scholarly journals Adfreezing strength of ice to model piles

1987 ◽  
Vol 24 (3) ◽  
pp. 446-452 ◽  
Author(s):  
V. R. Parameswaran
Keyword(s):  
Key Words ◽  
Surface Coating ◽  
Loading Rate ◽  
Surface Characteristics ◽  
Surface Coatings ◽  
Displacement Rate ◽  
Rate Model ◽  
Freshwater Ice

Results of tests to determine the adfreezing strength of freshwater ice to piles having different surface characteristics show that adfreeze strength increases with increase in the rate of displacement and loading of the pile. Surface coatings such as creosote on wood piles and paint and silicone sealer on metallic piles drastically decrease the adfreezing strength of ice. Key words: adfreezing strength, displacement rate, ice, loading rate, model piles, surface coating.

scholarly journals Impact of anti-biofouling surface coatings on the properties of nanomaterials and their biomedical applications

2018 ◽  
Vol 6 (1) ◽  
pp. 9-24 ◽  
Author(s):  
Yuancheng Li ◽  
Yaolin Xu ◽  
Candace C. Fleischer ◽  
Jing Huang ◽  
Run Lin ◽  
...  
Keyword(s):  
Surface Coating ◽  
Biomedical Applications ◽  
Biological Systems ◽  
Surface Coatings ◽  
Specific Interactions ◽  
Coating Materials

Various anti-biofouling surface coating materials for nanoparticles have been reviewed for the reduction of their non-specific interactions with biological systems.

scholarly journals Improved corrosion resistance of commercially pure magnesium after its modification by plasma electrolytic oxidation with organic additives

2018 ◽  
Vol 33 (5) ◽  
pp. 725-740 ◽  
Author(s):  
Monica Echeverry-Rendon ◽  
Valentina Duque ◽  
David Quintero ◽  
Sara M Robledo ◽  
Martin C Harmsen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrolyte Solution ◽  
Surface Coating ◽  
Plasma Electrolytic Oxidation ◽  
Biomedical Applications ◽  
The Body ◽  
Pure Magnesium ◽  
Surface Coatings ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

The optimal mechanical properties render magnesium widely used in industrial and biomedical applications. However, magnesium is highly reactive and unstable in aqueous solutions, which can be modulated to increase stability of reactive metals that include the use of alloys or by altering the surface with coatings. Plasma electrolytic oxidation is an efficient and tuneable method to apply a surface coating. By varying the plasma electrolytic oxidation parameters voltage, current density, time and (additives in the) electrolytic solution, the morphology, composition and surface energy of surface coatings are set. In the present study, we evaluated the influence on surface coatings of two solute additives, i.e. hexamethylenetetramine and mannitol, to base solutes silicate and potassium hydroxide. Results from in vitro studies in NaCl demonstrated an improvement in the corrosion resistance. In addition, coatings were obtained by a two-step anodization procedure, firstly anodizing in an electrolyte solution containing sodium fluoride and secondly in an electrolyte solution with hexamethylenetetramine and mannitol, respectively. Results showed that the first layer acts as a protective layer which improves the corrosion resistance in comparison with the samples with a single anodizing step. In conclusion, these coatings are promising candidates to be used in biomedical applications in particular because the components are non-toxic for the body and the rate of degradation of the surface coating is lower than that of pure magnesium.

Selective enhancement of human stem cell proliferation by mussel inspired surface coating

RSC Advances ◽  
2016 ◽  
Vol 6 (65) ◽  
pp. 60206-60214 ◽  
Author(s):  
Xiumei Jiang ◽  
Yanfang Li ◽  
Ying Liu ◽  
Chunying Chen ◽  
Menglin Chen
Keyword(s):  
Stem Cell ◽  
Surface Coating ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Surface Coatings ◽  
Human Stem Cell ◽  
Adhesion Properties ◽  
Stem Cell Proliferation ◽  
Induced Pluripotent ◽  
Selective Enhancement

The biocompatibility and cell adhesion properties of mussel inspired polydopamine and polynorepinephrine surface coatings on PCL fibers for human mesenchymal and human induced pluripotent stem cell derived mesenchymal stem cells were investigated.

Fracture Toughness of Freshwater Ice—Part I: Experimental Technique and Results

1996 ◽  
Vol 118 (2) ◽  
pp. 135-140 ◽  
Author(s):  
L. J. Weber ◽  
W. A. Nixon
Keyword(s):  
Fracture Toughness ◽  
Experimental Technique ◽  
Test Temperature ◽  
Significant Variation ◽  
Loading Rate ◽  
Companion Paper ◽  
Fractographic Analysis ◽  
Linear Elastic ◽  
Freshwater Ice ◽  
Crack Tip Plasticity

Experiments have been performed to determine the effect of loading rate and temperature on the fracture toughness of both granular and S2 columnar freshwater ice. Loading rate was varied from 0.04 to 40.0 kPam s-1, and over this range the fracture toughness was observed to decrease from 201 to 109 kPam. Examination of load—CMOD curves indicate that at a loading rate of 40 kPam s-1, the crack tip plasticity was sufficiently limited that the specimen behavior can be considered linear elastic, thus providing a valid Kq measurement. When test temperature was varied from −5 to −45°C for the S2 columnar ice, no significant variation in toughness was observed. In contrast, for granular ice, a higher toughness (144 kPam) was observed in the −5 to −20°C range than for the S2 columnar ice. However, the toughness of the granular ice at−45°C is not significantly different from that of the S2 columnar ice. A companion paper (Weber and Nixon, 1996) analyzes the results in greater detail comparing them with previous work, and presents a detailed fractographic analysis of the failure surfaces.

Fracture Toughness of Freshwater Ice—Part II: Analysis and Micrography

1996 ◽  
Vol 118 (2) ◽  
pp. 141-147 ◽  
Author(s):  
L. J. Weber ◽  
W. A. Nixon
Keyword(s):  
Fracture Toughness ◽  
Fracture Surface ◽  
Experimental Technique ◽  
Loading Rate ◽  
Process Zone ◽  
Crack Tip ◽  
Simple Method ◽  
Dislocation Activity ◽  
Freshwater Ice

Experiments have been performed to determine the effect of loading rate and temperature on the fracture toughness of freshwater ice. A first paper (Weber and Nixon, 1996) presents the experimental technique and results, while this paper focuses on discussion of the crack tip process zone and fracture surface micrography. A simple method to estimate the size of the process zone will be presented. Also, fracture surface micrography will be used to interpret the results of the temperature experiments by considering evidence of dislocation activity in preferentially oriented grains.

scholarly journals Preliminary study of thrombogenicity induced by the nanoparticle surface coating of intracranial stents

2019 ◽  
pp. 404-410
Author(s):  
A. Chiriac ◽  
Georgiana Ion ◽  
G. Stan ◽  
T. Popescu ◽  
Mihaela Sofronie ◽  
...  
Keyword(s):  
Surface Coating ◽  
Surface Coatings ◽  
In Vitro Tests ◽  
Thromboembolic Complications ◽  
Coagulation Time ◽  
Plasma Coagulation ◽  
Nanoparticle Surface ◽  
Preliminary Study ◽  
Stent Surface

Endovascular treatment of intracranial aneurysms with intracranial stents was proven to be clinically safe and effective, but is still associated with a risk of thromboembolic complications. Stent thrombosis could be a sever complication associated with specific stent surface coatings and designs. Standardized in vitro tests for investigation of thrombogenicity induced by different nanomaterials were used as the basic method in carrying out the present study. Therefore, the aim of this study was to evaluate the thrombogenicity of three different nanomaterials (ZnO, TiO2 si Fe3O4) possible used as surface coating for intracranial stents. This study is based on a procedure for in vitro analyses of plasma coagulation time. To measure the plasma coagulation time, platelet-poor plasma from human whole blood was in vitro exposed to nanoparticles and analysed in prothrombin (PT) and activated partial thromboplastin (APTT).

Effect of Silica on the Electrical Properties of Epoxy of Phenolic Resin/Carbon Black/Silica Composite Coating

2007 ◽  
Vol 546-549 ◽  
pp. 1525-1530 ◽  
Author(s):  
Wei Zhang ◽  
Richard Blackburn ◽  
Abbas Dehghani
Keyword(s):  
Electrical Properties ◽  
Carbon Black ◽  
Surface Coating ◽  
Phenolic Resin ◽  
Weight Ratio ◽  
Silica Content ◽  
Surface Coatings ◽  
Resin Matrix ◽  
Dispersion Effects ◽  
Mapping Analysis

Nanocomposites were prepared by embedding carbon black and silica into phenolic resin matrix, which was supported by SEM and particle size analyses. After milling stage, the obtained hybrids were applied to transparency film using K control coater. By the crosslinking procedure, homogenous surface coatings can be achievable. The electrical properties of surface coating can be tailored by variation of silica content with the amount of carbon black fixed. The conductivity of the surface coating increases steeply and then reaches a plateau with the increase of silica. When the weight ratio of silica to carbon black is around 1:2, relatively high conductivity can be desirable. Further increase in silica results in the decrease in conductivity. This can be interpreted in terms of aided or blocked dispersion effects on carbon black imposed by silica. Also, the uniformity of the film is verified by Si-mapping analysis.

scholarly journals Effect of Various Surface Coatings on De-Icing/Anti-Icing Fluids Aerodynamic and Endurance Time Performances

Aerospace ◽  
2019 ◽  
Vol 6 (10) ◽  
pp. 114 ◽  
Author(s):  
Eric Villeneuve ◽  
Jean-Denis Brassard ◽  
Christophe Volat
Keyword(s):  
Surface Coating ◽  
Test Methods ◽  
Surface Coatings ◽  
Test Surface ◽  
Acceptance Test ◽  
Endurance Test ◽  
Endurance Time ◽  
Current Test ◽  
Protection Systems ◽  
International Laboratory

The Anti-icing Materials International Laboratory (AMIL) has been testing SAE AMS1424 and AMS1428 ground de-icing/anti-icing fluids for more than 30 years. With the introduction of new surface coatings and their investigation as potential passive ice protection systems, or for hybrid use with other methods, it is important to understand their interaction with the ground de-icing/anti-icing fluids prior to applications on aircraft. In this study, five different surface coatings, both commercially available and under development, have been tested under two current test methods used to qualify the ground de-icing/anti-icing fluids: The Water Spray Endurance Test (WSET) and the Aerodynamic Acceptance Test (AAT). The tests were performed on three existing commercial de-icing/anti-icing fluids. The results have shown that the coatings tested in this study can considerably reduce the endurance time of the fluids and affect their ability to spread and wet the test surface. Superhydrophobic 1 coating also reduced the aerodynamic penalties created by the Ref. Fluid. Surface coatings, no matter their nature, can impact the performances and behaviour of the fluids and should be thoroughly tested before their use in the industry. The conclusions and methodology of this study were used in the development of sections of the SAE AIR6232 Aircraft Surface Coating Interaction with the Aircraft Deicing/Anti-Icing Fluids standard.

scholarly journals CONTROL STRATEGIES OF NITRITE ACCUMULATION IN A SUBMERGED BIOFILTER

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
BURHANETTIN GURBUZ
Keyword(s):  
Dissolved Oxygen ◽  
Key Words ◽  
Removal Efficiency ◽  
Constant Temperature ◽  
Loading Rate ◽  
Control Strategies ◽  
Nitrogen Loading ◽  
Partial Nitrification ◽  
Nitrite Accumulation ◽  
N Removal

Short-cut nitrification under various Nitrogen Loading Rate (NLR), dissolved oxygen (DO) concentrations and pHs at a constant temperature of 25 ±1 0C was investigated in a submerged biofilter reactor. The lowest NO2-N/NOx-N ratio was observed when the NLR was up to 160 g/m3·day. Further increase the NLRresulted in incomplete oxidation of ammonium and the effluent NH4-N and NO2-N concentration increased. Although the highest NO2-N/NOx-N ratio of 0.61 was achieved, the NH4-N removal efficiency was drastically dropped to 48% at the NLR of 294 g NH4-N/m3.day. The highest NO2-N/NOx-N ratio of 0.68 was achieved at the pH of 9.0 and 1.0 mg O2/l. However, NN4-N removal efficiency and the NO2-N/NOx-N ratio were sharply dropped to 33% and 0.55 by getting the NLR to 381 g NH4-N/m3⋅day at the DO concentrations of 2.0 mg/l. Key words: partial nitrification, NO2-N/NOx-N ratio.

scholarly journals Effect of Loading Rate on the Fracture Behaviour of High-Strength Concrete

2010 ◽  
Vol 24-25 ◽  
pp. 179-185 ◽  
Author(s):  
Gonzalo Ruiz ◽  
X.X. Zhang ◽  
R.C. Yu ◽  
E. Poveda ◽  
R. Porras ◽  
...  
Keyword(s):  
Fracture Energy ◽  
High Strength Concrete ◽  
Loading Rate ◽  
High Strength ◽  
Displacement Rate ◽  
Cohesive Law ◽  
Viscous Term ◽  
Strength Concrete ◽  
Loading Rates ◽  
Static Conditions

This research deals with the sensitivity of eight types of performance-designed high-strength concrete to the loading rate. Variations in the composition of the concrete produce the desired performance, for instance having null shrinkage or being able to be pumped at elevated heights without segregation, but they also produce variations in the fracture properties that are reported in this paper. We performed tests at five loading rates spanning six orders of magnitude in the displacement rate, from 1.74  10-5 mm/s to 17.4 mm/s. Load-displacement curves show that their peak is higher as the displacement rate increases, whereas the corresponding displacement is almost constant. Fracture energy also increases, but only for loading rates higher than 0.01 mm/s. We use a formula based on a cohesive law with a viscous term to study the results. The correlation of the formula to the experimental results is good and it allows us to obtain the theoretical value for the fracture energy under strictly static conditions. In addition, both the fracture energy and the characteristic length of the concretes used in the study diminish as the compressive strength of their aggregates increases.

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