Increase In Initial Temperature Research Articles

Studies of the diluent, temperature and pressure effect on the lower and upper flammability limits of ammonia in air

Ammonia safety and environmental protection research forms the basis for its role as a clean energy carrier. In this work, an experimental study was conducted in this work to analyze the effect of different inhibitors (nitrogen, argon and water vapor) on the flammability limits (FLs) of ammonia at elevated temperatures and pressures. In addition, the influence of diluents on the compositions and flame temperature changes was evaluated, and the temperature sensitivity coefficients of the elementary reactions and the ROP of free radicals and partial products at the FL concentrations were analyzed. The findings indicated that water vapor provided the strongest flame retardant effect on ammonia in three inhibitors. Within a certain temperature and pressure range, the FLs of ammonia in ammonia/diluent/air can be predicted using the extended Le Chatelier equation. The flame temperature decreased at the lower flammability limit (LFL) concentrations and increased at the upper flammability limit (UFL) concentrations of ammonia with increasing initial pressure. As the initial temperature increases, the flame temperature decreases during ammonia combustion. The influence of ammonia concentration on flame temperature is greater than that of diluents dilution. The elementary reactions H+O2<=>O+OH (R1) and NH2+NO<=>NNH+OH (R82) were the primary reactions that increased the flame temperature at the FL ammonia concentrations in ammonia/diluent/air. Conversely, NH2+NO<=>N2+H2O (R80) and H+O2(+M)<=>HO2(+M)(R15) were the main reactions that decreased the flame temperature. H, OH and NH2 radicals played a crucial role in the combustion reaction process at ammonia FL concentrations. At the LFL concentrations of ammonia, the molar fraction of the OH radical showed the greatest variation, while at the UFL concentrations of ammonia it was NH2 radical. The elementary reaction NH3+OH<=>NH2+H2O (R158) was the primary reaction that consumed OH radical and promoted the formation of NH2 radical. Free radical concentrations decreased with increasing pressure and temperature, while the change rate of free radical ROP accelerated with increasing pressure. In addition to nitrogen and water, the partial products were mainly nitric oxide at the LFL concentrations, while at the UFL concentrations were mainly hydrogen.

Influence of multi-walled carbon nanotubes on thermal behaviour and mechanical properties of pineapple leaf fibre-based natural rubber composites

Replacing synthetic fibres with natural fibres as reinforcement fillers in natural rubber (NR) tends to yield eco-friendly bio-composites. This study investigated the tensile and hardness properties, and the thermal behaviour of pineapple leaf fibre (PALF)-reinforced NR composites with and without the addition of multi-walled carbon nanotubes (MWCNT). The fibre content was varied at 0, 10, 20, and 30 parts per hundred rubber (phr) and the MWCNT content was fixed at 10 phr. The surface morphology of the tensile-fractured specimens was examined using scanning electron microscopy (SEM) to identify the rubber-matrix adhesion and tear mechanisms of the fibres in the NR matrix. The results revealed that including the PALF and MWCNT allowed the NR composites to exhibit excellent stretching stress at low elongations. Additionally, the composites displayed enhanced stiffness, further increasing the hardness of the composite, ranging from 46.8 to 62.8 Shore A. However, PALF reduces the thermal stability of the composite, where the initial degradation temperature increases. From the thermogravimetric analysis, the residues remaining in the NR composites ranged from 6-13% at various fibre loadings. Therefore, this study provides valuable insights into the tensile and hardness properties and the thermal behaviour of PALF-reinforced NR composites to improve end-use properties.

Experimental and simulation study on the expansion mechanism of polyurethane grout

Understanding the expansion mechanism of polyurethane polymer grout can supply guidance for accurate grouting. However, most of the polymer grout expansion calculations were defined simplistically by the polymer density-expansion pressure empirical relationship expression, which failed to meet the time history of the expansion pressure during the polymer reaction process. The objective of this paper was to investigate the expansion mechanism of polyurethane foam in various constraint conditions during the whole polymer reaction process. A model describing the expansion mechanism of polyurethane foam was established based on the energy conservation principle, the chemical reaction kinetic equation solved by the Runge-Kutta method, and the ideal gas state equation. The model was proved applicable compared to the experiments under fixed volume and fixed confining pressure boundaries. In addition, the effects of grouting quantity, confining pressure, initial temperature, and physical foaming agent content on the grout expansion pressure, density, and components conversions were discussed. The results showed that the expansion pressure of polymer grout gradually increased with time under the fixed volume conditions, and the grout expansion pressure increased as the density increased. The final grout expansion pressure will increase with the increase of initial temperature or the content of physical blowing agent. Under the fixed confining pressure condition, the polymer grout density gradually decreased with time, the grout density increased as the confining pressure increased while the conversions of the two components alcohol and isocyanate increased. The final density decreases with the increase of initial temperature or the content of physical blowing agent.

Preparation and characterization of halloysite nanotube‐silica/silicone rubber composites: Effect of HNTs on mechanical and thermal properties

AbstractA series of halloysite nanotube‐silica (HNTs‐SiO2) nanocomposite fillers were prepared by in‐situ assembly, and a reinforced SiO2/SR composite was obtained by filling them into silicone rubber (SR). The morphology and structural characterization of HNTs‐SiO2 and HNTs‐SiO2/SR and the properties of the HNTs‐SiO2/SR were studied. As a result, the small particle size SiO2 was firmly anchored onto the HNTs surface, and the obtained HNTs‐SiO2 nanofillers were uniformly dispersed in SR. At a 30 phr fixed filler loading, the weakest filler network and the best filler dispersion were obtained when HNTs content in HNTs‐SiO2 was 5%. This resulted in a maximum tensile strength obtained of 6.2 MPa, 1.55 times that of SiO2/SR with the same filler loading, and a maximum elongation at break of 418%, 1.67 times that of the SiO2/SR with the same filler loading, and at the same time the tearing strength and hardness are also improved. Furthermore, the silicone rubber also showed improved thermal stability, with an initial degradation temperature increase of 30°C under a nitrogen atmosphere.Highlights HNTs–SiO2 nanocomposites were successfully prepared by the self‐assembly method and used as fillers in SR as a new type of reinforcing material. The 1D HNTs act as a barrier to prevent SiO2 aggregation and improved fillers dispersion. The elongation at break and tensile strength of 5% HNTs‐SiO2/SR are 67% and 55% higher than those of SiO2/SR, respectively. The silicone rubber also showed improved thermal stability.

Experimental study on mechanical properties and evolution of fracture failure of granite considering initial temperature damage and prefabricated fissure length

With the increasing mining depth of deep mineral resources, the influence of high temperature on the fracture failure of surrounding rock with fissures becomes increasingly serious. To investigate the fracture mechanical properties and the evolutionary characteristics of fracture process of fissured rock experiencing initial temperature damage, the three-point bending experiment was conducted on the small sized granite samples with different initial damaging temperatures and prefabricated fissure lengths by applying a μTS mesoscopic testing system. Based on the digital image correlation methods, the evolution of fracture process zone of sample was revealed. Moreover, the macroscopic fracture failure of sample was predicted by the evolution of time-varying acoustic emission b-value. The results show that with the increase of initial damaging temperature and prefabricated fissure length, the peak load of granite sample has a decreasing trend and the fracture characteristics of sample experiencing initial temperature damage gradually transform from brittleness fracture to ductility fracture, resulting in a decrease in the fracture toughness of sample. The crack tip opening displacement, the critical opening displacement and the length of fracture process zone of sample all show an increasing trend. The time interval from the time when time-varying acoustic emission b-value continues to decline to the appearance moment of macroscopic cracks is selected as the warning time of fracture failure of sample, which can conclude that the warning time increases with increasing the initial damaging temperature and prefabricated fissure length, indicating an increase in ductility and a reduction in failure suddenness of sample.

Feasible Parameters of Ohmic Areas of YBaCuO Thin Films Switched via Moving Unstable Border between Superconducting and Normal States

A system of two equations based on one of the classical electricity laws was used to determine the sizes and temperatures of ohmic areas formed under action of overcritical nanosecond electrical pulses. Calculations were performed at five points for three experimentally obtained voltage–current (V-I) dependences for samples with the same geometry but different critical current density values. The system included two additional conditions to satisfy the known descriptive model of transition from superconducting (SC) to a normal (N) state—S-N switching—and to obtain physically acceptable solutions over the entire current range of V-I dependence. The solution for each point takes the form of a function, since the initial temperature increase of the primary channel across the film is entered as a parameter. Two modes of concentrated energy release in the channel were disclosed. Their random appearance leads to an unexpected degradation of the sample. As such, the obtained results correspond to the situations occurring during the experiments. The validity of applying additional conditions to the system is discussed. In the discussion, it is also explained at which moments the moving S-N border acquires the velocity of the order of ~106 m/s, comparable to the Fermi velocity. Consideration to describe the moving unstable S-N border as being constantly in a state of Richtmyer–Meshkov instability is presented.

Removal of broken abutment screws using ultrasonic tip - a heat development in-vitro study.

Dental implants can cause complications, including the loosening of the abutment screw or fracture. However, there is no standardized technique for removing broken abutment screws. This necessitates further research. This study aimed to measure heat generation during screw removal to better understand its implications for dental implant procedures. The experimental setup involved using synthetic bone blocks and titanium implants. An ultrasonically operated instrument tip was utilized for screw removal. Infrared thermometry was employed for accurate temperature measurement, considering factors such as emissivity and distance. Statistical analysis using linear regression and ANOVA was conducted. The findings revealed an initial rapid temperature increase during the removal process, followed by a gradual decrease. The regression model demonstrated a strong correlation between time and temperature, indicating the heat generation pattern. Heat generation during screw removal poses risks such as tissue damage and integration issues. Clinicians should minimize heat risks through an intermittent approach. The lack of a standardized technique requires further research and caution. Understanding the generated heat optimizes implant procedures.

Influence of temperature effect on properties of modified magnesium slag-based low-carbon paste backfill materials

Coal mining subsidence and bulk solid waste storage are the bottleneck problems for achieving green and low-carbon development in northern Shaanxi. Aiming at the demand of filling mining in coal mines in northern Shaanxi, a modified magnesium slag-based low-carbon paste backfill materials (MMS-PBM) was proposed, which realized the safe disposal and resource utilization of solid waste. In-depth understanding of the influence of temperature effect (initial temperature: 5 ∼ 50 °C and curing temperature: 20 ∼ 50 °C) on the performance of MMS-PBM is helpful to optimize the mix ratio and filling period of filling materials. Based on this, relevant tests and tests (including setting time test, Mini-slump test, rheological test, uniaxial compressive strength test, microscopic test and leaching toxicity test) were carried out to explore the influence mechanism of temperature effect on the performance of MMS-PBM. results showed: (1) The rheological curve of fresh MMS-PBM slurry is highly consistent with the Herschel-Bulkley (H-B) model, and the fluidity meets the pumping requirements of coal mine filling. With the increase of initial temperature, the yield stress and apparent viscosity of fresh slurry increased, while slump, expansion and thixotropy decreased. (2) The increase of initial temperature inhibits the development of early mechanical properties of MMS-PBM, which is mainly affected by the metastable film hypothesis. (3) The curing temperature is conducive to the development of mechanical properties of MMS-PBM, and meet the requirements of mechanical properties of coal mine. With the increase of curing temperature, the main growth range of mechanical properties gradually changes from 7–28 d to 3–7 d, which is consistent with the change of microstructure. (4) The leaching concentration of heavy metals in MMS-PBM meets the requirements of national standards, but the increase of curing temperature has an inhibitory effect on the solidification of heavy metals. The above results show that MMS-PBM is a safe, green and low-carbon all-solid waste filling material, which is beneficial to the coordinated development of coal resource mining and environmental protection.

Inhibition and enhancement of hydrogen explosion by perfluorohexanone

To explore the inhibition and enhancement of hydrogen explosion by perfluorohexanone (CF3CF2COCF(CF3)2), the experiments are conducted by changing the equivalence ratio, inhibitor content, initial pressure and initial temperature, and the maximum explosion overpressure (MEO), maximum rate of pressure rise (MRPR) and critical content of explosion inhibition are obtained. The adiabatic flame temperature, sensitivity coefficient and mole fraction of active radicals are calculated using CHEMKIN. The results show that on the lean side, the sub-inhibitory perfluorohexanone generates CO to be involved in the combustion, and the formation of HF releases lots of heat, which causes the combustion enhancement. On the stoichiometric and rich sides, H is captured by other fluorides, exhibiting the inhibitory effect. Increasing the initial pressure (initial temperature) causes an increase (decrease) in the MEO and the MRPR. As the equivalence ratio increases, initial pressure reduces and initial temperature increases, the critical content of explosion inhibition is effectively reduced.

Numerical analysis of temperature effect on CO2 storage capacity and CH4 production capacity during the CO2-ECBM process

Temperature is a key factor affecting the CO2 injection efficiency and CH4 production efficiency, so it is of great significance to clarify the evolution diagram of temperature change during the CO2-ECBM process. In this study, the crushed soft coal seam with low permeability in Huainan coalfield was taken as the research object. Firstly, the fully coupled mathematical models of CO2-ECBM process were constructed, and the influence of temperature field on CO2-ECBM process was emphasized. Secondly, the evolution law of CO2-ECBM process at different time was revealed. Then, the effects of injection temperature and initial temperature on the CO2-ECBM process were analyzed. Finally, the evolution mechanism of reservoir temperature during the CO2-ECBM process was illustrated, and the effect of temperature on temperature field of CO2-ECBM process was further illustrated. The results show that the longer the displacement time, the CH4 concentration gradually decreased, and the CO2 concentration gradually increased. The area where the temperature changes are more concentrated focuses on the vicinity of CO2 injection well, which are mainly determined by the dominant reaction of adsorption and desorption reactions of binary gas. Reservoir temperature and permeability are positively and negatively correlated with injection temperature, respectively. Both CO2 storage capacity and CH4 production capacity increase with the increase of injection temperature, and the sensitivity of CO2 storage capacity to temperature was greater than that of CH4 production capacity. With the increase of displacement time and injection volume, the effective displacement radius increases, but the increment of influencing radius gradually decreases. The lower the initial temperature of coal reservoir, the larger the influencing radius, and which increases with the increase of displacement time. CO2 storage capacity and CH4 production capacity decrease with the increase of initial temperature. Young's modulus and Poisson's ratio can effectively change the reservoir strength. CO2 storage capacity and CH4 production capacity decrease with the increase of Young's modulus, and increase with the increase of Poisson's ratio. This study can support the engineering landing of CO2-ECBM technology in crushed soft coal seam with low permeability, and promote the realization of China's “Dual Carbon” strategic goal.

Comparative study on the flame retardancy of CO2 and N2 during coal adiabatic oxidation process

To test the effectiveness of N2 and CO2 in preventing coal from spontaneously combusting, researchers used an adiabatic oxidation apparatus to conduct an experiment with different temperature starting points. Non-adsorbed helium (He) was used as a reference gas, and coal and oxygen concentration temperature variations were analyzed after inerting. The results showed that He had the best cooling effect, N2 was second, and CO2 was the worst. At 70℃ and 110℃, the impact of different gases on reducing oxygen concentration and the cooling effect was the same. However, at the starting temperature of 150℃, CO2 was less effective in lowering oxygen concentration at the later stage than He and N2. N2 and CO2 can prolong the flame retardation time of inert gas and reduce oxygen displacement with an initial temperature increase. When the starting temperature is the same, N2 injection cools coal samples and replaces oxygen more effectively than CO2 injection. The flame retardancy of inert gas is the combined result of the cooling effect of inert gas and the replacement of oxygen. These findings are essential for using inert flame retardant technology in the goaf.

Relationship between higher estrus-associated temperatures and the bovine preovulatory follicular fluid metabolome

IntroductionA higher estrus-associated temperature (HEAT) is a hallmark feature in sexually active females; however, its functional importance is unclear. Our objective was to examine the relationship between HEAT and the preovulatory follicular fluid metabolome. It was hypothesized that HEAT is functionally important as it affects fertility-related components in the preovulatory follicle.MethodsEstrus was synchronized in non-lactating Jersey cows. A Thermochron iButton temperature data logger was affixed to blank controlled internal drug release (CIDR) devices and intravaginally inserted after CIDR device removal. The follicular fluid was aspirated 14.9 h + 3.3 h after an animal first stood to be mounted. Regression models were performed using metabolite abundance and HEAT variables. Best-fit models were determined using backward manual selection (p &amp;lt; 0.05).ResultsA total of 86 metabolites were identified in cow follicular fluid samples. The vaginal temperature at first mount and when it was expressed as a change from baseline was positively related to the abundance of four metabolites (i.e., taurine, sn-glycerol 3-phosphate, glycine, and cysteine) and negatively related to one metabolite (i.e., serine). The vaginal temperature at the first standing mount was related to the differential abundance of two metabolites (i.e., jasmonate and N-carbamoyl-L-aspartate). Three metabolites were related to the maximum vaginal temperature (i.e., N-carbamoyl-L-aspartate, uracil, and glycodeoxycholate). When expressed as a change from baseline, the maximum vaginal temperature was related to the differential abundances of uracil, uric acid, and 6-phospho-D-gluconate. The time taken to reach maximum vaginal temperature was related to N-carbamoyl-L-aspartate, glycodeoxycholate, jasmonate, and tricarballylic acid. Pertaining to the combination of HEAT and its duration, the area under the curve associated with the time between the first increase in vaginal temperature and the maximum vaginal temperature was related to 6-phospho-D-gluconate, sulfolactate, guanidoacetic acid, and aspartate. The area under the curve associated with the time between the initial vaginal temperature increase and up to 10 h after a cow first stood to be mounted or when a cow’s temperature returned to baseline was related to the differential abundances of uracil, sn-glycerol 3-phosphate, methionine sulfoxide, and taurodeoxycholate.DiscussionOur findings support the notion that HEAT is related to changes in the preovulatory follicular fluid metabolites involved in energy metabolism, thermoregulation, and oxidative stress management.

Research on thermal performance of ground source heat pump based on artificial neural network predictive model

The long-term operation of ground source heat pump systems can affect the soil environment, causing a decrease in heat transfer performance of underground heat exchangers. Based on a real project, this study aims to determine the actual soil thermal property and propose optimization schemes. A combination of 1D-3D heat transfer model and artificial neural network model was proposed. This research confirms the possibility of using the outlet water temperature as input to predict the soil thermal property parameters. Through model calculations, the soil comprehensive thermal conductivity of 1.78 W/(m·K) and comprehensive heat capacity of 1909.8 J/(kg·K) was determined. On this basis, the impacts of burial depth, spacing, and initial ground temperature on the heat transfer of the underground heat exchangers was investigated. The results showed that the heat exchange is logarithmically related to the depth and spacing of the boreholes, but the heat exchange decreases as the initial ground temperature increases, following a quadratic function relationship. For the current hourly cooling demand, it is recommended to have the pile spacing of 5.5 m and the depth of 110 m. With the addition of a cooling tower that takes on 2/3 cooling load, the system's average coefficient of performance can reach 5.62, resulting in a 19.6 % improvement.

Investigation on the flammability limit and limiting oxygen concentration of propane/propylene mixture at elevated temperature and pressure

With the development of industrial technology, a new process has emerged for the production of acrylic acid using propane as a feedstock. There are few studies on the combustion characteristics of propane/propylene mixtures at elevated temperature and pressure. In this study, a flammability limit test system was used to determine the flammability limit and limiting oxygen concentration of propane and propane/propylene mixture at different initial temperatures (30–120 °C) and pressures (0.1–2 MPa). The results showed that with the increase of initial temperature and pressure, the flammability limit range expanded, and the limiting oxygen concentration reduced. In addition, the flammability limit range of the propane/propylene mixture is greater than that of propane, indicating that the addition of propylene increases the explosion risk. The empirical formula of the experimental gas was fitted to predict the combustion and explosion parameters under different conditions. In addition, the chemical reaction simulation of propane/propylene mixture was also investigated. The results showed that with the propylene ratio increased, the adiabatic flame temperature and adiabatic overpressure increased, the proportion of H-abstraction reaction decreased and the proportion of pyrolysis reaction increased significantly, which promoted the explosive reaction and the increase of explosion temperature.

Experimental and numerical study on the effects of initial pressure and temperature on the explosion characteristics of LPG mixtures

As a safe new renewable energy, liquefied petroleum gas (LPG) has the advantages of less environmental pollution and higher calorific value. Therefore, it is of great significance for the sustainable development of Chinese new energy sources to study the fuel explosion characteristics of LPG. The maximum explosion pressure (Pmax), maximum rates of the pressure rise ((dp/dt)max), and explosive index (KG) of LPG were investigated experimentally and numerically at various initial pressures (0.1–0.2 MPa) and temperatures (25–100 °C). Through the analysis of the experiment results, it was found that: as the initial pressure increases, the Pmax and (dp/dt)max of the mixed gas gradually increase. The Pmax of the mixture decreases with the increase of initial temperature. A fitting relationship between the other relevant combustion and explosion characteristic parameters (KG), initial temperature, and initial pressure is obtained within the experimental range. Numerical simulation was carried out with the help of the Chemical Kinetics (CHEMKIN) software. From the simulation results, it was found that the changes in Pmax and (dp/dt)max of the mixture were consistent with the experimental results. Through the sensitivity analysis of the mixture, the elementary reaction which plays an important role in the reaction process of the mixture was obtained. This work is expected to be conducive to safety management and the prevention of explosion accidents.

Simulation analysis of soot formation and laminar combustion characteristics of 2,5-dimethylfuran/air at different initial pressures and temperatures

In this research, we studied the soot formation and laminar combustion characteristics of 2,5-dimethylfuran (25DMF) at different initial temperatures and initial pressures, and conducted reactive force field molecular dynamics (ReaxFF MD) simulation and dynamical simulation method with a one-dimensional laminar combustion model through CHEMKIN's PREMIXED Code. The full process of soot formation during 25DMF combustion was revealed by ReaxFF MD simulation. There are three stages from the formation of the initial ring, the growth of polycyclic aromatic hydrocarbons (PAHs) and the formation and growth of the initial soot. The growth mechanism of polycyclic aromatic hydrocarbons was mainly divided into 4 types, which were hydrogen-abstraction-C2H2-addition (HACA), carbon-addition-hydrogen-migration (CAHM), clustering of hydrocarbons by radical-chain reactions (CHRCR) mechanism and internal ring formation. For the dynamical model of 25DMF combustion, the initial temperatures (Tu) were set to 298 K, 358 K, 393 K and 423 K, and the initial pressures (pu) were set to 1 atm, 3 atm, 5 atm and 10 atm. The results showed that the laminar burning velocities (LBVs) increased along with the increase of the initial temperature. The LBVs decreased with the increase of initial pressure. Both the increase of the initial temperature and pressure led to a decrease in flame thickness. Studies on soot precursors showed that C2H2, i-C4H5, C4H2, and C6H6 shift upstream in peak molar fraction with increasing initial pressure. C4H2 and C6H6 moved downstream first, then upstream and finally downstream with the increase of initial temperature. C2H2 and i-C4H5 shifted upstream and then downstream with increasing initial temperature.

Influence of plasma inhomogeneity and ohmic heating on the nonlinear absorption of intense laser pulse in collisional magnetized plasma

AbstractThe nonlinear absorption in the interaction of an intense laser pulse with a collisional magnetized plasma is studied by considering the effects of plasma inhomogeneity, ohmic heating, and ponderomotive force. For this purpose, we obtain the plasma electron density, the effective dielectric permittivity, and the wave equation using the Maxwell and hydrodynamic equations and solve this equation by the Runge–Kutta numerical method. The results are shown that by increasing the plasma inhomogeneity, the inverse bremsstrahlung absorption coefficient is increased, and also the density ramp parameter and its sign can affect more the absorption coefficient than the temperature ramp parameter . However, when the initial electron density and temperature increase, the laser field amplitude and the absorption coefficient are increased and the spatial damping rate of the laser pulse becomes highly peaked inside the plasma. It is shown by increasing laser pulse energy, the nonlinear bremsstrahlung absorption coefficient is decreased significantly. The results also indicate that by increasing the external magnetic field, the dielectric permittivity is decreased while the laser energy spatial damping, and the absorption coefficient are increased. Moreover, it is found that by considering the ohmic heating effect, the electrons absorb further energy from the fields and consequently the nonlinear absorption is increased.

Experimental and Numerical Studies on the Explosion Characteristics of Ethanol–Air Mixtures under Aviation Conditions

As a representative renewable biofuel, ethanol can reduce mankind’s dependence on petroleum resources and the emission of greenhouse gases and other pollutants. In recent years, the application of ethanol in the aviation field has begun to be a concern of scholars. As ethanol is a flammable liquid, it is significant to study its explosion characteristics in aviation conditions from a safety perspective. In this work, at 20 kPa, the explosion characteristics of ethanol–air mixtures (concentration 6~12%) were experimentally and numerically studied under an initial temperature range of 303 K~363 K. The effects of the initial temperature and concentration on the maximum explosion pressure, maximum rate of pressure rise, explosion time, and fast burning time were analyzed. In addition, the heat loss fraction and sensitivity analysis were examined and discussed. The main conclusions are as follows: A linear relationship exists between the maximum explosion pressure and the reciprocal of the initial temperature. The maximum rate of a pressure rise appears to decrease or at least approach a constant value as the initial temperature increases. The explosion time is significantly dependent on the concentration. At a constant concentration, the proportions of heat loss are approximately constant except for 12%. In our sensitivity analysis, R1 (H + O2 &lt;=&gt; O + OH) was the dominant elementary reaction.

Mechanism research on the application of liquid film microencapsulation technology based on natural lotion in strengthening recycled bio‐composite wallpaper material

AbstractLow‐carbon technology is currently one of the main research directions in sustainable research. The purpose of this research is to explore environmentally friendly low‐carbon technologies to apply NL and wastes to the development of bio‐composite. This research can not only inhibit the release of toxic atmosphere from composite wallpaper materials but also propose new perspective for recycling several bulk wastes such as agricultural waste, waste plastics, and waste cooking oil. This study not only conducted an exploratory research on the degree of filling load from a vertical perspective but also conducted comparative experiments to clarify the strengthening effect of NL in a horizontal perspective. Several valuable findings are obtained through the analysis of several measurements such as mechanical performance and scanning electron microscope (SEM) morphology. The heat transfer effect between components inside the bio‐composite is enhanced by the action of NL. A better heat transfer effect can prevent heat from accumulating in local areas of bio‐composite, resulting in an increase in the overall initial pyrolysis temperature of thermogravimetric analysis (TGA) curve. It is found through experiments that when the biomass filler is excessive, the mechanical performance of the sample sharply decreased. These negative phenomena are presented in the specific form of voids and aggregates in the internal structure of bio‐composite from a microscopic perspective. Comprehensive analysis manifested that NL can suppress the negative effect of filler agglomeration and strengthen the filler/matrix interface bonding. The research also found that the type of biomass filler can affect the actual effect of NL. These findings have certain academic significance and can promote the further development of sustainable research on diversified recycle of wastes.

Flash evaporation method for improved desalination and cooling applications: An experimental study

The present study involves the experimental analysis of flash evaporation when sudden depressurization is created into a vertical cylindrical tube having a water volume range of 120 to 180 ml. During experiments, low water pool volumes are used to prevent the impact of gravity on the change of saturation temperature. The investigation is carried out by varying the initial water temperature and back pressure of the vacuum tank in the range of 65 to 80 ∘C and 11.32 to 41.32 kPa, respectively. It is observed that the evaporation rate and cooling rate are both enhanced by increasing the initial pool temperature and decreased by increasing the back pressure. It is reported that the evaporation rate is improved by 29.7 % with an increase in initial water temperature of 5 ∘C and decreases by 152 % with an increase in the back pressure of 10 kPa. It is also found that the cooling rate is improved by 21.6 % with an increase in initial water temperature of 5 ∘C and decreased by 59.2 % with an increase of water volume of 30 ml. It is clear from the visualization procedure that the degree of superheat plays a vital role in flash evaporation.