Outer Plate Research Articles

Effects of particle diameter and plate thickness on transpiration cooling for double-layer porous plates

Transpiration cooling is a highly efficient active thermal protection technology, which has a great application prospect in the thermal protection of hypersonic vehicles. Nevertheless, the problem of large injection pressure caused by porous structure in transpiration cooling system has been ignored in previous studies. In this work, the transpiration cooling performance of double-layer sintered metal particle plates with different particle diameter combinations and plate thickness were simulated. The results showed that the cooling effectiveness of double-layer plates was improved when the particle diameter of the porous plate in direct contact with the main stream decreased. The inner plate particle diameter and plate thickness had little effect on cooling performance. By increasing inner plate particle diameter, the coolant injection pressure can be lowered by 41% while the structural thickness was maintained. Further reducing the thickness of the outer plate to 1/4 of the total thickness can reduce the injection pressure to 38% of the single plate, which provided an optimization direction for reducing engine power consumption caused by heat dissipation.

Janus Type Monolayers of S-MoSiN2 Family and Van Der Waals Heterostructures with Graphene: DFT-Based Study.

Novel representative 2D materials of the Janus type family X-M-ZN2 are studied. These materials are hybrids of a transition metal dichalcogenide and a material from the MoSi2N4 family, and they were constructed and optimized from the MoSi2N4 monolayer by the substitution of SiN2 group on one side by chalcogen atoms (sulfur, selenium, or tellurium), and possibly replacing molybdenum (Mo) to tungsten (W) and/or silicon (Si) to germanium (Ge). The stability of novel materials is evaluated by calculating phonon spectra and binding energies. Mechanical, electronic, and optical characteristics are calculated by methods based on the density functional theory. All considered 2D materials are semiconductors with a substantial bandgap (>1 eV). The mirror symmetry breaking is the cause of a significant built-in electric field and intrinsic dipole moment. The spin-orbit coupling (SOC) is estimated by calculations of SOC polarized bandstructures for four most stable X-M-ZN2 structures. The possible van der Waals heterostructures of considered Janus type monolayers with graphene are constructed and optimized. It is demonstrated that monolayers can serve as outer plates in conducting layers (with graphene) for shielding a constant external electric field.

Design Considerations for the Implementation of a High-Field-Side Transient CHI System on QUEST

Transient coaxial helicity injection (T-CHI), a method first developed on the small helicity injected torus (HIT-II) experiment and then validated on the much larger National Spherical Torus Experiment (NSTX) device, is a method to initiate an inductive-like tokamak plasma discharge without reliance on the central solenoid. A CHI discharge is initiated by driving current along magnetic flux that connects the inner and outer divertor plates on one end of the tokamak. To permit this, on both HIT-II and NSTX, toroidal ceramic insulators were used to electrically separate the inner and outer vessel components. The use of such large toroidal vacuum insulators may not be easy to implement in reactors. To address this issue, the Q-shu University experiments with steady-state spherical tokamak (ST) (QUEST) is developing a reactor-relevant CHI configuration in which one of the divertor plates is electrically insulated from the rest of the vessel. The first application of T-CHI on QUEST biased the CHI electrode to the outer vessel. While the CHI discharges could be easily generated, it was found that as the discharge filled the vessel, the separation distance between the injector magnetic flux footprints widened, a condition that is not favorable for the generation of closed flux surfaces. Biasing the electrode to the inner wall is a configuration similar to that used on NSTX and HIT-II, but initial testing in this configuration has proved to be challenging. The design described here overcomes the present limitation by locating the CHI electrode much closer to the CHI injector flux coil and using an NSTX-like gas injection manifold to enable high-field-side T-CHI startup on QUEST. The concepts described in this article should also benefit the future implementation of T-CHI systems in other tokamaks and spherical tokamaks.

Analysis Of The Placement And Needs Of General Cargo Ship Tanks With DWT 3650 Tons

The double bottom can enhance the ship's safety and a ballast tank. If the ship crashes into a rock and the outer bottom plate is torn, the watertight top tank will limit/protect the cargo from damage caused by water. The tank is a cargo storage container and is the central part of the liquid and gas transport vessel so that the cargo is maintained and safe. As a storage medium, the tank will always get a load from inside or outside the tank—calculating tank requirements using Simpson's approach. From the calculation results obtained fuel tank obtained 68,354 m3, and the diesel oil tank obtained 14,758 m3. The lubricating oil tank obtained 17,566 m3. The freshwater tank obtained 72,815 m3, and the Ballast tank obtained 356,098 m3.

Seismic research on column base joint of L-shaped CFST columns under cyclic loading

The newly exposed column base (ECB) for L-shaped concrete-filled steel tube (CFST) columns investigated in this study consists of an outer base plate, a concrete cushion, and anchor bolts. Three ECB specimens of the L-shaped CFST column were tested under constant axial loading and cyclic horizontal loading to investigate their seismic behavior. The failure mode, moment versus rotation relationship, hysteretic behavior, and ultimate moment strength were analyzed. The test results indicated that the failure mode of ECB is the failure of the concrete cushion and yielding of the base plate and anchor bolts. Furthermore, a parametric analysis based on a verified finite element model was performed to investigate the influence of various parameters on the ultimate moment strength. Finally, a simplified strength model of ECB for L-shaped CFST based on the composite yielding method was proposed.

Callovian (Middle Jurassic) Sphriganaria (Brachiopoda) from the Jordan Valley (Middle East)

ABSTRACT Middle Jurassic terebratulide brachiopods from the Jordan Valley are herein described and a new taxon is added to the previous faunal list. The Callovian rocks (Mughanniyya Formation) of the Tel el Dhahab section have yielded the following terebratulide taxa: Sphriganaria capax, S. costata, S. costellata, S. curtirostra, S. expansa, S. irregularis, S. subcircularis, S. nasuta, S. sp. 1, and S.? sp. 2. A new species Sphriganaria anyamiae sp. nov. is formally described herein. Internal characters of Sphriganaria costata, S. expansa, and S. nosuta have been studied. On the basis of shell microstructure, crural bases, outer and inner hinge plates were differentiated and defined for the first time in the genus Sphriganaria. The secondary layer is homogeneous built of very fine fibres, predominantly anisometric-like in cross-section, 25‒40 μm wide and 8‒15 μm thick. The Callovian Mughanniyya Formation of northwest Jordan is dominated by highly fossiliferous limestones intercalated with marlstone beds with very diverse brachiopod fauna, deposited in shallow, low-energy waters very near the equator. A paleobiogeographic interpretation of the brachiopod faunas in the Ethiopian Province suggests that brachiopods migrated from the north in the Early Jurassic and later became isolated for the remainder of the period.

Transient CHI System Design Studies for Pegasus-III

Transient coaxial helicity injection (transient CHI), first developed on the Helicity Injected Torus-II (HIT-II) and later on the National Spherical Torus Experiment (NSTX) for implementing solenoid-free plasma current startup capability in a spherical tokamak (ST), is now planned to be tested on the Pegasus-III ST using a novel double-biased configuration. Such a configuration is likely needed for transient CHI deployment in a reactor. The transient CHI system optimization will be studied on Pegasus-III to enable startup toroidal persisting currents at the limits permitted by the external poloidal field coils. A transient CHI discharge is generated by driving injector current along magnetic field lines that connect the inner and outer divertor plates on one end of the ST. Simulations using the Tokamak Simulation Code are used to assess the transient CHI toroidal current generation potential and electrode gap location on the Pegasus-III. While past transient CHI systems have used high-voltage, oil-filled capacitors for driving the injector current, for improved safety, Pegasus-III will use a high-current capacitor bank based on low-voltage electrolytic capacitors. The designed and fabricated system is capable of over 32 kA. The modular design features permit the system to be upgraded to higher currents, as needed, to meet the future needs of the Pegasus-III facility.

Cranial fasciitis in children: clinicoradiology features and management

BackgroundCranial fasciitis (CF) is a rare benign fibroproliferative lesion of the skull. To date, the summarized radiologic characteristics and the subtype of the disease have not been reported. our purpose was to summarize the characteristic clinicoradiology features and management of CF and to improve the knowledge of radiologists and clinicians.MethodsWe searched our institution’s database and retrieved the clinical and radiologic data of CF patients confirmed by histopathological examination. The clinicoradiology features and management of CF were analysed retrospectively.ResultsA total of 14 CF patients were included. A total of 85.7% of the patients presented with a painless, firm, nonmobile and single mass. Tenderness and multiple masses were found in 14.3% of the patients. The mass was clearly increased in 2 patients and gradually increased in 5 patients in the short term. We divided these patients into three types based on the CT characteristics. The characteristic features of type I (9 patients) presented as an expansive and osteolytic bone destruction with a soft tissue mass. Type II (2 patients) presented as a scalp mass with mild erosion of the outer skull plate. Type III (3 patients) presented as a scalp mass without skull destruction. All patients underwent surgical resection. For type I patients, craniectomy and cranioplasty were performed. For type II patients, complete excision of the scalp mass with local skull curettage was performed. For type III patients, complete excision of the scalp mass was performed. There were no cases of recurrence after follow-up.ConclusionsCF usually presents as a painless, firm, nonmobile and single mass with a clear boundary. There are generally three types of MSCT findings: bone destruction with a soft tissue mass, a scalp mass with erosion of the skull and a scalp mass. Different management strategies should be utilized for the various types of CF.

Comprehensive analysis of the results of surgical treatment of patients with degenerative diseases of the lumbar spine using rigid fixation systems

Introduction. According to the literature, the development of adjacent-level syndrome 10 years after posterior rigid stabilization is noted in 6.7–80 % of patients, of which 24 % require revision surgery.The aim: to conduct a comprehensive analysis of the results of surgical treatment of patients with degenerative diseases of the lumbar spine using rigid fixation systems.Materials and methods. A multicenter retrospective study of the results of surgical treatment of 268 patients with degenerative-dystrophic diseases of the lumbar spine, who underwent mono- or bisegmental decompression-stabilizing intervention with the implementation of the TLIF (Transforaminal Lumbar Interbody Fusion) technique and open transpedicular rigid fixation, was conducted. The study included radiography, MRI and CT (in 2-energy mode) of intervertebral discs and isolated facet degeneration of the upper adjacent level.Results and discussion. The combination of the initial degeneration of the adjacent spinal motion segment in the form of disc degeneration of grade III and higher according to Pfirrmann with threshold values of the density of the outer cartilaginous plate from 161.7 ± 18.8 to 164.8 ± 14.2 HU, the density of the outer facet – from 702.43 ± 12.3 to 713.65 ± 13.6 HU and the density of the inner facet – from 580.5 ± 11.6 to 582.1 ± 15.1 HU, as well as with signs of segmental instability of the adjacent segment can be considered as risk factors for the development of its degeneration. With the progression of degeneration of the upper intervertebral disc, revision interventions were performed within 12–60 months after surgery.Conclusion. Bisegmental stabilization with signs of initial degeneration in the intervertebral disc and facet joints in the upper segment has proven its clinical and instrumental effectiveness in the period of 36 months and reduces the risks of developing degenerative disease of the adjacent disc.

Seismic performance of braced frame structure with double-cylinder arc energy dissipator

A new type of braced frame structure with a double-cylinder arc energy dissipator is proposed in this paper. The energy dissipator is composed of an inner cylinder, an outer cylinder, and a stiffener fabricated and connected to a steel beam and column by welding, and the double cylinder arc energy dissipator is connected to a steel beam and steel column by welding. The seismic performance of the braced frame structure with a double-cylinder arc energy dissipator was analyzed by Abaqus. The results indicated that seismic energy could be dissipated through the deformation of the outer cylinder, inner cylinder, and rib plate. However, the double-cylinder arc energy dissipator could avoid the out-of-plane buckling deformation of the brace. Further, it exhibited properties similar to those of concentrically and eccentrically braced frames. The deformation of the braced frame with a double-cylinder arc energy dissipator mainly occurred on the dissipator and energy-dissipating beam (between the dissipator and column). During the loading process, the stiffener, outer and inner cylinders, and beam gradually yield. The height, thickness, and spacing of the stiffener of the double-cylinder arc energy dissipator were observed to significantly influence the seismic performance of the proposed braced frame. In contrast, the effect of the thicknesses of the inner and outer cylinder arcs on performance was negligible.

Experimental Study on Seismic Performance of Prefabricated Frame Column Joints with a High Axial Compression Ratio

A new type of an assembled monolithic concrete column encased by partial outsourcing steel was proposed, and the seismic performance was proposed. To study the seismic performance such as failure mode, hysteretic behavior, deformation, ductility of the specimen, and the influence of the outsourcing steel pipe on the mechanical performance of the specimens, the comparative tests of four full-scale specimens under low cyclic reciprocating load under a high axial compression ratio were carried out. The test results show that the monolithic column assembled with outsourced steel has better overall performance, and the failure of the specimen is the large eccentric compression failure with good ductility. The hysteresis and skeleton curves of the assembled columns are similar to the cast-in-site concrete column under the same conditions, which have a good ductility and energy dissipation capacity. It was established that increasing the thickness of the outer steel plate does not significantly improve the mechanical performance of the component when the load-bearing capacity of members satisfies the design requirements. The research results can provide a reference for theoretical research and practical engineering applications of assembled monolithic concrete column connections.

Performance Evaluation of Composite Wall with Boundary Column Having Triangular Corrugation

Abstract: Composite wall is an innovation in the field of Civil Engineering that enhances the constructability by eliminating reinforcing bars and formwork. Double skin composite wall consist of a concrete core is placed between outer steel plates. By providing corrugation in the steel plate improves the seismic behavior and also stability against buckling. This paper aims to the performance evaluation of corrugation on composite wall with boundary column. For this study, four FE models of composite wall with boundary column having triangular corrugation were analyzed using Ansys 2022 R1. Composite wall with different height of corrugation ie., 25 mm, 30 mm, 40 mm and 45 mm is evaluated under monotonic loading to understand the total deformation and equivalent stress. Also perform buckling analysis on the better model obtained from different geometry of corrugation. Study shows that model with 45 mm height of corrugation shows maximum load carrying capacity

A Permanent Magnet Synchronous Spherical Motor for High-Mobility Servo-Actuation

The development of direct-drive spherical motors offers a potential solution to the limitations of conventional multiple degree-of-freedom (DOF) actuators, which typically utilize single-DOF joints (rotational and/or prismatic), arranged in series or parallel and powered by multiple single-DOF actuators. These configurations can be accompanied by kinematic singularities, backlash, limited power density and efficiency, and computationally expensive inverse kinematics. This paper details the design, fabrication and experimental testing of permanent magnet synchronous spherical motors (PMSSM) for multi-DOF servo-actuation. Its stator-pole arrangement is based on a Goldberg polyhedron, with each pole comprised of hexagonal or pentagonal inner and outer plates. The stator geometry and winding configurations are optimized using electromagnetic finite element analysis. A custom-made controller board includes a microcontroller, servo drivers, a wireless serial interface, and a USB PC interface. Angular orientation is sensed using an inertial measurement unit in wireless communication with the microcontroller. A PID controller is implemented and demonstrated for time-varying reference trajectories.

Topology optimization of DC-biased pot-type reactor using design sensitivity in steady state of electromagnetic field with magnetic nonlinearity

Because reactors applied to electric vehicles are typically driven under a DC-biased current, a constant inductance property is required. When a high-performance DC-biased reactor is designed, the topology optimization (TO) is an effective design method owing to the high degree of structural change in the magnetic circuit. However, there exists no report regarding the TO method in the steady-state time domain with magnetic nonlinearity. In this paper, based on the time-domain adjoint variable method, a novel sensitivity analysis approach for the steady-state time domain with thorough consideration of the magnetic saturation is proposed. Through the proposed method, the TO of the iron core and winding structures in a pot-type reactor was carried out to enhance the DC-biased characteristics. Furthermore, the eddy current loss occurring on the aluminum plate installed outside the reactor was suppressed by the multi-objective TO. The interesting structure of a pot-type reactor that enhanced the DC-biased characteristics and reduced the eddy current loss on the outer conductor plate was also illustrated.

Research on lightweight and fatigue life of engine hood based on multi-objective particle swarm optimization

A multi-objective optimization method is presented in this paper, aiming at improving the fatigue life of the engine hood while achieving light weight. By analyzing the factors affecting the fatigue life of the engine hood, a multi-objective optimization model was established that considered five design variables including the thickness of the inner plate, the thickness of the outer plate, the stiffness of the hook, the stiffness of the sealing strip, and the height of the buffer block. Then, the multi-objective particle swarm method was used for optimization, and the optimal solution was obtained in the form of a Pareto set. The ideal compromise solution was determined from the Pareto set by using fuzzy membership functions. On this basis, the optimal solution was determined from the Pareto set by comprehensively considering the steel plate material specification, mold and cost constraints. The torsional deformation test and switch fatigue test show that for the optimized engine hood, the fatigue life is increased by 117%, the mass is reduced by 0.51 kg, and the torsional deformation of the engine hood does not increase significantly. The proposed multi-objective optimization method is proved to be feasible and effective in improving engine hood fatigue life and lightweight design.

Analysis Of The Placement And Needs Of General Cargo Ship Tanks With DWT 3650 Tons

The double bottom can enhance the ship's safety and a ballast tank. If the ship crashes into a rock and the outer bottom plate is torn, the watertight top tank will limit/protect the cargo from damage caused by water. The tank is a cargo storage container and is the central part of the liquid and gas transport vessel so that the cargo is maintained and safe. As a storage medium, the tank will always get a load from inside or outside the tank—calculating tank requirements using Simpson's approach. From the calculation results obtained fuel tank obtained 68,354 m3, and the diesel oil tank obtained 14,758 m3. The lubricating oil tank obtained 17,566 m3. The freshwater tank obtained 72,815 m3, and the Ballast tank obtained 356,098 m3.

WDFY3 mutation alters laminar position and morphology of cortical neurons

BackgroundProper cerebral cortical development depends on the tightly orchestrated migration of newly born neurons from the inner ventricular and subventricular zones to the outer cortical plate. Any disturbance in this process during prenatal stages may lead to neuronal migration disorders (NMDs), which can vary in extent from focal to global. Furthermore, NMDs show a substantial comorbidity with other neurodevelopmental disorders, notably autism spectrum disorders (ASDs). Our previous work demonstrated focal neuronal migration defects in mice carrying loss-of-function alleles of the recognized autism risk gene WDFY3. However, the cellular origins of these defects in Wdfy3 mutant mice remain elusive and uncovering it will provide critical insight into WDFY3-dependent disease pathology.MethodsHere, in an effort to untangle the origins of NMDs in Wdfy3lacZ mice, we employed mosaic analysis with double markers (MADM). MADM technology enabled us to genetically distinctly track and phenotypically analyze mutant and wild-type cells concomitantly in vivo using immunofluorescent techniques.ResultsWe revealed a cell autonomous requirement of WDFY3 for accurate laminar positioning of cortical projection neurons and elimination of mispositioned cells during early postnatal life. In addition, we identified significant deviations in dendritic arborization, as well as synaptic density and morphology between wild type, heterozygous, and homozygous Wdfy3 mutant neurons in Wdfy3-MADM reporter mice at postnatal stages.LimitationsWhile Wdfy3 mutant mice have provided valuable insight into prenatal aspects of ASD pathology that remain inaccessible to investigation in humans, like most animal models, they do not a perfectly replicate all aspects of human ASD biology. The lack of human data makes it indeterminate whether morphological deviations described here apply to ASD patients or some of the other neurodevelopmental conditions associated with WDFY3 mutation.ConclusionsOur genetic approach revealed several cell autonomous requirements of WDFY3 in neuronal development that could underlie the pathogenic mechanisms of WDFY3-related neurodevelopmental conditions. The results are also consistent with findings in other ASD animal models and patients and suggest an important role for WDFY3 in regulating neuronal function and interconnectivity in postnatal life.

Analysis on Welding Temperature Field and Stress Field of Boring Bar of New Boring Machine

Ansys software is used to simulate the welding process of the boring bar of the new cylinder head boring machine. The indirect coupling method is used to analyze the temperature field, then the stress field and deformation. It is found that for the double support structure, the highest temperature occurs at the outer stiffened plate of the small diameter end, and the lowest temperature occurs at both ends of the inner support structure. The deformation of the whole structure mainly comes from the axial deformation, and the maximum deformation occurs at the large diameter end of the outer rib plate. Because the role of the supporting web is to limit the large deformation of the whole structure, the structure at the small diameter end is firmer and has the ability of anti-deformation. In terms of technology, the influence caused by deformation can be compensated by the compensation design of machining amount.

Experimental /numerical study of a circular rib-stiffened flange connection with inner and outer flange plates under combined bending and tensile loading

Focusing on circular rib-stiffened flange connections with inner and outer flange plates, termed inner-outer flange, the mechanical behavior of the flange subjected to the combined bending and tensile loading is experimentally studied. Four nominally identical specimens were utilized to investigate the effects of the eccentricity on the mechanical behavior. The distribution of the gap between flange plates, as well as the distribution of the bolt forces, is presented. It is found that the neutral axis would gradually approach the central axis of the flange connection, as the eccentricity increases. Moreover, provided the sufficiently strong ribs, welds, and flange plates, the capacity of the flange is found to be mainly predominated by the bolt strength. A good agreement is found in the comparison of the results obtained via the finite element analysis, the semi-analytic method (SAM) and the experimental study. It corroborates the validity of using the bolt failure assumption and the plane cross-section assumption in the SAM for approximating the capacity of the inner-outer flange. In terms of the interaction of the tensile capacity with the bending capacity, the experimental results along with those in the literature are compared with the curves defined by the codes, and suggestions for design are concluded. Yield capacity, defined as the load when the bolt stress reaches the yield strength, is recommended herein for the design of a structure under in-service condition. It is found the specifications in the current codes for the rib-stiffened flanges with a single flange plate would occasionally overestimate the yield capacity of the inner-outer flanges under the combined bending and tensile loading. Moreover, both the experimental and the numerical results show a linear load interaction curve, in terms of the ultimate capacity.

Application of nanoindentation technology in testing the mechanical properties of skull materials

Three-point bending test, compression test and tensile test can detect the mechanical properties of the whole layer of skull, but cannot detect the mechanical properties of the inner plate, the diploe and the outer plate of the skull. In this study, nanoindentation technology was applied to detect mechanical properties of micro-materials of the skull, and differences in micro-mechanical properties of the inner, diploe and outer plates of the skull and cranial suture of human carcasses at different ages were analyzed. The differences in hardness (HIT) and modulus of elasticity (E) were statistically significant among different age groups (P < 0.01). In terms of structure, the E of diploe was higher than that of other structures, while HIT had no significant statistical difference. In terms of location, both HIT and E showed that left frontal (LF) was significantly higher than coronal suture (CS). The above results were consistent with the multi-factor ANOVAs. In addition, the multi-factor ANOVAs further explained the interaction of HIT and E with age, location and structure. It was believed that the nanoindentation technique could be used to analyze laws of micromechanical properties of different structures of human cadaveric skull and cranial suture.