bluuebunny/crossref_metadata_2025 huggingface dataset:
First test beam of the DMAPS-based proton tracker at the pMBRT facility at the Curie Institute
Authors: Granado-González M , Price T , Gonella L , Moustakas K , Hirono T , Hemperek T , De Marzi L , Patriarca A
Published: October 2024

Objective. Proton radiotherapy’s efficacy relies on an accurate relative stopping power (RSP) map of the patient to optimise the treatment plan and minimize uncertainties. Currently, a conversion of a Hounsfield Units map obtained by a common x-ray computed tomography (CT) is used to compute the RSP. This conversion is one of the main limiting factors for proton radiotherapy. To bypass this conversion a direct RSP map could be obtained by performing a proton CT (pCT). The focal point of this article is to present a proof of concept of the potential of fast pixel technologies for proton tracking at clinical facilities. Approach. A two-layer tracker based on the TJ-Monopix1, a depleted monolithic active pixel sensor (DMAPS) chip initially designed for the ATLAS, was tested at the proton minibeam radiotherapy beamline at the Curie Institute. The chips were subjected to 100 MeV protons passing through the single slit collimator (

0.4
×
20

mm2) with fluxes up to

1.3
×

10
7

p s−1 cm−2. The performance of the proton tracker was evaluated with GEANT4 simulations. Main results. The beam profile and dispersion in air were characterized by an opening of 0.031 mm cm−1, and a

σ
x

=
0.172

mm at the position of the slit. The results of the proton tracking show how the TJ-Monopix1 chip can effectively track protons in a clinical environment, achieving a tracking purity close to 70

%

, and a position resolution below 0.5 mm; confirming the chip’s ability to handle high proton fluxes with a competitive performance. Significance. This work suggests that DMAPS technologies can be a cost-effective alternative for proton imaging. Additionally, the study identifies areas where further optimization of chip design is required to fully leverage these technologies for clinical ion imaging applications.
PICASSO: a universal brain phantom for positron emission tomography based on the activity painting technique
Authors: Shanina Ekaterina , Spencer Benjamin A , Li Tiantian , Huang Bangyan , Qi Jinyi , Cherry Simon R
Published: October 2024

Objective. This study presents a universal phantom for positron emission tomography (PET) that allows arbitrary static and dynamic activity distributions of various complexities to be generated using a single PET acquisition. Approach. We collected a high-statistics dataset (with a total of 22.4 × 109 prompt coincidences and an event density of 2.75 × 106 events mm−3) by raster-scanning a single plane with a 22Na point source mounted on a robotic arm in the field-of-view of the uEXPLORER PET/CT scanner. The source position was determined from the reconstructed dynamic frames. Uniquely, true coincidences were separated from scattered and random events based on the distance between their line-of-response and the known source location. Finally, we randomly sampled the dataset to generate the desired activity distributions modeling several different phantoms. Main results. Overall, the target and the reconstructed phantom images had good agreement. The analysis of a simple geometric distribution showed high quantitative accuracy of the phantom, with mean error of <–3.0% relative to the ground truth for activity concentrations ranging from 5.3 to 47.7 kBq ml−1. The model of a high-resolution 18F-fluorodeoxyglucose distribution in the brain illustrates the usefulness of the technique in simulating realistic static neuroimaging studies. A dynamic 18F-florbetaben study was modeled based on the time-activity curves of a human study and a segmented brain phantom with no coincidences repeating between frames. For all time points, the mean voxel-wise errors ranged from –4.4% to –0.7% in grey matter and from −3.9% to +2.8% in white matter. Significance. The proposed phantom technique is highly flexible and allows modeling of static and dynamic brain PET studies with high quantitative accuracy. It overcomes several key limitations of the existing phantoms and has many promising applications for the purposes of image reconstruction, data correction methods, and system performance evaluation, particularly for new high-performance dedicated brain PET scanners.
Performance evaluation of an inorganic optical fibre dosimeter for use in external beam radiotherapy with pulsed beams
Authors: McDonnell C , McLaughlin O , McGarry C K , Hounsell A R , O’Keeffe S , Lewis E , Prise K M
Published: October 2024

Objective. Optical fibre dosimeters (OFDs) offer great promise for real-time in vivo dose measurement in radiation-based treatment modalities such as radiotherapy and brachytherapy. This is attributed to their many useful qualities such as high spatial resolution and sensitivity. However, there are several requirements that an optical fibre dosimeter must meet to be acceptable for dose measurement in a specified treatment modality. In this work, the dosimetric performance of a novel optical fibre dosimeter for use in external beam radiotherapy is presented. Approach. The dosimeter was characterised for photon beam energies between 6–15 MV using a Varian TrueBeam Linac at dose rates between 100–2400 MU/min and assessed based on its repeatability, dose dependence, dose rate dependence, energy dependence and dose-per-pulse dependence. Main Results. The results demonstrated excellent short-term repeatability of 0.3

%

, good linearity in response (

R

2

>

0.9997), and minor dose rate dependence between 0.53%–2.49% for all beam qualities investigated. As the scintillator of the OFD is non-water equivalent, Monte-Carlo-TOPAS simulations were used to calculate the absorbed dose energy dependence. A dose-per-pulse dependence was also investigated and compared with dosimetry measurements made with an ionisation chamber and simulated from the treatment planning system. An over-response of 20

%

was found at the lowest investigated dose-per-pulse, and an under-response of 34

%

was found at the highest investigated dose-per-pulse. This is believed to be due to an intrinsic energy dependence making this type of OFD unsuitable for external beam radiotherapy dosimetry. Significance. The OFD evaluated in this work was primarily designed for high-dose-rate brachytherapy whereas this study includes the first measurements made in external beam radiotherapy and highlights the challenges of transferability of the dosimeter to a different radiation source.
Multi-functional periodically heterogeneous structures for energy harvesting and vibration attenuation-effects of piezoelectricity and shunting circuits
Authors: Hosseinkhani A , Rohan E
Published: October 2024

We explore a kind of metamaterial plate structures intended for simultaneous energy harvesting and vibration control. These structures are designed using a periodically perforated piezoelectric plate (the matrix) with elastic inclusions situated in the holes and serving for the resonators. The design options comprise two- and three-phase configurations related to the mechanical connection between the matrix and inclusions. By introducing a singularity—the focal spot created as a defect in the perfectly periodic structure and using the theory of super-cell, an enhanced piezoelectric energy harvester is obtained. It is observed that such a meta-structure serves as a dual-purpose system: efficiently capturing vibrational energy at a focal spot while maintaining the overall vibration attenuation throughout the structure. The band gap analysis based on the Bloch’s wave decomposition theory shows that by concentrating energy and halting vibration propagation, approximately 10 times energy harvesting enhancement and a remarkable 100 dB reduction in vibrations are achieved simultaneously. Besides the passive response of these meta-structures, we consider its extension by an external electric circuit (EC). Such modified configurations enable to exploit ‘actively’ the piezoelectric plate property to transmit the mechanical response between two, or more distant locations. Due to nonlocal interactions introduced by means the controllable EC, we consider optimization of the EC impedance to reduce the vibrations at a selected location of the whole structure without any external energy supply. The computational study discovers perspectives and benefits of designing such active self-powered meta-structures.
Dynamical phase transitions, caustics, and quantum dark bands
Authors: Link Valentin , Strunz Walter T , O’Dell D H J
Published: October 2024

We provide a new perspective on quantum dynamical phase transitions (DPTs) by explaining their origin in terms of caustics that form in the Fock space representation of the many-body state over time, using the fully connected transverse field Ising model as an example. In this way we establish a connection between DPTs in a quantum spin system and an everyday natural phenomenon: The dark band between the primary and secondary bows (caustics) in rainbows known as Alexander’s dark band. The DPT occurs when the Loschmidt echo crosses the switching line between the evanescent tails of two back-to-back Airy functions that dress neighbouring fold caustics in Fock space and is the time-dependent analogue of what is seen as a function of angle in the sky. The structural stability and universal properties of caustics, as described mathematically by catastrophe theory, explains the generic occurrence of DPTs in the model and suggests that our analysis has wide applicability. Based on our thorough analytical understanding we propose a protocol which can be used to verify the existence of a DPT in a finite system experiment.
Nonlinearity-induced symmetry breaking in a system of two parametrically driven Kerr-Duffing oscillators
Authors: Hellbach F , De Bernardis D , Saur M , Carusotto I , Belzig W , Rastelli G
Published: October 2024

We study the classical dynamics of a system comprising a pair of Kerr-Duffing nonlinear oscillators, which are coupled through a nonlinear interaction and subjected to a parametric drive. Using the rotating wave approximation, we analyze the steady-state solutions for the amplitudes of the two oscillators. For the case of almost identical oscillators, we investigate separately the cases in which only one oscillator is parametrically driven and in which both oscillators are simultaneously driven. In the latter regime, we demonstrate that even when the parametric drives acting on the two oscillators are identical, the system can transition from a stable symmetric solution to a broken-symmetry solution as the detuning is varied.
Fractal analyses of AlxGa1−xN thin film surfaces on AlN at different annealing temperatures
Authors: Bayırlı Mehmet , Zeybek Orhan , Ilgaz Aykut
Published: October 2024

The determination of heteromorphological structures formed on the surface during annealing of AlxGa1−xN thin film grown on sapphire substrate using the metal organic chemical vapor deposition technique at different temperatures was investigated by fractal analysis method. The images of the surfaces of the thin films were taken by atomic force microscopy (AFM) at temperatures of 900, 1000, 1050 and 1200 °C respectively. AFM images were digitised in bitmap format according to the annealing temperatures. It was determined that the fractal dimensions obtained a linear correlation with the annealing temperatures. The results confirm the hypothesis that surface relaxation by the thermal action can produce fractal-like structures at particle or cluster boundaries. It is found that the observed cluster formation of superficial particles decreases as increasing temperature. The increase in temperature reduces the rate of superficial particle coating. To determine the surface roughness of the AlxGa1−xN thin film according to the annealing temperature, the AFM images were digitized in tagged image file format and the statistical root mean square, mean value, mean roughness, skewness and kurtosis values of the films were calculated. The roughness is a result of the thin film surface heteromorphology formed due to the specific annealing process. It is proved that the fractal dimensions of the AlxGa1−xN thin film increase as the annealing temperature rises. The particles coalesce on the surface and cluster in different types and sizes at each different annealing temperature, forming islets of different sizes. The skewness and kurtosis values show a different and irregular change.
Dynamic analysis of a modified Leslie-Gower model with Michaelis-Menten prey harvesting and additive allee effect on predator population
Authors: Mortuja Md Golam , Chaube Mithilesh Kumar , Kumar Santosh
Published: October 2024

In the current study, the dynamics of a Leslie-Gower model have been studied considering the Allee effect in the growth of the predator and the Michaelis-Menten type harvesting effect on the prey from biological and theoretical perspectives. Key findings highlight how these effects influence the existence of positive equilibria, with local stability properties and potential bifurcation behaviors examined using the center manifold theorem and linearization. Criteria for saddle-node bifurcation are established through Sotomayor’s theorem, while the direction and stability of Hopf bifurcation are explored via the first Lyapunov exponent. An optimal control model is developed to promote sustainable ecosystem development, utilizing the harvesting rate as a control parameter. Further, a few numerical simulations validate our significant findings using phase portrait diagrams.
Generalized flow-composed symplectic methods
for post-Newtonian Hamiltonian systems
Authors: Huang Shixiang , Zeng Kaiming , Niu Xinghua , Mei Lijie
Published: October 2024

Due to the nonseparability of the post-Newtonian (PN) Hamiltonian systems of compact
objects, the symplectic methods that admit the linear error growth and the near preservation of
first integrals are always implicit as explicit symplectic methods have not been currently found
for general nonseparable Hamiltonian systems. Since the PN Hamiltonian has a particular
formulation that includes a dominant Newtonian part and a perturbation PN part, we present the
generalized flow-composed Runge-Kutta (GFCRK) method with a free parameter λ to PN
Hamiltonian systems. It is shown that the GFCRK method is symplectic once the underlying RK method
is symplectic, and it is symmetric once the underlying RK method is symmetric under the setting
λ = 1/2. Numerical experiments with the 2PN Hamiltonian of spinning compact binaries
demonstrate the higher accuracy and efficiency of the symplectic GFCRK method than the underlying
symplectic RK method in the case of weak PN effect. Meanwhile, the numerical results also support
higher efficiency of the symplectic GFCRK method than the semi-explicit mixed symplectic method of
the same order.
Search for dark matter annihilation to gamma-rays from SPT-SZ selected galaxy clusters
Authors: Manna Siddhant , Desai Shantanu
Published: October 2024

We search for dark matter annihilation from galaxy clusters in the energy range from 1–300 GeV using nearly 16 years of Fermi-LAT data. For this purpose, we use 350 galaxy clusters selected from
the 2500 deg2 SPT-SZ survey. We model the dark matter distribution using the NFW profile for the main halo along with the Einasto profile for the substructure. The largest signal is seen for the cluster SPT-CL J2021-5257 with a significance of around 3σ. The best-fit dark matter mass and annihilation cross-section for this cluster are equal to (60.0 ± 11.8) GeV and ⟨σv⟩ = (6.0 ± 0.6) × 10-25 cm3 s-1 for the b̅ b annihilation channel. However, this central estimate is in conflict with the limits on annihilation cross-section from dwarf spheroidal galaxies, and hence cannot be attributed to dark matter annihilation. Three other clusters show significance between 2-2.5σ, whereas all the remaining clusters show null results. The most stringent 95% c.l. upper limit for the WIMP annihilation cross-section among all the clusters is from SPT-CL J0455-4159, viz. ⟨σv⟩ = 6.44 × 10-26 cm3 s-1 for m
χ = 10 GeV and b
b̅ annihilation channel.
A new solution for the observed isotropic cosmic birefringence angle and its implications for the anisotropic counterpart through a Boltzmann approach
Authors: Greco Alessandro , Bartolo Nicola , Gruppuso Alessandro
Published: October 2024

Cosmic Birefringence (CB) is a phenomenon in which the polarization of the Cosmic Microwave Background (CMB) radiation is rotated as it travels through space due to the coupling between photons and an axion-like field. We look for a solution able to explain the result obtained from the Planck Public Release 4 (PR4), which has provided a hint of detection of the CB angle, α = (0.30 ± 0.11)∘. In addition to the solutions, already present in the literature, which need a non-negligible evolution in time of the axion-like field during recombination, we find a new region of the parameter space that allows for a nearly constant time evolution of such a field in the same epoch. The latter reinforces the possibility to employ the commonly used relations connecting the observed CMB spectra with the unrotated ones, through trigonometric functions of the CB angle. However, if the homogeneous axion field sourcing isotropic birefringence is almost constant in time during the matter-dominated era, this does not automatically imply that the same holds also for the associated inhomogeneous perturbations. For this reason, in this paper we present a fully generalized Boltzmann treatment of this phenomenon, that is able, for the first time to our knowledge to deal with the time evolution of anisotropic cosmic birefringence (ACB). We employ this approach to provide predictions of ACB, in particular for the set of best-fit parameters found in the new solution of the isotropic case. If the latter is the correct model, we expect an ACB spectrum of the order of (10-15 ÷ 10-32) deg2 for the auto-correlation, and (10-7 ÷ 10-17) μK·deg for the cross-correlations with the CMB T and E fields, depending on the angular scale.
Impact of spatially varying transport coefficients in EMC3-Eirene simulations of W7-X and assessment of drifts
Authors: Bold David , Reimold Felix , Niemann Holger , Gao Yu , Jakubowski Marcin , Killer Carsten , Winters Victoria R. , Maaziz Nassim ,   the W7-X Team
Published: October 2024

Modelling the scrape-off layer of a stellarator is challenging due to the complex magnetic 3D geometry. The here presented study analyses simulations of the scrape-off layer (SOL) of the stellarator Wendelstein 7-X (W7-X) using spatially varying diffusion coefficients for the magnetic standard configuration, extending our previous study (Bold et al 2022 Nucl. Fusion
62 106011). Comparing the EMC3-Eirene simulations with experimental observations, an inconsistency between the strike-line width (SLW) and the upstream parameters was observed. While to match the experimental SLW a particle diffusion coefficient D ≈ 0.2 m2 s−1 is needed, D ≈ 1 m2 s−1 is needed to get experimental separatrix temperatures of 50 eV at the given experimental heating power. We asses the impact of physically motivated spatially varying transport coeffients. Agreement with experimental data can be improved, but various differences remain. We show that drifts are expected to help overcome the discrepancies and, thus, the development of SOL transport models including drifts is a necessary next step to study the SOL transport of the W7-X stellarator.
Virtual impedance optimization control strategy for wind turbine grid-forming converters in weak grid
Authors: Zhuang Shenglun , Kong Xiangmei , Sun Sujuan
Published: October 2024

Grid forming(GFM) technology is key to the effective consumption and grid-friendly integration of large-scale wind power. However, as the new type of power system sees a high penetration of new energy sources and a decrease in circuit capacity, leading to systems exhibiting weak grid characteristics, this paper studies the adaptive characteristics of grid-forming wind turbine converters under weak grid conditions. It investigates the dynamic relationship between power coupling characteristics and the system impedance ratio based on the virtual impedance method and proposes an impedance optimization method to improve the power decoupling accuracy and dynamic response capability of grid-forming converters. The research results show that the grid-forming controller can operate stably under weak grid conditions, an increase in grid impedance ratio leads to stronger power coupling intensity, and the voltage support capability of grid-forming converters weakens. The simulation verifies that the virtual impedance optimization strategy proposed in this paper can effectively improve the power coupling characteristics of the grid-forming converter and enhance the converter’s dynamic response performance under weak grid conditions.
Real-time voltage control of centralized and distributed coordination in active distribution network under multiple coupling
Authors: Dou Wenlei , Tong Yongji , Song Zhuoran , Zhang Mingli , Lu Sichen , Zhu Hongbo
Published: October 2024

At present, the “source-load interaction” distribution network operation mode has gradually replaced the “source-load operation” mode. The uncertainty and volatility of the distribution system have been enhanced, the controllability has been weakened, the voltage fluctuations have been frequent, and the power quality has been decreased. Voltage regulation is crucial to fully absorbing new energy generation and improving the operation safety of the active distribution network. To solve the problem of real-time control of distribution networks, this paper proposes a distributed voltage control method of active distribution networks with global sensitivity, establishes a distributed communication mechanism, and builds a distributed forward push-back communication rule to transfer power and voltage information between nodes. The global sensitivity of voltage, active power, and reactive power is used for real-time, independent, and effective control of multiple devices at each node, and the distributed control process is simulated according to actual production conditions. Furthermore, the centralized and decentralized real-time voltage control methods are proposed, and the centralized and distributed methods are implemented in medium voltage primary distribution network (MVPN) and low voltage secondary distribution network (LVSN), respectively, to play the advantages of high computing efficiency and fast control response. Based on model predictive control (MPC), intra-day rolling time scale voltage regulation is constructed, and second-level control is used to adapt the MPC results, finally promoting the optimal scheduling and rapid response of various controllable flexible resources in the multi-level active distribution network.
Harmonic characteristics analysis and power quality requirements of Light-Emitting Diode lamps used in nuclear power plant lighting system
Authors: Lu Jinjun , Jiang Geling
Published: October 2024

This article conducts an in-depth study of the application of LED (Light-Emitting Diode) lamps in nuclear power plant lighting systems and conducts a comprehensive analysis of its impact on the power quality of the plant’s low-voltage AC power system. First of all, through a detailed discussion of the harmonic characteristics of LED lamps and the power quality requirements of nuclear power plants, it is pointed out that the harmonics of LED lamp drivers will inevitably have an impact on the power quality of low-voltage AC power systems. Therefore, the harmonic characteristics of LED lamps must comply with certain constraints. Subsequently, the application of LED lamps under different capacity transformers was analyzed and combined with relevant standards and specifications, and application suggestions for LED lamps in nuclear power plant lighting systems were put forward. Finally, measures to improve the total harmonic distortion rate of LED lamp current were discussed, emphasizing the importance of power factor correction technology. In summary, this article provides important reference and guidance for the application of LED lamps in nuclear power plants, helping to ensure the safe and stable operation of nuclear power plants.
Developing the blue and circular economy through visionary eco-leadership in the fish waste processing agro-industry
Authors: Irawan NC , Widodo ZD
Published: October 2024

Significant environmental pollution is caused by fish scale waste, but its utilization is still limited, so it has the potential to cause food waste which is detrimental to the environment. Eco-leadership is essential in changing people’s behavior by teaching them to see waste scales as a source of value-added materials, creating a sustainable economy, and improving the quality of the surrounding environment. This study explores the relationship between visionary eco-leadership from employee perceptions and its influence on developing a blue and circular economy in the fish waste processing agro-industry. This study used a purposive location determination method with a population of employees of an agro-industrial fish waste processing company in Boyolali Regency and a sample of 60. Data analysis used structural equations and the Partial Least Square (PLS) method. This study concludes that visionary leaders who care about the environment in the fish waste processing agro-industry positively and significantly influence the development of a blue and circular economy.
Effect of supplement addition on fitness media on the physiological condition and survival of transport freshwater crablets (Parathelphusa convexa De Man, 1879)
Authors: Chofifakh U , Sulistiono S , Affandi R , Wildan DM , Widigdo B , Ervinia A
Published: October 2024

The population of freshwater crablets in nature has decreased due to a decrease in: the area of rice fields, discharge, and water quality. Domestication, pollution control, and catching freshwater crablets are important to maintain their sustainability. One effort to reduce the rate of exploitation is to save on the use of seeds in cultivation activities, especially by reducing mortality during transportation and initial post-transportation maintenance. This study aims to analyze the effect of adding supplements to the growing media before and after transportation on the physiological condition, survival and condition factors of freshwater crablets (P. convexa). This research was conducted from March to May 2023 at the Aquatic Animal Physiology Laboratory. This study used a completely randomized design (CRD) with one dose of the best supplement (10 ppm) and 10 replicates. The study used analysis of variance (ANOVA) test for each parameter measured least and significant difference (LSD) test with 95% confidence interval. Freshwater crablets were given four treatments, namely A: (TS-TS), B: (TS-DS), C:(DS-DS), and D: (DS-TS). The results showed that application of supplements with a dose of 10 ppm in the fermentation media before and after transportation (treatment C: DS-DS) was the best with blood glucose levels of 30.50 mg/dL and survival of 70%. The condition factor values of freshwater crablets in the four treatments tended to decrease at the end of the observation.
Growth patterns and condition factors of introduced crayfish population in Rawa Aopa-Watumohai National Park
Authors: Nur A I , Ariyatni N , Ketjulan R , Kamri S
Published: October 2024

Crayfish as an introduced species is now the primary catch of fishermen in the marsh ecosystems of Rawa Aopa-Watumohai National Park. Despite its significant economic impact on the area, caution is advised due to this species’ high ability to infiltrate a new ecosystem as a competitor, predator, pathogen, or parasite carrier. However, preliminary research is necessary to determine its basic biological elements, such as growth patterns and condition factors, as there is currently no information available for the ecosystem. A simple random sampling technique was used with 24 traps at 3 sites to catch the 810 total crayfish. The analysis results showed that the carapace length range was 19.5-99.4 mm predominantly by middle-size crayfish (44.4-60.9 mm). Based on the length-weight relationship by sex and month, the growth pattern was found negatively allometric (b:1.59-2.31) with strong correlations between length and weight (>0.9) indicating that the crayfish was thin. The result of the condition factor analysis by sex and month also showed that the crayfish was not plump (K:1.01–1.07). The crayfish’s body in the national park was shorter, thin, underweight, or generally unhealthy compared to crayfish from other areas of Indonesia. These results suggested that the population was likely suppressed by natural or human-related factors, necessitating a further study of the species’ other biological aspects.
Mapping the habitat distribution of horseshoe crabs (Tachypleus gigas) in Pamekasan, Madura Island, Indonesia
Authors: Ramadhan F , Maulana P , Darmawan D
Published: October 2024

Horseshoe crabs, often known as Belangkas or Mimi, is one of the ancient marine faunas with protected conservation status. Horseshoe crabs are distributed in coastal waters of Indonesia of the islands of Sumatra, Java, Kalimantan, and Sulawesi, which are often caught as bycatch. Horseshoe crabs’s bloods were uniquewhich contain amebocytes as a test material for the presence of endotoxin bacteria. The purpose of this study was to identify the species of horseshoe crabs and to analyze environmental conditions, as well as the distribution of horseshoe crabs in the coastal waters of Pamekasan, Madura Island. This study was conducted in June 2023 by collecting data from crab fishers. ArcGIS was applied to delineate the distribution of horseshoe crab. The identification results showed that there was one species horseshoe crab of the Tachypleus gigas in the waters of Polagan Village, Galis District, Pamekasan Regency. The environmental condition of the waters in Polagan Village, Galis District, and Pamekasan Regency was relatively good. Habitat mapping is one way to protect these animals from the threat of extinction and support conservation efforts.
Susceptibility analysis of cuttlefish (Sepia recurvirostra) to blue swimming crab fisheries in Keboromo village, Pati
Authors: Rizal ES , Mustabiq K , Satria MB
Published: October 2024

The coast of Pati Regency and its surroundings are one of the crab sanctuaries on the north coast of Java that have tended to increase in the last decade. The purpose of this study was to analyze the level of vulnerability of cuttlefish (Sepia recurvirostra) to crab fisheries in Keboromo Village, Pati. The sample used was the catch of cuttlefish by blue-swimming crab fishermen in Keboromo Village during the research period of June 2023. The productivity value was obtained from the literature, while the parameters of vulnerability were obtained from interviews with local fishermen, which were analyzed using productivity and susceptibility analysis (PSA). The average length of the cuttlefish was 80–125 mm, with a weight of 25–61.6 grams. While having a PSA score of 1.71 with an MSC score of 84.7 (limit > 80). The smaller PSA value indicates the level of vulnerability is still relatively low, so fishing activity pressure has not had a serious impact on the potential sustainability of cuttlefish.
Distance of fishing ground against blue swimming crab (Portunus pelagicus) catches using a gillnet in Gresik, East Java, Indonesia
Authors: Maulana P , Ramadhan F , Maulydya FYD
Published: October 2024

Information on fishing grounds is crucial in efforts to manage blue swimming crab capture fisheries. The further away the fishing location, the higher cost risk. The purpose of this study is to determine differences in catches and biological characteristics of crabs caught by the crab fishermen using gillnets on 0–2 miles and 5-7 miles from November 2022 to January 2023 in the waters of Mengare Island, Bungah District, Gresik Regency, East Java Province. Descriptive analysis and multivariate analysis of variance (MANOVA) were used to explain the biological characteristics of the blue swimming crabs and differences in the effect of fishing ground distance on crab catches. The results showed that the total yield of 2478 female crabs and 4360 male crabs with details at a distance of 0–2 miles was 1701 males and 925 females, while at a distance of 5-7 miles, there were 2659 males and 1553 females. Most crabs with mature level were found at 0–2 miles and 5-7 miles. The distance to the fishing ground affects the average width, average weight, and number of male crabs. Distance and fishing ground differences can affect the diversity of crab biological characteristics.
Catch composition and fishing season of blue swimming crab using a collapsible trap in Pemalang coastal water, Central Java
Authors: Arofah N , Sari MP , Ervinia A
Published: October 2024

The blue swimming crab (Portunus pelagicus) is an economically important fishery resources that has penetrated the export market that requires proper management. Pemalang Regency is still entirely dependent on natural catches, so information on seasonal patterns of blue swimming crab fishing is essential for fishermen to support the efficiency and effectiveness of the fishing activity. This research was conducted in Danasari village, Pemalang sub-district, in January–December 2022 with the aim of determining the composition of collapsible trap catches based on the crab fishing season in the waters of Pemalang Regency. Danasari fishermen classify the blue swimming crab fishing season into two, the west season starts in November–May (high rainfall), and the east season starts in June–October (low rainfall). The survey method was performed by collecting data of blue swimming crab catch as the main target and bycatch. Carapace width of the blue swimming crab was also measured. The data obtained was analyzed descriptively using Microsoft Excel 2010 software. The results showed that the catch composition of collapsible traps in Pemalang consisted of crustaceans, fish, and mollusks. The best season to catch blue swimming crabs was during the west season because the catch is more stable than during the east season.
The impact of construction of an integrated shell waste management site on social, economic, and environmental aspects in Cirebon, West Java
Authors: Sari M P , Arofah N , Satria M B , Nugraha B A
Published: October 2024

The concept of a blue economy encourages business growth and efficient investment while protecting the environment by making the most of spending and financing resources that will increase economic growth and improve people’s lives. Crab shell is one of the industrial wastes of the pasteurization of crab meat, which is growing along with the demand for exports. Direct stockpiling of crab shells creates an unpleasant odor and makes access difficult for collectors of crab shells. Therefore an Integrated Shell Waste Treatment Site (ISWTS) is very important to build to support the blue economy principle, where all economic operations are zero-waste, clean, and efficient. The purpose of the study is to examine the impacts of ISWTS development on the social, economic, and environmental aspects in the Cirebon Regency. Data was collected through focus group discussions and interviews with eight miniplant owners and one supplier of crab shells. Qualitative descriptive and triangulation were applied to analyze the increase in earnings in crab industry laborers, the impact of individual and group capabilities, the strength of partnership partners, and labor absorption. The result shows there is an increase in earnings, which can contribute to the fisheries sector to the Gross Regional Domestic Product (PDRB) in Cirebon Regency through the application of the website for making orders operated by laborers and customers. This business makes more strong connections among miniplants, dryer shells, and TPLCT side through labor absorption primarily to involved and utilize at TPLCTThe study findings show that the community supports the construction of the TPLCT because it employs many people, but the building must be carried out far from residential areas.
Multi scale analysis of social-ecological system of lobster (Panulirus spp.) fisheries in the Gunungkidul waters, Yogyakarta
Authors: Nugraha E C P , Adrianto L , Krisanti M , Effendi H , Yulianto G
Published: October 2024

Lobster is a high-value fisheries commodity in Gunungkidul Regency. Lobster resource management in the waters of Gunungkidul Regency has not been well identified in the social-ecological system (SES) framework. This study aims to describe and analyze the dynamics of interrelationships between the social-ecological system components of lobster fisheries in Gunungkidul Regency, which consists of the subsystem of resource systems (RS), resource units (RU), resource actors (RA), and resource governance (RG) and their interrelationships within and between subsystems to formulate a sustainable lobster management strategies in the waters of Gunungkidul Regency. This research was conducted from November 2022 until January 2023. The results of this study have indicated a dynamic interaction between the SES components of lobster fisheries. RS and RA are the SES components with the highest influence, so the slightest changes in RS and RA can cause co-evolutive changes to all the SES components of lobster fisheries in the waters of Gunungkidul Regency.
Mud crab (Scylla spp) resources status in Hoat Sorbay Bay, Southeast Maluku Regency
Authors: Abrahamsz J , Makailipessy M M , Thenu I M , Ingratubun M A
Published: October 2024

Ohoi Evu is one of the villages in Southeast Maluku Regency where fishermen utilize mud crab resources. Mud crab fishing areas are concentrated in the waters of Hoat Sorbay Bay. Information on mud crab fisheries in these waters is relatively limited, so the application of sustainable management efforts is still difficult to develop. This study aims to determine the status of mud crab resources through the adoption of a fishery management model with an ecosystem approach and formulate recommendations for improving its management. Data collection was carried out through surveys of fishing operations, interviews, and participatory mapping. This research was conducted for 13 months, starting from January 2021 to January 2022, at Hoat Sorbay Bay. The research focus is on the Wear Manun Joint Business Group (KUB) in Ohoi Evu. The indicators observed included CPUE, mud crab size trends, the proportion of juveniles caught, species composition, range collapse, and endangered, threatened, and protected (ETP) species caught. Descriptive statistical analysis, CPUE, and indicator analysis were carried out using a multi-criteria analysis approach through the assessment of composite indexes and flag model visualization. The results showed that the management status of the mud crab fishermen Ohoi Evu in Hoat Sorbay Bay was in the moderate category (yellow) with a composite value of 2.50. CPUE indicators and species composition were good categories with a score of 3 (green). Trend indicators for fish size, proportion of juveniles, ETP species, and range collapse are in the moderate category with a score of 2 (yellow).
The exploitation status and spawning potential ratio of blue swimming crab (Portunus pelagicus) in North Natuna Sea, Indonesia
Authors: Fauzi M , Pane A R P , Taufik M , Widyastuti H , Mardlijah S , Hufiadi H , Yusuf H N , Prihatiningsih P , Noegroho T , Chodrijah U
Published: October 2024

Blue Swimming Crab (BSC) has been exploited in various areas, including the North Natuna Sea, because of its high selling value and potential as an export commodity. Overexploitation can threaten its sustainability. Therefore, information is needed regarding population status and spawning potential, particularly in the North Natuna Sea. This research was performed over three years, from April to December 2018, February to November 2019, and March to December 2020. A total of 4960 individuals of BSC samples ranged in size from 60 to 160 mm, with 115 mm being the most dominant. BSC exploitation in this water has reached E = 0.6, indicating that it has been overfished. The SPR value obtained was 19 percent. Even though there is high fishing pressure, the spawning potential of crabs is relatively high. Appropriate management policies are needed to maintain their spawning potential, including limiting the catchable size to a minimum of 60 grams and a policy of closing spawning locations.
Determining demersal fisheries status in fisheries management arena (FMA) 712 under data limited situation
Authors: Natsir M , Adnina G S N , Rizal D R , Agustina S , Darmono O P , Hartati I D. , Rosdiana A , Retnoningtyas H , Yulianto I
Published: October 2024

Demersal fisheries in FMA 712 have been established since the early 1950’s, industrialization in demersal fisheries was started on 1970’s with the operation of trawl fleets in Java Sea. The exploitation continued until the 1980s when the Trawl Ban regulation was enacted. According to historical statical data from 1980 the number of demersal fishing fleets are still dominating and endangered the sustainability of demersal fish stock in FMA 712. This study presented alternatives approaches to determining demersal fisheries status in FMA 712 using the Bayesian surplus production model (cMSY) and Length-Based Spawning Potential Ratio (LBSPR). The cMSY analysis was conducted using time series production data and known CPUE represent the area in FMA 712 and the LBSPR model was conducted using the life-history parameters and the length frequency data. The results show that current demersal fisheries condition is overexploited, points of estimation of the Biomass condition based on 1980-2022 data: B/BMSY 0,803, F/FMSY 1,75 and MSY 323.000 ton. Additionally, the spawning potential ratio (SPR) of the dominant demersal fish species (Lutjanus malabarius and Portunus pelagicus) was lower than the limit reference point (<0,20), indicating overexploited. This study demonstrates that alternatives approaches could be applied to limited data fisheries and provide useful and robust recommendations.
The role of women in the blue swimming crab fisheries supply chain from gender perspective in Pamekasan
Authors: Qomariyah L , Arisandi A , Fairuz N
Published: October 2024

The blue swimming crab (Portunus pelagicus) fishery industry bring positive impact onwomen in coastal areas by providing livelihood opportunities through active involvement in various gender roles, both in preparation and post-capture processes as well as in the production chain. This study aimed to analyze the roles of women in the crab fishing supply chain. This study was conducted in June 2023 at Pagagan Village, Pademawu District, Pamekasan Regency. The research employed interview methods, field observation, and secondary data sources, including articles and journals. Six respondents participated in the study, representing fishermen’s wives, mini-plant owners, crab pickers, and crab suppliers. Results showed that fishermen’s wives play a significant role in marketing and selling the crab catch, as well as assisting their husbands in making and repairing fishing gear. In the case of crab suppliers, women or housewife contributed in weighing and boiling the crabs. At the mini-plant level, women play the main role as pickers in sorting and stripping process, while the mini-plant owner supervises the overall process. The study highlighted the substantial contribution of women in coastal areas to the local community, demonstrating a strong reliance on marine resources, which fluctuate with the seasons. Additionally, the income earned by coastal women significantly contributes to their families finances, thereby enhancing their household’s economic condition.
Assessment on demersal fisheries status in the FMA 573 under data-limited situation: A combination of statistic and CPUE data as inputs for bayesian surplus production model
Authors: Agustina S , Azizah Y , Marliana I , Natsir M , Hartati I D , Darmono O P , Rosdiana A , Retnoningtyas H , Yulianto I
Published: October 2024

Demersal stock potential, total allowable catch (TAC), and exploitation level status in the FMA 573 were assessed and determined by the National Commission of Stock Assessment (KOMNASKAJISKAN) through Ministerial Decree No. 19/2022. However, the fisheries status, i.e., the biomass level concerning the BMSY and the effort level compared to FMSY, was not completely determined. This study demonstrated the alternative approach to determining fisheries status under limited data. Statistical time series production and existing CPUE data were used to perform the Bayesian Surplus Production Model (cMSY). Based on the results, the stock of demersal fisheries in FMA 573 is overexploited, whereas the F/FMSY and B/BMSY are>1 and <1, respectively. The situation needs concern from all stakeholders. Rebuilding the stock formulation scheme through harvest strategy development for demersal fisheries in FMA 573 must be prioritized to ensure the sustainability of the stock and the fisheries business.
Refractive index sensing characteristics of PCF-SPR based on dual-plasmon materials
Authors: Ying Yu , Shang Tong , Gao Zhijun , Si Guangyuan
Published: October 2024

In this paper, a photonic crystal fiber (PCF) refractive index sensor based on surface plasmon resonance with dual plasmonic materials (indium tin oxide and gold) is proposed. We innovatively designed a dual-core PCF structure and pore arrangement effectively enhancing the coupling effect. Using two different plasma materials, phase matching is achieved at two different wavelengths for the evanescent and surface plasmon waves, resulting in dual resonance peaks. The refractive index sensing is accomplished by measuring the dual-peak resonance shift, which expands the detection wavelength and RI detection ranges. The sensor can detect analytes with refractive indices ranging from 1.32 to 1.43 at wavelengths between 0.4 µm and 1.4 µm. We optimized the PCF structure and studied the sensing performance of the sensor, improving its sensitivity. Simulation results indicate that the designed PCF sensor exhibits outstanding maximum dual-peak shift sensitivity, reaching up to 28 000 RIU−1, along with maximum amplitude sensitivity and wavelength sensitivity of 18 500 RIU−1 and 34 500 RIU−1, respectively, in the direction of y-polarization. Furthermore, the sensor achieves high resolution, and the figure of merit (FOM) values can reach up to 5.134 × 10−7 and 2758. Consequently, the proposed sensor can provide high-precision and extensive-range measurements of solution refractive indices within the visible and infrared light spectrum, and it holds potential application prospects in numerous fields, such as food safety testing and chemical substance detection.
Roadmap on basic research needs for laser technology
Authors: Kling Matthias F , Menoni Carmen S , Geddes Cameron , Galvanauskas Almantas , Albert Felicie , Kiani Leily , Chini Michael , Baker L Robert , Nelson Keith A , Young Linda , Moses Jeffrey , Carbajo Sergio , Demos Stavros G , Dollar Franklin , Schumacher Douglass , Tsai Janet Y , Fry Alan R , Zuegel Jonathan D
Published: October 2024

Motivated by the profound impact of laser technology on science, arising from an increase in focused light intensity by seven orders of magnitude and flashes so short electron motion is visible, this roadmap outlines the paths forward in laser technology to enable the next generation of science and applications. Despite remarkable progress, the field confronts challenges in developing compact, high-power sources, enhancing scalability and efficiency, and ensuring safety standards. Future research endeavors aim to revolutionize laser power, energy, repetition rate and precision control; to transform mid-infrared sources; to revolutionize approaches to field control and frequency conversion. These require reinvention of materials and optics to enable intense laser science and interdisciplinary collaboration. The roadmap underscores the dynamic nature of laser technology and its potential to address global challenges, propelling progress and fostering sustainable development. Ultimately, advancements in laser technology hold promise to revolutionize myriad applications, heralding a future defined by innovation, efficiency, and sustainability.