scholarly journals The nature of the ϒ-rays excited by β-rays

1912 ◽  
Vol 86 (590) ◽  
pp. 513-529 ◽  
Keyword(s):  
Thin Layer ◽  
Active Material ◽  
Atomic Weight ◽  
Detailed Account ◽  
Active Matter ◽  
Small Space ◽  
Lead Sulphate

In a previous paper, it was shown that the β -rays of radium E excited ϒ-rays in different materials, the amount increasing with the atomic weight of the substance used. It was found that the ϒ -radiation was largely increased when the β -rays fell on a lead screen suitably placed, and as the active material, radium (D + E + F), was mixed with lead sulphate confined in a small space, it was obvious that some, if not all, of the ϒ -radiation issuing from the mixture was due to ϒ -rays excited by β -rays in the lead impurity. It thus seemed possible that no primary ϒ -rays were emitted by radium E. By using a more suitable source, in which the active material was spread in a thin layer over biter paper, it has been found that a primary ϒ -radiation is emitted from the active matter. This radiation, however, is much sorter than that excited by the β -rays in lead. more detailed account of these primary rays will be given later.

Nanocrosses of lead sulphate as the negative active material of lead acid batteries

2014 ◽  
Vol 263 ◽  
pp. 1-6 ◽  
Author(s):  
Yi Liu ◽  
Pengran Gao ◽  
Xianfu Bu ◽  
Guizhi Kuang ◽  
Wei Liu ◽  
...  
Keyword(s):  
Active Material ◽  
Lead Sulphate ◽  
Lead Acid Batteries ◽  
Lead Acid

Synthesis and characterisation of tribasic lead sulphate as the negative active material of lead-acid battery

2018 ◽  
Vol 22 (9) ◽  
pp. 2829-2835
Author(s):  
Jian Tai ◽  
Fajun Li ◽  
Yanqing Zhou ◽  
Zhenzhen Fan ◽  
Huimin Wei ◽  
...  
Keyword(s):  
Active Material ◽  
Lead Acid Battery ◽  
Lead Sulphate ◽  
Lead Acid

A New MEMS Assembly Unit for Hybrid Self Micropositioning and Forced Microclamping of Submilimeter Parts

2010 ◽  
Vol 154-155 ◽  
pp. 1705-1712 ◽  
Author(s):  
Mohsen Hamedi ◽  
Milad Vismeh ◽  
Parisa Salimi
Keyword(s):  
Thin Layer ◽  
Active Material ◽  
Input Voltage ◽  
Rotary Table ◽  
Design Strategies ◽  
Temperature Dependent ◽  
Finite Element Software ◽  
Simulation Procedure ◽  
Shape Structure ◽  
Assembly Unit

In this paper we have presented an assembly unit equipped with electrothermally actuated microclamps (MCs), piezoelectric pad and rotary table to provide an environment for micropositioning and microclamping of submilimeter parts. The structural material of the system is considered to be <100> oriented Si with 20 µm thickness. Activating MCs, two approaches performed in the simulation procedure and results showed that utilizing 140 nm deposited Chromium thin layer on the U-shape structure as active material, reduces the overall input voltage and temperature in comparison with direct applying of potential difference to Si structure. To obtain more realistic results, both of these methods are simulated using finite element software in line with considering temperature-dependent thermophysical properties for structural and active material due to high operating temperatures. Design strategies and other advantages of using thin layer of chromium as active material are highlighted in the text.

Thin-layer chromatography of component A of the menstrual stimulant

1964 ◽  
Vol 19 (2) ◽  
pp. 315-318 ◽  
Author(s):  
H. J. Clitheroe
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Active Material ◽  
Solvent Mixture ◽  
Uterine Smooth Muscle ◽  
Liquid Extract ◽  
Biological Potency ◽  
Layer Chromatography ◽  
Chloroform Methanol ◽  
Separate Material

Thin-layer chromatography has been adapted to separate material of high biological potency from much of the inactive material contained in component A of the menstrual stimulant. The chromatoplates were developed with solvent mixture of chloroform, methanol, and water (60:10:1). Visualization of the spots was carried out by various methods; ultraviolet fluorescence of the charred material appeared to be the most sensitive. Samples of ricinoleic and phloionolic acids were used as reference standards. The biological active material of the component A preparations always ran just in front of phloionolic acid. Menstrual fluid was collected in vaginal cups; total volume and crude liquid extract measurements were also carried out on the fluid. uterine smooth muscle stimulant; menstrual flow rates Submitted on October 1, 1963

Our Changing Climate

2021 ◽  
pp. 14-24
Author(s):  
Michael P. Hoffmann ◽  
Carrie Koplinka-Loehr ◽  
Danielle L. Eiseman
Keyword(s):  
Thin Layer ◽  
Sea Level ◽  
Small Space ◽  
The Past ◽  
Changing Climate ◽  
The Earth ◽  
Apple Peel ◽  
Just Right

We live in a small space. Though the earth can seem vast, as can the endless skies above, in fact we exist in a wafer-thin layer of the atmosphere averaging about 7 mi. (11 km) above sea level.1 That’s it. A very thin layer—think apple peel—on a planet that has been not too hot, not too cold, but just right for the past ten thousand years....

Purification and properties of biologically active factors in lipid extracts of Listeria monocytogenes

1970 ◽  
Vol 16 (6) ◽  
pp. 535-544 ◽  
Author(s):  
R. A. Tadayon ◽  
K. K. Carroll ◽  
R. G. E. Murray
Keyword(s):  
Biological Activity ◽  
Listeria Monocytogenes ◽  
Thin Layer ◽  
Active Material ◽  
Chloroform Solution ◽  
Water Soluble ◽  
Biologically Active ◽  
Purification And Properties ◽  
Layer Chromatography ◽  
Soluble Material

Lipid extracts of Listeria monocytogenes, capable of producing monocytosis and lymphopenia in mice, were fractionated by column chromatography on acid-treated Florisil. The biological activity was associated with a phospholipid fraction and further separation of this fraction by thin-layer chromatography indicated that most of the activity was in the slower running components which gave a positive reaction with ninhydrin. Water-soluble ninhydrin-positive material was separated from either the crude lipids or the phospholipid fractions by techniques such as a Folch wash, chromatography on Sephadex, or dialysis of a chloroform solution of the lipids against water. These water-soluble materials were also able to produce monocytosis and lymphopenia in mice, but the remaining phospholipid was still ninhydrin-positive and biologically active. Most of the water-soluble material was dialyzable, but the biological activity appeared to be concentrated largely in the non-dialyzable fraction. This fraction contained protein, and digestion with Pronase appeared to enhance the biological activity and to make the active material more readily dialyzable. Extraction of the lipid-extracted bacterial residue with saline yielded additional non-dialyzable water-soluble material with activity comparable to that shown by the lipid extracts.

scholarly journals I. Contributions to the chemistry of storage batteries

1883 ◽  
Vol 35 (224-226) ◽  
pp. 66-70 ◽  
Keyword(s):  
Sulphuric Acid ◽  
Chemical Reactions ◽  
Chemical Change ◽  
Active Material ◽  
Storage Effect ◽  
Lead Sulphate ◽  
Usual Manner ◽  
Difference Of Opinion ◽  
The Subject ◽  
Storage Batteries

1. Chemical Reactions .—The chemical changes occurring during the charging and discharging of storage batteries have been the subject of considerable difference of opinion amongst chemists and physicists. Some writers believe that much of the storage effect depends upon the occlusion of oxygen and hydrogen gases by the positive and negative plates or by the active material thereon, some contend that lead sulphate plays an important part, whilst others assert that no chemical change of this sulphate occurs either in the charging or discharging of the plates. To test the first of these opinions, I made two plates of strips of thin lead twisted into corkscrew form, and after filling the gutter of the screw with minium, so as to form a cylinder that could be afterwards introduced into a piece of combustion-tubing, these plates were immersed in dilute sulphuric acid and charged by the dynamo-current in the usual manner. The charging was continued until the whole of the minium on the + and — plates respectively was converted into lead peroxide and spongy lead, and until gas bubbles streamed from the pores of the two cylinders.

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