bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards the establishment of national diagnostic reference levels for chest x-ray examinations in Sri Lanka: a multi-centric study
Authors: Welarathna Sachith , Velautham Sivakumar , Sarasanandarajah Sivananthan 
Published: September 2023

Abstract
The establishment of diagnostic reference levels (DRLs) is an effective tool for optimising radiation doses delivered to patients during medical imaging procedures. This study aimed to compare the institutional DRLs (IDRLs) and propose a multi-centric diagnostic reference level (MCDRL) for chest x-ray examinations in adult patients in Sri Lanka. A prospective cross-sectional study was conducted with 1091 adult patients across six major tertiary care hospitals. Data on patient characteristics, such as age, sex, weight, and body mass index, and exposure parameters, such as tube voltage (kVp) and the product of tube current and exposure time (mAs), were collected. Patient doses were measured in terms of kerma-area product (PKA) using a PKA meter mounted on the collimator of the x-ray tube. IDRLs were computed for each hospital according to the International Commission on Radiological Protection guidelines, and the 75th percentile PKA was used to propose the MCDRL. The relationship between patient weight and exposure parameters was examined using Spearman’s rank correlation to investigate the radiographic practice among hospitals. Results showed that IDRLs varied from 0.10 to 0.26 Gy cm2. The proposed MCDRL was 0.23 Gy cm2, substantially higher than the recently published DRLs from other countries. The median kVp ranged from 95 to 104, while mAs ranged from 2.5 to 5.6. Large variations in the PKA and exposure parameters were observed within and among hospitals. The elevated PKA values observed in this study were mostly due to the use of high mAs in clinical practice. The weak correlation observed between patient weight and exposure parameters suggests the need to standardise examination protocols concerning patient size. The observed dose variations demonstrate the need for the establishment of national DRLs. Until then, the proposed MCDRL can be considered as the benchmark dose level for chest x-ray examinations in Sri Lanka.
Evolution of Subkilometer-scale Impact Craters on the Lunar Maria as Constrained from Mini-RF Data and Topographic Degradation Model
Authors: Sun 孙 Qinghai 庆海 , Fa 法 Wenzhe 文哲 , Zhu 祝 Meng-Hua 梦华 , Du 都 Jun 骏 
Published: September 2023

Abstract
Physical properties (e.g., ejecta size and distribution) of impact craters are crucial and essential to understanding the ejecta excavation and deposition process, estimating rock breakdown rate, and revealing their evolution characteristics. However, whether these physical properties are scale-dependent and how they evolve in different radial regions needs further studies. In this study, we first investigated the physical properties and evolution of sub-kilometer (D ≤ 800 m) craters on lunar maria based on the radar circular polarization ratio (CPR). In addition, we estimated the periods over which rocks and blocky ejecta are exposed and buried in the shallow subsurface layer (termed as exposure time) in different radial regions and assessed the retention time and degradation states for potential radar anomalous craters. We found that in the central region of craters, the largest median CPR occurs after an 80 Myr delay following crater formation. In the rim region, there is no obvious CPR peak in the first 100 Ma, whereas in the upper wall region, an evident CPR peak occurs beyond 100 Ma and could last over one billion years. In addition, the probable exposure time of rocks and blocky ejecta is estimated to be ∼2.0 Gyr (central region), ∼2.7 Gyr (upper wall region), ∼2.1 Gyr (rim region), and ∼0.6 Gyr (continuous ejecta blanket region). We also propose that the retention time of radar anomalous craters depends on the crater size, whereas their degraded states are independent of crater size.
Saturated Fluid Variation Effect on Seismic Anisotropy: A Case Study of Deep-Water Reservoir
Authors: Oktariena Madaniya , Triyoso W , Fatkhan  , Sukmono S , Ambarsari D S , Septama E , Wardaya P D 
Published: September 2023

Abstract
Many factors can drive seismic anisotropy, whether it is the intrinsic condition of rock, external force, or longwave anisotropy. Saturated fluid, as one of the reservoir’s intrinsic elements, is known to trigger an anisotropic effect in far offset seismic with Vertical Transverse Isotropic character. Anisotropy on seismic presents as hockey stick curving that a combination of two-parameter could correct during move-out: V
NMO
and the elliptical anisotropy η parameter. This research means observing how the saturated fluid within the reservoir contributes to the observed anisotropy in seismic. Rock physics modelling (RPM) and fluid substitution (FRM) are conducted to investigate the saturated fluid effect at a particular temperature and pressure that reflects the deep-water environment. The anisotropy parameter is extracted by applying Tsvankin 4th Order NMO to obtain the elliptical anisotropy η parameter. Based on synthetic seismic modelling with VTI Rüger Reflectivity, saturated fluid has an effect on far offset seismic as a manifestation of seismic anisotropy η. In this case of a deep-water environment, gas saturated sand needs the most considerable η correction, followed by oil and water-saturated. Although the η value difference is relatively small and easily dismissed as insignificant, saturated fluid indeed does contribute to the observed seismic anisotropy.
Identification of the Groundwater Layer using the Resistivity Method of the Schlumberger Configuration in the Bumi Harapan Village Area
Authors: Saputra F , Arisalwadi M , Rahmania  , Sastrawan F D 
Published: September 2023

Abstract
This research applied the geoelectric method to determine the presence of aquifer layers in Bumi Harapan village. This method can determine the value of subsurface resistivity, and from this value, will know the lithology based on the distribution of subsurface resistivity. The lithology results will be described in the form of resistivity logs to make it easier to find the groundwater layer and its depth. Subsurface lithology obtained structures in the form of topsoil, clayey sand, sandy clay and clay. The layers suspected as groundwater layers are sandy clay and clayey sand. The results of the presence of average groundwater at a depth of 4 - 9 meters with sandy clay and clayey sand in the fourth and fifth layers were also found at a depth of 90 - 100 meters below the ground surface. The results of the resistivity values that are thought to be the groundwater layer are found to be 125 – 317 Ωm. Formation factor in determining the type of soil layer as an estimate of groundwater potential Below the surface. The formation factor in this study was found to be in the range of 1.7-8 with a type of aquifer layer to a medium aquifer.
Caldera-Like Delineation and Geological Resources Identification of Majenang Area, Indonesia by Gravity and Magnetic Data Inversions
Authors: Handyarso A. 
Published: September 2023

Abstract
Indonesia’s archipelago formed by the tectonic evolution proceeded with subduction, which was accompanied by volcanism. The systematic subduction zones produce the magmatic arcs with different periods since the Permian up to the Tertiary. However, only the recent Quaternary volcanic arc is recognized and lacked of information about the ancient volcanic environment. Calderas are a crucial feature in any volcanic environment due to the prospect site of geological resources. The Gravity and Magnetic methods are commonly used for preliminary study in almost any cases due to their light-weight, low-cost, and ability to map a wide area rapidly. The inverse-modeling scheme was invoked to estimate the sub-surface situation during the interpretation processes. The study intended to show the ability of both gravity and magnetic method for delineating of caldera-like environment including geological resources prospective site identification. According to the research, a northwest-southeast dextral strike-slip fault found in the area and belongs to the Pamanukan-Cilacap Fault Zone (PCFZ). A circular caldera-like anomaly delineated and interpreted as the ring fault of an ancient volcanic caldera in the study area. Several high gravity anomalies found within the caldera rims are interpreted as lava domes or intrusion rocks, while the high-density found following the outer part of the ring-fault terrain is interpreted as the buried lava. The ancient eruption point inferred around Majenang city, thus the study area proposed as the Majenang Caldera. A mineralization zone identified around the study area, which is comparable with the Cihonje people’s gold mining site as the proven prospective area.
Analyses of explosion earthquakes at Sinabung Volcano: characteristics of waveform, spectra, and energy
Authors: Pritaningtyas Aulia Dhita , Hasib Mohammad , Kriswati Estu , Indrastuti Novianti , Zera Tati 
Published: September 2023

Abstract
The characteristic of explosion earthquakes associated with lava avalanche at Sinabung volcano from October to December 2014 is investigated. The 1-component short-period seismometers which are Sukanalu (SKN), Laukawar (KWR), and Kebayaken (KBY) are used. All stations are located about 3-9 km away from the summit. The result shows the characteristics of these waveforms as follows; the amplitude increases rapidly to maximum for about 2-5 s, then the amplitude is almost constant for about 30-40 s followed by the gradual decrease of amplitude for about 40-50 s. Most of explosion earthquakes have a dominant frequency at about 1-4 Hz. The result also observed that the energy of explosion earthquake changes with lapse time and much stable for longer duration compared with explosion earthquake study at different volcano. Our result suggests that the explosion earthquake at Sinabung volcano may have a different waveform generation and/or mechanism to the general explosion earthquake at different volcano.
A Preliminary Tomography Inversion Study on the Palu Koro Fault, Central Sulawesi Using BMKG Seismic Network
Authors: Jayadi H , Santosa B J , Warnana D D , Zulfakriza Z , Jamroni R , Supendi P , Rosalia S , Muttaqy F , Rachman G , Putra A S , Wijaya A D , Meidji I U 
Published: September 2023

Abstract
The Palu Koro Fault, which frequently causes solid and destructive earthquakes, is the most exciting aspect of Central Sulawesi’s tectonics. We used local earthquake data from the area in this preliminary study. Our preliminary investigation entails analyzing local seismic data and estimating the velocity structure and hypocenter location using a tomographic approach that employs P-wave arrival times from the Agency for Meteorology, Climatology, and Geophysics earthquake observation network from 2010 to 2019. We use a 1-D initial velocity structural model in this tomographic inversion method, and the results are evaluated using the checkerboard test, derivative weight sum, and ray hit count. To the west and east of the Palu Koro Fault area, preliminary tomographic inversion results show a relatively high seismic velocity. These areas are interpreted as West Sulawesi Mandala and East Sulawesi Mandala Poso Fault and Wekuli Fault. The low-velocity anomaly is found near the Palu Koro Fault. Because of the high-speed thrusting, the relocated hypocenters also clustered around the Palu Koro Fault area. In the following activity, we will determine the speed structure of the S wave, which is expected to provide better geological information in the interpretation.
Early Results of Surface Tomography Using Automated Surface-Wave Phase-Velocity Measuring System (ASWMS) in Hawaii
Authors: Nursal K. 
Published: September 2023

Abstract
The Hawaiian Islands are a prominent place to conduct seismicity research. Geologically, occurring earthquakes in this region are unique since it is caused by the presence of a hot spot rather than the common fault activity. The research was conducted using a tomography method called Surface Wave Tomography. The goals of this study are to produce tomographic images of the Hawaiian Islands and to test the accuracy of the Automated Surface-Wave Phase-Velocity Measuring System (ASWMS). ASWMS employs a cross-correlation process to calculate the phase delay between stations, then Eikonal equation to invert the slowness vector to obtain apparent phase velocities, and lastly Helmholtz equation to correct the amplitude to obtain structural phase velocities. The teleseismic data used in this study were collected from stations located throughout the Hawaiian Islands between 2004 and 2009. This study discovered a low-velocity anomaly beneath the Hawaiian Islands with a value of 3.8 – 3.9 km/s, indicating the presence of a low-velocity body. The decrease in velocity with increasing depth suggests an increase in temperature associated with the path that magma takes from the Earth’s mantle to the Earth’s crust beneath the Hawaiian Islands.
Inverse modeling using geomagnetic data of field camp geophysics in Karangsambung (2005-2019)
Authors: Wahyudi Eko J 
Published: September 2023

Abstract
Geomagnetic data from field camp surveys in Karangsambung 2005-2019 were collected and merged. Before 2020 (the restriction of Covid-19 pandemic), there are 4713 and 5984 data of field and base observation in the study area. The purpose of works in this paper are presenting the data collection, simple data processing, and simple calculation of inverse modeling. Fifteen surveys from each year of field camp data acquisition are merged with 2017 survey as reference. The data observation from proton magnetometer are corrected with geomagnetic regional field and diurnal variation (using available data from base observation). Geomagnetic model for 2.5D is calculated using SW-NE slice sections with topographic variation in the study area. The program for inverse model calculation was built to recover distribution of magnetization contrast from surface geomagnetic anomaly. The interpretation of subsurface model should be able to be analyzed and correlated with rock susceptibility and geological surface maps in the study area. From this work, the values of geomagnetic anomaly map are shown in the range of -1600 to 1600 nanoTesla, and the inverse modeling conducted over the Volcanic Breccia in the part of Bukit Brujul area, Basalts and Diabas between Geopark Karangsambung-Parangan-Sadang area, and Clay Breccia in the Sadang-Totogan area.
Hypocenter relocation of the Mw 5.9 eastern Manggarai earthquake 2022 and its aftershocks based on BMKG seismic network
Authors: Ramdhan M , Priyobudi  , Mursitantyo A , Palgunadi K H , Panjaitan A L , Jatnika J 
Published: September 2023

Abstract
The moderate earthquake (Mw 5.9) struck eastern Manggarai and its surroundings on February 21, 2022, at 12:36:00 UTC. Although this earthquake was classified as a moderate earthquake, it produced a significant number of aftershocks. The aftershocks could be observed as the post-seismic activity, which was still well recorded until March 31, 2022. The hypocenter location of the aftershocks is updated by applying the double-difference method. The aftershock distribution is striking in west-east orientation and dipping to the south, emphasizing a geometry of faults. The strike and dip directions are consistent with the focal mechanism determined by the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). Most aftershocks after the relocation are distributed at a depth of < 25 km; the depth of the mainshock is 21.5 km. The aftershock distribution in this study shows that the earthquake sequence propagates toward the up-dip direction. The aftershock relocation also reveals that most aftershocks are situated slightly off the main fault plane in the complex splay faults. Therefore, we conjecture that the co-seismic activity may trigger the aftershocks. In addition, this study also shows that the fault system consists of several fault segments. Our study benefits earthquake disaster mitigation, especially in mapping the segment faults of the Flores backarc thrust.
Sediment thickness in the eastern part of Kalimantan from high-frequency receiver functions
Authors: Syuhada S , Pranata B , Anggono T , Ramdhan M , Febriani F , Prasetio A D , Dewi C N , Hasib M 
Published: September 2023

Abstract
We analyze high-frequency receiver functions from two seismic stations to characterize the sediment properties around the eastern coast of Kalimantan. First, we compute high-frequency receiver functions from teleseismic events using the time-domain deconvolution method. The obtained receiver functions are then stacked using the H-κ stacking approach to determine the sediment properties. The computed receiver functions show the complicated waveforms for the seismic station located near Kutai Basin. These waveforms may indicate the presence of multi sedimentary layers. The H-κ stacking results suggest that the sediment is thinner in the northern part of the area (∼1.34 km depth) than in the southern part of the region (∼3.0 km depth). These results are consistent with the previous geological and geophysical studies conducted in this region. The previous works suggested that the sediment thickness around the study area can reach up to 9 km.
Preliminary Results on Receiver Function Study in Mt Merapi, Central Java, Indonesia
Authors: Ramadanti F , Aldi M , Tambunan R P , Lubis H M 
Published: September 2023

AbstractMount Merapi, a stratovolcano, is the world’s most active volcano, with a relatively short eruption period. Mount Merapi formed in the Java region as a result of regional tectonics dominated by the Sunda Arc, resulting in a large earthquake. Many earth scientists are interested in studying the volcano’s subsurface conditions due to its relatively short eruption period and interesting geological features. The Receiver Function method was used in this study to determine the crust’s depth and assess the presence of a LVZ (low velocity zone) by reprocessing receiver function data. The Receiver function is used to identify the Moho discontinuity area by converting P to S waves. A total of 100 earthquake data from 8 teleseismic stations were successfully downloaded from the IRIS website, that was distributed into sections A-A′ (west side of Mount Merapi) and B-B’ (east side of Mount Merapi). The processing of the receiver function data, as shown by the stacking align results, shows that the closest teleseismic station at west side of Mount Merapi has a very strong negative amplitude response, which is represented as a LVZ or magma reservoir after the arrival of P wave. To estimate the zone for LVZ, a forward modeling receiver function technique was used to find the best correlation between the Synthetic Receiver Function curve and the Receiver Function observation curve. A forward modeling receiver function technique was used to find the best correlation between the Synthetic RFcurve and the RF observation curve to estimate the zone for the LVZ. The correlation between the synthetic RF curve from Ramdhan et al’s (2019) tomographic velocity model and the observed RF curve is poor. To improve the correlation, include the main signal source that affects the receiver function curve in the form of seismic wave velocity particularly Vs, LVZ Zone, thin sedimen layer or shallow reservoir, and depth of discontinuity by Suhardja et al (2019). The estimated depth of the LVZ at 10 - 17 km is thinning towards the south or towards Mount Merapi, according to the results of the synthetic receiver function curve modelling at the closest station to Mount Merapi.
Allowable Limit of Human Annoyance Towards Ground-Borne Vibration Velocity Induced by Rail Traffic: A Review
Authors: Lazi Mohd Khairul Afzan Mohd , Adnan Muhammad Akram , Sulaiman Norliana , Kamarudin Siti Nur Naqibah , Hassan Sitti Asmah , Warid Muhammad Naqiuddin Mohd , Samsudin Mohamad Saifullah , Jasmi Ahmad Razin , Zolkepli Muhammad Farhan 
Published: September 2023

Abstract
Many industrialized nations have created their own standards for determining and grading the dangers posed by ground-borne vibration, notably in terms of human irritation. Excessive vibrations created by trains have an impact not only on individuals, but also on sensitive machinery and buildings. The authority as well as practitioners have critical responsibilities in managing and accessing vibrations. This study discusses the differences between the standard and the limit of vibrations caused by trains that can irritate people. The local standard guideline was compared to the standards used by the US, Norway, Sweden, California, Germany, and the Netherlands. This study was mainly interested in the limitations of vibration velocity in residential settings.
From Rio Earth Summit to COP26: Malaysia’s pledges, political leadership, policies, administrative apparatus and performance
Authors: Aziz Abdul Rashid Abdul 
Published: September 2023

Abstract
This paper charts Malaysia’s green journey, beginning with its pledge at the Rio Earth Summit in 1992 to its most recent commitment at the COP26 (Conference of Parties 26) in 2021. Malaysia’s nationally-determined contributions (NDC) have progressed (as they should be) to the present ambitious claim that the nation will be carbon neutral by 2050. Malaysia has been led by several prime ministers during this 30 years journey. Despite coming from different political shades (especially in the last four years) their commitment to the green agenda has been unwavering, rhetorically at least until when the governments’ actions are scrutinised. Understandably, balancing climate change imperatives and socio-economic progress is not easy. To the layman, the series of policies and related documents unveiled over the course of the duration seem disconnected and do not add up to make a complete whole. Various parts of the administrative apparatus have been assigned the responsibility to address the green agenda through the years, though the disconnect of the various government documents suggests that they may not be in conversation with one another. All Paris Agreement signatories are required to submit biennial update reports (BUR) to the United Nations Framework Convention on Climate Change (UNFCC). In 2021, one major investigation by a reputable US newspaper accused Malaysia, just like many other countries, of under-reporting its greenhouse emissions to UNFCC, which the Malaysian government strongly denied. Making climate change pledges is the easy bit, fulfilling those pledges while addressing the nation’s aspirations is not easy. This challenge also manifests in policy formulation, administration and measurement methodology conundrum.