bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of wireless charging system along with power line communication used in Electric Vehicles
Authors: Alapati Sai Varun , Nadella Indusaiteja , Bobba Phaneendra Babu , Upadhayay Madhur Deo
Published: February 2019

Charging an Electric Vehicle wirelessly is the latest technology being developed for the electric vehicles replacing the traditional way of plugging to the supply. In this paper, authors explained how to integrate Power Line Communication along with wireless power transfer in EV. The entire system is implemented in ADS simulation software. We are adapting to magnetic resonance coupling method for wireless power transfer in EV. The overall ideology of the project is to design an innovative system which involves higher power transfer and implement smart communication system between vehicle and the grid while following the latest magnetic resonance charging standards.,
Capacity Fade Modeling of Li-Ion Battery using Evolutionary Algorithm
Authors: S Tamilselvi , N Karuppiah , B Rajagopal Reddy
Published: February 2019

Renewable sources are seasonal and cannot be considered as available energy source as their generation varies with time. The insufficient forecasting techniques lead to thought of storage of energy. Even though many techniques of energy storage are available, batteries play a vital role as the time taken to start delivering the stored energy is very less. The life period of the battery depends upon the charging and discharging characteristics which in turn depend on the internal parameters such as life period, charge rate, discharge rate of the battery. The energy stored in the battery can be calculated by finding these parameters. In this paper these parameters are estimated for a Sony lithium ion battery by evolutionary algorithm CMA-ES under different Charging and discharging rates. As the batteries are charged and discharged there is capacity loss in the battery. This loss is modelled by modified Arrhenius equation on practical conditions. Capacity loss of the sample battery is modelled for five different cycles starting from 50th cycle to 100th cycle in an interval of 10 cycles. The results are validated with those of manufacturer catalogue. The optimized battery capacity loss are found to coincide with the measured values.
Path tracking mobile robot using steppers
Authors: Deo Ankit , Gupta Ayush , Khemani Himanshu , Das Rashmi Ranjan
Published: February 2019

In control of mobile robots, precision plays a key role in path tracking. In this paper we have intended to use hybrid stepper motors for precise control of the two wheeled robot. A control algorithm was developed to control the robot along different trajectories. We have found that stepper motors are more accurate for path tracking than normal DC motors with wheel encoders and one can obtain the implicit coordinates of the robot in runtime more precisely. Getting the precise coordinates of the robot at runtime can be used in various SLAM and VSLAM techniques for more accurate 3D mapping of the environment.
Artificial Neural Networks based SPWM technique for speed control of Permanent Magnet Synchronous Motor
Authors: Tummala Suresh Kumar , G Dhasharatha
Published: February 2019

The advancement of industry apparatuses for some methods with specific tasks to control the working of a few actuators on the field. Among these actuators, Permanent magnet synchronous motor drives are a mainly all-inclusive machine. Proficient utilization of hesitance torque, generally effectiveness, minor misfortunes and smaller size of the motor are the principle attractions of PMSM when contrasted and different drivers. Precise and rapid torque reaction is one of the parameters to determine differentiating arrangements in the ongoing past. The field-situated power perceived the likely and vigorous answer to accomplish these prerequisites to empower the figuring of streams and voltages in different parts of the inverter and motor under transient and consistent conditions. The primary objective of this paper is to investigate Artificial Neural Network based control of speed for PMSM in both open and closed loop under no-load and loaded condition. A shut circle control framework with ANN procedure in the speed circle intended to work in steady torque and transition debilitating districts. MATLAB reproduction performed in the wake of preparing the neural system (directed learning), results for reference control applications are adequate and appropriate in the process business. Speed control in shut circle at different stacking conditions talked about in detail.
SITARe: a fast simulation tool for the analysis of disruptive effects on electronics
Authors: Micolau Gilles , Coulié Karine , Rahajandraibe Wenceslas , Portal Jean-Michel , Aziza Hassen
Published: February 2019

This paper is devoted to an exhaustive presentation of a fast computation numerical tool, dedicated to the simulation of transient currents induced by stochastic events in microelectronic devices. This is a part of a numerical platform, SITARe, combining a spice simulator with the semi-analytical model presented here. The paper describes the theoretical model, the calibration. An instance of application illustrates the ability of the tool.
Inductan: a simple, robust and fast numerical tool to evaluate self-inductance of arbitrarily shaped coil with few windings
Authors: Micolau Gilles , Pozzo Di Borgo Elisabeth
Published: February 2019

We built a numerical tool allowing the evaluation of self-inductance of arbitrarily shaped coils with few windings. This tool named Inductan aims to be relevant, reliable and reasonably fast in order to be integrated in a more complex model. It is based on a formulation involving the vector potential and the Biot & Savart equation. The general equation giving the self-inductance coefficient is simplified according to the hypothesis of the envisaged geometry allowing to transform a 3d integral in a curvilinear integral operating on just one dimension of space. The numerical implementation is presented as exhaustively as possible, with its particular issues linked to the discrete representation of the coil. The tool is validated first on canonical geometry for which it exists an analytical formulation and second with direct experimental measurements obtained on laboratory coils with controlled and known, but not canonical, shapes.
Singular graphene metasurfaces
Authors: Galiffi Emanuele , Pendry John , Huidobro Paloma Arroyo
Published: February 2019

The spatial tunability of the electron density in graphene enables the dynamic engineering of metasurfaces in the form of conductivity gratings, which can bridge the momentum gap between incident radiation and surface plasmons. Here, we discuss singular graphene metasurfaces, whose conductivity is strongly suppressed at the grating valleys. By analytically characterising their plasmonic response via transformation optics, we first review the physical principles underlying these structures, which were recently found to exhibit broadband, tunable THz absorption. We characterise the spectrum with different common substrates and then move to study in further detail how conductivity gratings may be finely tuned by placing an array of charged gold nanowires at sub-micron distance from the graphene.
Electrically small multiband antenna based on spoof localized surface plasmons
Authors: Shao Rong Lin , Li Bo , Yang Liu , Zhou Yong Jin
Published: February 2019

Here an electrically small multiband antenna based on spoof localized surface plasmons (LSPs) has been proposed using corrugated ring resonator printed on a thin dielectric substrate with complementary metallic spiral structure (MSS) on the ground plane. It has been found that the resonant frequencies of spoof LSPs redshift by tuning the arm length of the complementary MSS, which leads to the miniaturization of the antenna. The fabricated multiband antenna has a small size of only 0.11λ × 0.1λ, covering GSM900, GSM1800, and WiFi bands. Such electrically small multiband antenna with high gain is necessary for efficient wireless energy harvesting (WEH), which can find more applications in various areas including Internet of Things (IoT), wireless sensor network (WSN), etc.
Influence of Nano-bentonite in Hydraulic Conductivity Performance
Authors: Zainuddin Atiqah Najwa , Mukri Mazidah , Asmuni Raimi Syazwani , Ibrahim Nor Izzati , Che Azmi Nor Azizah
Published: February 2019

Nano-clay is one of the innovation recently been studies as one of the enhancing materials to the soils. By adding a slight amount of nano-clay can improve some of behaviour such as hydraulic conductivity. Therefore, this research will investigate the performance of the hydraulic behaviour of different percentage of nano-clay in developing new soil liner design to be used in landfill. To complete the objectives, bentonite was pulverized by the process of high energy milling to obtain nano-bentonite. The milling sample is being analysed using Zeta Potential Analyzer and Field Emission Scanning Electron Microscope (FESEM). The laboratory studies were conducted by the determination geotechnical properties of the liquid limit, plastic limit, plasticity index shrinkage limit, particle density, compaction characteristic and also hydraulic conductivity value of raw bentonite mixed with 0%1%,2% and 3% of nano-bentonite. The laboratories result shows that the value of liquid limit, plastic limit, particle density and maximum dry density is increase in every addition of nano percentages meanwhile the value of plasticity index, optimum moisture content and hydraulic conductivity is decrease after adding nano-bentonite in the sample. The result shows the improvement of the soil by the geotechnical properties with addition of small amount of nano-bentonite.
Mechanical and Microstructural Properties of Friction Stir Welded Dissimilar Aluminum Alloys and Pure Copper Joints
Authors: Winarto W. , Anis M. , Febryansyah B. Eka
Published: February 2019

Joining dissimilar metal alloys such as aluminum and copper is very difficult to be done because of alterations in chemical, metallurgical and physical behavior. Friction Stir Welding (FSW) is a solid-state welding technique which is one of the new methods used for joining the dissimilar metal. The material used is aluminum alloy 5052 and pure copper plates. The welding parameters were carried out with variable geometry shape of pin tools: taper and threaded cylindrical pin tools. Also preheating were performed on the part of copper plates with temperatures at both 25°C and 200°C. The friction stir welding of dissimilar joints was carried out at the rotary tool speed of 2800 rpm with the angle of 1 degree and the welding travel speed of 2 mm/sec. All welds were then carried out to several mechanical testing and microscopic observation. The results show that the variable geometry shape of pin tools and pre-heating on the copper part affect the microstructure grain size and the formation of Al-Cu inter-metallic phases. The creation of different structures influences the mechanical properties of the friction stir welds. The hardness of welds using threaded pin tools is higher than the tapper one. However, the tensile strength of dissimilar welds using the threaded cylindrical pin tools is lower than the tapper one. The fracture location commonly occurs at the part of aluminum plates having a brittle intermetallic phase.
Effect of Heat Sinks on Cooling Time to Weld Interpass Temperature
Authors: Laitila Juhani , Larkiola Jari , Porter David
Published: February 2019

In high- and ultrahigh-strength steel welding, interpass cooling time is an important factor affecting productivity and welding costs. Usually, welding heat input is restricted to meet the relatively short recommended cooling times between 800 and 500 °C (t8/5), which are prescribed by the need to meet weld strength and toughness properties. This, in turn, leads to the need for multipass welding with the interpass waiting times needed for the weld to cool to a sufficiently low interpass temperature. Welding productivity is affected by both the number of passes and the interpass waiting time. With a view to minimizing the total number of passes needed for a given preparation, it is beneficial for the interpass temperature to be as low as possible as this permits higher heat input for a given t8/5. On the other hand, low interpass temperature requires longer interpass waiting times. Therefore, this research concerns the potential of introducing copper heat sinks adjacent to the weld to reduce the time it takes for the weld to cool down to the interpass temperature. It is demonstrated that, in the case of a butt weld in a 6 mm thick base plate MAG welded with a weld energy of 1 kJ/mm and an interpass temperature of 100 °C, copper heat sinks almoust halve the interpass waiting time. This can have a marked effect on the overall productivity when welding highand ultrahigh-strength steels and increase their attractiveness for steel construction.
Mechanical Properties and Microstructure of the Repeated Weld-Repairs of Austenitic Stainless Steel Plates
Authors: Winarto W. , Anis M. , Refnaldi
Published: February 2019

Joining Most of the repair weld of parts and components cannot be avoided in any manufacturing industry. Weld procedure is commonly used to ensure the welded parts can be useful and safe. Weld repairs have to be carried out with suitable care and avoid premature failures of the weld components. The weld repairs often occur repeatedly on welded parts. Hence the investigation was done to evaluate the effects of repeated weld-repairs of austenitic stainless steels plates on both mechanical and microstructural properties. Weld samples were joined using gas tungsten arc welding (GTAW) with several numbers of weld repairs. The first weld was performed to join metal plates and assigned as 0R. The weld bead was then ground away and followed by the first weld repair using the same GTAW (designated as 1R). This repair process was continual until five times (identified as 5R). All specimen was characterized by the chemical composition test, the microstructure observation, and the mechanical tests. It was found that the HAZ hardness of repeated weld repair decreased when the number of repairs increased. The tensile test results of the repeated weld repair had a few effects on tensile strength. However, the result of the impact test on repeated weld repairs shows a substantial reduction in the toughness properties as the repeated number of weld repairs. The repeated weld repair influenced the mechanical properties of austenitic stainless steel plates and showed a tremendous decrease compared with the type of 304L stainless steel as the repeated numbers of weld repairs.
Techno-economic Feasibility of Modified Pulse Arc Deposition on Thick Section of Quenched and Tempered Steel
Authors: Cornish Neville , Kurji Rahim. , Roccisano Anthony , Ghomashchi Reza
Published: February 2019

Quenched and Tempered (Q&T) steels welded structures that have numerous applications, particularly in the defence industry. However these steels are particularly prone to Hydrogen Assisted Cold Cracking (HACC) and require a highly-skilled welder to fabricate defect-free structures. This is due to the selection of the manual metal arc welding process of shielded metal arc welding (SMAW). The introduction of Modified Pulsed arc mode of depositions; a variation to Pulsed Arc deposition, has advanced deposition rates and can be employed by welders with a greater variation in skill. In this body of work, full strength butt welds are fabricated on 20mm, sections of Q&T AS/NZS 3597 Grade 700 steel under a high level of restraint using Modified Pulse Gas Metal Welding (GMAW-P) and conventional Shielded Metal Arc Welding (SMAW). The study investigates the economic feasibly of the two modes of deposition and the propensity for cracking when welded under high restraint. The study concluded that modified GMAW-P achieved reduction of 63% in the ‘Arc-On' time and an 88% reduction in the total normalised fabrication time. However, due to the increased propensity to lack of fusion type defects, strict controls must be employed in optimising the welding procedure to mediate for such defects if GMAW-P is to provide a techno-economically beneficial alternative to conventional SMAW when welding Q&T steels.
Effect of Tools Geometry and Dwell Time on Mechanical Properties and Macrograph of Two-Stage Refilled Friction Stir Spot Micro Weld
Authors: Sunar Baskoro Ario , Azwar Amat Mohammad , Andre Widiyanto Muhammad
Published: February 2019

In this present study, the two independent tools were used in the RFSSW process to joint similar material of AA1100 with a thickness of 0.42 mm using lap joint configuration. Effect of tools geometry and dwell time on mechanical properties, and macrograph was investigated. The joints were successfully obtained with better surface appearance. The micro-hardness variation at 4 group location shows higher than the base metal, while the maximum micro-hardness was obtained at parameter TC-8 at the center of the weld. Macrograph analysis showed the important factor that brings the plug fracture in all combination of parameters. It was the upward bending hook that leads to the crack propagate along the stirred zone to the top sheet, resulted in tear-off the top sheet from the bounded region. Increasing dwell time and tools size will increase the maximum tensile shear load significantly. The best average value of maximum tensile shear load that has been achieved was 561±24 N using the parameter tool C with 8 s dwell time (TC-8).
Influence of Thermal Aging on Microstructure and Property of Gold Alloy Joint Soldered by Sn-based Solder
Authors: Mu Guoqian , Qu Wenqing , Lv Xixiao , Zhuang Hongshou
Published: February 2019

As an undisputed material of choice to guarantee reliability in a broad range of high performance and safety-critical applications in the electrical contacts and connectors, AuAgCu alloy was soldered with Ag-plated Cu wire using Sn-based solder. To clarify the embrittlement and strength reduction of the gold soldered joint, the microstructure and its influence on the macroand micro-mechanical properties of the soldered joint under various thermal aging conditions were studied. The result indicated that, taking the mechanical property consideration alone, Sn-based solder could be used to join AuAgCu alloy. Different from the embrittlement and strength reduction of the soldered joint of pure gold, although the brittle fracture features appeared in mechanical test of the soldered joints, the shear strength of soldered joint after thermal aging at 125 °C almost did not decrease in comparison with that before thermal aging. Nevertheless, too high temperature and long time still had bad influence on mechanical properties. Otherwise, thermal aging had a large effect on the IMCs layer, as aging temperature elevated and aging time increased, IMCs layer became thicker, more complex components and multiply-sublayers structure with different microhardness. The study provides a fundamental understanding for gold alloy soldering.
Electron Beam Welding of Large Components for The Nuclear Industry
Authors: Baufeld Bernd , Dutilleul Thomas
Published: February 2019

The nuclear industry requires rapid and high quality joining of large scale components. Electron beam welding (EBW) has the potential to respond to these requirements. The aim of Nuclear Advanced Manufacturing Research Centre (Nuclear AMRC) is to develop solutions for the future application of this technology. One example is the research on deep penetration EBW for joining large scale pressure vessels for small modular nuclear reactors. This will require several circumferential welds of ~ 6 metres length each. In addition joining of sections of the upper and lower vessel heads and of HIP sections with varying wall thickness must be developed. In collaboration with the US Electric Power Research Institute (EPRI) the Nuclear AMRC is working to produce two-thirds scaled demonstrators of the lower and the upper pressure vessel assembly (based on a generic NuScale model). 100 mm deep single track, full penetration welds of pressure vessel steel have been demonstrated. In addition, within 26 minutes joining of shells was achieved with 6 metres long circumferential welds (78 mm full penetration). In future the joining of complex sections and sections with variable thickness will be investigate.
Electron Beam Welding of 2099-T83 Aluminium-lithium Alloy Thick Plates
Authors: Bárta Jozef , Simeková Beáta , Marônek Milan , Dománková Mária
Published: February 2019

The paper deals with the welding of AW 2099-T83 aluminium lithium alloy being used for construction of lower wing stringers. The thickness of AW 2099-T83 aluminium lithium alloy was 25.4 mm. Electron beam welding with the accelerating voltage of 55 kV was used for production of welded joints. Welded joints were inspected by computer tomography, macroscopic and microscopic analysis, tensile strength test and microhardness measurement. Welded joints exhibited good weld joint formation, typical to electron beam welding. Weld metal was structure was dendritic formed by α solid solution. Decrease of microhardness was observed mainly in the centre of weld metal due to dissolution of precipitates. The fracture occurred in the weld metal during tensile strength test. Further research will focus on post-heat treatment of welded joints in order to improve mechanical properties of weld metal.
Laser Multi-Pass Narrow-Gap Welding – A Promising Technology for Joining Thick-Walled Components of Future Power Plants
Authors: Keßler Benjamin , Brenner Berndt , Dittrich Dirk , Standfuß Jens , Beyer Eckhard , Leyens Christoph , Maier Gerhard
Published: February 2019

Today, the average worldwide efficiency of coal-fired power plants stands at about 33 percent. The consistent use of state of the art technologies would enable an increase of the average efficiency of up to 47 percent and thus a sharp reduction of greenhouse gas emissions. The importance of improvements in this field becomes apparent when reviewing e.g. plans in Europe in 2017 for new power plants to be built across the continent. About 44 percent of the envisaged 153 gigawatts are still to be generated by fossil-fuel power plants [1]. One technical solution is to increase the steam turbine inlet temperature to 700°C. This, however, requires the use of nickel-based superalloys. Only these alloys satisfy all the requirements with regard to high-temperature, corrosion and oxidation resistance and creep behavior [2], [3]. Due to their relatively poor machinability, forgeability and high material costs compared to the steel-based alloys they are to replace, a more effective welding technology is needed to overcome the disadvantages of conventional welding technologies, i.e. large quantities of filler metal required and high energy input per unit length resulting in distortion and the potential reduction of high-temperature properties.
Non-contacted Permanent Magnetic Absorbed Wall-climbing Robot for Ultrasonic Weld Inspection of Spherical Tank
Authors: Ding Yulin , Sun Zhenguo , Chen Qiang
Published: February 2019

A novel wall-climbing robot for the onsite weld inspecting of spherical tank with Time of Flight Diffraction (TOFD) method has been developed, in order to liberate operators from dangerous and heavy working environment. Patented non-contacted permanent magnetic absorbed technology was adopted to realize reliable and flexible all-position moving along the weld seam on the surface of spherical tank. To ensure stable coupling for TOFD test, a surface adaptive probe holder which can provide constant contact force, have been particularly designed. Equipped with a visual sensing based weld seam tracking unit and industrial PC station, the robot could perform automatic flaw detection remotely even in the darkness environment. Onsite ultrasonic weld inspections have been carried out on a 4000m3spherical tank with 28mm in thickness. It is verified that the robot could accomplish tasks in any position and the acquired TOFD images satisfy the requirements of engineering evaluation.
Weld Repair of Steam Turbine Rotor with 12 Cr Weld to Mitigate Corrosion Issues
Authors: Gowreesan Vamadevan , Ario Dhimas , Hanifa Hepy , Greaves Wayne
Published: February 2019

Weld repair of steam turbine rotors has become an acceptable practice to extend the life of rotors. Depending on the type of damage, the extent of weld repair can range from weld build-up of integral discs to stubbing a new forging to replace the damaged portion of an old rotor. Steam turbine rotors made of low alloy steels experience corrosion related damages such as stress corrosion cracking, pitting corrosion, corrosion-erosion etc., Traditional weld repairs have been using low alloy steel welds. While the low alloy welds may have mechanical properties comparable to or even slightly exceeding that of the low alloy steel rotor alloys, the corrosion resistance of the low alloy welds are not great. 12 Chromium weld will provide better resistance to corrosion related damages than typical low alloy welds. However using 12 Chromium weld on low alloy steel rotors provides some additional challenges and limitations. These include selection of optimal combination of weld wire and flux for rotor welding, selection of optimal post weld stress relieve temperature and dealing with abrupt change in chemical composition at the weld interface. This paper discusses development of such a weld procedure and provides some examples where the 12 Chromium weld was successfully applied on steam turbine rotors that experienced corrosion related damages.
Low-cycle Fatigue and Fracture Behaviour of 9%Ni Steel Flux Cored Arc Welding joint at Cryogenic Temperature
Authors: Mu Weidong , Li Yuzhang , Cai Yan , Wang Min
Published: February 2019

In the present work, low-cycle fatigue (LCF) test and crack tip opening displacement (CTOD) test were performed for 9% Ni steel flux cored arc welding (FCAW) joint at room temperature (296 K) and cryogenic temperature (80 K). At cryogenic temperature, the strain amplitude had a far greater impact on fatigue life of 9%Ni steel welded joint and it decreased dramatically lead to a significant increase in fatigue life. It was found that most fracture initiation of joints located in fusion area at room temperature, while it occurred in weld seam at low temperature. The fracture toughness of weld seam was higher than that of fusion zone no matter the testing temperature. The effect of precipitated phase was the true reason. The fatigue cracks propagated in transgranular mode at room temperature, ultimately, and intergranular mode at low temperature in both LCF specimens and CTOD specimens.
Research on Adaptive Controller for Variable Polarity Plasma Arc Welding Power Supply with High-Frequency
Authors: Zhou Yang , Qi Bojin , Zheng Minxin
Published: February 2019

Aiming at the problem of output current waveform distortion caused by superimposed high frequency components in the output current of varying polarity of VPPAW power supply. A novel adaptive PID controller with automatic switching is introduced in this paper, and the controller is established based on the evolution path of the operating point of the VPPAW power supply. Compared with the traditional linear PID controller, the adaptive controller proposed in this paper is very suitable for the control of arc load with strong dynamic characteristics and can effectively improve output waveform of the welding system.
Estimation of Contact Tip to Work Distance (CTWD) using Artificial Neural Network (ANN) in GMAW
Authors: Mahfudianto Fuad , Warinsiriruk Eakkachai , Joy-A-Ka Sutep
Published: February 2019

A method for optimizing monitoring by using Artificial Neural Network (ANN) technique was proposed based on instability of arc voltage signal and welding current signal of solid wire electrode (GMAW). This technique is not only for effective process modeling, but also to illustrate the correlation between the input and output parameters responses. The algorithms of monitoring were developed in time domain by carrying out the Moving Average (M.A) and Root Mean Square (RMS) based on the welding experiment parameters such as travel speed, thickness of specimen, feeding speed, and wire electrode diameter to detect and estimate with a satisfactory sample size. Experiment data was divided into three subsets: train (70%), validation (15%), and test (15%). Error back-propagation of Levenberg-Marquardt algorithm was used to train for this algorithm. The proposed algorithms on this paper were used to estimate the variety the Contact Tip to Work Distance (CTWD) through Mean Square Error (MSE). Based on the results, the algorithms have shown that be able to detect changes in CTWD automatically and real time with takes 0.147 seconds (MSE 0.0087).
Removal of Oxide Inclusions in Aluminium Scrap Casting Process with Sodium based Fluxes
Authors: Widyantoro  , Dhaneswara Donanta , Fajar Fatriansyah Jaka , Reza Firmansyah Muhammad , Prasetyo Yus
Published: February 2019

The investigation of Oxide Inclusions removal in aluminium scrap casting process with sodium based fluxes has been carried out. The purpose of this research is to investigate the effect of Na2SO4 and NaCl based fluxes addition onto the fluidity and microstructure of aluminium product. The alloy which is used in this investigation is Al-Si which mixed with metal scrap using gravity casting method. The variation of melting temperature in this investigation are 700°C, 740°C, and 780°C. In this research, material characterization was determined using DSC, EDAX, XRD, and fluidity test. The results show that the number of oxide inclusions decrease as the addition of 0,2% wt. flux, and completly removed after the addition of 0,4% wt. flux. The highest fluidity and tensile strength was obtained after the addition of 0,4% wt. flux. at 740°C.
Evaluation of behavior and performance of the braced/ unbraced four story of steel frame with semi rigid connection
Authors: Rumbi Teruna Daniel
Published: February 2019

Structural analysis and design with taken into account the flexibility of the beam to the column connections of steel frameworks takes on importance of the growing development and utilization of new commercial software. However, for design purposes, the beam to the column connection are usually considered to be either pinned or fully rigid, and drastically simplifies the analysis and design procedures. In this paper, a four story of unbraced and concentric braced steel moment resisting frame having different connection stiffness is analysed using linear and nonlinear static procedure. In the finite element modelling, the semi rigid connection is modelled by rotational spring having linear moment and rotation relationship. To account the inelastic behaviour of beam and column members, concentrated plastic hinges based on FEMA 356 are applied for both ends of the member. It was found that, the response quantity of the unbraced frame are influenced by the flexibility connection. However, for the braced frame the effect of the initial connection stiffness parameter on the response quantity can be neglected due to present of the braces. Furthermore, the higher the initial connection stiffness parameter, the smallest the story drift index. Moreover, the present of the braces at the moment resisting frame (braced frame) reduce the sensitivity of the connection stiffness on the behaviour and the performance frame under consideration.
Studies on nonlinear behavior of retrofitted reinforced concrete beam column joints after experiencing severe damage from earthquake load simulation
Authors: Gosal Nelson , Imran Iswandi , Riyansyah Muhammad
Published: February 2019

For an earthquake resistant structure, reinforced concrete building must have certain performance level under certain level of earthquakes such as when it is subjected to a strong level earthquake, it may experience severe damages, but without partial or full collapse, thus some reparations could be done to recover the functions of those damaged structures. However, repairing methods were usually done to slightly-damaged structures, while for severely-damaged structures, more studies are still needed to optimize the effectivity of the repair. Therefore, the objective of this study is to evaluate the performance of a structure that is retrofitted using high strength concrete after experiencing severe damage from an earthquake. Reinforced concrete beam column joints - that are used as specimens for this study - were initially subjected to cyclic loading up to 5% drift. The specimens’ beams are then repaired by replacing the damaged concrete with the new, stronger concrete without replacing the existing reinforcement bars. The retrofitted specimens are then subjected to the same cyclic loading and their nonlinear behaviors are compared to the behavior of their initial condition. The experimental results show that there are mostly reductions in lateral strengths, although there is an increase of strength in one specimen, while there are also reductions in energy dissipated.
Correlation between shear and normal strength for brittle reinforced concrete member considering internal stress condition of concrete
Authors: Ahmad Safi Walid , Hibino Yo
Published: February 2019

Formulas used to predict shear strength of reinforced concrete in different standards do not always correspond to each other due to the complexity of the shear transfer mechanism. Currently there is no generally accepted method of shear strength pridiction, however, traditionally, shear strength anticipation of a structural concrete elements is performed differently on members with or without shear reinforcement. These empirical approches tend to predict the shear strength too conservatively; alternatively, shear strength of concrete can be easily predicted by Mohr-Coulomb theory. In case of high-axial load and low shear reinforcement, the strength is likely to be determined by the concrete's shear crack. Therefore, a method to predict the strength of concrete with Mohr-circle has been proposed but the circles crossed the boundary and could not evaluate the strength correctly. Mohr circle can be used for prediction of diagonal tension failure strength but the circle cannot be evaluated. In this paper, Mohr circles were investigated considering all steps of cyclic loading until shear crack occurred. It also investigates a correlation between shear strength and normal strength through recognition of the Mohr-Coulomb failure criteria for each specimen.
Consumer's point of view on parcel lockers in DKI Jakarta
Authors: Nahry  , Farhan Vilardi Alvin
Published: February 2019

Online shopping businesses grow significantly in Indonesia, especially in Jakarta. Consumers find out that purchasing products online is more effective. Most of consumers in Jakarta choose direct (home) delivery as their last-mile delivery method, which proposes consumers to receive the purchased goods at home. E-commerce could minimize trip distance travelled by consumers, but distance travelled by delivery service vehicles increase. It causes new problems such as environmental issues. Parcel lockers method appeared as the solution, which proposes advantages for consumers and package delivery operators. Its scheme could minimize distance travelled by both. The packages that dropped in the lockers would be picked up, sorted, and delivered to other lockers. Consumers would pick up their goods by travelling to destination lockers. It could minimize delivery trips. This study observed the consumer's point of view on parcel lockers method, and analyse the potency of parcel lockers. This study was carried out by two online surveys with four main variables that are location, information, cost, and punctuality. The results found that punctuality is the most affecting factor (38.8%) for consumers in choosing type of delivery service. Based on the services, respondents prefer to choose parcel lockers (68.4%) rather than direct delivery.
Verification of modulus and fatigue cracking models for hot-mix asphalt with asbuton in laboratory scale
Authors: Nugraha Juan , Kosasih Djunaedi , Rahman Harmein
Published: February 2019

Design and analysis of flexible pavement structure using mechanistic approaches require, among other input data, the dynamic modulus of asphalt layer (E*) and it's resistance to fatigue cracking (Nf). These material characteristics can be obtained from both laboratory test results and calibrated against field conditions and from mathematical models, such as the Asphalt Institute's. The two values are to be compared for assessing the applicability of the models for mixes using petroleum bitumen (pen 60/70) and using modified asphalt (with 8% asbuton). The laboratory tests were conducted using Asphalt Mixture Performance Test (AMPT) and Four Point Loading equipment. It was found that the resulting curves are consistent with the Asphalt Institute's model for both types of mixes. Meanwhile, fatigue life model curves show a similar trend to the Asphalt Institute's model on the conservative side. This is explainable the laboratory model needs to be calibrated for variations of wheel track and loading time occuring on site.
Porous concrete basic property criteria as rigid pavement base layer adjusting field gradation
Authors: Ridwan Aldila Melania Care Frisky , Sugeng Subagio Bambang , Rahman Harmein , Yamin R. Anwar
Published: February 2019

Porous concrete has been widely used for many purposes in this couple of days. In reality, it might be difficult to create an ideal uniform graded porous concrete mixture proportion with the field gradation circumstances. The aim of this study was to find a porous concrete mix-design proportion that could adjust field gradation and meet Specifications requirements by utilizing continuous graded aggregate. Compressive strength and vertical permeability produced by porous concrete using continuous graded aggregate stayed above the minimum limit for base layer required by Specifications. Continuous graded porous concrete from mix-design variation II produced higher compressive strength, but lower void content and vertical permeability compared to mix design variation I at the age of 28-days. It was found that continuous graded porous concrete from both mix-design variations had an optimum basic parameters in specific value as well. Porous concrete that adjust the field gradation gave a better basic property criteria compared to ideal gradation. The relationship between void content and vertical permeability from continuous graded porous concrete had a similar behavior with uniform graded porous concrete. Overall, the use of continuous graded porous concrete would be very helpful in Indonesia because it can adjust the gradation on the field.
Mode choice model for public transport (ferry, fast ship and aircraft) study case: Kupang - Rote Route
Authors: Bolla Margareth E. , Bella Rossy A. , Nomleni Aprianto , Yuliaty Tungga Desy
Published: February 2019

The mode of transportation that travels from Kupang City to Rote Ndao Regency is currently a mode of sea transportation and air transportation. This study aims to find out user information based on its mode choices and model it in the multinomial log function, besides that it's hoped that this result can be used as a reference in determining policies that improve functions and facilities for mobilizing people, goods and services carried out on the Kupang to Rote.Data analysis was carried out in two ways, namely with descriptive statistical analysis techniques to explain the characteristics of respondents and multinomial logistic regression analysis to create a model of mode transportation selection for Kupang-Rote service. The results of the study showed that users of transportation services from Kupang to Rote, generally men prefer to use ferry boats while women prefer to use fast boats. The characteristics of respondents is age 20-39 years. While the factors that influence the choice of transportation are the influence of luggage, weather and comfort. For the selection model, the probability of a speedboat is 34.65%,the probability of choosing a ferry is 42.96%, and the probability of choosing an aircraft is 22.3%.
Payment for environmental service of conservation in Cokro Tulung spring, Klaten regency, Indonesia
Authors: Faisal  , Gravitiani Evi , Suryanto  , Raharjo Mugi
Published: February 2019

This study aims to: (1) determine the conservation of water resources willingness to pay (WTP) of the community, (2) determine the determinants that significantly affect the value of PAPs for additional benefits due to increase management of water resources conservation, and (3) determine whether reforestation environment is a type of conservation that community desires. Respondents from this study are Surakarta citizens, precisely in the southern region of Surakarta, Laweyan District, Central Java. They are customers of Surakarta Municipal Water Supply Company, especially the water distribution of the Cokro Tulung spring. This study uses linear analysis and Contingent Valuation Method (CVM). The interviews result with 106 respondents revealed that: (1) the average value of WTP in R2 is Rp 1,872,-, the average value of WTP in R3 is Rp 3,238,-, the average value of WTP in R4 is Rp 2,769,-, and the average value of WTP in trade group 1 is Rp 3,846,-, (2) education variables and perception variables on the importance of conservation have a significant effect on WTP of conservation of water resources, and (3) survey results show that there are 73.6% of respondents intend to do greening around Cokro Tulung spring.
Effect of extreme rain and land covering change in Jatihandap on 20 March 2018 flash flood
Authors: Wiyono Hadi Soeharn Agung , Farid Mohammad , Salma Abidah Dhiya , Ravena Maitsa Tias , Setianingsih  , Majidah Nurul
Published: February 2019

Flash flood occurred on March 20, 2018, in Jatihandap, Bandung City, West Java due to the overflow of Cipamokolan River. This has caused considerable losses, especially for people living in the area. The flood occurred due to high rainfall intensity and inadequate land covering, especially in the upstream area (North Bandung Region) where the area is filled with housing, villas, and open land. Consequently, the water catchment area decreases. The objective of this study is to identify flood discharge that occurs due to high rainfall intensity and land covering. Flood discharge is calculated using a rational method. Based on BMKG data, rain intensity on March 20, 2018, is 45 mm/hour. The results of this study show that with this intensity, the Cipamokolan River flow brings water with sediment and debris waste. The discharge of the river is 207 m3/s. It equals to 2.2 times river basin discharge and causing water to overflow into the land around the river. The debris flow also damage the levees in Jatihandap then it caused flash floods.
Analysis of climate change and future projection of rainfall, temperature, and potential evapotranspiration in Riam Kanan catchment area, Banjar Regency, South Kalimantan
Authors: Putri Purnama Olivia , Kardhana Hadi , Indrawan Harry , Rasgianti  , Cahyono M. , Nurganah Chaidar Dan Anna
Published: February 2019

Climatic conditions in Indonesia warm up indicated by the increasing of the average annual temperature by 0.3°C. This may cause higher water evaporation and increased rainfall intensity. Changes in rainfall patterns shift the start of the rainy season to be slower and end faster. These changes the dry season to become longer with shorter time intervals. In case of dam operation, dam manager needs to adapt the effects of climate change. This paper presents trend and future projection in Riam Kanan Catchment Area, Banjar Regency, South Kalimantan. Climate change historical trend analysis was carried out with the observation data used were rainfall and maximum temperature from BMKG climatology station, Banjarbaru Station, in the period 1983 - 2017. Future projection analysis was carried out by using RCP2.6 and RCP8.5 scenario data for projecting rainfall and temperature in the period 2018 - 2100. The result shows that the rainfall, maximum temperature, and evapotranspiration trends in Banjarbaru from 1983 - 2017 were not too significant by +0.1 mm, -0.5°C, and +0.1 mm. While the projection of RCP2.6 and RCP8.5 scenario shows increase by +0.1 mm, +0.1°C, +0.1 mm and by +0.1 mm, +3.3°C, and +0.1 mm. Keywords: Climate Change, Trend, Rainfall, Temperature, Evapotranspiration, RCP 2.6, RCP8.5.
Application of aerated submerged spongebed biofilter for raw water pre-treatment in drinking water installation
Authors: Novia Asih Christami Margareta , Sarwanto Moersidik Setyo , Nazech El Khobar M , Silvia Yenny
Published: February 2019

Pesanggrahan River has been contaminated by domestic wastewater. High contamination of Pesanggrahan River with the maximum observed TSS (243,8 mg/L), COD (165,2 mg/L), Total Phosphate (0,74 mg/L), and NH3-N (1,04 mg/L) has exceeded the Raw Water for Drinking Water standard based on Government Regulation Number 82 the Year 2001. Aerated Submerged Sponge-bed Biofilter can be proposed as pre-treatment recommendation for Drinking Water Treatment Plant processing due to its environment-friendly property and ability to reduce the organic pollutant. A lab-scale experiment with the modified volume of 15% media was applied in a 6L reactor with 7 L/min oxygen supply. Retention time variation was evaluated at 1, 1,5, and 2 hours. It was found that the highest removal efficiency occurred at HRT 1,5 hours with the reduction capability of 75,5±0,12% TSS; 59,1±0,14% COD; 57,1±0,27% Total Phosphate; and 45,5±0,37% NH3-N. On the same HRT (1,5 hours), ammonia reduction obtained at k(0-order)= 0,005 g/m2day. This biofilter also decreased the optimum coagulant (PAC) concentration needed.
Study of flood characteristic in Cikalumpang River by using 2D flood model
Authors: Rizaldi Akbar , Riyando Moe Idham , Farid Mohammad , Mulia Aribawa Teguh , Bayuadji Gatut , Sugiharto Tanto
Published: February 2019

Flood is one of the natural disasters that occur in Indonesia frequently. At least there are 8.498 occurrences since 1980 through Indonesia. In order to prevent and resolve that natural disaster, some actions should be done. To know the best solution to solve flood, we should know the flood characteristic (what causes it, the inundation area, the height, how long it occurs, and etc.). The characteristic of flood will be easily known only when the flood occurs. Thus, it is necessary to build a model with high accuracy. The model was obtained by re-modeling the inundation incident that happened on March 7th, 2018, and validated with observed data from several locations in that period. The result shows a good agreement with the observed data. This is evident from the extent and depth of the puddle from the modeling results similar to the value of field observation data. From the results, it can be concluded that the Cikalumpang River model has been obtained with a good correlation. From field observations, it is known that flooding is caused by quite complex problems, such as decreasing river capacity due to illegal building construction, sedimentation, land cover change, and climate change.