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Surface tension isotherms and calculated air-water interfacial (AWI) adsorption data are presented for solution mixtures of per- and polyfluoroalkyl substances (PFAS), specifically a series of binary and one ternary mixtures of homologous linear perfluorocarboxylic acids (PFCAs) in a simulated groundwater, and two 8-component mixtures containing both PFCAs and linear perfluoroalkane sulfonates (PFSAs). In all cases, non-ideal competitive adsorption was observed that favored the most surface-active component(s) of the solution mixture. The multi-component extended Langmuir (EL) isotherm model was observed to accurately predict the competitive adsorption observed in the binary and ternary PFCA solution mixtures. However, the predictive utility of the EL model was observed to diminish when mixtures contained both PFCAs and PFSAs, which differ in their hydrophile structure, resulting in overpredictions and underpredictions of the AWI adsorption isotherms derived from measured data depending on the specific components present in the solution mixtures. Observations indicate that the individual component adsorptive affinities for the AWI can change in response to competitive preferential adsorption as their solution concentrations increase that is not being captured by the EL model. Our results demonstrate that alternative mathematical models are needed that support concentration dependent affinity coefficients for non-similar mixtures of PFAS, such that the transport of individual target PFAS components within a larger mixture of components can be accurately predicted across a wider range of solution concentration.

Nature has created photonic structures in cells and assembled them to make photonic layers for a living. Inspired from nature, we design amphiphilic photonic tiles and assemble them at air-water interface to compose highly reconfigurable photonic layers. The photonic tiles are prepared by photolithographically defining the shape of the disc using a photocurable dispersion of repulsive particles. The tiles are further treated by directional dry etching to selectively render top and side surfaces of the discs hydrophobic. The amphiphilic photonic tiles deform the air-water interface by gravity, which causes a strong attractive force driven by capillarity. Therefore, the tiles form two-dimensional (2D) dense-packing, which rapidly adapts dynamic fluctuation and shape change of the interface, providing highly reconfigurable photonic layers. In addition, the assembly can be transferred into target solid surfaces through the Langmuir-Blodgett method to make photonic coatings. Moreover, the amphiphilic tiles can be assembled on the surface of water drops, forming a photonic shell on liquid marbles which resembles photonic structures in nature. We believe that our strategy based on a 2D tile assembly at the free interface will provide a simple yet useful means to create photonic layers on various purposes.

Air–water gas exchange velocities (k) are critical components of many biogeochemical and ecological process studies in aquatic systems. However, their high spatiotemporal variability is difficult t ...

[EN] Filling and emptying processes are common maneuvers while operating, controlling and managing water pipeline systems. Currently, these operations are executed following recommendations from technical manuals and pipe manufacturers; however, these recommendations have a lack of understanding about the behavior of these processes. The application of mathematical models considering transient flows with entrapped air pockets is necessary because a rapid filling operation can cause pressure surges due to air pocket compressions, while an uncontrolled emptying operation can generate troughs of sub-atmospheric pressure caused by air pocket expansion. Depending on pipe and installation conditions, either situation can produce a rupture of pipe systems. Recently, reliable mathematical models have been developed by different researchers. This paper reviews and compares various mathematical models to simulate these processes. Water columns can be analyzed using a rigid water column model, an elastic water model, or 2D/3D CFD models; air-water interfaces using a piston-flow model or more complex models; air pockets through a polytropic model; and air valves using an isentropic nozzle flow or similar approaches. This work can be used as a starting point for planning filling and emptying operations in pressurized pipelines. Uncertainties of mathematical models of two-phases flow concerning to a non-variable friction factor, a polytropic coefficient, an air pocket sizes and an air valve behavior are identified., This work was supported by the Program Fondecyt Regular (Chile) [Project 1180660]; Fundacion Centro de Estudios Intedisciplinarios Basicos y Aplicados, CEIBA (Colombia).

Self-propulsion of magneto-elastic composite microswimmers is demonstrated under a uniaxial field at both the air-water and the water-substrate interfaces. The microswimmers are made of elastically linked magnetically hard Co-Ni-P and soft Co ferromagnets, fabricated using standard photolithography and electrodeposition. Swimming speed and direction are dependent on the field frequency and amplitude, reaching a maximum of 95.1 μm/s on the substrate surface. Fastest motion occurs at low frequencies via a spinning (air-water interface) or tumbling (water-substrate interface) mode that induces transient inertial motion. Higher frequencies result in low Reynolds number propagation at both interfaces via a rocking mode. Therefore, the same microswimmer can be operated as either a high or a low Reynolds number swimmer. Swimmer pairs agglomerate to form a faster superstructure that propels via spinning and rocking modes analogous to those seen in isolated swimmers. Microswimmer propulsion is driven by a combination of dipolar interactions between the Co and Co-Ni-P magnets and rotational torque due to the applied field, combined with elastic deformation and hydrodynamic interactions between different parts of the swimmer, in agreement with previous models.

Development of new methods for producing large-area nanocrystals with specific shapes is crucial for advancements in various fields. In this study, submillimeter-sized sheet-structured gold crystals with nanoscale thicknesses were fabricated by chemical reduction of HAuCl4 in the presence of long-chain amidoamine-derived surfactants (CnAOH; n = 12, 14, 16, or 18) in aqueous solutions. Using the C18AOH system at 30 °C, large-area sheet-structured crystals with widths of ∼100 μm and thicknesses of 30 nm were effectively obtained at the air/water interface. The crystal size depended on the temperature and the alkyl-chain length of the surfactant. An investigation of the relationship between the crystal growth and the interfacial properties of CnAOH revealed that large-area crystals were obtained when densely packed molecular layers of long-chain CnAOH were formed at the air/water interface. The interfacial molecular layer of C18AOH showed most effective soft-templating effect and contributed in promoting the...

Particle size and chemistry determine surface segregation in colloidal assemblies, leading to unique control of structural colors., Surface segregation in binary colloidal mixtures offers a simple way to control both surface and bulk properties without affecting their bulk composition. Here, we combine experiments and coarse-grained molecular dynamics (CG-MD) simulations to delineate the effects of particle chemistry and size on surface segregation in photonic colloidal assemblies from binary mixtures of melanin and silica particles of size ratio (Dlarge/Dsmall) ranging from 1.0 to ~2.2. We find that melanin and/or smaller particles segregate at the surface of micrometer-sized colloidal assemblies (supraballs) prepared by an emulsion process. Conversely, no such surface segregation occurs in films prepared by evaporative assembly. CG-MD simulations explain the experimental observations by showing that particles with the larger contact angle (melanin) are enriched at the supraball surface regardless of the relative strength of particle-interface interactions, a result with implications for the broad understanding and design of colloidal particle assemblies.

There has been a recent surge of interest in the use of food-grade nanoparticles (NPs) for stabilizing food foams and emulsions. Cereal proteins are a promising raw material class to produce such NPs. Studies thus far have focused mostly on wheat gliadin and maize zein-based NPs. The former are effective interfacial stabilizing agents, while the latter due to their high hydrophobicity generally result in poor interfacial stability. Several strategies to modify the surface properties of wheat gliadin and maize zein NPs have been followed. In many instances, this resulted in improved foam or emulsion stability. Nonetheless, future efforts should be undertaken to gain fundamental insights in the interfacial behavior of NPs, to further explore NP surface modification strategies, and to validate the use of NPs in actual food systems. ispartof: Current Opinion in Food Science vol:25 pages:19-27 status: published

From simultaneous air and water polychlorinated biphenyl (PCB) measurements collected in September 2010, we re-evaluated the direction and magnitude of net air-water exchange of PCBs in southwest Lake Michigan and compared them with estimations made using similar approaches 15 years prior. Air and water samples were collected during a research expedition on Lake Michigan at 5 km off the coast of Chicago, with prevailing winds from the southwest of our location. Gas-phase ΣPCB concentrations ranged from 190 to 1100 pg m(−3) with a median of 770 pg m(−3), which is similar to the concentrations measured in the City of Chicago at the same time and similar to concentrations measured in this part of the lake over the last 20 years. Water dissolved-phase ΣPCB concentrations ranged from 150 to 170 pg L(−1) with a median of 160 pg L(−1), which is one-tenth of that measured in the 1990s. ΣPCB net fluxes showed a slightly absorptive behavior, with a median of (−) 21 ng m(−2) d(−1) and an interquartile range of (−) 47 to (+) 5 ng m(−2) d(−1), where (−) and (+) fluxes indicate absorption and volatilization, respectively. Airborne PCB concentrations were higher when the winds were coming from Chicago and drive the deposition. Our fluxes are not significantly different from estimations from 1994 and 1995, and suggest that absorption of PCBs into the waters is slightly more prevalent than 15 years ago. It was confirmed that Chicago remains an important atmospheric source of PCBs to Lake Michigan.

Advanced nuclear power plants are equipped with passive systems for emergency decay heat removal from reactor equipment (PEHRSs) in case of development of accidents accompanied with primary cooling circuit leakage and for transferring heat to the final heat absorber (ambient air). Here, intensity of heat dissipation to air from the heat exchanger outer surface achieved by buoyance induced natural convection is extremely low, which necessitates the need to expand heat conductivity surfaces and to apply different types of heat transfer intensifiers (grooves, ribs and extended surfaces, positioning at higher altitudes, etc.). Intensity of heat removal is also strongly dependent on the ambient air temperature (disposable temperature head). Construction of nuclear power plants in countries with high ambient temperatures (Iran, Bangladesh, Egypt, Saudi Arabia and others) with characteristic high level of ambient air temperature imposes additional requirements on the expansion of heat exchange surfaces. Results of experimental investigation of intensification of heat exchange by low energy-intensity ultrasound supply of super-small liquid droplets (size ~3 mm) in the cooling air are provided in the present paper. In such case, transfer of heat between the cooled surface and cooling airflow involves the following three physical effects: convection, conductive heat exchange and evaporation of water droplets. The latter two effects weakly depend on the ambient air temperature and ensure active heat removal in any type of situation. Investigation was performed using high-precision calorimeter with controlled rate of heat supply (between 7800 and 12831 W/m2) imitating heated surface within the range of Reynolds numbers from 2500 to 55000 and liquid (water) flow rates from 23.39 to 111.68 kg/m2·h-1. The studies demonstrated that presence of finely dispersed water results in significant increase of heat transfer compared with the case of application of purely air-cooling. With fixed heat flow energy efficiency increases with increasing concentration of water reaching the values in excess of 600 W/m2·degree-1, which is 2.8 times higher than for the case of air-cooling. Application of the suggested technology for intensification of heat exchange in dry cooling towers of nuclear and thermal power plants used in the conditions of hot and extreme continental climate is possible subject to further investigation for the purpose of specification of optimal ranges of heat exchange intensification. © 2019 Obninsk Institute for Nuclear Power Engineering, National Research Nuclear University 'MEPhI'. All rights reserved.

In the present work, the detailed mathematical model of a dual air/water solar collector (DAWC) has been developed and experimentally verified. To demonstrate the application of the DAWC, three buildings with different energy performance levels and three building locations were chosen in analyzed case studies. Four solar collector systems were compared with one another. The solar yield of the described systems was determined by simulation using the detailed theoretical model of DAWC. The results indicate that in the case of combining a domestic hot water preparation system and recirculating-air heating system based on DAWC, it is possible to achieve up to 30% higher solar energy yield compared to a conventional solar domestic hot water preparation system dependent on climate and building performance.

In this paper the authors analysed the impact of the calculation method of the partial load conditions and the accuracy of the energy demand profile on the simulation results of the air/water heat pump operation supplying the heating system. All the analyses results were compared to the results acquired for the real installation of the air/water heat pump located in Poland. The authors assessed the inaccuracy of the unit’s efficiency estimation resulting from the simplified thermal load profile of the air/water heat pump. It has been showed that using the monthly energy demand as the input data gives satisfactory results. Inaccuracy of the monthly simulation results in relation to simulations carried out on the actual hourly energy demand by no more than 7% is acceptable. On average, this deterioration did not exceed 3%.

The air water mix is a major concern for the environmental application. This paper proposes an experimental method to accede simultaneously at the water flow velocity field and at the void fraction. Instantaneous and mean fields, as well as the evolution with the flow parameters variation are obtained in cavitation or aerated flows. This method allows a good accuracy for the flow velocity fields (2%) and void (vapours or air) contours (4%).

Pressure fluctuation in single-phase pumps has been studied widely, while less attention has been paid to research on multiphase pumps that are commonly used in the petroleum chemical industry. Therefore, this study investigates the pressure fluctuation for a multiphase rotodynamic pump handling air–water two-phase flow. Simulations based on the Euler two-fluid model were carried out using ANSYS_CFX16.0 at different Inlet Gas Void Fractions (IGVFs) and various flow rate values. Under conditions of IGVF = 0% (pure water) and IGVF = 15%, the accuracy of the numerical method was tested by comparing the experimental data. The results showed that the rotor–stator interaction was still the main generation driver of pressure fluctuation in gas–liquid two-phase pumps. However, the fluctuation near the impeller outlet ascribe to the rotor–stator interaction was weakened by the complex gas–liquid flow. For the different IGVF, the variation trend of fluctuation was similar along the streamwise direction. That is, the fluctuation in the impeller increased before decreasing, while in the guide vane it decreased gradually. Also, the fluctuation in the guide vane was generally greater than for the impeller and the maximum amplitude appeared in the vicinity of guide vane inlet.

[EN] Emptying pipelines can be critical in many water distribution networks because subatmospheric pressure troughs could cause considerable damage to the system due to the expansion of entrapped air. Researchers have given relatively little attention to emptying processes compared to filling processes. The intricacy of computations of this phenomenon makes it difficult to predict the behaviour during emptying, and there are only a few reliable models in the literature. In this work, a computational model for simulating the transient phenomena in single pipes is proposed, and was validated using experimental results. The proposed model is based on a rigid column to analyse water movement, the air¿water interface, and air pocket equations. Two practical cases were used to validate the model: (1) a single pipe with the upstream end closed, and (2) a single pipe with an air valve installed on the upstream end. The results show how the model accurately predicts the experimental data, including the pressure oscillation patterns and subatmospheric pressure troughs., This study was supported by the Program Fondecyt Regular [Project 1180660] of the Comision Nacional de Investigacion Cientifica y Tecnologica (Conicyt), Chile, http://data.crossref.org/fundingdata/funder/10.13039/501100002848.

Introduction: All-ceramic restorations are being widely used due to its various advantages. However, they have restricted durability and may have to be removed. The conventional procedure for removal is grinding the restoration with rotary instruments which are considered time-consuming and inconvenient. A newer advantageous method is the application of lasers for debonding ceramics from the tooth surface. The objective of this study is to provide a comprehensive literature review on laser-aided ceramic restorations debonding. Methods: We searched PubMed and Google Scholar databases. Seven articles from 2011 to 2018 were identified. Studies were assessed for the efficacy of laser application and the amount of pulpal temperature rise. Results: Studies selected were categorized according to variables including shear bond strength, debonding time and intrapulpal temperature. Oztoprak and Iseri investigated that erbium-doped yttrium, aluminum, and garnet (Er:YAG) laser application reduced shear bond strength of ceramic laminate veneers. The time of debonding took an average of 190 seconds in Rechmann’s study and 106 seconds in Morford’s study. One of the main issues while using the laser is thermal irritation of the pulp. A 5.5°C temperature increase may cause pulpal damage according to Zach and Cohen. Philips et al and Rechmann et al reported no intrapulpal harm due to temperature increase. Additionally, Phillips et al demonstrated that the laser setting affects both the debonding time and the temperature alterations and that a laser adjustment of 2.5 W/25 Hz would be the best safest group. Conclusion: Removal of ceramic crowns and veneers from tooth surfaces can be successfully done by Er:YAG laser application in a less time-consuming procedure and without any harm to the underlying dentin. However, a temperature rise in the pulp may occur which could be overcome by adequate air water cooling.

International audience; A two-phase liquid pumping test ring is built to study the flow induced characteristics of centrifugal pump under the air-water flow working condition. Pump performances are measured under different flow rates and different inlet air void fraction (a). Pressure pulsation signal spectrums and their probability density maps are also recorded. The calculations, using URANS k-epsilon turbulence model combined with the Euler-Euler inhomogeneous two-phase model, are also performed to obtain inner flow structure inside the impeller and volute channels under different air-water conditions in order to understand the pump characteristic evolutions. The results show that the performance of centrifugal pump is more sensitive to air inlet injection at low flow rates. The maximum air void fraction of model pump could reach 10% when the pump operates at the highest efficiency point, and the performance drops sharply when the air void fraction is more than 8%. The dominant frequency of pump outlet pressure pulsation is still at the blade passing frequency even under two-phase condition. Frequency amplitude increases with the increase of a. The greater the a, the more low frequency appears in broadband characteristics. With the increase of a, the probability density amplitude of pressure pulsation decreases gradually, and its span becomes gradually wider as well. Comparisons between numerical local results, experimental unsteady pressure can explain part of the phenomena that are found in the present paper.

The operation of an air-to-water heat pump system providing space heating production for an administrative building in Varna has been explored. For this purpose, discontinuous operational mode of the heat pump system during wintertime is considered. Study has been performed by use of real values for external ambient temperature and operating characteristics of the heat pump system. The seasonal efficiency of the heat pump operation has been calculated. Also, the minimal external ambient temperature until the heat pump may work in heating regime and operation duration at outdoor air temperatures higher than the design air temperature can be determined. The economic analysis of the heat pump system exploitation has been made finally.

Two-phase flow rate measurement is extremely important in many industrial sectors (nuclear, chemical, oil and gas, etc.). Nevertheless, the instrumentation required to perform these measurements is still very limited despite the huge research efforts during the last years. In the frame of the development of instrumentation for the two-phase flow rate measurement, the main aim of this study is the characterization of a spool piece consisting of a Venturi Flow Meter, and two Electric Capacitance Probes mounted in a horizontal test section, where an air-water two phase flow occurs. The probes response is analyzed versus superficial velocities of liquid and gas, flow patterns and void fraction. The test section consists of a nominal ID 80 mm horizontal transparent pipe equipped with a Venturi Flow Meter, a new capacitance probe with concave electrodes and a SIET designed electrical capacitance probe with ten long linear electrodes. In this experimental campaign, the air flow rate is in the range 0.048-0.119 kg/s (superficial velocity from 8 to 19 m/s) and the range of water flow rate is 0.0040-0.0535 kg/s (superficial velocity from 0.0006 m/s to 0.0103 m/s). These ranges of superficial velocities correspond to wavy stratified and annular-dispersed flow patterns along the test section.

To improve the cooling performance for the future generation of gas-cooled equipment, experimental studies on air/water mist heat transfer of single sphere inside a cylindrical channel have been carried out with an aim to investigate the heat transfer enhancement by suspending tiny water mist into air flow. The effect of the different key factors such the inlet Reynolds number, surface heat flux and water flux density on friction flow and heat transfer characteristics are examined. Experiments were performed in five cases using air as well as air/water mist two phase flow as working coolant for range of water flux density (j = 23.39-111.68 kg m-2 hr-1). The results obtained from the related experimental work revealed that the presence of water mist leads to a significant increase in heat transfer over the use of air coolant alone. The Nusselt numbers are respectively 1%, 19.7%, 90.2% and 134% higher than those in single phase-cooling for all cases of water flux density respectively. It was also found that the water flux density has little influence on friction factor. When the surface heat flux is fixed, the heat transfer enhancement factor increases with the increasing of water flux density. © Published under licence by IOP Publishing Ltd. The work was supported by Act 211 02.A03.21.0006

Upward two-phase flow in two different vertical narrow gaps was investigated experimentally. For better understanding the characteristics of air-water flow in rectangular channels, the visual images were captured through high-speed cameras and the void fraction results were obtained through three impedance void meters. The flow pattern was identified through ReliefF-FCM clustering algorithm to avoid the subjectivity of human observation. The flow regime maps were plotted in two different forms, superficial velocities and void fraction and compared with the previous model in the open literature. Through the analysis of the experimental results, the air-water flow in narrow rectangular channels is characterized by the limitation of bubble distribution, coalescence and movement. The probability of bubble coalescence in narrow rectangular channels is increased compared with those in conventional channels due to the restriction of the narrower side walls. New transition criteria was obtained according to the drift-flux model and the force balance analysis which shows satisfactory agreements with existing experimental data for gaps of 1–6 mm.

The treatment of wastewaters containing hazardous volatile organic compounds (VOCs) requires the simultaneous treatment of both water and air. Refractory toluene, extensively studied for its removal, provides a basis for the comparison of its abatement methods. The oxidation of aqueous toluene by gas-phase pulsed corona discharge (PCD) in combination with the subsequent photocatalytic treatment of exhaust air was studied. The PCD treatment showed unequalled energy efficiencies in aqueous and gaseous toluene oxidation, reaching, respectively, up to 10.5 and 29.6 g·kW−1·h−1. The PCD exhaust air contained toluene residues and ozone in concentrations not exceeding 0.1 and 0.6 mg·L−1, respectively. As a result of the subsequent photocatalytic treatment, both airborne residues were eliminated within a contact time with TiO2 as short as 12 s. The results contribute to the possible application of the studied approach in closed-loop energy-saving ventilation systems.

The main research content of this project is the water recovery efficiency of the hot-pressure-driven air water-taking device when the phase-change material is used for energy supply, and combined with the research process, an automatic water-taking device using desert temperature difference and phase-change material storage is designed. At a time when energy sustainability is of great concern, we must make the development of green energy a core goal. Among them, solar energy as a green non-polluting new energy, its development and utilization is an important research topic and direction. The desert areas have plenty of solar energy and enough temperature differences to take advantage of these two resources and combine the lack of fresh water in the area. The purpose of this project is to design a device that uses phase-change materials to store heat to provide heat pressure, guide air directional flow, and use high-efficiency coaxial water collection sails for air water collection, with less human and material input, to obtain the fresh water necessary for life. And from the theoretical and physical level to demonstrate its feasibility, explore the direction of marketing.

This paper provides a justification for the assessment of the effectiveness of the use of air-water heat pumps in the heating systems of individual residential buildings in conjunction with the water boiler. The criterion for the cost-effectiveness of the heating system with a combined heat source is the relative cost of equipment and operation of the system, given to the duration of the heating period. Cost components are presented in the form of a system of equations reflecting the dependence of the price parameters of heating system equipment on thermal characteristics. The proposed method of assessing the benefits of renewable energy is applicable to different climatic areas.

International audience; Rapeseed protein isolate has promising functional properties (e.g. emulsifying and foaming), but is often extracted with intensive purification steps. This requires a considerable use of resources and damages protein functionality regarding, for instance, foam stabilization. We studied the interfacial and foaming properties of a mildly obtained rapeseed protein concentrate that contained oleosomes, and of its derived defatted rapeseed protein concentrate after solvent-based defatting. The air-water interfaces were deformed with large amplitude dilatational and shear deformations, which were analysed with Lissajous plots. At low bulk concentrations (0.01% w/w), the rapeseed protein-stabilised interfaces behaved as viscoelastic solids. The interfacial films became weaker and more stretchable at higher concentrations, suggesting that more non-protein components interfere with the intermolecular interactions between the adsorbed proteins at higher bulk concentrations. We confirmed the presence of such non-protein components at the interface by analysing Langmuir-Blodgett films with atomic force microscopy. The stability and air bubble size of foams prepared with either rapeseed protein concentrate or defatted rapeseed protein concentrate were similar. Mild purification of rapeseed resulted in a protein concentrate containing lipids in their native oleosome form, which have a minor destabilizing effect on foams. We conclude that mild purification is a suitable method to obtain sustainably produced protein concentrates with promising foaming properties.

With the gradual aggravation of desertification, aquatic plants are very rare, rain is scarce, and the air is very dry in desert areas, which poses unprecedented challenges to the survival of local residents. In order to solve the crisis of lack of fresh water, the research on air water intake was carried out, and the corresponding design of air purification device was carried out. The benefit and feasibility of the air purification device were analyzed by using the model and software.

The auxiliary navigation device described in this paper can effectively make up for the shortcomings of the existing navigation mode. It has designed a targeted detection module for various unstable factors in complex waters, such as large ship flow, frequent water level changes, low visibility, hidden reefs and floating ice. With the advantages of both water and air, excellent navigation performance and all-round detection means on water and underwater, the device can achieve excellent auxiliary pilot effect. In addition, the device has the advantages of low operation difficulty, short training period, high safety, good social and economic benefits, which is suitable for wide range promotion in navigation areas such as ports, inland rivers and coastal areas.

The work is devoted to the spread processes mathematical modelling of impurities in a reservoir in areas located far from river runoff. An aerodynamic processes mathematical model is proposed that takes into account a variety factors: increased air humidity, variability of atmospheric pressure and temperature, etc. The model discretization was carried out taking into account the partial filling of the calculated cells, which made it possible to significantly reduce the error at the boundary. For the calibration and verification of the pollutants transport model, the expeditionary research data were used.

This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

Countercurrent flow limitation (CCFL) may occur under certain flow conditions in the surge line, restricting the draining of water from the pressurizer and thus affecting the coolant inventory and ...

Golden-mouth turban (Turbo chrysostumus, L.) belongs to the phylum of molluscs that inhabits coral reef ecosystem in group. Golden-mouth turban normally uses algae for their food. Study on survival and growth of the juvenile golden-mouth turban focussing on different density under air water lift sys-tem is still limited. This study was conducted on 7 January – 6 May, 2015, in a laboratory to observe the effect of different density on the survival and growth of golden-mouth turban under air water lift system. Based on the analyses of variance (ANOVA), there was no significant different (P>0.05) on mortality rate for different stock density treatment (5 ind., 10 ind., 15 ind., and 20 ind. each in 10 liter water volume). However, based on growth rate, the density of 5 individuals produced the highest monthly growth rate of 1.88 mm/month of shell height, 1.18 mm/month of mouth opening, and 1.1 gr/month of wet weight with the highest daily mean food absorption of 91.55 %. For all treatment, the correlation of shell height and wet body weight exhibited a similar growth pattrern i.e., allometry minor (bKetwords: Survival, growth, golden-mouth turban (Turbo chrysostumus), stocking density, air water lift system.

Fil: Camara, Candelaria Ines. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones en Fisico-quimica de Cordoba. Universidad Nacional de Cordoba. Facultad de Ciencias Quimicas. Instituto de Investigaciones en Fisico-quimica de Cordoba; Argentina