bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Thin Film Cu Nanowire and Reduced Graphene Oxide as A Gas Sensor
Authors: Wijayanti Noviana Candra , Cahyaningrum Ratih Dwi , Harsojo  
Published: May 2020

Abstract
Reduced graphene oxide (RGO) has potential as various gas sensors. However, the sensitivity depends on the size of layers and the number of exfoliated planes. We fabricated a gas sensor based on the RGO on top of silver electrode and RGO on top of copper nanowires put on similar electrodes. The graphene oxide (GO) was synthesised using Hummer’s method. It was made into RGO using hydrazine as a reduction media. We constructed the gas sensor on top of silver electrodes. The distance between electrodes was 0.5 mm. The RGO sensor was tested to detect several gases in the resistive mode. We also compared the performance RGO sensor on top of Cu nanowires (CuNWs) with the RGO without the CuNWs. The result indicated that the response was in the order of percent when exposed to different concentrations in the range of 100 ppm and 500 ppm. However, the RGO sensor put on directly on Ag electrodes are more sensitive compared to RGO CuNW-Ag sensor.
Estimation of Ideal Configuration and Dimension of Pico Hydropower using Euler-Lagrange Equation and Runge-Kutta Method
Authors: Aminuddin J. , Nurhayati  , Widiyani A. , Razi P. , Wihantoro  , Aziz A.N. , Abdullatif R.F. , Arifin A. 
Published: May 2020

Abstract
Pico hydropower is a type of hydropower that can produce electric power under or equal to 5000 Watt. Consisting of one turbine to rotate one generator, it has been used in remote areas to provide for electricity supply. Although the system serves quite well, sometimes the necessity for electricity supply is larger than the system can supply. The solution would be to build two pico hydropower systems. However, the cost of such a solution will also double. In addition to that, the water source and landscape may not sustain more than one pico hydropower. An alternative solution that is being proposed to resolve the problem is by using one turbine to rotate two electric generators in a unity pico hydropower system. The objective of the study concerning the proposed solution is to obtain a configuration and dimension of the energy converter. They are sought by determining the equation of motion for energy converter which is configured in several wheels. The equation of motion, which is in differential form, is obtained using the Euler-Lagrange procedure in classical mechanics. Both configuration and dimension of energy converter are solved using numerical methods. The numerical method used in this study is the fourth-order of the Runge-Kutta method for analyzing some physical parameters i.e.: angular velocity of the energy converter, friction coefficient, driving force, radius and inertia of the wheels. By employing varying numbers in the computational process using the fourth-order of the Runge-Kutta method in Matlab, we seek that the pico hydropower system with ideal configuration and dimension of energy converter based on the radius of the wheels are configured as r
1> r
3>r
2>r
4>r
5=r
6. The configuration yield an optimum rotation of the coupled wheels (r
5 and r
6) as a representation of the electric generator’s axis although the thrust is assumed lower. The design expected to be a solution for optimizing a pico hydropower, especially in remote areas with lower water flow.
Designing of Muffler Part for Car Exhaust System with Low Emission and Noise using Conjugate Gradient Method
Authors: Aminuddin J. , Wihantoro  , Bilalodin  , Sunardi  , Rauf N. 
Published: May 2020

Abstract
The exhaust is an important spare part of the car for reducing noise and emission. The Noise is an unexpected sound from the roar of the engine that caused a hearing problem. The emission is originated from the combustion of an engine that causes air pollution. In this study, we enhance an exhaust performance for decreasing noise and emission by optimizing of the muffler part. Through the conjugate gradient method, we estimate an ideal dimension of the muffler part for circulating thermal energy at around 26 kcal/mole for 13.39 seconds in the closed system. From the results of the conjugate gradient estimation, we develop the muffler plus a re-heater with 58 and 14 cm of length and diameter, respectively. Furthermore, the muffler’s performance is evaluated by doing a measurement of both noise and emission. The measurements are conducted by comparing the muffler without and with re-heater. From the measurement process of sound intensity level, we seek that the noise is decreased by approximately 3.79 and 3.00 % in the lower and faster rotation of the engine, respectively. Besides, the test result shows that utilizing re-heater can reduce of CO, CO2, and HC of 0.35, 14.6, and 76.29 % compare to the muffler without re-heater. The results indicate that the muffler with re-heater designed in this study is effective in reducing noise and emission from the roar and combustion of the engine, respectively.
Cimandiri Fault Identification Using Earthquake Tomography Double-Difference Method
Authors: Simanjorang R G , Rosid M S , Sembiring A S , Daryono  , Heryandoko N 
Published: May 2020

Abstract
Cimandiri Fault is one of major faults in West Java, which has a considerable potential hazard to the surrounding populated area. Therefore, it’s important to have a better understanding about the fault in order to improve disaster mitigation effort in Indonesia. This study is done to identify the Cimandiri Fault based on tomography earthquake data. The recorded data of 290 events were acquired from 15 BMKG seismograph stations located in the vicinity of study area. All events have a total of 2,895 phases consisted of 2,072 P-wave phases and 823 S-wave phases. The method used in this study to produce images beneath the surface of Western Java is double-difference travel time seismic tomography. Inversions were performed using the TomoDD algorithm to image seismic velocity models with horizontal variations from Banten Province and West Java. The final results of this study show the existence of Cimandiri Fault located in the southern part of West Java and extends with direction of North East-South West through Pelabuhan Ratu until it reaches the ocean in the south of Banten.
Tomato Harvesting Arm Robot Manipulator; a Pilot Project
Authors: Oktarina Yurni , Dewi Tresna , Risma Pola , Nawawi Muhammad 
Published: May 2020

AbstractPromoting digital farming might be the answer for current challenges in the agriculture industry by employing a robot to provide continuous information of its deployed area and gives the right analysis in many aspects of farming. This paper discusses the pilot project of employing robot as a harvesting robot. The fruit to be picked is red and green tomatoes. The objective of this study is to set the initial project in creating a series of robots applied in agricultural to realize the idea of digital farming. The novelty of this study is that this method is simple, and image processing is kept simple to accommodate processors limited computation resources. The robot designed is customized according to the size of the tomato tree and tomato. The tomato location is indicated by a circle resulted from the image processing and divided into left, right, and middle position in the image plane. The image plane resolution in this study is 320 × 180 pixels. Ifx= 15 pixels andy= 42 pixels, then the output angle of servo motor on the based is 1150, servo motor joint1 is 900, and servo motor joint2 is 1000. The arm robot moves to the left and harvests the tomato. The average time for harvesting red tomato is 4.932 s, and green tomato is 5.276 s. The required time for the robot from detecting red tomato and return to standby position is 9.676 s, and 10.586 s for the green tomatoes. This time difference is due to robot distance to tomato and not the color of the tomato. The experiment shows that the robot successfully harvests the tomatoes in the setting given in this study, and proves the effectiveness of this robot design as an agriculture robot.
Odd-even harmonic generation from oriented CO and NO molecules within strong-field approximation
Authors: Le Cam-Tu , Phan Ngoc-Loan 
Published: May 2020

Abstract
Recently, the pure-even high-order harmonic generation (HHG) has theoretically found by the ab initio methods for CO molecules interacting with an intense laser. An examination of this phenomenon using the analytical approach such as the Lewenstein model, and for another polar molecular with other symmetry is needed. In this study, we theoretically investigate the odd-even harmonic generation from the CO and NO molecules in the linearly polarized laser field by using the Lewenstein model. Firstly, we confirm entirely the pure-odd and pure-even emission from CO whose molecular axis is perpendicular to the polarization direction of the laser. Secondly, we show that the odd-even behavior of the HHG spectra from NO is similar to that from the CO molecule. The HOMO’s symmetricity of the linear molecule does not change the odd-even property of the HHG spectra.
Sensitivity of gas-phase electron diffraction images to the molecular potential parameters
Authors: Phan Ngoc-Loan , Nguyen Hien T 
Published: May 2020

Abstract
The gas-phase electron diffraction (GED) is a conventional method to extract the geometrical structure and the vibration parameters of molecules. In practice, the mean vibration amplitude is retrieved successfully, while the anharmonicity parameter is usually fixed by a relation with the former. To explicit the reason, we examine the sensitivity of the molecular scattering curve (sM(s)) of N2 molecule to the vibration parameters. The results show that the sM(s) curve is sensitive to the mean vibration amplitude but considerably stable with the changing of the anharmonic parameter even at a high temperature. Besides, many recent studies also focus on the investigation of the laser-induced electron diffraction (LIED) since its high temporal and spatial resolution. However, it is hard to extract the vibration parameters from the LIED data because of the shortage of the analytical form of sM(s) caused by the complicated physical process. So we propose to directly reconstruct the molecular potential instead of extracting the vibration parameters from the LIED. The preliminary purpose is to test the sensitivity of the sM(s) curve to the potential parameters of the Morse potential of N2 considering the nuclear vibration for GED. We demonstrate that the sM(s) curve is sensitive to the change of the potential parameters; thus, the molecular potential can be reconstructed from the GED. This statement is an essential precondition for further investigation of not only the influence of the vibrational effect on the probing of the molecular dissociation but also the reconstruction of the molecular potential from the LIED data.
Mechanisms of nonsequential double ionization process of argon by near-single cycle laser pulse
Authors: Truong Thu D H , Pham Vinh N T 
Published: May 2020

Abstract
In this paper, the near-single cycle laser pulse is used to trigger the nonsequential double ionization process of argon atom due to its ability to eliminate the contamination from secondary recollisions. The mechanisms and distributions of recollision-ionization channels are thoroughly investigated for two representative laser intensities which provide returning energies well below and above the recollision-ionization threshold of argon. The results indicate that recollision-induced excitation with subsequent ionization and direct ionization mechanisms are dominant for low and high intensity of laser, respectively. In addition, the extraction of cross-shaped structure in the correlated two-electron momentum distribution is presented along with the investigation to understand the origin of this interesting structure.
Electrically controlled magnetism in iron thin film
Authors: Van Quang Tran 
Published: May 2020

Abstract
The coupling of ferroelectric and ferromagnetic order parameters in low dimension materials has been of great interest due to the potential spintronic applications. In this report, by employing first-principles density-function-theory calculation without including spin-orbital coupling, it is demonstrated that the magnetization of iron thin film increases in proportion to the external electric field and it prefers to be perpendicular to the film plane. This intriguing property stems from the spin-dependent screening of the electric field which leads to a spin imbalance of the excess surface charge. The result is in agreement with previous publications. We suggest that the electrically controlled magnetism might be used in advanced magnetic and electronic devices.
Biexciton in 2D parabolic quantum dot in magnetic fields
Authors: Hong Quang Nguyen , Anh Dung Tran 
Published: May 2020

Abstract
We theoretically study biexciton, exciton and charged excitons confined in 2D parabolic quantum dots in a magnetic field by using an unrestricted Hatree-Fork method. The energy and binding energy of exciton and biexciton are presented as a function of magnetic field which show their increase with increasing magnetic field, although small. Our results for the case of strong confinement in InAs/GaAs self-assembled quantum dots show that, while the binding energies of both exciton and negatively charged exciton are positive, the binding energies of the biexciton and positively charged exciton are negative indicating that biexcitons in this system are antibinding.
Temperature-dependent transport properties of two-dimensional hole gas in Ge channel modulation-doped square quantum wells
Authors: Thi Hai Tran , Thi Dung Nguyen , Thi Thao Nguyen 
Published: May 2020

Abstract
We present a theoretical study of the transport properties of two-dimensional hole gas (2DHG) in Ge channel modulation-doped square quantum wells, with very high room-temperature drift mobilities. Within the variational approach, we obtain analytic expressions for the carrier distribution, and autocorrelation functions for various scattering mechanisms. The results were used to determine the hole mobility where only the relevant scattering processes, namely acoustic phonons (Deformation potential and Piezoelectric coupling), ionized impurity, surface roughness were considered. The partials and total mobility dependences on temperature were found. It is shown that acoustic phonon and surface roughness scattering are the dominant mechanism. The interpretation of these results is carried out and the scattering mechanisms limiting the 2DHG mobility in Ge quantum wells of SiGe heterostructure are discussed.
The quantum Ettingshausen effect in parabolic quantum wells with in-plane magnetic field in the presence of laser radiation under the influence of confined optical phonon
Authors: Nguyen Thi Lam Quynh , Nguyen Thu Huong , Nguyen Ba Duc , Nguyen Quang Bau 
Published: May 2020

Abstract
The quantum Etttingshausen e˙ect in a parabolic quantum well subjected to a constant electric field, magnetic field in the presence of laser radiation is studied by using the quantum kinetic equation method. The analytic expressions for conductivity tensors and dynamic tensors as well as the Ettingshausen coe˚cient (EC) are obtained in the case of the confined electron-confined optical phonon (COP) scattering. The EC depends on specific quantities for external field (such as magnetic field, amplitude and frequency of laser radiation), temperature of the system and quantum well length, especially quantum number m-characterizing the confinement of optical phonon (OP). When m is set to zero, we get the results corresponding to the case of unconfined OP. The analytic results are numerically evaluated and graphed for GaAs/AlGaAs parabolic quantum well. When examining the e˙ect of temperature, the EC has greater values due to the COP. Meanwhile, when quantum well length and amplitude of the laser radiation (LR) increase, the EC has greater values without the confinement of OP. Because of the approach of system to bulk semiconductor structure when the quantum well length approaches micrometer-size, the EC reaches constant. The quantum number m leads to the change of resonance peaks position within the change of the magnetic field and the frequency of LR. In addition, the EC exerts non-linear dependence on the amplitude the LR. All results indicated that the COP a˙ects not only qualitatively but also the transformation rules of the EC. It provides new insights and contributes to the orientation of research into quantum e˙ects in low-dimensional semiconductor systems (LDS).
Classical interpretation of dynamics of ultracold atoms in the titled optical lattice
Authors: Pham Vinh N T , Ho Huy H 
Published: May 2020

Abstract
In this paper, we study the dynamics of ultracold 87Rb under the influence of tilted optical lattice via Bloch oscillation in the single-band regime. By simulating the intraband dynamics of wavepacket in position and momentum spaces, the dependences of amplitude and period of the oscillation on tilted coefficient and lattice height are shown and compared with classical theory under tight-binding approximation. We also verify the limit of the single-band approximation where the Landau-Zener transition is neglected.
Thermal expansion for ordered Cu3Au alloy at higher temperature and under pressure.
Authors: Duy Tan Pham , Dinh Tam Pham , Duc Tinh Bui 
Published: May 2020

Abstract
The thermodynamic properties of alloys are studied using the statistical moment method (SMM), which allows us to take into account the anharmonicity of the thermal lattice vibration. Within the forth-order moment approximation, the free energy, equation of state and lattice spacing of the binary ordered alloys with cubic structure are given explicitly in terms of the effective pair potentials and the second - and fourth - order vibrational coefficients. Applying to ordered Cu
3
Au alloy, we determine these properties at higher temperature and under pressure in simple analytic form. Numerical results for the lattice parameter, pressure-volume dependence of this alloy in different temperatures and pressures are in good agreement with experiments, better than other calculations.
Protein escape at an atomistic model of the ribosomal exit tunnel
Authors: Thuy Bui Phuong , Xuan Hoang Trinh 
Published: May 2020

Abstract
We study the post-translational escape of nascent proteins at the ribosomal exit tunnel by using the Go-like model for proteins and a real shape atomistic tunnel built on the protein data bank (PDB) structure of a ribosome of Haloarcula marismortui. The full translation and escape processes of the immunoglobulin binding B1 domain of protein G (GB1) at the tunnel were simulated by using Langevin dynamics. We show that at the simulation temperature corresponding to a physiological temperature, the escape time follows quite well the one-dimensional diffusion model proposed in our earlier works. The relationship between folding and escape obtained for the atomistic tunnel is similar to those obtained previously for the cylinder tunnel.
Different space characteristics of air temperature variation in North Sumatra Indonesia
Authors: Prasetya T A E , Munawar  , Chesoh S , Lim A , McNeil D R 
Published: May 2020

AbstractLand Surface Temperature (LST) can be used as an indicator of measuring temperature change in the regions. The changing variation can be produced or affected by some factors such as elevation, land cover products, and Normalized Difference Vegetation Index (NDVI). This study aimed to investigate LST variation based on elevation, land cover products, and NDVI in the North Sumatra area, Indonesia. Land products satellite data between 2000 and 2018 were downloaded from the moderate resolution imaging spectroradiometer (MODIS) website. Multiple linear regression was used to find the patterns of LST variation. The highest LST variation was found in Evergreen Broadleaf (EB) forest and urban area with the average change 0.4 and 0.5 °C/decade and the lowest was found in water surface area with the average change more than -1 °C/decade. The overall mean of LST changing was -0.1 °C/decade with r-square 31.4%. There was a unique LST variation in EB forest land cover when the elevation increased, the LST also increased from -0.4 to 0.5 °C/decade. The same condition also appears in Savannas and cropland/natural vegetation mosaic (Crop. Mos.). In conclusion, the changing of LST in North Sumatra was affected by elevation, land cover products, and NDVI.
Techno-economic analysis of satellite implementation as a broadband internet provider in Indonesia
Authors: Mubarak R , Budiyanto S , Wulandari P 
Published: May 2020

AbstractIndonesia is an archipelago that consisting of a group of islands from Sabang to Marauke. To be able to communicate each other, it needs a telecommunications network that can load all regions of Indonesia, without exception. The use of satellites as a means of telecommunications is very suitable to be applied in Indonesia. Because by using satellites, operators can provide internet services to rural areas that cannot access internet services by terrestrial networks. This is what causes businesses in this field is very promising. However, this business is not an expensive business because it requires very large costs in planning until operating. Therefore, it takes a research that shows the feasibility of this business for people to investment. In this paper shows that, NPV value during the active period of the satellite was USD 555,804,583 with an IRR value of 7% with PBP 5 years 8 months. Based on these parameters it can be seen that the investment is still classified as feasible to continue.
Readiness analysis of accreditation data: a case study for Indonesian higher education
Authors: Primadewi A , Hanafi M , Sasongko D , Setiawan A , Arumi E R , Sunarni  , Nugroho S , Artha E U 
Published: May 2020

AbstractHigher Education as Indonesian education products must have a strategy to deal with the 4.0 Industrial Revolution. Accreditation of Higher Education is one of the parameters of higher education success in increasing capacity and competitiveness. Accreditation is a process of evaluating quality towards Higher Education Institutions as a whole to determine institutional commitment. This commitment is related to institutional capacity and educational effectiveness based on accreditation standards established by BAN-PT. This research takes the Zachman framework as an Enterprise Architecture because it can position business functions, application functions, and data entities simultaneously.
Buckling analyses of carbon nanotube reinforced functionally graded composite cylindrical panels
Authors: Huang Zhong-Tong , Lin Bin , Zhang Shun-Qi , Gao Ying-Shan , Lin Lv-Sheng 
Published: May 2020

Abstract
This paper investigates the buckling analyses of carbon nanotube (CNT) reinforced composite cylindrical panels via a geometrically nonlinear finite element model with large rotations based on the first-order shear deformation (FOSD) hypothesis. Fully geometrically nonlinear strain-displacement relations and large rotation of shells are considered in the model. First, the proposed model is validated by a frequency analysis of a simply supported CNT reinforced composite cylindrical panel from an existing reference. Then, the model is applied to simulate the behaviors of carbon nanotube reinforced functionally graded (CNT-FG) composite cylindrical panels. The effects of curvature ratio, different buckling behaviors and four representative forms of CNT distributions are studied for their material performance comparatively.