Addition Of Paraffin Research Articles

Excretion of β-hexachlorocyclohexane by the rat as influenced by oral paraffin, squalane, and lutrol E 400

Following the administration of 1.5 ppm β-hexachloro[ 14C]cyclohexane (β-HCH) for 1 week in the diet, excretion of radioactivity with urine and feces was measured for 8 weeks in 20 male rats. Eight percent light liquid paraffin added to the diet for the whole 8 weeks significantly enhanced the elimination of radioactivity with feces as well as with urine. Whole-body elimination half-lives of the second compartment of a two-compartment model were reduced from 71 to 37 days in paraffin-fed rats. Addition of paraffin to the diet only in the second 4 weeks of the elimination phase also stimulated the excretion of β-HCH. Eight percent Lutrol E 400 added to the diet was as effective as paraffin; 8% squalane added to the diet did not enhance the excretion of β-HCH during the second 4 weeks of the elimination phase. Paraffin and squalane did not affect body weight gain; Lutrol significantly reduced body weight gain in rats.

ChemInform Abstract: PHOTOCYCLIZATION OF 2′‐HYDROXYCHALCONES TO 4‐FLAVANONES

AbstractProduktbildung und Reaktionsgeschwindigkeit bei der Photocyclisierung der Chalkone (I) werden in Abhängigkeit vom Lösungsmittel untersucht.

Photocyclization of 2′-Hydroxychalcones to 4-Flavanones

Abstract On irradiation with light of λ≥365 nm, parent and methoxy-substituted 2′-hydroxychalcones undergo facile photocyclization to give corresponding 4-flavanones in high efficiencies in ethyl acetate or dioxane, whereas in low or nil efficiencies in benzene, chloroform, carbon tetrachloride, ether, acetonitrile, ethanol, or t-butyl alcohol. The low reactivity in benzene is, however, significantly increased by the addition of liquid paraffin to increase the solvent viscosity. 3′,4′-Benzo-2′-hydroxychalcone showed low reactivities in any solvents. The formation of 4-flavanones is neither quenched by triplet quenchers nor depressed by the addition of free radical scavengers. The reaction mechanism is discussed in terms of enolization.

Quick identification and analysis of plasticizers in PVC by programmed‐temperature gas chromatography using the best stationary phases

AbstractA quick and safe identification method is shown for plasticizers in PVC using programmed‐temperature gas chromatography. Plasticizers were identified by their retention index values measured by using normal paraffins. Several stationary phases with quite different polarity are proposed: with silicone polymers (SE 30, OV 17, and QF 1) and a porous polymer such as Tenax. Operational conditions were optimized. The initial column temperatures was chosen at a low value of 100°C with the first three phases and 180°C for the fourth. The best rate of temperature increase with time seemed to be 10°C/min. The calculation method for retention values (temperature, time, indices) was chosen just because it needed no approximation. Thermodynamic values for the solution of plasticizers were measured by using isothermal chromatography with all the stationary phases. Our method allows the analyst to operational conditions (solvent, percent, temperature) for chromatography, to solve his own problem by making use of a pocket computer. Quantitative analysis of plasticizers was obtained with good accuracy after a previous extraction and the addition of normal paraffin as internal standard.

The interaction between corrosion inhibitors and load carrying additives in mineral oil

Corrosion tests carried out on blends of load carrying additives in liquid paraffin showed that these were not more corrosive than the neat oil; indeed, in some cases a measure of protection was given. With the addition of corrosion inhibitors to these blends, protection was excellent, in most cases similar to that given in the absence of the load carrying additives. Corrosion inhibitors did not in general affect the antiwear properties in mixed blends, but this was not the case in the EP region, where the presence of corrosion inhibitors in blends containing load carrying additives gave a small but definite reduction in performance, compared with those oils containing the additive alone. Reasons for these findings are postulated

Thermocouple sheaths for measuring metal temperatures continuously during melting

For the preparation of sheaths, a body was developed consisting of magnesia, fired at 1400°C, and electrofused magnesia, in the ratios 80∶20 with an addition of 3% B2O3. The boric anhydride plays the roles of mineralizer during the firing, and of plasticizer, increasing the fluidity of the body during hot casting under pressure. The introduction of B2O3 halves the required addition of paraffin.

Foundamental Studies on Pressing of Powder dy Means of Hydrostatic Pressing Method

Hydrostatic pressing method is radically different from ordinary mechanical ones, having high pressure resisting chamber in which green compact setin rubber die or rubber envelope can be pressed by Pascalian hydraulic force. This report is related to study green strength of TiC-Co system cermet powder compacted by hydrostatic pressing device, specially constructed to be able to endure until under hydraulic pressure of 10, 000kg/cm2, and here concerns especially with transverse strength of green compact, previously pressed slightly in metal or plastic die and finally compacted strongly in rubber envelope.As a factorial design, L81 340 type orthogonal design was used, adopting 5 factors as following…… A: Co powder content (0, 20, 40%), B: paraffin percentage (1, 2, 3%), C: time effect between the intervals of addition of paraffin and preliminary pressing (2, 24, 48hr.), D : preliminary pressing force (100, 200, 300kg/cm2) and F: hydrostatic pressing pressure (1, 2, 3ton/cm2). In addition, as auxiliary experiments, two designs of more increased levels among A, B and F were tested to get more precise imformation. Transverse strength as characteristic value was measured by the specially ordered testing apparatus having very high sensive mechanism to small amount of load and reveals that the main effects of A, B, C and F are significant, and interactions AXB, AXF are also significant. Each linear and cubic effect of A, B and F are significant, while each quadric effect is non-significant except A.

エナメル質齲蝕の研究

Of the variaus methods of section-making devised by many people to study enamel caries histo-pathologically, the Imagawa's direct paraffin embedding has been turned aut to be an effective method for studying enamel caries. This method is the one contrary to the standard section-making-first, by embedding the part necessary for the study of surface layer with paraffin and after taking off the unneclssary part by decalcification, observing the section of the necessary part remaining.I have examined this method and, adopted the method of using the crawn part of the teeth only, or using a lower pressure in paraffin embedding and decalcification, or using stained paraffin in the last paraffin addition. I have improved the method.Consequently I have faund out that this method is simple and easy to operate, the time taken to make a section is much shortened and a thin section is made. Moreover, in the paraffin negative model got after decalcification, we have an advantage of abserving cubically the form of normal grooves and fissures and the pracess of the early enamel caries. So I have been able to make the use of the Imagawa's direct paraffin embedding more valuable.By using this method improved by me I have studied the birth and origin of the early enamel caries histo-pathologicalyl about human and animal teeth and got these uew results.1) By using a stereoscopic microscope I haue abserved the paraffin negative model of human teeth grooves and fissuses and got results as follows-a) The form of grooves and fissures is not a simple one, but a complex cupola one.b) The individual characteristics can be seen in the height, form, color of the grooves and fissuses, in the same individual, the symmetrical form in the grooves and fissures of the teeth which are in the same jaws and have the same names.c) The caries of fissures is not always begun at its bottom. And the early caries of fissures sometimes a completely indefinite enlargement.2) By using the direct paraffin embedding I have observed microscopically the grooves and fissures of human teeth and their proximal surface and got results as follows-a) In the normal fissures and on the proximal surface can be found filaments grawing always on the enamel cuticle.b) These filaments are dyed into Gram positivity and iodine dying appears positively in some of them.c) Filamentous organisms, on which other bacteria, food remnants and cells fix themselves, form “bacterial plague”.d) The first and second enamel cuticles are always demonstred in the normal fissures and on the proximal surface.e) The early enamel cariee always begins directly below “baetereial plaque” the enamel cuticles break up, and the net-warks (zone of decalcification) grow and bacteria intrude.3) By using the direct paraffin embedding I have observed microscopically the graoves and fissures of gnimal teeth got results follows-a) In the normal grooves and fissures and on the proximal surface of animals-such as, rat, hamster, guinea pig, cow, horse, pig, goat, dog, cat, nutria-can always be found filamentous organisms grawing.b) Every animal has different forms of filaments grawing on the surface of its teeth.c) In the animal filaments, the Gram positive ones are mixed up with the Gram negative ones. The iodine dying, in every case, is negative.d) In the experimental dental caries with rats and hamsters, the microscopic findings of the early enamel caries accord with those of human dental caries.

Sensitization and antibody formation in monkeys injected with tubercle bacilli in paraffin oil: Casals, J., and Freund, J.: J. Immunol. 36: 399, 1939

Coulaud (1) has shown that the addition of paraffin to heat-killed tubercle bacilli promotes the sensitization of rabbits to tuberculin. Saenz (2) found that the solid paraffin could be replaced by liquid paraffin oil. He produced very intense and lasting sensitization in guinea pigs by subcutaneous or intramuscular injections of 1 cubic centimeter of paraffin oil containing a large amount of heat-killed and dried tubercle bacilli. Freund, Casals and Hosmer (3) observed that, both in the guinea pig and the rabbit, the addition of small amounts of paraffin oil to heat-killed tubercle bacilli augmented not only sensitization but also the formation of complement-fixing antibodies. The purpose of the present work was to determine whether paraffin oil containing heat-killed tubercle bacilli effectively sensitizes Macacus rhesus monkeys, a species said to be lacking in the capacity to develop cutaneous sensitization to tuberculin.

Sensitization and Antibody Formation in Monkeys Injected with Tubercle Bacilli in Paraffin Oil

Abstract Coulaud (1) has shown that the addition of paraffin to heat-killed tubercle bacilli promotes the sensitization of rabbits to tuberculin. Saenz (2) found that the solid paraffin could be replaced by liquid paraffin oil. He produced very intense and lasting sensitization in guinea pigs by subcutaneous or intramuscular injections of 1 cubic centimeter of paraffin oil containing a large amount of heat-killed and dried tubercle bacilli. Freund, Casals and Hosmer (3) observed that, both in the guinea pig and the rabbit, the addition of small amounts of paraffin oil to heat-killed tubercle bacilli augmented not only sensitization but also the formation of complement-fixing antibodies. The purpose of the present work was to determine whether paraffin oil containing heat-killed tubercle bacilli effectively sensitizes Macacus rhesus monkeys, a species said to be lacking in the capacity to develop cutaneous sensitization to tuberculin.