bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of crack opening in steel beam based on strains measured from distributed optical fiber sensor
Authors: Ying Yu , Morgese Maurizio , Ansari Farhad , Gao Zhijun
Published: September 2023

Optical fiber sensors based on the Brillouin optical time domain analysis (BOTDA) have good accuracy of crack opening displacement (COD) measurements. In this paper, we propose a method for COD quantification based on the area under the Brillouin frequency peaks induced by a crack. The study adopted a three-dimensional (3D) finite element model (FEM) to simulate the strain distribution within a segment of an optical fiber. The simulation results revealed that an increase in COD was associated with an increase in the Brillouin frequency peak area. The peak strain increased by 93 μϵ when the COD increased from 30 μm to 110 μm. The numerical findings were proved experimentally by employing a BOTDA interrogator for distributed sensing of strains. Two cracks in a 15-m-long steel beam were detected with the smallest error of 13%. The COD was predicted from the areas under the crack-introduced strain peaks under varying loads of 97, 196, 294 and 392 N. The effect of different spatial resolutions (10, 20 and 50 cm) and intervals (1, 2.5 and 5 cm) on sensing performance was discussed. Compared to previous research, the 3D FEM not only accurately predicted the changes in distributed optical fibers with cracks but also simplified traditional theoretical analysis. For the first time, a method has been introduced to predict cracks by comparing the area under the Brillouin peaks. This approach not only enhanced linearity but also reduced errors. The proposed method can be easily implemented in engineering practice for multi-point crack sensing in civil infrastructure.
Use of memristor-based chaotic circuits in AM-DCSK and FM-DCSK modulation
Authors: Sahin Muhammet Emin , Kolumbán Géza , Hamamci Serdar Ethem , Guler Hasan
Published: September 2023

In this paper, digital communications systems are built by taking advantage of hyperchaotic circuits implemented with an active flux-controlled memristor. The signals produced by these hyperchaotic circuits with rich chaotic dynamics obtained by replacing the nonlinear element with the memristor in the Chua circuit and the Wien bridge oscillator are used as carriers in digital communications systems. The dynamic behavior of memristor-based hyperchaotic circuits has a high degree of disorder. Therefore, they offer better system performance in many practical applications such as broadband signal generation, encryption and secure communications compared to the already used ordinary chaotic systems. To demonstrate the excellent system performance of memristor-based chaotic circuits, they are applied to two variants of differential chaos shift keying (DCSK) communications schemes. Both the Amplitude Modulated Differential Chaos Shift Keying (AM-DCSK) and Frequency-modulated differential chaos shift keying (FM-DCSK) have been considered. The Bit Error Rate (BER) performances of the proposed AM-DCSK and FM-DCSK systems are evaluated in an Additive White Gaussian Noise (AWGN) channel.
Design and analysis of arbitrary shaped bifunctional cloaks for multifunctional material composites
Authors: Raza Muhammad , Ahsan Muhammad , Alonazi Wadi B , Naqvi Syed Aftab , Braaten Benjamin
Published: September 2023

The conventional cloaks that execute two physical fields in a single structure are often limited in their applications due to their regular geometry. This work proposes a solution to this problem by introducing an irregular shape bifunctional cloak that shields the cloaked region from both electric and thermal fields. Unlike previous cloaks, the proposed cloak can be designed with arbitrary shapes, which greatly expands its potential applications. The cloak is designed using Transformation Optics (TO) theory to derive the constitutive parameters required to execute the cloaking phenomenon. The numerical simulation setup is then devised based on the calculated parameters, and the functionality of the cloak is thoroughly validated. The results show that the proposed cloak can efficiently cloak a conductive or non-conductive material under both plan wave and point source excitation conditions. Moreover, the ability to cloak conductive materials make it an ideal candidate for engineering and medical applications where regular geometries are restricted.
A projection method for solving monotone nonlinear equations with application
Authors: Abbass Ghulam , Chen Haibo , Abdullahi Muhammad , Abba Baba Muhammad , Musa Sani
Published: September 2023

Nonlinear equations are one of the most trending research areas due to their vast applications in the sciences, social sciences, and engineering. However, the conjugate gradient method (CG) is one of the most rapidly developing iterative techniques for solving nonlinear monotone problems. Recently, much work has been done on using the CG method to solve monotone nonlinear equations. This paper discusses a new variant for solving constrained monotone nonlinear equations. The method satisfies the sufficient descent condition and proves global convergence and R-linear convergence with the help of some reasonable assumptions. In addition, two sets of numerical tests were conducted. The first experiment shows the good performance of the proposed method compared to existing methods, while the second experiment displays the performance of the proposed algorithm in compressive sensing.
Image encryption algorithm based on hyperchaotic system and dynamic DNA encoding
Authors: Liang Wuyan , Zhang Limin , Yang Zhongbao , Yu Tingting , Li Jingjing , Li Xianli
Published: September 2023

Since the existing DNA encryption algorithms only have fixed DNA coding and decoding rules and a single algorithm that cannot meet more complex and more secure encryption requirements, an image encryption algorithm based on hyperchaotic system and dynamic DNA coding is proposed. The algorithm proposes two new operation methods in the DNA operation rules, namely the equal-additive column transformation and the equal-subtractive column transformation. which combine the SHA-256 function and the external key to generate the initial value of the chaotic system to ensure that key and plaintext of algorithm are correlated. In the encryption process, the plaintext image is firstly converted into a two-dimensional matrix for rotation and scrambling. Then the chaotic sequence generated by the hyperchaotic Chen system is used to perform DNA dynamic encoding, decoding and operation on the scrambled matrix and block matrix generated by logistic chaotic sequence. Finally, the encrypted matrix is scrambled in one dimension. Simulation results show that the improved encryption algorithm has a larger key space, breaks the strong correlation between image pixel layers, and can effectively resist multiple attacks.
A quantum algorithm for finding collision-inducing disturbance vectors in SHA-1
Authors: Duan Jiheng , Li Minghui , Ian Hou
Published: September 2023

Modern cryptographic protocols rely on sophisticated hash functions to generate quasi-unique numbers that serve as signatures for user authentication and other security verifications. The security could be compromised by finding texts hash-mappable to identical numbers, forming so-called collision attack. Seeding a disturbance vector in the hash mapping to obtain a successful collision is that a major focus of cryptography study in the past two decades to improve hash protocols. We propose an algorithm that takes advantage of entangled quantum states for concurrent seeding of candidate disturbance vectors, out of which the one entailing collision is selected through a combination of quantum search, phase gating, diffusion gating, and information feedbacks from classical computing machinery. The complexity reduction is shown to be on the order of


(

2

n

/

2
+
1

)

where n is the number of qubits encoding addresses. We demonstrate the practicality of the proposed by an implementation scheme based on degenerate optical parametric oscillators.
Quantum teleportation and phase quantum estimation in a two-qubit state influenced by dipole and symmetric cross interactions
Authors: Hosseiny Seyed Mohammad
Published: September 2023

In this paper, we address the problem of quantum teleportation in single and two-qubit scenarios based on the Heisenberg XYZ two-qubit chain model under the influence of atomic dipole and Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEWA) interactions. Using the concepts of fidelity threshold and average fidelity in classical and quantum, we reveal the effectiveness of the current channel to remain in the quantum limits. In addition, we investigate the quantum estimation of the encoded phase in single and two-qubit scenarios at the teleportation destination. By using different variables of the system, the average fidelity of the quantum teleportation and the quantum estimation of the encoded phase in one and two teleported qubit(s) can be improved.
Typical bipartite steerability and generalized local quantum measurements
Authors: Schumacher Maximilian , Alber Gernot
Published: September 2023

Recently proposed correlation-matrix-based sufficient conditions for bipartite steerability from Alice to Bob for arbitrary measurements are applied to local informationally complete positive operator valued measures (POVMs) of the (N,M)-type. These POVMs include a large class of local generalized measurements of current interest [Siudzińska K 2022
Phys. Rev.
A
105
042209]. It is shown that the trace norm of correlation matrices with local (N,M)-POVMs is proportional to that of local orthonormal hermitian operator bases (LOOs). This implies that all types of informationally complete (N,M)-POVMs are equally powerful in detecting bipartite steerability from Alice to Bob and, in addition, they are as powerful as LOOs. In order to explore the typicality of steering numerical calculations of lower bounds on Euclidean volume ratios between steerable bipartite quantum states from Alice to Bob and all quantum states are determined with the help of a hit-and-run Monte-Carlo algorithm. These results demonstrate that with the single exception of two qubits this correlation-matrix-based sufficient condition significantly underestimates these volume ratios. These results are also compared to a recently proposed method that determines bipartite steerability from Alice’s qubit to Bob’s arbitrary dimensional quantum system by bipartite entanglement detection. It is demonstrated that in general this method is significantly more effective in detecting typical steerability provided non local entanglement detection methods are used which transcend local measurements.
Exploring the physical properties of quaternary fluoro-elpasolites A2 NaInF6 (A = Cs,Rb)compounds for prospective technological applications
Authors: Khawar Sadia , Shaukat Rabia , Husain Mudasser , Afzal M Qadeer , Tirth Vineet , Algahtani Ali , Alghtani Abdulaziz H , Al-Mughanam Tawfiq , Rached Ahmed Azzouz , Alrobei Hussein , Rahman Nasir
Published: September 2023

The double perovskite materials possess exceptional traits that make them highly suitable for energy-related applications, owing to their eco-friendliness, efficiency, and lack of toxicity. Using the density functional theory implemented in WIEN2K, we conducted a thorough examination of the electronic, structural, optical, and elastic characteristics of A2NaInF6 (A = Cs, Rb) double perovskite materials. The energy formation and the Birch-Murnaghan equation of state fitting curve guarantee both thermodynamic and structural stability. The optimized lattice parameters obtained from our computations are in agreement with the experimental values for the relevant compounds. For calculating the electronic and optical properties of both materials, the widely used TB-mBJ (Trans Blaha modified Becke–Johnson) approximation is utilized. The replacement of ‘Cs’ with ‘Rb’ results in the tuning of the band gap from 7.70 eV to 5.01 eV. After analyzing the mechanical properties, it is anticipated that both materials exhibit elastic stability, brittleness, and relatively lower hardness. The optical properties are computed, analyzed, and presented across a broad energy range of 0–30 eV of incident photon energy. The absorption coefficient, which is a part of the optical properties, highlights the potential of these materials as fundamental components for optoelectronic devices operating in the extreme ultraviolet (XUV) region. The outcomes of our study could provide valuable insights for the development of high-performance optoelectronic devices.
Vacancy defects on structural and optoelectronic properties of double perovskite Cs2AgInCl6: A density functional theory investigation
Authors: Lin Zhonghai , Wu Qingyu , Wang Pingjian , Sun Chengshuai , Zeng Ruiyang , Liu Mengdi , Zhang Xiaoxiao , Qiao Zhuhui , Wei Guangfen
Published: September 2023

This study systematically investigates the effects of Cs, Ag, In, and Cl vacancy defects on the structure, electronic, and optical properties of double perovskite Cs2AgInCl6 through density functional theory calculations. The research demonstrates that different vacancy structures lead to a reduction in the stability of the structure, with Cs2AgInCl6: VCl showing relatively lower impact and Cs2AgInCl6: Vcs exhibiting the a more pronounced effect. The vacancies alter the conductivity of Cs2AgInCl6, where Cs2AgInCl6: VIn and Cs2AgInCl6: VCl exhibit p-type and n-type conductivity, respectively. Cs2AgInCl6: VCs and Cs2AgInCl6: VAg remain direct bandgap semiconductors with band gaps of 2.672 eV and 3.859 eV, respectively. Additionally, the study investigates the real and imaginary parts of the dielectric constants as well as the optical absorption coefficient to explore the material’s optical properties. Regarding optical properties, different vacancy defect systems exhibit distinct absorption capabilities in the visible and ultraviolet light ranges, with the material demonstrating optimal optical performance as the incident photon energy increases. These research findings provide essential references for a deeper understanding of perovskite materials’ properties and optimizing the performance of optoelectronic devices. Future research can further explore the influence of other defect types and external conditions on material properties to expand its potential applications in solar cells, optical communications, metamaterials, and other fields.
Electromagnetically induced transparency and Autler-Towns effect in multi-level cascade type system in 133Cs
Authors: Mondal Suman , Bandyopadhyay Amitava
Published: September 2023

The probe field propagation through a twelve-level Ξ type atomic system, having two ground energy levels, four intermediate energy levels and six upper energy levels, is studied theoretically in presence of a control field connected from intermediate energy levels to upper energy levels of the

6
S

1

/

2

→

6
P

3

/

2

→

6
D

5

/

2

transitions of 133Cs atom. Optical Bloch equations (OBEs) for the system are derived by density matrix formalism and are solved numerically under Doppler free and Doppler  broadened conditions. The control field can simultaneously remain resonant or nearly resonant with certain hyperfine transitions and highly detuned with respect to other transitions. Under Doppler free condition the probe absorption curve shows multiple electromagnetically induced transparency peaks (EIT) formed within largely separated Autler-Towns (A-T) peaks. The A-T peaks are formed due to the dressing of the hyperfine transitions coupled by a highly detuned control field. The EIT windows get widened with increase in the Rabi frequency of the control field. The numerical result is compared with analytically solved reduced three-level Ξ type system. At room temperature the multiple transparency peaks get masked due to thermal averaging and an overall transparency like feature appears in the simulated Doppler broadened probe absorption curve.
Performance analysis of a hybrid FSO/mmWave/THz system for short-range communication under rain and fog conditions
Authors: Verma Deepika , Prince Shanthi
Published: September 2023

For fronthaul cellular networks, the suitability of a hybrid free space optical (FSO)/radio frequency (RF) high data rate communication systems such as millimeter wave (mmWave) and terahertz (THz) with reliable connectivity under weather conditions (rain and fog) is proposed and analyzed. The aim of this hybrid system is to suit short-range communication covering 5G/6G and beyond cellular networks. The 4 pulse amplitude modulation (PAM) scheme parallel transmission and adaptive receiver approach is considered for the work. The theoretical work on estimating the attenuation characteristics under various weather conditions is carried out followed by the simulation of a hybrid communication system for obtaining the received power at different link lengths. Based on the received power for a data rate of 1 Gbps signal-to-noise ratio (SNR) and bit error rate (BER) is calculated for a link length of 0.2 km, 0.5 km, and 1 km for 4 PAM. For varying fog conditions, mmWave/THz carrier is found to be suitable with a BER of 10−10 at a link length of 0.5 km. For varying rain rates, FSO performs well with a BER of 10−8. The link length and performance can be improved with increased transmit power in both communication systems. The THz carrier offers a high data rate, and a hybrid system is proposed with FSO/THz to have reliable connectivity in harsh weather scenarios.
Relaxation strategy for the block Landweber method
Authors: Liu Yuhan , Qu Gangrong
Published: September 2023

The block Landweber iteration is a general method for the solution of linear systems which is widely applied for image reconstructions. The convergence behavior of the block Landweber iteration is of both theoretical and practical importance. When the linear system is consistent, we derive a neat iterative representation and find an optimal relaxation coefficient by minimizing the 2-norm of the newly derived iteration matrix in the range of the conjugate transpose of the corresponding block matrix. We also establish the accelerating convergence relaxation strategies based on the maximum eigenvalue of each block matrix. When the linear system is inconsistent, we normalize each block matrix by the 2-norms of the each weighted block matrix at a uniform scale to give the relaxation strategies. The numerical simulations show that the relaxation strategies proposed for the block Landweber iteration in both consistent and inconsistent cases in this paper have the better reconstruction performances. Compared with the Landweber iteration, the block Landweber iteration has superiority in reconstruction results.
Improved mechanical and wear properties of AISI-420 steel by cathodic cage plasma vanadium nitride deposition
Authors: Filho M V M , Naeem M , Monção R M , Díaz-Guillén J C , Hdz-García H M , Costa T H C , Safeen Kashif , Iqbal Javed , Khan K H , Sousa R R M
Published: September 2023

In this study, a cathodic cage plasma deposition (CCPD) system equipped with a vanadium cathodic cage is used to deposit vanadium nitride coating on AISI-420 steel. This study aims to improve the tribological and mechanical properties. Specifically, this system is used because it can deposit not only a hard coating but also form a nitrogen diffusion layer that can enhance the load-bearing capacity of the sample and coating adhesion with the substrate. The XRD shows that vanadium nitride (VN) coating is polycrystalline, with a favored orientation along the (200) plane. The SEM results depict that at 673 K, the surface consists of uniformly disseminated spherical nanoparticles agglomerate to form coralloid granular nitrides. At 723 K, polygonal particles are uniformly distributed over the entire surface. The thickness of vanadium nitride films is 0.6 and 1.1 μm for 673 K and 723 K temperatures. The hardness of the sample increased up to 3 times over the untreated sample, whereas mechanical properties, including elastic modulus, and hardness-elastic modulus ratios

H

/

E

,

H

2

/

E

,

H

3

/

E

2

are upgraded, specifically at 723 K. Remarkably, the wear rates are reduced more than ten times, and a significant decrease in friction coefficient due to the deposition of VN coating. After the ball-on-disc wear analysis, the wear track is smooth and narrow for coated samples and still covered with vanadium and nitrogen elements, which indicates deposited coating is not detached from the substrate. It shows that VN coating can be deposited effectively to enhance the mechanical and tribological properties of AISI-420 steel.
Effect of RF-sputtering temperature of ITO electrodes on the resistive switching behaviour of ITO/RbPbI3/Cu devices
Authors: Dehingia Anurag , Ota Subhrakant , Deb Rajesh , Das Ujjal , Roy Asim
Published: September 2023

In this work, we deposit Indium doped Tin Oxide (ITO) on a glass substrate using the Radio-Frequency Sputtering technique at different temperatures and studied its structural and optical properties. Various structural, optical, and morphological studies are conducted on the ITO substrates. In addition, we have used these ITO films as conducting electrodes in MIM (metal-insulator-metal) type structures for resistive memory application. A resistive switching memory device based on RbPbI3 with sputtered ITO films as the bottom electrode is fabricated and studied for its electrical performance. It has been found that the device showed the write-once-read-many (WORM) nature at a sputtering temperature of 300 °C with a good OFF/ON ratio. The devices with ITO film sputtered a temperature below 300 °C do not show any switching behavior due to lower conductivity and improper surface morphology.
Metric-Affine Cosmologies: kinematics of Perfect (Ideal) Cosmological Hyperfluids and first integrals
Authors: Iosifidis Damianos
Published: September 2023

We consider a generic Metric-Affine Cosmological setup and classify some particularly
interesting specific cases of Perfect Hyperfluids. In particular, we present the form of
conservation laws for the cases of pure spin, pure dilation and pure shear fluids. We also develop
the concept of an incompressible hyperfluid and pay special attention to the case of a
hypermomentum preserving hyperfluid. We also give a specific example on the emergence of the spin,
dilation and shear currents through matter-connection couplings. In addition, starting from the
generalized acceleration equation for the scale factor including torsion and non-metricity we
provide a first integral of motion relating the latter with the rest of the hyperfluid
variables. These results then formalize the analysis of the non-Riemannian effects in Cosmology.
Effect of metallurgical step-graded quantum barrier on the performance of InGaN-based laser diode
Authors: Sapra Kashish , Mazumder Indrani , Aagiwal Harshita , Lohani Kamal , Rawal D S , Chauhan Ashok , Singh Kuldip , Mathew Manish
Published: September 2023

In this paper, a metallurgical step-graded uniform quantum barrier (QB) laser diode (LD) structure is proposed, which leads to performance enhancement in terms of reduced electron seepage current, reduced threshold current, diminished polarization charges at interfaces, and increased laser power, hole injection efficiency, optical confinement etc. The proposed LD structure demonstrated the best results among all the three structures considered in this study. The laser output power was increased from 118 mW to 160 mW in the metallurgical step-graded uniform QB LD structure as compared to the ungraded QB reference structure. The optical confinement was improved from 0.94% to 1.09% in the photon-generating region. The electron potential barrier height has increased from 191 meV to 242 meV, while the hole potential barrier height has decreased from 133 meV to 116 meV at 120 mA injection current. In addition, the electron seepage flux has reduced from 1374 A cm−2 to 768 A cm−2 at 120 mA injection current.
The Possibility of Detecting our Solar System through Astrometry
Authors: Wu Dong-Hong
Published: September 2023

Searching for exoplanets with different methods has always been the focus of astronomers over the past few years. Among multiple planet detection techniques, astrometry stands out for its capability to accurately determine the orbital parameters of exoplanets. In this study, we examine the likelihood of extraterrestrial intelligent civilizations detecting planets in our solar system using the astrometry method. By conducting injection-recovery simulations, we investigate the detectability of the four giant planets in our solar system under different observing baselines and observational errors. Our findings indicate that extraterrestrial intelligence could detect and characterize all four giant planets, provided they are observed for a minimum of 90 yr with signal-noise ratios exceeding 1. For individual planets such as Jupiter, Saturn, and Neptune, a baseline that surpasses half of their orbital periods is necessary for detection. However, Uranus requires longer observing baselines since its orbital period is roughly half of that of Neptune. If the astrometry precision is equal to or better than 10 μas, all 8707 stars located within 30 pc of our solar system possess the potential to detect the four giant planets within 100 yr. Additionally, our prediction suggests that over 300 stars positioned within 10 pc from our solar system could detect our Earth if they achieve an astrometry precision of 0.3 μas.
Understanding the differences in the effect of urbanization on land surface temperature and air temperature in China: insights from heatwave and non-heatwave conditions
Authors: Wang Nan , Chen Jiayue , He Tong , Xu Xinliang , Liu Luo , Sun Zongyao , Qiao Zhi , Han Dongrui
Published: September 2023

Accelerated urbanization and frequent heatwave events pose significant threats to human health. Analyses of the differences in air and land surface temperature (LST) under extreme climates can aid in understanding human-nature ecosystem coupling and the required adaptations to climate change. In this study, we quantified differences in urban and rural temperatures in China under heatwave (CHW) and non-heatwave periods (NHW) conditions and the influence of meteorological factors on these differences. Based on impervious surface data, 2421 urban and rural stations were dynamically classified from 2008 to 2017. Heatwaves were identified using relative thresholds, and differences were explored using meteorological data and MODIS LST data. For LST, urban–rural temperature difference (U-RTempdiff) was highest during the day, whereas air temperature peaks occurred at night, under both NHW and CHW conditions. During CHWs, the daytime U-RTempdiff was greater for LST than for air temperature, reaching 4.24 ± 3.38 °C. At night, U-RTempdiff was slightly lower (1.04 ± 1.41 °C). The proportion of air U-RTempdiff contributed by rural air temperature was significantly higher during CHW nights than during NHW nights, whereas the proportion of land surface and air U-RTempdiff remained relatively stable during daytime. Spatially, the daytime temperature difference in the north decreased with latitude, whereas the difference in the south was lower. Under CHWs, urbanization had a stronger effect on LST than on air temperature, with a slightly smaller difference (0.01 °C yr−1) during the day and a slightly larger difference (0.03 °C yr−1) at night. The contribution of urbanization to LST was higher than that to air temperature, particularly during the day (16.34%). The effects of wind speed and precipitation on the average air urban–rural temperature difference was greater than those of LST under CHW, accounting for 16.13%, with the effects of wind speed being more significant. These results show that a comprehensive perspective is needed to understand the risks associated with a temperature rise risk under extreme climate conditions and to formulate effective mitigation measures that will they improve human thermal comfort under climate change.
Identification of Shallow Fault with Seismic Refraction Modelling in Gondang Area, Bojonegoro
Authors: Rasif Nahari , Rachman Aditya Aulia , Mariyanto Mariyanto
Published: September 2023

There are various considerations in determining whether a field is said to have geothermal potential or not. One of them is the appearance of shallow faults in the area. This shallow fault can function as a permeable layer that is used as a fluid flow path in the geothermal system. Due to the emergence of manifestations around Mount Pandan in the Gondang area, Bojonegoro, seismic refraction measurements are also needed that can support and validate the geothermal potential in the area with the hope of shallow faults that are visible through the interpretation of seismic wave propagation velocity. This measurement produces an anomaly that is thought to be a shallow fault on the track that passes through the main fault, namely on tracks 1, 2, and 5, not far from the manifestation of the Banyukuning hot spring. This is also reinforced by direct observation of the surface conditions as a result of the appearance of shallow faults.
Geoelectric Analysis for Potential Slip Plane Interpretation in Labuan Bulan Hill, Salem District, Brebes Regency, Central Java
Authors: Dinata Indra A. , Praja M. Khalifah B.Y. , Sadisun Imam A. , Kuswanto Agus
Published: September 2023

Landslide is a natural disaster which often occurs in Indonesia. Based on National Disaster Management Agency (BNPB), there were 1,321 landslide incidents which occurred in 2021. Labuan Bulan Hill located on high susceptibility landslide seen from Landslide Susceptibility Zone of Brebes Regency, furthermore, soil tensile cracks presence with 5 - 50 cm width and 15 - 125 cm height at upper slope. In this study, the identification of subsurface lithologies and potential slip plane was carried out using geoelectric survey method with Wenner – Schlumberger configuration. The Wenner – Schlumberger configuration has deeper penetration than other geoelectric survey configurations. Geoelectric surveys are carried out on two lines with 240 m length and 5 m electrode space. Geoelectric line is made parallel and perpendicular with slope direction to estimate subsurface conditions easier with the help of tensile cracks presence in the surface. Results of measurements identified that the upper layer consists of poorly graded silty sand with 285 Ωm – 1700 Ωm resistivity, the second layer is a moderate - highly weathered volcanic breccia with 129 Ωm – 285 Ωm resistivity, and the third layer is fresh – slightly weathered volcanic breccia with 285 Ωm – 1388 Ωm resistivity. A fresh – slightly weathered volcanic breccia layer was identified as potential slip plane with 20 – 30 m depth.
3D Check shot Modeling for Time-Depth Conversion
Authors: Irawan Jefri Bambang , Triyoso Wahyu
Published: September 2023

Time-depth conversion is one of the keys to successful drilling with a specific target. However, if the drilling target is incorrectly defined, it can cause significant material losses. For example, several cases found that the hydrocarbon depth was deeper than the expected target. As a result, the well will be considered dry even though it still has hydrocarbon reserves. In this study, we intend to develop 3D check shot modeling in which check shot and formation marker data are referred to and taken at the well to obtain a precise time-depth relationship to overcome this problem. The well data with check shot available that can be used for velocity modeling, for the time-depth conversion process is very limited. However, in development fields with dozens or even hundreds of wells, the time-to-depth conversion process becomes a challenge where it is not enough when using one single velocity. In addition, the velocity model must accommodate lateral heterogeneity so the depth structure map can match the well formation markers. On the other hand, seismic data can indirectly measure subsurface velocities vertically and horizontally. This research combines well-check shot data with seismic semblance velocity data to build a velocity model calibrated by well data. The time-to-depth conversion process with the calibrated velocity model has an average residual of less than 5 meters compared to only using check shot data, with an average residual is 25-meters.
Delineation of Gas Sand Reservoir Prospect in the “A” Field, Deep Water Area of Kutai Basin
Authors: Wardaya P D , Novianto A , Pratiknyo A K , Hamdalah H , Rizkianto Y , Handini A M , Karimah A K , Nugraheni E S
Published: September 2023

Kutai basin hydrocarbon’s potential is not only in the delta area but extends to the deepwater area of East Kalimantan. The result of the integration method based on petrophysical, inversion, and seismic multiattribute aim to delineate the gas reservoir potential zone in the research area. The reservoir rocks consist of graywacke to sublitharenite of Upper Miocene sandstone with an average shale volume content 19%, porosity 23%, and water saturation 55%. The reservoir gas is reflected in the Vp/Vs ratio range of 1.58 to 1.8, the Poisson ratio value of 0.17 to 0.3 GPa, and the incompressibility value of 8 to 22 Gpa*g/cc. The distribution potential reservoir zone is indicated by the low acoustic impedance anomaly value of 4000 to 7500 m/s*gr/cm3, high RMS attribute anomaly value of 2000 to 10000, and distribution of low shale volume, high porosity, and low incompressibility will be estimated by using multi-attribute linear regression and probabilistic neural network methods that concentrated on the upper slope fan in the southern area.
Applying Map Filters and Inversion Model for Gravity Data in Matlab-based Application
Authors: Tsaqif Ghifari M , Fitrianto Fawwaz Byru , Raharjo Wiji
Published: September 2023

In general, there are two types of processes using the gravity method, that is the basic processes and the advanced processes. The basic process includes Gravity Meter reading conversion until the gravity corrections process. While the advanced process is a process to put an edge on the geological appearance of the research area that is already in the form of a map. The advanced process includes map filtering and inversion modeling. This advanced processing of gravity data is very useful, one of which is to separate regional anomalies and local anomalies, while inversion modeling is useful for knowing the approximate location of the anomaly depth. What will be applied to the software is advanced processing, because in its application this processing is required in every geophysical research and requires data processing support tools. However, for now, gravity data processing software, especially for the filtering and data modeling process is available as a licensed software. Where not everyone can access it because of limited costs and those who are still in the learning stage in lectures need practicing to process the geophysical data. The purpose of implementing this filtering process and inversion modeling is to provide access to gravity data processing for free and open source so that it can make it easier for students to process the data while practicing in the field, and in the future this software can be the basis for learning and development in the field of geophysical computing. This research was made using a descriptive method with a complete step and explanation of the creating and applying of the geophysical data processing into a software, so the detail processes inside it can be known. A literature study was also conducted to determine the basic formula that will be used as a reference in calculating gravity data in order to obtain the expected processing and modeling results. After that, the final step is to apply all of the components in a program to create a software based on MATLAB for the final result of this research. This software will containing map filtering and inverse modeling for gravity data which can be used for data processing.
The Early Model of Tomography in Eastern Indonesia Using FMTOMO
Authors: Wulan E P , Madrinovella I , Saputra R , Asyidah S N , Haqi Y S , Wijaya F C , Rosyid M A , Yasir M
Published: September 2023

Eastern Indonesia has a complicated structure due to the collision of the Eurasian Plate, the Pacific Plate, the Indo-Australian Plate, and the Philippine Plate, creating an active seismic zone. The Banda - Seram segment of eastern Indonesia comprises subduction, rollback, detachment, slab tear, back-arc thrust, and the Banda volcanic arc. Sri Widiyantoro did a previous study in Eastern Indonesia utilizing seismic tomography methods to detect the upper mantle and the 180-degree curved transition zone under the Banda arc. In addition, Robert Hall and Spakman’s research of the upper mantle revealed the existence of a spoon-shaped mechanism in the band arc. Seismic tomography modeling, this research seeks to identify the tectonic features in Eastern Indonesia, such as partial melting, subduction, slab rips, back-arc thrust, Banda volcanic-arc, detachment, and faults, and to establish the most suitable mitigation strategies. This study uses earthquake data from the Meteorology Climatology Geophysics Agency database (BMKG) and the form of P waves. In this research from 1 January 2016 to 31 December 2020, with coordinates 1 - 12 LS and 120 - 135 BT, there were 81 recording stations and 11299 earthquake occurrences consisting of 175643 P waves and 27338 S waves. This work applies the FMTOMO method to a seismic tomographic model. This research indicates that high-velocity anomalies characterize subduction to a depth of 650 kilometers. On Buru Island, the high-velocity anomaly is diagnosed as a slab tear at a depth of more than 400 kilometers. This research identifies a 100-kilometer-deep Back-arc thrust on Wetar Island that produces shallow earthquakes. In addition, a low-velocity anomaly at a depth of 70 kilometers - 90 kilometers is characterized as partial melting due to its parallel location with the Banda volcanic arc. This study examines the connection between subduction and intense seismic and magmatic activity in Eastern Indonesia.
Tomographic Inversion Code Analysis Using Regularization Iteratively Reweighted Norm (Irn)
Authors: Natasya B A , Rizkiyana A
Published: September 2023

Indonesia is an area located in the ring of fire, which was formed as a result of the interaction between four plates, namely the Eurasian Plate on the south, the Eurasian Plate on the, the Philippine Plate, and the Pacific Plate on the northeast. The interaction between these plates causes Indonesia to have many active volcanoes and experience many geological natural disasters. In the tomographic inversion process, ill-condition problems are often found in matrix making. Therefore, a regularization technique is needed to obtain a consistent result. The regularization technique can be done using Matlab software with a package called IR Tools (Gazzola et al., 2018). In this research, inversion techniques are used in the form of Least Square and Iteratively Reweighted Norm (IRN). This study aims to analyze the tomographic inversion code with the regularization technique using the Iteratively Reweighted Norm (IRN). In this study, two types of data were used, synthetic data and real data. Based on the results, it shows that using the Least Square method has better where the resulting checkerboard is more than adequate to reconstruct the initial velocity and amplitude model, which is described more clearly and strongly. Based on the results of the real data inversion, it shows that there is a low Vp anomaly (red) in the lower area of Mt. Merapi and Mt Merbabu. Low seismic velocity anomalies are associated with magmatic zones, partial melting, or magma reservoirs. However, there is also a high seismic velocity anomaly (blue) associated with the subduction zone of the Indo-Australian Plate to the Eurasian Plate.
Moment tensor inversion implementation in determining focal mechanism solution of Palu-Koro and Matano fault events: processing strategy
Authors: Kusumawati Dian , Sahara David P. , Puspito Nanang T. , Baskara Aria Widhi , Kurniawan Andri , Tanihaha Wahyu , Solihin Leonardo Junior Johan , Pratama Muhamad Diva , Patimah Sindi Hajah , Sasmi Annisa Trisnia , Muhammad Hilmy , Muhammad Hammam , Natafrisca Widjra Cyiena Christi , Bening Maulidia Ain
Published: September 2023

Earthquake focal mechanisms are helpful in analyzing seismotectonic features in a specific area, as they can depict subsurface structures. Earthquake focal mechanism solution can result from the first polarity or moment tensor inversion method. The moment tensor inversion can produce complete information of focal mechanism solution than the first polarity method. However, the procedure is slightly more complicated, for it is based on waveform inversion. Several problems related to signal processing might arise. Strategies should be applied to overcome the difficulties and obtain reliable focal mechanism solutions. In this study, we used moment tensor inversion to produce focal mechanisms data of Palu-Koro and Matano Fault events. We processed the focal mechanism of events with a depth of less than 60 km and with a minimum magnitude of Mw 4.7. The moment tensor inversion is conducted using Isolated Asperities (ISOLA) software. Full waveform inversion of stations located near Palu-Koro and Matano Fault is applied. The cause of waveform fitting difficulties using the data in this study area and the solution are discussed. For instance, the existence of unseen signal noise and clear-yet-disturbing signals are observed. Improved solutions can be achieved by station reselection and bandpass frequency adjustment.
Processing Receiver Function Data in Mentawai Region, Sumatra
Authors: Aldi M , Silaen N , Siregar I R , Dhaifullah D , Suhardja S K , Madrinovella I
Published: September 2023

The Mentawai Islands are located in the western part of Sumatra, in the Indo-Australian and Eurasian plate subduction zone. Because of these tectonic settings, the Mentawai Region has a high level of seismicity, making it particularly appealing for subsurface structure study. We used the receiver function method in this study to see response receiver function on plate subduction zone and compare the two deconvolution. This method uses the conversion of P-to-S waves, which have a larger amplitude in the radial component than vertical waves. The deconvolution technique is used to extract the two components of the receiver function signal. Water level deconvolution and iterative deconvolution were employed in this study. In practice, any deconvolution method cannot produce a suitable receiver function due to various methodologies that cannot be used in all conditions. Therefore, an evaluation is needed of each deconvolution method used to obtain the best results. This study utilizes two teleseismic stations located in the north and south of Mentawai, which were obtained through the IRIS website, and applied the Butterworth filter to obtain organized and noise-free data. The first results show that the water level is stronger than the iterative, which is more sensitive to the Gaussian filter width parameter. However, they produced almost identical results at both stations, precisely the arrival time of Ps, which was in 3-4 seconds and was followed by a low velocity.
The Adoption and Adaption of CEEQUAL’s Sustainability Attributes in Assessing the Malaysian Infrastructure Projects: A Review
Authors: Najib Nurul ‘Ulyani Mohd , Ghazali Farid Ezanee Mohamed
Published: September 2023

The rapid growing of urban populations has triggered the deterioration of natural resources and acceleration of climate change. Therefore, the development of sustainable infrastructure is playing an important role in order to minimize these issues. Generally, most of the sustainable rating tools are designed to focus on building projects only but not applicable to infrastructure projects. Specifically in Malaysia, there is limited studies have been done on the application of sustainable rating system to the infrastructure projects and literature also reveals that the Malaysian construction industry players still have little understanding on the sustainable infrastructure assessment. With these limitations, hence, this paper corresponds to fill the gap by exploring the sustainability attributes in assessing the infrastructure projects. In this paper, an extensive literature review was conducted to give an overview of several worldwide practical sustainable infrastructure rating tools and identifies the most important attributes for assessing the infrastructure projects, which is based on comprehensive and conventional reviews of considerable volume of published journals from 1993 until 2023 in the area of sustainable infrastructure rating system. Based on the best reference of CEEQUAL sustainability topic areas, the results of the review clarified that a total of 14 attributes like effects on neighbours, users, and the workforce; relation with the local community and other stakeholders; transport; material use; waste management; use of land; restoration of contaminated land; landscape issue; water environment; water resources; flood risk; historic environment; ecology and biodiversity; besides energy consumption and carbon emissions are identified as the relevant sustainability attributes for assessing the development of infrastructure projects in Malaysia.
Perception and Capacity of People with Disabilities Entering the Malaysia Construction Industry: Preliminary Findings
Authors: Majid Masidah Abdul , Osman Nurul Aini , Mohd Suhaimi Mohd Saifulnizam , Kamarudin Suhaida Suhana , Ashaari Norul Izzati M.
Published: September 2023

People with Disabilities (PWDs) seek the same chances and experiences as everyone else, yet due to a number of hurdles they are frequently excluded from fulfilling jobs. There are few statistics available globally to give an accurate knowledge of the number of workers with disabilities, and there is still a dearth of study on employment, disability, and construction, particularly in Malaysia. This study aims to determine the students and trainer at the Industrial Training and Rehabilitation Centre for People with Disabilities (PLPP) in Bangi, Selangor feel about participating the construction industry and their capacity to do so. It investigates how eager and capable students are to meet the requirements of IR4.0 in the construction industry. The interviews with 2 students who have physical disabilities, and 1 instructor are included in the data. These students are registered and classified as physical disability by the Malaysian Social Welfare Department. The interviews were transcribed verbatim. Extracting, grouping, and interpreting keywords or phrases into themes. The results show the PWDs have a high motivation to have an added-on skill in IR4.0 courses like drone, BIM and VR which will open bigger opportunity to enter construction industry. It also reveals that the participants have a basic skill of AutoCAD which shows that they able to perform a technical understanding.
Comparative assessment of high efficiency flat solar thermal collectors’ performances
Authors: Ciocan Mihaela , Serban Alexandru , Dobrovicescu Alexandru , Hiris Daniel P , Dudescu Mircea C. , Balan Mugur C
Published: September 2023

The study investigates the performances of high efficiency flat solar thermal collectors, under the climatic conditions of Galați, Romania. The same mathematical model was used to evaluate the stationary and the transitory thermal behavior of 12 high effic iency collectors, with reduced heat losses. The thermal characteristics of the collectors were extracted from the technical reports of two European independent testing laboratories. The annual specific energy production was found to vary in a large domain between 415.9 kWh/m2 and 947.9 kWh/m2, the maxim value representing more than the double of the minimum one. It was highlighted that both the optical efficiency and the heat losses contribute to the global efficiency of the flat solar thermal collectors, and the most efficient one is the flat evacuated one.