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Assessment of the Voltage Stability of the Power System Using Stability Indices and Artificial Neural Network
No full textVoltage stability indicators (VSI) play a significant role in determining the voltage stability of the power system. In order to forecast the voltage instability of the system using voltage stability indicators, this paper presents an implementation of an artificial neural network (ANN) based on the Levenberg Marquardt (LM) technique. In this context, the performance of three voltage stability indicators—the line voltage stability index (LVSI), the line stability index (Lmn), and the fast voltage stability indicator (FVSI) are compared. Based on the maximum active power loadability of load buses of the IEEE-14 and IEEE-118 bus systems, these indicators are used to assess their vulnerability. The LVSI, Lmn, and FVSI indices obtained from the Newton-Raphson method of the most severe buses of both test systems are compared with the forecasted values by the ANN method under base load to critical loading conditions. The real and reactive power losses of the lines associated with the most severe bus of the systems and totally real and reactive power losses of the systems are forecasted by the MATLAB NN toolbox under wide variations in active power loading. The Static Synchronous Compensator (STATCOM) is used to enhance the voltage of the most severe bus of the systems. The outcomes show that the methods for assessing voltage stability using ANN under the variation of the real power demand of the critical bus is highly précised and technically feasible
Determinants of Climate Change Adaptation Strategies Among Beef Cattle Farmers in East Java, Indonesia
No full textClimate change poses a serious challenge to the livestock sector in Indonesia, particularly for beef cattle farmers in East Java who face declining productivity due to droughts, shifting rainfall patterns, and rising temperatures. Adaptation is therefore essential to sustain livestock production and maintain household economic stability. This study analyses the socioeconomic factors influencing the choice of adaptation strategies among beef cattle farmers in response to climate change. A total of 300 farmers were selected using a multistage sampling technique, and data were collected through structured interviews. The analysis employed a Multinomial Logit Model to examine the effects of socioeconomic characteristics on the choice between on-farm, off-farm, and combined strategies. The results show that 63 % of farmers adopted off-farm strategies such as enterprise diversification and secondary employment, while 11 % focused on on-farm strategies, and 26 % combined both approaches. Education, primary occupation, and access to agricultural residues significantly influenced the choice of adaptation strategy. Higher education and better access to agricultural residues increased the likelihood of adopting off-farm strategies, whereas having livestock farming as the primary occupation reduced the tendency toward diversification. These findings highlight the importance of human, natural, and financial capital in shaping farmers' adaptive capacity. Strengthening farmers' skills and optimizing local resource utilization are key to promoting sustainable and inclusive adaptation in the livestock sector
The Inclusion Effect of Premix Additive in Joper Chicken Feed on The Morphological Body Size Characteristics
No full textThis research aimed to evaluate the inclusion effect of premix as a feed additive on the morphological characteristics of Joper chickens. The study used 192 Joper chickens reared from 21 to 56 days old. A Completely Randomized Design (CRD) with four treatments (T0: without premix, T1: 0.2% premix, T2: 0.3% premix, and T3: 0.4% premix) and six replications was applied. Observed variables included chest circumference, femur length, tibia length, shank length, and shank circumference. Data were analyzed using ANOVA and Duncan's Multiple Range Test for significant differences. Results showed that premix addition did not significantly affect all parameters (P>0.05), although improvements were observed in T1 and T2. The highest average values were found in T1 for shank length (86.46 mm) and shank circumference (4.13 cm), T2 for chest circumference (24.77 cm) and tibia length (114.29 mm), and T3 for femur length (83.70 mm). It can be concluded that premix addition does not significantly affect the body morphology of Joper chickens. Tibia length can serve as the best indicator in estimating body weight. Further studies are needed to evaluate long-term premix effects under different rearing conditions
Contrasting responses of
No full textThe widespread use of gadolinium‐based contrast agents (GBCAs) in medical imaging has raised concerns regarding their persistence in aquatic environments and potential ecotoxicological impacts. This study evaluated the effects of gadolinium (Gd) exposure, under environmentally relevant concentrations (10 µg/L), on two ecologically and economically important bivalves from the Ria de Aveiro, Ruditapes philippinarum and Mytilus galloprovincialis, while considering the role of salinity fluctuations (30 and 40) associated with climate change. Organisms were exposed for 14 days and a suite of biochemical markers was analysed, including antioxidant and biotransformation enzymes, energy metabolism, neurotoxicity, oxidative damage, and osmoregulation. Both species bioaccumulated Gd, with clams showing higher tissue concentrations at salinity 30 compared to 40, while mussels accumulated lower levels overall. Multivariate analyses revealed species‐specific biochemical responses. Clams primarily mobilised energy reserves and detoxification pathways under moderate salinity, while at hypersalinity they shifted towards antioxidant defenses (SOD, CAT), indicating oxidative stress management. In contrast, mussels showed an energy‐conserving profile: at salinity 30 Gd depressed SOD and induced CbEs, while at salinity 40 both antioxidant (SOD, CAT) and conjugation (GSTs) activities were reduced. Integrated Biomarker Response Index version 2 (IBRv2) peaked at salinity 40 (with and without Gd), confirming salinity as the dominant driver of response. These findings demonstrate that salinity modulates Gd toxicity and highlight interspecific differences in resilience strategies. Overall, the results underscore the importance of integrating emerging pollutants and climate‐related stressors in ecotoxicological assessments to better predict risks to marine ecosystems
Potential of
No full textCheese is a perishable dairy product that is highly susceptible to microbial spoilage and oxidative degradation, necessitating the development of sustainable bioactive packaging to enhance its shelf-life. This study aimed to evaluate the potential of Moringa oleifera extract (MOE) as a natural additive in gelatine whey protein edible film formulations. Fresh Moringa leaves were extracted using food-grade ethanol, and the resulting extract— characterized by high phenolic content (526.17 mg GAE/100 g), flavonoids (40.75 mg QE/100 g), nano-scale particle size (30 nm), and strong antioxidant capacity (IC50 43.6 ug/mL) was incorporated into edible film solutions at various concentrations. The physicochemical characteristics of the film solutions, including pH and total bacterial count (TBC), were assessed, alongside antimicrobial activity against Escherichia coli and Salmonella spp. The addition of MOE maintained film solution pH within 5.52-5.73 and reduced TBC compared to control, indicating improved microbial stability during preparation. Antimicrobial assays demonstrated clear inhibition zones for MOE-enriched films, with the highest activity observed at increased extract concentrations. These bioactive films also exhibited strong antioxidant behaviour consistent with the phytochemical profile of Moringa. The findings indicate that MOE effectively enhances both the antioxidant and antimicrobial properties of gelatine whey protein edible films without compromising physicochemical stability. Overall, Moringa oleifera extract shows significant potential as a natural additive for developing sustainable, biodegradable, and functional edible films suitable for cheese preservation. Future studies should explore the films performance during actual storage, their mechanical properties, and consumer acceptability for commercial application
Morphometric Characteristics of Doe Pote Goats Based on Population Structure in Bangkalan, Madura
No full textThis study investigated the morphometric characteristics and population structure of doe Pote goats, a local genetic resource originating from Bangkalan, Madura. Goats play an important role in traditional farming systems due to their adaptability and contribution to rural livelihoods, making the documentation of local breeds essential for conservation and development programs. A total of 253 does were evaluated using direct observation, body measurements, and interviews with goat owners. The variables analyzed included population structure as well as qualitative and quantitative traits. The population in Tragah District consisted of 62 male kids (11.27%), 107 female kids (19.45%), 32 young males (5.81%), 103 young females (18.72%), 10 bucks (1.81%), and 236 does (42.90%). The mean values of quantitative traits were: withers height 67.63 ± 4.39 cm, body length 68.71 ± 5.08 cm, chest girth 75.38 ± 5.82 cm, ear length 18.37 ± 1.88 cm, and body weight 36.30 ± 8.01 kg. Qualitative observations showed that Pote goats are predominantly characterized by a solid white coat color, relatively small body size, short pendulous ears, and straight horns. Morphometric comparisons with Kacang goats—currently the only breed with an established national standard (SNI)—indicated significant differences, confirming the distinctiveness of Pote goats. These findings highlight the potential of Pote goats as a promising local genetic resource that can be further developed and conserved to support livestock diversity and farmer welfare
The 3D pulsar magnetosphere with machine learning: First results
No full textContext. All particle-in-cell (PIC) simulations of the pulsar magnetosphere over the past decade show closed line regions that end a significant distance inside the light cylinder, and manifest thick, strongly dissipative separatrix surfaces instead of thin current sheets, with a tip that has a distinct pointed Y shape rather than a T shape.
Aims. We need to understand the origin of these results, which were not predicted by our earlier numerical simulations of the pulsar magnetosphere. To gain new insight into this problem, we set out to obtain the theoretical steady-state solution of the ideal 3D force-free magnetosphere with zero dissipation along the separatrix and equatorial current sheets. To achieve this goal, we developed a novel numerical method.
Methods. We solved two independent magnetospheric problems without current sheet discontinuities in the domains of open and closed field lines and adjusted the shape of their interface (the separatrix) to satisfy the pressure balance between the two regions. We obtained the solution using meshless physics-informed neural networks (PINNs).
Results. We present our first results for an inclined dipole rotator using the new methodology. We are able to zoom-in around the Y-point and inside the closed line region, and we observe new interesting features. This is the first time the steady-state 3D problem is addressed directly, rather than through a time-dependent simulation that eventually relaxes to a steady state.
Conclusions. We trained a neural network that instantaneously yields the three components of the magnetic field and their spatial derivatives at any given point. Our results demonstrate the potential of the new method to generate new solutions of the ideal pulsar magnetosphere
Detection of low-luminosity X-ray pulsations from the accreting millisecond pulsar IGR J17511−3057: An ever-thinning thread between bright accretion and subluminous states
No full textAfter nearly a decade in quiescence, the accreting millisecond pulsar IGR J17511−3057 displayed a new outburst on 2025 February 11, its third since discovery, following previous activity in 2009 and 2015. We report on an XMM-Newton Target of Opportunity observation performed on 2025 March 4, more than twenty days after the outburst onset. From the X-ray spectrum – which is well described by an absorbed Comptonization model – we estimated an unabsorbed 0.5–10 keV luminosity of LX ∼ 7 × 1033 erg s−1 (assuming a source distance equal to the upper limit of 6.9 kpc). To put this into context, we analyzed an archival Chandra observation performed in 2019, which yielded a quiescent luminosity of LX, q ∼ 2 × 1032 erg s−1 in the same energy band. Although this comparison indicates that the source was still well above its quiescent level during the XMM-Newton observation, the estimated low luminosity during the late stage of the 2025 outburst would typically place the source in the propeller regime. Nevertheless, we unexpectedly detected coherent X-ray pulsations with an amplitude peaking at ∼42% in the 0.3–3 keV band. We also observed a spectral softening compared to the early stages of the outburst. Finally, we report a 3σ upper limit of 60 μJy beam−1 on the source flux density at 5.5 GHz from ATCA observations acquired on 2025 April 12, following a decline in the accretion activity, as indicated by our analysis of NICER data from 2025 March 15, which revealed no significant X-ray pulsations at a luminosity level of LX ∼ 1 × 1034 erg s−1. We discuss our findings in the context of other accreting millisecond pulsars and draw comparisons with transitional systems in the subluminous disk state
Convection signatures in early-time gravitational waves from core-collapse supernovae
No full textContext. Gravitational wave emitted from core collapse supernova explosions are critical observables for extracting information about the dynamics and properties of both the progenitor and the post-bounce evolution of the system. They are prime targets for current interferometric searches and represent a key milestone for the capabilities of next-generation interferometers.
Aims. This study aims to characterise how the gravitational waveform associated with prompt stellar convection depends on the rotational rate and magnetic field topology of the progenitor star.
Methods. We carried out a series of axisymmetric simulations of a 16.5 M⊙ red supergiant with five configurations of initial magnetic fields and varying degrees of initial rotation. We analysed the contribution of early-time convection and the proto-neutron star core to the waveform using ensemble empirical mode decomposition, alongside spectral and Fourier analyses, to facilitate the comparison and interpretation of the results.
Results. Our simulations show that the first six intrinsic mode functions dominate the early post-bounce gravitational wave signal, with variations due to rotation and magnetic fields influencing the signal strength. Strong magnetic fields decelerate core rotation, affecting mode excitation. Regardless of the initial rotation, convection consistently drives a low-frequency mode that lasts throughout the evolution.
Conclusions. We conclude that prompt convection can produce gravitational wave amplitudes comparable to or exceeding those of core bounce, with a persistent low-frequency component detectable in next-generation detectors
Evolution of ultracompact neutron star–helium star binaries
No full textContext. Ultracompact binaries (detached and X-ray-emitting) are regularly detected and studied; however, it is not known whether even more compact configurations featuring degenerate stars exist. The recent discovery of PSR J1928+1815, which has a helium companion in a 3.6 h orbit, suggests a hitherto largely unexplored evolution toward “hyper-compact” configurations with Porb of ≤1 min.
Aims. This work aims to establish whether helium companions drive systems into hyper-compact configurations, and to clarify the evolutionary status of PSR J1928+1815.
Methods. We modeled the evolution of binary systems formed by a neutron star and a helium star that possibly previously experienced a common envelope phase. After an initial mass transfer episode, the donor detaches and this leads to the formation of a system with a white dwarf companion. We followed the evolution after detachment, when the donor becomes a compact degenerate star, up to the onset of the final Roche lobe overflow in hyper-compact conditions of the binary.
Results. We show that a sufficiently light helium secondary is compatible with the current state of PSR J1928+1815. After undergoing a Roche lobe overflow, the system first evolves into a detached configuration, with orbital periods in the range of the observed value of the PSR J1928+1815 system, and later into a hyper-compact configuration. We predict extremely short orbital periods for the latter state.
Conclusions. Our results indicate that the PSR J1928+1815 system is young (≲107 yr), since the second epoch that could match the observed orbital period is unable to explain the length of pulsar eclipses. We find that the evolution of such systems toward extremely short orbital periods (Porb) of ≲1 min is unavoidable unless the secondary becomes massive enough to explode as an electron-capture supernova. The hyper-compact stage is not prevented by evaporation, and strong gravitational wave emission is expected during this phase, with the system eventually ending up as a bright optical and gamma-ray transient