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Natural gas production from reservoirs is often associated with water, which poses numerous challenges, such as methane hydrate formation, sludge, corrosion and flow assurance issues in gas processing plants and sales gas transmission pipelines. To effectively remove water from natural gas, there is a need to design, compare and modify dehydration plants. This study investigated the performance difference between a conventional triethylene glycol (TEG)‐based dehydration system with a cooler at the TEG inlet to the contactor, and a newly proposed TEG‐based dehydration system with a heat exchanger replacing the cooler at the TEG inlet with the contactor. The advanced process simulation software Aspen HYSYS was used to design and compare two dehydration system configurations. The modified design configuration exhibited better performance in terms of energy conservation and water‐removal capability. The material balance of molar flow, mass flow and volume flow of dry gas produced in the absorber/contactor column showed a higher volume of dry gas produced in the modified system configuration, indicating that it is a better design. The modified design configuration also produced dry gas within the recommended temperature range for underground storage and transmission. There was a significant difference in the percentage difference of 64% between the conventional and modified designs in terms of energy consumption, whereas the percentage differences of 0% and 0.6% showed nonsignificant and significant differences between the two plant design configurations. Both plant design configurations showed a significant reduction (from 0.005 to 0.0002 mol%) in the water composition of natural gas after the simulation. [ABSTRACT FROM AUTHOR]

The work is devoted to determining the characteristics of turbine stages in off-design modes that arise when pressures and temperatures change before or after the stage, a transition to a different rotation speed, or, for example, when the composition of the working fluid changes. As part of the project, a quasi-one-dimensional method for calculating the characteristics of a turboexpander assembly (TEA) stage when changing operating parameters and/or working fluid has been developed, which differs from known methods by using the equations of the state of real gas, adaptation to purely radial stages, and a simplified approach to determining the pressure at the outlet of the guide vane for assessing the degree of reactivity and the ability to switch to another working fluid, including a mixed one. The analytical methodology was verified by comparison with the experimental data of other authors and the results of calculations using CFD methods for radial-axial stages as well as with approaches to the calculation of purely radial turbomachines due to the lack of experimental data for this type of TEA in the public domain. An extended characteristic of a radial stage operating in air (turbo map) was constructed, and the dependences of the isentropic efficiency, degree of reactivity, mass flow and power of the stage on the relative circumferential speed were assessed. An assessment was made of the impact of switching to another working fluid (for example, switching from air to methane was chosen). It is shown that the characteristics do not change qualitatively but they shift from one another along the axis of the relative peripheral velocity. Further development of the technique involves taking into account possible phase transitions (volume condensation) in the flow part. [ABSTRACT FROM AUTHOR]

Micro-hole aerostatic bearings are important components in micro-low-gravity simulation of aerospace equipment, and the accuracy of micro-low-gravity simulation tests is affected by them. In order to eliminate the influence of air resistance on the attitude control accuracy of remote sensing satellites and achieve high fidelity of micro-low-gravity simulation tests, in this study, a design and parameter optimization method was proposed for micro-hole aerostatic bearings for a vacuum environment. Firstly, the theoretical analysis was conducted to investigate the impact of various bearing parameters and external conditions on the bearing load capacity and mass flow. Subsequently, a function model describing the variation in bearing load capacity and mass flow with bearing parameters was obtained utilizing a BP neural network. The parameters of aerostatic bearings in a vacuum environment were optimized using the non-dominated sorting genetic algorithm (NSGA-II) with the objectives of maximizing the load capacity and minimizing the mass flow. Subsequently, experimental tests were conducted on the optimized bearings in both atmospheric and vacuum conditions to evaluate their load capacity and mass flow. The results show that in a vacuum environment, the load capacity and mass flow of aerostatic bearings are increased compared to those in standard atmospheric conditions. Furthermore, it has been determined that the optimal solution for the bearing's load capacity and mass flow occurs when the bearing has an orifice aperture of 0.1 mm, 36 holes, and an orifice distribution diameter of 38.83 mm. The corresponding load capacity and mass flow are 460.644 N and 11.816 L/min, respectively. The experimental and simulated errors are within 10%; thus, the accuracy of the simulation is verified. [ABSTRACT FROM AUTHOR]

We explored the microplastic (MPs) emissions of Japanese municipal solid waste incinerators (MSWIs); specifically, the numbers and types of MPs in wastewaters discharged by three MSWIs. We calculated the MSWI MPs emission factors and inventories, and we discuss the results. More than fifteen types of MPs, principally fragments shape were detected. It was important to obtain composite samples because the nature of raw wastewater fluctuated significantly during both day and night in response to the MSWI treatments. MSWI wastewater treatments tended to remove larger particles; over 99% of MPs (in terms of both number and weight) were ultimately removed. The MP emission inventory from MSWIs to public water bodies was 7.22 × 105–1.64 × 106 MPs/year for MPs sized 100–5000 µm. This is very low, at only 0.0053–0.026% of the total MP emission inventory Japanese WWTPs. It is, therefore, possible to remove almost 100% plastics in input waste via incineration and wastewater treatment. [ABSTRACT FROM AUTHOR]

Objective Conventional capillary laminar flow measurement technology has nonlinear problems such as inlet and outlet pressure loss due to the structure of laminar flow sensing element. Therefore, it is necessary to improve the laminar flow sensor to solve the nonlinear problem. Methods A conical laminar flow element was proposed, which could effectively solve the nonlinear pressure loss problem in the initial stage of laminar flow by taking advantage of direct pressure extraction in the fully developed stage of laminar flow and directly reflect the linear relationship between flow and differential pressure. Three kinds of conical laminar flow elements with different gaps were designed and manufactured, and the gas micro and small flow measurement system was built. Results Within the flow range of 0.015 0-2.348 1 kg/h, the measurement errors of the three sets of devices are in the range of ±2%, and the measurement error of the conical laminar flow element device based on the gap of 0.7 mm is the smallest, in the range of ±1%. Conclusion It is proved that the conical laminar flow element has good performance in measuring small and micro natural gas and other gas flow. [ABSTRACT FROM AUTHOR]

Micro-hole aerostatic bearings are important components in micro-low-gravity simulation of aerospace equipment, and the accuracy of micro-low-gravity simulation tests is affected by them. In order to eliminate the influence of air resistance on the attitude control accuracy of remote sensing satellites and achieve high fidelity of micro-low-gravity simulation tests, in this study, a design and parameter optimization method was proposed for micro-hole aerostatic bearings for a vacuum environment. Firstly, the theoretical analysis was conducted to investigate the impact of various bearing parameters and external conditions on the bearing load capacity and mass flow. Subsequently, a function model describing the variation in bearing load capacity and mass flow with bearing parameters was obtained utilizing a BP neural network. The parameters of aerostatic bearings in a vacuum environment were optimized using the non-dominated sorting genetic algorithm (NSGA-II) with the objectives of maximizing the load capacity and minimizing the mass flow. Subsequently, experimental tests were conducted on the optimized bearings in both atmospheric and vacuum conditions to evaluate their load capacity and mass flow. The results show that in a vacuum environment, the load capacity and mass flow of aerostatic bearings are increased compared to those in standard atmospheric conditions. Furthermore, it has been determined that the optimal solution for the bearing’s load capacity and mass flow occurs when the bearing has an orifice aperture of 0.1 mm, 36 holes, and an orifice distribution diameter of 38.83 mm. The corresponding load capacity and mass flow are 460.644 N and 11.816 L/min, respectively. The experimental and simulated errors are within 10%; thus, the accuracy of the simulation is verified.

Dynamic explosion in a compartment damages the structure, resulting in flooding and even sinking of the ship. To study the flooding characteristics of damaged compartments and floating states of the hull under deformation of the bulkhead caused by explosion, the damage effects on a single compartment and multiple compartments under dynamic explosion are illustrated. Then, the flooding characteristics are analyzed for single compartment models with two types of damage modes and one multi-compartment asymmetric damage model. The results indicate that the deflection of the bulkhead increases the capacity of the compartment, resulting in variations in the flooding process of damaged compartments. Compared with the single models without deflection deformation, the final flooding quantity of the two types of models with deflection deformation increased by 62.49% and 65.48%. The difference in flooding characteristics led to deviation in the six-degree-of-freedom motion of the two types of hull models. Significantly, the amplitude of heave in the models with deflection deformation under the two types of asymmetric damage modes increased by 60% and 66% compared to that of the models without deflection deformation, and the pitch increased by 66% and 50%. Nevertheless, in the multi-compartment models, there were no distinct differences in the flooding process and six-degree-of-freedom motion. These results can support the rapid assessment of the unsinkability of ships in explosive environments.

Heat and mass transfer in the process of friction stir welding (FSW) determine the weld formation quality. Meanwhile, the formation of voids in FSW limits welding speed improvement and welding efficiency. Although superimposing ultrasonic vibration can be adopted as an effective means to restrain the formation of voids, the potential suppression mechanism was still unrevealed. Herein, a multi-physical model using the shear stress boundary conditions was put forward to quantitatively study the influence of ultrasonic vibration on the heat and mass transfer behaviors and the resulting weld formation which was also validated experimentally. Our results show that ultrasonic vibration in FSW slightly enhances the heat flux at the tool-workpiece interfacial contact surface as well as the plastic deformation heat generation near the tool. Therefore, the high-temperature area (higher than 690 K) near the tool pin side increases from 2.11 to 2.29 mm. The slightly higher heat rate and temperature enhance the fluidity of plastic material, resulting in an obvious increase in the flow velocity. As a consequence, the plastic material moves farther to fill the cavity at the rear advancing side, which is conducive to eliminating the void defects. The maximum strain rate on z = 2 mm horizontal plane at the AS is 206.7 s−1 in UVeFSW, while it is 13.5 s−1 in CFSW. The strain rate of the contact interface on AS increases by nearly 5 times, which implies an enhanced plastic material flow and is the main reason for suppressing void defects by superimposing ultrasonic vibration in FSW. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power is the property of Electric Power Editorial Office 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.)

A rare study on the quantitative relationship between the energetic impact of debris flows on the intensity and duration of growth disturbances of tree rings was carried out, partly due to a lack of feasible approaches and detailed field evidence. In this study, we first used a dendrogeomorphic technique to determine the age of a recent debris flow derived from historic landslide deposits at Qingyang Mountain (QYM) on the northeastern Tibet plateau. We acquired the quantitative data on the annual widths of tree rings in history and confirmed the influence of the debris flow rather than other factors (e.g., climatic events and inset outbreaking) in disturbing the growth of tree rings in a specific year. Using this approach, we determined that the age of the debris flow at QYM occurred in 1982, which was speculated to be triggered by the high monthly precipitation registered during July 1982. Subsequently, based on the boundaries of historic debris flow identified on remote sensing images before and after 1982 and the depth-integrated continuum model, we reconstructed the process of the 1982 debris flow and obtained the kinematic energy of the debris flow impacting the sampled trees. Based on the study, we observed that two growth disturbance patterns of tree rings influenced by the reconstructed 1982 debris flow were revealed, including growth suppression and asymmetric growth. We obtained a raw logarithm relationship between duration (i.e., lasting time for the disturbed tree rings to recover the initial width) and intensity of growth disturbances (i.e., growth suppression ratio of disturbed tree rings). We concluded that there is a negative exponential relationship between the simulated kinematic energy of debris flow impacting the disturbed trees and the time to recover the initial width of corresponding tree rings.

Proton exchange membrane fuel cells are gaining increasing importance in vehicle applications. The exhaust gas composition regarding the water and oxygen content and the mass flow are important parameters in fuel cell research (e.g., for designing the test bed, quantifying the hydrogen loss in the exhaust, performing experiments with air pollutants, and monitoring degradation). The exhaust gas composition is also important for vehicle applications (e.g., ensuring safe hydrogen levels in the exhaust). Performing direct measurements of the exhaust mass flow and the relative humidity is challenging due to the high-humidity environment. This article presents a mathematical thermodynamic model used to calculate the exhaust gas mass flow and relative humidity, validated by balancing the gas species composition between cathode inlet and exhaust and by using data measured at the fuel cell system test bed. Four calculation model variations and their analyses are discussed. Furthermore, the exhaust gas composition throughout the fuel cell system operating range is presented. The results of air pollutant experiments provide comprehensive examples for the application of the calculation model. These results demonstrate the suitability of the model for its application in fuel cell system research. [ABSTRACT FROM AUTHOR]

Background: The mineral nutrient concentrations in plants are usually decreased under elevated CO2 concentration ([CO2]), while warm root‐zone temperature (RZT) can improve plant growth and the absorption of mineral nutrients in plants. Aims: The effects of RZT on the growth and mineral nutrient concentrations in cucumber (Cucumis sativus L.) plants were investigated under different [CO2] levels. Methods: A soil‐cultured pot experiment was carried out on cucumber plants under two [CO2] levels (ambient and elevated) and two RZT levels (cold and warm) in four open‐top chambers. Results: Although elevated [CO2] promoted root growth, it did not counteract the decrease in the concentration of nitrogen ([N]), potassium ([K]), calcium ([Ca]), and magnesium ([Mg]) in cucumber plants due to the decreased mass flow indicated by the decreased transpiration rate (Tr) under cold RZT. In comparison, warm RZT increased the [N], [K], [Ca], and [Mg] in cucumber plants under elevated [CO2], attributed to a higher Tr and better root growth. In addition, the concentration of phosphorus ([P]), iron ([Fe]), manganese ([Mn]), and zinc ([Zn]) in cucumber plants was maintained or increased under elevated [CO2] by the promoted root growth related to interception by warm RZT. Conclusions: Under elevated [CO2], warm RZT could ensure the [N], [K], [Ca], and [Mg] in cucumber plants mainly by increasing the Tr and improving the root growth. Whereas warm RZT maintained or increased [P], [Fe], [Mn], and [Zn] primarily relied on the improved interception as indicated by the better root growth. [ABSTRACT FROM AUTHOR]

To establish the mass flow to a reciprocating compressor there are several relationships used in the construction and analysis of these types of compressors. The use of relationships is based on the geometric elements of the compressor. It is also necessary to know the composition of the gas and the operating conditions with which: the adiabatic exponent, the volumetric efficiencies and the compressibility factor are determined. The paper aims to establish the compressor mass flow with the help of modern means. The modeling was done in the LMS Amesim program. We use elements from the library of program to create a virtual model of the compression system. A comparison is made with the results obtained by the classical methods. The results show that there are no big differences between the values of the mass flow obtained through the usual relations and those obtained based on the realized model, that includes the main elements necessary for a precise calculation. However, the proposed method opens a wider horizon of understanding of the compression system through direct correspondence with the real model and the graphical possibilities of displaying the time variation of the system characteristics.

Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology 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.)

When modeling the processes of gas injection into an elementary section and gas outflow from it into an unlimited space, quasi-one-dimensional equations of gas pipeline transport in the approximation of a short pipeline are used, when the gas pressure gradient is formed only under the influence of the local component of the gas inertia force, and N.E. Zhukovsky's formula on the gas outflow rate. The equations for the conservation of momentum and mass are linearized with the introduction of the gas mass flow rate, and the first boundary condition is presented as a linear dependence on the sought functions. The solution area is divided into rectangles with the dimensions of the section length of the section and the conditional period of the problem, which corresponds to the travel time of the perturbation over the entire length of the section. For the first conditional period, the formulas for calculating the pressure and gas mass flow rate are obtained by the method of characteristics. The ways of using these formulas to obtain a solution for the subsequent conditional periods are shown. Separate results of the calculations for the pressure, mass flow, and gas flow rate are presented for constant values of the functions involved in the boundary conditions. It is found that the difference between the external pressure and the gas pressure in the subregions, as well as the gas mass flow rate, decreases exponentially over time. [ABSTRACT FROM AUTHOR]

Cartridge filters are widely utilized in industrial dust removal due to their advantages of high dust removal efficiency, compact size relative to bag filters, and the capacity to reuse collected dust. However, the conventional upright installation of the cartridges' front row directly faces the air inlet, which is directly impacted by the high-velocity dirt airflow and is often broken. This setup also disrupts airflow distribution, leading to uneven mass flow distribution and localized high velocity. To address these challenges, this study proposes horizontally installing the cartridges, by utilizing the bottom cone to buffer the airflow. This not only resolves issues of localized cartridge breakage but also promotes uniform airflow distribution, thereby prolonging filter service life. Computational Fluid Dynamics (CFD) is employed to simulate the changes in the flow field within the physical model, using finite element iterative calculations. This approach reduces experimental costs while providing precise data. Therefore, numerical simulation is used to verify the effectiveness of horizontal cartridges in improving the uniformity of the flow field distribution in the cartridge filter. The results showed that the horizontal cartridge filter improved the mass flow distribution uniformity by 54.9%, the peak velocity difference was reduced by 69.63%, and the maximum velocity was reduced by 68.42% compared to the upright cartridge filter. Horizontal cartridges have a more uniform flow field distribution, effectively avoiding problems such as abrasion and rupture of the filter media caused by excessive local air velocity. [Display omitted] • Effect of cartridge installation method on uniformity of flow field was studied. • Horizontal cartridge filters have a more uniform distribution of the flow field. • Mass flow distribution uniformity of horizontal cartridge filter improved 54.9 %. • Peak velocity of horizontal cartridge filter is 69.63 % lower than upright filter. • Horizontal cartridge filters have low turbulence intensity and better cleaning effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar promoted CH 4 component in biogas to 89.0 ± 6.3 % in the AnMBR. • Biochar increased 0.74 mol e- /g VS /min of electron transfer velocity in AD system. • Biochar was involved in electroactive microbial floravias metabolism via DIET. • The rate for acetate converted into CH 4 was enhanced 3.14 times by biochar. • Ambient temperature anaerobic digestion is a key to achieve net energy output. The anaerobic membrane bioreactor (AnMBR) is an alternative technology with energy neutrality potential when treating municipal wastewater (MWW). However, the poor bio-reaction kinetic conditions caused by low COD concentrations in MWW greatly limits the CH 4 yield. In this study, the average methanogenesis rate was significantly increased from 164.8 to 275.5 mL/g COD with the two times biochar addition of 5 g/L. And following the second time addition of 5 g/L biochar, the CH 4 component significantly increased to a high level of 89.0 ± 6.3 %. In addition, the rate for acetate converted into CH 4 increased from 3.3 to 10.5 mmol/(g VS ·d) with biochar addition of 10 g/L, indicating that acetotrophic methanogenesis route was significantly promoted by biochar. Bio-electrochemistry analysis showed that biochar accelerated 0.74 mol e-/g VS /min of electron transfer velocity in AD system. The addition of biochar enriched organic metabolism bacteria such as Ancinetobacter_lwoffii , Comamonas and Geobacter , and upregulated the expression of functional genes related to organics degradation such as lldD , sucD and fumC, facilitates the direct transfer of electrons and acetates produced by Comamonas and Geobacte r to convert CO 2 into CH 4 through microbial mediation. Thus, the COD flow shifted significantly towards more CH 4 production. The COD mass flow showed that biochar facilitated more bio-catabolism (up about 52.7 %) and less bio-anabolism (down about 92 %), and more COD in wastewater was converted to CH 4 , resulting a significant promoting of energy production. The energy balance analysis indicated that the net energy consumption was reduced by 15 % after two times addition of 5 g/L biochar, and the key to achieve the net energy output during treating MWW is the efficient operation of AnMBR at ambient temperature. [ABSTRACT FROM AUTHOR]

Small pumps with excellent performance are in demand in various industrial fields. In the present study, a new type of small underwater insertion pump that combines electromagnetic force and mechanical resonance was developed. A prototype electromagnetic-vibration pump with a one-valve structure in which the vibration component and water are separated by a thin film was constructed. The shape of this pump was optimally designed for the casing and valves. Rod and piston-type casings have been proposed to effectively use the displacement of the vibration component. By the inertial effect of water due to the operating principle, thin film separation, and shape optimization, the maximum efficiency of this pump was 19.1%, which exceeds that of previously proposed small pumps. In addition, as a normal use of the prototype pump, the pump with an acrylic pipe attached to the inlet port was improved, and its flow rate characteristics were examined. These two pumps can be directly driven by the power of a power outlet by tuning the resonance frequency of the vibration component. The proposed pump can be used in two ways depending on the application. [ABSTRACT FROM AUTHOR]

Prerequisite for an undisturbed investigation of fan self-noise generating mechanisms is a fan inflow with negligible spatial and temporal nonhomogeneity. For this purpose, an inflow control device (ICD) was constructed for a low-speed aeroacoustic fan rig operated in laboratory environment. The ICD was built using flexible honeycomb covered on both sides with a thin wire mesh to ensure maximum turbulence reduction. The performance of the ICD was assessed both aerodynamically by means of hot-wire and total pressure rakes, and the fan noise emission was recorded by a microphone array. The ICD established a homogeneous inflow in terms of both turbulence intensity and the mean axial flow velocity. Both the turbulence intensity and the integral length scale profile along the radial direction were fully characterized. Turbulence levels of around 0.1% were achieved in the freestream when the ICD was installed on the inlet. Acoustic measurements revealed more stable rotor-coherent tones, along with a strong reduction of narrowband components around the blade passing frequencies. A reduction of the fan noise broadband levels was also observed. [ABSTRACT FROM AUTHOR]

A low-amplitude high-frequency flow control strategy for mitigation of transient tip stall is demonstrated for the case of a finite swept wing using high-fidelity wall-resolved large-eddy simulations. A wing of aspect ratio =4 and NACA 0012 section is considered at freestream Mach number M∞=0.1 and chord Reynolds number Rec=2×105. The wing undergoes an oscillatory pitching motion with reduced frequency k=π/16 and angle of attack between α=4 and 22 deg, resulting in deep dynamic tip stall for the uncontrolled case. Spanwise uniform low-amplitude pulsed forcing is imparted through a zero-net mass flow blowing/suction slot located on the wing lower surface near the leading edge using both moderate and high frequencies, Stf=fc/U∞=5 and 50, respectively. The imposed small fluctuations are amplified through the natural receptivity of the laminar separation bubble (LSB) and, in the case of the highest frequency, completely inhibit its bursting along the wing, which precludes outboard flow separation and subsequent dynamic tip stall. The lower-frequency forcing cannot overcome eventual bursting of the LSB near the wingtip; however, the resulting separation is localized to the tip region unlike the full outboard unloading of the uncontrolled case. Conditioning of the leading-edge flow through targeted manipulation of the LSB and its inherent dynamics maintained or enhanced the effectively attached flow throughout the pitching cycle, resulting in significant reductions in the cycle-averaged drag and in the force and moment excursions. [ABSTRACT FROM AUTHOR]

Fungi need water for all stages of life. Notably, mushrooms consist of ∼90% water. Fungi degrade organic matter by secreting enzymes. These enzymes need water to be able to break down the substrate. For instance, when the substrate is too dry, fungi transport water from moist areas to arid areas by hydraulic redistribution. Once nutrients are freed from the substrate, they are taken up by transporters lining the cell membrane. Thereby an intracellular osmotic potential is created which is greater than that of the substrate, and water follows by osmosis. Aquaporins may facilitate water uptake depending on the conditions. Since fungi possess a cell wall, the cell volume will not increase much by water uptake, but the cell membrane will exert higher pressure on the cell wall, thereby building up turgor. Fungi have tightly coordinated osmotic regulatory controls via the HOG pathway. When water is getting scarce, this pathway makes sure that enough osmolytes are synthesized to allow sufficient water uptake for maintaining turgor homeostasis. The fungal network is interconnected and allows water flow when small pressure differences exist. These pressure differences can be the result of growth, differential osmolyte uptake/synthesis or external osmotic conditions. Overall, the water potential of the substrate and of fungal tissues determine whether water will flow, since water flows from an area of high- to a low water potential area, when unobstructed. In this review we aim to give a comprehensive view on how fungi obtain and translocate water needed for their development. We have taken Agaricus bisporus growing on compost and casing soil as a case study, to discuss water relations during fruiting in detail. Using the current state-of-the-art we found that there is a discrepancy between the models describing water transport to mushrooms and the story that water potentials tell us. • Mechanisms driving water uptake, turgor homeostasis and transport are examined. • The impact of the location(s) of water uptake/exit on transport is discussed. • The concept of water potential is explained and example calculations are provided. • Impact of water balance in Agaricus bisporus cultures is analysed during fruiting. • Pressure potential is proposed as the missing link in water transport to mushrooms. [ABSTRACT FROM AUTHOR]

Accurately quantifying unsteady methane venting from key oil and gas sector sources such as storage tanks and well casing vents is a critical challenge. Recently, we presented an optical sensor to meet this need that combines volume fraction and Doppler shift measurements using wavelength modulation spectroscopy with 2f harmonic detection to quantify mass flux of methane through a vent line. This paper extends the previous effort through a methodical component-by-component investigation of potential sources of thermally-induced measurement drift to guide the design of an updated sensor. Test data were analyzed using an innovative signal processing technique that permitted quantification of background wavelength modulation spectroscopy signal drift linked to specific components, and the results were successfully used to design a drift-resistant sensor. In the updated sensor, background signal strength was reduced, and stability improved, such that the empirical methane-fraction dependent velocity correction necessary in the original sensor was no longer required. The revised sensor improves previously reported measurement uncertainties on flow velocity from 0.15 to 0.10 m/s, while markedly reducing thermally-induced velocity drift from 0.44 m/s/K to 0.015 m/s/K. In the most general and challenging application, where both flow velocity and methane fraction are independently varying, the updated design reduces the methane mass flow rate uncertainty by more than a factor of six, from ±2.55 kg/h to ±0.40 kg/h. This new design also maintains the intrinsic safety of the original sensor and is ideally suited for unsteady methane vent measurements within hazardous locations typical of oil and gas facilities. [ABSTRACT FROM AUTHOR]

The effect of a rotating gliding arc (RGA) plasma discharge on the flame in a downscaled Siemens Energy dry low emission, SGT-750, burner was experimentally investigated under atmospheric combustion conditions. The central pilot section of the burner, named RPL (rich-pilot-lean), was redesigned with an integrated high-voltage electrode to generate an RGA. The exhaust gas was sampled and analyzed in terms of CO and NOx emissions, and the CO emission data show that the RGA extends the lean blowout limit. High-speed OH chemiluminescence imaging was employed to understand the transient behavior of the flame in both conditions, with and without RGA, and also to study the process of flame restabilization by the assistance of the RGA. A flame kernel, initiated around the RGA channel, was observed to play an important role in the restabilizing process of the flame. Although the NOx emission for the flame with RGA was found to be higher than that without RGA, it was still less than what previous data show for operating conditions with the RPL flame. [ABSTRACT FROM AUTHOR]

An optical sensor employing tunable diode laser absorption spectroscopy with wavelength modulation and 2f harmonic detection was designed, prototyped, and tested for applications in quantifying methane emissions from vent sources in the oil and gas sector. The methane absorption line at 6026.23 cm–1 (1659.41 nm) was used to measure both flow velocity and methane volume fraction, enabling direct measurement of the methane emission rate. Two configurations of the sensor were designed, tested, and compared; the first used a fully fiber-coupled cell with multimode fibers to re-collimate the laser beams, while the second used directly irradiated photodetectors protected by Zener barriers. Importantly, both configurations were designed to enable measurements within regulated Class I / Zone 0 hazardous locations, in which explosive gases are expected during normal operations. Controlled flows with methane volume fractions of 0 to 100% and a velocity range of 0 to 4 m/s were used to characterize sensor performance at a 1 Hz sampling rate. The measurement error in the methane volume fraction was less than 10,000 ppm (1%) across the studied range for both configurations. The short-term velocity measurement error with pure methane was <0.3 m/s with a standard deviation of 0.14 m/s for the fiber-coupled configuration and <0.15 m/s with a standard deviation of 0.07 m/s for the directly irradiated detector configuration. However, modal noise in the multimode fibers of the first configuration contributed to an unstable performance that was highly sensitive to mechanical disturbances. The second configuration showed good potential for an industrial sensor, successfully quantifying methane flow rates up to 11 kg/h within ±2.1 kg/h at 95% confidence over a range of methane fractions from 25–100%, and as low as ±0.85 kg/h in scenarios where the source methane fraction is initially unknown within this range and otherwise invariant. [ABSTRACT FROM AUTHOR]

The aero-engine will produce fouling during operation, which will affect the engine performance. On-line cleaning can effectively remove fouling, in order to solve the problem of the poor cleaning effect for aero-engine on-wing cleaning and carry out numerical simulation of the on-line cleaning process. The discrete phase model is used to optimize the particle size and mass flow of the cleaning fluid. The erosion rate and vorticity of the droplets on the blade surface are used as the effect target to simulate and optimize the cleaning process parameters to obtain a better particle size range and the ratio of cleaning fluid to air mass flow. Through the evaluation of the cleaning process parameters of the aero-engine on-wing cleaning test and the analysis of the engine exhaust temperature margin (EGTM) data, it is concluded that the cleaning effect is improved by nearly 40%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Food waste anaerobic digestion based on nitrogen-carbon separation was investigated. • Three-phase separation redistributed carbon and nitrogen before anaerobic digestion. • 78.4% of C and 48.3% of N in food waste were separated in the centrifugation. • The main endpoints for C, N, and P are crude oil, fine slag, and biogas slag. • Separation utilization of carbon and nitrogen improve resource recovery level. Anaerobic digestion of food waste can recover carbon in the form of biogas, while the high concentration of ammonia nitrogen in the digestion effluent becomes troublesome. Therefore, some new treatment plants use three-phase centrifugation to separate homogenized food waste into nitrogen-rich fine slag for insect cultivation and carbon-rich liquid for anaerobic digestion. To analyze the effects of the carbon–nitrogen separation, an upgraded plant's material and elementary flows were investigated. The three-phase separation process redistributed carbon and nitrogen, and the biogas slurry was the primary output. The principal endpoint for C was the crude oil, capturing 57.1 ± 13.1 % of the total input; the find slag collected 48.3 ± 6.9 % of the total N input, and the biogas slag accepted 52.9 ± 4.4 % of the P input. The carbon–nitrogen separation strategy can improve digestion efficiency and increase treatment benefits significantly, marking a promising direction for future developments in food waste utilization. [ABSTRACT FROM AUTHOR]

The purpose of this work is the design and construction of a non-invasive meter for concentration in saline solutions and the proposal of a low-cost mass flow meter for absorption refrigeration systems with LiBr/H 2 O. The proposed meter makes use of a capacitive sensor relating the electrical capacitance of the LiBr/H 2 O mixture to the mass fraction of LiBr in the solution. Thus, an experimental apparatus composed of a capacitive sensor with cylindrical geometry, high-frequency oscillators, and a temperature control system was built. Tests involving samples of the solution at concentrations from 50 to 64% LiBr were conducted to reproduce the typical operating conditions of the absorption chiller, establishing correlations between concentration, voltage, and temperature. The matches of these correlations between concentration and density were very good with maximum relative errors of less than 2.5%. The same procedure was performed for the density measurement, achieving a density, voltage, and temperature relationship with errors of less than 0.27%. For the determination of the volumetric flow rates, a turbine-type meter, equipped with a Hall effect sensor W1305347 and an Arduino microcontroller (MEDY FLOW), was adopted, which proved to be effective when dealing with the LiBr/H 2 O salt solution and good accuracy when compared to conventional meters, showing statistically proven relative errors of less than 4%. The results showed a satisfactory level of repeatability and accuracy with errors of 0.4% and 2.5%, for the range of operation evaluated. Experimental bench used for measuring concentration and mass flow rate for saline solutions. [Display omitted] • A proposal of non-invasive meter for concentration in saline solutions was proposed. • A low-cost mass flow meter for absorption refrigeration systems with LiBr/H 2 O was tested. • Numerical correlations of concentration, density, voltage, and temperature were proposed. • The maximums errors between the estimated and experimented values were less than 4%. • Satisfactory repeatability and accuracy (errors of 0.4% and 2.5%) were achieved. [ABSTRACT FROM AUTHOR]

Labyrinth seals are widely used in centrifugal compressors, turbines, and many other pneumatic systems due to their simplicity of design, reliability, and low cost. The calculation scheme for the movement of the working medium in a labyrinth seal is constructed by analogy with the movement of the working medium through holes with a sharp edge. Annular and flat slots, holes, and such a factor as the shaft rotation with a calculated sector of 3 degrees were studied. The purpose of the study is to determine the flow coefficient when the working medium flows through slots of various shapes. To achieve this purpose, modeling of the working medium flow in the FlowVision software was performed. The mass flow and flow coefficients are determined for the studied slot shapes. The convergence of the calculation results was determined by comparing the values of the mass flow rate at the inlet and outlet of the slot. Differences in visualizations of the flow for the studied variants of slots were established. The resulting difference should be taken into account in practical calculations of the working medium mass flow through the slot using a conditional flow rate factor which is determined by the slot design. [ABSTRACT FROM AUTHOR]

The modeling method of the pogo system of launch vehicles with a staged combustion cycle engine is mainly limited to the transfer matrix modeling method, which contains transcendental functions that are difficult to solve. A state-space modeling method for the pogo system of launch vehicles with a staged combustion cycle engine is proposed in this paper. First, the second-order differential dynamic equation of the gas path is constructed by approximating the exponential term in each element of the gas path with Taylor expansion and inverse Laplace transformation. Second, the liquid and gas paths are combined in the form of mass flow to establish the second-order dynamic equation of the propulsion system. Third, the state-space equation of the coupled system is obtained by combining the structural and propulsion systems. Finally, an example of a propulsion system is modeled using the transfer matrix modeling method and the proposed method to verify the correctness of the proposed method, and the stability of the model is analyzed when the parameters of the accumulator and gas path change. The major contributions are as follows: 1) the proposed method is a systematic method that is universally applicable to the pogo analysis of a launch vehicle with a staged combustion cycle engine; 2) the proposed method inherits the advantages of Rubin's state-space method for liquid rockets. [ABSTRACT FROM AUTHOR]

Current studies on the reactive extraction of fumaric acid with Amberlite LA-2 from aqueous phases with different viscosities using three solvents highlighted the influences of rheological properties of the fermentation medium on the efficiency of the extraction system. The obtained results showed that increasing the viscosity of the aqueous phase influences both the efficiency of the reactive extraction and the magnitude of the diffusional and kinetic resistances. The negative effect of increasing the viscosity of fumaric acid solutions on the interfacial mass flow of the product resulting from the reaction between acid and extractant was described by the reduction factor. For dichloromethane, by increasing the speed from 200 to 1000 rpm, the R factor increases 1.05 times for 8 cP and 3.56 times for 64 cP, while for n-heptane R factor increases 1.11 times for 8 cP and 9 times for 64 cP. The positive effect of alcohol was quantified using the amplification factor, which reached maximum values for n-heptane, under similar experimental conditions. The influences of studied factors on interfacial mass flow of the complex formed by reaction of fumaric acid with amine extractant have been quantified by mathematical expressions, proposed for extraction system without and with 1-octanol. [ABSTRACT FROM AUTHOR]

Summary: Understanding how plant water uptake interacts with acquisition of soil nitrogen (N) and other nutrients is fundamental for predicting plant responses to a changing environment, but it is an area where models disagree.We present a novel isotopic labelling approach which reveals spatial patterns of water and N uptake, and their interaction, by trees. The stable isotopes 15N and 2H were applied to a small area of the forest floor in stands with high and low soil N availability. Uptake by surrounding trees was measured. The sensitivity of N acquisition to water uptake was quantified by statistical modelling.Trees in the high‐N stand acquired twice as much 15N as in the low‐N stand and around half of their N uptake was dependent on water uptake (2H enrichment). By contrast, in the low‐N stand there was no positive effect of water uptake on N uptake.We conclude that tree N acquisition was only marginally dependent on water flux toward the root surface under low‐N conditions whereas under high‐N conditions, the water‐associated N uptake was substantial. The results suggest a fundamental shift in N acquisition strategy under high‐N conditions. [ABSTRACT FROM AUTHOR]

Facies and facies succession analysis from four sections in a ~12 m thick carbonate succession, hitherto undescribed, exposed over an east-west transect over 600 km from the topmost part of the Palaeoproterozoic Sleemanabad Formation, Mahakoshal Group, Central India reveals facies development in a proximal-distal relation. The facies types include microbialite and stromatolite, interbedded limestone-mudstone, intraclastic conglomerate, pyrite bearing dark-coloured limestone and massive/normal-graded conglomerate and fine-grained sandstone. While microbialites and isolated stromatolites (rarely conjoined) with seafloor precipitate are interpreted as a product of proximal peritidal deposition, the dark-coloured pyrite bearing limestone represents the distal platform deposition below storm wave base. [ABSTRACT FROM AUTHOR]

Volcaniclastic diamictons, while found in all ancient and modern volcanic settings across New Zealand, are most commonly associated with stratovolcanoes. Lahar refers to a volcanic mass flow that consists of variable amounts of water and particles of different-sized volcanic lithologies; such flows can exhibit a range of rheologies that rapidly change at temporal and spatial scales. At Mt. Taranaki time packages of lahar deposits were originally grouped into chronostratigraphic formations, such as the 22,500–11,000 yrs B.P. Warea Formation, which consists of lahar deposits that display a range of sediment-water interactions reflecting variable rheological regimes. In historic times, lahars have been rare at Mt. Taranaki with the most recent events occurring in 1999 and 2008. In contrast, Mt. Ruapehu has been extremely active over the last 170 years with regular small-volume eruption-induced events and larger, more significant Crater-Lake breakout lahars. The Onetapu Formation comprises flows of the last 2,000 years that are 1–2 orders of magnitude greater in volume, stage and discharge. To better understand the hazard potential of such events, a range of numerical modelling and simulations have been created, with computational simulations being applied to hindcast and forecast the potential hazards of lahars from New Zealand's stratovolcanoes. [ABSTRACT FROM AUTHOR]

In this paper, influences of structure parameters on mass flow and atomization characteristics (spray cone angle, SMD, liquid film fusion and separation) of dual-orifice atomizers were investigated using Fraunhofer diffraction optical instrument and high-speed shadowgraph technique. The main influential structure parameters are obtained by structural parameter sensitivity analysis. Liquid film fusion and separation is an important atomization characteristic lacking of in-depth research. Results of liquid film fusion and separation illustrate that three patterns (separation-fusion-secondary separation) of main stage liquid film and pilot stage liquid film appear with the increase of Δ P. Liquid film fusion makes SMD larger, and there is a delay in liquid film separation when reduce Δ P after liquid film fusion. In addition, mass flow and spray cone angle are key factors which affect liquid film fusion pressure, liquid film secondary separation pressure and distance between two liquid films. The smaller the pilot stage mass flow is, the larger the effect of the main stage on pilot stage spray cone angle will be. Results in this paper could be used to the design and optimization of new dual-orifice atomizers. [ABSTRACT FROM AUTHOR]

In this paper, the optimization method we obtained from dual-orifice atomizers previously is used to design and optimize new dual-orifice atomizers, whereas there are some differences between the new dual-orifice atomizer and dual-orifice atomizer used in Part I. For example, the mass flow is much smaller, there is an expansion angle at pilot nozzle to regulate pilot stage spray cone angle, and there is no recess length between main nozzle and pilot nozzle. Influences of structure parameters on mass flow, spray cone angle and liquid film fusion and separation are investigated, which are consistent with the expectation. Structure parameters that meet performance requirements of dual-orifice atomizer are analyzed. In addition, a new phenomenon has been found is that liquid film oscillation appears with the increase of Δ P, which should be avoided during the design and optimization of new atomizers. Pilot liquid film oscillation will influence the development of dual-orifice liquid film. Pilot swirling groove depth and expansion angle of pilot nozzle are key parameters that influence liquid film oscillation. Conclusions in this paper can be used to guide the design and optimization of new dual-orifice atomizers. [ABSTRACT FROM AUTHOR]