scholarly journals Morphological transformation of arched ribbon driven by torsion

2022 ◽  
Vol 170 ◽  
pp. 108511
Author(s):  
Yuanfan Dai ◽  
Bohua Sun ◽  
Yi Zhang ◽  
Xiang Li
Keyword(s):  
Morphological Transformation

Effects of Aging on the Morphology of Rubber-Brass Interfacial Layer

2011 ◽  
Vol 39 (1) ◽  
pp. 20-43 ◽  
Author(s):  
A. Ashirgade ◽  
P. B. Harakuni ◽  
W. J. Vanooij
Keyword(s):  
Chemical Composition ◽  
Interfacial Layer ◽  
Secondary Ion Mass Spectrometry ◽  
Morphological Changes ◽  
Grazing Incidence ◽  
Complex Nature ◽  
Rubber Compound ◽  
Tire Cord ◽  
Morphological Transformation ◽  
Adhesion Promoter

Abstract Adhesion between rubber compound and brass-plated steel tire cord is crucial in governing the overall performance of tires. The rubber-brass interfacial adhesion is influenced by the chemical composition and thickness of the interfacial layer. It has been shown that the interfacial layer consists mainly of sulfides and oxides of copper and zinc. This paper discusses the effect of changes in the chemical composition and the structure of the interfacial layers due to addition of adhesion promoter resins. Grazing incidence x-ray diffraction (GIXRD) experiments were run on sulfidized polished brass coupons previously bonded to five experimental rubber compounds. It was confirmed that heat and humidity conditions lead to physical and chemical changes of the rubber-steel tire cord interfacial layer, closely related to the degree of rubber-brass adhesion. Morphological transformation of the interfacial layer led to loss of adhesion after aging. The adhesion promoter resins inhibit unfavorable morphological changes in the interfacial layer, thus stabilizing it during aging and prolonging failure. Tire cord adhesion tests illustrated that the one-component resins improved adhesion after aging using a rubber compound with lower cobalt loading. Based on the acquired diffraction profiles, these resins were also found to impede crystallization of the sulfide layer after aging, leading to improved adhesion. Secondary ion mass spectrometry depth profiles and scanning electron microscopy micrographs strongly corroborated the findings from GIXRD. This interfacial analysis adds valuable information to our understanding of the complex nature of the rubber-brass bonding mechanism.

scholarly journals Myricetin as an Antivirulence Compound Interfering with a Morphological Transformation into Coccoid Forms and Potentiating Activity of Antibiotics against Helicobacter pylori

2021 ◽  
Vol 22 (5) ◽  
pp. 2695
Author(s):  
Paweł Krzyżek ◽  
Paweł Migdał ◽  
Emil Paluch ◽  
Magdalena Karwańska ◽  
Alina Wieliczko ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Morphological Transformation ◽  
High Tendency ◽  
Minimal Inhibitory Concentrations ◽  
Coccoid Form ◽  
Stomach Diseases ◽  
Fold Reduction ◽  
H Pylori

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.

scholarly journals Synthesis of magnesium carbonate hydrate from natural talc

2020 ◽  
Vol 18 (1) ◽  
pp. 951-961
Author(s):  
Qiuju Chen ◽  
Tao Hui ◽  
Hongjuan Sun ◽  
Tongjiang Peng ◽  
Wenjin Ding
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Crystal Growth ◽  
Crystal Morphology ◽  
Magnesium Carbonate ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
Morphological Transformation ◽  
X Ray ◽  
Carbonation Process

AbstractVarious morphologies of magnesium carbonate hydrate had been synthesized without using any organic additives by carefully adjusting the reaction temperature and time during the talc carbonation process. At lower temperatures, magnesium carbonate hydrate was prone to display needle-like morphology. With the further increase of the carbonation temperature, the sheet-like crystallites became the preferred morphology, and at higher aging temperatures, these crystallites tended to assemble into layer-like structures with diverse morphologies, such as rose-like particles and nest-like structure. The reaction time had no effect on the crystal morphology, but it affected the particle size and situation of the crystal growth. X-Ray diffraction results showed that these various morphologies were closely related to their crystal structure and compositions. The needle-like magnesium carbonate hydrate had a formula of MgCO3·3H2O, whereas with the morphological transformation from needle-like to sheet-like, rose-like, and nest-like structure, their corresponding compositions also changed from MgCO3·3H2O to 4MgCO3·Mg(OH)2·8H2O, 4MgCO3·Mg(OH)2·5H2O, and 4MgCO3·Mg(OH)2·4H2O.

Transition-metal ion-mediated morphological transformation of pyridine-based peptide nanostructures

2021 ◽  
Vol 45 (1) ◽  
pp. 153-161
Author(s):  
Narendra Singh ◽  
Ramesh Singh ◽  
Swati Sharma ◽  
Khushboo Kesharwani ◽  
Khashti Ballabh Joshi ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ion ◽  
Chemical Structure ◽  
Morphological Transformation ◽  
Transition Metal Ion

Pyridine-mediated constitutionally isomeric artificial metallopeptides possess remarkable advantages over the natural counterparts mainly due to their tailor-made chemical structure.

Solubilization Effect of Surfactants on Morphological Transformation of Cadmium and Pyrene in Co-Contaminated Soils

2015 ◽  
Vol 226 (5) ◽  
Author(s):  
Qian Wang ◽  
Xiaoyan Liu ◽  
Chuanhua Wang ◽  
Xinying Zhang ◽  
Hongbing Li ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Morphological Transformation

scholarly journals Monitoring morphology and properties of hybrid organicinorganic materials from in situ polymerization of tetraethoxysilane in polyimide polymer: 1. Effect of the coupling agent on the microstructure and interfacial interaction

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Hamid Kaddami ◽  
Carsten Becker-Willinger ◽  
Helmut Schmid
Keyword(s):  
Mechanical Properties ◽  
Hybrid Materials ◽  
Coupling Agent ◽  
In Situ Polymerization ◽  
Interfacial Interaction ◽  
Inorganic Materials ◽  
Hybrid Films ◽  
Morphological Transformation ◽  
Temperature Relaxation ◽  
Saxs Analysis

AbstractTransmission electron microscopy (TEM), small angle X-ray (SAXS) and dynamical mechanical thermal analysis (DMTA) were used to characterize the morphology and thermo-mechanical properties of hybrid organic inorganic materials. These materials were based on polyimide (PI) and tetraethoxysilane (TEOS). Polyimide polymer is prepared from 4,4’-oxydianiline (ODA) 2,2-Bis(3- amino-4-hydroxyphenyl) hexafluoro-propane (6F-OHDA) pyromellitic dianhydride (PMDA) polyamic polymer. In one family of hybrid materials 3- isocyanatopropyltriethoxysilane (ICTS) is used as coupling agent in order to enhance the interfacial interaction between polyimide and silica. It was possible to modulate the morphology as well as the optical and thermo-mechanical properties of these hybrid materials depending on the formulation used. TEM and SAXS analysis indicated that silica domains on the nanoscale level are obtained when coupling agent is used in the formulation. Additionally the TEM and SAXS analysis indicated that miscibility of the organic and the inorganic phases on the molecular scale is obtained in the hybrid films when ICTS as coupling agent is added to the polyamic acid. These techniques show a fractal structure of the hybrid materials with coupling agent. This was confirmed with DMTA analysis which shows very high temperature relaxation (more than 450°C). From this result it could be derived that the addition of ICTS causes a morphological transformation from discrete particulate microstructure to fine interpenetrated or co-continuous phases. The intimate miscibility of the phases is accompanied at the same time by the amelioration of thermo-mechanical properties of the hybrid films.

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