Circular Mesh Research Articles

Removal of contaminants of emerging concern and Escherichia coli from effluent using an optimized electrochemical reactor

Contaminants of emerging concern (CECs) in wastewater are a matter of great importance as they have a huge environmental impact. This work investigated the electrochemical oxidation (EO) technology as an alternative tertiary treatment in wastewater treatment plants (WWTP) aiming to simultaneous remove CECs and Escherichia coli. Platinum titanium (Pt/Ti) and metal mixed oxide (MMO, RuO2–IrO2/Ti) electrode materials with different shapes (bar, mesh and circular mesh) were tested. The results obtained showed that removal rate not only depends on CECs structure and physicochemical characteristics, but electrode material and shape play a key role in the whole treatment process. Overall, the removal efficiency increased (20–50%) for the recalcitrant CECs when using MMO with the electrode characterized by a higher surface area with a circular-mesh as both anode and cathode. Varying the current intensity had a relatively minor effect on the yield of CECs removal. CECs removals were greater than 90% with simultaneous removal of E. coli within 2 h. Overall, EO can be considered an eco-friendly process since no reagents were added and has a low estimated treatment cost of 1.1 €/m3.

Chaos of the Six-Dimensional Non-Autonomous System for the Circular Mesh Antenna

In the process of aerospace service, circular mesh antennas generate large nonlinear vibrations under an alternating thermal load. In this paper, the Smale horseshoe and Shilnikov-type multi-pulse chaotic motions of the six-dimensional non-autonomous system for circular mesh antennas are first investigated. The Poincare map is generalized and applied to the six-dimensional non-autonomous system to analyze the existence of Smale horseshoe chaos. Based on the topological horseshoe theory, the three-dimensional solid torus structure is mapped into a logarithmic spiral structure, and the original structure appears to expand in two directions and contract in one direction. There exists chaos in the sense of a Smale horseshoe. The nonlinear equations of the circular mesh antenna under the conditions of the unperturbed and perturbed situations are analyzed, respectively. For the perturbation analysis of the six-dimensional non-autonomous system, the energy difference function is calculated. The transverse zero point of the energy difference function satisfies the non-degenerate conditions, which indicates that the system exists Shilnikov-type multi-pulse chaotic motions. In summary, the researches have verified the existence of chaotic motion in the six-dimensional non-autonomous system for the circular mesh antenna.

High optical correction system based 800x600 analog spatial light modulator

In this work, a modern optical system based on modulation technique is constructed to achieve the retrieval of optical defects and distortions of the images behind dark barriers. A 800x600 analog spatial light modulator (SLM) is used in this technique with a 632.8nm He-Ne laser, a circular metallic mesh (CMM) is imaged and disturbed and then dealing with our system. The SLM was confirmed for irregularity improvement such as variable diffracted optical element (DOE) control. The obtained results showed that the effect of distortion has been treated and reduced to be minimum by controlling phase and amplitude modulation of the scattered wave front utilizing the SLM. The obtained images showed identical to the original image with limitation in the intensity distribution due to the pixelated structure of SLM. This technique represents the most appropriate solution to the problem of dispersion in images with the lowest costs and best results. The most important applications of this technology are the ability of providing high-resolution imaging where viewing through a deviant medium is inevitable.

Optimization of the Biostabilization Process of an Italian Mechanical–Biological Treatment Plant to Account for Changes in Waste Composition

In this paper, we present a case study on the optimization of the biostabilization process of an Italian mechanical–biological treatment (MBT) plant to account for changes in feed waste composition related to a progressive increase in separate collection of MSW fractions, biowaste in particular. After ten years of operation (2009–2019), a decrease of the stabilization degree of the output material of the plant was detected, with Dynamic Respiration Index (DRI) values above the established limit of 1,000 mgO2/kgVS/h (average values of 4,000 mgO2/kgVS/h determined weekly for eight weeks). The investigations carried out in 2019 on the waste samples feeding the MBT plant showed that paper and plastic materials constitute around 75% of the input waste to the two aerobic bioreactors of the MBT plant, against 55% at the start-up (2009). Furthermore, the airflow rates and the moisture content analyzed weekly for eight weeks in the bioreactors resulted below the optimal values suggested in the literature. To improve the performances of the biostabilization process, a series of modifications were implemented in the plant. The main modification involved the primary mechanical treatment by varying the mesh size of the screens to 50 mm circular holes mesh. Furthermore, the configuration of the aerobic bioreactors was changed by placing the two bioreactors in series (instead of the previous configuration in parallel) and using a screening unit (25 mm) between the two bioreactors instead of at the end of the process. In this way, the residence time of the materials in the aerobic treatment was enhanced from 16 days with the previous configuration to 27 days. Together with an increase of the airflow rates of around 40% and a water supply of approximately 10% in the bioreactors, these modifications allowed to achieve the desired stability of the output waste, with DRI values below 1000 mgO2/kgVS/h.Graphical

Dairy wastewater treatment using immobilized bacteria on calcium alginate in a microbial electrochemical system

The present study was conducted to assess the effect of immobilized Pseudomonas aeruginosa at calcium alginate beads for improving protease and lipase production as the main biocatalysts for dairy wastewater treatment in a microbial electrochemical system. A single-chamber cylindrical bioreactor with adequate volume of 3 L equipped with circular steel mesh and carbon cloth as the cathode and anode electrodes was utilized for the experiments. The main operating variables, including percent of alginate beads, pH, concentration, current density, and time were studied. The obtained results showed that the maximum production of protease and lipase in pH = 6.0 and induced current of 8.0 mA were 193.81 and 47.89 IU/L, respectively. The best precentage of calcium alginate in the bioreactor were obtained 40%. Moreover, the enzyme production time compared to the non-alginate reactor decreased from 12 to 4 h. According to the obtained results, the immobilization of Pseudomonas aeruginosa on calcium alginate along with the electrical stimulation of the bacteria increases the enzyme activities and thus reduces the time of treatment of dairy wastewater in the microbial electrochemical system.

Curcumin-incorporated 3D bioprinting gelatin methacryloyl hydrogel reduces reactive oxygen species-induced adipose-derived stem cell apoptosis and improves implanting survival in diabetic wounds.

BackgroundGelatin methacryloyl (GelMA) hydrogels loaded with stem cells have proved to be an effective clinical treatment for wound healing. Advanced glycation end product (AGE), interacting with its particular receptor (AGER), gives rise to reactive oxygen species (ROS) and apoptosis. Curcumin (Cur) has excellent antioxidant activity and regulates intracellular ROS production and apoptosis. In this study, we developed a Cur-incorporated 3D-printed GelMA to insert into adipose-derived stem cells (ADSCs) and applied it to diabetic wounds.MethodsGelMA hydrogels with Cur were fabricated and their in vitro effects on ADSCs were investigated. We used structural characterization, western blot, ROS and apoptosis assay to evaluate the antioxidant and anti-apoptotic activity, and assessed the wound healing effects to investigate the mechanism underlying regulation of apoptosis by Cur via the AGE/AGER/nuclear factor-κB (NF-κB) p65 pathway.ResultsA 10% GelMA scaffold exhibited appropriate mechanical properties and biocompatibility for ADSCs. The circular mesh structure demonstrated printability of 10% GelMA and Cur-GelMA bioinks. The incorporation of Cur into the 10% GelMA hydrogel showed an inhibitory effect on AGEs/AGER/NF-κB p65-induced ROS generation and ADSC apoptosis. Furthermore, Cur-GelMA scaffold promoted cell survival and expedited in vivo diabetic wound healing.ConclusionsThe incorporation of Cur improved the antioxidant activity of 3D-printed GelMA hydrogel and mitigated AGE/AGER/p65 axis-induced ROS and apoptosis in ADSCs. The effects of scaffolds on wound healing suggested that Cur/GelMA-ADSC hydrogel could be an effective biological material for accelerating wound healing.

Evaluation of large deflection response of circular mesh tubes (1st report: without considering the effect of the ovalization)

Evaluation of large deflection response of circular mesh tubes (1st report: without considering the effect of the ovalization)

Multi-pulse chaotic dynamics and global dynamics analysis of circular mesh antenna with three-degree-of-freedom system

Multi-pulse chaotic dynamics and global dynamics analysis of circular mesh antenna with three-degree-of-freedom system

Numerical Study on Crushing Law of Iron Ore under Different Impact Velocity Using CDEM

Ore crushing is one of the most important steps in mine engineering, and numerical simulation is a useful way to predict the crushing effect under impact load. Based on continuum discontinuum element method (CDEM), by introducing the linear elastic constitutive law into the element and the cohesive model into the virtual interface, the iron ore crushing simulation under different impact velocities was realized. The 2D single circular iron ore mesh and nine circular iron ores mesh with the diameter 3cm were established, the fracture and fragmentation process of iron ores under different impact velocities was simulated, and the evolution laws of fracture degree, damage degree, and the grading curve of fragments were obtained. The results show that, with the increase of impact velocity, the fragments of iron ores increase gradually; The bottom ore is crushed most seriously, while the top ore is damaged lightest, which demonstrates that the lower iron ores have an obvious buffering effect on the upper ores. In the single iron ore impacting case, when the impact velocity increases from 25m/s to 150m/s, the median particle size D50 decreases from 14.7mm to 2.2mm, the fracture degree increases from 1.6% to 28.9%, and the damage degree increased from 5.6% to 43.3%. In the nine iron ore impacting case, when the impact velocity increases from 50m/s to 150m/s, the fracture degree increases from 6.0% to 31.0%, the damage degree increases from 12.3% to 45.4%. When the impact velocity is 100m/s, the median particle size D50 at bottom, middle ant top part is 1mm, 3.6mm and 14.7mm, respectively. The above conclusions can provide basis for optimal design of impact crushing process of iron ore.

V13-07 PROPHYLACTIC MESH PLACEMENT AT TIME OF ILEAL CONDUIT CREATION: A SIMPLE SUBLAY TECHNIQUE

You have accessJournal of UrologyBladder & Upper Tract Urothelial Oncology (V13)1 Sep 2021V13-07 PROPHYLACTIC MESH PLACEMENT AT TIME OF ILEAL CONDUIT CREATION: A SIMPLE SUBLAY TECHNIQUE Da David Jiang, Kyle Gillis, Kenneth Softness, Nicholas Chakiryan, Alison Levy, Vitaliy Poylin, Andrew Wagner, and Peter Chang Da David JiangDa David Jiang More articles by this author , Kyle GillisKyle Gillis More articles by this author , Kenneth SoftnessKenneth Softness More articles by this author , Nicholas ChakiryanNicholas Chakiryan More articles by this author , Alison LevyAlison Levy More articles by this author , Vitaliy PoylinVitaliy Poylin More articles by this author , Andrew WagnerAndrew Wagner More articles by this author , and Peter ChangPeter Chang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002100.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: A prospective randomized study of prophylactic mesh placement at the time of cystectomy and ileal conduit found a significant reduction the cumulative incidence of parastomal hernias by approximately 50%.We present a novel simple sutureless prophylactic sublay permanent mesh placement at the time of ileal conduit creation. METHODS: Bard VentralightTM ST mesh is a permanent medium weight monofilament propylene mesh. It has an absorbable hydrogel barrier on the posterior side based on Sepraâ Technology (ST). A circular mesh with 6cm in diameter is formed; a cruciate cut is made centrally. The space between the posterior sheath and the rectus is bluntly dissected circumferentially. The conduit is brought out of the stoma site and the mesh is thread over the conduit with the shiny ST side down; the ST side is in contact with the conduit and prevents adhesions. The mesh is then gently tucked into the dissected space. The rest of the conduit is matured in standard fashion. RESULTS: We first placed prophylactic mesh in this fashion in 3/2019; since 8/2020, we perform this technique on every ileal conduit diversion. To date, 38 cases have been done; 34 via robotic intracorporeal diversion. Median follow up is 4 months (IQR 2-8). There have been no mesh-related complications such as mesh erosion, mesh infection, mesh pain, or need for mesh explant. The follow-up is too short to determine efficacy, but no clinically apparent parastomal hernias have developed. 21 patients had postoperative imaging with a median radiographic follow-up of 5 months (IQR 3-10); of these, 1 patient (5%) had radiographic evidence of a parastomal hernia. CONCLUSIONS: We present a novel simple sutureless technique for prophylactic mesh placement at time of ileal conduit creation. With short follow-up, there are no evidence of mesh-related complications. Longer follow-up is needed to determine efficacy. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e1080-e1080 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Da David Jiang More articles by this author Kyle Gillis More articles by this author Kenneth Softness More articles by this author Nicholas Chakiryan More articles by this author Alison Levy More articles by this author Vitaliy Poylin More articles by this author Andrew Wagner More articles by this author Peter Chang More articles by this author Expand All Advertisement Loading ...

Friction and cutting characteristics of micro-textured diamond tools fabricated with femtosecond laser

Micro-textures have been preliminarily applied to reduce the wear of metallic, ceramic, and carbide tools. However, it is still unclear which micro-textures will be effective in reducing the wears of single-crystal diamond tools. In this paper, the effectivity of micro-textures on the friction and cutting characteristics of single-crystal diamond tools were verified. Four types of micro-textures including straight grooves array, concentric circular texture, ring sequence, and mesh texture were generated on the rake face of the diamond tools with the femtosecond laser. Experimental results showed that the cutting forces and friction coefficients of the micro-textured diamond tools were greatly decreased except for concentric circular texture. Meanwhile, the cutting performances of the single-crystal diamond tools were effectively improved.

Bifurcation of Periodic Solutions and Its Maximum Number in a Circular Mesh Antenna System with 1:2 Internal Resonance

In this paper, we study the bifurcation of periodic solutions for a four-dimensional deployable circular mesh antenna system. The tools for proving these results are the averaging theory and Brouwer degree theory. Based on constructing displacement maps, we study the bifurcation of the periodic solutions of linear center, and to discuss the maximum number of periodic solutions in certain parameter control conditions. The results in this paper are helpful to the study of nonlinear dynamic characteristics and vibration control of deployable circular mesh antenna model.

Progress in individualizing autologous islet isolation techniques for pediatric islet autotransplantation after total pancreatectomy in children for chronic pancreatitis.

Total pancreatectomy with islet autotransplantation is performed to treat chronic pancreatitis in children. Successful islet isolation must address the challenges of severe pancreatic fibrosis and young donor age. We have progressively introduced modifications to optimize enzymatic and mechanical dissociation of the pancreas during islet isolation. We evaluated 2 islet isolation metrics in 138 children-digest islet equivalents per gram pancreas tissue (IEQ/g) and digest IEQ per kilogram body weight (IEQ/kg), using multiple regression to adjust for key disease and patient features. Islet yield at digest had an average 4569 (standard deviation 2949) islet equivalent (IEQ)/g and 4946 (4009) IEQ/kg, with 59.1% embedded in exocrine tissue. Cases with very low yield (<2000 IEQ/g or IEQ/kg) have decreased substantially over time, 6.8% and 9.1%, respectively, in the most recent tertile of time compared to 19.2% and 23.4% in the middle and 34.1% and 36.4% in the oldest tertile. IEQ/g and IEQ/kg adjusted for patient and disease factors improved in consistency and yield in the modern era. Minimal mechanical disruption during digestion, warm enzymatic digestion using enzyme collagenase:NP activity ratio<10:1, coupled with extended distension and trimming time during islet isolation of younger and fibrotic pediatric pancreases, gave increased islet yield with improved patient outcomes.

Network Mesh Nanostructures in Cross‐Linked Poly(Dimethylsiloxane) Visualized by AFM

AbstractMesh network structures are visualized by peak force tapping atomic force microscopy on cross‐linked poly(dimethylsiloxane) (PDMS) at the nanometer length scale. The images directly capture network mesh structures with mesh diameter values, from 10 to 16 nm at the free surface of PDMS. Perpendicular to the free surface, in cross‐sectional areas exposed by cryo‐fracturing, similar mesh structures are observed. When exposed to uniaxial stress, the circular mesh features become elongated, showing network deformation at the nanoscale, as a result of mechanical stress. Following Soxhlet solvent extraction the mesh‐like appearance remains unchanged, but mesh diameter values decrease, which are attributed to the removal of non‐crosslinked chains and silica filler.

A Mesh Deformation Method for CFD-Based Hull form Optimization

Computational fluid dynamics (CFD) is an effective tool for ship resistance prediction and hull form optimization. A three-dimensional volume mesh is essential for CFD simulation, and mesh generation requires much time and effort. Mesh deformation can reduce the time for mesh generation and simulation. The radial basis function (RBF) and inverse distance weighted (IDW) methods are well-known mesh deformation methods. In this study, the two methods are compared and a novel mesh deformation method for hull form optimization is proposed. For the comparison, a circular cylinder polyhedral mesh was deformed to the National Advisory Committee for Aeronautics (NACA) 0012 mesh. The results showed that the RBF method is faster than the IDW method, but the deformed mesh quality using the IDW method is better than that using the RBF method. Thus, the RBF method was modified to improve the deformed mesh quality. The centroids of the boundary layer cells were added to the control points, and the displacements of the centroids were calculated using the IDW method. The cells far from the ship were aligned to the free surface to minimize the numerical diffusion of the volume of fluid function. Therefore, the deformable region was limited by the deformed boundary, which reduced the time required for mesh deformation. To validate its applicability, the proposed method was applied for varying the bow shape of Japan Bulk Carrier (JBC). The resistances were calculated with the deformed meshes. The calculation time was reduced to approximately one-third using the result of the initial hull form as the initial condition. Thus, the proposed mesh deformation method is efficient and effective enough for CFD-based hull form optimization.

Parametric Analysis of an L-Band Deployable Offset Reflector for CubeSats

Thanks to the advances in the miniaturization and improved power consumption efficiency of electronics, computers, cell phone technologies, etc., today's spacecrafts and payloads are reducing their size and increasing their performance. However, not all systems can be reduced, as their dimensions are determined by the laws of physics. This study is focused on the design of an L-band reflector antenna for a CubeSat-based Earth observation mission devoted to measure the surface soil moisture. Two configurations of deployable parabolic reflector antennas and meshes are presented from the mechanical point of view. The electromagnetic analyses including the antenna feeder are also presented. It is found that the regular circular mesh performs slightly better than the irregular one, although requires a more careful manufacturing process.

Periodic Solutions for a Four-Dimensional Coupled Polynomial System with N-Degree Homogeneous Nonlinearities

This paper studies the periodic solutions of a four-dimensional coupled polynomial system with N-degree homogeneous nonlinearities of which the unperturbed linear system has a center singular point in generalization resonance 1 : n at the origin. Considering arbitrary positive integers n and N with n ≤ N and N ≥ 2 , the new explicit expression of displacement function for the four-dimensional system is detected by introducing the technique on power trigonometric integrals. Then some precise and detailed results in comparison with the existing works, including the existence condition, the exact number, and the parameter control conditions of periodic solutions, are obtained, which can provide a new theoretical description and mechanism explanation for the phenomena of emergence and disappearance of periodic solutions. Results obtained in this paper improve certain existing results under some parameter conditions and can be extensively used in engineering applications. To verify the applicability and availability of the new theoretical results, as an application, the periodic solutions of a circular mesh antenna model are obtained by theoretical method and numerical simulations.

Nonlinear breathing vibrations of a circular mesh antenna based on a equivalent model of a composite laminated circular cylindrical shell with membranes

This paper is focused on the nonlinear breathing vibrations of the circular mesh antenna based on a composite laminated circular cylindrical shell with radially pre-stretched membranes at both ends and clamped along a generatrix. The finite element model of the circular mesh antenna are established, we study the effects of different mesh stiffness on the first six orders frequencies. It is found that there is an approximate threefold relationship between the first-order frequency and the forth-order frequency. Based on the particular integer multiple relationship, we can conclude that there is the 1:3 resonance between the first-order and the forth-order vibrations of the circular mesh antenna. The method of multiple scales is employed to obtain the four-dimensional nonlinear averaged equation based on the two degree of freedom non-autonomous nonlinear equations of the equivalent model of circular mesh antenna and the 1:3 internal resonance is considered here. Then, based on the numerical method, the chaotic dynamics of the equivalent model of circular mesh antenna are studied by the bifurcation diagrams, the phase portraits, the waveforms, the power spectrums and the Poincaré map. The temperature parameter excitation shows that the complex chaotic phenomena occur under the certain initial conditions.

An equivalent cylindrical shell model of vibration analysis based on simplified repeating unit cell for ring truss structure

This paper investigates the potential use of an equivalent cylindrical shell model to analyze the vibration of a ring truss structure for a large deployable circular mesh antenna clamped along one generatrix. The simplified method, which reduces the three-dimensional cell structure into a two-dimensional “flattened” cell structure of the ring truss, is presented. According to the drum-like structure of the antenna, the equivalent cylindrical shell model of the ring truss structure is established. Using the flattened cell structure, the equivalent membrane stiffness and bending stiffness are derived by using the equivalent process and the homogenization method. The differential governing equation of motion for the equivalent cylindrical shell clamped along one generatrix is established based on the Donnell thin shell theory. The theoretical results are verified by numerical simulations. The natural frequencies of the equivalent cylindrical shell are calculated with the non-normal boundary condition clamped along one generatrix. The natural frequencies are compared to ones obtained using a full-scale model by using the finite element method (FEM). The mode shapes of the equivalent cylindrical shell agree well with the ones of the ring truss structure for the full-scale finite element.

Energy efficient piezoelectrically actuated transducer for direct-contact ultrasonic drying of fabrics

Current clothes drying technology is an energy-intensive process that involves blowing hot air across tumbling wet fabrics to evaporate water. To address the relatively low energy efficiency of this drying technique, a new cloth drying technology was proposed in our prior study. This technology utilizes high frequency ultrasonic vibrations to extract water from a fabric in the liquid phase, resulting in a dramatical reduction in energy consumption and drying time. A piezoelectrically actuated transducer was designed and fabricated. The transducer design was based on a piezoelectric actuator that excites axisymmetric resonant modes in a thin circular metal mesh. The device was constructed by bonding a piezoelectric ring to a thin metal mesh with a hole diameter of 120 µm. Test results demonstrated that the new ultrasonic transducer efficiently dried clothes at an order of magnitude lower resonant frequency compared with the previous commercial devices, 23 kHz versus 135 kHz. Also, the power consumption per area of the new transducer was an order of magnitude less than the commercial devices. Depending on operating conditions, the device was 3–24 times more efficient compared to the commercial ultrasonic transducers utilized in our prior ultrasonic clothes drying studies.