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Development of the Thermal-FSI (Fluid Solid Interaction) let to accurate the process of cooling the steam turbine set. It provide to shorter times of maintenance and repairs of the turbine sets. The cooling of the steam turbine which temperature exceeds 500°C can take time of one week. Insulation and housing is taken off when temperature reaches 100°C. In analysis was applied thermal-FSI which takes into account temperature changes between solid material and fluid. In the paper authors propose this way to estimate effort of the turbine structure caused by an intrusion of water into the flow channels.

Bricks has stand for many years as durable construction substantial, especially in the area of civil engineering to construct buildings. Brick commonly used in the structure of buildings as a construction wall, cladding, facing perimeter, paving, garden wall and flooring. The contribution of ordinary Portland cement (OPC) in cement bricks production worldwide to greenhouse gas emissions. Due to this issue, some researchers have done their study with other materials to produce bricks, especially as a by-product material. Researchers take effort in this regard to synthesizing from by-product materials such as fly ash, bottom ash and kaolin that are rich in silicon and aluminium in the development of inorganic alumina-silicate polymer, called geopolymer Geopolymer is a polymerization reaction between various aluminosilicate oxides with silicates solution or alkali hydroxide solution forming polymerized Si-O-Al-O bonds. This paper summarized some research finding of mechanical properties of geopolymer brick using by-product materials.Bricks has stand for many years as durable construction substantial, especially in the area of civil engineering to construct buildings. Brick commonly used in the structure of buildings as a construction wall, cladding, facing perimeter, paving, garden wall and flooring. The contribution of ordinary Portland cement (OPC) in cement bricks production worldwide to greenhouse gas emissions. Due to this issue, some researchers have done their study with other materials to produce bricks, especially as a by-product material. Researchers take effort in this regard to synthesizing from by-product materials such as fly ash, bottom ash and kaolin that are rich in silicon and aluminium in the development of inorganic alumina-silicate polymer, called geopolymer Geopolymer is a polymerization reaction between various aluminosilicate oxides with silicates solution or alkali hydroxide solution forming polymerized Si-O-Al-O bonds. This paper summarized some research finding of mechanical properties of geopolymer brick u...

Ultra-short laser pulse interaction with a micro-structured surface of a melted metal is a promising source of hard X-ray radiation. Micro-structuring is achieved by a weak prepulse which produces narrow high density micro-jets. Interaction of the main laser pulse with such jets is shown to be a 100 times more efficient X-ray source than ordinary metal targets. This paper presents the results of optical and x-ray studies of laser-plasma interaction physics under such conditions supported by numerical simulations of fast electron generation.

In this paper, effects of polyurethane foam filler on the folding behaviour of the honeycomb panels as a thin walled structure are studied, experimentally. For this purpose, some specimens of the empty and foam‐filled honeycombs were prepared. All panels had 63 hexagonal cells and made of an aluminum alloy. The effects of foam filler on the energy absorption capacity, wavelength of the folds and the number of formed folds were investigated. Folding tests were performed by a drop hammer machine. Polyurethane foam was prepared with the density of 65 kg/m3 to fill the honeycomb cells. The hammer was selected with the weight of 5.48 kg and the initial drop height of 70 cm. The results of the drop hammer tests show that the foam filler causes the increasing in the energy absorption and number of the formed folds and decreasing in the wavelength of the folds.

The paper reports on latest developments for the ITER Ion Cyclotron Heating and Current Drive system: imminent acceptance tests of a prototype power supply at full power; successful factory acceptance of candidate RF amplifier tubes which will be tested on dedicated facilities; further design integration and experimental validation of transmission line components under 6MW hour-long pulses. The antenna Faraday shield thermal design has been validated above requirements by cyclic high heat flux tests. R&D on ceramic brazing is under way for the RF vacuum windows. The antenna port plug RF design is stable but major evolution of the mechanical design is in preparation to achieve compliance with the load specification, warrant manufacturability and incorporate late interface change requests. The antenna power coupling capability predictions have been strengthened by showing that, if the plasma scrape-off layer turns out to be steep and the edge density low, the reference burning plasma can realistically be displaced to improve the coupling.

In previous papers, we reported the successful flight of paper‐airplane about 5 cm. Application of such micro‐airplane to CO2 measurement and tornado observation is proposed. For practical application, repetitive water supply system and levitation system are proposed and examined by experiments. The latter can also be used for launching waste of nuclear reactor and structural materials for space station. Some future applications like stratospheric airplane and microship in human blood vessel are discussed.

Dyes act as major pollutants in water and can be degraded by photocatalysis. This paper establishes the role of electrochemically generated nanostructures of Zinc-Molybdenum oxides (ZMO) as photocatalysts by degrading EBT (Eriochrome Black- T) taken as a model pollutant under UV light. A facile, rapid and low cost process to synthesize these nanostructures (ZMO) is presented. Various factors that affect the synthesis and photocatalytic activity of these nanostructures are discussed. The role of calcination temperature and pulverization on the photocatalytic action has also been established. Particles have been synthesized in pure form as well as using surfactants such as cetrimide (cetyl trimethyl ammonium bromide), polyethylene glycol (PEG) and SDS (sodium dodecyl sulphate) to enhance their photocatalytic action. This paper also discusses the characterization of these nanoparticles by powder XRD, SEM, FT-IR and UV-Visible spectroscopy. Decolourisation was achieved to completion under optimum experimental conditions at room temperature ascertaining the application of these nanostructures as effective photocatalysts.

The operational floating current conveyor (OFCC) is a versatile active block due to the availability of both low and high input and output impedance terminals. This paper addresses the realization of OFCC based voltage and transadmittance mode instrumentation amplifiers (VMIA and TAM IA). It employs three OFCCs and seven resistors. The transadmittance mode operation can easily be obtained by simply connecting an OFCC based voltage to current converter at the output. The effect of non-idealities of OFCC, in particular finite transimpedance and tracking error, on system performance is also dealt with and corresponding mathematical expressions are derived. The functional verification is performed through SPICE simulation using CMOS based implementation of OFCC.

Safety is a main concern in nuclear power plant projects. The instrumentation and control system of nuclear power plant which propose to be built in Indonesia are expected to make extensive use of digital system. Common cause failures are among safety issues in digital technology which may compromise plant safety if occurred. The review includes investigation of available documentation of protection against common cause failures and diversity implementation. This paper describes the characteristics and nature of digital common cause failures. The instrumentation and control system require to be designed with defense against CCFs within and between systems. The result of review is a framework for defense against common causes failures that include: echelons of defense, diversity strategies and assessments of the adequacy of defense.

Backpressure is considered as an obstruction on the flow of exhaust for any internal combustion (IC) engine. The level of backpressure can affect the amount of emissions and fuel consumption and the performance of the engine. Hence, the backpressure is considered a bad factor for an engine. Even though backpressure could not be eliminated completely, it could be minimized through design optimization of exhaust system. This paper shows the effects of exhaust manifold’s bending radius of 115 cc spark ignition (SI) engine on low-end RPM. The aim of this study was to optimize the bending radius of exhaust manifold in order to minimize backpressure. CFD analysis was conducted to predict the backpressure of exhaust manifold samples based on design of experiment (DOE) through Taguchi’s method. From the analysis result, it is observed that bending radius which is towards the outlet is the most contributing factor to the backpressure and the optimized exhaust manifold reduces backpressure by 10.5% from the existing design. The finding shows that the optimized design offers lower backpressure which could significantly reduce negative impacts to the engine’s performance.

Heart failure is a condition that affects a great part of the world population. A heart transplant is one of the alternatives to survive heart failure. Since the organ donors are very limited and the wait list for the organ is very long it is difficult to find the organ. A viable alternative until the organ becomes available is the total artificial heart (TAH) and ventricle assisting devices. The total artificial heart is used to bridge the time to heart transplants. There are different types of artificial hearts. In this paper, we compared the various TAH devices by creating a database, and by using a simulation we determined which device is the best out in the market. We used Fuzzy Promethee as the methodology. It is observed that with pneumatic (SynCardia) TAHs as a bridge to transplant, promising results have been achieved, but still, they are not free of problems. Nevertheless, implantable total artificial hearts have a long way to go if they are to replace the natural heart permanently, made for destination therapy. So far, the only device that is commercially approved is SynCardia TAH, it's the only one in the market for patient use.

The paper presents the results of the assessment of the applicability of structured laser illumination in combination with Rayleigh scattering or spontaneous Raman scattering methods for evaluating the local density and temperature distribution in a premixed methane flame. The examples presented in this paper show that the use of structured laser illumination makes it possible to obtain a signal free of background and reflected light by registering the scattering signal only at one S-polarization of the laser. The best quality of image reconstruction was obtained using a grating with a line spacing of 0.5 mm. Gratings with a larger step gave a strong blurring and loss in spatial resolution, a grating with a smaller line spacing during reconstruction led to the formation of secondary structures with lines.

This paper discusses stereoscopic images gain using library in OpenCV on Python platform. The simple stereo camera system that can provide stereoscopic images in both as a picture (PNG) or as a video (AVI) is developed. The system comprises a stereo camera, a USB connector, a tripod, and a notebook with programming language of Python 3.7, along with the free library of OpenCV 4.0 installed inside the notebook. The system has successfully provided both images and videos. However, the spatial resolution and the frame rate depend to the specifications of the stereo camera being used. The camera resolution of 1280 × 360 with a frame rate of 5 fps is obtained based on the stereo camera specifications in this study. The disparity of the stereo camera as a function of distance of the camera to the object of interest is measured. From the experimental results, the p constant is 1059.4, q constant is -0.527 over a distance of 10–100 cm. It shows that farther the object from the camera, the disparity decreases. This system will be used for performing physical measurement in the future.

The paper presents a study of the effect of high temperatures (up to 180°C) and an alkaline environment on the physical and mechanical properties of fiber from a copolymer of polyacrylonitrile with methyl acrylate. These studies are of interest for fiber reinforced concrete and the technologies of its production. Such studies are also useful in studying the properties of fiber reinforced concrete used and exposed to high temperatures. As a result of the research, the tensile strength, strain-to-failure, deformation as a function of temperature and FTIR-spectra for fiber were obtained. The results clearly demonstrate that use polymer fiber from a copolymer of polyacrylonitrile with methyl acrylate for reinforcing fiber concrete is possible at temperatures up to 60°C, at this temperature in an alkaline environment there is a slight decrease in the mechanical characteristics of the fiber.

Within this work, we provide a comprehensive overview about research activities and current status with respect to rotary printed metallization for silicon solar cells. We will present the major results of the research project »Rock-Star« and previous activities which focused on the metallization of Si solar cells using flexographic printing and rotary screen printing. We demonstrate that the rear side metallization of passivated emitter and rear cells (PERC) can be realized with rotary screen printing on the same quality level as state-of-the-art flatbed screen printing. Furthermore, it is shown that both rotary screen printing and flexographic printing are able to realize the fine line front side metallization. Fine line front side contacts down to approx. 40 µm for rotary screen printing and around 30 µm for flexographic printing are demonstrated. However, further optimization is required to reduce finger width, increase finger height and thus decrease the mean lateral finger resistance. A major result of project »Rock-Star« is the development of an innovative demonstrator platform to enable rotary printed solar cell metallization with high printing speed and low cycle time per wafer. Newly developed transport, alignment and printing concept enables a cycle time of down to 0.45 s/wafer. The concept and features of the demonstrator machine are presented within this paper.

In modern agriculture, vegetables growth in greenhouses is valuable to adapt to customers preferences and climate changes. As most of the greenhouses are still heated by gas, the energy production from renewable sources is a axis of development in this field. The purpose of this study is to present the potentiality of an innovative heating system for greenhouse with photovoltaic-thermal solar PVT panels as a unique cold source for a brine/water heat pump. An analysis was made for the solar radiation in a typical winter day with the PolySun software for a 6,000 m² greenhouse in Angers, France. In this paper, the results show to interesting potential of this renewable coupling to cover a large part of the needs for this typical winter day, but also the difficulty to reach a autonomy as it is, which calls for optimizations.

Solar vapor generation is emerging as a reliable way to directly transfer solar irradiation to water evaporation. Graphene-based porous photothermal materials are considered as promising absorbers in this system owing to the broadband absorption and excellent photothermal properties. In this paper, a three-dimensional (3D) graphene foam with self-foaming method for solar vapor generation was produced. Abundant porous channels and a hydrophilicity effect are simultaneously achieved by foam formed. The result shows that graphene foam 3.00 wt% at 30 min stirring time can be achieved highest solar water evaporation at 278% compared to foam without GnPs loading at same stirring time. The FESEM detected more porous channels appears at 3.00 wt.% GnPs loading foams.

In this paper, photo-absorption cross section for selective multi-line excitation of target isotopologues within the SILARC method as a function of laser pulse spectrum in irradiation cell implemented as laser resonator has been derived. More accurate expression for excitation rate, which takes into account effective fraction of molecules interacting with laser radiation, to estimate upper and lower bounds on laser intensity, implied by applicability of this method, has been derived.

In this paper, gold thin films were prepared on n-type region of solar cell in a method of plasma sputtering technique with different thicknesses. The purpose is to enhance the conversion efficiency of single crystalline silicon solar cell compared to the bare cell. Different thicknesses of gold film 10 nm, 20 nm, and 30 nm were used to find the best thickness that improves efficiency. The obtained solar cell efficiency was (16.76 %) at (10 nm) thickness of gold film and (14.52 %) at (20 nm) whereas it was (4.64 %) for a bare solar cell. The reason for the high efficiency is the presence of free electrons in the nano-islands that disperse light when it falls on the gold film. This increases the amount of light entering the cell. The optical properties were also studied (absorbance, transmittance, and reflectance) of the gold thin film. The result showed that higher transmittance, less absorbance, and reflectance at a thickness of (10 nm).

Recently, the extensive usage of electronic devices in the electrical system increases the magnitude of non-linear loads, significantly. These devices are essential at residential, factories, commercial, and office premises. Modern equipment which produced non-linear load are computers, heat pump, air conditioning system, light dimmer, and others. These appliances inject pulses into the system’s current waveform and generate harmonics throughout the electrical system. This phenomenon will increase the heating of utility and other appliances which resulting in system resonance and failure of the device. A lot of harmonic mitigation methods are now available to minimize the effect. The methods categorized into the passive, active, and hybrid harmonic filter. The efficiency of each method depends mainly on applications and conditions of the system, while others need extensive systems analysis. This review paper describes the different harmonic mitigation approaches with their standard circuit connection dealing with the electrical power system.

Welding process is known as one of the well-known of hazard-expose operations in manufacturing. In every welding method or process, safety is the most important element that need to take care. Safety and health in employment is an area which aims to protect the safety and health of people who are working. This case study is about the welder that killed while his colleagues injured his left hand due to diesel tank explosion during welding. In this accident, the victims were welding on the diesel tank before the tank suddenly explode. Thus, this paper highlight report on hazard identification, and risk control applied in the accident. The aim of this case study is to investigate the work-related accident at welding workshop and the hazards working there. This case study had been conducted by using 3 method which is fishbone diagram, HIRARC table and Pareto chart way of a walk-through observation and the identified risk images were taken. From the experiment result, there are 5 hazards that can be related which is the hazard identification are exposure to fumes and gases, heat, fire and burns, Electric Shock, Bright Light and Noise. In conclusion, the highlight of the hazards and risk tend to make a corrective action on minimizing or eliminating the risk of injuries and to ensure a safe workplace

The paper presents the results of an experimental study of the thermal modes of a supersonic combustion chamber at Mach numbers at the channel inlet 3-4, operating on hydrogen. Model is made in the form of a rectangular channel with a combined flame holder with a backward-facing step and wedge-shaped injectors. The experiments were carried out in the mode of a connected pipeline under conditions close to flight ones. It was found that the maximum level of heat flux is reached in the region where the ignition of the mixture is initiated, and this value is achieved during the non-stationary ignition of the combustion chamber. The position of this region shifts upstream with a decrease in the Mach number, which depends on the change in the position of the separation region of shock waves interaction with the boundary layer. With an increase in the Mach number to 4, intense combustion does not occur due to the displacement of this region downstream into the diverging channel and is accompanied by a significant increase in the flow rate. The data obtained show that when developing systems for thermal protection of the combustion chamber, it is necessary to take into account the uneven distribution of heat fluxes along the combustor length in order to prevent local destruction of the walls and possible saving of the coolant resource.

This paper shows the application of three low-temperature silver pastes on silicon heterojunction (SHJ) solar cells and Cu(In1-xGax)Se2 modules by parallel dispensing and flatbed screen printing. The goal was to improve the finger shape as well as to increase the applicable process velocity resulting in reduced silver consumption per SHJ solar cell. In case of the thin-film technology an advantageous electrical performance of applying a front contact metallization on the modules was demonstrated. By dispensing optimized paste formulations, the core finger width was reduced to wcore = 25 µm and the optical aspect ratio was increased to ARo = 0.55 obtaining an efficiency gain of Δη = 0.3%abs. compared to the screen-printed reference on SHJ solar cells. Additionally, a simple integration solution for the parallel dispensing into existing industrial solar cell metallization process line was presented.

Recently assembly line balancing (ALB) is an ultimate focus issue in manufacturing industries for optimizing both common goals which were the number of workstations and the production rate. Metaheuristic is one of optimization problem-independent technique. This paper focusses on the short review of metaheuristic optimization in solving assembly line balancing problems. Hence, to produce a summary of the review, this paper selects some publications for the past 3 years from year 2016 to 2019. From the review shows the metaheuristic optimization that often used are Artificial Bee Colony (ABC), Ant Colony Optimization (ACO), Differential Evaluation (DE), Evolutionary Algorithm (EA), Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Simulated Annealing (SA). Besides, GA is most frequently used to solve ALB problems. Finally, recommendation for future research for solving ALB Problems using metaheuristic optimization are discussed.

The utilization of calcined clays as pozzolanic materials are in demand by many industries as valuable mineral resource mainly in cement industry including geopolymer concrete. This is due to the content of the SiO2 and Al2SiO3 that are very similar to the Portland Cement. Studies on the pozzolanic properties of concrete incorporation with representative samples of the calcined clays would contribute to the sustainability of concrete production. Not only that, the determination of the specification of acceptance criteria for raw clays and calcined products are also need to be taken into account. This paper presents some research finding about pozzolanic properties of calcined clays (metakaolin, illite, montmorillonite) with focus on the effect of calcination temperature on clay, its compressive strength and the geopolymer concrete itself. Metakaolin is a pozzolanic material and can be obtained by the calcination of kaolinitic clay. It is being used very commonly as pozzolanic material in mortar and concrete, and has exhibited considerable influence in enhancing the mechanical and chemical properties of mortar and concrete.

The performance of solid oxide fuel cells (SOFCs) is significantly affected by the properties of its components which are electrolyte, electrodes (cathode and anode) and interconnect. Among the components, cathode is considered as the most critical component as high cathode polarization resistance (Rp) contributes to a major loss in SOFC performance. Thus, developing of good materials as cathode has been attempted to cater the problem. The development of cathode materials for SOFCs started with pure electronic conductor. This type of cathode materials provides limited electrochemical reaction sites, resulting in high Rp. Next, mixed ionic-electronic conductor (MIEC) cathode materials have been developed and followed by composite cathode materials. Both types of cathode materials are better than pure electronic conductor as they provide larger electrochemical reaction sites. However, some of them still resulting in high Rp especially at operating temperatures ranging from 400 °C to 800 °C. Then, the current researches are devoted to develop triple-conducting (H+/O2-/e-) oxide (TCO) cathode materials. This type of cathode materials is particularly useful for proton-conducting SOFC application. Therefore, this paper aims to provide a short review on the properties and performance of the TCO cathode materials along with the factors influencing its properties and performance.

This paper reported on performance assessment of a field-effect transistor-based biosensor with different widths of the silicon nanowire transducer channel. Silvaco ATLAS device simulation software was used to model the device design with three different channel widths, which are 100, 150, and 200 nm. In this simulation, the bounded target biomolecules during actual detection using the biosensor were represented by several negative interface charge density values applied on the surface of the transducer channel. Increase in accumulation of hole carriers beneath the channel’s surface was observed due to the availability of negative interface charges on the surface, hence increased the output drain current. Furthermore, width reduction of the device’s channel had allowed more significant change in drain current due to application of different interface charge density values and increased the device’s sensitivity. Among the simulated devices, silicon nanowire field-effect transistor-based biosensor with transducer channel width of 100 nm had shown highest sensitivity (-56.45 nA/e−cm2) with lowest interface charge density detection (2.79×1010 e/cm-2), which means it enhances the interface charge detection by providing better response and allows lower limit of detection. Therefore, in actual detection, possibility for reaction of the transducer channel to the specific target biomolecule can be increased.

The paper deals with the dust cleaning system at the construction industry, in particular, at the production of granulated foam glass ceramics. The analysis of the construction companies’ activity and their harmful emissions has been carried out. The applied methods of protecting working areas from dust, their effectiveness and the need for their use in various industries have been studied. It is proposed to make changes to the dust cleaning system used in the production of granulated glass ceramic foam. To increase the degree of cleaning, it is proposed to install a Venturi scrubber instead of a cyclonic one.

The main development directions in modern power engineering industries are related to increasing the output power and improving the economic and ecological performance of the engine. The group of pistons inside the engine highly affects the reliability of the reciprocating engine and its power and economic performance. This paper presents a mathematical model developed by the authors to calculate the hydrodynamic characteristics of the oil layer, taking into account the transverse motion of a two-piece piston, piston skirt deformations and variable viscosity of the lubricant in the interface. The conducted research is aimed at developing a piston design that will provide liquid friction in the piston skirt-cylinder junction during the entire operation cycle. Particular attention is paid to the evaluation of the accuracy of the obtained results. The results of the study of the computational mesh size in the numerical solution of the elastic-hydrodynamic problem on the accuracy of calculation of the hydrodynamic characteristics of the oil layer in the piston skirt-cylinder junction considering the piston skirt deformations are presented. This paper provides an example on studying the influence of the piston skirt profile on the hydrodynamic characteristics of the oil layer and the lateral movement of the piston skirt. The calculations were carried out using program codes developed by the authors.

In this paper, cadmium oxide (n-CdS) deposited on porous Si substrates from p-type by pulse laser induced plasma (PLIP). n-CdS/p-PSi heterojunction. Nd: AYG laser has been utilized in PLD system with wavelength of 1064 nm at different laser energies from 220 mJ to 520 mJ with increment of 100 mJ in each sample. The number of laser pulses has been set constant 100 pulses in each step.solar cell measurement has been studied by J-V characteristics for the back and front contacts. As we note that the laser energy increases from 220 to 520, the solar cell efficiency value increases from 1.55 to 3.4.

Recently Molten Salt Reactor (MSR) gains more interest among nuclear researchers due to its promising competitiveness and safety features. ThorCon MSR (TMSR500) is this kind of reactor projected to be built in Indonesia. Due to a limited number of proven operating reactors and limited knowledge of reactor characteristics, several aspects have to be studied, such as neutronic features, material, fuel circulation, fuel management, etc. This paper reveals some important neutronic safety features of MSR, referring to ThorCon design, such as temperature reactivity feedback of fuel, moderator, and reflector. Void reactivity feedback and neutron energy spectrum behavior during voiding were also examined by performing MCNP6 calculations and nuclear data ENDF/B-VII. Full core geometry was modeled, and the drift effect was not taken into account. Neutron flux and power density distribution were also addressed. The purpose of this paper is to review the aforementioned important safety parameters by doing the Monte Carlo code calculations. The results indicated that the core induces negative reactivity feedback due to temperature increase in fuel and moderator, but positive for temperature increase in the reflector. The temperature reactivity coefficient of fuel, moderator, and reflector exhibited −5.82×10−3 (%dk/k)/°C, −9.68×10−4 (%dk/k)/°C, and +1.84×10−4 (%dk/k)/°C, respectively. The introduction of void in the core either as a result of boiling or pump cavitation would induce positive reactivity of +0.115 (%dk/k)/(%void). Overall, the temperature reactivity coefficients exhibited large negative, and there is a comfortable margin between the operating temperature to the boiling point that might prevent void generation due to fuel boiling.

Cognitive radio (CR) is the latest type of wireless technology and provides more flexibility in terms of spectrum utilization. in CR, secondary user uses primary user’s spectrum during primary user’s absence without interrupting the primary user’s transmission. However, the secondary user’s transmission is interrupted as primary user reconnects to their spectrum. The secondary user needs to identify a new available spectrum for retransmission. This paper presents the development of cognitive radio network using Android based smart phone for the data transmission. Both Bluetooth and WiFi spectrum detection are focused here. The used sensing method is energy based sensing method. The CR is developed using Java based Android Eclipse. The developed CR network is verified using Android based smart phone. Result shows that the proposed CR network is able to sense the spectrum with accuracy of approximately of 81%. The developed CR network is able to help secondary users to sense and use spectrum (licensed) for data transmission.

Curing concrete is actually maintaining the moisture content as long as possible in order for concrete to develop its hardening properties during its early stages. However, good curing is rarely to occur and that’s due to lack of knowledge by workers at site and shortage of water at the site area. Therefore, to investigate and produce a self-curing concrete that relays on itself in curing without the need of an outer source of water as a curing agent with a similar performance of a normal concrete using external water as a source of curing agent. This paper is investigating the effect of baby diapers as a self-curing agent. The mix design consists of high strength ordinary Portland cement with a grade of 52.5 along with coarse aggregate and washed river sand as a fine aggregate mixed along with silica fume to enhance the strength of concrete side by side with super-plasticizer to improve the workability of concrete, with the addition of baby diapers. Mix proportion has been divided into 4 mix with different proportion of baby diapers acting as the changeable variable while the rest of the components is fixed, the 4 mixes are said to be Control Mix (CM), 1% of baby diapers polymer, 2% of baby diapers polymer, and 3% of baby diapers polymer. In order to have a fair comparison in an equal number of cubes, cylinders, and prisms are molded and distributed equally to be tested under 3 different situations which are curing tank, room temperature, and sun-dry. The results can be concluded that the optimum baby-diapers ratio to be used is 1% and the optimum curing condition is said to be room-temperature as it gave the highest compressive strength and split tensile strength.

Solid oxide fuel cells (SOFCs) are one of the hit in the sustainable energy industry as it provides an efficient energy production through heat and the chemical reaction of fuel cell stacks (anode, cathode, electrolyte) to produce electrical energy and are connected via interconnects. SOFCs interconnects functions as a barrier for gas that sections the air (cathode electrode) and hydrogen (anode electrode) on the adjacent repeating unit cell. Electrophoretic deposition (EPD) is preferred as it provides an easy, cost effective and geometrically flexible colloidal process. Due to its excellent control of thickness and surface morphology, it is suitable as each component layers of SOFCs have different requirements. As to optimize EPD parameters, time deposition and voltage deposition is crucial as this affects the deposition rate of coating and coating quality. Thus, further discussion is to be implemented in this paper on the EPD mechanism in improving the effectiveness of SOFCs.

This paper proposed the modelling and simulation of generator protection for power system using digital reverse power relay. The operations of the power plant are often interrupted by the reverse power generation. Therefore, generators need to be closely monitored and controlled. In this study, 11 kV synchronous generators are connected to 220 kV load through a step-up transformer, and a new model of reverse power relay is added for generator protection. The reverse power relay proposed in this paper is a digital relay with high accuracy and high reacting speed. Several cases based on various types of mechanical inputs to the generator were studied to test the operation of the reverse power relay. This simulation was done using MATLAB/Simulink. The results show that the 11 kV generator protection is successful with this new model reverse power relay. Besides, the simulation results were similar result compared to the theory result. From the simulation results, the integral output of the relay will reach the threshold value ‘L’ whenever there is a reversed power flow fault found in the system. Consequently, the relay will be triggered to provide protection for the generator. This model has been added into online resources of MATLAB Power System Tools. In addition, this model may also help the engineers to develop the analytical skills under various conditions.

Two‐beam electron accelerators suggested and designed at the Lawrence Berkeley Laboratory (1,2) are mainly intended for research in high energy physics. This paper studies the ‘‘two‐beam concept’’ in order to make high current ion accelerators. As is known, one basic setback hinders the current enhancement in existing linear accelerators. Indeed, if special measures are not taken the accelerating RF field is defocusing in the radial direction. In a two‐beam ion accelerator it is possible for the driver electron beam to excite RF fields in an ion linear accelerator that are accelerating and focusing at the same time. A considerable gain may be obtained in the current of accelerated ions and in the acceleration rate.

At present, the aeronautical equipment manufacture involves up-to-date high-strength aluminum alloys of decreased density resulting from the lithium admixture. Various technologies of fusible welding of these alloys are being developed. The paper presents experimental investigations of the optimization of the laser welding of aluminum alloys with the scandium-modified welded joint after thermomechanical treatment. The effect of scandium on the micro- and macrostructure is studied along with strength characteristics of the welded joint. It is found that thermomechanical treatment allows us to obtain the strength of the welded joint 0.89 for the Al-Mg-Li system and 0.99 for the Al-Cu-Li system with the welded joint modified by scandium in comparison with the base alloy after treatment.

The quadrotor type of UAV (QUAV), is arguably the most popular type for civilian purposes, since it does not mandate a complicated remote controlling skill to operate it. This popularity, however, has yet to be balanced with research in mathematical modelling, design, and analysis. This paper describes a mathematical modelling process of a QUAV, by exploiting the usage of MATLAB/Simulink software. The main aim is to provide a proper mathematical model to design and evaluate the control system to maintain QUAV stability. Along with the model, three basic automatic control systems were also designed, i.e., the forward-speed hold, sideward-speed hold, and altitude hold system. Several simulations were conducted afterward, to test both the model and the designed control system, which showed satisfying results in representing a QUAV system. QUAV dynamic characteristics can be observed from the simulation, including the logical commands to alter the rotors thrust, the rotor limitation in handling many commands at once, the vehicle dependency of automatic control systems, and the fact that a motion in one degree of freedom can easily affected others. The developed model evidently has a good potential as a base for QUAV analyses and control design.

In this paper, we report the tuning of optical gain spectra of nano-scale heterostructure based on type-II band alignment and made of the GaAsSb/InGaAs material system. The designed heterostructure is of “W” shape. In order to tune the optical gain as well as the optical wavelength, a uniaxial high pressure (ranging from 5 GPa to 20 GPa) is applied on heterostructure along (100) direction. On applying such pressure range, the optical gain is found to be reduced significantly; while the wavelength has shown a red shift. This result may be useful for designing the tunable diode lasers.

This paper presents the effect of hot isostatic pressure post-treatment on tin powder particle under elevated temperature in order to obtain the spherical particle shape. The tin powder particle obtained from the gas atomization as used as a precursor. The powder was placed in the liquid olive oil within the Teflon-lined autoclave, which was then subjected to the hot isostatic pressure post-treatment at five type temperature for specified time. The as-treated powder was rinsed, dried, and observed morphologically using high resolution digital microscope. It is found that the ratio of spherical particle shape is increased by 2.4 - 3 times, relative to the untreated powder particle, which can be achieved after 210 minutes post-treatment at temperature of 90% of its melting point. The density of the post-treated powder is increased by 1.05 - 1.15 times, and the porosity is increased by 5.7 – 8.0 times. These results offer another possible method to obtain spherical and enhance density metal powder particle for specific purposes.

Regarding the physical and chemical performances, Fe3O4 and multi-wall carbon nanotubes (MWCNT) combined with other metal oxide such as titanium dioxide open new opportunity to be widely used for energy application such as supercapacitor. In this paper, we report the preparation of Fe3O4/MWCNT nanocomposite combined with titanium dioxide using sonochemical-precipitation method. The nanocomposite was characterized using X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscopy, and UV-Vis spectrometer. The results of diffraction data analysis showed the presence of crystalline phase in nanocomposite derived from Fe3O4 and titanium dioxide with cubic inverse spinel and anatase structures, respectively. The existence of MWCNT was then confirmed by functional groups data which indicated the vibration of C=C functional group at the wavenumber of 1400-1600 cm−1, while the vibration of Fe-O was detected at the wavenumber of 409 cm-1 and 667 cm−1 overlapped with Ti-O functional group. MWCNT was considered to be crosslinked the surface of Fe3O4 or titanium dioxide nanoparticles. The bandgap energy of the nanocomposite was 2.17 eV for Fe3O4/MWCNT, and 3.27 eV for Fe3O4/MWCNT. Furthermore, the magnetization value of the sample was 50 emu/g exhibited as a superparamagnetic character.

The development of communication technologies shows that fiber optics is in the main communication improvement in the last decade. Fiber optics is moved from laboratory to be a reality. Transmission of the data using the light as a signal carrier is a revolutionary improvement in the communication era. However, to enable this technology several obstacles should be addressed, such as achieving the longest distance transmission with less possible bit error rate (BER). One of the solutions was performed by careful selection of the optical modes profiles with the help of the nonlinear electrical equalizer (NLEE) to solve the problem of the mode coupling. This paper investigates on the compensation of different modes profiles in optical communication systems over few-mode fiber (FMF) based on Space Division Multiplexer (SDM) with an electrical non-linear equalizer utilized to equalize nonlinear distortions. The result shows that the LG mode achieved the best transmission distance comparing to the other modes which make it the best option to be used. Basically, the evaluation of the system has been done based on standard evaluation metrics such as BER and Eye Diagram. These results can optimize the data transmission quality.

A process for non-covalent functionalization of synthesized multi-walled carbon nanotubes (CNTs) with phenol-red is reported in this paper. The SEM images confirmed the existence of CNTs and the sensors morphology. These results show that the aggregated red phenol molecules get attached and anchor the surface of CNTs. We have utilized the prepared nano-composites to fabricate very fast and sensitive sensors for detection of ammonia vapors. The sensors having resistivity in the kilo-ohms range show response and recovery times of few seconds. However, the response and recovery times and change in resistance are strongly dependent on the type of red phenol and the chemical vapors. We also report the progresses made in the field of the synthesis techniques of CNTs using s low cost natural carbon sources method. The high quality CNTs have been synthesized by pyrolysis of mustard oils in insufficient supply of air under ambient condition. The synthesized CNTs were purified through oxidative treatment by using the mixture of dilute nitric and sulphuric acid (3:1).

This paper presents the results analysis of switching’s effect when capacitor bank operation against the amount of inrush current on the circuit breaker. The capacitor bank switching causes inrush current and high-frequency oscillation if there are two or more capacitor banks connected on the same bus. When it occurs repeatedly, the insulation from the electric equipment will weaken and breakdown. For this reason, we propose a method to reduce the inrush current using new controlled switching. Switching control is used to find the time (t) of circuit breakers’ switching. So it can be seen the configuration of capacitor banks’ switching causes minimal inrush current. We have done a case study 3 capacitors using Simulink. Variables used are inrush current (ii), controlled switching time (t), and damping reactor (Lreactor). Inrush currents can be reduced by 99.8% using the proposed switching control method. The amount of inrush current is below the capability of the power breaker rating so that it does not cause a power breaker to interrupt and also does not cause overcurrent in the system. If the circuit breaker does not trip when there is a high inrush current in a short time, it can be dangerous for the electrical system equipment.

The metal oxides nanocomposites spanned as high-capacity electrode materials in both battery and supercapacitor applications. In this paper, Graphene composite with metal oxide has been explored as a platform for energy storage devices by decorating graphene sheets with SnO2 nanostructures. Facile and efficient synthesis process has been used to prepare the composites of SnO2−nanocrystal/graphene-nanosheets i.e. chemical reduction (GNs/SnO2) which was simply based on the reduction of graphene oxide (GO) by Sn2+ ion. X-ray diffraction (XRD). The mean crystallite size was calculated to be about 4.0 nm. Dielectric properties show the decrease of dielectric loss with increase in frequency and at higher frequency it shows the constant behavior. AC conductivity of GNs/SnO2 nanocomposite was calculated as 4.3*10−4 (ohm m)−1. The electrochemical analysis shows the GNs/SnO2 nanocomposite has the capacitance of 1.06348 mF at the scan rate of 50 mV/sec which was evaluated from the cyclic voltammetry.

This paper describes a fiber extensometer system that utilizes pulse width modulation in its light source for power efficiency reason. The fiber extensometer was used to monitor displacement by intensity modulation techniques based on macro bending effects. The fiber extensometer consisted of an Arduino microcontroller; to modulate laser sources into optical pulses and to regulate data transmission; a bent fiber for displacement sensor, detector and amplifier, GSM module, antennas and power supply system which was solar cell based. The ON - OFF pulse timer from the programming using the C + language in the Arduino sets the pulse time difference ON - OFF of laser light. The modulated light was then launched to the sensor fiber, received and amplified by detector system. When displacement occurs, the diameter of the fiber bent will change as well as the sensor output. Furthermore, the microcontroller instructed the GSM module to send the output signals contain information about displacement to the user’s mobile phone in the form of short message service (SMS). It was obtained that power savings that can be achieved using pulse width modulation techniques on this fiber extensometer system reached 30%, compared to that of fiber extensometers that used continuous laser.

The dispersion plays an important role in pulse propagation in an optical fiber. The effect of higher order dispersion terms are generally neglected for pico second pulse propagation. In this paper we have tried to discuss the propagation length upto which the third order dispersion (TOD) parameter may be neglected. Beyond this length the ignorance of this parameter is not possible as it may affect the pulse shape. Semiconductor Bloch equations are applied to determine the Polarization induced in the medium due to incident Gaussian pulse. The analysis of induced polarization is made by Non linear Schrodinger equation. To represent the pulse propagation behavior linear partial differential equation is used. The results of the numerical calculations provide a support for the fact that the third order dispersion parameter in an optical fiber may be neglected only upto a specified length depending upon the input pulse width.

This paper reports on the investigation of the features of using screws as turbines in free-flow floating and submerged micro-HPP with different geometric parameters by optical diagnostics (particle image velocimetry) and numerical simulation (large eddy simulation). The numerical simulation shows the good agreement with the experimental results. Change of screw pitch lead to significant effect on the structure of the flow downstream of the screw rotor. Screw rotor with a screw pitch equal to half the length of the rotor has the good energy characteristics and shows the best hydrodynamic flow structure.

Earlier, welding was employed only for joining two metals of same kind and dissimilar metals were usually joined by fasteners. Friction welding is a true engineering marvel of making welds between dissimilar metals without any melting or fillers involved. The friction welding doesn’t involve heat generation from electricity and it’s purely based on friction. Besides these facts the friction stud welding has numerous advantage and applications. This paper focuses on the application of friction welding in automotive components.

The present paper deals with the numerical optimization of CIGS based thin film solar cells using solar cell capacitance simulator (SCAPS). In the present work we have tried to study the variation of electrical parameters such as: Voc, Jsc, η and FF with the variation in material parameter particularly the absorber layer thickness and the operating temperature. Conversion efficiency of 23.58% was observed using 1.7 μm thickness and 1.35eV bandgap of CIGS layer under the AM1.5 G spectrum having a constant illumination of 1000W/m2 and 1 sun, also the simulation results inferred that the efficiency increases on increasing the CIGS layer thickness which is due to the large number of photon absorption.