Search Results (105)

Fifty high-risk bull calves were used in a completely randomized design (ten calves/treatment) to evaluate the optimal period of calcium propionate (CaPr) supplementation following arrival into the feedlot. The variables evaluated were the growth performance, dietary energetics, body fat reserves, serum metabolites, and economic return at day 56 of arrival. Calves, which were weighed at the moment of reception (156.2 ± 1.57 kg off-truck body weight, BW), were received with a 50:50 forage-to-concentrate ratio diet and clean water. At 12 h from reception, they were housed in individual pens during a 56 d feeding period and assigned to treatments consisting of a daily supplementation of a commercial product (Propical^® Dresen Química, SAPI de CV., Mexico City, Mexico) that provided 19 g CaPr/calf for 0, 14, 28, 42, or 56 d following arrival into the feedlot. Compared with the other treatments, the calves receiving CaPr during the initial 42 d had a greater average daily weight gain (p ≤ 0.035) without affecting the dry matter intake (p ≥ 0.24). Thus, the gain efficiency (p ≤ 0.050) and dietary energy utilization were improved (p ≤ 0.046). Rib fat thickness (p ≥ 0.090) and Longissimus lumborum muscle area (p ≥ 0.112) were not affected by the CaPr supplementation, whereas calves showed the greatest values (p ≤ 0.038) to the rump back fat thickness at 42 and 56 days of CaPr supplementation. With the exception of the total albumin (being maximal at day 56 (p ≤ 0.024)) and total cholesterol (which, compared to the controls, was maximal at 28 and 42 d; p = 0.030), the serum metabolic profiles were not affected by the treatments. Using the profit estimated for the control group as a baseline, supplementing CaPr for 42 d yielded a greater net income (USD 34.84 more/calf). CaPr supplementation for more or less than 42 d showed a very similar profit (~USD 6.80/calf). Because the cost of gain was very similar for these treatments and the controls (USD 1.42 vs. 1.46/kg), the positive difference in profit was mediated mainly by an increase in income selling (+USD 13.02/calf) for the CaPr calves. Based on the performance, serum metabolites, and profit, it is concluded that the optimal duration of supplemental CaPr is 42 d. Offering 19 g CaPr during this period enhanced the growth performance, dietary energy, and economic returns. Full article

The piglet nursery phase is one of the critical moments in production, especially in the first few weeks after weaning. Growth-promoting antibiotics have always been used in this phase, but the world is banning or limiting the use of antibiotics for this purpose, which has led researchers to seek alternatives, with an emphasis on organic and natural ones. As a result, this study aimed to evaluate whether a combination of organic acids and their derivatives (ammonium formate, formic acid, ammonium propionate, and acetic acid) and yeast wall (mannan oligosaccharides and beta-glucans) in piglet feeding during the nursery phase has positive effects on the SCFA profile in feces and animal health reflected in greater weight gain. A 40-day experiment was conducted in a completely randomized design containing three treatments, each with nine replicates and three piglets per replicate: negative control (NC: without additives), and a combination of organic acids and yeast wall at doses of 1 and 2 kg/ton (AO+YW-1 and AO+YW-2, respectively). Animals received four diets: pre-starter 1 (d1–7), pre-starter 2 (d8–14), starter 1 (d15–25), and starter 2 (d26–40). The animals were weighed on the day of the diet change. Blood and feces were collected on days 14 and 40 of the experiment. Piglets from the AO+YW-1 group showed more significant weight gain than NC. Feed intake was higher in piglets from the AO+YW-1 group considering the first 25 days of the experiment compared to NC; there was no treatment effect on feed conversion. Piglets from NC had higher levels of C-reactive protein and ferritin, while AO+YW-2 had higher levels of interleukin 10 and lower levels of TNF-α. A greater quantity of SCFA was observed in the feces of piglets on d40, related to the changes in propionic, butyric, isovaleric, and valeric acids. Therefore, the combination of organic acids and yeast wall used at a dose of 1 kg/ton proved to be an additive option for the diet of piglets in the nursery phase to enhance weight gain and reduce the number of doses of injectable antibiotics. Full article

Assisting patients with weakened hand and wrist strength during meals is essential. While various feeding devices have been developed, many do not utilize patients’ residual finger functions, leading to an increase in the risk of disuse syndrome and loss of joy in life. Recently, assist-as-needed support for spoon grasping by soft hand rehabilitation devices has been studied. Moreover, in our previous study, we investigated finger motions for the required scooping angle and verified them with a dummy hand driven by soft actuators. However, eating with a spoon requires not only spoon grasping and rotating but also plunging the spoon into food and lifting it afterward. The goal of this study is to achieve self-feeding with spoons using soft actuators for individuals with partial finger disabilities. To address this, we measured scooping movements using inertial measurement units, identified feasible finger motions for spoon plunging and lifting, and verified our findings through experiments with a dummy hand driven by soft actuators. As a result, we found a way to achieve the two motions by regulating the moment applied to the spoon. These results highlight the potential of soft actuators for assisting scooping movements. This study marks an important step toward feeding assistance that leverages patients’ residual finger functions. Full article

The paper presents a new control concept based on the process moment instead of the process states or the process output signal. The control scheme is based on separate control of reference tracking and disturbance rejection. The tracking control is achieved by additionally feeding the input of the process model by the scaled output signal of the process model. The advantage of such feedback is that the final state of the process output can be analytically calculated and used for control instead of the actual process output value. The disturbance rejection, including model imperfections, is controlled by feeding back the filtered difference between the process output and the model output to the process input. The performance of tracking and disturbance rejection is simply controlled by two user-defined gains. Several examples have shown that the new control method provides very good and stable tracking and disturbance rejection performance. Full article

Shrimp farming is a growing industry, and automating certain processes within aquaculture tanks is becoming increasingly important to improve efficiency. This paper proposes an image-based system designed to address four key tasks in an aquaculture tank with Penaeus vannamei: estimating shrimp length and weight, counting shrimps, and evaluating feed pellet food attractiveness. A setup was designed, including a camera connected to a Raspberry Pi computer, to capture high-quality images around a feeding plate during feeding moments. A dataset composed of 1140 images was captured over multiple days and different times of the day, under varying lightning conditions. This dataset has been used to train a segmentation model, which was employed to detect and filter shrimps in optimal positions for dimensions estimation. Promising results were achieved. For length estimation, the proposed method achieved a mean absolute percentage error (MAPE) of 1.56%, and width estimation resulted in a MAPE of 0.15%. These dimensions were then used to estimate the shrimp’s weight. Shrimp counting also yielded results with an average MAPE of 7.17%, ensuring a satisfactory estimation of the population in the field of view of the image sensor. The paper also proposes two approaches to evaluate pellet attractiveness, relying on a qualitative analysis due to the challenges of defining suitable quantitative metrics. The results were influenced by environmental conditions, highlighting the need for further investigation. The image capture and analysis prototype proposed in this paper provides a foundation for an adaptable system that can be scaled across multiple tanks, enabling efficient, automated monitoring. Additionally, it could also be adapted to monitor other species raised in similar aquaculture environments. Full article

Duralumin 2024-T351 is an alloy characterized by a good mechanical strength, relatively high hardness and corrosion resistance frequently used in the aeronautical, automotive, defense etc. industries. In this paper, the variation of axial forces and torques when drilling aluminum alloy 2024-T351 was investigated, analyzing the measured values for different cutting regimes. Experimental data on the forces and moments generated during the drilling process were collected using specialized equipment, and these data were preprocessed and analyzed using MatLab R218a. The experimental plan included 27 combinations of the parameters of the cutting regime (cutting depth, cutting speed, and feed), for which energetic cutting parameters were measured, the axial force and the torsion moment, respectively Based on these data, a neural network was trained, using the Bayesian regularization algorithm, in order to predict the optimal values of the cutting energy parameters. The neural model proved to be efficient, providing predictions with a relative error below 10%, indicating a good agreement between measured and simulated values. In conclusion, neural networks offer an accurate alternative to classical analytical models, being more suitable for materials with complex behavior, such as aluminum alloys. Full article

The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) faces challenges in establishing high-precision rigid connections between the receiver and the reflective surface due to its vast spatial span. Innovatively, FAST suspends the feed cabin in mid-air using six supporting cables. The precise positioning of the feed focal point is achieved through the coordinated control of cable extension and retraction, along with the A-B axis and the Stewart platform within the cabin. The cables and the feed cabin form a large parallel mechanism. Since the cables are flexible, and the feed cabin remains at a high altitude during observations, it is inevitably subject to internal and external disturbances. To quickly dissipate these disturbances, the system requires a certain level of damping, which directly affects the pointing and tracking accuracy of FAST. During the 2022–2023 operational period, there were multiple instances where the pulleys of the curtain mechanism on the supporting cables became stuck and were carried to the top of the towers by the cables. This also led to the phenomenon where the pulleys, after being stuck, would rapidly slide down the cables due to accumulation. At such moments, the cabin-cable system would experience instantaneous excitation, causing vibrations. This study uses the intrinsic time-scale decomposition (ITD) method to analyze the inertial navigation data installed in the cabin during these events, identifying modal frequencies and damping ratios. The analysis results show that the lowest primary vibration frequency of the FAST cabin-cable suspension system ranges from approximately 0.12 to 0.2 Hz, with a damping ratio of no less than 0.004. These data indicate that the current structure of FAST has a strong energy dissipation capability, providing important reference points for improving the control accuracy of FAST and for the upgrade of the feed support system. Full article

Electric arc furnaces are commonly used in foamed slag technology for the production of steel from steel scrap through an electric process. The effects of using this technology include increased efficiency, reduced consumption of refractory materials, reduced energy consumption, reduced electrode wear, and improved arc stability. The world is constantly looking for solutions to optimize the feeding of the foaming agent to the electric furnace, including determining the moment of starting its feeding. The authors propose using two parameters to determine the optimal moment of introducing the foaming agent: the change in the sound level emitted by the arc furnace and the fluctuations in active power consumption. In order to determine the above parameters, tests were carried out on an industrial alternating UHP arc furnace with a capacity of 70 tons. The sound intensity level was determined at which the feeding of the foaming agent to the furnace’s working space should begin. A moving coefficient of power consumption variation was developed and decision variables of the software for online foaming agent feeding were determined. As a result of implementing the developed solutions to the electric furnace control system and conducting comparative tests, savings were obtained in the form of reduced foaming agent consumption. Full article

Aim: This study aimed to determine whether the Kumagai method could be followed by watching an instructional video and to compare the feeding actions of specialists and the general population. Materials and Methods: Eleven adults from diverse backgrounds were recruited and asked to feed a baby doll using a bottle feeder with a long nipple, and their actions were recorded. Then, they watched a 2.5-min instructional video of the Kumagai method and were asked to bottle-feed again. Video recordings of the participants were used to evaluate whether their actions followed the Kumagai method. Differences in the feeding actions of the specialists and participants were determined from still images in the videos. The McNemar test was used to analyze the differences between the participants’ actions before and after. The Kruskal–Wallis test was also used to determine differences between the actions of participants and specialists. Results: Feeding movements significantly improved after watching the video. Participants’ actions, which differed significantly from those of the specialists, were evident in “the angle of the nipple at the moment the nipple was brought close to the lips” and “the angle change of the nipple from the lip to the mouth”. Conclusions: Watching our short instructional video was effective in improving the technique of the Kumagai method; however, it is insufficient for feeding a real child with cleft lip and palate. Including the rationale of each action in the video and adding direct instruction as a supplement is required. Full article

Tool wear in machining is inevitable, and determining the precise moment to change the tool is challenging, as the tool transitions from the steady wear phase to the rapid wear phase, where wear accelerates significantly. If the tool is not replaced correctly, it can result in poor machining performance. On the other hand, changing the tool too early can lead to unnecessary downtime and increased tooling costs. This makes it critical to closely monitor tool wear and utilize predictive maintenance strategies, such as tool condition monitoring systems, to optimize tool life and maintain machining efficiency. Acoustic emission (AE) is a widely used technique for indirect monitoring. This study investigated the use of Short-Time Fourier Transform (STFT) for real-time monitoring of tool wear in machining AISI 4340 steel using carbide tools. The research aimed to identify specific wear mechanisms, such as abrasive and adhesive ones, through AE signals, providing deeper insights into the temporal evolution of these phenomena. Machining tests were conducted at various cutting speeds, feed rates, and depths of cut, utilizing uncoated and AlCrN-coated carbide tools. AE signals were acquired and analyzed using STFT to isolate wear-related signals from those associated with material deformation. The results showed that STFT effectively identified key frequencies related to wear, such as abrasive between 200 and 1000 kHz and crack propagation between 350 and 550 kHz, enabling a precise characterization of wear mechanisms. Comparative analysis of uncoated and coated tools revealed that AlCrN coatings reduced tool wear extending tool life, demonstrating superior performance in severe cutting conditions. The findings highlight the potential of STFT as a robust tool for monitoring tool wear in machining operations, offering valuable information to optimize tool maintenance and enhance machining efficiency. Full article

This article investigates the design of time-accurate input signals in the angle-of-attack and pitch rate space to identify the aerodynamic characteristics of a generic triple-delta wing configuration at subsonic speeds. Regression models were created from the time history of signal simulations in DoD HPCMP CREATE^TM-AV/Kestrel software. The input signals included chirp, Schroeder, pseudorandom binary sequence (PRBS), random, and sinusoidal signals. Although similar in structure, the coefficients of these regression models were estimated based on the specific input signals. The signals covered a wide range of angle-of-attack and pitch rate space, resulting in varying regression coefficients for each signal. After creating and validating the models, they were used to predict static aerodynamic data at a wide range of angles of attack but with zero pitch rate. Next, slope coefficients and dynamic derivatives in the pitch direction were estimated from each signal. These predictions were compared with each other as well as with the ONERA wind tunnel data and some CFD calculations from the DLR TAU code provided by the NATO Science and Technology Organization research task group AVT-351. Subsequently, the models were used to predict different pitch oscillations at various mean angles of attack with given amplitudes and frequencies. Again, the model predictions were compared with wind tunnel data. Final predictions involved responses to new signals from different models. A feed-forward neural network was then used to model pressure coefficients on the upper surface of the vehicle at different spanwise sections for each signal and the validated models were used to predict pressure data at different angles of attack. Overall, the models predict similar integrated forces and moments, with the main discrepancies appearing at higher angles of attack. All models failed to predict the stall behavior observed in the measurements and CFD data. Regarding the pressure data, the PRBS signal provided the best accuracy among all the models. Full article

The present study was undertaken to evaluate cypermethrin (CYP)-induced oxidative stress [reactive oxygen species (ROS) and lipid peroxidation (LPO) in gills, muscles, brain, and liver tissues] and DNA damage/genotoxicity (peripheral blood erythrocytes) in a freshwater teleost rohu (Labeo rohita) and the protective role of vitamin C. The LC₅₀ of CYP against rohu was found to be 4.5 µg/L in a semi-static culture system through probit analysis. Fingerlings of rohu were distributed into four groups (Group 1st served as a control, fed 35% protein basal diet and was not exposed to CYP; Group 2nd was fed a basal diet and exposed to CYP; Group 3rd and Group 4th were fed diets supplemented with vitamin C at the rate of 100 and 200 mg/kg diet, respectively, and exposed to CYP). Fingerlings were reared on a basal and vitamin C-supplemented diet for 28 days prior to exposure to CYP. The results indicate a time-dependent significant increase in ROS and LPO (indicated by time course increase in TBARS level) as well as DNA damage in terms of number of comets, % DNA in tail, tail moment, tail length, and olive tail moment after exposure to LC₅₀ of CYP. However, statistically comparable results in both Groups 1st and 4th indicate the protective role of vitamin C. The results reveal the effectiveness of vitamin C as a feed additive for countering pesticides toxicity in Labeo rohita. The current study indicates CYP as a potential genotoxicant for fish and classifies SCGE as a reliable and sensitive tool for assessing DNA damage. Full article

The rate of six-month-old infants exclusively breastfed in Spain remains below the recommended rate. This study aimed to explore in detail the evolution of feeding during the first six months of life of a group of newborns, as well as to identify the reasons reported by the mothers for feeding change. A secondary analysis of two prospective longitudinal observational studies was conducted. In both studies, women participants, during the clinical puerperium, opted for exclusive breastfeeding for their newborns. The participants were followed up during the infants’ first six months. A sample size of 314 participants was obtained, of which 77.1% (n = 232) were of Spanish origin, and 51% (n = 160) were primiparous. The prevalence of exclusive breastfeeding at six months was 55.4% (n = 174). During the first four months of life, the main reason for early abandonment of breastfeeding was the perception of insufficient milk production. After the fourth month, the predominant reason was starting work. Statistically significant differences were observed between the reasons for giving up and the total weeks of exclusive breastfeeding (p < 0.001) and total weeks of breastfeeding (p = 0.002). Early weaning from breastfeeding is a multifactorial phenomenon. However, depending on the moment cessation occurs, some reasons predominate over others and, in many cases, can be prevented. These results indicate the need to continue investing efforts to promote and protect breastfeeding in Spain. Full article

The introduction of closed-loop systems in the pediatric population has been a revolution in the management and evolution of diabetes. However, there are not many published studies in situations in which the feeding, schedules, and activities of the children deviate from the routine for which the systems were programmed, as in the case of a summer camp for children and adolescents with diabetes, where the specific programming of this device is not well known. It was a single-center prospective preliminary study. A total of twenty-seven patients (mean age 11.9 ± 1.9 years, 40% male, duration of diabetes 6.44 ± 2.83 years) were included (twenty with Medtronic MiniMed 780G system and seven with Tandem Control-IQ). Glucometric variables and pump functionality were monitored during the 7-day camp and in the following 3 weeks. There was no decrease from the objective TIR 70% at any moment. The worst results in Time Below Range were at 72 h from starting the camp, and the worst results in Time Above Range were in the first 24 h, with a progressive improvement after that. No episodes of level 3 hypoglycemia or ketoacidosis occurred. The use of specific programming in two integrated systems, with complex blood glucose regulation algorithms and not-prepared-for situations with increased levels of physical activity or abrupt changes in feeding routines, did not result in an increased risk of level 3 hypoglycemia and ketoacidosis for our pediatric type 1 diabetes (T1D) patients, regardless of the closed-loop device. Full article

This research proposes a low-cost system consisting of a hardware setup and a deep learning-based model to estimate broiler chickens’ feed intake, utilizing audio signals captured by piezoelectric sensors. The signals were recorded 24/7 for 19 consecutive days. A subset of the raw data was chosen, and events were labeled in two classes, feed-pecking and non-pecking (including singing, anomaly, and silence samples). Next, the labeled data were preprocessed through a noise removal algorithm and a band-pass filter. Then, the spectrogram and the signal envelope were extracted from each signal and fed as inputs to a VGG-16-based convolutional neural network (CNN) with two branches for 1D and 2D feature extraction followed by a binary classification head to classify feed-pecking and non-pecking events. The model achieved 92% accuracy in feed-pecking vs. non-pecking events classification with an f1-score of 91%. Finally, the entire raw dataset was processed utilizing the developed model, and the resulting feed intake estimation was compared with the ground truth data from scale measures. The estimated feed consumption showed an 8 ± 7% mean percent error on daily feed intake estimation with a 71% R2 score and 85% Pearson product moment correlation coefficient (PPMCC) on hourly intake estimation. The results demonstrate that the proposed system estimates broiler feed intake at each feeder and has the potential to be implemented in commercial farms. Full article