Hydrophilicity and Hydrophobicity Control of Plasma‐Treated Surfaces via Fractal Parameters

2021 ◽  
Vol 8 (19) ◽  
pp. 2100724
Author(s):  
Cecilia Piferi ◽  
Kateryna Bazaka ◽  
Debora L. D'Aversa ◽  
Rocco Di Girolamo ◽  
Claudio De Rosa ◽  
...  
Keyword(s):  
Fractal Parameters ◽  
Hydrophilicity And Hydrophobicity

scholarly journals Hydrophilicity and Hydrophobicity Control of Plasma‐Treated Surfaces via Fractal Parameters (Adv. Mater. Interfaces 19/2021)

2021 ◽  
Vol 8 (19) ◽  
pp. 2170104
Author(s):  
Cecilia Piferi ◽  
Kateryna Bazaka ◽  
Debora L. D'Aversa ◽  
Rocco Di Girolamo ◽  
Claudio De Rosa ◽  
...  
Keyword(s):  
Fractal Parameters ◽  
Hydrophilicity And Hydrophobicity

Experimental Observation of Fractal-Regular Surfaces and a Transformation Scheme for Extracting Fractal Parameters

2005 ◽  
Author(s):  
Shao Wang ◽  
Wai Kin Chan
Keyword(s):  
Silicon Wafer ◽  
Roughness Parameter ◽  
Hard Disk ◽  
Spectral Density Function ◽  
Power Spectral ◽  
Fractal Parameters ◽  
Asperity Contacts ◽  
Fractal Roughness ◽  
Magnetic Hard Disk ◽  
Wafer Surfaces

To account for the effects of asperity contacts at various length scales, it is appropriate to characterize an engineering surface as a fractal-regular surface. In spite of significant theoretical advancement, there is a desperate need for experimental verification of the theory of fractal-regular surfaces and a consistent scheme of obtaining the fractal parameters. In the present study, the existence of a fractal region and a regular-shape region in the power spectral density function for fractal-regular surfaces was confirmed experimentally, for the first time, with data obtained from magnetic hard disk and silicon wafer surfaces. A novel scheme involving a variable transformation was developed to extract fractal parameters. This scheme was validated by accurate recovery of fractal parameters from simulated surfaces. The fractal dimension, the fractal roughness parameter and the fractal domain length were found for magnetic hard disk and silicon wafer surfaces.

scholarly journals Trimethylamine-N-oxide: its hydration structure, surface activity, and biological function, viewed by vibrational spectroscopy and molecular dynamics simulations

2017 ◽  
Vol 19 (10) ◽  
pp. 6909-6920 ◽  
Author(s):  
Tatsuhiko Ohto ◽  
Johannes Hunger ◽  
Ellen H. G. Backus ◽  
Wataru Mizukami ◽  
Mischa Bonn ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Molecular Dynamics Simulations ◽  
Surface Activity ◽  
Vibrational Spectroscopy ◽  
Biological Function ◽  
Molecular Simulations ◽  
Structure Surface ◽  
Dynamics Simulations ◽  
Hydrophilicity And Hydrophobicity

Vibrational spectroscopy and molecular simulations revealed the hydrophilicity and hydrophobicity of TMAO in aqueous solution.

SECURE FRACTAL IMAGE CODING BASED ON FRACTAL PARAMETER ENCRYPTION

Fractals ◽  
2009 ◽  
Vol 17 (02) ◽  
pp. 149-160 ◽  
Author(s):  
SHIGUO LIAN ◽  
XI CHEN ◽  
DENGPAN YE
Keyword(s):  
Image Coding ◽  
Parameter Distribution ◽  
Self Similarity ◽  
Image Encoding ◽  
Coding Scheme ◽  
Fractal Image ◽  
Fractal Image Coding ◽  
Fractal Parameters ◽  
Fractal Encoding ◽  
Computational Resources

In recent work, various fractal image coding methods are reported, which adopt the self-similarity of images to compress the size of images. However, till now, no solutions for the security of fractal encoded images have been provided. In this paper, a secure fractal image coding scheme is proposed and evaluated, which encrypts some of the fractal parameters during fractal encoding, and thus, produces the encrypted and encoded image. The encrypted image can only be recovered by the correct key. To maintain security and efficiency, only the suitable parameters are selected and encrypted through investigating the properties of various fractal parameters, including parameter space, parameter distribution and parameter sensitivity. The encryption process does not change the file format, keeps secure in perception, and costs little time or computational resources. These properties make it suitable for secure image encoding or transmission.

scholarly journals EFFECT OF POLYMERS ON THE PHYSICOCHEMICAL AND DRUG RELEASE PROPERTIES OF TRANSDERMAL PATCHES OF ATENOLOL

2018 ◽  
Vol 10 (4) ◽  
pp. 68
Author(s):  
Manish Kumar ◽  
Vishal Trivedi ◽  
Ajay Kumar Shukla ◽  
Suresh Kumar Dev
Keyword(s):  
Drug Release ◽  
Hydroxypropyl Methylcellulose ◽  
Research Work ◽  
High Moisture ◽  
Transdermal Drug Delivery System ◽  
Permeable Membrane ◽  
Transdermal Patches ◽  
Egg Membrane ◽  
Hydrophilicity And Hydrophobicity

Objective: The objective of this research work was to develop a transdermal drug delivery system containing atenolol with different ratios of hydrophilic and hydrophobic polymeric combinations, using solvent evaporation technique and to examine the effect of hydrophilicity and hydrophobicity of polymers on the physicochemical and drug release properties of transdermal patches.Methods: Solvent casting method has been used to formulate transdermal patches. Hydroxypropyl methylcellulose (HPMC), Polyvinylpyrrolidone (PVP), Ethylcellulose (EC) in different combination ratios were used as the polymer. Propylene glycol was used as a plasticizer. Permeation enhancers such as span 80 were used to enhance permeation through the skin. In vitro diffusion study was carried out by franz diffusion cell using egg membrane as a semi-permeable membrane for diffusion.Results: Result showed that the thickness of the all batch of patches varied from 0.32 to 0.39 mm with uniformity of thickness in each formulation. Formulations F1 to F3 had high moisture content varied from 2.07±0.09 to 2.56±0.15 and high moisture uptake value varied from 3.21±0.35 to 4.09±0.38, due to a higher concentration of hydrophilic polymers. Drug content of all batches was ranged between 85.92±1.32 to 95.71±1.42. Folding endurance values off all batches were more than 75. Formulation batches F1 to F3 showed higher cumulative drug release varied from 61.34% to 68.11% as compared to formulation batches F4 to F6.Conclusion: Higher proportion of hydrophilic polymer in the formulation of transdermal patches, gives higher percentage drug release from prepared patches. The finding of the study indicates that hydrophilicity and hydrophobicity of polymer effects the physicochemical and drug release properties of transdermal patches and an optimum proportion of hydrophilic and hydrophobic polymer is required for the preparation of effective transdermal patches. 

Three-Dimensional Compatible Sacrificial Nanoimprint Lithography for Tuning the Wettability of Thermoplastic Materials

2018 ◽  
Vol 6 (4) ◽  
Author(s):  
Molla Hasan ◽  
Imrhankhan Shajahan ◽  
Manesh Gopinadhan ◽  
Jittisa Ketkaew ◽  
Aaron Anesgart ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Characteristic Length ◽  
Three Dimensional ◽  
Thermoplastic Elastomer ◽  
Growth Conditions ◽  
Surface Wetting ◽  
Chemical Surface ◽  
Patterned Surface ◽  
Elastomeric Material ◽  
Hydrophilicity And Hydrophobicity

We report the tuning of surface wetting through sacrificial nanoimprint lithography (SNIL). In this process, grown ZnO nanomaterials are transferred by imprint into a metallic glass (MG) and an elastomeric material, and then etched to impart controlled surface roughness. This process increases the hydrophilicity and hydrophobicity of both surfaces, the Pt57.5Cu14.7Ni5.3P22.5 MG and thermoplastic elastomer (TPE), respectively. The growth conditions of the ZnO change the characteristic length scale of the roughness, which in turn alters the properties of the patterned surface. The novelty of this approach includes reusability of templates and that it is able to create superhydrophilic and superhydrophobic surfaces in a manner compatible with the fabrication of macroscopic three-dimensional (3D) parts. Because the wettability is achieved by only modifying topography, without using any chemical surface modifiers, the prepared surfaces are relatively more durable.

scholarly journals Development of Novel Fractal Method for Characterizing the Distribution of Blood Flow in Multi-Scale Vascular Tree

2021 ◽  
Vol 12 ◽  
Author(s):  
Peilun Li ◽  
Qing Pan ◽  
Sheng Jiang ◽  
Molei Yan ◽  
Jing Yan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fractal Dimension ◽  
Flow Distribution ◽  
Multifractal Spectrum ◽  
Vascular Structure ◽  
Blood Flow Distribution ◽  
Vascular Tree ◽  
Multi Scale ◽  
Fractal Parameters ◽  
Vascular Trees

Blood perfusion is an important index for the function of the cardiovascular system and it can be indicated by the blood flow distribution in the vascular tree. As the blood flow in a vascular tree varies in a large range of scales and fractal analysis owns the ability to describe multi-scale properties, it is reasonable to apply fractal analysis to depict the blood flow distribution. The objective of this study is to establish fractal methods for analyzing the blood flow distribution which can be applied to real vascular trees. For this purpose, the modified methods in fractal geometry were applied and a special strategy was raised to make sure that these methods are applicable to an arbitrary vascular tree. The validation of the proposed methods on real arterial trees verified the ability of the produced parameters (fractal dimension and multifractal spectrum) in distinguishing the blood flow distribution under different physiological states. Furthermore, the physiological significance of the fractal parameters was investigated in two situations. For the first situation, the vascular tree was set as a perfect binary tree and the blood flow distribution was adjusted by the split ratio. As the split ratio of the vascular tree decreases, the fractal dimension decreases and the multifractal spectrum expands. The results indicate that both fractal parameters can quantify the degree of blood flow heterogeneity. While for the second situation, artificial vascular trees with different structures were constructed and the hemodynamics in these vascular trees was simulated. The results suggest that both the vascular structure and the blood flow distribution affect the fractal parameters for blood flow. The fractal dimension declares the integrated information about the heterogeneity of vascular structure and blood flow distribution. In contrast, the multifractal spectrum identifies the heterogeneity features in blood flow distribution or vascular structure by its width and height. The results verified that the proposed methods are capable of depicting the multi-scale features of the blood flow distribution in the vascular tree and further are potential for investigating vascular physiology.

A stress sensitivity model for the permeability of porous media based on bi-dispersed fractal theory

2018 ◽  
Vol 29 (02) ◽  
pp. 1850019 ◽  
Author(s):  
X.-H. Tan ◽  
C.-Y. Liu ◽  
X.-P. Li ◽  
H.-Q. Wang ◽  
H. Deng
Keyword(s):  
Porous Media ◽  
Fractal Dimension ◽  
Fractal Theory ◽  
Stress Sensitivity ◽  
Maximum Diameter ◽  
Proposed Model ◽  
Fractal Parameters ◽  
Stress Changes ◽  
Capillary Bundle ◽  
Definition Of

A stress sensitivity model for the permeability of porous media based on bidispersed fractal theory is established, considering the change of the flow path, the fractal geometry approach and the mechanics of porous media. It is noted that the two fractal parameters of the porous media construction perform differently when the stress changes. The tortuosity fractal dimension of solid cluster [Formula: see text] become bigger with an increase of stress. However, the pore fractal dimension of solid cluster [Formula: see text] and capillary bundle [Formula: see text] remains the same with an increase of stress. The definition of normalized permeability is introduced for the analyzation of the impacts of stress sensitivity on permeability. The normalized permeability is related to solid cluster tortuosity dimension, pore fractal dimension, solid cluster maximum diameter, Young’s modulus and Poisson’s ratio. Every parameter has clear physical meaning without the use of empirical constants. Predictions of permeability of the model is accordant with the obtained experimental data. Thus, the proposed model can precisely depict the flow of fluid in porous media under stress.

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