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A paper battery is a 6 cm × 4 cm × 1 mm dimension battery that uses CuCl as a cathode, magnesium as an anode, and urine as an electrolyte. CuCl2 dan CuSO4 as used to synthesis CuCl was analyzed. A simple and cheap sandwiched fabrication model has been identified using the low-cost CuCl synthesis process. This paper battery has passed experimental testing and delivers the best power generation at 169,588 mW and continuously up to 4 hours. Voltage also measured and provided a stable voltage at least for 6 hours at 582.667 mV. Method 2 of using CuSO4, which has price lower than CuCl2 showed better power generation and stability.

Photobioreactor have been a prominent way to produce biomass in case of biofuel production. One of the most important procedure in this line of production is harvesting. Nowadays, microalgae biomasses are harvested by using many methods such as flocculation, filtration, centrifugation, and the other methods. Those methods are the commonly used by many bioenergy companies to accumulate their biomass before extraction phase. This process requiring a lot of cost and times. In order to increase cost and time efficiency, examination of ultrasound wave trapping method has been done. A harvesting module was assembled as a system consisted of two piezoelectric circuit (ultrasound wave generator) in a transparent box. Data shown by generating 1.7 MHz wave for 20 minutes, turbidity of Synechococcus (coccoid cyanobacteria) biomass was decreased from 56.3 NTU to 55.6 NTU. The other data also shown decreased turbidity of mixed culture biomass from 46.5 NTU to 16.4 NTU. This results also followed by weight measurement for both biomasses. This module capable to accumulating microalgal biomass a number of 0.0138 gram for Synechococcus and 0.8544 gram for mixed culture. The difference in biomass accumulation results are caused by cell size and density. Synechococcus cell size range between 0.5-2 µm with a very low density. This phenomenon makes any kind of small-sized coccoid cyanobacteria are need more time to be accumulated. Meanwhile mixed culture of microalgae is easier to accumulated due their variety of size and density.

Gasoline used in an Otto engine can be substituted by pure Bioethanol or Gasoline-Bioethanol blends. The engine performance can be affected by the mixture. Specifically, the blends can affect (Increasing or decreasing) power, torque, and emission produced by the engine. It is caused by the different characteristic of the Gasoline-Bioethanol blends depending on the volume percentage of the Bioethanol. Theoretically, as the increasing of the volume percentage of Bioethanol to the mixture, the power and torque produced would be decreased because of the lower energy contained rather than gasoline. As a biofuel, Bioethanol is a natural product and created by the fermentation of plants containing sugar and starch which has a similar physical and chemical characteristic to gasoline. The objective of this experiment was to determine the effect of Bioethanol-gasoline blended fuels on the performance of an engine. In this case, the performance includes specific fuel consumption, power, and torque. The experimental test was using gasoline with octane number 88, 92, 98, and 30%, 40% Bioethanol blend. The effect carried out by increasing the volume number of Bioethanol to the gasoline is the increasing of the power and torque produced by the engine. Keywords: Gasoline, bioethanol, research octane number, engine performance.

The level consumption of Polyethylene Terephthalate (PET) as a packaging of colored beverage bottles occupies the fourth largest in the world. In Indonesia, PET consumption increased reaches 7% per year so that it can cause environmental impacts. This study aims to process the recycling PET waste by obtaining a simple potential process to remove the color from PET waste. The decolorized PET waste will be an alternative carbon source for Carbon Nanotube (CNT) synthesis. The colors of PET waste are blue and green bottles. The selected color removal agent is hydrogen peroxide (H2O2) because it is inexpensive reagent and has lower toxicity to environment. The colored PET waste and H2O2 will be heated in the oil bath system at temperature 110°C and pressure 1 atm. The result showed that color removal time for blue PET waste faster than the green PET waste, 72 and 115 minutes per 15 grams PET waste. The quality of color removal of blue PET waste is better than the green PET waste because it has a reflectance value closer to colorless PET waste, namely 80%. The CNT synthesis process from decolorized blue PET waste produce 8.58% yields. The average diameter of CNT crystals from its process is obtained at 37 nm. This shows that PET waste plastic which has been discolored can be used as a carbon source in CNT synthesis.

Batik industry in Indonesia frequently dispose liquid waste containing high level of toxic and carcinogenic dyes to the drainage without being treated. In accordance with it, plasma electrolysis has been proved as the efficient method to degrade dyes waste, yielding higher hydroxyl radicals than other methods. The experiment was conducted by generating plasma in circulated reactor using stainless steel cathode and tungsten anode with 2 cm depth immersed in 0.02 M Na2SO4 electrolyte solution added by 20 mg/L Fe2+ and 100 mg/L of Remazol Red initial concentration, with addition of varying air injection rate at maintained power. The results show that 1 L/min is the optimum air injection rate value to operate this reactor effectively at 450 W of optimum operating power so that it could lower the breakdown voltage, reduce energy consumption, produce more OH radicals and other reactive species, and elevate the degradation percentage. The experiment conducted in optimum operating condition provide result of 99.61% in degradation percentage for 60 minutes with final concentration of dye is 0.39 mg/L, 41.55 mg/L of COD, and 3177.16 kJ of energy consumption.

Hydrogen is an alternative energy source that can replace fossil fuels. The latest breakthrough idea for producing hydrogen fuel is by utilizing biomass in bioelectrochemical systems, which is Microbial Electrolysis Cell (MEC). MEC is a method for producing hydrogen gas that is managed from organic materials, including from wastewater. In addition to very low energy consumption, the MEC system is able to use sludge waste as a substrate for the bacterial community to be implemented. The rate of hydrogen production with MEC is relatively lower when compared to air fermentation and electrolysis methods. Efforts that can be made to increase hydrogen production are by operating the MEC system at optimal distance between electrodes. One of the major problems that arises from the use of the MEC system is methanogens, the methane-producing bacteria. This methanogen consumes biohydrogen produced at the cathode which cause the loses of biohydrogen production in MEC system. In this research, biological control methods is utilized in bioelectrode by enriching it with denitrifier bacteria to inhibit the growth of methanogens. The MEC reactor is carried out in configuring a single-chamber MEC. Variation in denitrifier bacteria used and distance between electrodes aim to find the optimal conditions. The composition of the reactor chamber gas head is supported by using Gas Chromatography to analyze hydrogen and methane reserves. The addition of Pseudomonas stutzeri as biological control of methanogenesis could reduce the methane up to 76.28% compared to the control reactor at the first cycle. The presence of Pseudomonas stutzeri was also able to increase the H2 produced 128% higher compared to the control reactor. With the electrode spacing 0.5 cm, the H2 produced 65% was higher than the MEC reactor with 1 cm-electrode spacing. The 0.5 cm space was the optimum space for this experiment since it still supported the growth of the exoelectrogen bacteria and reduced the internal resistance within the MEC system.

Nitrogen is the most important substance in fertilizer to produce high quality harvest. Nitrogen, which comes from the air, can formed as ammonia and nitrate in fertilizer. In industry, the most common fertilizer contain ammonia not nitrate because of its production process easiness compared to nitrate. Ammonia has fertilization efficiency 40% and nitrate has fertilization efficiency 60%. Industrial fertilizer production process nowadays, ammonia synthesis which called Haber-Bosch process, still not environmental friendly and also consume high energy. Environmental friendly and lower energy process is needed to produce fertilizer. Some study related to nitrogen fixation to produce fertilizer has been made including plasma electrolysis method. Plasma electrolysis is an effective method to fix nitrogen from the air because of its ability to produce OH radicals and other radicals to break the N2 bound to produce nitrate with lower energy consumption compared to Haber-Bosch process. This method is implemented in batch reactor with variation of anode depth. This study has proven can produce nitrate up to 1,200 ppm in condition power 800 watt, anode depth 1.5-3.5 cm and Na2SO4 electrolyte concentration 0.02 M.

Driven by the exacerbating urbanization and population, there has been a shoot up in the global energy demand over the past few years. The technological exploration efforts in the field of biofuels have proven to be a promising alternative to the slumping fossil reserves. The main aim of this work is to inspect the potential of palm oil as a biofuel with aluminum oxide nanoparticles as an additive in it. The experimental work was carried out on a single-cylinder four-stroke CI engine running at a constant speed of 1500 rpm at varying loads using palm oil biodiesel blends and the emissions and performance parameters were compared with that of neat diesel. The results concluded a significant increase in BTE with increase in alumina concentration in the blend owing to catalytic behavior of alumina which accelerates the combustion process. Furthermore, reductions in HC and CO emissions were also recorded.

Water filter has been made to improve well water quality by using filtration concept in which activated carbon from cocoa rind waste and clay was used. The filter was made by varying the composition of cocoa rind waste and clay in activated carbon at the ratios of 85%:15%, 80%:20%, 75%:25%, 70%:30% and 65%:35%. The combustion temperature was varied at 200°C, 230°C, 260°C, 290°C and 320°C. Then it was molded by using mold and press conventional technique. The characterization results showed optimum composition was reached at 65%:35% ratios under 320°C combustion where the absorbance and porosity of water filter were at 86% and 52.38% respectively. Whereas density of 0.617 g/cm3 and 0.00514 MPa compressive strength were obtained from 85%:15% composition at 200°C combustion temperature. The performance test for the filter in purifying well water gave 3.2 NTU for turbidity, 7 TCU for color, 338 µS/cm conductivity, 6.7 pH level and Fe content of 1.0 mg/L. The analysis done showed that the water filtered has met the standard quality of clean water.

The production of bioethanol from date molasses is one of the effective discoveries in the field of Sustainable development represented in positive exploiting of renewable energies mainly biomass energy. The paucity of ethanol gas at the Sirte University was the stimulator for considering this research. The study was conducted in the chemistry labs at the Sirte University in 2018 to investigate the possibility of producing bioethanol from date molasses determining the effect of different temperature, PH, yeast quantity and fermentation time in molasses on the amount of ethanol produced. Three samples of molasses were taken in different sizes. Bioethanol was indirectly extracted through alcoholic fermentation of date molasses in anaerobic conditions. Because of the lack of a low-pressure distillation device, a normal distillation device was used. The best amount of bioethanol (25ml) was extracted at the largest quantity of yeast (2g), the longest fermentation time (236h), the highest fermentation’s temperature and PH 4.8. Ethanol specifications were examined via qualitative tests.

Emulsions are dispersion systems, where one phase is dispersed in another phase in the presence of an emulsifying agent (surfactant). Emulsion fuel can reduce cylinder peak pressure from the combustion chamber compared to using neat diesel fuel. This research use a single-cylinder diesel engine, operates using water diesel emulsion with water percentage of 30% and 35% by volume and diesel fuel as a comparison. Diesel operates with a speed of 1500 rpm and engine load 1000-4000 watts at 500-watt intervals. The results of research at high load showed that fuel consumption of E30 and E35 increased by 15.5% and 16.6%, thermal efficiency increased by 21% and 35.8% (respectively). Whereas HC and CO emissions increase along with the increase in water percentage.Emulsions are dispersion systems, where one phase is dispersed in another phase in the presence of an emulsifying agent (surfactant). Emulsion fuel can reduce cylinder peak pressure from the combustion chamber compared to using neat diesel fuel. This research use a single-cylinder diesel engine, operates using water diesel emulsion with water percentage of 30% and 35% by volume and diesel fuel as a comparison. Diesel operates with a speed of 1500 rpm and engine load 1000-4000 watts at 500-watt intervals. The results of research at high load showed that fuel consumption of E30 and E35 increased by 15.5% and 16.6%, thermal efficiency increased by 21% and 35.8% (respectively). Whereas HC and CO emissions increase along with the increase in water percentage.

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.

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 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.

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.

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.

A Coupling is a device which is responsible for the operative power transmission between two shafts rotating at particular rpm. Coupling is used to connect two different shafts at their end and can slip or fail depending upon the torque limit. It is the crucial part of any power transmission and may last for very long time if designed and maintained properly. The present study of this paper is to reduce the stress that acting on the bolts by making it uniform strength coupling. The stress in the threaded part of the bolt will be higher than that in the shank. Hence a greater portion of the will be absorbed at the region of the threaded part which may fracture the threaded portion because of its small length. An axial hole is drilled at the center of the bolt through the head as far as thread portion such that the stress in the bolt is uniformly distributed along the length of the bolt. The present study of this paper is to reduce the maximum shear stress by selecting a suitable material for flange coupling. For this purpose, modelling of the rigid-flange coupling is carried out in Solidworks and analysed in ANSYS Workbench. Objective is to design a flanged coupling to connect the drive shaft of a 10 kW Kirloskar diesel generator operating at a rated speed of 1500 rpm to an alternator. The above specifications show a maximum torque transmission of 63.662 Nm. A standard shaft of ∅25 mm is used, and the analysis for basic rigid flange is done, including varying the materials. From the results obtained, the existing design is modified to reduce the weight and improve performance.

In the present paper, we have simulated the high performing SnS based solar cell by using SCAPS. SCAPS is one dimensional simulating software which is used for the simulation of solar cell. The solar cell consists of SnS based absorber layer, Zn (O, S): N buffer layer and ZnS as window layer. The p-SnS/Zn (O, S): N/ZnS is device structure of solar cell. The effect of absorber layer thickness and temperature on electrical parameter of solar cell have been reported in the present paper.

In this paper brake performance is studied under varying brake pressure. This brake pressure depends upon the pedal ratio. Along with theoretical analysis software like ANSYS is used to determine the sustainability of the disc under varying load that are obtained by varying force applied on pedal and pedal ratios. A brake is a mechanical device that hinders movement by retaining kinetic energy from a moving component. It is utilized for halting a moving vehicle, wheel, tire, disc or to keep its movement, regularly achieved by means of friction. The parts involved in the braking system are simple but the performance of these brakes greatly varies with slight variations involved in it. Though there are many factors that vary the performance of brakes initially the variations can be done at brake pedal level. The proper selection of the pedal ratio is important for the brake performance. This importance of this small part is the concept of this paper. The importance of this part is described and its effects are detailed in this paper.

Bioethanol is one of the new renewable energy alternatives that have the potential to be used as vehicle fuel by mixing a certain percentage of gasoline. However, the characteristic of this mixture has some differences from pure gasoline fuel. These differences may cause that the mixture fuel is not matched with the standard engine requirements. It will cause a reduction in the value of engine performance. All of these matters have brought us to research for optimizing engine performance that uses gasoline-ethanol fuel. In this paper, a study about ignition time is carried out as a solution for optimizing the performance. The purpose of this research is to optimize the engine performance through engine test using a dynamo testbed. We all know that the Engine Control Module (ECM) is a device to control some systems that run-in engine. One of the systems that controlled by ECM is ignition timing. In this paper, we change the degree for ignition time by expecting that these changes will have some effect on the result. The ignition time and the fuel mixture are the parameters for this research. As a result, we find that changing the ignition time become an advance mode will increase the engine performance and the specific fuel consumption. Keywords: Gasoline, Bioethanol, Engine Control Module, Engine Performance, and Ignition Time.

The paper reports on the results of experimental studies of the operation of the vortex ejector. In particular, different geometrical options for a vortex chamber of the ejector are studied. In order to carry out experimental research, six plastic models of the vortex chamber differing in their diameter have been made. The experimental results show that the most effective operation corresponds to the ratio of the diameters of the vortex and mixing chambers equal to dvc/dmc = 2. This provides the highest values of the ejection coefficient and the lowest values of the relative pressure at the passive nozzle. Both, increase and decrease in dvc/dmc leads to the reduction of these parameters and overall efficiency of the ejector.The paper reports on the results of experimental studies of the operation of the vortex ejector. In particular, different geometrical options for a vortex chamber of the ejector are studied. In order to carry out experimental research, six plastic models of the vortex chamber differing in their diameter have been made. The experimental results show that the most effective operation corresponds to the ratio of the diameters of the vortex and mixing chambers equal to dvc/dmc = 2. This provides the highest values of the ejection coefficient and the lowest values of the relative pressure at the passive nozzle. Both, increase and decrease in dvc/dmc leads to the reduction of these parameters and overall efficiency of the ejector.

This paper describes the probabilistic nonlinear analysis of the hermetic steel door of the reactor shaft failure due to extreme pressure and temperature. The scenario of the hard accident in nuclear power plant (NPP) and the methodology of the calculation of the fragility curve of the failure overpressure using the probabilistic safety assessment PSA 2 level is presented. The model and resistance uncertainties were taken into account in the response surface method (RSM).This paper describes the probabilistic nonlinear analysis of the hermetic steel door of the reactor shaft failure due to extreme pressure and temperature. The scenario of the hard accident in nuclear power plant (NPP) and the methodology of the calculation of the fragility curve of the failure overpressure using the probabilistic safety assessment PSA 2 level is presented. The model and resistance uncertainties were taken into account in the response surface method (RSM).

Because the winding resistance of small power transformer is far bigger than the inductance of winding, it is difficult to obtain the leakage inductance parameters of small power transformer winding accurately by traditional experimental methods. In order to solve the above problems, this paper proposes a method of obtaining leakage inductance by applying step voltage, establishes the T-type equivalent circuit model of transformer, carries out the measurement experiment of leakage inductance, and carries out Simulink simulation with the parameters obtained by applying step voltage. The results show that the simulation results are in good agreement with the experimental results, which verifies the validity of the method.Because the winding resistance of small power transformer is far bigger than the inductance of winding, it is difficult to obtain the leakage inductance parameters of small power transformer winding accurately by traditional experimental methods. In order to solve the above problems, this paper proposes a method of obtaining leakage inductance by applying step voltage, establishes the T-type equivalent circuit model of transformer, carries out the measurement experiment of leakage inductance, and carries out Simulink simulation with the parameters obtained by applying step voltage. The results show that the simulation results are in good agreement with the experimental results, which verifies the validity of the method.

The KDamper is a novel passive vibration absorption concept, based essentially on the optimal combination of appropriate stiffness elements, which include a negative stiffness element. In this paper, the implementation of the KDamper as a seismic Absorption Base (KDAB) is considered. The paper proceeds to the assessment of the performance of the KDamper as seismic absorption base in a typical flexible 5-storey concrete building structure with a fundamental period of 0.5 sec. The structure is excited by artificial accelerograms, generated to be compatible with the highly demanding Eurocode 8 case C with a PGA of 0.36g, and by real earthquake records. The performance of the KDAB is compared not only to the original structure but also to the cases of conventional and highly damped base isolation systems, as well as the case of a Tuned Inerter Damper (TID). Alternative options for the selection of the KDamper natural frequency are considered, leading to two limit cases. In the first case, the nominal KDamper frequency is selected equal to the low frequency of a conventional base isolation system, resulting in a drastic improvement of the overall structural performance. However, another interesting option is revealed, which foresees the implementation of the KDAB with a nominal frequency much higher than that of the base isolation system. This choice leads to a drastic reduction of the relative base displacement, in the order of few centimeters, combined with acceptable structural performance with respect to drift and absolute acceleration. As a consequence, the KDamper can be implemented as “stiff seismic absorption base”, overcoming the disadvantages of the conventional base isolation systems, and thus leading towards alternative seismic protection technologies.

The proper application of multi-material design is an effective way of saving energy costs and reducing CO2-emissions. In the production of heavy-duty components, the tailored forming technology offers the possibility of bringing the right material to the right place. In this context, this paper deals with the challenges that arise during compound forging such components using the example of a bi-metal bearing bushing. For this purpose, steel is placed into the highly stressed bearing surface, where high performance characteristics are required, while the rest of the part is made of aluminium to reduce the total weight of the component. Due to the different material properties of steel and aluminium, the process design for bi-metal compound forging is very demanding and requires process-specific heating and forming strategies, which are presented and discussed in this paper. After the implementation, forging experiments were carried out and the bearing bushings obtained were evaluated by metallurgical and mechanical tests. A crucial aspect in assessing the quality of such components is the bond strength, which generally depends on the development of intermetallic phases. Therefore, an analysis of the joint and phase formation in the area of the joining zone of the compound forged parts was performed initially using optical microscopy. The metallurgical studies showed good bonding with form- and force-closed joint and insular intermetallic phases along the joining zone. Afterwards, the bond strength was determined by push-out tests, whose results were finally correlated with the metallurgical findings.

This paper constructed a new high speed and power density servo motor design scheme based on magnetic pole eccentricity proposed according to the requirements of electrical performance parameters. The analytical formulae were deduced in view of the theory of thick-walled elastic cylinders and the actual model by analytical calculations and finite element calculations. The structure strength of permanent magnet was analyzed. Furthermore, comprehensively comparing and analyzing the calculation results of the two methods verify the accuracy of the analytical calculation method and the rationality of the permanent magnet structure design. In brief, this paper provides a reference for the design of high-speed motor magnetic pole eccentricity.

There are two thermodynamic models of the closed and vented heat pump drying process described in the paper. The models have been used for optimization of process design parameters with respect to drying rate and energy efficiency, respectively. The optimization was performed in points of parametric space defined by refrigerant and air flow rates. Results of the optimization shows the same maximal drying rate performance for closed cycle and both objective functions. There is higher potential of drying time reduction for vented cycle in comparison to closed cycle.There are two thermodynamic models of the closed and vented heat pump drying process described in the paper. The models have been used for optimization of process design parameters with respect to drying rate and energy efficiency, respectively. The optimization was performed in points of parametric space defined by refrigerant and air flow rates. Results of the optimization shows the same maximal drying rate performance for closed cycle and both objective functions. There is higher potential of drying time reduction for vented cycle in comparison to closed cycle.

One of the vital components for the pebble reactor is the fuel handling system which was employed to load, recirculate and discharge the depleted fuel during the operation of reactor. The previous fuel handling design and experience of the High Temperature Reaktor 10 MWth (HTR-10) and HTR-PM were beneficial for the development of High Temperature Gas-cooled Reaktor (HTGR) in Indonesia such as for the Reaktor Daya Eksperiment (RDE) 10 MWth and PELUIT 150 MWth. One of the focus for the development especially for the control is an important factor to ensure that the reliability and the safety during operation were guarantee. Therefore, aims of this paper is to understand and develop the automatic control system of the fuel handling. The development was done by applying the logic flowchart of the fuel handling HTGR with the HTR-10 as the reference. Some modification was made considering the future application in Indonesia It was demonstrated that the automation systems with Programmable Logic Controller (PLC) can control handling systems easily because each valve can be drive to open and close immediately as requested from the sensor. It was also demostrated that the timing chart monitoring confirms the control of flowchart process description for the new fresh fuel loading.One of the vital components for the pebble reactor is the fuel handling system which was employed to load, recirculate and discharge the depleted fuel during the operation of reactor. The previous fuel handling design and experience of the High Temperature Reaktor 10 MWth (HTR-10) and HTR-PM were beneficial for the development of High Temperature Gas-cooled Reaktor (HTGR) in Indonesia such as for the Reaktor Daya Eksperiment (RDE) 10 MWth and PELUIT 150 MWth. One of the focus for the development especially for the control is an important factor to ensure that the reliability and the safety during operation were guarantee. Therefore, aims of this paper is to understand and develop the automatic control system of the fuel handling. The development was done by applying the logic flowchart of the fuel handling HTGR with the HTR-10 as the reference. Some modification was made considering the future application in Indonesia It was demonstrated that the automation systems with Programmable Logic Controller (PLC)...

The use of Natural Gas (NG) in internal combustion engines has been increased in this decade. The objective of this paper is to investigate the NG injection timing on the dual-fuel engine. In this paper experimental based on dual fuel engine strategy (DFE strategy) was tested with several variations of gas injection based on CA at the modified direct - injection engine into a DFE strategy. In the data test, the variation is CA 260, 244, 230, 214 bTDC. This research is for observed how it affects the engine performance. The indication of the effect of NG injection based on the CA variation is the non-homogenization of the NG-air mixture in the intake manifold, and the delay in mixing NG-air to go into the combustion chamber. From several data tests that have been done, there is an increase in engine power, thermal efficiency and a decrease in SFOC fuel consumption. The optimum combination of the DFE strategy has a fluctuating value when taken from test experimental data. The trend is seen, that CA 230 bTDC is the optimum value to be operated in the DFE strategy. Because there is an increase in Torque, Efficiency thermal, and a decrease in SFOC of fuel consumption.

Selective laser melting is a new manufacturing technique that can easily facilitates metal parts with complex structural shapes and high performance. This paper processed 316L stainless steel by SLM technology, and characterized the microstructure and mechanical properties of the as-built specimen. The complex microstructure with cells and columnar grains was observed in the specimen, the specimen density is about 97% and the hardness can reach 189 HV. The wear test results show that the average friction coefficient of the SLM sample is 0.642.Selective laser melting is a new manufacturing technique that can easily facilitates metal parts with complex structural shapes and high performance. This paper processed 316L stainless steel by SLM technology, and characterized the microstructure and mechanical properties of the as-built specimen. The complex microstructure with cells and columnar grains was observed in the specimen, the specimen density is about 97% and the hardness can reach 189 HV. The wear test results show that the average friction coefficient of the SLM sample is 0.642.

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...

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...

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.