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Every production process requires monitoring system, so the desired efficiency and productivity can be monitored at any time. This system is also needed in the job shop type of manufacturing which is mainly influenced by the manufacturing lead time. Processing time is one of the factors that affect the manufacturing lead time. In a conventional company, the recording of processing time is done manually by the operator on a sheet of paper. This method is prone to errors. This paper aims to overcome this problem by creating a system which is able to record and monitor the processing time automatically. The solution is realized by utilizing electric current sensor, barcode, RFID, wireless network and windows-based application. An automatic monitoring device is attached to the production machine. It is equipped with a touch screen-LCD so that the operator can use it easily. Operator identity is recorded through RFID which is embedded in his ID card. The workpiece data are collected from the database by scanning the barcode listed on its monitoring sheet. A sensor is mounted on the machine to measure the actual machining time. The system’s outputs are actual processing time and machine’s capacity information. This system is connected wirelessly to a workshop planning application belongs to the firm. Test results indicated that all functions of the system can run properly. This system successfully enables supervisors, PPIC or higher level management staffs to monitor the processing time quickly with a better accuracy.Every production process requires monitoring system, so the desired efficiency and productivity can be monitored at any time. This system is also needed in the job shop type of manufacturing which is mainly influenced by the manufacturing lead time. Processing time is one of the factors that affect the manufacturing lead time. In a conventional company, the recording of processing time is done manually by the operator on a sheet of paper. This method is prone to errors. This paper aims to overcome this problem by creating a system which is able to record and monitor the processing time automatically. The solution is realized by utilizing electric current sensor, barcode, RFID, wireless network and windows-based application. An automatic monitoring device is attached to the production machine. It is equipped with a touch screen-LCD so that the operator can use it easily. Operator identity is recorded through RFID which is embedded in his ID card. The workpiece data are collected from the database by scanni...

This paper presents a numerical study on prediction of the performance of liquid jet gas ejector. RANS study using the k-e turbulence model has been carried out for an experimental model of ejector as published by researcher in previous paper. This simulation considered a high quality of the structured mesh up to Δy+

The reliability of the crane product in engineering is the core competitiveness of the product. This paper used Monte Carlo method analyzed the reliability of the weld metal structure of the bridge crane whose limit state function is mathematical expression. Then we obtained the minimum reliable welding feet height value for the welds between cover plate and web plate on main beam in different coefficients of variation. This paper provides a new idea and reference for the growth of the inherent reliability of crane.

Graphene oxide, sister material of Graphene has generated tremendous research interest in fields of energy storage, catalyst material, adsorbent material for heavy metals and dyes, green energy production, drug delivery agent, a gas sensing material as well as in membrane based water purification and desalination systems1-3 etc. In this paper, we are reporting the effect of concentration variation in GO membranes on water flux. GO has been synthesized by Hummer’s method with related characterizations like XRD, Raman, SEM and FTIR carried out. GO membranes have been developed using pressure assisted filtration assembly (Water Vac-100) over Cellulose Acetate membrane support (47 mm dia. and 0.45 µm pore size), Millipore.Graphene oxide, sister material of Graphene has generated tremendous research interest in fields of energy storage, catalyst material, adsorbent material for heavy metals and dyes, green energy production, drug delivery agent, a gas sensing material as well as in membrane based water purification and desalination systems1-3 etc. In this paper, we are reporting the effect of concentration variation in GO membranes on water flux. GO has been synthesized by Hummer’s method with related characterizations like XRD, Raman, SEM and FTIR carried out. GO membranes have been developed using pressure assisted filtration assembly (Water Vac-100) over Cellulose Acetate membrane support (47 mm dia. and 0.45 µm pore size), Millipore.

In this paper, an altitude control system is designed to increase the positioning accuracy of a mini-UAV on the z-axis of the inertial system and to improve conventional altitude control systems relying only on GPS, barometer or laser sensors which may have significant errors in certain flight conditions. The main objective of the mini-UAV is to monitor and detect a Corona Discharge that usually occurs on high voltage powerlines which implies a very good infrastructure in terms of on-board equipment because of the danger which occur when UAV flies quite close to the powerlines and into an intense electromagnetic field. To design the altitude controller for the longitudinal dynamics a control structure method, based on successively closed loops with different types of classic controllers was used. We concluded that the command structures with speed constraint was necessary to implement a speed device that automatically maintains a constant speed. Thus, the speed device is trying to maintain a constant speed using the throttle control. After modelling the longitudinal dynamics, numerical simulations were performed in MATLAB, Simulink and the obtained results confirmed a good performance of the proposed control strategy flight altitude control based on the automated speed device.In this paper, an altitude control system is designed to increase the positioning accuracy of a mini-UAV on the z-axis of the inertial system and to improve conventional altitude control systems relying only on GPS, barometer or laser sensors which may have significant errors in certain flight conditions. The main objective of the mini-UAV is to monitor and detect a Corona Discharge that usually occurs on high voltage powerlines which implies a very good infrastructure in terms of on-board equipment because of the danger which occur when UAV flies quite close to the powerlines and into an intense electromagnetic field. To design the altitude controller for the longitudinal dynamics a control structure method, based on successively closed loops with different types of classic controllers was used. We concluded that the command structures with speed constraint was necessary to implement a speed device that automatically maintains a constant speed. Thus, the speed device is trying to maintain a constant spee...

Insulation oils are a vital part in power transformers. Insulation oil is not only work as electrical insulation but also as a coolant inside the transformer. Due to the increasing tight regulations on the environment and safety in recent years, vegetable oils are being considered for insulation oils in power transformer. This paper presents two conditions of Rapeseed Oil (RO), which are as received (new) and dried (dry) under difference uniform field electrodes configuration (mushroom-to-mushroom and sphere-to-sphere) with gap distance at 2.5 mm as recommended by the international standards. A comparative study of AC breakdown voltage, dissipation factor (tan δ), and resistivity under variation of temperature were investigated. The experimental works were done according to the IEC 60156 and IEC 60247 standards. The results indicated that the breakdown voltages of both condition are comparable to mineral oil. The dielectric constant and resistivity of two conditions are decreased along with the increasing temperature. However, the dissipation factor properties rose up along with the temperature. The Weibull distribution was used to determine the withstand voltages at 1% and 50% for RO in two probabilities conditions.Insulation oils are a vital part in power transformers. Insulation oil is not only work as electrical insulation but also as a coolant inside the transformer. Due to the increasing tight regulations on the environment and safety in recent years, vegetable oils are being considered for insulation oils in power transformer. This paper presents two conditions of Rapeseed Oil (RO), which are as received (new) and dried (dry) under difference uniform field electrodes configuration (mushroom-to-mushroom and sphere-to-sphere) with gap distance at 2.5 mm as recommended by the international standards. A comparative study of AC breakdown voltage, dissipation factor (tan δ), and resistivity under variation of temperature were investigated. The experimental works were done according to the IEC 60156 and IEC 60247 standards. The results indicated that the breakdown voltages of both condition are comparable to mineral oil. The dielectric constant and resistivity of two conditions are decreased along with the increasing...

The paper is focused on measurement and evaluation of thermal properties of Ultra High Performance Fiber Reinforced Concrete (UHPFRC). The examined concretes are reinforced with hybrid reinforcement based on combination of steel and polypropylene fibers. The investigated thermal properties are accessed in dependence on temperature, in the temperature interval starting from laboratory temperature up to 1200 °C. The studied materials are measured by the step-wise transient method and the obtained data is mutually compared.The paper is focused on measurement and evaluation of thermal properties of Ultra High Performance Fiber Reinforced Concrete (UHPFRC). The examined concretes are reinforced with hybrid reinforcement based on combination of steel and polypropylene fibers. The investigated thermal properties are accessed in dependence on temperature, in the temperature interval starting from laboratory temperature up to 1200 °C. The studied materials are measured by the step-wise transient method and the obtained data is mutually compared.

2Development of the mmc with fibers and filler materials as a replacement material for some engineering purpose such as automobiles, aerospace are indispensable. Therefore, the studies related to hybrid mmc’s of Al6061 were noted in this paper. In this work, Al6061 reinforced with E glass fibers and micro Titanium particles. Hybrid composites was prepared by very feasible and commercially used technique Stir casting and by varying composition of Al6061, Titanium and E-glass fibre. Experiments were done by varying weight fraction of Titanium (0%, 1%, 3% and 5%) and E glass fibre (0%, 1%, 3% and 5%). Wire EDM were used to prepare the specimens required for tensile and hardness according to standards and tests conducted. The proportion of elements which are present the mmc’s are identified by EDAX. Optical microscopy were conducted by SU3500 machine Scanning Electron Microscope and Microstructure shows the distribution of reinforced Ti particles and E glass fibres. The characterization of Al6061 hybrid mmc’s is having significant impact on the mechanical properties.2Development of the mmc with fibers and filler materials as a replacement material for some engineering purpose such as automobiles, aerospace are indispensable. Therefore, the studies related to hybrid mmc’s of Al6061 were noted in this paper. In this work, Al6061 reinforced with E glass fibers and micro Titanium particles. Hybrid composites was prepared by very feasible and commercially used technique Stir casting and by varying composition of Al6061, Titanium and E-glass fibre. Experiments were done by varying weight fraction of Titanium (0%, 1%, 3% and 5%) and E glass fibre (0%, 1%, 3% and 5%). Wire EDM were used to prepare the specimens required for tensile and hardness according to standards and tests conducted. The proportion of elements which are present the mmc’s are identified by EDAX. Optical microscopy were conducted by SU3500 machine Scanning Electron Microscope and Microstructure shows the distribution of reinforced Ti particles and E glass fibres. The characterization of Al6061 hybrid mmc’s...

This paper presents the preparation of CePO4 and Yb doped CePO4 using simple solid state reaction method. PL measurements indicated significant energy transfer from Ce3+ to Yb3+ ions. Further evidence of energy transfer was provided by analysis of Luminescence Decay measurements. Energy transfer efficiency of 50% was obtained for 5%Yb doping. Energy transfer from Ce3+ to Yb3+ ions takes place by Cooperative energy transfer mechanism. Such phosphors can be used in white LED’s, Lasers and energy saving fluorescent lamps.This paper presents the preparation of CePO4 and Yb doped CePO4 using simple solid state reaction method. PL measurements indicated significant energy transfer from Ce3+ to Yb3+ ions. Further evidence of energy transfer was provided by analysis of Luminescence Decay measurements. Energy transfer efficiency of 50% was obtained for 5%Yb doping. Energy transfer from Ce3+ to Yb3+ ions takes place by Cooperative energy transfer mechanism. Such phosphors can be used in white LED’s, Lasers and energy saving fluorescent lamps.

The generator is one of the tools that used in power system circuit. The working system of electrical generators is converted the mechanical energy from an external source into electrical energy as output. The generator works by exploiting the electric flux generated by a magnetic field that passes through the rotation of the coil on the generator engine. Both of these are things that affect the efficiency level of the generator. If the efficiency of a generator is higher so the electrical energy generated is also greater. In this paper will be analyzed theoretically mathematically to improve the efficiency of the alternating current generator. The analytical review will be performed on magnetic field strength and coil rotation speed. With the increase of these two factors is expected to increase generator efficiency is also increasing so that the electrical energy which is the output of the generator system is also higher.The generator is one of the tools that used in power system circuit. The working system of electrical generators is converted the mechanical energy from an external source into electrical energy as output. The generator works by exploiting the electric flux generated by a magnetic field that passes through the rotation of the coil on the generator engine. Both of these are things that affect the efficiency level of the generator. If the efficiency of a generator is higher so the electrical energy generated is also greater. In this paper will be analyzed theoretically mathematically to improve the efficiency of the alternating current generator. The analytical review will be performed on magnetic field strength and coil rotation speed. With the increase of these two factors is expected to increase generator efficiency is also increasing so that the electrical energy which is the output of the generator system is also higher.

Since Portland cement manufacturing processes are classified among the major reasons which are causing the global warming due the significant amount of carbon dioxide emitted every day. These facts have led the researchers to scrutinize an alternative which is more eco-friendly. In this paper, several experimental attempts were conducted to understand the effect of different of various factors on the strength behavior of fly ash based geopolymer composites.Since Portland cement manufacturing processes are classified among the major reasons which are causing the global warming due the significant amount of carbon dioxide emitted every day. These facts have led the researchers to scrutinize an alternative which is more eco-friendly. In this paper, several experimental attempts were conducted to understand the effect of different of various factors on the strength behavior of fly ash based geopolymer composites.

This paper discusses Ca-doped MgO catalysts using Sol-Gel method. The doping of Ca is expected to increase the basicity of the catalyst. The basicity of catalyst has effect on the monoglycerides production by glycerolysis reaction. The Ca/MgO catalyst was prepared by sol gel method by using solution as a precursor. This method was expected to produce a more homogeneous mixture of Mg and Ca. The catalyst was characterized using X-Ray Diffraction (XRD) and the basicity was analyzed using Hammett titration method. The monoglycerides yield was analyzed using Gas Chromatography Mass Spectrometry (GC/MS). Based on Hammett’s titration method, the basicity value was calculated in which the largest value was obtained by the dopant concentration of 2% Ca and calcination temperature of 800°C. The 2% Ca/MgO catalyst that has the highest basicity value was tested for the production of monoglycerides through glycerolysis reaction. This reaction carried on the conditions of 200°C, the catalyst amount of 0.1% weight of oil, the ratio of glycerol : oil = 3 : 1, reaction time of 3 hours, and stirring speed of 700 rpm. The composition of monoglyceride on oil phase product was 100%, while without catalysts composition was 7.43%.This paper discusses Ca-doped MgO catalysts using Sol-Gel method. The doping of Ca is expected to increase the basicity of the catalyst. The basicity of catalyst has effect on the monoglycerides production by glycerolysis reaction. The Ca/MgO catalyst was prepared by sol gel method by using solution as a precursor. This method was expected to produce a more homogeneous mixture of Mg and Ca. The catalyst was characterized using X-Ray Diffraction (XRD) and the basicity was analyzed using Hammett titration method. The monoglycerides yield was analyzed using Gas Chromatography Mass Spectrometry (GC/MS). Based on Hammett’s titration method, the basicity value was calculated in which the largest value was obtained by the dopant concentration of 2% Ca and calcination temperature of 800°C. The 2% Ca/MgO catalyst that has the highest basicity value was tested for the production of monoglycerides through glycerolysis reaction. This reaction carried on the conditions of 200°C, the catalyst amount of 0.1% weight of o...

This paper reports the feasibility of measuring weak magnetic fields generated by the electrical activity of the heart using a portable tri-axial fluxgate magnetometer inside a magnetically shielded room. Measurement of Magnetocardiogram (MCG) signals could be successfully demonstrated from a healthy subject using a novel set-up involving a reference fluxgate sensor which simultaneously measures the magnetic fields associated with the ECG waveform measured on the same subject. The timing information provided by R wave peaks of ECG recorded by the reference sensor is utilized to generate trigger locked average of the sensor output of the measurement fluxgate, and extract MCG signals in all the three orthogonal directions (X, Y and Z) on the anterior thorax. It is expected that such portable room temperature measurements using fluxgate sensor could assist in validating the direction of the equivalent current dipole associated with the electrical activity of the human heart. This is somewhat difficult in conventional MCG measurements using SQUID sensors, which usually furnish only the z component of the magnetic field and its spatial derivatives.This paper reports the feasibility of measuring weak magnetic fields generated by the electrical activity of the heart using a portable tri-axial fluxgate magnetometer inside a magnetically shielded room. Measurement of Magnetocardiogram (MCG) signals could be successfully demonstrated from a healthy subject using a novel set-up involving a reference fluxgate sensor which simultaneously measures the magnetic fields associated with the ECG waveform measured on the same subject. The timing information provided by R wave peaks of ECG recorded by the reference sensor is utilized to generate trigger locked average of the sensor output of the measurement fluxgate, and extract MCG signals in all the three orthogonal directions (X, Y and Z) on the anterior thorax. It is expected that such portable room temperature measurements using fluxgate sensor could assist in validating the direction of the equivalent current dipole associated with the electrical activity of the human heart. This is somewhat difficult in con...

Optical code-division multiple-access (OCDMA) is considered as a good technique to provide optical layer security. Many research works have been published to enhance optical network security by using optical signal processing. The paper, demonstrates the design of the AWG (arrayed waveguide grating) router-based optical network for spectral-amplitude-coding (SAC) OCDMA networks with Walsh Code to design a reconfigurable network codec by changing signature codes to against eavesdropping. In this paper we proposed a code reconfiguration scheme to improve the network access confidentiality changing the signature codes by cyclic rotations, for OCDMA system. Each of the OCDMA network users is assigned a unique signature code to transmit the information and at the receiving end each receiver correlates its own signature pattern a(n) with the receiving pattern s(n). The signal arriving at proper destination leads to s(n)=a(n).Optical code-division multiple-access (OCDMA) is considered as a good technique to provide optical layer security. Many research works have been published to enhance optical network security by using optical signal processing. The paper, demonstrates the design of the AWG (arrayed waveguide grating) router-based optical network for spectral-amplitude-coding (SAC) OCDMA networks with Walsh Code to design a reconfigurable network codec by changing signature codes to against eavesdropping. In this paper we proposed a code reconfiguration scheme to improve the network access confidentiality changing the signature codes by cyclic rotations, for OCDMA system. Each of the OCDMA network users is assigned a unique signature code to transmit the information and at the receiving end each receiver correlates its own signature pattern a(n) with the receiving pattern s(n). The signal arriving at proper destination leads to s(n)=a(n).

Multi cusp DC arc-discharge hydrogen negative ion (H−) source has been developed for the proton cyclotron applications. The purpose of this study is to understand the dependence of the H− production on the operation parameters and optimize the H− production in the source. In this paper, we focus on the effect of magnetic filter field on the H− volume production. The H− volume production in the source has been numerically calculated in the two case of magnetic filter field by using 3D electron transport code and 0D rate equations. The result has suggest that the effect of magnetic filter field on H− beam current could be explained by the enhanced electron density in the extraction region.Multi cusp DC arc-discharge hydrogen negative ion (H−) source has been developed for the proton cyclotron applications. The purpose of this study is to understand the dependence of the H− production on the operation parameters and optimize the H− production in the source. In this paper, we focus on the effect of magnetic filter field on the H− volume production. The H− volume production in the source has been numerically calculated in the two case of magnetic filter field by using 3D electron transport code and 0D rate equations. The result has suggest that the effect of magnetic filter field on H− beam current could be explained by the enhanced electron density in the extraction region.

In the present paper, the study of electrostatic electron cyclotron parallel flow velocity shear instability in presence of perpendicular inhomogeneous DC electric field has been carried out in the magnetosphere of Saturn. Dimensionless growth rate variation of electron cyclotron waves has been observed with respect to k⊥ ρe for various plasma parameters. Effect of velocity shear scale length (Ae), inhomogeneity (P/a), the ratio of ion to electron temperature (Ti/Te) and density gradient (enρe) on the growth of electron cyclotron waves in the inner magnetosphere of Saturn has been studied and analyzed. The mathematical formulation and computation of dispersion relation and growth rate have been done by using the method of characteristic solution and kinetic approach. This theoretical analysis has been done taking the relevant data from the Cassini spacecraft in the inner magnetosphere of Saturn. We have considered ambient magnetic field data and other relevant data for this study at the radial distance of ∼4.82-5.00 Rs. In our study velocity shear and ion to electron temperature ratio have been observed to be the major sources of free energy for the electron cyclotron instability. The inhomogeneity of electric field caused a small noticeable impact on the growth rate of electrostatic electron cyclotron instability. Density gradient has been observed playing stabilizing effect on electron cyclotron instability.In the present paper, the study of electrostatic electron cyclotron parallel flow velocity shear instability in presence of perpendicular inhomogeneous DC electric field has been carried out in the magnetosphere of Saturn. Dimensionless growth rate variation of electron cyclotron waves has been observed with respect to k⊥ ρe for various plasma parameters. Effect of velocity shear scale length (Ae), inhomogeneity (P/a), the ratio of ion to electron temperature (Ti/Te) and density gradient (enρe) on the growth of electron cyclotron waves in the inner magnetosphere of Saturn has been studied and analyzed. The mathematical formulation and computation of dispersion relation and growth rate have been done by using the method of characteristic solution and kinetic approach. This theoretical analysis has been done taking the relevant data from the Cassini spacecraft in the inner magnetosphere of Saturn. We have considered ambient magnetic field data and other relevant data for this study at the radial distance of...

This paper describes the calibration of the National Standard of Resistance using an Automatic Direct Current Comparator Bridge (DCC Bridge). We will also discuss the various sources of uncertainty in the measurements and their estimations based on Type A and Type B evaluations. Furthermore, we discuss the uncertainty budget and report the results at k = 2 for the coverage probability of approximately 95% for a normal distribution.This paper describes the calibration of the National Standard of Resistance using an Automatic Direct Current Comparator Bridge (DCC Bridge). We will also discuss the various sources of uncertainty in the measurements and their estimations based on Type A and Type B evaluations. Furthermore, we discuss the uncertainty budget and report the results at k = 2 for the coverage probability of approximately 95% for a normal distribution.

This paper reports the preparation and complete Mid-TR analysis of strontium hexaferrite nanoparticles synthesized by using gel to crystallization technique. Citric acid, iron and strontium nitrate were used as starting materials to prepare ultrafine particles by keeping the pH of bath solution at 6-7. The prepared ferrites were heat treated for 5 hrs at 900°C and sample were analyzed by using Fourier transform infrared spectroscopy. Mid-TR analysis reveals the formation of hexagonal phase due to the occurrence of strong absorption frequency band or vibrations of metal-oxygen bond at octahedral and tetrahedral sites.This paper reports the preparation and complete Mid-TR analysis of strontium hexaferrite nanoparticles synthesized by using gel to crystallization technique. Citric acid, iron and strontium nitrate were used as starting materials to prepare ultrafine particles by keeping the pH of bath solution at 6-7. The prepared ferrites were heat treated for 5 hrs at 900°C and sample were analyzed by using Fourier transform infrared spectroscopy. Mid-TR analysis reveals the formation of hexagonal phase due to the occurrence of strong absorption frequency band or vibrations of metal-oxygen bond at octahedral and tetrahedral sites.

A multi-channel isolation power supply is designed for the problems of different MOSFET or IGBT in the non-equipotential circuit in this paper. It mainly includes the square wave generation circuit, the high-frequency transformer and the three-terminal stabilized circuit. The first part is used to generate the 24V square wave, and as the input of the magnetic ring transformer. In the second part, the magnetic ring transformer consists of one input and three outputs to realize multi-channel isolation output. The third part can output different potential and realize non-equal potential function through the three-terminal stabilized chip. In addition, the multi-channel isolation power source proposed in this paper is Small size, high reliability and low price, and it is convenient for power electronic switches that operate on multiple different potentials. Therefore, the research on power supply of power electronic circuit has practical significance.

Steady-state operation of a fusion neutron source (FNS) requires plasma heating and current drive by means of additional power delivered by neutral beams. Six neutral beam injectors (NBI) will provide DEMO-FNS machine with additional heating power up to 30 MW, with neutral particle energy 500 keV. NBI systems developed for ITER can serve as the prototype for DEMO-FNS, as both systems have similar ion source current, with accelerated beam power in ITER NBI (1 MeV) being twice as large as in DEMO-FNS. The paper describes the NBI system with account of its integration to DEMO-FNS tokamak complex.Steady-state operation of a fusion neutron source (FNS) requires plasma heating and current drive by means of additional power delivered by neutral beams. Six neutral beam injectors (NBI) will provide DEMO-FNS machine with additional heating power up to 30 MW, with neutral particle energy 500 keV. NBI systems developed for ITER can serve as the prototype for DEMO-FNS, as both systems have similar ion source current, with accelerated beam power in ITER NBI (1 MeV) being twice as large as in DEMO-FNS. The paper describes the NBI system with account of its integration to DEMO-FNS tokamak complex.

The aim of the paper is to analyze the synchronization phenomenon of a rotating structure composed of three beams attached to a rigid hub. It is assumed in the calculations that one beam is 10% thicker comparing to the remaining ones. Furthermore, two possible variants of excitation are considered: (a) torque given by harmonic function or (b) torque produced by a chaotic oscillator. Next, the equations have been solved numerically and the resonance curves and time series have been analyzed in terms of synchronized motion of the hub and blades of the rotor. The influence of hub’s mass moment of inertia have been checked as well. For the system with chaotic Duffing oscillator Poincare maps have been obtained.The aim of the paper is to analyze the synchronization phenomenon of a rotating structure composed of three beams attached to a rigid hub. It is assumed in the calculations that one beam is 10% thicker comparing to the remaining ones. Furthermore, two possible variants of excitation are considered: (a) torque given by harmonic function or (b) torque produced by a chaotic oscillator. Next, the equations have been solved numerically and the resonance curves and time series have been analyzed in terms of synchronized motion of the hub and blades of the rotor. The influence of hub’s mass moment of inertia have been checked as well. For the system with chaotic Duffing oscillator Poincare maps have been obtained.

Power loss minimization have many advantagess to the distribution system radial among others reduction of power flow in feeder lines, freeing stress on feeder loading, deterrence of power procurement from the grid and also the cost of loss compensating instruments. This paper, presents capacitor and photovoltaic (PV) placement as alternative means to decrease power system losses. The paper aims to evaluate the best alternative for decreasing power system losses and improving voltage profile in the radial distribution system. To achieve the objectives of paper, they are used three cases tested by Electric Transient and Analysis Program (ETAP) simulation. Firstly, it performs simulation of placement capacitor. Secondly, simulated placement of PV. Lastly, it runs simulation of placement capacitor and PV simultaneously. The simulations were validated using the IEEE 34-bus test system. As a result, they proved that the installation of capacitor and PV integration simultaneously leading to voltage profile correction and power losses minimization significantly.

With the progress of China’s nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key components is presented, aiming at revealing the characteristics and rules of finite element modeling of nuclear power valves, and putting forward aprecision control strategy for finite element models for nuclear power valve characteristics analysis.With the progress of China’s nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key compone...

In this paper, we deal with the oblique electromagnetic electron cyclotron (EMEC) waves in the Uranus magnetosphere. The expression of the dispersion relation is plotted by using the method of the feature solution. After the kinetic method, the growth rate and the actual frequency of the EMEC wave are studied theoretically in the Uranian system. NASA, Voyager 2, the observed results of the space detectors show that the spin axes of the planets are abnormally oriented and that there are more particles in the high energy tail of the Uranian magnetospheric plasma. Therefore, this paper uses the Kappa distribution instead of the usual Maxwell distribution. The study extends to the tilt propagation of EMEC waves, which has a change in temperature anisotropy and propagation angle with respect to the direction of the magnetic field. These parameters were found to support the growth rate of EMEC waves. However, the response of the actual frequency of these waves is not the same as the rate of growth in all cases. These results apply to the detailed comparison of planetary studies of the space plasma environment and the magnetosphere system.

Image segmentation methods are essential in computer vision applications. This paper proposes a new algorithm to detect a hand in an image and then to create a convex hull around it. A hand thus detected, via a stationary video camera placed in front of the user, could serve to control robots of various kinds. This goal is achieved by proposing a new process of hand segmentation and recognition utilizing Open CV image processing framework. The algorithm is able to identify hand in the picture and prepare the separated object for gesture recognition. Final implementation was written and verified in the C# language.Image segmentation methods are essential in computer vision applications. This paper proposes a new algorithm to detect a hand in an image and then to create a convex hull around it. A hand thus detected, via a stationary video camera placed in front of the user, could serve to control robots of various kinds. This goal is achieved by proposing a new process of hand segmentation and recognition utilizing Open CV image processing framework. The algorithm is able to identify hand in the picture and prepare the separated object for gesture recognition. Final implementation was written and verified in the C# language.

The Rim-driven Thruster (RDT) is a new type of marine electric thruster proposed in recent years. In this paper, the author proposed a new type of permanent magnet synchronous rim thrust motor (RTM). The motor uses a Halbach array permanent magnet rotor, which can improve the torque density of the propulsion motor by utilizing the unilateral magnetic field of the Halbach array. In this paper, the electromagnetic properties of the motor were measured and compared with that of the ordinary magnetic pole motor through numerical analysis. The results show that at the same power, the new motor can significantly reduce the thickness of the rotor’s permanent magnet and yoke core, and has obvious advantages in power density, moment of inertia, dynamic performance, and cost.

Water mist is a new type of photoelectric interfering material. It can exert a strong interference and shielding effect on infrared light, laser and radar wave through scattering, reflection, refraction and absorption. Based on this, this paper illustrates the application of an artificial high pressure water mist technology in infrared interference system. First, the operating principle of the infrared interference system is introduced. Next, the design principle of self-excited rotary vortex nozzle, the key part of the system, is elaborated. Then, the calculation of the main control parameters of the system is clarified. In the end, the paper verifies interference and shielding effect of the system by experiment. Experiment shows that the interference system can significantly reduce infrared signature of the target, featuring excellent infrared interference performance and high practical value.

This paper aims to reduce inventory levels in the production process as well as to minimize the defective ratios resulting in these processes. This article presents the general use model with a special case. In the general use model, ratios of defectives have been taken at all workstation under consideration as well as the impact of the total cost function of the product. In the special case, the impact of the defective ratios is reduced. It means that the batch size was produced without defects (neglecting the defective ratios) and the impact rates of defective in the batch size. The paper also presented the analytical variations regarding defective rates changing to be fixed at all stages and measuring their impact on the batch size and the total cost of the product. Before that, recycling has been taken into consideration at all workstation under study and then analyzed by the program written. The model in the special case is more efficient, and it reduces costs, while it also reduces the size of the production cycle.This paper aims to reduce inventory levels in the production process as well as to minimize the defective ratios resulting in these processes. This article presents the general use model with a special case. In the general use model, ratios of defectives have been taken at all workstation under consideration as well as the impact of the total cost function of the product. In the special case, the impact of the defective ratios is reduced. It means that the batch size was produced without defects (neglecting the defective ratios) and the impact rates of defective in the batch size. The paper also presented the analytical variations regarding defective rates changing to be fixed at all stages and measuring their impact on the batch size and the total cost of the product. Before that, recycling has been taken into consideration at all workstation under study and then analyzed by the program written. The model in the special case is more efficient, and it reduces costs, while it also reduces the size of the p...

This paper is a proposal of a new device that may be used as a component of natural smoke ventilation systems – an external aerodynamic baffle used to limit the wind effect at the most adverse angle. Natural ventilation is not only affected by the external wind, but also dependent on the angle of wind attack. It has been proven, that at angles between 45° to 60° the performance of such device is the lowest. This is the reason why additional device is proposed – external baffle that could hypothetically increase the performance at chosen angles. The purpose of this paper is to explore this idea by numerical modelling of such external elements on a validated natural ventilator model, with use of ANSYS® Fluent® CFD model.

Geopolymer technology was developed by Joseph Davidovits in 1970s based on reactions among alumino-silicate resources in high alkaline conditions. Geopolymer has been recently gaining attention as an alternative binder for Ordinary Portland cement (OPC) due to its low energy and CO2 burden. The raw materials used for geopolymerization normally contain high SiO2 and Al2O3 in the chemical compositions such as meta-kaoline, rice husk ash, fly ash, bottom ash, blast furnace slag, red mud, and others. Moreover, in this paper, coal bottom ash (CBA) and rice husk ash (RHA), which are industrial and agricultural wastes, respectively, were used as raw materials with high alumino-silicate resources. Both CBA and RHA were mixed with sodium hydroxide (NaOH) solution for 20 minutes to obtain the geopolymer pastes. The pastes were filled in 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room condition for hardening of the geopolymer specimens. After 24 hours, the specimens were removed out of the molds and continuously cured at room condition for 27 days. The geopolymer-based materials were then tested for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). Results indicated that the material can be considered lightweight with volumetric weight from 1192 to 1425 kg/m3; compressive strength at 28 days is in the range of 12.38 to 37.41 MPa; and water absorption is under 189.92 kg/m3.Geopolymer technology was developed by Joseph Davidovits in 1970s based on reactions among alumino-silicate resources in high alkaline conditions. Geopolymer has been recently gaining attention as an alternative binder for Ordinary Portland cement (OPC) due to its low energy and CO2 burden. The raw materials used for geopolymerization normally contain high SiO2 and Al2O3 in the chemical compositions such as meta-kaoline, rice husk ash, fly ash, bottom ash, blast furnace slag, red mud, and others. Moreover, in this paper, coal bottom ash (CBA) and rice husk ash (RHA), which are industrial and agricultural wastes, respectively, were used as raw materials with high alumino-silicate resources. Both CBA and RHA were mixed with sodium hydroxide (NaOH) solution for 20 minutes to obtain the geopolymer pastes. The pastes were filled in 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room condition for hardening of the geopolymer specimens. After 24 hours, the specimens were removed out of the mo...

This paper presents the results of an investigation into the potential application of Natural rubber (NR) containing Carbon Nanotubes (CNTs) by measuring its shear modulus and damping ratio. Four different types of rubber specimens which fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. It is observed that the shear modulus and damping ratio of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs.This paper presents the results of an investigation into the potential application of Natural rubber (NR) containing Carbon Nanotubes (CNTs) by measuring its shear modulus and damping ratio. Four different types of rubber specimens which fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. It is observed that the shear modulus and damping ratio of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs.

Natural circulation has an important role in the safety system of a nuclear reactor. It is part of passive system, which is operated without any external prime mover. The behavior of natural circulation shall be known to be effectively incorporated in the safety system of a nuclear reactor. This paper describes the preliminary results of the study on natural circulation conducted at a vertical rectangular experimental facility FASSIP-01. The RELAP5 code is used to simulate the experiment. The goal is to study the validity of the RELAP 5 model to analyze the natural circulation in FASSIP-01. The simulation could provide a reasonable good results describing the natural circulation established in the rectangular loop of FASSIP-01. However, there are still discrepancies with the experimental results, especially with regard to mass flow rate and temperature distribution in the loop. The model needs be improved and further comprehensive data from experiments are necessitated for better validation, as well.Natural circulation has an important role in the safety system of a nuclear reactor. It is part of passive system, which is operated without any external prime mover. The behavior of natural circulation shall be known to be effectively incorporated in the safety system of a nuclear reactor. This paper describes the preliminary results of the study on natural circulation conducted at a vertical rectangular experimental facility FASSIP-01. The RELAP5 code is used to simulate the experiment. The goal is to study the validity of the RELAP 5 model to analyze the natural circulation in FASSIP-01. The simulation could provide a reasonable good results describing the natural circulation established in the rectangular loop of FASSIP-01. However, there are still discrepancies with the experimental results, especially with regard to mass flow rate and temperature distribution in the loop. The model needs be improved and further comprehensive data from experiments are necessitated for better validation, as well.

In this paper, simulation of double loop mirrors multi-wavelength Brillouin fiber laser utilizing semiconductor optical amplifier based on single mode fiber as gain medium was demonstrated. In optical communications, the fiber laser with nonlinear optical loop mirror multi-wavelength Brillouin fiber laser is expected to play a key role in optical signal processing applications. This paper presents the use of double loop in order to produce a stable multi -wavelength comb signals. This fiber laser configuration was integrated a semiconductor optical amplifier with 0.8A of injected current and polarization controller in both loop mirror placed after a 6km of single mode fiber, a tunable laser sources with different of injected Brillouin pump power from -12 dBm up to 12 dBm are demonstrated. From the results, by using -1 dBm of BP input power, 7 output signals at 1550 nm can be obtained with average optical signal to noise ratio at 22 dB.

Now a day’s rocket engines (air-breathing type) are being used for aerospace purposes but the studies have shown that these are less efficient, so alternatives are being searched for these. Pulse Detonation Engine (PDE) is one such efficient engine which can replace the rocket engines. In this review paper, different researches have been cited. As can be observed from various researches, insertion of obstacles is better. Deflagration to Detonation(DDT) transition process is found to be most important factor. So a lot of researches are being done considering this DDT chamber. Also, the ignition chamber and ejector were found to improve the effectiveness of PDE. The PDE works with a range of Mach 0-4. Flame acceleration is also found to increase the DDT process. Use of valve and valveless engine has also been compared. Various other factors have been focused in this review paper which is found to boost PDE performance.Now a day’s rocket engines (air-breathing type) are being used for aerospace purposes but the studies have shown that these are less efficient, so alternatives are being searched for these. Pulse Detonation Engine (PDE) is one such efficient engine which can replace the rocket engines. In this review paper, different researches have been cited. As can be observed from various researches, insertion of obstacles is better. Deflagration to Detonation(DDT) transition process is found to be most important factor. So a lot of researches are being done considering this DDT chamber. Also, the ignition chamber and ejector were found to improve the effectiveness of PDE. The PDE works with a range of Mach 0-4. Flame acceleration is also found to increase the DDT process. Use of valve and valveless engine has also been compared. Various other factors have been focused in this review paper which is found to boost PDE performance.

Two new studies are summarized in this paper. In the first, we compare recent GPR measurements on the same bridge to those obtained in 2012. The newer measurements use both the 1.6 GHz antenna used in the earlier work and an alternative higher frequency antenna (2.6 GHz). We discuss similarities and differences between the old and new results at 1.6 GHz, and also summarize the effect of the frequency change on the newer measurements. Many factors can contribute to the strength of the GPR echo seen from a given rebar, including the rebar’s length, its distance from and tilt angle relative to the antenna, and the location and size of the metal-loss region. In the second section of the paper we discuss new laboratory measurements to systematically investigate these geometric effects. In 2016 we studied such effects using a simplified measurement setup where only an air layer separated the antenna from the rebar. Here we discuss similar measurements simulating rebar embedded in concrete. For our concrete “phantom” we use a layer of moist sand in between two parallel concrete blocks. When the moisture content is properly chosen, the EM properties of sand are similar to those of cured concrete. The block/sand/block sandwich then serves as a concrete-like medium in which a rebar can be inserted and readily repositioned. Results of GPR measurements using this new sandwich approach are reported and compared with those of the earlier “air layer only” measurements.

This paper introduces the working principle and system constitution of the linear Fresnel solar lithium bromide absorption refrigeration cycle, and elaborates several typical structures of absorption refrigeration cycle, including single-effect, two-stage cycle and double-effect lithium bromide absorption refrigeration cycle A 1.n effect absorption chiller system based on the best parameters was introduced and applied to a linear Fresnel solar absorption chiller system. Through the field refrigerator performance test, the results show: Based on this heat cycle design and processing 1.n lithium bromide absorption refrigeration power up to 35.2KW, It can meet the theoretical expectations and has good flexibility and reliability, provides guidance for the use of solar thermal energy.This paper introduces the working principle and system constitution of the linear Fresnel solar lithium bromide absorption refrigeration cycle, and elaborates several typical structures of absorption refrigeration cycle, including single-effect, two-stage cycle and double-effect lithium bromide absorption refrigeration cycle A 1.n effect absorption chiller system based on the best parameters was introduced and applied to a linear Fresnel solar absorption chiller system. Through the field refrigerator performance test, the results show: Based on this heat cycle design and processing 1.n lithium bromide absorption refrigeration power up to 35.2KW, It can meet the theoretical expectations and has good flexibility and reliability, provides guidance for the use of solar thermal energy.

This paper presents the experimental results of the Cleanergy's C11S solar engine-generator tested in the KTH solar simulator. The paper focuses on the analysis of the thermal performance of the ca ...

Many new superconducting materials have been discovered in recent years. This includes hydrogen sulfide which superconducts at 203 K under high pressure and Fe-As based materials. To this date the copper oxide-based materials remain as the highest transition temperature superconductor under normal pressure. In this paper we discuss the use of nano-sized particle as pinning center in the Ag-sheathed high temperature superconductor tapes to enhance the transport properties. When the size d of the pinning center is between the coherence length ξ and the penetration depth λ (ξ < d < λ), a stronger interaction between the pinning center and flux lines leading to higher transport critical current density, Jc can be expected. The effect of nanoparticle with size between the coherence length and the penetration depth i.e. ξ < d < λ, Co3O4 on superconductor tapes is discussed in this paper. Three types of Bi(Pb)-Sr-Ca-Cu-O starting materials namely from co-precipitation method without Co3O4 and with 30 nm and 50 n...

There are many important roles of the orthotic insoles, such as for the convenience purpose of diabetic patient’s foot problem, and also to enhance athlete’s performance in sports. Therefore, highly customised insoles were in demand, where it has to be fabricated by moulding plaster of Paris on the person’s leg to customise the insole. The main purpose of the paper is to study the ability to implement additive manufacturing technology in the fabrication process of customised orthotics insole. The recent invention of flexible material (Filaflex) in Fused Deposition Modelling is the most significant reason that makes this fabrication process possible. By implementing a new approach to the 3D scanning of the foot, we produced the computer-aided drafting (CAD) drawing which was able to modify to desired shape and dimension. After the editing has been completed, the file was converted to Stereolithography format file (STL) as to enable it to be printed using Makerware or any other related software by sending command (G-code) to Flashforge 3D printer. The printed insole was tested its fit, form and function (also known as 3F). In the end, printed insole performs the function test which measures the plantar pressure of the foot compared with bare foot. The results show that the insole distributes pressure well throughout the foot surface, in which it reduced the peak pressure to half from 218KPa to 109KPa. Hence, it is concluded that the method proposed in this paper can produce a functional insole so that it can be the alternative way to make customised orthotic insoles.

In this paper, considering the traditional reactive power optimization cannot realize the continuous voltage adjustment and voltage stability, a dynamic reactive power optimization strategy is proposed in order to achieve both the minimization of network loss and high voltage stability with wind power. Due to the fact that wind power generation is fluctuant and uncertain, electrical equipments such as transformers and shunt capacitors may be operated frequently in order to achieve minimization of network loss, which affect the lives of these devices. In order to solve this problem, this paper introduces the derivation process of analytical impedance ratio based on Thevenin equivalent. Thus, the multiple objective function is proposed to minimize the network loss and analytical impedance ratio. Finally, taking the improved IEEE 33-bus distribution system as example, the result shows that the movement of voltage control equipment has been reduced and network loss increment is controlled at the same time, wh...

Air filtration system plays an important role in getting good quality air into turbo machinery such as gas turbine. The filtration system and filters improve the quality of air and protect the gas turbine parts from contaminants which could bring damage. This paper is focused on the configuration of the self-cleaning canister filter in order to obtain the minimal pressure drop along the filter. The configuration includes a modified canister filter cap that is based on the basic geometry that conforms to industry standard. This paper describes the use of CFD to simulate and analyze the flow through the filter. This tool is also used to monitor variables such as pressure and velocity along the filter and to visualize them in the form of contours, vectors and streamlines. In this study, the main parameter varied is the inlet velocity set in the boundary condition during simulations, which are 0.032, 0.063, 0.094 and 0.126 m/s respectively. The data obtained from simulations are then validated with reference ...

This paper reviews and explains the potential of more applicable geopolymer binder for use. This method is called: “Dry Mixing Method of Geopolymer Binder-Cement Geopolymer”. The mean is that the geopolymer binder is presented in a dry form (like cement powder), which is contains some solid alkali activator and pozzolan materials. How to use it exactly the same as mixing portland cement in general. Through this dry mixing method, it is expected to create a new industry that produces geopolymer cement. With the presence of geopolymer cement, people no longer need to calculate the composition of molarity ratio of the chemicals in the form of the activator alkali solution and pozzolan materials commonly used (wet method of geopolymer binder). In this paper the author will briefly explain the concept in calculating the composition of dry mixing method of geopolymer binder

In order to adapt to the dynamical changeable channel condition and improve the transmissive reliability of the system, a cooperation system of rate-compatible low density parity check (RC-LDPC) codes combining with multi-relay selection protocol is proposed. In traditional relay selection protocol, only the channel state information (CSI) of source-relay and the CSI of relay-destination has been considered. The multi-relay selection protocol proposed by this paper takes the CSI between relays into extra account in order to obtain more chances of collabration. Additionally, the idea of hybrid automatic request retransmission (HARQ) and rate-compatible are introduced. Simulation results show that the transmissive reliability of the system can be significantly improved by the proposed protocol.In order to adapt to the dynamical changeable channel condition and improve the transmissive reliability of the system, a cooperation system of rate-compatible low density parity check (RC-LDPC) codes combining with multi-relay selection protocol is proposed. In traditional relay selection protocol, only the channel state information (CSI) of source-relay and the CSI of relay-destination has been considered. The multi-relay selection protocol proposed by this paper takes the CSI between relays into extra account in order to obtain more chances of collabration. Additionally, the idea of hybrid automatic request retransmission (HARQ) and rate-compatible are introduced. Simulation results show that the transmissive reliability of the system can be significantly improved by the proposed protocol.

In LED-based visible light communication, the choice of light source device is an important issue. In this paper, the frequency response (FR) of different types of blue LEDs and phosphors is measured. On the basis of that, this paper proposes the FR model of phosphor and supplements the FR model of blue LED. And also, a method is proposed to calculate the FR of phosphor coated LEDs using FR of blue LED and that of phosphor. On this basis, this paper analyses the influencing factors of the FR of blue LED and FR of phosphor respectively. It provides guidance for not only selecting the light source device but also selecting and blending phosphor in visible light communication based on LED.

Solar power, as alternative renewable energy source, has gained momentum in global energy generation in recent time. Solar photovoltaics (PV) systems now fulfill a significant portion of electricity demand and the capacity of solar PV capacity is growing every year. PV cells efficiency has improved significantly following decades of research, evolving into third generations of PV cells. These third generation PV cells are set out to provide low-cost and efficient PV systems, further improving the commercial competitiveness of solar energy generation. Among these latest generations of PV cells, perovskite solar cells have gained attraction due to the simple manufacturing process and the immense growth in PV efficiency in a short period of research and development. Despite these advantages, perovskite solar cells are known for the weak stability and decomposition in exposure to humidity and high temperature, hindering the possibility of commercialization. This paper will discuss the role of carbon nanotubes (CNTs) in improving the efficiency and stability of perovskite solar cells, in various components such as perovskite layer and hole transport layer, as well as the application of CNTs in unique aspects. These includes the use of CNTs fiber in making the perovskite solar cells flexible, as well as simplification of perovskite PV production by using CNT flash evaporation printing process. Despite these advances, challenges remain in incorporation CNTs into perovskite such as lower conversion efficiency compared to rare earth metals and improvements need to be made. Thus, the paper will be also highlighting the CNTs materials suggested for further research and improvement of perovskite solar cells.

In this paper we present construction and analysis of nuclear micro battery driven by Strontium 90 (Sr-90). Our design based on charge deposition on the plates of a capacitor and polarization of dielectric materials between the plates. In the construction we have used liquid Sr-90 with activity 100 mCi in cylindrical ampoule coiled up by thin film graphene as one plate and Manganase dioxide (MnO2) as other plate of the capacitor. A dielectric material (paper) is inserted between the plates. The high energetic beta particles from the Sr-90 penetrate graphene to produce ionization and then electrons are removed from graphene to dielectric material. Electrons inside the dielectric material cause polarization of dipoles. Consequently the radiation from the isotope produces an external current. We discuss effect of beta particles on dielectrics and electrodes beside advantage and disadvantage of a battery of this type.

In accordance with the problem such as isolated subsystems, weak system linkage and expansibility of the bus type buildings management system, this paper based on the modern intelligent buildings has studied some related technologies of the intelligent buildings and internet of things, and designed system architecture of the intelligent buildings based on the Internet of Things. Meanwhile, this paper has also analyzed wireless networking modes, wireless communication protocol and wireless routing protocol of the intelligent buildings based on the Internet of Things.

This research is an approach to improve the surface roughness for acrylic door panel by using polishing process. The polishing process involve is sanding process by 3 types of sand paper. The sanding process used to improve the surface roughness by using the different grit sizes of sand paper. The experiment was done by using two types of material s, that is plywood and medium density board (MDF). These two materials are the main materials in producing the arcrylic door panel. The surface roughness of these two materials affects the qualities and quantities of the acrylic door panel. The surface structure was measured by using Optical Microscope and Scanning Electron Microscope (SEM) and the surface roughness was measured by using Mitutoyo surfest SJ 400 Tester. Results indicates that using the different types of grit are influence the surface roughness of the material. When the higher types of grit sizes had been used, the average roughness of the surface are decrease. In summary, a good surface roughness condition produced when using the higher types of grit sizes sand paper.

LS-type screw conveyor has been extensively used in the transportation of powder coal mine. Reasonable selection and design of the structure and parameters of conveyor body is the most significant for the transportation of powder coal mine. The whole structure and the working principle of the LS-type screw conveyor were introduced in the paper. And then the design and calculation formula of key components on LS-type spiral conveyor body, such as screw shaft, spiral blade and intermediate bearing are given. This paper makes a further research on design of key components on LS-type spiral conveyor, providing theoretical basis for the application of the screw conveyor in powder coal mine.

The paper reviews the publications on low-frequency vibration in power plants. It is noted that the regulatory literature poorly defines the issues of rating and diagnosing self-excited and subharmonic vibrations. Analysis of the literature and ISO standards shows that despite the considerable experience gained by specialists in low-frequency vibration control, a number of issues, such as subharmonic resonances and nonlinear properties of complicated multi-seated rotor systems supported by journal bearings, are still understudied and require further calculations and experiments. The paper presents some results obtained in experiments of low-frequency vibrations for a rotor supported by journal bearings and having a residual deflection. The experimental results confirmed the classical hysteresis of self-excited vibrations – the difference in the boundaries of self-excited vibrations during ascent and descent is about 4 Hz. The arears of appearance and disappearance of subharmonic vibrations are shown using the spectral characteristics of vibrations and cascade spectra.