bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the hardware detection device of the IR46 intelligent IoT electric energy meter
Authors: Liu Yongping , He Chuanliang , Xia Xin , Lv Yingjie , Wang Shouzhi , Xia Shaoxian
Published: December 2020

Based on the characteristics and design concept of the IR46 intelligent IoT electric energy meter (hereinafter referred to as the IoT electric energy meter), from the perspective of verifying its design, practicability, and quality, a hardware detection device solution that satisfies the IoT electric energy meter is proposed. It satisfies its multi-core modular hardware detection requirements, can effectively guarantee the network access detection of IoT electric energy meters, improve detection efficiency, and reduce the difficulty of development of electric energy meter manufacturers. A reasonable hardware detection device solution is provided for the implementation of IR46 electric energy meters in China.
Design and application of digital phase locked loop based on Quartus II
Authors: Xie Yan , Zhou Jin , Kang Shengwu
Published: December 2020

The traditional phase locked loop (PLL) is realized by analog circuit. Compared with PLL realized by traditional analog circuit, digital phase locked loop (DPLL) has the advantages of high precision, not affected by temperature and voltage, adjustable loop bandwidth and center frequency, and easy to construct high-order PLL. With the rapid development of communication technology and integrated circuit technology, DPLL will be more widely used. In this paper, the PLL macroblock is used to design and realize the functions of frequency division, frequency doubling and phase locking in Quartus II development environment. The validity of the design and application of the DPLL is verified by practical verification.
Design of a full-bridge type fault current limiter
Authors: Zeng Yonghao , Wang Wenjie , Fan Xinming , Peng Yuanquan , Liu Yijun
Published: December 2020

Compared to AC system, DC power system is more likely to be damaged by short current, because in DC system the fault current increases faster and doesn’t have zero crossing point. The DC current limiter (FCL) can limit the rise of the current, thus it is efficient to use FCL to improve the reliability of the power system. Based on the previous research, we proposed an improved topology, established its mathematical model and analyzed its working processes. Besides, parameter design methods of solid-state DC current limiter are proposed by combining modeling and image analysis. And the control strategy of DC transformer short circuit fault crossing and recovery is put forward. Simulation and experiment results proved the effectiveness of topology and control strategy we proposed.
The Chilean electricity market and its implications
Authors: Wang Hechun , Xie Zhonghua , Le Qin , Wang Kai , Li Hua , Tao Jing , Liu Dunnan
Published: December 2020

Chile was one of the first countries in the world to successfully reform its electricity market. Limited by the dilemma of energy dependence on imports, Chile’s electricity price fluctuates greatly. Therefore, in recent years, Chile has been committed to the transformation of the new energy structure and introduced a series of policies to promote its energy development. This paper analyzes the current situation, the reform process, and the operation mechanism of the electricity market in Chile, Focused on the characteristic mechanisms and policies in Chile’s energy transition. Finally, combined with the current situation of China’s electricity market, draw lessons from Chile’s electricity market construction highlights and put forward relevant thinking and suggestions.
Multistep finite-control-set model predictive control of active power filter
Authors: Bi EnZi , Yang JianFeng , Liu Yang , Wang XiaoQing
Published: December 2020

The traditional finite-control-set model predictive control (FCS-MPC) of three-phase active power filter (APF) has the problems of low compensation precision and long control delay. In order to address this problem, this paper proposes a multistep prediction compensation control method for the FCS-MPC of APF, it does not require modulation of PWM link. By utilizing the discrete mathematic model of three-phase parallel APF and keeping the advantages of traditional FCS-MPC, the prediction model is established based on the structural model of traditional FCS-MPC, the predictive controller is designed for predictive control of DC-side voltage. AC-side current and fixed switching frequency, and simulation study is also conducted. The simulation results show that the multi-step predictive control method can effectively track and compensate harmonic, reduce the harmonic component of power grid, and increase the compensation precision of parallel APF.
Research on Constant Current Technology of High Current Power Amplifier for Relay Protection Test Device
Authors: Zhou Xueqing , Zhao Yuhao , Li Tiecheng , He Lei , Wang Xianzhi , Yuan Zhenyu
Published: December 2020

In order to provide more accurate and consistent reference current for power system under different loads, the constant current performance of the high-current power amplifier is studied. This paper presents a circuit topology suitable for high-current power amplifier circuits, and analyses the key factors that affect its constant current characteristics. It is found that resistance matching plays a decisive role in the constant current characteristics. Through quantitative analysis and verification, the boundary conditions of the output resistance of the high-current power amplifier under the specified resistance accuracy are also found. Then based on Monte Carlo analysis and worst-case analysis, the previous theoretical derivation afterwards is conducted. Finally, an effective method of resistance matching is brought forward, which is authenticated in the contrast test later.
A Novel Hybrid Piezoelectric-Electromagnetic Micro-Power Generator by Harvesting Low Frequency Acoustic Energy
Authors: Chen Yuansheng , Gu Cong , Chen Wei , Zhao Pengcheng
Published: December 2020

In order to harvest low frequency acoustic energy, a novel hybrid piezoelectric-electromagnetic micro-power generator was developed with Helmholtz resonator, piezoelectric patch, coil and permanent magnet. When the sound waves enter Helmholtz resonator, piezoelectric patch and coil will be vibrated then the electric energy are generated from them. With Multisim software, the circuit of proposed micro-power generator was simulated and its output performance was analysed. Results show that there is always an optimal resistance to maximize the output power of the novel hybrid piezoelectric-electromagnetic micro-power generator. Especially when the sound waves at 82Hz, the output power of proposed hybrid generator can more than the sum of independent piezoelectric and electromagnetic micro-generator. It indicates the power generation efficiency is significant significantly improved by the proposed hybrid method.
Study on the Microscopic Mechanism of Adsorption Layer on the Surface of Particles in Nanofluids
Authors: Zhang Liang , Tian Linchao , Zhang Anlong
Published: December 2020

In this paper, the method of molecular dynamics simulation is used to study the Cu-Ar nanofluid. It is found that when Cu nanoparticles of different volume fractions are added to liquid Ar, the thermal conductivity of the nanofluid can increase by 32.1%; adding different sizes of Cu nanoparticles. In the case of particles, the thermal conductivity of nanofluids can increase by 15.2%. On this basis, the strengthening mechanism of the thermal conductivity of the nanofluid was analyzed from a microscopic point of view, and it was found that the microstructure of the base fluid has changed after adding nanoparticles. The degree of change of the microstructure of the base fluid is greatly affected by the size of the nanoparticles. The closer to the nanoparticle base fluid, the more significant the microstructure changes. The thickness of the adsorption layer was calculated by dividing the surface of the nanoparticle and tracking the movement trajectory of Ar atoms in these areas and counting changes in the number of argon atoms. It was found that the adsorption layer was a key factor leading to the improvement of the thermal conductivity of nanofluids.
Experimental research on the decay charateristics of GIS busbar residual voltage/charge
Authors: Jiang Kui , Fu Zhong
Published: December 2020

GIS is the significant equipment in UHV network. However, after the UHV GIS busbar switch is opened, there will be a higher residual voltage on the GIS busbar, which causes the basin insulator flashover during the commissioning of the substation, which seriously affects the insulation and safety performance of the power system. It is very necessary to study the residual voltage on the GIS busbar. Therefore, we established a set of the GIS busbar residual voltage measurement system. Based on electric field measurement method, the GIS busbar residual voltage is measured in sulfur hexafluoride gas. The decay characteristics of the GIS busbar residual voltage under different polarity, different amplitude voltage and different temperature are studied. Research shows that the GIS busbar residual decays exponentially, and the decay of residual voltage is closely related to amplitude, temperature; at 26 °C and 0.4 MPa SF6 gas, the decay time of the GIS busbar residual voltage is as long as 22 hours after applying +450kV DC voltage, and the decay time constant is about 104 s order of magnitude.
Macro excel (VBA) implementation in designing booking information systems in uniform convection (Case Study: Kholidi Taylor SME, Medan Denai)
Authors: Ishak Aulia , Ginting Rosnani , Amalia Tasya
Published: December 2020

The development of information technology today is very influential in every field of work, especially in Small and Medium Enterprises (SME) which often require the implications of these technologies to support their work. This information technology is expected to help work become faster, more accurate, flexible, and efficient. Kholidi Taylor Convection SME is a business that produces uniforms or printed screen printing that can be customized by its buyers. Therefore, this SME needs an information system that can provide a place for buyers to order the uniform they want easily. This study uses the VBA Macro Excel application where this application will be used by buyers to order the desired uniform. Data Flow Diagrams (DFD) are needed to determine the most important entities and their correlation in order to create a good VBE ordering application.
Integration of Kano Model and Quality Function Deployment (QFD) to Improve Product Quality: A Literature Review
Authors: Ishak Aulia , Ginting Rosnani , Suwandira Bayu , Fauzi Malik Alfin
Published: December 2020

Companies must continue to improve service quality in order to face increasingly fierce competition. The design developed by the company must be a design that prioritizes the needs and wants of consumers. The purpose of this literature study is to make an analysis and synthesis of existing knowledge related to the topic to be studied in order to find gaps for the research to be carried out. In product design and development, there are many methods that can be used, one of which is using the Kano model and the Quality Function Deployment method. The kano model is widely applied as a useful tool for understanding customer needs and analyzing the effect of meeting customer needs on customer satisfaction levels. Meanwhile, Deployment Quality Function is used to translate the needs and desires of consumers which are then developed to meet product and service design requirements. This paper explains the extent to which the two methods are applied, namely the Kano model and the Quality Function Deployment method by analyzing several relevant journals. The author hopes that this paper can be used as a future reference for researchers in product design.
Facility Layout Redesign with Static Facility Layout Planning (SFLP) and Dynamic Facility Layout Planning (DFLP) at Convection and Computer Embroidery Industry
Authors: Tarigan U , Ishak A , Simanjuntak L S , Rizkya I , Putri K S , Tarigan U P P
Published: December 2020

UD. XYZ is a private company engaged in the convection and computer embroidery industry. This company uses raw materials in the form of fabrics to make various kinds of products such as t-shirts, shirts, training pants, jackets, emblems and various types of clothing. Problems that are being faced by this company is a cross-movement, low efficiency, and layout of facilities that do not consider consumer demand for the product so that it can affect the flow of material and increase material handling costs. Based on these problems, this research was conducted to redesign the layout of facilities with Static Facility Layout Planning (SFLP) and Dynamic Facility Layout Planning (DFLP). The method used in redesigning the layout is software CRAFT (Computerized Relative Allocation of Techniques). After redesigning the facility layout with SFLP, material handling costs amounted to IDR 393,510.01 or a cost reduction of 7.41% while the redesign with DFLP had a total cost amounting to IDR 345,685.11 or a reduction in costs of 18.66%. The results of this study show that the proposed layout chosen is the proposed layout with DFLP.
Optimizing Production Line Using the Rank Positional Weight (RPW) Method at PT. X
Authors: Ginting Rosnani , Lumongga Nst Alfri
Published: December 2020

Line balancing is a series of work stations (machinery and equipment) that are used in manufacturing products. Line balancing usually consists of a number of work areas called work stations handled by one or more operators and it is possible to be handled using a variety of tools. The purpose of research in the case of the production line is to obtain the lowest RPW weight value from the production PT. X with Rank Potential Weights method which is optimal for production lines without bottlenecks at the work station. The allocation of elements at work stations is limited by main constraints, namely zoning constraints. This method is usually better known as ranked positional weight system (RPW). The first step is to make a precedence diagram and precedence matrix. Calculate the positional weights for each element obtained from working time of that element. Calculating the production process time, each work element requires a cycle time using stopwatch time study. The method of ranking positional weight system (RPW) in this case the Production Track is in the initial condition with a cycle time of 1857 seconds and there are 5 work station. The known value of balance delay is 26.74%, efficiency is 37.34%.
Lassy dairy farm business development strategy using business canvas model method
Authors: Hasan Alizar , Tri Putri Nilda , Fithri Prima , Disti Adzhani Siti
Published: December 2020

Lassy is one of the small medium enterprises which produces processed dairy cattle, located in West Sumatra. The number of demands that tends to increase and the superiority of products without preservatives supports Lassy Dairy Farm to expand more widely. To increase the number of products, product quality and expand the marketing area of the product in order to be able to compete with similar products, proper business strategy planning is required. This study aims to design a new business model at Lassy using the Business Model Canvas (BMC) method and SWOT analysis. IE matrix results show that Lassy rank is at cell IV, which means that Lassy is in a growing and developing state. The strategy that can be carried out by Lassy Dairy Farm is based on the results of the SWOT matrix with an intensive strategy, an integration strategy, and a diversification strategy. The main strategy that Lassy can do is intensive strategy with a total score of attractiveness of 7.272. This intensive strategy is illustrated in the business model in the proposed Business Model Canvas.
Increase Productivity by Eliminating Waste and Using Systematic Layout Planning in Airline Catering Service
Authors: Rizky Alfiansyah Nofal , Awibowo Setijo , Saraswati Triarti
Published: December 2020

This research is conducted in PT. XYZ Indonesia facility. In addition, PT. XYZ is an inflight catering service provider. The purpose of this research is to solve the company problem that occurred in the dishwashing area, which is unable to meet the flight demand expectation. In order to analyze the problem, this paper is implementing the DMAIC framework methodology. After defining the problem that occurred in the dishwashing area, the data will be gathered, and it will be used for developing a new alternative layout. Furthermore, changing the plant layout process will follow a systematic layout planning procedure, and it will be supported with Tecnomatix simulation to simulate the improvement situation. As a result, new alternative layouts are being proposed to increase productivity in the operational area. Also, to maintain the quality of the operation process, a new standard operating procedure and audit form are being proposed to the company.
A Review: The Use of Nanoparticles in Cutting Fluid as an Effort to Improve the Performance of Hard Machining in Sustainable MQL Systems
Authors: Panjaya D , Ginting A , Nasution D Y
Published: December 2020

To obtain high machining performance on metal cutting, several supporting factors include the selection of tools and workpieces. To obtain the environmentally friendly cutting conditions known as green machining currently a minimum quantity cutting fluid (MQL / MQCL) is required. Based on the literature related to green machining problems in the material cutting process, this paper focuses on the addition of nanoparticle additives and observes aspects of operator safety and environmental pollution. The focus of selecting machining methods is in the form of dry and wet machining, the use of minimized fluids (MQL), and the use of vegetable oil as the base material for cutting fluids. The approach taken to focus attention is MQL / MQCL, the use of tools, and machinability which includes machining process parameters. Most of the studies indicated that the addition of nanoparticles to the developed cutting fluid had a significant effect on the machining performance parameters using the MQL / MQCL method. The study presented in this paper is a summary analysis of the impact of the nanoparticles on cutting fluid developed on the performance of the machining process carried out to help generate new research ideas for realizing green machining technology in the future.
MQL Applied for Hard Machining of Ferrous Alloys Using Hardmetals: A Review
Authors: Dalimunthe F N , Ginting A , Sutarman
Published: December 2020

Today, mostly of machining process is carried out under dry machining or minimum quantity lubricant (MQL) method. The MQL is considered as the proper solutions to reduce the amount of lubricant. This is not only reducing in cost, but also maintaining the machine life, safety, and environmentally friendly. Previous research was attempted to develop a minimum quantity cooling technique that made a major contribution to the solution of problems that affect the parts of dry machining operations. However, a gradual phase tool wear should be conditioned to make the tool work optimally and reach better performance. Therefore, this study is aimed to review the effect of the MQL use for both cermet and carbide tools that focused on the tool wear, tool life and economic advantage in hard machining process. The review revealed that MQL with cermet tool derives the good quality lubrication, better penetrates to the cutting area, reduce the cutting temperature, and increase the quality of the surface roughness, thus it recommended instead of carbide for hard machining.
A Review: Palm Oil-Based Cutting Liquid for MQL System Feeders in Hard Machining Application
Authors: Purba U I , Ginting A , Nasution D Y
Published: December 2020

The cutting fluid has an important role to cool the cutting zone by lubricating the workpiece surface and cutting tools. But if the use of cutting fluid and the disposal method is not carried out properly it can affect human health and have a negative impact on the environment. In addition, expensive cutting fluids make industrial production costs increase. Currently, among the various techniques that exist in metal cutting, one of them is the MQL (Minimum Quantity Lubricant) technique, which is a cutting technique using an air jet to flow it (cutting fluid droplets) into the cutting zone. in the form of a spray. This paper contains an explanation of the MQL technique and various cutting fluid engineering. Several experimental studies suggest that the MQL technique provides better surface finish than dry and wet machining. In addition, the MQL technique also has other advantages such as reducing the coefficient of friction, tool wear, cutting temperature, cutting force compared to dry and wet machining techniques. Therefore, the MQL technique is a viable alternative to lubrication. In addition, the cutting fluid used must also be able to decompose naturally (biodegradable).
Numerical Simulation The Fluid Flow of a Triple Concentric Tube Heat Exchanger with Computational Fluid Dynamic (CFD)
Authors: Ginting Terang U H S , Sitorus Tulus B , Ariani Farida , Julianto T E
Published: December 2020

Heat Exchanger (HE) is an important equipment in engineering application. It is widely used in many industries, such as automotive industries, power plant and food industries etc. This study aims focuses on Triple Concentric Tube Heat exchanger which it developed from double tube HE to know outlet temperature each fluid with Computational fluids dynamic method and then experimental study is used to validation for this study. It used for cooling water with the same fluid, in this research variation are inlet hot fluid temperature 50°C, 55 °C, 60 °C and mass flowrate 0.0249kg/s, 0,033kg/s and 0.041kg/s counter flow fluid.
The presence of stearamide as a rubber chemical in silica loaded-styrene butadiene rubber: The curing properties
Authors: Dhoni R , Ginting M , Surya I
Published: December 2020

This research-study investigated the influences of stearamide on the curing properties of silica-loaded styrene-butadiene rubber (SBR). The SBR was loaded with silica at a fixed loading (thirty phr) and the stearamide was added into the silica-loaded SBR compounds with varied doses from two to eight phr. The influences of stearamide additions on the scorch time, optimum curing time and cure rate index (CRI) of silica-loaded SBR were investigated. It was observed that the stearamide caused an enhancement in the rate of the curing process on the SBR compounds. The stearamide decreased both the times to scorch and optimum curing times but increased the CRI. The bigger the stearamide doses caused in the lower were the scorch time, curing time and CRI. The decreases in CRI was attributed to the role of a reactant that interacted chemically inside the silica-loaded SBR compounds. The amine content of stearamide presumably triggered the chemical reaction between the SBR, silica filler and amine itself.
The incorporations of palmitamide as a rubber chemical into carbon black-loaded styrene-butadiene rubber: cure rate index and torque properties
Authors: Khosman H , Hafni K N , Surya I
Published: December 2020

This study studied the effect of palmitamide as a new rubber chemical on the index of healing rate and torsion properties of carbon black (CB) (CB) charged styrene-butadiene rubber compounds. SBR was loaded with CB at a fixed load (thirty phr) and palmitamide was added to the CB-loaded SBR compound at doses varying from two to eight phr. The effect of palmitamide addition on the healing rate index and torsional properties of SBR CB loads were investigated. It was revealed that palmitamide caused an increase in the speed of the healing process in SBR containing CB. The greater the palmitamide dose, the higher the CRI. The increase in CRI is associated with the role of palmitamide as an additional accelerator for CB-loading SBR. The amine content of palmitamide increases CRI. It was also revealed that palmitamide lowers the minimum torque but increases the maximum torque as well as the torque difference by up to six palmitamide additions. The minimum torque reduction is due to the plasticizing effect of palmitamide. The increase in maximum torque and difference in torque is due to the increased intercalation process due to the action of palmitamide as an acting agent which increases CB dispersion.
The Success of 5S and PDCA Implementation in Increasing the Productivity of an SME in West Sumatra
Authors: Zadry H R , Darwin R
Published: December 2020

SME X is one of the micro, small, and medium enterprises in Padang, West Sumatra, engaged in the manufacture of handmade shoes. SME X has four work stations for the production process. There were found problems related to defects in shoe products with an average of 12% per month. After identifying the causes using fishbone diagrams, problems were found related to the categories of Man, Methods, Machine, and Material, which could be solved by implementing the 5S (Seiri, Seiton, Seiso, Seiketsu, and Shitsuke) concept and PCDA (Plan, Do, Check, Action) methods. After implementing the 5S and PDCA for one month, there was a decrease in defective products from 12% to 0% per month. Costs incurred during the implementation of the 5S and PDCA concept are Rp. 708,000, which is classified as economical because it is only done once during the implementation process and reduces losses due to defective shoe products, which were previously Rp. 1,250,000 per week to zero. It is very beneficial for the company to increase revenue and profit from sales. In terms of workers, there is an increase in productivity, and workers can work effectively, comfortable, safe, healthy, and efficient.
Analysis of Human Error Risk with Human Reliability Methods in Construction Projects
Authors: Priska Sinabariba M A , Ghifari M R , Muslim E , Moch B N
Published: December 2020

Work injury rates in Indonesia are relatively high, resulting in an urgency to maintain the safety of workers whose numbers are increasing. The biggest sector contributing to work accidents in Indonesia is the construction area, including building construction and causing large physical and financial losses. Workplace accidents are usually caused by human error and are strongly related to human reliability. The use of Fuzzy Cognitive Reliability and Error Analysis Method (Fuzzy CREAM) method is aimed at research to analyze patterns of worker behavior that affect the risk of workplace accidents combined with Bayesian Network simulation. 176 construction workers in the Jakarta and surrounding areas became the object of research. The value of Human Error Probability (HEP) was successfully obtained and the solution was given based on the characteristics of workers in the Control Mode category.
Analysis Roofing Quality Control Using Statistical Quality Control (SQC) (Case Study: XYZ Company)
Authors: Ishak Aulia , Siregar Khawarita , Ginting Rosnani , Manik Afrianti
Published: December 2020

Quality is a dynamic condition related to products, services, people, processes and the environment that satisfy or exceeds expectations. Quality is the main factor for consumers in choosing products. The quality of products by company determine based on certain sizes and characteristics. XYZ company is a company engaged in Baja Lembaran Lapis Seng (BJLS) which produces zinc roofing. In order to survive in competitive market, improving quality and productivity of product is must for any company. Based on production on 2019 showed that there were 49,660 defective products out of 824,574 total production meaning that there were 5.95% of defective products that exceeded the companys tolerance limit of 2%. many products that defective products that cause repeat activities and losses finished products cause harm to the company. This study reports the application of statistical quality control techniques to ensure roofing quality and to minimize the presence of defective products. the results of the analysis with the P control map show that all data on the number of defects are still in the control limit with a Cp value of 0.9410, which is low improvements the product or process so able to continue to improve the quality of its products.
The Fuzzy Failure Mode and Effect Analysis (FMEA) Method to Improve Roofing Product’s Quality (case study : XYZ Company)
Authors: Ishak Aulia , Siregar Khawarita , Ginting Rosnani , Manik Afrianti
Published: December 2020

Evaluation and improvement of production performance are things that must be considered in an effort to maintain and improve the quality of production results. One level in measuring production performance is smooth production. Good risk management can support and maintain the smooth production process in the company. This research was conducted at PT XYZ with the aim to reduce the risk of failure of zinc products and propose improvements to the risk of product failure to improve the quality of zinc products. The method used in this case is Fuzzy FMEA (Failure Mode and Effect Analysis). Fuzzy logic approach is preferred to eliminate this shortcoming in setting risk priorities number. The use of the Fuzzy FMEA method can generate priority figures for failure modes so that problems can be solved efficiently in an effort to improve production performance. The results of this study are failure modes. One of the rollers got the highest FRPN value of 880,289 so that failure due to incorrect grinding machine settings and the lack of operator accuracy in positioning zinc was recommended as a major improvement to minimize milling error failures in the production process.
Analysis of Obstacles in The Unloading Process with Failure Mode and Effect Analysis (FMEA) in PT. XYZ
Authors: Siregar Khawarita , Tarigan Ukurta , Spencer Richard
Published: December 2020

Distraction that occur can have a bad effect on time, financially and product quality. This disorder can be caused by various factors such as the influence of human factors, machinery and production equipment, work environment, and work methods. Based on preliminary observations, many obstacles occur during the unloading process both mechanically and electrically. Thus, an analysis is carried out on the process of unloading wheat from the ship to the silo with FMEA. Based on the analysis after calculating the RPN, the recommendation for problem on silo is to increase the number of silos so that the production process is more efficient. Based on the calculation of the RPN, obtained that resistance at PT. XYZ the weigher to be aware of is the sensor that is often damaged. Recommendations for improvement are regular checks on the sensors weigher. In the unloading process, there are some disturbances that occur so that it is not optimal.
Maritime inventory routing problem with undedicated compartments: A case study from the cement industry
Authors: Rusdianto M , Siswanto N
Published: December 2020

The cost of sea transportation in the cement industry located in an archipelago country has a large contribution of the overall cost because cement is a heavy product but the price is cheap and must be distributed to packing plants that are spread across several islands. The high level of competition among cement companies makes the issue of cost efficiency and inventory availability a major concern for companies. This paper proposed a solution to maritime inventory routing problems (MIRP) to minimize the cost of sea transportation faced by a cement company in the Indonesian archipelago in meeting the needs at the consumption port. Unlike other multi-product handling such as oil and other chemicals that require the use of special compartments on ships, undedicated ship compartments are generally used on multi-product cement carriers. To solve this problem, we developed a mixed-integer linear programming (MILP) model to minimize transportation costs with an inventory level that remains unfulfilled during the planning horizon period. The results of this optimization provide a global optimum with the total cost of transportation about IDR 3.69 billion for the second week period in October 2019 and maintained the availability of cement during this period.
Lean Hospital Approach for Improving The Process of Taking Drug Services in Outpatient Pharmacy Installations
Authors: Nina Y , Hakim I M
Published: December 2020

Lean is a method to reduce activities in the form of waste to increase efficiency in manufacturing or production lines and can be implemented in health services. This study analyse the flow of prescription services in BPJS Outpatient Pharmacy Installation as data for improvement. The results showed non-value added activities of 22%, value added activities of 74%, necessary non-value added activities of 4%, and process cycle efficiency of 74%. As for non-concoction drugs, non-value added activities are around 39%, value added is 61% and process cycle efficiency is 61%. The data shows that there is a process of non-value added and necessary non value added which causes the waiting time for outpatient pharmacy. Furthermore, using fishbone analysis to determine the cause of the problem and build improvements based on FMEA results. From the research results obtained that waste that often occurs is waiting that occurs in the taking of drugs. The recommended improvements are the addition of human resources in the collection and compounding of drugs, classifying and allocating types of drugs based on the speed of the drug and the implementation of 5S in BPJS outpatient pharmacy.
A condition-based maintenance policy for a system deteriorating with age and usage
Authors: Lubis Debby C , Iskandar Bermawi P
Published: December 2020

The rapid development of sensor and maintenance technologies support the implementation of a Condition-Based Maintenance (CBM) policy. The CBM policy is an effective way for reducing or even eliminating failure of a system and hence it will minimize the maintenance cost and increase the system’s availability and productivity. In this study, we propose a CBM policy with periodic inspection to control the system’s deterioration level. The deterioration is modelled by using a Gamma process with its shape parameter is assumed to be affected by the system’s age and usage. The maintenance action is imperfect in the sense that it restores the level of the deterioration to a fixed level that is not as-good-as-new condition. We use a simulation approach to simulate the deterioration process and the impact of maintenance action to the deterioration level, and to find an optimal inspection interval for a given preventive threshold, which minimizes the total maintenance cost.
Effect of Reaction Time on Biodiesel Production from Palm Fatty Acid Distillate by Using PTSA as a Catalyst
Authors: Burmana A D , Tambun R , Haryanto B , Alexander V
Published: December 2020

This study aims to determine the effect of reaction time on the production of biodiesel (methyl ester) from palm fatty acid distillate (PFAD) by using para-toluene sulphonic acid (PTSA) as a catalyst. The reaction carried out is the esterification reaction which reacts PFAD with methanol to produce methyl esters and water. In this study, the molar ratio of methanol to PFAD is 6:1 and the reaction is carried out at 65 °C. The amount of PTSA catalyst used is 5%, 10%, 15%, and 20% of the amount of fatty acids. Acid value observation is carried out at the reaction time of 60 minutes, 75 minutes, 90 minutes, 105 minutes, and 120 minutes. The results obtained indicate that the optimum conditions for producing biodiesel from PFAD are with a reaction time of 105 minutes and a catalyst amount of 15%. The acid value obtained does not decrease again or the amount of fatty acids converted to methyl esters does not increase again when the reaction time and the amount of catalyst are increased. The lowest acid value at this optimal condition is 13.37 mg KOH/g, and in this condition, 95.84% of the fatty acid is converted to methyl ester.
Dry turning of hard 2379 steel using a ZTA5Ce0.7La ceramic cutting insert: A study
Authors: Hakim Hassan Mohd Nor , Rejab Nik Akmar , Ishak Aulia , Baharuddin Abdullah Ahmad , Arifin Ahmad Zainal
Published: December 2020

The aim of this work is to evaluate the dry turning ability of zirconia toughened alumina reinforced with 5 wt.% CeO2 and 0.7 wt.% La2O3 (ZTA5Ce0.7La) ceramics as cutting insert in turning of 2379 steel with hardness of 43 HRC. Triangular cutting inserts were fabricated using this material composition via powder metallurgy route. Results of the cutting insert were measured based on the average width of flank wear and surface finish of machined workpiece. Results show that the tool was able to machine tool steel and good surface finishes were obtained for most of the cutting speeds used in the machining test, except for the highest cutting speed of 237.5 m/min. The longest life (12.5 minutes) of the cutting inserts according to the measured flank wear for the turning at cutting speed of 87.1 m/min with considerably good surface finish (Ra of 0.778 μm). Therefore, this ZTA5CeO0.7La cutting inserts is possible to be used as a successful dry turning process of 2379 steel.
Fast and accurate robotic optical detection of exfoliated graphene and hexagonal boron nitride by deep neural networks
Authors: Shin Young Jae , Shin Wheemyung , Taniguchi Takashi , Watanabe Kenji , Kim Philip , Bae Sung-Ho
Published: December 2020

Van der Waals (vdW) heterostructure constructed from atomically thin layered materials provides quantum material platforms with emergent physical phenomena and novel device applications. While stacking atomically thin vdW layers in combination with automate machine vision identification and semi-automated stacking have been demonstrated, a combination of machine learning based automatic detection/identification assembly capability is necessary to further advance vdW heterostructure fabrication. Here, we developed a new automatic optical detection technique with a deep neural network (DNN) incorporated into a motorized microscope that automatically scans entire silicon wafers to detect and identify two-dimensional (2D) materials. We demonstrated the automated combination on an optical microscope (OM) with a DNN algorithm that enables identification and classification of graphene with different sizes, shapes and thicknesses. For this purpose, we trained a representative DNN for object detection with approximately 1000 OM images, resulting in high accuracy in detection and classification. We further verified the effectiveness of graphene trained DNN (GT-DNN) in practice, by confirming the yield of flakes depending on exfoliation method. In addition, we also showed the transferability of our method to other 2D materials. Our pre-trained GT-DNN was used to train a detection model for hexagonal boron nitride with only a few samples, resulting in further improvement of the accuracy of DNN-based detection. Our experimental method can effectively be extended to automatic detection and assembly of a plethora of 2D materials.
Effect of heat treatment on microstructure and mechanical properties of low-alloy wear-resistant steel NM450
Authors: Liang Liang , Lixin Yan , Guanghui Li , Yi Cao , Xiangtao Deng , Zhaodong Wang
Published: December 2020

In this study, we investigated the effects of the quenching and tempering temperatures on the microstructure and mechanical properties of low-alloy wear-resistant steel NM450. The quenching temperatures were 870 °C–1200 °C, and held for 36 min. After quenching with 910 °C, the tempering temperatures were 200 °C–600 °C for 60 min. The results showed that as the quenching temperature increasing, the original austenite grain size increased and the proportion of high-angle grain boundaries gradually decreased, which was detrimental to the toughness of the steel. The inter-lamellar-retained austenite remaining in the martensite lath during quenching satisfied the Kurdjumov-Saches relationship with martensite. At the tempering temperatures lower than 250 °C, carbon atoms precipitated in the form of fine carbides, which improved the yield strength of the steel. With the increasing of the tempering temperature, the activity of the carbon atoms increased, the size of the carbides increased, the effects of solid solution strengthening and precipitation strengthening weakened, so the tensile and yield strengths of the steel decreased. The low-alloy wear-resistant steel tempering at 250 °C exhibited the satisfactory combination of properties. The quasi-cleavage fracture occurred mainly over the tempering temperature range of 300 °C–400 °C, and the fracture mechanism turned into ductile fracture when the tempering temperature was higher than 500 °C.
Single-step synthesis of hierarchical flower-like silver structures with assistance of gallic acid
Authors: Mei Linyu , Li Sha , Shao Yunpeng , Zhang Congyun , Wang Junyuan
Published: December 2020

We synthesize hierarchical flower-like silver microspheres with tunable size and shape, using ascorbic acid as reducing agent and gallic acid as structure-directing agent. The chemical nature of the gallic acid plays a vital role in the process of assembling silver particles into Chinese rose hierarchical structures. By changing the amount of gallic acid or silver nitrate solution (AgNO3), it is easy to adjust the anisotropic morphologies of as-synthesized silver structures and promote the preferential growth, resulting in a complete, clear, and stable multi-layered floral silver structure. This single-step wet-chemical synthesis method provides a new synthetic strategy for the anisotropic growth and morphology control of flower-like silver particles.
Structural and electrical properties of La3+ ions substituted MnFe2O4 ferrite nanoparticles synthesized via cost-effective reverse micelles strategy
Authors: Baig Mirza Mahmood , Yousuf Muhammad Asif , Zulfiqar Sonia , Safeer Affan , Agboola Philips O , Shakir Imran , Warsi Muhammad Farooq
Published: December 2020

La3+ ions substituted manganese ferrite (MnFe2-x
La
x
O4) nanoparticles via reverse micelles strategy were synthesized and their structural and electrical properties are discussed in this article. Using low-cost precursors, mono-dispersed, and well crystalline MnFe2-x
La
x
O4 nanoparticles were prepared at low temperature. X-ray diffraction (XRD) explored cubic spinel structure with minute secondary phase as LaFeO3. The crystallite size of MnFe2-x
La
x
O4 was found to increase from 12.82 nm to 15.95 nm with increased La3+ ions contents. The room temperature Fourier transform infrared (FTIR) spectra were recorded in the wavenumber range 1000–400 cm−1 that showed the vibrational bands of octahedral and tetrahedral complexes. These bands are the fingerprints of spinel ferrites. Surface morphology characterized by field emission scanning electron microscopy (FESEM) revealed the relative spherical morphology of prepared spinel ferrite particles. The elemental composition analysis from Energy-dispersive x-ray (EDX) spectroscopy confirmed the presence of expected elements in the samples. The modification in resistivity and the enhancement in the dielectric parameters suggested the possible utilization of these soft ferrite nanoparticles in advanced electronics, especially the devices that are required to operate at high frequencies.
Neutralizing antibodies against SARS-CoV-2: current understanding, challenge and perspective
Authors: Huang Yang , Sun Hui , Yu Hai , Li Shaowei , Zheng Qingbing , Xia Ningshao
Published: December 2020

The rapid emergence of Coronavirus disease-2019 (COVID-19) caused by severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2) as a pandemic that presents an urgent human health crisis. Many SARS-CoV-2 neutralizing antibodies (NAbs) were developed with efficient therapeutic potential. NAbs-based therapeutics against SARS-CoV-2 are being expedited to preclinical and clinical studies with two antibody drugs, LY3819253 (LY-CoV555) and REGN-COV2 (REGN10933 and REGN10987), approved by the US Food and Drug Administration for emergency use authorization for treating COVID-19. In this review, we provide a systemic overview of SARS-CoV-2 specific or cross-reactive NAbs and discuss their structures, functions and neutralization mechanisms. We provide insight into how these NAbs specific recognize the spike protein of SARS-CoV-2 or cross-react to other CoVs. We also summarize the challenges of NAbs therapeutics such as antibody-dependent enhancement and viral escape mutations. Such evidence is urgently needed to the development of antibody therapeutic interventions that are likely required to reduce the global burden of COVID-19.
A Hierarchical Approach Using Marginal Summary Statistics for Multiple Intermediates in a Mendelian Randomization or Transcriptome Analysis
Authors: Jiang Lai , Xu Shujing , Mancuso Nicholas , Newcombe Paul J , Conti David V
Published: December 2020

Previous research has demonstrated the usefulness of hierarchical modeling for incorporating a flexible array of prior information in genetic association studies. When this prior information consists of estimates from association analyses of single-nucleotide polymorphisms (SNP)-intermediate or SNP-gene expression, a hierarchical model is equivalent to a 2-stage instrumental or transcriptome-wide association study (TWAS) analysis, respectively. We propose to extend our previous approach for the joint analysis of marginal summary statistics to incorporate prior information via a hierarchical model (hJAM). In this framework, the use of appropriate estimates as prior information yields an analysis similar to Mendelian randomization (MR) and TWAS approaches. hJAM is applicable to multiple correlated SNPs and intermediates to yield conditional estimates for the intermediates on the outcome, thus providing advantages over alternative approaches. We investigated the performance of hJAM in comparison with existing MR and TWAS approaches and demonstrated that hJAM yields an unbiased estimate, maintains correct type-I error, and has increased power across extensive simulations. We applied hJAM to 2 examples: estimating the causal effects of body mass index (GIANT Consortium) and type 2 diabetes (DIAGRAM data set, GERA Cohort, and UK Biobank) on myocardial infarction (UK Biobank) and estimating the causal effects of the expressions of the genes for nuclear casein kinase and cyclin dependent kinase substrate 1 and peptidase M20 domain containing 1 on the risk of prostate cancer (PRACTICAL and GTEx).