e., ≈200%) and bursting pressure. We have also reported structure-dependent piezoelectricity of the RS film that shows a piezoelectric effect out of the plane. We hope that in the future, bowel anastomosis can be simplified by providing a multifunctional bio-film that makes feasible the mechanical tissue joint without the need for specific tools and could be used in piezoelectric sealant heads.
13
Yang, Changhua, and Zhenye Yu. "A Study on the Oil-Bearing Stability of Salt-Resistant Foam and an Explanation of the Viscoelastic Phenomenon." Processes 11, no. 9 (August 30, 2023): 2598. http://dx.doi.org/10.3390/pr11092598.
Анотація:
Foam is a medium-stable system composed of gas and liquid phases, which has the advantages of low density at the gas phase and high viscosity at the liquid phase, and has a wide application in oil and gas field development and mineral flotation, but its special medium-stable system also brings many problems in industry applications. Scientists have carried out extensive analyses and research on the foam stability and bubble-bursting mechanism, which initially clarified the rules of bubble breakage caused by environmental factors such as temperature and pressure, but the mechanism of bubble bursting under the action of internal factors such as liquid mineralization and oil concentration of the films is still not clearly defined. In this paper, we propose a compound salt-resistant foaming agent, investigated the influence of the aggregation and adsorption behavior of oil droplets on the liquid films and boundaries, and established a relevant aggregation and adsorption model with the population balance equation. We put forward a liquid film drainage mechanism based on the distribution, aggregation, and transport of oil droplets in the liquid films, so as to explain the changes in foam stability under the action of oil droplets. On the other hand, the viscoelastic analysis of foam fluid is performed with a rheometer, and the results show that in comparison with conventional power-law fluid, foam fluid has a complex rheological behavior for low shear thickening, but high shear thinning.
14
Tammaro, Daniele, Vinny Chandran Suja, Aadithya Kannan, Luigi Davide Gala, Ernesto Di Maio, Gerald G. Fuller, and Pier Luca Maffettone. "Flowering in bursting bubbles with viscoelastic interfaces." Proceedings of the National Academy of Sciences 118, no. 30 (July 22, 2021): e2105058118. http://dx.doi.org/10.1073/pnas.2105058118.
Анотація:
The lifetime of bubbles, from formation to rupture, attracts attention because bubbles are often present in natural and industrial processes, and their geometry, drainage, coarsening, and rupture strongly affect those operations. Bubble rupture happens rapidly, and it may generate a cascade of small droplets or bubbles. Once a hole is nucleated within a bubble, it opens up with a variety of shapes and velocities depending on the liquid properties. A range of bubble rupture modes are reported in literature in which the reduction of a surface energy drives the rupture against inertial and viscous forces. The role of surface viscoelasticity of the liquid film in this colorful scenario is, however, still unknown. We found that the presence of interfacial viscoelasticity has a profound effect in the bubble bursting dynamics. Indeed, we observed different bubble bursting mechanisms upon the transition from viscous-controlled to surface viscoelasticity-controlled rupture. When this transition occurs, a bursting bubble resembling the blooming of a flower is observed. A simple modeling argument is proposed, leading to the prediction of the characteristic length scales and the number and shape of the bubble flower petals, thus paving the way for the control of liquid formulations with surface viscoelasticity as a key ingredient. These findings can have important implications in the study of bubble dynamics, with consequences for the numerous processes involving bubble rupture. Bubble flowering can indeed impact phenomena such as the spreading of nutrients in nature or the life of cells in bioreactors.
15
Chen, Chao, Yong Ling Yu, Li Hua Lv, and Jing Cui. "Process Optimization and Performance Analysis of the Decorative Composites Prepared by Silk Fabric / PE Film." Advanced Materials Research 175-176 (January 2011): 323–27. http://dx.doi.org/10.4028/www.scientific.net/amr.175-176.323.
Анотація:
The decorative composites composed of silk fabric/PE film were characterized by easy cleanness, corrosion-resistance, anti-oxidation and other virtues. In this paper, silk fabric/PE film decorative composites were prepared by hot pressing method. The optimum thickness of the silk fabrics and PE film was fixed by color difference analysis. The effects of hot-pressing temperature, hot-pressing pressure, and hot-pressing time on mechanical properties were studied through single factor analysis method at a certain thickness. The results showed that under the hot pressing conditions (temperature145 °C, pressure 3 MPa, time 4 min and thickness 0.3 mm), silk fabric/PE film decorative composites with ideal tensile strength, bursting strength, tearing strength and color vividness could be obtained. This paper provided an effective approach to the comprehensive utilization of silk fabrics for preparation of decorative composites.
16
Ming, Xianglan, Haitao Chen, and Dianming Ju. "Performance and Environmental Impact of Rice Straw Fiber Mulching Films Manufactured with a Warming Agent." Transactions of the ASABE 62, no. 2 (2019): 315–20. http://dx.doi.org/10.13031/trans.13094.
Анотація:
Abstract. This research evaluates the effects of adding various warming agents to rice straw fiber (RSF) films as sustainable alternatives to polyethylene-based films. The results for the mechanical properties of the RSF films with various warming agents show that the mean values of dry tensile strength and bursting strength of the films significantly differed according to the warming agent; in contrast, the mean wet tensile strengths and tearing strengths were not significantly different. The dry tensile strengths of films containing titanium dioxide were 9.7% and 26.8% higher than those of the films containing talc and kaolin, respectively. Additionally, the bursting strengths of the films containing titanium dioxide, calcium carbonate, and talc were 10.5%, 4.4%, and 15.8% higher, respectively, than those of the films containing kaolin. Thus, titanium dioxide was considered the best of the four warming agents for implementation in these films. The absorption peaks of the films with and without titanium dioxide were similar, with some differences in the peak position and relative intensities by Fourier transform infrared spectroscopy. Soil covering tests were conducted with films containing titanium dioxide (TDF), films with no added titanium dioxide, and a blank group. The degradation rate of the TDF reached grade 3 during the bolting stage of bok choy. At soil depths of 0, 5, and 10 cm, the total accumulated temperature of the TDF group was 11.53%, 7.78%, and 5.38% higher, respectively, than that of the blank group. Both TDF degradation and increased soil temperature improved the crop growth and soil microclimate. These results can serve as a reference to further improve the popularization and application of RSF film. Keywords: Degradable films, Mechanical properties, Rice straw, Soil temperature, Titanium dioxide.
17
Wu, Jin. "Film drops produced by air bubbles bursting at the surface of seawater." Journal of Geophysical Research 99, no. C8 (1994): 16403. http://dx.doi.org/10.1029/94jc01181.
18
Spiel, Donald E. "On the births of film drops from bubbles bursting on seawater surfaces." Journal of Geophysical Research: Oceans 103, no. C11 (October 15, 1998): 24907–18. http://dx.doi.org/10.1029/98jc02233.
19
Gevod, V. S., and I. A. Borisov. "Influence of air bubble flow structure on the rate of water purification by the bubble-film extraction method." Water Supply 19, no. 8 (August 12, 2019): 2298–308. http://dx.doi.org/10.2166/ws.2019.112.
Анотація:
Abstract Bubble-film extraction (upgraded bubble flotation) is one of the modern methods for purifying contaminated water from surface-active impurities. The features of this method have been considered from the standpoints of the equilibrium and dynamics of surfactant accumulation on floated air bubbles with different sizes. Within a certain ratio of dimension and quantity of air bubbles in their stream transferring adsorbed surfactants from the water bulk into the bubble-film extractor, the productivity of the process increases many times. The effect is ensured by a collective fusion of big and small air bubbles in their close-packed state (embedded system) inside the bubble-film extractor. The driving forces are impulses of capillary waves initiated at the bursting of big air bubbles as constituent ‘destructive’ units of that system.
20
Peng, Pengjie, Xiaofan Zhou, and Jinxia Ma. "Water glass compound starch used as surface sizing agent to improve the strength of linerboard." BioResources 6, no. 4 (August 31, 2011): 4158–67. http://dx.doi.org/10.15376/biores.6.4.4158-4167.
Анотація:
With the rapid development of the packaging industry, the requirements for physical properties of corrugated paperboard tend to become higher and higher, especially for the strength properties. A water glass-starch compound system was employed as a surface sizing agent to improve the strength of linerboard in this work. The viscosity of water glass-starch compound system, and its impacts on ring-crush strength and bursting strength of linerboard were evaluated. Cobb value and contact angle were used to characterize the waterproof performance of paper after surface sizing. Compared with conventional surface sizing agents, water glass-starch compound system overcame the defects of low coating weight and inadequate stiffness of the sizing layer, allowing ring-crush strength and bursting strength of linerboard to increase by 91% and 50%, respectively. Additionally, the compound system had higher solids content, low viscosity, and good film-forming ability, which will bring a lot of convenience to production.
21
Yang, Zhi Yuan, Hai Zhen Shi, and Yan Jun Tang. "Changes in Layer Properties and Physical Properties of Papers from Old Corrugated Container Fibres with PDADMAC/HEC Polyelectrolyte Multilayers." Advanced Materials Research 496 (March 2012): 67–70. http://dx.doi.org/10.4028/www.scientific.net/amr.496.67.
Анотація:
In this paper, Old Corrugated Container (OCC) was used as the raw material for making paper. The layer-by-layer (LBL) assembly process of creating highly structured thin films was adopted to modify the surface of OCC fibres. Poly dimethyldiallylammonium chloride (PDADMAC) and hydroxyethyl cellulose (HEC) have been used to build up polyelectrolyte multilayers on OCC fibres under a certain condition. Zeta potential analyzer was used to monitor the dynamic adsorption of PDADMAC and HEC with different amount on OCC fibers. Strength measurements of the sheets including tensile index and bursting index were also determined, showing a significant improvement in physical strength with the increase of adsorbed layer number. Compared with not being processed sheets, tensile index and bursting index of sheets from treated fibre with polyelectrolyte multilayers were raised by 36.65% and 49.50%, respectively. Furthermore, filtration time analysis of OCC fibre suspension showed that the built up of PDADMAC and HEC on OCC fibres could improve the fiber-fiber joint strength of joints from polymer-treated fibers, which made the filtration time decline from 30 s to 10.6 s. In addition, SEM was introduced to observe the morphology of the PDADMAC/HEC multilayers. The images revealed that the surface of OCC fibres structured a film like plastic, which could be ascribed to the adsorption layer of polyelectrolyte.
22
Xia Zhi-Lin, Guo Pei-Tao, Xue Yi-Yu, Huang Cai-Hua, and Li Zhan-Wang. "Investigation of the plasma bursting process in short pulsed laser induced film damage." Acta Physica Sinica 59, no. 5 (2010): 3523. http://dx.doi.org/10.7498/aps.59.3523.
23
Deane, Grant B. "Determining the bubble cap film thickness of bursting bubbles from their acoustic emissions." Journal of the Acoustical Society of America 133, no. 2 (February 2013): EL69—EL75. http://dx.doi.org/10.1121/1.4773069.
24
SNYDER, HERMAN E., and ROLF D. REITZ. "Direct droplet production from a liquid film: a new gas-assisted atomization mechanism." Journal of Fluid Mechanics 375 (November 25, 1998): 363–81. http://dx.doi.org/10.1017/s0022112098002997.
Анотація:
X-ray lithography and micro-machining have been used to study gas-assisted liquid atomization in which a liquid film was impinged by a large number of sonic micro-gas jets. Three distinct breakup regimes were demonstrated. Two of these regimes share characteristics with previously observed atomization processes: a bubble bursting at a free surface (Newitt et al. 1954; Boulton-Stone & Blake 1993) and liquid sheet disintegration in a high gas/liquid relative velocity environment (Dombrowski & Johns 1963). The present work shows that suitable control of the gas/liquid interface creates a third regime, a new primary atomization mechanism, in which single liquid droplets are ejected directly from the liquid film without experiencing an intermediate ligament formation stage. The interaction produces a stretched liquid sheet directly above each gas orifice. This effectively pre-films the liquid prior to its breakup. Following this, surface tension contracts the stretched film of liquid into a sphere which subsequently detaches from the liquid sheet and is entrained by the gas jet that momentarily pierces the film. After droplet ejection, the stretched liquid film collapses, covering the gas orifice, and the process repeats. This new mechanism is capable of the efficient creation of finely atomized sprays at low droplet ejection velocities (e.g. 20 μm Sauter mean diameter methanol sprays using air at 239 kPa, with air-to-liquid mass ratios below 1.0, and droplet velocities lower than 2.0 m s−1). Independent control of the gas and the liquid flows allows the droplet creation process to be effectively de-coupled from the initial droplet momentum, a characteristic not observed with standard gas-assisted atomization mechanisms.
25
Genç, Gamze, Kemal Koca, and Mustafa Serdar Genç. "Unsteady aerodynamics over surface of a chambered airfoil at stall angle and low Reynolds number." EPJ Web of Conferences 269 (2022): 01016. http://dx.doi.org/10.1051/epjconf/202226901016.
Анотація:
The proposal of this paper is clear to reveal and understand the unsteady flow characteristics over the surface of chambered airfoil operating especially at low Reynolds numbers by detecting boundary layer separation and laminar separation bubble (LSB). Experiments including smoke-wire technique for flow visualization, velocity measurement via hot-wire sensor and quasi-wall shear stress measurement by means of the hot-film sensor have been performed over the suction surface of NACA 4412 airfoil at Reynolds number of 5x104 and angle of attack of 14°. Experiments indicate that the airfoil at a stall angle exhibits the bistable characteristics over the suction surface because of the unsteady bubble bursting at low Reynolds numbers. That is, either laminar flow separates from the leading-edge of the airfoil owing to a dominant adverse pressure gradient (APG) or it does not separate along downstream. It is also noted that unsteady boundary layer formation may affect the flow characteristics by changing airfoil’s stability appreciably, causing the periodic fluctuations with the occurring bubble bursting and the leading edge and trailing edge vortex merging. This may conclude undesirable problems such as noise, vibration and flutter for the flight vehicles and wind turbines.
26
Wisniewski, M., A. Sionkowska, H. Kaczmarek, J. Skopinska, S. Lazare, and V. Tokarev. "The influence of KrF excimer laser irradiation on the surface of collagen and collagen/PVP films." International Journal of Photoenergy 2006 (2006): 1–7. http://dx.doi.org/10.1155/ijp/2006/35126.
Анотація:
The surface properties of collagen and collagen/poly(vinyl pyrrolidone) (PVP) films after KrF excimer laser irradiation (λ=248nm) were investigated by means of the technique of scanning electron microscopy (SEM) and optical microscopy (OM). The laser irradiation of the used specimens caused an expansion of materials above their surface with pronounced sings of its melting. The height of the ablated volume in a case of collagen film at a fluence of1.1J/cm2was approximately 5μm. A white damage appears on the treated surfaces at a threshold of0.5J/cm2with a single pulse and becomes more visible for a higher fluence. It is also noteworthy that along with increasing fluences (beginning from the fluence of1.7J/cm2), the characteristic filaments at the spot edges are observed. The local heat and pressure generated by the laser radiation were able to induce bubble formation on the surface. Further bubble colliding and bursting produce a three-dimensional polymer “microfoam” structure with interconnected pores. These results can be of interest for some new applications.
27
Zuo, Lili, Qi Zhang, Chengwei Sun, Xiaosong Zhu, and Changchun Wu. "Molecular Dynamics Simulation and Experiment on the Microscopic Mechanism of the Effect of Wax Crystals on the Burst and Drainage of Foams." Sustainability 14, no. 11 (June 1, 2022): 6778. http://dx.doi.org/10.3390/su14116778.
Анотація:
In recent years, with the goal of “carbon peaking and carbon neutralization”, the CO2 flooding technology in carbon capture, utilization, and storage (CCUs) has been paid great attention to the oil fields. However, the CO2 flooding of crude oil may produce foams in the oil and gas separation process. In addition, the precipitation of wax components in crude oil might enhance the stability characteristics of these foams and lower the separator’s efficiency. Based on a crude oil depressurization foaming device, the influence of wax crystals on the bursting of oil foam was studied using simulated oil, and the microstructure of the wax crystal and foam liquid film was observed using freeze-etching and microscopic observation. In addition, the gas–liquid interface model of the wax oil was established by a molecular dynamics (MD) simulation to analyze the influence mechanism of wax crystals on foam drainage and gas diffusion among foams in the microlayer. The results show that the precipitation of wax crystals overall reduces the rate of defoaming and drainage and increases the grain diameter of the foam. The formation and growth of the wax crystal-shaped network impede the flow of liquid in the drainage channel and stabilize the foam. Moreover, it impedes the diffusion of CO2 among foams, inhibiting the bursting of the foams. The results of the combined experiments and MD simulation verify the accuracy and applicability of the molecular model, which further clarifies the effect of wax crystals on foam stability and its mechanism of action on foam film. These findings are a benchmark for the enhancement of defoaming and separation efficiency and a theoretical framework for future study and modeling.
28
OVSYANNIKOV, S. N., and V. N. OKOLICHNYI. "POWER TESTING OF ETFE FILM." Building and reconstruction 103, no. 5 (2022): 3–12. http://dx.doi.org/10.33979/2073-7416-2022-103-5-3-12.
Анотація:
Studies of mechanical properties of ethylene-tetrafluoroethylene (ETFE) film they are relevant for wide application in the construction of translucent coatings in the climatic conditions of Russia, especially in the Arctic zone. Power tests were performed for a film with a thickness of 250 microns on an INSTRON bursting machine, as well as with a uniformly distributed load at positive and negative temperatures. The initial modulus of elasticity according to GOST 34370-2017 was established, which was 1090 MPa. Three loading stages have been identified for the calculations of translucent coatings. In the elastic stage of operation of the ETFE film, the average modulus of elasticity was 35.8 MPa, in the elastic-plastic stage – 1.78...2.71 MPa and in the plastic stage of operation – 0.06...0.086 MPa. Force tests of a membrane made of ETFE film with a thickness of 250 microns on a power triangular frame with a uniformly distributed load of up to 8,577 kPa did not lead to rupture of the membrane at any positive (+15 ...+18 оС) not at subzero temperatures (-23...-29 оС). Repeated mechanical damage (cuts) of the membrane under a load of 8.50 kPa at a temperature of -26 оС also did not lead to its rupture. The deflections of the membrane at positive temperatures reached 84 mm, at negative temperatures – 58.2 mm. Power tests of the ETFE film have shown its ultra-high strength characteristics, which makes it possible to widely use it to create a comfortable environment in structures erected in the Arctic and other territories of Russia when localizing production in Russia.
29
Gordillo, J. M., and J. Rodríguez-Rodríguez. "Capillary waves control the ejection of bubble bursting jets." Journal of Fluid Mechanics 867 (March 25, 2019): 556–71. http://dx.doi.org/10.1017/jfm.2019.161.
Анотація:
Here we provide a theoretical framework describing the generation of the fast jet ejected vertically out of a liquid when a bubble, resting on a liquid–gas interface, bursts. The self-consistent physical mechanism presented here explains the emergence of the liquid jet as a consequence of the collapse of the gas cavity driven by the low capillary pressures that appear suddenly around its base when the cap, the thin film separating the bubble from the ambient gas, pinches. The resulting pressure gradient deforms the bubble which, at the moment of jet ejection, adopts the shape of a truncated cone. The dynamics near the lower base of the cone, and thus the jet ejection process, is determined by the wavelength $\unicode[STIX]{x1D706}^{\ast }$ of the smallest capillary wave created during the coalescence of the bubble with the atmosphere which is not attenuated by viscosity. The minimum radius at the lower base of the cone decreases, and hence the capillary suction and the associated radial velocities increase, with the wavelength $\unicode[STIX]{x1D706}^{\ast }$. We show that $\unicode[STIX]{x1D706}^{\ast }$ increases with viscosity as $\unicode[STIX]{x1D706}^{\ast }\propto Oh^{1/2}$ for $Oh\lesssim O(0.01)$, with $Oh=\unicode[STIX]{x1D707}/\sqrt{\unicode[STIX]{x1D70C}R\unicode[STIX]{x1D70E}}$ the Ohnesorge number, $R$ the bubble radius and $\unicode[STIX]{x1D70C}$, $\unicode[STIX]{x1D707}$ and $\unicode[STIX]{x1D70E}$ indicating respectively the liquid density, viscosity and interfacial tension coefficient. The velocity of the extremely fast and thin jet can be calculated as the flow generated by a continuous line of sinks extending along the axis of symmetry a distance proportional to $\unicode[STIX]{x1D706}^{\ast }$. We find that the jet velocity increases with the Ohnesorge number and reaches a maximum for $Oh=Oh_{c}$, the value for which the crest of the capillary wave reaches the vertex of the cone, and which depends on the Bond number $Bo=\unicode[STIX]{x1D70C}gR^{2}/\unicode[STIX]{x1D70E}$. For $Oh>Oh_{c}$, the jet is ejected after a bubble is pinched off; in this regime, viscosity delays the formation of the jet, which is thereafter emitted at a velocity which is inversely proportional to the liquid viscosity.
30
Vidal, V., J. C. Géminard, T. Divoux, and F. Melo. "Acoustic signal associated with the bursting of a soap film which initially closes an overpressurized cavity." European Physical Journal B 54, no. 3 (December 2006): 321–39. http://dx.doi.org/10.1140/epjb/e2006-00450-0.
31
Wei, Yansong, Hao Chen, Haifeng Gu, Linlin Chen, and Xiang Yu. "Experimental investigation of the puncture position and film rolling speed of bubbles bursting under different liquid pool conditions." Progress in Nuclear Energy 129 (November 2020): 103510. http://dx.doi.org/10.1016/j.pnucene.2020.103510.
32
Uyanik, Seval, and Hatice Kübra Kaynak. "A comparative study on the performance properties of breathable and non-breathable baby diaper back sheet." Tehnički glasnik 12, no. 2 (June 28, 2018): 74–78. http://dx.doi.org/10.31803/tg-20180125164806.
Анотація:
Disposable diapers are very important in terms of babies’ health because they are in touch with the baby’s skin. Disposable diapers have sheets with different functions from each other. The main layers of disposable diapers are as follows: top sheet, absorbent layer and back sheet. The function of the top sheet is to pass the liquid to the lower absorbent layer whereas the function of the absorbent layer is to absorb the liquid. As for the back sheet, this layer keeps the liquid inside and prevents it from leaving the diaper. The back sheet is usually a nonwoven/ polyethylene (PE) film composite. Considering the babies’ health, breathable back sheets are mostly used in baby diapers to keep the skin drier. These have a positive effect on the baby’s skin, especially in terms of occlusion, diaper dermatitis. In this study, the performance properties of some commercial baby diaper back sheet layers have been investigated. For this purpose, weight, thickness, air permeability, water vapor permeability and water resistance tests were applied to back sheet samples with different fabric mass as breathable and non-breathable films. All back sheet samples are SMS nonwoven/ polyethylene (PE) film composites. Breathable samples have a larger fabric mass than non-breathable samples. For breathable samples, while increasing mass, air permeability and water vapor permeability decrease, water resistance increases. On the other hand, the same tendency is not seen in non-breathable samples. Breathable samples have higher air permeability, water vapor permeability, water resistance, and bursting strength than non-breathable samples. Consequently, the using of a baby diaper containing breathable back sheet is more proper in terms of baby’s skin health.
33
Bald, Robert H. "Hole Swallows Car, Film @ 11:00 Greensboro's Pilot Program for Water Pipe Bursting Leads to Expanded City Wide Program." Proceedings of the Water Environment Federation 2013, no. 6 (January 1, 2013): 7080–92. http://dx.doi.org/10.2175/193864713813726821.
34
Forsgren, La Donna L. "The Wiz Redux; or, Why Queer Black Feminist Spectatorship and Politically Engaged Popular Entertainment Continue to Matter." Theatre Survey 60, no. 03 (August 6, 2019): 325–54. http://dx.doi.org/10.1017/s0040557419000243.
Анотація:
I don't remember the very first time I watched The Wiz (1978). Growing up in a black household during the 1980s, the film was as much a part of my upbringing as the countless hours I spent removing my Jheri curl activator from the sofa, practicing the moonwalk, or listening to my mother and sister's annual Thanksgiving argument about how much salt should go into the collard greens. What I do remember is how much I enjoyed watching The Wiz. Each Thanksgiving Day my six sisters and I would gather around the television set and watch our heroine Dorothy (Diana Ross) travel from her aunt's Harlem apartment to the magical land of Oz. We celebrated the fact that Dorothy ultimately vanquishes her seemingly more powerful foe Evillene, the Wicked Witch of the West (Mabel King). As young black girls, we identified with Dorothy's plight. While we were not battling powerful witches, we were constantly resisting our mother's attempts to socialize us into “respectable” young women. As such, we were fascinated by Evillene, the most oppressive force within Dorothy's life. The gargantuan size of Evillene's body, the hideousness of her face, and the force of her supernatural powers both excited and repulsed us. We eagerly anticipated her first appearance in the film, bursting through the doors of her sweatshop belting, “Don't Nobody Bring Me No Bad News.” We reveled in drawing comparisons between Evillene and our mother, hoping that one day we too could defeat her.
35
Kit, E., C. M. Hocut, D. Liberzon, and H. J. S. Fernando. "Fine-scale turbulent bursts in stable atmospheric boundary layer in complex terrain." Journal of Fluid Mechanics 833 (November 8, 2017): 745–72. http://dx.doi.org/10.1017/jfm.2017.717.
Анотація:
Turbulence in the atmospheric boundary layer (ABL) is usually measured using sonic anemometers (sonics), but coarse spatial (${\sim}10$ cm) and temporal (${\sim}32$ Hz) resolutions of sonics preclude direct measurement of fine-scale parameters such as the turbulent kinetic energy (TKE) dissipation rate $\unicode[STIX]{x1D700}$. Instead, $\unicode[STIX]{x1D700}$ is estimated using techniques based on Kolmogorov theory. Fine-scale measurements of ABL turbulence down to Kolmogorov scale were made with a sonic and hot-film anemometer dyad (a ‘combo’ probe) during the field campaigns of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) programme. The hot-film probe was located on a gimbal within the sonic probe volume, and was automated to rotate in the horizontal plane to align with the mean flow measured by sonic. This procedure not only helped satisfy the requirement of hot-film alignment with the mean flow, but also allowed in situ calibration of hot-film probes. This paper analyses a period of nocturnal flow that was similar to a stratified parallel shear flow. The combo-probe measurements showed an interesting phenomenon – the occurrence of strong bursts, characterized by short-term increase of velocity fluctuations and simultaneous increase of TKE dissipation rate by orders of magnitude. These bursts were indicative of unusual turbulence activity at finer (${\sim}0.1$–0.4 m) scales that are not captured by sonics since the smallest scales resolved by the latter are greater than 0.6 m. With bursting present, the spectra exhibited bumps at scales intermediate to inertial and dissipation subranges, resembling a bottleneck phenomenon. Its manifestation, although unequivocally related to bursts, may not convincingly fit into the framework of previous bottleneck-effect theories that allude to either viscous effects or buoyancy effects modifying the local energy cascade via non-local effects. The origins of burst are yet to be identified. Stratified ABL with bursts exhibits non-Kolmogorov behaviour, and hence should be modelled with caution.
36
Mutlu, Betul, Muhammad Farhan, and Israfil Kucuk. "T-Shaped Microfluidic Junction Processing of Porous Alginate-Based Films and Their Characteristics." Polymers 11, no. 9 (August 23, 2019): 1386. http://dx.doi.org/10.3390/polym11091386.
Анотація:
In this work, highly monodisperse porous alginate films from bubble bursting were formed on a glass substrate at ambient temperature, by a T-shaped microfluidic junction device method using polyethylene glycol (PEG) stearate and phospholipid as precursors in some cases. Various polymer solution concentrations and feeding liquid flow rates were applied for the generation of monodisperse microbubbles, followed by the conversion of the bubbles to porous film structures on glass substrates. In order to compare the physical properties of polymeric solutions, the effects of alginate, PEG stearate (surfactant), and phospholipid concentrations on the flowability of the liquid in a T-shaped microfluidic junction device were studied. To tailor microbubble diameter and size distribution, a method for controlling the thinning process of the bubbles’ shell was also explored. In order to control pore size, shape, and surface as well as internal structure morphologies in the scalable forming of alginate polymeric films, the effect of the feeding liquid’s flow rate and concentrations of PEG-stearate and phospholipid was also studied. Digital microscopy images revealed that the as-formed alginate films at the flow rate of 100 µL·min−1 and the N2 gas pressure of 0.8 bar have highly monodisperse microbubbles with a polydispersity index (PDI) of approximately 6.5%. SEM captures also revealed that the as-formed alginate films with high PDI value have similar monodisperse porous surface and internal structure morphologies, with the exception that the as-formed alginate films with the help of phospholipids were mainly formed under our experimental environment. From the Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements, we concluded that no chemical composition changes, thermal influence, and crystal structural modifications were observed due to the T-shaped microfluidic junction device technique. The method used in this work could expand and enhance the use of alginate porous films in a wide range of bioengineering applications, especially in tissue engineering and drug delivery, such as studying release behaviors to different internal and surface morphologies.
37
Liang, Xiangdang, Hongfei Cai, Geng Sun, Zihao Liu, Wen Chen, and Peifu Tang. "A novel method of defective vascular reconstruction using 2-octyl-cyanoacrylate and homemade prosthetic component." Chinese Medical Journal 127, no. 5 (March 5, 2014): 882–86. http://dx.doi.org/10.3760/cma.j.issn.0366-6999.20132632.
Анотація:
Background Currently, adhesive technique is popular in vascular repair but not widely used for defective vessels. This study aimed to determine the feasibility and effectiveness of repairing defective vessels with 2-octyl-cyanoacrylate and a homemade prosthetic component. Methods Homemade prosthetic component consisting of expanded polytetrofluoroethylene (ePTFE), terylene film, and homemade soluble hollow stent mixed with adhesive can replace autologous graft and suture in repairing defective vessels, can fix vessels better using the stent without occlusive bleeding. Forty male mongrel dogs were used, 20 for biomechanical tests and 20 for animal experiments. In the biomechanical test, dogs were randomly divided into two groups (n=10 each), one group repaired on the two sides of the carotid arteries with 2-octyl-cyanoacrylate and homemade component and another group repaired with suture and ePTFE. Of the 40 specimens, 10 were used for adhesive and 10 for suture specimens for tension strength test, whereas the remaining specimens were used for bursting pressure test. In animal experiments, dogs were also divided into adhesive and suture groups (n=10), only of the left carotid artery. Recording the operational time, bleeding or not. Vessels were tested using color Doppler ultrasound, the inner diameter was measured, and the degree of stenosis at 8 weeks was evaluated digital subtraction angiography (DSA) were also performed. Specimens were then analyzed histologically. Results In the adhesive and suture groups, the specimens could afford atension strength of (23.80±1.51) N versus (24.60±1.08) N (P>0.05), the bursting pressure was (52.03±2.43) kPa versus (50.04±3.51) kPa (P>0.05), and the mean time of anastomosis was (15.20±0.55) minutes versus (25.97±0.58) minutes (P <0.05). One dog in the adhesive group was bleeding from the suture. One dog from each group presented with thrombosis at 1 week. After measuring using ultrasound, the stenosis degree of all dogs were no more than 30% except the two thromboses. DSA and histological observation showed no obvious difference between the two groups. Conclusion Defective vascular anastomosis with 2-octyl-cyanoacrylate and our homemade prosthetic component is feasible, effective, timesaving, and easy to master.
38
Gücüs, Mehmet Onurhan. "Physical and surface properties of food packaging paper coated by thyme oil." BioResources 18, no. 4 (September 7, 2023): 7333–40. http://dx.doi.org/10.15376/biores.18.4.7333-7340.
Анотація:
Paper coated with natural materials has advantages over paper coated with fossil resources, including easy recycling, renewable components, and cost-effective formulation. Coating the paper surface with thyme oil has antibacterial and antioxidant properties and is known to improve packaging product quality. In the current study, the water resistance of the materials was measured by the Cobb30 values. The base paper, the starch-coated paper, and the thyme oil and starch-coated paper had Cobb30 values of 20, 17.5, and 15.7 g/m2, respectively. The tensile strength index of uncoating and coating paper samples was, respectively (machine direction M.D.) 64.3 and 64.7, and (cross direction C.D.) 32.2 and 37.2. The bursting strength index results were 72.7 and 84.0. Hence, according to the tensile strength results, the treated paper burst strength values were higher than the base paper samples. The starch and thyme oil coatings formed a film layer on the paper surface, which may have helped impart better burst-strength properties. Besides, compared to the untreated base papers, the surface of the coated papers was denser and smoother, with a less porous structure, according to SEM results. In addition, resistance features of papers that are desired in the end-use of paper are shown in this work based on paper strength property tests.
39
Cong, Li, Huang Ying, and Tan Jianping. "Boiling-condensation heat transfer and flow characteristics in ultrathin limited enclosed space based on numerical simulation and visualization experiment." Thermal Science, no. 00 (2021): 348. http://dx.doi.org/10.2298/tsci210622348c.
Анотація:
Boiling-condensation heat transfer in ultrathin flat heat pipes are complicated and difficult to observe. In this study, a visualization experiment and simulation analysis in an ultrathin limited enclosed space were carried out. Width of the ultrathin enclosed space was 1 mm, with anhydrous ethanol as the working medium. The enclosed space was oriented vertically with the heating section on the bottom and the cooling section on the top. Flow characteristics of the anhydrous ethanol were photographed using a high-speed camera through the quartz cover. The boiling-condensation heat transfer and fluid flow in the limited enclosed space were simulated. Effective heat transfer coefficient calculated based on the experimental data varied from 1.0 to 1.1 W/?C, while that of the inner wall obtained by the simulation varied within the range of 1.068-1.076 W/?C. The maximum error was 2.9%, which verified the reliability of the simulation results. By analyzing the pressure change in condensation section, it was found that the boiling-condensation heat released in the enclosed space changed periodically, because of the growth and bursting of bubbles and falling of the working medium due to gravity. Restricted by the thickness, the bubbles produced by boiling of the working medium grew in flat and irregular shapes, promoting the upward movement of the rest of the liquid working medium, and a liquid film was formed at the heated inner surface for evaporation heat transfer, which enhanced the heat transfer capacity of the heating section.
40
Mahajan, C. M., A. G. Godbole, S. P. Gumfekar, S. H. Sonawane, and M. G. Takwale. "Characterization of Transparent Conducting Al:ZnO Thin Films Deposited by Chemical Spray Pyrolysis." Advanced Materials Research 67 (April 2009): 103–8. http://dx.doi.org/10.4028/www.scientific.net/amr.67.103.
Анотація:
Nanocrystalline undoped and Al doped ZnO thin films were synthesized by the chemical spray pyrolysis of Zinc acetate and Aluminium chloride solution. The optoelectronic properties of undoped and Al:ZnO films were investigated. The XRD patterns of films were preferably oriented along c-axis [0 0 2] plane with the hexagonal wurtzite structure. The Al-doping caused no additional X-ray diffraction peaks when compared with XRD of undoped film, indicating Al2O3 content was below the detection limit. The crystallite size of undoped and Al doped film was 48 nm and 51nm respectively, as measured from X-ray diffractogram. The films are of high optical transmittance (≥ 90%). The resistivity of the film was found to decrease because of Al doping. The dark resistivity measurement for Al:ZnO film was of the order of 10-3 Ω-1cm-1. The band gap energy of the film was found to vary from 3.25 to 3.32eV indicating the Moss Burstein shift. Al:ZnO films can be used as transparent conducting oxide layers for photovoltaic applications.
41
BREMOND, N., and E. VILLERMAUX. "Bursting thin liquid films." Journal of Fluid Mechanics 524 (February 10, 2005): 121–30. http://dx.doi.org/10.1017/s0022112004002411.
42
Chowdhury, Debashish, and Dietrich Stauffer. "Bursting of soap films." Physica A: Statistical Mechanics and its Applications 186, no. 1-2 (July 1992): 237–49. http://dx.doi.org/10.1016/0378-4371(92)90379-5.
43
Burrows, S. M., O. Ogunro, A. A. Frossard, L. M. Russell, P. J. Rasch, and S. Elliott. "A physically-based framework for modelling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria." Atmospheric Chemistry and Physics Discussions 14, no. 5 (March 3, 2014): 5375–443. http://dx.doi.org/10.5194/acpd-14-5375-2014.
Анотація:
Abstract. The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely-sensed chlorophyll a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC), a polysaccharide-like mixture associated primarily with semi-labile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecules. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll a and organic fraction are similar to existing empirical parameterizations, but can vary between biologically productive and non-productive regions, and seasonally within a given region. Major uncertainties include the bubble film thickness at bursting and the variability of organic surfactant activity in the ocean, which is poorly constrained. In addition, polysaccharides may enter the aerosol more efficiently than Langmuir adsorption would suggest. Potential mechanisms for include the formation of marine colloidal particles that may be more efficiently swept up by rising particles, and cooperative adsorption of polysaccharides with proteins or lipids. These processes may make important contributions to the aerosol, but are not included here. This organic fractionation framework is an initial step towards a closer linking of ocean biogeochemistry and aerosol chemical composition in Earth system models. Future work should focus on improving constraints on model parameters through new laboratory experiments or through empirical fitting to observed relationships in the real ocean and atmosphere, as well as on atmospheric implications of the variable composition of organic matter in sea spray.
44
Burrows, S. M., O. Ogunro, A. A. Frossard, L. M. Russell, P. J. Rasch, and S. M. Elliott. "A physically based framework for modeling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria." Atmospheric Chemistry and Physics 14, no. 24 (December 19, 2014): 13601–29. http://dx.doi.org/10.5194/acp-14-13601-2014.
Анотація:
Abstract. The presence of a large fraction of organic matter in primary sea spray aerosol (SSA) can strongly affect its cloud condensation nuclei activity and interactions with marine clouds. Global climate models require new parameterizations of the SSA composition in order to improve the representation of these processes. Existing proposals for such a parameterization use remotely sensed chlorophyll a concentrations as a proxy for the biogenic contribution to the aerosol. However, both observations and theoretical considerations suggest that existing relationships with chlorophyll a, derived from observations at only a few locations, may not be representative for all ocean regions. We introduce a novel framework for parameterizing the fractionation of marine organic matter into SSA based on a competitive Langmuir adsorption equilibrium at bubble surfaces. Marine organic matter is partitioned into classes with differing molecular weights, surface excesses, and Langmuir adsorption parameters. The classes include a lipid-like mixture associated with labile dissolved organic carbon (DOC), a polysaccharide-like mixture associated primarily with semilabile DOC, a protein-like mixture with concentrations intermediate between lipids and polysaccharides, a processed mixture associated with recalcitrant surface DOC, and a deep abyssal humic-like mixture. Box model calculations have been performed for several cases of organic adsorption to illustrate the underlying concepts. We then apply the framework to output from a global marine biogeochemistry model, by partitioning total dissolved organic carbon into several classes of macromolecules. Each class is represented by model compounds with physical and chemical properties based on existing laboratory data. This allows us to globally map the predicted organic mass fraction of the nascent submicron sea spray aerosol. Predicted relationships between chlorophyll a and organic fraction are similar to existing empirical parameterizations, but can vary between biologically productive and nonproductive regions, and seasonally within a given region. Major uncertainties include the bubble film thickness at bursting, and the variability of organic surfactant activity in the ocean, which is poorly constrained. In addition, polysaccharides may enter the aerosol more efficiently than Langmuir adsorption would suggest. Potential mechanisms for enrichment of polysaccharides in sea spray include the formation of marine colloidal particles that may be more efficiently swept up by rising bubbles, and cooperative adsorption of polysaccharides with proteins or lipids. These processes may make important contributions to the aerosol, but are not included here. This organic fractionation framework is an initial step towards a closer linking of ocean biogeochemistry and aerosol chemical composition in Earth system models. Future work should focus on improving constraints on model parameters through new laboratory experiments or through empirical fitting to observed relationships in the real ocean and atmosphere, as well as on atmospheric implications of the variable composition of organic matter in sea spray.
45
Wang, Fang-Hsing, Jen-Chi Chao, Han-Wen Liu, and Tsung-Kuei Kang. "Physical Properties of ZnO Thin Films Codoped with Titanium and Hydrogen Prepared by RF Magnetron Sputtering with Different Substrate Temperatures." Journal of Nanomaterials 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/936482.
Анотація:
Transparent conducting titanium-doped zinc oxide (TZO) thin films were prepared on glass substrates by RF magnetron sputtering using 1.5 wt% TiO2-doped ZnO as the target. Electrical, structural, and optical properties of films were investigated as a function of H2/(Ar + H2) flow ratios (RH) and substrate temperatures (TS). The optimalRHvalue for achieving high conducting TZO:H thin film decreased from 10% to 1% whenTSincreased from RT to 300°C. The lowest resistivity of9.2×10-4 Ω-cm was obtained asTS=100°C andRH=7.5%. X-ray diffraction patterns showed that all of TZO:H films had a hexagonal wurtzite structure with a preferred orientation in the (002) direction. Atomic force microscopy analysis revealed that the film surface roughness increased with increasingRH. The average visible transmittance decreased with increasingRHfor the RT-deposited film, while it had not considerably changed with differentRHfor the 300°C-deposited films. The optical bandgap increased asRHincreased, which is consistent with the Burstein-Moss effect. The figure of merits indicated thatTS=100°C andRH=7.5% were optimal conditions for TZO thin films as transparent conducting electrode applications.
46
Debrégeas, G., P. Martin, and F. Brochard-Wyart. "Viscous Bursting of Suspended Films." Physical Review Letters 75, no. 21 (November 20, 1995): 3886–89. http://dx.doi.org/10.1103/physrevlett.75.3886.
47
Jayarathne, Thilina, Dilini Kirindigoda Gamage, Kimberly A. Prather, and Elizabeth A. Stone. "Enrichment of saccharides at the air–water interface: a quantitative comparison of sea surface microlayer and foam." Environmental Chemistry 19, no. 8 (March 3, 2023): 506–16. http://dx.doi.org/10.1071/en22094.
Анотація:
Environmental context Saccharides contribute substantially to dissolved organic carbon in the ocean and are enriched at the ocean surface. In this study, we demonstrate that saccharides are more enriched in persistent whitecap foam compared to the sea surface. The maturation of bubbles at the air–water interface is thus expected to enhance the enrichment of organic matter at the ocean surface and ultimately in the sea spray aerosol that forms when bubbles burst at the ocean surface. Rationale Organic matter accumulates at the ocean surface. Herein, we provide the first quantitative assessment of the enrichment of dissolved saccharides in persistent whitecap foam and compare this enrichment to the sea surface microlayer (SSML) during a 9 day mesocosm experiment involving a phytoplankton bloom generated in a Marine Aerosol Reference Tank (MART). Methodology Free monosaccharides were quantified directly, total saccharides were determined following mild acid hydrolysis and the oligo/polysaccharide component was determined as the difference between total and free monosaccharides. Results Total saccharides contributed a significant fraction of dissolved organic carbon (DOC), accounting for 13% of DOC in seawater, 27% in SSML and 31% in foam. Median enrichment factors (EFs), calculated as the ratio of the concentrations of saccharides relative to sodium in SSML or foam to that of seawater, ranged from 1.7 to 6.4 in SSML and 2.1–12.1 in foam. Based on median EFs, xylitol, mannitol, glucose, galactose, mannose, xylose, fucose, rhamnose and ribose were more enriched in foam than SSML. Discussion The greatest EFs for saccharides coincided with high chlorophyll levels, indicating increasing ocean surface enrichment of saccharides during phytoplankton blooms. Higher enrichments of organic matter in sea foam over the SSML indicate that surface active organic compounds become increasingly enriched on persistent bubble film surfaces. These findings help to explain how marine organic matter becomes highly enriched in sea spray aerosol that is generated by bursting bubbles at the ocean surface.
48
Liu, Wei-Sheng, Yu-Lin Chang, Chun-Yuan Tan, Cheng-Ting Tsai, and Hsing-Chun Kuo. "Properties of N-Type GaN Thin Film with Si-Ti Codoping on a Glass Substrate." Crystals 10, no. 7 (July 5, 2020): 582. http://dx.doi.org/10.3390/cryst10070582.
Анотація:
In this study, n-type gallium nitride (GaN) films were fabricated by a silicon–titanium (Si-Ti) codoping sputtering technique with a zinc oxide (ZnO) buffer layer on amorphous glass substrates with different post-growth annealing temperatures for optimizing the GaN crystal quality. Si-Ti-codoped n-type GaN films that were thermally annealed at 400 °C had a low thin-film resistivity of 2.6 × 10−1 Ω-cm and a high electron concentration of 6.65 × 1019 cm−3, as determined through Hall measurement. X-ray diffraction (XRD) results revealed a high (002) XRD intensity with a narrow spectral line and a full width at half maximum (FWHM) value that indicated the superior crystal growth of a hexagonal structure of the GaN thin films. In addition, photoluminescence measurement results demonstrated a near-band-edge emission at 365 nm, indicating the crystal growth of GaN thin films on glass substrates. The Burstein–Moss effect was observed in the Tauc plot results, indicating that the Fermi level inside the conduction band moves upward and thus improves the n-type properties of the GaN thin film. X-ray photoelectron spectroscopy measurement results revealed that all atoms doped into the GaN film are present and that both Si and Ti atoms bond with N atoms.
49
Brenner, Michael P., and Denis Gueyffier. "On the bursting of viscous films." Physics of Fluids 11, no. 3 (March 1999): 737–39. http://dx.doi.org/10.1063/1.869942.
50
Tseng, H. H., F. S. Lai, and C. K. Lee. "Pneumatic bursting characteristics of plastics films." Polymer Engineering and Science 33, no. 8 (April 1993): 504–12. http://dx.doi.org/10.1002/pen.760330810.