International Journal of Nanomanufacturing (8 papers in press)
Research on Non-contact Ultrasonic Vibration Assisted Rotating Electrical Discharge Machining?EDM? Machine Tool
by Yinghuai Dong, Song Jianbao, Li Guangyan, Wang Yan, Xue Wei
Abstract: EDM is a nontraditional machining method by using pulsed spark discharge between workpiece and electrode to melt and remove metal. The traditional power supply method uses carbon brush and slip ring. This contact type has power supply at the contact point. Problems such as carbon deposition, leakage, and easy generation of electric sparks restrict the improvement of the rotation speed of the electrode and pose a safety hazard. The non-contact power supply technology based on the principle of electromagnetic induction can effectively solve the above problems, which can provide conditions for high-speed rotation of the electrode. In order to improve the processing quality and efficiency, this study aimed to design a small ultrasonic vibration assisted EDM machine, which can effectively avoid spark concentration and abnormal arc generation.
Keywords: EDM; electromagnetic induction; non-contact; ultrasonic vibration; EDM machine.
Spectrophotometric determination of buspirone HCl and doxazosin mesylate using citrate-capped silver nanoparticles.
by Magda Ayad, Hisham Ezzat, Mervat Hosny, Naglaa Kabil
Abstract: A simple and rapid spectrophotometric method was developed for determination of buspirone HCl and doxazosin mesylate in bulk and pharmaceutical formulations. In this article silver nanoparticles (Ag-NPs) were prepared chemically using sodium citrate as reducing and stabilizing agent. Silver nanoparticles showed an absorption band at 420 nm. Aggregation of citrate stabilized silver nanoparticles (Ag NPs) were used for quantitative determination of the studied drugs with formation of a new red shifted band at 545, 690 nm for buspirone HCl and doxazosin mesylate respectively. Different experimental factors were optimized and the calibration curves were linear with concentrations of (0.10-0.60 ?g/mL), (5.0-14.0 ?g/mL) for buspirone HCl and doxazosin mesylate respectively. Validation of the analytical performance of the method was carefully investigated, and the results were satisfactory.
Keywords: silver nanoparticles; buspirone HCl and doxazosin mesylate.
Submicron centroid position measurement method of screw connected structure under temperature load
by Xiao Chen, Muzheng Xiao, Zifu Wang, Zhijing Zhang, Xin Jin
Abstract: This paper presents a submicron centroid position measurement method. Two laser displacement sensors are placed in the two ends of a screw connected structure for a real-time measurement. The entire measuring device is placed in a temperature controllable environment to measure the position change of the screw connected structure while temperature load is applied. The centroid position change of screw connected structure is calculated from the measured data. Uncertainty of the measurement method is analysed and a measurement experiment is carried out on the design structure. Under the action of a pre-tightening force about 400 N and a temperature change of 40°C, the maximum centroid position change of the structure is 7.46 μm. Finally, simulation based on surface form error of the measured structure is carried out to confirm 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 20-25nm. 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 three 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 synthesised 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 methods, electrolytic deposition technique with black tea leaf extract as capping agent, was designed to synthesise 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 μg/ml.
Keywords: green technology; silver nanoparticles; He-La cervical cell lines; IC50 values; nanomanufacturing.
Measurement and compensation method of gantry CNC machine tool based on single laser synchronisation method
by Minqiang Jia, Ran Gao, Lei Sun, Qianqian Guan
Abstract: The gantry CNC machine tool has unique structure and characteristic. It does not always form a symmetrical structure and symmetrical force during the machining process. The inconsistency will cause a non-synchronised error in the biaxial synchronous system. The no-synchronised 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 synchronisation 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 synchronisation method, 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; nanotechnology; 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 non-metal 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; coupling potential function; the damage layer.
Control of crystal morphology in energetic drop-on-demand inkjet method
by Ruirui Zhang, Jun Luo, Hongcheng Lian, Lehua Qi
Abstract: Nano-energetic materials have 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 nanocrystallisation of energetic droplets in one step. A proprietary uniform energetic micro-droplet printing equipment is utilised to reveal the influence of temperature, frequency on the particle size of energetic materials. Uniform line, with the particle size between nanometre 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 inkjet printing; printing parameters; insensitive high-energy explosives; nanometre explosive; inkjet printing; energetic material; micro-energetic devices; microscale charge; control the particle size; crystal morphology; supersaturation; crystal nucleation and growth; grain refinement.