Temperature Of Mixture Research Articles

Experimental investigation of bluff body geometry effects on nitrogen oxides emissions from Cambridge stratified burner

In this study, a series of experiments are done to analyze the effect of bluff body geometry on the NOx reduction of a natural gas-air stratified swirl burner. The stratified burner of Cambridge University is chosen to study the mentioned geometrical effect, and the geometry modification of bluff body is used as a simple method for NOx reduction, which can be easily applied to the systems using these burners, including gas turbines. The bluff body geometrical change to an annular bluff body is inspired by the fact that the areas in which the edge of the bluff body is in contact with the unburned flow have lower temperatures, which can drastically affect combustion parameters, especially emissions. This new geometry is called the Annular Bluff body Stratified Burner, ABSB. The comparison of the mentioned burners is made for three equivalence ratios, Ф, stratification cases: premixed, moderately stratified, and highly stratified with a global equivalence ratio of 0.75, in the conditions of atmospheric pressure and the temperature of the inlet mixture of 26 degrees of Celsius. Flame spectroscopy compares the chemiluminescence intensities of OH*, CH*, C2*, H2O*, and CO2*. Digital image processing, flame edge detection, and exhaust gas analysis are also utilized to measure flames’ general dimensions and emissions. According to experiments, for ABSB cases, a general decrease of about 14% in Nitrogen Oxides, especially NO and NO2, and an increase of about 17% in Carbon Monoxide are observed. Besides, the average bluff body temperature dropped by about 20% in ABSB for all three stratification cases.

Effects of Wall Temperature on Scalar and Turbulence Statistics During Premixed Flame–Wall Interaction Within Turbulent Boundary Layers

Abstract Direct numerical simulations (DNS) have been utilised to investigate the impact of different thermal wall boundary conditions on premixed V-flames interacting with walls in a turbulent channel flow configuration. Two boundary conditions are considered: isothermal walls, where the wall temperature is set either equal to the unburned mixture temperature or an elevated temperature, and adiabatic walls. An increase in wall temperature has been found to decrease the minimum flame quenching distance and increase the maximum wall heat flux magnitude. The analysis reveals notable differences in mean behaviours of the progress variable and non-dimensional temperature in response to thermal boundary conditions. At the upstream of the flame–wall interaction location, higher mean friction velocity values are observed for the case with elevated wall temperature compared to the other cases. However, during flame–wall interaction, friction velocity values decrease for isothermal walls but initially rise before decreasing for adiabatic walls, persisting at levels surpassing isothermal conditions. For all thermal wall boundary conditions, the mean scalar dissipation rates of the progress variable and non-dimensional temperature exhibit a decreasing trend towards the wall. Notably, in the case of isothermal wall boundary condition, a higher scalar dissipation rate for the non-dimensional temperature is observed in comparison to the scalar dissipation rate for the progress variable. Thermal boundary condition also has a significant impact on Reynolds stress components, turbulent kinetic energy, and dissipation rates, showing the highest magnitudes with isothermal case with elevated wall temperature and the lowest magnitude for the isothermal wall with unburned gas temperature. The findings of the current analysis suggest that thermal boundary conditions can potentially significantly affect trubulence closures in the context of Reynolds averaged Navier–Stokes simulations of premixed flame–wall interaction.

The effect of synthetic wax additives on adhesive properties of bitumen binders

Introduction. Currently, in road construction, in order to reduce energy costs and harmful emissions, warm asphalt concrete mixture technologies are being increasingly used. One way to reduce the temperature of asphalt concrete mixture prepared is to use additives based on natural and synthetic waxes. In this regard, it is important to study the influence of wax additives on the properties of bitumen binder as a basic component of asphalt concrete mixture. The adhesion between the binder and the mineral filler is the most important property that determines the durability of an asphalt concrete pavement. The purpose of this article is to study the effect of synthetic wax additives on the adhesive properties of bitumen.Materials and methods. The characteristics of the studied synthetic wax additives Viskodor PV-2, Sasobit and Licomont BS-100 have been presented. To simulate binder aging, the heating method in a thin layer, according to GOST 18180, was used with the temperature control time increased to 9 hours. To assess the adhesion between original and modified bitumen binder, as well as the aged binder, the method of boiling stone material coated with bitumen was used, and the assessment of its appearance in accordance with GOST 11508 was made. The study of the adhesion mechanism for the bitumen binder and the mineral filler was carried out by means of spectral analysis.Results and discussion. The influence of synthetic wax additives on the adhesion between bitumen binder and mineral material was analyzed. A change in the adhesive properties of bitumen modified with the studied additives during thermal-oxidative aging was revealed. A comparison was made of the IR spectra of the original and modified bitumen before and after interaction with stone material and the differences in the mechanisms of affecting the adhesion to the mineral filler by the introduced additives were determined. It has been established that the Viskodor PV-2 additive significantly improves bitumen adhesion. Moreover, the effect of improved bitumen adhesion with this additive remains after thermal-oxidative aging, though slightly reduced. Imported additives Sasobit and Licomont BS-100 have a significantly less impact on the adhesive properties of bitumen.Сonclusion. The results obtained show that the use of synthetic wax additives improves the adhesive properties of bitumen, which can positively affect the durability of the road surface. Since the domestic additive Viskodor PV-2 is superior in the effect of improving the adhesive properties of bitumen compared to the studied additives Sasobit and Licomont BS-100, the introduction of this additive into production instead of expensive imported additives will provide both improvement in the quality of asphalt concrete pavement and reduction of costs.

Determining the optimal oxidation temperature of non-isothermal liquid fuels injections using modeling based on statistical droplet distribution

Single-hole injections of liquid hydrocarbon fuels (isooctane and dodecane) under high turbulence have been investigated using direct numerical simulation based on the statistical model considering the droplets’ atomization, distribution, and combustion. The study objects are the heat and mass transfer processes during atomization and combustion of liquid fuels injections within the combustion chambers of thermal engines. The temperature and carbon dioxide concentration distributions of the fuel-air mixture, the distributions of the droplets, their velocities, and the Sauter mean radius within the isooctane and dodecane oxidation in the engine’s combustion space were obtained. An investigation of the oxidizer’s initial temperature influence on the droplets’ atomization and combustion processes showed that the optimal temperature for both fuels is 900 K. The obtained modeling results were confirmed in good agreement with theoretical and experimental data. Thanks to the integrated use of approaches from statistical theory, numerical algorithms and 3D computer modeling techniques, the results obtained are distinguished by high accuracy, efficiency in reducing computational resources, scientific novelty in the type of droplet atomization and suitability for practical application for technological solutions not only for single-hole, but also for multi-hole injections of liquid fuels and studying the jet-to-jet interaction phenomena. The obtained research results can be applied in miscellaneous internal combustion engines development with different atomization types, which will allow us to contemporaneously settle the concerns of streamlining the combustion process, improving the completeness of fuel combustion and reducing emissions of harmful substances

Substantiating technological factors for preparing fermented milk-containing products with a combined composition of raw materials with a long storage period

This paper substantiates and defines the technological parameters for obtaining stable emulsions when making fermented milk-containing products. The object of research was the modes of mechanical and heat treatment of mixtures with a combined composition of raw materials based on dairy and vegetable fats. The task to be solved was to obtain stable emulsions by two-stage homogenization of the cream-vegetable mixture and the heat treatment temperature of the fermented cream-vegetable mixture with a combined composition of raw materials with a fat content of 10 % and 15 %. It is shown that during the homogenization of a cream-vegetable mixture with a mass fraction of fat of 10 %, the pressure in the first stage should be 10.0–12.0 MPa, in the second – 2.5–3.0 MPa; for a cream-vegetable mixture with a mass fraction of fat of 15 %, the pressure in the first stage is 8.0–10.0 MPa, in the second – 2.5–3.0 MPa. Modes of thermomechanical processing of the fermented cream-vegetable mixture at temperatures of 65±2 and 70±2 °C to ensure the microbiological stability of the milk-containing product during storage have been substantiated. A stabilizing system based on milk proteins has been selected. It was established that in order to improve the consistency, increase heat resistance, and avoid foaming of the finished product, it is necessary to perform thermomechanical processing of the fermented cream-vegetable mixture with a fat content of 10 % and 15 % at temperatures of 70±2 °С and 65±2 °С, respectively, and mass fraction stabilizer – 0.5 % and 0.15 %, respectively. The research data do not always coincide with previously established patterns, which is due to the difference in the chemical composition of the studied food systems, as well as the methods of their preparation and use. The results of the work could be used in the technology of milk-containing products with a combined fat composition

Analysis of the effect of construction technology factors on controlling thermal cracking in mass concrete

A comprehensive numerical study was conducted in this study to evaluate the effects of construction technology factors including curing temperature, initial temperature of fresh concrete mixture, type of formwork, type of cement, and cement content on controlling thermal cracking in mass concrete. The probability of cracking will also be included in the analysis to align with the trend of thermal cracking control planning in some countries today. Stress-temperature field analysis will be performed using the finite element heat flow analysis tool of Midas/Civil software. The reliability and accuracy of the proposed method are verified by comparing the analysis results with a experimental result of a mass concrete sample with dimensions of 2.5 × 2.5 × 2.5 m. Based on the validated numerical model, a parametric study was conducted on a typical mass concrete block with dimensions 5.0 × 5.0 × 5.0 m to investigate the impact of construction technology parameters on temperature development in mass concrete. The obtained results demonstrate that construction technology factors significantly affect thermal cracking in mass concrete. An effective construction solution will contribute significantly to the overall plan for controlling thermal cracking in mass concrete.

Prediction of Critical Temperature and Critical Volume of Mixtures by a New Group Contribution Method

Prediction of Critical Temperature and Critical Volume of Mixtures by a New Group Contribution Method

Study on the Explosion Mechanism of Low-Concentration Gas and Coal Dust

In coal mines, the mixture of coal dust and gas is more ignitable than gas alone, posing a high explosion risk to workers. Using the explosion tube, this study examines the explosion propagation characteristics and flame temperature of low-concentration gas and coal dust mixtures with various particle sizes. The CPD model and Chemkin-Pro 19.2 simulate the reaction kinetics of these explosions. Findings show that when the gas concentration is below its explosive limit, coal dust addition lowers the gas’s explosive threshold, potentially causing an explosion. Coal particle size significantly affects explosion propagation dynamics, with smaller particles producing faster flame velocities and higher temperatures. Due to their larger surface area, smaller particles absorb heat faster and undergo thermal decomposition, releasing combustible gases that intensify the explosion flame. The predicted yield of light gases from both coal types exceeds 40 wt% daf, raising combustible gas concentrations in the system. When accumulated reaction heat elevates the gas concentration to its explosive limit, an explosion occurs. These results are crucial for preventing gas and coal dust explosion accidents in coal mines.

Photocatalyst for Visible-Light-Driven Sm(II)-Mediated Reductions.

Commercially available coumarin 343 in combination with reducible Sm(III) ions catalyzed divalent lanthanide-mediated C═O, C-halogen, P-Cl, and N═N reductions at ambient temperature in aqueous solvent mixtures. The catalyst absorbs visible light efficiently. The active divalent species is formed by photoinduced electron transfer from coumarin 343 to the stable trivalent precursor, and the coumarin could be regenerated by strictly 1 equiv of ascorbic acid.

АНОМАЛЬНАЯ КИНЕТИКА ГИБЕЛИ ИЗОМЕРОВ 4-(N,N-ДИМЕТИЛАМИНО)ФЕНИЛНИТРОЗООКСИДА

The termination kinetics of the adduct of molecular oxygen (3Σg- ) and 4-(N,N-dimethylamino)-phenylnitrene generated by pulse photolysis from the corresponding azide in hexane has been studied using UV spectroscopy in a wide temperature range. The adduct is represented by cis- and trans-isomers of 4-(N,N-dimethylamino)- phenylnitroso oxide (4-Me2NC 6 H4 NOO). It was experimentally established that an abnormal increase in the ter- mination rate of aryl nitroso oxide is observed with decreasing temperature of the reaction mixture. A two-center five-step mechanism of nitroso oxide transformation is proposed. A satisfactory description of the kinetic curves of the change in the optical density of the reaction mixture can be achieved according to the mechanism: along with ortho-cyclization of the cis-isomer of aromatic nitroso oxide, accompanied by the formation of the corre- sponding nitrile oxide, the interaction of trans- and cis-isomers of the nitroso oxide fragments, leading to a prereaction complex, is possible. The structural features of the complex allow its decomposition either (channel I) into nitro- and nitroso compounds or (channel II) trans-isomers of aryl nitroso oxide. With a decrease in the temperature of the reaction mixture the stability of the complex increases. The latter ensures a more probable decomposition through one of the aforementioned channels.

Effects of injection timing on combustion and mixture formation of a methanol direct injection engine equipped with a small volume passive pre-chamber

The pursuit of high efficiency and cleanliness has always been the focus of engine research. As one of the most promising low-carbon renewable alternative fuel, methanol has gained increasing attention in engine applications. Inspired by the advantages of gasoline direct injection (GDI) in fuel economy, methanol direct injection (MDI) engine has also become a research hot spot. Similar to GDI, the mixture distribution is crucial for MDI engines, especially in the late injection stratified operation mode, an unreasonable mixture distribution of rich and lean regions will result in slow and incomplete combustion, or even flame quenching. Due to the characteristics of multi-point ignition and the high ignition energy, pre-chamber jet flame ignition has the potential to effectively enhance combustion. In this paper, the effect of injection timing on combustion characteristics in a methanol direct injection engine equipped with a small volume pre-chamber are studied experimentally. The mixture formation processes in both the main-chamber and the pre-chamber at different injection timings were also explored through simulations. The research findings indicated that the engine exhibits optimal power performance at the injection timing of − 270 °CA ATDC (after top dead center), primarily attributed to the enhanced volumetric efficiency and improved mixture homogeneity. However, the mixture concentration in the pre-chamber is leaner, resulting in the longest ignition delay period. When the injection timing is located on the middle state of the intake stroke, specifically − 210 °CA ATDC, the ignition delay period is the shortest, indicating that the mixture concentration and temperature in the pre-chamber are conducive to the flame kernel formation and flame propagation. In addition, the volumetric efficiency of this injection case is maximized due to the combined effects of spray-wall interaction, spray-air interaction, and the flow field. When injection occurs on compression stroke, the mixture concentration in the pre-chamber is higher; however, there exists a significant and discontinuous concentration gradient in the main-chamber, which limits the enhancement of the flame propagation speed and the combustion efficiency, especially for − 120 °CA ATDC injection case, the engine exhibits longest combustion duration and the lowest IMEP. The conclusions can provide theoretical basis and empirical data support for enhancing the combustion of methanol direct injection engines equipped with passive pre-chambers.

Determining the Compaction Temperature of Warm-Mix Anti-Rutting Asphalt Mixture

In order to study the effect of a warm-mix agent on the compaction characteristics of an anti-rutting asphalt mixture, this study compared the compaction temperature of an anti-rutting asphalt mixture with different warm-mix-agent contents from two aspects: asphalt viscosity and asphalt mixture voids. Based on the rheological properties of asphalt, the optimal content of the anti-rutting agent was first determined as 6% by the weight of asphalt. Four warm-mix-agent contents of 0% (control group), 1%, 2%, and 3% were designed. The viscosity–temperature curve of the warm-mix anti-rutting modified asphalt was obtained by the Brookfield viscosity tests. After that, AC-20 standard Marshall specimens were prepared to conduct a series of consecutive temperature compaction tests. The voids were calculated based on the bulk density of the specimen measured by the saturated surface-dry method. Industrial Computerized Tomography (CT) was employed to further quantify the internal voids. Two voids–compaction temperature curves were constructed based on the saturated surface-dry and CT results, respectively. The comparative results show that significant differences exist between the compaction temperatures obtained from the three curves. The viscosity–temperature curve shows that when the warm-mix agent is increased from 0% to 3%, the compaction temperature only declines about 7.9%. However, the voids–compaction temperature curves from saturated surface-dry and CT, respectively, indicate a temperature decrease of 22.7% and 19.2%. This is because a warm-mix agent will interact with asphalt, resulting in a decrease in asphalt intermolecular adsorption, whereas an anti-rutting agent mixed with asphalt will increase the degree of cross-linking and aggregation between asphalt molecules. Both additions have a certain impact on the viscosity of the asphalt binder; thus the traditional method of using the asphalt viscosity–temperature curve to determine the compaction temperature of warm-mix anti-rutting asphalt mixture has become ineffective. It is suggested to use the equal voids method to determine the compaction temperature of warm-mix anti-rutting asphalt mixtures.

Temperature-Based Long-Term Stabilization of Photoacoustic Gas Sensors Using Machine Learning.

In this study, we address the challenge of estimating the resonance frequency of a photoacoustic detector (PAD) gas cell under varying temperature conditions, which is crucial for improving the accuracy of gas concentration measurements. We introduce a novel approach that uses a long short-term memory network and a self-attention mechanism to model resonance frequency shifts based on temperature data. To investigate the impact of the gas mixture temperature on the resonance frequency, we modified the PAD to include an internal temperature sensor. Our experiments involved multiple heating and cooling cycles with varying methane concentrations, resulting in a comprehensive dataset of temperature and resonance frequency measurements. The proposed models were trained and validated on this dataset, and the results demonstrate real-time prediction capabilities with a mean absolute error of less than 1 Hz for frequency shifts exceeding 30 Hz over four-hour periods. This approach allows continuous, real-time tracking of the resonance frequency without interrupting the laser operation, significantly enhancing gas concentration measurements and contributing to the long-term stabilization of the sensor. The results suggest that the proposed approach is effective in managing temperature-induced frequency shifts, making it a valuable tool for improving the accuracy and stability of gas sensors in practical applications.

The Effect of the Pyrolysis Temperature of a Leather-Textile Mixture from Post-Consumer Footwear on the Composition and Structure of Carbonised Materials.

This paper presents an investigation into the use of pyrolysis to valorise solid waste in the form of post-consumer footwear uppers. A heterogenous leather and textile mixture is studied, produced by crushing some representative samples of post-consumer footwear uppers. The waste has a low ash content and a high net calorific value, which translates into the high gross calorific value of the material. In addition, it contains relatively little S and Cl, which is promising for its use in the process of pyrolysis. The effect of the pyrolysis temperature on the efficiency of carbonising leather and textile mixtures, their physico-chemical parameters, elemental composition, and structure, as well as the development of a specific surface, is investigated. The research results imply that as the pyrolysis temperature grows, the carbonisation efficiency declines. The produced materials consist primarily of C, O, N, and H, whose contents depend on the pyrolysis temperature. Moreover, all the carbonised materials display the presence of two G and D bands, which is typical for carbon materials. Based on the peak intensities of the bands, ID/IG coefficients are calculated to assess the organisation of the materials' structures. As the pyrolysis temperature rises, the structural organisation declines, contributing to an increased material porosity and, thus, a greater specific surface of the carbonised materials. This study contributes data on the thermal management and pyrolysis of leather and textile waste into useful carbonised materials. Investigating the applicability of carbonised materials is projected as the next stage of research work.

Experimental Investigation of Ammonia/Oxygen/Argon Combustion: The Role of Equivalence Ratio and Nozzle Shape in a Constant Volume Combustion Chamber with Sub-chamber

The global rise in carbon emissions presents a rising challenge for current and future generations. In the pursuit of zero carbon emissions, ammonia (NH3) has emerged as an attractive alternative energy source. Ammonia offers a carbon-free fuel option with a higher energy density than liquid hydrogen while maintaining ease of transport and storage. However, ammonia still has its drawbacks, such as a high autoignition temperature, slow burning velocity, and low heating value, that demand further investigation of its combustion characteristics. This experiment was done to study the effect of nozzle shape and equivalence ratio (ɸ) on the combustion of an ammonia/oxygen/argon mixture using a constant volume combustor equipped with a sub-chamber. The fuels were premixed for 10 minutes and conditioned to an initial pressure of 0.2 MPa and an initial mixture temperature of 423 K. The results show that the different nozzle shapes each have their advantages in terms of pressure and jet speed. Overall, the lean mixtures (ɸ0.6 and ɸ0.8) consistently performed better compared to the stoichiometric mixtures (ɸ1.0) in all categories investigated in this study. The round nozzle generates higher pressure, while the special shape nozzle enhances jet speed, highlighting trade-offs between the two.

Evaluation of Mixing Temperature in the Preparation of Plant-Based Bigels.

Understanding gel structures and behavior is a prerequisite for attaining the desired food application characteristics. The mixing temperature is crucial when incorporating thermolabile active compounds into gels. This study evaluated the effect of mixing temperature on the physical and chemical properties of a bigel system prepared using a carnauba wax/canola oil oleogel and Arabic gum hydrogels. The results showed that bigels prepared at lower temperatures (30 and 40 °C) resulted in a solid-like state under crystallization temperature, resulting in matrices with larger hydrogel droplets, softer texture, and lower adhesiveness, spreadability, and solvent binding capacity. In contrast, bigels prepared at higher temperatures (50 and 60 °C), around crystallization temperature but with no solid state, resulted in matrices with smaller hydrogel droplets and higher firmness, adhesiveness, and spreadability. These bigels had a higher apparent viscosity, especially at lower shear rates, and solid-like behavior in the linear viscosity range. During the bigel preparation process, adjusting the mixture temperature had no effect on the samples' oxidative stability, FTIR spectra, or thermal properties. The results highlighted the importance of hydrogel droplet size on the microstructure of the formed bigels, and smaller droplets could act as effective fillers to reinforce the matrix without making chemical changes.

Circular Economy for Transport Infrastructure: An Overview of the Sustainable Use of Recycled Asphalt Shingles in Asphalt Mixtures

In North America and Europe, asphalt shingle waste created during the installation of roofing membranes and tear-off shingles retrieved at the end of the membrane’s life cycle are two major sources of municipal solid waste. Since almost 15–35% of recycled asphalt shingles (RAS) consist of an asphalt binder, the effective recycling of RAS into asphalt mixtures could also allow a reduction in the consumption of non-renewable resources such as asphalt binders. In this context, several studies investigating the use of RAS in asphalt mixtures can be found in the literature, although they exhibit widespread and sometimes conflicting information about the investigated materials, the mix preparation and testing methodologies and the experimental findings. Given this background, this review paper aims at summarizing the existing information and research gaps, providing a synthetic and rational picture of the current literature, where similar attempts cannot be found. In particular, different research studies show that the use of RAS in asphalt mixtures is an economical as well as an eco-friendly option. RAS with up to 20% by weight of binder or 5% by weight of aggregate/mixtures (eventually in combination with 15% reclaimed asphalt pavement aggregate) were found to be relatively suitable to improve the performance properties of asphalt mixtures, both in the laboratory and in the field. Adding RAS to asphalt mixtures could enhance their stiffness, strength and rutting resistance (i.e., high-temperature properties), while negatively affecting the mixtures’ fatigue and thermal cracking resistance. However, the addition of specific biomaterials (e.g., bio-binders, bio-oils) or additives to asphalt mixtures can mitigate such issues, resulting in lower brittleness and shear susceptibilities and thus improving the anti-cracking performance. On the other hand, the literature review revealed that several aspects still need to be studied in detail. As an example, RAS-modified porous asphalt mixtures (fatigue, rutting, moisture susceptibility and thermal cracking) need specific research, and there are no comprehensive research studies on the effects of the RAS mixing time, size and mixing temperature in asphalt mixtures. Moreover, the addition of waste cooking/engine oils (biomaterials) as asphalt binder rejuvenators in combination with RAS represents an attractive aspect to be studied in detail.

Adaptive Robust Control of Nonlinear Constrained Stirred‐Tank Reactors via Self‐Organizing Fuzzy Neural Network

ABSTRACTThis paper presents an adaptive robust constraint controller for a continuous stirred tank reactor (CSTR) system based on a self‐organizing fuzzy neural network (SOFNN). Due to the high complexity of the chemical reactions, the CSTR system contains many strong nonlinearities and uncertainties. This is the first time to introduce the SOFNN into the adaptive controller design of the CSTR system, which improves the adaptability to dynamic system changes through the adjustment of the fuzzy network structure. Meanwhile, the time‐varying integral barrier Lyapunov functions (TVIBLFs) are employed to ensure the dimensionless reactant concentration and mixture temperature within a reasonable scope, which can improve the stability and safety of the CSTR system. Based on Lyapunov stability analysis, all the signals in a closed‐loop system are ultimately bounded. Simulation results substantiate the efficacy of the proposed control scheme.

Mechanical, rheological and functional consequences of healing of porous asphalt mixtures by magnetic induction

Magnetic induction technology has been extensively developed so far. However, the mechanical, rheological and functional consequences of repeated self-healing are still unknown. For this reason, this paper investigates the consequences of repeated healing cycles by magnetic induction in four chapters: first, the healing temperature of the experimental mixtures was determined and compared with a reference mixture, that was left to stand at room temperature for 90 days to assess the actual self-healing capacity of the asphalt mixtures. Second, the performance against particle loss was evaluated by applying different healing cycles in the cantabro test and particle loss by brush test. Third, rheological consequences on the binder were determined by penetration, ring and ball and dynamic shear rheometer. Fourth, functional consequences on the mixture were studied in terms of permeability and noise absorption capacity. In this way, we are analyzing the impact of the healing cycles on the mechanical performance of the mixture, the properties of the binder and the functional properties respectively. Regarding the results, healing by magnetic induction in porous asphalt mixtures reduces particle loss to a third. Furthermore, there are no statistically significant differences in the performance of the residual binders of the reference mixture without healing cycles and the residual binder of the experimental mixtures after 20 healing cycles. Finally, with respect to their functional properties, repeating the healing cycles 20 times produces a small decrease in the permeability capacity, which is not statistically significant. At the same time, repeated healing cycles significantly increase the noise absorption capacity of the asphalt mixture, possibly due to a slight draining of the binder, which increases the porosity at the top of the mixtures.

가루쌀분말 압출성형물의 특성에 대한 전분 첨가 및 종류의 영향

This study investigated the effects of starch addition and type on the characteristics of extruded products of floury rice powder (FRP). Native starches from waxy, normal, and high-amylose corn, wheat, tapioca, and potatoes were used. Each starch replaced 30% of the dry weight of FRP. FRP and FRP-starch mixtures were extruded using a twin screw extruder at 19–20% moisture content, 18 Hz screw speed, and barrel temperature of 160℃, followed by drying at 80℃ for 3 h. The water absorption and water solubility indices of the FRP-starch mixtures were higher than those of starch alone, whereas swelling power exhibited the opposite trend. The gelatinization temperatures of the FRP-starch mixtures, except for the FRP-wheat starch mixture, shifted to higher temperatures than those of FRP, whereas their gelatinization enthalpies were lower. The pasting viscosities of the FRP-starch mixtures, except for the FRP-high-amylose cornstarch mixture, were higher than those of FRP. Regarding the extruded products, partial replacement of FRP with starch improved the expansion ratio and specific volume of the extrudates. The failure strength, measured using a 3-point bending test, was higher for the FRP-starch mixture (except for high-amylose corn and tapioca starches) than for FRP.