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It is important to increase the production rate of oil and gas as the usage of them is increasing day by day. To increase the production rate of oil and gas, design of an efficient centrifugal pump impeller plays very important role. Due to the usual submergible pump, there might be the chances for failure and it is so complex when the pump is failed. So an alternative method such as artificial lift is necessary on behalf of submergible pumps for different flow rates. In the present study, 3D simulation of impeller and its stationary flow of centrifugal pump casing are analyzed using CFD. Pressure head and efficiency of the pump for different flow rates are analyzed as well as the data from pump manufacturers are taken and have good satisfactory agreement. Finally, the structural analysis of single impeller blade is carried out by changing different materials. These data are very useful to design the pumps in manufacturing industries.

Murray-Darling Freshwater Research CentreMDFRC item.We investigated the importance of lacunar gas transport for the release of methane from beds of Eleocharis sphacelata R. Br. in a freshwater wetland in southeastern Australia. Gases were transported in the E. sphacelata lacunar system by pressurized convective flow, which was apparently driven by humidity induced pressurization. Internal culm temperatures were 1.9–4.2° C lower than at the external culm surface, suggesting that thermal transpiration was not responsible for lacunar pressurization. Some of the culms (influx culms) provide a net gas flux from the atmosphere into the plant, whereas others (efflux culms) act as conduits for flux from the rhizosphere to the atmosphere. The mean gas influx was 1.0±0.2 (SE) ml min−1 per culm, and the mean gas efflux was 0.2±0.0 (SE) ml min−1 per culm. The difference in influx and efflux flow rates is due to unequal numbers of the two culm types, and the total gas flux through three adjacent E. sphacelata beds was estimated from this flow ratio and the total culm density. It ranged from 1.1 to 2.5 1 m−2 h−1. The methane concentration in the efflux culms was 2–3%, resulting in a total methane efflux from E. sphacelata of 22–75 ml CH4 m−2 h−1. These rates represented 1–15 times the rate of methane release from the E. sphacelata beds by ebullition of methane in bubbles released from the sediment. Diffusive methane fluxes in the lacunar s system (< 300 μl m−2 h−1) were an insignificant mechanism of methane release compared with lacunar convective flow and ebullition fluxes from sediments. The interstitial methane concentration in sediments from E. sphacelata beds was approximately 0.6 times that of adjacent unvegetated sediment, highlighting the role of convective flow by E. sphacelata in accelerating methane release from sediments.

Murray-Darling Freshwater Research CentreMDFRC item.Profile conditions were examined in both small experimental and pilot scale sub-surface flow wetlands. The study systems differed in their hydraulic design. The experimental systems had a vertical up-flow design whereas the pilot system was a horizontal flow trench design. Both systems were found to have significant physical, chemical and biological gradients within the sub-surface profile. System age and plant root density appear to be important factors in determining profile differentiation within the experimental systems. Root densities were found to be partitioned between the upper and lower layers on a 70%/30% split respectively. However, in the experimental systems as the systems aged and root densities increased beyond 112-251 g.m(-2) chemical water quality differentiation id the profile disappeared. Pilot scale systems were found to have physical gradients within the profile as evidenced by hydraulic short-circuiting. Vertical root density distribution is proposed as a major cause of this condition in horizontal flow systems.

Flow boiling in mini- and microchannels offer very high heat transfer capabilities and find applications in many emerging technologies, such as electronics cooling and fuel cells. The low flow rate employed in such geometries, coupled with the small flow channels, often results in a laminar flow with all flow as liquid. Since the single-phase flow with all liquid is in the laminar range, the flow boiling correlations developed for conventional tubes with an inner diameter larger than 3 mm and turbulent flow need to be carefully reviewed. In the present work, flow boiling correlation for large diameter tubes developed by Kandlikar [1, 2] is modified for flow boiling in minichannels by using the laminar single-phase heat transfer coefficient for all liquid flow. The correlation is also extended for flow boiling in microchannels using the nucleate boiling as the dominant part of the original correlation. The trends in heat transfer coefficient versus quality are compared in the laminar and deep laminar regio...

Horizontal gas-liquid two-phase flows widely exist in petroleum, chemical, and other important industrial fields. The flow structures forming during gas-liquid flows can be complex. The transition between flow patterns greatly depends on many factors, such as the fluid properties and the flow rate. Notably, there are multi-scale flow structures even in the same flow pattern. Therefore, it is a great challenge to accurately measure the gas holdup in the horizontal gas-liquid flows by single-mode sensor technology. In this study, we designed a novel combined ultrasonic-conductance sensor (CUCS) consisting of a multi-electrode conductance sensor (MCS) and a transmission ultrasonic sensor (TUS). A flow pattern map of the horizontal gas-liquid flow was obtained in the experiment, and the responses of the CUCS under different flow patterns were collected. The stratified smooth (ST) flow, stratified wavy (SW) flow, and Taylor bubbles in intermittent flow were visualized by the MCS, and the corresponding measurement model of the gas holdup was presented. For the slug region (SR) in intermittent flow, a physical model for measuring the gas holdup was established based on the attenuation characteristics of the transmitted ultrasonic wave. The result indicates that the CUCS has a higher measurement accuracy for the gas holdup of the horizontal gas-liquid flows with different flow patterns.

This paper presents a new sampling head design and the method used to evaluate it. The elemental composition of aerosols collected by two different sampling devices in a semi-arid region of Tunisia is compared by means of compositional perturbation vectors and biplots. This set of underused mathematical tools belongs to a family of statistics created specifically to deal with compositional data. The two sampling devices operate at a flow rate in the range of 1 m3 h−1, with a cut-off diameter of 10 µm. The first device is a low-cost laboratory-made system, where the largest particles are removed by gravitational settling in a vertical tube. This new system will be compared to the second device, a brand-new standard commercial PM10 sampling head, where size segregation is achieved by particle impaction on a metal surface. A total of 44 elements (including rare earth elements, REEs, together with Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sc, Se, Sr, Ti, Tl, U, V, Zn, and Zr) were analysed in 16 paired samples, collected during a 2-week field campaign in Tunisian dry lands, close to source areas, with high levels of large particles. The contrasting meteorological conditions encountered during the field campaign allowed a broad range of aerosol compositions to be collected, with very different aerosol mass concentrations. The compositional data analysis (CoDA) tools show that no compositional differences were observed between samples collected simultaneously by the two devices. The mass concentration of the particles collected was estimated through chemical analysis. Results for the two sampling devices were very similar to those obtained from an online aerosol weighing system, TEOM (tapered element oscillating microbalance), installed next to them. These results suggest that the commercial PM10 impactor head can therefore be replaced by the decanter, without any measurable bias, for the determination of chemical composition and for further assessment of PM10 concentrations in source regions.

In this manuscript, peristaltic transport induced by a sinusoidal traveling wave in the case for a viscous incompressible Newtonian fluid mixed with rigid spherical particles in the presence of a flexible inner tube, where the inner tube is also moving with a sinusoidal traveling wave of moderate amplitude is studied. The governing equations of the mixture (fluid-particle suspension) are written in two-dimensional cylindrical coordinates. The long-wavelength approximation is used to simplify the system of equations (d<

Nozzle flowmeter is widely used in industry. In this paper, in order to study the influence of different flow rates and inner wall temperatures on the thermal effect and flow field of the nozzle flowmeter, the fluid-solid coupling numerical calculation of the thermal effect and flow field of nozzle flowmeter is carried out under four different flow rates and five different inner wall temperatures. It is found that, with the increase of flow rate, the heat transfer effect of the nozzle flowmeter is weakened under different inner wall temperatures. The pressure distribution in the fluid domain, the dynamic stress, and fluid-induced vibration deformation generated by the fluid of the nozzle flowmeter are less affected by inner wall temperatures.

Time-dependent flow of a viscoelastic material through a wavy curved channel is studied. The flow traversing the wavy curved domain is modelled in the curvilinear coordinates. The viscoelastic fluid is described by the fluid relaxation and retardation times, and their variations are considered in relation to the flow characteristic time scale. The wavy walls of the curved channels are in sinusoidal form, with arbitrary phase difference. Using domain perturbation technique, the analytical solution of the model is obtained, including the velocity and the volumetric flow rate. The analytical solution is explained as a function of the flow domain structure, the viscoelastic fluid properties, and the flow generating force. Flow enhancement due to the flow domain is discussed; we have shown that the flow augmentation depends on the properties of the viscoelastic fluid. Furthermore, comparisons have been made with Newtonian fluid flow, and the prominent variations in the flow behaviours have been reported.

The polarization curve is the most important profile to evaluate the performance of proton-exchange membrane fuel cells (PEMFCs). To explore the important thermodynamic parameters and their correlation with the composition, fabrication, and operational settings, a comprehensive data set consisting of 446 polarization curves from 191 perfluorosulfonate and 255 sulfonated hydrocarbon-based PEMs is collected. Then, a Markov chain Monte Carlo simulation within the Bayesian frame provides higher than 93% confidence to extract six important thermodynamic parameters including open-circuit potential, the transfer coefficient, the current loss, the reference exchange current density, the internal resistance, and the limiting current density. An extreme gradient boosting algorithm affords a mean determinative coefficient of 0.89 to predict the whole polarization curve and a confidence of 94% to predict the peak power density (PPD). Both approaches to explore the polarization curve for PEMFCs show good robustness in the blind test. Overall, the PPD is positively correlated with the ion-exchange capacity of the polymer, operational temperature, and humidity and is negatively affected by internal resistance, membrane thickness, and the loading of the catalyst. The flow rate of fuels can effectively enhance them, while the increase of catalyst loading or fuel concentration shows deleterious impacts.

In order to eliminate the disadvantages of the high cost of underground pipe drilling and space occupation, according to the relevant practices of existing energy underground structures, the idea of embedding the buried pipe of the ground source heat pump system into the tunnel lining of protection engineering was proposed. An analytical model of the heat transfer process of the ground heat exchanger was established, and the explicit expressions of the calculated parameters were obtained. The reliability of the model was verified by the existing experimental data. The model was used to analyze the influence of different air temperature and flow rate on the heat transfer performance of the ground heat exchanger. The study found that every time the air temperature rises by 1 °C, the heat transfer per unit passageway length was reduced by about 200W. The increase in air flow velocity has a limited impact on the heat transfer. The method of enhancing heat transfers by increasing the flow velocity can only be performed at a small flow velocity. In the total heat exchange per unit length, the proportion of the heat exchange on the air side and the heat exchange on the surrounding rock side affect the protection capability of the project in an isolated state. The greater the proportion of heat exchange on the side of the surrounding rock, the stronger the protection capability in the isolated state.

Isoamyl acetate esters were synthesized under supercritical CO2 (SC-CO2) in a continuous packed-bed reactor (PBR) using immobilized lipase (Novozym 435) as the catalyst. A fractional factorial design (24−1) was applied to evaluate the effects of pressure (10–20 MPa), temperature (40–60 °C), substrates (fusel oil + acetic anhydride) flow rate ( Q S 1 / S 2 : 0.2–0.6 mL/min), and CO2 flow rate ( Q C O 2 : 0.4–1.2 L/min) on the isoamyl acetate conversion (X, %). Results showed that only the effects of Q S 1 / S 2 were statistically significant at the level of 5%. Mathematical modeling of the PBR was applied using the law of conservation of mass that resulted in two partial differential equations for fluid and enzymes. The model was solved using finite difference methods and successfully validated with the experimental data in terms of isoamyl alcohol concentration. Finally, the model was employed to examine the impact of the input molar ratio of fusel oil per acetic anhydride (IMFA) and the length per diameter ratio (L/D) of the PBR on its performance.

The present work investigates the evolution of the energy characteristics of a household-size, vacuum-tube solar collector system by controlling the flow rate of the solar circuit. First, based on measurements the collector efficiencies were compared when the solar loop worked with different but constant flow rates. Second, based on simulations using the TRNSYS model of the real system, the obtained results from the flow control and the on–off control which commonly used in household-size system are compared. Then the realization of the flow control with a frequency regulator is presented and the results obtained from the measurement data are presented. The main results are as follows: the rate of transient part is significantly reduced, the thermal stratification improves, and increases the daily gathered energy by the system. The system efficiency is increased with the average of 13% in the considered time period. The effect of this control is bigger if the radiation is lower, if the weather is variable cloudy or if the stored water temperature higher. The obtained results show that the flow control in household-sized systems can also be important.

Heat storage efficiency is required to maximize the potential of combined heat and power generation or renewable energy sources for heating. Using a phase change material (PCM) could be an attractive choice in several instances. Commercially available paraffin-based PCM was investigated using T-history method with sufficient agreement with the data from the manufacturer. The introduced LHTES with cylindrical capsules is simple and scalable in capacity, charging/discharging time, and temperature level. The overall stored energy density is 9% higher than the previously proposed design of similar design complexity. The discharging process of the designed latent heat thermal energy storage (LHTES) was evaluated for two different flow rates. The PCM inside the capsules and heat transfer fluid (HTF) temperature, as well as the HTF flow rate, were measured. The lumped parameter numerical model was developed and validated successfully. The advantage of the proposed model is its computational simplicity, and thus the possibility to use it in simulations of a whole heat distribution network. The so-called state of charge (SoC), which plays a crucial role in successful heat storage management, is a part of the evaluation of both experimental and computational data.

Most of the existing flow sensors are expensive and limited in their capabilities for sensing bidirectional flow. Low-cost and accurate flow sensors with bidirectional sensing capability have numerous applications in the residential and irrigation sectors. Evaluation of a low-cost, cantilever-based sensor, suitable for measuring flow rates under turbulent flow conditions is presented in this article. Such sensors are reported for micro-fluidic applications but its potential application in large diameter pipes under turbulent flow has not been studied yet. A cantilever formed using a thin stainless-steel strip is used as the sensing element in the proposed sensor. One of the ends of the cantilever is firmly fitted to the inner wall of the pipe, and it bends or deflects towards the direction of the flow as a function of the flow rate. To experimentally evaluate the sensor in detail, the mean deflection angle of the cantilever is measured using a camera, and an image processing algorithm. In practice, the angle can be sensed using simpler methods. The performance of the prototype sensor has been evaluated after building an appropriate regression model. The results are subsequently expressed in terms of the mean flow velocity, thereby providing its potential utility in pipes of other dimensions. The shape of the mean flow velocity with respect to the mean angle of deflection characteristic of the proposed sensor matched well with the theoretical deflection computed. The sensor developed has given an accuracy of 3 % of full scale, for flow rates in the range of 2-15.5 m3/hr. The proposed sensing mechanism can realize cost-effective, simple, and reliable flow sensors. Such sensors will find applications in residential and industrial domains.

The solar desalination system is experimentally investigated according to humidification dehumidification methodology (HDH) with hot air stream flow and heat pump as a condensation unit. The effects of high frequency ultrasound atomizer number, water height and hot air stream flow rate on distillate yield are studied. The results illustrated that increasing of atomizer number and decreasing water height increases the daily distillate production. The maximum daily freshwater productivity occurred at six atomizer number with an increase of 38.6% and 115% compared with atomizer number four and two, respectively. Furthermore, water height at 1 cm is the most efficient with an increment of 16% and 28.6% compared with 2 cm and 3 cm, respectively. The optimum hot air stream flow rate is 0.011 kg/s with an increment of 36.88%, 31.07%, 6.48%, 11.72%, 23.52% and 38.60% compared with 0.009, 0.010, 0.013, 0.014, 0.016, and 0.017 kg/s, flow rates, respectively. The air mass flow rate has a significant impact on system performance. The maximum gain output ratio (GOR) of the system is about 1.54. The daily production reaches 7.72 kg∖day, the system energy efficiency is 33.84% and 1.43% exergy efficiency the estimated cost is 0.0112 US$/L.

We employed the computational fluid dynamics (CFD) simulation to capture the flow behavior in spinnerets based on various flow angles (90°, 75°, 60°, and 30°), different power-law fluids (0.5 ≤ n ≤ 1), and two different flow rates (0.2 mL/min and 1.4 mL/min). The simulation results moderately agreed with the semi-analytical solution obtained from the literature. The sensitivity analysis was performed, showing that spinneret's flow angles and power-law indices are additional critical variables that facilitate the alignment of the polymeric chain in the dope solution due to the enhanced shear rate. The maximum viscosity reduction is observed in this study when a more shear-sensitive dope fluid extrudes through the spinneret at a given flow rate. The low shear rate gradient prevalence elevates the viscosity in the annular spinneret region, strongly dependent on the flow and shear-sensitive fluid (n

Background: The control and manipulation of the hydrodynamics of droplets primarily relate to flow governing and geometrical parameters. This study has explored the influences of capillary number ( 10 − 4 ≤ C a c ≤ 1 ) and flow rate ratio ( 0.1 ≤ Q r ≤ 10 ) on the hydrodynamics of droplet generation in two-phase flow through T-junction cross-flow microfluidic device. Methods: The finite element method is used to solve the Eulerian framework of a mathematical model based on mass continuity, Navier-Stokes, and conservative level set equations at fixed flow ( R e c = 0.1 ). Significant findings: Results are presented in terms of the instantaneous phase flow field, droplet size, droplet detachment time, and generation frequency as a function of governing parameters ( C a c and Q r ). The flow regimes namely squeezing, first transition, dripping, second transition, parallel, and jet flow are marked. In contrast to reported value of threshold C a c ≈ 10 − 2 , squeezing regime exists for all C a c and 2 ≤ Q r ≤ 10 . The flow regimes are also mapped into droplets and non-droplet zones by using threshold C a r which scales quadratically with Q r . The droplet length varies linearly with Q r in the squeezing regime. Both droplet size and frequency show the power-law relations with C a c and Q r in the droplet zone. Finally, predictive correlations are presented to guide the engineering and design of droplet microfluidics devices.

Waste production is an important problem for the developing world and globalization. The waste materials can be reused through recycling process and its environmental effects can be minimized. Utilizing renewable energy sources at the maximum level is also an important issue for a sustainable development in future as well as waste management. In this study, small-scale solar air heating systems were produced from waste materials to analyze the usability of waste material in renewable energy systems. Scrap metal elbows were used in the production of heaters. The first solar heater is hollow (SH) and the second one was modified by filling it with aluminum wool (SHAW). Both heaters were tested simultaneously at different flow rates (0.014, 0.010 and 0.006 kg/s). According to the experimental results, the thermal efficiency values for SH and SHAW were found in the range of 33.63-42.90% and 42.69-56.98%, respectively. In addition, it was observed that a low cost modification such as using aluminum wool can significantly increase thermal performance of the solar heating system.

In this study, a cyclone separator that can be used as a sampling inlet for portable black carbon (BC) monitors operating at a flow rate of less than 200 mL/min was developed. A prototype was fabricated to evaluate its performance by experiments, and the cut-off size of the cyclone separator was predicted through numerical analysis by applying various turbulence models. The RNG k–e model was found to be suitable for the analysis of the cyclone separator operating at Reynolds numbers of less than 1000. Cyclone separators were designed through simulation and fabricated for each operating flow rate (50, 100, 150, and 200 mL/min) of a BC monitor, and their performances were experimentally verified. Meanwhile, when the non-dimensional analysis method of the previous study conducted at Reynolds numbers of 1000 or higher was used, the cyclone separator operating at Reynolds numbers of less than 1000 also exhibited a similar linear tendency.

Water is a key ingredient to the potential for life, and several icy moons, such as Europa and Enceladus, are thought to harbor a dynamic subsurface ocean of liquid water. An ice probe or “cryobot” is a proposed technology to penetrate the surrounding ice shell and deliver a life-detection payload to these oceans. As the ice probe descends, it is surrounded by a thin melt film of liquid water. This paper focuses on the fluidics of the melt film for the case of a general ice probe shape, leading to a new approximate equation for the force balance constraints (validated to 0 . 4 % error by numerical model). In addition to the introduction of water by melting, the analysis allows for consideration of additional volumetric flow via a pumped jet of recirculated water. The general force balance equation is explored in more detail for the example of a cylindrical probe geometry with flat circular end caps. The thickness of the melt film below and to the side of the cylindrical probe is constrained by the force balance such that the probe typically operates in one of two asymptotic regimes, moving or stalled.

Microfibers-weaved ceramic filters are in increasing demand due to their high filtration efficiency, stable structure and remarkable ceramic properties in water and gas treatment. To date, it remains a challenge to find an effective way to weave ceramic microfibers. This work demonstrates a novel strategy that combines gel-casting and in situ cross-flow microfluidic molding to fabricate highly flexible and shape-retentive green microfibers and then weaves them before sintering. By tailoring the curing temperature and flow rate, the diameter and surface morphology of the microfiber is accordingly tuned. Besides mesh structure, the microfibers can also be weaved into more complex three-dimensional structures such as dragonfly knot, Chinese knot, etc. Benefitting from the widely used solution system and microfluidic method, this system can serve as a general and stable platform for preparing microfibers-weaved ceramic filters made from different materials, thus holds great potential in a wide range of working conditions.

Novel multi-effect diffusion solar distiller (MED) was developed to improve the performance and reliability of conventional MED. Conventional MED consists of several flat metal plates (effect plates), each one equipped with a wick that serves as both an evaporation surface and a seawater feeding medium. However, the wick-plate structure has several problems such as higher manufacturing cost, lower performance, and durability deterioration. The new wick-free plates (WFPs) have many horizontally patterned grooves on an evaporation surface of a flat plate and can evenly spread and retain the feed saline water on the surface like as fabric wick. Experimental results showed that the performance of the proposed novel MED equipped with WFP (WFP-MED) is similar to that of conventional MED with wick-plate and even better productivity up to 7 % due to lower thermal resistance of WFP. Production stability with respect to the fluctuation of feed flow rate of WFP-MED is better than that of conventional MED. Moreover, WFP-MED is more effective in increasing productivity by increasing the number of effects. The 3-effect diffusion distiller with WFP has 0.84 of distillation efficiency under 10.8 MJ/m2 of solar insolation.

The solar collectors’ shape is an essential parameter in the thermal performance of solar water heaters, and absorption of maximum radiation at different hours, regardless of the angle of the collector, is an important issue. A spherical solar water heater is experimentally investigated in practical dimensions. This solar water heater is a fixed, symmetrical collector with the ability to track the sun independent of the optimal placement angle. The heat transfer surface is also increased by designing the fluid passage bed as a spherical absorber coil. When the flow rate intensifies, the temperature difference between the input and output currents reduces. The maximum instantaneous and average daily thermal efficiencies are 87% and 69.7%, respectively, for a flow rate of 1.6 lit/min. In this case, the hot water required by 6.35 people is provided, then at higher flow rates, the thermal efficiency is reduced. At solar noon, the upper and lower semi-spheres absorb the maximum and minimum radiations, respectively. In general, the trend of changes in the absorption of the solar radiation has no absolute extremes, meaning proper tracking of the sun and stable performance during the day. This solar heater can be easily used in the facade of buildings.

An efficient and environment-friendly method for simultaneous determination of 13 typical derivatives of polycyclic aromatic hydrocarbon (PAH) in petroleum-polluted soil with nitro-, oxy- and alkyl-functional group was developed using supercritical fluid extraction (SFE) followed by ultra-high performance supercritical fluid chromatography (UHPSFC). Parameters of UHPSFC, including type of stationary phase and mobile phase modifiers, gradient elution process, backpressure, column temperature, and the flow rate of mobile phase, were systematically optimized, achieving a fast separation within 4.2 min. Limits of detection (LOD) were 0.005–0.1 μg mL−1 or 0.1–2.0 ng g−1, respectively, with a good repeatability (RSD

Particle transport in a vertical nonplanar fracture is a typical but poorly understood element in hydraulic fracturing. Particle-fluid flow in a nonplanar fracture with a narrowing width is investigated experimentally by a laboratory-scale slot, and the relevant transport mechanisms are compared with that in the planar slot. The effects of fluid flow rate, particle density, particle size, and particle volume fraction on particle distribution are investigated. The results indicate that the narrowing width complicates the slurry flow and lowers the bed coverage area. The vortex flow appears at the contraction of the cross-section as the bed grows to a threshold height and resuspends more particles further into the slot. An irregular bed with a descending stepped surface is formed due to non-uniform placement. Smaller size sands injected at a high flow rate and a low particle volume fraction build up a smaller bed. Larger and denser particles would reverse the trend. A rational model expressed by four dimensionless numbers is developed by the linear regression method to predict the coverage percentage of the particle bed. The model and experimental results provide directions to quantitatively evaluate the particle transport and distribution in a nonplanar fracture.

Effective methods for rapid sorting of cells according to their viability are critical in T-cells based therapies to prevent any risk to patients. In this context, we present a novel microfluidic device that continuously separates viable and non-viable T-cells according to their dielectric properties. A dielectrophoresis (DEP) force is generated by an array of castellated microelectrodes embedded into a microfluidic channel with a single inlet and two outlets; cells subjected to positive DEP forces are drawn towards the electrodes array and leave from the top outlet, those subjected to negative DEP forces are repelled away from the electrodes and leave from the bottom outlet. Computational fluid dynamics is used to predict the device separation efficacy, according to the applied alternative current (AC) frequency, at which the cells move from/to a negative/positive DEP region and the ionic strength of thesuspension medium. The model is used to support the design of the operational conditions, confirming a separation efficiency, in terms of purity, of 96% under an applied AC frequency of 1.5 × 106 Hz and a flow rate of 20 µl/h. This work represents the first example of effective continuous sorting of viable and non-viable human T-cells in a single-inlet microfluidic chip, paving the way for lab-on-a-chip applications at the point of need.

In this work, performance of laboratory-synthesized dolochar has been investigated for adsorption of Cd2+ ions in a large-scale process with the application of Aspen Adsorption. Moreover, the optimum values of the operating parameters (namely, flow rate, bed height, and inlet metal ion concentration) that would result into maximum amount of cadmium ion adsorption (high exhaustion capacity) in minimum time (less exhaustion time) for a fixed mass of dolochar have been calculated via the application of response surface methodology. It was found that, at optimum values of bed height (3.48 m), flow rate (76.31 m3/day), and inlet concentration (10 ppm), the optimized value of exhaustion capacity and exhaustion time for cadmium ion adsorption in dolochar packed bed is equal to 1.85 mg/g and 11.39 h, respectively. The validity of these simulation experiments can be proven by the fact that the obtained exhaustion capacity of dolochar packed bed always remained in close proximity of the experimentally obtained value of adsorption capacity of the dolochar in batch process mode (equal to 2.1 mg/g).

The use of information and measurement systems in the oil and gas industry helps to improve the commercial gas consumption metering supplied to consumers in order to ensure mutual settlements with consumers. Gas distribution stations (GDS) are one of the main objects of main gas pipelines. Gas distribution stations are designed to perform the following operations: receiving gas from the main gas pipeline; gas purification from mechanical impurities; decrease in pressure to a predetermined value; automatic maintenance of pressure at a given level; distribution of gas to consumers; measuring the amount of gas. In addition, secondary odorization of gas is carried out at the gas distribution station. Regardless of the throughput, the number of consumers, the inlet and outlet pressure, the nature of the load change (gas consumption), the process flow diagram of the gas distribution station consists of the following main units: the connection diagram of the gas distribution station to the gas pipelines, gas purification, pressure regulation, gas flow measurement and instrumentation devices (instrumentation), gas odorization. The unit for measuring the flow rate and amount of natural gas (hereinafter referred to as the gas metering unit) is designed to measure, record the measurement results and calculate the volume of gas reduced to standard conditions, as well as, if necessary, determine its quality indicators, including component composition, density, humidity, specific heat of combustion. Various types of flow meters were analyzed and an ultrasonic flow meter was selected.

By applying the optimized DC arc plasma torches (DCAPTs) to gas atomization (GA), the new hybrid atomization (HA) system with three DCAPTs was developed to improve typical GA techniques by using higher superheats from plasma jets with high heat flux. Before mounting on a HA system, the anode structure of a DCAPT was optimized by the experimental investigation with flow simulation. A DCAPT had high thermal efficiency about 80% for the stable operation of a DCAPT at power of 15–20 kW and nitrogen gas flow rate of 80 SLM with the optimized anode structure. First experimental results of tin, copper, and stainless steel metal powders by the developed HA system with three DCAPTs were analyzed by using the scanning electron microscope (SEM). High quality of spherical shape was observed from the atomized tin, copper, and stainless steel powders. The atomized powders with high size distribution were observed as tin (

A pulsed electric field (PEF) produces pasteurized liquid foods with fresh and nutritional properties. The treatment chamber is a crucial part of the PEF processing system where a high voltage is applied, producing an electric field to treat the liquid foods. The proper construction of the treatment chamber regulates the distribution of the electrical field inside the treatment zone. Mixing of liquid inside the treatment zone is an effective tool to overcome this heterogeneous effect. The coaxial treatment chamber offers a heterogeneous electric field and temperature distribution inside the treatment zone. A helical insulator inside the coaxial treatment chamber provides a mixing effect. In this research, a numerical simulation was done to measure the electric field in different geometries of treatment chambers at different flow rates. The simulation aimed to optimize the new coaxial treatment chamber design. The modelling findings showed homogeneous electrical field strength in the helical treatment chamber. This study provides new insights for industrial-scale setup using multiple helical chambers in a continuous flow PEF treatment.

The presence of suspended contaminants in water and wastewater such as algae, colloids, fats and oil, necessitates the use of systems such as dissolved air flotation (DAF) for their removal. In the current study, a novel setup has been proposed for bubble enhancement. An industrial scale (pilot) DAF system was tested at saturator pressures of 3 to 7 atm and flow rates of 5 to 20 L/min in three different configurations, namely, empty, packed, and the innovative two-stage (TS) configuration. In the TS system, after the nucleation of micro bubbles, the water is returned to the saturator to undergo pressurization for a second time before it is passed through the nozzle once more and is released. The results show that the highest volume of released air as well as the smallest microbubbles are seen in the TS configuration, followed by packed mode, with the empty configuration showing the least favorable results. Moreover, the bubbles produced at the lowest residence time and pressure (3 atm) with the novel setup are better than the bubbles produced by the standard configuration even with pressures as high as 7 atm. Thus, the novel TS setup can allow for significantly lower energy requirements and lower capital costs. For real-world application of the TS system, the feed for the saturator would have to be extracted from within or near the contact zone, i.e., where the bubbles are released in the DAF tank.

An electronic pressure control unit, coupled with a small built-in compressed air chamber, is applied to a field-portable gas chromatograph to precisely adjust the column head pressure with an accuracy of

Wellbore instability is a frequent problem of shale drilling. Accurate calculation of surge-swab pressures in tripping processes is essential for wellbore pressure management to maintain wellbore stability. However, cutting plugs formed in shale horizontal wells have not been considered in previous surge-swab pressure models. In this paper, a surge-swab pressure model considering the effect of cutting plugs is established for both open pipe string and closed pipe string conditions; In this model, the osmotic pressure of a cutting plug is analyzed. The reduction of cutting plug porosity due to shale hydration expansion and dispersion is considered, ultimately resulting in an impermeable cutting plug. A case study is conducted to analyze swab pressures in a tripping out process. The results show that, in a closed pipe condition, the cutting plug significantly increases the swab pressures below it, which increase with the decrease of cutting plug porosity and the increase of cutting plug length. Under the give condition, the swab pressure at the bottom of the well increases from 3.60 MPa to 8.82 MPa due to the cutting plug, increasing by 244.9%. In an open pipe string condition, the cutting plug affects the flow rate in the pipes and the annulus, resulting in a higher swab pressure above the cutting plug compared to a no-cutting plug annulus. The difference increases with the decrease of the porosity and the increase of the length and the measured depth of the cutting plug. Consequently, the extra surge-swab pressures caused by cutting plugs could result in wellbore pressures out of safety mud density window, whereas are ignored by previous models. The model proposes a more accurate wellbore pressure prediction and guarantees the wellbore stability in shale drilling.

Effects of internal fins in absorber pipes are analysed experimentally on fabricated cylindrical collector with different lengths of fins at various flow rates on different days. Comparative analys...

This study describes the linkage leakage in sewage pipes through a porous media using computational fluid dynamics with the presence of one leak through fluid simulations using the Ansys fluent 17.2 commercial software based on standard k-ε model under steady-state condition. The pipe section is three-dimensional with a pipe length of 40 mm, a pipe diameter of 20 mm, and leak orifice diameter of 2 mm with a porous media of length 25 mm and width 30 mm. The interest of this study was to reduce the rate of sewage leakage in pipes laid underground by use computational fluid dynamics. The simulation results obtained shows that when the flow is subjected to an outlet pressure between 100000 Pa to 275000 Pa the sewage leaks at pressures of 99499 Pa to 278799.8 Pa indicating that increase of outlet pressures increases the pressure at the leak point and also an increase in the inlet velocity resulted into an increase of velocity at the leak point and no significant change in sewage flow rate with increased inlet velocities. Therefore, monitoring of the pressure and velocity fields along the pipeline is an extremely important tool to identify leaks since these fields are affected by perturbations both before the leak point and after the leak point.