Changes In Rules Research Articles

The influence of air distribution ratio on the fluctuation characteristics and stability of horizontal jet diesel non-premixed flame under extreme sub-atmospheric pressures

The burning problem in the plateau environment attracts more and more people’s attention, and the plateau adaptability and flame stability of burner are the focus of recent research. The main purpose of this paper is to reveal the horizontal jet spray flame fluctuation characteristics and stability change rule under extremely low pressure (0.05 MPa) at a high altitude (about 5500 m) inhabited by human beings. Flame morphology and temperature properties were investigated in a low-pressure chamber with different secondary air ratios (23–53 %). It is found that the normalization of the flame trajectory equation is not affected by the ratio of secondary air. The temperature in the flame recirculation zone can be increased by 110 K as the proportion of secondary air increases to 45 %, but the maximum temperature is still lower than 1500 K. A continuous flame image processing method was implemented to define and analyze the flame fluctuation region. The results show that the dimensionless fluctuation parameter γ can predict the flame stability in advance than β. When the secondary air ratio is 40 %, the flame has the largest upward fluctuation; and when it exceeds 45 %, the flame stability becomes worse. This work is the first to obtain the results of the study on flame morphology and stability of horizontal jet spray flame distribution ratio under extremely low atmospheric pressure, which provides a theoretical scientific basis for the design of plateau burner, flame control, and flame stability improvement.

Research on the effect of apparent density on the rheological properties of lightweight and heavyweight concrete

This paper investigated the influence from apparent density on rheological property of lightweight and heavyweight concrete. The apparent densities of 1761 kg/m³, 3048 kg/m³ and 3548 kg/m³ were selected. The obtained results showed when the slump for lightweight and heavyweight concrete was controlled in the range of 160 ± 10 mm, the yield stress (τ0) and plastic viscosity (μp) increased significantly as the addition of the apparent density. The slump tests of fresh lightweight and heavyweight concrete were numerically simulated with an error of less than 3.0 % using lattice Boltzmann method (LBM). The established slump model could accurately predict the flow behavior and characteristics of lightweight and heavyweight concrete at different apparent densities. By comparing the distribution of physical fields such as velocity and pressure, the effect of apparent density upon the flow behavior of lightweight/heavyweight concrete was analyzed in depth, and the changing rule in rheological performance of concrete with different apparent densities was clarified.

Extraction and Hemagglutination Activity Study of Lectins from Hygrophorus lucorum Kalchbr

Edible fungus lectin hasanti-tumor, anti-virus, immune regulation and other functions. In this experiment, the wild Hygrophorus lucorum Kalchbr was used as the material, and the lectin was extracted by leaching method. The lectin was treated with physical and chemical factors, and the hemagglutination method was used to detect the change rule of lectin agglutination activity. The extraction process of lectin was optimized by single factor experiment and orthogonal experiment. The study of agglutination activity showed that: glycerol, lactose and maltose had significant inhibitory effects; when treated at 80℃, the agglutination activity was lost; pH<5.0 or pH>9.0, the agglutination activity was greatly inhibited; AI3+, Fe3+ had obvious promoting effects. Lectin extraction single factor test results: PBS (0.50mol/L, pH6.5) was used as the extraction reagent, the ratio of solid to liquid(g/mL) was1:10, and the fruiting bodies were extracted for 5 hours at 30℃. 40% saturation ammonium sulfate salting-out treatment, the salting-out product has the highest agglutination activity. The optimal process combination obtained by the or thogonal test is: using PBS (0.50mol/L, pH 6.5) as the extractant, according to the solid-liquid ratio (g/mL) 1:10, 40℃, leaching for 4h, the quantitative agglutination activity of lectin was 0.9609.

Simulation analysis of the evolution law of creep rupture crack extension in X-fractured rock body

Creep is the macroscopic manifestation of the process of generation, expansion, and penetration of microscopic cracks in a rock body. In this study, the GDEM continuous–discontinuous numerical simulation software was used to model a rock body containing X-fractured for the purposes of exploring creep crack expansion and rupture in the rock body, analyzing the effects of various factors on X-fractured the rock body under the rule of change of the creep curve, and assessing the influences of the intersection angle of the fracture and other factors on the non-parallel fractured rock body on the creep rupture process. The results show that an X-fractured rock body exhibits a mixed tensile–shear damage mode, with tensile damage being the main type of damage. In the isotropic creep stage of a rock body with X-fractured , the steady-state creep rate initially increases and then decreases as the sub- fracture length increases, with the change of the fracture angle of the creep rate of the w-type; the sub-fracture length of h is 14 mm, the rock body is the first to enter into the accelerated creep stage, for the different fracture intersection angle of the rock body For the rock mass with different fracture angles, the time sequence of entering the accelerated creep stage is consistent with the creep rate; when the fracture intersection angle is 45°, and the sub-fracture length is 12 mm, the rock mass has the largest degree of fragmentation, which has a significant impact on the creep damage; after using a single variable processing, it is found that the fracture intersection angle, the sub-fracture length and other factors compared to the fracture intersection angle has a greater impact on the creep damage of the X-fractured rock body. This paper can provide theoretical basis and reference for the study of rock engineering creep damage law and mechanical properties of X-fractured rock body.

CFD of the diffusion movement and concentration distribution of culinary particles in the respiratory zone of restaurant diners

Released aerosol particles during restaurant culinary activity affect diners' health. The air conditioning system is crucial for regulating indoor air quality. However, its improper air distribution increases the individuals' exposure to particle pollution. This study investigates restaurants employing side-up airflow during summer with numerous heat sources and examines the culinary particle diffusion in the diners’ respiratory zone under the combined influence of air conditioning cold jet air supply and culinary heat source heat plume. It elucidates the change rule of the concentration distribution of culinary particles under the combined action of these two heterogeneous airflows.This study investigated the movement and concentration distribution of indoor particle by numerical simulation under various air supply velocities, culinary heat source strengths and positions and tuyere opening modes. In restaurants with culinary sources, the thermal buoyancy by the heat plume causes particles to rise. However, the drag force exerted by the cold air supply jet impedes the particles’ upward motion. The particle concentration distribution is significantly influenced by both the air supply velocity and the relative positioning of the heat source and the tuyere. Particle concentration increases by 27.13 % in the respiratory zone when the air supply jet trajectory is above the pollution emission source than below. Therefore, lowered air supply velocity is ideal with increased horizontal distance between the emission source and the tuyere under the condition of comfort satisfaction. This scenario mitigates the downward movement exerted by the jet on the particles. The drag force is increased with the air supply velocity increasing from 2.5 m/s to 4.0 m/s. Particle concentration is raised to 41.38 % in the respiratory zone. The drag force by the cold jet on the particles is also heightened with the bilateral tuyere than its single-side counterpart which increases particle concentration maximum by 40.30 % in the respiratory zone.

Digital reconstruction of three‐dimensional contours and its application to microstructural evaluation of postblast rock fissure surfaces

AbstractFracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks. Based on the improved cube covering method and the 3D contour digital reconstruction model, this study proposes a quantitative microstructure characterization method combining the roughness evaluation index and the 3D fractal dimension to study the change rule of the fracture surface morphology after blasting. This method was applied and validated in the study of the fracture microstructure of the rock after blasting. The results show that the fracture morphology characteristics of the 3D contour digital reconstruction model have good correlation with the changes of the blasting action. The undulation rate of the three‐dimensional surface profile of the rock is more prone to dramatic rise and dramatic fall morphology. In terms of tilting trend, the tilting direction also shows gradual disorder, with the tilting angle increasing correspondingly. All the roughness evaluation indexes of the rock fissure surface after blasting show a linear and gradually increasing trend as the distance to the bursting center increases; the difference between the two‐dimensional roughness evaluation indexes and the three‐dimensional ones of the same micro‐area rock samples also becomes increasingly larger, among which the three‐dimensional fissure roughness coefficient JRC and the surface roughness ratio Rs display better correlation. Compared with the linear fitting formula of the power function relationship, the three‐dimensional fractal dimension of the postblast fissure surface is fitted with the values of JRC and Rs, which renders higher correlation coefficients, and the degree of linear fitting of JRC to the three‐dimensional fractal dimension is higher. The fractal characteristics of the blast‐affected region form a unity with the three‐dimensional roughness evaluation of the fissure surface.

A novel adaptive trajectory tracking control for complex environments based on accelerated back-propagation neural network

This work addresses the issue of trajectory tracking accuracy degradation for vehicle dynamics parameters and road conditions changing, an adaptive trajectory tracking controller is designed for the intelligent vehicle. Based on the yaw dynamics model, a model predictive controller (MPC) is developed for the trajectory tracking process. Meanwhile, the impacts of different control parameters on trajectory tracking at various speeds are compared. And the change rule between optimal control parameter values and reference speeds is determined by cubic polynomial fitting to ensure minimal error during the trajectory following process. Then, an estimator for vehicle tire cornering stiffness and road adhesion coefficient is designed and tested based on the accelerated back-propagation neural network (ABPNN) model, with its estimation values being compared to those obtained through recursive least square method. Last, a co-simulation platform combining MATLAB/Simulink and CarSim software is established to conduct the trajectory tracking experiment under variable working conditions. Experimental results show that the proposed adaptive controller not only exhibits high accuracy in trajectory tracking but also demonstrates excellent stability and adaptability under medium to low speed conditions, particularly when encountering changing road conditions.

An examination of competitive rule evolution in the National Football League

ABSTRACT Purpose/rationale Competitive rules, which have implications for player safety, fairness, and entertainment, change over time, yet institutional accounts offer only a high-level view of rule change. This study centers, and looks within, competitive rules to examine how they evolve in professional sport. Design/methodology/approach Using an inductive approach, we conducted a qualitative document analysis of NFL rule books published between 1980 and 2020. We developed and examined longitudinal trajectories of player conduct rules. Findings The analysis reveals rule components (i.e. actions, actors, times, spaces, sanctions) and patterns of change. Rules generally expanded in scope and length. We draw on communications from NFL leaders to connect the findings to institutional factors. Practical implications The findings offer a framework for rule managers as they iterate rules to make sport safer, fairer, and more entertaining. Research contribution This study sheds light on how competitive rules evolve at the level of component parts, providing a foundation for future institutional scholarship on the causes and consequences of rule change. Originality/value This research offers a microfoundations and longitudinal understanding of rule change in sport, with insights for academics and rule managers.

Mechanical properties of recycled aggregate concrete containing brick particles

To investigate the mechanical properties of recycled aggregate concrete containing brick particles (RACB), compressive strength tests were conducted on RACBs with different water/cement ratios and recycled fine aggregate substitution rates. The changes in compressive strength, elastic modulus and peak strain of RACB were analysed as a function of the proportion of substituted recycled fine aggregate, and a stress–strain equation was established. A damage model was established using ultrasonic non-destructive testing technology to reveal the damage mechanism of RACB. Results show that the basic mechanical properties of RACB are best when the replacement proportion of recycled fine aggregate (r) is 30%. The model parameter a of the stress–strain curve equation is consistent with the change of elastic modulus with r. The model parameter b has a quadratic function relationship with r, reflecting the brittleness of RACB. The initial damage of RACB is relatively large, and cracks penetrate the recycled coarse aggregate, leading to specimen failure.

Water Injection Into Coal Seams for Outburst Prevention: The Coupling Effect of Gas Displacement and Desorption Inhibition.

Gassy coal seams generally have low permeability and dry coal bodies, which are susceptible to coal and gas outburst hazards in the process of mining. Water injection into coal seams can significantly alter the gas release rate and flow behavior. However, water has dual effects on coal seams: gas displacement and water-locking, and the coupling mechanism of these two effects is not clear in the whole process of coal seam water injection. By measuring high-pressure gas adsorption isotherms and gas diffusion initial velocity, it was found that both the Langmuir adsorption constant a and gas diffusion initial velocity ΔP decrease with the increase of water content, which would reduce outburst risks. Through the self-developed integrated experimental device of "gas adsorption + water injection displacement + gas desorption″, the changing rules of gas displacement amount, desorption amount, and water lock amount under different water injection conditions were studied. The results show that when the water injection ratio increases from 6 to 25%, the gas displacement would increase from 0.62 to 1.16 mL/g, with an increase of 87.09%. Also, at the same time, the gas desorption capacity would decrease from 4.86 to 4.05 mL/g after pressure relief, with a decrease of 16.67%. The amount of water-locking increased from 0.11 to 0.38 mL/g. The effect of water injection to control coal and gas outburst occurs in two different water injection stages. In the process of water injection, water plays a major role in gas displacement, which is conducive to reducing the gas content of the coal seam. After the completion of water injection, the static water pressure remaining in the coal seam can reduce the gas emission rate. The combination of these two effects can effectively reduce the risk of outbursts.

Analysis of HZSM‐5 molecular sieve particles attrition behavior under fluidized conditions

AbstractThe attrition behavior of HZSM‐5 zeolite catalyst particles at room temperature was investigated in a laboratory‐scale fluidized bed. The effects of three fluidization conditions on particle attrition were investigated, and a new attrition model was proposed. The results demonstrate that the attrition rate is inversely proportional to the initial particle size and proportional to the apparent gas velocity. After increasing to 80 μm and .3 m/s respectively, they are no longer the main factor affecting attrition. The effect of bed pressure on attrition rate is nonlinear, and the lowest attrition rate is obtained when the diameter‐height ratio is 1:1. Unsteady attrition stage can be divided into initial stage and deceleration stage. Surface delamination dominates particle attrition throughout the whole process, and bulk fracture is the dominant mechanism only in the deceleration stage. Based on the Gwyn equation, a new attrition model in the form of cubic polynomial is established with the ratio of total attrition rate to unstable attrition rate P as a parameter. The model has high accuracy and repeatability and is suitable for various fluidization conditions. It can effectively describe the attrition process and change rule of particles and reasonably predict the fluidization attrition rate of particles.

Using the institutional grammar to understand collective resource management in a heterogenous cooperative facing external shocks

AbstractWorker cooperatives in the gig economy can involve large and heterogeneous memberships, which makes them vulnerable to member opportunism depleting collective resources. External shocks may present another challenge for collective resource management. This raises the question of how heterogeneous cooperatives design rules to mitigate opportunistic behavior and whether these rules evolve in the face of external shocks. We study the case of Smart Belgium between 2017 and 2022, thereby covering the COVID‐19 pandemic and new cooperative legislation as external shocks. Building on the institutional grammar methodology, we analyze 412 rules of Smart. The findings indicate that external shocks with sudden resource scarcity do not necessarily motivate rule changes (COVID‐19) while external shocks without an effect on collective resources can motivate rule changes (national policy change). The study also shows what kind of rules heterogeneous cooperatives may design to mitigate opportunism.

Experimental and numerical study on the shear performance of stainless steel-GFRP connectors for use in precast concrete sandwich panels

Precast Concrete Sandwich Panel (PCSP) is composed of concrete load-bearing panels, thermal insulation panels, and decorative panels, which are assembled through connectors, integrating load-bearing, thermal insulation, and decorative functions. The connector bears the main shear force between the wall panels, and the shear resistance and insulation performance of the connector largely determine the mechanical stability and insulation effect of the wall panels, which is a key component in PCSPs. The current common practice is to cross assemble stainless steel insulation (SSI) connectors and Glass-Fiber-Reinforced Plastic (GFRP) connectors into PCSPs, which can reduce building energy consumption and save resources while meeting strength and insulation requirements. A large-scale pull-out test on a PCSP with intersecting SSI-GFRP connectors was conducted in this paper. The damage process and damage pattern of PCSP were observed and the shear performance of SSI-GFRP connectors was analyzed. Secondly, a numerical analysis model of the test PCSP was built using ABAQUS finite element software and its validity was verified through the test data. In addition, parameters such as connector diameter, connector number ratio and concrete strength were analyzed for their effect on the shear performance of SSI-GFRP connectors and it was found that connector diameter and connector number ratio had a significant effect. Finally, it is found that there are some differences between the classical theory for calculating the shear performance of SSI-GFRP connectors and the actual results. A theoretical correction factor (ζ) is given to improve the accuracy of the calculation of the classical theory, and its influencing factors and changing rules are investigated.

Rolling discrete grey periodic power model with interaction effect under dual processing and its application

Time series characterized by periodic fluctuations are widespread in reality behavioural systems, and accurate forecasting of them has important practical application value. In this paper, based on the idea of discrete grey model, dual interaction effects and the nonlinear characteristics of the system are considered under the perspective of dual processing, and the fluctuating trend of the periodic sequence is portrayed through the introduction of the periodic dummy variable, and at the same time, combined with the extended periodic rolling time window method, the rolling discrete grey periodic power model with the interaction effect under dual processing is proposed, namely DIE-RDGM(1,1,T)α model. Differential evolution algorithm (DE) are employed to determine the optimum power index. Finally, the new model was compared with nine other forecasting models by three instances and applied to the problem of agricultural drought forecasting in Zhoukou City and Anyang City, Henan Province. The results show: (1) The new model has demonstrated strong competitiveness, confirming its rationality, validity, and superiority. (2) The DE is suitable for power index optimization search. (3) The new model can better describe the periodic change rule of seasonal-scale soil moisture in the two cities, and the forecast results are consistent with the actual drought conditions.

A Comparison of Rapid Rule-Learning Strategies in Humans and Monkeys.

Interspecies comparisons are key to deriving an understanding of the behavioral and neural correlates of human cognition from animal models. We perform a detailed comparison of the strategies of female macaque monkeys to male and female humans on a variant of the Wisconsin Card Sorting Test (WCST), a widely studied and applied task that provides a multiattribute measure of cognitive function and depends on the frontal lobe. WCST performance requires the inference of a rule change given ambiguous feedback. We found that well-trained monkeys infer new rules three times more slowly than minimally instructed humans. Input-dependent hidden Markov model-generalized linear models were fit to their choices, revealing hidden states akin to feature-based attention in both species. Decision processes resembled a win-stay, lose-shift strategy with interspecies similarities as well as key differences. Monkeys and humans both test multiple rule hypotheses over a series of rule-search trials and perform inference-like computations to exclude candidate choice options. We quantitatively show that perseveration, random exploration, and poor sensitivity to negative feedback account for the slower task-switching performance in monkeys.

Targeted synthesis, macroscopic and microscopic evaluation of permeability performance of a new high-permeability fog seal

To improve the working performance of fog seal material and leverage its quality enhancement role in maintaining pavement, the new fog seal materials with significant permeability and bonding properties were prepared by adding penetrant. The change rules in the permeability of fog seal materials at different working conditions were studied. The macroscopic and microscopic combined method for evaluating the permeability of fog seal materials was proposed, and the correlation between permeability and asphalt mixture porosity was determined. The results showed that the fog seal materials with 4 % II penetrant have best permeability. The recommended spraying volume of fog seal is 0.6 kg/m2, and the construction temperature is 25 °C. The fog seal has a penetration depth of 8.4–34.4 mm at a porosity of 4 %−10 %. The proposed penetration depth evaluation method combining indoor testing and CT scanning can accurately evaluate the penetration performance of fog seal materials.

Spiritual Intelligence as a Moderation Between Professional Ethics and Professionalism of Public Accountants

Purpose: This study aims to investigate the implementation of professional ethics on professionalism of Public Accountants with spiritual intelligence as moderating variable. Theoretical framework: Professional ethics and spiritual intelligence are needed by public accountants to achieve professionalism. The professional ethics contain principles regarding professional behavior that will govern the relationship between accountants and clients as well as the public. Spiritual intelligence is the reflection between the body and the human spirit in action. The existence of spiritual intelligence allows humans to think more creatively, broad-minded, can make or even change rules that will make the person work better. Method: This study uses quantitative approach. The population in this study is Public Accountants in the Malang area which include partners, managers, supervisors, senior auditors and junior auditors. The sample was 53 Public Accountants of 11 Public Accountants. This study uses Moderate Regression Analysis (MRA) analysis techniques. Results and conclusions: The implementation of Professional Ethics has a positive effect on the Professionalism of Public Accountants and Spiritual Intelligence moderates (strengthens) the influence of the implementation of Professional Ethics on the Professionalism of Public Accountants. Research implications: Implementation the professional ethics can improve the professionalism of the Public Accountants. The higher spiritual intelligence of public accountant can motivate him/her to implement professional ethics and finally can improve his/her professionalism. Originality/value: Including the spiritual intelligence in the professional ethics of public accountants.

Sport-related concussion (SCR) prevention and the nature of sport: possibilities and limitations

ABSTRACT Concussions are traumatic brain injuries that can result from a blow to the head or a jolt to the body. Athletes in many sports are exposed to concussion risks. There is a growing concern in sport and society about sport-related concussions (SRC) and an increasing awareness of the importance of proper diagnosis, treatment, and prevention. A traditional, reactive approach emphasizes sound protocols in cases of suspected SRC. A proactive approach involves identifying various causes of SRC and implementing preventive measures. For example, to reduce SRC prevalence in Canadian youth ice hockey, a ban on body checking has been introduced. When a preventive SRC measure implies a change in the main rules of a sport, it impacts its nature and alters how it is played. This can lead to tensions between SRC prevention and sporting concerns. By employing an extended consequentialist framework that includes normative analyses of the values of sport, I will examine the possibilities and limitations of preventive SRC measures in terms of constitutive rule changes. More specifically, I will propose a consequentialist framework to determine the conditions under which athlete exposure to SRC risks in a given sport can be considered unacceptable, acceptable, and even valuable.

Impact of desulphurized electrolytic manganese residue-assisted cementitious materials on silicate cement hydration and environmental safety assessment

The use of electrolytic manganese residue (EMR) as a mineral admixture is an efficient way of utilization, but its high content of gypsum phase limits its utilization. In this paper, EMR was desulphurized by means of high temperature reduction roasting to remove the hindrance when utilized as a mineral admixture. The effect of desulphurized EMR (D-EMR) on the formation of major hydration products such as C–S–H and calcium hydroxide (CH), as well as on the degree of hydration of cement clinker, was explored based on mechanical properties, hydration kinetics, thermogravimetry-differential scanning calorimetry (TG-DTG) and Quantitative X-ray diffraction analysis (QXRD). In particular, the mineral phase evolution, the change rule of pore solution and the leaching behavior of heavy metals were simulated in conjunction with thermodynamics. The results show that the D-EMR content of 15 %, comparable mechanical properties and microscopic morphology to the control group can be obtained, while C3S and C2S hydration can be promoted by a factor of 1.08 and 1.28, respectively, without the risk of heavy metal leaching. Based on the thermodynamic simulation of heavy metal solidification by cement clinker minerals, it can be seen that heavy metals in D-EMR composite slurry are solidified mainly by Mn(OH)2 precipitation and weak adsorption effect, and it is safe even at the level of 30 % replacement, provided that the pH value of the leaching solution is greater than 7.5. In addition, the desulphurization technology is feasible from the perspective of environmental protection, and saves 200,000 CNY in emission costs.

Social dilemmas in a mixed traffic flow of buses and personal vehicles in transport mode choice

This paper presents an analysis of social dilemmas that arise when passengers are faced with choosing between personal vehicles and buses in a mixed traffic flow. We conducted the computer simulation using a cellular automata framework to analyze the case. The Revised S-NFS model describes the dynamics of vehicles in a single lane, while Kukida's model defines the rules for lane changing. The presence of social dilemma is determined by the social efficiency deficit. We selected four scenarios that represent different states on the fundamental diagram of personal vehicle flow: free flow, critical point, congested flow, and heavy congested flow. The simulations were performed on an infinite two-lane road. The results show that a social dilemma of the prisoner type exists in congested and heavy congested flow, but not in free flow. Additionally, we have conducted a simulation for the scenario with a dedicated bus lane. This simulation has shown the presence of the chicken-type social dilemma. Simulation results can enhance our comprehension of choosing transportation modes.