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The Effect Catalyst Natural Zeolite of Lampung On The Synthesis Of α-Terpineol From Turpentine
Full text linkThe major component of turpentine is α-pinene. Alpha pinene can be hydrated using an acid catalyst to produce α-terpineol. It can be used as a perfume, anti -insect, and disinfectants. The using of heterogeneous catalysts as natural zeolite can be a new alternative to replacehomogeneous catalysts. The purpose of this study was to determine the effect of zeolite catalysts and the reaction time which resulting the highest conversion on hydration reactions of turpentine to α-terpineol. Parameters were the effect of catalyst concentration of (5%, 10% and 15%) and the reaction time (60 minutes, 120 minutes and 180 minutes). The turpentine, aquadest and isopropyl alcohol were reacted in the three neck flask at the temperature of 70°C. The result of this study showed that the best condition the hydration of turpentine α-terpineol was achieced at 15% catalyst concentration and the reaction time of 180 minutes. The convertion was obtained to be 4.875%.Keywords— Turpentine, Hydration, Alpha terpineol, Catalys,Natural Zeolite
Bitcoin mining, the way to process transaction information or the way to make money?
Full text linkBitcoin is a crypto currency introduced by Satoshi Nakamoto in 2008. It has the features of decentralization cross-border and fixed total amount and has become one of the most widely used crypto-currencies. Bitcoin, as a new digital currency system, innovatively makes the use of cryptographic elements and consensus mechanisms and builds up a secure decentralized system. The Blockchain, as the core of Bitcoin, uses peer-to-peer network communications and backs up transaction data in every node of the system, thus creating a huge distributed public book. It is essentially a decentralized distributed ledger database, and the decentralization means that the transaction is broadcast to the entire network, where everyone is involved in book keeping. In order to make every participant in the Blockchain willing to participate in the bookkeeping, the reward mechanism of the Bitcoin system is mining. This article first introduces the concept of Blockchain technology, then expounds the principle and the operation mechanism of the Bitcoin and the Bitcoin mining principle, introduces an example of Bitcoin mining in-depth study and analysis, finally, summarize and prospect the development of the Bitcoin mining
Development of Horticultural Supply Chain with Value Co-Creation to Improve Farmers' Competitiveness and Incomes
Full text linkVegetables are one of the horticultural commodities that have high economic value and opportunity in the market. However, vegetables supply chain in Indonesia is often identified with the traditional supply chain of long marketing chains, difficult market access for farmers, low competitiveness, farmers’ low income, and injustice to supply chain actors, especially between farmers and wholesalers. In creating a structured supply chain, value co-creation intervention applied to synergize farmers and wholesalers in Ciwidey Sub-district to understand each other’s problems then seek solutions to solve them. This research has been conducted in Ciwidey Sub-district, West Java. This research aims to measure the competitiveness and farmers income of each wholesaler’s group before and after value co-creation intervention. The result shows that variables competitiveness and income of Sari Hejo Farmer Group and Hidayah Alam Farmer Group have significant positive changed, while one of three indicator variable of competitiveness has not significantly changed
Design of Inward-Turning External Compression Supersonic Inlet for Supersonic Transport Aircraft
Full text linkInward-turning external compression intake is one of the hybrid intakes that employs both external and internal compression intakes principle. This intake is commonly developed for hypersonic flight due to its efficiency and utilizing fewer shockwaves that generate heat. Since this intake employ less shockwaves, this design can be applied for low supersonic (Mach 1.4 - 2.5) intakes to reduce noise generated from the shockwaves while maintaining the efficiency. Other than developing the design method, a tool is written in MATLAB language to generate the intake shape automatically based on the desired design requirement. To investigate the intake design tool code and the performance of the generated intake shape, some CFD simulation were performed. The intake design tool code can be validated by comparing the shockwave location and the air properties in every intake's stations. The performance parameters that being observed are the intake efficiency, flow distortion level at the engine face, and the noise level generated by the shockwaves. The design tool written in MATLAB is working as intended. Two dimensional axisymmetric CFD simulations validation has been done and the design meets the minimum requirement. As for the 3D inlet geometry, with a little modification on diffuser and equipping vent to release the buildup pressure, the inlet has been successfully met the military standard on inlet performance (MIL-E-5007D). This design method also has feature to fit every possible throat cross sectional shapes and has been proven to work as designed.Keywords— Inward-turning, Supersonic, Engine Intakes, Low- noise, Design Metho
Financial Feasibility Analysis of Red Chili Pepper Seedling at Karanganyar, Poncokusumo, Malang
Full text linkThis research aims to analyse financial feasibility of red chili peppers (Capsicum annum L.) seedling business conducted at Karanganyar, Poncokusumo, Malang. The respondents were farmers who breed red chili peppers and the data collected from March to April 2018. The primary data was collected through interviews based on structure questionnaire to obtain information from selected farmers in the study area. The qualitative study is utilized to analyse the financial feasibility based from Net Present Value (NPV), Internal Rate of Return (IRR), Net Benefit-Cost Ratio (BCR), and Payback Period (PP). This study findings showed a positive NPV (IDR 15403419), IRR is 23.19%, Gross B/C is 1.05, Nett B/C is 1.13, BCR > 1 (1.05), and PP as 19 months. Despite the costly investment and development, the red chili peppers seedling business is financially feasibl
Design and Simulation of Air to Air Missile Homing System
Full text linkThis paper will talk about AIM 120 AMRAAM missile guidance for pursuing a moving target. The missile guidance system itself consists of missile dynamics, control system, seeker, and guidance methods. For general purpose, the missile dynamics approach will use non-linear equation of motions. The control surface that will be discussed follow the rule BTT (Bank-to-Turn) and control system that will be used is PID control system that widely used for control design. Lastly, the guidance method that will be studied here is proportional navigation and constant bearing course approach. The simulation will be conducted using MATLAB Simulink. The Simulink model consist of target dynamics, and guidance system. From the result of simulation, it will be shown that the missile can pursue its target quite well. Hence, the simulation system can be used well for preliminary design purpose.Keywords—Homing System, Control System, Proportional Navigation, Missile Dynamics, Seeker, Bank-to-Turn, Constant Bearing Course
DECEPTIVE IS EFFECTIVE NEGOTIATION STRATEGIES TO CUSTOMERS FOR USING CONDOMS CONSISTENTLY
Full text linkThe Consistency of condom use by the sex customers is very low. These problems occur due to the lack of negotiations carried out by the sex workers into their customers. This study aims to determine the most effective negotiation strategies for the customers to consistently using condoms. The study was conducted by using a survey cross-sectional of sex workers directly with the sample of 100 peoples, which who selected by a random cluster sampling in Denpasar city. The data collected by interviews conducted by using a questionnaire about the characteristics and modification Condom Influence Strategy Questionnaire (CISQ) developed by Noar. The results of the study show that about 63% of customers consistently used condoms in the past week. The effective negotiation strategies used so that customers consistently using condoms is deceptive by sex workers to their client's variables associated with consistent condom use is the availability of condoms and sex worker's age. Deceptive is the most effective strategy to increase consistent condom use.Keywords— Negotiations Condoms, Female Sex Workers, Consistency of Condom Us
DEVELOPMENT OF NUMERICAL PLATFORM FOR AIRCRAFT SYSTEMS SIMULATION
Full text linkThis paper discusses the development of a numerical simulation platform that can be used for representing the principal works of aircraft systems. The platform consists of some parts each of which is intended to replicate the operation of a system implemented in a modern aircraft, such as hydraulic line, electrical system, landing gear system, control system, etc. The platform is intended to be a tool for modeling and analyzing the operation and performance of certain systems configuration. To some extend the platform can be viewed as a virtual Iron Bird System. Iron Bird is a term representing a platform for simulating the works of aircraft systems using real components, which is very important for aircraft system development. At this stage, the numerical platform will only involve some sub-systems, namely main hydraulic line, control surface actuation, landing gear, and control system. These sub-systems are chosen to be the basis for further development where other sub-systems will be added and integrated to the platform.Keywords—Aircraft System, Numerical Simulation, System Analysi
Manganese Recovery from Hydrocracking Spent Catalyst Using Citric Acid and Its Kinetics
Full text linkAiming for recovery and kinetics of manganese from hydrocracking spent catalyst using citric acid, this study has been conducted. In order to justify the performance of citric acid, a comparative study has been conducted using both inorganic and organic acids in the same pH condition of about 1,5 - 2. pH was used as the controlled variable due to the different dissociation degree of the acids. In comparison to that of inorganic acid, the manganese recovery is four times higher when citric acid was applied. Acetic acid performed 33% lower in manganese recovery compared to the citric acid. Moreover, kinetics study was conducted with three varying temperature of 30C, 60C, and 90C. From the resulted data, it can be concluded that the kinetics of mengan leaching from spent catalyst using citric acid is in accordance to the shrinking core model. The controlling step is product diffusion with activation energy (Ea) of about 23.27 kJ/mol calculated using Arrhenius expression. With higher selectivity and leaching reagent which is harmless to the environment, the application of citric acid in manganese leaching from spent catalyst will indeed support the enactment of sustainable development aspect in recycle processin
Risk Assessment Approach in Airport Security
Full text linkNaturally, the threat to flight is generated from all activities at the airport by passenger or freight. With the growth of air transport, the level of threat to flight activity will also increase. Due to ensure the security of passengers, staff, and all elements of the airport, the airport as a place of the flight operations need a reliable protection system. The purpose of this study is to develop a methodology for assessing the risk level at the airport in order to improve the level of protection at the airport. The level of threats that could jeopardize airport security is categorized into several levels, then analyzed to what extent the risk level can be tolerated as a reference to the formulation of standard protection systems at the airport. The results of this study can be used to deal with threats that occur in the airport through preventive action by setting up a reliable protection system. The risk assessment approach also able to evaluate the airport's existing protection system whether it is tolerable to deal with threats or not, so action can be taken to improve the protection system if the failure rate is still high and have massive consequences to the all airport elements.Keywords— airport security, failure rate, protection system, risk assessment, tolerable risk level