scholarly journals The mechanism of a thunderstorm

1927 ◽  
Vol 114 (768) ◽  
pp. 376-401 ◽  
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Negative Polarity ◽  
Meteorological Conditions ◽  
General Consideration ◽  
Positive Type ◽  
Electrical Fields ◽  
Lightning Discharges ◽  
Water Drops ◽  
Large Water

In 1909 I described a theory of the origin of the electricity in thunderstorms based on the observation that when a drop of water is broken up in the air the water obtains a positive charge while the corresponding negative charge is given to the air. Little attempt was then made to work out the details of the processes involved in a thunderstorm; only the most general consideration was given to the quantities involved and no description of the nature of the lightning discharges was attempted. This was mainly because very little was then known of the air currents in a thunderstorm and still less of the associated electrical fields. Recently a number of papers have been published recording the electrical fields associated with thunderstorms and the sudden changes in the field which accompany lightning discharges. The authors of these papers have expressed the opinion that their observations of changes in field-strength do not agree with what is to be expected according to the theory which I have propounded. This opinion is most strongly expressed in the paper by Schonland and Craib, where it is stated (p. 242): “Such a predominance of the positive type suggests that Simpson’s theory of the production of the charge by the breaking up of large water-drops in an ascending air current, which would produce a cloud of negative polarity, must either be rejected or radically altered.” On the other hand, the data on which these criticisms are based, together with the further knowledge of the meteorological conditions in thunderstorms which has recently been attained, provide the means of completing the details of the theory which were lacking in 1909, and it is now possible to describe the complete mechanism of a thunderstorm both qualitatively and quantitatively. This is the object of the present paper, in which I hope to be able to show that the criticisms are in error and that the theory completely explains all the observations at present available.

Progressive lightning. VII Directly-correlated photographic and electrical studies of lightning from near thunderstorms

1947 ◽  
Vol 191 (1027) ◽  
pp. 485-503 ◽  
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Electrical Field ◽  
Return Stroke ◽  
Electrical Studies ◽  
Negative Pole ◽  
Slow Discharge ◽  
Lightning Discharges ◽  
Negative Field ◽  
Camera Shutter

An analysis has been made of the direct correlation of luminous and electrical field-changes produced by thirty-seven lightning discharges to ground. These discharges comprised 199 separate strokes, most of which were within a distance of 6 km. A new form of drum camera and a camera shutter operated by the first leader were em ­ ployed, and many records were obtained in daylight. When compared with results previously reported for flashes at distances of 10 km. or more, the following major differences are found: negative field-changes from near leaders, absence of electrical effects of first leader steps and hook-shaped field-changes during the period immediately following the return stroke. The hook field-changes are shown to be associated with components in the continuing luminosity of the channel of the type investigated by Malan & Collens and to be due to subsidiary discharges in this channel. These ' M ’ components carry negative charge to ground in quantities between one-fifth and one-hundredth of those carried by main strokes. The height of the lower negative charge in these thunderclouds is found to be from 4 to 9 km. During a discharge to ground, no rapid discharges occur within the cloud or elsewhere than in the cloud-ground channel. A fairly slow discharge of the upper positive charge in the thundercloud appears to occur to the upper air immediately after the lower negative pole has discharged to ground.

On the electric charge collected by water-drops falling through a cloud of electrically charged particles in a vertical electric field

1935 ◽  
Vol 151 (874) ◽  
pp. 665-684 ◽  
Keyword(s):  
Electric Field ◽  
Electric Charge ◽  
Negative Charge ◽  
X Rays ◽  
Vertical Electric Field ◽  
Water Drops ◽  
Cloud Particles ◽  
Large Water ◽  
Electrically Charged ◽  
Positively Charged

The experiments described in this paper are a continuation of work described in a former paper, and have for their object the examination of a mechanism suggested by Wilson in connection with the theory of thunder-clouds. In the former work the interaction of large water-drops with ions produced by X-rays was investigated. In the present work the interaction of large water-drops with electrically charged cloud particles is investigated, and the mechanism suggested by Wilson takes the following form. Consider an uncharged water-drop falling vertically through a cloud of very small water-droplets, each of which has an electric charge either positive or negative. Let there be a vertical electric field which will be taken to be of positive potential gradient so that positively charged cloud particles move down and negatively charged cloud particles move up. The electric field induces equal charges of opposite signs on the upper and lower halves of the drop. In the case considered the upper charge is negative and the lower one positive. A charged cloud particle has a definite small mobility depending on its radius and the charge it carries. Suppose now that the mobility is so small that in strong electric fields, such as occur in thunder-clouds (up to 10,000 volts/cm), the velocity with which the positively charged cloud particles move down is less than the velocity of the falling drop. Under these conditions, those positive cloud particles which are above the drop cannot overtake the drop and so do not reach it, although attracted by the negative charge on its upper half. Those positive cloud particles, which are below and which the drop over-takes, are first repelled by the lower positive charge on the drop before being attracted by the upper negative charge and, since these charges are equal in the neutral drop, these cloud particles do not reach it. Negative cloud particles coming up to meet the falling drop are attracted to its lower positively charged half and give the drop a net negative charge. This destroys the equality of the induced charges, and some of the positive cloud particles which the drop overtakes are now attracted to it. In the presence of equal numbers of positively and negatively charged cloud particles a limiting condition is approached in which the drop collects equal numbers of positive and negative cloud particles per second and has a net negative charge equal to some fraction of the induced charge.

scholarly journals Outbreak of Negative Narrow Bipolar Events in Two Mid-Latitude Thunderstorms Featuring Overshooting Tops

2021 ◽  
Vol 13 (24) ◽  
pp. 5130
Author(s):  
Feifan Liu ◽  
Baoyou Zhu ◽  
Gaopeng Lu ◽  
Ming Ma
Keyword(s):  
Doppler Radar ◽  
Radio Signal ◽  
Low Frequency ◽  
Negative Polarity ◽  
Meteorological Conditions ◽  
Rare Occurrence ◽  
Very Low Frequency ◽  
Spectrum Width ◽  
Radio Signals ◽  
Lightning Discharges

Lightning discharges are the electrical production in thunderclouds. They radiate the bulk of radio signals in the very low-frequency and low-frequency (VLF/LF) that can be detected by ground-based receivers. One kind of special intra-cloud lightning discharges known as narrow bipolar events (NBEs) have been shown to be rare but closely linked to the convective activity that leads to hazardous weather. However, there is still lack of understanding on the meteorological conditions for thunderstorm-producing NBEs, especially for those of negative polarity, due to their rare occurrence. In this work, we aim to investigate what meteorological and electrical conditions of thunderclouds favor the production of negative NBEs. Combining with the VLF/LF radio signal measured by Jianghuai Area Sferic Array (JASA), S-band Doppler radar observation and balloon sounding data, two mid-latitude thunderstorms with outbreaks of negative NBEs at midnight in East China were analyzed. The comparison with the vertical radar profile shows that the bursts of negative NBEs occurred near thunderclouds with overshooting tops higher than 18 km. Manifestation of negative NBEs is observed with a relatively low spectrum width near thundercloud tops. Our findings suggest that the detection of negative NBEs would provide a unique electrical means to remotely probe overshooting tops with implications for the exchange of troposphere and stratosphere.

scholarly journals Zerumbone Inhibits Helicobacter pylori Urease Activity

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2663
Author(s):  
Hyun Jun Woo ◽  
Ji Yeong Yang ◽  
Pyeongjae Lee ◽  
Jong-Bae Kim ◽  
Sa-Hyun Kim
Keyword(s):  
Helicobacter Pylori ◽  
Carbon Atom ◽  
Natural Compound ◽  
Urease Activity ◽  
Negative Charge ◽  
Positive Charge ◽  
Gastric Epithelium ◽  
Functional Inhibition ◽  
Electrical Gradient ◽  
H Pylori

Helicobacter pylori (H. pylori) produces urease in order to improve its settlement and growth in the human gastric epithelium. Urease inhibitors likely represent potentially powerful therapeutics for treating H. pylori; however, their instability and toxicity have proven problematic in human clinical trials. In this study, we investigate the ability of a natural compound extracted from Zingiber zerumbet Smith, zerumbone, to inhibit the urease activity of H. pylori by formation of urease dimers, trimers, or tetramers. As an oxygen atom possesses stronger electronegativity than the first carbon atom bonded to it, in the zerumbone structure, the neighboring second carbon atom shows a relatively negative charge (δ−) and the next carbon atom shows a positive charge (δ+), sequentially. Due to this electrical gradient, it is possible that H. pylori urease with its negative charges (such as thiol radicals) might bind to the β-position carbon of zerumbone. Our results show that zerumbone dimerized, trimerized, or tetramerized with both H. pylori urease A and urease B molecules, and that this formation of complex inhibited H. pylori urease activity. Although zerumbone did not affect either gene transcription or the protein expression of urease A and urease B, our study demonstrated that zerumbone could effectively dimerize with both urease molecules and caused significant functional inhibition of urease activity. In short, our findings suggest that zerumbone may be an effective H. pylori urease inhibitor that may be suitable for therapeutic use in humans.

scholarly journals Indication of the Coronavirus Model Using a Nanowire Biosensor

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 50
Author(s):  
Vladimir Generalov ◽  
Olga Naumova ◽  
Dmitry Shcherbakov ◽  
Alexander Safatov ◽  
Boris Zaitsev ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Negative Charge ◽  
Positive Charge ◽  
Silicon On Insulator ◽  
Nanowire Surface ◽  
Before And After ◽  
Effect Transistor ◽  
Current Value ◽  
Silicon On Insulator Technology

The presented results indicate virus-like particles of the coronavirus (CVP) using a nanowire (NW) biosensor based on silicon-on-insulator technology. In the experiment, we used suspensions of CVP and of specific antibodies to the virus. Measurements of the current value of the field-effect transistor before and after the introduction of the CVP on the surface of the nanowire were performed. Results showed antibody + CVP complexes on the phase section with the surface of the nanowire modulate the current of the field-effect transistor; CVP has an electrically positive charge on the phase section “nanowire surface-viral suspension»; antibody + CVP complexes have an electrically negative charge on the phase section “nanowire surface-viral suspension”; the sensitivity of the biosensor is made up of 10−18 M; the time display was 200–300 s.

scholarly journals The mechanism of spray electrification: the waterfall effect

2016 ◽  
Author(s):  
James K. Beattie
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Hydrophobic Hydration ◽  
General Phenomenon ◽  
Aqueous Interfaces ◽  
Preferential Adsorption ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Low Permittivity ◽  
Net Positive Charge

Abstract. The waterfall effect describes the separation of charge by splashing at the base of a waterfall. Smaller drops that have a net negative charge are created, while larger drops and/or the bulk maintain overall charge neutrality with a net positive charge. Since it was first described by Lenard (1892) the effect has been confirmed many times, but a molecular explanation has not been available. Application of our fluctuation-correlation model of hydrophobic hydration accounts for the negative charge observed at aqueous interfaces with low permittivity materials. The negative surface charge observed in the waterfall effect is created by the preferential adsorption of hydroxide ions generated from the autolysis of water. On splashing, shear forces generate small negative drops from the surface, leaving a positive charge on the remaining large fragment. The waterfall effect is a manifestation of the general phenomenon of the negative charge at the interface between water and hydrophobic surfaces that is created by the preferential adsorption of hydroxide ions.

THE EFFECT OF PROCOAGULANT PHOSPHOLIPID VESICLES WITH NET POSITIVE CHARGE ON THE ACTIVITY OF PROTHROMBINASE

1987 ◽  
Author(s):  
J Rosing ◽  
H Speijer ◽  
J W P Govers-Riemslag ◽  
R F A Zwaal
Keyword(s):  
Vitamin K ◽  
Negative Charge ◽  
Positive Charge ◽  
Coagulation Factor ◽  
Phospholipid Vesicles ◽  
Electrostatic Model ◽  
Acidic Phospholipid ◽  
Positively Charged ◽  
Net Positive Charge ◽  
Prothrombin Activation

It is generally thought that procoagulant phospholipid surfaces that promote the activation of vitamin K-dependent coagulation factors should have a net negative charge in order to promote calcium-dependent binding of the enzymes (FVIIa, FIXa and FXa) and substrates (prothrombin and FX) of the coagulation factor-activating complexes. Two models have been proposed to explain calcium-mediated association of vitamin K-dependent proteins with phospholipid: a) an electrostatic model, in which a positively-charged protein-calcium complex is attracted by a negatively-charged phospholipid surface and b) a chelation model in which a coordination complex is formed between calcium ions, γ-carboxyglutamic acids of the proteins and negatively-charged membrane phospholipids. To study the effect of the electrostatic potential of phospholipid vesicles on their activity in the pro-thrombinase complex the net charge of vesicles was varied by introduction of varying amounts of positively-charged stearylamine in the membrane surface. Introduction of 0-15 mole% stearylamine in phospholipid vesicles that contained 5 mole% phosphatidylseri-ne (PS) hardly affected their activity in prothrombin activation. Electrophoretic analysis showed that vesicles with > 5 mole% stearylamine had a net positive charge. The procoagulant activity of vesicles that contained phosphatidic acid, phosphatidylglyce-rol, phosphatidylinositol or phosphatidyl-glactate (PLac) as acidic phospholipid was much more effected by incorporation of stearylamine. Amounts of stearylamine that compensated the negative charge of acidic phospholipid caused considerable inhibition of the activity of the latter vesicles in prothrombin activation. The comparison of vesicles containing PS and PLac as acidic phospholipid is of special interest. PS and PLac only differ by the presence of NH+ 3-group in the serine moiety of PS. Thus, in spite of the fact that vesicles with PLac are more negatively charged than vesicles with PS, they are less procoagulant. Our results show that a) although procoagulant membranes have to contain acidic phospholipids there is no requirement for a net negative charge, b) the amino group of phosphatidylserine has an important function in the interaction of procoagulant membranes with vitamin K-dependent proteins and c) the chelation model can satisfactorily explain calcium-mediated lipid-protein association.

Electrokinetic properties of Cassiterite

1953 ◽  
Vol 6 (3) ◽  
pp. 278 ◽  
Author(s):  
DJ O'Connor ◽  
AS Buchanan
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Weak Acid ◽  
Surface Conductivity ◽  
Surface Ionization ◽  
Conductivity Measurements ◽  
The Third ◽  
Three Samples ◽  
Negative Surface ◽  
Flotation Collector

Simultaneous ζ-potential and surface conductivity measurements have been made on three samples of cassiterite (SnO2) in water, in solutions of HCl, alkalis, inorganic salts, and the flotation collector reagent sodium cetyl sulphate. It is probable that the intrinsic surface charge of cassiterite in water is negative and that it is due to surface ionization as a very weak acid. Two of the solids possessed a negative surface whilst the positive charge of the third seemed to be due to ionization of a strongly basic impurity. Those samples having a negative charge showed little reaction with sodium cetyl sulphate alone, but appreciable adsorption of cetyl sulphate ion took place in acid solution. On the other hand, the sample with the positive surface reacted with cetyl sulphate ion even in the absence of acid. In all cases adsorption of cetyl sulphate was completely reversible.

scholarly journals Growth Modes of Ice Crystals in Supercooled Water and Aqueous Solutions

1967 ◽  
Vol 6 (47) ◽  
pp. 651-662 ◽  
Author(s):  
H. R. Pruppacher
Keyword(s):  
Aqueous Solutions ◽  
Tube Wall ◽  
Pure Water ◽  
Supercooled Water ◽  
Seed Crystal ◽  
Ice Crystals ◽  
Tube Axis ◽  
Growth Modes ◽  
Water Drops ◽  
Large Water

The growth modes of ice crystals in supercooled water and various aqueous solutions were studied at different supercoolings by a motion-picture technique. ln pure water contained in plastic capillary tubes, ice dendrites formed which at supercoolings between 1 and 4°C. grew parallel to the tube axis. At supercoolings larger than 4°C. the direction of growth was inclined to the tube axis such that the dendrites hit the tube wall and afterwards proceeded growing in a new direction. As a result it appeared that the ice crystals grew in a zig-zag or screw fashion. This growth mode became enhanced when the supercooling was increased or salts were dissolved in the water. In large water drops, ice dendrites formed which at supercoolings smaller than 1°C. were co-planar with the seed crystal and between 1° and 5°C. split into two dendritic segments. At supercoolings larger than 5°C. multiple splitting of the seed crystal was observed and this became strongly enhanced when salts were dissolved in the water. Tentative explanations for these results are given.

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