Research on the Exploration of Sprayed Clay Material and Modeling System

As a traditional building material, clay has been used by humans for a long time. From early civilisations, to the modern dependence on new technologies, the craft of clay making is commonly linked with the use of moulds, handmade creations, ceramic extruders, etc. (Schmandt and Besserat, 1977). Clay in the form of bricks is one of the oldest building materials known (Fernandes et al, 2010). This research expands the possibilities offered by standardised bricks by testing types of clay, forms, shapes, porosity, and structural methods. The traditional way of working with clay relies on human craftsmanship and is based on the use of semi-solid clay (Fernandes et al., 2010). However, there is little research on the use of clay slurry. With the rise of 3D printing systems in recent years, research and development has been emerging on using clay as a 3D printing filament (Gürsoy, 2018). Researchers have discovered that in order for 3D-printed clay slurry to solidify quickly to support the weight of the added layers during printing, curing agents such as lime, coal ash, cement, etc. have to be added to the clay slurry. After adding these substances, clay is difficult to be reused and can have a negative effect on the environment (Chen et al., 2021). In this study, a unique method for manufacturing clay elements of intricate geometries is proposed with the help of an internal skeleton that can be continuously reused. The study introduces the process of applying clay on a special structure through spraying and showcases how this method creates various opportunities for customisation of production

An MILP model and a hybrid evolutionary algorithm for integrated operation optimisation of multi-head surface mounting machines in PCB assembly

This paper focuses on an operation optimisation problem for a class of multi-head surface mounting machines in printed circuit board assembly lines. The problem involves five interrelated sub-problems: assigning nozzle types as well as components to heads, assigning feeders to slots and determining component pickup and placement sequences. According to the depth of making decisions, the sub-problems are first classified into two layers. Based on the classification, a two-stage mixed-integer linear programming (MILP) is developed to describe it and a two-stage problem-solving frame with a hybrid evolutionary algorithm (HEA) is proposed. In the first stage, a constructive heuristic is developed to determine the set of nozzle types assigned to each head and the total number of assembly cycles; in the second stage, constructive heuristics, an evolutionary algorithm with two evolutionary operators and a tabu search (TS) with multiple neighbourhoods are combined to solve all the sub-problems simultaneously, where the results obtained in the first stage are taken as constraints. Computational experiments show that the HEA can obtain good near-optimal solutions for small size instances when compared with an optimal solver, Cplex, and can provide better results when compared with a TS and an EA for actual instances

Fabrication of Complex Clay Structures Through an Augmented Reality Assisted Platform

The relationship between clay manufacturing and architectural design has a long trajectory that has been explored since the early 2000s. From a 3D printing or assembly perspective, using clay in combination with automated processes in architecture to achieve computational design solutions is well established. (Yuan, Leach & Menges, 2018). Craft-based clay art, however, still lacks effective computational design integration. With the improvement of Augmented Reality (AR) technologies (Driscoll et al., 2017) and the appearance of digital platforms, new opportunities to integrate clay manufacturing and computational design have emerged. The concept of digitally transferring crafting skills, using holographic guidance and machine learning, could make clay crafting accessible to more workers while creating the potential to share and exchange digital designs via an open-source manufacturing platform. In this context, this research project explores the potential of integrating computational design and clay crafting using AR. Moreover, it introduces a platform that enables AR guidance and the digital transfer of fabrication skills, allowing even amateur users with no prior making experience to produce complex clay components

Influence of dietary zinc on growth, zinc bioaccumulation and expression of genes involved in antioxidant and innate immune in juvenile mud crabs (Scylla paramamosain)

The aim of present study was to investigate the effects of dietary Zn level on growth performance, Zn bioaccumulation, antioxidant capacity and innate immunity in juvenile mud crab (Scylla paramamosain). Six semi-purified diets were formulated to contain dietary Zn levels of 44.5, 56.9, 68.5, 97.3, 155.6 or 254.7 mg·kg-1, respectively. Dietary Zn level significantly influenced percent weight gain (PWG), with highest observed in crab fed the diet containing 97.3 mg·kg-1 Zn. Tissue Zn concentrations significantly increased as dietary Zn levels increased from 44.5 to 254.7 mg·kg-1. Retention of Zn in hepatopancreas increased with dietary Zn levels up to 68.5 mg·kg-1 and then significantly decreased. Moreover, inadequate dietary Zn (44.5 and 56.9 mg·kg-1) reduced anti-oxidation markers including total superoxide dismutase and copper/zinc superoxide dismutase activities and total anti-oxidant level. Crabs fed the diet with 44.5 mg·kg-1 Zn also showed significantly lower expression of genes involved in antioxidant status, such as Cu/Zn sod, glutathione peroxidase, catalase and thioredoxin than those fed diets containing 68.5 and 97.3 mg·kg-1 Zn. Highest activities of phenoloxidase and alkaline phosphatase were recorded in crab fed the diets containing 68.5 and 97.3 mg·kg-1 Zn. Expression levels of prophenoloxidase and toll-like receptor 2 were higher in crab fed the 97.3 mg·kg-1 Zn diet compared to crab fed the other diets. Based on PWG alone, the optimal dietary Zn level was estimated to be 82.9 mg·kg-1, with 68.5 to 97.3 mg·kg-1 recommended for maintaining optimal Zn bioaccumulation, oxidation resistance and innate immune response of juvenile mud crab

Toxicological mechanism of excessive copper supplementation: Effects on coloration, copper bioaccumulation and oxidation resistance in mud crab Scylla paramamosain

Copper is a widespread pollutant in marine environments, and marine animals can ingest large amounts of copper through the food chain. Here, an 8-week feeding trial was designed to investigate the effects of different dietary copper levels on coloration, copper bioaccumulation, stress response and oxidation resistance of juvenile mud crab Scylla paramamosain. The results indicated that crabs fed the diet with 162 mg/kg copper exhibited a dark-blue carapace and hemolymph. The accumulation of copper in tissues was positively correlated with the level of copper in feed. High/excess dietary copper (162 mg/kg) up-regulated the expression of stress response related genes, and reduced the expression/activities of anti-oxidation genes/enzymes. The activity of phenoloxidase decreased significantly when dietary copper level was 86-162 mg/kg, and the expression of hemocyanin was up-regulated in crab fed the diets with 28-162 mg/kg copper. Overall, the results of the present study indicated that high dietary copper led to parachrea in carapace and hemolymph of mud crab, and caused copper deposition abnormality in carapace and hepatopancreas. The data suggested that the toxic effects of dietary copper were concentration-dependent such that, excess dietary copper (162 mg/kg) had adverse impacts on oxidation resistance

Dietary lipid and n-3 long-chain PUFA levels impact growth performance and lipid metabolism of juvenile mud crab, Scylla paramamosain

An 8 weeks feeding trial was conducted to evaluate the effects of dietary n-3 LC-PUFA levels on growth performance, tissue fatty acid profiles and relative expression of genes involved in lipid metabolism of mud crab (Scylla paramamosain). Ten isonitrogenous diets were formulated to contain five n-3 LC-PUFA levels at 7 % and 12 % dietary lipid levels. Highest weight gain and specific growth rate were observed in crabs fed the diets with 19.8 and 13.2 mg g-1 n-3 LC-PUFA at 7 % and 12 % lipid, respectively. Moisture and lipid contents in hepatopancreas and muscle were significantly influenced by dietary n-3 LC-PUFA at the two lipid levels. The DHA, EPA, n-3 LC-PUFA contents and n-3/n-6 PUFA ratio in hepatopancreas and muscle significantly increased as dietary n-3 LC-PUFA levels increased at both lipid levels. The expression levels of Δ6 FAD and ACO in hepatopancreas increased significantly, and expression levels of FAS, CPTⅠ and HSL were down-regulated, with increased dietary n-3 LC-PUFA regardless of lipid level. Based on weight gain, the n-3 LC-PUFA requirements of S. paramamosain were estimated to be 20.1 mg g-1 and 12.7 mg g-1 of diet at 7 % and 12 % dietary lipid, respectively. Over all, dietary lipid level influenced lipid metabolism, and purified, high-lipid diets rich in palmitic acid reduced the n-3 LC-PUFA requirement of juvenile mud crab

Dietary fenofibrate attenuated high-fat-diet-induced lipid accumulation and inflammation response partly through regulation of pparα and sirt1 in juvenile black seabream (Acanthopagrus schlegelii)

An 8-week feeding trail was conducted in Acanthopagrus schlegelii with an initial body weight of 8.34±0.01g. Three isonitrogenous diets were formulated, (1) Control: medium-fat diet (12%); (2) HFD: high-fat diet (18%); (3) HFD+FF: high-fat diet with fenofibrate (0.15%). Liver histological analysis revealed that, compared to HFD, vacuolar fat drops were smaller and fewer in fish fed fenofibrate. Expression of lipid catabolism regulator peroxisome proliferator-activated receptor alpha (pparα) was up-regulated by fenofibrate compared with HFD. In addition, fenofibrate significantly increased the expression level of silent information regulator 1 (sirt1). Meanwhil e, the expression level of anti-inflammatory cytokine interleukin 10 (il-10) in intestine was up-regulated, while pro-inflammatory cytokine interleukin 1β (il-1β) in liver and intestine were down-regulated by dietary fenofibrate supplementation. Overall, the present study indicated that fenofibrate reduced fat deposition and attenuated inflammation response caused by HFD partly through a pathway involving regulation of pparα and sirt1

Antibacterial activity and mechanism of sanguinarine against Staphylococcus aureus by interfering with the permeability of the cell wall and membrane and inducing bacterial ROS production

Staphylococcus aureus (SA) is representative of gram-positive bacteria. Sanguinarine chloride hydrate (SGCH) is the hydrochloride form of sanguinarine (SG), one of the main extracts of Macleaya cordata (M. cordata). There are few reports on its antibacterial mechanism against SA. Therefore, in this study, we investigated the in vitro antibacterial activity and mechanism of SGCH against SA. The inhibitory zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were measured, and the bactericidal activity curve was plotted. In addition, the micromorphology, alkaline phosphatase (AKP) activity, Na+K+, Ca2+Mg2+-adenosine triphosphate (ATP) activity, intracellular reactive oxygen species (ROS), and fluorescein diacetate (FDA) were observed and detected. The results showed that the inhibitory zone of SGCH against SA was judged as medium-sensitive; the MIC and MBC were 128 and 256 μg/mL, respectively; in the bactericidal activity curve, SGCH with 8 × MIC could completely kill SA within 24 h. SGCH was able to interfere with the integrity and permeability of the SA cell wall and membrane, as confirmed by the scanning electron microscopy (SEM) images, the increase in extracellular AKP and Na+ K+, Ca2+ Mg2+-ATP activities as well as the fluorescein diacetate (FDA) staining experiment results. Moreover, a high concentration of SGCH could induce SA to produce large amounts of ROS. In summary, these findings revealed that SGCH has a preferable antibacterial effect on SA, providing an experimental and theoretical basis for using SG as an antibiotic substitute in animal husbandry and for the clinical control and treatment of diseases caused by SA

Dietary soybean oil aggravates the adverse effects of low salinity on intestinal health in juvenile mud crab Scylla paramamosain

Salinity is one of the important factors affecting the physiological state of crustaceans in marine environments. Lipid plays major roles in energy supply and is main sources of essential fatty acids for membrane integrity, which is critical in adaptations to changes in salinity. Here we evaluated the effects of salinity (medium, 23 ppt and low, 4 ppt) and dietary lipid source (fish oil, FO and soybean oil, SO) on intestinal health of the marine crustacean mud crab Scylla paramamosain. The results indicated that low salinity and dietary SO (LSO group) significantly affected intestinal histomorphology, with a significant decrease of intestinal fold height and width as well as down-regulation of intestinal mRNA levels of tight junction genes compared to crab reared at medium salinity and fed FO diets (MFO group). Crabs reared at low salinity and fed SO showed an increased inflammatory response in intestine, which stimulated a physiological detoxification response together with apoptosis compared to crab in the MFO group. Low salinity and SO diets also could be responsible for multiply the pathogenic bacteria of Photobacterium and inhibit the beneficial bacteria of Firmicutes and Rhodobacteraceae in intestine, and act on a crucial impact on the development of intestinal microbial barrier disorders. The results of microbial function predictive analysis also support these inferences. The findings of the present study demonstrated that soybean oil as the main dietary lipid source could exacerbate the adverse effects of low salinity on intestinal health of mud crab, and provided evidence suggesting that dietary lipid source and fatty acid composition may play vital roles in intestinal health and the process of adaptation to environmental salinity in marine crustaceans