scholarly journals Ion Selective Transport of Alkali Ions through a Polyelectrolyte Membrane

2020 ◽  
Vol 7 (13) ◽  
pp. 2000419
Author(s):  
Viviana Motta ◽  
Martin Schäfer ◽  
Jonas Hühn ◽  
Robert Zierold ◽  
Robert H. Blick ◽  
...  
Keyword(s):  
Alkali Ions ◽  
Selective Transport ◽  
Polyelectrolyte Membrane

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

Upconversion Luminescence of MgSc2O4: Er3+/Yb3+ Nanocrystals Co-doped Alkali Ions

2020 ◽  
Vol 41 (11) ◽  
pp. 1351-1357
Author(s):  
Mei-juan YUANG ◽  
◽  
Jing LI ◽  
Hui-lian QIN ◽  
Ya-ru PENG ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Alkali Ions ◽  
Co Doped

scholarly journals Molecularly imprinted membrane for transport of urea, creatinine, and vitamin B12 as a hemodialysis candidate membrane

2021 ◽  
Vol 19 (1) ◽  
pp. 806-817
Author(s):  
Muhammad Cholid Djunaidi ◽  
Nabilah Anindita Febriola ◽  
Abdul Haris
Keyword(s):  
Polyethylene Glycol ◽  
Vitamin B12 ◽  
Kidney Function ◽  
Cross Linking ◽  
Vitamin B ◽  
Molecularly Imprinted ◽  
Selective Transport ◽  
Molecularly Imprinted Membrane ◽  
Better Than ◽  
Imprinted Membrane

Abstract High levels of urea and creatinine in the blood are a sign of decreased kidney function. To remove these substances from the blood, hemodialysis which utilizes membranes could be used. In this study, a molecularly imprinted membrane (MIM) was synthesized for the selective transport of urea. The synthesis is initiated with the polymerization of eugenol into polyeugenol and then into polyeugenoxy acetate (PA). The PA is then contacted with urea and then used as the functional polymer in the synthesis of MIM with polysulfone as the membrane base, and polyethylene glycol as the cross-linking agent. The result was later analyzed with FTIR and SEM-EDX. The membrane is then used in the transport of urea, creatinine, and vitamin B12 and then compared with the non-imprinted membrane (NIM) performance. By using UV-Vis spectrophotometry, the results showed that the membrane with 10 h heating variation is able to transport more urea and is more selective than NIM; this proves that the urea template on the MIM enables it to recognize urea molecules better than creatinine and vitamin B12. The order of transport from the best results is urea > creatinine > vitamin B12.

Atomistic Mechanism of Passivation of Halide Vacancies in Lead Halide Perovskites by Alkali Ions

2021 ◽  
Vol 33 (4) ◽  
pp. 1285-1292
Author(s):  
Wei Li ◽  
Juan Zhan ◽  
Xiaorui Liu ◽  
Jianfeng Tang ◽  
Wan-Jian Yin ◽  
...  
Keyword(s):  
Alkali Ions ◽  
Halide Perovskites ◽  
Lead Halide

An Ion Transport Switch Based on Light-Responsive Conformation-Dependent G-Quadruplex Transmembrane Channels

2021 ◽  
Author(s):  
Chunying Li ◽  
Hui Chen ◽  
Xiaohai Yang ◽  
Kemin Wang ◽  
Jianbo Liu
Keyword(s):  
Ion Transport ◽  
Selective Transport ◽  
G Quadruplex ◽  
Transmembrane Channels

A light-responsive ion transport switch has been developed based on conformation-dependent azobenzene-incorporated lipophilic G-quadruplex channels, which provides a new smart approach for the selective transport of K+ ions across the...

scholarly journals Selective Transport of Airborne Microparticles Through Micro-channels Under Microgravity

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Monia Makhoul ◽  
Philippe Beltrame
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Bifurcation Analysis ◽  
Metal Particles ◽  
Microgravity Environment ◽  
Ratchet Effect ◽  
Selective Transport ◽  
Microgravity Experiments ◽  
Particle Drift ◽  
Micro Channels

AbstractThis paper analyzes the possibility of obtaining the selective transport of microparticles suspended in air in a microgravity environment through modulated channels without net displacement of air. Using numerical simulation and bifurcation analysis tools, we show the existence of intermittent particle drift under the Stokes assumption of the fluid flow. The particle transport can be selective and the direction of transport is controlled only by the kind of pumping used. The selective transport is interpreted as a deterministic ratchet effect due to spatial variations in the flow and the particle drag. This ratchet phenomenon could be applied to the selective transport of metal particles during the short duration of microgravity experiments.

scholarly journals Electrochemical concentration of alkali ions in activated pores of electrochemically pretreated glassy carbon fibers.

1989 ◽  
Vol 5 (5) ◽  
pp. 613-614 ◽  
Author(s):  
Tsutomu NAGAOKA ◽  
Yoshihisa UCHIDA ◽  
Kotaro OGURA
Keyword(s):  
Carbon Fibers ◽  
Glassy Carbon ◽  
Alkali Ions
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