The Effects of Proöxygenic Substances on Reclaimed Rubber

1946 ◽  
Vol 19 (1) ◽  
pp. 123-124
Author(s):  
A. Haehl
Keyword(s):  
Caustic Soda ◽  
Chemical Structure ◽  
The Other ◽  
Rubber Mixture ◽  
Great Resistance ◽  
Other Hand

Abstract It might at first be assumed that antioxygenic compounds originally present in scrap rubber used in the manufacture of the reclaimed rubber would be sufficient to explain the extraordinary resistance of the reclaimed rubber to the action of proöxygenic compounds. It is, however, highly improbable that these antioxygenic compounds survive caustic soda treatment at 190° C. On the other hand, a crude-rubber mixture, even when protected by an antioxygenic compound, never shows such great resistance to proöxygenic compounds as that shown by the reclaimed-rubber vulcanizates described in the present work. It seems probable, therefore, that this insensitivity of reclaimed rubber to proöxygenic compounds, both during plasticization and during aging after vulcanization, is in some way connected with the actual chemical structure of the reclaimed rubber itself.

PTCDA Films Deposited by Ionized Beam Method

1993 ◽  
Vol 316 ◽  
Author(s):  
Hiroaki Usui ◽  
Kiyoshi Kashihara ◽  
Kuniaki Tanaka ◽  
Seizo Miyata
Keyword(s):  
Thin Films ◽  
Molecular Orientation ◽  
Chemical Structure ◽  
Chemical Change ◽  
The Other ◽  
Ion Acceleration ◽  
Ionization Condition ◽  
Other Hand ◽  
Beam Method

ABSTRACTThin films of 3,4,9,10-perylenetetracarboxylic-dianhydride (PTCDA) were deposited by an ionized beam method. The molecular orientation and chemical structure of the films were studied in connection with ionization and ion acceleration conditions. At a low ionization condition, the molecules are oriented in parallel with the substrate, and the crystallinity was improved by an appropriate ion acceleration. At higher ionization conditions, on the other hand, ion acceleration resulted in a loss of crystallinity. Deposited molecules undergo chemical change in such a condition, leading to dissociation of dianhydride groups.

scholarly journals Production of Polyvinylpyrrolidone Nanowebs Containing Zinc Cyclohexane Mono Carboxylate via Electrospinning and Investigatıon of Antibacterial Effıciency

2019 ◽  
Vol 27 (6(138)) ◽  
pp. 91-96
Author(s):  
Aylin Yildiz ◽  
Riza Atav ◽  
Mine Aydin
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Structure ◽  
Antibacterial Properties ◽  
The Other ◽  
Antibacterial Efficiency ◽  
E Coli ◽  
Other Hand ◽  
Edx Analyses

In this study, after the synthesis of zinc cyclohexane mono carboxylate, its chemical structure was analysed with FTIR and TGA. Then electrospun polyvinylpyrrolidone nanofibres containing zinc cyclohexane mono carboxylate were produced and antibacterial properties of the nanowebs obtained were investigated for their use in the textile field When the FTIR results of the nanofibres containing different concentrations of zinc cyclohexane monocarbocylate are examined, an –OH peak similar to that of PVP fibres is noticed. These results clearly indicate that zinc cyclohexane monocarboxylate is included in PVP. When the TGA spectra of CHMCZn-doped nanofibres at different ratios are examined, it is seen that they give more similar results than polyvinylprolidone nanofibres alone. According to the SEM-EDX analyses, it was observed that the fibre diameters obtained were in the range of 145 - 947 nm. On the other hand, antimicrobial activity against B. subtilis, S. aureus and E. coli strains was detected, found regardless of the CHMCZn concentration.

Plasticity Measurements in the Rubber Industry

1933 ◽  
Vol 6 (2) ◽  
pp. 244-260
Author(s):  
J. Behre
Keyword(s):  
High Pressure ◽  
Elastic Recovery ◽  
The Other ◽  
Compressed Air ◽  
Dead Weight ◽  
Rubber Mixture ◽  
Rubber Industry ◽  
Other Hand ◽  
Narrow Opening

Abstract With the growing realization of its importance in factory operations, the plasticity of raw rubber and rubber stocks is being studied more and more. As far as can be seen from the literature, four methods for measuring plasticity are known up to the present time. The most commonly used apparatus is probably that developed by Williams, which depends upon measuring the change in the thickness of rubber under a load. The same principle is followed in the recently published method of Karrer, except that in this case the elastic recovery is also measured. The other two methods, which were used first by Marzetti and by Griffith, depend on the other hand upon a wholly different principle. Here the rubber or the rubber mixture is extruded through a narrow opening under high pressure and the quantity extruded is measured. Griffith used a dead weight whereas Marzetti used compressed air to produce the pressure. For several years the author has worked with an apparatus constructed according to the Marzetti principle, and the present paper deals with experiments with this apparatus.

Fate of Triglycerides and Phospholipids of Lymph and Artificial Fat Emulsions: Disappearance From the Circulation

1958 ◽  
Vol 193 (2) ◽  
pp. 294-300 ◽  
Author(s):  
Esther L. McCandless ◽  
D. B. Zilversmit
Keyword(s):  
Chemical Structure ◽  
The Other ◽  
Plasma Lipoproteins ◽  
Disappearance Rate ◽  
Fat Emulsion ◽  
Fat Emulsions ◽  
Other Hand

Artificial fat emulsions labeled in either triglyceride or phospholipid component were administered to unanesthetized normal dogs to determine the disappearance rates of the two lipids from the circulation. Similar experiments were carried out using lymph from donor dogs fed I131-triolein or P32-phosphate with unlabeled triglyceride. Triglycerides were found to be rapidly removed from the circulation whether they were administered as an artificial fat emulsion or as a physiological emulsion, lymph. On the other hand, the emulsifying agents, liver lecithin or lymph phospholipid, required several hours for removal from the circulation. Evidence is presented that the slow disappearance rate of chylomicron phospholipids cannot be accounted for by exchange with plasma lipoproteins and indicates a slow removal of chylomicra phospholipid from the circulating blood. These findings are discussed in reference to current concepts of the chemical structure of lymph chylomicrons and of particulate fat in an artificial fat emulsion.

Effect of feldspar filler on physical and dynamic properties of SBR/CB based tire tread compounds: Effect of addition method of silane coupling agent

2021 ◽  
pp. 009524432110061
Author(s):  
Neşe Kaynak ◽  
Sinan Şen
Keyword(s):  
Hybrid Composites ◽  
Dynamic Properties ◽  
Rolling Resistance ◽  
The Other ◽  
Inorganic Filler ◽  
Addition Method ◽  
Rubber Mixture ◽  
Other Hand ◽  
Damping Parameter ◽  
Tan Δ

In this work, the effects of using feldspar (FLD) as an alumina-silicate inorganic filler, with carbon black (CB) as a novel binary filler system, on the properties of SBR compounds were investigated for tire applications. The bis(triethoxysilylpropyl) disulfide (TESPD) was used for modification of FLD. The SBR hybrid composites were produced by replacing 10 phr of CB filler with neat FLD and functionalized FLD (F-FLD). The TESPD was added directly to the rubber mixture including neat FLD. The SBR composite which has only CB filler (50CB) was found to have the highest damping parameter (tan δ) value at 60°C. On the other hand, the composites loaded with the CB and the FLD fillers exhibited relatively lower tan δ at the same temperature showing lower rolling resistance meaning better fuel saving performance. The lowest rolling resistance was achieved for the 40CB-10F-FLD most probably due to its stronger interaction with the SBR elastomer molecules through the silane agent-assisted crosslinks of the F-FLD. As another dynamic property, the storage moduli at −20°C were found to be lower for the SBR hybrid composites as compared to that of the 50CB composite, exhibiting enhanced winter traction performance of the composites having FLD filler together with CB. The composites containing only 10 phr of FLD and F-FLD, on the other hand, exhibited very low tensile strength values which are not acceptable for tire tread materials.

III. On rubian and its products of decomposition

1853 ◽  
Vol 143 ◽  
pp. 67-107 ◽  
Keyword(s):  
Caustic Soda ◽  
Sulphuric Acid ◽  
Cold Water ◽  
The Other ◽  
General Terms ◽  
Other Hand ◽  
Alkaline Earths

Action of Alkalies and Alkaline Earths on Rubian. In the first part of this paper I have described, in general terms, the effect produced on rubian by alkalies. It is only the fixed alkalies that are capable of effecting the decomposition of rubian. Ammonia produces no perceptible change in a watery solution of this substance, except that of altering its colour from yellow to blood-red. This blood-red colour remains unchanged even after long-continued boiling, and the solution still contains rubian, for on supersaturating the ammonia with acid, the solution again becomes yellow, and not the slightest precipitate is produced. The fixed alkalies, on the other hand, act very differently. On adding caustic soda to a solution of rubian, the colour of the solution first changes to blood-red. On boiling the liquid, however, its colour soon changes again from blood-red to purple. This alteration in colour indicates the formation of alizarine. If the boiling be continued, there is deposited, as the liquid becomes more concentrated, a dark purple powder, which consists mainly of a compound of alizarine and soda, and separates in conse­quence of its insolubility in caustic lye. After the liquid has been boiled for some time, then, provided the quantity of soda employed be sufficiently large, the rubian is entirely decomposed. On now adding sulphuric acid in excess, a quantity of orange- coloured flocks, exactly like those produced by the action of acids on rubian, is pre­cipitated, while the liquid becomes almost colourless. These flocks are separated by filtration and washed with cold water, until the sulphate of soda and sulphuric acid are entirely removed. They now consist mainly of four substances, viz. 1st, Alizarine ; 2ndly, Rubiretine ; 3rdly, Verantine and 4thly, a substance which has not hitherto been observed, and to which I shall give the name of Rubiadine .

The Ammonia in Soils

1910 ◽  
Vol 3 (3) ◽  
pp. 233-245 ◽  
Author(s):  
Edward John Russell
Keyword(s):  
Caustic Soda ◽  
Low Pressure ◽  
The Other ◽  
Ammonium Salts ◽  
No Decomposition ◽  
Ammonia Content ◽  
Reduced Pressure ◽  
Pressure Method ◽  
Other Hand

It has long been recognised that the amount of ammonia in soils cannot be determined by distillation with a solution of caustic soda or potash since these strong alkalis slowly decompose the complex nitrogenous matter and evolve a coutinuous stream of ammonia. Boussingault showed more than fifty years ago how this difficulty could be obviated. By using magnesia in place of soda or potash the decomposition of such substances as urea, asparagin, and albumin was not great even on long boiling, but when the distillation was carried out under reduced pressure at 38°—40° there was no decomposition at all. Ammonium salts, on the other hand, were completely broken up in these circumstances. He used this low pressure method in his researches on the ammonia content of urine, but does not appear to have applied it to soils. Sufficiently accurate results could, he considered, be obtained by distillation at 100°, and this method was for many years generally adopted. It gave results varying according to the nature of the soil from 10 to 100 parts of nitrogen per million (·001 to ·01 per cent.), which may still be found quoted in some of the agricultural text books.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

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