Wax Plug Research Articles

Geochemical monitoring of waxes and asphaltenes in oils produced during the transition from primary to secondary water flood recovery

Results are presented on changes in the content and composition of waxes and asphaltenes of oil produced during the transition from primary to secondary recovery following water flooding. Oil samples have been collected for a period of about three years from one well in Prairie Gem field in central Oklahoma. Wax and asphaltene fractions have been isolated from the produced oils and analyzed, qualitatively and quantitatively, by high temperature gas chromatography. The results demonstrate significant variations in the asphaltene and wax content of the oil produced during the transition period from primary to secondary water flood recovery, ranging from 0.7 to 5 wt%, and 11 to 33 wt%, respectively. Moreover, these variations are found to be accompanied by changes in wax composition and to precede specific production events. The oil produced a month before the response of the well to water flooding indicated an enhanced concentration of nC 22–C 35 alkanes in the wax. The following episode of wax plugging in well equipment was preceded by increased amounts of asphaltenes and high molecular weight (nC 35–C 50) alkanes in the wax of produced oils. Changes in the asphaltene and wax compositions are discussed in terms of processes displacing weakly adsorbed organic material from the pore spaces of the reservoir under increased reservoir pressure and flowing fluid volumes related to water flooding.

Imbricacy and Stomatal Wax Plugs Reduce Maximum Leaf Conductance in Southern Hemisphere Conifers

An examination of the relationship between theoretical maximum leaf conductance as calculated from stomatal dimensions, and measured maximum leaf conductance was undertaken in a group of Southern Hemisphere conifers. The relative effects of stomatal wax plugs, found in most species of conifers in the Southern Hemisphere, and imbricate leaf arrangement were expressed as a percentage inhibition of maximum leaf conductance (gmax) calculated from the ratio of measured gmax to theoretical gmax Because of the similar stomatal dimensions of all species, measured gmax was proportional to stomatal density in plugged and unplugged species, with species without wax plugs producing maximum leaf conductances on average 91% of calculated gmax, while in species with plugged stomata measured gmax was on average only 35% of theoretical gmax. There was no effect produced by imbricacy in itself, but when combined with epistomy, gmax was significantly reduced to about 17% of theoretical gmax. This is clearly illustrated by comparisons of juvenile-adult foliage, and closely related imbricate and non-imbricate species. The adaptational advantages of imbricacy and wax plugs, and the potential for inferring gmax of fossil taxa are discussed.

5611912 Production of high cetane diesel fuel by employing hydrocracking and catalytic dewaxing techniques: Han Scott; Heck Roland; Ehlers Michael E Lawrenceville, NJ, United States assigned to Mobil Oil Corporation

Diesel fuels contain n-paraffins in the range from C10 to C25. At low temperatures, some of the heavier n-paraffins crystallize as wax crystals and plug fuel filters. A thermodynamic model has been developed to predict the cloud point and the amount and composition of wax formed at low temperatures in diesel fuels. In this model, the amounts of all n-paraffins in a diesel fuel are converted into equivalent amounts of a reference n-paraffin, and the fuel is then treated as a solution in which the only solute is the reference n-paraffin. Cloud point, wax content and composition of several diesel fuels were measured and compared with values predicted by the model. The agreement between the measured and predicted values was good.

Can ear irrigation cause rupture of the normal tympanic membrane?: an experimental study in man.

Rupture of the tympanic membrane (TM) during ear irrigation is a rare but unhappy event. In this study the maximum overpressures obtained in the deep part of the external auditory meatus (EAM) during ear irrigation were measured postmortem in 20 cadavers. The highest pressures were obtained in normal- or wide-dimension EAMs when a metal syringe was used. With this device, the median maximum overpressure was 240 mmHg (range 200-300 mmHg). Experiments with simulation of an obturating wax plug did not increase the maximum overpressure. Compared with the lowest overpressures which can rupture TMs the pressures measured in this study were insufficient to rupture normal TMs but sufficient to rupture atrophic TMs with the lowest tensile strength. This finding may have medicolegal implications.

Bacterial factors in the formation of renal scars. An experimental study on the role of Escherichia coli P-fimbriation and hydrophobicity.

A model capable of comparing the effects of bacterial virulence factors on renal scarring in vivo has been developed using the female piglet. By creating, at open surgery, unilateral vesicoureteric reflux (VUR) and quantifying scarring both by uptake of an isotope bound to functioning renal parenchyma and by planimetry of the surface area scarred, the effects of 2 organisms, a P-fimbriate Escherichia coli and an E. coli K1 have been compared. The P-fimbriate E. coli was shown to express P-fimbriae in freshly voided urine, was more hydrophobic and produced smaller scars. This indicates that neither the hydrophobicity nor P-fimbriation of the organism causing urinary tract infection (UTI) is of prime importance for the development of renal scars and is evidence against the "big bang" theory for the development of renal scars. Studies on the association of UTI with VUR showed that infection with both E. coli under study led to VUR on the side contralateral to the side undergoing surgery. It seems likely that a non-specific effect of UTI, such as bladder oedema, is responsible for this acquired VUR. An effect of the 2 bacteria under study on the lower urinary tract was observed in that infection with the P-fimbriate E. coli allowed the retention of an intravesical wax plug, whereas infection with E. coli K1 did not. Epidemiological data have shown that the majority of upper urinary tract infections in children are associated with UTI by P-fimbriate organisms. Such an association may be explained in part by an effect of P-fimbriate bacteria on lower urinary tract function rather than an effect on the upper urinary tract.

Cuticular Micromorphology of Pagiophyllum bladenensis, Comb. nov., from the Late Cretaceous of the North Carolina Coastal Plain, U. S. A.

MICKLE, J. E. (Department of Botany, North Carolina State University, Box 7612, Raleigh, NC 27695). Cuticular micromorphology of Pagiophyllum bladenensis, comb. nov., from the Late Cretaceous of the North Carolina Coastal Plain, U.S.A. Bull. Torrey Bot. Club 120: 387391.1993-Abundant leafand branch compressions referable Araucaria bladenensis Berry have been recovered from Late Cretaceous gray mudstones of the Tar Heel Formation along the Tar River in Pitt County, NC. Leaves are up to 21.2 mm long by 9.9 mm wide, flat, sessile, coriaceous, and fusiform, and have entire margins, acute tips, and numerous parallel, unbranched veins. Leaves are borne helically and are imbricate. Cuticle was recovered using 20% CrO3 and is incompletely preserved. Epidermal cells are irregular to rectangular in shape with thin, straight anticlinal walls. Sunken stomata are in discontinuous rows with the long axis of guard cells typically parallel to that of the leaf. Stomata are encyclocytic with a surrounding ring of three to five encircling cells. External stomatal wax plugs are commonly present. Florin rings are present but not observed consistently. Other stomatal features are indistinct due to incomplete preservation. Leaf morphology is similar to that seen in Araucariaceae and in Nageia sect. Nageia de Laubenfels (Podocarpaceae). Among cuticular features, the presence of Florin rings is consistent with Agathis Salisbury (Araucariaceae) and Podocarpaceae, and encircling cells are common in Araucariaceae and other conifers. It is concluded that this material shows its greatest affinities with Araucariaceae but does not fit precisely within any known taxa. Consequently, A. bladenensis is transferred to the form-genus Pagiophyllum Heer as P. bladenensis comb. nov.

Bone Regenerate Formation in Cortical Bone During Distraction Lengthening

The aim of this study was to delineate the pattern of bone regeneration from cortical bone segments during distraction lengthening. The lengthening procedure was applied for various periods through the Ilizarov system on the forearms of mature dogs. Bone was sectioned either by corticotomy, preserving the nutrient artery integrity, or by osteotomy. When an osteotomy was performed, the marrow cavity was in some cases plugged with either resorbable bone wax or nonresorbable material. Under distraction, both periosteal and medullary callus on either side of the gap gave rise to new bone trabeculae. The trabeculae on either side were oriented along the direction of distraction and progressively approached one another. This striated callus emerging from both sides was the most characteristic pattern of bone regeneration subsequent to distraction lengthening. Fusion was achieved approximately four weeks after the end of the lengthening period. Most of the new bone was formed by membranous ossification; some cartilaginous nodules developed. Corticalization of the bone trabeculae that had begun at three months was not fully achieved at five months after the lengthening period. There were no differences found in the pattern of bone healing and the amount of newly formed bone after corticotomy or osteotomy with or without resorbable bone wax plugging.

Wax plugs and cotton buds.

Three hundred and ten patients were examined by otoscopy. Age, sex, social class and use of cotton buds for aural toilet were recorded. The incidence of visually occlusive wax plugs in the external auditory canals was not significantly different between users and non-users of cotton buds, either in children or in adults.

Rasterelektronenmikroskopische Untersuchungen an Stomata von Fichten‐ und Tannennadeln nach Begasung und saurer Beregnung1

Abstract Scanning electron microscopical investigations on stomatal wax plugs of fir and spruce needles after fumigation and acid rain treatment Alterations of stomatal wax plugs of fir and spruce needles have been investigated in order to demonstrate the effects of different air pollutants. After acid rain treatment, and in addition to SO2 fumigation, heavily melted wax crystals were observed. It is assumed that acid rain causes mainly the changes of the stomatal wax plugs.

A thermodynamic model for predicting n-paraffin crystallization in diesel fuels

Diesel fuels contain n-paraffins in the range from C 10 to C 25. At low temperatures, some of the heavier n-paraffins crystallize as wax crystals and plug fuel filters. A thermodynamic model has been developed to predict the cloud point and the amount and composition of wax formed at low temperatures in diesel fuels. In this model, the amounts of all n-paraffins in a diesel fuel are converted into equivalent amounts of a reference n-paraffin, and the fuel is then treated as a solution in which the only solute is the reference n-paraffin. Cloud point, wax content and composition of several diesel fuels were measured and compared with values predicted by the model. The agreement between the measured and predicted values was good.

Die Entnahme von Beckenkammknochen

The paper covers diagnoses indicating removal of bone from the iliac crest, positioning, an approach to the iliac crest, and techniques for removing bone. The hazards incident to the removal of spongiosa, cortical substance, or spongeous-cortical bone chips are described. Haemorrhages from the spongiosa must be staunched carefully with wax plugs or fibrin glue (Tissucol1). Complications such as perforation, hernia, hyperaesthesia, muscular atrophy, and changes in contour are discussed, as well as suitable measures to avoid complications.

Development of directional responses toward sound by young guinea pigs

Infant guinea pigs were tested in a circular apparatus for their tendencey to approach the source of auditory stimulation. A tape recording of guinea pig vocalizations was played over a loud speaker and the incidence of directional responses was noted. Even without external reinforcement there was a tendency to approach the particular stimulus used in this study within the first four days after birth. In order to determine the cues involved in infant localization, animals were tested with wax plugs inserted in one ear or in both ears. The plugs attenuated but did not totally eliminate sound entering the ear. Directional responding was reduced to chance by monaural blocking, but not by binaural blocking. Similar results were obtained with older animals eleven to thirty-one days of age. Furthermore, directional responding was impaired in animals raised from birth with monaural ear plugs, but tested without ear plugs. These results indicate that sound localization occurs early in development in the guinea pig, that binaural cues are important, and that monaural deprivation can affect subsequent responding.

Foreign bodies of the external auditory canal

Under foreign bodies of the ear in the proper sense of the word should be considered only those that enter the external auditory canal from the outside. However, this notion is now somewhat expanded to include in the group of foreign bodies of the ear deposits of the glandular apparatus of the external ear with the formation of accumulations of wax - "wax plugs". In general, all these bodies, of one origin or another, can be divided into two groups: animate and inanimate (Tsytovich, Fink).

Foreign bodies of the external auditory canal

Under foreign bodies of the ear in the proper sense of the word should be considered only those that enter the external auditory canal from the outside. However, this notion is now somewhat expanded to include in the group of foreign bodies of the ear deposits of the glandular apparatus of the external ear with the formation of accumulations of wax - "wax plugs". In general, all these bodies, of one origin or another, can be divided into two groups: animate and inanimate (Tsytovich, Fink).