scholarly journals Saline oscillator as a teaching experiment

2011 ◽  
Vol 33 (4) ◽  
pp. 4310-4310
Author(s):  
Lucas S. del Lama ◽  
Marcelo Mulato
Keyword(s):  
Sodium Chloride ◽  
Copper Sulfate ◽  
Mass Density ◽  
Biological Systems ◽  
Electrical Potential ◽  
Teaching Experiment ◽  
Deionized Water ◽  
Undergraduate Teaching ◽  
Capillary Diameter ◽  
Potential Oscillations

The saline oscillator consists of two aligned containers that are filled in by a pair of different solutions, exhibiting electrical potential oscillations when released. These oscillations occur due to a difference of mass density presented by the fluids and they cause varying ions flow, leading to electrical potential variations between both reservoirs. Many biological systems can be understood by this model. In this work, the saline oscillator was investigated using copper sulfate, CuSO4, and sodium chloride, NaCl, solutions, changing parameters as the diameter and length of the capillary, diameter of the internal compartment and amount of unwanted ions in the main reservoir (distillated and deionized water). The system is shown to be very useful in undergraduate teaching classes.

Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

scholarly journals Thermal switch of oscillation frequency in Belousov–Zhabotinsky liquid marbles

2019 ◽  
Vol 6 (4) ◽  
pp. 190078 ◽  
Author(s):  
Andrew Adamatzky ◽  
Claire Fullarton ◽  
Neil Phillips ◽  
Ben De Lacy Costello ◽  
Thomas C. Draper
Keyword(s):  
Ambient Temperature ◽  
Oscillation Frequency ◽  
Electrical Potential ◽  
Powder Coating ◽  
External Control ◽  
Potential Oscillations ◽  
Bz Reaction ◽  
Liquid Marbles ◽  
Thermal Switch ◽  
Oscillation Dynamics

External control of oscillation dynamics in the Belousov–Zhabotinsky (BZ) reaction is important for many applications including encoding computing schemes. When considering the BZ reaction, there are limited studies dealing with thermal cycling, particularly cooling, for external control. Recently, liquid marbles (LMs) have been demonstrated as a means of confining the BZ reaction in a system containing a solid–liquid interface. BZ LMs were prepared by rolling 50 μl droplets in polyethylene (PE) powder. Oscillations of electrical potential differences within the marble were recorded by inserting a pair of electrodes through the LM powder coating into the BZ solution core. Electrical potential differences of up to 100 mV were observed with an average period of oscillation ca 44 s. BZ LMs were subsequently frozen to −1°C to observe changes in the frequency of electrical potential oscillations. The frequency of oscillations reduced upon freezing to 11 mHz cf. 23 mHz at ambient temperature. The oscillation frequency of the frozen BZ LM returned to 23 mHz upon warming to ambient temperature. Several cycles of frequency fluctuations were able to be achieved.

FRACTAL GROWTH PATTERNS AND OSCILLATIONS IN POTENTIAL DURING ELECTROPOLYMERIZATION OF ANILINE WITH MONO- AND MIXED SURFACTANTS

Fractals ◽  
2011 ◽  
Vol 19 (03) ◽  
pp. 317-328 ◽  
Author(s):  
ISHWAR DAS ◽  
NAMITA R. AGRAWAL ◽  
RINKI CHOUDHARY ◽  
SANJEEV KUMAR GUPTA
Keyword(s):  
Electrical Conductivity ◽  
Average Particle Size ◽  
Sodium Dodecyl ◽  
Electrical Potential ◽  
Growth Patterns ◽  
Ammonium Bromide ◽  
Average Particle ◽  
Diffusion Limited Aggregation ◽  
Fractal Growth ◽  
Potential Oscillations

Fractal growth patterns of polyaniline were developed during electropolymerization of aniline using the surfactants sodium dodecyl sulphate (NaDS) and NaDS containing cetyl trimethyl ammonium bromide (CTAB). Growth kinetics was studied and electric potential oscillations were monitored as a function of time. On addition of CTAB polymer growth was inhibited due to coordination of CTAB with the growing polyaniline chain. The average particle size of the polymer aggregate obtained from aniline- NaDS-H2O system was ~150 nm as evident by Transmission Electron Microscopy (TEM) results. Polymer aggregates were characterized by electrical conductivity measurements, X-ray diffraction (XRD) and Thermogravimetric (TG) studies. An interaction between NaDS and aniline was observed in the absence of electric field as evident by (i) electrical conductivity of aqueous solution of NaDS in the absence and presence of aniline, and (ii) their crystallization patterns on microslides. A mechanism for the development of fractal patterns and electrical potential oscillations is proposed on the basis of diffusion limited aggregation process.

scholarly journals Osmolarity-independent electrical cues guide rapid response to injury in zebrafish epidermis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Andrew S Kennard ◽  
Julie A Theriot
Keyword(s):  
Sodium Chloride ◽  
Tissue Injury ◽  
Osmotic Shock ◽  
Ionic Composition ◽  
Electrical Potential ◽  
Chloride Ions ◽  
Wound Response ◽  
Cell Swelling ◽  
Detection Mechanism ◽  
Skin Cells

The ability of epithelial tissues to heal after injury is essential for animal life, yet the mechanisms by which epithelial cells sense tissue damage are incompletely understood. In aquatic organisms such as zebrafish, osmotic shock following injury is believed to be an early and potent activator of a wound response. We find that, in addition to sensing osmolarity, basal skin cells in zebrafish larvae are also sensitive to changes in the particular ionic composition of their surroundings after wounding, specifically the concentration of sodium chloride in the immediate vicinity of the wound. This sodium chloride-specific wound detection mechanism is independent of cell swelling, and instead is suggestive of a mechanism by which cells sense changes in the transepithelial electrical potential generated by the transport of sodium and chloride ions across the skin. Consistent with this hypothesis, we show that electric fields directly applied within the skin are sufficient to initiate actin polarization and migration of basal cells in their native epithelial context in vivo, even overriding endogenous wound signaling. This suggests that, in order to mount a robust wound response, skin cells respond to both osmotic and electrical perturbations arising from tissue injury.

The Psychophysical Relationship Between Color and Sodium Chloride Concentrations in Model Systems

1986 ◽  
Vol 49 (12) ◽  
pp. 977-982 ◽  
Author(s):  
S. R. GIFFORD ◽  
F. M. CLYDESDALE
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Deionized Water ◽  
Model Systems ◽  
Color Parameter ◽  
Color Intensity ◽  
B Values ◽  
Chicken Broth ◽  
Commercial Chicken ◽  
Chloride Concentrations

A 10-member taste panel evaluated the effect of color on salt perception using magnitude estimation. Samples, colored to simulate commercial chicken broth were formulated by addition of increasing amounts (0.00 – 4.10%) of 0.05% FD&C Red 40 to a constant volume of 0.10% FD&C Yellow 5 in double-distilled deionized water. In each of four experiments, five color intensities were evaluated at five NaCl concentrations over a range of 0.14 – 1.06% (w/v). The Gardner XL - 23 colorimeter was used to obtain L, a and b values from which the objective color parameter log cot−1 (a/b) was calculated. Log cot−1 (a/b) correlated well with log color intensity and was therefore, suitable as a predictor. In all experiments, panelists were able to detect differences among the NaCl concentrations (P<0.001) regardless of color. The perception of saltiness increased with increasing salt concentration as a linear power function with slopes greater than one. Although color tended to confuse the perception of saltiness, this effect was not significant.

scholarly journals Moisture-induced autonomous surface potential oscillations for energy harvesting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu Long ◽  
Peisheng He ◽  
Zhichun Shao ◽  
Zhaoyang Li ◽  
Han Kim ◽  
...  
Keyword(s):  
Surface Potential ◽  
Liquid Crystal Display ◽  
Electrical Potential ◽  
Ammonium Hydroxide ◽  
Potential Oscillations ◽  
Practical Applications ◽  
Energy Harvesters ◽  
In Series ◽  
Chaotic Nature ◽  
The Stability

AbstractA variety of autonomous oscillations in nature such as heartbeats and some biochemical reactions have been widely studied and utilized for applications in the fields of bioscience and engineering. Here, we report a unique phenomenon of moisture-induced electrical potential oscillations on polymers, poly([2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide-co-acrylic acid), during the diffusion of water molecules. Chemical reactions are modeled by kinetic simulations while system dynamic equations and the stability matrix are analyzed to show the chaotic nature of the system which oscillates with hidden attractors to induce the autonomous surface potential oscillation. Using moisture in the ambient environment as the activation source, this self-excited chemoelectrical reaction could have broad influences and usages in surface-reaction based devices and systems. As a proof-of-concept demonstration, an energy harvester is constructed and achieved the continuous energy production for more than 15,000 seconds with an energy density of 16.8 mJ/cm2. A 2-Volts output voltage has been produced to power a liquid crystal display toward practical applications with five energy harvesters connected in series.

Transport of sodium and chloride by the isolated rumen epithelium

1964 ◽  
Vol 206 (5) ◽  
pp. 1099-1105 ◽  
Author(s):  
Charles E. Stevens
Keyword(s):  
Sodium Chloride ◽  
Active Transport ◽  
Chloride Transport ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Exchange Diffusion ◽  
Rumen Epithelium ◽  
Tissue Resistance ◽  
Affected Tissue

Transepithelial electrical potential, short-circuit current, and resistance measurements were made under different conditions of tissue collection and maintenance. The collection procedure greatly affected tissue resistance and, since the magnitude of the current was relatively independent of the procedure, potential was affected to about the same degree. The highest and least variable resistances were recorded when the tissue was removed from the anesthetized cow and the epithelium carefully dissected free. Short-circuit current and net ion flux decreased with time but the decrease was relatively linear and sufficiently slow to allow their comparison. Rumen epithelium of both species demonstrated active transport of Na and Cl in the direction of lumen to blood. Calculation of partial Na conductances indicated that part of the sodium was transported by exchange diffusion or a sodium chloride transport system.

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