scholarly journals Two-Stage Discrete Mechanical Modelin Three-Dimensional Space for Garment Simulation

2019 ◽  
Vol 19 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Xuan Luo ◽  
Gaoming Jiang ◽  
Honglian Cong

Abstract This paper focuses on the better performance between the garment simulation result and the simulation speed. For simplicity and clarity, a notation “PART” is defined to indicate the areas between the garment and the human body satisfying some constraints. The discrete mechanical model can be achieved by the two-stage process. In the first stage, the garment can be divided into several PARTs constrained by the distance. In the second stage, the mechanical model of each PART is formulated with a mathematical expression. Thus, the mechanical model of the garment can be obtained. Through changing the constrained distance, the simulation result and the simulation speed can be observed. From the variable distance, a desired value can be chosen for an optimal value. The results of simulations and experiments demonstrate that the better performance can be achieved at a higher speed by saving runtime with the acceptable simulation results and the efficiency of the proposed scheme can be verified as well.

2010 ◽  
Vol 46 (4) ◽  
pp. 777-783
Author(s):  
Antônio Edson de Souza Lucena ◽  
Divaldo de Almeida Sampaio ◽  
Ednaldo Rosas da Silva ◽  
Virgínia Florêncio de Paiva ◽  
Ana Cláudia Santiago ◽  
...  

Highly purified intravenous immunoglobulin G concentrate (IV IgG) was produced with the use of polyethylene glycol associated to a single-stage precipitation by ethanol, instead of the classic Cohn-Oncley process, which employs cold alcohol as the precipitating agent, in a three-stage process. Precipitation of crude fraction containing more than 95% of immunoglobulin G was performed by liquid chromatography with a cation exchanger, CM-Sepharose, as a stationary phase. During the process, the product was subjected to two-stage viral inactivation. The first stage was performed by the action of sodium caprylate, 30 mM at pH 5.1+/- 0.1, and the second stage was performed by the action of a solvent-detergent mixture. The finished product was formulated at 5% with 10% sucralose as the stabilizing agent. The process yields 3.3g of IgG/liter of plasma. The finished product analysis showed an anti-complementary activity lower than 1CH50. Polymer and aggregate percent levels were lower than 3% in the five batches studied. The analysis of neutralizing capacity showed the presence of antibacterial and antiviral antibodies in at least three times higher concentrations than the levels found in source plasma. The finished product fulfilled all purity requirements stated in the 4th edition of the European pharmacopeia.


2020 ◽  
Vol 10 (11) ◽  
pp. 3860
Author(s):  
Song Huang ◽  
Jinxin Cheng ◽  
Chengwu Yang ◽  
Chuangxin Zhou ◽  
Shengfeng Zhao ◽  
...  

Due to the complexity of the internal flow field of compressors, the aerodynamic design and optimization of a highly loaded axial compressor with high performance still have three problems, which are rich engineering design experience, high dimensions, and time-consuming calculations. To overcome these three problems, this paper takes an engineering-designed 2.5-stage highly loaded axial flow compressor as an example to introduce the design process and the adopted design philosophies. Then, this paper verifies the numerical method of computational fluid dynamics. A new Bezier surface modeling method for the entire suction surface and pressure surface of blades is developed, and the multi-island genetic algorithm is directly used for further optimization. Only 32 optimization variables are used to optimize the rotors and stators of the compressor, which greatly overcome the problem of high dimensions, time-consuming calculations, and smooth blade surfaces. After optimization, compared with the original compressor, the peak efficiency is still improved by 0.12%, and the stall margin is increased by 2.69%. The increase in peak efficiency is mainly due to the rotors. Compared with the original compressor, for the second-stage rotor, the adiabatic efficiency is improved by about 0.4%, which is mainly due to the decreases of total pressure losses in the range of above 30% of the span height and 10%–30% of the chord length. Besides, for the original compressor, due to deterioration of the flow field near the tip region of the second-stage stator, the large low-speed region eventually evolves from corner separation into corner stall with three-dimensional space spiral backflow. For the optimized compressor, the main reason for the increased stall margin is that the flow field of the second-stage stator with a span height above 50% is improved, and the separation area and three-dimensional space spiral backflow are reduced.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Subrata Das ◽  
Ashim Jyoti Thakur ◽  
Dhanapati Deka

Biodiesel was produced from high free fatty acid (FFA)Jatropha curcasoil (JCO) by two-stage process in which esterification was performed by Brønsted acidic ionic liquid 1-(1-butylsulfonic)-3-methylimidazolium chloride ([BSMIM]Cl) followed by KOH catalyzed transesterification. Maximum FFA conversion of 93.9% was achieved and it reduced from 8.15 wt% to 0.49 wt% under the optimum reaction conditions of methanol oil molar ratio 12 : 1 and 10 wt% of ionic liquid catalyst at 70°C in 6 h. The ionic liquid catalyst was reusable up to four times of consecutive runs under the optimum reaction conditions. At the second stage, the esterified JCO was transesterified by using 1.3 wt% KOH and methanol oil molar ratio of 6 : 1 in 20 min at 64°C. The yield of the final biodiesel was found to be 98.6% as analyzed by NMR spectroscopy. Chemical composition of the final biodiesel was also determined by GC-MS analysis.


2010 ◽  
Vol 177 ◽  
pp. 238-244 ◽  
Author(s):  
Guang Hui Bai ◽  
Peng Xu ◽  
Peng Cheng Li ◽  
Tong Song Wang

Thermal dehydration kinetics of aluminum sulfate hydrates was studied with TG/DTA under static open air environment. It was found that the thermal dehydration of the aluminum sulfate hydrates was a two-stage process. The first stage happened in the temperature range from 90 to 300°C with 13 water loss. The second stage happened in the temperature range from 300 to 380 °C with 2 water loss. Activation energy and former factor of each staged were obtained by regression the TG/DTA data with 19 differential and integral functions based on non-isothermal Achar method as well as Coats-Redfern method. The result indicated that the mechanism for the first stage dehydration was the proliferation of three-dimensional, spherical symmetry, 3D, D3, slow-α-t curve, n = 2, reaction is reaction 2. The mechanism of the second stage dehydration was random nucleation and subsequent growth, A3, S-shaped α-t curve, n=1/3, m = 3, reaction is reaction 1/3. Identified that the most likely mechanism of Al2(SO4)3•15H2O dehydration is 2 and 1/3 reactions two process.


2015 ◽  
Vol 1087 ◽  
pp. 64-67 ◽  
Author(s):  
Alinda Samsuri ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Fairous Salleh ◽  
Mohamed Wahab Mohamed Hisham ◽  
Rizafizah Othaman ◽  
...  

A metallic molybdenum is formed by a two-stage process that was carburized MoO2 with carbon monoxide followed by heat treatment. XRD techniques were employed to identify the phase’s changes in the sample. It was found that by the present of carbon monoxide during carburization process until 900 °C, Mo2C is formed first, compared to metallic molybdenum, due to the high thermodynamic barrier for formation of metallic molybdenum. In the second stage, Mo2C further reacts with the remaining MoO2 at 900 °C to produce metallic molybdenum.


Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 41 ◽  
Author(s):  
Michael W. Förster ◽  
Stephan Buhre ◽  
Bo Xu ◽  
Dejan Prelević ◽  
Regina Mertz-Kraus ◽  
...  

The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1–3 GPa have not successfully produced melts with K2O >5 wt%–6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%–8.5 wt% K2O and K/Na of 6–7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting.


2017 ◽  
Vol 09 (03) ◽  
pp. 1750034 ◽  
Author(s):  
Reza Ahmadzadeh ◽  
Sohrab Kordrostami ◽  
Alireza Amirteimoori

Recently, network data envelopment analysis (NDEA) models have been developed to evaluate the efficiency of decision making units (DMUs) with internal structures. The network structures range from a simple two-stage process to a complex system. Looking through the literature on two-stage network structures, we see that Li et al. (2012) extended a model by assuming that the inputs to the second stage include both the outputs from the first stage and additional inputs to the second stage. In the current study, a model is proposed to evaluate the performance of these types of general two-stage network structures. To this end, we provide a linear model using fractional programming. In fact, previous models were often nonlinear models which were solved with heuristic methods. But, since the model presented in this paper is a linear model, then it can be solved easily as a linear programming problem. In order to clarify the newly proposed approach of this study, it has been applied to a case of regional Research and Development (R&D) system related to 30 provincial level regions in China and results have been compared with the heuristic method of Li et al. (2012).


2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Bowei Yu ◽  
Guozhi Fan ◽  
Sijiu Zhao ◽  
Yuchan Lu ◽  
Qiao He ◽  
...  

AbstractConvertible cellulose and lignin were simultaneously isolated from wheat straw using a two-stage process via simply varying temperature and H2SO4 concentration. At the first-stage, cellulose was obtained by pretreating wheat straw at lower temperature and acid concentration using an organosolv process. The purity, yield and recovery rate of cellulose reached 86.8 wt%, 55.2 and 92.8% at 150 °C with 1 wt% H2SO4. At the second stage, the residual liquid was further treated at higher temperature and acid concentration, giving 17.4% lignin yield with 86.6% recovery rate and 93.2 wt% purity at 180 °C with 1.5 wt% H2SO4. The conversion of the as-isolated cellulose and lignin into chemicals was further investigated. The total yield of 5-hydroxymethylfurfural and glucose derived from wheat straw cellulose reached 82.5%, and 18.3% yield of monophenolic compounds from lignin were obtained, respectively. These results indicated that the two-stage process was effective for obtaining high-quality cellulose and lignin from wheat straw. Both of them displayed excellent convertible property.


Author(s):  
Jianfeng Ruan ◽  
Dawei Pi ◽  
Kaihang Jiang ◽  
Hongliang Wang ◽  
Boyuan Xie

In this paper, a two-stage expectation stability controller was proposed for driving stability of four wheel independent drive electric vehicles. The proposed controller has three levels. There were three steps to the stability control of the vehicle. First, the three-dimensional state portraits were drawn based on the 14DOFs vehicle model and used the s tem equation to find two-stage expectation. The surface was derived from the analysis of the tire-road adhesion divides the portraits into safe areas and unsafe areas. Second, the stability controller with sliding mode algorithm was designed. When the state parameter is in the unsafe areas, the safe boundary surface is taken as the first-stage expectation; after the system enters the safe areas, the stem is taken as the second-stage expectation. Then the fuzzy algorithm is applied to distribute the control demand of yaw moment to generate the torques of each in-wheel motor. Finally, simulation verification is performed in Simulink-CarSim co-simulation environment. The simulation results show that the designed control strategy can improve the lateral stability while the loss of longitudinal speed is within 3.25%.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2365
Author(s):  
Agata Kaczmarek ◽  
Piotr Denis ◽  
Marcin Krajewski ◽  
Tomasz Mościcki ◽  
Artur Małolepszy ◽  
...  

An improved method for the production of luminescent carbon nanoparticles is proposed in this work. The new method overcomes the disadvantages of commonly used approaches. It involves two-stage laser ablation in water and in aqueous solutions, where the first stage is the laser ablation of a graphite target and the second is the shredding of particles produced in the first step. The two-stage method offers the optimization of the laser pulse fluence for the performance of each process. It was found that the two-stage process of laser ablation allows producing photoluminescent carbon structures in pure water. The additional reagent may be added either in the first or second stage. The first stage performed in pure water allows avoiding the contamination of the target. Moreover, it simplifies the identification of the origin of photoluminescence. Two synthesis routes for the preparation of carbon nanoparticles by the proposed method using pure water as well as urea aqueous solution are investigated. It was found that the use of urea as a reagent results in luminescence properties similar to those obtained with other more hazardous amine-based reagents. The influence of the synthesis approach and process parameters on the structural and luminescent properties of nanoparticles is also explored in this work.


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