Gap Elements Research Articles

경증 장애인과 가족 돌봄자의 효과적인 미술관 융합교육을 위한 뮤지엄 액티브 러닝 방법론 연구

This study presents the following objectives for the necessity of art museum activities necessary for the disabled and family caregivers. First, active art museum factors for people with mild disabilities and families are discovered. Second, we propose an active learning range centered on effectiveness and self-efficacy. Third, we find the Gap elements of art museum activity and present effective art museum service design. Fourth, we will build a museum active learning model that embraces both disabilities and non-disabilities. As a result of studying the special program of art museums centered on the last three years, Case-based learning is advantageous for the disabled, and family caregivers predict that Goal-based learning, Team-based learning, and Problem-based learning methods are effective. Disabled and family caregivers can try Flipped learning, Action learning, and Project-based learning together. The results of this study: First, there should be many cultural and artistic service programs by expanding public care for the developmentally disabled and the elderly with dementia. Second, m service design should help disabled people and their families with a sense of accomplishment, satisfaction, and social resilience. Third, art museum experience education services for the mildly disabled and their families should prioritize various activities, familiar living materials, and space accessibility

Research on the dynamic behavior of flexible drilling tools in ultrashort-radius radial horizontal wells

A flexible drilling tool is a special drilling tool for ultrashort-radius radial horizontal wells. This tool is composed of many parts and has the characteristics of a multibody system. In this paper, a numerical method for the dynamic analysis of flexible drilling tools is proposed. The flexible drill tool is discretized into spatial beam elements, while the multilayer contact of the flexible drilling tool is represented by the multilayer dynamic gap element, and the dynamic model of the multibody system for the flexible drilling tool’s multilayer contact is established, considering the interaction force between the drill bit and the rock. The nonlinear dynamic equation is solved using the Newmark method and Newton–Raphson method. An analysis of the dynamic behavior of a flexible drilling tool is conducted. The results indicate that the flexible drilling tool experiences vortex formation due to the interaction between the flexible drilling pipe and the guide pipe, leading to increased friction and wear. This situation hinders safe drilling operations with flexible drilling tools. The collision force of the flexible drilling tool near the bottom of the hole is more severe than that of the other tool types, which may lead to failure of the connection.

Seismic performance of rocking braced frames with double base plate connections

This paper presents a rocking system for concentrically braced frames (CBFs) to mitigate the seismic demands induced by seismic motions. The proposed system incorporates double base plate connections (DBPCs) at the base of the braced-bay columns, enabling them to uplift and initiate a rocking motion. The DBPC comprised two base plates: the upper one is thin, connected to the column and designed to yield under uplift loading, while the lower one primarily distributes compressive loads to the foundation. The DBPC was modeled using a combination of spring and gap elements in SAP2000 software. A comparative study was performed to investigate the seismic performance of the proposed rocking system against a conventional CBF system. Key parameters such as the thickness of the upper base plate and the arrangement of anchor rods were considered. Four prototype frames of different heights (3, 6, 9, and 12 stories) were investigated under the Sylmar-x record using the nonlinear time history analysis. The results demonstrated that utilizing rocking braced frames with double base plate connections can remarkably mitigate the base shear force by softening the structural response, decreasing the seismic damage experienced by the structure. The upper base plate acted similarly to a footing damper, absorbing a substantial amount of energy by yielding. Importantly, the residual drifts caused by the plastic deformations of the upper base plate remained within the acceptable performance limits for self-centering systems. Moreover, the self-centering mechanism was achieved solely through the structure’s self-weight, eliminating the need for additional re-centering devices.

New Nurse Perceptions of Preparedness: Elements of Academic-Practice Gap

New Nurse Perceptions of Preparedness: Elements of Academic-Practice Gap

Photophysical properties of Pt(ii) complexes based on the benzoquinoline (bzq) ligand with OLED implication: a theoretical study.

In this study, we investigate photophysical properties of eight inorganic Pt(ii) complexes containing the bzq (benzoquinoline) ligand for OLED applications using high-level density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. We explore the radiative and non-radiative relaxation constants (k r, k nr), spin-orbit coupling (SOC) matrix elements, and spectral properties. To ensure compatibility between the host and guest compounds, we determine the HOMO and LUMO energy levels, as well as the triplet excitation energies of the selected systems, and evaluate their efficiency for OLED devices. Our findings indicate that all systems, except for 2a and 2b, exhibit a small S1-T1 energetic gap (ΔE ≤ 0.60 eV) and promising SOC matrix elements (25-93 cm-1), leading to a significant intersystem crossing (ISC) process. These complexes also show promising radiative relaxation rates (k r = ∼10-4 s-1) and high phosphorescent quantum yields (Φ > 30%). Thus, our results confirm that six out of the eight selected Pt(ii) complexes are promising candidates for use in the emitting layer (EML) of OLED devices as efficient green emitters.

Longitudinal seismic displacement analysis of Quasi Seismic Isolation Bridge based on Energy-based Multimodal Pushover Method with and without collision

This paper aims to evaluate the longitudinal seismic displacement of the Quasi Seismic Isolation Bridge (QSIB) based on the Energy-based Multimodal Pushover Method (EMPM), including the pier-beam relative displacement and the collision effect. As a simplified seismic analysis method, the EMPM invokes the concept of energy balance into the modal pushover analysis to assess the nonlinear seismic behavior of Laminated Rubber Bearing (LRB) on bridges. In this method, the energy-based capability curve is obtained by the modal pushover analysis, while the energy-based demand curve is estimated under the ground motion record. The target performance criterion can be derived by intersecting the capability curve with the demand curve. The effect of several key factors in EMPM, such as the mode classification and selection, collision effect, energy coefficient and ductility factor, are studied by a case study of a prototype QSIB under ChiChi and El Centro earthquakes. The results of EMPM are compared with those from Nonlinear Time History Analysis (NTHA), to illustrate the effectiveness and accuracy of this method for evaluating the maximum seismic displacement, and the pier-beam relative displacement with and without collision. Results show that the EMPM is found to be able to estimate the longitudinal seismic displacement of the QSIB with and without collision, and can be used as an effective alternative for rapid assess the seismic performance of bridges. The results also indicate that LRB stiffness for modal analysis should be taken as the stiffness pre- or post-sliding when without or with the gap element. Collision effect enlarges the peak displacement and the maximum bias of EMPM.

Genome sequencing and application of Taiwanese macaque Macaca cyclopis

Formosan macaque (Macaca cyclopis) is the only non-human primate in Taiwan Island. We performed de novo hybrid assembly for M. cyclopis using Illumina paired-end short reads, mate-pair reads and Nanopore long reads and obtained 5065 contigs with a N50 of 2.66 megabases. M. cyclopis contigs > = 10 kb were assigned to chromosomes using Indian rhesus macaque (Macaca mulatta mulatta) genome assembly Mmul_10 as reference, resulting in a draft of M. cyclopis genome of 2,846,042,475 bases, distributed in 21 chromosomes. The draft genome contains 23,462 transcriptional origins (genes), capable of expressing 716,231 exons in 59,484 transcripts. Genome-based phylogenetic study using the assembled M. cyclopis genome together with genomes of four other macaque species, human, orangutan and chimpanzee showed similar result as previously reported. However, the M. cyclopis species was found to diverge from Chinese M. mulatta lasiota about 1.8 million years ago. Fossil gene analysis detected the presence of gap and pol endogenous viral elements of simian retrovirus in all macaques tested, including M. fascicularis, M. m. mulatta and M. cyclopis. However, M. cyclopis showed ~ 2 times less in number and more uniform in chromosomal locations. The constrain in foreign genome disturbance, presumably due to geographical isolation, should be able to simplify genomics-related investigations, making M. cyclopis an ideal primate species for medical research.

Estimating the seismic pounding force between adjacent buildings and study the effect of gap distance on seismic pounding

Insufficient separation distance between adjacent buildings may lead to their pounding during strong earthquakes causing damage or local failure. Accordingly, most of the design codes specify a minimum separation or gap distance between adjacent buildings to prevent their seismic pounding. Main objectives of this research are studying the seismic pounding between adjacent reinforced concrete (RC) buildings under various ground motions and studying the effect of gap distance on seismic pounding. The studied buildings are modeled as three-dimensional frames to idealize the adjacent buildings. This study considers adjacent frame buildings having the same number of floors as well as frames having a different number of floors. Nonlinear finite element time history analysis is performed using ETABS commercial software. Three different real earthquake records with different characteristics are scaled and used to simulate ground motion. Nonlinear gap element is used to model pounding between buildings at their interface points. The results of the study indicate that, the maximum pounding force was investigated for each of the studied cases. Pounding does not occur between buildings having equal height. Increasing separation distance between buildings reduces the pounding force between them. Separation distance, which is estimated by the Egyptian code, is conservative.

Uplift resistance of buried pipelines: The contribution of seepage forces

Pipelines are commonly buried, and can buckle upwards when heated if there is insufficient soil uplift capacity. Interface tension beneath the buried pipe significantly influences the uplift capacity at shallow embedments. Conventional design approaches, which consider either zero or unlimited interface tension, do not assess and quantify the effect of interface tension on uplift capacity. The present study bridges the gap between conventional “no tension” and “full tension” capacities. Mobilisation of interface tension is governed by seepage forces which in turn directly control the formation of a gap beneath the pipe. A large deformation finite element approach, which simulates this phenomenon of gap formation using a thin layer of gap elements below the pipe, is adopted to study the soil response for various cases of uplift velocity, embedment and soil weight. The enhancement in undrained shear strength of soil at higher uplift velocities due to strain rate effects has also been considered. The interface tension mobilised at these different velocities and embedments varies systematically in a way that is expressed by modifying Hvorslev's intake factors. The proposed expressions may be used with the existing methodologies to assess pipe stability during operation, demonstrated here through a design example.

Research on the Design Safety Factor of the Supporting Falsework Considering the Installation Gaps

In order to fully consider the influence of the top installation gaps on the axial forces of the vertical poles during the erection of the supporting falsework, a finite element model of the 25 vertical poles considering the top gap element was established based on a large number of field measured data of the top installation gaps. The size of installation gap in this model considered two kinds of distribution: uniform distribution and random distribution. The uniform distribution value of the gap was 1.4mm and the value interval of the random distribution was [0, 0.7] and [0, 1.4]. The numerical simulation results showed that the axial forces of the vertical poles were uniformly distributed without considering the top installation gaps of the vertical poles. When considering the top gaps of the vertical poles, the calculation results of the two distribution types showed that the axial forces were non‐uniform distribution and the maximum axial force of the pole increased by 2.3 times. Besides, according to the measured test data of the axial forces of a certain engineering project, the distribution law of the vertical pole’s axial forces in the actual project was also analyzed and the results showed that the maximum value of the axial force was about twice the minimum value. Since it is impossible to ensure that the elevations of the top of the vertical poles are exactly the same during the actual erection of the falsework, the top installation gaps are inevitable. When designing the bearing capacity of the falsework, the influence of the top installation gaps on the axial forces of the vertical poles should be fully considered. The recommended safety factor range of the bearing capacity of vertical pole is 1.7‐2.1.

Shear Correction Factor Effects on Functionally Graded Materials (FGMs) Beams using Discrete Shear Gap (DSG) Element

Materials and computational methods are essential to support the development of infrastructure. Composite material has been used in many applications; in the laminated composite, failure due to excessive interlaminar stresses between two material

Post-buckling analysis of two-layer contact concentric tubular strings in pipe

Buckling of concentric tubular strings in pipe is an essential problem in the fields of medical, biological, and nanomaterials, especially in petroleum engineering. Completely different from the buckling of the classic Euler compression columns, the buckling of concentric tubular strings involves geometric nonlinearity and contact nonlinearity, and has more complicated geometric deformations and buckling configurations. In this paper, a finite element method combining the spatial beam element and the two-layer contact gap element is proposed, and a virtual transient dynamic method is introduced to solve the static buckling of concentric tubular strings. The internal concentric tubular strings are discretized into spatial beam elements, and the contact relationships between tubular strings are described by two-layer contact gap element. Meanwhile, the larger damping is used to attenuate the dynamic response of the system, so as to find the static part of the transient dynamic solution. Appropriate damping and element length are determined by numerical simulation. The structural characteristics and contact states of eight post-buckling configurations are studied. The helix pitch values of specific configurations are in good agreement with the theoretical solutions. In addition, the distribution of bending moment, shear force and contact force in various post-buckling configurations is studied. For the full helical buckling, it is found that there is only one non-contact section in the transition section of inner tube and two non-contact sections in the transition section of middle tube. The research results of this paper provide a theoretical basis and reference for further study on the buckling of multi-layer concentric tubular strings.

Dynamic performance of soft-storey structures with gap elements at beam-column joints

Soft-storey structures are more susceptible to failure for seismic vibrations, which is well-known to the world. But, in multi-storey apartments, it is a practice to provide a parking place at the ground storey, inducing soft-storey effects. In the present study, an effort is made to reduce the soft-storey effect on the structure's dynamic performance by introducing an arrangement of gap elements at beam-column joints. To that context, a numerical assessment is carried out to check the performance of the RC structure. The gap element is modelled as a spring either in a beam or in a column or both.The research has been performed in two parts; the first part of the analysis is focused on optimizing the gap element pattern. Diagonal compressive struts replace the infill walls, and the ground storey is modelled as an open ground storey without infill walls, which is considered a soft-storey. From the first part, an optimal gap element pattern from five different arbitrary patterns is obtained from the results of linear dynamic response spectrum analysis, depending upon the comparison of various seismic parameters. The second part of the analysis involves checking the effect of the gap element's optimized pattern for four levels of structures with vertically varied aspect ratios. Response spectrum analysis is performed, and a study is conducted to compare the seismic parameters for the four levels. The models with gap elements have shown an apparent reduction in storey displacements, inter-storey drift ratios, over-turning moments, and increment in storey stiffness when compared to the conventional models, thus exhibiting constructive outcomes.

Parametric responses of carbon-epoxy composite with delamination using cohesive gap element

This paper focuses on the various parametric responses of the delaminated carbon-epoxy composite beam using a gap element. The analysis is based on the cohesive zone modelling approach, and it is implemented using the finite element software ANSYS APDL. In the study, a zero-thickness cohesive gap element that varies the cohesive stresses with the interfacial opening displacement along the localized fracture process zone is used. The available published results of the double cantilever beam test are used to validate the results obtained from the current analysis. The effects of fracture length, number of layers, angle of plies and thickness on delamination of a composite cantilever beam with edge pull is considered in this paper. The results show that the separation between the composite plies is proportional to the stiffness of the cohesive element, and an increase in the number of layers depicts a transition from anisotropy to orthotropy. Under mode I delamination, composite plies with 450 fibre angles exhibits increased torsional stiffness and global resistance. Also, a comparison between thin and thick laminates demonstrate that a laminate of 5 mm thick dissipates about 85% more energy than a composite laminate of 50 mm thick.

Seismic Behaviour of Spring Anchored Unbonded Post-Tensioned Rocking Systems

ABSTRACT The construction of low damage, self-centering, unbonded post-tensioned seismic systems requires special techniques and equipment such as hydraulic jacks to stress tendons that may not be readily available in developing communities. The recently proposed spring anchored rocking system (SARS) uses a spring at the anchorage of the post-tensioning tendon to facilitate applying force to the tendons using simple techniques such as torque wrenches. The seismic behaviour of the SARS is investigated using finite element models developed in OpenSees. The self-centering lateral force resisting system of a 3-story timber structure was anchored with springs having four different configurations, and subjected to a set of 22-pair ground motions. The finite element models consisted of elastic beam column elements to model the frame members, nonlinear truss element to model the post-tensioning tendon, spring element to model the anchorage of the tendon, and gap element to model the spring closure. It is found that the spring at the post-tensioning anchorage introduces flexibility, reduces the tendon force, and generally increases the rigid body deformations of the SARS compared to conventionally anchored systems using nuts set on bearing plates.

ОПРЕДЕЛЕНИЕ ПРЕДЕЛЬНЫХ СМЕЩЕНИЙ В ОДНОБОЛТОВЫХ СОЕДИНЕНИЯХ РАСПОРНЫХ КРЕПЛЕНИЙ

Using the existing engineering methodology of designing bolt joints taking up shear loads of dimension chains with gap elements according to N. N. Streletski and other authors’ methodology give similar results, both for the analysis of single bolt joints accuracy and for that of multi-bolt joints. In this article there is considered the affect of gap elements number on the accuracy of multi-bolt joints. There is established the character of the intrinsic errors distribution functions interaction, particularly, limit displacements occurring when mounting single bolt joints, and errors distribution functions determining the accuracy of multi-bolt joints elements mutual orientation. There are considered theoretical schemes of forming setting errors for basic elements in the plane of formed joints for a more complicated case, when shearing forces cause element displacements not obligatory reaching limit values. An analysis of the revealed theoretical schemes for the formation of displacements of the installed elements in the plane of the formed bolted joints shows that the parameters of the displacement distribution are significantly different from the same parameters obtained when calculating dimensional chains with gap units.

Design finite element method based models of floating dry docks strength

The features of global strength modelling of floating dry docks using finite element method are considered. Comparative analysis of two- and three-dimensional models was performed considering the interaction of the floating dry dock and the ship. To solve the problem of reducing the complexity of creating and the size of the finite element model, it is proposed to use the elements of a volumetric orthotropic body to model the main transverse beams of the pontoon. Hydrostatic elastic base of floating dry dock is represented as spring elements. The model of the dock support device includes spring and gap elements. The vessel is considered in the equivalent beam model. Results were obtained on such effects as redistribution of buoyant force due to deformation of the dock, incomplete inclusion of the towers in the general longitudinal bending of the dock, the effect of ship stiffness not only on the longitudinal, but also on the transverse bending of the dock.

Temporal trends of inorganic elements in a common kestrel (Falco tinnunculus) population from south west Spain.

Historical variations (1966-2016) in the exposure to inorganic elements in raptors of South West Spain have been little studied. Therefore, uncertainty exists concerning whether environmental or anthropogenic inputs, as well as dietary strategy shift, may cause changes in exposure patterns. To address this gap, essential and non-essential inorganic elements were measured in Common kestrel (Falco tinnunculus) feathers from museum specimens and free-living individuals spanning a 50-year period. Moreover, stable isotopes of δ13C and δ15N were also measured as proxies of Common kestrel feeding ecology over time. In general, all elements showed significant increasing trends overtime, suggesting changes of inputs from local sources. Moreover, δ15N signatures were correlated to the variations in Al, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, P, Pb, Rb, Sr, Ti, V and Zn concentrations, suggesting trophic changes in this kestrel population as well as possible biomagnification processes. Finally, some values of Cr, Mn and Pb were above the threshold concentrations of potential toxicity.

Dynamic response of horizontally curved composite steel I-girder bridges

The dynamics behavior of horizontally curved composite steel I-girder bridges is investigated by using three-dimensional finite element models. The analyzed bridge is modeled by using ANSYS 15.0 program with SOILD185 and SHELL181 elements to represent concrete and steel members, respectively. AASHTO HL-93 truck is simulated as 3D mass-spring-damper model consisting of five lumped-masses which connected by rigid beams and supported by spring-damper elements which are used to represent the suspension of vehicle body and tires. Gap and actuator elements are used to represent the separation between the tires and road surface and surface roughness condition, respectively. Four different roughness profiles are generated based on power spectral density (PSD) for very good, good, average, and poor roads. The dynamic analysis is carried out under different cases of vehicular loading positions for bridges with radius of curvature ranged from (35 to 200 m). Seven vehicle speeds are chosen to investigate the effect of this factor on the bridge dynamic response, also the effect of bump height at approach span is studied. The results are presented in terms of Impact Factors (IM). The results show that the IM-radius of curvature relationship is significantly influenced by the position of vehicle on transverse sections of the bridge. For the out-lane loading, the IM values for all girders tend to increase as the radius of curvature decreases. A 45 km/hr vehicle speed provides higher IM value for the good roughness bridge to be at 120 km/hr under poor road surface. The bump heights has a significant effect on IMs at lower speed limit, where the IM value increases with the increasing of bump height.

A 2-D Hybrid FE Model With Double Air Gap Elements for Eccentric Magnetic Harmonic Gears

Eccentric magnetic harmonic gears with high gear ratios exhibit high torque densities. However, the revolution and rotation of the eccentric rotor increase the magnetic field analysis complexity. This paper presents a hybrid finite element approach of magnetic field analysis for magnetic harmonic gears. The eccentric air gap region has been divided into three parts: two uniform layers, adjoining the stator and the rotor respectively, are treated as air gap elements; one non-uniform middle layer, as a variable air gap permeance, is discretized by FE meshes similar to the stator and the rotor. Mesh reconstruction can be avoided because the annular cylindrical rings of the two air gap elements are introduced. The mixed eccentric motion of the rotor can be easily treated. In order to save the computational time an equivalent motion mode is introduced and the sliding surface technique is applied by which the coefficient calculation of the air gap elements only needs to be done once wherever the rotor moves. The torques are calculated from the flux densities of the air gap elements. A prototype test confirms the validity of the prediction, and the accuracy of the obtained results is evaluated with FEM.