bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of ground state degeneracy to long-range interactions
Authors: Lapa Matthew F , Levin Michael 
Published: January 2023

Abstract
We show that some gapped quantum many-body systems have a ground state degeneracy that is stable to long-range (e.g. power-law) perturbations, in the sense that any ground state energy splitting induced by such perturbations is exponentially small in the system size. More specifically, we consider an Ising symmetry-breaking Hamiltonian with several exactly degenerate ground states and an energy gap, and we then perturb the system with Ising symmetric long-range interactions. For these models we prove (a) the stability of the gap, and (b) that the residual splitting of the low-energy states below the gap is exponentially small in the system size. Our proof relies on a convergent polymer expansion that is adapted to handle the long-range interactions in our model. We also discuss applications of our result to several models of physical interest, including the Kitaev p-wave wire model perturbed by power-law density–density interactions with an exponent greater than 1.
The Solution of Structure Constrained Problem Using Decomposition Method
Authors: Cipta Hendra , Suwilo Saib , Sutarman  , Mawengkang Herman 
Published: January 2023

Abstract
In practice, linear programming problems may have many variables and constraints. The decomposition method can be applied to problems with some special structure in order to obtain the solution. This method allows determining the optimal solution by decomposing structure constraints into several parts of the problem, then completing the parts of the problem independently. The purpose of this study is to provide on optimal solution to large scale constraints problem by decomposition method.
Comparison of completion of VAM, TCOM-SUM Transportation problems with Stepping Stone to Determine optimal solutions
Authors: Amisah Lubis Loria , Mardiningsih  
Published: January 2023

Abstract
This research discusses to optimize the path and find out the distribution of minimum transportation costs using the VAM (Vogel’s Approximation Method) method, TOCM-SUM is then optimized through the stepping stone test. The VAM method is one of the methods of preparing a initial feasible solution by Determining the distribution table allocation to the cell that has the least cost. TOCM-SUM method to find a suitable initial solution of the transportation problem. The optimal stepping stone test aims to test the initial solution table by calculating the cost of empty cells that are passed by the stepping stone path.
Purification of glycerol from biodiesel by-product by using kitchen vinegar
Authors: Rizky Y , Panggabean S , Sigalingging R , Raju  
Published: January 2023

Abstract
Indonesia is a country that produces large amounts of palm oil. Oil palm plantations are often found in Sumatra and Kalimantan. Palm oil is usually used as a raw material for making cooking oil. Apart from that, it can be used as a raw material for biodiesel production from vegetable oil taken from palm oil. The production of biodiesel from palm cooking oil produces a by-product in the form of glycerol, where the glycerol is still in the form of crude glycerol which cannot be utilized. Glycerol purification is carried out by the method of acidification and evaporation to remove the KOH catalyst and methanol that are still present in the crude glycerol. The acid used was 2 ml of kitchen vinegar and was carried out 3 times. The purpose of this study was to obtain glycerol and water content. The results of this study showed that the highest glycerol content was 83.47%, the lowest water content was 1.83%, the lowest pH was 12.00 and the color of glycerol was blackish brown.
Regeneration of spent bleaching earth using microwave assisted extraction method with hexane as solvent for the bleaching of crude palm oil
Authors: Nugraha  , Iriany  , Misran E 
Published: January 2023

Abstract
One of the wastes in palm oil mills is spent bleaching earth (SBE) which is produced from the bleaching process. In landfills, SBE can produce unpleasant odors, pollute the land and can be quickly oxidized and spontaneously auto ignition occurs. SBE consists of residual oil, phospholipids and several minor components resulting from the bleaching process. Microwave-assisted extraction (MAE) has several advantages over conventional extraction methods because its selective heating increases the effectiveness of the extraction process. The effect of different variables such as irradiation power, contact time and solid to solvent ratio was investigated. After extraction, regenerated spent bleaching earth (RSBE) is used in the bleaching of palm oil with activated bleaching earth (ABE) as a comparison. From this study it can be concluded that MAE can be used in the regeneration of SBE with hexane as solvent. The best conditions for each variable were an extraction time of 40 minutes, a solid to liquid ratio of 1: 4 and a microwave power of 450 W. Using RSBE, the highest yield obtained was 18.63%. Thus, RSBE can be reused in the bleaching process. However, to obtain the same quality results as treated using ABE, more RSBE is needed.
Ethnobotany of Medicinal Plants Community in Saroha Village, Tanjung Botung, Barumun District, Padang Lawas Regency, Uatara, North Sumatra
Authors: Rambey R , Lubis A S J 
Published: January 2023

Abstract
Indonesia is a country with a high level of diversity, both flora and fauna. One of the biological diversity that is owned is various types of medicinal plants used by the community. The purpose of this study was to make an inventory of the ethnobotany types of medicinal plants in the community around Saroha Tanjung Botung Village, Barumun District, Padang Lawas Regency. The research was conducted from July to November 2020 in Tanjung Botung Saroha Village, Barumun District, Padang Lawas Regency. The research method used is snowball sampling by means of interviews with key informants in the community. Based on the results of the study, there are 40 types belonging to 31 families of medicinal plants found in the village of Saroha Tanjung Botung as traditional medicine. The percentage of the most widely used family were Zingiberaceae (12,9%), Asteraceae (9,6 %), Malvaceae (6,45 %), Myrtaceae (6,45 %), Clusiaceae (6,45%) and Poaceae (6,45%).
Analysis of Eucalyptus Supply Chain Methods Based on Influencing Factors: A Review
Authors: Sembiring N , Napitupulu H L , Azmi N N , Radot R 
Published: January 2023

Abstract
The success of a supply chain is an important key in achieving the goals set by producers. The success of a supply chain has multiple objectives that are key to consumer satisfaction. These goals are high quality, low prices, on time delivery, and good customer service. This goal can be achieved if the management can design a good supply chain. In this study, an analysis will be carried out from the results of previous research, regarding the efforts made to increase supply chain productivity for Eucalyptus plants. Every scientific article goes through a rigorous selection process to get articles that are in accordance with the objectives of this research. The results show that the approach using simulation methods is the best way to analyze and evaluate a supply chain. Each simulation approach can provide actual information required for improvement of the supply chain. Improvements are generally carried out on an ongoing basis for each specified period.
Sustainable Development Goals and Green Sustainable Supply Chains: a Review
Authors: Sembiring N , Junika C , Azmi N N 
Published: January 2023

Abstract
This study establishes the practice of Green Supply Chain Management (GSCM) from a broad perspective and to analyze topics in recent years, by analyzing the literature review of articles published mostly in 2019-2020. The use of GSCM was developed by the concept of green innovation with new methods and ideas for producers. GSCM practices have an impact on environmental implementation that this study tries to find out how manufacturing organizations improve their environmental performance with green innovation practices and GSCM. This paper presents GSCM practices that provide practical evidence for organizations that contribute to determining their ideal environmental strategies. This study also contributes to innovations that enhance green innovation, and hence providers a broad assessment with consideration of green innovations at the green supply chain stage.
Computational Analysis for Dam Stability Against Water Flow Pressure
Authors: Tulus  , Marpaung T J , Marpaung J L 
Published: January 2023

Abstract
Fatigue analysis of an object’s structure is very important because it can provide a numerical value that can be used as a reference before acting. The finite element method is a numerical method that can calculate the value of the fatigue and stability of a structure by calculating the reynold value and the pressure given. This study aims to conduct a structural fatigue analysis of the dam that focuses on the Reynold value in order to provide an analysis and representation of the dam structure. The result to be achieved is a mathematical model that analyzes the fatigue of the dam structure by connecting the elevation angle, water velocity, time, and the force obtained from the kinetic energy in the water flow.
Finite element analysis of mechanical properties of bambusa vulgaris bamboo from eastern region of Sumatera Utara
Authors: Handana M A P , Surbakti B , Karolina R , Utami H 
Published: January 2023

Abstract
Indonesia is the right area to develop bamboo as a construction material because this country is a well-known bamboo producing country in the Asia-Pacific region. One of the bamboo species that can be studied is Bambusa vulgaris because this species grows in almost all parts of Indonesia. This study focused on Finite Element simulation to calculate the compressive strength and tensile strength of Bambusa vulgaris sourced from Deli Serdang, Langkat, and Sedang Bedagai district. The results of the strength obtained from the simulation will be compared with the results from the previous study with the same species and the same location, to see the reliability of the model simulation with software. From simulation results, it is found that the compressive strength is 46.70 MPa, 58.33 MPa, and 47.65 MPa. For tensile strength, the results obtained from the simulation are 194.08 MPa, 182.49 MPa, and 156.44 MPa.The difference given between the simulation result and the test results in previous studies for compressive strength is 5.38 – 10,09% and for tensile strength is 1,96 – 9,39%. This result indicates that simulation with Finite Element Analysis can provide results that are sufficiently close to a laboratory test.
Analysis of the relationship between urban heat island (UHI) phenomenon and land cover change in Medan city using Landsat satellite imagery
Authors: Pohan S A , Sulistiyono N 
Published: January 2023

Abstract
The increase in population accompanied by an increase in the amount of built-up land has led to an increase in the LST of many cities, including the city of Medan. The city of Medan is the capital of the province of North Sumatra, Indonesia. The utilization of Landsat satellite imagery can be used to monitor land cover changes and LST changes. This study aims to obtain information due to changes in land cover to LST in Medan City. The use of thermal Infrared band in Landsat satellite imagery can monitor LST changes that have occurred. The results of the study show that in the period 2000 to 2019 there has been an increase in the area of built-up land and a decrease in the area of vegetation in the city of Medan. In 2000 the LST ranged from 12-30°C while in 2019 it ranged from 18-33°C. This has triggered the occurrence of UHI, especially in urban centers in the city of Medan.
Design of Monitoring System Temperature And Humidity Using DHT22 Sensor and NRF24L01 Based on Arduino
Authors: Azhari  , Nasution T I , Sinaga S H , Sudiati  
Published: January 2023

Abstract
The monitoring system is used for know or get an information on a situation or condition in a certain place or area, with various methods used, so that many monitoring systems are developed and applied to assist human tasks in carrying out monitoring. The hardware design consists of 2 nodes namely the base node and the client node. At the base node there are 2 hardware components used, namely: Arduino Uno and the wireless communication module nRF24L01. The use of the NRF24L01 module is a reliable data communication module so that the data received is in accordance with the data sent by testing the module in different rooms and the same range with a distance of ± 800 m. Buzzer works well with temperature performance results ≥ 32 °C buzzer on and with ≤ 65% humidity buzzer on. The sensor network system can run well, because the ratio of the DHT22 sensor with the thermohygro, the average error is 1.4% for temperature and 3.8% for humidity from the results of data collection.
Simulation and design of the circular polarization microstrip antenna with CSRR metamaterial structure
Authors: Rambe A H , Nasution F A , Sinulingga E P 
Published: January 2023

Abstract
This paper has discussed the design of a circular polarized microstrip single patch antenna using a complementary split-ring resonator (CSRR) placed in the patch section. The design used an epoxy FR4 substrate with a thickness of 1.6 mm. Antenna specifications that resonate at a frequency of 1.57 GHz are very supportive for GPS applications. The design is carried out with the AWR simulator. The implementation of CSSR metamaterial structure in the patch was successful in improving the design performance compared to the design without using CSRR. Based on the simulation results, the minimum return loss is -40.92 dB at a frequency of 1.57 GHz and an axial ratio below 3 is achieved for the frequency range of 1.56 – 1.59 GHz. Reduction of substrate and patch dimensions was achieved by 36.5% and 46.9%, respectively.
Construction of Ultrasonic Fruit Fly Repellent Device in Orange Orchard
Authors: Rahayu S U , Nasruddin  , Susilawati  , Sianturi H A , Faturrahman  , Manurung J G 
Published: January 2023

Abstract
Ultrasonic waves are stated to be able to repel several types of pests. This study aimed to design a device to repel fruit fly in orange orchard using ultrasonic waves with a frequency range of 20-80 KHz. The device employed a microcontroller and real time clock (RTC) to control the ultrasonic wave transmitter automatically, in which the electrical energy is obtained from solar panel. The objective of using the solar panels is to directly powered device without installing the cable to the main power source (PLN) because the device should be placed in the middle of the orchard, which is located far from the main power source. Based on the design analysis, the solar panel should be placed facing the southern part of the orchard with the angle of around 5ºC since the orchard in the Karo regency, Sumatera Utara, Indonesia. The current was measured for each frequency, and based on that measurement the electrical power was calculated to be 142.56 Watt, so by using the battery of 1200 Watt, the device could work properly for 8 hours even without full sunlight. The resulted frequency was measured using oscillator; the results show that the average accuracy is 0.24%, which shows that the ultrasonic wave transmitters generate the ultrasonic wave accurately. Based on these results, it can be concluded that the ultrasonic fruit fly repellent device designed in this study is successfully constructed and works properly to generate the ultrasonic wave with the range frequency satisfied the condition to repel the fruit fly.
Humidity Detection Based on Chitosan/PEO Film Sensor
Authors: Cuana R , Nasution T I , Agusnar H , Susilowati A , Lubis N S , Pradana I S 
Published: January 2023

Abstract
PEO (Polyethylene Oxide) addition in chitosan has been successfully fabricated as a humidity sensor. In this study, 3% w/v chitosan solution was added by 0.1, 0.2, 0.3, 0.4 and 0.5 (%w/v) of PEO respectively. The sensing properties of chitosan and chitosan/PEO films as humidity sensors have been characterized using Air Handling Unit Trainer, model KT-2000AHU to determine response, repeatability, and recovery toward relative humidity (20-90% RH). The results show that the chitosan/PEO films have a good response when exposed to 90 %RH at room temperature. Those are 288,09 mV obtained by pure chitosan film; 338.97, 384.44, 406.81, 359.69, and 345.84 mV for 0.1, 0.2, 0.3, 0.4, and 0.5% of PEO films respectively that show higher electrical response. The smooth and porous film morphology and chemical interaction between chitosan and PEO through hydrogen bond obtained by SEM and FTIR could be responsible for the higher electrical response. Furthermore, humidity sensing material based on chitosan/PEO films shows good recovery and repeatability.
Effect of blanching treatment on drying time and the quality of hybrid system solar dried red chilli
Authors: Romauli N D M , Sihombing H V , Sinamo K N , Ambarita H , Manurung H 
Published: January 2023

Abstract
This research aims to determine the effect of blanching treatment and the effectiveness of hybrid system solar dryer for drying red chilli. The dried red chilli quality parameters such as moisture content, total microba and L*,a*,b* for colour values were determined. The experimental results showed the drying box of hybrid system solar drying can reach maximum temperature from 55.2°C to 57.1°C. Blanching treatment combined with hybrid system of solar drying shortened drying time, gave lower moisture content and lower total plate count of dried red chilli compared with nonblanched-conventional drying.
The approaches for the two parameters of the Weibull Distribution
Authors: Lestari S , Sutarman  
Published: January 2023

Abstract
This study aims to determine the MLE and Bayes approach on the Weibull distribution. Through literature study done by analyzing the MLE approach to the Weibull distribution and the priordistribution for Bayesian methods in this approach by using prior information Jeffrey expansion with two parameters α and β.
Computational analysis dynamics fluid of flow in dam using COMSOL Multiphysics
Authors: Masna  , Tulus  , Sawal  
Published: January 2023

Abstract
One way to utilize river flows in Indonesia is to make a dam to get benefits in various fields. The river flow that enters the dam and which will flow again makes flow in the dam which causes a fluid dynamics. The fluid dynamics that occur in dams produce several events such as precipitation, flow turbulence, and so on. To see how the flow is, in this study a simulation was carried out by making a dam model followed by fluid dynamics analysis of the dam model. Then it will be solved by the finite element method. In its completion, a COMSOL Multiphysics program is used that applies the finite element method to get results and simulations. The results to be obtained using the mesh transfer method. Where mesh displacement applies the speed of surface displacement as the velocity of fluid flow when entering, the solution to the equation in mesh displacement uses displacement on the node, and the Navier Stokes equation is solved by substituting the displacement equation on the mesh. The results obtained at an interval of approximately 3 seconds with a speed of 0.7 m/s will produce turbulence flow at the dam where the maximum speed on the surface is 0.4 m/s. As a result, if there are other elements in the flow other than water, it will cause mixing of substances in the middle of the dam in 3 seconds and then precipitation will occur. In the next study, different dam models will be carried out and have a faster flow rate.
The resistive wall impedance and the effects of the non-evaporable getter thickness in an ultra-low emittance ring
Authors: Talebi Motlagh S. , Rahighi J. , Zamani F. , Saeidi F. 
Published: January 2023

Abstract
In modern particle accelerators with ultra-low emittance,
the vacuum chambers are designed based on Non-Evaporable Getter
(NEG)-coated vacuum chambers. The thickness of the NEG coating plays
a critical role in the dynamic beam effects. So, in this paper, the
longitudinal and transverse impedance of a copper chamber coated
with a NEG are investigated, and the effects of the NEG thickness
over a wide range of frequencies have been studied. A good selection
of NEG layer thickness could minimize the coating effects on the
longitudinal and transverse beam impedance. The numerical results in
this work show that the beam dynamic effects could be minimal with
selecting a NEG coating thickness of about 1 μm.
Friction stir lap joining techniques effects on microstructure and tensile properties of high-strength automotive steel top hat sections
Authors: Abhilash V , Lakshminarayanan A K 
Published: January 2023

Abstract
Dual Phase (DP) steel, a type of Advanced High Strength Steel (AHSS) with a thickness of 1.7 mm, is used to fabricate single-hat components that are then joined to the base plate using two friction stir welding processes: friction stir lap welding (FSLW) and friction stir spot lap welding (FSSLW). It is difficult to join this assembly using fusion welding techniques. The welding variables for the FSLW process, tool rotation speed (TRS), tool traverse speed (TTS), and plunge depth (PD), were optimized using the design of an experiments-based response surface method by experimentally measured tensile shear failure load (TFL) of top hat assembly. For the FSSLW process, the welding variable TTS was replaced by dwell time (DT). Peak temperature, microstructure at different zones, microhardness mapping, and energy absorption capacity of both processes were evaluated under optimal welding conditions. For both processes, the stir zone and the heat-affected zone had the highest and lowest microhardness, which can be correlated with the level of martensite tempering, martensite lath spacing, polygonal ferrite volume, and precipitated carbides. Under optimum welding conditions, the TSL and energy absorption of FSLW joints were 14 kN and 170 J, respectively, which is 20% and 47 higher than the TSL and energy absorption of FSSLW joints.
Thermal cycle stability of glass-to-metal seals with glass preforms produced via powder-metallurgy and casting-machining methods
Authors: Gong Keqian , Cai Yangyang , Liu Zheng , Zhang Yong 
Published: January 2023

Abstract
In order to evaluate the influence of preform preparation processes on thermal cycle stability of glass-to-metal seals, this work embraced two different methods to produce the preform for seals. For the conventional powder metallurgy (PM) method, the molten glass was quenched to form frits, then the frits were ball milled to prepare glass powders. These glass powders were pressed into green bodies and heated to prepare preforms. While for the casting-machining (CM) method, the molten glass was cast into a graphite mold and annealed before accurate machining to preforms. In contrast to the PM method, the CM method provided an ultralow-porosity preform structure and a low porosity glass seal region. Field emission scanning electron microscope (FE-SEM) was conducted to investigate the bubbles and cracks in glass region. Furthermore, thermal cycling tests confirmed that these two tremendously different glass regions strongly affected the thermal cycle stability of the seals. To support the understanding of cracking in seals, the damage features of the samples were observed by FE-SEM and the extended finite element method (XFEM) was used to simulate the crack initiation and propagation. The experimental results demonstrated that cracking in the seals made from CM preforms occurred in the glass region near the sealing interface. However, cracks initiated from the bubbles in the seals made from PM preforms, which was verified by the XFEM simulation results. In addition, the CM seals demonstrated little degradation of the leakage rate until 105 thermal cycles, while cracking was found in the PM seals after 70 thermal cycles, indicating a decreased thermal cycle stability and resulting in hermetic failure.