Home / Advanced Search

  • Title/Keywords

  • Author/Affliations

  • Journal

  • Article Type

  • Start Year

  • End Year

Update SearchingClear
  • Articles
  • Online
Search Results (796)
  • Open Access

    ARTICLE

    Thermal-Mechanical Characterization of Polyurethane Rigid Foams: Effect of Modifying Bio-Polyol Content in Isocyanate Prepolymers

    Luis Daniel Mora-Murillo1, Felipe Orozco-Gutierrez2, José Vega-Baudrit2, Rodolfo Jesús González-Paz2*

    Journal of Renewable Materials, Vol.5, No.3-4, pp. 220-230, 2017, DOI:10.7569/JRM.2017.634112

    Abstract Nowadays, green polyurethane (PU) foams are mostly synthesized by replacing an amount of petrochemical polyol with biobased polyol. Here we report five different families of isocyanate prepolymer formulations that were prepared with biobased sources and the correlation between the structure of chains and the properties of the produced PU foam. Foam behavior in tension, torsion, compression, shape memory tests and physical properties were studied by dynamic mechanical thermal analysis (DMTA); interactions in the polymer chains were analyzed by Fourier transform infrared spectroscopy (FTIR); and thermal analysis was performed by thermogravimetry (TGA) and differential scanning calorimetry More >

  • Open Access

    ARTICLE

    Hydroxytyrosol as Active Ingredient in Poly(vinyl alcohol) Films for Food Packaging Applications

    Elena Fortunati1*, Francesca Luzi1, Chiara Fanali2, Laura Dugo2, Maria Giovanna Belluomo2, Luigi Torre1, José Maria Kenny1, Luca Santi3, Roberta Bernini3

    Journal of Renewable Materials, Vol.5, No.2, pp. 81-95, 2017, DOI:10.7569/JRM.2016.634132

    Abstract Hydroxytyrosol (HTyr), a biophenol found in extra-virgin olive oil or olive oil by-products, well known for its strong antioxidant activity, was used as active ingredient for poly(vinyl alcohol) (PVA) matrix to develop film formulations by solvent casting process. The effect of HTyr on the morphological, thermal stability, optical, mechanical and release properties of PVA were investigated, while water absorption capacity, migration with food stimulants, water vapor permeability and antioxidant properties were tested taking into account the final application as food packaging systems. Morphological investigations evidenced homogeneity of all PVA/HTyr films, while the presence of HTyr More >

  • Open Access

    ARTICLE

    The Effect of Posterior Pedicle Screws Biomechanical Fixation for Thoracolumbar Burst Fracture

    Baogang Tian1, Yang Shao1, Zhijiong Wang1, Jian Li2,*

    Molecular & Cellular Biomechanics, Vol.14, No.3, pp. 187-194, 2017, DOI:10.3970/mcb.2017.014.187

    Abstract The purpose of this study was to explore the clinical efficacy and safety of posterior pedicle screw fixation in the treatment of thoracolumbar burst fracture. A total of 120 patients with thoracolumbar burst fractures were selected from January 2014 to December 2016. 60 patients were divided into the study group, and 60 patients were as the control group. The patients in the study group were treated with posterior pedicle screw fixation. The control group was treated with posterior non-traumatic pedicle screw fixation. After treatment, there were six months follow up. The clinical indexes, complications, and… More >

  • Open Access

    ARTICLE

    Mechanical Properties of Stem Cells from Different Sources During Vascular Smooth Muscle Cell Differentiation

    Ruikai Chen1, Delphine Dean1,*

    Molecular & Cellular Biomechanics, Vol.14, No.3, pp. 153-169, 2017, DOI:10.3970/mcb.2017.014.153

    Abstract Vascular smooth muscle cells (VSMCs) play an important role in regulating blood flow and pressure by contracting and relaxing in response to a variety of mechanical stimuli. A fully differentiated and functional VSMC should have both the ability to contract and relax in response to environmental stimuli. In addition, it should have the proper mechanical properties to sustain the mechanically active vascular environment. Stem cells can differentiate towards VSMC lineages and so could be used as a potential treatment for vascular repair. However, few studies have assessed the time it takes for stems cells to… More >

  • Open Access

    ARTICLE

    Comparison of Right Ventricle Morphological and Mechanical Characteristics for Healthy and Patients with Tetralogy of Fallot: An In Vivo MRI-Based Modeling Study

    Dalin Tang1,*,2, Heng Zuo2,*, Chun Yang2, Zheyang Wu2, Xueying Huang3, Rahul H. Rathod4, Alexander Tang4, Kristen L. Billiar5, Tal Geva4

    Molecular & Cellular Biomechanics, Vol.14, No.3, pp. 137-151, 2017, DOI:10.3970/mcb.2017.014.137

    Abstract Patients with repaired tetralogy of Fallot (TOF) account for the majority of cases with late onset right ventricle failure. Comparing TOF patients with healthy people may provide information to address this challenge. Cardiac magnetic resonance (CMR) data were obtained from 16 TOF patients (patient group, PG) and 6 healthy volunteers (healthy group, HG). At begin-of-ejection, better patient group (n=5, BPG) stress was very close to HG stress (54.7±38.4 kPa vs. 51.2±55.7 kPa, p=0.6889) while worse patient group (n=11, WPG) stress was 84% higher than HG stress (p=0.0418). Stress may be used as an indicator to differentiate More >

  • Open Access

    ARTICLE

    Simvastatin Inhibits the Proliferation and Apoptosis of Macrophages Induced by Mechanical and/or Oxidized Low-Density Lipoprotein

    Kefeng Liu1,2, §, Zhengyu Zhang1,3, §, Ting Pei1, Ziqing Li4, Jingjing Wang1, Hong Wang1, Suning Ping1, Lie Deng1, Linli Wang1, Jintao Huang5, Puyi Sheng4, Shuying Liu1, Chaohong Li1

    Molecular & Cellular Biomechanics, Vol.14, No.2, pp. 101-123, 2017, DOI:10.3970/mcb.2017.014.099

    Abstract This study was designed to investigate the effects of mechanical (MS) and/or oxidized low-density lipoprotein on proliferation and apoptosis of RAW264.7 macrophages and the underlying mechanisms. The cultured quiescent RAW264.7 macrophages were subject to stimulation with MS and/or in the presence or absence of simvastatin and then harvested for Western blot, and immunoflourecence. Either MS or alone could cause increase in cell proliferation and apoptosis, while their combination led to an additive effect. In terms of mechanisms, MS and/or significantly increased phosphorylation levels of MAPKs (ERKs, JNKs and p38MAPK), promoted the reactive oxygen species (ROS) More >

  • Open Access

    ARTICLE

    Research on Instability Mechanism and Type of Ore Pillar based on the Fold Catastrophe Theory

    Zhengzheng Cao1, Feng Du2,3,4, Zhenhua Li2, Qinting Wang1, Ping Xu1, Haixiao Lin1

    CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.3, pp. 275-293, 2017, DOI:10.3970/cmes.2017.113.287

    Abstract The stability of ore pillar in mine is essential for the safe and efficient mining. Based on the energy evolvement rule in ore pillar and roadway roof system, the roadway roof and ore pillar are treated as energy release body and energy dissipation body, respectively. Therefore, the double-block mechanical model is established with energy dissipation body and energy release body, and the energy mechanism of ore pillar instability is obtained, based on the fold catastrophe mathematical theory. The research result indicates that the dynamic instability of ore pillar is a physical instability problem caused by… More >

  • Open Access

    ARTICLE

    Deformation and failure analysis of river levee induced by coal mining and its influence factor

    Meng Li1,2, Jixiong Zhang1,3, Nan Zhou1, Qiang Zhang1

    CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.2, pp. 183-194, 2017, DOI:10.3970/cmes.2017.113.189

    Abstract To study the influence of coal mining on the stability of river levees, a mechanical model of mining-induced river levee deformation was established. This was based on the mining-induced deformation characteristics of river levees and the application of a typical surface subsidence function. Meanwhile, a failure criterion was proposed for river levees. Using some examples, the deformation of, and stress distribution through, river levees under the influence of mining were obtained: the maximum tensile stress on the bottom of the river levee was less than the tensile strength, under which circumstance the river levee remained More >

  • Open Access

    ARTICLE

    Multiscale Nonlinear Thermo-Mechanical Coupling Analysis of Composite Structures with Quasi-Periodic Properties

    Zihao Yang1, Liang Ma2, Qiang Ma3, Junzhi Cui1,4, Yufeng Nie1, Hao Dong1, Xiaohong An5

    CMC-Computers, Materials & Continua, Vol.53, No.3, pp. 219-248, 2017, DOI:10.32604/cmc.2017.053.235

    Abstract This paper reports a multiscale analysis method to predict the thermo-mechanical coupling performance of composite structures with quasi-periodic properties. In these material structures, the configurations are periodic and the material coefficients are quasi-periodic, i.e., they depend not only on the microscale information but also on the macro location. Also, a mutual interaction between displacement and temperature fields is considered in the problem, which is our particular interest in this study. The multiscale asymptotic expansions of the temperature and displacement fields are constructed and associated error estimation in nearly pointwise sense is presented. Then, a finite More >

  • Open Access

    ARTICLE

    Influence of functionalization on the structural and mechanical properties of graphene

    L.S. Melro1,2, L.R. Jensen1

    CMC-Computers, Materials & Continua, Vol.53, No.2, pp. 109-127, 2017, DOI:10.3970/cmc.2017.053.111

    Abstract Molecular dynamics simulations were applied in order to calculate the Young’s modulus of graphene functionalized with carboxyl, hydroxyl, carbonyl, hydrogen, methyl, and ethyl groups. The influence of the grafting density with percentages of 3, 5, 7, and 10% and the type of distribution as a single cluster or several small clusters were also studied. The results show that the elastic modulus is dependent on the type of functional groups. The increasing coverage density also evidenced a decrease of the Young’s modulus, and the organization of functional groups as single cluster showed a lesser impact than More >

Displaying 561-570 on page 57 of 796. Per Page