Search Results (117)

Three experiments were conducted to evaluate methodologies and determine the digestibility of calcium (Ca) in ingredients of animal origin, using a completely randomized design. In the first experiment, the direct, regression, and substitution methods were compared to determine the true digestibility of calcium in fishmeal (FM). The true ileal digestibility coefficients (TIDCs) obtained were 0.7558 (substitution), 0.6856 (direct), and 0.6130 (regression). Compared with the regression method, the substitution method resulted in greater digestibility. In the second experiment, the TIDCs of three meat and bone meals (MBM) were evaluated by the direct method. The observed values were 0.6212 (MBM1), 0.5393 (MBM2), and 0.8181 (MBM3). The MBM3 resulted in greater digestibility, while there was no significant difference between MBM1 and MBM2. In the third experiment, the TIDC values of the calcium in three poultry byproduct meal (PBM) samples were determined by the direct method, with coefficients of 0.9440 (PBM1), 0.8673 (PBM2), and 0.9127 (PBM3). No significant differences were observed between the evaluated PBM. The substitution and direct methods were effective for FM. The TIDCs of the MBMs ranged from 0.5393 to 0.8181, whereas those of the offal meals ranged from 0.8673 to 0.9440, indicating the importance of considering the differences in calcium digestibility among the ingredients. The direct method is the most efficient and recommended method for estimating true Ca digestibility because of its simplicity and reduced need for analysis and animals. Individually evaluating each source of Ca in broiler feed formulations is essential because of the wide variation in digestibility between them. Full article

The main distributing valve (MDV) plays a core role in hydraulic amplification and precise control within the hydro-turbine governing system, and its spool position dynamics directly affect the regulation quality and stability of the hydro-turbine generator unit. However, developing a high-fidelity dynamic model of the MDV remains challenging, as existing methods typically rely on linearization assumptions and fail to fully account for system uncertainties, resulting in limited accuracy and poor cross-condition stability. To address this issue, this paper proposes a mechanistic–data-driven hybrid modeling method. Firstly, a modular modeling strategy is adopted to accurately construct a nonlinear mechanism-based model (MBM) that conforms to the actual industrial system. Secondly, to address the unknown dynamics not captured by the MBM, a Bayesian optimization-enhanced Light Gradient Boosting Machine (BO-LightGBM) model is developed. Then, a cascade–additive architecture is employed to achieve effective integration of the two. Finally, verification experiments are conducted under various dynamic processes based on the actual operating data of the governor. The results show that the proposed hybrid model significantly outperforms the other five comparison models in terms of accuracy and stability while retaining physical interpretability. This provides a more practically valuable solution for the dynamic modeling and simulation of hydroturbine actuators. Full article

We present a combined experimental and modeling study of premixed atmospheric-pressure tetralin flames. Chemical speciation in near-stoichiometric (φ = 0.8–1.0) tetralin/O₂/Ar flames was characterized by probe-sampling molecular-beam mass spectrometry (MBMS) with soft ionization (12.3–18 eV). Total ionization cross-sections (TICSs) for heavy intermediates were computed ab initio to enable quantitative MBMS processing. Laminar burning velocities (LBVs) of tetralin/air flames were measured in a range of equivalence ratios (φ = 0.75–1.5) on a nozzle burner via the stretch-corrected total area method. This is the first reported LBV data for tetralin/air flames (maximum LBV was 47.3 ± 2 cm/s at φ = 1.1). The experimental mole fraction profiles and LBVs were interpreted using three detailed mechanisms. None of the mechanisms were able to correctly describe the LBV profile, and a number of discrepancies were observed in the mole fraction profiles. Reaction network and sensitivity analyses were performed to identify specific sub-mechanisms requiring refinement. In particular, the subchemistry of naphthalene and indene strongly affects the accuracy of model predictions, whereas the flame speciation data indicate large uncertainties in the simulated concentrations of these species. Full article

With the continuous expansion of global trade, achieving sustainable maritime transport optimization and operations has become a key strategic direction for transforming maritime transport companies. To summarize the current state of research and identify emerging trends in sustainable maritime transport optimization and operations, this study systematically examines representative studies from the past decade, focusing on three dimensions, technology, management, and policy, using data sourced from the Web of Science (WOS) database. Building on this analysis, potential avenues for future research are suggested. Research indicates that the technological field centers on the integrated application of alternative fuels, improvements in energy efficiency, and low-carbon technologies in the shipping and port sectors. At the management level, green investment decisions, speed optimization, and berth scheduling are emphasized as core strategies for enhancing corporate sustainable performance. From a policy perspective, attention is placed on the synergistic effects between market-based measures (MBMs) and governmental incentive policies. Existing studies primarily rely on multi-objective optimization models to achieve a balance between emission reductions and economic benefits. Technological innovation is considered a key pathway to decarbonization, while support from governments and organizations is recognized as crucial for ensuring sustainable development. Future research trends involve leveraging blockchain, big data, and artificial intelligence to optimize and streamline sustainable maritime transport operations, as well as establishing a collaborative governance framework guided by environmental objectives. This study contributes to refining the existing theoretical framework and offers several promising research directions for both academia and industry practitioners. Full article

The development of alternative methods that link cellular and predictive toxicity to high-level toxicity is a key focus of current research within the framework of the 3Rs in animal experimentation. In this context, this study aimed to evaluate the previously developed in vitro approach using the zebrafish liver cell line (ZFL) for assessing bioaccumulation and biotransformation of the compound BDE-47, which is more hydrophobic than phenanthrene, and is the compound used in the previous study. For this purpose, experimentally, the internal concentrations in the cells (C_cell) and the exposure medium of both BDE-47 and its main metabolites were quantified at different exposure times by GC-MS. Additionally, the free bioavailable concentration (C_free) was determined with a solid-phase microextraction (SPME) experiment. With the aim of refine models, C_cell and C_free were also estimated using a predictive chemical distribution model (MBM). Bioconcentration factors (BCFs) were determined by relating all these values, as well as by toxicokinetic fitting and by in vitro–in vivo extrapolation modelling (IVIVE). The results showed a high concordance with the values obtained in vivo. Moreover, the study highlighted the importance of experimentally determining C_free and C_cell, as the predicted values can vary depending on the chemical, thereby influencing the BCF outcome. This variation occurs because models do not account for the absorption and biotransformation kinetics of the compounds. The data presented may contribute to refining predictive models. Full article

Precise modeling of differential drive robots is crucial for effective control and trajectory planning in autonomous systems. A comparative analysis of two modeling approaches for a four-wheel differential drive robot is presented in this paper. The first approach, named Motor-Based Model (MBM), identifies four transfer functions, one for each motor, while the second approach, named Simplified Model (SM), uses only two transfer functions, one for linear velocity and another for angular velocity. Both models were validated by comparing their predicted trajectories against real odometry data obtained from a SLAM system implemented on a differential-drive robot. This provided a practical assessment of each model’s accuracy and underscored the importance of model selection in control design and navigation tasks. The results showed that the Motor-Based Model (MBM) consistently outperformed the Simplified Model (SM) in terms of odometry accuracy, both in position and orientation. Across all trajectories, the average RMSE for position using MBM was 0.309 m, while the SM recorded a higher average RMSE of 0.414 m. Similarly, the maximum position error averaged 0.522 m for MBM and 0.710 m for SM, confirming that MBM is more accurate and consistent in position tracking. Regarding the results of orientation estimation, when averaged across all experiments, the MBM maintained a lower angular RMSE of 0.170 rad in contrast to SM, which achieves an RMSE of 0.239 rad. The maximum angular error was also higher for the MBM at 0.316 rad, compared to 0.447 rad for the SM. Moreover, the computational performance evaluation indicated that the SM consistently outperformed MBM, achieving a 30% reduction in simulation time and substantially lower memory usage. These results demonstrate the relationship between model complexity and accuracy and suggest that the motor-specific model is more appropriate for applications requiring precise mapping or localization, such as SLAM, while the simplified model may be suitable for simpler use cases with lower computational requirements, such as embedded systems with limited resources. This paper provides a practical evaluation of the accuracy and computational performance of two modeling approaches, highlighting the implications of model selection for the design of navigation tasks. Full article

The aim of this study is to determine the effects of increasing doses of meat and bone meal (MBM) and the year of the experiment on the feed value of maize silage. A three-year field experiment with silage maize was conducted. The following treatments were established: (1) zero-fert (no fertilization); (2) inorganic nitrogen (N), phosphorus (P), and potassium (K); (3) 1.0 t∙ha⁻¹ MBM; (4) 1.5 t∙ha⁻¹ MBM; (5) 2.0 t∙ha⁻¹ MBM. Both N and K were applied at constant rates, while P was applied at increasing rates: 0.0, 45, 68, and 90 kg∙ha⁻¹. Replacing conventional P fertilizer and, partially, N fertilizer with MBM in silage maize cultivation had a positive influence on the ensiled herbage, compared with the zero-fert treatment. The fermentation parameters and feed value of silage made from maize fertilized with MBM were comparable with the parameters of maize fertilized with inorganic NPK fertilizers. In turn, the content of crude protein (CP) and protein digested in the small intestine when energy is limiting (PDIE) was highest in the silage made from maize supplied with mineral fertilizer. The mineral composition of maize silage, i.e., the content of calcium (Ca) and magnesium (Mg) was modified by fertilization. Full article

Despite the fact that organochlorine pesticides (OCPs) were banned many years ago, their residues are still present in the natural environment and pose a potential health risk to humans and animals. This study was undertaken to evaluate the effect of meat and bone meal (1.0, 2.0 and 3.0 t ha⁻¹ MBM) derived from animal by-products and used as fertilizer on the content of γ-HCH (γ-hexachlorocyclohexane), DDT (1,1,1-Trichloro-bis-2,2 [4-chlorophenyl]-ethane) and its metabolites (DDD, dichlorodiphenyldichloroethane and DDE, dichlorodiphenyldichloroethylene) in MBM, soil, and maize grain. A long-term small-area field experiment with MBM applied to maize grown in monoculture was conducted at the Agricultural Experiment Station in Tomaszkowo, Poland (53°71′ N, 20°43′ E) from 2014 to 2017. The concentration of γ-HCH in soil decreased gradually, whereas the levels of DDT and its metabolites continued to increase in successive years of the experiment. A minor increase in DDT accumulation in maize grain was also observed, particularly in treatments supplied with mineral fertilizers. Meat and bone meal affected grain contamination levels, and the highest MBM rates decreased the content of DDT metabolites in grain. The results of the study suggest that MBM could be a secondary source of OCPs in the agricultural environment and that their availability to plants varies depending on soil parameters and weather conditions. Full article

Based on the B-site modification strategy, excellent energy storage properties were achieved in this work by substituting Nb with Ta of the same valence in niobate-based glass ceramics. Ta substitution was found to lead to the transformation of crystal structures, and the space point group evolved from the non-centrosymmetric P4bm to the centrosymmetric P4/mbm, resulting in a transition from relaxor ferroelectric to paraelectric glass ceramics. Furthermore, the addition of Ta led to a significant decrease in grain size and interfacial activation energy, as well as an increase in the optical band gap, resulting in a dramatic increase in BDS from 800 kV/cm to 1300 kV/cm. The KBSN-4.0mol%Ta₂O₅ glass ceramic exhibited optimal energy storage properties, including a discharge energy density of ~5.62 J/cm³ and a superfast discharge rate of ~9.7 ns, resulting in an ultrahigh discharge power density of about ~1296.9 MW/cm³ at 1300 kV/cm. Furthermore, this KBSN-Ta glass ceramic also displayed good thermal stability over a temperature range of 20–120 °C, with the W_d decreasing by 9.0% at 600 kV/cm. B-site modification engineering in glass ceramics has proved to be an important way to effectively optimize energy storage performance. Full article

Maritime transport carries over 80% of global trade by volume and remains the most energy-efficient mode for long-distance goods movement. However, the sector contributes approximately 3% of global Greenhouse Gas (GHG) emissions, a share that could rise to 17% by 2050 without effective regulation. In response, the International Maritime Organization (IMO) has introduced initial and short-term measures to enhance energy efficiency and reduce emissions. In 2023, IMO Strategy expanded on these efforts with medium-term measures, including Market-Based Mechanisms (MBMs) such as a GHG levy, a feebate system, and fuel intensity regulations combined with carbon pricing. This study evaluates the economic and environmental impacts of these measures using an integrated computational simulation model that combines Ocean Engineering and Economics. Our results indicate that all proposed measures support the IMO’s intermediate emission reduction targets through 2035, cutting absolute emissions by more than 50%. However, economic impacts vary significantly across regions, with most of Africa, Asia, and South America experiencing the greatest adverse effects on GDP and trade. Among the measures, the GHG levy exerts the strongest pressure on economic activity and food prices, while a revised fuel intensity mechanism imposes lower costs, particularly in the short term. Revenue redistribution mitigates GDP losses but does so unevenly across regions. By leveraging a general equilibrium model (GTAP) to capture indirect effects often overlooked in prior studies, this analysis provides a comprehensive comparison of policy impacts. The findings underscore the need for equitable and pragmatic decarbonization strategies in the maritime sector, contributing to ongoing IMO policy discussions. Full article

Maritime transport accounts for approximately 3% of global greenhouse gas (GHG) emissions, a figure projected to rise by 17% by 2050 without effective mitigation measures. Achieving zero-emission shipping requires a comprehensive strategy that integrates regulatory frameworks, alternative fuels, and energy-saving technologies. However, existing studies often fail to provide an integrated analysis of regulatory constraints, economic incentives, and technological feasibility. This study bridges this gap by developing an integrated model tailored for international maritime transport, incorporating regulatory constraints, economic incentives, and technological feasibility into a unified framework. The model is developed using a predictive approach to assess decarbonization pathways for global shipping from 2018 to 2035. A multi-criterion decision analysis (MCDA) framework, coupled with techno-economic modeling, evaluates the cost-effectiveness, technology readiness, and adoption potential of alternative fuels, operational strategies, and market-based measures. The results indicate that technical and operational measures alone can reduce emissions by up to 44%, while market-based measures improve the diversity of sustainable fuel adoption. Biofuels, particularly BISVO and BIFAME, emerge as preferred alternatives due to cost-effectiveness, while green hydrogen, ammonia, and biomethanol remain unviable without additional policy support. A strict carbon levy increases transport costs by 46%, whereas flexible compliance mechanisms limit cost increases to 14–25%. The proposed approach provides a robust decision-support framework for policymakers and industry stakeholders, ensuring transparency in evaluating the trade-offs between emissions reductions and economic feasibility, thereby guiding future regulatory strategies. Full article

This paper proposes an adaptive pre-distortion method for mitigating LED nonlinear distortion in Visible Light Communication (VLC)-OFDM systems. The inherent nonlinear characteristics of LEDs disrupt the orthogonality among OFDM subcarriers, causing signal distortion and performance degradation. To overcome this issue while minimizing computational complexity at the transmitter, we introduce a feedback-based nonlinear parameter estimation approach using the Least Squares Method (LSM) and Median Based Method (MBM). These estimated parameters are then fed back to the transmitter, enabling efficient adaptive pre-distortion based on the inverse function of the estimated nonlinear characteristics. This approach reduces computational costs at the transmitter compared to conventional methods requiring high-performance processing. Additionally, we incorporate Frequency Symbol Spreading (FSS) to further enhance robustness against channel impairments such as Rician fading by equalizing the Signal-to-Noise Ratio (SNR) across subcarriers. Simulation results under various channel conditions, including AWGN, Rician fading, and realistic multi-LED lighting scenarios, demonstrate a significant improvement in Bit Error Rate (BER) performance, validating both the effectiveness and practical advantages of the proposed approach. Full article

The purpose of this field study was to assess the impact of meat and bone meal (MBM) on maize. The experimental procedures were as follows: (1) without fertilization; (2) inorganic nitrogen, potassium, and phosphorus; (3) 1.0 Mg·ha⁻¹ MBM; (4) 1.5 Mg·ha⁻¹ MBM; and (5) 2.0 Mg·ha⁻¹ MBM. Each year, MBM was applied before sowing. Nitrogen and potassium were applied at constant rates, and phosphorus was applied at increasing rates of 0.0, 45, 68, and 90 kg·ha⁻¹. The herbage yields were significantly higher in fertilized treatments. Fertilization contributed to a significant increase in the crude protein content of maize herbage. The yield and other herbage parameters were affected by weather conditions and the amount of time that passed since the MBM application. The study demonstrated that the lowest dose of MBM (1.0 Mg·ha⁻¹), which supplied 45 kg phosphorus·ha⁻¹, fully met the phosphorus requirements of maize. Full article

Methylcyclohexane (MCH, C₇H₁₄) is a typical component in hydrocarbon fuels and is frequently utilized in surrogate fuel mixtures as a typical representative of alkylated cycloalkanes. However, comprehensive experimental studies on speciation during its combustion remain limited. This research investigates for the first time the chemical structure of laminar premixed flames of lean and stoichiometric mixtures (φ = 0.8 and 1.0) of MCH/O₂/Ar under atmospheric pressure. Using probe-sampling molecular-beam mass spectrometry (MBMS), the spatial distribution of 18 compounds, including reactants, products, and intermediates, in the flame front was measured. The obtained results were compared with numerical simulations based on three established chemical–kinetic models of MCH combustion. The comparative analysis demonstrated that while the models effectively describe the profiles of reactants, primary products and key intermediates, significant discrepancies were observed for various C₂–C₆ compounds. To indicate the roots of the discrepancies, a rate of production (ROP) analysis was performed in each simulation. ROP analyses revealed that the primary cause for the discrepancies could be attributed to the overprediction of the rates of initial stages during MCH decomposition. Particularly, the role of non-elementary reactions was emphasized, indicating the need for refinement of the mechanisms based on new experimental data. Full article

Background: There are no active treatment options for patients with progressive melanoma brain metastases (MBM) failing immune checkpoint blockade (ICB) and BRAF/MEK inhibitors (BRAF/MEKi). Regorafenib (REGO), an oral multi-kinase inhibitor (incl. RAF-dimer inhibition), can overcome adaptive resistance to BRAF/MEKi in preclinical models. Methods: This is a single-center retrospective case series of patients with refractory MBM treated with REGO plus BRAF/MEKi (compassionate use). Results: A total of 22 patients were identified (18 BRAF-mutant, 4 NRAS^Q61-mutant; 19 with progressive MBM; 11 on corticosteroids). Thirteen BRAF^V600-mutant patients were progressing on BRAF/MEKi at the time of REGO association. BRAF-mutant patients received REGO (40–80 mg once daily) combined with BRAF/MEKi, NRAS-mutant patients were treated with REGO + MEKi (+low-dose BRAFi to mitigate skin-toxicity). Grade 3 TRAE included arterial hypertension (n = 4) and maculopapular rash (n = 3). There were no G4/5 TRAE. In BRAF-mutant patients, overall and intracranial objective response rates (overall ORR and IC-ORR) were 11 and 29%, and overall and intracranial disease control rates (overall DCR and IC-DCR) were 44 and 59%, respectively. In NRAS-mutant patients overall ORR and IC-ORR were 0 and 25% and overall DCR and IC-DCR were 25 and 50%, respectively. The median PFS and OS were, respectively, 7.1 and 16.4 weeks in BRAF-mutant and 8.6 and 10.1 weeks in NRAS-mutant patients. Conclusions: In heavily pretreated patients with refractory MBM, REGO combined with BRAF/MEKi demonstrated promising anti-tumor activity with an acceptable safety profile. In BRAF^V600-mutant melanoma patients, responses cannot solely be attributed to BRAF/MEKi rechallenge. Further investigation in a prospective trial is ongoing to increase understanding of the efficacy. Full article