Model Of Interaction Mechanism Research Articles

Interfacial interaction mechanism and theoretical bond strength model between UHPC-CA and steel bar

The bond property is the basis of the bear collectively load between the steel bar and Ultra-High Performance Concrete with Coarse Aggregate (UHPC-CA). In this paper, the theoretical calculation method of bond strength between UHPC-CA and high-strength steel bar is studied. The chemical adhesion strength, friction coefficient, and mechanical interlock process of the two were investigated respectively through the refined bond property tests. The failure model is established from the interlock failure characteristics, and the bond strength is obtained theoretically. Results show that the chemical adhesion strength and friction coefficient between UHPC-CA and steel bars are 0.07MPa and 0.5, respectively. The friction coefficient between UHPC-CA is 1.15. The interlock failure process of UHPC-CA and steel bars can be divided into three stages: uncracked stage, crack development stage, and split stage. The crack develops at an angle of 52° to the steel bar's axis and tends to stagnate at a height of 4.5 times the rib. A theoretical bond strength model is established and it is proved that the model is applicable not only to UHPC-CA but also to UHPC. This study can provide a theoretical basis for determining the anchorage length of steel bars in the design of UHPC-CA/UHPC structure, and can also provide a reference for the formulation of relevant standards.

Investigation on the multi-scale interactions in gas–liquid jet bubbling reactor

Due to the unreliability of the mechanical seal of the mechanical stirring reactor in traditional carbonyl synthesis reactions, a gas–liquid jet bubbling reactor has been developed that is a new type of hydraulic stirring. A cold model device was constructed to address the complex flow field characteristics of a gas–liquid jet bubbling reactor, and a gas–liquid phase testing method was established to obtain the gas–liquid phase flow parameters in the cold model device. A mathematical model of a cold model device was established based on computational fluid dynamics. The reliability and accuracy of the calculation model were verified by combining experimental data of the cold model device, and the gas–liquid two-phase flow characteristics of an industrial grade reactor were obtained. The multiscale characteristics of gas–liquid two-phase signals in industrial reactors and the multiscale gas–liquid two-phase interactions were analyzed by combining wavelet analysis, power spectrum analysis, and fractal analysis. Based on the multiscale gas–liquid interaction mechanism model of gas–liquid interaction, the liquid phase interaction in d1-d6 inside the reactor was increased. The gas–liquid mass transfer process was enhanced, and the liquid level fluctuation and temperature difference of industrial grade reactors were significantly reduced.

Insight into volatile-char interaction mechanisms of biomass torrefaction based on three major components

Volatile-char interaction is an important phenomenon in biomass thermal conversion process, which significantly contributes to the decomposition, deoxygenation and upgrading of biomass. However, the deep insight into volatile-char interaction mechanisms between hemicellulose, cellulose and lignin is currently unclear. In this work, above mechanism was studied through systematic single-/bi-component torrefactions and the follow-up char analysis. Results demonstrate that only hemicellulose volatile and cellulose char interaction exists during torrefaction at 250 °C, causing over 19.9 wt% of mass loss and 27.3 wt% of O removal for cellulose. This volatile-char interaction causes significant depolymerization and amorphization of cellulose by hydrolysis, acid hydrolysis and esterification reactions. The depolymerized and amorphous cellulose partly thermally decomposes to dehydrated sugars and aromatic compounds through dehydroxylation and aromatization reactions. A volatile-char interaction mechanism model is thus developed. This work provides theoretical insight into biomass thermal conversion and provides basis for the development of new thermochemical method.

An Investigation on Stress States of the Cataclastic Rock Specimen under Confined Compression Based on Modified Thick-walled Cylinder Model

In high in-situ stress zones, cataclastic rocks have exerted a significant influence on the stability of engineering structures. However, the mechanical properties of cataclastic rocks can not be accurately studied due to difficulties in sampling and laboratory testing. In this paper, laterally confined compression tests for specimens that were obtained by the developed in-situ sampling devices were performed to investigate the stress states. A modified thick-walled cylinder model considering axial shear stress was introduced. The interaction mechanics model for a compressed sample and an equivalent single-layer cylinder was established. Based on the principle of elasticity, the laterally confined stress, the axial shear stress, and the axial stress of the sample were derived and obtained. Moreover, the effects of mechanical and geometric parameters of the equivalent cylinder on the force condition of the specimen were analyzed. The results show that the confined stress is positively correlated with the equivalent elastic modulus and the geometric factor. Therefore, the confined stress can be strengthened by increasing the elastic modulus, alternatively, increasing the outer diameter and decreasing the inner diameter. However, the axial stress is little affected by the equivalent elastic modulus and the geometric factor and is not affected by the equivalent Poisson's ratio. As the distance from the center height increases, the axial stress decreases linearly and the difference in axial stress becomes larger considering axial shear stress and ignoring axial shear stress.

Inulin for surimi gel fortification: Performance and molecular weight-dependent effects

Inulin is a prebiotic carbohydrate widely used in food industry due to its health benefits and unique rheological properties. For the first time, this study explores the potential of natural inulin as a sustainable food additive to enhance surimi gel characteristics, specifically focusing on understanding its molecular weight effects. The good solubility of inulin facilitates the conversion of α-helix to other secondary conformations which are favorable for protein denaturation and aggregation during gelation. Moreover, the abundant –OH groups at the surface of inulin can boost the chemical forces within surimi proteins to reinforce the gel network. Compared to short-chain inulin, long-chain inulin can alleviate proteolysis, enhance hydrophobic interactions and intertwine with myosin molecules, thereby reinforcing the gel network. A more viscous long-chain inulin solution formed within surimi gels fills the space between aggregated proteins and facilitates the lock of water molecules, improving the water-holding capacity (WHC). Thus, an addition of 12 % long-chain inulin leads to an enhanced hardness of surimi gel from 943 to 1593 and improved WHC from 72 % to 85 %. A new inulin-myosin interaction mechanism model is also proposed to provide useful guidelines for surimi processing and expanding the application of inulin within the food industries.

An analysis of digging anchor machine stability and track wear under digging conditions

To analyse the stability of a digging anchor machine under digging conditions, the dynamics model of the anchor machine and the interaction mechanics model between its tracks and the roadway floor are constructed with a Sandvik MB670-1 digging anchor machine in the context of the Zhang Jiamao 5–2 coal seam of the Shaanxi Coal and Chemical Industry Group. The discrete element method (DEM) and multibody dynamics (MBD) two-way coupling algorithm is used to simulate the cutting process of a full coal seam and coal rock containing gangue by using a digging anchor machine in a roadway. The changes in the cutting depth of the digging anchor machine drum, the sliding distance of the track and the stress‒strain pattern of the roadway floor are obtained. Finally, through shear slip testing, the stress distribution and deformation pattern of the roadway floor under different grouser parameters of the digging anchor machine track shoe, as well as the wear characteristics of the track shoe, are obtained. The results of this study can provide a theoretical basis for the control and reliability of the digging anchor machine and the life fatigue prediction of its tracks.

Interaction mechanics model for screw‐drive wheel of granary robot traveling on the loose grain terrain

AbstractThe screw drive mechanism has excellent driving performance on soft terrain and it is a good application for granary robot traveling on the loose grain surface. The investigation on screw drive wheel‐terrain contact mechanics is necessary to predict the traveling performance of the novel Screw‐Drive Granary Robot. Because the motion of grain particles is extremely complex beneath the wheel in the space, shearing displacement is decomposed into the longitudinal and tangential shearing displacement in this paper, and the corresponding shearing stress is calculated separately. Then the screw‐drive wheel‐terrain contact mechanics theory based on terramechanics is established by integrating the normal stress and shearing stress. Through driving experiments on corn‐terrain, the slip sinkage is determined and the sinkage modeling is modified simultaneously considering both vertical load and slip to improve the accuracy of prediction. And the calculated total resistance and the bulldozing resistance show that there is a linear proportional coefficient between them and slope of the line is 2.74 in this case. Finally, the improved mathematical model for screw‐drive wheel is proposed, the average error of predicted resistive torque is 15.72% and the mean error of drawbar pull is 16.2%.

Synthesis of 2-aminonaphthalene-1-sulfonic acid Schiff bases and their interactions with human serum albumin

Abstract Objectives Human serum albumin (HSA) can bind and transport many substances to cells to meet various needs of the organism. The binding efficacy of HSA to these substances directly affects their functions. In this paper two Schiff base compounds were synthesized to explore the interaction between HSA and both compounds. Methods Fluorescence spectra and an AutoDock model were utilized to investigate the interaction mechanism and binding model between proteins and Schiff base products. The conformation change of HSA was detected by resonance light scattering and circular dichroism spectra. Results The two compounds bound easily with HSA, with binding constants of 104. The binding sites for both compounds in HSA were within an appropriate distance for long-range interactions. Both compounds are accommodated in hydrophobic domains of HSA. However, electrostatic interactions and other supermolecular forces coexist between the compounds and protein. Binding of these compounds disturbed the protein secondary structure and caused a certain degree of destabilization. Conclusions The two Schiff base compounds can interact with HSA with high efficacy, which is helpful for explore the application of this type of Schiff base in biomedical research.

MLAA-34 knockdown shows enhanced antitumor activity via JAK2/STAT3 signaling pathway in acute monocytic leukemia.

MLAA-34 is a novel leukemia-associated gene closely related to the carcinogenesis of acute monocytic leukemia (AML). MLAA-34 over expression has been observed to inhibit apoptosis in vitro. JAK2/STAT3 pathway plays an important role in cell proliferation, differentiation and inhibition of apoptosis in number of cancers. However, the relationship and interaction between MLAA-34 and JAK2/STAT3 has never been investigated in AML.This study investigates and reports a novel relationship between MLAA-34 and JAK2/STAT3 pathway in AML both in vitro and in vivo. We constructed MLAA-34 knockdown vector and transfected U937 cells to observe its apoptotic activities in relation to JAK2/STAT3 signaling pathway in vitro and then in vivo in mouse model. Levels of expression of MLAA-34 and JAK2/STAT3 and its downstream targets were also measured in AML patients and a few volunteers.We found that MLAA-34 knockdown increased U937 apoptosis in vitro and inhibited tumor growth in vivo. Components of the canonical JAK2/STAT3 pathway or its downstream targets, including c-myc, bcl-2, Bax, and caspase-3, were shown to be involved in the carcinogenesis of AML. We also found that the JAK2/STAT3 pathway positively regulated MLAA-34 expression. We additionally identified a STAT3 binding site in the MLAA-34 promoter where STAT3 binds directly and activates MLAA-34 expression. In addition, MLAA-34 was found to form a complex with JAK2 and was enhanced by JAK2 activation. Correlation of MLAA-34 and JAK2/STAT3 was further confirmed in AML patients.In conclusion, MLAA-34 is a novel regulator for JAK2/STAT3 signaling, and in turn, is regulated by this interaction in a positive feedback loop. Thus we report a novel model of interaction mechanism between MLAA-34 and JAK2/STAT3 which can be utilized as a potential target for a novel therapeutic approach in AML.

Scale effect mechanism research of insect-imitating hexapod robot

The scale parameter is one of the key factors which influence the structure and locomotion characteristics of the legged robot. The scale effect mechanism of animals in nature was revealed, and the influence of scale parameters on animal was analyzed. This paper establishes a dynamic model of insect-imitating hexapod robot. A high-fidelity simulation platform for hexapod robot was established based on Vortex, and the foot-ground interaction mechanics model was established and applied to the developed simulation platform. Based on the existing six-legged robot prototype, the validity of the relevant model and the fidelity of the simulation platform are verified. The influence of a robot’s mass and characteristic size on its feature locomotion was analyzed. The foot force rises with the increase of the whole robot mass, and the foot force of the unit robot mass decreases with the increase of the whole robot mass, eventually tending to a fixed value. The maximum joint torque rises with the increase of the whole robot mass. The system power rises with the increase of the whole robot mass, but the system power of unit robot mass is basically a constant value. The peak system power decreases with the increase of the distance between the front and the rear leg, and the joint torque rises with the increase of the distance between the front and rear leg. The related research results have guiding significance and reference value for the system design of hexapod robots.

Microstructure-based modeling on structure-mechanical property relationships in carbon nanotube/aluminum composites

The present work investigates structure-mechanical property correlations of carbon nanotube/aluminum (CNT/Al) composites through characterization and microstructure-based modeling. The nanoscale architecture of these composites, produced by flake powder metallurgy, was established using a transmission electron microscope equipped with an automated crystal orientation mapping system. The architecture mainly consists of elongated Al grains with submicron widths and micron lengths, intergranular CNTs and an interfacial reaction product, namely Al4C3 particles. The stress-strain behavior found with our dislocation-boundary/reinforcement interaction mechanical model, matched our experimental tensile curves. This model was also used to predict several key factors, namely grain dimensions, CNTs volume fraction, intergranular or intragranular distribution and aspect ratio, interfacial reaction rate, impacting tensile strength and ductility. It was found that intergranular CNTs induced strengthening will not result in lower uniform elongations, while intragranular distribution of low aspect ratio CNTs and Al4C3 nanoparticles can increase both strength and uniform elongations by the Orowan mechanism. It is expected that the model in the present work can assist in microstructure design of metal matrix nanocomposites.

Drag reduction and wear resistance mechanisms of a bionic shovel by discrete element method simulation

The ostrich has a steady and enduring high-speed running ability. Toenails are one key part of ostrich feet and their unique morphology is crucial in insertion into sand and for traction provision. In this study, information of bionic curves was extracted through studying the toenail structure and morphology, and three-dimensional reconstruction of toenails by reverse engineering. Based on the principle of bionic engineering, a bionic shovel was designed by optimizing the traditional shovel. A shovel–soil interaction mechanical model was established via the discrete element method. The insertion into soil processes of the bionic shovel and the common plate were simulated. The dynamic mesoscopic mechanical behaviors of soil particles around the shovel surface, the contact force field, and the velocity field, as well as the forces acting on the shovel surface were analyzed. The bionic shovel outperformed the common plate in insertion. The main reason for drag reduction in the bionic shovel was the inner concave bending surface, along which the soil particles climbed, and the particle movement trend was consistent. Simulations showed stress concentrated at the tip of the shovel, which facilitated the production of fatigue wear. Therefore, the tip needs to be considered firstly during bionic shovel design in the future.

Pressure-Bearing Parameter Identification for Martian Soil Based on a Terramechanics Model and Genetic Algorithm

AbstractA wheel-terrain interaction mechanics model based on terramechanics and simplified force and moment reconstruction is introduced. The model comprises pressure-bearing parameters (combined d...

Interaction mechanism model for a nonisothermal air jet and a buoyant plume

If high-power machines are used and a large number of people are present, a significant amount of heat will be generated, which forms an upward thermal plume. The interaction problem occurs when the cold jet and the thermal plume meet. This article presents the interaction mechanism between a momentum source and a buoyancy source and deduces the interaction parameter β to investigate the effects of parameters such as the power of the source, the air-supply velocity, plume spacing, and nozzle spacing height. Experiments were carried out to investigate the flow field of the air jet affected by the plume and to validate the theoretical work.

A theoretical model of honeycomb material arresting system for aircrafts

• Arresting properties of metal honeycomb material are studied. • A tire-honeycomb material interaction mechanical model is presented. • The arresting simulation on aircraft B737-900ER and B727-100 is done. • Honeycomb material can stop the overrunning aircraft efficiently. • The stopping process is safe for the passengers and aircraft. Takeoff and landing overruns account for most of the accidents that occur on or in the immediate vicinity of the runway, and it would cause accidental aircraft damage and loss of life. The current Engineered Material Arresting System (EMAS) materials are weak in water resistance and durability, expensive in acquiring and installing, and have negative environmental impacts. So it is significantly required to find a new alternative material with good mechanical properties, higher arresting coefficient and excellent environmental performance. In this article, the arresting properties of metal honeycomb material are studied. A Tire-Honeycomb material Interaction Mechanical Model (THIMM) is proposed. Combining with the dynamic model of aircraft, the theoretical model is coded by MATLAB to finish arresting simulation on aircraft B737-900ER and B727-100. In addition, finite element model of the tire-honeycomb material interaction was built to verify the correctness of the theoretical model. The results obtained by finite element simulation are in a good agreement with the theoretical results. In comparison with the results for traditional materials, the calculated results show that the honeycomb material can stop the overrunning aircraft more efficiently in the condition that the forces induced by the stopping process are safe for the passengers and aircraft.

Performance evaluation of a wire mesh wheel on deformable terrains

Because of the unique lunar environment, a suitable wheel for lunar rover decides the rover’s trafficability on deformable terrains. The wire mesh wheel (hereinafter referred to as WMW) has the advantages of light weight and superior stability, been widely adopted for lunar rovers. But a comprehensive research on performance of WMW on deformable terrains has not been conduct. This paper would provide particular study on a type WMW, including quasi-static pressure-sinkage test and driving performance. A novel pressure-sinkage model for the WMW on deformable soils was presented. In order to investigate the sinkage characteristics of the WMW, tests were performed using a single-wheel testbed for the WMW with different loads and velocities. The effects of load and velocity on sinkage were analyzed, and the relationship between real and apparent sinkage was presented. The research on traction performance of WMW under different slip ratios (0.1–0.6) was also conducted, contrast tests were proceed by using a normal cylindrical wheel (hereinafter referred to as CW). The traction performance of WMW is analyzed using performance indices including wheel sinkage, drawbar pull, driving torque, and tractive efficiency. The experimental results and conclusions are useful for optimal WMW design and improvement/verification of wheel–soil interaction mechanics model.

From the microscopic interaction mechanism to the grinding temperature field: An integrated modelling on the grinding process

The microscopic interaction mechanism between grains and workpiece material in grinding contact zone is extremely complicated which will take many interrelated and coupled factors into consideration, such as grinding wheel topographies, grain distributions, physical and mechanical properties of material, the emergence of grinding forces and heat energies, the partitioning and transfer of grinding heat, etc. However, the current theories and models are unable to integrate all of the above factors into an organic-whole model. Former researchers usually focused on several of above aspects and made assumptions to simplify those theories. However, these assumptions will weaken the mathematical relationship between grinding conditions and ground surface qualities and will increase the difficulties of understanding on the nature of grinding process. The work of this paper is an attempt on this purpose. It is based on the author's previous work of a microscopic interaction mechanism model between grains and workpiece material in grinding contact zone which will describe the interaction situation of a grain with any size, protrusion height and location, then the distributions of each type of grains were obtained. Single plowing and cutting grain force models were developed based on R.L. Hecker's single grain force model and M.E. Merchant's metal cutting theory, then led into grinding force distribution. The heat partition ratio model of W.B. Rowe was applied on the discrete grinding contact zone, a new developed heat flux profile transferred into workpiece surface was obtained, which was usually assumed to be rectangular, triangular and parabolic in shape in former researches. In order to confirm the rationality of this new heat flux profile, a comparison on temperature fields and grinding forces has been made between results from FE-models and experiments, under both wet and dry grinding conditions. Comparison results showed that this new developed integrated grinding process model has more precise prediction ability on grinding forces and grinding temperatures.

BACKGROUND OF INTERACTION MECHANISM FORMATION BETWEEN A BANK AND CUSTOMERS

The article investigates the development of conceptual approaches of the banking marketing management in a competitive environment that is increasing. The comparative characteristics of the relations marketing and a concept of omni-channel (integrated) communications of a bank have been carried out. The semantics of such categories as relations, communication, interaction, relationships has been developed. A new set of marketing mix tools has been proposed. A theoretical model of the organizational-economic interaction mechanism between banking institutions and customers has been formed.

Study on gob-side entry retaining in fully-mechanized longwall with top-coal caving and its application

Based on the engineering background of gob-side entry retaining in fully-mechanized longwall with top coal caving (GER-FLTC) on N2105 working face of Yuwu coal mine, by adopting the methods of theoretical analysis and numerical calculation, the control techniques of surrounding rocks in GER-FLTC working face are studied in this paper. The two main difficulties of stability of surrounding rocks at gob-side retained entry in fully-mechanized longwall working face are the stability control of top coal and control of large deformation of GER-FLTC working face. Interaction mechanical model between roofing and roadside backfilling in GER-FLTC is established and the equations for the calculation of roof-cutting resistance of roadside backfilling are derived. Results of numerical calculation show that the damage zones of top coal can be categorized into the delaminating zone of top coal above the backfilling, tensile damage zone of top coal above the retained roadway and shear damage zone of the upper rib of the solid coal. Stability control of top coal is the critical part to success of GER-FLTC. With consideration of large deformation of surrounding rocks of gob-side retained entry in fully-mechanized longwall, the support technique of “roofing control and wall strengthening” is proposed where high strength and highly prestressed anchor rods and diagonal tensile anchor cables support are used for top coal, high strength and highly prestressed yielding anchor rod support is used for solid coal and roadside prestressed load-carrying backfilling is constructed by high-water material, in order to maintain the integrity of the top coal, transfer load, high resistance yielding load-carrying of solid coal, roof-cutting of roadside backfilling and support, and to achieve GER-FLTC. Results from this study are successfully applied in engineering practice.

Spray–combustion interaction mechanism of multiple-injection under diesel engine conditions

Multiple-injection has shown significant benefits in the reduction of combustion emissions and soot formation. However, there is a need to understand the secondary flow-induced air–fuel mixture formation and subsequent combustion mechanism under multiple-injection. An experiment was performed by changing the dwell time between the pilot and main injections under the conditions of 23kg/m3 ambient density with 0% O2 (non-combusting) and 15% O2 (combusting) ambient conditions, at an injection pressure of 120MPa. The mass ratios of pilot and main injections in the study were 15/85% and 20/80%. A hybrid shadowgraph and Mie scattering imaging technique in a nearly simultaneous mode along the same line of sight was used to visualize the spray and flame luminosity. Pilot-main spray flame properties including ignition delay, ignition location, and lift-off length were characterized from experimental images. CFD simulation of pilot-main spray combustion was performed under the same experimental conditions to provide additional insights into the combustion process. The air–fuel mixing field and ignition process followed by main injection flame structure are significantly altered at different dwells. The spray-to-flame interaction mechanism model has been established for the development of an optimal multiple-injection scheme for, possibly, low soot formation and emissions.