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BACKGROUND: Cowpea is a rich source of low‐cost protein, but it remains underutilised due to the development of the hard‐to‐cook phenomenon. However, milling hard‐to‐cook (HTC) seeds has shown potential for their utilisation in developing food products. Also, yellow maize is a relatively underutilised grain that is rich in nutrients, including vitamin A. Extrusion cooking of blends including yellow maize and HTC cowpea in snack formulations has the potential to improve their utilisation. Therefore, the objective of the study was to formulate a nutritious acceptable extruded snack using a combination of HTC cowpea and yellow maize flours. RESULTS: The results showed that addition of HTC cowpea flour increased ash (0.56–1.47%), fibre (3.56–5.31%) and protein content (10.20–12.38%) for flour blends. While carbohydrate (2.39–1.57%) and moisture content (10.33–9.74%) decreased. Blended formulations had lower fat content (4.17–4.41%) than yellow maize (4.80%). Furthermore, addition of HTC cowpea increased water (21.18–30.07%) and oil absorption capacities (14.12–22.03%) for flour blends. While expansion ratio (2.39–1.57%) of snacks decreased. The formulation with 15% HTC cowpea and 85% yellow maize flour had higher sensory ratings for overall acceptability (6.98). CONCLUSION: HTC cowpea addition in yellow maize flour improved the proximate and functional properties. Also, blending of yellow maize‐based snacks with HTC cowpea improves consumer acceptability. Yellow maize and HTC cowpea flour blends have potential for industrial utilisation and can be useful in food formulations. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry 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.)

To design hydrosteam turbines of the Segner-wheel type, it is necessary to have reliable characteristics of a Laval nozzle with a large expansion ratio when water strongly subcooled to a saturation temperature is fed to the nozzle. The authors have given a review of a number of works on determining the flow-rate coefficient μ and the coefficient of velocity ϕ when water subcooled to a saturation temperature flows out of Laval nozzles. The complexity of the process of outflow of a steam–water mixture has been noted, which is dependent on the relation of the temperature and pressure at entry into the nozzle, pressure behind the nozzle and the nozzle expansion ratio, and the configuration of the entrance region. Experimental data have been given on blowdowns of geometrically similar nozzles with measuring the jet thrust and determining the flow-rate and velocity coefficients. It has been shown that the linear dimensions of the nozzle throat do not influence μ when a constant relation of the length of the throat to its diameter is observed. The velocity coefficient during the outflow of a boiling liquid depends on the linear dimensions of the expanding section of the nozzle, i.e., testing of geometrically similar nozzles do not ensure a correct determination of φ. It has been shown that the nozzles' efficiency must be compared in the design regime when the pressure on the exit section is equal to the pressure in the chamber where the steam–water mixture flows. Analysis results will be useful for calculating and designing a reaction hydrosteam turbine. [ABSTRACT FROM AUTHOR]

The object of this study is the properties of compressed air foam with the use of modified additives: its drainage time and expansion ratio. The main properties of compressed air foam that affect the effectiveness of fire extinguishing are its drainage time and expansion ratio. At the same time, a number of authors have confirmed that the introduction of chemically modified additives into the composition of water fire extinguishing substances makes it possible to increase the effectiveness of fire extinguishing. The problem to be solved was to determine the influence of five modified additives (N4)2HPO4, N4H2PO4, (N4)2СO3, K2CO3 and KCl in the concentration range of 1–5 % by mass on the expansion ratio and drainage time of the compressed air foam. The results showed that the content of additives (N4)2HPO4, N4H2PO4 and (N4)2СO3 in the aqueous solution of the foaming agent does not affect its expansion ratio within the given limits. On the other hand, with K2CO3 and KCl additives, it was not possible to obtain compressed air foam with a expansion ratio of 5–20, that is, their inefficiency in compressed air foam was noted. The characteristic dependence of the effect of (N4)2HPO4, NH4H2PO4 and (N4)2СO3 additives on drainage time has been determined. The greatest drainage time is characteristic of the K≈20 generation mode. The highest recorded drainage time index was established for N4H2PO4, namely 5.45 min; for (NH4)2HPO4 the drainage time was lower by 8 %; for (N4)2СO3 the drainage time was lower by 20 %. At the same time, with the use of (N4)2HPO4, N4H2PO4 and (NH4)2СO3, it is characteristic to obtain a foam with lower drainage time compared to foam of a conventional composition. Thus, for foam with a expansion ratio of K≈20, the drainage time of foam with NH4H2PO4 is lower by 17 %, with (NH4)2HPO4 by 23 %, and with (NH4)2СO3 by 33 %. The effect of reducing the drainage time of the foam can have a decisive role in reducing its effectiveness when used for extinguishing flammable liquids due to the extinguishing mechanism but is not decisive for extinguishing solid substances. Therefore, the fire-extinguishing effectiveness of compressed air foam with modified additives during the extinguishing of solid combustible materials in comparison with the conventional CAF composition requires further study [ABSTRACT FROM AUTHOR]

The expanded web depth of steel beams leads to improved strength and stiffness. In some design scenarios, such as cellular, castellated, or expanded steel beams, increasing the depth of the web improves the strength and performance of the steel beam. The expanded web of steel beams can be accomplished by creating a horizontal cutting in the web and then adding a plate between the two web section halves, which are called spacer plates. This method leads to improved stiffness and strength. Numerical models have been developed to accurately predict the properties of these beams. This study investigates the use of incremental plates to increase the depth of hot-rolled wide-flange steel beams. The experimental results were validated first with the Finite Element (FE) numerical model created by ABAQUS software, and then Finite Element Analysis (FEA) methods were used to create and analyze new numerical models by considering parameters that provided more models at a lower cost. The load-mid-span deflection curve behavior of both models (experimental and theoretical) was similar. Also, the load-deflection behavior of steel beams with two types of openings was studied. For the first type of opening (B1 NUM), with a smaller opening width of 30 mm and a higher hole number (24), the ultimate load increased by 53%, 111%, and 184%, the deflection at 0.95 Pu increased by 160%, 293%, and 81% of beams with ratio 150%, 200%, and 250% compared with the reference beam. For the second type of opening (B2 NUM), with a larger opening width of 60 mm and smaller hole number (12), the ultimate load capacity increased by 51%, 147%, and 177%, for beams with a ratio of 150%, 200%, and 250%, compared with the reference beam. The deflection at 0.95 Pu increased by 46% and 15% for beams with a ratio of 150%, and 200%, and decreased by 8% for beams with a ratio of 250%. Accordingly, for the first type of opening, the expanded ratios of 150% and 200% performed best with a reduction of only 1%-12% in the ultimate load capacity. However, for the second type of opening, the beam with a ratio of 250% performed better than the first type. Using prestress strands may highly improve steel beams' performance with the expanded webs containing openings by creating a stronger section that can withstand higher loads and exhibit improved structural performance, especially from beams with a ratio of 150%. [ABSTRACT FROM AUTHOR]

To investigate the effect of ultrasound assisted NaCl soaking on the structure and digestive characteristics of black beans, the scanning electron microscopy, infrared spectroscopy analysis, X-ray diffraction and other methods were used to analyze the mechanism of NaCl on the structure of black beans. And the thermal properties, water absorption, and swelling rate were used to clarify the changes in the properties of the black beans during the ripening process, and the in vitro digestive properties of starch were analyzed. The results showed that ultrasound-assisted NaCl soaking decreased the densification of black bean powder particles and made the gap between particles larger while reducing the damage to the starch crystallization region. With the increase of NaCl concentration, the swelling rate of black bean particles increased by 28%, 48%, and 56% compared to water soaking, and the hardness significantly decreased. The gelatinization degree increased to 40%, 43%, and 45%, and the hydrolysis rate of black bean starch decreased to 19.05%, 17.93%, and 17.48%, respectively. This indicated that sodium ions could inhibit starch digestion, the NaCl soaking treatment in this study would provide a theoretical basis for the development of low GI functional foods.

One of the efficient and cost-effective structural elements is the castellated steel beam (CSB) which can significantly lower building costs. This fact encourages studying the structural behavior of such beams and determining the castellation ability to maximize flexural stiffness while avoiding shear failure. For this purpose, experimental and theoretical investigations were carried out. The experimental work consisted of fabricating and testing six beams with span lengths of 2000 and 1038 mm and expansion ratios of 1.0, 1.25, and 1.50. Meanwhile, the theoretical part included an adopted analytical procedure that produced an unprecedented theory-based formula giving the maximum expansion ratio ( ψ m ), thus determining the nominal flexural strength of any castellated section. On the other hand, the experimental results, which covered a variety of mechanisms and failure modes, including overall flexural failure, shear and compression buckling of the web posts, tearing and inelastic local buckling, and compression buckling of the top tee, confirmed that ψ m should not be exceeded to fully utilize the flexural capacity of CSBs. The formula for ψ m was then graphed for design purposes, and it was found that it relies on three major parameters: loading type factor (Cc), span length (L), and properties of the root section, upon which any castellated section has a distinct ultimate flexural strength. Furthermore, the ultimate flexural strength increases as the loading type factor decreases and the span length increases. [ABSTRACT FROM AUTHOR]

To investigate the effect of ultrasound assisted NaCl soaking on the structure and digestive characteristics of black beans, the scanning electron microscopy, infrared spectroscopy analysis, X-ray diffraction and other methods were used to analyze the mechanism of NaCl on the structure of black beans. And the thermal properties, water absorption, and swelling rate were used to clarify the changes in the properties of the black beans during the ripening process, and the in vitro digestive properties of starch were analyzed. The results showed that ultrasound-assisted NaCl soaking decreased the densification of black bean powder particles and made the gap between particles larger while reducing the damage to the starch crystallization region. With the increase of NaCl concentration, the swelling rate of black bean particles increased by 28%, 48%, and 56% compared to water soaking, and the hardness significantly decreased. The gelatinization degree increased to 40%, 43%, and 45%, and the hydrolysis rate of black bean starch decreased to 19.05%, 17.93%, and 17.48%, respectively. This indicated that sodium ions could inhibit starch digestion, the NaCl soaking treatment in this study would provide a theoretical basis for the development of low GI functional foods. [ABSTRACT FROM AUTHOR]

Micro-nozzles play a critical role in various applications, such as micro-/nano-satellites in aerospace and heat dissipation and cooling in microelectronic systems (MEMS). The flows inside micro-nozzles can experience both continuum and rarefied flow due to their small size. In this research, we explore the optimal geometry configuration of micro-nozzles to achieve comprehensive performance and size, as well as background pressure compensation. Using classical computational fluid dynamics (CFD) and direct simulation Monte Carlo methods (DSMC), we investigate the effects of the expansion ratio, cross-profile shape, and plug on the performance of micro-nozzles operating over a wide range of pressures (0. 5 − 100 kPa). The results reveal that micro-nozzle performance is influenced by the interplay between flow expansion and viscous loss induced by the subsonic layer next to the micro-nozzle wall. The findings show that micro-nozzle performance improves with increasing expansion ratio in slip and continuum flow regimes, but decreases in the transition flow regime. Additionally, the results indicate that the axisymmetric micro-nozzle (with a circular cross-profile) outperforms the linear micro-nozzle (with a rectangular cross-profile) in terms of both performance and size when subject to the same conditions, making it the recommended choice for practical applications. We also find that plugs designed at the throat decrease performance, but increase stability under diverse background pressures. This study provides valuable insights for the design of high-efficiency micro-nozzles in applications such as nanosats and MEMS heat dissipation units. • Geometry configuration effects on micro-nozzle performance are studied numerically. • Viscous loss and flow expansion degree are pivotal for micro-nozzle performance. • Low expansion ratio micro-nozzle is better for comprehensive performance and size. • The axisymmetric micro-nozzle surpasses the linear micro-nozzle. • The plug micro-nozzle performs well in variable pressure ambient. [ABSTRACT FROM AUTHOR]

In some design cases, such as in castellated beams, cellular beams, or steel beams with expanded web, it is advantageous to strengthen and enhance the performance of steel beams by increasing the web depth. However, expanding the web of a steel beam is a unique engineering strategy. This modification not only enhances its ability to bear heavy loads but also reduces any bending or flexing while enabling longer distances between supports. The expanded steel beams can be achieved by making a horizontal cutting in the steel beam web and then adding an increment plate (with the same web thickness), called spacer plate, between the two halves of the web sections, thus improving stiffness and strength. To evaluate the behavior of such beams, nine specimens of HEA steel beams with expanded web ratios of 150%, 200%, and 250%, and one specimen as a reference beam, were fabricated. The specimens were evaluated under two-point load over a clear span length of 280 cm. From the experimental work it was found that for steel beams with expanded web that have 18 openings with 80 mm, the beams with an expansion ratio of 150% had the best performance according to load-deflection behavior with a reduction in load capacity by only 11%. Additionally, the beams with expansion ratios of 200% and 250% had no economic viability according to the analysis of load-deflection behavior with a reduction in load capacity by 49% and 62%, compared with the solid expanded steel beam with the same expansion ratio. For the second type of steel beam with expanding web with 9 openings of 160 mm width, the beams with expansion ratios of 200% and 250% were observed to perform better than the first type with a reduction in load capacity by 28% and 50%. Using larger opening width and a smaller opening number is considered the best option for beams with expansion web ratios of 200% and 250%, while on the contrary, using smaller opening width and higher numbers seems to be a better option for beams with 150% expansion web ratio. Expanding the depth of a steel beam provides design flexibility, reduces deflections, and allows for longer spans. These benefits enhance material efficiency and open up new architectural possibilities. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of 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.)

If the cemented paste backfill (CPB) does not contact the roof, it will cause mining safety problems such as roof collapse, and the passive roof contact technology cannot effectively solve the problem. Therefore, the active roof-contact technology based on expansion agent was developed. The orthogonal experiments were carried out to study the influence of mass concentration, tailings-to-cement ratio and expansion agent content on the expansion ratio and mechanical properties of CPB. Through the range analysis of the expansion ratio and unconfined compressive strength (UCS), the significance of influencing factors on the expansion ratio and UCS was obtained. The experimental results show that the tailings-to-cement ratio has the greatest influence on the UCS, and the expansion agent content influence the expansion ratio more. The multivariate nonlinear regression models can accurately predict the expansion ratio and UCS of CPB. It is found that the sensitivity of expansion agent content to the expansion ratio decreases with the increase of tailings-to-cement ratio. According to the requirement of the mine for the expansion ratio and UCS, the expansion ratio and UCS were optimized by multi-objective optimization, and the optimal proportioning schemes suitable for the CPB in mines were obtained. Finally, the expansion mechanism was revealed by scanning electron microscope (SEM), and the evolution of the expansion agent with hydration process was analyzed. This study is of great significance to realize the roof-connect of metal mines, and has important practical value for the safe mining.

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) 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.)

Large resources of thermal and industrial waters at a temperature of 100–150°С can be employed to generate electricity in both a single-circuit thermal cycle with direct usage of natural steam in condensing turbines and a double-circuit cycle with a low-boiling working fluid. Both options require high capital expenditures for their implementation. A new power-generation method on the basis of low-grade heat is to install a full-flow hydro-steam turbine (HST), which utilizes the heat of separated liquid from a geothermal station or the heat of industrial waters, in a single-circuit thermal cycle. Capital expenditures for these units are much lower since special equipment for preparation of the working fluid is not required. The efficiency of a hydro-steam turbine is directly related to the efficiency of its main element, which is the Laval nozzle. Designing this turbine requires reliable data on the performance of a Laval nozzle with a high expansion ratio when it operates on highly subcooled water. Such information can only be obtained experimentally since this region of operation of Laval nozzles has been poorly studied as of yet. To determine the required characteristics of the nozzles, an experimental setup was designed and manufactured with a set of Laval nozzles, including nozzles with different opening angles of the diverging section and nozzles with an oblique cut. The working fluid was water under conditions close to the operating conditions in an HST. The results are presented of the experimental study of Laval nozzles in a wide range of expansion ratios for operation on boiling water. The experiments were performed at different pressures downstream of the nozzle, and their results were compared with previously obtained experimental data. The experimental setup and design features of the nozzle are described. The experimental data on the flow coefficient, velocity coefficient, expansion ratio, initial conditions, nozzle shapes, and size effect, on which the conclusions made are based, have been analyzed. Characteristics have been found that enable us to predict the efficiency of a reaction hydro-steam turbine and properly calculate its output. [ABSTRACT FROM AUTHOR]

AbstractIn recent times, extrusion cooking is being used to develop nutrient-dense products with an aim to benefit humans and to cater their nutritional requirements. The present paper discusses various aspects of twin-screw extrusion cooking and behaviour of its process parameters in relation to cereal–pulse blend. Profiling of raw material, i.e. moisture, protein, lipid, and starch, along with the assessment of product parameters including expansion ratio, bulk density, water absorption index, and water solubility index has been extensively reviewed to develop a desirable product. Therefore, in the present review paper, extrusion cooking has been highlighted and discussed in detail as a suitable technology for the development of cereal–pulse-based snacks/products.

In this study, the frozen surimi was select as the main raw material, and the effects of starch types, and the additions of starch, salt, leavening agent and egg white powder on the gel strength, expansion ratio, texture properties, and sensory score of surimi billets expanded by microwave were investigated by using single factor experiments. The key factors that influence the quality of surimi billets were screened by the Plackett-Burman experiment, and the optimal formulation of the microwave expanded surimi billets was determined by Box-Behnken design and response surface methodology. The results showed that the optimal starch added in the microwave expanded surimi billet was glutinous rice starch. The amount of salt, glutinous rice starch and leavening agent were the three key factors that determined the quality of surimi billets. The optimal formula of microwave expanded surimi billet was obtained at the salt amount of 2.16% , the glutinous rice flour amount of 6.26%, the compound leavening agent amount of 0.49% and the egg white powder amount of 0.9%, based on the weight of surimi. Under this condition, the gel strength of microwave expanded surimi billet was 16729.33±270.72 g·mm, and the sensory score was 85.8±0.84, respectively, and there were no significant difference between the verification value and the predicted values (P>0.05). The study provided a reference to the development of new surimi products.

The relevance of the research is caused by the need to conduct numerical studies of combustion in existing internal combustion engines with various injection designs and ignition systems for the fuel-air mixture of steam-gas pyrolysis products to generate mechanical energy on the crankshaft shaft. These directions will expand the role of pyrolysis of biomass, secondary products of wood processing enterprises and municipal solid waste in the field of heat and power complex. The main aim of this study is to evaluate the efficiency of combustion of gas-steam products of pyrolysis of wood waste in an internal combustion engine designed to use diesel fuel in order to be able to test this system. Objects: four-stroke diesel internal combustion engines of a V-shaped cylinder arrangement with and without a turbocharger, powered by the combustion of combined-cycle products of pyrolysis of wood waste. Methods: numerical studies based on mathematical algorithms of systems, cycles and main parts of naturally aspirated and turbocharged diesel internal combustion engines based on thermal calculations and thermal balance. Results. The authors have developed the mathematical model and a simulation program for thermal calculation of a four-stroke internal combustion engine with a V-shaped arrangement of cylinders with direct injection of combined-cycle products of wood pyrolysis into the combustion chamber with and without a turbocharging system. The analysis of the influence of the crankshaft speed, the number of cylinders on power, torque, and specific fuel consumption was carried out. It is shown that an increase in the number of cylinders with the same working volume of an internal combustion engine leads to growth in power and torque, while the specific consumption of steam-gas pyrolysis products decreases. It is noted that the combustion of steam-gas products of pyrolysis in an internal combustion engine leads to an increase in the temperature of the exhaust gases relative to diesel fuel combustion. For turbocharged internal combustion engines, the increase in exhaust gas temperature is about 50 °C, without turbocharging – about 100 °C. It was established that in the four-stroke diesel engine of internal combustion when burning pyrolysis gas obtained from wood waste, mass consumption is 7,5÷8,6 times more than diesel fuel is required to produce the same amount of electric energy. It was revealed that a diesel engine with a turbocharger is more economical and effective than a power unit without a supercharger. At a speed of 3000 min–1 of a 12 cylinder engine with a turbocharger, pyrolysis gas consumption saving is 11,9 %, effective capacity and torque are 10,0 % higher than that of an internal combustion engine without a supercharger. One of the most available at the moment for burning pyrolysis gas is a four-stroke V12 diesel engine with a turbocharged YAMZ 845.10 with a working volume of 25,86 liters, maximum capacity of 537 kW (730 hp), maximum torque of 2788 N⸱m at rotation frequency 1500÷3000 rpm.

A three-phase foam is considered one of the promising advanced materials for fighting fires. However, the preparation conditions, cost and effect are key factors for industrial applications. In this study, new three-phase foam systems with fly ash and a complex surfactant are proposed. Five types of surfactants alcohol polyoxyethylene ether sodium sulfate, coconut oil diethanolamine, sodium lauryl sulfate, polyacrylamide and polyether-modified silicone resin emulsion were selected as foaming agents. Through laboratory experiments, the effect on the expansion ratio and foam stability of the surfactant type/concentration, fly ash particle concentration/size and pH were investigated. The foaming condition was determined by numerical optimization. The results of this study may serve as a reference for understanding the preparation of a novel threephase foam. It is hoped that this work could provide useful guidance for the preparation of efficient three-phase fire-extinguishing foam for the safe guarding of process safety in the field of chemical production, transportation, and storage suitable for drug delivery than Al12P12 and Al12N12 based on their recovery times.

Thermoplastic polyurethane elastomer (TPU) foams were prepared using the high-pressure autoclave with supercritical fluid carbon dioxide (SC-CO2). The effects of foaming variables (i.e. saturation temperature, saturation pressure, and depressurization rate) on cellular structure and expansion ratio were investigated. The model between expansion ratio and foaming variables was constructed using the Box-Behnken design (BBD) of response surface methodology (RSM), and analysis of variance (ANOVA) was conducted to evaluate the validity and significance of the model. Finally, the interactive effects of foaming variables on the expansion ratio were investigated, and the expansion ratios of maximum and center point from numerical model were verified by experiment. The result showed higher saturation pressure and depressurization rate resulted in the more uniform cellular structure and higher cell density, however the higher saturation temperature resulted in the bigger cell and nonuniform structure. The ranges of average cell diameter and cell density were 15.26–45.4 μm and 0.32 × 108 to 6.24 × 108 cells/cm3, respectively. The model obtained using BBD of RSM was valid to predict the expansion ratio in the design window. The saturation temperature was the most important factor influencing the expansion ratio. With the increase of saturation temperature, the expansion ratio always increases in the design window. The maximum expansion ratio from numerical optimization was 4.91, which was located at saturation temperature 190°C, saturation pressure 12.51 MPa, and depressurization rate 5 MPa/s, and the corresponding experiment value was 4.56. The error between them was 7.13%. [ABSTRACT FROM AUTHOR]

Exploring the development characteristics and influencing factors of the mixing layer (ML) inside the hydrogen recirculation ejector is of great importance for enhancing the recirculation properties of the ejector and promoting green and sustainable energy development. However, the evolution of ML in the ejector and the transport and diffusion characteristics of the fluid are problematic, in particular, the influence of the expansion ratio on the properties of the ejector is unclear. Therefore, in this study, a CFD numerical model of an ejector was established to simulate the flow of fluids in the ejector. The evolution of ML was elucidated, and the interaction mechanism between the mixing and the recirculation performance of the ejector was revealed. The findings showed that the velocity difference is a significant driving force for the development of ML, and the formation of an adverse pressure gradient contributes to the diffusion of hydrogen and the rapid development of ML. The development process of ML in the ejector can be divided into three stages under the interaction of the velocity difference and the convective Mach number: the rapid growth stage, the slow growth stage, and the exponential growth stage. By studying the evolution of ML at different expansion ratios, it was found that there exists a critical expansion ratio for the ejector, which results in the largest of the non-mixing length ratio and the effective mixing thickness, the strongest relative mass transfer capability of the entrained flow, the fullest development of ML, and the optimal hydrogen recirculation performance. • Mixing model of an ejector within the PEMFC system was established. • The radial transport properties of the fluid in the mixing layer were elucidated. • The development of the mixing layer at different expansion ratios were investigated. • The interaction mechanism between mixing and recycling performance was revealed. [ABSTRACT FROM AUTHOR]

Environmental impact concern of conventional polymer foams has attracted considerable interest for the development of natural‐based polymer foams. Starch is a biopolymer that is gaining acceptability due to its renewability, availability, environmental biodegradation, and low cost. Extrusion is particularly desirable to produce starch‐based foams because it can produce a homogeneous mixing, high heat transfer, high pressure, reduction of the residence time, and low production costs. This review explains the transformation of starch during the foam processing and their relationship with extrusion conditions such as water content, barrel temperature, screw configuration and speed, die temperature, and die dimensions and how all these factors impact on the cell morphology, apparent density, expansion ratio, and final properties of starch‐based foams. The strategies to reduce water sensitivity are described, as well as the effect of amylose content and the addition of additives to improve the starch‐based foams performance as alternative for expanded polystyrene. The extrusion processing conditions can be controlled to obtain the desirable properties for specific applications such as cushioning, packaging, and loose‐fill, among others. Also, a brief look at the starch‐based foams trends, challenges, and perspectives are also discussed. [ABSTRACT FROM AUTHOR]

To assess the influence of nanopowder dispersion, performance was scrutinized between two plates. The upper one is permeable and below one is stretching and hot. The distance between two plates changes with time. The final equations were solved via MAPLE, and to analyze the impact of active factors, two significant functions were calculated. Two new formulas for Nu and En were suggested based on numerical data and outputs were summarized as contours and plots. Nu has various behaviors with change of α. Results depict that Nu declines about 21.29% with rise of α from 0 to 2. Positive impact of R on Nu is more significant for lower α and 37.44% augmentations were reported when R augments. Thinner boundary layer with rise of m results in higher Nu and 437% augmentation can be seen with rise of m from 0 to 3. With rise of particle interaction with rise of φ, temperature augments and greater heat transfer rate appears. Inclusion of nanopowders leads to augmentation in Nu about 3.54%. At first Nu rises with rise of R augments and then reduces, while opposite trend was observed for α. Nu for α = 2 is 1.13 times greater than that of α = 0 when R = 5, m = 1. To reach greater influence of nanoparticle dispersion, the lower values of m should be selected. As m augments, Nu reduces about 57.58% which means that a higher value of m leads to lower conduction mode. [ABSTRACT FROM AUTHOR]

The implications of physicochemical, rheological, and thermal properties of seven eminent Indian rice cultivars (PR 114, 121, 122, 123, 124, 126, and 127) on the extrusion behavior and physico‐functionalities of the extrudates were investigated. The amylose and amylopectin content of the cultivars ranged between 12.72 to 28.86% and 71.14 to 87.28% in addition with protein and crude fat content that varied from 7.05 to 9.15% and 0.49 to 1.17%, respectively. The onset (r = 0.98), peak (r = 0.95), and conclusion (r = 0.98) temperatures of the cultivars were in positive correlation with amylose. Likewise, pasting temperature (r = 0.979), final viscosity (r = 0.91), set back viscosity (r = 0.89), and stability ratio (r = 0.90) of the cultivars demonstrated a significant positive correlation with the amylose content. However, peak (r = − 0.879) and hold viscosity (r = − 0.89) were negatively correlated. The cultivars were extruded at feed moisture of 15%, screw speed of 500 rpm and barrel temperature of 150°C. The extrudates characteristics viz., expansion ratio—1.82 (PR 123); bulk density—184 g/cc (PR 123); specific mechanical energy—262.35 Wh/kg; water absorption index (WAI)—6.26 (PR 122); water solubility index—48.52% (PR 123); hardness—148.63 N (PR 122); and hydration power—284% (PR 122) were viably hyphenated with the physicochemical and rheological behavior of cultivars. The physico‐functional characterization of the extrudates in terms of their starch and protein structural indexes, α‐amylase susceptibility; water soluble carbohydrates and proteins revealed the possibility of exploring these cultivars as a functionally viable and diverse ingredient for the production of ready‐to‐eat extrudates. [ABSTRACT FROM AUTHOR]

An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model, and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward. The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature. Variations in the length of the mixing chamber Lm and length of the diffuser Ld with respect to variations in the outlet temperature of the ejector Tc, outlet pressure of the ejector pc, and the expansion ratio of the pressure of the primary flow to that of the secondary flow pg/pe were investigated. Moreover, variations inLm and Ld with respect to variations in the ratio of the diameter of the throat of themotivenozzle to thediameterof themixing chamber dg0/dc3 and ratioof the outlet diameter of thediffuser to the diameter of themixing chamber dc/dc3 were investigated. The distribution of flowfields in the ejector was simulated. Increasing Lm and dc3 reduced Tc and pc. Moreover, reducing pg/pe or dg0/dc3 reduced Tc and pc. The length of the mixed section Lm2, which was determined on the basis of the Fano flow model, increased as pg increased and decreased as dc3 increased. The mixing length Lm1, which was considered the primary flow expansion, showed the opposite trend with that of Lm2. Moreover, Ld increased as pg/pe and dc/dc3 increased. When the value of dc was 1.8 to 2.0 times as high as that of dc3, the semi-cone angle of the diffuser ranged between 6° and 12°. At a constant dc/dc3, decreasing Tc and pc increased Ld. [ABSTRACT FROM AUTHOR]

During the backfilling process, there is often a problem of no roof-contact, and the time and state of roof-contact cannot be predicted, seriously affecting the backfilling safety and efficiency. Therefore, the expansion effect, mechanism, and time dependence of the expansion agents used to achieve roof-contact were studied through expansion ratio tests, strength tests, and microscopic analysis. The expansion ratio of the MgO-type expansion agent (MEA) can meet the requirement of backfilling, and the unconfined compressive strength (UCS) of the expansive cemented paste backfill (ECPB) was attenuated compared to that of ordinary cemented paste backfill (CPB). Through scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) of the MgO-type ECPB, it is found that the ECB produces Mg(OH) 2 crystals, which improves the compensation space inside the ECPB. MIP analysis results also show that the ECPB has higher porosity and more macropores, which is the reason for the strength attenuation of the ECPB. It is found that the expansion ratio and sedimentation ratio of fresh ECPB are time-dependent, and they both conform to logarithmic function. Afterwards, through the dynamic relationship between the sedimentation and expansion of fresh ECPB, the synthetic criterion of roof-contact based on the time-dependent model of expansion ratio and sedimentation ratio was established. The theoretical shortest roof-contact time of different experimental groups was obtained. Finally, through a comparative analysis of backfilling costs, the lowest cost and reasonable backfilling scheme were obtained. It is of great value for judging the effectiveness of roof contact, optimizing the backfilling proportion scheme, ensuring backfilling safety, and saving backfilling and mining costs. • A comprehensive analysis of the expansion effect was conducted. • The expansion mechanism was revealed through SEM and MIP methods. • The expansion ratio and the sedimentation ratio are time-dependent. • A roof-contact synthetic criterion of fresh ECPB was established. • The economical backfilling proportion was realized. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane (TPU) foams are favorable for their elasticity and compression performance. However, high shrinkage rate, low expansion ratio, and insufficient compression performance greatly limit its application. In this work, to prepare the desired TPU foam and to gain insight into the influence of micro-crosslinking structure on their effect, cross-linked TPU foams were prepared and subsequently foamed by supercritical CO2 foaming technology. Effects of micro-crosslinking structure on the rheological and foaming behavior of samples were systematically investigated. Rheological results indicated that the introduction of a chain extender in the TPU matrix increases the branching degree of molecular chain. Compared with pure sample, the expansion ratio of composite foam increased from 3.5 to 6.5 and specific compressive strength from 3.19 to 11.81 MPa. [ABSTRACT FROM AUTHOR]

This research shows how expansion ratio gets affected by the different input parameters of fiber laser. In this research all input parameters were studied and scrutinize the final parameters which affects or influence the mechanical properties of the stent. In this research the input parameters were selected after performing pilot experiments. ANOVA analysis is used to finding out the percentage contribution of each factors on expansion ratio. Mathematical model has also been derived for prediction of expansion ratio without performing actual experiments. It is observed less effect of gas pressur, contributed 10.36%, Percentage contribution of laser power is 61.88 % and frequency is contributing 26.64%. Software developed featured with which can predict expansion ratio of stent without performing actual performance. [ABSTRACT FROM AUTHOR]

The migration, enrichment, and crystallization of soluble salt are important reasons for weathering of the Yungang Grottoes. The production in the Datong areas is mainly coal burning. SO2 easily forms acidic rainfall and becomes a salt solution that passes through the soil and rock mass, enters the grotto, and accumulates on the surface of the grotto. It causes the deterioration of grotto cultural relics because environmental temperature and humidity change repeatedly. Therefore, anti-seepage on the topsoil layer is an important task of the Yungang Grottoes protection project. Bentonite is commonly used as an anti-seepage engineering material because of its low permeability. The loess in the Datong area and bentonite are mixed as a loess-bentonite anti-seepage material. Penetration, expansion, and compression tests under the infiltration of deionized water or salt solution are conducted to study the permeability and deformation characteristics with changes in bentonite content and salt solution concentration. The study indicates that as the bentonite content increases, the permeability coefficient decreases. When the bentonite content reaches 20% or more, the permeability coefficient is stable. The saturated permeability coefficient of the mixture increases linearly with an increase in salt solution concentration and void ratio. When the bentonite content is less than 20%, the mixture can maintain a slightly expanded state. Under the same bentonite content, the expansion ratio decreases with increasing salt solution concentration. Combining the results of these tests and considering economic factors, a mixture with a content of 20% is the optimal dosage. [ABSTRACT FROM AUTHOR]

SUMMARY: Flammability limits are important safety parameters of each flammable material. Thermal theory of flame propagation suggests existence of a threshold temperature above which a flame propagates. Density theory of flame propagation suggests existence of a threshold density factor above which a flame propagates; density factor is defined as the ratio of before ignition to after ignition density. Based on a general version of thermal theory of flame propagation, constancy of values of adiabatic flame temperature at each flammability limit can be used to predict flammability limits. Similarly, based on a general version of the density theory of flame propagation, constancy of values of density factor at each flammability limit can be used to predict flammability limits. This work reports and compares predictions of general versions of both thermal theory and density theory of flame propagation for lower flammability limits and for upper flammability limits. This work shows that thermal theory and density theory both perform well at predicting the lower flammability limit while density theory performs far better than thermal theory at predicting the upper explosive limit. [ABSTRACT FROM AUTHOR]

The supercritical carbon dioxide foaming characteristics of the biodegradable polymer poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) are studied for environmentally friendly packaging materials. The effect of the 4HB composition of the P(3HB-co-4HB) copolymers on the foaming conditions such as pressure and temperature is studied and the density and the expansion ratio of the resulting P(3HB-co-4HB) foam are together evaluated. The increase in the 4HB content reduces the crystallinity and tan δ value of P(3HB-co-4HB) required for the growth of the foam cells. Therefore, the foaming temperature needs to be lower to retain a suitable tan δ value of P(3HB-co-4HB) for foaming. It was found that P(3HB-co-4HB) with less crystallinity showed better formability and cell uniformity. However, foaming is not possible regardless of the foaming temperature when the 4HB content of P(3HB-co-4HB) is over 50%, due to the high tan δ value. A lower foam density and higher expansion ratio can be obtained with crystalline P(3HB-co-4HB) of low 4HB content, compared with non-crystalline P(3HB-co-4HB) of high 4HB content. The expansion ratio of P(3HB-co-4HB) foams can be increased slightly by using a chain extender, due to the lowing of crystallinity and tan δ. This is most effective in the case of P(3HB-co-4HB), whose 4HB content is 16%. [ABSTRACT FROM AUTHOR]

The micro foaming performance, moisture resistance and dynamic viscosity of scCO2-aid glutaraldehyde/hexametaphosphate/thermoplastic tapioca starch (GA/SHMP/TOS) foams were considerably improved by proper NaOH treatment. The expansion ratio, resilience rate, dynamic viscosity values of these NaOH modified foams improved to a maximum, as the time for NaOH treatment approached a proper value. The dynamic viscosity, expansion ratio and resilience rate of the scCO2-aid GA/SHMP/TOS foams modified using 110 atm scCO2-pressure, the proper alkali treatment time, SHMP loading and varying montmorillonite (MMT) loadings improved further, as their MMT loadings approached a proper value of 2.5 part per hundred parts of tapioca starch (PHTOS). Relatively large dynamic viscosity (7.1x104 Pa·s), extremely large expansion ratio (∼75), cell density (1.1x109 cells/cm3) and/or resilience rate (∼80%) were acquired for the scCO2-aid GA/SHMP/TOS/MMT foam modified using the proper alkali treatment time and MMT loading. Thermal analyses results showed that crystallization onset temperatures and crystallization rates of scCO2-aid GA/SHMP/TOS/MMT foams modified using the proper alkali treatment time and varying MMT loadings improved to a highest value by adding 2.5 PHTOS of MMT nano-platelets. Possible reasons accounting for the considerably improved micro foaming performance of scCO2-aid GA/SHMP/TOS/MMT foams modified using the proper alkali treatment time and MMT loading are proposed in this study. [ABSTRACT FROM AUTHOR]

This paper fabricated the cross‐linking poly(butylene succinate) foaming materials with high expansion ratio, high mechanical strength, and high degradation rate though cross‐linking and molding compression methods. With dicumyl peroxide content increasing, complex viscosity, and storage modulus appear to increase tendency. The properties of cell size, distribution, mechanical properties, and thermal conductivity all appear the first increasing and then decreasing trend with dicumyl peroxide content increasing. When dicumyl peroxide concentration is 6 wt% and azodicarbonamide concentration is 1 wt%, pure cross‐linking poly(butylene succinate) foaming material's expansion ratio and compression strength could reach 7.03 and 5.61 MPa, respectively. In addition, this pure cross‐linking poly(butylene succinate) foaming material has high degradability, and the degradation ratio could get 80% in alkaline aqueous solution. [ABSTRACT FROM AUTHOR]

Mung bean and oat flour were utilized to extrude snacks with high protein content using response surface methodology. Raw material ratio was standardized using NDpCal% to ensure mutual supplementation of essential amino acids such as lysine, methionine, cysteine, threonine and tryptophan. Moisture content ranging between 11% to 20% and barrel temperature 95 °C to 180 °C had shown significant influence on the development of extrudates. Parameters such as moisture content (4.94–6.21%), moisture retention (17.53–59.58%), expansion ratio (2.60–3.82), bulk density (0.021–0.79 g/cm3), water absorption index (4.86–7.53%), water solubility index (18.3–25.2%), water holding capacity (74.65–88.65%) were analyzed. Addition of moisture to feed mixture has significantly affected the expansion ratio, bulk density, water absorption index, water solubility index and water holding capacity (p

The effect of extrusion parameters like barrel temperature (100-150°C), screw speed (110-350 rpm) and feed moisture content (12-20% wb) on product quality of extruded products prepared from composite mixture was performed. Central composite rotatable design was used to frame the experiment and statistically analyzed the data. The effect of parameters on expansion ratio (ER), bulk density (BD), hardness (H), crispness (Cr), water absorption index (WAI) and water solubility index (WSI) of extruded products were investigated and found significantly. The feed moisture had positive effect on BD, hardness and WAI whereas negative effect on ER, crispness and WSI of the extruded products. The barrel temperature and screw speed had negative effect on BD, hardness and WAI whereas reverse effect on ER, crispness and WSI. The developed models for all the product qualities were significant at 1% level. ER, BD, hardness, crispness, WAI and WSI values of extruded products was ranged from 2.017–3.391, 0.13–0.28 g/cm3, 12.43–19.04 N, 10–25 fractures, 5.76–7.25 g/g and 12.76–20.97%, respectively. The higher expansion ratio, crispness and WAI along with lower bulk density, hardness and WSI of extruded product were found at the process parameters combination of feed moisture 14% (wb), barrel temperature 110°C and screw speed 301 rpm.

A way to make short fiber get radial orientation in rubber matrix during extrusion has been studied. Firstly, a type of dam-expanding die has been designed according to theory analysis. Secondly, the physical model and mathematical model of short fiber radial orientation have been built, which indicates that half expansion angle and expansion ratio are important factors that affect radial orientation of short fiber. Therefore, the type of dam-expanding dies with different half expansion angles and expansion ratios has been manufactured to carry out radial orientation of short fiber. Finally, experiments have been done with the manufactured dies. The experiments' results indicate that the mathematical model could be used to forecast radial orientation of short fiber, and the type of dam-expanding die with half expansion angle 75° and expansion ratio 5 can carry out the radial orientation of short fiber in rubber matrix with short fiber-rubber composite materials. Furthermore, with these conditions, short fibers could get orientation angle about 84°. Some physical–mechanical properties of composite materials can reach a new level, such as tensile strength 28.95 MPa, tear strength 87.82 kN/m and Akron wear 0.172 cm3/1.6 km. Moreover, physical–mechanical properties of composite materials got from S-test are much better than those got from V-test, which indicates that if short fibers are well radial orientated, the composites will be in obvious anisotropy. [ABSTRACT FROM AUTHOR]

This study investigates the physicochemical and thermal properties of styrene–butadiene rubber (SBR) nanocomposite foam. Nano-calcium carbonate (CaCO3) was prepared from eggshells (ESs) waste. Sponge rubber nanocomposites were prepared and were irradiated by electron beam (EB) radiation at 25, 75, and 150 kGy. Their physicochemical properties, including foam density, compression set (CS), hardness, abrasion loss, and expansion ratio, and their thermal stability were investigated. The physicochemical properties were enhanced by adding 2.5 phr of a foaming agent. Among the composites examined, the foam composites containing nano-CaCO3 had the lowest CS, abrasion loss, and expansion ratio and the highest hardness and foam density. The results confirmed that the thermal stability was improved by incorporating nano-CaCO3 into the SBR foam and as the radiation dose increased. The sponge containing nanoclay demonstrated an intermediate behavior, whereas that with CaCO3 nanoparticles showed low average cell diameter and size and high cell wall thickness. The radiation process enhanced the foam density, CS, abrasion loss, hardness, and thermal property of the developed nanocomposites by inducing the formation of intermolecular crosslinks within the composite matrix. The results showed that physicochemical properties improved by increasing the radiation dose at 25 kGy. [ABSTRACT FROM AUTHOR]

Teknolojik gelişmeler sayesinde asfalt üretim sıcaklıkları düşürülerek sıcak karışımlara benzer performanslı karışımlar elde edilebilmektedir. Sıcak karışım asfaltların malzemelerinin yani agrega ve bitümün yüksek sıcaklıklarda ısıtılması nedeniyle yarattıkları olumsuz çevresel etkiler, üretim maliyetlerinde meydana gelen sürekli artış ve hammadde kaynaklarındaki azalma nedenleriyle asfalt üretim sıcaklıklarının düşürülmesi eğilimi ve malzemelerin geri kazanımının popülerliği giderek artmaktadır.Köpük bitüm ve geri kazanılmış/doğal agrega kullanılarak uygulanan köpük bitümle geri kazanım yöntemi, çevresel ve ekonomik olarak avantajları olan bir yöntemdir. Köpük bitümle uygun bir karışım hazırlayabilmek için ilk aşama, karışımda kullanılacak bitümün en ideal köpürme özelliklerinin (genleşme oranı ve yarılanma süresi) doğru şekilde belirlenebilmesidir. Bu nedenle çalışmada, farklı asfalt çimentolarının köpürme özellikleri deneysel olarak belirlenmiştir. Ayrıca deneylerde kullanılan bitümlerin köpürme özellikleri Bulanık Mantık ve ANFIS yöntemleri kullanılarak modellenmiş ve sonuçlar deneysel olarak elde edilen verilerle kıyaslanmıştır.Elde edilen veriler ışığında kullanılan tüm bitümlerin farklı köpürtme su yüzdeleri için kullanımlarının literatürde önerilen minimum köpürme özelliklerini sağladığı ve kullanılan tahminleme yöntemlerinin benzer sonuçlarla deneysel verileri desteklediği sonucuna ulaşılmıştır.

In view of the coal spontaneous combustion accident caused by air leakage in the mine, this paper studied the foaming cement solidified filling material used for mine filling and plugging with cement as the base material, foaming agent, gypsum and polypropylene fiber as additives. Through the single factor test method, the optimized ratio of the main components affecting the compressive strength and expansion ratio of the foamed cement solidified filling material was determined as the water-cement ratio 0.5, the foaming agent content 1%, and the gypsum content 6%, polypropylene fiber 0.4%. Taking Cuimu Mine as the experimental background, through the design of reasonable and effective filling technology scheme, the 21303 wind tunnel in the lower part of 22306 working face of Cuimu Mine was filled. The test results show that the foamed cement solidified material effectively enhances the airtightness of the wind tunnel and the roadway.