bluuebunny/crossref_metadata_2025 huggingface dataset:
A model of interacting quantum neurons with a dynamic synapse
Authors: Torres J J , Manzano D
Published: June 2022

Motivated by recent advances in neuroscience, in this work, we explore the emergent behaviour of quantum systems with a dynamical biologically-inspired qubits interaction. We use a minimal model of two interacting qubits with an activity-dependent dynamic interplay as in classical dynamic synapses that induces the so-called synaptic depression, that is, synapses that present synaptic fatigue after heavy presynaptic stimulation. Our study shows that in absence of synaptic depression the two-qubits quantum system shows typical Rabi oscillations whose frequency decreases when synaptic depression is introduced, so one can trap excitations for a large period of time. This creates a population imbalance between the qubits even though the Hamiltonian is Hermitian. This imbalance can be sustained in time by introducing a small energy shift between the qubits. In addition, we report that long time entanglement between the two qubits raises naturally in the presence of synaptic depression. Moreover, we propose and analyse a plausible experimental setup of our two-qubits system which demonstrates that these results are robust and can be experimentally obtained in a laboratory.
SU (1,1) the hidden dynamical symmetry group for an exact bound state of the Hulthen potential
Authors: Etebu Woyengipere Oluwaseun
Published: June 2022

In this research work, an exact normalised bound eigenstate and energy eigenvalue of the Hulthen potential, for the zero angular momentum within the framework of the non-relativistic time independent Schrödinger wave equation were obtained using the Nikiforov–Uvarov method. Also, their self-adjoint differential creation and annihilation (ladder) operators were derived, andfrom the commutation relations their Casimir operator was defined. These results showed that the non-compact

S
U

(
1
,
1
)

group is the dynamical group for this exact bound state, described by the representation

D

+

(
i
)

with a spectrum bounded below.
Restoration of complex movement in the paralyzed upper limb
Authors: Hasse Brady A , Sheets Drew E G , Holly Nicole L , Gothard Katalin M , Fuglevand Andrew J
Published: June 2022

Objective. Functional electrical stimulation (FES) involves artificial activation of skeletal muscles to reinstate motor function in paralyzed individuals. While FES applied to the upper limb has improved the ability of tetraplegics to perform activities of daily living, there are key shortcomings impeding its widespread use. One major limitation is that the range of motor behaviors that can be generated is restricted to a small set of simple, preprogrammed movements. This limitation stems from the substantial difficulty in determining the patterns of stimulation across many muscles required to produce more complex movements. Therefore, the objective of this study was to use machine learning to flexibly identify patterns of muscle stimulation needed to evoke a wide array of multi-joint arm movements. Approach. Arm kinematics and electromyographic (EMG) activity from 29 muscles were recorded while a ‘trainer’ monkey made an extensive range of arm movements. Those data were used to train an artificial neural network that predicted patterns of muscle activity associated with a new set of movements. Those patterns were converted into trains of stimulus pulses that were delivered to upper limb muscles in two other temporarily paralyzed monkeys. Main results. Machine-learning based prediction of EMG was good for within-subject predictions but appreciably poorer for across-subject predictions. Evoked responses matched the desired movements with good fidelity only in some cases. Means to mitigate errors associated with FES-evoked movements are discussed. Significance. Because the range of movements that can be produced with our approach is virtually unlimited, this system could greatly expand the repertoire of movements available to individuals with high level paralysis.
Study on Properties of Cement Stabilized Macadam with Recycled Aggregate of Different Replacement Rates under Vibrating Mixing
Authors: Si Yongming , Wang Wangning , Cao Feng , Li Taotao , Zhang Liangqi , Lv Xiaowu
Published: June 2022

It has the goal of green construction to use recycled aggregate of waste cement concrete in cement stabilized macadam base to replace recycled aggregate of base. In this paper, the properties of cement stabilized macadam with natural aggregate and recycled aggregate under different replacement ratios are compared. The test results show that the physical properties (apparent density, mud content, crushing value, water absorption, etc.) of recycled aggregate are lower than those of natural aggregate, but meet the requirements of the specification. With the increase of the proportion of recycled aggregate in cement stabilized macadam, the optimal moisture content required for the maximum dry density of fully recycled aggregate mixture increased by 20.6% compared with that of natural aggregate mixture; the unconfined compressive strength of cement stabilized macadam with recycled aggregate at 7d and 28d showed a downward trend, and the strength of cement stabilized macadam with fully replaced recycled aggregate at 7d and 28d decreased by 10% and 1% respectively 0%. In addition, the strength of full substitution 28 increased by 11.1%. The research shows that the recycled aggregate base can meet the construction requirements, and the vibration mixing has better advantages, which provides a reference for engineering application.
Effect of Temperature on Properties of Concrete in Stirring Process
Authors: Yan Qingyao , Shen Zhenzong , Wang Zengqiang , Yin Zhuangfei , Yao Yunshi
Published: June 2022

Taking composite silicate concrete as the research object, the double horizontal shaft mixing method is used to mix concrete. The setting time, strength and workability tests are carried out to study the influence of temperature on the mechanical properties of concrete in the ordinary mixing process. The results show that the temperature has great influence on the setting time, compressive strength and splitting strength of concrete. Reasonable control of cement temperature has important guiding significance and theoretical basis in practical construction application.
Effect of Particle Combination Ratio of Soil Rock Mixture on Shear Strength
Authors: Li Shengting , Zhou Rui , Yang Fan , Zhang Yangchun , Du Yongjun
Published: June 2022

With the increase of fine-grained soil content, the properties continue to transform to fine-grained soil, which will affect the permeability and strength of the soil. Even if the content of silt and clay in fine-grained soil is not high, it will significantly impact soil properties. When the content of coarse particles is low, the nature of soil depends on the fine particles in the soil. When the content of coarse particles gradually increases, and the coarse particles are overhead, the nature of soil only depends on the coarse-grained soil, and the influence of fine particles on the nature of soil gradually weakens. To reveal the interaction mechanism between coarse and fine particles in high moisture content clayey gravel, this project conducts a systematic experimental study on the high moisture content clayey gravel, takes 0.5mm as the particle size limit, takes the separation of coarse and fine particles in the soil sample as the control test, and systematically tests the shear strength of the separated fine particles; systematic shear strength tests were also carried out on the separated coarse particles. In addition, shear strength tests were carried out on soil samples with different fine particle content.
Research on Data Fusion Method of Revit and Non-BIM Software in Complex Shaped Buildings
Authors: Gao Chao , Li Shengting , Wang Zhenkai
Published: June 2022

BIM is a collection of building information data in the whole process, and it is of great significance to integrate non-BIM data into BIM. As the most mainstream BIM software in the world, Revit can complete almost all BIM data, but it still cannot be completed for some complex shapes. Therefore, it needs to be done with traditional 3D software. Therefore, fusing the data of non-BIM software into Revit and forming BIM data has important research significance and application value. This research introduces in detail the method and development process of fusing Revit data and Rhino data.
Research on the Key Technology of Prefabrication and Assembling of the Viaduct Substructure in the Urban Central Area of the Middle Earthquake Region
Authors: Zhou Zhendong
Published: June 2022

Facing the difficulty of construction of viaducts in the central area of the city with short construction period and large daytime traffic. Relying on the Nairobi Airport viaduct project in Kenya, the problems in the construction of this project and the special seismic intensity of the area were analyzed. The key technologies in the design and construction of the bridge substructure using prefabricated assembly technology were studied, and a reasonable substructure analysis was put forward. Block principle and assembly connection plan, and focus on the key construction technology of pier column and cap beam assembly. Through the research on the key technology of substructure design and prefabrication assembly and the application of engineering examples, the problem of viaduct construction in urban restricted road sections in the earthquake zone with moderate intensity is effectively solved.
Grey Clustering Evaluation of Prefabricated Building Construction Safety Based on Anp
Authors: Bao Xuanxuan
Published: June 2022

Starting from the four common types of safety accidents at the construction site of prefabricated buildings, the theory of cause of accidents is used to discover the main causes of accidents, and the construction safety evaluation indicators are extracted from them and the safety risk evaluation index system is constructed. Then combined with the application of network level analysis and mixed central point triangle whitening weight function to build a model that can evaluate the safety risk of prefabricated building construction. Finally, the model is tested with examples, and factors in an unsafe state are identified and suggestions are made. Provide models and references for the safety management of prefabricated construction sites, thereby reducing safety accidents on the construction site.
Research on Differences and Effects of Lateral Distribution Characteristics of Multi-lane Traffic Flow on Freeway
Authors: Zhao Shaojie , Ruan Luquan
Published: June 2022

In order to obtain the probability distribution characteristics and change rules of the vehicle flow in different lanes of the expressway, based on the WIM data, the probability statistics analysis of the distribution characteristics of the vehicle type, the distance between the heads, the vehicle weight, and the speed on the different lanes of the expressway was carried out, and based on the extreme value theory. The extreme vehicle weights of different lanes were extrapolated, and the load effect was further analyzed. The results show that the probability distribution of vehicle types in each lane is different. Vehicles on one-way two-lane expressways have obvious two-tier distribution probabilities. For slow lanes, the selection probability of vehicles with 3 axles and above exceeds 0.85;The selection probability of cars with 3 axles and above on the slow lane of a one-way 3-lane expressway is higher than 0.4, while the selection probability of cars with 2 axles is about 0.15; The lateral distribution of vehicle weight meets the law of increasing from the inner lane to the outer side. The average vehicle weight of the same model on the slow lane is about 1.3-2.0 times that of the fast lane, and the average total weight of the middle lane of the three lane high-speed is the largest; The probability density distribution of vehicle weight in slow lane shows the characteristics of thick tail and long tail, while that in fast lane shows single peak distribution, and the vehicle weight is mainly concentrated in 3000kg; Each vehicle has a specific speed range, and the vehicle mixing ratio has a certain impact on the vehicle speed. The average speed of 2-axle vehicles in the same lane is 20km · h-1 higher than that of 3-axle and above vehicles. The extrapolation results of the extreme value of the load effect show that the bending moment effect of the slow lane is about 1.3-1.4 times that of the fast lane and 1.1-1.2 times that of the middle lane. The middle-span bending moment effect value increases from the inner lane to the outer lane. The transverse reduction coefficients of vehicle load on multi-lane expressways are all higher than the normative values.
Optimization of the Underground Bidirectional BRT Ventilation Systems
Authors: Shen Tianqing , Shen Xingwei
Published: June 2022

The urban traffic is a common concern in the large cities around the world, and th calls for high technology to improve its efficiency and reduce its costs. The underground traffic development is one solution used often in the metropolitan cities like Paris and London. In China, the ventilation system of the underground bidirectional BRT still needs more refinement to achieve the sustainable development, though the underground traffic system has developed very fast. The airfoil structure is adopted abroad to dilute the polluted air in the subway stations and increase the ventilation efficiency, yet it has not been applied in China. This paper studies the reduction of the piston wind loss by airfoil structure on the basis of piston principle, so as to improve the role of the piston wind in the ventilation process. In the mathematical simulation, it is also proved that this method can substantially increase wind energy by 63.27% per meter of the underground road, improving the ventilation efficiency of the underground BRT. Due to the failure to refine the parameter curve of the airfoil structure, the simulation data has some deviations. In future studies, in order to make up for the shortcomings of this study, it is necessary to use XFLR software to carry out refined parameter analysis of laminar airfoil.
Fire Characteristics of High-speed Intercity Train with Different Door Opening in Tunnel
Authors: Chen Zheng , Guo Chun , Zhao Wei , Zhang Ke
Published: June 2022

In order to explore the fire characteristics of high-speed intercity train running with fire under different door opening conditions in the tunnel, this paper studied the fire of intercity train running with fire based on the fire simulation software, calculated and designed 10 different door opening conditions, and obtained: when the side door behind the fire source is opened and the door in front of the car is also opened, the distribution range of high temperature and smoke in the fire carriage is reduced by about half, and the visibility less than 5m only exists behind the fire source. When all the front and rear doors of the train are opened, the maximum temperature at the monitoring point is the lowest. It is suggested that after passengers of the burning intercity train are evacuated to other carriages, close the corridor door of the external carriage, and open all side doors at the front and rear sides of the on-fire train carriage for ventilation and cooling.
Human-Induced Response and Reliability Analysis of Stochastic Dynamic System
Authors: Yang N , Jia Y T
Published: June 2022

This paper proposed a method analyzing crowd-induced stochastic vibration response by the dynamic reliability method. The efficiency of the probability density evolution method (PDEM) is improved by embedding the Kullback-Leibler (K-L) relative sensitivity analysis in response analysis of stochastic dynamic system. Then the complicated point selection technique of high dimension uncertain variables is avoided. The proposed method is illustrated by the response analysis of random crowd-structure interaction system where the load parameter randomness is considered. The acceleration induced by the crossing of crowd is predicted with the proposed method. Results obtained highlight the computation improvement in PDEM probabilistic response analysis in high dimension dynamic system. And the method could be used as an efficient way to predict and evaluate vibration serviceability of structures with human-induced vibration.
High order compact split step finite difference method for two-dimensional coupled nonlinear Schrödinger system
Authors: Zhu Pengfei , Wang Lan , Li Qiang
Published: June 2022

In this paper, a decoupled and efficient finite difference method is developed for two-dimensional coupled nonlinear Schrödinger (CNLS) system. The proposed method uses split step technique for the temporal discretization and high order compact (HOC) difference approximation for the spatial discretization. The original problem is decomposed into a two-dimensional linear subproblem and a two-dimensional nonlinear subproblem. For the two-dimensional linear subproblem, the Lie-Trotter splitting formula is adopted in time to reduce computational cost. While for the nonlinear subproblem, it can be integrated directly and exactly. By the von Neumann approach, it is showed that the proposed method is unconditionally stable. Numerical examples are conducted to compare it with other scheme and numerical results verified the superiority of the proposed method in terms of accuracy and efficiency. The new method also exhibits good numerical performance in long-time simulation.
Study on inter-provincial transmission model based on new energy
Authors: Song Li , Li Guodong , Sun Tian
Published: June 2022

With the increasing proportion of new energy into the power grid, environmental management and energy supply issues are becoming more and more prominent. In the current severe environment and energy situation, high-quality development of new energy and rational allocation of energy has become an urgent problem to be solved. In China, some regions are rich in clean energy resources, such as wind and solar energy. New Energy can not be absorbed on the spot. In view of this, on the premise of satisfying the security and stability of the power grid and the efficient operation of the transmission channel, the wind-fire combined transmission mode is proposed, the interests of all parties involved in the cross-provincial transaction are analyzed, and the inter-provincial transmission model is constructed, effectively relieves the pressure of the abandoned wind power and the abandoned nest power.
Keyphrase generation algorithm based on co-occurrence graph
Authors: Fang Haisheng , Yang Peng
Published: June 2022

In the keyphrase prediction task, it is usually difficult for a single corpus information to help the model learn enough core information, so this paper improves the current keyphrase generation method based on the corpus. From the developments of the co-occurrence, the use of the word conformity is mentioned in the original selection of the relevant text, and the purpose of achieving the maximum utilization of the spending information is achieved. At the same time, this paper proposes the CG-Net model, which uses the GAT network to learn co-present diagrams and implements a replication mechanism, which ultimately surpasses the current optimal method on the NUS test set.
Enhanced Communication in Void Region of Underwater Wireless Sensor Network using Vector-Based Void Avoidance Comparing with Void Aware Pressure Routing Protocol
Authors: Murali Krishna M. , Sivasakthiselvan S.
Published: June 2022

The aim of the proposed work is to improve the energy efficiency of sensor nodes in underwater wireless sensor networks using Vector-based void avoidance (VBVA) in comparison with void-aware pressure routing (VAPR). The performance of vector-based void avoidance uses the vector shift and backpressure mechanisms compared with the void-aware pressure routing protocol. A total of 34 samples are collected and 17 samples for each group is taken to the data sets. The proposed algorithm is tested in an underwater virtual environment by Aquasim in the NS2 simulator. The throughput, energy consumption, and packet delivery ratio are calculated to evaluate the performance of the proposed VBVA Protocol. The energy efficiency of the proposed vector-based void avoidance protocol is improved by avoids of void nodes and forward data packets. The Throughput mean value is (1.3297), Energy consumption mean value is (0.9960) and Packet delivery ratio mean value is (91.1735) achieved using VBVA protocol. This work has obtained significance (<0.01). The simulation results show that reduction of packet loss and improve the energy efficiency of the sensor network using the proposed VBVA algorithm in comparison with VAPR.
Investigation of PCM thermal effectiveness towards an optimised design of cooling building envelope
Authors: Al-Obaidi A S M , Chew H J , Gunasagaran S , Hoi J W
Published: June 2022

The buildings are responsible to 40% of the global greenhouse gas emission. To tackle the climate change, the development of sustainable building is urgent. Phase Change Material (PCM) as a potential material was suggested to integrate in building envelope to maintain a constant room temperature. This paper investigated the thermal performance of the PCM in building envelope at tropics and optimizes the cooling effect by manipulating melting temperature, thickness, position, and the type of PCM. ANSYS FLUENT software is used to model the 2D cross-sectional area of the steel roof and brick wall. With the input of 2 normal days outdoor temperature, the results of simulated indoor surface temperature are compared with the control set to determine the optimum setting while monitoring on its cost-effectiveness. The results showed that the optimum melting temperature of PCM is 29 °C for brick wall application and 31 °C for steel roof application. In normal day, PCM can reduce the peak indoor surface temperature up to 4 °C. Although in the evening, PCM delays the time for the room to cool off, but for the normal warehouse operating hours this is not affecting the thermal comfortability of the workers.
Reduction of energy consumption for tire test room through efficient heat management
Authors: Wong J S , Tien D T K , Lim S C , Sarmin K R
Published: June 2022

Maintaining temperature stability and minimizing the time taken to reach the desired test temperature range in tire test rooms were challenges faced by Continental Tyre Technology Centre Malaysia. Heat generated during the endurance test increased the temperature of the room and if it exceeded the test temperature range, a restart of the test is required which leads to greater energy consumption. The objective of this study was to maintain temperature stability during testing and to reach the desired test temperature range efficiently during start up. Computational Fluid Dynamics (CFD) simulation through ANSYS Fluent was performed using information obtained from Continental. The heat distribution of the heater and the air-conditioner, and the airflow of the air-conditioner in the existing tire test room were investigated through simulation. Based on the results, a modified version of the tire test room was simulated to investigate for possible improvements. From this simulation, recommendations were proposed to Continental. The findings showed that optimizing the layout and location of the air-conditioner yielded improvements in the cooling rate at certain regions while a more suitable location for heater reduced the time taken to heat up certain regions.
Modelling Background Seismicity Source For Probabilistic Seismic Hazard Analysis In Manado City, North Sulawesi
Authors: Zulkifli M. , Triyoso Wahyu
Published: June 2022

This study is used a background source model to calculate probabilistic seismic hazard analysis (PSHA) in Manado City. The gridded seismicity model is applied to characterize the background source model based on the seismicity rate on each grid 0.1 × 0.1 degrees. The results obtained from this study was the contribution of background sources for PSHA in Manado City for the probability of excedence 10% in 50 years is 0.18 ≥ g ≤ 0.19.
Hypocenter Determination using a Non-Linear Method in Bali, Lombok, and Nusa Tenggara Regions: Preliminary Result
Authors: Priyambada F R , Nugraha A D , Supendi P
Published: June 2022

Bali, Lombok, and Nusa Tenggara are the region in the south of the Indonesia Archipelago. This region has relatively high seismicity due to subduction activity and faulting. The first step of the tomography study for inferring the geometry structure beneath Bali, Lombok, and Nusa Tenggara is to conduct precise hypocenter location. In this study, we used waveform data from the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG), which the study area is between 1120 – 1280 E and 40 – 130 S. Our preliminary results, we have re-picked 7,967 P-wave and 3,254 S-wave arrival times for 933 events in the period from January to March 2019. The non-linear method was conducted using the oct-tree sampling algorithm from the NLLoc program to determine the hypocenter’s location. We also compared the results with BMKG catalog data. Our results show better clustering earthquakes with RMS error mostly close to zero and represent the geological structure in this region. The results show a shift in the location of the epicenters between 0.1 km to 1000 km, while for the focus depth between 0.006 - 500 km, with the azimuth shift being dominated to the northeast and southwest. The future and ongoing works, we will conduct a tomography study to imaging 3-D seismic velocity models beneath Bali, Lombok, and Nusa Tenggara regions using the fast-marching method.
Exploring multi-planet system wasp-148 using n-body simulation and deep learning
Authors: Ikhsan M. I. , Arifyanto M. I.
Published: June 2022

The search of exoplanets this day is focusing on finding planet with small mass or exoplanet with similar mass with Earth. One of the detection methods that sensitive enough to detect this kind of planet is transit timing variation method (TTV). This method detects planet using its perturbation to the transiting planet that could be observed by its small variation on the transit curve. From the TTV signal, the planets parameter such as mass and eccentricity could be estimated. One of the methods to determine exoplanet parameters from TTV signal is using N-body simulation to find the best planet configuration that could replicate the TTV signal from observation. However, this method is computationally expensive because there are so many combinations of planet configuration that must be simulated to find the best configuration. By using machine learning technique, we can make this simulation faster and more efficient by predicting the initial condition before hands. We combine photometric data from space and ground based observation for exoplanet system WASP-148 and use that data as input on our machine learning model. Then finally we can estimate the exoplanet parameters using N-body simulation
Terrain Correction in Gravity Data Processing using Hybrid Land Survey and Shuttle Radar Topography Mission Digital Elevation Model: A Case Study in Mount Pandan, Indonesia
Authors: Gunawan I , Alawiyah S
Published: June 2022

A clean corrected complete Bouger anomaly would perform reasonable geological subsurface interpretation. As a part of the processing phase, the terrain correction has a significant influence. Since the terrain correction entangles a vast area, it is not easy to fulfill with land survey. Our study aimed to apply an SRTM DEM in addition to land survey data to overcome a satisfactory terrain correction. We have applied the SRTM data to calculate the terrain correction for the outer zone (i.e., D to M) using the Hammer method. In Mount Pandan, Indonesia, we have set this method to generate a complete Bouguer anomaly as a case study. The terrain correction in the outer zone has corrected the gravity anomaly up to 14.74 mGal. The result shows that the hybrid elevation data may provide sufficient terrain correction in gravity data processing for practical geological subsurface interpretation.
Study to explore the use of Quality Factor of Body Waves (S waves) as a tool to investigate the soil liquefaction potential
Authors: Handayani G. , Hariawan A. F.
Published: June 2022

Liquefaction events occur in deposits of saturated loose sand. Due to the incompressible nature of water, the pore water pressure rises dramatically. Built-up pressure pushes sand particles so that the effective stress between particles becomes zero. Or in other words, these sand particles do not touch each other in the water. So these sand particles are now ^swimming^ in water. These sand deposits behave like water, can flow, and do not have shear strength like normal soil. Not having shear strength means that this soil does not have the carrying capacity of the regular soil against loads above the ground such as buildings etc. This research investigates the possibility of using the Q (quality) factor of seismic waves to estimate the potential liquefaction of soil deposits. We employ Ottawa sand in the laboratory and apply various vibrations using small shaking tables. The results promise of possibilities of using the Q (quality) factor to estimate potential liquefaction.
Measurement of multi-stage triaxial compression test and static elastic parameters of shale samples from the Talangakar formation for a feasibility study of shale gas in the South Palembang sub-basin, South Sumatra
Authors: Prayanto Dwi Tunggal Adi , Nurhandoko Endar Bagus B. , Sunardi Edy
Published: June 2022

Shale gas is an unconventional gas source that has great potential to be developed and produced in the future. One area that has great potential in Indonesia is in the South Sumatra basin. For good hydrofracturing planning, we used samples from core rock specimens from field well B in the Talangakar formation at a depth of 2289 m with shale lithology located within the South Palembang sub-basin in the South Sumatra basin. We tested the sample by multi-stage triaxial (MST). MST is a compression test requiring only one rock specimen to be tested in three cycle stages with different confined pressures From this test, the curve of Stress-Strain, yield point, elastic zone and plastic zone is obtained. Then it can also be generated Mohr-Coulomb curve, elastic parameters, i.e: Young’s modulus, Poisson’s ratio, etc. The results of this measurement are also useful for predicting the minimum horizontal stress which is very important in the design of hydraulic fracturing in shale gas.
Digital Rock Physics Application in Determining The Porosity of Shale Rock
Authors: Pramana A A , Riantomo G , Oktaviani A P , Setiabudi I , Latief F D E , Gibrata M A
Published: June 2022

This research is focusing on determining the porosity of shale rock using the Digital Rock Physics (DRP) method. The DRP method uses fiji software to process μCT-scan data of shale coreplug through segmentation and thresholding processes to determine the pores of the rock and then to determine the value of rock porosity. The purpose of this research is to be able to determine the value of rock porosity more quickly and to verify the DRP porosity result to that of laboratory test. The result shows that the porosity value obtained by the DRP method and laboratory test has a small difference so that the DRP method is quite reliable.
Relative Permeability from Digital Analysis of a Carbonate Synthetic Core
Authors: Pramana A A , Ray D R M , Latief F D E , Gibrata M A
Published: June 2022

This research discusses the digital core to understand better the petrophysics parameters, especially the relative permeability of carbonate rocks. The method used in this research is descriptive-analytic by using primary data. The primary data is sample core data (digital data) collected and processed directly to compare results from digital data to laboratory data. This research indicates a relationship between the results from digital data with the results from laboratory data such as porosity, permeability, and trendline of a curve from relative permeability. Analysis from the research results shows that the relative permeability value was caused by several factors, i.e., wettability, cementation, clay, and bound water constant.
Temporal variation in crustal shear wave splitting associated with a moderate earthquake around Nias Island, Indonesia
Authors: Syuhada S , Anggono T , Febriani F , Arifin J , Prasetio A D , Dewi C N , Hasib M , Sulaiman A
Published: June 2022

We investigate temporal variation in shear-wave splitting parameters of local earthquakes around Nias Island, the northern part of Sumatran forearc. We analyse a total of 79 high-quality splitting measurements recorded at a GEOFON seismic station (GSI) from 2009-2015. We observe that there is no clear time variation in the fast polarization of the splitting waves. On the other hand, an increase in the delay time of the splitting waves is found prior to a medium earthquake that occurred around the island in August 2010. Therefore, we suggest that this temporal change may be related to the change in crack geometry of rocks following the accumulation of the stress in the crust before the earthquake occurred.
Natural Radioctivity Of Rock And Potential Availability Of Uranium-Thorium Minerals In Indonesia
Authors: Adi Rahmansyah A.A , Srigutomo Wahyu
Published: June 2022

Radioactivity in rocks arises as a consequence of the presence of the radioactive elements uranium and thorium. These radioactive elements bond with other elements and form radioactive minerals that evolve on earth through a complex process that takes a very long time. In Indonesia, uranium and thorium mineralization are found in sandstone, metamorphic, volcanic types. volcanic, and intrusive. Generally, mineralization occurs due to hydrothermal processes caused by tectonic and volcanic activities. The potential for these radioactive minerals is spread from Aceh to Papua, with the highest concentrations found in Kalan (West Kalimantan), Mamuju (West Sulawesi), Sibolga (North Sumatra), and Bangka-Belitung. The main uranium minerals found are uraninite, davidite, cofinite, carnonite, while the main minerals for thorium are monazite and thorianite. Exploration of the potential content of nuclear minerals has been carried out by BATAN since 1970 until now. Interim results show that the potential reserves of uranium and thorium in Indonesia are 89,483 tU3O8 and 143,234 tTh, which is a combined number of hypothetical, inferred, and measurable potentials. More detailed exploration needs to be carried out in order to produce measurable reserve figures and also expand exploration to other areas that also have the potential for the presence of uranium and thorium mineralization.
Maintaining Favourable Fermentation Conditions in Sargassum Liquid Fertilizer Production using Siphon in A Two-Containers System Resulting in Acceptable Levels of Heavy Metals
Authors: Nurhayati  , Asmara Anjar Purba , Huslina Feizia
Published: June 2022

A U-shapedsiphon was used to connect two 600 mL disposed of mineral water-plastic bottles called container A and B. Container A served as a decomposer drum for mixingSargassum porridge, EM4 (effective microorganisms 4), organic nutrients, and water to allow an anaerobic fermentation to occur within 25 days.B was an aeration drum containing an acceptable volume of freshwater. Between these two containers, the siphon was set to bridge the air between containers above the suspension. There were 14 different configurations including a siphon with three different diameters (0.5, 1, 1.5 cm), four different lengths (16, 18, 20, 22 cm), and three different connections (connected to aeration drum, opened to air, closed). The last two configurations did not need the siphon. During the fermentation process, gas and heat were perceptibly released inone way-flowing from A to B and creating bubblesin Bleading to a maintained condition of the fermentation. As the one of main challenging aspects in the production of sargassum liquid fertilizer (SFL) is the considerable number of heavy metals, therefore, we measured some transition metals levels extracted in the filtrate post-25 days to estimate the safety level of the product compared to those mentioned in the Regulation of the Indonesian Ministry of Agriculture (Permentan70/SR/140/10/2011). All data excluding sample S4 were below the limit, except Cd level, whereby two configurations gave the least values of potentially toxic elements, which might be linked to the role of the siphon in giving a favourable condition for preventing the release of the heavy metals trapped in the cell walls.
Determination of Soil Corrosion Potential for Gas Pipeline Cathodic Protection System Planning
Authors: Solehudin A , Permana E , Salam H
Published: June 2022

Research has been carried out to identify the potential for soil corrosion for the design of the cathodic gas pipeline protection system. The research location is in Cimanggis - Bitung, West Java, which is located at coordinates 6°19’00 “- 6°28’00” South Latitude and 106°43’00 “- 106°55’30” East Longitude. Measurement of soil resistivity using the Wenner method which refers to ASTM G37, with variations in distance of 0.75m, 1.50m, 2.50m and 6.00m at each point. The number of measurement points is 185 points. DC electric current is injected into the ground, then the current and potential values between the electrodes are read on the device. Then the soil resistivity is calculated using the equation ρ = 2πAR. The results of the measurements are soil type resistance which is then categorized according to the level of corrosion. Based on the results of data processing and interpretation of soil resistivity, some locations have low to extreme corrosion rates. The degree of soil corrosion will affect the corrosion of buried pipes. Therefore, for these locations, planning and technical calculations are needed for the protection of the pipes to be installed.
Electrochemical Performance of Symmetric Supercapacitor Based on Activated Carbon Biomass TiO2Nanocomposites
Authors: Diantoro M , Luthfiyah I , Istiqomah  , Wisodo H , Utomo J , Meevasana Worawat
Published: June 2022

A supercapacitor (SC) is an energy storage device with high energy density, high power density, long life cycle and a bundant material in nature.. Activated carbon based on coconut shell waste (ACCS) is one of the most promising supercapacitor base materials due to its abundance in nature, environmentally friendly, and high surface area. Activated carbon based on coconut shell (ACCS) waste is a potential material as a supercapacitor base material. This is because ACCS has undergone chemical and physical activation, has a high surface area, is abundant in nature, and is environmentally friendly. However, ACCS has common ionic transport diffusion, resulting in inefficient utilization of activated carbon surface area. Therefore, ACCS composite with TiO2material is needed. TiO2material with a small particle size can be used to reduce the aggregation so it can increase the electrolyte to an active redox site. Therefore, this research was conducted to obtain information about the most optimum activation method for ACCS biomass and the supercapacitors enhancement with ACCS-TiO2composite to obtain great ionic diffusion performance and an effective surface area utilization. In brief, the experiment was started by preparing the composite solutions with various compositions of TiO2(0%, 10%, 15%, and 20%). The deposition was carried out using the doctor blade technique on the aluminum foil based substrate and the liquid electrolyte of 1 M Et4NBF4was injected between the electrodes. The crystal structure, morphology, and elemental analysis of the composite were identified using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX), respectively. Charge Discharge was applied to measure the electrical performance of the device. The highest performance of symmetric supercapacitor was performed by TiO215% that able to show its cyclic reversibility at the voltage range of 0-2 V, generated a specific capacitance of 53.10 F g-1with the power density and maximum energy density of 367.05 W kg-1and 26.15 Wh kg-1, respectively. Over 50 cycles, its maximum energy density was decreased to 24.83 Wh kg-1with the capacity retention of 94.64 %.
Modelling of Motion of a Volvox Colony using Many-Body System and Its Qualitative Comparison with Observations
Authors: Dini Septian Ulan , Nurafni Sevi , Fairuza Achmad Zacky , Taufik Intan
Published: June 2022

Approximately 500-60,000 volvox cells constructed a colony with a spherical or elliptical hollow form. Each cell can use its flagella to move. For a colony of hundred cells to perform a direct motion, there must be a coordination of the flagella. In this work, we assume that the cells already form the spherical colony and can perform some simple motion types, i.e., translational (TRAN), roll (ROLL), spin (SPIN), and superposition of the motions, and neglect detail of each flagellum. It is possible to map each cell in the colony using angular positions with a constant radius R and different θ _i and ϕ_i, where i = 1, 2,…, N with N is the number of cells constructing a colony. The center of the colony is R = (x, y, z). The TRAN mode can be obtained, wherex(t) = x(0) + υxt, y(t) = y(0) + υyt, z(t) = z(0) +υzt, ROLLmode with θ(t) = ω(0) + ωθt and SPIN with ϕ(t) = ω(0) + ωϕt. Through the available observation video, the model of volvox colony motion is also shown to have a qualitative agreement.
Monte Carlo simulations for quantum harmonic and anharmonic oscillators within epistemically restricted phase-space representation
Authors: Kholili M J , Rifianti S A , Latifah E , Nugraha A R T
Published: June 2022

We investigate Monte Carlo simulations within the epistemically-restricted phase-space (ERPS) representation of quantum mechanics for harmonic and anharmonic oscillators. Compared to the variational Monte Carlo (VMC) simulations in the conventional representation, the calculation time in the ER phase-space representation is quite competitive. We also numerically show that the distribution function of the global random variable on the order of Planck’s constant in the ER phase-space representation does not significantly affect the energy accuracy, yet a particular choice of the distribution function may give a better calculation time. This work gives an alternative approach to the Monte Carlo simulations beyond those in the conventional representation of quantum mechanics.
The Effect of Molecular Orientation in Disperse Red-1 Film on Its Refractive Index
Authors: Herman H. , Narayana I.G. , Hidayat R.
Published: June 2022

The refractive index of materials is an important physical quantity in the design of various photonic devices. For thin-film based devices, the fabrication method should be compatible with existing processes in microelectronic fabrication and allow for controlling the refractive index. In this research, the material used is a polar Disperse Red 1 (DR1) molecule. The film fabrication was carried out using the physical vapor deposition method which had been equipped with an electric poling installation. The poling of the electric field during the deposition process was applied perpendicular to the substrate. The thickness measurement and the refractive index of the films were carried out using a reflectometer where the light was incident perpendicular to the substrate. The refractive index was determined by the multiple beam interference method. As a result, it was found that the application of an electric field causes a change in the orientation of the molecules, which were initially parallel to the substrate to become perpendicular. Increasing the field strength further reduces the number of molecules parallel to the substrate. This correlates with a decrease in the refractive index of the film.
Inflation with Einstein-Gauss-Bonnet, non-minimal, and non-minimal derivative couplings: the constant-roll condition
Authors: Supriyadi I , Hikmawan G
Published: June 2022

In our research, we consider and study the inflation theories of Einstein-Gauss-Bonnet, minimal, non-minimal, and non-minimal derivative coupling with the constant-roll condition. Given the gravitational wave event, GW170817, which produces the speed of gravitational waves that was almost equal to the speed of light in vacuum, we constrain that the speed of the tensor perturbation was nearly equal to unity,

c
T
2

≃
1

. We involve a scalar field potential whose function can be obtained from an equation of motion by choosing the Gauss-Bonnet coupling functions. We use the linear and quadratic coupling functions, which are their simplest functions. The one result obtained are able to produce observed quantities such as the spectral index for scalar perturbation, ns
= 0.9642, the spectral index for tensor perturbation, nT
= −5.2471 × 10−4, and tensor-scalar ratio, r = 0.0041, which are compatible with the newest Planck data using the slow-roll parameters obtained analytically.
Fabrication of Polyvinylpyrrolidone (PVP) Nanofibrous Membranes using Mushroom-Spinneret Needleless Electrospinning
Authors: Latiffah Efa , Agung Bertolomeus Haryanto , Hapidin Dian Ahmad , Khairurrijal Khairurrijal
Published: June 2022

Mushroom-spinneret is an improved spinneret design for needleless electrospinning apparatus, which has a bowl-shaped base with a mushroom-shaped cover. The mushroom spinneret can overcome some limitations that is often associated with the needleless electrospinning technique, i.e., high excitation voltages, poor stability of free liquid, and difficulty of controlling the spatial motion of multiple jets. In this study, we fabricate polyvinylpyrrolidone (PVP) nanofibrous membranes using mushroom-spinneret needleless electrospinning and determine the effect of solution concentration and applied voltage on the fiber morphology and diameter. The solution concentration had significant effect on the fibers diameter. When the solution concentration was increased from 8 wt% to 12 wt%, the average fibers diameter increased from 0.99 μm to 1.31 μm and the fibers diameter distribution became wider. Moreover, the average fiber diameter decreased from 1.31 μm to 1.16 μm when the applied voltage was increased from 30 kV to 45 kV. The coefficient of variations (CV) for all membrane samples ranged from 0.12 - 0.26, indicated uniform fibers.
Development of COVID-19 Detection Using SPR Sensors: A Preliminary Result
Authors: Feraliana  , Khoirunnisa SZ , Septiani NL W , Iqbal M , Sutarti T , Nugrahapraja H , Yuliarto B
Published: June 2022

Coronavirus disease or COVID-19 is a virus from the Coronaviridae family that has caused pandemics throughout the world since the end of 2019. The virus spreads ten times faster through human interaction than SARS-CoV. The RNA sequence of COVID-19 has a 79.5% similarity with SARS-CoV. Fast and specific detection of COVID-19 is needed so that patient detection can be done quickly and accurately. One method that can be developed as a COVID-19 biosensor is aptamers-based biosensors. The aptamer is an artificial oligo nucleic acid that can specifically bind to target molecules. The aptamer is easily and chemically modifiable for increasing stability and reducing toxicity. It shows a comparable affinity for the target virus and better thermal stability than monoclonal antibodies. This advantage makes aptamer a promising candidate in diagnostic and detection applications. The goal of this research is to use an RNA aptamer as the specific recognition element in a portable surface plasmon resonance (SPR) biosensor for the detection of COVID-19 in humans. An aptamer RNA 1 COVID-19 was designed using the COVID-19 sequence from GISAID using the in silico method. End of 3’ aptamer RNA 1 was modified with dithiol. And Then, the aptamer was immobilized on the gold nanoparticle sensor surface via Cysteine-dithiol binding. The RNA solution, that had been extracted from swab samples, was diluted ten times before being used as a sample. The immobilized aptamer RNA 1 captured COVID-19 in RNA solution, causing an increase in refraction index (r.u). An aptamer RNA 1 was found to bind RNA virus of COVID-19 where the positive sample of COVID-19 has refraction index (r.u) between 3 r.u – 10 r.u for various Ct values.