Search Results (1,186)

Laser Metal Deposition (LMD) is an advanced Additive Manufacturing (AM) technology widely used for metal component fabrication, cladding, and repair. Despite its potential, issues such as geometrical inaccuracies and deposition flaws can significantly affect part quality and process efficiency. Existing optical monitoring approaches mainly focus on geometric features and generally do not provide real-time estimates of deposition efficiency, which is critical for both product performance and resource utilization. Furthermore, evaluating deposition efficiency in industrial settings is often time-consuming and difficult to implement. This preliminary study introduces an innovative in-process methodology for assessing deposition efficiency during multi-track deposition. The approach exploits end-track scan data acquired by a laser line scanning system to estimate the deposited volume and the corresponding deposition efficiency for each track. A validation test on a two-layer sample demonstrates the capability of the method to detect defects induced by partially clogged and non-clogged nozzle conditions. Comparison with metallographic measurements shows an average deviation of 4.3%. By enabling timely identification of powder feeding anomalies and supporting improved powder utilization, the proposed methodology contributes to waste reduction, enhanced process stability, and more sustainable industrial implementation of LMD. Full article

The present study investigates the thermal conductivity (λ) and convective heat transfer coefficient (h) of AA 6082 aluminum cellular structures immersed in water and air using a thermal conductivity probe (TCP) manufactured by the authors. The probe is a cylindrical needle 0.6 mm in diameter (D) and 60 mm in length (L), obtaining an L/D ratio = 100 ratio, which satisfies the infinite line-source assumption and enables discrimination between pure-fluid and composite (fluid + solid) thermal behavior. Cellular samples are manufactured with the Lost-PLA process and tested at temperatures of 5, 20, and 40 °C, feeding the TCP with different currents, under controlled heating conditions. The results show that the presence of the aluminum cellular structure enhances heat transfer compared with that of pure fluids. In air, the effective thermal conductivity is higher by approximately 37–45% than that in pure air, reaching about 0.038 W m⁻¹ K⁻¹ at higher temperatures. In water, λ increases from approximately 0.8 to 1.2 W m⁻¹ K⁻¹ over the investigated temperature range, corresponding to an enhancement of about 45–80% compared with that of pure water. Similarly, the convective heat transfer coefficient is higher by about 22–32% in air (h ≈ 38–41 W m⁻² K⁻¹) and 19–54% in water (up to ~440 W m⁻² K⁻¹), depending on temperature. These results indicate that the high thermal conductivity of the aluminum skeleton mainly improves conduction (“thermal bridging”), while convection may be locally affected within the pores. This study confirms the capability of the TCP method to discriminate between fluid and composite heat transfer contributions and highlights the potential of additively manufactured aluminum cellular structures for lightweight thermal management applications. Full article

In most countries, male siblings of laying hybrids are culled immediately after hatching because their rearing is economically unfeasible due to low growth performance, poor feed efficiency, and a body composition unacceptable to consumers. In Germany, however, culling male day-old chicks has been prohibited for animal welfare reasons since 2022, making their rearing mandatory. Currently, no recommendations exist for protein and amino acid supply for these birds. This study aimed to determine the requirements for standardized ileal digestible (SID) methionine + cysteine (Met + Cys) and SID lysine (Lys) during the starter period (days 1–21) in male LSL Classic chicks by a dose–response approach. Two trials were conducted with 120 male chicks each, fed six diets containing SID Met + Cys concentrations ranging from 0.36% to 0.71% (Trial 1) or SID Lys concentrations ranging from 0.50% to 0.89% (Trial 2). Optimal concentrations were estimated using broken-line and exponential models based on body weight gain, feed intake, and feed conversion ratio. Considering all criteria, the optimal SID Met + Cys concentration was 0.58% (0.42 g/MJ AME_N), and the optimal SID Lys concentration was 0.74% (0.56 g/MJ AME_N). The calculated optimum SID Met + Cys:SID Lys ratio when standardized to an identical energy level was 74:100. These findings provide a basis for adjusting SID Met + Cys and SID Lys levels in starter diets for male chicks of a layer breed, supporting more efficient and sustainable rearing practices under current animal welfare regulations. Full article

This study presents a quantitative, cross-sectional analysis of work-related musculoskeletal disorders (WRMSDs) among sick leave recipients in Brazil’s meat production chain, using official surveillance data. A marked temporal shift was observed; women remained more affected by upper limb injuries, such as shoulder and wrist disorders. In 2022, male notifications surpassed female ones, marking a turning point linked to improved reporting and the inclusion of WRMSDs in Brazil’s compulsory notification list. Workers aged 20–49 were the most impacted group, with diagnoses including shoulder lesions, tenosynovitis, carpal tunnel syndrome, back pain, and occupational risk exposure. The findings highlight systemic barriers, including underreporting, inadequate protection, and weak return-to-work protocols. Implementing gender-differentiated ergonomic protocols is crucial, as it requires reducing repetitive strain for women in line-feeding/cutting roles, and mitigating environmental hazards (such as cold, vibration, and chemical exposure) for men in farming/slaughtering. These results underscore the urgent need for gender-sensitive preventive strategies and occupational health policies tailored to the meat processing industry. Full article

Mating and feeding behavioural differences have been observed between male and female wasps (Hymenoptera: Aculeata). It is hypothesised that these behavioural differences are supported by morphological dimorphisms in their sensory systems. Here, this hypothesis was tested in the parasitoid aculeate wasp Scolia hirta (Scoliidae), which attacks beetle larvae located in the soil. We have found evidence of a link between the main stimuli used by the sexes to access their target resources and the morphology of the sensory system. Males have a more developed visual system with enlarged eyes, ocelli and a higher number of ommatidia, sinc they have to visually locate and chase females immediately after they emerge. Males possess nine types of sensilla (primarily hygrothermo- and mechanoreceptors), and females possess seven types of sensilla, primarily olfactory. In females, the sensilla placoidea occur in greater numbers and are larger in size, in line with their underground host-seeking behaviour. Furthermore, the females had a blunt tip on their distal flagellomere and wider fore tibiae, which suggests that they may use vibrational sounding to detect concealed hosts, similarly to what has been described for some non-aculeate parasitoid wasps. Full article

To study the forming, microstructures, and mechanical properties of high-speed laser cladding thin-walled tube, 1Cr17Ni2 powder was used to perform high-speed laser cladding on a 1Cr17Ni5 stainless steel tube with a thickness of 1 mm. The effects of powder feeding rate, laser power, rotation speed, protective gas flow rate, powder defocusing amount, and powder feeding gas flow rate on the width, height, and penetration depth of the weld beads were investigated. Subsequently, the cladding of multi-pass was carried out, and the microstructures and microhardness of the cladding layer were studied. The results showed that laser power had the most significant effect on the width of the weld bead, and the width gradually increased with the increase in power. The powder feeding rate had the most significant effect on the height of the weld bead, and the height gradually increased with the increase in powder feeding speed. The powder feeding rate also had the most significant effect on the penetration depth, and the penetration depth gradually decreased with the increase in powder feeding speed. When multiple passes overlap, the microstructure of the cladding layer exhibits a distinct periodic distribution. Large-sized primary austenite columnar crystals exist in the cladding layer, and the main microstructure in the columnar crystals is martensite and possesses a small amount of residual austenite. The base material is composed of austenite and a small amount of martensite. The average microhardness of the substrate is 366 HV, and the microhardness of the cladding layer gradually decreases with increasing distance from the fusion line, from 562 HV to 532 HV. Due to the heat effect of the cladding on the substrate, the microhardness of the substance near the fusion line is only 239 HV. As the distance from the fusion line increases, the influence of heat effect decreases, and the microhardness gradually increases. Full article

The determination of the actual series and sequence impedances, including the reduction factor of a certain HV or EHV distribution cable line, as well as the resulting screening factor of its sheaths and surrounding metal installations, including its inductive influence on any of the surrounding metal installations, is not possible by calculations alone. Considering the inductive influence of surrounding metal installations on the values of these quantities is possible only by the method that includes the test measurements during a simulated ground fault in the supplied substation. However, such measurements presuppose putting at least one HV substation and its feeding line out of service. That is why electricity distribution companies rarely allow such measurements, i.e., only immediately before the commissioning of a newly built HV substation or during a periodical overhaul. In this paper, it is demonstrated that these characteristics of cable lines can also be determined based on the results of synchronous measurements performed permanently in the substations at their ends. In this way, the need to perform a simulated ground fault and corresponding test measurements in HV distribution substations practically disappears, and the necessary characteristics can be determined whenever they are required. Full article

Non-contact monitoring of human vital signs using microwave radar has attracted increasing attention due to its capability to operate unobtrusively and through clothing or light obstacles. In vector network analyzer (VNA)-based radar systems, vital signs can be extracted from phase variations in the forward transmission coefficient $S_{21}$, whose sensitivity strongly depends on the electromagnetic performance of the antenna system. This work presents the design, optimization, fabrication, and experimental validation of a high-gain 12 GHz 4 × 4 microstrip patch antenna array specifically developed for phase-based vital signs monitoring. The antenna array was progressively optimized through coaxial feeding, slot-based impedance control, stepped transmission line matching, and mitered bends, achieving a simulated gain of 17.8 dBi, a measured gain of 17.06 dBi, a reflection coefficient of −26 dB at 12 GHz, and a total efficiency close to 74%. The antenna performance was experimentally validated in an anechoic chamber and subsequently integrated into a continuous-wave VNA-based radar system. Comparative measurements were conducted against a commercial biconical antenna, a single patch radiator, and an MIMO antenna under identical conditions. Results demonstrate that while respiration can be detected with moderate-gain antennas, reliable heartbeat detection requires high-gain, narrow-beam antennas to enhance phase sensitivity and suppress environmental clutter. The proposed array significantly improves pulse detectability in the (1–1.5) Hz band without relying on advanced signal processing. These findings highlight the critical role of antenna design in $S_{21}$-based biomedical radar systems and provide practical design guidelines for high-sensitivity non-contact vital signs monitoring. Full article

This paper presents the design of an omnidirectional-mobile paddle boat (OMPB) used in narrow rivers, ponds, and canals. Compared with common propeller boats, the OMPB has advantages such as zero turning radius and shallow draft. Firstly, a prototype is built in which there are four paddles connected with four DC motors, allowing the boat to move like an omnidirectional Mecanum-wheeled vehicle. Subsequently, to develop the OMPB’s autonomous navigation algorithms, a kinematic model is established and dynamic analysis is performed. To improve the ability of resisting disturbances and control precision, a control algorithm based on fuzzy controller is designed for trajectory tracking. Experimental validations cover trajectory tracking performance during both straight-line navigation and turning maneuvers. The results demonstrate that the OMPB is competent to carry out omnidirectional movement, and the actual navigation trajectory is highly consistent with the theoretical trajectory, with a tracking error within 40 mm and a heading angle error within 1.8°. The OMPB platform can be reformed into special-purpose vessels for floating garbage collection and fish feeding in narrow water areas. Full article

Indium is a strategically important metal, essential for the production of transparent conductive oxides, flat panel displays, thin-film photovoltaics, and advanced optoelectronic devices. Due to its limited natural abundance and its occurrence in trace amounts alongside other metals in both primary and secondary sources, the recovery of indium through efficient separation techniques has gained increasing attention. This review discusses three major separation strategies for indium recovery: solvent extraction, ion-exchange, and membrane processes, applied to both synthetic solutions and real leachates. D2EHPA has demonstrated its applicability as an effective agent for indium separation, not only in solvent extraction but also as an impregnating agent in polymer resins and membranes. While solvent extraction achieves high recovery rates, ion-exchange resins and membrane-based methods offer significant advantages in terms of reusability, reduced chemical consumption, and minimal environmental impact. The selective separation of indium from impurities such as Fe³⁺ and Sn²⁺ remains a key consideration, which can be addressed by optimizing feed solution conditions or adjusting the selective stripping stages. A comparative overview of these methods is provided, focusing on separation efficiency, operational conditions, and potential integration into close-loop systems. The article highlights recent innovations and outlines the challenges involved in achieving sustainable indium recovery, in line with circular economy principles. Full article

Power supply for traction substations (TSs) of AC railways has traditionally been provided by 110–220 kV overhead transmission lines (OHL). These OHLs can be damaged during strong winds and ice formation. Furthermore, these lines generate significant electromagnetic fields (EMFs), which adversely affect maintenance personnel, the public, and the environment. Mitigating the resulting damages requires the establishment of protection zones, necessitating significant land allocation. Enhancing the reliability of power supply to traction substations and reducing EMF levels can be achieved through the use of gas-insulated lines (GIL), whose application in the power industry of many countries is continuously increasing. The aim of the research presented in this article was to develop computer models for determining the EMF of a GIL supplying a group of traction substations, taking into account actual traction loads characterized by non-sinusoidal waveforms and asymmetry. To solve this problem, an approach implemented in the Fazonord AC-DC software package, based on the use of phase coordinates, was applied. This allowed for the correct accounting of the skin effect and proximity effect in the massive current-carrying parts of the GIL, as well as the influence of asymmetry and harmonic distortions. The simulation results showed that the use of GIL brings the voltage unbalance factors at the 110 kV busbars of the traction substations within the permissible range, with the maximum values of these coefficients not exceeding 2%. The results of the harmonic distortion assessment demonstrated a significant reduction in harmonic distortion factors in the 110 kV network for the GIL compared to the OHL. The performed electromagnetic field calculations confirmed that the GIL generates magnetic field strengths one order of magnitude lower than those of the OHL. The obtained results lead to the conclusion that the use of gas-insulated lines for powering traction substations is highly effective, ensuring increased reliability, improved power quality, and a reduced negative impact of EMF on personnel, the public, the environment, and electronic equipment. Full article

Predation of sea turtles by jaguars (Panthera onca) in the Santa Rosa National Park (SRNP) has been well documented over the past decade. However, the factors that influence jaguar feeding behavior, including environmental factors or characteristics of the beaches and the adjacent forest, are poorly known. This study aimed to identify the relationship between vegetation density and human activity on the distribution of feeding sites of jaguar on sea turtles at nesting beaches in Santa Rosa National Park, Costa Rica. We sampled three beaches (Naranjo, Nancite, and Colorada), where we identified and registered sea turtle carcasses preyed on by jaguars between June and November 2019. Through systematic searches of the forest adjacent to the beach, we documented the species, geographic coordinates, carcass length and width, vegetation cover at the carcass site, and the average vegetation coverage corresponding to the date and beach of each sea turtle carcass. In total, we recorded 338 sea turtle carcasses preyed on by jaguars, 156 at Naranjo beach, 103 at Nancite beach, and 89 at Colorada beach. The beach with the highest average density of carcasses was Colorada (8.7 (SD = 5.42)/ha), followed by Nancite (6.06 (SD = 5.58)/ha) and Naranjo (2.64 (SD = 1.79)/ha). The dragging distance from the beach line to sea turtle carcasses was best explained by the interaction of nesting beach and canopy cover at the carcass. Our canopy cover results may reflect that jaguars select sites that better hide their prey, in the same way that green turtles (Chelonia mydas) usually prefer areas with good coverage to nest in, contrasting to the nesting behavior of olive ridleys (Lepidochelys olivacea). On beaches, higher concentrations were observed where there was less human presence and this may reflect both turtle nesting and jaguar predation activity. Full article

Background/Objectives: RELiZORB immobilized lipase cartridge (ILC) is a single-use digestive enzyme cartridge that connects in-line with enteral feeding circuits to hydrolyze triglycerides in enteral formulas. It is cleared by the FDA for pediatric and adult use. Limited data have been published regarding the effect of ILC use on growth in children younger than 5 years of age. Methods: We performed a retrospective evaluation of real-world data extracted from a third-party reimbursement program database. All patients in the program database who initiated ILC use with enteral formula when 1 to 4 years of age between 2019 and 2023 were included. Baseline and follow-up weight, height/length, and body mass index (BMI) data were collected for up to 12 months. Results: A total of 186 patients from 90 clinics in the United States were included. A subset (143 patients) with baseline and follow-up growth measurements was included in the efficacy analysis population; 76% were diagnosed with cystic fibrosis. Mean weight and BMI z-scores improved significantly (0.63 [p < 0.001] and 0.53 [p = 0.006], respectively) from baseline to 12 months after initiation of ILC use. Significant improvement in the mean weight z-score was observed after 3 months. Among people with cystic fibrosis (pwCF) who initiated ILC use when 2 to 4 years of age, those with a BMI ≥ 50th percentile increased from 22% at baseline to 43% after 12 months (p = 0.021). Improvement in weight-for-length was also observed in 1-year-old pwCF. Conclusions: Real-world evidence showed that initiation of ILC use was associated with significant improvements in mean weight and BMI z-scores among young children. Full article

Background: Postnatal growth failure in very preterm infants remains a major concern in neonatal care and clinical management is complicated by the lack of a standardized definition. This study aims to identify risk factors for growth faltering (GF) and undernutrition (UN) at hospital discharge, defined according to the latest consensus definitions established by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). Methods: We conducted a retrospective observational study of 416 preterm infants (gestational age < 32 weeks and/or birth weight < 1500 g). Growth was monitored using the Intergrowth 21st standards. In line with ESPGHAN criteria, GF was defined longitudinally as a weight for age (WFA) z-score decline ≥ 1 SD from birth, while UN was defined cross-sectionally as a WFA or length for age z-score < −2 SD at discharge. Logistic regression models were used to determine independent predictors for both growth phenotypes. Results: At discharge, the prevalence of GF and UN was 45.3% and 33.1%, respectively. In infants born without growth restriction (GR), UN was almost entirely driven by GF (89.7%). In contrast, 85.5% of infants born with GR remained undernourished at discharge. Multivariate analysis identified bronchopulmonary dysplasia and higher maximal postnatal weight loss as major independent risk factors for GF, while female sex and human milk feeding at discharge were associated with a lower risk of GF. For infants born with adequate weight, maternal hypertension, extremely low birth weight, and the co-occurrence of GF were the strongest predictors of UN. Conclusions: Nearly half of very preterm infants experience significant growth impairment before discharge. By assessing the dynamic process of GF and the static endpoint of UN, we identified distinct clinical trajectories. Standardized ESPGHAN criteria allow for the identification of high-risk “phenotypes”—particularly those with GR at birth or severe neonatal morbidity—enabling more targeted and intensive nutritional management during the critical developmental window. Full article

The mung bean (Vigna radiata) is rich in nutrients and bioactive compounds and is valuable for its antioxidant content in functional food development. However, mung bean seed coats are discarded or used as a low-value feed owing to their coarse texture. Here, 12 homozygous mung bean lines with different seed coat colors were selected from six recombinant inbred lines. The seed coats and cotyledons were separated and quantitatively analyzed for protein, starch, dietary fiber, polyphenols, flavonoids, vitexin, isovitexin, and antioxidant activities using standard chemical assays and HPLC, followed by statistical analysis and principal component analysis. The cotyledons contained more protein (26.97–28.34%) and starch (50.40–56.25%), whereas the seed coat contained more dietary fiber (74.17–79.93 g/100 g) and bioactive compounds. Polyphenolic compounds were significantly higher in the seed coat than in the cotyledons (p < 0.05) and were positively correlated with seed coat darkness, indicating that the black mung bean had higher bioactive functions. This study provides evidence for mung bean variety improvement and functional food development. Full article