IPTEK The Journal of Engineering
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Performance of High-Damping Rubber Bearings for Seismic Isolation – Case Study of Nayumi Sam Tower Malang Apartment
Get PDFThe base-isolation system is a highly effective earthquake-resistance technique. Especially when the building is under soft soil, however, it is detrimental to the horizontal displacement control of the isolation layer and less effective in decreasing the seismic response of the superstructure. Rubber bearings with high damping can produce substantial hysteretic damping and exhibit a hardening effect at high-shear strains. The research investigates the Nayumi Sam Tower Malang apartment as a case study with 10 stories of reinforced concrete with a double system structure which is in a soft soil location. High-damping rubber bearings (HDRBs) is used as a parameter study to understand the alteration and give a recommendation. The seismic response of the building is evaluated, and the HRDB alternative systems is confirmed using ETABS. It is pointed out that the HRDBs system can reduce the impact of earthquakes by close to 25% with the smallest section of structural dimension. According to new regulation building in Indonesia, the precise values of test circumstances, such as compressive force, shear displacement, and frequency, are developed. The findings are thoroughly discussed, the applicability of HRDBs for seismic isolation of residential buildings is concluded. Building with HRDBs isolation implied to have lower base shear and inter-storey drift which improved the performance of the structure with less damage.
Numerical Procedure for Modeling Crack Closure Induced Plasticity
Get PDFNumerical procedures are utilized to predict crack closure-induced plasticity on planar surfaces. Skinner's algorithm is presented as an APDL macro command set. Procedures for controlling element size are developed to ensure the continuity of element size gradation. A loading generator is constructed using the *dim parameter, and the Newman model is explored for comparison. The analysis, based on conducted research, yields results lower than 0.05Sy
Forecasting the Consumer Confidence Index for Economic Conditions Prediction in Ambon, Indonesia
Get PDFEconomic developments in Maluku Province show positive growth. However, this is not accompanied by an increase in the confidence index from consumers. It was recorded that from July to September 2022, there was a decrease in the Consumer Confidence Index of around 7.6% to 8.2%. The value of the Consumer Confidence Index can be forecasted using time series analysis. Time series analysis is a method intended to make an estimation and forecasting for the future. Some methods that can be used in forecasting in this study are naive, moving average, single exponential smoothing, double exponential smoothing, and time series regression. This method can be used to forecast the value of the Consumer Confidence Index in Ambon City after the Covid-19 pandemic. It can be concluded from the analysis results that the best model for forecasting the condition of the consumer confidence index value is the Double Exponential Smoothing method with a combination of Alpha = 0,4 and Gamma = 0,5, The forecast results showed a decrease in the value of the consumer confidence index, although the index still showed a relatively optimistic value
Analysis of The Effectiveness of Household Scale Smart Window Panel as a New Renewable Energy Source Using PVsyst Software
Get PDFIncreasing electrical energy consumption causes problems because it produces greenhouse gas emissions. The problem is that the fuel used so far is not renewable. Carbon emissions can trigger global warming. Global warming causes the temperature on earth to increase, causing icebergs in the polar regions to melt and sea levels to rise. Efforts can be made to minimize this problem by transitioning to alternative energy, such as solar panels. Using solar panels as an energy source has an excellent opportunity to be implemented because Indonesia gets sunlight throughout the year. However, solar panels have drawbacks, such as surfaces that are difficult to clean, depending on location and weather conditions, and their installation requires a large area. Therefore, this research was conducted by designing smart window panels that are easy to apply on a household scale so that their effectiveness is known when implemented. The method used in this study is a simulation method using the PVsyst software. The simulation was carried out with a variable angle of installation of the smart window panel, 0°,30°,45°,60°, and 90°. The results showed that the best results were obtained from modules with an installation angle of 90° because the EfrGrid value was 19168 Kw/year and E_Solar was 104.28 Kw/year. Increasing the number of modules used can be done by using suitable inverters so that optimizing the use of smart window panels on the household scale can be done to reduce carbon emissions and achieve energy security in Indonesia
Workability Analysis of 3D Printing Materials for Applications in The Construction Industry
Get PDFThe development of 3D Printing machine technology as a printing tool that uses an additive manufacturing method system with the aim of producing a three-dimensional (3D) object or object according to the default digital design file. 3D Printing was created to facilitate construction work, with 3D Printing construction work becoming lighter because this tool saves time, and costs, and reduces the risk of work accidents. With 3D Printing, work runs quickly and avoids problems in the development process. In the last few decades, many developed countries have used 3D Printing technology in making buildings. The 3D printing process basically consists of three different stages namely, data preparation, material preparation and transfer to the printer, and the printing stage. In the data preparation stage, the components are designed as 3D CAD models, then converted to STL (Stereolithography) format and sliced with the desired layer depth. The preparation of concrete involves mixing and placing it into a container. Once fresh concrete has been placed into the container, it can be channeled smoothly through a pump-pipe-nozzle system to print self-compacting concrete filaments, which build structural components layer by layer. The material used in this 3D printing method was Portland cement where this cement is easy to find among the public. Portland cement itself is the cement that is commonly used as a basic material for making concrete, plaster, mortar, and non-specialized mortar. In addition, fly ash and silica fumes are also added as a mixture. The addition of silica fumes increases the compressive strength of concrete. Furthermore, the addition of fly ash to the concrete has the effect of reducing drying shrinkage; but reducing the compressive strength of the concrete. In this study, the author focuses on the workability of 3D Printing concrete materials, and the impact of the material was added with additional type C fly ash and silica fume, namely flowability. The result is a concrete mix design that has good flowability value to be applied to the 3D Printing metho
Design of Horizontal Axis Wind Turbine Simulator Using Smart Monitoring System
Get PDFWind turbine shows the direct utilization of mechanical energy and occurs as follows: the wind that moves hitting the wing of the ferris wheel causes the ferris wheel to spin. The rotation of the ferris wheel causes the formation of mechanical energy, while the conversion of wind energy into electrical energy is as follows: the wind through the ferris wheel plants causes the ferris wheel to spin. The spin of the ferris wheel causes the generator to spin. Inside the wind energy generator is converted into electrical energy. In the Final Task that did the design of this prototype, do a comparison between the horizontal axis wind turbine with variations in the number of blades, with blade variations totaling 3 and 5. So, there will be 2 wind turbines with different numbers of blades in one prototype. Comparisons are made to find out the performance carried out by the two wind turbines that aim as a learning medium in the Measurement Instrumentation Laboratory. This final task is divided into five stages: including, tool design, tool characterization, tool validation, tool testing, and comparing tools. The process of designing tools that are divided into two methods, namely covering the formation of hardware and the formation of software. From the graph data contained in the discussion shows the performance with the propeller amounting to 5 produces a higher current and voltage output and rpm on this prototype scale than the number of propellers 3, with the value for example at the acceleration of fan 5 with a wind speed of 3.9 m / s on the propeller amounting to 5 resulting in an average current value of 3.2 mA, a voltage of 1.98 V, and rotor rotation of 234 RPM. While at the number of propellers 3 with the same wind speed produces smaller current output, voltage and rpm, which is obtained an average current of 2.3 mA, a voltage of 1.88 V, and rotor rotation of 243 RPM
Drying Process Optimization and Efficiency of Aluminum Fluoride (AlF3) Plant
Get PDFAluminum Fluoride (AlF3) is a substantive material used to reduce the melting point temperature of the Aluminum from 1500oC to 600-850oC. The production applies a wet process using raw materials of Fluosilicic Acid and Aluminum Hydroxide with a by-product of Silica Dioxide. In this case, AlF3 products are expected to have a maximum H2O content of 2.6%. However, in the production process, the H2O content reached 3% due to the inoptimum drying process. Therefore, the optimization process was carried out by increasing the dry air temperature of the recycle from stage 2 to stage 1 in the drying process, so that the mass transfer of H2O from AlF3 crystals to the air can be maximized. After the optimization, it was found that the H2O content has met the quality standard of 1.8%
Optimation Front Upright Racing Car Using Finite Element Analysis
Get PDFUpright is part of the car's suspension system that plays an important role in creating and comforting the car. Supporting driving safety, upright components must be designed to be light but strong to withstand loading when the car is in conditions of acceleration, deceleration and cornering. Not only strong as a benchmark, but components must also be lightweight, so we need a method, namely a topology optimization method. Using finite element software makes the optimization process very easy and very fast with maximum accuracy. The process is by inputting the model from CAD software, defining materials, input constraints and vector styles, meshing process, and finally the solution process. From the simulation results, it will be known the value of the solution in the form of stress, deformation and safety factor of the upright component. From several topology optimization designs, they will be compared to find out which is the best design which will be used as a design recommendation. By referring the result, 43% mass reduction is the best optimum design, its safety factor is 4.956
Bioethanol Production From Tapioca Solid Waste In A Batch Reactor
No full textTapioca solid waste is a by-product of processing tapioca flour in the form of dregs and contains a lot of carbohydrates which can be developed benefits by treating the waste through an enzymatic process by hydrolysis as bioethanol. Bioconversion technology is an enzymatic conversion of materials by hydrolysis which can be used to increase the value of tapioca solid waste. The purpose of this research is to convert starch from solid waste of tapioca flour industry into bioethanol through enzyme hydrolysis and fermentation processes. This study was conducted to determine the effect of the ethanol content produced from the concentration of 50 gr/l, 100 gr/l, and 150 gr/l waste of tapioca concentrations with 10ml, 15, and 20ml enzymes. The cassava samples were hydrolyzed using Alpha-amylase enzymes with various concentrations of 10ml, 15, and 20ml and 10ml Glucoamylase enzymes. In the liquefaction process, glucose content is analyzed every 30 minutes for 2 hours, then in the saccharification process, glucose content is analyzed every 30 minutes for 3 hours. The acid hydrolyzate solution was adjusted to pH 4.5 and then fermented for 3 days and analyzed every 12 hours. From the results of the study, it was found that the optimal treatment variable was the concentration variable of 150 gr/l waste of tapioca (solid waste tapioca flour) with a concentration of 20 ml of Alpha-amylase enzyme. The ethanol content obtained from the fermentation process is 3.98% (v/v)
The Production of Gelatin from Snapper Scales (Lutjanus camphecanus Sp.) through Enzymatic Pretreatment
Get PDFFish wastes such as fish bones and scales have a potential to be used as a gelatin source. It can be used as an alternative material to replace pork or bovine which ordinarily conflicted with religion issue. Gelatin from fish has different characteristics compared with mammalian source. It has several advantageous properties such as high amount of hydrophobic amino acids, less proline and hydroxy proline, lower gelling ability, and melting point. In this study, gelatin was produced from fish waste especially snapper scales using the bromelain enzyme at the pre-treatment stage to improve its characteristic. The snapper scales soaking in hot water at 80⁰C for about 30 minutes to remove the fat which attached the scales. A pre-treatment has been conducted using bromelain enzyme solution at various concentrations of 1%, 2%, 3%, 4% and 5% for 6 hours to remove non-collagenous proteins and loosen the bonds of the fish scales. The next step is demineralization using a 15% concentration of citric acid solution for 3 days. The ossein formed in the demineralization stage was then hydrolyzed at 50⁰C and 70⁰C for 9 hours with stirring at 300 rpm. The best gelatin yield was obtained from the pretreatment of bromelain enzyme solution with a concentration of 3% at a hydrolysis temperature of 70⁰C with a yield of 9.13%, pH value of 3.86, water content of 8%, ash content of 0.80%. FTIR spectra shows the presence of functional groups correspond to gelatin formation, such as carbon, hydrogen, hydroxyl group (O-H), carbonyl group (C=O), amine group (N-H) and alkene group (C=C). The heavy metal content test showed that the gelatin contained no heavy metal content of lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As)