Development and Calibration of a 3D Micromodel for Evaluation of Masonry Infilled RC Frame Structural Vulnerability to Earthquakes

Within the scope of literature, the influence of openings within the infill walls that are bounded by a reinforced concrete frame and excited by seismic drift forces in both in- and out-of-plane direction is still uncharted. Therefore, a 3D micromodel was developed and calibrated thereafter, to gain more insight in the topic. The micromodels were calibrated against their equivalent physical test specimens of in-plane, out-of-plane drift driven tests on frames with and without infill walls and openings, as well as out-of-plane bend test of masonry walls. Micromodels were rectified based on their behavior and damage states. As a result of the calibration process, it was found that micromodels were sensitive and insensitive to various parameters, regarding the model’s behavior and computational stability. It was found that, even within the same material model, some parameters had more effects when attributed to concrete rather than on masonry. Generally, the in-plane behavior of infilled frames was found to be largely governed by the interface material model. The out-of-plane masonry wall simulations were governed by the tensile strength of both the interface and masonry material model. Yet, the out-of-plane drift driven test was governed by the concrete material properties.

Solution of the Schrödinger torsion equation in the basis set of Mathieu functions: verification by numerical experiment

The efficiency of the algorithm for the numerical solution of the Schrödinger torsion equation in the basis of Mathieu functions has been considered. The computational stability of the proposed algorithm is shown. The energies of torsion transitions determined in the basis sets of plane waves and Mathieu functions have been compared with the results of spectroscopy. A conclusion about the applicability of the algorithm using the basis set of Mathieu functions to the solution of the Schrödinger equation with a periodic potential has been derived.

Large eddy simulation of converging Richtmyer–Meshkov instability based on subgrid-scale dissipation similar method

This paper focuses on large eddy simulation of the Richtmyer–Meshkov instability (RMI) in spherical and cylindrical converging geometries with a Mach number [Formula: see text] based on subgrid-scale (SGS) dissipation similar method (SDSM). Based on the converging RMI problem, we obtain from a priori test and theoretical analysis that the suggested method can provide accurate structural correlation while ensuring the computational stability. Comparing the numerical simulation results with direct numerical simulation (DNS) and existing model in converging RMI problem, we could find that the suggested method overcomes some defects of the existing model, such as the Smagorinsky model cannot predict transition accurately and the helicity model can only predicts the quasi-two-dimensional flow precisely. It provides a beneficial tool for the research of converging RMI.

A study of stability of difference scheme of Markov counting chain method for fluidization modeling

Devices with a fluidized bed of granular material are applied in many energy power technology processes. The fluidized bed is a heterogeneous system, so mathematical models assuming its spatial discretization are necessary for its proper description. Markov chain theory is one of the most effective tools for the mathematical description of the fluidized bed structure. Many research papers are devoted to the issues of the theory application when developing mathematical models of various technological processes in the fluidized bed. At the same time, much less attention is paid to the issue of stability analysis of the proposed algorithms. Thus, it is a highly topical issue to analyze the computational stability of models of fluidized bed based on the mathematical principles of the Markov chain theory. The Markov chain approach is used as a mathematical basis for modeling of the flow patterns in a fluidized bed. The parametric identification of the model is performed using the dependencies known from the scientific papers, and the transition matrices are aligned with the physical parameters of the mass flows, which makes the proposed model nonlinear. The mixed criterion of the stability algorithm is formulated. It shows the influence of the spatiotemporal parameters of the problem sampling on the stability of computational procedures. The stability of the difference scheme to calculate formation of a fluidized bed of a monodisperse granular material is studied. The influence of the time sampling frequency on the stability of the resulting solution is considered. The effect of various parameters of the model on the loss of computational stability is estimated. It is proved that the time and spatial sampling frequencies should be chosen as a result of a mixed stability criterion. The study proves that the methodology of the Markov chain theory is an acceptable tool to describe the structure of such particle systems as a fluidized bed. It is established that macro-diffusion parameter of particle motion is the most influential in the process of computational stability loss. Thus, on the one hand, it is relevant to conduct further comparative studies of existing models of macrodiffusion, and on the other hand, it is possible to use models based on the theory of Markov chains considering the proposed stability criterion.

MODELING MATEMATIS DAN SIMULASI DROPLET UNTUK PENDINGINAN ALAT-ALAT TEKNOLOGI INFORMASI DAN KOMPUTER DENGAN METODE LATTICE-BOLTZMANN

Abstrak : Kebutuhan inovasi skema pendinginan untuk pemeliharaan perangkat elektronik dengan suhu aman dibawah batas yang telah ditentukan oleh batasan material dan kendala realibilitas yang terkait pada miniaturisasi microchip yang agresif pada komponen elektronik. Pergeseran dari ketergantungan pada sistem berpendingin kipas menjadi ke skema pendinginan yang memanfaatkan pendingin cairan dielektrik menggunakan berbagai skema pendinginan fase tunggal. Perekayasa (engineer) sistem pendingin memusatkan perhatian pada skema pendinginan dua fase, untuk memanfaatkan kedua system pendingin. Sifat yang harus dimiliki perekayasa sistem pendingin ini yaitu konveksi fluida dan panas laten untuk memindahkan jumlah kalor yang jauh lebih besar dari pada skema fase tunggal, sambil mempertahankan suhu perangkat yang lebih rendah. Beberapa skema pendingin cairan dua fase telah direkomendasikan untuk menghilangkan fluks kalor tinggi dari perangkat yang digunakan diaplikasi. Momentum droplet memungkinkan cairan menembus penghalang uap yang dibuat oleh gelembung nukleasi dan secara lebih efektif mengisi kembali permukaan, keduanya sangat bermanfaat untuk pendinginan fluks tinggi. Pada model dan simulasi pengembangan droplet menggunakan metode LBM multi fase, parameter penting yang selalu didapatkan adalah arus semu maksimum (maximum spurious currents) yang menetukan stabilitas komputasi. Kata kunci : Modeling Matematis, Simulasi Droplet, Metode Latice-Boltzman Abstract: The need for innovative cooling schemes for maintaining electronic devices with safe temperatures below predetermined limits by material limitations and reliability constraints associated with aggressive microchip miniaturization of electronic components. Shifting from reliance on fan-cooled systems to cooling schemes that utilize dielectric liquid cooling using a variety of single-phase cooling schemes. The cooling system engineer focuses on two-phase cooling schemes, to take advantage of both cooling systems. Properties that these cooling system engineers must possess are fluid convection and latent heat to transfer a much greater amount of heat than a single-phase scheme, while maintaining a lower device temperature. Several two-phase liquid cooling schemes have been recommended to remove the high heat flux from the apparatus used in the application. The droplet momentum allows the liquid to penetrate the vapor barrier created by the nucleation bubbles and more effectively replenish the surface, both of which are very beneficial for high flux cooling. In droplet development models and simulations using the multi-phase LBM method, an important parameter that is always obtained is the maximum spurious currents which determine the computational stability. Keywords: Mathematical Modeling, Droplet Simulation, Latice-Boltzman Method

Thermostable and Long-Circulating Albumin-Conjugated Arthrobacter globiformis Urate Oxidase

Urate oxidase derived from Aspergillus flavus has been investigated as a treatment for tumor lysis syndrome, hyperuricemia, and gout. However, its long-term use is limited owing to potential immunogenicity, low thermostability, and short circulation time in vivo. Recently, urate oxidase isolated from Arthrobacter globiformis (AgUox) has been reported to be thermostable and less immunogenic than the Aspergillus-derived urate oxidase. Conjugation of human serum albumin (HSA) to therapeutic proteins has become a promising strategy to prolong circulation time in vivo. To develop a thermostable and long-circulating urate oxidase, we investigated the site-specific conjugation of HSA to AgUox based on site-specific incorporation of a clickable non-natural amino acid (frTet) and an inverse electron demand Diels–Alder reaction. We selected 14 sites for frTet incorporation using the ROSETTA design, a computational stability prediction program, among which AgUox containing frTet at position 196 (Ag12) exhibited enzymatic activity and thermostability comparable to those of wild-type AgUox. Furthermore, Ag12 exhibited a high HSA conjugation yield without compromising the enzymatic activity, generating well-defined HSA-conjugated AgUox (Ag12-HSA). In mice, the serum half-life of Ag12-HSA was approximately 29 h, which was roughly 17-fold longer than that of wild-type AgUox. Altogether, this novel formulated AgUox may hold enhanced therapeutic efficacy for several diseases.

Incorporation of gradient-enhanced microplane damage model into isogeometric analysis

Purpose This study aims to develop a new analysis approach devised by incorporating a gradient-enhanced microplane damage model (GeMpDM) into isogeometric analysis (IGA), which shows computational stability and capability in accurately predicting crack propagations in structures with complex geometries. Design/methodology/approach For the non-local microplane damage modeling, the maximum modified von-Mises equivalent strain among all microplanes is regularized as a representative quantity. This characterization implies that only one additional governing equation is considered, which improves computational efficiency dramatically. By combined use of GeMpDM and IGA, quasi-static and dynamic numerical analyses are conducted to demonstrate the capability in predicting crack paths of complex geometries in comparison to FEM and experimental results. Findings The implicit scheme with the adopted damage model shows favorable numerical stability and the numerical results exhibit appropriate convergence characteristics concerning the mesh size. The damage evolution is successfully controlled by a tension-compression damage factor. Thanks to the advanced geometric design capability of IGA, the details of crack patterns can be predicted reliably, which are somewhat difficult to be acquired by FEM. Additionally, the damage distribution obtained in the dynamic analysis is in close agreement with experimental results. Originality/value The paper originally incorporates GeMpDM into IGA. Especially, only one non-local variable is considered besides the displacement field, which improves the computational efficiency and favorable convergence characteristics within the IGA framework. Also, enjoying the geometric design ability of IGA, the proposed analysis method is capable of accurately predicting crack paths reflecting the complex geometries of target structures.

Automatic Segmentation and 3D Printing of A-shaped Manikins using a Bounding Box and Body-feature Points

A novel algorithm for 3D-printing technology was proposed to generate large-scale objects, especially A-shaped manikins or 3D human body scan data. Most of the conventional 3D printers have a finite printing volume, and it is the users’ work to convert the target object into a printable size. In this study, an automatic three-step segmentation strategy was applied to the raw manikin mesh data until the final pieces had a smaller size than the 3D printer’s maximum printing volume, which is generally called “beam length”. Human body feature point information was adopted for fashion and textile researchers to easily specify the desired cutting positions. A simple bounding box, especially orienting bounding box, and modified Boolean operator were proposed to extract the specified segments with computational stability. The proposed method was applied to graphically synthesized manikin data, and 1/8, 1/4, and 1/2 scale manikins were successfully printed, minimizing the amount of support structure.