Acoustic location echo signal extraction of buried non-metallic pipelines based on EMD and wavelet threshold joint denoising

In the acoustic detection process of buried non-metallic pipelines,the echo signal is often interfered by a large amount of noise,which makes it extremely difficult to effectively extract useful signals.An denoising algorithm based on empirical mode decomposition(EMD)and wavelet thresholding was proposed.This method fully considered the nonlinear and non-stationary characteristics of the echo signal,making the denoising effect more significant.Its feasibility and effectiveness were verified through numerical simulation.When the input SNR(SNRin)is between-10 dB and 10 dB,the output SNR(SNRout)of the combined denoising algorithm increases by 12.0%-34.1%compared to the wavelet thresholding method and by 19.60%-56.8%compared to the EMD denoising method.Additionally,the RMSE of the combined denoising algorithm decreases by 18.1%-48.0%compared to the wavelet thresholding method and by 22.1%-48.8%compared to the EMD denoising method.These results indicated that this joint denoising algorithm could not only effectively reduce noise interference,but also significantly improve the positioning accuracy of acoustic detection.The research results could provide technical support for denoising the echo signals of buried non-metallic pipelines,which was conducive to improving the acoustic detection and positioning accuracy of underground non-metallic pipelines.

Effect of continuous casting speed on mold surface flow and the related near-surface distribution of non-metallic inclusions

For the control of surface defects in interstitial-free(IF) steel, quantitative metallographic analyses of near-surface inclusions and surface liquid flow detection via the nail-board tipping method were conducted. The results show that, at casting speeds of 0.8 and 1.0 m/min, a thin liquid mold flux layer forms and non-uniform floating of argon bubbles occurs, inducing the entrainment and subsequent entrapment of the liquid flux; fine inclusion particles of Al_2O_3 can also aggregate at the solidification front. At higher casting speeds of 1.4 and 1.6 m/min, the liquid mold flux can be entrained and carried deeper into the liquid steel pool because of strong level fluctuations of the liquid steel and the flux. The optimal casting speed is approximately 1.2 m/min, with the most favorable surface flow status and, correspondingly, the lowest number of inclusions near the slab surface.

Study on non-metallic inclusions in Al killed high strength alloy steel refined by high basicity and high Al_2O_3 content slag

Laboratory and industrial studies were carried out to investigate non-metallic inclusions in high strength alloy steel refined by high basicity and high Al_2O_3 slag.It was found that the steel/slag reaction time largely affected non-metallic inclusions.With the reaction time increased from 30 min to 90 min in laboratory study,MgO-Al_2O_3 spinels were gradually changed into CaO-MgO-Al_2O_3 system inclusions surrounded by softer CaO-Al_2O_3 surface layers.By using high basicity slag which contained as much as 41%Al_2O_3 in the laboratory study,ratio of low melting temperature CaO-MgO-Al_2O_3 system inclusions was remarkably increased to above 80%.In the industrial experiment,during the secondary refining,the inclusions changed in order of 'Al_2O_3→MgO-Al_2O_3→CaO-MgO-Al_2O_3'.Through the LF and RH refining,most inclusions could be transferred to lower melting temperature CaO-Al_2O_3 and CaO-MgO-Al_2O_3 system inclusions.

Current Trends and Perspectives of Detection and Location for Buried Non-Metallic Pipelines

Buried pipelines are an essential component of the urban infrastructure of modern cities.Traditional buried pipes are mainly made of metal materials.With the development of material science and technology in recent years,non-metallic pipes,such as plastic pipes,ceramic pipes,and concrete pipes,are increasingly taking the place of pipes made from metal in various pipeline networks such as water supply,drainage,heat,industry,oil,and gas.The location technologies for the location of the buried metal pipeline have become mature,but detection and location technologies for the non-metallic pipelines are still developing.In this paper,current trends and future perspectives of detection and location of buried non-metallic pipelines are summarized.Initially,this paper reviews and analyzes electromagnetic induction technologies,electromagnetic wave technologies,and other physics-based technologies.It then focuses on acoustic detection and location technologies,and finally introduces emerging technologies.Then the technical characteristics of each detection and location method have been compared,with their strengths and weaknesses identified.The current trends and future perspectives of each buried non-metallic pipeline detection and location technology have also been defined.Finally,some suggestions for the future development of buried non-metallic pipeline detection and location technologies are provided.

Three-dimensional analysis technology for accurately characterizing non-metallic inclusion particles in steel

In this paper, a kind of three-dimensional analysis technology for characterizing non-metallic inclusions in steel was clearly elaborated. It is an electron microscopy observation, namely the non-aqueous electrolysis extraction method with a settled coulometer. In the research,the extraction effects of non-metallic inclusions in different electrolysis systems were studied, and it was concluded that alkalescent 2% TEA non-aqueous electrolyte was applicable for extracting most of non-metallic inclusion particles in steel. And then, in order to ensure the microscopic characterization and statistical calculation of inclusion particles, some electrolysis parameters should be confirmed, such as the size of the sample, control of the electrolysis mass, electric current, etc. Furthermore, for preventing the disturbance of carbides and presenting clear three-dimensional appearance by microscopic characterization, magnetic separation was utilized to separate the inclusion particles from carbides, which was useful for getting more veracious types, particle sizes and chemical composition of inclusions. Moreover, through calculation of quantity and particle size of inclusions in continuous determinate fields, the total quantity per unit volume or area and the particle size distribution of inclusions could be acquired by conversion with electrolysis loss. Besides, the comparison between this method and traditional quantitative metallography was also discussed, and finally, a conclusion was drawn that both of them have respectively applications in characterizing inclusions.

A presumed iridocyclitis developed to panophthalmitis caused by a non-metallic intraocular foreign body

Dear Editor,I write to present one case report of a patient suffered the panophthalmitis caused by non-metallic foreign body with no etiologic agent and recovered quickly by phacoemulsification and vitrectomy with silicone oil tamponade.Ocular trauma remains a major cause of blindness, particularly in the working-age population.

Behavior of Non-metallic Inclusions in Centrifugal Induction Electroslag Castings

In order to know the behavior of non-metallic inclusions in centrifugal induction electroslag castings (CIESC), non-metallic inclusions in 5CrMnMo and 4Cr5MoSiV1 were qualitatively and quantitatively analyzed. The largest size of inclusions in the casting and the thermodynamic possibility of TiN precipitation in steel were also calculated. The results show that sulfide inclusions are evenly distributed and the content is low. The amount of oxide inclusions in CIESC: 4Cr5MoSiV1 steel is close to the ESR steel and lower than that in the EAF steel, and there are some differences along radial direction. Nitride inclusions are fine and the diameter of the largest one is 3-1 mum. With the increase of the centrifugal machine's rotational speed, the ratio of round inclusions increases and the ratio of sharp inclusions decreases. According to the experiment and the calculation results, it is pointed out that the largest diameter of non-metallic inclusions in the CIESC 4Cr5MoSiV1 casting is only 6.6 mum, and [N%][Ti%] in 4Cr5MoSiV1 steel should be controlled less than 4.4x 10(-5) in order to further reduce the amount and size of TiN inclusions.

Major discoveries and progress of Chinese metal and non-metallic mineral prospecting and exploration in 2019

Global mineral products have been declining in 2019,which has led to a very sluggish global geological prospecting and mineral exploration.Statistics show that in 2019,the iron ore imports of China accounted for 64%of the world’s total,copper ore accounted for 56%,and bauxite ore accounted for 76%.Driven by rigid demand,the metal and non-metallic geological prospecting and mineral exploration in China are uniquely outstanding with fruitful results.This journal summarizes the above results and reports to the society to increase the social impact of geological exploration.

Discussion on New Evaluation Technology of Non-Metallic Composite Continuous Pipe for Oil and Gas Field

In view of the serious lack and lag of the test and evaluation technology of non-metallic composite continuous pipe, and focusing on the characteristics of the application of non-metallic composite continuous pipe in oil field, this paper discusses a series of new full-scale test and evaluation technologies for accurately evaluating the product quality and practical application performance of non-metallic composite continuous pipe, which effectively solves the major technical problem that the new products of non-metallic pipe cannot be accurately evaluated. Based on the characteristics of the application of non-metallic composite continuous pipe in oil field, a series of new full-scale test evaluation technologies which can accurately evaluate the product quality and practical application performance of non-metallic pipe are designed through a large number of tests. The test and evaluation technology can accurately evaluate the key performance of high and low pressure cycle, high and low temperature cycle, gas permeability resistance, minimum bending radius etc. It provides a scientific evaluation basis for the standardized application of non-metallic continuous pipe and a reliable quality control method for the selection of products in oil field.

Non-metallic Inclusions in Continuously Cast Aluminum Killed Steels

In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Probe Microanalysis) and by analyzing the total oxygen. The results showed that in the slabs the total oxygen was quite low and the inclusions discovered were mainly small-sized angular alumina inclusions. This indicates that most inclusions have been removed by floating out during the continuous casting process. In addition, the countermeasures were discussed to decrease the alumina inclusions in the slabs further.

Studies of non-metallic organic disinfectants on inactivation of avian influenza viruses

Six different kinds of non-metallic or organic disinfectants were obtained in this research study including “Neutral Electrolyzed Water”, “M22” organic disinfectant solution, Superoxy Food Wash disinfectant, Hydrogen Peroxide, Clorox Germicidal Bleach and Clidox-S. The effectiveness of these disinfectants was studied against various subtypes of avian influenza virus (AIV). The virus-disinfectant mixtures were prepared in serial dilutions of each disinfectant with a constant virus titer and incubated at ambient temperature in different time intervals for virus inactivation. The virus inactivation results were determined by virus recovery in embryonating chicken eggs. Among the six different kinds of nonmetallic disinfectants obtained for this research project, Neutral Electrolyzed Water, “M22” solution, Clorox Germicidal Bleach and Clidox-S were effectively inactivated AIV with appropriate working dilutions and reaction times. Superoxy Food Wash disinfectant and Hydrogen Peroxide were found having limited effect on virus inactivation with extended exposure times of more than 2 hours. These research findings provide scientific data to poultry industry with guidelines to select and use non-metallic organic disinfectants for poultry flock sanitation and disinfection to effectively prevent and control of avian influenza outbreaks.

Evaluation of Characteristics of Non-Metallic Inclusions in P/M Ni-Base Superalloy by Automatic Image Analysis

Non-metallic inclusions,especially the large ones,within P/M Ni-base superalloy have a major influence on fatigue characteristics,but are not directly measurable by routine inspection.In this paper,a method,automatic image analysis,is proposed for estimation of the content,size and amount of non-metallic inclusions in superalloy.The methodology for the practical application of this method is described and the factors affecting the precision of the estimation are discussed.In the experiment,the characteristics of the non-metallic inclusions in Ni-base P/M superalloy are analyzed.

Study on the separation process of non-metallic inclusions at the steel-slag interface using water modeling

The separation process of non-metallic inclusions at the steel–slag interface was simulated by physical modeling. Three different kinds of particles (octahedral, plate-like, and spherical) and three different oils (kerosene, bean oil, and pump oil) were used to model inclusions and slags, respectively. The effects of inclusion geometry (shape and size) and slag properties (viscosity and interfacial tension) on the separation process were investigated. The results revealed that the variation of surface free energy and the viscosity of the slag are two significant factors affecting the separation process of inclusions at the steel–slag interface. The variation of surface free energy helped inclusions enter the slag phase, whereas the decrease of slag viscosity shortened the separation time. The deformation of the steel–slag interface could give rise to the resistance force, which would resist inclusions passing through the interface. A liquid film formed on the inclusion as it passed through the steel–slag interface, which might be related to the inclusion’s shape. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

The extending length calculation of hydraulic drive non-metallic completion screen pipe running into ultra-short radius horizontal well

Focusing on the extending length restriction of the completion screen pipe resistance running into ultra-short radius horizontal well,this paper proposed technology of hydraulic drive completion tubular string running into ultra-short radius horizontal well.Innovative hydraulic drive tools and string structure are designed,which are composed of guide tubing,hydraulic drive tubing and non-metallic completion screen pipe from inside to outside.A novel mechanical-hydraulic coupling model is established.Based on the wellbore structure of an ultra-short radius horizontal well for deep coalbed methane,the numerical calculations of force and hydraulic load on tubular strings were accomplished by the mechanical-hydraulic coupling model.The results show that the extending length of completion tubular string with the hydraulic drive is 17 times that of conventional completion technology under the same conditions.The multi-factor orthogonal design is adopted to analyze the numerical calculations,and the results show that the extending length of the completion tubular string is mainly affected by the completion tubular string structure and the friction coefficient between the non-metallic composite continuous screen pipe and the wellbore.Two series of hydraulic drive completion tubular string structures suitable for ultra-short radius horizontal wells under different conditions are optimized,with the extending limits of 381 m and 655 m,respectively.These researches will provide theoretical guidance for design and control of hydraulic drive non-metallic composite continuous completion screen pipe running into ultra-short radius horizontal wells.

Charging of Materials Non-Metallic Used in Underground Mines Endangered by Firedamp and/or Coal Dust

The expansion parts and components of non-metallic in devices have become a fait accompli. In the case parts, components of non-metallic are used in atmospheres explosive and may be a potential source of ignition [1]. Ignition hazards due to static electricity from the charged non-conductive non-metallic materials are well known [2]. The prevalence protection metal parts and components of anti-corrosion exist in any device equipped with a metal casing. Inherent risks associated services are caused by static electricity. Electrostatic phenomena arise in many situations, in a variety of environments and industries. The occurrence of charge static in many cases unexpected is unwanted and requires the use of expensive preventive measures. Brush discharge and propagating brush discharge (e.g. composite coating about non-conductive electrostatic properties of an isolated base conductive) create explosion hazard in underground endangered by firedamp and/or coal dust [3].

Motion behavior of non-metallic particles under high frequency magnetic field

Non-metallic particles, especially alumina, are the main inclusions in aluminum and its alloys. Numerical simulation and the corresponding experiments were carried out to study the motion behavior of alumina particles in commercial pure aluminum under high frequency magnetic field. At the meantime, multi-pipe experiment was also done to discuss the prospect of continuous elimination of non-metallic particles under high frequency magnetic field. It is shown that: 1) results of numerical simulation are in good agreement with the experimental results, which certificates the rationality of the simulation model; 2) when the intensity of high frequency magnetic field is 0.06 T, the 30 μm alumina particles in melt inner could migrate to the edge and be removed within 2 s; 3) multi-pipe elimination of alumina particles under high frequency magnetic field is also effective and has a good prospect in industrial application.

Characterization and analysis of non-metallic inclusions in Ni42-Fe expansive alloy

Cracks and ruptures always occur during wire drawing process of 42% nickel-iron expansive alloy. In order to study the reasons of these phenomena,a method of metallographic observation in combination with sample electrolysis was used to characterize the non-metallic inclusions in the alloy wire. The results indicate that the inclusions in the alloy are oxidation products during the process of melting. There are single or complex phase inclusions composed of elements such as Al,Si,Ca,Ti,Fe,and O2. Among them,the macro-inclusions are TiO2 compound inclusions formed by the adhesion of Al and Si oxides on them. These inclusions are fragile ones with a low strain rate,as well as a rather high hardness,so that they are the main reason that leads to the surface cracks and ruptures in the alloy wires. The analysis has educed that the key point to enhance the product quality is to promote the cleanliness of the melt,control the types and quantity of non-metal inclusions in the alloy.

On the thermodynamics of plasticity during quasi-isentropic compression of metallic glass

Entropy production in quasi-isentropic compression (QIC) is critically important for understanding the properties of materials under extremeconditions. However, the origin and accurate quantification of entropy in this situation remain long-standing challenges. In this work, a framework is established for the quantification of entropy production and partition, and their relation to microstructural change in QIC. Cu50Zr50is taken as a model material, and its compression is simulated by molecular dynamics. On the basis of atomistic simulation-informed physicalproperties and free energy, the thermodynamic path is recovered, and the entropy production and its relation to microstructural change aresuccessfully quantified by the proposed framework. Contrary to intuition, entropy production during QIC of metallic glasses is relativelyinsensitive to the strain rate ˙γ when ˙γ ranges from 7.5 × 10^(8) to 2 × 10^(9)/s, which are values reachable in QIC experiments, with a magnitudeof the order of 10^(−2)kB/atom per GPa. However, when ˙γ is extremely high (>2 × 10^(9)/s), a notable increase in entropy production rate with˙γ is observed. The Taylor–Quinney factor is found to vary with strain but not with strain rate in the simulated regime. It is demonstrated thatentropy production is dominated by the configurational part, compared with the vibrational part. In the rate-insensitive regime, the increase inconfigurational entropy exhibits a linear relation to the Shannon-entropic quantification of microstructural change, and a stretched exponential relation to the Taylor–Quinney factor. The quantification of entropy is expected to provide thermodynamic insights into the fundamentalrelation between microstructure evolution and plastic dissipation.

Corrosion and in vitro cytocompatibility investigation on the designed Mg-Zn-Ag metallic glasses for biomedical application

In the present work,seven Mg-Zn-Ag alloys with the nominal composition of Mg_(96-x)Zn_(x)Ag_(4)(x=17,20,23,26,29,32,35 in at.%)were prepared by induction melting and single-roller melt-spinning.The X-ray diffraction(XRD)analyses indicate the metallic glasses with three composition of Mg_(73)Zn_(23)Ag_(4),Mg_(70)Zn_(26)Ag_(4),and Mg_(67)Zn_(29)Ag_(4)were obtained successfully.The differential scanning calorimetry(DSC)measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis.The maximum glass transition temperature(Trg)was found to be 0.525 with a composition close to Mg_(67)Zn_(29)Ag_(4),which results in the best glass-forming ability.Moreover,the immersion test in simulated body fluid(SBF)demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses.The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content.The sample Mg_(67)Zn_(29)Ag_(4)has the lowest corrosion rate of 0.19mm/yr,which could meet the clinical application requirement well.The in vitro cell experiments show that the Madin-Darby canine kidney(MDCK)cells cultured in sample Mg_(67)Zn_(29)Ag_(4)and its extraction medium have higher activity.However,the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma(RD)tumor cells.The present investigations on the glass-forming ability,corrosion behavior,cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.

Failure pattern in ceramic metallic target under ballistic impact

The ballistic resistance and failure pattern of a bi-layer alumina 99.5%-aluminium alloy 1100-H12 target against steel 4340 ogival nosed projectile has been explored in the present experimental cum numerical study.In the experimental investigation,damage induced in the ceramic layer has been quantified in terms of number of cracks developed and failure zone dimensions.The resultant damage in the backing layer has been studied with variation in the bulge and perforation hole in the backing layer with the varying incidence velocity.The discussion of the experimental results has been further followed by three dimensional finite element computations using ABAQUS/Explicit finite code to investigate the behaviour of different types of bi-layer targets under multi-hit projectile impact.The JH-2 constitutive model has been used to reproduce the behaviour of alumina 99.5%and JC constitutive model has been used for steel 4340 and aluminium alloy 1100-H12.The total energy dissipation has been noted to be of lesser magnitude in case of sub-sequential impact in comparison to simultaneous impact of two projectiles.The distance between the impact points of two projectiles also effected the ballistic resistance of bi-layer target.The ballistic resistance of single tile ceramic front layer and four tile ceramic of equivalent area found to be dependent upon the boundary conditions provided to the target.