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The advent of Automated Fiber Placement (AFP) systems have aided the rapid manufacturing of composite aerospace structures. One of the challenges that AFP systems bring is the variability of the deposited prepreg tape layers, which are prone to gaps, overlaps and twists. The current detection method used in industry involves halting fabrication and performing a time consuming visual inspection of each tape layer. Typical AFP systems use a quartz lamp to heat the base layer to make the surface tacky as it deposits another tape layer. The innovation discussed in this paper is to use the preheated base layer as a through transmission heat source and inspect the newly added tape layer in situ using a thermographic camera mounted onto the AFP structure. Such a system would not only increase manufacturing throughput by reducing inspection times, but would also aid in process development for new structural designs or material systems. To this end, a small thermal camera was mounted onto an AFP robotic research platform at NASA, and thermal data was collected during typical and experimental layup operations. The data was post processed to reveal defects such as tow overlap/gap, wrinkling, and peel-up. Defects that would have been impossible to detect visually were also revealed in the data, such as poor/loss of adhesion between plies and the effects of vacuum debulking. This paper will cover the results of our experiments, and the recent progress on the data reduction algorithms in preparation for machine learning development.

Operator support systems are extensively studied and developed to support human operators for their activities in especially an abnormal condition of a nuclear power plant. By the advancement of computer technology and artificial intelligence, an operator support system can provide detailed support information based on detailed models and utilizing detailed simulation of plant dynamics and/or complicated inference algorithms. However, human operators may not understand the detailed support information under high mental pressure in an abnormal plant condition. In such a case, it is important how to provide essential and understandable support information. This paper deals with a technique to simplify functional models in order to display operator support information that is generated based on detailed functional models. This paper defines eight cognitive states of human operators from the viewpoint of cognitive abilities of human. In addition, three ways to simplify functional models are identified.

The aim of the paper is to present a regulation and control model of the two link manipulator end effector position. Attention is paid to kinematic and dynamic analysis of the manipulator. Then the simulation model with a control algorithm of its end effector position is proposed. MSC Adams Control Toolkit is used for computer simulation. Finally the results of the simulation are presented in graphical form. An example of a robot model that will be the objective of the solution in the paper consists of two members. The industrial robot can be considered as an open chain mechanism consisting of rigid links and joints. The movable arms are mounted on a solid base ensuring its stability in operation. A working tool, in our case a basket, is fixedly connected to the movable upper arm. Our aim is to describe the movement of the basket of the end member. The control of the position of the end member was performed by the MSC Adams program, which offers the possibility to build a control system and also the possibility of using regulator. In this case a proportional regulator with Kp gain is used. The stability of the basket is eliminated by the control circuit by applying a balancing torque that allows the basket to stabilize during movement. For the control system a feedback control circuit is provided. The regulator controls the equalization torque to keep the basket in a horizontal position during arm rotation. The aim was also to obtain results from the manipulation of the robot’s end effector and to prove the ability and functionality of the designed balancing torque controller. The course of the current and desired angle while moving by trajectory is displayed graphically.The aim of the paper is to present a regulation and control model of the two link manipulator end effector position. Attention is paid to kinematic and dynamic analysis of the manipulator. Then the simulation model with a control algorithm of its end effector position is proposed. MSC Adams Control Toolkit is used for computer simulation. Finally the results of the simulation are presented in graphical form. An example of a robot model that will be the objective of the solution in the paper consists of two members. The industrial robot can be considered as an open chain mechanism consisting of rigid links and joints. The movable arms are mounted on a solid base ensuring its stability in operation. A working tool, in our case a basket, is fixedly connected to the movable upper arm. Our aim is to describe the movement of the basket of the end member. The control of the position of the end member was performed by the MSC Adams program, which offers the possibility to build a control system and also the possi...

Today’s scenario shows that mostly everywhere especially automotive industry prefers to use lightweight materials to increase the efficiency of vehicles. Fiber Reinforced Thermoplastics (FRT) are the commonly used composites for this purpose due to their abundant availability, cheaper, lighter than metals, non-corrosive and also satisfactorily efficient etc.. For injection molded parts, glass and carbon fibers are the commonly used ones to enhance their mechanical and thermal properties. The orientation of fibers in the parts plays a vital role in making the mechanical properties better. In this work, manual polishing and scanning technique using an optical microscope is implemented to observe the flow pattern of the fibers. The samples are injection-molded products of Polypropylene (PP) reinforced with 50% and 40% weightage of long glass fibers in it. The glass fibers have an average length of 25 mm and average diameter of 17 µm are reinforced with polypropylene in the form of pellets and are used in the injection molding machine to form the product. The sample cut out of the product is then put inside the PMMA, polished and scanned in the cross-sectional direction to see the flow of fibers in the composite. Using 5 grinding papers and 2 polishing papers, the sample is polished using a grinder-polisher. The polished samples are scanned under an optical microscope layer by layer and the microscope is operated using a software, ‘pylon viewer’. The scanned images show the fibers’ flow layer by layer throughout the part. Defects like-fiber bundles, voids and weld lines in the samples are discovered during the work. The flow phenomenon of fibers is observed in all the layers and there is no layered structure and the fibers are randomly oriented in-plane. The flow phenomenon is more likely to be plug flow.Today’s scenario shows that mostly everywhere especially automotive industry prefers to use lightweight materials to increase the efficiency of vehicles. Fiber Reinforced Thermoplastics (FRT) are the commonly used composites for this purpose due to their abundant availability, cheaper, lighter than metals, non-corrosive and also satisfactorily efficient etc.. For injection molded parts, glass and carbon fibers are the commonly used ones to enhance their mechanical and thermal properties. The orientation of fibers in the parts plays a vital role in making the mechanical properties better. In this work, manual polishing and scanning technique using an optical microscope is implemented to observe the flow pattern of the fibers. The samples are injection-molded products of Polypropylene (PP) reinforced with 50% and 40% weightage of long glass fibers in it. The glass fibers have an average length of 25 mm and average diameter of 17 µm are reinforced with polypropylene in the form of pellets and are used in the...

Combining such methods of plasma registration as spectral, probe and optical diagnostics, in this paper propagation of laser plasma in a vacuum magnetic field was studied. By means of Langmuir and magnetic probes such plasma parameters as velocity and the angle of expansion were measured, as well as the size of magnetic cavity. Using optical monochromator combined with CCD a Doppler broadening of a number of ionic and atomic lines was measured and the transversal speed of the plasma cloud expansion was calculated. The data plasma cloud propagation velocity and expansion angle obtained by two methods was compared with gated imaging data and magnetic probe measurements of cavity size.Combining such methods of plasma registration as spectral, probe and optical diagnostics, in this paper propagation of laser plasma in a vacuum magnetic field was studied. By means of Langmuir and magnetic probes such plasma parameters as velocity and the angle of expansion were measured, as well as the size of magnetic cavity. Using optical monochromator combined with CCD a Doppler broadening of a number of ionic and atomic lines was measured and the transversal speed of the plasma cloud expansion was calculated. The data plasma cloud propagation velocity and expansion angle obtained by two methods was compared with gated imaging data and magnetic probe measurements of cavity size.

The surrounding environment of overhead transmission lines is complex and changeable, which often causes short circuit trip because of the foreign objects such as kite, colored ribbon and plastic film. It brings serious threat to the security of power grid and causes great economic loss. In this paper, an advanced laser distance removing method is proposed in this paper, which can quickly and reliably remove the foreign objects on the line. In this paper, the principle analysis of overhead line laser removal is carried out, and the comparison test results with different lasers of different kinds of lasers are carried out, and the optimal selection scheme of laser is obtained. Laser aiming technology, cooling technology and safety guarantee measures are developed. It has high application value for removing obstacles from overhead lines.

We proposed the design of a respiration system based on laser reflection for an infant incubator that is able to continuously operate. The device consists of a laser diode (λ=650 nm; P=5 mW), a paper reflector, photodiode array as a detector, comparator, microcontroller Arduino UNO R3, and LCD. Also, there is a buzzer for anticipating emergency situations such as apnea. It utilizes the reflection of laser light on paper reflector attached to an infant simulator. Next, the reflection will be received by photodiode array and comparator which connects to the Arduino UNO R3. Then, the result was displayed on an LCD. From the experiment results, it was indicated that the system could measure respiratory rate from 10 up to 70 breaths per minute with an error of 2.357%.

In this paper, we propose and study a time-delay compartmental model for human immunodeficiency virus (HIV) transmission, a disease which may lead to an advanced stage of infection called acquired immunodeficiency syndrome (AIDS), in a sexually active population with the presence of media coverage. The inclusion of vertical transmission in the recruitment of infected individuals is also considered. Moreover, two time delays are incorporated in the model. One delay τ1 covers the period from the time of gathering statistical data on the total number of infections in the community up to the time that these information are reported to the public through media. The other delay τ2 corresponds to the period that an infected newborn baby reaches the age of sexual maturity. If the threshold value R0 < 1, then the only equilibrium point is the disease-free equilibrium which is globally asymptotically stable. If the threshold values R0 and R00 are both greater than 1, then a unique endemic equilibrium exists, which is globally asymptotically stable when media coverage is not considered. When there is no vertical transmission but media coverage is considered, the system undergoes a Hopf bifurcation at some critical value of the media delay. Numerical simulations are presented to illustrate theoretical results.In this paper, we propose and study a time-delay compartmental model for human immunodeficiency virus (HIV) transmission, a disease which may lead to an advanced stage of infection called acquired immunodeficiency syndrome (AIDS), in a sexually active population with the presence of media coverage. The inclusion of vertical transmission in the recruitment of infected individuals is also considered. Moreover, two time delays are incorporated in the model. One delay τ1 covers the period from the time of gathering statistical data on the total number of infections in the community up to the time that these information are reported to the public through media. The other delay τ2 corresponds to the period that an infected newborn baby reaches the age of sexual maturity. If the threshold value R0 < 1, then the only equilibrium point is the disease-free equilibrium which is globally asymptotically stable. If the threshold values R0 and R00 are both greater than 1, then a unique endemic equilibrium exists, which ...

This paper presents investigation results on effect of neutron irradiation embrittlement on cyclic hardening behavior of core shroud assembly in pressurized water reactor under beyond-design basis earthquake (BDBE). In order to simulate the cyclic hardening behavior considering the neutron irradiation embrittlement, the previous user subroutines developed for monotonic hardening behavior were updated based on some cyclic hardening test results of irradiation-simulated specimens. Finite element (FE) elastic-plastic seismic analysis was performed by using Chaboche combined hardening models considering cyclic hardening or cyclic softening and a bi-linear kinematic hardening model. As a result, it is found that the bi-linear kinematic hardening model derived the most conservative results, and the Chaboche combined hardening model considering cyclic softening derived the analysis results close to those of the bi-linear kinematic hardening model. In addition, variation of the FE elastic-plastic seismic analysis results vs. neutron irradiation dose was investigated using the bi-linear kinematic hardening model. Finally, it is identified that von-Mises effective stress and plastic strain energy increase and equivalent plastic strain decreases with increasing the neutron irradiation dose.This paper presents investigation results on effect of neutron irradiation embrittlement on cyclic hardening behavior of core shroud assembly in pressurized water reactor under beyond-design basis earthquake (BDBE). In order to simulate the cyclic hardening behavior considering the neutron irradiation embrittlement, the previous user subroutines developed for monotonic hardening behavior were updated based on some cyclic hardening test results of irradiation-simulated specimens. Finite element (FE) elastic-plastic seismic analysis was performed by using Chaboche combined hardening models considering cyclic hardening or cyclic softening and a bi-linear kinematic hardening model. As a result, it is found that the bi-linear kinematic hardening model derived the most conservative results, and the Chaboche combined hardening model considering cyclic softening derived the analysis results close to those of the bi-linear kinematic hardening model. In addition, variation of the FE elastic-plastic seismic analysis...

This paper describes a simple and quick method to determine the concentrations of aqueous solutions using a Broad Side Coupled Split Ring Resonator (BCSRR) metamaterial structure operating at microwave frequencies. A capillary tube is placed between the symmetrically arranged BCSRR rings fabricated on two separate strips of the same substrate in such a way that the sample comes along the split-gap of the rings where the field concentration is maximum. As the sample liquid enters to the capillary tube, a resonance frequency shift is observed with respect to the variation in concentration. Resonance frequency shifts of the BCSRR due to varying concentrations (0-2 M) of Sodium Chloride (NaCl) and Potassium Chloride (KCl) solutions are measured using Vector Network Analyser (VNA) by arranging the transmitting and receiving probes of the VNA on the two sides of the BCSRR test setup.This paper describes a simple and quick method to determine the concentrations of aqueous solutions using a Broad Side Coupled Split Ring Resonator (BCSRR) metamaterial structure operating at microwave frequencies. A capillary tube is placed between the symmetrically arranged BCSRR rings fabricated on two separate strips of the same substrate in such a way that the sample comes along the split-gap of the rings where the field concentration is maximum. As the sample liquid enters to the capillary tube, a resonance frequency shift is observed with respect to the variation in concentration. Resonance frequency shifts of the BCSRR due to varying concentrations (0-2 M) of Sodium Chloride (NaCl) and Potassium Chloride (KCl) solutions are measured using Vector Network Analyser (VNA) by arranging the transmitting and receiving probes of the VNA on the two sides of the BCSRR test setup.

The magnificent increase in the performance of integrated circuits is made possible by semiconductor Physics. Due to very large-scale integration, scaling has approached its fundamental limits, which is the biggest challenge for the semiconductor industry. Therefore, in the recent years researchers across the globe are focusing on emerging field of spintronics. In this thrust area of spintronics research, spin field effect transistor (s-FET) is an extensively studied device. In literature, researchers have studied and optimized two main types of spin field effect transistors namely Ballistic and Non-Ballistic spin-field effect transistors. This research paper has presented the recent developments in the field of Ballistic and Non-Ballistic spin-field effect transistors. This paper has briefly explained the approach to design, development and fabrication of s-FET by taking a case study. Firstly, the spin field effect transistor was proposed by Datta–Das, which has proved to be the milestone in the area of spintronic technology. Mainly, spin transistor is prepared using a ballistic semiconductor, sandwiched between ferromagnetic metallic source and drain contacts.The magnificent increase in the performance of integrated circuits is made possible by semiconductor Physics. Due to very large-scale integration, scaling has approached its fundamental limits, which is the biggest challenge for the semiconductor industry. Therefore, in the recent years researchers across the globe are focusing on emerging field of spintronics. In this thrust area of spintronics research, spin field effect transistor (s-FET) is an extensively studied device. In literature, researchers have studied and optimized two main types of spin field effect transistors namely Ballistic and Non-Ballistic spin-field effect transistors. This research paper has presented the recent developments in the field of Ballistic and Non-Ballistic spin-field effect transistors. This paper has briefly explained the approach to design, development and fabrication of s-FET by taking a case study. Firstly, the spin field effect transistor was proposed by Datta–Das, which has proved to be the milestone in the area of ...

Combined cycle power plants are often used to produce power. These days prediction of power plant output based on operating parameters is a major concern. This paper presents an approach to using computational intelligence technique to predict the output power of combined cycle power plant. Computational intelligence techniques have been developed and applied to many real world problems. In this paper, tree architectures of fuzzy neural networks are considered to predict the output power. Tree architectures of fuzzy neural networks have an advantage of reducing the number of rules by selecting fuzzy neurons as nodes and relevant inputs as leaves optimally. For the optimization of the networks, two-step optimization method is used. Genetic algorithms optimize the binary structure of the networks by selecting the nodes and leaves as binary, and followed by random signal-based learning further refines the optimized binary connections in the unit interval. To verify the effectiveness of the proposed method, combined cycle power plant dataset obtained from the UCI Machine Learning Repository Database is considered.

In this paper, we present the theoretical study of double electromagnetically induced transparency (EIT) in a four-level V-type system which is formed by two co-propagating laser fields and the Zeeman sublevels of hyperfine transitions of 87Rb D2 line. The density matrix equations for the four-level V-type system are derived from the Liouville’s equation of motion and numerically solved under steady state condition to get the EIT signals. We consider both the probe and pump transmission spectra for the observation of double EIT signals under both Doppler free and Doppler broadened conditions. In case of Doppler free medium, two EIT peaks are formed in the two Lorentzian shape dips present in the both Doppler free probe and pump transmission spectra. When the medium becomes Doppler broadened, the two EIT peaks are formed in the probe transmission spectrum having Doppler broadened background, but the pump transmission spectrum gives two EIT peaks in the Doppler free background. The effect of probe intensity variation on the two EIT peaks is studied in case of Doppler broadened probe transmission spectrum. It is found that the heights of the EIT peaks decrease as the probe intensity increases, and interestingly one EIT peak converts into EIA (electromagnetically induced absorption) dip at some strong probe intensity value. The depth of the EIA dip is significantly increased as the intensity of the probe field increases. We also present the effect of probe intensity variation on the EIT peaks in the pump transmission spectrum and found that the EIT peak heights are increased as the probe intensity increases.In this paper, we present the theoretical study of double electromagnetically induced transparency (EIT) in a four-level V-type system which is formed by two co-propagating laser fields and the Zeeman sublevels of hyperfine transitions of 87Rb D2 line. The density matrix equations for the four-level V-type system are derived from the Liouville’s equation of motion and numerically solved under steady state condition to get the EIT signals. We consider both the probe and pump transmission spectra for the observation of double EIT signals under both Doppler free and Doppler broadened conditions. In case of Doppler free medium, two EIT peaks are formed in the two Lorentzian shape dips present in the both Doppler free probe and pump transmission spectra. When the medium becomes Doppler broadened, the two EIT peaks are formed in the probe transmission spectrum having Doppler broadened background, but the pump transmission spectrum gives two EIT peaks in the Doppler free background. The effect of probe intensity...

An intense short pulse laser through dense plasma expels electrons and ions from the focal spot by the ponderomotive pressure and forms a channel, which acts as a propagation guide for the laser beam. Transport properties of electrons has been observed in the direction of laser propagation for different ramped profile plasma. Based on this analogy in the present paper we make an analytical investigation of intense laser plasma interaction studies with dense plasma. For the given values of plasma frequency and laser frequency, propagation of laser beam are characterized by dimensionless beam width parameter. The variation of beam width with distance of propagation has been obtained for typical values of parameters in ramped density plasma.An intense short pulse laser through dense plasma expels electrons and ions from the focal spot by the ponderomotive pressure and forms a channel, which acts as a propagation guide for the laser beam. Transport properties of electrons has been observed in the direction of laser propagation for different ramped profile plasma. Based on this analogy in the present paper we make an analytical investigation of intense laser plasma interaction studies with dense plasma. For the given values of plasma frequency and laser frequency, propagation of laser beam are characterized by dimensionless beam width parameter. The variation of beam width with distance of propagation has been obtained for typical values of parameters in ramped density plasma.

Spherical Tokamak (ST) path to Fusion has been proposed [1] and experiments on STs demonstrated feasibility of this approach. Advances in High Temperature Superconductor technology [2] allows significant increase in the toroidal field (TF) which was found to improve confinement in STs. The combination of the high normalised plasma pressure, β, which has been achieved in STs [3], and high TF that can be produced by HTS TF magnets, opens a path to lower-volume fusion reactors, in accordance with the fusion power scaling proportional to β2Bt4V. Modular approach then becomes an alternative to high power, GW-scale Fusion reactors [4,5]. Feasibility of low-power compact ST reactor module and physics and engineering challenges of the accelerated, ST path to Fusion Power are discussed in this paper, on example of the first our prototype on this route, high-field compact spherical tokamak ST40.Spherical Tokamak (ST) path to Fusion has been proposed [1] and experiments on STs demonstrated feasibility of this approach. Advances in High Temperature Superconductor technology [2] allows significant increase in the toroidal field (TF) which was found to improve confinement in STs. The combination of the high normalised plasma pressure, β, which has been achieved in STs [3], and high TF that can be produced by HTS TF magnets, opens a path to lower-volume fusion reactors, in accordance with the fusion power scaling proportional to β2Bt4V. Modular approach then becomes an alternative to high power, GW-scale Fusion reactors [4,5]. Feasibility of low-power compact ST reactor module and physics and engineering challenges of the accelerated, ST path to Fusion Power are discussed in this paper, on example of the first our prototype on this route, high-field compact spherical tokamak ST40.

Crude oil consumption is about 201.90 MMT in India for 2017-18. It is found that about 3/4th of crude oil is been utilized in transportation section, this has resulted in manufacturers globally to reduce the oil consumption without any sacrifice in performance of vehicles. Biodiesel, LPG, CNG and electric vehicles are some alternative methods used to reduce oil consumption. Many research work has been carried out globally by blending of Ethanol into Diesel or Hydrogen into Diesel are carried out by many researchers, but this has not been implemented commercially. Renewable and oxygenated fuel, ethanol is an attractive alternative fuel which aides in complete combustion of fuel in compression ignition engines (CI Engines). In this paper, engine performance has been studied with the addition Ethanol and Hydrogen. The investigation has been carried out on a single cylinder compression ignition engine (CI Engine) developing a maximum power of 3.7kw at 1500 rpm. Experimental analysis has been carried out for Crude Diesel (baseline fuel) and ratios of Diesel-Ethanol blends for various loading condition. Form the experimental investigations the following performance parameters has been recorded: brake thermal efficiency, brake specific fuel consumption, brake power and exhaust gas temperature. The results showed that the performance parameters were marginally inferior to the crude Diesel test results. From the investigation the reading clearly shows that for two fuel blending without much compromise Crude Diesel and Ethanol can be blended up to a ratio of 25% Ethanol 75% Diesel. Experimental investigations for Diesel-Hydrogen has been carried out with 6.9 liters per hour of constant hydrogen addition. This mixture had the most optimum performance characteristics. For three fuel combination i.e., Bio-Diesel (Ethanol & Diesel) and Hydrogen, Hydrogen was supplied at a constant rate of 6.9 liters per hour. From the investigations it has been found that E15-D85-H has the better performance characteristics.Crude oil consumption is about 201.90 MMT in India for 2017-18. It is found that about 3/4th of crude oil is been utilized in transportation section, this has resulted in manufacturers globally to reduce the oil consumption without any sacrifice in performance of vehicles. Biodiesel, LPG, CNG and electric vehicles are some alternative methods used to reduce oil consumption. Many research work has been carried out globally by blending of Ethanol into Diesel or Hydrogen into Diesel are carried out by many researchers, but this has not been implemented commercially. Renewable and oxygenated fuel, ethanol is an attractive alternative fuel which aides in complete combustion of fuel in compression ignition engines (CI Engines). In this paper, engine performance has been studied with the addition Ethanol and Hydrogen. The investigation has been carried out on a single cylinder compression ignition engine (CI Engine) developing a maximum power of 3.7kw at 1500 rpm. Experimental analysis has been carried out for C...

In this paper, the isolated DC-DC converters fly back, forward converter, and hybrid converter topologies are considered for analysis. However, each topology has definite boundaries that are hard to resolve that can be overcome by the hybrid topology. This paper presents a hybrid type of forward, and fly back converter, allocation of the transformer utilization factor a better manner, has exceptionally high voltage gain and high efficiency. Achieving soft switching with control and design is easy. The forward fly back converters are simulated using MATLAB Simulink employing the results are analyzed and compared the efficiencies with theoretical and simulated values. The theoretical analysis of flyback-forward converter using DSPIC30F4011 is verified by comparing the theoretical and simulation results with a prototype of 100W and 2 kHz switching frequency.

This paper presents the design, modeling and fabrication of the prototype of Hydro-Magneto-Electric- Regenerative Shock Absorber (HMERSA) with two electric generators in series for vehicle suspension. The designed HMERSA converts reciprocating linear motion of vehicle suspension into unidirectional fluid flow which turn the two electric generators in series and generate electricity. The HMERSA was modeled and simulated to study the damping force characteristic, the performance, and the generated power. Further, the prototype of HMERSA was manufactured and implemented in the vehicle suspension. The vehicle was tested on a bumping road. The vehicle body acceleration was measured as well as the generated voltage and current. The results are analyzed and discussed in this paper.

Mufflers represent devices used to reduce sound and pulsations for internal combustion engines and other equipment like volumetric compressors. Depending on application they are designed to reduce low, medium or high frequency pulsations. The main design is represented by acoustic filters which use the acoustic analogy method. Dealing with low frequency pulsations this type of filters result in bulky constructions. The use of metamaterials results in a more compact design for these type of mufflers. This paper investigates by numerical simulations the transmission loss (TL) of such muffler based on acoustic black hole (ABH) metamaterial principle. In the first part of the paper the FEM results are compared with the acoustic measurements performed on an adapted impedance tube, in order to validate the model. In the second part the influences of the geometric parameters (length of the muffler, lamellae depth and thickness) will be investigated. The comparative analysis between the FEM and the measured results indicates good agreement. The geometric parameters analysis highlighted that the acoustic attenuation can be increased by using a long muffler.

High speed vehicle as a vibration system, resonance generated in flight may be harmful to high speed vehicles. It is possible to solve the resonance problem by acquiring the natural frequency of the high-speed aircraft and then taking some measures to avoid the natural frequency of the high speed vehicle. Therefore, In this paper, the modal test of the high speed vehicle was carried out by using the running hammer method and the PolyMAX modal parameter identification method. Firstly, the total frequency response function, coherence function of the high speed vehicle are obtained by the running hammer stimulation test, and through the modal assurance criterion (MAC) to determine the accuracy of the estimated parameters. Secondly, the first three order frequencies, the pole steady state diagram of the high speed vehicles is obtained by the PolyMAX modal parameter identification method. At last, the natural frequency of the vibration system was accurately obtained by the running hammer method.High speed vehicle as a vibration system, resonance generated in flight may be harmful to high speed vehicles. It is possible to solve the resonance problem by acquiring the natural frequency of the high-speed aircraft and then taking some measures to avoid the natural frequency of the high speed vehicle. Therefore, In this paper, the modal test of the high speed vehicle was carried out by using the running hammer method and the PolyMAX modal parameter identification method. Firstly, the total frequency response function, coherence function of the high speed vehicle are obtained by the running hammer stimulation test, and through the modal assurance criterion (MAC) to determine the accuracy of the estimated parameters. Secondly, the first three order frequencies, the pole steady state diagram of the high speed vehicles is obtained by the PolyMAX modal parameter identification method. At last, the natural frequency of the vibration system was accurately obtained by the running hammer method.

The coastal areas of Java, especially Semarang and Demak, are tidal flooding-prone areas. In fact, tidal flooding decreases the quality of life in coastal areas due to the capacity of seawater in destroying the building, houses, and environment. One innovation is introduced in this paper, which is the premixed mortar additive to repair masonry walls of house in tidal-prone areas. Principally, some measures should be done to address the problems caused by tidal flooding. In this research, masonry walls were improved by applying premixed mortar additive. The results were investigated after its long term performance, for more than one year, by using non destructive Rebound Hammer Test. This research was conducted by experimental activity. There were two masonry walls that had been repaired about a year ago. Some old masonry and concrete bricks of the walls had been substituted by new concrete bricks made of polymer-modified mortar with Moringa oleifera and Gracilaria Sp. and then covered by premixed mortar additive. Those masonry walls were built in Sriwulan village, Sayung and Pucang Gading— as the control site. Non destructive Rebound Hammer Test was applied on the masonry walls aged 12, 13, and 14 months. Each masonry wall was tested by 5 (five) zones (A, B, C, D, and E). Ten shoots were applied on each zone. The findings revealed: 1) In dry area, Pucang Gading site, there is a consistent performance of compressive strength masonry wall aged 12, 13, and 14 months, 2) In tidal flooding-prone area, Sayung site, there is fluctuative performance of compressive strength masonry wall aged 12, 13, and 14 months, 3) Compressive strength of masonry walls aged 14 months in Pucang Gading site is generally fluctuative, particularly at zone A to E (39.4 MPa to 44 MPa), while in Sayung site, compressive strength of zone A to E indicates declining values (44.3 MPa to 40.8 MPa), 4) At age 14 months, the compressive strength of zone B and E in Sayung site is lower than that in Pucang Gading site, due to tidal flooding, and 5) Slight distinction of compressive strength in Pucang Gading and Sayung site may be provided by premixed mortar additive that covers the walls.The coastal areas of Java, especially Semarang and Demak, are tidal flooding-prone areas. In fact, tidal flooding decreases the quality of life in coastal areas due to the capacity of seawater in destroying the building, houses, and environment. One innovation is introduced in this paper, which is the premixed mortar additive to repair masonry walls of house in tidal-prone areas. Principally, some measures should be done to address the problems caused by tidal flooding. In this research, masonry walls were improved by applying premixed mortar additive. The results were investigated after its long term performance, for more than one year, by using non destructive Rebound Hammer Test. This research was conducted by experimental activity. There were two masonry walls that had been repaired about a year ago. Some old masonry and concrete bricks of the walls had been substituted by new concrete bricks made of polymer-modified mortar with Moringa oleifera and Gracilaria Sp. and then covered by premixed mortar a...

Tube hydroforming presents a very good alternative to conventional forming processes for obtaining good quality mechanical parts used in several industrial fields, such as the automotive and aerospace sectors.Research in the field of tube hydroforming is aimed at improving the formability, stiffness and weight reduction of manufactured parts using this process. In recent years, a new method of hydroforming appears; it consists of deforming parts made from welded tubes and having different thicknesses. This technique which contributes to the weight reduction of the hydroformed tubes is a good alternative to the conventional tube hydroforming. This technique makes it possible to build rigid and light structures with a reduced cost. However, it is possible to improve the weight reduction by using dissimilar tailor welded tubes (TWT).This paper is a first attempt to analyze by numerical simulation the behavior of TWT hydroformed in square cross section dies, commonly called (Corner Fill Test). Considered tubes are composed of two materials assembled by butt welding. The present analysis will focus on the effect of loading paths on the formability of the structure by determining the change in thickness in several sections of the part. A comparison between the results obtained by hydroforming the butt joint of tubes made of dissimilar materials and those obtained using single-material tube is achieved. Numerical calculations show that the bi-material welded tube has better thinning resistance and a more even thickness distribution in the circumferential directions when compared to the single-material tube.Tube hydroforming presents a very good alternative to conventional forming processes for obtaining good quality mechanical parts used in several industrial fields, such as the automotive and aerospace sectors.Research in the field of tube hydroforming is aimed at improving the formability, stiffness and weight reduction of manufactured parts using this process. In recent years, a new method of hydroforming appears; it consists of deforming parts made from welded tubes and having different thicknesses. This technique which contributes to the weight reduction of the hydroformed tubes is a good alternative to the conventional tube hydroforming. This technique makes it possible to build rigid and light structures with a reduced cost. However, it is possible to improve the weight reduction by using dissimilar tailor welded tubes (TWT).This paper is a first attempt to analyze by numerical simulation the behavior of TWT hydroformed in square cross section dies, commonly called (Corner Fill Test). Considered tube...

In this paper the morphology and structure of TiO2-CNT nanocomposite powder obtained by an in situ sol-gel process were investigated. The synthesized nanocomposite powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and diffuse reflectance spectroscopy (DRS). The effect of functionalizing of CNT on the properties was studied. XRD results showed amorphous structure before calcination. Also, anatase phase TiO2 was formed after calcination at 400 °C. The SEM results indicate different distributions of TiO2 on CNTs. As a result, well dispersed TiO2 microstructure on the surface of CNTs was observed after functionalizing, while compact and large aggregated particles were found without functionalizing. The average thickness of uniform and well-defined coated TiO2 layer was in the range of 30-40 nm. The DRS results have determined the reflective properties and band gap energies of nanocomposite powders and have shown that functionalizing of CNTs caused the change of band-gap energy from 2.98 to 2.87 eV.In this paper the morphology and structure of TiO2-CNT nanocomposite powder obtained by an in situ sol-gel process were investigated. The synthesized nanocomposite powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and diffuse reflectance spectroscopy (DRS). The effect of functionalizing of CNT on the properties was studied. XRD results showed amorphous structure before calcination. Also, anatase phase TiO2 was formed after calcination at 400 °C. The SEM results indicate different distributions of TiO2 on CNTs. As a result, well dispersed TiO2 microstructure on the surface of CNTs was observed after functionalizing, while compact and large aggregated particles were found without functionalizing. The average thickness of uniform and well-defined coated TiO2 layer was in the range of 30-40 nm. The DRS results have determined the reflective properties and band gap energies of nanocomposite powders and have shown that functionalizing of CNTs caused the c...

This paper presents the design and development of the distributed ultrasonic waveguide temperature sensors using some stepped-helical structures. Distributed sensing has several applications in various industries (oil, glass, steel) for measurement of physical parameters such as level, temperature, viscosity, etc. This waveguide incorporates a special notch or bend for obtaining ultrasonic wave reflections from the desired locations (Gage-lengths) where local measurements are desired. In this paper, a multi-location measurement wave-guide, with a measurement capability of 18 locations in a single wire, has been fabricated. The distribution of these sensors is both in the axial as well as radial directions using a stepped-helical spring configuration. Also, different high temperature materials have been chosen for the wave-guide. Both lower order axi-symmetric guided ultrasonic modes (L(0,1) and T(0,1)) were employed. These wave modes were generated/received (pulse-echo approach) using conventional longitu...

To enhance the security in optical image encryption system and to protect it from the attackers, this paper proposes new digital spiral phase mask based on Fresnel Transform. In this cryptosystem the Spiral Phase Mask (SPM) used is a hybrid of Fresnel Zone Plate (FZP) and Radial Hilbert Mask (RHM) which makes the key strong and enhances the security. The different keys used for encryption and decryption purposed make the system much more secure. Proposed scheme uses various structured phase mask which increases the key space also it increases the number of parameters which makes it difficult for the attackers to exactly find the key to recover the original image. We have also used different keys for encryption and decryption purpose to make the system much more secure. The strength of the proposed cryptosystem has been analyzed by simulating on MATLAB 7.9.0(R2008a). Mean Square Errors (MSE) and Peak Signal to Noise Ratio (PSNR) are calculated for the proposed algorithm. The experimental results are provided to highlight the effectiveness and sustainability of proposed cryptosystem and to prove that the cryptosystem is secure for usage.To enhance the security in optical image encryption system and to protect it from the attackers, this paper proposes new digital spiral phase mask based on Fresnel Transform. In this cryptosystem the Spiral Phase Mask (SPM) used is a hybrid of Fresnel Zone Plate (FZP) and Radial Hilbert Mask (RHM) which makes the key strong and enhances the security. The different keys used for encryption and decryption purposed make the system much more secure. Proposed scheme uses various structured phase mask which increases the key space also it increases the number of parameters which makes it difficult for the attackers to exactly find the key to recover the original image. We have also used different keys for encryption and decryption purpose to make the system much more secure. The strength of the proposed cryptosystem has been analyzed by simulating on MATLAB 7.9.0(R2008a). Mean Square Errors (MSE) and Peak Signal to Noise Ratio (PSNR) are calculated for the proposed algorithm. The experimental results are provid...

Recently, the increasing interest in geopolymer field has promoted the research in terms of full replacement of Portland cement binder and feasible utilization of waste materials. In this paper, the effect of fiber reinforcement on the strength, toughness, physical and long term shrinkage behaviors of fly ash based geopolymers will be illustrated.Recently, the increasing interest in geopolymer field has promoted the research in terms of full replacement of Portland cement binder and feasible utilization of waste materials. In this paper, the effect of fiber reinforcement on the strength, toughness, physical and long term shrinkage behaviors of fly ash based geopolymers will be illustrated.

The ITER baseline foresees 2 Heating Neutral Beams (HNB’s) operating at 1 MeV 40 A D0, each capable of delivering 16.5 MW of deuterium neutrals to the plasma, with a 3rd HNB injector foreseen as an upgrade option that would bring up the total neutral beam power to 50MW [1]. In addition a dedicated Diagnostic Neutral Beam (DNB) will be injecting 100 keV 60 A of H0 for charge exchange recombination spectroscopy (CXRS) [2]. This paper highlights the impact of the staged approach on the ITER NBI, presents the new installation strategy and reports on the status of the adopted design refinements and the integration of the HNB’s and the DNB into the ITER plant.The ITER baseline foresees 2 Heating Neutral Beams (HNB’s) operating at 1 MeV 40 A D0, each capable of delivering 16.5 MW of deuterium neutrals to the plasma, with a 3rd HNB injector foreseen as an upgrade option that would bring up the total neutral beam power to 50MW [1]. In addition a dedicated Diagnostic Neutral Beam (DNB) will be injecting 100 keV 60 A of H0 for charge exchange recombination spectroscopy (CXRS) [2]. This paper highlights the impact of the staged approach on the ITER NBI, presents the new installation strategy and reports on the status of the adopted design refinements and the integration of the HNB’s and the DNB into the ITER plant.

This paper discusses the superelastic behavior of shape memory alloy, NiTi when used as reinforcement in concrete beams. The ability of NiTi to recover and reduce permanent deformations of concrete beams was investigated. Small-scale concrete beams, with NiTi reinforcement were experimentally investigated under monotonic loads. The behaviour of simply supported reinforced concrete (RC) beams hybrid with NiTi rebars and the control beam subject to monotonic loads were experimentally investigated. This paper is to highlight the ability of the SMA bars to recover and reduce permanent deformations of concrete flexural members. The size of the control beam is 125 mm × 270 mm × 1000 mm with 3 numbers of 12 mm diameter bars as main reinforcement for compression and 3 numbers of 12 mm bars as tension or hanger bars while 6 mm diameter at 100 mm c/c used as shear reinforcement bars for control beam respectively. While, the minimal provision of 200mm using the 12.7mm of superelastic Shape Memory Alloys were employed to replace the steel rebar at the critical region of the beam. In conclusion, the contribution of the SMA bar in combination with high-strength steel to the conventional reinforcement showed that the SMA beam has exhibited an improve performance in term of better crack recovery and deformation. Therefore the usage of hybrid NiTi with the steel can substantially diminish the risk of the earthquake and also can reduce the associated cost aftermath.

Now a days red emitting Mn4+ activated dialkali fluorosilicate phosphors have found applications in solid state lighting and displays. In this paper we describe development of K2SiF6 phosphor doped with Mn synthesized by simple method using Si metal powder with addition of oxidizing agent KMnO4. The photoluminescence spectra of K2SiF6:Mn show that emission is in the red region. In addition to this we studied LED spectra by coating the LED with phosphor mixed in different proportions with epoxy.Now a days red emitting Mn4+ activated dialkali fluorosilicate phosphors have found applications in solid state lighting and displays. In this paper we describe development of K2SiF6 phosphor doped with Mn synthesized by simple method using Si metal powder with addition of oxidizing agent KMnO4. The photoluminescence spectra of K2SiF6:Mn show that emission is in the red region. In addition to this we studied LED spectra by coating the LED with phosphor mixed in different proportions with epoxy.

In this paper, we obtain sufficient conditions for compactness of the commutator for the Riesz potential [b, Iα] in global Morrey-type spaces GMpθw .In this paper, we obtain sufficient conditions for compactness of the commutator for the Riesz potential [b, Iα] in global Morrey-type spaces GMpθw .

Growing energy consumption leads to discovery of new technology to accommodate global energy demand. Stirling Engine is one of the traditional engine which can harvest solar energy with minimal modification on the configuration. This paper covers literature review on Solar Powered Stirling Engine technology. The development of traditional Stirling Engine will be discussed on earlier part. The second part covers the integration of solar power with Stirling Engine and application of this combined system in industry. There were many researches and studies carried out previously on the development and application of traditional Stirling Engine and solar powered Stirling Engine. This paper is focus on optimization of performance of Solar Powered Stirling which will provide comprehensive details on the factor needed to be optimized in order to develop all rounded Solar Stirling Engine for future studies.

The present paper describes the design and setting up of an indigenouslydevelopedmagnetostriction(MS) measurement setup using four probe method atroom temperature.A standard strain gauge is pasted with a special glue on the sample and its change in resistance with applied magnetic field is measured using KeithleyNanovoltmeter and Current source. An electromagnet with field upto 1.2 tesla is used to source the magnetic field. The sample is placed between the magnet poles using self designed and developed wooden probe stand, capable of moving in three mutually perpendicular directions. The nanovoltmeter and current source are interfaced with PC using RS232 serial interface. A software has been developed in for logging and processing of data. Proper optimization of measurement has been done through software to reduce the noise due to thermal emf and electromagnetic induction. The data acquired for some standard magnetic samples are presented. The sensitivity of the setup is 1microstrain with an error in measurement upto 5%.The present paper describes the design and setting up of an indigenouslydevelopedmagnetostriction(MS) measurement setup using four probe method atroom temperature.A standard strain gauge is pasted with a special glue on the sample and its change in resistance with applied magnetic field is measured using KeithleyNanovoltmeter and Current source. An electromagnet with field upto 1.2 tesla is used to source the magnetic field. The sample is placed between the magnet poles using self designed and developed wooden probe stand, capable of moving in three mutually perpendicular directions. The nanovoltmeter and current source are interfaced with PC using RS232 serial interface. A software has been developed in for logging and processing of data. Proper optimization of measurement has been done through software to reduce the noise due to thermal emf and electromagnetic induction. The data acquired for some standard magnetic samples are presented. The sensitivity of the setup is 1microstrain with an error in meas...

The paper deals with the challenges of the machinery vibroacoustic signal modeling. The purpose of this paper is to form a phenomenological model for the structure of vibroacoustic oscillations and signals appeared in case of malfunctions and defects. It presents particular structural models for vibroacoustic signals of some reciprocating machine malfunctions. Mathematical description of the vibroacoustic signal reveals the informative parameters of the malfunction diagnostic signs. The model enables us to define in detail the informative vibroacoustic signal parameters. The model also allows us to select the diagnostic signs of the given malfunctions and defects in certain machine parts and components. At the same time, it is considered that the signal is received in certain points on the machine taking into account the excitation sources, conditioning channel and propagation of the vibroacoustic oscillations. The model has been constructed considering the presence and interaction of the three main sources of excitation of the asset vibroacoustic oscillations, which are identified by the types of excited oscillations. It is assumed that there are damped natural, undamped induced, random broadband and narrowband vibrations. The parameters of the vibroacoustic signal structural model also take into account the properties of converting the vibroacoustic oscillation to the vibroacoustic signal by means of a piezoelectric sensor. The model shows that the vibroacoustic signal has not only the components from each source, but their mutually modulated components. We developed partial models for mechanisms of structuring the vibroacoustic signal appeared in case of malfunctions and defects in rotating parts and couplings, machine shaft and drive shaft misalignment, increased clearances and other defects and failures of the rotating and reciprocating parts and components. The proposed phenomenological structural models of the vibroacoustic signals appeared in case of malfunctions of reciprocating machines show that for the diagnostic purposes it is necessary to analyze vibroacoustic signals either in the time domain according to the cyclogram of the reciprocating machine operation or in the envelope spectrum at characteristic frequencies or the noise component. In the event of defects and malfunctions in the centrifugal rotating parts and components, there are excited the vibroacoustic signals, which are advisable to analyze in the direct spectrum or in the spectrum of the noise component envelope. The proposed models enable us to select and form scientifically grounded systems of the machine failure diagnostic signs.

A method of thermal reduction of graphene oxide has been developed. Samples of paper-like graphene oxide film produced by the standard Hummers method were experienced by thermal processing at various temperatures which resulted in a partial reduction of graphene oxide which accompanied with an enhancement of the conductivity of this material. The most pronounced jump in the conductivity occurs at the annealing temperature of about 170°C, when the conductivity of the samples increased by 5 orders of magnitude comparing to the initial samples. The samples of partially reduced graphene oxide obtained were used for reinforcement of a steel surface. The reinforcement procedure was described in detail in the preceding work [1], where fullerene C60 and nanocarbon soot formed as a result of electrical arc sputtering followed by the extraction of fullerenes were used as a reinforcing coating. A film of partially reduced graphene oxide is applied on a steel surface after which the surface is experienced by laser. The dependences of the reinforcement degree on the degree of the graphene oxide reduction and the laser intensity are measured. The results of measurements indicate a notable (up to 400 %) enhancement of the microhardness of the surface processed so that the depth of the reinforcement layer accounts tens micrometers.A method of thermal reduction of graphene oxide has been developed. Samples of paper-like graphene oxide film produced by the standard Hummers method were experienced by thermal processing at various temperatures which resulted in a partial reduction of graphene oxide which accompanied with an enhancement of the conductivity of this material. The most pronounced jump in the conductivity occurs at the annealing temperature of about 170°C, when the conductivity of the samples increased by 5 orders of magnitude comparing to the initial samples. The samples of partially reduced graphene oxide obtained were used for reinforcement of a steel surface. The reinforcement procedure was described in detail in the preceding work [1], where fullerene C60 and nanocarbon soot formed as a result of electrical arc sputtering followed by the extraction of fullerenes were used as a reinforcing coating. A film of partially reduced graphene oxide is applied on a steel surface after which the surface is experienced by laser. T...

In the field of metal rolling, the quality of the steel roller’s surface is significant for the final rolling products, e.g. metal sheets or foils. Besides the dimensional accuracy and surface roughness, the optical uniformity of the roller surface is also required for high quality rolling application. The typical optical defects of rollers after finish grinding include speckles, chatter marks, feed traces, and combination of all above. Unlike surface roughness, the optical defects can hardly be characterized by the topography or scanning electrical microscope measurement. Only the inspection by bared eyes of experienced engineers appears to be the effective manner for surface optical defects examination for large steel rollers. In this paper, an on-site machine vision system is designed to add on to the roller grinding machine to capture the surface image, and then an improved optical defects segmentation algorithm is developed based on the active contour model. Finally, experiments are carried out to verify the efficacy of the improved model.In the field of metal rolling, the quality of the steel roller’s surface is significant for the final rolling products, e.g. metal sheets or foils. Besides the dimensional accuracy and surface roughness, the optical uniformity of the roller surface is also required for high quality rolling application. The typical optical defects of rollers after finish grinding include speckles, chatter marks, feed traces, and combination of all above. Unlike surface roughness, the optical defects can hardly be characterized by the topography or scanning electrical microscope measurement. Only the inspection by bared eyes of experienced engineers appears to be the effective manner for surface optical defects examination for large steel rollers. In this paper, an on-site machine vision system is designed to add on to the roller grinding machine to capture the surface image, and then an improved optical defects segmentation algorithm is developed based on the active contour model. Finally, experiments are carried out to ve...

The interaction of a shock wave with a rough free surface may lead to the ejection of high velocity (∼ km/s) particles of small size (∼ µm). This process is a safety issue for various applications such as pyrotechnics or inertial confinement fusion. To complement data obtained by other groups under explosive loading or plate impacts, we use laser driven shock loading to study microjetting from V-shaped grooves of various angles in copper and tin samples, with a combination of complementary experimental techniques. To simulate such experiments, we have chosen to use the Smoothed Particles Hydrodynamics formulation, well-suited for the very high strains involved in jet expansion and subsequent fragmentation. In this paper, we report some advances in this modelling effort, then we compare computed predictions with new experimental results including fragments size distributions inferred from post-test micro-tomography after soft recovery in a low density gel. Special focus is made on the dependence of the ejecta ballistic properties (velocity and mass distributions) on numerical parameters such as the initial inter-particular distance, the smoothing length and a random geometrical noise introduced to simulate inner irregularities of the material.The interaction of a shock wave with a rough free surface may lead to the ejection of high velocity (∼ km/s) particles of small size (∼ µm). This process is a safety issue for various applications such as pyrotechnics or inertial confinement fusion. To complement data obtained by other groups under explosive loading or plate impacts, we use laser driven shock loading to study microjetting from V-shaped grooves of various angles in copper and tin samples, with a combination of complementary experimental techniques. To simulate such experiments, we have chosen to use the Smoothed Particles Hydrodynamics formulation, well-suited for the very high strains involved in jet expansion and subsequent fragmentation. In this paper, we report some advances in this modelling effort, then we compare computed predictions with new experimental results including fragments size distributions inferred from post-test micro-tomography after soft recovery in a low density gel. Special focus is made on the dependence of the eje...

A next generation heavy ion accelerator complex HIAF (High Intensity heavy ion Accelerator Facility) was proposed by IMP and officially approved for nuclear physics and high energy density physics research. HIAF requests ion source that is able to deliver 50 pμA of 238U35+ pulsed beam and 25 pμA of 238U35+ CW beam for injector of a superconducting heavy ion linac. In order to meet the beam intensity requirements of highly charged heavy ions, a 45 GHz superconducting ECR ion source FECR (a Fourth generation ECR ion source) is under intense R&D at IMP. The effective power absorption form the microwaves to the plasma is key issue for increasing the beam intensity. Therefore, we introduced a 45 GHz gyrotron system which is capable for providing output power up to 20 kW in both CW and pulse modes as a microwave power source for FECR. Other than the gyrotron oscillator, the microwave power transmission coupling and ECR heating are critical issues for FECR. Since the wavelength of 45 GHz microwave is about 6.67 mm and the maximum power level is 20 kW, the quasi-optical transmission scheme is utilized for high power transmission. The technical details of transmission line and coupling system will be presented in this paper. After off-line tests of microwave transmission efficiency and mode purity, 45 GHz gyrotron microwave source will be commissioned with SECRAL II (a superconducting ECR ion source optimized for 28 GHz operation), and some preliminary results of ECR heating and intense beam production will be discussed in this paper.

This paper focuses on the impact towards the performance of silicon nanowire field-effect transistor (SiNW-FET) for biosensing application based on different channel lengths of the nanowire. A device numerical modelling tool, Silvaco ATLAS was used to design three p-type SiNW-FET biosensors with different lengths of 0.5, 1.0, and 10.0 μm. The designed devices were simulated in order to observe and compare the effect of different channel length towards the electrical characteristic of the devices. Increase of the nanowire channel length had caused reduction of drain current, ID flowed through the channel from drain to source region. This is related to the increase of electrical resistance, R of the nanowire with the increase of nanowire length, L. In a way to study the effect of different channel lengths on the performance of the SiNW-FET biosensor, several negatively interface charge densities, QF (i.e. −0.1×1012, −0.5×1012, and −1×l012 cm−2) were introduced on the surface of the SiNW channel to represent as the actual target deoxyribonucleic acid (DNA) captured by the bioreceptor of the biosensor. Based on the results, these negatively QF attracted the hole carriers below the surface of p-type nanowire to form an accumulation of charge carriers in the channel, causing an increase in the device output ID. Increase of the applied negative charge density had allowed for more ID to flow across the channel between drain and source region. The changes of ID with the applied QF are utilized to determine the sensitivities and limit of detections (LOD) for all designed biosensor with different channel lengths. In comparison, the smallest nanowire length of 0.5 μm produced the highest sensitivity and lowest LOD of 2.17 μA/cm−2 and 7.85×1010 cm−2, respectively, hence demonstrates better performance of SiNW-FET biosensor for the detection of specific charged DNA in analyte.This paper focuses on the impact towards the performance of silicon nanowire field-effect transistor (SiNW-FET) for biosensing application based on different channel lengths of the nanowire. A device numerical modelling tool, Silvaco ATLAS was used to design three p-type SiNW-FET biosensors with different lengths of 0.5, 1.0, and 10.0 μm. The designed devices were simulated in order to observe and compare the effect of different channel length towards the electrical characteristic of the devices. Increase of the nanowire channel length had caused reduction of drain current, ID flowed through the channel from drain to source region. This is related to the increase of electrical resistance, R of the nanowire with the increase of nanowire length, L. In a way to study the effect of different channel lengths on the performance of the SiNW-FET biosensor, several negatively interface charge densities, QF (i.e. −0.1×1012, −0.5×1012, and −1×l012 cm−2) were introduced on the surface of the SiNW channel to represent...

The paper deals with linear-quadratic optimal control problems with a weak control and the fixed left point in a critical case, where a matrix standing in front of a state variable in the state equation is singular for any argument value if the small parameter is equal to zero.Using the direct scheme method, consisting in immediate substituting a postulated asymptotic solution into the problem condition and obtaining problems for finding asymptotics terms, the zero order asymptotic solution is constructed under some conditions.In contrast to the paper: N. T. Hoai, J. Optim. Theory Appl., vol. 175, 324–340 (2017), where the considered problem was studied, the projector approach is applied here. This approach allows us to make the algorithm of constructing asymptotic solution clearer and to correct some inaccuracies in the paper mentioned.

To solve the problems in the DEM simulations of the screening process of a swing-bar sieve, in this paper we propose the real-virtual boundary method to build the geometrical model of the screen deck on a swing-bar sieve. The motion of the swing-bar sieve is modelled by the planer multi-body kinematics. A coupled model of the discrete element method (DEM) with multi-body kinematics (MBK) is presented to simulate the flowing and passing processes of soybean particles on the screen deck. By the comparison of the simulated results with the experimental results of the screening process of the LA-LK laboratory scale swing-bar sieve, the feasibility and validity of the real-virtual boundary method and the coupled DEM-MBK model we proposed in this paper can be verified. This work provides the basis for the optimization design of the swing-bar sieve with circular apertures and complex motion.

The effect of incident laser energy on the surface plasmon resonance (SPR) and size of silver nanoparticles synthesized via pulsed laser ablation of silver immersed in distilled water is reported in this paper. The broadening in the plasmonic bandwidth of the synthesized nanoparticles with the increase in the laser energy incident onto the silver target indicates the reduction in size of the nanoparticles. This is confirmed by the transmission electron microscope (TEM) images which show a decrease in the average particle size of the nanoparticles from approximately 15 to 10 nm with the increase in incident laser energy from 30 to 70 mJ, respectively. The structural features as revealed by the selected area electron diffraction and ultra-high resolution TEM studies confirmed the formation of both silver as well as silver oxide nanoparticles.The effect of incident laser energy on the surface plasmon resonance (SPR) and size of silver nanoparticles synthesized via pulsed laser ablation of silver immersed in distilled water is reported in this paper. The broadening in the plasmonic bandwidth of the synthesized nanoparticles with the increase in the laser energy incident onto the silver target indicates the reduction in size of the nanoparticles. This is confirmed by the transmission electron microscope (TEM) images which show a decrease in the average particle size of the nanoparticles from approximately 15 to 10 nm with the increase in incident laser energy from 30 to 70 mJ, respectively. The structural features as revealed by the selected area electron diffraction and ultra-high resolution TEM studies confirmed the formation of both silver as well as silver oxide nanoparticles.

The emerging applications of coordination and cooperation between mobile robots, as well as interaction between mobile robots and humans, demands for an early and well designed robotic education. In addition, research and development in this area needs to be supported with an-easy-to-implement mobile robot platform. An availability of a low-cost and open source mobile robots will be beneficial, especially in a development country such as Indonesia. In this paper we propose a low cost and open source mobile robot platform that can be used for education and research specific in mobile robots and coordination between the robots. The “low cost” is defined as the availability and easiness to find the components in Indonesia or at least easily found in online shop. The “open source” means that the resulting design and implementation can be accessed in open source library and follow the GNU license. The first generation of the robot has been validated in terms of individual sensor and performance. The platform has been extended up to second generation and is used in different applications such as indoor mapping and remote control manipulation.The emerging applications of coordination and cooperation between mobile robots, as well as interaction between mobile robots and humans, demands for an early and well designed robotic education. In addition, research and development in this area needs to be supported with an-easy-to-implement mobile robot platform. An availability of a low-cost and open source mobile robots will be beneficial, especially in a development country such as Indonesia. In this paper we propose a low cost and open source mobile robot platform that can be used for education and research specific in mobile robots and coordination between the robots. The “low cost” is defined as the availability and easiness to find the components in Indonesia or at least easily found in online shop. The “open source” means that the resulting design and implementation can be accessed in open source library and follow the GNU license. The first generation of the robot has been validated in terms of individual sensor and performance. The platform h...

In order to investigate the possible structural diseases brought to the top flange of existing prestressed concrete box girder bridge due to the shrinkage and creep difference between new and old bridge, the stress state of the existing box girder before and after widening and the mechanisms of potential structural diseases were analyzed using finite element method in this paper. Results showed that the inner flange of the old box girder were generally in the state of large tensile stress, the main reason for which was the shrinkage and creep effect difference of the new and old bridge. And the tensile stress was larger than tensile strength of C50 concrete, which would most likely cause crack in the deck plate of box girder. Hence, reinforcement measures are needed to be designed carefully. Meanwhile, the transverse deformation of widened structure had exceeded the distance between the anti-seismic block and the web of box girder at the end cross section, which would squeeze anti-seismic block severely. Therefore, it is necessary to limit the length of continuous bridge in need of widening.In order to investigate the possible structural diseases brought to the top flange of existing prestressed concrete box girder bridge due to the shrinkage and creep difference between new and old bridge, the stress state of the existing box girder before and after widening and the mechanisms of potential structural diseases were analyzed using finite element method in this paper. Results showed that the inner flange of the old box girder were generally in the state of large tensile stress, the main reason for which was the shrinkage and creep effect difference of the new and old bridge. And the tensile stress was larger than tensile strength of C50 concrete, which would most likely cause crack in the deck plate of box girder. Hence, reinforcement measures are needed to be designed carefully. Meanwhile, the transverse deformation of widened structure had exceeded the distance between the anti-seismic block and the web of box girder at the end cross section, which would squeeze anti-seismic block severely. ...

In this paper is presented a wind turbine model operating in the maximum power zone and an H∞ controller is synthesized for the system. The developed turbine model consists of: a model of the wind speed, mechanical and electrical model of the generator and a model of the tower oscillations. The controller adjusts the pitch angle of the blades so that the rotor angular velocity stays close to its nominal value and as a result the tower oscillations are decreased. Finally, the operation of the closed-loop system model is validated by simulationsIn this paper is presented a wind turbine model operating in the maximum power zone and an H∞ controller is synthesized for the system. The developed turbine model consists of: a model of the wind speed, mechanical and electrical model of the generator and a model of the tower oscillations. The controller adjusts the pitch angle of the blades so that the rotor angular velocity stays close to its nominal value and as a result the tower oscillations are decreased. Finally, the operation of the closed-loop system model is validated by simulations

This paper presents modelling of both single and double-phase powder sintering processes at the macroscopic level. In particular, its constitutive formulation, numerical implementation and numerical tests are described. The macroscopic constitutive model is based on the assumption that the sintered material is a continuous medium. The parameters of the constitutive model for material under sintering are determined by simulation of sintering at the microscopic level using a micro-scale model. Numerical tests were carried out for a cylindrical specimen under hydrostatic and uniaxial pressure. Results of macroscopic analysis are compared against the microscopic model results. Moreover, numerical simulations are validated by comparison with experimental results. The simulations and preparation of the model are carried out by Abaqus FEA - a software for finite element analysis and computer-aided engineering. A mechanical model is defined by the user procedure “Vumat” which is developed by the first author in Fortran programming language. Modelling presented in the paper can be used to optimize and to better understand the process.This paper presents modelling of both single and double-phase powder sintering processes at the macroscopic level. In particular, its constitutive formulation, numerical implementation and numerical tests are described. The macroscopic constitutive model is based on the assumption that the sintered material is a continuous medium. The parameters of the constitutive model for material under sintering are determined by simulation of sintering at the microscopic level using a micro-scale model. Numerical tests were carried out for a cylindrical specimen under hydrostatic and uniaxial pressure. Results of macroscopic analysis are compared against the microscopic model results. Moreover, numerical simulations are validated by comparison with experimental results. The simulations and preparation of the model are carried out by Abaqus FEA - a software for finite element analysis and computer-aided engineering. A mechanical model is defined by the user procedure “Vumat” which is developed by the first author in F...

This paper demonstrates a Junction-less Double Gate n-p-n Impact ionization MOS transistor (JLDG n-IMOS) on a very light doped p-type silicon body. Device structure proposed in the paper is based on charge plasma concept. There is no metallurgical junctions in the proposed device and does not need any impurity doping to create the drain and source regions. Due to doping-less nature, the fabrication process is simple for JLDG n-IMOS. The double gate engineering in proposed device leads to reduction in avalanche breakdown via impact ionization, generating large number of carriers in drain-body junction, resulting high ION current, small IOFF current and great improvement in ION/IOFF ratio. The simulation and examination of the proposed device have been performed on ATLAS device simulatorsoftware.This paper demonstrates a Junction-less Double Gate n-p-n Impact ionization MOS transistor (JLDG n-IMOS) on a very light doped p-type silicon body. Device structure proposed in the paper is based on charge plasma concept. There is no metallurgical junctions in the proposed device and does not need any impurity doping to create the drain and source regions. Due to doping-less nature, the fabrication process is simple for JLDG n-IMOS. The double gate engineering in proposed device leads to reduction in avalanche breakdown via impact ionization, generating large number of carriers in drain-body junction, resulting high ION current, small IOFF current and great improvement in ION/IOFF ratio. The simulation and examination of the proposed device have been performed on ATLAS device simulatorsoftware.

Over the past decades the piston is designed to transfer force to the crank shaft through a piston rod by the expansion of gases in the cylinder. During working piston has to tolerate the cyclic gas pressure and the inertial forces, due to which the piston experiences fatigue damages such as piston side wear, piston head cracks and so on. Earlier pistons were made up of cast iron or aluminium due to their lightweight and high heat transfer rate. After some experiments it was noted that on heating cast iron expands due to which it covers the clearance level that comes to seize the engine. This paper aims to design a piston using composite material such as Al-GHS 1300, Al-GHY 1250, Al-Si-C, A6061 and A4032 that will differ the material and the characteristics of the traditional engine piston. This paper describes the thermal and mechanical properties of the piston when the study is done by taking five different materials.

The focus of the present paper is to develop a fundamental understanding of the heat conduction process in single-walled carbon nanotubes and to elucidate the contribution of the various factors which affect it at the nanometer level. As the sizes of electronic and mechanical devices are decreased to the micron and nanometer level, it becomes particularly important to predict the thermal transport properties of the components. The heat conduction in finite length SWNTs was simulated by the finite element method. Temperature at each end of an SWNT was controlled in the simulation, and the thermal conductivity was calculated from the measured temperature gradient and heat flow value. The thermal conductivity was measured for (10, 10) SWNTs with various lengths from 40 through 80 nm. The measured thermal conductivity for smaller diameter (10, 10) nanotube did not converge to a finite value with increase in tube length but obeyed a striking power law relation. The thermal conductivity of several single-wall carbon nanotubes has been calculated over a temperature range of 100-500 K using finite element method. In all cases, starting from similar values at 100 K, the thermal conductivities show a peaking behavior. The output result (Thermal Conductivity) varied from 1000 to 5266 w/m-k. The simulation results are quite similar with the results that are obtained by molecular dynamics simulation and photon spectrum analysis. We have also simulated the effect of defects in our SWNT structure. In the paper the difference of thermal conductivity between a defective and non-defective SWNT is also being discussed. M ore detailed analysis can be done to understand the defect influence on the thermal conductivity of carbon nanotube. The specific heat is a function of temperature [1]. We used 700 J/kg-k here as our average temperature is 300k. So, in future we hope there will be these corrections to determine the more accurate conductivity.

The miniaturization of electronic devices with high processing components is promoting the rapid increase in heat generation of devices/systems. Synthetic jet cooling flexible thin device has major advantages in order to suit the device miniaturization and compactness. Diaphragm motion is the main component in the device that generate fluid motion for cooling application. In this paper, the synthetic jet diaphragm has been characterized using Laser Doppler to record the motion to determine the motion type. Based on the recorded motion, a User Define Function coding has been develop to imitate the motion in Computational Fluid Dynamic (CFD) software in order to simulate the fluid motion based from the actual diaphragm motion. The diaphragm motion showed a dome shape motion as the laser tracking result were plotted at three points across the diaphragm diameter. Results show that the diaphragm has sinusoidal motion which produce maximum amplitude at 500Hz driving frequency. The UDF program for diaphragm motion has been able to mimic the experimental result.The miniaturization of electronic devices with high processing components is promoting the rapid increase in heat generation of devices/systems. Synthetic jet cooling flexible thin device has major advantages in order to suit the device miniaturization and compactness. Diaphragm motion is the main component in the device that generate fluid motion for cooling application. In this paper, the synthetic jet diaphragm has been characterized using Laser Doppler to record the motion to determine the motion type. Based on the recorded motion, a User Define Function coding has been develop to imitate the motion in Computational Fluid Dynamic (CFD) software in order to simulate the fluid motion based from the actual diaphragm motion. The diaphragm motion showed a dome shape motion as the laser tracking result were plotted at three points across the diaphragm diameter. Results show that the diaphragm has sinusoidal motion which produce maximum amplitude at 500Hz driving frequency. The UDF program for diaphragm moti...

The laser forming technique has an important disadvantage, which is the limitation of plastic deformation generated by a single laser beam pass. To increase the plastic deformation it is possible to apply external forces in the laser forming process. In this paper, we investigate the influence of external pre-loads on the laser bending of steel plate. The pre-loads investigated generate bending towards the laser beam. The thermal, elastic-plastic analysis is performed using the commercial nonlinear finite element analysis package ABAQUS. The focus of the paper is to identify how this pattern of the pre-load influence the final bend angle of the plate.