Mathematical Model and Experiment Validation of Fluid Torque by Shear Stress under Influence of Fluid Temperature in Hydro-viscous Clutch

The current design of hydro-viscous clutch（HVC） in tracked vehicle fan transmission mainly focuses on high-speed and high power. However, the fluid torque under the influence of fluid temperature can not be predicted accurately by conventional mathematical model or experimental research. In order to validate the fluid torque of HVC by taking the viscosity-temperature characteristic of fluid into account, the test rig is designed. The outlet oil temperature is measured and fitted with different rotation speed, oil film thickness, oil flow rate, and inlet oil temperature. Meanwhile, the film torque can be obtained. Based on Navier-Stokes equations and the continuity equation, the mathematical model of fluid torque is proposed in cylindrical coordinate. Iterative method is employed to solve the equations. The radial and tangential speed distribution, radial pressure distribution and theoretical flow rate are determined and analyzed. The models of equivalent radius and fluid torque of friction pairs are introduced. The experimental and theoretical results indicate that tangential speed distribution is mainly determined by the relative rotating speed between the friction plate and the separator disc. However, the radial speed distribution and pressure distribution are dominated by pressure difference at the lower rotating speed. The oil film fills the clearance and the film torque increases with increasing rotating speed. However, when the speed reaches a certain value, the centrifugal force will play an important role on the fluid distribution. The pressure is negative at the outer radius when inlet flow rate is less than theoretical flow, so the film starts to shrink which decreases the film torque sharply. The theoretical fluid torque has good agreement with the experimental data. This research proposes a new fluid torque mathematical model which may predict the film torque under the influence of temperature more accurately.

An internal ballistic model of electromagnetic railgun based on PFN coupled with multi-physical field and experimental validation

To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore damage.In this paper,a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun,and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network(PFN)is carried out.Various test methods such as spectrometer,fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity,transient magnetic field strength and stress-strain of rail.Combining the simulation results and experimental data,the damage condition of the contact surface is analyzed.

Adaptive Robust Servo Control for Vertical Electric Stabilization System of Tank and Experimental Validation

A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.

Exploring Xiaojianzhong decoction's potential in gastric cancer treatment:Integrative insights and experimental validation

Gastric cancer(GC)remains a formidable global health concern with significant morbidity and mortality rates,despite the fact that numerous advances have been made to improve conventional therapies.Xiaojianzhong decoction(XJZ),a traditional Chinese medicine,has garnered academic attention as a multicomponent,multitarget approach to managing GC.The present editorial explores the potential of XJZ in the treatment of GC through a comprehensive analysis of network pharmacology and experimental validation.Network pharmacology was used to identify key molecular targets of XJZ,including interleukin 6,prostaglandin-endoperoxide synthase 2,and matrix metalloproteinase 9,and in vitro experiments were used to confirm the efficacy of XJZ in inhibiting cell proliferation,inducing apoptosis,and modulating gene expression associated with GC progression.This editorial highlights XJZ as a promising therapeutic strategy for GC and indicates a need for further clinical exploration and validation of its efficacy.

Prediction of ground-borne vibration induced by impact pile driving:numerical approach and experimental validation

Deep foundations are currently used in engineering practice to solve problems caused by weak geotechnical characteristics of the ground.Impact pile driving is an interesting and viable solution from economic and technical points of view.However,it is necessary to ensure that the environmental drawbacks,namely ground-borne vibration,are adequately met.For this purpose,the authors propose an axisymmetric finite element method-perfectly matched layer(FEM-PML)approach,where the nonlinear behavior of the soil is addressed through an equivalent linear methodology.Given the complexity of the problem,an experimental test site was developed and fully characterized.The experimental work comprised in-situ and laboratory soil characterization,as well as the measurement of vibrations induced during pile driving.The comparison between experimental and numerical results demonstrated a very good agreement,from which it can be concluded that the proposed numerical approach is suitable for the prediction of vibrations induced by impact pile driving.The experimental database is available as supplemental data and may be used by other researchers in the validation of their prediction models.

Potential-dependent insights into the origin of high ammonia yield rate on copper surface via nitrate reduction:A computational and experimental study

Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum solvation model to predict the reaction energetics of NO3RR on pure copper surface in alkaline media.The potential-dependent mechanism on the most prevailing Cu(111)and the minor(100)and(110)facets were established,in consideration of NO_(2)_(−),NO,NH_(3),NH_(2)OH,N_(2),and N_(2)O as the main products.The computational results show that the major Cu(111)is the ideal surface to produce ammonia with the highest onset potential at 0.06 V(until−0.37 V)and the highest optimal potential at−0.31 V for ammonia production without kinetic obstacles in activation energies at critical steps.For other minor facets,the secondary Cu(100)shows activity to ammonia from−0.03 to−0.54 V with the ideal potential at−0.50 V,which requires larger overpotential to overcome kinetic activation energy barriers.The least Cu(110)possesses the longest potential range for ammonia yield from−0.27 to−1.12 V due to the higher adsorption coverage of nitrate,but also with higher tendency to generate di-nitrogen species.Experimental evaluations on commercial Cu/C electrocatalyst validated the accuracy of our proposed mechanism.The most influential(111)surface with highest percentage in electrocatalyst determined the trend of ammonia production.In specific,the onset potential of ammonia production at 0.1 V and emergence of yield rate peak at−0.3 V in experiments precisely located in the predicted potentials on Cu(111).Four critical factors for the high ammonia yield and selectivity on Cu surface via NO3RR are summarized,including high NO3RR activity towards ammonia on the dominant Cu(111)facet,more possibilities to produce ammonia along different pathways on each facet,excellent ability for HER inhibition and suitable surface size to suppress di-nitrogen species formation at high nitrate coverage.Overall,our work provides comprehensive potential-dependent insights into the reaction details of NO3RR to ammonia,which can serve as references for the future development of NO3RR electrocatalysts,achieving higher activity and selectivity by maximizing these characteristics of copper-based materials.

Potential application of Nardostachyos Radix et Rhizoma-Rhubarb for the treatment of diabetic kidney disease based on network pharmacology and cell culture experimental verification

BACKGROUND Diabetic kidney disease(DKD)is one of the serious complications of diabetes mellitus,and the existing treatments cannot meet the needs of today's patients.Traditional Chinese medicine has been validated for its efficacy in DKD after many years of clinical application.However,the specific mechanism by which it works is still unclear.Elucidating the molecular mechanism of the Nardostachyos Radix et Rhizoma-rhubarb drug pair(NRDP)for the treatment of DKD will provide a new way of thinking for the research and development of new drugs.AIM To investigate the mechanism of the NRDP in DKD by network pharmacology combined with molecular docking,and then verify the initial findings by in vitro experiments.METHODS The Traditional Chinese Medicine Systems Pharmacology(TCMSP)database was used to screen active ingredient targets of NRDP.Targets for DKD were obtained based on the Genecards,OMIM,and TTD databases.The VENNY 2.1 database was used to obtain DKD and NRDP intersection targets and their Venn diagram,and Cytoscape 3.9.0 was used to build a"drug-component-target-disease"network.The String database was used to construct protein interaction networks.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis and Gene Ontology analysis were performed based on the DAVID database.After selecting the targets and the active ingredients,Autodock software was used to perform molecular docking.In experimental validation using renal tubular epithelial cells(TCMK-1),we used the Cell Counting Kit-8 assay to detect the effect of NRDP on cell viability,with glucose solution used to mimic a hyperglycemic environment.Flow cytometry was used to detect the cell cycle progression and apoptosis.Western blot was used to detect the protein expression of STAT3,p-STAT3,BAX,BCL-2,Caspase9,and Caspase3.RESULTS A total of 10 active ingredients and 85 targets with 111 disease-related signaling pathways were obtained for NRDP.Enrichment analysis of KEGG pathways was performed to determine advanced glycation end products(AGEs)-receptor for AGEs(RAGE)signaling as the core pathway.Molecular docking showed good binding between each active ingredient and its core targets.In vitro experiments showed that NRDP inhibited the viability of TCMK-1 cells,blocked cell cycle progression in the G0/G1 phase,and reduced apoptosis in a concentrationdependent manner.Based on the results of Western blot analysis,NRDP differentially downregulated p-STAT3,BAX,Caspase3,and Caspase9 protein levels(P<0.01 or P<0.05).In addition,BAX/BCL-2 and p-STAT3/STAT3 ratios were reduced,while BCL-2 and STAT3 protein expression was upregulated(P<0.01).CONCLUSION NRDP may upregulate BCL-2 and STAT3 protein expression,and downregulate BAX,Caspase3,and Caspase9 protein expression,thus activating the AGE-RAGE signaling pathway,inhibiting the vitality of TCMK-1 cells,reducing their apoptosis.and arresting them in the G0/G1 phase to protect them from damage by high glucose.

Numerical simulation and experiment validation on lightning-induced effects of a special vehicle

In recent years, with the development of the system integration technology, the outside integrative special vehicles, such as big oil tank, trucks loading with dangerous goods and so on, are becoming more and more important. When the vehicle is under way, it will inevitably encounter the nature environment, including lightning. If the lightning strikes directly or very close to the vehicle, the lightning-induced effects will be very destructive. Therefore, for a better understanding of the lightning-induced effects produced on the special vehicle by the lightning strike, the research on lightning-induced effects of a special vehicle for aerospace system transportation was proposed. In the paper, a numerical simulation model for the special vehicle is established, the lightning-induced effects are analyzed successfully by using tram.smission-line matrix （TLM） algorithm, and the experiment validation example is also implemented. By comparing the numerical simulation with the actual experiment results, the correctness trend of the numerical simulation is validated and a mass of invaluable research data is obtained, which has a deep significance on the lightning research in our country.

A Train-Bridge Dynamic Interaction Analysis Method and Its Experimental Validation

The train-bridge dynamic interaction problem began with the development of railway technology, and requires an evaluation method for bridge design in order to ensure the safety and stability of the bridge and the running train. This problem is studied using theoretical analysis, numerical simulation, and experimental study. In the train-bridge dynamic interaction system proposed in this paper, the train vehicle model is established by the rigid-body dynamics method, the bridge model is established by the finite element method, and the wheel/rail vertical and lateral interaction are simulated by the corresponding assumption and the Kalker linear creep theory, respectively. Track irregularity, structure deformation, wind load, collision load, structural damage, foundation scouring, and earthquake action are regarded as the excitation for the system. The train-bridge dynamic interaction system is solved by inter-history iteration. A case study of the dynamic response of a CRH380BL high-speed train running through a standard-design bridge in China is discussed. The dynamic responses of the vehicle and of the bridge subsystems are obtained for speeds ranging from 200 km-b-1 to 400 km.h-1, and the vibration mechanism are analyzed.

Research Progress in Digging and Validation of miRNA Target Genes Using Experimental Methods

MicroRNAs （miRNAs） are a group of regulatory RNAs that regulate gene expression post-transcriptionally by the degradation or translational inhibition of their target messenger RNAs （mRNAs）. Regulation is accomplished when the 22-25 nucleotide miRNAs bind to complementary sequences in the 3＇-untranslated regions （UTR）. One barrier to miRNA research is to find target genes. Although computational target predictions have shed light on important aspects of microRNA target recognition, questions remain concerning the rates of false positives. In addition, we do not completely understand how microRNAs can recognize and regulate their targets. As such, experimental positive predictions and allow for an unbiased stu ap dy proaches are required, which can reflect in vivo processes, eliminating false of microRNA target recognition. In this review, we summarized experimental approaches that have been described for the identification and validation of mRNA targets associated with specific miRNAs.

Experimental validation method of elastic thin rod model for simulating the motional cable harness

To analyze the spring disturbance torque caused by motionai cable harness in a stabilized platform, the Kirchhoff theory based cable harness model has been previously developed to dynamically simulate the motional cable harness. In this paper, this model was validated by comparing the simulation results with the experiment results （ both the spring force and the deformed profile of the motional cable harness）. In the experiment, a special optical measuring instrument based on binocular vision was developed and the motion and deformation of cable harness were measured. A simpli- fied stabilized platform system was constructed, and the absolute value of spring disturbance force during the motion of this simplified frame was obtained by using a force gauge （0. 02 N precision）. The physical parameters of experimental specimen were also measured. The experimental and simulated results showed good agreement. These results should be useful for better motional cable harness layout design and reliable evaluation of the spring disturbance torque.

The BOUT Project; Validation and Benchmark of BOUT Code and Experimental Diagnostic Tools for Fusion Boundary Turbulence

A boundary plasma turbulence code BOUT is presented. The preliminary encour- aging results have been obtained when comparing with probe measurements for a typical Ohmic discharge in HT-7 tokamak. The validation and benchmark of BOUT code and experimental diagnostic tools for fusion boundary plasma turbulence is proposed.

Experimental Study of a Modified Icaro Solar Dryer: The Case of Coffee Drying

Food losses in the developing country are thought to be 50% of the fruits and vegetables grown and 25% of harvested food grain. Food preservation can reduce wastage of a harvest surplus, allow storage for food shortages, and in some cases facilitate export to high-value markets. Drying is one of the oldest methods of food preservation. Drying makes produce lighter, smaller, and less likely to spoil and helps to minimize the moisture content in coffee beans as high moisture content during storage is certain to ruin the taste and appearance of coffee. This work presents the results of an experimental study of forced convection drying of coffee cherries in a modified Icaro solar dryer. The study aims to validate the numerical models developed for further research. The experimental tests envisaged also aim to determine the mass loss curves of the product by fixing or calculating its initial mass (1 kg), its initial water content (70%), the ambient temperature, the drying airflow (0.02 m3.s-1 to 0.09 m3.s-1) and the exchange coefficients. The influence of these aerothermal parameters on the drying time of a most commercialized coffee variety (Robusta) was studied. Finally, the results revealed an increase in the efficiency of the heat transfer air and a reduction in the water content of the coffee cherry from 70% to 9.87%, after 30.2 hours.

Multi-omics Approach Reveals Influenza-A Virus Target Genes Associated Genomic,Clinical and Immunological Characteristics in Cancers

Objective To examine the precise function of influenza A virus target genes(IATGs)in malignancy.Methods Using multi-omics data from the TCGA and TCPA datasets,33 tumor types were evaluated for IATGs.IATG expression in cancer cells was analyzed using transcriptome analysis.Copy number variation(CNV)was assessed using GISTICS 2.0.Spearman’s analysis was used to correlate mRNA expression with methylation levels.GSEA was used for the enrichment analysis.Pearson’s correlation analysis was used to examine the association between IATG mRNA expression and IC50.The ImmuCellAI algorithm was used to calculate the infiltration scores of 24 immune cell types.Results In 13 solid tumors,IATG mRNA levels were atypically expressed.Except for UCS,UVM,KICH,PCPG,THCA,CHOL,LAMI,and MESO,most cancers contained somatic IATG mutations.The main types of CNVs in IATGs are heterozygous amplifications and deletions.In most tumors,IATG mRNA expression is adversely associated with methylation.RT-PCR demonstrated that EGFR,ANXA5,CACNA1C,CD209,UVRAG were upregulated and CLEC4M was downregulated in KIRC cell lines,consistent with the TCGA and GTEx data.Conclusion Genomic changes and clinical characteristics of IATGs were identified,which may offer fresh perspectives linking the influenza A virus to cancer.

Analysis of the cracks formation on surface of extruded magnesium rod based on numerical modeling and experimental verification

To reduce the surface cracks of extrusion rod for AZ31 magnesium caused by nonhomogeneous metal flow in extrusion process, 3D computer finite element （FE） simulations of extruding a wrought magnesium alloy AZ31 into rods have been performed and the results have been verified in extrusion experiments under identical conditions. The tendency to generate the dead zone is decreased by employing the die angle 60° at the cone-shaped die comparing with the die angle 180°. The surface additional tensile stresses of the rod at the die exit are decreased greatly so that the surface cracks caused are avoided by using the die angle 60°. The extrusion die with die angle 180° would increase the higher temperature rise and possibility of crack formation on the rod surface that caused by die angle 60° and temperature rise decrease tensile strength of the AZ31 rod. The experimental results show that die angle 180° could cause continuous cracks on the surface of the extruded rod. The extrusion force required is reduced approximately 15 ton by employing the die angle 60°. Theoretical results obtained by the DeformTM-3D simulation agreed well with the experiments. The obtained results provide the fundamental and also practical guidelines for the design and correction of dies to produce magnesium rod with good surface quality.

Numerical modeling of centrifuge cyclic lateral pile load experiments

To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoire Central des Ponts et Chaussees. Three types of cyclic loading were applied, two asymmetric and one symmetric with respect to the unloaded pile. An approximately square-root variation of soil stiffness with depth was obtained from indirect in-flight density measurements, laboratory tests on reconstituted samples, and well-established empirical correlations. The tests were simulated using a cyclic nonlinear Winkler spring model, which describes the full range of inelastic phenomena, including separation and re-attachment of the pile from and to the soil. The model consists of three mathematical expressions capable of reproducing a wide variety of monotonic and cyclic experimentalp-y curves. The physical meaning of key model parameters is graphically explained and related to soil behavior. Comparisons with the centrifuge test results demonstrate the general validity of the model and its ability to capture several features of pile-soil interaction, including： soil plastification at an early stage of loading, ＂pinching＂ behavior due to the formation of a relaxation zone around the upper part of the pile, and stiffness and strength changes due to cyclic loading. A comparison of the p-y curves derived from the test results and the proposed model, as well as those from the classical curves of Reese et al. （1974） for sand, is also presented.

Experimental study of partially decoupled oxidation of ethane for producing ethylene and acetylene

With increasing amount of unconventional natural gas,the production of ethane,propane and other low alkanes continues to increase.In our previous works,a partially decoupled process(PDP) was proposed for conversion of ethane based on numerical simulations,which showed higher acetylene and ethylene selectivities than the original partial oxidation process.In the current work,the PDP of ethane for producing acetylene and ethylene was studied experimentally to verify the PDP concept.In the PDP of ethane,coke-oven gas or other cheap gas combusts with stoichiometric oxygen as heat carrier,and ethane is mixed with the heat carrier and undergoes pyrolysis at high temperatures.The jet-in-cross-flow(JICF) reactor was designed and manufactured to realize the PDP.A positioning device of 0.1 mm accuracy and a mass spectrometer were used to measure the spatial profiles of the species concentrations.The maximum combined yield(52.7%) of acetylene and ethylene was obtained even at the condition of heat loss,confirming that the PDP of ethane was advantageous over the partial oxidation process and at least comparable to the steam cracking process.

Hover performance estimation and validation of battery powered vertical takeoff and landing aircraft

Battery powered vertical takeoff and landing(VTOL) aircraft attracts more and more interests from public, while limited hover endurance hinders many prospective applications. Based on the weight models of battery, motor and electronic speed controller, the power consumption model of propeller and the constant power discharge model of battery, an efficient method to estimate the hover endurance of battery powered VTOL aircraft was presented. In order to understand the mechanism of performance improvement, the impacts of propulsion system parameters on hover endurance were analyzed by simulations, including the motor power density, the battery capacity, specific energy and Peukert coefficient. Ground experiment platform was established and validation experiments were carried out, the results of which showed a well agreement with the simulations. The estimation method and the analysis results could be used for optimization design and hover performance evaluation of battery powered VTOL aircraft.

Prediction of the mechanisms of liver injury of Epimedii Folium by network pharmacology and validation in HepaRG Cells

Objective:EpimediiFolium(EF),a traditional Chinese medicinal material,has the effect of tonifying kidney Yang,strengthening bones and treating rheumatism.However,its clinical applications are limited by its drug-induced liver injury(DILI)effects and the underlying mechanisms have not been elucidated.Methods:Active EF compounds were obtained from the TCMSP database and their targets predicted in Targetnet.Next,DILI-targets were obtained from CTD,Genecards and Digsee databases.Protein-protein interactions of EF DILI-targets were determined using STRING and hub targets identified via topological analyses.Then,hub targets were subjected to GO and KEGG pathway enrichment analyses.Finally,HepaRG cells were used for further validation of molecular mechanisms.Results:Fifty seven active compounds and 164 targets that interacted with these active compounds were identified with Sagittatoside A,icariside I,and Icariin being the best active compounds.Enrichment analysis revealed the PI3K/Akt and NF-kB signaling pathways to be markedly enriched.Molecular docking revealed that Sagittatoside A,icariside I and Icariin had good binding activities to RAC1,PTGS2,and NOS3.Validation analysis in HepaRG cells revealed that Epimedium flavonoids upregulated RAC1,PTGS2 and NOS3 levels.Conclusion:Our findings show that EF induces oxidative stress,inflammation,and apoptosis via PI3K/Akt and NF-kB signaling pathways,and provides a basis for more in-depth studies on EF-induced DILI.

Understanding the alkyl effect of geminal dinitropropyl ester energetic plasticizers on hydroxyl terminated polybutadiene(HTPB):Simultaneous tuning on low temperature behavior and processability

Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane chain parts, and systematically investigate their structure-property relationships.Results show that DNPEPs have impact sensitivities all higher than 25.2 J, thermal decomposition temperatures all higher than 254 ℃, and glass transition temperatures(T_(g)) lower than-90 ℃.Furthermore, the effects of DNPEPs as plasticizer are studied on hydroxyl terminated polybutadiene(HTPB) in detail, including the viscosity, glass transition temperatures and others. It is noteworthy that 2,2-dinitropropyl nonanoate(DNPNc) among these DNPEPs exhibits the most expected simultaneous tuning effects on both viscosity and T_(g) of HTPB systems, providing favorable potentials to replace the conventional plastizers as dioctyl sebacate(DOS) in the HTPB based propellants and explosives.