Kinetic Characteristic Research Articles

Action of actinomycin D on auxin-induced growth of Avena coeleoptile section

Double-stranded DNA and in a lesser degree ATP reduce the inhibitory action of actinomycin D on auxin-induced elongation growth. The reduction of inhibition by DNA is significant in the initial phase of elongation up to the 4th hour of growth. The effect of ATP is similar but less pronounced. Both substances applied jointly do not completely abolish the inhibitory action of actinomycin D. The foregoing data and the kinetic characteristic of the auxin-induced elongation in the presence of actinomycin D suggest that this antibiotic inhibits growth by blocking synthesis of RNA essential for elongation growth and causes, moreover, certain distinct cellular changes which cannot be explained by the inhibition of DNA-depend RNA synthesis.

3D-kinetic characteristics of slow fatigue crack growth in the aluminum alloy D16T

It is presented the technique based on macro structural analysis of a typical fatigue fracture of a cylindrical specimen of alloy D16T with an annular notch in bending of constructing the diagram of stress intensity coefficient defined the period growth of fatigue crack. Analytical calculation of the change in the exponent m in Peris formula for calculating the speed of fatigue crack growth with respect to depth a in a system with consideration of the increase in the number of cycles N of high-cycle fatigue has be established using experimental data of fatigue fractures of the aluminum alloy D16T. This made it possible to draw the kinematic diagram of a slow fatigue crack growth of D16T in a 3-dimensional coordinate system. Analyzed and numerically determine volumes are formed with the space curve the kinetic diagram of a slow fatigue crack growth. Installed a new kinetic characteristic of fatigue crack growth; i.e. the amount of work of the stress intensity coefficient used to connect parameters of low-cycle fatigue and high-cycle fatigue.

A hysteresis nonlinear model of giant magnetostrictive transducer

In order to describe the hysteresis nonlinear performance of giant magnetostrictive transducer, based on the relationship between complex permeability and magnetization, eddy current effects of Terfenol-D, and kinetic characteristic of giant magnetostrictive transducer, a new hysteresis nonlinear model is developed, which consists of quasi-static model and dynamic model considering eddy current effect of Terfenol-D, dynamic of power amplifier, and magnetic aftereffect in the magnetization process. After that, to identify model parameters and improve the accuracy of the proposed model, an experiment platform is established and a modified hysteresis nonlinear model is put forward. Finally, experiments are conducted to demonstrate the effectiveness of the modified model and the corresponding identification method. The modified model prediction results of giant magnetostrictive transducer agree well with experiment results not only under quasi-static operating conditions but also under dynamic operating conditions. Additionally, the proposed model’s parameters have definite physical meaning, but the parameters to be identified are less and model expression is more simple than that of the other hysteresis nonlinear models such as the Jiles–Atherton model. The present model can be used in the simulation and performance prediction of giant magnetostrictive transducer, which is especially suitable for the real-time control system of giant magnetostrictive transducer.

Yield Improving Strategy for SNP Detection on DNA Origami Chip by Employing Au Nanoparticles

Detection of single nucleotide polymorphisms (SNPs) is critical for early stage diagnosis. However, available clinical methods for detecting SNPs require strict assay conditions or complicated enzyme reactions. DNA hybridization by Au nanoparticles is a new microscopic method for DNA detection, which offers many advantages over traditional ones. But currently, this method is limitedly used because of low yield of hybridization. Here we report novel strategies which use toehold-mediated strand displacement on DNA origami Chip by employing AuNPs, and we greatly improved the yield of hybridization to 80% from less than 10%. Based on the kinetic characteristic of toehold-mediated strand displacement reaction, DNA strands with unmatched sequences can be easily replaced by fully complementary ones, and the exchange rate depends on the length of the toehold region. Therefore, variation on ssDNA sequence can be differentiated by their different displacement time. With this approach we detect SNPs of age-related macular degeneration on DNA origami chip. This approach offers a new, simple and sensitive way to detect SNP. Keywords: Age-related macular degeneration (AMD), atomic force microscope (AFM), Au nanoparticle (AuNP), DNA origami chips, single- nucleotide polymorphisms (SNPs).

Modeling and Simulation of Omni-Directional Mobile Robot with Mecanum Wheel

In this paper, an omni-directional mobile robot with mecanum wheel was designed. Based on mathematical modeling theory and the virtual prototype software called Adams, the mathematical model of mobile robot was built and the kinetic characteristic was simulated. So we can ensure that the mobile robot with mecanum wheel has omni-directional movement characteristic. The reliability of the mathematical model has been verified through the comparision of the the mathematical calculation and simulation result. At the same time a new method was put forward to ensure all the mobile platform wheels can fully contact with the ground when running on the uneven road surface. Then the stability of the motion control system has also been improved.

Stereoselective Property of 20(S)-Protopanaxadiol Ocotillol Type Epimers Affects Its Absorption and Also the Inhibition of P-Glycoprotein

Stereoselectivity has been proved to be tightly related to drug action including pharmacodynamics and pharmacokinetics. (20S,24R)-epoxy-dammarane-3,12,25-triol (24R-epimer) and (20S,24S)-epoxy-dammarane-3,12,25-triol (24S-epimer), a pair of 20(S)-protopanaxadiol (PPD) ocotillol type epimers, were the main metabolites of PPD. Previous studies have shown that 24R-epimer and 24S-epimer had stereoselectivity in pharmacological action and pharmacokinetics. In the present study, the aim was to further study the pharmacokinetic characteristics of both epimers, investigate their absorption mechanism and analyze the selectivity effects of ocotillol type side chain and C24 stereo-configuration on P-glycoprotein (P-gp) in vivo and in vitro. Results showed that the absolute bioavailability of 24R-epimer was about 14-fold higher than that of 24S-epimer, and a linear kinetic characteristic was acquired in doses of 5–20 mg/kg for both epimers after oral administration. Furthermore, the apparent permeability coefficients of 24R-epimer were 5–7 folds higher than that of 24S-epimer having lower efflux ratios in Caco-2 cell models. Moreover, both 24R-epimer and 24S-epimer had similar inhibitory effects on P-gp by increasing cellular retention of rhodamine 123 in Caco-2 cells and decreasing efflux of digoxin across Caco-2 cell monolayers. In situ in vivo experiments showed that the inhibition of 24R-epimer on P-gp was stronger than that of 24S-epimer by single-pass intestinal perfusion of rhodamine 123 in rats. Western blot analyses demonstrated that both epimers had no action on P-gp expression in Caco-2 cells. In conclusion, with respect to the stereoselectivity, C24 S-configuration of the ocotillol type epimers processed a poor transmembrane permeability and could be distinguished by P-gp. Sharing a dammarane skeleton, both 24R-epimer and 24S-epimer were potent inhibitors of P-gp. This study provides a new case of stereoselective pharmacokinetics of chiral compounds which contributes to know the chiral characteristics of P-gp and structure-action relationship of PPD type and ocotillol type ginsenosides as a P-gp inhibitor.

Design and Motion Simulation of the Clamping Mechanism of Micro-Structure Injection Molding Machine

Micro-structure injection molding machine is mainly used for processing the plastic products in micron-size or with micro-structures. This paper focuses on the design and control of the clamping mechanism of micro-structure injection molding machine. Firstly, the deformation of the clamping mechanism was analyzed. The simulation results shows that the clamping force is 5.0051×105N, and it’s bigger than the design value 500kN. Secondly, the kinetic characteristic of the clamping was simulated by ADAMS software. The curves of the displacement, velocity, clamping force of moving platen were analyzed. Thirdly, the control model of clamping mechanism was established. And the LQR controller was designed and simulated by Matlab. The rise time is 0.010s, the settling time is 0.026s and the steady-state is 0.307m.

Internal Impact Analysis of a Novel Controllable Metamorphic Palletizing Robot Mechanism

Metamorphic mechanism would result in impact when it was changing from one configuration to the next. As a result, the internal impact force would bring about great vibration for the mechanism. What was more, it would make the mechanism be unstable. Therefore, the internal impact for metamorphic mechanism was expected to be analyzed. The controllable metamorphic palletizing robot mechanism was investigated in this paper. First of all, its kinetic characteristic was analyzed. In addition, the total momentum of the link which suffered impact was calculated. Furthermore, the impact force of the link was known. Finally, the relationship between the impact time when the mechanism was changing configuration and the momentum of the link was described through example study. The work of this paper provides some references for stability study of metamorphic mechanism.

Kinematics Simulation of a New CVT Based on Virtual Prototype Technology

In order to study the kinetic characteristic of a new continuously-variable-transmission (CVT), a three-dimensional model of the CVT was first established by Pro/E solid design and it was saved as Parasolid file format. Then, a kinematics simulation model of drive system of the CVT was established by importing the Parasolid file into ADAMS and the simulation was realized by replacing the traction drive of elasto-hydrodynamic lubrication (EHL) oil film with the contact constraint joints between the input and output wheel discs and the intermediate idler wheels. The simulation results demonstrate that the three-dimensional simulation model of the CVT is accurate, and the equivalent drive system of the CVT is reasonable.

Modern Multi-unit Housing in Japan and the Dōjunkai Apartments (1924–34)

The Dōjunkai Apartments were built in Tokyo between 1924 and 1934. The period coinciding with the construction of these buildings by the Dōjunkai Association marked a crucial phase in the history of housing architecture. Certainly by the 1930s, theories on four types of residential organisational structures were consolidated to include the neighbourhood (Garden City); the block (H. Berlage's plan of expansion of Amsterdam); the quarter (German Siedlungen); and the megastructure (Le Corbusier's La Ville Radieuse). Influenced by European models, the Dōjunkai schemes are typified by an original combination of endogenic and exogenic forms. Drawing on the comparison with Western counterparts and on the analyses of plans and of other archival material, this article will demonstrate the peculiar organisational structure of the Dōjunkai Apartments. This will be defined as a “segmented block”, characterised by fortuity, fragmentariness and linearity. Further, the article will propose the idea that these elements recall the archetypes of the nagaya (a type of traditional Japanese row house), the linear village and the kinetic spatial structure characteristic of the city of Edo-Tokyo.

Study on Kinetic Characteristics of Solid-Liquid Two-Phase in Transporting Pipeline of Natural Gas Hydrate

Based on multiphase flow theory and calculation method, the distribution of internal multiphase flow field in the vertical rise pipeline of natural gas hydrate is simulated with FLUENT as a tool and the mixture of natural gas hydrate solid particles and water as a medium. The change rules of velocity field and volume concentration field are described and the effect of solid particles diameter, density and volume concentration of the natural gas hydrate on the pressure loss and resistance loss of pipeline is also analyzed deeply. It provides theoretical basis on transporting of natural gas hydrate solid particles by pipeline. Keywords:natural gas hydrate. pipeline. solid-liquid two-phase flow. kinetic characteristic. numerical simulation.

DEM Study of Wet Cohesive Particles in the Presence of Liquid Bridges in a Gas Fluidized Bed

A modified discrete element method (DEM) was constructed by compositing an additional liquid-bridge module into the traditional soft-sphere interaction model. Simulations of particles with and without liquid bridges are conducted in a bubbling fluidized bed. The geometry of the simulated bed is the same as the one in Müller’s experiment (Müller et al., 2008). A comparison between the dry and the wet particular systems is carried out on the bubble behavior, the bed fluctuation, and the mixing process. The bubble in the dry system possesses a regular round shape and falling of scattered particles exists while the bubble boundary of the wet particles becomes rough with branches of agglomerates stretching into it. The mixing of the dry system is quicker than that of the wet system. Several interparticle liquid contents are applied in this work to find their influence on the kinetic characteristic of the wet particle flow. With an increase of liquid content, the mixing process costs more time to be completed. Symmetrical profiles of the velocity and granular temperature are found for two low liquid contents (0.001% and 0.01%), while it is antisymmetrical for the highest liquid content (0.1%).

Analysis for Suspension Hardpoint of Formula SAE Car Based on Correlation Theory

According to the correlation of the hardpoints, double wishbone suspension of Formula SAE Car can be improved and optimized. For Formula SAE car, performance and kinetic characteristic of the suspension follow very closely to handling stability, comfort ability, handling of steering and service life of tire, etc. Double wishbone suspension is chosen as front suspension of Formula SAE car in the paper. Based on the multi-body dynamics and suspension kinematics theory, simulation model of front suspension is built and analyzed. With correlation theory, the correlation for the hardpoints of the suspension is studied and discussed. Through all the testing, not only a lot of four wheel alignment parameter variations can be obtained, but also the rational designing for hardpoints which can provide an useful reference for vehicle designing.

Formation of microemulsion particles with surfactant—A coarse-grained molecular dynamics simulation study

It is of great interest to understand how surfactant molecules influence the formation of micro-emulsion particles in order to support application of microemulsions in various fields. In this paper, the effect of surfactants on the formation of microemulsion particles was studied using molecular dynamics simulations coupled with Martini force field. n -Dodecane (C12H26) and sodium dodecyl sulfate (SDS) were used as the models-representing oil and surfactant molecules respectively. Twelve simulation boxes containing C12H26 and SDS with different concentrations were used in simulations running for 100 ns. Simulation results showed that the phase separations occurred rapidly for systems without surfactants, and were accompanied with decreases of potential energies. For the systems with surfactants, stable oil particles covered by surfactants were observed in the same time. The initial kinetic characteristic of the formation of microemulsion particles can be expressed as the second order reaction approximately, and the activation energy is estimated to be 14.6 kJ/mol.

The Calculating Method of the Degree of Freedom about the Rigid-Flexible Hybrid Mechanism

The learning and interchange of the research workers in mechanical engineering field is very difficult because the high error probability and difficult understanding in the degree of freedom calculation about the rigid-flexible hybrid mechanism.In this paper,the pairing and mechanism characteristics of flexible mechanism have been firstly researched based on the kinetic characteristic of flexible mechanism.The degree of freedom calculating method of the flexible mechanism has been provided.This method is then expanded to the degree of freedom calculating of the rigid-flexible hybrid mechanism.The above methods are correct and validity by some examples testing.and it can efficiently support the design concept verifying.

Fractal analysis of the fatigue fracture surface of metal of welded joints

The results of investigations of special features of fatigue failure of the metal of welded joints using the new methods of fractal analysis of the fracture surfaces in metals science of welding are presented. The fractal dimension of the fracture surface is determined and its relationship with the kinetic characteristic of the process – the fatigue crack growth rate – is investigated. The relationships governing the effect of the composition of electrode coatings on the fatigue fracture characteristics are determined.

Do MAO A and MAO B utilize the same mechanism for the C–H bond cleavage step in catalysis? Evidence suggesting differing mechanisms

The detailed molecular mechanism proposed for the MAO-catalyzed oxidation of amines has been controversial with the basic assumption that both MAO A and MAO B follow the same pathway for the C-H bond cleavage step. Using the mechanistic approach of investigation of electronic effects of various benzylamine ring substituents in experiments at pH 9.0, human MAO A exhibits a kinetic behavior characteristic of an H(+) abstraction, while human MAO B exhibits kinetic properties characteristic of a H(-) abstraction. These results lead to the conclusion that the assumption that MAO A and MAO B follow identical mechanisms is incorrect.

Analysis for Resolution of Bistatic SAR Configuration with Geosynchronous Transmitter and UAV Receiver

Bistatical SAR with geosynchronous illuminator and unmanned aerial vehicle receiver (GEO-UAV BiSAR) has significant potential advantages in the field of continuous local observation under a dangerous environment within nearly 24 h. Due to the extreme platform velocity differences, the ellipse orbital movement of GEOSAR makes this BiSAR configuration not like the conventional spaceborne BiSAR. In this paper, based on the orbital kinetic characteristic of GEOSAR, we theoretically analyze the variations of bistatic configuration effect on common azimuth coverage and coherent accumulated time. In addition, two-dimension the resolution is deduced by geometrical configuration on the basis of gradient method. The simulations show that the appropriate selection of initial bistatic configuration can restrain from the appearance of the dead zone in common coverage. And the image results are obtained by frequency domain RD based on Method of Series Reversion (MSR). It is shown that GEO-UAV BiSAR has the high resolution ability.

Disposal of hazardous organic substances in supercritical water

Studies devoted to the eco-friendly disposal of hazardous organic substances (OS) and waste through oxidation in supercritical water (SCW) are reviewed. One advantage of using SCW is the possibility of complete and rapid oxidation of OS in closed systems. The oxidation rate is determined by the temperature, proportions between the reagents, bond dissociation energies, and solubility of OS in SCW, decreasing in the series aliphatic > aromatic, heterocyclic > polyaromatic compounds. The main oxidation products are carbon dioxide, nitrogen, and water; sulfur, phosphorus, and halogens are converted into the respective mineral acids. There are a number of difficulties in the implementation of particular processes on the industrial scale, which impede the achievement of an acceptable performance of installations in terms of safety and stability. These difficulties are mainly associated with heterogeneous processes on the reactor walls, such as the corrosion of constructional materials and deposition of salts, which lead with time to changes in the kinetic characteristic of the main and coupled reactions.

Kinetic characteristic of zeoliteforming process from thermoactivated kaoline

Results of investigation zeolite NaA and NaХ izothermic crystallization process in hydrothermal conditions are represented in current article. Studied kinetical regularities of occurrence zeolite phase in dependence from the time of crystallization and presyntetic exposure of reation mixture