bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic analysis of maize grain yield components and physiological determinants under contrasting nitrogen availability
Authors: Hisse Ignacio R. , D’Andrea Karina E. , Otegui María E.
Published: July 2022

Context Most maize breeding is conducted under high-input conditions, with nitrogen supply being crucial due to its impact on yield. Aims This study aimed to investigate broad-sense heritability, and general and specific combining ability variances of physiological traits defining grain yield under contrasting soil nitrogen supply. Methods A six-parent full diallel cross was analysed under high (fertilised with 200 kg N/ha) and low (unfertilised control) nitrogen supply in two seasons. We measured kernel number per plant and kernel weight, the associated traits of plant growth during the critical and grain-filling periods, and source–sink relationships in both periods. Key results Heritabilities of traits ranged from 0.54 to 0.88, and general surpassed specific combining ability for most traits. At low nitrogen (1) the relative importance of general combining ability estimated by Baker’s ratio increased across traits (low nitrogen: 0.90 vs high: 0.85) because the decrease in combining ability variance was larger for specific than general (–78% vs −39%), and (2) source–sink relationship during grain filling had the highest Baker’s ratio (0.96) and heritability (0.78). Plant growth rates during the critical period and kernel number increased substantially at high nitrogen (40 and 34%, respectively), and they had the highest heritability (0.79 and 0.88) and Baker’s ratio (>0.90). Conclusions Low nitrogen environments increased the relative importance of general combining ability effects, and high yield can be obtained by improving the source–sink relationship during grain filling, whereas high nitrogen increased yield by improving plant growth rate during the critical period and kernel number. Implications Knowledge of source–sink relationship during effective filling period, plant growth during the critical period and kernel number may result in a more targeted selection program.
fMRI spectral signatures of sleep
Authors: Song Chen , Boly Melanie , Tagliazucchi Enzo , Laufs Helmut , Tononi Giulio
Published: July 2022

Sleep can be distinguished from wake by changes in brain electrical activity, typically assessed using electroencephalography (EEG). The hallmark of nonrapid-eye-movement (NREM) sleep is the shift from high-frequency, low-amplitude wake EEG to low-frequency, high-amplitude sleep EEG dominated by spindles and slow waves. Here we identified signatures of sleep in brain hemodynamic activity, using simultaneous functional MRI (fMRI) and EEG. We found that, at the transition from wake to sleep, fMRI blood oxygen level–dependent (BOLD) activity evolved from a mixed-frequency pattern to one dominated by two distinct oscillations: a low-frequency (<0.1 Hz) oscillation prominent in light sleep and correlated with the occurrence of spindles, and a high-frequency oscillation (>0.1 Hz) prominent in deep sleep and correlated with the occurrence of slow waves. The two oscillations were both detectable across the brain but exhibited distinct spatiotemporal patterns. During the falling-asleep process, the low-frequency oscillation first appeared in the thalamus, then the posterior cortex, and lastly the frontal cortex, while the high-frequency oscillation first appeared in the midbrain, then the frontal cortex, and lastly the posterior cortex. During the waking-up process, both oscillations disappeared first from the thalamus, then the frontal cortex, and lastly the posterior cortex. The BOLD oscillations provide local signatures of spindle and slow wave activity. They may be employed to monitor the regional occurrence of sleep or wakefulness, track which regions are the first to fall asleep or wake up at the wake–sleep transitions, and investigate local homeostatic sleep processes.
De novo design of protein homodimers containing tunable symmetric protein pockets
Authors: Hicks Derrick R. , Kennedy Madison A. , Thompson Kirsten A. , DeWitt Michelle , Coventry Brian , Kang Alex , Bera Asim K. , Brunette T. J. , Sankaran Banumathi , Stoddard Barry , Baker David
Published: July 2022

Function follows form in biology, and the binding of small molecules requires proteins with pockets that match the shape of the ligand. For design of binding to symmetric ligands, protein homo-oligomers with matching symmetry are advantageous as each protein subunit can make identical interactions with the ligand. Here, we describe a general approach to designing hyperstable C2 symmetric proteins with pockets of diverse size and shape. We first designed repeat proteins that sample a continuum of curvatures but have low helical rise, then docked these into C2 symmetric homodimers to generate an extensive range of C2 symmetric cavities. We used this approach to design thousands of C2 symmetric homodimers, and characterized 101 of them experimentally. Of these, the geometry of 31 were confirmed by small angle X-ray scattering and 2 were shown by crystallographic analyses to be in close agreement with the computational design models. These scaffolds provide a rich set of starting points for binding a wide range of C2 symmetric compounds.
Prince Rupert’s Drops: An analysis of fragmentation by thermal stresses and quench granulation of glass and bubbly glass
Authors: Cashman Katharine V. , Liu Emma J. , Rust Alison C.
Published: July 2022

When volcanic eruptions involve interaction with external water (hydrovolcanism), the result is an ash-rich and energetic volcanic plume, as illustrated dramatically by the January 2022 Tonga eruption. The origin of the high explosive energy of these events remains an important question. We investigate this question by studying Prince Rupert’s Drops (PRDs)—tadpole-shaped glass beads formed by dripping molten glass into water—which have long fascinated materials scientists because the great strength of the head contrasts with the explosivity of the metastable interior when the tail is broken. We show that the fragment size distribution (FSD) produced by explosive fragmentation changes systematically with PRD fragmentation in air, water, and syrup. Most FSDs are fractal over much of the size range, scaling that can be explained by the repeated fracture bifurcation observed in three-dimensional images from microcomputed tomography. The shapes of constituent fragments are determined by their position within the original PRD, with platey fragments formed from the outer (compressive) shell and blocky fragments formed by fractures perpendicular to interior voids. When molten drops fail to form PRDs, the glass disintegrates by quench granulation, a process that produces fractal FSDs but with a larger median size than explosively generated fragments. Critically, adding bubbles to the molten glass prevents PRD formation and promotes quench granulation, suggesting that granulation is modulated by heterogeneous stress fields formed around the bubbles during sudden cooling and contraction. Together, these observations provide insight into glass fragmentation and potentially, processes operating during hydrovolcanism.
Centriole growth is limited by the Cdk/Cyclin-dependent phosphorylation of Ana2/STIL
Authors: Steinacker Thomas L. , Wong Siu-Shing , Novak Zsofia A. , Saurya Saroj , Gartenmann Lisa , van Houtum Eline J.H. , Sayers Judith R. , Lagerholm B. Christoffer , Raff Jordan W.
Published: July 2022

Centrioles duplicate once per cell cycle, but it is unclear how daughter centrioles assemble at the right time and place and grow to the right size. Here, we show that in Drosophila embryos the cytoplasmic concentrations of the key centriole assembly proteins Asl, Plk4, Ana2, Sas-6, and Sas-4 are low, but remain constant throughout the assembly process—indicating that none of them are limiting for centriole assembly. The cytoplasmic diffusion rate of Ana2/STIL, however, increased significantly toward the end of S-phase as Cdk/Cyclin activity in the embryo increased. A mutant form of Ana2 that cannot be phosphorylated by Cdk/Cyclins did not exhibit this diffusion change and allowed daughter centrioles to grow for an extended period. Thus, the Cdk/Cyclin-dependent phosphorylation of Ana2 seems to reduce the efficiency of daughter centriole assembly toward the end of S-phase. This helps to ensure that daughter centrioles stop growing at the correct time, and presumably also helps to explain why centrioles cannot duplicate during mitosis.
Characterizing the lipid fingerprint of the mechanosensitive channel Piezo2
Authors: Lin Yiechang , Buyan Amanda , Corry Ben
Published: July 2022

Piezo2 is a mechanosensitive ion channel that plays critical roles in sensing touch and pain, proprioception, and regulation of heart rate. Global knockout of Piezo2 leads to perinatal lethality in mice, and Piezo2 gain-of-function mutations are associated with distal arthrogryposis, a disease characterized by congenital joint contractures. Emerging evidence suggests that Piezo channels (Piezo1 and Piezo2) can be regulated by their local membrane environment and particularly by cholesterol and phosphoinositides. To characterize the local Piezo2 lipid environment and investigate key lipid–protein interactions, we carried out coarse-grained molecular dynamics simulations of Piezo2 embedded in a complex mammalian membrane containing >60 distinct lipid species. We show that Piezo2 alters its local membrane composition such that it becomes enriched with specific lipids, such as phosphoinositides, and forms specific, long-term interactions with a variety of lipids at functionally relevant sites.
Comparison of primary gas flow standard spanning the range from 2 mL/min to 10 L/min
Authors: Chiang Chun-Lin , Wright John , Kang Woong , Chahine Khaled , Morioka Toshihiro , Krajicek Zdenek , Spazzini Pier Giorgio , Barbe Jean , Niederhauser Bernhard , Kramer Rainer , Lin Win-Ti , Lin Ying-Chun , Shaw Jiunn-Haur
Published: July 2022

Main text

The CCM.FF-K6.2017 comparison was organised for the purpose of determination of the degree of equivalence of the national standards for low-pressure gas flow measurement over the range 2 mL/min to 10 L/min. Four molbloc-L flow elements and a molbox1+ were used as the transfer standards.

Ten laboratories from three RMOs participated between August 2017 and January 2020 - EURAMET: INRIM (Italy); LNE (France); PTB (Germany); METAS (Switzerland); CMI (Czech Republic); SIM: NIST (USA); APMP: NMIJ/AIST (Japan); KRISS (Korea); NMIA (Australia); CMS (Chinese Taipei). The measurements were provided at prescribed reference pressure and temperature conditions. All results were used in the determination of the key comparison reference value (KCRV) and the uncertainty of the KCRV. The reference value was determined at each flow separately following the procedure presented by M G Cox [1]. The degree of equivalence with the KCRV was calculated for each flow and laboratory. This KCRV can now be used in further regional comparisons.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Study of alpha particle concentration effects as the ash of deuterium-tritium fusion reaction on ignition criteria
Authors: Rajablou L , Motevalli S M , Fadaei F
Published: July 2022

In this study, the ignition criteria in the International Thermonuclear Experimental Reactor (ITER) associated with helium concentration is investigated. The main fuels used in this study are deuterium-tritium. Helium as the ash of deuterium-tritium reaction cannot be avoided. In this work, the effects of alpha particle concentration on plasma operation are investigated. The calculations were performed by using zero-dimensional power and particle balance equations. The results of our calculations show that the temporal evolution of alpha particle concentration becomes constant at 0.14. Then, ignition criteria and saddle points have been studied in n

e

τ

E
−T, and

P

ht

τ

E

2

−T planes for different alpha particle concentrations.
Exploring the MeV sky with a combined coded mask and Compton telescope: the Galactic Explorer with a Coded aperture mask Compton telescope (GECCO)
Authors: Orlando Elena , Bottacini Eugenio , Moiseev A.A. , Bodaghee Arash , Collmar Werner , Ensslin Torsten , Moskalenko Igor V. , Negro Michela , Profumo Stefano , Digel Seth W. , Thompson David J. , Baring Matthew G. , Bolotnikov Aleksey , Cannady Nicholas , Carini Gabriella A. , Eberle Vincent , Grenier Isabelle A. , Harding Alice K. , Hartmann Dieter , Herrmann Sven , Kerr Matthew , Krivonos Roman , Laurent Philippe , Longo Francesco , Morselli Aldo , Philips Bernard , Sasaki Makoto , Shawhan Peter , Shy Daniel , Skinner Gerry , Smith Lucas D. , Stecker Floyd W. , Strong Andrew , Sturner Steven , Tomsick John A. , Wadiasingh Zorawar , Woolf Richard S. , Yates Eric , Ziock Klaus-Peter , Zoglauer Andreas
Published: July 2022

The sky at MeV energies is currently poorly explored. Here we present an innovative mission concept that builds upon the heritage of past and current missions improving the sensitivity and, very importantly, the angular resolution. This consists in combining a Compton telescope and a coded-mask telescope. We delineate the motivation for such a concept and we define the scientific goals for such a mission.

The Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO) is a novel concept for a next-generation telescope covering hard X-ray and soft gamma-ray energies.
The potential and importance of this approach that bridges the observational gap in the MeV energy range are presented.
With the unprecedented angular resolution of the coded mask telescope combined with the sensitive Compton telescope, a mission such as GECCO can disentangle the discrete sources from the truly diffuse emission. Individual Galactic and extragalactic sources are detected. This also allows to understand the gamma-ray Galactic center excess and the Fermi Bubbles, and to trace the low-energy cosmic rays, and their propagation in the Galaxy. Nuclear and annihilation lines are spatially and spectrally resolved from the continuum emission and from sources, addressing the role of low-energy cosmic rays in star formation and galaxy evolution, the origin of the 511 keV positron line, fundamental physics, and the chemical enrichment in the Galaxy. Such an instrument also detects explosive transient gamma-ray sources, which, in turn, enables identifying and studying the astrophysical objects that produce gravitational waves and neutrinos in a multi-messenger context. By looking at a poorly explored energy band it also allows discoveries of new astrophysical phenomena.
A finite element model of the mechanical interactions between peripheral nerves and intrafascicular implants
Authors: Akouissi Outman , Lacour Stéphanie P , Micera Silvestro , DeSimone Antonio
Published: July 2022

Objective. Intrafascicular peripheral nerve implants are key components in the development of bidirectional neuroprostheses such as touch-enabled bionic limbs for amputees. However, the durability of such interfaces is hindered by the immune response following the implantation. Among the causes linked to such reaction, the mechanical mismatch between host nerve and implant is thought to play a decisive role, especially in chronic settings. Approach. Here we focus on modeling mechanical stresses induced on the peripheral nerve by the implant’s micromotion using finite element analysis. Through multiple parametric sweeps, we analyze the role of the implant’s material, geometry (aspect-ratio and shape), and surface coating, deriving a set of parameters for the design of better-integrated implants. Main results. Our results indicate that peripheral nerve implants should be designed and manufactured with smooth edges, using materials at most three orders of magnitude stiffer than the nerve, and with innovative geometries to redistribute micromotion-associated loads to less delicate parts of the nerve such as the epineurium. Significance. Overall, our model is a useful tool for the peripheral nerve implant designer that is mindful of the importance of implant mechanics for long term applications.
Application of K-Means Cluster Analysis for Magnetic Susceptibility Zoning of Urban Topsoil in Bandung City
Authors: Kirana Kartika Hajar , Iryanti Mimin , Nugraha Muhamad Gina , Agustine Eleonora , Fitriani Dini
Published: July 2022

Bandung is one of the metropolitan cities in Indonesia which has a dense population. As a result, the number of vehicles is increasing, which causes an abundance of particulates on the urban topsoil. Motor vehicle particulates can be identified through the value of magnetic susceptibility. The greater the magnetic susceptibility value on the topsoil, the more magnetic minerals are associated with the number of particulates produced by vehicles. To zone the value of magnetic susceptibility in an area, a clustering method is needed. In this study, magnetic susceptibility zoning analysis was conducted using the K-mean cluster method. The data processing results on 38 samples divided into three clusters showed that 12 samples were in cluster 1, 23 samples were in cluster 2, and 3 samples were in cluster 3. The samples in each cluster were influenced by the magnetic susceptibility value between the sample centre and the neighbouring samples. The validation of the clustering results is shown through the F test, which shows that the calculated F is greater than the F table at a significance level of 0.05. Thus, it can be said that there is an association between the magnetic susceptibility values in a cluster.
Effect of Pretreatment Spent Coffee Ground with Natural Deep Eutectic Solvent (NADES) on Coffee Oil Yield
Authors: Erdawati  , Dianhar Hanhan , Khairunnisa Hasna
Published: July 2022

This study aims to identify spent coffee ground pretreatment with NADES solvent effect on coffee oil yield. The types of NADES used are choline chloride: urea, choline chloride:fructose, and choline chloride:glucose. Spent coffee grounds were pretreated and extracted using Ultrasound-Assisted Extraction (UAE) method. Pretreatment at 1:10 (g/g) SCG:NADES ratio, 6 minutes on 55°C temperature. Then pretreated spent coffee grounds are extracted with n-hexane and separated solvent from coffee oil from pretreatment coffee oil are palmitic acid (46,75%), linoleic acid (48,07%), and stearic acid (1,66%)using a rotary evaporator. Pretreatment coffee oil yields are 17,6%, meanwhile the non-pretreatment yields only 13,53%. Fatty acid in coffee oil was identified using FTIR and GC-MS. The fatty acid compounds
The Effect of Calcium Carbonate (CaCO3) and Polystyrene (PS) Composition on Contact Angle and Compressive Strength of Hydrophobic Cement Mortar
Authors: Septiana Delvi , Ratnawulan  , Syaputri Oktaviani , Salam Muhammad
Published: July 2022

In the building there are several elements such as pillars, floors and walls. The wall is the outermost part of the building that directly receives changes in weather such as rain. As a result, the walls of the building are easily fragile and make the walls damaged. To reduce damage, it is necessary to test cement that is resistant to water (hydrophobic) so that the walls of the building are not easily damaged by water and durable with the help of hydrophobic agent additives in the form of CaCO3 and polystyrene. The purpose of this study was to investigate the effect of variations in the composition of CaCO3/polystyrene on the contact angle of the hydrophobic layer and the compressive strength of portland cement. Precursors were made by varying the composition of CaCO3 1%, 2%, 3% and polystyrene/tetrahydrofuran 1:0,065; 2:0,065; 3;0,065 and the calcination temperature used was 60°C using an oven. The optimum contact angle measurement results were obtained at the composition variation of CaCO3 3% and Polystyrene 3:0.065, which was 114.986° and the highest compressive strength value was at variations in the composition of CaCO3 1% and Polystyrene 3:0,065, which was 238.10 kg/cm2.
Effect of composition CaCO3/polyurethane (PU) on contact angle of the surface and compressive strength of mortar
Authors: Nazein  , Wazellin Deya , Fachrozy Mhd , Jingga Shintia Purnama , Ratnawulan
Published: July 2022

Infrastructure development, especially in the field of construction material technology, one of them is mortar. The water content greatly determines the energy performance and durability of the mortar. Water can enter building materials or mortar through rain. Damage caused by moisture is common, especially in areas with high moisture content. To solve this problems, a hydrophobic or water-repellent mortar was created, one of which was by using a hydrophobic additive, namely CaCO3/PU. The purpose of this research was to determine the effect of the composition of CaCO3/PU on the surface contact angle and mortar strength. This research uses spray coating method. The hydrophobic layer was made with various compositions of 5%, 10% and 15% and the carbonation temperature used was 60°C using an oven. This research resulted in optimum contact angle at 15% PU variation of 120.8936° and optimum compressive strength of 187,68 kg/cm2 at 10% CaCO3 immersion.
The Effect of Sintering Temperature on Hydrophobic characteristic of Silica Manganese/Polystyrene (SiMn/PS) Nanocomposite
Authors: Ratnawulan  , Septiana D , Putri S R , Putri S G , Fauzi A
Published: July 2022

Currently a lot of research has been done on hydrophobic layers, but in its application the layer is easily damaged and is not corrosion resistant. Therefore, this research intends to decide the effect of variations in sintering temperature on the hydrophobic characteristic of SiMn/PS nanocomposite layers using a sintering temperature of 60°C, 100°C, 140°C, 180°C and 200°C for 1 hour using a furnace.. This research uses HEM-3D (High Energy Milling Ellipse-3D Mention), XRD (X-Ray Difraction) and SEM (Scanning Electron Microscope) tools. The precursor was made by giving 0.5 grams of polystyrene, 0.2 grams of silica powder and 0.2 grams of manganese powder. Coating is done by spin coating method. The results of this research from the variation of the sintering temperature showed that the SiMn/PS nanocomposite layer was hydrophobic based on the contact angle test. The highest contact angle is at a temperature of 60°C.
Magnetic Susceptibility Properties of Portland Cement
Authors: Ningsih Ella Destari , Rifai Hamdi , Dwiridal Letmi
Published: July 2022

The raw materials for making cement consist of raw materials and auxiliary materials where the raw materials consist of Limestone (CaO) (± 80 %), Silica (SiO2) (± 10 %), Clay (Al2O3) (± 8 %), and Iron Sand (Fe2O3) (± 2%) while the auxiliary materials consist of Gypsum (Ca(SO4).2H2O), Pozzolan and Limestone (High Grade). The purpose of this study was to analyze the mineral content contained in iron sand (Fe2O3) used in cement mixtures. To see the mineral content in this cement, can use the magnetic method, one of which is the susceptibility method which is also assisted by the extraction method on cement to purify the iron sand contained in the cement later. The tool used is a Magnetic susceptibility meter type MS2B and extracted using strong and weak magnets 10 times. The extraction results with weak and strong magnets were obtained from 0.011759 gr to 0.35648 gr from 100 gr cement. Sensitivity test was carried out on cement samples with values ranging from 41.27 x 10-8 m3/kg to 44.2 x 10-8 m3/kg.
The Effect of SiMn/PS Composition on Hydrophobic Properties of Nanocomposite Thin Layer
Authors: Ratnawulan  , Putri Sisi Gusti , Septiana Dian , Putri Suchi Ramadhani , Fauzi Ahmad
Published: July 2022

Many researches on the synthesis of hydrophobic coatings have been carried out, but in use, the coating is easily scratched, easily damaged by contact with other objects and easy to corrode, thereby reducing the quality of the coating. This can hinder the application of hydrophobic coatings in industry and others. Therefore, it is necessary to develop a hydrophobic coating that is strong and durable and anti-corrosion so that it can improve the quality of a surface. For this reason, research is carried out by mixing a substrate that has anti-corrosion properties such as silica and is hard such as manganese in order to overcome the problems that occurred previously using the spin coating method. The precursor was made by adding 0.5 grams of polystyrene composition, with varying SiMn composition. The coating was carried out using the spin coating method and the calcination temperature was 60°C using an oven for 1 hour. The results of this study from the composition variation showed that the SiMn/PS nanocomposite layer was hydrophobic based on the contact angle test. The largest contact angle at 50%:50% composition.
Magnetotelluric data analysis using 2D resistivity modelling in Gondang region, Bojonegoro
Authors: Priambodo Galih , Mariyanto Mariyanto , Lestari Wien
Published: July 2022

Previous studies in Gondang Subdistricthave identified underground mud reservoirnear a rock intrusion, while another study near Gondang Subdistrict has identified deep fault structures. This study will identify the distribution and characteristics of possible geological features in the area using magnetotelluric (MT) method to further describe the relationship between the geological features related to local geology. MT data measurements were conducted on 7 stations alonga north-south line, then modelled in 2D using nonlinear conjugate gradient algorithm. The model was used to describe the subsurface resistivity distribution and to identify the geological features. The results show 5 resistive zones (20–1250 Ω⋅m) and 4 conductive zones (≤10 Ω⋅m). The former consist of 4 vertical zones, 1 vertical zone deeper than 5 km, and 1 horizontal zone near the surface. 2 conductive zones surround a resistive zone, while 2 others stretch below the horizontal resistive zone. The vertical resistive zones are interpreted as andesite intrusions, and the horizontal one as volcanic breccia. The conductive zones are interpreted consisting of tuff and marl with possible saline water content. 3 vertical intrusions are thought to have the same source, and all vertical intrusions are suspected to co-occurr with the Pandan Volcano intrusion.
Landslides Investigation in Gado-Gado Hill South Padang District Using Geodetic GPS As a Reference for Landslide Disaster
Authors: Anaperta Yoszi Mingsi , Octova Adree , Maiyudi Riko , Hutahayan Cahaya Permai
Published: July 2022

South Padang District is a landslide-prone area. Almost 70% of South Padang District is hilly. This study uses GPS Geodetic with 10 measurement points along Siti Nurbaya Street to Bukit Gado-Gado Street. Based on observations, the moving average is 16.29251 mm. The largest movement occurred at point 7, namely 24.69818 mm in the azimuth direction. While the smallest movement at point 5 was 8 mm in the azimuth 90° direction. The horizontal movement was divided to the north and south. Point 7 experienced the largest change in vertical position, namely 25.5 cm and point 8 experienced the smallest change in vertical position, namely 2.8 cm. The majority of the movement is in the upward direction, only one point has a downward movement, namely at point 9 of 3.7 cm. Based on the data obtained, the highest landslide velocity occurred at point 7. This movement has a value of 0.148 m/year in the horizontal direction and 1.530 m/year in the vertical direction. The smallest horizontal velocity occurs at point 5 which is 0.048 m/year and the slowest movement direction occurs at point 8 and above at 0.168 m/year.
Analysis of Vibrating Sample Magnetometer (VSM) data of Brantas river sediments using HYSITS
Authors: Mariyanto Mariyanto , Ramadhan Djody Virgiawan , Purba Theresia Romauli , Nabilah Feninda Amalia
Published: July 2022

Several vital activities in East Java are supported by the Brantas River, ranging from irrigation, supply of water raw materials, to industry. Along with the growing population, has the potential to increase the pollution that occurs in the Brantas River. VSM data was taken from the measurement results in Brantas River sediments. The aim of this study is to analyze the VSM measurement data in the Brantas River using the HYSITS script. The analysis was carried out to determine the type of magnetic domain contained in the Brantas river sediment. HYSITS program is used to provides a deeper and better analysis and interpretation. The results show that HYSITS produces 2 curves besides hysteresis loop graphic, that is 1st derivative of ΔM curve and ΔM curve. From the Hysteresis curve of sample, it is known that the Saturation Magnetization (Ms) value are 5.3262 - 5.998587 emu/g, the Saturation Remanent Magnetization (Mrs) value are 1.1537 - 1.545586 emu/g, the Magnetic Coercivity (Bc) value are 0.0188 - 0.020784 T, and Magnetic Remanent Coercivity (Bcr) are 0.059891 - 0.0815. Result of the analysis indicates that the magnetic minerals in Brantas River are strongly suspected to represent ferrimagnetic minerals with Pseudo-Single Domain (PSD).
HYSGUITS: A MATLAB Graphical User Interface (GUI) for hysteresis loop simulation in Vibrating-Sample Magnetometer (VSM) data
Authors: Antareza Muhammad Archie , Salim Christopher , Mariyanto Mariyanto , Rochman Juan Pandu Gya Nur , Lestari Wien
Published: July 2022

In rock magnetism, Vibrating-Sample Magnetometer (VSM) data displays magnetic moment in specific magnetic field applied in descending and ascending magnitude, which results in a pattern called hysteresis loop. This loop characterizes different magnetic materials depending on its shape. In recent years, the usage of computer software to analyze hysteresis loop has become necessary due to its precision. Easily executable, intuitive, and user-friendly open-source programs for analyzing VSM data are still not widely available despite their necessary utilization. HYSGUITS was designed with this issue in mind to further improve the development of tools in this field. HYSGUITS is a Graphic User Interface (GUI) to analyze the hysteresis loop of VSM data. MATLAB is a suitable base for producing this GUI compared to other programming language due to its sophisticated features and clean data visualization. This software is able to visualize hysteresis loop in different ways, mainly through the difference of ascending with descending magnetization value and its 1stderivative. The GUI displays the graph as an interactive plot window which provides detailed observation on each data points, supported by features such as interpolation and smoothing. This article introduces of the functionalities of HYSGUITS and demonstrates its utilization with example use case.
Dynamics of West Coast of Sumatra and Island Arc Mentawai during the Coseismic Phase of the Mentawai Mw7.8 25 October 2010 Earthquake
Authors: Marzuki  , Ramadhan Ravidho , Friska Vira , Primadona Herizon , Ramadhan Reza Ananda , Monica Fadilla , Arisa Deasy , Namigo Elistia Liza
Published: July 2022

Sumatra is located along the Sunda megathrust where the Indo-Australian plate subducts beneath the Eurasian plate. This condition provides a favorable setting for the formation of small to large scale earthquakes which can lead to other natural disasters. On October 25, 2010, an Mw7.8 earthquake near Mentawai occurred and followed by a tsunami. The Mentawai Islands and the West Coast of Sumatra’s dynamics were observed before, during, and after the rupture using the Global Positioning System (GPS) technology, widely known as the Sumatran GPS Array (SuGAr) network. RINEX data from several SuGAr’s stations in Mentawai (BSAT, SLBU, PRKB, SMGY, KTET, PPNJ) and West Coast of Sumatra (LNNG, MKMK, LAIS, MNNA) was processed using GAMIT/GLOBK software to obtain the coseismic deformation data. No anomalies were found in the preseismic phase (29 days before the earthquake) that could be used as precursors for the earthquake. The largest deformation was observed at the SLBU station in North Pagai, Mentawai, as a 29.97 cm southwestward coseismic jump and the coseismic jump at the stations in Sumatra (LNNG, MKMK, LAIS, MNNA) was below 3 cm toward the same direction. During the 29 days after the earthquake, plate relaxation at the postseismic phase was observed. This suggest that some period of time is required to recover to its normal deformation trend. This shifted postseismic trend is indicated by a change in the direction of plate movement compared to the preseismic trend.
Intraseasonal Change in Diurnal Cycle of Precipitation over Sumatra from IMERG Observation
Authors: Yusnaini Helmi , Marzuki  , Vonnisa Mutya
Published: July 2022

This study investigates the intraseasonal change in the diurnal cycle of rainfall over Sumatra in terms of Madden Julian oscillation (MJO) phases. Change in the peak time of mean accumulation (PA), frequency (PF), and intensity (PI) of precipitation from Integrated Multi-Satellite Retrievals of GPM (IMERG) final run product version 06 data during 2016-2019 was investigated. Data were classified into active (2,3,4, and 5) and inactive (1,6,7 and 8) MJO. Rainfall in the Sumatra region is generally dominated by short rainfall duration, as found by a previous study. During the active MJO, the increase the number of rain events over the mainland Sumatra is dominated by rain lasting less than 6 h. In the Indian Ocean region, the increase in rain events is dominated by short and long-duration rain. The means of PA and PF during the active MJO showed a significant increase (0.4 mm/h and 10%), especially in the western part of Sumatra. On the other hand, the average PI during the active MJO tends to decrease (~ 1.5 mm/h), especially in the southern mainland of Sumatra. Finally, we found no significant change in the peak time of PA, PF, and PI during the active MJO and inactive MJO.
Fault Zone Identification for Groundwater Flow Assessment Based On Seismic Reflection Survey Data at the Area of Felda Lepar Utara, Pahang, Malaysia
Authors: Putra Ahmad Dedi , Sulaiman Norasiah , Roslan Norsyafina , Jamil Habibah , Alias Khairunnisa
Published: July 2022

Geological structures such as faults and fractures have an important influence in the process of fluid movement below the surface. The hydraulic behavior in aquifers can be determined by proper characterization of fractures, fault zones and their connectivity. In this study, we concern on detection and identification of fault zones in the groundwater basin to verify whether faults in the basin area connect to the surface, and whether the fault zones occurring serve as conduits or barriers for groundwater to flow. The seismic reflection method with Common Depth Point (CDP) profiling technique has been applied in this study. Through this study, we have identified that several large and small-scale faults were found in the study area. Generally, these large-scale faults cut the bedrock (granodiorite) up to impermeable layer. This large-scale fault group can be a barrier that block the groundwater flow. The fault zone is connected to the surface as evidenced by the presence of normal fault that is clearly observed at the surface. This seismic method is good to apply in this study because it can be used to record deeper subsurface conditions, especially for fault zone detection purposes.
Digital experiment system of uniform circular motion with remote laboratory based on website
Authors: Yohandri  , Asrizal  , Chazanah Iddya
Published: July 2022

Circular motion experiment is an important activity to develop the abilities of students in learning physics. The covid-19 pandemic has caused experimental activities in the laboratory don’t be carry out properly. A solution to solve this problem is to develop a uniform circular motion experiment system with remote laboratory based on website. The objective of this research was to determine the accuracy and precision of the circular motion experimental system with remote laboratory based on website. This research can be classified into engineering research, which is an activity in the design of a product that isn’t continuous. Data collection techniques were carried out in two ways, namely direct measurement and indirect measurement. The research data were analyzed by error theory and descriptive statistics. Based on the analysis of the data obtained, it can be stated from the digital uniform circular motion modelling tool with a length of 54 cm, a width of 43 cm and a height of 21 cm with an accuracy and precision of controlling a stepper motor of 99.03 % and 98.84 %. The accuracy and precision of the uniform circular motion modelling tool with a remote laboratory is close to 100%.
The effectiveness of discovery learning model on exoplanet materials in distances learning
Authors: Susanti Dwi , Serevina Vina , Kartini  , Mahligawati Fahdarina
Published: July 2022

Advances in exoplanet research need to be balanced with basic skills in analyzing laws related to the solar system. This study discusses the effectiveness of the Discovery Learning model on exoplanet material in online learning using the Zoom application. In this study, using a pre-test and post-test to determine the effectiveness of the discovery learning model on exoplanet material in online learning. This research method uses experimental methods and uses a qualitative approach. The descriptive type of qualitative method was chosen in this study to collect data about the actual conditions. Data collection techniques in this study used a pre-test and post-test to determine the extent of discovery learning model on exoplanet material in distance learning. In this study used the paired samples T-test. Based on the results of the evaluation that was carried out on 20 students of Public High School 51 in Jakarta, Indonesia using the pre-test and post-test, it was found that discovery learning model on exoplanet materials effective for distance learning.
Impact of computer assisted resitation program on students’ conceptual undestanding on static fluid topics
Authors: Taqwa Muhammad Reyza Arief , Amalina Askiyah , Suyudi Agus
Published: July 2022

A computer-assisted recitation program has been developed to improve students’ conceptual understanding in static fluid materials. This program consists of 68 multiple choice questions with direct feedback. This research aims to test the effectiveness of computer-assisted recitation programs in improving conceptual understanding. This research is an experimental research with one group pretest-posttest design. The subjects consisted of 138 first-year physics students who were taking the Basic Physics I. The research instrument consisted of 12 reasoned multiple choice questions. Data analysis was performed using paired sample t-test, N-gain, and d-effect size. The results of the study found that the recitation program could significantly improve students’ conceptual understanding with N-gain of 0.46 (upper medium category) and a d-effect size of 1.80 (very strong category). However, we still found difficulties for students, especially in comparing the magnitude of the Archimedes force on identical blocks in different fluids.
The Development of ‘Do-It-Yourself’ Water Rocket Launcher Kit for Pre-Service Science Teachers
Authors: Shaharin Ahmad Faiz , Ayop Shahrul Kadri , Daud Anis Nazihah Mat
Published: July 2022

This study aimed to develop a water rocket launcher kit with a Do-It-Yourself (DIY) concept for science trainee teachers. The research design is the developmental research using the ADDIE model. The need analysis found that many trainee teachers had never handled water rocket activities. The intended kit was successfully developed with an acceptable Content Validity Index of 0.92 from three experts. The water rocket kit consisted of an easily assembled launcher of segmented PVC pipes and several essential components with an instruction manual. Qualitative feedback was obtained from a group of science trainee teachers in an accessible population of a Malaysian university. This study implies that water rocket activities can be performed by trainee teachers with simple kits that can be built on their own, thereby achieving the specific learning objectives in the planned classroom. In addition, this study can also provide early exposure to trainee teachers in the construction and operation of water rocket launchers in schools.
Development of Computer Based Instruction (CBI) Learning Device on Solar System Material
Authors: Ilham Andri , Serevina V , Zalika L , Munggarani M E
Published: July 2022

The purpose of this research is to develop interactive learning tools for independent learning based on CBI (Computer Based Instruction) on the material of the solar system at Junior High School 7 Tangerang and to find out the feasibility of interactive learning devices with Computer Based Instruction. This research is useful for developing interactive learning tools whose usefulness can help students learn the material of the solar system better. This research is a research development (R&D) adapted from the ADDIE development model, but it is only implemented until the development stage. The feasibility assessment was carried out by two materials experts, two media experts, two learning experts and one science subject teacher. The data collection used a questionnaire distribution, descriptive quantitative, and qualitative method. The results obtained from this research are the average validation score: 4.52 (very feasible) from material experts, 4.56 (very feasible) from media experts and 4.27 (very feasible) from learning experts and the total average validation result is 4.45 with very feasible category. So, with a Computer Based Instruction (CBI) based learning devices on the material of the solar system for 8th grade Junior high school, it is feasible to use as a learning device
The Effect of Telescope Use on High School Student Understanding and Learning Motivation
Authors: Meganingtyas Devi Eka Wardani , Serevina Vina , Heriyoso Angestu , Rijaluddin Muhammad
Published: July 2022

A study on the use of telescopes has been conducted on high school students. The purpose of this experiment is to find out how much influence the use of a telescope has on student’s understanding and learning motivation. In this experiment, the common ground or terrestrial telescopes were used. The experiment used the Class Action Research (PTK) method. The results of this experiment were considered satisfactory because they succeeded in increasing student’s understanding and motivation to learn.
First-year evaluation toward the implementation of physics learning online during Covid-19 Pandemic: Students’ perceptions
Authors: Sundari P D , Azhar A , Sarkity D
Published: July 2022

The spreading of Covid-19 in Indonesia caused changes in the learning process from conventional to distance learning, including higher education. The implementation of online learning at university has been accomplishing for approximately one year. This research focused on the perceptions of students toward physics learning online. As many as 198 students from three departments in the FMIPA UNP act as respondents. The data was obtained from an online survey using the Google Form. The results showed that most students had negative perceptions about the implementation of physics learning online. Although students thought online learning was the best solution during the Covid-19 pandemic. However, most of the students complained about the workload given by the lecturers and the limited feedback given regarding assignments. Lack of readiness, effectiveness, and difficulties during one year of online learning implementation could act as positive feedback for the university to improve the quality of online learning in the future. Therefore, online learning is more beneficial for students.
Needs Analysis as a Basis for the Development of POE-Based Physics Learning Tools to improve Science Process Skills
Authors: Amelia Rini , Yohandri
Published: July 2022

The era of the industrial revolution 4.0 is a challenge for the world of education. One of the skills that prepares students to be able to compete in the era of globalization is science process skills. One of the appropriate learning models to improve students’ science process skills is the POE (Prediction, Observation, Explanation) model. In order for the POE model syntax in learning to be carried out properly, the POE model syntax must be integrated in a learning tool in the form of lesson plans, student worksheet and assessment instruments. The purpose of this study is to analyze the needs that exist in the field as the basis for developing learning tools based on the POE model. Needs analysis in this research is front end analysis, student characteristic analysis and learning material analysis. This research uses descriptive analysis method. The results of the study indicate that it is necessary to develop learning tools based on the POE model which is in accordance with the characteristics of students, materials and learning objectives so as to improve students’ science process skills.
Meta-analysis of the influence of 21st century high school students’ skills in learning physics using a guided inquiry model
Authors: Hidayatullah Silmi , Wulan Ratna
Published: July 2022

Education is one of the important things in current government policies. Education is pursued by the government in accordance with the demands of the 21st century. The current demand for education is the industrial revolution 4.0 where education further enhances student skills. In fact, students’ skills are still low, especially aspects of science process skills, critical thinking, and students’ mastery of concepts. Researchers analyzed 30 journals that used a guided inquiry model on 3 aspects of student skills. Student skills will be seen during the learning process and can be assessed from the effectiveness of the guided inquiry model. The guided inquiry model is a learning process with an inquiry process that has scientific work steps to hone students’ skills. The purpose of this research is to see the effect of 21st century high school students’ skills in learning physics using a guided inquiry model. The type of research used is meta-analysis and analysis based on the category of subject matter, class, and the influence of guided inquiry models on 21st century skills. The results showed that the 21st century high school students’ skills in learning physics using the guided inquiry model were very influential.
Development of online learning devices based on project based learning (PjBL) in optical materials
Authors: Serevina Vina , Ekayanti Andi Nisfananda , Aliftika Olivia
Published: July 2022

In the twenty fisrt century Science and Technology (IPTEK) is developing very rapidly, including in the aspect of communication. This is closely related to everyday life because of the use of technology as a tool that makes human work easier. Long distance communication is commonplace in this era. Currently due to the COVID-19 pandemic, student learning is being carried out online using one of the online media, namely Google Meet. So with this technological advancement, learning can be done anywhere and anytime. The purpose of this study was to develop online lesson plan or lesson plans using the Project Based Learning (PjBL) learning model on optical materials. The method used is ADDIE (Analysis), Design (Design), Development (Development), Implementation (Implementation), and Evaluation (Evaluation). After going through the process of validation and testing on students, the results of the development of this learning device are valid so that they can be used