Characterization of 3D Printed Auxetic Sinusoidal Patterns/Nylon Composite Fabrics

Indonesia, as the world's largest archipelagic country, plays a strategic role in international trade, maritime transportation, and maritime defense, making efficient and reliable ship propulsion technology a key priority. Waterjet thrusters offer advantages in maneuverability, energy efficiency, and resistance to cavitation compared to conventional propellers, with the geometric design of components such as impellers, inlets, and outlets, as well as Thermoplastic Polyurethane (TPU) materials produced via 3D printing, significantly influencing thrust performance. The twin waterjet thruster system provides fault-tolerant benefits, while TPU has adjustable mechanical properties and potential biocompatibility. This experimental research designed a twin waterjet thruster prototype using SolidWorks, produced components (4-blade impeller, 12-blade inlet, 12-blade outlet) via FDM 3D printing with an Anet A8 Plus PRO machine and TPU filament, and tested it in a water tank using a 22 HP engine at 1000-4100 rpm with thrust measurement via a scale. Results showed thrust increased linearly with engine speed: 2.6 kg (25.5 N) at 1000 rpm, 5.2 kg (51.01 N) at 2000 rpm, 7.4 kg (72.59 N) at 3000 rpm, and 11.3 kg (111.24 N) at 4100 rpm, with small variations between experiments indicating stable performance. Overall, the TPU-based twin waterjet thruster demonstrated consistent and efficient performance, potential for small-to-medium-sized vessels, with further development including hydrodynamic design optimization, stronger materials, and electric motors for energy sustainability.

Effect of dietary 25-hydroxycholecalciferol supplementation and high stocking density on performance, egg quality, and tibia quality in laying hens

High stocking density is used in aquaculture to optimize farming. However, such strategies can stress territorial fish by increasing aggression, thus harming the fish welfare and productive performance. Here, we tested the effect of long-term tactile body stimulation (TS) on alleviating the impact of high stocking density in Nile tilapia (Oreochromis niloticus). Ten males were grouped for 21 days into four treatments (10 replicates each one) combining TS with high (1.2 kg·m³) or low (0.6 kg·m³) densities: (1) without TS and high density; (2) without TS and low density; (3) with TS and high density; and (4) with TS and low density. A rectangular PVC frame fitted with vertical plastic sticks sided with silicone bristles was placed in the center of aquarium. The fish receive TS when passing through the bristles. An apparatus without bristles was used as control. We found higher cortisol levels under TS conditions. All parameters of productive performance (growth, food efficiency, and condition factor) were higher in the treatment with TS and low density, lower in the treatment without TS and high density, and similar between treatments high density with TS and low density without TS. The results suggest that TS improves productive performance of Nile tilapia, counteracting the negative effects of high stocking density.

Leather manufacturing process involves a lot of waste disposal which pollutes environment, some of the processes are inevitable. In the present investigation, 3D printing technology was used to reduce the wastage and to cover defective regions in leather. The present study focuses on synthesis of acrylic binder using emulsion polymerization technique. These binders were analysed for solid content for better optimisation of the amount of binder to be utilised for finishing operation. The experimental binder was prepared with 26% solids. Particle size and thermogravimetric analyses were carried out to understand the size and shape of the particles and their thermal resistance. These binders were used for leather finishing and the performance of leather was studied. Surface morphology changes of leathers were studied using Scanning Electron Microscopy (SEM). Wet and dry rub fastness, finish film adhesion, light fastness and organoleptic properties were studied and found to be superior compared with control leathers. The acrylic finished leather with minor defects was taken for 3D printing and designed using Thermoplastic Polyurethane (TPU) as filament. The acrylic finished leather shows good adhesion for TPU and it results in numerous designs in short duration. The new additive was added to leather using 3D printing technology to produce a tailor-made valuable design without any waste disposal and chemical discharge. This invention may convert the rejected waste leather into valuable material and lead to the new generation hybrid leather for use.

Cortisol level changes in response to stocking density in the early stages of rainbow trout were measured. Eggs were exposed to low, normal, and high (2.55, 5.10 and 7.65 eggs cm(-2)) densities during the incubation period. Cortisol of maternal origin was found in pre-fertilized eggs (5.09 ± 0.12 ng g(-1)) of rainbow trout. In newly fertilized eggs, resting Cortisol levels (3.68 ± 0.14 ng g(-1)) decreased to 0.58 ± 0.08, 0.60 ± 0.12, and 0.57 ± 0.16 ng g(-1) at low, normal and high densities by day 10 (organo-genesis), respectively. Resting Cortisol levels remained constant until the eyed stage (day 18). Then, Cortisol showed an increase at hatching to 1.16 ± 0.11, 1.20 ± 0.12, and 1.21 ± 0.14 ng g(-1) at low, normal, and high densities, respectively. The pattern of change in Cortisol level was similar in all three densities. Interrenal cells were observed in 1-day old alevins at all three densities. Hematopoietic tissue, renal tubules and nucleated red blood cells were clarified through the head part of kidney. Higher numbers and larger interrenal cells were observed at high-density groups. Chronic density stress test conducted on embryonic stages of rainbow trout revealed no differences in Cortisol levels, but had an effect on the abundance and size of the interrenal cells. Densities were equaled after hatching (200 alevins per replicate) to investigate the different densities of eggs on stress indices in rainbow trout alevins. An acute stress (air exposure of eggs for five minutes) was applied in three treatments two weeks after hatching, and samples were taken at 0, 1, 3, 6, and 24 hps (hours post stress). Cortisol content increased under low density in 1 hps and reached from 5.21 ± 0.13 ng g(-1) to 6.01 ± 0.18 ng g(-1) (P < 0.05). Cortisol levels increased under normal density in 1 hps from 6.03 ± 0.28 ng g(-1) to 10.84 ± 0.18 ng g(-1) (P < 0.05). In high density also Cortisol increased from 6.83 ± 0.23 ng g(-1) to 8.86 ± 0.26 ng g(-1) (P < 0.05). At 3 hps;, Cortisol level was returned to basal level under low (P > 0.05) and normal (P > 0.05) densities, but significantly decreased (P < 0.05) under high density. Results revealed that the Cortisol biosynthesis was observed in rainbow trout between eyeing to the hatching stage. An increase in the density of eggs until 7.65 egg cm(-2) impaired Cortisol secretion and feedback system in alevins. However, more studies are needed to identify the exact time for Cortisol synthesis ability from eyeing to hatching in this species.

In this study, we investigate the effect of local adaptation to developmental density on male mating success in laboratory populations of Drosophila melanogaster. Mating success is known to be influenced by body condition which can in turn be influenced by local adaptation. We test the hypothesis that males adapted to a given environment have higher mating success when assayed in that environment. We used males selected for adaptation to high larval density and their controls which are reared at low larval density. We grew assay males in low and high densities whereas the focal females (raised at low larval density) used for the experiment belonged to the common ancestor of selected and control populations. We considered selected males grown at high density and control males grown at low density as 'adapted'. Similarly, we considered selected males grown at low density and control males grown at high density as 'nonadapted'. Selected male belonging to a given treatment (larval density) was made to compete with control male of the same treatment for mating with ancestral female. We quantified components of reproductive fitness: mating latency, copulation duration, mating success and number of progeny sired by the 'adapted' and 'nonadapted' males. The results show that local adaptation does not lead to higher mating success in populations adapted to their own larval rearing environment.

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Fused Deposition Modeling (FDM) is a highly adaptable additive manufacturing method that is extensively employed for creating intricate structures using a range of materials. Thermoplastic Polyurethane (TPU) is a highly versatile material known for its flexibility and durability, making it well-suited for use in industries such as footwear, automotive, and consumer goods. Hoses, gaskets, seals, external trim, and interior components are just a few of the many uses for thermoplastic polyurethanes (TPU) in the automobile industry. The objective of this study is to enhance the performance of Fused Deposition Modeling (FDM) by optimizing the parameters specifically for Thermoplastic Polyurethane (TPU) material. This will be achieved by employing a Taguchi-based Grey Relational Analysis (GRA) method. The researchers conducted experimental trials to examine the impact of key FDM parameters, such as layer thickness, infill density, printing speed, and nozzle temperature, on critical responses like dimensional accuracy, surface finish, and mechanical properties. The Taguchi method enabled the systematic exploration of parameters through the design of experiments (DOE). The experimental data was analyzed using Grey Relational Analysis (GRA) to determine the optimal parameter settings. The GRA methodology offers a comprehensive approach to assess and prioritize various performance criteria, taking into account the inherent uncertainties in the manufacturing process. The results demonstrated the efficacy of the Taguchi-based GRA method in pinpointing the optimal parameter combinations for improving the printing quality and efficiency of TPU components. This study enhances the comprehension of Fused Deposition Modeling (FDM) for Thermoplastic Polyurethane (TPU) material and provides a useful framework for optimizing the manufacturing process. Manufacturers can enhance printing productivity, quality, and reliability by utilizing Taguchi-based GRA. This, in turn, promotes the wider use of FDM technology in various industrial applications that demand flexible and long-lasting components.&lt;/div&gt;&lt;/div&gt;

<p class="MsoNormal" style="margin: 0in; line-height: normal; font-size: 10.5pt; font-family: DengXian; color: rgb(0, 0, 0);"><a name="_Hlk71656368"><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;">This design, consisting of a high waist skirt and a sleeveless vest, is the outcome of the designers’ 3D printing (3DP) textile innovation challenge, especially focusing on the seamless joint process of 3D printed panels for wearables and drapability of the newly developed 3D printed textile. The design comprised with 164 panels embedding two flower-inspired textile motifs. Considering wearers’ function and comfort, 3D printed fabrics were developed with lace pattern structures that provide better flexibility and stretchability. </span></a><span style="font-size: 12pt; font-family: &quot;Times New Roman&quot;, serif;">With the flexible 3DP filament, lace structured patten, and seamless adhesive joint method, 3D printed textiles in this design were created to replicate traditional lace structured fabrics, considering high drapability. The wearables created by using this novel 3D printed seamless textiles opens the great potential of 3DP for the use in fashion. Fused deposition modeling 3DP method with thermoplastic polyurethane filaments was applied to create this design.<o:p></o:p></span>

Archery hunting in Oregon has increased dramatically over the past 2 decades. At the same time, spring juvenile to adult female ratios of Rocky Mountain elk (Cervus elaphus) have been declining. This has raised concern that archery seasons may be disrupting elk breeding and contributing to the decline in recruitment. Two mechanisms could contribute to reduced juvenile:female ratios: 1) reduced pregnancy rates, and 2) delayed conception dates because of human disturbance during the rut. We varied the number of archery hunters at the Starkey Experimental Forest and Range over 13 years to evaluate effects of archer density on reproduction of elk. Archer densities were maintained at high densities during 4 years $({\bar {x}} = 1.09\,{\rm tags}\;{\rm sold}/{\rm km}^{_{2} } )$, low densities during 3 years $({\bar {x}} = 0.53\,{\rm tags}\,{\rm sold}/{\rm km}^{_{2} } )$, and no archers during 6 years. We determined pregnancy status, age, kidney fat index (KFI), lactation status, and fetus conception dates for 622 female elk harvested in December. We found pregnancy rate differences of 0.105, 0.080, and 0.021 between high and no archer density years (P = 0.004), high and low archer density years (P = 0.054), and low and no archer density years (P = 0.616), respectively. Conception dates were 4 days later for high archer density compared to low archer density (P = 0.006), but did not differ between high and no archer years (2 days; P = 0.136) or between low and no archer years (2 days; P = 0.108). We compared generalized linear model estimates of pregnancy rates and determined pregnancy rates for 28% of the lactating female elk to be affected by high archer density, whereas archer densities had no significant affect on pregnancy rate estimates for non‐lactating females. We found no difference in conception dates among archer densities when comparing model estimates. Our results suggest that archer density and its interaction with nutritional condition of elk influence pregnancy rates of lactating females with low KFI levels; however, the effect of archer density alone does not explain the magnitude of decline in juvenile to female ratios observed in Oregon. © 2012 The Wildlife Society.

Fused deposition modeling (FDM) uses lattice arrangements, known as infill, within the fabricated part. The mechanical properties of parts fabricated via FDM are dependent on these infill patterns, which make their study of great relevance. One of the advantages of FDM is the wide range of materials that can be employed using this technology. Among these, polylactic acid (PLA)-wood has been recently gaining attention as it has become commercially available. In this work, the stiffness of two different lattice structures fabricated from PLA-wood material using FDM are studied: hexagonal and star. Rectangular samples with four different infill densities made of PLA-wood material were fabricated via FDM. Samples were subjected to 3-point bending to characterize the effective stiffness and their sensitivity to shear deformation. Lattice beams proved to be more sensitive to shear deformations, as including the contribution of shear in the apparent stiffness of these arrangements leads to more accurate results. This was evaluated by comparing the effective Young’s modulus characterized from 3-point bending using equations with and without shear inclusion. A longer separation between supports yielded closer results between both models (~41% for the longest separation tested). The effective stiffness as a function of the infill density of both topologies showed similar trends. However, the maximum difference obtained at low densities was the hexagonal topology that was ~60% stiffer, while the lowest difference was obtained at higher densities (star topology being stiffer by ~20%). Results for stiffness of PLA-wood samples were scattered. This was attributed to the defects at the lattice element level inherent to the material employed in this study, confirmed via micro-characterization.

Fibroblasts are actively and dynamically involved in wound healing (dermal regeneration, wound contraction, and scar contracture) and fibrosis. Fibroblast-seeded collagen gels provide an in vitro model for these processes. Over time, fibroblasts will contract the gels, but the mechanisms are not completely understood. This research investigated the influence of cell density and collagen crosslinking on the contraction of fibroblast-populated gels by varying seeding density and blocking the catalyzing enzyme lysyl oxidase, respectively. Collagen gels were seeded with fibroblasts at either 3 x 104 or 1 x 105 cells/mL and incubated with or without the lathyrogen beta-aminoproprionitrile (BAPN) for 8 days. In all, four experimental groups were analyzed: low cell density control, high cell density control, low density plus BAPN, and high density plus BAPN. Digital images were taken daily and gel area was calculated. Contraction was dependent on cell concentration, with higher density gels being contracted to a greater extent. BAPN had no effect until after day 2 when it inhibited (high density) or almost completely blocked (low density) the gel contraction. BAPN also reduced total long-term contraction. The results demonstrated a bimodal nature to fibroblast-mediated gel contraction: a cell density-dependent component, most likely mediated through cellular forces, and a delayed collagen crosslinking component that could be blocked by BAPN. In the long-term, similar contraction rates among the four experimental groups, particularly between the two BAPN groups, implies that the collagen crosslinking effect is discrete and independent of cell density.

Context Egg production rate (EPR) is the main criteria for egg producers and egg quality is important for consumers. Exposed to music, layers kept at appropriate stocking density could display optimal production performance without compromising egg quality. Aims This study aimed to investigate the possibility of employing instrumental music stimulus and regulating stocking density to maximise egg production performance and improve egg quality in Xiandao green-shell layers. Methods In total, 378 30-week-old layers were randomly distributed into nine treatments across three types of sound sources (natural sound, instrumental music, or mixed road noise) × three different stocking densities (4, 7 and 10 birds/cage corresponding to low, medium, and high density respectively), with six replicates per treatment. The 24-day experimental period was equally divided into four phases. EPR, average egg weight, and serum IgG concentration were determined at the end of each phase. Egg quality and organ indices were determined at the end of experiment. Results Hens exposed to music had a significantly higher EPR and laid eggs of better quality than did hens subjected to mixed road noise. Across all parameters, hens exposed to music did not significantly differ from hens exposed to natural sound. Stocking density had significant impacts on EPR, relative eggshell weight, and serum IgG concentration, with hens kept at high stocking density (357 cm2/hen) exhibiting the lowest values. Hens kept at medium density (510 cm2/hen) and low density (892 cm2/hen) showed no significant differences in tested parameters except that the former produced eggs with a significantly higher relative eggshell weight. Significant interactions between sound and density were observed in EPR, relative yolk weight, and spleen index, with hens exposed to music and kept at low density displaying the highest values. Conclusions Music and low stocking density had favourable effects on improving egg production and egg quality, while road noise and high stocking density exerted negative influences on them. Implications Xiandao green-shell layers are recommended to be kept at medium density to maximise the production benefits. The integration of music playback into management practices will not compromise layers’ production potential displayed under natural sound exposure.

With the purpose of making soft robotic structures with embedded sensors, additive manufacturing techniques like fused deposition modeling (FDM) are popular. Thermoplastic polyurethane (TPU) filaments, with and without conductive fillers, are now commercially available. However, conventional FDM still has some limitations because of the marginal compatibility with soft materials. Material selection criteria for the available material options for FDM have not been established. In this study, an open-source soft robotic gripper design has been used to evaluate the FDM printing of TPU structures with integrated strain sensing elements in order to provide some guidelines for the material selection when an elastomer and a soft piezoresistive sensor are combined. Such soft grippers, with integrated strain sensing elements, were successfully printed using a multi-material FDM 3D printer. Characterization of the integrated piezoresistive sensor function, using dynamic tensile testing, revealed that the sensors exhibited good linearity up to 30% strain, which was sufficient for the deformation range of the selected gripper structure. Grippers produced using four different TPU materials were used to investigate the effect of the Shore hardness of the TPU on the piezoresistive sensor properties. The results indicated that the in situ printed strain sensing elements on the soft gripper were able to detect the deformation of the structure when the tentacles of the gripper were open or closed. The sensor signal could differentiate between the picking of small or big objects and when an obstacle prevented the tentacles from opening. Interestingly, the sensors embedded in the tentacles exhibited good reproducibility and linearity, and the sensitivity of the sensor response changed with the Shore hardness of the gripper. Correlation between TPU Shore hardness, used for the gripper body and sensitivity of the integrated in situ strain sensing elements, showed that material selection affects the sensor signal significantly.

This study presents the design, analysis, dynamical modeling and control of a planar, flexure based closed chain compliant mechanism. Mechanism is designed as a single piece and comprised of rigid-flexure links connected in series. Base links of the mechanism can be actuated through two servo motors and translated along the horizontal direction using two step motors. Two servo motors are mounted on a rail-cart system and carts are equipped with belt drive to enable horizontal displacement. Dynamical model of the mechanism is derived by adapting pseudo rigid body modeling method, vector closure loop equations, Euler’s laws of motion and geometric constraints. Mechanism is 3D printed using thermoplastic polyurethane filament (TPU), motion of the mechanism is video recorded and position of the tip along with the motion of center of each links are captured using image processing. Mathematical model is simulated in Matlab Simulink and validated with the experimental data. A reference trajectory drawn within the workspace of the mechanism on iPad is successfully traced in real time using the simplified model, mirror imaging program and inverse kinematics. The proposed mechanism can be utilized as a haptic device and a compliant manipulator in industrial applications where high precision and larger workspace is desired.

Towards a thoracic conductive phantom for EIT