International Journal of Nanomanufacturing (25 papers in press)
Carbon nanotubes synthesis using Fe-Co-Mo/MgO tri-metallic catalyst: study the effect of reaction temperature, reaction time and catalyst weight
by Puguh Setyopratomo, Praswasti PDK Wulan, Mahmud Sudibandriyo
Abstract: MgO supported tri-metallic catalyst containing combination of transition metals Fe, Co, and Mo was used to synthesize carbon nanotubes (CNT) from liquefied petroleum gas by chemical vapor deposition (CVD) method. The effect of reaction temperature, reaction time and catalyst weight to the yield and the CNT properties was investigated. It found that the CNT yield increased with increasing the reaction temperature. Besides, increasing the reaction temperature lead to the increase of the diameter and wall thickness of the CNT. Moreover, it was found that the crystallinity of the synthesized CNT increase when the reaction temperature is raised. The yield is steadily increased with increasing reaction time and reach the highest yield at 21.95 g CNT/g catalyst which corresponds to reaction time 5 hours. The micro pores volume, BJH pores volume and total pores volume, all show a decrease when the reaction time is increased. The meso pores dominate the pore structure of the CNT product and contribute around 90 % of the total pores volume. Meanwhile, micro pores with pore size range around 0.3-0.4 nm dominate the micro pores and contribute approximately 50-60 % of the total micro pores volume. It also found that the CNT yield is decreased along with the increasing catalyst weight.
Keywords: carbon nanotubes; reaction time; reaction temperature; yield; liquefied petroleum gas; supported catalyst.
Fractal Description and Adsorption-Desorption Behavior of Coke Treated by Benzene pyrolysis carbons
by Zezhi Zhang
Abstract: For explaining why benzene pyrolysis carbons could inhibit coke deterioration in blast furnace, the adsorption-desorption data of coke sample treated by benzene pyrolysis carbons were obtained to establish adsorption-desorption isotherms and to fit fractal description model with Frenkel-Halsey-Hill equation. The SEM photographs of coke revealed that the pores of the infiltrated coke were almost filled with pyrolysis carbon particles. The fitted curves showed that the types of isotherms were similar to type II of IUPAC classification, and the hysteresis loops belonged to type H3 which represents a typical multilayer adsorption. Model tests indicated that the pore structure of the coke samples have obvious fractal feature and the fractal dimensions of coke sample treated by benzene pyrolysis carbons were smaller than that of original coke sample. So, it explained that benzene pyrolysis carbons can effectively inhibit coke deterioration by infiltrating into the pore structure of coke and reducing pore roughness.
Keywords: coke; inhibition deterioration; benzene pyrolysis carbons; adsorption-desorption; fractal description.
Precision of prestressed ball screw thermal behaviour in machine tool operating conditions
by Zbigniew Kowal, Jerzy Jedrzejewski, Taeweon Gim
Abstract: This paper presents an FEM model of a feed drive with a ball screw stiffness-wise, thermally and motion-wise integrated with the machine tool structure. The model takes into account the moving heat sources, the frictional and inertial interaction of the masses being shifted and the variable thermoelastic and stiffness interactions within the drive and the machine tool load-bearing structure. The results of heating up and displacement calculations for the ball screw, the bearing supports and the whole machine tool are analyzed with regard to positioning accuracy.
Keywords: machine tool; ball screw; model.
Study on engineering module design for liquid macromolecular ingredient content detection
by Xiaotong Na, Zhen Zhou, Chunyu Wang, Jia QI
Abstract: The liquid milk with the main ingredients of protein and fat was used as the research background for liquid macromolecular ingredient content detection in this paper. A model for the protein and fat ingredient content was established with the theory of scattered through ratio. Based on this, the photoelectric detection module was designed. Multiple photoelectric detection module circuit boards had been tested, the average error of the scattered light direction photoelectric detection circuit was 0.0072, and the average error of the photoelectric detection circuit in the direction of transmission light was 0.0094. The correlation coefficient of the established model can reach 0.97, and the system measurement uncertainty is about 0.078. The above test results show that the design meet the engineering application indicators basically. The detection module designed in this paper had the convenience, fast and efficient real-time performance, the reproducibility and stability was satisfactory.
Keywords: ingredient content detection; liquid macromolecular; engineering; module design; scattered through ratio.
INFLUENCE OF BORON NITRIDE NANO ADDITIVES IN CUTTING FLUID FOR IMPROVING SURFACE ROUGHNESS WITH MRR
by Manikanda Prabu Narayanasamy, Maniiarasan P, Nallusamy S, Jeevanantham S
Abstract: Surface quality of machined component is the essential requirement in industrial sectors by focusing on customer needs. Under this consideration, lot of researches brought in to proven results to enhance the surface quality in various machining Centre in different ways. Surface quality depends on the certain machining parameters which may have direct impact on output parameters such as surface roughness, MRR and indirectly correlated with the frictional resistance and heat transfer characteristics due to the relative motion of work and tool material. Previous results discussed the reduction state of frictional characteristics of machining in which selection of cutting fluids plays a vital role in reducing frictional resistance between tool and work. At present, quality and machining characteristics of cutting fluids attain better focus in such a way to improve the surface finish using additives and obviously Nano additives are assumed to be a possible solution to provide betterment of machining outcome. Present experimental work discusses the Preparation of Nano cutting fluids using boron nitride, Characteristics and influence on Machining parameters such as MRR, Tool life particularly surface quality in surface grinding operation. Result revealed that the addition of boron nitride Nano particles with base fluid is providing greater surface finish when compared to the conventional cutting fluids.
Keywords: Cutting Fluid; Grinding; Nano Additive; Surface Finish; MRR.
The behavior of nanofluids flooded in printed mini channels when excited by a small electrical potential
by Ahmad Yusairi Bani Hashim, Azri Nazran Afandi, Imran Syakir Mohamad, Syazwani Zainal Abidin, Amirah Abdullah
Abstract: This work sought to observe the response of a nanofluid put along in an electrical circuit while seeing the behavior of the fluid. Would the nanofluids have a characteristic of an electrolyte? Two mini channels were constructed using additive manufacturing approach. The nanofluids were flooded in the channels where they were connected in series with a generic resistor in a low voltage circuit. The fluids behaviors were observed through the recorded voltage drops at the resistor and also at the channels start and end points, respectively. The results showed minute currents were flowing in the circuit as the fluids recorded high resistances. Therefore, the nanofluids are naturally high resistance electrolytes. However, the real nature of the fluids exposed to electrical potentials for a longer duration is unknown.
Keywords: Mini channel; hydraulic diameter; carbon nanotube; carbon nanofiber; electrical conductivity; 3D printing; high resistance electrolyte.
Tailoring of Nanoparticles for Chemical Enhanced Oil Recovery Activities: A Review
by Augustine Agi, Radzuan Junin, Afeez Gbadamosi
Abstract: Nanotechnology has found its way to Petroleum Engineering, as it is a well-accepted path in the oil and gas industry to recover more oil trapped in the reservoir. The challenge in nanotechnology in the oil and gas industry is full-scale field application, due to cost. A considerable research and development investment is needed for the implementation of the technology in formulating cheap, readily available and environmentally friendly nanoparticles. In this review, methods of synthesizing the different types of nanoparticles is described, detailing the parameters involved in these techniques with the aim of tailoring their distinct properties such as; large surface area and ability to manipulate their behaviour for enhanced oil recovery. The difference between the natural and synthetic polymer nanoparticles and their various method of synthesis is discussed and their advantage in enhanced oil recovery is highlighted. The methods of synthesis can lower the interfacial adsorption of polymer with surface-active properties, prevent aggregation when the nanoparticle is subjected to flow, and prevent degradation. It can also form micelles and liposomes which can lower critical micelle concentration (CMC) and influence phase behaviour. The challenges encountered have opened new frontier for research and are also highlighted herein.
Keywords: Nanotechnology; Nanoparticle; Synthesis; Chemical Enhanced Oil Recovery; Polymer.
Tolerance Analysis of Slider-crank Mechanism for Assembly Functionality Check
by XUSONG XU
Abstract: Tolerance analysis is an effective way to improve the quality and decrease the cost of product. Functionality check is an important aspect of tolerance analysis. The purpose of functionality check is to analyse the stack-up of geometric deviation of part/feature whether it meets the demand of geometry and is it in the range of assembly tolerance. Geometric variations exist in the process of tolerance stack-up and transmission, on the other hand, the part itself has geometric error. In addition, since geometric deviation exists in the assembly feature between the parts, so the objects of tolerance analysis should contain part tolerance and assembly clearance. However, the usual tolerance analysis model does not include the assembly clearance. Aiming at this problem, we have done some research. Firstly, the nominal geometric transfer model and the stack-up model are established based on the Small Displacement Torsor(SDT) and Homogeneous Transformation Matrix(HTM). Secondly, HTM expression of the tolerance loop is constructed. Next, the assembly tolerance analysis matrix model is established and a new tolerance analysis method for assembling feasibility is put forward. The main advantages of the method are: 1) analysis object not only contains the tolerance, but also contains the assembly clearance; 2) it can analyse the stack-up deviation of the multiple assembly clearance; 3) it can effectively perform the assembly functionality check and the evaluation of the tolerance allocation results. At last, taking slider-crank mechanism as an example, the contrastive study of tolerance analysis for functionality check is done after establishing stack-up model of assembly tolerance analysis. The results show that it is prone to lead to misjudge when analysing only dimension tolerance, the analysis results of considering dimension tolerance, geometric tolerance and assembly clearance are more restrictively. However, it is more compliance with actual engineering.
Keywords: Tolerance analysis; Assembly tolerance; Tolerance stack-up model; Assembly clearance; Slider-crank Mechanism.
An Approach to Calculate Master Curve for Glass Molding Press Based on Finite Element Simulation
by Zhiguo Zhang, Yuxuan Sun
Abstract: A new approach is proposed to calculate the master curve (MC) of glass. It can solve the problem: when the temperature is higher than T_(t,l) (defined later), the measured shear relaxation modulus cant describe the mechanical response of the annealing stage during glass molding press(GMP) through the thermal rheological simple (TRS) theory. Based on the temperature dependent Yang's modulus and TRS theory, the MC with a reference temperature less than T_(t,l) is calculated by an iterative process.In order to verify the suitability of MC at high temperature, the MC and shear relaxation moduli are used in the finite element(FE) simulation at the isothermal compression stage. Similar von Mises stresses are shown and the usability of the MC at molding temperature is proved by the simulation results. In order to predict residual stress within the formed glass lens, the MC is used to conduct FE simulation for the whole GMP process.
Keywords: Glass molding press; Viscoelasticity; Thermal rheological simple; Master curve; Finite element.
Study on Novel Temperature Sensor based on Amorphous Carbon Film
by Qi Zhang, Xin Ma, Meiling Guo, Lei Yang, Yulong Zhao
Abstract: In this study, a new type of thermistor temperature sensor was developed. The sensing materials was amorphous carbon (a-C) film prepared using electron cyclotron resonance (ECR) plasma processing system under low energy electron irradiation sputtering. The nanostructure of a-C film was observed by transmission electron microscope (TEM), the atomic bonding and carbon hybridization condition was analyzed by Raman spectra and X-ray photoelectron spectroscopy (XPS) respectively. The linearity of temperature-resistance curve of this kind of a-C film was very good in certain temperature range, with high temperature coefficient of resistance (TCR). The a-C film by 50 eV electron irradiation can measure larger temperature range from -75 degree centigrade to 155 degree centigrade, with good repeatability. The working temperature range of a-C film by 100 eV electron irradiation was much smaller, but TCR absolute value of this film was higher. It can be concluded that the lower sp2 / sp3, the better linearity of temperature-resistance curve, the lower TCR absolute value in certain working temperature range. The research shows that this kind of a-C film temperature sensor has good linearity and repeatability, also it can be integrated with other MEMS sensor simply.
Keywords: Amorphous carbon film; Thermistor; Temperature sensor; Temperature resistance characterization; Temperature coefficient of resistance.
One Step Synthesis of ZnO Nanoparticles with Zinc Acetate Dehydrates and Potassium
by Md. Zaved Hossain Khan, Partha P. Das, Md. Abdullah
Abstract: In this study, pure ZnO nanoparticles have been synthesized by one step method where zinc acetate dehydrates and potassium use as a precursor. The UV-vis absorption spectrum was indicated that the reduction and stabilization of ZnO nanoparticles in aqueous medium. The peaks in X-ray diffraction pattern were revealed that the formation of ZnO in nanoscale and it good treaty with that of crystalline hexagonal structure. It was observed that ZnO elicited in form of nanoparticles and nanoflowers in spherical shape as well as homogeneous dispersion. The grain size were found to be 18-40nm. Thermo gravimetric analysis and Diffractive thermal analysis results were showed the thermal stability of ZnO nanoparticles in the temperature region of room temperature to 10000C. FTIR measurement was revealed that the synthesized Zn ion have potential interaction towards organic aqueous fluid to form of ZnO nanoparticles.
Keywords: ZnO nanoparticles; ZnO nanoflowers; crystalline structure; morphology; thermal analysis.
The Use Of Surface Plasmon Resonance Band Of Green Silver Nanoparticles and Conductometry For Quantitative Determination Of Minor Concentrations of Doxycycline hyclate And Oxytetracycline HCl in Pure and Pharmaceutical Dosage Forms.
by Rania A. Sayed, Manal S. El- Masry, Wafaa S. Hassan, Magda Y. El-Mammli, Abdalla Shalaby
Abstract: Two novel and sensitive methods for quantitative determination of doxycycline hyclate and oxytetracycline HCl were developed. The first method (Method A) is based on the reducing character of the cited drugs which causes chemical reduction of silver ions to silver nanoparticles (Ag-NPs) in the presence of polyvinyl pyrrolidone (PVP) as a stabilizing agent producing surface plasmon resonance which has absorption peaks at 424 and 428 nm for doxycycline hyclate and oxytetracycline HCl, respectively. The nanoparticles were characterized by UV-VIS spectrophotometry and transmission electron microscopy (TEM). The plasmon absorbance of the Ag-NPs was used for the quantitative spectrophotometric determination of the cited drugs. The second method (Method B) is a conductometric method which is based on the reaction of the cited drugs with phosphotungstic acid to form ion associates in aqueous system. Validation of the proposed methods was carried out.
Keywords: Silver nanoparticles; doxycycline hyclate; oxytetracycline HCl; conductometry and phosphotungstic acid.
Design and Simulation of MEMS Piezoelectric Vibration Energy Harvesters with Center Mass Block
by Lu Wang, Dejiang Lu, Shenrong Zhang, Zhikang Li, Yong Xia, Yunyun Luo, Libo Zhao, Zhuangde Jiang
Abstract: Abstract: MEMS-based piezoelectric vibration energy harvesters (MEMS-PVEHs) with center mass block are designed with the overall size 10102 mm3, two prototypes including piezoelectric unimorph and bimorph beams are used respectively. The MEMS-PVEHs have a lower resonant frequency (109.20Hz for unimorph beam and 84.80Hz for bimorph beam), and high optimal mechanical and piezoelectric power density (22.30mW/(g2cm3) for unimorph and 29.02mW/(g2cm3) for bimorph beam). This paper studies the characteristics of MEMS-PVEHs by modeling and simulation in COMSOL. Their eigenfrequencies are analyzed firstly, their optimal piezoelectric outputs are explored by changing excitation frequency and load resistance secondly, then the piezoelectric unimorph & bimorph beams are compared finally. The simulation results show that the optimal excitation frequency is slightly higher than the eigenfrequency, and the maximum piezoelectric power of the PVEH can be obtained only when the appropriate excitation frequency and load resistance are selected, and the power generation efficiency is 0.5. By comparing the unimorph and bimorph beams, it is suggested that the unimorph and bimorph MEMS-PVEHs should be designed to improve the piezoelectric output by decreasing resonant frequency and increasing input mechanical power. Finally, the piezoelectric unimorph with double opposite electrodes is designed based on the MEMS fabrication process.
Keywords: Energy harvesting; Piezoelectric; MEMS; Resonant frequency; Power optimization.
Preparation and characterization of nanokaolinite photocatalyst for removal of P-nitrophenol under UV irradiation
by S.M. El-Sheikh, Ahmed Shawky, Sabrin M. Abdo, Mohamed Nageeb Rashed, Thanaa I. El-Dosoqy
Abstract: A nanokaolinite photocatalyst was prepared successfully using intercalating method which depends on insertion of chemical reagent between bulk kaolinite layers followed by delamination process. The as-prepared nanokaolinite photocatalysts were characterized by X-ray diffraction, FTIR analysis, Transmission electron microscope (TEM) and UV-vis diffuse reflectance spectroscopy. XRD data show that the crystals size of exfoliated nanokaolinite in the range ~ 26-32 nm. FTIR peaks assign to presence of nitrogen between nanokaolinite layers, which maybe lead to decrease the band gap of prepared samples. The photocatalytic activity of nanokaolinite photocatalysts was investigated by degradation of PNP under ultra-violet irradiation. The ideal nanokaolinite sample (K/urea) show extraordinary photocatalytic activity (100%) toward PNP within 30 min. due to its enhanced band gap value.
Keywords: Delamination; Kaolinite; phyllosilicates family; Intercalation; Photodegradation; P-nitrophenol; Paper filler; Photocatalytic activity.
Research on processing technology of grinding aspheric workpiece in the five-axis machine tool
by Jianfeng Liu
Abstract: Aspheric optical components have been widely used recently because of their unique advantages. Thus, it is necessary to investigate processing technology of such aspheric parts. In this paper, an aspherical mirror is ground with cup wheel in five-axis CNC (Computer Numerical Control) machine tool and corresponding processes were investigated. To improve machining efficiency and reduce tool wear, the workpiece is firstly ground to be a spherical mirror, and then it is ground to be the aspheric contour. The best fitting spherical mathematical equation is derived by the axisymmetric quadratic aspheric generatrix equation. A aspheric mirror was ground with cup wheel with five-axis CNC (Computer Numerical Control) machine tool. The aspheric curve is processed into a paraboloid shape. The experimental results show that the surface profile of the aspherical lens is consistent with the designed profile, and the PV (Peak Value) value of the error is . Such results can be accepted in consideration of working allowance for polishing. According to the experimental results, the cause of the error was analyzed and methods for improving precision were proposed.
Keywords: five-axis machine tool; cup wheel; aspheric surface; fitting spherical radius.
Study on the influence of spindle vibration on the surface roughness of ultra-precision fly cutting
by Jianpu Xi, Bin Li, Dongxu Ren, Zexiang Zhao, Huiying Zhao
Abstract: Spindle vibration is a key factor influencing the quality of the processed surfaces during ultra-precision fly cutting. An extremely tiny vibration will directly influence the quality of the surface at the nanoscale. Therefore, in this study, a mathematical model of aerostatic spindle vibration under pulsed excitation was established by analyzing the characteristic cutting path of a fly cutter head and the state of the spindle under interrupted cutting force, and then, the axial and radial of the aerostatic spindle to pulses during periodically interrupted fly cutting were calculated using a Fourier series. Under the periodic processing mode of high-speed fly cutting, a simulation and experimental analysis on the spindle vibration were conducted. The experimental results show that the cutting force and spindle speed are major factors influencing surface roughness. According to the simulation and experimental analysis, reliable theoretical guidance is provided for the improvement and prediction of surface quality of an ultra-precision fly cutting.
Keywords: aerostatic spindle; fly cutting; dynamic response; vibration; surface roughness.
Coaxiality Detection Method with Non-adjustment for Installation Errors
by Xin Jin, Qiushuang Zhang, Ke Shang, Yimin Pu, Zhijing Zhang, Huan Guo
Abstract: During the assembly of the engine casing, the coaxiality detection for the two assemblies are essential. And the modern manufacturing industry has put forward higher requirements for the coaxiality measurement with the development of the industrial technology. The existing coaxiality detection methods are mostly based on manual measurements. It takes long time to adjust the axes of assembly parts and turntable to coincide by the current measurement method, which greatly affects production efficiency. To solve the problem, this paper proposes a coaxiality detection method which can compensate assembly installation errors automatically. The coaxiality measurement method based on the position of the assembly is deduced by introducing the measurement mechanism of the coordinate measuring machine. The data processing uses coordinate transformation and least squares fitting method. Experimental verification shows that the method do not need to adjust the assembly part repeatedly, so measuring time is reduced greatly. The method simplifies the measurement steps, and provide supports of methods and techniques for automatic detect.
Keywords: Installation errors; Coaxiality; Non-adjustment; Automation; Detection method.
Submicron Centroid Position Measurement Method of Screw Connected Structure under Temperature Load
by Xiao Chen, Muzheng Xiao, Zifu Wang, Zhijing Zhang, Xin Jin
Abstract: In this paper, a symmetrical fixed structure was designed, and two laser displacement sensors were placed in the two ends of screw connection structure for a real-time measurement. The entire measuring device was placed in a temperature controllable environment to measure the position change of the screw connection structure while temperature load is applied. The centroid position change of screw connection structure was calculated from the measured data. Uncertainty of the measurement method was analyzed which is about 0.1μm. And a measurement experiment was carried out on the design structural. Under the action of a pre-tightening force of 400N and a temperature change of 40℃, the maximum centroid position change of the structure was about 7.4μm. Finally, simulation of the measured structure was carried out to confirmed that the measurement method proposed in this paper is effective.
Keywords: submicron; measurement method; screw connected structures; temperature load; screw pre-tightening force.
Novel green synthesis of silver nanoparticles from newly discovered Putranjivaceae plant leaf extract and their antibacterial studies
by Shareefraza J. Ukkund, Momin Ashraf, Abhinaya Nellerichale, Apoorva B. Udupa, Sapna Kannan, Vinaya B. Koradoor, P. Prasad, Krishanraja Acharya
Abstract: Silver nanoparticles (AgNPs) have been synthesised by many plant extracts so far. In this novel study we have synthesised AgNPs from Putranjivaceae leaf extract. The new plant Putranjivaceae was discovered in 2017 (Krishna et al., 2017) in West Bengal, India. The AgNO3 is treated with the leaf extract and subjected to microwave irradiation to get AgNPs. The nanoparticles were synthesised in just 10 minutes and subjected to characterisation for structural and morphological studies. The synthesis was rapid and shape of nanoparticles found uniform in nature by SEM and TEM analysis observed to of 2025nm. The primary confirmation of AgNPs was done by UV-visible-spectrophotometer and EDAX. The synthesised silver nanoparticles were optimised by several parameters like pH, salinity and substrate concentration to observe the maximum production. The silver nanoparticles were then conjugated with several antibiotics for antibacterial studies out of which erythromycin showed 3 fold increments in its efficiency.
Keywords: Drypetes species; Putranjivaceae leaf extracts; silver nanoparticles; antibacterial studies; UV-visible spectrophotometer.
Study of Silver Nanoparticles activity against He-La Cell Lines
by Shweta Rajawat, M.M. Malik
Abstract: In the present work, poly-dispersed silver nanoparticles (Ag NPs), using principles of green chemistry, are synthesized and their anti-cancer activity against He-La cell lines is studied. The synthesis method is easy, simple, environment friendly and does not require any sophisticated labs. One of the physical synthesis method, electrolytic deposition technique with black tea leaf extract as capping agent, was designed to synthesize silver nanoparticles. Elemental analysis using X-ray patterns show synthesis of highly pure silver nanoparticles. Activity against cell lines was observed in a dose-dependent manner using MTT assay. The IC50 value of sample against He-La cervical cancer cell lines were obtained at 30-fold dilutions of concentration of 178
Keywords: Green Technology; Silver Nanoparticles; He-La cervical cell lines; IC50 values.
Measurement and Compensation Method of Gantry CNC Machine Tool Based on Single Laser Synchronization Method
by Jia Minqiang, Gao Ran, Sun Lei, Guan Qianqian
Abstract: The gantry CNC machine tool has unique structure and characteristic. The gantry machine tool does not always form a symmetrical structure and symmetrical force during the machining process, as well as various uncertainties in the course of operation. The inconsistency will cause a non-synchronized error in the biaxial synchronous system. The no-synchronized error will affect the machining accuracy, cause the beam to be pulled and the gantry frame or drive element to be damaged. Therefore the biaxial synchronization error of the CNC machine tool is one of its most important specifications, and it should be solved firstly when compensating. This paper presents a new method called single laser synchronization method, which bases on the structure and operation characteristics of the gantry CNC machine tool, and puts forward the measurement method and compensation method of positioning error. This new method includes a special optical path layout, a characteristic way of measurement and compensation. This method has some advantages such as high precision, low-cost, efficiency etc.
Keywords: Gantry CNC Machine Tool; Measurement; Compensation; Laser.
Study on grinding damage of high chromium alloy based on molecular dynamics
by Xiaoguang Guo, Xiaoli Wang, Song Yuan, Yang Li, Renke Kang, Zhuji Jin
Abstract: The new cast high chromium alloy is the conventional material of the nuclear main pump thrust-bearing with good wear and corrosion resistance. According to the structural characteristics of high chromium alloy, the simulation model and the coupling potential function were constructed to study the grinding damage layer using molecular dynamics method. The simulation results show that the crystal lattice distortion caused by carbon atoms in the formation of interstitial solid solution leads to the occurrence of amorphous structure after full relaxation. The break and recombination of metal bond and nonmetal bond between atoms in the alloy result in the occurrence of damaged layer under grinding. And the bond angles between the atoms in the damage layer are less than that in the alloy matrix. The damage layer is mainly composed of atoms in front of the abrasive particle and the atoms of extrusion deformation in the bottom. Moreover, with the increase of grinding depth, the cutting force and the damage layer thickness increase. The study is conducive to understand the damage formation mechanism of high-chromium alloy materials in micro-nano processing, and provides a theoretical reference value for the actual processing.
Keywords: Molecular dynamics; High chromium alloy; Nanoscratch; The coupling potential function; The damage layer.
Control of Crystal morphology in Energetic Drop-on-demand Inkjet Method
by Ruirui Zhang, Qi Lehua
Abstract: Nano-energetic materials are attracted the worldwide attention since they play an important role in fabricating insensitive high-energy explosives, micro-energetic devices, and explosive detectors. Here, we report a simple, but an eﬀective strategy to control droplet coalescence during inkjet printing, as a major variable, to tailor the nanoscale morphology of energetic materials produced upon evaporation of all-liquid inks. We expect to achieve energetic materials with nanoscale particles by integrating the deposition and the nanocrystallization of energetic droplets in one step. A proprietary uniform energetic micro-droplet printing equipment is utilized to reveal the influence of temperature, frequency on the particle size of energetic materials. Uniform line, with the particle size between nanometer and microns, is successfully obtained, showing the feasibility of the proposed method for preparing the microscale charge of nano-energetic materials. We also discussed the effect of droplet coalescence on the crystal morphology.
Keywords: uniform droplet injecti；printing parameters; insensitive high-energy explosives ;nanometer explosive; inkjet printing; energetic material; micro-energetic devices; microscale charge; control the particle size; crystal morphology; supersaturation; crystal nucleation and growth; grain refinement.
Study on Point Target Tracking Technology Based on Neural Network
by Xianyu Meng, Change Zeng, Yuxiao Tang, Qiongying Lv, Bing Jia, Shan Xue, Guohua* Cao*
Abstract: There exist some drawbacks when using laser scanning radarto obtain the external ballistic trajectory information of various point targets, such as large coordinate bindingerror, small test window and less measurement pointsunabletoget the real-time feedback of the target position, etc. In order to solve the above issues, a point target tracking method is proposed in this paper based on neural network. By the method, the trajectory point data captured through the two-dimensional scanning galvanometer is used to effectively predict the external ballistic data, and the real-time ballistic calculation method is given.This research work provides an effective theoretical basis for the design of light weapons ballistic scanning radar.
Keywords: coordinate binding;external ballistic; neural network; lidar.
A Novel Technique for Minimization of March Test Using Read Equivalent Stress
by PRINCY P, SIVAMANGAI N.M
Abstract: Static Random Access Memory is popularly used in the cache memories due to its infinite and very fast read/write operations. As technology advances, size of devices shrinks and the percent of manufacturing defects in integrated circuits increases significantly which results in different types of faults. The most crucial part regarding testing is achieving maximum fault coverage with minimal test time. March SR+ is one of the test used frequently in the industry, which has a higher percentage of fault detection with a test length of 18N. In this paper, we propose a novel technique to minimize the test time of March SR+.On this basis, we introduce a more efficient alternative to March SR+. The reformulation of March SR+ is essentially based on introducing a particular addressing sequence and read/write data sequence. This modification does not alter the capability of March SR+ to detect the former target faults, but extends the ability of many conventional March based test solutions in detecting Dynamic Read Destructive Faults (DRDFs)without any test modification. Moreover, fault detection using the proposed methodology results in a significant reduction of 11.1% in test time and 11.04%in average power consumption.
Keywords: SRAM; word line; March AI; DRDF; fault testing; static; conventional; power reduction; march test; read equivalent stress (RES); etc.