Showing papers on "Liquid paraffin published in 2003"

A Fast Way for Preparing Crack-free Mesostructured Silica Monolith

Abstract: Large-sized, crack-free silica monoliths with highly ordered mesostructure are prepared by a fast and easy way via liquid-paraffin-medium protected solvent evaporation. By employing the inert liquid paraffin as the morphology “protector”, cracks of the materials can be successfully avoided and the processing time can be reduced to 8 h. The block copolymer−silica composite monoliths are transparent and crack-free with a large size. The mesoporous silica monoliths have been characterized by small-angle powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption, which show that the materials have a highly ordered hexagonal mesostructure of space group p6mm and narrow pore size distribution, with a mean pore diameter of 5.65 nm. In addition, metal ions can be easily doped into the monoliths, indicating potential optical, electronic, magnetic, and catalytic properties. This fast synthetic method is valuable for the applications of mesostructured silica monoliths in optics a...

Preparation and tribological properties of tetrafluorobenzoic acid-modified TiO2 nanoparticles as lubricant additives

Abstract: A tetrafluorobenzoic acid-modified TiO 2 nanoparticles with average diameter of 40 nm were chemically synthesized. The nanoparticles were amorphous and had good thermal stability. The nanoparticles were characterized by transmission electron microscope, Fourier transformation infrared ray, X-ray Diffraction, and their thermal stability was investigated by means of TGA and differential thermal analysis. The tribological properties of the FA–TiO 2 nanoparticles as additive to liquid paraffin were evaluated with a four-ball tester. The morphologies on the worn surfaces of the lubricated GCr15 steel were studied using scanning electron microscope. The results show that the FA–TiO 2 nanoparticles exhibit good performance in wear and friction reduction. The antiwear and load capability of liquid paraffin increased and the wear scar diameter strikingly deceased after adding nanometer TiO 2 .

An evaluation of dermoscopy fluids and application techniques.

Abstract: SummaryBackground Dermoscopy, a noninvasive technique used to help physicians better visualize pigmented skin lesions, is becoming widely used by dermatologists. Yet despite its popularity, to our knowledge basic aspects such as the best immersion fluid (IF) to use and proper procedures for applying the IF and dermatoscope have never been the subject of a systematic investigation. Objectives To determine the best techniques for application of IF and the dermatoscope; to discover which IF results in the least amount of air inclusions; to determine which IF provides the best image quality. Methods and materials This study was divided into three phases. Phase I examined several techniques of taking digital dermoscopic photographs in an attempt to eliminate air bubbles. Phase II tested seven IFs to analyse quantitatively the number of air inclusions for each IF. Phase III investigated these same IFs to judge the image quality for each. Results Phase I: in our hands, the best technique to apply an IF is to use an eyedropper and place the IF directly onto the skin in combination with a ‘roll-on technique’: the dermatoscope's edge is placed on the skin first and is then rotated until the glass plate lies flat against the skin. Phase II: the alcoholic IF resulted in the least amount of air bubble inclusions (70% ethanol, 90% isopropanol and alcoholic disinfectant), while liquid paraffin (a mineral oil) resulted in the most air bubbles. Phase III: dermoscopic structures were equally clear with alcohols and liquid paraffin, but slightly blurry with ultrasound gel and water. Conclusions Although 90% isopropanol performed slightly better in terms of air inclusions, we prefer to use 70% ethanol in most circumstances because it has the advantage of being odourless, unlike its counterpart. Additionally, ethanol will not stain clothing, does not crystallize on the dermatoscope, disinfects and evaporates immediately (does not need to be wiped off). For certain local considerations, such as dermoscopy on mucosa or the nail, we prefer to use ultrasound gel because it will not flow.

Development and in vitro evaluations of gelatin A microspheres of ketorolac tromethamine for intranasal administration.

Abstract: Gelatin A microspheres (MS) of ketorolac tromethamine (KT) for intranasal systemic delivery were developed with the aim to avoid gastro-intestinal complications, to improve patient compliance, to use as an alternative therapy to conventional dosage forms, to achieve controlled blood level profiles, and to obtain improved therapeutic efficacy in the treatment of postoperative pain and migraine. Gelatin A microspheres were prepared using the emulsification-crosslinking technique. The drug was dispersed in polymer gelatin and formulated into a w/o emulsion with liquid paraffin, using glutaraldehyde as a crosslinking agent. The formulation variables were drug loading and the concentrations of polymer (gelatin), co-polymer (chitosan) and the crosslinking agent. All the prepared microspheres were evaluated for physical characteristics, such as particle size, incorporation efficiency, swelling ability, in vitro bioadhesion on rabbit small intestine and in vitro drug release characteristics in pH 6.6 phosphate buffer. All the microspheres showed good bioadhesive properties. Gelatin A and chitosan concentrations, percentage of the crosslinking agent and also the drug loading affected significantly the rate and extent of drug release. The data indicated that the KT release followed Higuchi's matrix model.

Preparation and in vitro release behaviour of 5-fluorouracil-loaded microspheres based on poly (L-lactide) and its carbonate copolymers.

Abstract: A modified oil-in-oil (o/o) emulsion solvent evaporation technique was adopted to prepare 5-fluorouracil (5-Fu)-loaded poly (L-lactide) (PLLA) or its carbonate copolymer microspheres. The disperse phase was a drug:polymer solution using a solvent mixture of N, N-dimethylformamide (DMF) and acetonitrile and the continuous phase was liquid paraffin containing 1–10% (w/v) Span 80®. The effects of preparative parameters, such as the composition of the inner oil phase, drug:polymer ratio, polymer concentration and agitation rate, on 5-Fu entrapment efficiency and microsphere characteristics were investigated. By introducing 25% (v/v) DMF into the inner oil phase, microspheres with high drug entrapment efficiency and an ameliorated burst effect were achieved. Using this modified method, microspheres with various particle sizes could be produced with a high 5-Fu entrapment efficiency (about 80%). In vitro drug release tests showed a burst release of 5-Fu from PLLA microspheres, followed by a sustained release ov...

Self-Organizing Polycondensation of (E)-4-Acetoxycinnamic Acid for Preparation of Poly(p-oxycinnamoyl) Microspheres

Abstract: Preparation of poly(p-oxycinnamoyl) (POC) microspheres was examined by the reaction-induced phase separation of oligomers during the polycondensation of (E)-4-acetoxycinnamic acid in various solvents. Polymerization in liquid paraffin yielded the microspheres having a smooth surface at 270−330 °C, of which the average diameter was 4.6 μm. In contrast to this, the morphology of the products was drastically changed in Therm S 800 (TS8) and Therm S 900 (TS9) by polymerization temperature. When the polymerization was carried out at 310 °C in TS8 and 300 °C in TS9, the microspheres were obtained, of which the average diameter was 3.9 and 3.3 μm, respectively. The platelike crystals were formed under these temperatures, of which thickness was approximately 0.1 μm. The formation of the microspheres was highly related to the miscibility between the oligomers and the solvents. The average diameter of the microspheres increased with the decrease of the miscibility, and this tendency could be accounted for by the in...

Styrene resin foam comprising graphite powder

Abstract: PROBLEM TO BE SOLVED: To provide a styrene resin foam having low thermal conductivity and excellent thermal insulating properties, and a method for manufacturing the foam. SOLUTION: This styrene resin foam comprises a graphite powder, and has a density of 10-100 Kg/m 3 , a closed cell ratio of not less than 60%, and an average cell diameter of 20-1,000 μm. The aspect ratio of the graphite powder is not less than 5. In the manufacturing method of the styrene resin foam, a styrene resin, the graphite powder and a dispersant are blended by means of an extruder, the mixture is then extruded, cooled, and pelletized. The graphite powder-containing styrene resin particles thus obtained are suspended in water into which a foaming agent is supplied, so as to obtain foamable styrene resin particles impregnated with the foaming agent. The particles are then subjected to foaming with heating followed by molding. A liquid paraffin is used as the dispersant. COPYRIGHT: (C)2005,JPO&NCIPI

The maintenance and preservation of keratinophilic fungi and related dermatophytes.

Abstract: Summary A total of 239 fungi belonging to nine genera and 23 species were maintained on agar slopes in a refrigerator at +8 ± 1 °C and in sterile distilled water, under liquid paraffin, dried on silica gel, in sterile soil at room temperature. A limited number has been stored by freeze-drying between 1985 and 1998. It is recommended that each isolate should be maintained by at least two of these methods. The choice of the method will depend to a large extent on the equipment and facilities available in the laboratory. It is reported that simple methods can be used for preservation of keratinophilic fungi and related dermatophytes. Zusammenfassung Es wurden 239 Pilzstamme (9 Genera, 23 Arten) auf Schragagar verimpft und in einem Kuhlschrank bei +8 °C unter sterilem Aquadest oder unter flussigem Paraffin oder aber auf Silicagel oder in sterilisiertem Boden bei Raumtemperatur aufbewahrt. Eine kleinere Zahl wurde gefriergetrocknet 13 Jahre lang aufbewahrt. Die Langzeitaufbewahrung von Pilzstammen sollte stets mit wenigstens zwei der vorgeschlagenen Methoden erfolgen.

A multi-functional graphite/epoxy-based thermal energy storage composite for temperature control of sensors and electronics

Abstract: A novel multi-functional plate-like lamination that combines a thermal energy storage capability with a structural capability is described. The lamination consists of a paraffin impregnated porous graphitic core (the energy storage volume) encapsulated between rigid graphite/epoxy composite skins. Heat storage is via solid-liquid phase transition of the paraffin. Stacked laminations form a sandwich structure. A thermal response model shows that the graphite foam is an effective thermal conductivity enhancer to the imbedded paraffin. It will effectively immobilize liquid paraffin so that the thermal storage process will be unaffected by up to a 10g load. Furthermore, the foam can accommodate the relatively large specific volume change that accompanies paraffin phase transition. However, it does so at the expense of reduced thermal performance. Structural analysis shows that graphitic foam has a low strength and elasticity modulus, and the material displays tension-compression asymmetry. The paraffin fill is shown to increase the compressive ultimate strength and elasticity modulus. The use of carbon fiber/epoxy skin greatly enhances the overall strength of the structure.

Structural properties of nonionic surfactant/glycerol/paraffin lyotropic liquid crystals

Abstract: Lamellar lyotropic liquid-crystalline systems are thermodynamically stable, optically isotropic and are formed spontaneously. New possibilities for the development of controlled drug delivery systems are inherent in these systems in consequence of their stability and special, skin-friendly structure. The aim was to formulate and study two-component or multicomponent compositions with a relatively low Brij 96V content, liquid paraffin, glycerol and water for therapeutic purposes. The liquid crystals were examined by polarizing light microscopy and transmission electron microscopic observation of replicas produced by the freeze–fracture technique to demonstrate the presence of lamellar liquid-crystalline domains. The existence of a regular structure was determined by X-ray diffraction.

Thermal analysis of polyolefin and liquid paraffin mixtures

Abstract: The thermal decomposition of the polypropylene and liquid paraffin mixtures with inorganic additives was studied in dynamic conditions. Thus, typical thermal analyses were carried out and thermal decomposition of samples in a specially designed apparatus was also processed. One can observe for samples of sufficiently low mass that thermal analysis allows clear distinction of samples that contain and do not contain liquid paraffin, respectively. Moreover, it is possible to separate two stages of the decomposition process. The relationship between the logarithm of conversion degree and temperature (so called three-parameter model) was used for the description of these processes. Relations between coefficients in three-parameter equation in micro-scale, and characteristic temperatures of thermal decomposition in laboratory scale were observed in spite of meaningful differences in the course of the processes.

Tribological properties of P‐ and N‐containing organic compounds as potential extreme‐pressure and antiwear additives

Abstract: An amine salt of an alkoxylphosphate (a P- and N-containing organic compound, PN) was synthesised. Its extreme-pressure, antiwear, and friction-reducing properties were evaluated as an additive in liquid paraffin and a mineral oil. Tests were performed on a four-ball friction and wear tester with an AISI 52100 steel ball self-mated pair and the results were compared with those of sulphurised olefin (SO), zinc di-n-butyldithio-phosphate (ZDDP), and dibutylphosphite (DBP). The morphologies of the worn steel surfaces were observed using a scanning electron microscope, while the binding energies of some typical elements on the worn surfaces were determined using X-ray photoelectron spectroscopy. The additives were found to increase the load-carrying capacity and to reduce wear and friction coefficient considerably. PN as an additive exhibits better load-carrying, antiwear, and friction-reducing properties than SO, ZDDP, and DBP under the same test conditions.

Cleaning agent for diesel oil system

Abstract: The cleaning agent for fuel oil system includes: 5-20% of macromolecular cleaning dispersing agent which can be one of polyisobutyramide, polyether amine, polyalkylphenol, alkylpolyuerthane and polyisobutylene succimide, 10-30% of breakout oil which can be one of alkylpolypropylene glycol ether, alkalpolybutaglycol ether, engine oil, base oil, liquid paraffin and vegetable oil, 5-20% of water-removing agent which can be one or two kinds of main group phenol polyethenoxy ether, octadecyl polyethenoxy ether, Peregral, dodecyl alcohol amide, Tween-80 and Span-80, 15-35% of polar solvent which can be one or several kinds of isopropanol, isobutanol, ethylene glycol monomethyl ether and ethylene glycol monobutyl ether and 30-65% of diluting agent.

Caustic stress corrosion cracking of a spheroidal graphite cast iron: laboratory investigation

Abstract: This paper presents the results of an experimental investigation into the stress corrosion cracking (SCC) of an engineering cast iron (namely a spheroidal graphite (SG) cast iron), in a highly caustic solution (namely synthetic Bayer liquor (SBL)) at high temperature. In order to ascertain experimental conditions under which plain iron - carbon materials may fracture predominantly by SCC in a caustic environment, slow strain rate testing (SSRT) was performed on carbon steel specimens, employing various combinations of strain rates and temperatures, in SBL and an inert environment of liquid paraffin. Under the conditions identified to be most conducive for caustic SCC of mild steel, specimens of the SG cast iron were subjected to SSRT in SBL and liquid paraffin, and the fracture behaviour was investigated by detailed fractography and microstructural characterisation.

Paraffinoma in anterior abdominal wall mimicking liposarcoma

Abstract: Paraffinoma of breast is a recognized complication of paraffin injection for breast augmentation. Liquid paraffin can extend along fascial planes to involve adjacent tissues. A rare case of paraffinoma in anterior abdominal wall, which was misdiagnosed as a soft tissue liposarcoma before surgical excision, is reported. It was heterogeneous with marked posterior acoustic shadowing and small peripheral cysts on ultrasound. On MRI, it had ill-defined margins and was heterogeneous in signal intensity. Small round components which were hypointense on all sequences were demonstrated. There is significant overlapping of imaging features between paraffinoma and soft tissue liposarcoma. Histological differentiation from well-differentiated liposarcoma may also be difficult. A detailed clinical history of previous paraffin injection for breast augmentation is very important for correct interpretation of imaging and histopathological findings.

Altered cytokeratin expression during chemoprevention of hamster buccal pouch carcinogenesis by S-allylcysteine.

Abstract: We examined the effect of S-allylcysteine (SAC), a water-soluble garlic constituent, on cytokeratin expression, a sensitive and specific marker for differentiation status during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis in male Syrian hamsters. Hamsters were divided into four groups of six animals each. Animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin on the right buccal pouches three times a week for 14 weeks. Group 2 animals were painted with DMBA as in group I, and in addition they received orally 200 mg/kg of SAC on days alternate to DMBA application. Group 3 animals received SAC as in group 2. Group 4 animals received neither DMBA nor SAC and served as the control. The hamsters were killed after an experimental period of 14 weeks. Cytokeratin expression was detected by Western blot analysis using monoclonal antibodies AE1 and AE3. In DMBA-induced HBP tumors, the decreased expression of high molecular weight cytokeratins of molecular mass between 55-70 kDa was observed. Administration of SAC (200 mg/kg) to animals painted with DMBA suppressed the incidence of DMBA-induced carcinomas and was associated with restoration of normal cytokeratin expression. The results of the present study suggest that inhibition of HBP tumorigenesis by SAC may be due to its regulatory effects on differentiation, tumor invasiveness, and its ability to migrate and form metastases.

Effect of Antitranspirants on growth, photosynthetic rate and yield characters of brinjal

Abstract: A field study was conducted with different antitranspirants viz kaolin, phenyl mercuric acetate, salicylic acid and liquid paraffin on brinjal to find out their effects on growth, photosynthesis and yield characters. Antitranspirants significantly influenced the plant biomass, number of branches, plant height, leaf area and number of flowers. Kaoline (7.5%) spray was found to be the best which improved both plant biomass and number of flowers. All antitranspirants affected the photosynthetic characters such as net photosynthetic rate, stomatal conductance, intercellular CO 2 concentration, transpiration and relative water content (RWC). Maximum net photosynthetic rate, RWC and minimum transpiration were observed with kaolin (7.5%), which was at par with salicylic acid (1000 ppm) and liquid paraffin (1.5%). Fruit yield was significantly increased with kaolin (7.5%) and salicylic acid (1000 ppm).

Epoxide containing spherical beads from PVC

Abstract: Dehydrochlorination of poly (vinylchloride) (PVC) bead particles (410-840 μm) has been performed by heating in liquid paraffin or pre-treatment with KOH-isopropanol and subsequent heating at 200 °C. These procedures give crosslinked dark-colored products with retention of the bead shapes. Catalytic epoxidation of the dehydrochlorinated products with t-butyl hydroperoxide yields gray-white to dark products with reasonable epoxide contents (1.7-4.7 mmol per gram). The method presented offers a simple pathway to prepare epoxidized spherical beads, starting from PVC. The resulting products are very useful as functional group carriers, due to high reactivity of the epoxy groups.

Investigation on the tribological properties of boron and lanthanum permeated mild steel

Abstract: AISI 1045 steel was permeated with boron and co-permeated with boron and lanthanum by means of solid permeation technique. The tribological behavior of boron and lanthanum co-permeated AISI-1045 steel under dry sliding in air was investigated and compared with that of the boron permeated and tempered AISI-1045 steel specimens with a reciprocal friction and wear tester. The cross-section of the permeated and co-permeated coatings and the morphologies of the worn surface and wear debris were examined by means of scanning electron microscopy, and the chemical states of the wear debris examined by means of X-ray photoelectron spectroscopy. Then the wear mechanisms of the permeated and co-permeated layers were discussed. As the results, boron and lanthanum co-permeated specimen shows much better wear resistance than the boron permeated and tempered specimens under a load of 20 to ∼100 N and a frequency of 20 to ∼60 Hz. However, the permeation has little effect on the coefficient of friction, but liquid paraffin is significantly reducing coefficient of friction. The treated specimens contain Fe 2 B phase and exhibit more compact structure and higher hardness, and the corresponding wear debris is smaller than that of the tempered ones. The surface layers of the boron-permeated and the boron and lanthanum co-permeated specimens show some kind of solid lubricity and hence prevent the direct metallic contact of the frictional pair, thus the improved wear-resistance is reached. Moreover, Fe 2 B and B 2 O 3 in the surface layers of the boron-permeated and boron and lanthanum co-permeation specimens restrain wear during the friction process, with the generation of iron oxide and boron oxide. This leads to wear of the specimens at extended test duration.

Cosmetics excellent in texture and oil-dispersibility

Abstract: A cosmetic excellent in texture which contains a crosslinked poly-Ϝ-glutamic acid compound and/or a crosslinked poly-Ϝ-glutamic acid salt having a particle size of from 0.1 to 100 μm and an average particle size of from 1 to 50 μm. This cosmetic shows no stickiness in using, is highly compatible with the skin and hair, exerts a moistening effect and has a favorable moist feeling and improved texture such as smoothness and oil-free feeling. A cosmetic excellent in oil-dispersibility which comprises an oily component selected from among vegetable oils, higher alcohols, esters thereof, higher fatty acid esters and liquid paraffin together with a crosslinked poly-Ϝ-glutamic acid compound and/or a crosslinked poly-Ϝ-glutamic acid salt as an oil-dispersibility improving agent. This cosmetic shows no stickiness in using, is highly compatible with the skin and hair and yet shows well dispersion of the oily component even though the content of a surfactant is lessened.

Process formula of skin-care liquid

Abstract: The present invention is the formulation and preparation process of whitening and beautifying face nursing liquid The whitening and beautifying face nursing liquid is prepared with Chinese medicinal materials Chuanxiong rhizome, ledebouriella root, pubescent angelica root and wormwood root; water phase including glycerine, sodium dodecyl alkoxide and ethanol; and oil phase including olive oil, BHT and liquid paraffin The technological process includes the steps of: extracting Chinese medicine juice; heating the water phase to 85 degc, adding the water phase to the oil phase slowly and adding Chinese medicine juice through stirring; and bottling The present invention has high treating effect on chloasma, freckle and acne, no irritation to face and no side effect

Influence of solvent on size of poly(p-oxybenzoyl) whiskers prepared from p-acetoxybenzoic acid

Abstract: Poly(p-oxybenzoyl) (POB) crystals are prepared by the polymerization of p-acetoxybenzoic acid (p-ABA) at 320°C in various solvents to clarify the influence of miscibility between oligomer and solvent on the morphology as well as the size of the crystal. Concerning the morphology, whiskers are formed in less miscible solvents such as liquid paraffin and Barrel process oil B27. On the other hand, bundle-like aggregates of fibrillar crystals tend to be formed in the solvents having higher miscibility such as Therm S 900 and 800, which are aromatic heat exchange media. Further, the solvents having higher temperature at which p-ABA is completely dissolved during polymerization (Ts) yield a larger number of the whiskers with smaller width. The higher supersaturation of oligomers in less miscible solvents causes the formation of a larger number of nuclei with smaller size. Bundle-like aggregates are formed in the solvents whose Ts is lower than 140°C by the fibrillation of pillar-like crystals during polymerization owing to the reorganization. This shows a clear relationship between the width and Ts, and between the number of the crystals and Ts. Hence, the size of the whisker such as the length and the width can be predicted by the calculation with Ts, which is very valuable for the preparation of POB whiskers for use as industrial materials. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1129–1136, 2003