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Abstract: Direct hydrogenolysis of glycerol to 1,3-PDO is a cost-effective solution to both production of 1,3-PDO with an increasing industrial demand and valorization of the biomass-derived glycerol, and the oxophilic tungsten oxide was found beneficial to the selective formation of 1,3-PDO from glycerol combined with platinum group metals. However, role of tungsten oxide on the structure, properties and catalytic performances has remained unsolved. Pt-WOx/SiO2 catalysts were prepared by a sequential impregnation method, and the resulting samples were systematically characterized and their catalytic performances were probed by selective hydrogenolysis of glycerol to 1,3-PDO in liquid phase. There was a strong interaction found between the tungsten oxide species and the metallic platinum on the synthesized Pt-WOx/SiO2. A non-stoichiometric ratio of WOx was detected and the polytungstate were predominating on the optimized Pt-10WOx/SiO2 catalyst, and a rather high ratio of W5+ species and the possible oxygen vacancies were suggested. WOx doping enhanced the surface acidity of Pt/SiO2 and promoted the dispersion degree of metallic platinum on it. The glycerol conversion and 1,3-PDO selectivity can be markedly improved by WOx doping into Pt/SiO2 catalysts, and the enhancement in the selectivity to 1,3-PDO was believed to proceed by restraining the transformation of 1,3-PDO to 1-propanol.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Titanium (Ti) and its alloys have received significant attention recently, particularly for medical science, automobile, and aerospace applications. Drilling is used for around 40% to 60% of the material removal processes of an aeronautical product. Non-conventional machining can obtain an optimal quality of drilled holes. The present study has employed a pulsed Nd:YAG laser having 250 W average power to perform the microdrilling on a titanium alloy of 0.45-mm-thick sheet. The study focuses on determining the impact of laser parameters (gas pressure (4 ~ 8 bar), laser input current (200 ~ 260 A), pulse width (4 ~ 8 ms), and pulse repetition rate (1 ~ 7 Hz)) on performance characteristics during microdrilling on a thin foil of titanium alloy having 0.45 mm thickness. To evaluate the quality of microdrilled holes, aspects, e.g., circularity, spatter area, and taper, have been considered. The response surface methodology (RSM) based on the design of the experiment technique was employed to estimate the influence of parameters on performance characteristics with the least number of experiments. The study indicates that assistant gas pressure, pulse width, and laser input current are the essential parameters in taper formation and spatter deposition. The study suggests that the increase in pulse repetition rate and pulse width improves the circularity of the hole. The electron micrography of the drilled holes helps to determine the development of the heat-affected zone (HAZ) and microcracks near drilled holes. The presented research provides a new understanding of how the process parameters contribute to the HAZ development, crack occurrence and intensity. [ABSTRACT FROM AUTHOR]

In modern manufacturing sectors, mechanical drilling of high-strength carbon fiber–reinforced polymer represents the most challenging task as compared to conventional low-strength carbon fiber–reinforced polymer drilling due to the extremely superior mechanical/physical properties involved. The poor machinability of the composite usually results in serious geometric imperfection and physical damage in drilling and hence leads to a large amount of part rejections. In this article, an experimental investigation concerning the cutting-induced damage when drilling high-strength carbon fiber–reinforced polymer laminates was presented. The studied composite specimen was a newly developed high-strength T800S/250F carbon fiber–reinforced polymer composite. A special concentration was made to inspect and characterize the phenomena of various cutting-induced damage promoted in the material drilling. The work focused on the study of the influence of cutting parameters on the distribution and extent of hole damage formation. The experimental results highlighted the most influential factor of feed rate and tool wear in affecting the final extent of induced hole damage when drilling high-strength T800S/250F carbon fiber–reinforced polymer. For minimizing the various damage formation, optimal cutting parameters (high spindle speed and low feed rate) and rigorous control of tool wear should be seriously taken when drilling this material. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of supranutritional dietary selenium (Se) on selenoproteins expression in three immune organs of chickens. A total of 160 1-day-old male Cobb broilers were randomly divided into two groups and fed a Se-deficient corn-soybean basal diet supplemented with 0.3 (adequate) and 3.0 (excess) mg/kg Se for 42 days. Immune organs were collected, and effects of supranutritional Se on messenger RNA abundance of 23 selenoprotein genes and eight inflammation-related genes were compared at day 42. Also enzyme activities were measured at days 14, 28 and 42. The results showed supranutritional dietary Se depressed growth performance of chicken and down-regulated nine and three selenoprotein genes in thymus and spleen, respectively, and only Sepp1 was up-regulated in the bursa of Fabricius. Also three, three and seven inflammation-related genes were up-regulated in three organs, respectively. Supranutritional Se elevated ( P < 0.05) activities of superoxidase dismutase, total antioxidant capacity and glutathione peroxidase, mainly in early stages. In summary, supranutritional Se resulted in down-regulation of selenoprotein genes and up-regulation of inflammation-related genes in three immune organs of chicken, which indicated potential roles of those selenoprotein genes in immune organs of the chicken. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymers (CFRPs) have been extensively used in diverse industrial fields owing to their superior properties and excellent functions. Mechanical drilling has become a compulsory operation to shape these composites to target dimensions and desired quality for assembly purposes. Cutting-induced damages are critical issues when dealing with the manufacturing of CFRPs as they adversely affect the performance and acceptance of eventually-machined composite parts. In this paper, a critical review has been conducted to offer a comprehensive understanding of drilling-associated damages for CFRPs by focusing on illustrating the damage formation mechanisms, classification, evaluation, and suppression. Recent advances addressing the damage issues in drilling CFRPs are also carefully reviewed by critically analyzing the scientific findings reported in the open literature. The fundamental effects of the fiber layup, process parameters, tool geometries/materials, cutting environments and process strategies on the formation and progression of composite damage are discussed. The article also outlines potential solutions and strategies to suppress the formation of drilling-induced damages for CFRP composites. Both researchers and manufacturers will benefit from this review article as they seek to achieve damage-free drilling of CFRP composites. [ABSTRACT FROM AUTHOR]

• Unsupervised clustering technology was firstly used to find the lying center of grouped pigs, and then we redefine the lying pattern of grouped pigs. • The lying pattern center of grouped pigs showed positional variations over time. • CNN-SVM model was firstly used to classify lying patterns of grouped pigs into five types, and we found that the proportion of five lying patterns of grouped pigs changed significantly with time. • The aggregation degree, namely standard deviation of grouped pigs showed positive correlation with pigsty temperature. Changes in lying pattern and lying center position can reflect information about the production efficiency, health, and welfare of pigs. This study investigates the lying pattern and lying center position of grouped pigs by using unsupervised clustering, deep learning, and image processing technology under commercial farming conditions. Images of the lying pattern of grouped pigs under commercial conditions were collected over 110 days, and then ellipse fitting was used to calculate the center of the target pigs. Unsupervised clustering was used to calculate the cluster center of pigs (lying pattern central location). Variance and standard deviation of the distance from the cluster center to each pig were calculated, Finally, the lying patterns of pigs were classified as "Crowded," "Close," "Normal," "Dispersed," and "Far." These patterns were based on the standard deviation. In this research, a Convolutional Neural Network-Support Vector Machine (CNN-SVM) classification model was used to classify five lying patterns of grouped pigs; classification accuracy was up to 97.1%. We studied the change in the lying pattern center of grouped pigs over time, and found that the lying pattern center of grouped pigs showed positional variations over time. We collected experimental site data during the period from July 15, 2021 to October 31, 2021 and analyzed the lying patterns of the grouped pigs. Our results showed that pigs mainly had three lying patterns: "Crowded," "Close," and "Normal." Their proportions were 35%, 33.75%, and 18%, respectively. In addition, the study also found that there were significant changes among the five lying patterns in a day. Standard deviation of grouped pigs showed positive correlation with pigpen temperature, and lying pattern variation of grouped pigs was affected by pigpen temperature. Based on these conclusions, suitable environmental conditions could be created for grouped pigs. In the future, more experiments and research will be extended to other types of livestock, as this technology is helpful for large-scale automatic welfare breeding of livestock. [ABSTRACT FROM AUTHOR]

• Used an image segmentation method (GrabCut) without capturing background images to extract target objects. • Solved the over-segmentation problem by marking the segmentation area before watershed segmentation. • CNN-SVM model was better than single CNN and SVM models for recognition of multiple postures about grouped pigs. • Realized the automatic recognition of multiple postures about grouped pigs under commercial conditions using depth image. Animal posture is a manifestation of animal behavior, and an animal's behavior provides information about their health, welfare, and living environment. In recent years, machine vision and machine learning technologies have been widely used to detect individual or group behavior of pigs. The purpose of this study is to use machine vision and deep learning technologies to recognize and score multiple postures (standing, sitting, sternal recumbency, ventral recumbency and lateral recumbency) of pigs under commercial conditions based on depth images. In this study, the Azure Kinect DK depth camera with a top view was used to obtain the depth image of pigs, and the target pig image was obtained by GrabCut image segmentation and watershed segmentation of target object calibration. Then, based on the characteristics of the image, the convex hull, boundary, and the depth distance of the shoulder and the hip were obtained. The ratio of the convex hull perimeter to the boundary and the ratio of the convex hull area to the boundary, as well as the depth distance of the shoulder and the hip, and the depth distance ratio of the shoulder to the hip were obtained as the input of the Convolutional Neural Network-Support Vector Machine (CNN-SVM) classification model, and the model was trained and tested. In various classifier detection experiments, the performance of our pig posture classifier for standing posture and lateral recumbency posture was better, with the area under the receiver operating characteristic (AUC) values being 0.9969 and 0.9967, respectively. However, the performance of sitting posture, sternal recumbency posture and ventral recumbency posture classifier was slightly worse but still had good performance: AUC values were 0.9790, 0.9355 and 0.9795, respectively. The model in this article was used to detect the average postures of pigs in one day (taking the average for eight consecutive days), and it was found that the proportion of lying postures was higher than other postures (lying postures were 72%, standing postures were 20%, and sitting postures were 8%). The proportion of standing postures in the daytime was higher than that in the evening, and lying posture was the opposite. The proportion of the three lying postures also changes over time. This study compared the difference of posture recognition accuracy between the model in this paper (CNN-SVM), SVM and CNN; using the same training data and experimental data, the accuracy of posture recognition of the three models was 94.6368%, 92.2175% and 90.5396%, respectively. Therefore, the recognition accuracy of the model in this paper was improved greatly compared with CNN and SVM. [ABSTRACT FROM AUTHOR]

Sintering is a comprehensive process that involves the complex evolution of material microstructures and properties, being recognized as a critical factor to improve the machinability of ceramics. The present work aims to address the evolution of the material removal mechanisms of the 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) during the sintering process based on the micro scratching tests. The impacts of sintering temperatures on the material removal behaviors, including scratching forces, scratch morphologies, specific scratching energies, and critical transition depths, were rigorously studied. The acquired results indicate that the intergranular bonding strength is a critical factor that determinines the material removal mechanisms of 3Y-TZP, and 1100 °C signifies the transition threshold for the material removal mode. After 1100 °C, the material removal mechanism has gradually converted into the typical ductile-brittle removal regime. Moreover, the critical depth in ductile regime at 1200 °C is about 1.89 times that at 1500 °C, and the critical depth of ductile-brittle transition at 1200 °C is approximately 2.08 times that at 1500 °C. [ABSTRACT FROM AUTHOR]

Selective aerobic oxidation of toluene to benzaldehyde has gained vast attentions due to its characteristics in environmental friendliness, atomic economy and a waiver of chlorine contamination. The separation, recovery and reuse of homogeneous catalysts will, however, be tricky. In this work, cobalt ions were immobilized by coprecipitation followed by a special washing, and the prepared cobalt-containing intermediate exhibited excellent textural properties and an exclusively low chemical state. 3-(Glycidoxypropyl) trimethoxysilicane (GPTMS) was used as a linking molecule to anchor N-hydroxyphthalimide (NHPI) onto the intermediate by C–O–N and Si–O–Si bonds, respectively, and a reliable covalent combination of NHPI was confirmed by the decomposition temperature and chemical states of N element in the co-immobilized NHPI/Co catalyst. The synthesized NHPI-GPTMS-CS catalyst exhibited a toluene conversion of 42.5% and a selectivity to benzaldehyde of 52.6% in hexafluoropropan-2-ol, which is much higher than the reactivity of toluene observed on the catalyst combination of commercial silica anchored NHPI (NHPI-GPTMS-SiO 2) and homogeneous cobaltous ions, testifying an accessibility and a better synergy between N-oxyl radicals and cobaltous ions co-immobilized. There was no appreciable leaching of cobalt species and anchored NHPI observed for the co-immobilized catalyst and its activity for toluene oxidation was well remained, indicating an excellent reusable capability. It was observed that benzaldehyde is converted into benzoic acid, but benzyl alcohol into benzaldehyde and toluene via oxidation and disproportionation, respectively, over the synthesized co-immobilized catalyst. Toluene oxidation is suggested to proceed via a free radical mode and the produced water is one of the quenching agents. [Display omitted] • NHPI and cobaltous ions were co-immobilized on SiO 2 to catalyze toluene oxidation. • The co-immobilized NHPI/Co(II) exhibited well in toluene oxidation to benzaldehyde. • The co-immobilized catalyst showed excellent reusability. [ABSTRACT FROM AUTHOR]

Jet array impingement boiling is promising to be used in the applications of large-area high-heat-flux cooling. In this study, the bubble dynamics and pressure oscillations of a one-dimensional confined jet array impingement boiling of highly subcooled water on smooth silicon wafer surface under periodical heat fluxes are investigated experimentally. It is found nucleate boiling mainly occurs nearby wall jet collision (WJC) zones and the initial bubble nucleation starts after a certain period of time in each heating cycle, which is insensitive to heating frequency under the present experimental conditions but related to the positions of WJC zones due to the crossflow effect. The initial bubbles have relatively larger size and will departure from heating surface or not, while the offspring bubbles have relatively smaller size and will not departure from heating wall but collapse on the heating wall. The collapsing of the above two kinds of normal-sized bubble will generate microbubbles (i.e., Microbubble emission boiling, MEB) and the number of microbubbles in jet chamber increases during the heating period. The periodical bubble growth and collapse causes high frequency pressure oscillation, with its frequencies being related to the bubble nucleation rates. The peak oscillation frequency shows somewhat increasing trend with the increasing of heating frequency. [ABSTRACT FROM AUTHOR]

Basalt fibre-reinforced polymer (BFRP) composites probably tend to replace some carbon fibre-reinforced polymer (CFRP) applications due to their excellent specific strengths and sustainability. Despite the published early promising results concerning the material properties of BFRP, their application is not widespread, and their machinability is not supported widely by published experiences. The main aim of the present study is to experimentally investigate the drilling-induced geometrical damages of BFRP and CFRP composites. Drilling experiments were conducted at various feed and cutting speed levels using a solid carbide twist drill. The drilling-induced burr was analysed by a Mitutoyo 361–804 digital microscope, a Mitutoyo SJ400 surface tester recorded the surface roughness, and the microstructure was analysed by a Zeiss Evo MA 10 scanning electron microscope. The measured data were evaluated through digital image processing (DIP), response surface methodology (RSM), and analysis of variances (ANOVA). The experimental results show that drilling-induced burr is more severe and surface roughness is worse in BFRP than in CFRP. The composite type influenced the geometrical damages primarily, followed by the feed in the case of burrs and by the cutting speed in the case of surface roughness. The present experimental study suggests that the drilling of BFRP is even more challenging than drilling CFRP from the point of view of burr formation and micro geometrical properties. [ABSTRACT FROM AUTHOR]