bluuebunny/crossref_metadata_2025_split huggingface dataset:
Archaeomagnetic results from Cambodia in Southeast Asia: Evidence for possible low-latitude flux expulsion
Authors: Cai Shuhui , Doctor Rashida , Tauxe Lisa , Hendrickson Mitch , Hua Quan , Leroy Stéphanie , Phon Kaseka 
Published: March 2021

Significance
The geomagnetic field contains information about interior dynamics of the Earth and is closely related to human beings on maintaining a habitable planet. Understanding variations of the field in the past, especially during the Holocene, is helpful for deciphering modern geomagnetic behaviors or even predicting future variations. Archaeomagnetism is efficient in recovering field information over the past millennia. However, the present data are not distributed evenly across the globe, limiting interpretation of the field features. We conducted an archaeomagnetic study on an iron-smelting site from Cambodia in Southeast Asia, an area currently devoid of data. The results will fill gaps in the present datasets and provide constraints for understanding specific geomagnetic features and their interior driving mechanism.
A specific RIP3
+
subpopulation of microglia promotes retinopathy through a hypoxia-triggered necroptotic mechanism
Authors: He Chang , Liu Yan , Huang Zijing , Yang Ziqi , Zhou Tian , Liu Sheng , Hao Zhaozhe , Wang Jing , Feng Qiumin , Liu Yizhi , Cao Yihai , Liu Xialin 
Published: March 2021

Significance
Retinopathy is the leading cause of blindness, and development of effective therapy is urgently needed. Here, we defined an unprecedented subgroup of microglia that is responsible for causing retinopathy under hypoxia. Mechanistic studies demonstrated the signaling pathway of hypoxia-induced necroptosis of retinal microglia, i.e., the hypoxia–RIP1–RIP3–MLKL signaling axis, triggered an explosive release of FGF2, which in its turn to induce retinal neovascularization. Simultaneous targeting of necroptosis–FGF2 pathway and VEGF produces synergistic effects for treating retinopathy. On the basis of our findings, we propose a concept of necroptotic microglia-induced retinal angiogenesis and highlight a combination therapy for effective treatment of retinopathy.
Mössbauer spectroscopy study of nematicity in Ba(Fe0.962Cu0.038)2As2 single crystal: enhanced orbital effect
Authors: Li Yang , Xue Jijun , Hu Shixin , Pang Hua 
Published: March 2021

Abstract
The origin of the nematic order remains unclear due to the strong coupling between orbital, spin and lattice degrees of freedom in iron-based superconductors. Although the driving force of hole-doped BeFe2As2 is still controversial, the nematic fluctuation of electron-doped compounds is generally believed to be spin fluctuation driven. Here, we present a comprehensive study of the nematic phase transition in Ba(Fe0.962Cu0.038)2As2 single crystal by using Mössbauer spectroscopy. The electric field gradient and its in-plane asymmetry on Fe nucleus, which are directly determined by the occupation of individual t
2g
orbital, are sensitive to the local nematicity of Fe ions. The nematic phase transition happens at T
nem ≈ 73.8 K in the compound while the band splitting between d

xz
/d

yz
orbitals begins far above T
nem and reaches 18.8 meV at 30 K. The temperature evolution of the hyperfine parameters proves the existence of electron–phonon interaction and non-Fermi-liquid behaviour near T
nem. However, the spin–lattice relaxation signal is only evident below T
nem. These observations show that the role of orbital degrees of freedom is more active in driving nematicity than in Co- or Ni-doped BaFe2As2 compounds, and can be attributed to enhanced electronic localization caused by Cu doping.
Comparative analysis of Al2O3-47 nm and Al2O3-36 nm hybrid nanoparticles in a symmetric porous peristaltic channel
Authors: Khan M Ijaz , Chu Yu-Ming , Alzahrani Faris , Hobiny Aatef 
Published: March 2021

Abstract
This study explores the flow of

47

nm

and

36

nm

size alumina-water nanoparticles in a symmetric porous peristaltic channel. Considered flow situation is modelled via magnetohydrodynamics (MHD), porous medium, linear radiation, dissipation due to viscosity, Joule heating and heat generation assumptions. Propagating channel walls contains the first order momentum and thermal slip aspects. Entropy is modelled using the thermodynamics second law. Here different effective viscosity models are introduced for

47

nm

and

36

nm

size alumina-water particles respectively. Lubrication theory is utilized here to simplify the dimensionless system. Numerical solution through built-in procedure is attained for coupled system of equation with respective boundary constraints. This numerical procedure gives the result of each flow quantity in the form of graphs for involved parameters. Further graphical results predicts that due to porous characteristics of walls secondary velocity decreases. Pressure gradient rises for higher magnetic parameter. All the plots of present analysis emphasized that

36

nm

size alumina nanoparticles are more effective than the

47

nm

size alumina nanoparticle.
Computational based on GUI MATLAB for back propagation method in detecting climate change: case study of mataram city
Authors: Syaharuddin  , Sari D A , Sabaryati J , Zonyfar C , Sihotang S F , Fadillah A , Sari T H N I , Putra D S , Harun R R , Mandailina V 
Published: March 2021

AbstractClimate change is a global phenomenon in which its impact can be perceived locally. In the face of this phenomenon, it is necessary to prepare and overcome this threat by developing various mitigation and adaptation strategies for climate change. To support this strategy, climate data such as temperature (maximum and minimum), rainfall, number of rainy days, as well as necessary information in the future need to be detected to prepare good and directional policies. The study aims to determine the climate parameters in Mataram city using forecasting by constructing the algorithm the Back Propagation method. In using the Matlab GUI application by analyzing climate change in Mataram city by using monthly data for the last 10 years. In the simulation stage, the data taken are the maximum temperature, minimum temperature, rainfall, and the number of rainy days in Mataram city. Based on the results of the training and testing process for climate data in the city of Mataram with a prediction of maximum temperature occurred in November at 32,580C and maximum rainfall occurred in December as much as 399.2931 mm, while for the maximum number of rainy days occurred in January with a total of 21.99 days. These results can be used as an alternative policy in the handling and preparation of extreme climate change.
What is the rate of groundwater level decline on peatlands in South Sumatera during the 2019 extreme dry season?
Authors: Irfan M , Satya O C , Arsali  , Ariani M , Sulaiman A , Iskandar I 
Published: March 2021

Abstract
Groundwater level is a parameter that is closely related to fire events in peatlands. The lowering of the groundwater level causes a decrease in soil moisture so that the peatlands become dry and flammable. This study looked for the rate of decline in groundwater levels at 6 locations on peatlands in South Sumatera. The data used are in-situ data from 6 measuring stations belonging to the Peat Restoration Agency on peatlands in South Sumatera. The purpose of this study was to determine the characteristics of the groundwater level which is one of the fire control parameters as an effort to mitigate fire disasters on peatlands. The groundwater level decline rate obtained was (cm/day): 1.68, 1.45, 1.41, 0.85, 0.75, and 0.39 respectively for Sungai Saleh-1, Padang Sugihan-2, Karang Agung, Padang Sugihan-3, Cinta Jaya-1, and Cinta Jaya-2.
Excess reactivity optimization on High Temperature Gas Reactor (HTGR) design for remote area
Authors: Yuningsih N , Irwanto D 
Published: March 2021

Abstract
East Nusa Tenggara (NTT) is an island that has an electrification ratio of 85.84%. Small power nuclear power plant could be applied in such a remote area, and High-Temperature Gas Reactor (HTGR) is one of the potential options. Based on data obtained from the Central Statistics Agency (BPS), an HTGR was designed. The purpose of the present study was to find the optimal excess reactivity for HTGR using the basic model of Japan’s HTTR (High-Temperature Engineering Test Reactor). The calculation was conducted using the Standard Reactor Analysis Code System (SRAC) with the Japanese Evaluated Nuclear Data Library (JENDL) 4.0 as the nuclear data library. Calculations for modified HTTR geometry and fuel configuration was performed and analyzed. As a result, for 1.6 times the HTTR geometry model, (7.00 - 8.75)% fissile enrichment with the addition of 0.065% B4C material is the best configuration to obtain the optimal excess reactivity. Meanwhile, for 1.5, 1.4 and 1.3 times HTTR geometry the best configuration values were (5.00 - 6.75)% fissile enrichment with 0.035% B4C, (6.00 - 7.75)% fissile enrichment with 0.045% B4C and (7.00 - 8.75)% fissile enrichment with 0.050% B4C, respectively.
Effect of learning media tank ripple wave with the implementation of guided inquiry model on concept mastery of high school students
Authors: Susilawati  , Doyan A , Harjono A , Jana M 
Published: March 2021

Abstract
This study aims to determine the effect of the wave ripple learning media with the implementation of the guided inquiry model on the mastery of concepts for high school students. The material in the learning media for the wave ripples under study is reflection, diffraction refraction and interference. This type of research is an experimental research design with pre-test and post-test group design. The population in this study were all students of class XI high school in Mataram. Sampling using total sampling technique with class XIA as the experimental class and class XIB as the control class. The research hypothesis was tested using t-test with pretest and posttest and the improvement of learning outcomes was tested using the N-gain equation. Based on the results of hypothesis testing to master the concept, the value of t count (1.986) > t table (1.732) is obtained at the 5% significance level, so it can be concluded that there is an effect of the wave ripple learning media with the implementation of guided inquiry models on the mastery of concepts for high school students. Furthermore, the increase in concept mastery can be seen from the highest N-gain score in the experimental class found in the interference sub-material of 89.45%, while the highest N-gain score for the control class is in the refraction sub-material at 76.41%.
Coleman-De Luccia tunneling wave function with Non-Minimal coupling
Authors: Gerwin A A , Ramadhan H S 
Published: March 2021

Abstract
We examine a novel method in Coleman-de Luccia vacuum decay analysis by using tunneling wave function approach with additional non-minimal coupling term. Our approach has an advantage that the wave function analysis needs no time dependence, thus consistent with Wheeler-de Witt equation. In the calculation, we use WKB approximation and Hamilton-Jacobi Equation. We discover that the probability of tunneling is lower than the previous study and the tunneling probability depends on both the false and true vacuum state of the scalar field.
TOV equations form of anisotropic pressure on two fluid models
Authors: Rahmansyah A , Sulaksono A 
Published: March 2021

Abstract
We construct Tolman Oppenheimer Volkoff (TOV) equations for anisotropic pressure of two non-interacted perfect fluid with different four-velocities. This paper’s primary motivation is that we obtain the result that could describe the neutron stars (NS) admixed with dark matter (DM) that satisfying constraint from GW190814. Otherwise, our result also can investigate other compact objects that are admixed with two non-interacting fluids. In this work, we extend the formalism in Ref [1] by considering each fluid’s anisotropic pressure. Therefore, the total energy-momentum tensor is the sum of two non-interacting anisotropic fluids with different four-velocities. The velocity difference of both fluids denotes here by b where it comes from each of four-velocities under transformation rotation. Our result’s direct impact is that we can assess each fluid’s impact of anisotropic pressure in two fluids formalism in NS or other compact objects properties.
The acceptable range of roughness instrument calibration factor
Authors: Rahman A , Alfiyati N , Novyanto O , Kartika N L , Amdani R Z 
Published: March 2021

Abstract
There were no studies that show an acceptable range of calibration factor value on precision surface roughness instruments. It is generally known that the calibration factor plays an essential role in precision surface roughness instruments. This study demonstrates the acceptability range for the calibration factor using the Shewhart control chart method. Calibration factor data were obtained by comparing the calibration certificate of a type A artifact with the measurement results obtained from a surface roughness instrument. During the last five years, the calibration factor data from the Talysurf i120 surface roughness machine were analysed using the Shewhart control chart to determine the lower (LCL) and upper control limits (UCL) the range of acceptability. The results showed that the acceptance range was between 0.849 and 1.041, with a doubt level of 1%. These results are expected to be useful for metrologists, industries, and surface roughness practitioners in general to analyse the reliability of their surface roughness instruments/profilometer.
The comparison of essential oil concentration to maximum air quality produced by diffuser based on Internet of Things (IoT) technology to create a healthy room
Authors: Hikmah I , Ramadhani A D , Syifa F T 
Published: March 2021

Abstract
The efforts to maintain indoor air quality from dangerous viruses need to be improved. One way is by sterilizing the room using a disinfectant which has a weakness, namely that it is unsafe if the disinfectant is exposed to the body, especially, when entering the respiratory system, it will become dangerous toxins. Therefore, an innovation of a healthy room that is safe for the respiratory system is needed by applying essential oil as a natural antiseptic liquid which is converted into gas through a diffuser that is connected to a gas sensor equipped with the Internet of Things (IoT) technology. It can record air quality data and connect to an Internet server to monitor indoor air quality easily and practically. The research was conducted by making different variations in the concentrations of essential oil to obtain maximum air quality. From the results we obtained, the level of air quality is getting better when the oil concentration is increased because more gas particles can bind contaminant molecules in the air.
Thermal conductivity of coconut shell particle epoxy resin composite
Authors: Ismail I , Hatta Z N , Mursal  , Jalil Z , Md Fadzullah S H S 
Published: March 2021

Abstract
Coconut shell is one of the agricultural wastes that are widely available in Indonesia and other tropical countries. Unfortunately, the coconut shell waste has not been used optimally for new materials, especially for thermal insulation material. In this work, the composite from coconut shell particles using epoxy resin adhesives has been prepared. The particle sizes of coconut shells for composite samples were 60, 80, 100, and 120 mesh. The compositions of samples for each particle size (ratio between coconut shell and epoxy resin) were 70/30, 75/25, 80/20, and 85/15 (vol %). The thermal conductivity of each composite sample has been examined by using a single-plate method. The density of each sample has also been measured. The results showed that the thermal conductivity of composite sample for 60 mesh of particle size with 70/30 vol.% composition was 0.071 W/m K. As the composition of coconut shell was increased to 85 vol.%, the value of thermal conductivity decreased to 0.062 W/m K. It was found that the thermal conductivity of composite sample decreased as the composition of coconut shell was increased. For the composition of 70/30 vol.%, the thermal conductivity increased to 0.078 W/m K for 120 mesh of particle size. This behavior was also the same for other compositions, where the value of thermal conductivity of composite increased as the coconut shell particle size decreased. The density of the composite was found in the range of 0.799 – 0.938 g/cm3. As the particle size of the coconut shell was reduced, the density of the composite increased. This study revealed that both thermal conductivity and density of coconut shell epoxy composite are dependent on the particle size of the coconut shell. The thermal conductivity of all samples was less than 0.1 W/m K indicating that the coconut shell epoxy composite is quite potential for thermal insulation.
Causalitic-learning model to improve reasoning-ability in learning physics in terms of student creativity during the covid-19 pandemic
Authors: Nurjamilah  , Rokhmat J , Sahidu H , Harjono A , Hikmawati  
Published: March 2021

Abstract
This study aims to examining the effect of 1) the causalitic-learning model (CLM) on reasoning-ability (RA), 2) creativity on RA, and 3) the interaction between the CLM and creativity on RA. This research is quasi-experimental with a 2x2 factorial design. The population is all students of class X-IPA. Sampling uses purposive-technique with consideration of the ability and support of parents in facilitating students and obtained students of class X-IPA-3 (31-students) as an experimental class and class X-IPA-4 (30-students) as a control class. The data of RA and creativity were gathered by using four description-tests. The results show that the data is normally distributed and homogeneous as indicated by chi-square counted (10.87) < chi-square table (11.07), Fcount (1.57) < Fcount (1.85) (for RA) and Fcount (1.50) < Fcount (1.85) (for creativity). The hypothesis was tested using two-way ANOVA with the help of the SPSS 18 application. The conclusion is that in learning physics during the Covid-19 pandemic: 1) there is an influence of the CLM on RA, 2) there is an influence of creativity on RA, and 3) there is no interaction effect between the CLM and creativity on RA. Recommendation: In implementing a CLM to improve RA, it is better to use creativity-related phenomena in the form of pictures to facilitate students to do causality-thinking and argument formulation.
Theoretical study of complex susceptibility of Pd and Pt
Authors: Sitorus R M , Azhar A , Cahaya A B , Nugraha A R T , Majidi M A 
Published: March 2021

Abstract
Spin transfer torque in a multilayer magnetic system can be understood in terms of interaction between a normal metal and a ferromagnetic layer on the multilayer, in which the interaction is characterized by the magnetic susceptibility. Most of experimental studies on this subject utilizes heavy metals, such as Pd and Pt, while a recent theory assumes a light metal as the normal metal. We aim to reconcile this discrepancy and achieve consistency with the experiments by studying magnetic susceptibility of Pd and Pt. We theoretically investigate the complex magnetic susceptibility of Pd and Pt by combining Tight-binding Approximation, Hubbard Model, and Density Functional Theory. We calculate a single band susceptibility for Pd and Pt. Our results show that the band structure is dominated by the d-orbitals and the susceptibility is enhanced by its large repulsive interaction.
The influence of the Ag nanostructures dimensions on the pattern of electric field distribution in cases of blood cancer
Authors: Farahdina U , Zulfa V Z , Firdhaus M , Endarko E , Rubiyanto A , Nasori N 
Published: March 2021

Abstract
Above normal concentrations of leukocyte can indicate blood cancer in humans. This study uses a finite difference time domain (FDTD) based on the Ag nanostructure array experiment from previous study. The influence of leukocyte and blood medium and also Ag nanostructures dimensions the on the pattern of electric field distributions in Ag nanostructure arrays was described on this study. The electric field distribution and transmittance of Ag nanostructure arrays using different medium was analysed. The electric field in Ag nanosquare with side size 50 nm irradiated with electromagnetic wave at a wavelength of 350 nm has value 1.78 × 10−5 V/m and has the highest electric field value compared to the other dimensions and wavelengths of electromagnetic wave. The maximum difference value of transmittance Ag nanosquare array between blood and leukocyte is 8.06 a.u. This value is resulted from Ag nanosquare with side size 50 nm irradiated with electromagnetic wave at a wavelength of 250 nm. These result provide an initial interpretation of optimum wavelength of electromagnetic wave and size of Ag nanosquare arrays for therapy and detection of blood cancer.
Crystallographic and optical bandgap study of LaFe1-xMgxO3 (x=0.01 and 0.05) nanoparticle
Authors: Dwimivanusa R R H , Triyono D , Abdillah M N 
Published: March 2021

Abstract
In this study, material with x = 0.01 and x = 0.05 have been successfully synthesized using the sol-gel method. Characterization of the material was carried out by X-ray Diffraction spectroscopy (XRD), Ultraviolet-Visible Spectrophotometry (UV-VIS), and Fourier Transform Infrared Spectroscopy (FTIR). The XRD data of LaFe1-x
MgxO3 was confirmed single-phase with orthorhombic structure and Pbnm space groups for all samples. The lattice parameter value increases with increasing Mg content, which is predicted due to the larger ionic radii Mg2+ successfully substituted Fe3+. The crystallite size indicated that samples were nano-scale particles. FTIR spectra confirm that the increased Mg substitution increases the distortion of LaFeO3 lattice, which correlates with XRD results. The UV-Vis characterization aimed to measure the optical bandgap energy. The optical bandgap energy value decreases with increasing Mg doping. Lower optical bandgap value makes a positive impact as promising candidates for photocatalytic applications.
A numerical study of Hydro-Hydraulic energy on Undular Tidal Bore phenomenon
Authors: Putra Y S , Noviani E , Nurhasanah  , Nurhanisa M , Azwar A 
Published: March 2021

Abstract
A preliminary study of hydro-hydraulic energy on undular bores may support the invention of various kinds of technology related to renewable energy sourced from the potential of natural resources of Indonesia. Energy could be generated from one type of hydraulic jump that occurs in the river channel, namely undular tidal bore. The tidal bore phenomenon also exists in Indonesia, which occurs in the Kampar River, Riau, known as Bono. A numerical study of energy on wave-like tidal bore has been done for one type of bores, namely undular bores. The simulation of undular bores has been generated using the Computational Fluid Dynamics (CFD) approach assisted by the open-source CFD software, OpenFOAM which applied a turbulent model, namely one-equation Large Eddy Simulation (LES). The undular bores simulation in this study has been validated using experimental and numerical data from selected scientific references. Six simulations of undular bores have been performed based on six different values of Froude number, Fr = 1.04, 1.13, 1.20, 1.27, 1.34, and 1.41. Furthermore, the free surface of undular bores simulation was analyzed by emphasizing on the depth of upstream and downstream flows (d0
and d2
respectively). The rate of change of flow depth ( ), energy dissipation ( ), the rate of energy dissipation ( ), and hydraulic power dissipated of undular bores (PUB
) will increase as a function of the Froude number.