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Copyright of Journal of Petrochemical Universities / Shiyou Huagong Gaodeng Xuexiao Xuebao is the property of Journal Editorial Department Of Liaoning Shihua University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Life Sciences & Biotechnology (2651-4621) is the property of International Society of Academicians and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The nata de coco industry produces liquid waste which, if thrown directly into water bodies (rivers) without prior processing, has the potential to pollute the surrounding environment. Laboratory test results show that the parameters BOD 1145 mg/L, COD 1737 mg/L, and TSS 206 mg/l are far above the thresholds set by the government. The aim of this research is to determine the optimum conditions for fine bubble and micro bubble treatment of nata de coco liquid waste in reducing the characteristic values of nata de coco liquid waste. This research was carried out using experimental methods with test samples of 40 liters and 60 liters. Data collected through direct observation includes DO, TDS, pH, temperature whit measured every 2 hours, while data collected through laboratory testing of BOD, COD and TSS which are tested every 12 hours and 24 hours. The data was then processed using the Taguchi method with the aim of optimizing the fine bubble treatment for changes in the characteristics of nata de coco liquid waste. The research results showed that the optimum conditions were found in the fine bubble treatment with an aeration period of 24 hours and a volume of 40 liters. The best percentage reduction in BOD was found to be 94% or 68 mg/L. COD reduction obtained the best percentage reduction of 93% and/or became 121 mg/L and TSS obtained the best percentage reduction of 69% or became 77 mg/L. These results are in accordance with the Regulation of the Minister of Environment of the Republic of Indonesia Number 5 of 2014 concerning Wastewater Quality Standards. [ABSTRACT FROM AUTHOR]

We confirmed that bubble-surrounded cells (BSCs) contained in flow were retained on the walls of an artificial blood vessel by forming an acoustic field with multiple focal points using tempo-spatial division emission. In order to realize the cell delivery system, we investigated the relationship between the concentration of T-cells and brightness in the microscopic images. Next, we defined the applied acoustic intensity, derived from the sound pressure distribution of every type of acoustic field. We studied the retention performance of BSCs versus various flow velocities, number and spatial intervals of the focal points, and maximum sound pressure. From the results, the optimal acoustic field to retain the cells depends on both acoustic intensity and flow velocity, where multiple focal points with an acoustic intensity of 50–120 mW cm−2 were more effective than the single focal point with 180 mW cm−2 in the range of a flow velocity of 10–20 mm s−1. [ABSTRACT FROM AUTHOR]

In this paper, the bubbly flow characteristics of a Venturi channel was revealed by using the population balance model (PBM) within the framework of computational fluid dynamics (CFD) numerical simulation and focused on the bubble size distribution and pressure drop △P of different regions. The simulation results indicated that bubble breakup mainly occurred in the diverging section of the Venturi channel, and the average diameter of the daughter bubbles davg in the sidewall region was much smaller than that in the central region. Through the correlational analysis between the bubble size distribution and turbulent flow field, the bubble breakup in the diverging section was positively related to the turbulent flow. Considering the influence of geometric parameters on davg and △P, the davg decreased and △P increased with the increasing of the diverging angle β. As the throat diameter D increased, the davg increased and △P decreased gradually. In order to quantify the bubble breakup characteristics, the concept of bubble breakup ratio τ is introduced and defined as the ratio of inlet average bubble diameter di to the outlet average bubble diameter do. Through dimensionless transformation, the fitting relationship between τ or △P and angle ratio a was Sinusoidal function (SINE), respectively, and was Boltzmann with the throat length‐diameter ratio b. Due to the relationship of first‐order linear function between τ and △P, the bubble breakup ratio can be obtained by measuring the pressure drop of the Venturi tube, which was significant to the practical engineering application. [ABSTRACT FROM AUTHOR]

Biological wastewater treatment plants (WWTPs) produce large amounts of excess sludge. One approach to reduce sludge is treatment with ozone, which promotes sludge disintegration and solubilization. Here we report the first application of ultra-fine- and micro-bubble (UFB/MB) ozonation to sludge reduction in a full-scale WWTP. UFB/MB ozonation using a spiral liquid-type UFB generator was applied to concentrated excess sludge in the storage tank instead of to return sludge. At an ozone dose of 15 mgO3 gSS–1, a 92% reduction in sludge accumulation rate was achieved during a 237-day ozonation period with ozonation relative to a 100-day no ozonation period without ozonation. This reduction was larger than expected, and was partly due to a 20–30% greater average concentration of suspended solids in the influent during the no ozonation period. Addition of UFB/MB ozonation to the existing activated sludge process did not reduce the water quality in the effluent. We can conclude that UFB/MB ozonation for concentrated excess sludge in the storage tank using a spiral liquid-type UFB generator remarkably reduced the ozone dose required to sludge reduction by more than half of the reported conventional ozonation (30–150 mgO3 gSS–1) without the negative impact on effluent water quality. [ABSTRACT FROM AUTHOR]

The tiny bubbles with diameters less than 1 m are called ultrafine bubbles (UFB). And the application of UFB in agriculture, fishery and environment is highly anticipated. In this study, the changes in the properties of oxygen, 5% hydrogen (95% nitrogen), and nitrogen UFBs were investigated with droplet formation. The UFB water was ejected through the orifice nozzle (diameter: 280pm) and formed tiny droplets. Particularly in the case of oxygen UFB, a change in the distribution of the bubble size was observed. We observed higher microbubble concentration and smaller bubble size below 50pm in the sprayed UFB water compared with in the control distilled water. The distribution of oxygen UFB itself changed before and after spraying, and its diameter tended to be larger. In addition, its water contained more MB, which resulted in a higher cleaning effect. [ABSTRACT FROM AUTHOR]

The use of fine bubbles is a promising approach to remove surfactant efficiently during the rinsing process of clothing, to fulfill a requirement. Therefore, the influence of fine bubbles on the removal performance of surfactant from cloth during the rinse process of pulsator washing machine (top loading type) was investigated. The test apparatus was assembled by connecting a microbubble generation tank and a small washing machine with tubes and circulating fine bubble water to a small washing machine. Swatches of cloth with a specified amount of linear alkylbenzene sulfonate (LAS) adsorbed from aqueous solution, were rinsed with tap water, and the LAS concentration in the rinse water was examined with an HPLC system equipped with a high‐precision fluorescence detector. The average bubble diameter of the fine bubble water used was 0.13–1.4 μm. In the rinsing experiment, no difference was found in the final LAS removal efficiency between water with and without bubbles; but the former increased the LAS removal rate during the initial stage of rinsing. This tendency was particularly noticeable when the stirring power of the washing machine was weak. Therefore, it was concluded that the fine bubble effect on the removal of the surfactant is mainly a kinetic effect rather than an equilibrium effect. [ABSTRACT FROM AUTHOR]

Micro bubbles measuring tens of micrometers or less in diameter have recently been paid much attention. Swirl-type, pressurizing dissolution, and perforated plate methods have been proposed for micro bubble generation. The swirl-type method can generate micro bubbles even under low-pressure power in a simple structure. The enlarged inlet diameter of the swirl chamber can reduce the average bubble diameter. This study examined the effect of the swirl chamber inlet diameter on the flow around chamber outlet in a swirl-type micro bubble generator by numerical analysis. The Inlet diameter of the swirl chamber was changed to 30 mm, 60 mm, and 90 mm, the flow velocity distribution and the wall shear stress around the chamber outlet were calculated. As a result, when the inlet diameter of the swirl chamber was enlarged, it was clarified that the circumferential flow velocity and the wall shear stress around the chamber outlet increased, which reduced the average bubble diameter. [ABSTRACT FROM AUTHOR]

Micro bubbles measuring tens of micrometers or less in diameter have recently been paid much attention. Swirl type, pressurizing dissolution, and perforated plate methods have been proposed for micro bubble generation. The swirl type method can generate micro bubbles even under low-pressure power in a simple structure. This study examined the effect of the swirl chamber inlet diameter on the bubble diameter in a swirl type micro bubble generator. The swirl chamber inlet diameter was varied in the range of 15-90 mm and the effect was examined. In order to clarify the effect of enlarged inlet diameter, the micro bubbles diameter was measured under changing water supply pressure and air flow rate, the behavior of air column in the swirl chamber was visualized, and the velocity distribution around outlet of swirl chamber was measured. As a result, when the swirl chamber inlet diameter was enlarged, the outflow form changed from an axial outflow to a radial outflow. The average bubble diameter could also be reduced. An average bubble diameter of 28 -m could be realized under the conditions of swirl inlet diameter of 90 mm and water supply pressure of 0.1 MPa gage. [ABSTRACT FROM AUTHOR]

The method of micro bubbles is widely applied in the fields of water and soil treatment. A novel treatment method of NO in flue gas through a gas–liquid two-phase system formed by micro bubbles is proposed in this study. The system depends on the generation of hydroxyl radicals. The NO removal performance of the micro gas–liquid dispersion system induced by catalysts and O3 was explored and the reaction pathways were elucidated. Micro bubbles, Fe2+, and Mn2+ in solution improved NO removal performance significantly. Salinity and surfactants affected the removal performance of NO by altering micro bubbles. In the presence of Fe2+, the NO removal rate reached 65.2% at pH 5, 75.8% under 0.5 g/L NaCl and 82.1% under 6 mg/L sodium dodecyl sulfate. In the presence of Mn2+, the NO removal rate reached 69.2% at pH 5, 83.2% under 0.5 g/L NaCl and 92.3% under 6 mg/L sodium dodecyl sulfate. However, in the presence of both Mn2+ and Fe2+, NO conversion rate was 93.2%. The NO removal rate in the presence of O3 was further improved under the same conditions. The study provides the basis for the application and development of micro bubbles in flue gas treatments for NO removal. The results can help to solve the problems of high operating cost, large oxidant consumption, secondary pollution, and high energy consumption in traditional NO removal methods. [ABSTRACT FROM AUTHOR]

Enhanced oil recovery (EOR)and improved oil recovery (IOR) technologies have been applied to various oil and gas fields for many years. However, the environment for EOR/IOR has been severe in low oil price and increase of development cost and more effective and economical EOR technology is expected. We focused the application of micro bubble as cutting-edge EOR technology. Micro bubble technology has been applied to various industries as medical, agriculture and environment fields. And micro bubble has some characteristics in relative to the effect of EOR such as improvement of sweep efficiency and oil density and viscosity. We have studied about the efficiency of micro bubble technology and its mechanism from laboratory test and flow simulation. We evaluated the improvement of the sweep efficiency, solubility to oil and oil recovery by micro bubble injection from core flooding test which was one of the laboratory tests and it was indicated that the capillary pressure affected the injection area from flow simulation. We expect micro bubble technology will become useful as new EOR technology from our study. [ABSTRACT FROM AUTHOR]

Electrical discharge machining (EDM) is the process of removing a material by means of electrical discharge inside an insulating working fluid. The material is melted by the discharge and is blown off by the vaporizing explosion of the working fluid. Expansion and contraction of the insulated fluid bubbles affect the process of removing a material. The stronger the vaporizing explosion, the larger is the quantity of material removed and the worse is the surface roughness, and vice versa. The power of the vaporizing explosion is determined by the input energy and quantity of material removed is determined by the power of the vaporizing explosion. Recently, there have been some studies on micro bubbles that are 50 μm or less in diameter. Micro-bubbles possess special characteristics, such as an increased interior gas pressure and increased ion concentration around the gas–water interface. We considered changes in the characteristics of EDM by using a fluid mixed with micro bubbles. The vaporizing explosion was considered to be weakened by using fluid containing micro-bubbles, and the surface roughness seemed to improve Therefore, we performed EDM using pure water and micro-bubble mixed fluid, and researched the characteristics of EDM. Initially, We were expecting a change in the machining removal rate. Indeed, in oil dielectric fluid, there was no change, and there was little difference with the machining rate achieved using pure water dielectric fluid. However, a clear difference was observed in terms of the skewness (Rsk) of surface roughness. In this paper, this difference is described as a change in surface roughness in micro-bubble mixed EDM. [ABSTRACT FROM AUTHOR]

Hypothesis The effects of varying carbon chain lengths (CCLs) and concentrations of aqueous solutions of imidazolium based ionic liquids on bubble particle attachment (BPA) will provide a better understanding in catering for the varying degrees of surface activities in the application of the flotation technology. The general trends of this study should also be applicable to homologous series of other cationic surfactants and ionic liquids. Experiments Zeta potentials of small air bubbles and bunker oil drops dispersed in aqueous solutions of n -methylimidazolium chloride ionic liquids (n = 0, 2, 3, 6, 8, 10, 12) of concentrations ranging from 1000 PPM to 8000 PPM, as were interfacial tensions of these solutions with bunker oil (180 cst) and contact angles made by air bubbles at interfaces between these solutions and thin layers of bunker oil on flat solid surfaces were investigated. Finally, interparticle forces analysis using the Derjaguin-Landau, Verwey-Overbeek (DLVO) theory is also included. Findings Analysis using the DLVO theory showed attractive forces between the oil particles and micro-bubbles are significantly more prevalent in short CCLs solutions of imidazolium-based ILs in low concentrations, namely [C 0 mim][Cl] and [C 2 mim][Cl] at a maximum zeta potential difference of 75.3 mV. The results from CA measurements follows similarly whereby low concentrations of ILs with short CCLs were in favor for the bubble-particle attachment process with angles ranging between 93.95° for [C 0 mim][Cl] and 97.28° for [C 2 mim][Cl]. IFT which is important in reducing coalescence for the preferential BPA process to occur in flotation decreases with an increase of CCL and concentration of IL. [ABSTRACT FROM AUTHOR]

Gas embolisms can hinder blood flow and lead to occlusion of the vessels and ischemia. Bubbles in microvessels circulate as tubular bubbles (Taylor bubbles) and can be trapped, blocking the normal flow of blood. To understand how Taylor bubbles flow in microcirculation, in particular, how bubbles disturb the blood flow at the scale of blood cells, experiments were performed in microchannels at a low Capillary number. Bubbles moving with a stream of in vitro blood were filmed with the help of a high-speed camera. Cell-free layers (CFLs) were observed downstream of the bubble, near the microchannel walls and along the centerline, and their thicknesses were quantified. Upstream to the bubble, the cell concentration is higher and CFLs are less clear. While just upstream of the bubble the maximum RBC concentration happens at positions closest to the wall, downstream the maximum is in an intermediate region between the centerline and the wall. Bubbles within microchannels promote complex spatio-temporal variations of the CFL thickness along the microchannel with significant relevance for local rheology and transport processes. The phenomenon is explained by the flow pattern characteristic of low Capillary number flows. Spatio-temporal variations of blood rheology may have an important role in bubble trapping and dislodging. [ABSTRACT FROM AUTHOR]