bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep learning for high-resolution dose prediction in high dose rate brachytherapy for breast cancer treatment
Authors: Quetin Sébastien , Bahoric Boris , Maleki Farhad , Enger Shirin A
Published: April 2024

Objective. Monte Carlo (MC) simulations are the benchmark for accurate radiotherapy dose calculations, notably in patient-specific high dose rate brachytherapy (HDR BT), in cases where considering tissue heterogeneities is critical. However, the lengthy computational time limits the practical application of MC simulations. Prior research used deep learning (DL) for dose prediction as an alternative to MC simulations. While accurate dose predictions akin to MC were attained, graphics processing unit limitations constrained these predictions to large voxels of 3 mm × 3 mm × 3 mm. This study aimed to enable dose predictions as accurate as MC simulations in 1 mm × 1 mm × 1 mm voxels within a clinically acceptable timeframe. Approach. Computed tomography scans of 98 breast cancer patients treated with Iridium-192-based HDR BT were used: 70 for training, 14 for validation, and 14 for testing. A new cropping strategy based on the distance to the seed was devised to reduce the volume size, enabling efficient training of 3D DL models using 1 mm × 1 mm × 1 mm dose grids. Additionally, novel DL architecture with layer-level fusion were proposed to predict MC simulated dose to medium-in-medium (D

m,m
). These architectures fuse information from TG-43 dose to water-in-water (D

w,w
) with patient tissue composition at the layer-level. Different inputs describing patient body composition were investigated. Main results. The proposed approach demonstrated state-of-the-art performance, on par with the MC D

m,m
maps, but 300 times faster. The mean absolute percent error for dosimetric indices between the MC and DL-predicted complete treatment plans was 0.17% ± 0.15% for the planning target volume V
100, 0.30% ± 0.32% for the skin D
2cc
, 0.82% ± 0.79% for the lung D
2cc
, 0.34% ± 0.29% for the chest wall D
2cc
and 1.08% ± 0.98% for the heart D
2cc
. Significance. Unlike the time-consuming MC simulations, the proposed novel strategy efficiently converts TG-43 D

w,w
maps into precise D

m,m
maps at high resolution, enabling clinical integration.
Effects of low-frequency voltage on nonlinear standing wave excitation, plasma uniformity, and ion dynamics in dual-frequency asymmetric capacitive discharges
Authors: Zhou Fang-Jie , Wen De-Qi , Liu Jian-Kai , Su Zi-Xuan , Zhao Kai , Zhang Yu-Ru , Wang You-Nian
Published: April 2024

It is known that in very-high-frequency (VHF) capacitively coupled plasmas, the higher harmonics generated by nonlinear sheath motion can enhance the standing wave effect (SWE), which can lead to center-peaked plasma density profiles. In this work, an improved nonlinear electromagnetic model incorporating a transmission line model, an electron momentum balance model, a bulk plasma model, a collisionless nonlinear numerical sheath model, and an ion Monte-Carlo collision (MCC) model is developed to study the effects of low-frequency (LF) voltage

V

L

on the nonlinear standing wave excitation, plasma uniformity, and ion energy and angular distribution functions (IEDFs and IADFs) in dual-frequency (DF) asymmetric capacitive argon discharges at relatively low pressure of 3 Pa. The plasma diffusion in the radial direction and ion dynamics within the LF oscillating sheath are self-consistently considered. The LF voltage

V

L

at 2 MHz varies from 0 to 700 V while the HF voltage

V

H

at 60 MHz is fixed at 100 V. Simulation results indicate that without the addition of an LF source (i.e.

V

L

=

0 V), there are a considerable number of high-order harmonics with short wavelengths, leading to significant SWE and central peak in the radial plasma density profile. Nevertheless, the high-order harmonic excitations tend to be weakened and merely occur around the phase of the full LF sheath collapse due to a shorter characteristic damping time of the surface waves as

V

L

increases. This, combined with increased surface wavelengths of both the driving frequency and the higher harmonics at a higher

V

L

, leads to suppressed standing waves and improved plasma uniformity. Meanwhile, the simulations show that both the low and the high energy peaks of IEDF move towards higher energies, and the energy peak separation width ΔE becomes wider with the increase of

V

L

. The IEDF at the radial center of the powered electrode exhibits a broader ΔE than that at the edge. For the IADF, an increased

V

L

results in more ions incident on the electrode with a smaller deflection angle. Because of a thinner sheath and a higher sheath voltage at the electrode center, the peak value of IADF at the electrode center is greater than that at the edge.
Biexcitons and quadrons in self-assembled quantum dots
Authors: Hong Quang Nguyen , Thi Kim Thanh Nguyen , Que Huong Nguyen
Published: April 2024

We theoretically study biexcitons and quadrons in quantum dots with parabolic confinement and give a complete comparison between the two excitations. The calculation of quadron and biexciton binding energies as functions of electron-to-hole confinement potentials and mass ratios, using the unrestricted Hartree–Fock method, shows the essential differences between biexcitons and quadrons. The crossover between the negative and positive binding energies is indicated. The effect of an external magnetic field on the quadron and biexciton binding energies has also been investigated. In addition, the crossover between anti-binding and binding of both excited quadron and biexciton states in a certain range of the electron-to-hole oscillator length ratios has been found.
Design, fabrication and experimental verification of a drag sail based on thermal-driven controllable bi-stable shape memory polymer composite booms
Authors: Ming Guangqing , Chen Siling , Li Bingxun , Li Fengfeng , Liu Liwu , Liu Yanju , Leng Jinsong
Published: April 2024

Deployable drag sails are used for passively deorbiting defunct satellites and other spacecraft. Designing the deployable boom is the main challenge in this technology. We present a bi-stable shape memory polymer composite (Bi-SMPC) boom with high stiffness, a high unfolding/folding ratio, and consistent roll-out deployment. It was designed and fabricated by a strategy of controlling the gradual release of elastic energy stored in a bi-stable composite structure through thermal-driven SMP matrix. Two heating layer strategies were investigated experimentally to determine the optimal driving layer and driving parameters. Based on these parameters, verification tests of a four-stage deployment Bi-SMPC boom were conducted. Meanwhile, a proof-of-concept prototype of a four-stage deployment drag sail based on the Bi-SMPC booms was designed and fabricated. Tests were conducted to verify the effectiveness of the drag sail deployed by the booms. It was found that SMPs can effectively control the deployment of bistable composite structures. The nickel-chromium alloy heating layer offers a more uniform driving temperature field compared to carbon fiber. The drag sail can be deployed successfully under the driving of four Bi-SMPC booms.
Does anti-Unruh effect assist quantum entanglement and coherence?
Authors: Wu Shu-Min , Teng Xiao-Wei , Li Jin-Xuan , Zeng Hao-Sheng , Liu Tonghua
Published: April 2024

In this paper, we use the concepts of quantum entanglement and coherence to analyze the Unruh and anti-Unruh effects based on the model of Unruh–DeWitt detector. For the first time, we find that (i) the Unruh effect reduces quantum entanglement but enhances quantum coherence; (ii) the anti-Unruh effect enhances quantum entanglement but reduces quantum coherence. This surprising result refutes the notion that the Unruh effect can only destroy quantum entanglement and coherence simultaneously, and that the anti-Unruh can only protect quantum resources. Consequently, it opens up a new source for discovering experimental evidence supporting the existence of the Unruh and anti-Unruh effects.
Switching of topological phase and topological channel via asymmetric hopping modulations in a one-dimensional superconducting circuit lattice
Authors: Li Zi-Meng , Xiang Lü , Wang He , Wang Yi-Ping
Published: April 2024

We propose a theoretical scheme for a one-dimensional superconducting circuit lattice system to achieve that topological phase transition and topological multi-channel transfer, which is adjusted by the asymmetric hopping modulations. The system consists of an array of coupled superconducting microwave cavities, the hopping between its can be modulated by the qubits. Here, we explore topological stages by introducing parameters to expand the hopping modulation range. We found that the energy bands in the system exhibit different structural characteristics, which can achieve topological phase switching. Meanwhile, the edge modes can undergo a flipping process, which can not only realize dual-channel topological quantum information transfer, but also can achieve four-channel. Furthermore, it is noted that the defect can induce new topological phases, which can be optimized by adjusting the hopping parameters, while disorder can only cause band fluctuations and inversions, but does not change the position and period of edge states, verifying that the edge state transport is robust. The results obtained in this work can be applied to the storage and transmission of quantum information, and have a guiding role in the future development of quantum technology.
Systematic study of α-decays from the ground and isomeric states of the nuclei with 67 ≤ Z ≤ 106
Authors: Anjali V K , Santhosh K P , Zuhail K P
Published: April 2024

The Modified Generalised Liquid Drop Model (MGLDM) is employed to analyze both the favored and unfavored α-decays in the ground states (g.s.) and isomeric states (i.s.) of some nuclei having proton numbers, 67 ≤ Z ≤ 106. The calculated half-lives closely match the experimental results, with a least standard deviation, 0.3598, which shows that the g.s. model ‘MGLDM’ with some improvements can effectively be applied to the isomeric state decay. Royer’s formula and Qian’s formula are employed in our calculations and the reported results of the Two Potential Approach (TPA) and the GLDM are included, to compare the half-lives reproduced by MGLDM. The straight-line behaviour of New Geiger-Nuttall (New G-N) plots for various isotopes for different kinds of transitions shows the New G-N law can be applied successfully in the isomeric state α-decays also.
On the heart rhythm analysis using a nonlinear dynamics perspective: analytical study and electronic simulation
Authors: Fonkou R F , Kengne Romanic , Wamba M D , Fotsing Kamgang Herton Carel , Talla P K
Published: April 2024

Biological systems are highly complex, so understanding them requires extensive analysis. Cardiac rhythms are one such analysis. These rhythms are linked to a complex dynamic system defined on the basis of the electrical activity of cardiac cells. This electrical activity is essential to human physiology, defining numerous behaviours that include normal or pathological rhythms, generally measured by the electrocardiogram (ECG). This article presents a mathematical model to describe the electrical activity of the heart, using a nonlinear dynamics perspective. The stability analysis of this model in its autonomous state, uni-directionally coupled, shows a very rich dynamical behaviour characterized by periodical regions of stability and unstability. The model studied makes it possible to construct synthetic ECGs. These ECGs demonstrate a variety of responses, including normal and pathological rhythms: ventricular flutter, ventricular fibrillation, ventricular tachycardia and ventricular extrasystole. A quantitative analysis of the model is also carried out using bifurcation diagrams and the corresponding maximum Lyapunov exponents. In addition, variations in sinus rhythm are described by a time-dependent frequency (a dynamic variable varying in a disordered manner or following a given law), representing transient disturbances. This type of situation can represent transitions between different pathological behaviours or between normal and pathological physiologies. In this respect, the perspective of nonlinear dynamics is used to describe cardiac rhythms, which makes it possible to represent normal or pathological behaviours. An electronic simulation performed with the OrCAD-Pspice software for a real implementation of the cardiac system is carried out. The results obtained are in agreement with those obtained numerically.
Benchmarking discrete truncated Wigner approximation and neural network quantum states with the exact dynamics in a Rydberg atomic chain
Authors: Shenoy Varna , Dattatraya Naik Vighnesh , Li Weibin , Nath Rejish
Published: April 2024

We benchmark the discrete truncated Wigner approximation (DTWA) and Neural quantum states (NQS) based on restricted Boltzmann-like machines with the exact excitation and correlation dynamics in a chain of ten Rydberg atoms. The initial state is where all atoms are in their electronic ground state. We characterize the excitation dynamics using the maximum and time-averaged number of Rydberg excitations. DTWA results are different from the exact dynamics for large Rydberg-Rydberg interactions. In contrast, by increasing the number of hidden spins, the NQS can be improved but still limited to short-time dynamics. Interestingly, irrespective of interaction strengths, the time-averaged number of excitations obtained using NQS is in excellent agreement with the exact results. Concerning the calculation of quantum correlations, for instance, second-order bipartite and average two-site Rényi entropies, NQS looks more promising. Finally, we discuss the existence of a power law scaling for the initial growth of average two-site Rényi entropy.
Probing scalar induced gravitational waves with PTA and LISA: the importance of third order correction
Authors: Chang Zhe , Kuang Yu-Ting , Wu Di , Zhou Jing-Zhi
Published: April 2024

We revisit the calculation of third order scalar induced gravitational waves (SIGWs) and extend it from a monochromatic primordial power spectrum to a more general log-normal one. We investigate the impact of third order SIGWs on signal-to-noise ratio (SNR) of
Laser Interferometer Space Antenna (LISA) and pulsar timing array (PTA) observations, and find that third order SIGWs significantly contribute to the total energy density spectrum of gravitational waves (GW) in high-frequency region. For a primordial power spectrum amplitude of Aζ
= 10-2 ∼ 10-1, the effects of third order SIGWs lead to a 40% to 400% increase in the SNR for LISA. Additionally, our PTA data analysis reveals that third order SIGWs diminish both the amplitude Aζ
and the peak frequency f
* of the primordial power spectrum.
On the Galactic radio signal from stimulated decay of axion dark matter
Authors: Bhupal Dev P.S. , Ferrer Francesc , Okawa Takuya
Published: April 2024

We study the full-sky distribution of the radio emission from the stimulated decay of
axions which are assumed to compose the dark matter in the Galaxy. Besides the constant
extragalactic and CMB components, the decays are stimulated by a Galactic radio emission with a
spatial distribution that we empirically determine from observations. We compare the diffuse
emission to the counterimages of the brightest supernovæ remnants, and take into account the
effects of free-free absorption. We show that, if the dark matter halo is described by a cuspy NFW
profile, the expected signal from the Galactic center is the strongest. Interestingly, the
emission from the Galactic anti-center provides competitive constraints that do not depend on
assumptions on the uncertain dark matter density in the inner region. Furthermore, the anti-center
of the Galaxy is the brightest spot if the Galactic dark matter density follows a cored
profile. The expected signal from stimulated decays of axions of mass ma
∼ 10-6 eV is within reach of the Square Kilometer Array for an axion-photon coupling
 gaγ
≳ (2-3) × 10-11 GeV-1.
Characterization and Optimization of Skipper CCDs for the SOAR Integral Field Spectrograph
Authors: Villalpando Edgar Marrufo , Drlica-Wagner Alex , Plazas Malagón Andrés A. , Bakshi Abhishek , Bonati Marco , Campa Julia , Cancino Braulio , Chavez Claudio R. , Estrada Juan , Fernandez Moroni Guillermo , Fraga Luciano , Gaido Manuel E. , Holland Stephen , Hur Rachel , Jonas Michelle , Moore Peter , Tiffenberg Javier
Published: April 2024

We present results from the characterization and optimization of Skipper charge-coupled devices (CCDs) for use in a focal plane prototype for the Southern Astrophysical Research Integral Field Spectrograph (SIFS). We tested eight Skipper CCDs and selected six for SIFS based on performance results. The Skipper CCDs are 6k × 1k, 15 μm pixels, thick, fully depleted, p-channel devices that have been thinned to ∼250 μm, backside processed, and treated with an anti-reflective coating. We demonstrate a single-sample readout noise of <4.3 e− rms pixel−1 in all amplifiers. We optimize the readout sequence timing to achieve a readout noise of 0.5 e− rms pixel−1 after 74 non-destructive measurements, which can be accomplished in a region covering 5% of the detector area in a readout time of <4 minutes. We demonstrate single-photon-counting in all 24 amplifiers (four amplifiers per detector) with a readnoise of σ

N
∼ 0.18 e− rms pixel−1 after N
samp = 400 samples, and we constrain the degree of nonlinearity to be ≲1% at low signal levels (0 e− to 50 e−). Clock-induced charge (CIC) remains an important issue when the Skipper CCD is configured to provide a large full-well capacity. We achieve a CIC rate of <1.45 × 10−3 e− pixel−1 frame−1 for a full-well capacity of ∼900 e−, which increases to a CIC rate of ∼3 e− pixel−1 frame−1 for full-well capacities ∼40,000–65,000 e−. We also perform conventional CCD characterization measurements such as charge transfer inefficiency (3.44 × 10−7 on average), dark current (∼2 × 10−4 e− pixel−1 s−1), photon transfer curves, cosmetic defects (<0.45% “bad” pixels), and charge diffusion (point-spread function < 7.5 μm) to verify that these properties are consistent with expectations from conventional p-channel CCDs used for astronomy. Furthermore, we provide the first measurements of the brighter-fatter effect and absolute quantum efficiency (≳80% between 450 and 980 nm; ≳90% between 600 and 900 nm) using Skipper CCDs.
Stellar Populations of AGN-host Dwarf Galaxies Selected with Different Methods
Authors: Li Xiejin , Zhao 赵 Yinghe 应和 , Bai Jinming
Published: April 2024

In this paper we investigate the stellar populations and star formation histories of 235 active galactic nucleus (AGN)-host dwarf galaxies, consisting of four samples identified separately with different methods (i.e., radio, X-ray, mid-IR and variability), utilizing the synthesis code STARLIGHT and spectra from the Sloan Digital Sky Survey Data Release 8. Our results show that the variability sample is the oldest, while the mid-IR sample is the youngest, for which the luminosity at 4020 Å is dominated (>50%) by the young population (t < 108 yr). The light-weighted mean stellar age of the whole sample is in general about 0.7 dex younger than the optical sample studied in Cai et al. We compare the population results between fitting models with and without a power-law (PL) component and find that the neglect of a PL component would lead to an under- and over-estimation by 0.2 and 0.1 dex for the light- and mass-weighted mean stellar age, respectively, for our sample of dwarf galaxies, which has a mean fractional contribution of ∼16% from the AGN. In addition, we obtain further evidence for a possible suppression of star formation in the host galaxy by the central AGN. We also find that there exists an anti-correlation between the extinction-corrected [O iii] luminosity and light-weighted mean stellar age, confirming our previous finding that there is a physical connection between AGN and star-forming activities in AGN-host dwarfs.
Spectral Index Distribution of Various Scale Components in Supernova Remnant Cassiopeia A
Authors: Lei Xianhuan , Zhu Hui , Yin Zongyao , Zhang Haiyan , Tian Wenwu , Yu Xianchuan
Published: April 2024

Cassiopeia A (Cas A) is a well-known candidate for studying cosmic-ray acceleration, in which compact features of various scales have attracted much attention. Based on observations by the Very Large Array of Cas A at 6 cm and 21 cm, we measure the spectral index distribution of various scale components using the observation of the 1998 epoch. We decompose its total density image into nine scale components, and map the temperature spectral index distribution of each component, which ranges from −2.48 ± 0.01 to −2.91 ± 0.05. We find that the spectral indices increase from the small scale to large scale components. A damped post-shock magnetic field model with a strength larger than ∼200 μG and a damping length scale less than ∼10% of the remnant radius can account for the spectral index variation naturally.
Plasma beta dependence of turbulent transport suggesting an advantage of weak magnetic shear from local and global gyrokinetic simulations
Authors: Ishizawa A. , Kishimoto Y. , Imadera K. , Nakamura Y. , Maeyama S.
Published: April 2024

A higher plasma β is desirable for realizing high performance fusion reactor, in fact, one of the three goals of JT-60SA project is to achieve a high-β regime. We investigate key physical processes that regulate the β dependence of turbulent transport in L-mode plasmas by means of both local and global gyrokinetic simulations. From local simulations, we found that the turbulent transport does not decrease as β increases, because the electromagnetic stabilizing effect is canceled out by the increase of the Shafranov shift. This influence of the Shafranov shift is suppressed when the magnetic shear is weak, and thus the electromagnetic stabilization is prominent in weak shear plasmas, suggesting an advantage of weak magnetic shear plasmas for achieving a high-β regime. In high β regime, local gyrokinetic simulations are suffered from the non-saturation of turbulence level. In global simulations, by contrast, the electromagnetic turbulence gets saturated by the entropy advection in the radial direction to avoid the zonal flow erosion due to magnetic fluctuations. This breakthrough enables us to explore turbulent transport at a higher β regime by gyrokinetic simulations.
Effects of cavity pre-detuning on RF power transients at injection into the LHC
Authors: Karlsen-Baeck B.E. , Argyropoulos T. , Butterworth A. , Calaga R. , Karpov I. , Timko H. , Zampetakis M.
Published: April 2024

At injection into the Large Hadron Collider (LHC), the radio
frequency (RF) system is perturbed by beam-induced voltage resulting
in strong RF power transients and the instant detuning of the
cavities. The automatic tuning system, however, needs time for the
mechanical compensation of the resonance frequency to take
place. Acting back on the beam, the transients in RF power are
expected to limit the maximum injected intensity by generating
unacceptable beam loss. Reducing them is therefore essential to
reach the target intensity during the High Luminosity (HL) LHC
era. At LHC flat bottom, the cavities are operated using the
half-detuning beam-loading compensation scheme. As implemented
today, the tuner control algorithm starts acting only after the
injection of the first longer bunch train which causes the bunches
for this injection to experience the largest power spikes. This
contribution presents an adapted detuning scheme for the RF cavities
before injection. It was proposed as a path to decrease the
transients, hence increasing the available intensity margin for the
available RF power. The expected gain is evaluated in particle
tracking simulations and measurements acquired during operation.
Evaluating the potential of iron-based interventions in methane reduction and climate mitigation
Authors: Meidan Daphne , Li Qinyi , Cuevas Carlos A , Doney Scott C , Fernandez Rafael P , van Herpen Maarten M J W , Johnson Matthew S , Kinnison Douglas E , Li Longlei , Hamilton Douglas S , Saiz-Lopez Alfonso , Hess Peter , Mahowald Natalie M
Published: April 2024

Keeping global surface temperatures below international climate targets will require substantial measures to control atmospheric CO2 and CH4 concentrations. Recent studies have focused on interventions to decrease CH4 through enhanced atmospheric oxidation. Here for the first time using a set of models, we evaluate the effect of adding iron aerosols to the atmosphere to enhance molecular chlorine production, and thus enhance the atmospheric oxidation of methane and reduce its concentration. Using different iron emission sensitivity scenarios, we examine the potential role and impact of enhanced iron emissions on direct interactions with solar radiation, and on the chemical and radiative response of methane. Our results show that the impact of iron emissions on CH4 depends sensitively on the location of the iron emissions. In all emission regions there is a threshold in the amount of iron that must be added to remove methane. Below this threshold CH4 increases. Even once that threshold is reached, the iron-aerosol driven chlorine-enhanced impacts on climate are complex. The radiative forcing of both methane and ozone are decreased in the most efficient regions but the direct effect due to the addition of absorbing iron aerosols tends to warm the planet. Adding any anthropogenic aerosol may also cool the planet due to aerosol cloud interactions, although these are very uncertain, and here we focus on the unique properties of adding iron aerosols. If the added emissions have a similar distribution as current shipping emissions, our study shows that the amount of iron aerosols that must be added before methane decreases is 2.5 times the current shipping emissions of iron aerosols, or 6 Tg Fe yr−1 in the most ideal case examined here. Our study suggests that the photoactive fraction of iron aerosols is a key variable controlling the impact of iron additions and poorly understood. More studies of the sensitivity of when, where and how iron aerosols are added should be conducted. Before seriously considering this method, additional impacts on the atmospheric chemistry, climate, environmental impacts and air pollution should be carefully assessed in future studies since they are likely to be important.
Dugong dugon (Muller 1776) and Its Habitat in Coastal Areas and Small Islands of East Java Province, Indonesia
Authors: Dewi C S U , Wahyudi S , Widodo  , Tarno H , Ciptadi G , Wiadnya D G R
Published: April 2024

Dugong dugon, an endangered marine mammal is listed the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Dugongs are classified as herbivorous mammals that live in the shallows associated with seagrass beds. The objectives of this study are (1) to collect data on dugong encounters in East Java, both direct encounters and literature studies; and (2) to analyze seagrass meadows that are potentially dugong grazing habitats in East Java. This study was conducted from January to July 2023 in the coastal area of East Java. Dugong and seagrass data, which were descriptively analyzed, were obtained from the literature, questionnaire interview, and by direct observation. Distribution of dugongs in East Java is known to be in the southeastern side of Banyuwangi, Situbondo, Sumenep, Lamongan, and Bawean Island. Direct encounters with live and dead dugongs in East Java have been recorded in several locations, including Bawean Island. Seagrass beds in East Java can be found on the coastal area of Lamongan, Bawean Island - Gresik, Sumenep, Bangkalan, Situbondo, Banyuwangi, Malang, and Pacitan. The seagrass species found in these eight areas are: E. acoroides, T. hemprichii, C. modocea rotundata, C. serrulata, H. pinifolia, H. uninervis, H. decipiens, H. ovalis, H. minor, S. iseotifolium, and T. ciliatum. Although, dugong status is fully protected in Indonesia, and its distribution is limited, further steps are needed to protect dugongs and their food habitats. Marine Protected Area is one of the policies that could be recommended to protect dugongs and their habitat.
Analysis of the Vulnerability of Small-Scale Capture Fisheries in Pangpang Bay, Banyuwangi Regency, Indonesia
Authors: Setyaningrum E W , Harahab N , Wiadnya D G R , Sambah A B
Published: April 2024

Pangpang Bay is called a multi-use area because it has the potential not only for capture fisheries and aquaculture, but also for mangrove conservation. However, small-scale fishermen in Pangpang Bay feel the impact of climate change. The impact of climate change on fisheries can lead to vulnerability to the sustainability of fishing communities in particular The benefits of research as a basis for developing small-scale capture fisheries in Pangpang Bay, Banyuwangi Regency, Indonesia. The research was conducted from March to July 2023. The method used in this study is a quantitative descriptive method, with data collection methods using surveys and direct observation. The analytical method used is the vulnerability of capture fisheries, with data analysis carried out on 1) Exposure, the variable is sea surface temperature (SST); 2) Sensitivity, the variables are analyzed being the catch and the number of fishermen; 3) Adaptive capacity, the variables are mangrove area, number of fish landings and number of fishery instructors. The results of the study showed that for small-scale capture fisheries in Pangpang is in the category of moderate vulnerability to climate change. In this case, it has implications for policies that can increase adaptive capacity and reduce sensitivity
Potential Carbon Stock of Seagrass Biomass in Malang Regency
Authors: Dewi C S U , Handayani M , Kurniawan F , Yona D , Rohenda A A , Asadi M A
Published: April 2024

Research on blue carbon content in seagrass beds also has important implications for coastal ecosystem management. The goals of this research are: (1) To determine the composition of seagrass species; (2) to analyze the health of the seagrass ecosystem; and (3) and to analyze the carbon content stored in seagrass biomass on the coast of Malang Regency. This research was conducted in 2018 at five stations, namely: Kondang Merak Beach (St 1), Balekambang Beach (St 2), Gatra Beach (St 3), Sendangbiru Beach (St 4), and Waru-Waru Beach (St 5) of Malang Regency. The method used to collect data refers to Seagrass Watch. The biomass value of seagrass species can be estimated by measuring the wet weight and dry weight of seagrass. Analysis of carbon content in seagrass biomass can be calculated using a method that refers to The First Nation-Wide Assessment Identifies Valuable Blue-carbon. There are five types of seagrasses found on five beaches in Malang Regency, namely: Halodule pinifolia, Halodule uninervis, Halophila ovalis, Syringodium isotifolium, and Thalassia hemprichii. This seagrass meadow ecosystem is in an unhealthy condition, with a small biomass value. Seagrass beds that are formed only in the form of small spots (1.19 Ha) are known to be able to store carbon of 0.0544 Mg C.
Comparative Study of Growth Performance of Three Tilapia Strain in Intensive Culture System
Authors: Nugroho K C , Rizky P N , Harijono T , Halim A M , Nasuki  , Ritonga L BR
Published: April 2024

High stocking density is an important factor in cultivation to increase the eficency if fish farming for nutrition requirements. High stocking density generally impact on fish physiology and growth performance. However, many studies on individual fish have different growth perfromance from different strain. Some technology had been developed to optimize tilapia production in high stocking density. This study aimed to determine the growth performance of three different strain of tilapia (red tilapia, nirwana tilapia, and jatimbulan tilapia) reared in 20 m3 of round tarpaulin with additional of microbubble generator. This study used an intensive system with 100 fish/m3 of stocking density. The results showed that the microbubble generator was able to increase the carrying capacity of water quality such as increasing dissolved oxygen in the waters, temperature and pH. The high content of dissolved oxygen in the water significantly increasing the growth of tilapia. The highest weight was found in red tilapia with a final weight of 199.56 ± 0.05 gr, followed by Nirwana tilapia with 176.59 ± 0.10 gr, and Jatimbulan tilapia with 153.91 ± 0.06 gr. In addition, the high content of dissolved oxygen in the waters also affect the rearing period of tilapia.
Total suspended solid (TSS) pollution load model at the Jagir River Estuary, Surabaya, East Java
Authors: Supriatna  , Putri V E , Maizar A , Anitasari S , Darmawan A
Published: April 2024

The research aims to create a TSS spatial distribution map model and a pollution load model at the Jagir River Estuary—a descriptive method for the last six years to describe the TSS pollution load model. Satellite image data processing uses SNAP software with the application of the Laili algorithm (2015). The distribution of TSS pollution values and loads still meets the quality standards for mangrove ecosystems. The average value of TSS distribution in 2018 - 2023, respectively, is 18,966 mg/L, 14,578 mg/L, 17,267 mg/L, 16.921 mg/L, and 15,013 mg/L with the highest TSS pollution load occurring in 2023 and the lowest in 2021 and 2022. The average pollution load from 6 research stations in 2019 – 2023 still does not exceed the capacity limit of the Jagir River to accommodate TSS accumulation. The TSS pollution load model in the Jagir River Estuary, Surabaya, East Java, follows a quadratic pattern with the regression equation y = -173.01X2 + 2339.20X - 2299.80 (R2 = 0.7674) with a peak TSS pollution load reaching 5,607.05 tons m3/month in January and lowest in August
Sediment metals content in upstream Citarum river, West Java Province, Indonesia
Authors: Sugiarti  , Sudarso J , Ibrahim A , Yamin M , Zamroni M , Aisyah S
Published: April 2024

Study of metal content in sediments is important for monitoring condition of Citarum river. This study aims to determine several metal namely Fe, Cu, Mn, Zn, Ni, Cr, Cd, Pb, Hg, and As in upstream Citarum river sediments. Research was conducted in the Cirasea sub-watershed, namely Gunung Wayang, Babakan Village, Cikitu Village, Wangi Sagara, Puncak Cae, Koyod, Andir, and Nanjung. Sediment samples were taken once a month from September to November 2022. Several physico-chemical parameter were carried insitu and laboratory. Sediment metal analysis was carried out using the ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometry) technique. Metal concentrations were compared with standards and the relationship between metal parameters and physico-chemical parameters was analyzed by PCA (Principal Component Analysis). Metals that were not found in all stations were Hg and Cd. The metal found with the largest concentration was Fe, otherwise metal found with the smallest concentration was As. Based on PCA, there are three groups based on metals and physico-chemical parameters. Advanced metal analysis needs to be carried out in the Citarum river from upstream to downstream to determine water quality of Citarum river.
Embryonic and Larval Development of Hybrid Giant Grouper × Potato Grouper (PGGG) Male and Tiger Grouper (TG) Female
Authors: Fahrudini F. , Yuniartik M. , Muzaki A. , Mahardika K. , Ismi S. , Supii A.
Published: April 2024

This study aims to collect data and information of embryonic and larval development on the cross breeding between hybrid Giant Grouper × Potato Grouper (PGGG) male and Tiger Grouper (TG). The body weight of broodfish above 20 kg for male and 4 kg for female. Broodstock selection of Hybrid Giant Grouper × Potato Grouper (PGGG) male can usually be stripped by applying gentle pressure to the abdomen between the pelvic and the vent fins. Induced spawning by mixing sperm and eggs manually. Signs of a mature gonadal female are characterized by an enlarged abdomen, slow movements and tend to tilt, the genital opening increasingly swollen and red in colour. The results show that spawning at night 23.30 with an average egg diameter of 0.85±0.09 mm. The eggs hatch at 15.45 or 16 hours 15 minutes. Hatching rate being 24%-32%.
Machinability studies of Al–4Mg/in-situ MgAl2O4 nano composites: measurement of cutting forces and machined surface roughness
Authors: Satish Kumar T , Thankachan Titus , Čep Robert , Kalita Kanak
Published: April 2024

The present research aims to study the dry turning machinability characteristics of in situ Al-4Mg/MgAl2O4 nanocomposite by High-Speed Steel tool. The influence of various machining process parameters, such as feed rate, depth of cut and cutting speed on the surface roughness and cutting force of the nanocomposites was measured while performing dry turning. From the turning operation results, it is noticed that up to 100 m min−1, the cutting force increased and with further increases in cutting speed, the cutting force starts decreasing up to 150 m min−1. The type of chips and built-up edge (BUE) development were studied using a scanning electron microscope. BUE formations were higher at low cutting speeds (50 m min−1) and lower at high cutting speeds (150 m min−1). At a given depth of cut and feed rate, with an increase in cutting speed, the length of the chip and chip curls increased. Further, higher 2 wt% of in situ MgAl2O4 addition changes long-curled chips to segmental-type chips. With a feed rate of 0.14 mm/rev, the Al-4Mg/1 wt% MgAl2O4 nanocomposite showed the lowest surface roughness value of 2.4 μm proving usage of high speed steel can provide a better surface finish while turning Al-4Mg/MgAl2O4 nanocomposite.
Efficient quantum algorithm for all quantum wavelet transforms
Authors: Bagherimehrab Mohsen , Aspuru-Guzik Alán
Published: April 2024

Wavelet transforms are widely used in various fields of science and engineering as a mathematical tool with features that reveal information ignored by the Fourier transform. Unlike the Fourier transform, which is unique, a wavelet transform is specified by a sequence of numbers associated with the type of wavelet used and an order parameter specifying the length of the sequence. While the quantum Fourier transform, a quantum analog of the classical Fourier transform, has been pivotal in quantum computing, prior works on quantum wavelet transforms (QWTs) were limited to the second and fourth order of a particular wavelet, the Daubechies wavelet. Here we develop a simple yet efficient quantum algorithm for executing any wavelet transform on a quantum computer. Our approach is to decompose the kernel matrix of a wavelet transform as a linear combination of unitaries (LCU) that are compilable by easy-to-implement modular quantum arithmetic operations and use the LCU technique to construct a probabilistic procedure to implement a QWT with a known success probability. We then use properties of wavelets to make this approach deterministic by a few executions of the amplitude amplification strategy. We extend our approach to a multilevel wavelet transform and a generalized version, the packet wavelet transform, establishing computational complexities in terms of three parameters: the wavelet order M, the dimension N of the transformation matrix, and the transformation level d. We show the cost is logarithmic in N, linear in d and superlinear in M. Moreover, we show the cost is independent of M for practical applications. Our proposed QWTs could be used in quantum computing algorithms in a similar manner to their well-established counterpart, the quantum Fourier transform.
Pansharpening and spatiotemporal image fusion method for remote sensing
Authors: Anand Sakshi , Sharma Rakesh
Published: April 2024

In last decades, remote sensing technology has rapidly progressed, leading to the development of numerous earth satellites such as Landsat 7, QuickBird, SPOT, Sentinel-2, and IKONOS. These satellites provide multispectral images with a lower spatial resolution and panchromatic images with a higher spatial resolution. However, satellite sensors are unable to capture images with high spatial and spectral resolutions simultaneously due to storage and bandwidth constraints, among other things. Image fusion in remote sensing has emerged as a powerful tool for improving image quality and integrating important features from multiple source images into one, all while maintaining the integrity of critical features. It is especially useful for high-resolution remote sensing applications that need to integrate features from multiple sources and hence a vital pre-processing step for various applications, including medical, computer vision, and satellite imaging. This review initially gives a basic framework for image fusion, followed by statistical analysis and a comprehensive review of various state-of-the-art image fusion methods, where they are classified based on the number of sensors used, processing levels, and type of information being fused. Subsequently, a thorough analysis of STF and pansharpening techniques for remote sensing applications has been covered, where the dataset of the DEIMOS-2 satellite is employed for evaluating various pansharpening methods while MODIS and Landsat images are employed in the spatiotemporal fusion method. A comparative evaluation of several approaches has been carried out to assess the merits and drawbacks of the current approaches. Several real-time applications of remote sensing image fusion have been explored, and current and future directions in fusion research for remote sensing have been discussed, along with the obstacles they present.
Enhancing robotic manipulator fault detection with advanced machine learning techniques
Authors: Khan Faiq Ahmad , Jamil Akhtar , Khan Shaiq Ahmad , Hameed Alaa Ali
Published: April 2024

The optimization of rotating machinery processes is crucial for enhanced industrial productivity. Automatic machine health monitoring systems play a vital role in ensuring smooth operations. This study introduces a novel approach for fault diagnosis in robotic manipulators through motor sound analysis to enhance industrial efficiency and prevent machinery downtime. A unique dataset is generated using a custom robotic manipulator to examine the effectiveness of both deep learning and traditional machine learning in identifying motor anomalies. The investigation includes a two-stage analysis, initially leveraging 2D spectrogram features with neural network architectures, followed by an evaluation of 1D MFCC features using various conventional machine learning algorithms. The results reveal that the proposed custom CNN and 1D-CNN models significantly surpass traditional methods, achieving an F1-score exceeding 92%, highlighting the potential of sound analysis for automated fault detection in robotic systems. Additional experiments were carried out to investigate 1D MFCC features with various machine learning algorithms, including KNN, DT, LR, RF, SVM, MLP, and 1D-CNN. Augmented with additional data collected from the locally designed manipulator, our experimental setup significantly enhances model performance. Particularly, the 1D-CNN stands out as the top-performing model on the augmented dataset.
Characteristics study of heterojunction III-nitride/β-Ga2O3 nano-HEMT for THz applications
Authors: Rao G Purnachandra , Lenka Trupti Ranjan , Vadalà Valeria , Nguyen Hieu Pham Trung
Published: April 2024

In this research study, a recessed gate III-Nitride high electron mobility transistor (HEMT) grown on a lattice matched β-Ga2O3 substrate is designed. This research investigation aims to enhance DC and RF performance of AlGaN/GaN HEMT, and minimize the short-channel effects by incorporating an AlGaN back layer and field plate technique, which can enhances electron confinement in two-dimensional electron gas (2DEG). A precise comparison analysis is done on the proposed HEMT’s input characteristics, output characteristics, leakage current characteristics, breakdown voltage properties, and RF behaviour in presence and absence of AlGaN back layer in regards to field plate configuration. The inclusion of back barrier aids in raising the level of conduction band, which reduces leakage loss beneath the buffer, and aids in keeping the 2DEG to be confined to narrow channel. Furthermore, the field plate design offers an essential electric field drift between gate and drain, resulting to enhanced breakdown voltage characteristics.
β-Ga2O3 nanostructures for photocatalytic degradation of red amaranth toxic dye
Authors: Castillo-Saenz J R , Domínguez D , Arias A , Arce L A , Farías M H , Pérez-Landeros O M , Valdez B , Nedev N , López - Medina J.
Published: April 2024

Beta gallium oxide (β-Ga2O3) microstructures composed of ∼50 nm nanoparticles were synthesized by the hydrothermal method. Using the Tauc plot method a value of ∼4.9 eV was obtained for the optical band gap of β-Ga2O3. TEM and XRD analyses revealed high crystallinity of the β-phase of gallium oxide nanostructures. Since there are few publications for the photocatalytic properties of β-Ga2O3 the obtained results contribute to better understanding of the photocatalytic effect of this material on toxic dye red amaranth. Moreover, it is shown that β-Ga2O3 is a very efficient photocatalyst leading to high percentage degradation of dyes for relatively short periods. For example, the degradation of red amaranth and rhodamine B toxic dyes under UV light irradiation reached 97% and 100% after 165 and 120 min, respectively.
Multiple orthogonal polynomials, 𝑑-orthogonal polynomials, production matrices, and branched continued fractions
Authors: Sokal Alan
Published: April 2024

I analyze an unexpected connection between multiple orthogonal polynomials,

d
d

-orthogonal polynomials, production matrices and branched continued fractions. This work can be viewed as a partial extension of Viennot’s combinatorial theory of orthogonal polynomials to the case where the production matrix is lower-Hessenberg but is not necessarily tridiagonal.
The association between cannabis use and neuroimaging measures in older adults: findings from the UK biobank
Authors: Vered Shiraz , Sznitman Sharon , Weinstein Galit
Published: April 2024

Background

Cannabis use has increased in recent years. However, the long-term implications of cannabis use on brain health remain unknown. We explored the associations of cannabis use with volumetric brain magnetic resonance imaging (MRI) measures in dementia-free older adults.

Methods

This cross-sectional and longitudinal study included dementia-free participants of the UK Biobank aged ≥60 years. Linear regression models were used to evaluate the association of cannabis use and patterns of use with volumetric brain MRI measures. The association between cannabis use and change in brain MRI measures over time was also tested. All models were adjusted for potential confounders.

Results

The sample included 19,932 participants (mean age 68 ± 5 years, 48% men), 3,800 (19%) reported lifetime use of cannabis. Cannabis use was associated with smaller total, white, grey and peripheral cortical grey matter volumes (B = −6,690 ± 1,157; P < 0.001, B = −4,396 ± 766; P < 0.001, B = −2,140 ± 690; P = 0.002 and B = −2,451 ± 606; P < 0.001, respectively). Among cannabis users, longer duration of use was associated with smaller total brain, grey and cortical grey matter volumes (B = −7,878 ± 2,396; P = 0.001, B = −5,411 ± 1,430; P < 0.001, B = −5,396 ± 1,254; P < 0.001, respectively), and with increased white matter hyperintensity volume (B = 0.09 ± 0.03; P = 0.008). Additionally, current vs. former users (B = −10,432 ± 4,395; P = 0.020) and frequent versus non-frequent users (B = −2,274 ± 1,125; P = 0.043) had smaller grey and cortical grey matter volumes, respectively. No significant associations were observed between cannabis use and change in brain MRI measures.

Discussion

Our findings suggest that cannabis use, particularly longer duration and frequent use, may be related to smaller grey and white matter volumes in older ages, but not to late-life changes in these measures over time.