scholarly journals Mineralogical and physico-chemical properties of halloysite-bearing slip surface material from a landslide during the 2018 Eastern Iburi earthquake, Hokkaido

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jun Kameda
Keyword(s):  
Colloidal Stability ◽  
Slip Surface ◽  
High Capacity ◽  
Chemical Properties ◽  
High Mobility ◽  
Electrophoretic Analysis ◽  
Surface Material ◽  
Solution Ph ◽  
Ground Shaking ◽  
Physico Chemical

AbstractDestructive landslides were triggered by the 6.7 Mw Eastern Iburi earthquake that struck southern Hokkaido, Japan, on 6 September 2018. Heavy rainfall on 4 September in addition to intermittent rainfall around the Iburi Tobu area saturated and weakened the slope-forming materials (mostly altered volcanoclastic soils), making them susceptible to failure because of the earthquake’s strong ground motion. Most of the shallow landslides exhibited long runouts along gentle hill slopes, with characteristic halloysite-bearing slip surface at the base of the volcanic soils. This study investigated the mineralogical and physico-chemical properties of the slip surface material with the aim of understanding weakening and post-failure behaviors during the landslides. Halloysite in the slip surface had irregular-to-hollow-spherical morphology with higher mesopore volumes than tubular halloysite, which is related to a high capacity for water retention after rainfall. To reproduce possible chemical changes in the slip surface during rainfall, the sample was immersed in varying amounts of rainwater; solution pH increased and ionic strength decreased with increasing water content. These findings, alongside electrophoretic analysis, suggest that rainwater infiltration could have increased the absolute zeta potential value of the slip surface material. It is suggested that rainfall before the earthquake enhanced the colloidal stability of halloysite particles within the slip surface, owing to an increase in electrostatic repulsion. This decreased the material’s cohesive strength, which might have led to destabilization of the slope during ground shaking generated by the earthquake, and subsequent high-mobility flow after failure.

scholarly journals Mineralogical and Physico-chemical Properties of Halloysite-bearing Slip Surface Material From a Landslide During the 2018 Eastern Iburi Earthquake, Hokkaido

2020 ◽  
Author(s):  
Jun Kameda
Keyword(s):  
Colloidal Stability ◽  
Slip Surface ◽  
Flow Behavior ◽  
High Capacity ◽  
Chemical Properties ◽  
High Mobility ◽  
Electrophoretic Analysis ◽  
Surface Material ◽  
Solution Ph ◽  
Ground Shaking

Abstract Destructive landslides were triggered by the 6.7 Mw Eastern Iburi earthquake that struck southern Hokkaido, Japan on 6 September 2018. Heavy rainfall on 4 September in addition to intermittent rainfall around the Iburi Tobu area saturated and weakened altered volcanoclastic soils containing halloysite minerals, making them susceptible to failure because of the earthquake’s strong ground motion. The landslides exhibited laminar flow behavior, with long runouts along gentle hill slopes. This study investigated the mineralogical and physicochemical properties of the halloysite-bearing slip surface material with the aim of understanding weakening and post-failure behaviors during the landslides. Halloysite in the slip surface had irregular-to-hollow-spherical morphology with higher mesopore volumes than tubular halloysite, which is related to a high capacity for water retention after rainfall. To reproduce possible chemical changes in the slip surface during rainfall, the sample was immersed in varying amounts of rainwater; solution pH increased and ionic strength decreased with increasing water content. These findings, alongside electrophoretic analysis, suggest that rainwater infiltration could have increased the absolute zeta potential value of the slip surface material. It is suggested that rainfall before the earthquake enhanced the colloidal stability of halloysite particles within the slip surface, owing to an increase in electrostatic repulsion. This decreased the material’s cohesive strength, which might have led to destabilization of the slope during ground shaking generated by the earthquake, and subsequent high-mobility flow after failure.

scholarly journals Coating Matters: Review on Colloidal Stability of Nanoparticles with Biocompatible Coatings in Biological Media, Living Cells and Organisms

2018 ◽  
Vol 25 (35) ◽  
pp. 4553-4586 ◽  
Author(s):  
Jonas Schubert ◽  
Munish Chanana
Keyword(s):  
Colloidal Stability ◽  
Biological Fluids ◽  
Chemical Properties ◽  
Coating Material ◽  
Living Systems ◽  
Biological Media ◽  
Coating Materials ◽  
Physico Chemical ◽  
Environment Temperature ◽  
To Come

Within the last two decades, the field of nanomedicine has not developed as successfully as has widely been hoped for. The main reason for this is the immense complexity of the biological systems, including the physico-chemical properties of the biological fluids as well as the biochemistry and the physiology of living systems. The nanoparticles’ physicochemical properties are also highly important. These differ profoundly from those of freshly synthesized particles when applied in biological/living systems as recent research in this field reveals. The physico-chemical properties of nanoparticles are predefined by their structural and functional design (core and coating material) and are highly affected by their interaction with the environment (temperature, pH, salt, proteins, cells). Since the coating material is the first part of the particle to come in contact with the environment, it does not only provide biocompatibility, but also defines the behavior (e.g. colloidal stability) and the fate (degradation, excretion, accumulation) of nanoparticles in the living systems. Hence, the coating matters, particularly for a nanoparticle system for biomedical applications, which has to fulfill its task in the complex environment of biological fluids, cells and organisms. In this review, we evaluate the performance of different coating materials for nanoparticles concerning their ability to provide colloidal stability in biological media and living systems.

scholarly journals Nanoparticle colloidal stability in cell culture media and impact on cellular interactions

2015 ◽  
Vol 44 (17) ◽  
pp. 6287-6305 ◽  
Author(s):  
Thomas L. Moore ◽  
Laura Rodriguez-Lorenzo ◽  
Vera Hirsch ◽  
Sandor Balog ◽  
Dominic Urban ◽  
...  
Keyword(s):  
Cell Culture ◽  
Colloidal Stability ◽  
Culture Media ◽  
Chemical Properties ◽  
Cellular Interactions ◽  
Biological Media ◽  
Cell Culture Media ◽  
Biological Fate ◽  
Physico Chemical ◽  
Shed Light

This review discusses nanoparticle colloidal stability in biological media in an attempt to shed light on the difficulty correlating nanoparticle physico-chemical properties and biological fate.

scholarly journals Interaction of colloidal nanoparticles with their local environment: the (ionic) nanoenvironment around nanoparticles is different from bulk and determines the physico-chemical properties of the nanoparticles

2014 ◽  
Vol 11 (96) ◽  
pp. 20130931 ◽  
Author(s):  
Christian Pfeiffer ◽  
Christoph Rehbock ◽  
Dominik Hühn ◽  
Carolina Carrillo-Carrion ◽  
Dorleta Jimenez de Aberasturi ◽  
...  
Keyword(s):  
Colloidal Stability ◽  
Debye Length ◽  
Chemical Properties ◽  
Local Environment ◽  
Ion Concentration ◽  
Colloidal Nanoparticles ◽  
Quenching Effect ◽  
Low Concentrations ◽  
Physico Chemical ◽  
Ligand Free

The physico-chemical properties of colloidal nanoparticles (NPs) are influenced by their local environment, as, in turn, the local environment influences the physico-chemical properties of the NPs. In other words, the local environment around NPs has a profound impact on the NPs, and it is different from bulk due to interaction with the NP surface. So far, this important effect has not been addressed in a comprehensive way in the literature. The vicinity of NPs can be sensitively influenced by local ions and ligands, with effects already occurring at extremely low concentrations. NPs in the Hückel regime are more sensitive to fluctuations in the ionic environment, because of a larger Debye length. The local ion concentration hereby affects the colloidal stability of the NPs, as it is different from bulk owing to Debye Hückel screening caused by the charge of the NPs. This can have subtle effects, now caused by the environment to the performance of the NP, such as for example a buffering effect caused by surface reaction on ultrapure ligand-free nanogold, a size quenching effect in the presence of specific ions and a significant impact on fluorophore-labelled NPs acting as ion sensors. Thus, the aim of this review is to clarify and give an unifying view of the complex interplay between the NP's surface with their nanoenvironment.

Regulatory Considerations of Nanotechnological Products in Developed Countries

1970 ◽  
Vol 1 (1) ◽  
pp. 25-32
Author(s):  
Karthik A Gopal V.S ◽  
Udupa N Ranjith Kumar A
Keyword(s):  
Chemical Properties ◽  
High Mobility ◽  
Developed Countries ◽  
Engineered Nanoparticles ◽  
Drug Delivery Vehicles ◽  
Safety Regulations ◽  
Physico Chemical ◽  
Potential Applications ◽  
Risk And Benefit ◽  
Inhaled Nanoparticles

Nanotechnology is a revolutionary field of micro-manufacturing involving manipulation by chemical or physical processes of individual atoms and molecules. It is important that safety regulations of nanotherapeutics keep pace with this growing level of pharmaceutical industry interest. Current and potential applications of nanotechnology in medicine range from research involving diagnostic devices, drug delivery vehicles to enhanced gene therapy and tissue engineering procedures. Safety regulations of nanotherapeutics may present unique risk assessment challenges, given the novelty and variety of products, high mobility and reactivity of engineered nanoparticles, and blurring of the diagnostic and therapeutic medicines. Major efforts are underway, however, very little attention is devoted to assessment of health risks to human or to the ecosystem. Inhaled nanoparticles have already been related to lung injury. It is recognized that physico-chemical properties in conjunction with environmental factors and stability of the nanomaterial all contribute to the overall toxicological responses. Nanotoxicological information, currently insufficient, will be vital in aiding regulatory bodies in elucidating the mechanisms of action, balancing its risk and benefit and thus to lay down the regulations. The present work is aimed at the regulatory considerations of nanoparticulate systems in various regions such as United States, European Union and Australia

Adsorption of Nickel and Cobalt Ions on Magnesium Silicate

2013 ◽  
Vol 726-731 ◽  
pp. 2855-2858
Author(s):  
Hua Yang ◽  
Hai Zeng Wang
Keyword(s):  
Ph Value ◽  
Average Pore Size ◽  
Chemical Properties ◽  
Magnesium Silicate ◽  
Solution Ph ◽  
Average Pore ◽  
Cobalt Ions ◽  
Physico Chemical ◽  
Short Time ◽  
Adsorption Desorption

Magnesium silicate (MS) was successfully prepared and the physico-chemical properties were determined by N2adsorption/desorption isotherm and Scanning Electron Microscopy (SEM). Surface area and the average pore size were 120 cm3·g-1and 10 nm. Adsorption experiments of removal of nickel and cobalt ions were investigated as the function of initial concentration, adsorbent dose, adsorption time and solution pH value. The maximum removal was reached with pH equal to 5 for the removal of nickel and cobalt ions. Adsorption process was rapid and adsorption equilibriums were attained in a short time.

scholarly journals Interactions between Cocoa Husk Catechin and Casein Micelles and their Impact on Physico-chemical Properties

2021 ◽  
pp. 21-33
Author(s):  
Premy Puspitawati Rahayu ◽  
Abdul Manab ◽  
Manik Eirry Sawitri ◽  
Ria Dewi Andriani ◽  
Mulia Winirsya Apriliyani ◽  
...  
Keyword(s):  
Particle Size ◽  
Fourier Transform ◽  
Chemical Structure ◽  
Protein Profile ◽  
Chemical Properties ◽  
Electrophoretic Analysis ◽  
Animal Science ◽  
Physico Chemical ◽  
Infra Red ◽  
Microscopy Analysis

Aims: The purpose of this research was to investigate the influence of physicochemical properties of interaction casein with different concentration catechin sources of the cocoa husk. Study design: Casein was added catechin with various concentration treatments (0 (control), 20, 40 and 60 (μg/ml)). Place and Duration of Study: This study was conducted between April until August 2020 at the Faculty of Animal Science, Universitas Brawijaya. Methodology: Casein was added catechin with various concentration treatments (0, 20, 40 and 60 (μg/ml)). An analysis is carried out to determine interaction using UV-Vis detection, chemical structure using Fourier Transform Infra-Red, microscopy analysis by Scanning Electron Microscopy, particle size by Zetasizer Nano Series Software Version 7.01, Malvern Instrument and electrophoretic analysis. Results: The interaction between casein and catechin was investigated by the method of UV-Vis detection and chemical structure analysis by Fourier Transform Infra-Red showed that it was indicated that catechin could detected in casein. It is similar with recent research. The interaction of casein and catechin showed to decrease the particle size and showed on microscopy analysis. Protein profile showed to increase the molecular weight with the addition of catechin, it can be indicated that presence interaction both on casein with catechin. Conclusion: Casein interacted with catechins 60 µg/ml was able to increase casein stability, maintain nano size, casein components were still detected in the protein profile, the resulting microstructure looked compact and functional groups of bioactive compounds were still detected using Fourier Transform Infra-Red.

scholarly journals USING OF ESTERS AS DISPERSION MEDIUM OF POLYUREA PLASTIC GREASES

2019 ◽  
Vol 62 (9) ◽  
pp. 73-78
Author(s):  
Boris P. Tonkonogov ◽  
Anastasiya Yu. Kilyakova ◽  
Sabina Z. Shumakaeva ◽  
Vladimir A. Vinokurov ◽  
Ravilya Z. Safieva ◽  
...  
Keyword(s):  
Dispersion Medium ◽  
Colloidal Stability ◽  
Viscosity Index ◽  
Chemical Properties ◽  
High Viscosity ◽  
Operational Parameters ◽  
Wear Properties ◽  
Physico Chemical ◽  
First Results ◽  
Polyurea Grease

This article presents first results of the investigated physico-chemical and operational parameters of composition greases obtained with the use of esters of different nature as a dispersion medium and the polyurea as a thickening agent, including the addition of nanocellulose. The choice of the ester base for the production of greases is possible due, on the one hand, to good combination of the physico-chemical properties (high viscosity index, low volatility, high flash and ignition temperature, low pour point, good anti-wear properties). On the other hand, in the production of greases with good ecological characteristics biodegradability of its components is of great importance, which in this case is provided by the use of esters as an oil base and an organic thickener, nanocellulose, as a component of the polyurea dispersed phase. It has been shown that from the dicarboxylic acid esters studied, the polyurea greases based on dioctyl adipate are superior to the dropping point and better colloidal stability as compared to dioctyl sebacate and dibutyl sebacate. The smaller size of the ether molecule provides the stronger structure of the polyurea grease. Similarly, for branched ethers, the grease based on tri-basic alcohols is more effective than the four-basic alcohols. The possibility of using nanocellulose as a thickener component was demonstrated. An increase in the content of nanocellulose to 3.5% increases the colloidal stability and the dropping temperature of the synthesized greases. The obtained samples have a wider range of operating temperatures, better rheological indicators than imported and domestic analogues.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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