Zigzag Shape Research Articles

Analyzing the morphology and avian β-defensins genes (AvβD) expression in the small intestine of Cobb500 broiler chicks fed with sodium butyrate

BackgroundSodium butyrate is a potential antibiotic growth promoter and has had advantageous effects on the poultry industry.MethodsEvaluating the effect of sodium butyrate on the intestinal villi and the humoral part of innate immunity of the male Cobb 500 broiler using scanning electron microscopy and quantitative real-time PCR analysis, the control group and treated group of Cobb 500 with SB supplemented received water containing 0.98 mg sodium butyrate.ResultsThe administration of sodium butyrate changed the villi characters, as the shape changed from tongue to long tongue. They were mainly parallel to each other and long finger-like at the duodenum. The tips of the villi in the control group appeared thin-slight curved with a prominent center in the duodenum, thin rectangular in the jejunum, and ileum in the control group. In contrast, in the treatment group, they changed to thick rectangular in the duodenum and ileum zigzag shape in the jejunum. The epithelium lining of the duodenal villi showed a dome shape, the jejunal villi showed a polygonal shape, and the ileal villi appeared scales-like. The epithelium lining showed irregular microfolds and many different-sized pores, and the treatment group showed islands of long microvilli in the duodenum and solitary long microvilli in the ileum. Real-time PCR of AvBD 1, 2, 10, and 12 significantly (P < 0.01). The better expression of AvBD 1, 2, and 12 was determined in the duodenum, while AvBD 10 was in the jejunum.ConclusionSodium butyrate enhanced the chicks’ growth and small intestine parameters, modified the morphology of the intestinal villi, and improved the humoral part of innate immunity.

Investigating the influences of the geometry and orientation of corrugation in the steel shear walls on the cyclic behavior through the use of finite element analysis

To dampen the loading sequences in the constructions, using the shear walls is recommended. Shear walls, which withstand the lateral forces (i.e., parallel to the plane of the wall) of wind and seismic activity, prevent buildings from collapsing while columns and load-bearing walls support the structure’s compression load all the way to the foundation. Besides, some new techniques are innovated for strengthening the structure like outrigger system. The steel shear walls are mostly used in the steel structures due to their high strength, ductility, and low weight. Recently, implementing Corrugated Steel Shear Walls (CSSWs) has gained more attention because they can absorb much amount of energy compared to flat steel shear walls. There are two important parameters in the CSSWs that play crucial roles in controlling their strength; corrugation geometry and orientation. Therefore, the current research paper aims to study numerically the effects of four corrugation geometries (trapezoidal, square, zigzag, and curved) with two orientations on the cyclic behavior of the CSSWs. Finite Element Analysis (FEA) is used to simulate the seismic loading conditions and finally, this procedure is validated through the comparison of the modeled flat shear wall with the experimentally published results. The difference between the peak loads of hysteresis curves obtained numerically and experimentally is about 8.5%. The stated FEA procedure in this paper can be regenerated by other researchers. The results confirmed the applicability of the CSSWs compared to the flat shear walls. Also, the vertical corrugation infill patterns result in higher strength in comparison to the horizontal ones. For instance, in the zigzag and square corrugation shapes, the plastic energy dissipation of the vertically oriented specimens (13.84 and 14.01 KJ, respectively) is higher around 7% and 29%, respectively than the horizontally oriented ones (12.9 and 10.84 KJ, respectively). Besides, the trapezoidal and curved corrugation geometries show the highest cumulated energy and plastic energy dissipation.

Enhancement of Scan Strategy for Improving Surface Characteristics of the SLMed Inconel 718 Alloy Component

The technique of selective laser melting has garnered significant interest due to its capacity to fabricate metal parts of any shape using a single printing process. In this study, a scan strategy was proposed for printing the inner structure part based on the varying performance of the Inconel 718 alloy part produced using different scan techniques. The test findings indicated that the surface quality of the printed material along the scan line exhibited significantly superior performance in comparison to that produced in a vertical direction to the scan line. Regarding the scan strategy, it is evident that the zigzag shape scan strategy exhibited superior performance in terms of the microstructure of the printed part. This is attributed to the more consistent cooling rate on each scan track. On the other hand, the square-framed scan strategy demonstrated a relatively optimal condition for the bending deformation of the printed part compared to other scan strategies. This is due to the more appropriate behavior of the molten pool during the outer edge printing process. After considering all of these criteria, a novel scan approach was created that included various scan strategies. The test findings indicated that the component produced using this novel scanning technique exhibited the combined benefits of both the square-shaped and zigzag-shaped scanning strategies.

3D-Printed Piezoelectric Stents for Electricity Generation Driven by Pressure Fluctuation.

Vascular stenting is a common procedure used to treat diseased blood vessels by opening the narrowed vessel lumen and restoring blood flow to ischemic tissues in the heart and other organs. In this work, we report a novel piezoelectric stent featuring a zigzag shape fabricated by fused deposition modeling three-dimensional (3D) printing with a built-in electric field. The piezoelectric composite was made of potassium sodium niobite microparticles and poly(vinylidene fluoride-co-hexafluoropropylene), complementing each other with good piezoelectric performance and mechanical resilience. The in situ poling yielded an appreciable piezoelectricity (d33 ∼ 4.2 pC N-1) of the as-printed stents. In vitro testing revealed that materials are nontoxic to vascular cells and have low thrombotic potential. Under stimulated blood pressure fluctuation, the as-printed piezoelectric stent was able to generate peak-to-peak voltage from 0.07 to 0.15 V corresponding to pressure changes from 20 to 120 Psi, giving a sensitivity of 7.02 × 10-4 V Psi-1. Biocompatible piezoelectric stents bring potential opportunities for the real-time monitoring of blood vessels or enabling therapeutic functions.

Woven Fabric Muscle for Soft Wearable Robotic Application Using Two-Dimensional Zigzag Shape Memory Alloy Actuator.

In this study, we propose a fabric muscle based on the Zigzag Shape Memory Alloy (ZSMA) actuator. Soft wearable robots have been gaining attention due to their flexibility and the ability to provide significant power support to the user without hindering their movement and mobility. There has been an increasing focus on the research and development of fabric muscles, which are crucial components of these robots. This article introduces a high-performance fabric muscle utilizing zigzag-shaped shape memory alloy (SMA), ZSMA, a new form of SMA actuator. Through modeling and experimentation of the ZSMA actuator, we identified an optimized actuator design and detailed the fabric muscle fabrication process. The proposed fabric actuator, weighing only 7.5 g, demonstrated the impressive capability to lift a weight of 2 kg with a contraction displacement of 40%. This significant achievement paves the way for future research possibilities in soft wearable robotics.

Growth mechanism of Mn-doped diamond (111) layers in microwave plasma chemical vapor deposition

Mn-doped diamond (111) layers were grown by microwave plasma chemical vapor deposition using bis(methylcyclopentadienyl)manganese as a Mn source. The Mn concentration ([Mn]) was intentionally controlled in the range between ∼1 × 1015 and ∼1 × 1017 cm−3 by regulating the Mn/C molar ratio in the gas phase within 0.15%–3.0%. When [Mn] &amp;gt; ∼1 × 1016 cm−3, the step edges of the growing surface changed from straight to a zigzag shape. Using a model based on the classic theory by Cabrera and Vermilyea, we show that this roughening of the step edges resulted from step pinning due to Mn atoms absorbed on the diamond surfaces.

Experimental Study of Transverse Mode Suppression on Wideband Hetero Acoustic Layer Surface Acoustic Wave Resonator.

Transverse mode suppression is a great challenge for high-performance surface acoustic wave (SAW) resonators. Conventional methods work well on narrowband resonators, but their performances on wideband resonator have not been demonstrated. In this article, we give an in-depth study on the transverse mode suppression of wideband resonators using 11° YX-LiNbO3 (LN)/70 °Y90°X -quartz (Qz) hetero acoustic layer structure as a platform. Two groups of design, including new dummy electrode and zigzag shape apodization, are proposed. The measured results show that the shape of the dummy electrode is not the dominant factor to affect the transverse mode. The proposed zigzag shape apodization can effectively suppress the transverse, at the same time maintain the quality ( Q ) factor at the same level with the normal type. Additionally, stronger suppression ability can be realized with a tiny tradeoff of Q -factor.

Thiophene-fused fulminenes (FuDTs): promising platforms for high-mobility organic semiconductors with a zigzag shape.

Zigzag-shaped [6]phenacene isomers with fused thiophene rings, fulmineno[2,1-b:10,9-b']dithiophene (FuDT-α) and fulmineno[1,2-b:9,10-b']dithiophene (FuDT-β), were syntheized and their p-type organic semicondutor properties were studied. Small effective masses of holes were estimated from the crystal structures of both isomers, which was particularly demonstrated by the hole mobility of 10.5 cm2 V-1 s-1 for FuDT-α single crystals.

Central pattern generators for biomorphic robotics

Typically, the structure of the robot fish frame significantly differs compared to the real organism. One significant difference is in the number of body segments. While live fish can have between 16 (moon fish) to 400 belt fish [1] segments, robots usually have only 5–6 segments since substantial precision is unnecessary when simulating movement. At the same time, this method limits a significant portion of the control circuit’s structure compared to a fish’s nervous system because it only requires control over a smaller number of body segments. Control systems using different oscillators can simulate the functioning of fish central generators [2–4]. Typically, each half-center of the fish’s CPGs is interconnected with and mutually inhibitory towards the others, with each being responsible for the antagonist muscles. In this case, the generator’s pattern characteristics stem from the mutual influence of oscillator-antagonist pairs connected to each other. The half-centers’ interaction mechanism with each other is designed to match the movement pattern’s desired final parameters. This “artificial” approach is unsuitable for working with spike neurons because the mechanisms of cellular interaction are well-defined. Altering how cells interact with each other when creating a biologically relevant model is also undesired. Here we present evidence that incorporating select physiological traits of fish into the design of a CPG structure utilizing spike neurons can enhance the system’s functional capacity. Previously, we demonstrated a half-center CPG model using Izhikevich neurons [5]. This model can serve as a control loop for a tuna robot. Although this development aligns with the fundamental principles of CPG organization in fish, reproducing the typical generator mode of operation for pike on it proved challenging. This is due to the fact that the anguliform type of locomotion implies the presence of a moving wave, which means a phase lag in the activation of half-centers. One potential solution to the problem lies in the physiology of fish, specifically the structure of their muscle fibers. Fish have muscle segments called myomeres, which correlate with the number of vertebrae and spinal centers that create the CPG. A distinguishing feature of these myomeres is their zigzag shape. To achieve body bending at a single point, it requires a collaborative action between multiple myomeres and corresponding CPG segments. While our model assumes control of the entire fish with only 5 segments of the CPG, the actual pike includes 56–65 segments. To attain the necessary difference in activation phase between generator segments, we propose increasing the number of generator nodes responsible for operating a single propulsion unit. Indeed, increasing the number of transmission segments resulted in a steady divergence in activation phases among successive segments of the CPG. However, the incorporation of supplementary segments fails to address the challenge of managing the frequency of the CPG’s operation and shifting between patterns. Consequently, we intend to integrate CPG neurons of diverse types outlined in the model, along with introducing feedback to rectify its modes of operation in the future.

On the Flow of CO2-Saturated Water in a Cement Fracture

Cement fractures represent preferential leakage pathways in abandoned wells upon exposure to a CO2-rich fluid. Understanding fracture alteration resulting from geochemical reactions is critical for assessing well integrity in CO2 storage. This paper describes a mathematical model used to investigate the physical and the chemical changes in cement properties when CO2-saturated water is injected into a wellbore. This study examines the flow of a solution of CO2-saturated water in a two-dimensional fractured cement. In this approach, a micro-continuum equation based on the Darcy–Brinkman–Stokes (DBS) equation is used as the momentum balance equation; in addition, reactive transport equations are used to study the coupled processes of reactant transport and geochemical reactions, and the model for cement porosity alteration and fracture enhancement. This paper focuses on the effects of cement porosity, fracture aperture size, and surface roughness. Mineral dissolution and precipitation mechanisms are also considered. Our simulations show that smaller initial fracture apertures tend to a high mineral precipitation self-sealing. However, a complete sealing of the fracture is not observed due to the continuous flow of CO2-saturated water. The calcite precipitation mechanism of a rough fracture (random zigzag shape) differs from that of a smooth/flat fracture surface.

Experimental performance evaluation of solar still with zig-zag shape air cooled condenser: An energy–exergy analysis approach

In the present experimental effort is made to increase the performance of a solar still (SS) by including a novel design of a zig-zag-shaped air-cooled condenser (ZZACC) and cuprous oxide (CuO) as a nanomaterial. Research work is conducted in the climatic conditions of Gandhinagar, Gujarat, India, from September to November 2020. A comparison was made to assess the performance of a conventional solar still (CSS) and a solar still equipped with a zig-zag shape air-cooled condenser (SSWZZACC) with CuO. The experiments’ findings showed that adding CuO to SSWZZACC increases the distillate production by 46.83% and the daily energy efficiency by 45.98%, respectively, compared to CSS. Also, SSWZZACC demonstrates a better efficiency of exergy and latent heat of vaporization than CSS because CuO causes an increase in the evaporative heat transfer coefficient of water. In life cycle cost analysis study discovered that SSWZZACC has a 27.77% lower cost per litre of water (CPL) than CSS. The obtained maximum energy and exergy efficiency values for CSS and SSWZZACC were 2.36% & 25.75% and 3.9% & 37.59%, respectively. In economic and environmental aspects, it was found that SSWZZACC with CuO showed a cost-effective desalination unit and was highly effective from a carbon credit point of view (CCP) by CO2 mitigation.

LaB6 hollow cathode with a novel graphite heater

In this study, the design and experimental characterization of a LaB6 hollow cathode utilizing a novel heater made of graphite are presented. Hollow cathodes commonly use heaters where a refractory metal wire is wound around a high temperature ceramic insulator with grooves. These heaters have issues related to thermal fatigue and the recrystalization embrittleness of the heater wire at high temperatures causing the cathode to malfunction, leading to short lifetime. Rather than using refractory metals, a heater made of graphite is designed and integrated into an existing hollow cathode. The graphite can be manufactured easily and does not show any embrittlement at high temperatures, which increases its operational life time. Additionally, due to its lower sputtering yield, undesirable operational conditions are eliminated. A zig-zag shape is used to tailor the geometry to reach desired resistance value of the heater. The presented graphite-heater eliminates these problems as long as enough care is taken in its initial manufacturing and assembly stage. Additionally, the design of the graphite-heater can be modified in such a way to provide heating to a targeted area, which help decrease the required heater power as well as increase the heating speed of the cathode insert material. Successful tests of the hollow cathode with the novel graphite heater indicate long lifetime and steady operation performance, making it suitable for use in real space missions.

Post-buckling development in soft particulate composites

In this paper, we investigate the post-buckling development of instability-induced patterns in soft particulate composites. Upon reaching the critical strain level, the composite experiences microstructural buckling. Interestingly, in the post-buckling regime, the initial buckling mode may evolve into different new patterns. These transformations are governed by the initial microstructure parameters. In particular, depending on the initial distance between the columns of inclusions, the initial instabilities may develop into (i) inclusion chains with a zigzag or wavy shapes, (ii) a combination of inclusion sets in different length scales, (iii) seemingly disordered inclusion sets, (iv) and structures with strictly doubled periodicity. The different post-buckling patterns are further characterized via the discrete Fourier transform (DFT) analysis. Our results also show that the initially formed post-buckling patterns can further evolve into rather complex new shapes beyond a simple amplification in deformation.

Crack initiation and propagation dominated by strain localization in quasi-single crystal and poly-crystalline of a Ni-based complex concentrated alloy

Cracking is the precursor of the final fracture for most engineering materials, often affected by various microstructural characteristics including grain orientation, boundary, precipitation, etc. In this study, the fracture behaviour of a typical Ni-based complex concentrated alloy (CCA) was systematically investigated. These CCAs were fabricated using fine-grain casting and directional-solidification processes, which consists of quasi-single crystal (QSC) and poly crystalline structures respectively. Quasi-static tensile test results combined with morphology characterizations and crystal plasticity analyses suggest that microcracks tend to nucleate at the matrix/carbide interfaces in QSC and then propagate along the maximum slip direction at the crack tips. The crack path showed a distinctive zig-zag shape, beneficial for consuming the crack propagation energy. In consideration of carbide morphology, script-typed carbides were found to be very effective in hindering dislocation movements, resulting in admirable work hardening ability. In polycrystalline, however, microcracks are commonly found near the carbides that precipitate at grain boundaries, then developed quickly to connect with each other, leading to premature intergranular fracture. Grain boundary carbides were detrimental to mechanical performance. Considering the large amounts of investigations on second phase and precipitation, these new findings about carbide-related crack behaviours could be extended to other second phase hardening materials, providing new routes to design high-performance alloys by controlling the precipitation morphology and position.

Wideband Decoupled 8-Element MIMO Mobile Phone Antenna for Sub-6GHz 5G NR Bands

A broadband decoupled dual antenna pair suitable for sub-6G mobile terminal application is proposed and designed. The multiple input multiple output (MIMO) antenna pair is arranged on the metal frame of the mobile phone, with two antenna pairs on each metal frame. The slotted antenna element structure and defect ground decoupling structure are used to achieve wide band and high isolation. Based on the decoupled antenna pair, an eight-element MIMO antenna is designed. Similarly, the coupling between antenna pairs is effectively reduced by etching the decoupled defect structure of a zigzag shape on the system surface. The prototype of the antenna array is successfully fabricated and tested. Simulation and experimental results show that the proposed eight-element MIMO antenna can fully cover the n77/n78/n79 band of 5G New Radio and 5 GHz band of WLAN. The overall efficiency of the antenna is 50%-75%, the envelope correlation coefficient (ECC) is below 0.08, and the isolation between any two ports is better than 11 dB.

Using a mixed layered soil model to optimize the layout of coastal direct current (DC) grounding electrodes

Abstract In recent years, with the rapid development of the coastal economy and the large-scale development of marine resources, power demand has risen sharply. So it is urgent to promote the construction of UHVDC projects. Coastal saline areas often contain more chloride and other salts than other inland areas due to the high humidity, salinity and light intensity of the marine climatic and environmental conditions, which lead to the different electrical performance of grounding electrodes under different layouts. Therefore, one of the key issues to realizing the rapid development of UHVDC in coastal countries is how to choose the best layout of the coastal DC grounding electrode. It is intended to simulate the coastal environment and establish a mixed stratified soil model using CDEGS to verify the validity of the model through experiments in this paper. Based on the mixed soil model, the changes in grounding resistance, surface potentials and step voltage of grounding electrode sites under zigzag shape, two-row and circular shapes layouts are studied. The results show that when the zigzag shape layout is selected, the ground potential amplitude of the grounding electrode is reduced by 45.77% and 42.7%, the step voltage amplitude is decreased by 39.85% and 32.22%, and the grounding resistance is decreased by 28.45% and 27.68%, compared with the two-row and circular layout. In addition, its utilization rate of electrodes is better than the other two layout shapes.

A Novel Method for Deflection Calculation of Reinforced Concrete Stair Slabs considering Step Stiffness

Stair slabs are some of the most common structural members with zigzag shapes in various buildings. However, the calculated deflection is usually overestimated during the design of stair slabs. In this article, the overestimated deflection is amended by utilizing step stiffness. To this end, it is assumed that the stress distribution of a unit cell in stair slabs is linear or bilinear under a constant bending moment. Stair slabs can be approximately regarded as flat slabs to derive the equivalent thickness based on the same bending strain energy. Subsequently, finite element (FE) models are established to verify that the obtained equivalent thickness can be applied to reinforced concrete (RC) stair slabs. To improve computational efficiency, the normalized models of stair slabs are adopted for further analysis. On this basis, a novel design method is proposed considering step stiffness for RC stair slabs. Furthermore, numerical examples are presented to compare the improved design method with the FE method and the conventional method. The results demonstrate that the design method considering step stiffness can not only ensure structural safety but also reduce concrete and steel consumption, making the design of stair slabs more economical and reasonable.

Investigation of thermal characteristics and entropy generation in a solar collector including Fly Ash-Cu hybrid nanofluids: Numerical approach using mixture model

Heat transfer enhancement is one of the substantial challenges in solar energy conversion systems. By using two different working fluids, namely water and Fly Ash-Cu/water hybrid nanofluids (80:20 Vol.%), this numerical research aims to improve heat transfer by modeling the flat plate solar collector's (FPSC) tube in a zigzag shape instead of a common straight pipe. The innovation of the present study is to evaluate the second law of thermodynamics in a proposed solar collector including Fly Ash-Cu/water hybrid nanofluids and compare the second law of thermodynamics’ results with the Mixture model. Also, various thermal characteristics, such as the Nusselt number, convection heat transfer coefficient (HTC), friction factor, and outlet temperature, are examined at different nanoparticle concentrations, two inlet temperatures, and different mass flow rates. The system works under conjugated laminar mixed convection and constant solar irradiation, 800 W m-2. Results reveal that working fluid pumps with a higher flow rate increase Nusselt number, convection heat transfer coefficient, and friction entropy generation, about 33.33%, 41%, and 88%, respectively, while outlet temperature, friction factor, and thermal entropy generation decrease with increasing mass flow rate. Furthermore, using nanoparticles with a higher concentration considerably increase friction and thermal entropy generation.

Three Regimes of Internal Gravity Wave–Stable Vortex Interaction Classified by a Nondimensional Parameter δ: Scattering, Wheel-Trapping, and Spiral-Trapping with Vortex Deformation

Abstract The internal wave–vortex interaction was investigated for a broad parameter range except near inertial waves, by 1) scaling, 2) numerical experiments, and 3) the estimation of possible occurrences. By scaling, we identified a nondimensional parameter, δ = (V/c)[1/(kR)], where V is the vortex flow speed, R is the radius, c is the incident wave phase speed, and k is the horizontal wavenumber. As δ appears in all terms related to the interaction, it is important in the classification of the wave–vortex interaction. Numerical experiments were conducted on internal waves incident on a stable barotropic vortex with a parameter range of δ = [0.001, 1.7], which is much broader than that used in previous studies (δ ≪ 1). We found new phenomena for δ &gt; 0.15, in addition to previously known scattering for δ ≤ 0.15 (scattering regime). For 0.15 &lt; δ ≤ 0.4, part of the incident internal wave is trapped in a vortex, forming a wheel-like shape maintaining a superinertial frequency (wheel-trapping regime). When δ &gt; 0.4, incident waves are trapped, but with a spiral shape (spiral-trapping regime). Spiral-shaped trapped waves release momentum by wave breaking, which deforms the vortex into a zigzag shape in the vertical direction. Vortex deformation produces vertical shear, which rapidly increases the vertical wavenumber of the incident wave. The distribution of δ in the Pacific Ocean was estimated using a high-resolution (1/30°) ocean general circulation model output. We found the occurrences of all three regimes. The scattering and wheel-trapping regimes are distributed broadly and varied seasonally, thus affecting mixing variability. Significance Statement Oceanic internal waves constitute the fundamental forcing of overturning and material circulation, because internal waves eventually break and cause vertical mixing. Interactions between internal waves and vortices affect wave properties and, therefore, mixing. However, as far as we are aware, all previous studies have focused on large weak vortices relative to waves. Here, we investigated such interactions for a much larger parameter space and identified two new regimes, in which vertical mixing is caused by newly found internal wave trapping and vortex deformation processes. We identified a nondimensional parameter that classifies the regimes and estimated their spatiotemporal distribution. These results suggest new energy routes from internal waves to turbulence and are applicable to other types of waves and vortices.

Influence of The Number of Trapezoidal Labyrinth Weir Cycles on The Hydraulic Characteristics of The Weir

The labyrinth weir that is viewed from above has a zig-zag shape. The main objective is to extend the spillway so that the water level upstream of the weir is as low as possible or to increase the discharge capacity. The shapes of labyrinth weirs based upon cycle shape are triangular, trapezoidal, and rectangular. However, besides the shape of the spillway, several parameters affect its hydraulic characteristics. Therefore, this paper intends to explore the effect of the number of cycles on the trapezoidal labyrinth weir on the hydraulic characteristics of the weir, based on an experimental study. There are two types of model tests one-cycle and two-cycle. Both of the models have a 2300 mm length of the spillway and were made of fiber cement board with a thickness of 20 mm and tested in a rectangular flume of 950 mm width, under various discharges to fulfill the goals of this study. The results of this study show that the discharge capacity through a one-cycle model (0.0064m3/s to 0.0150 m3/s) has a larger capacity than that of a two-cycle model (0.0023m3/s to 0.0095 m3/s). Analyzing can determine that the most efficient hydraulically are the less cycle number of labyrinth weir.