Mixture Of Paraffin Oil Research Articles

Continuous stationary phase gradient preparation on planar chromatographic media using vapor phase deposition of silane

A new, versatile, and straightforward vapor phase deposition (VPD) approach was used to prepare continuous stationary phase gradients (cSPGs) on silica thin-layer chromatography (TLC) plates using phenyldimethylchlorosilane (PDCS) as a precursor. A mixture of paraffin oil and PDCS was placed at the bottom of an open-ended rectangular chamber, allowing the reactive silanes to evaporate and freely diffuse under a controlled atmosphere. As the volatile silane diffused across the length of the TLC plate, it reacted with the surface silanol groups thus functionalizing the surface in a gradient fashion. Characterization of the gradient TLC plates was done through UV visualization and diffuse reflectance spectroscopy (DRS). Visualizing the fluorescent gradient plates under UV radiation shows the clear presence of a gradient with the side closest to the vapor source undergoing the most modification. More quantitative characterization of the shape of the gradient was provided by DRS. The DRS showed that the degree of modification and shape of the gradient was dependent on the concentration of silane, VPD time, and relative humidity. To evaluate the chromatographic performance, a mixture of three aromatic compounds (acetaminophen (A), aspirin (As), and 3-hydroxy-2-naphthoic acid (3H)) was spotted on the high (GHP) and low phenyl (GLP) ends of the gradient TLC plates and the results compared to the separations carried out on unmodified and uniformly modified plates. The GHP TLC plates showed retention factors (Rf) of 0.060 ± 0.006, 0.391 ± 0.006, and 0.544 ± 0.006, whereas the unmodified plate displayed Rf values of 0.059 ± 0.006, 0.092 ± 0.003, and 0.037 ± 0.002 for the analytes A, As, and 3H, respectively. From the Rf values, it was observed that each modified plate exhibited different selectivity for the analytes. The GHP TLC plates exhibited better separation performance, and improved resolution compared to the GLP, unmodified, and uniformly modified plates. Overall, VPD is a new, cost-effective method for creating a gradient on the stationary phase which has the potential to advance chromatographic separation capabilities.

An Efficient Switching-Off of Coherent Anti-Stokes Raman Scattering via Double Stimulated Raman Scattering Processes of Heteromolecular Vibrational Modes.

Recently, we introduced a new switching-off technique applicable to subdiffraction-limited coherent Raman imaging, where a coherent anti-Stokes Raman scattering (CARS) signal can be selectively suppressed via competitive stimulated Raman scattering (SRS) processes between vibrational modes of a single molecular species. Here, we show that such a three-beam CARS suppression can be made via double SRS processes between vibrational modes of heteromolecular species, a mixture of paraffin oil and benzene. We achieve more than 80% suppression of the pump-Stokes-beam CARS signal for the ring-breathing mode (target mode) of benzene when the C-H stretching mode (acceptor mode) of paraffin oil is used to deplete the pump photons via the pump-depletion-beam SRS process. The freedom in the choice of acceptor mode for depletion, which could be a critical advantage of the present switching-off scheme, can be of use for overcoming current challenges of depletion-based super-resolution coherent Raman imaging of biomolecules.

Cerebral gustatory activation in response to free fatty acids using gustatory evoked potentials in humans

There is some evidence of specific oro-detection of FFAs in rodents and humans. The aim of this study was to record gustatory evoked potentials (GEPs) in response to FFA solutions and to compare GEPs in response to linoleic acid solution with GEPs obtained after stimulation with sweet and salty tastants. Eighteen healthy men were randomly stimulated with fatty (linoleic acid), sweet (sucrose), and salty (NaCl) solutions at two concentrations in the first experiment. Control recordings (n = 14) were obtained during stimulation by a paraffin oil mixture without FFA or by water. In the second experiment, 28 men were randomly stimulated with five FFA solutions and a paraffin emulsion. GEPs were recorded with electroencephalographic electrodes at Cz, Fz, and Pz. GEPs were observed in response to FFA in all participants. GEP characteristics did not differ according to the quality and the concentration of the solutions in the first experiment and according to the FFA in the second experiment. This study describes for the first time GEPs in response to FFA and demonstrates that the presence of FFA in the mouth triggers an activation of the gustatory cortex. These data reinforce the concept that fat taste could be the sixth primary taste.

Experiments on Reducing Negative Skin Friction of Piles

The objective of this study was to investigate the effect of different moisture contents of clay (13%, 15%, 17%, 19%, and 21%) and different coatings on the ability to reduce negative skin friction during a large‐scale shear test. Four coating treatments of the concrete surface were investigated, i.e., no treatment, coating with a paraffin‐oil mixture, coating with a polymer nanomaterial, and coating with paint. The results showed that when the moisture content of the clay was slightly larger than that of the plastic limit, the ability to reduce negative skin friction was the best, and the performance was similar for the paraffin‐oil mixture, the polymer nanomaterial, and the paint. When the moisture content of the clay was lower than that of the plastic limit, the paraffin‐oil mixture provided the best performance. The position of the neutral point can be determined by different methods, and the negative skin friction of piles should be reduced by applying coatings that are most suitable to different conditions.

Force and Deformation of a Shallow Soil-Buried Super-Long Box Culvert during Jacking Construction on a Highway

An example of a project on an oversized box culvert jacked into highway subgrade in Guangdong area was investigated to determine the mechanical behavior of shallow soil-covered super-long box culvert in the jacking construction process. On the basis of 3D finite element simulation, the law for stress-strain change and the effective construction area of the box were studied by considering different lengths and thicknesses and drag reduction versus non-drag reduction of overburden soil. Result shows that under the same working condition, the stress-strain of the roof and bottom plate exhibits an 'armchair' change shape with an increase in jacking length, whereas the side wall presents a 'trapezoid' shape in the box culvert jacking process. The thickness and characteristics of the covered soil (on top of the box culvert) exert considerable influences on the stress-strain of the box culvert structure. If the covered soil is thick and dense, then the stress-strain of the structure will be high. The pavement (on top of the box culvert) settlement ranges from 7.0-17.1 mm due to the effect of vibrations produced during box culvert jacking construction, and the scope of the disturbed roadbed and road surface is 23-30 m along the jacking direction. The drag reduction effect of the paraffin oil mixture is more effective than that of slurry drag reduction. The research results will play a significant guiding role in the design and construction of similar projects.

Formulation and Characterization of Potential Antifungal Oleogel with Essential Oil of Thyme.

The aim of this research was to formulate oleogel with thyme essential oil with potential antimicrobial activity, design optimal formulation, and evaluate the influence of ingredients on texture parameters of preparation. Central composite design was applied to statistical optimization of colloidal silica and paraffin oil mixture for the modeling of oleogel delivery system. The influence of designed formulations on response variables (texture parameters), firmness, cohesiveness, consistency, and index of viscosity, was evaluated. Quality of essential oil of thyme was assessed by determinate concentration of thymol and carvacrol using gas chromatography with flame ionization detection (GC-FID). Microbiological tests have shown that oleogel with thyme essential oil affects Candida albicans microorganism when thyme essential oil's concentration is 0,05% in oleogel mixture.

Influence of Sophorolipid Structure on Interfacial Properties of Aqueous‐Arabian Light Crude and Related Constituent Emulsions

AbstractSophorolipids (SLs) offer an “environmentally friendly” alternative to chemically produced surfactants currently used in formulations for crude oil extraction, processing, and reclamation. Studies herein describe how sophorolipid structure influences its interfacial properties for environmentally and industrially relevant oil–water systems where the oil phase is Arabian light crude oil, paraffin oil, decane, hexadecane, a 1:1 vol/vol mixture of o‐xylene and 1,2‐dimethylcyclohexane, or a mixture of paraffin oil, o‐xylene, and 1,2‐dimethylcyclohexane (synthetic crude oil). SL‐hexyl ester (SL‐HE) reduces the crude oil–water interfacial tension (IFT) by 57 and 91% at 0.001 and 0.5 mg/mL, respectively. Crude oil displacement tests reveal that SL‐ethyl ester (SL‐EE) and SL‐HE contract a crude oil slick on water to about 20% of its starting volume allowing for easier burning of spilled crude oil on marine surfaces. Water retention and emulsion phase (e.g., o/w vs. w/o) are determined by SL‐structure/concentration, oil concentration, and oil composition to understand their performance for crude oil transportation and clean‐up. For the first time, w/o emulsions were obtained using SLs and their formation occurred after homogenization when the oil phase consisted of a 1:1 mixture of o‐xylene and 1,2‐dimethylcyclohexane. Generally, the performance of SL‐esters in the above studies was superior to that using Triton X‐100, a comparison nonionic surfactant. Hence, SL‐esters offer a valuable platform for tuning interfacial properties to optimize surfactant performance.

Detection and analysis of paraffin oil adulteration in coconut oil using fiber optic long period grating sensor

A fiber optic sensing system for the detection of adulteration of coconut oil by paraffin oil is experimentally demonstrated. The sensing mechanism is based on the sensitive dependence of the resonance peaks of a long period grating (LPG) on the changes of the refractive index of the environmental medium surrounding the cladding surface of the grating. The wavelength shift of the attenuation bands of the LPG was measured with the sensor immersed in a mixture of paraffin oil and pure coconut oil in different proportions. Detection limit of adulteration was found to be 3% for coconut oil–paraffin oil binary mixture.

Comparative Analysis of Potential, Current, and Electrolyte Resistance Fluctuations in Two-Phase Oil/Water Mixtures

Abstract The fluctuations of potential, current, and electrolyte resistance generated by uniform corrosion processes on a mild-steel rotating disk electrode in a mixture of paraffin oil and brine have been measured. The mixture composition has been varied to assess the possibility of characterizing the type of hydrodynamic flow from the noise measurements. Results have shown that, contrary to electrochemical potential and current noise, electrolyte resistance fluctuations, both in the time and frequency domains, are a highly sensitive parameter for monitoring changes in the flow composition.

Relationship between Hardness of Wax-Oil Mixtures and Physico-Chemical Properties of Oils

The hardness of a mixture prepared from a heat-dissolved solution of a wax and oil for cosmetics varied with the properties of the oil used. These properties were thus examined so as to clarify the mechanism for variation in hardness.The hardness of solid paraffin-oil mixture was found to be closely related to the solubility (g/100g solution) of solid paraffin in the oil used. That is, a solid paraffin-oil mixture comprising the oil with a lower solubility of solid paraffin gave rise to a higher degree of hardness. For a carnauba wax-oil mixture, the same relationship between hardness and solubility as that of the solid paraffin-oil mixture was found. Consequently, in the preparation of mixtures of a wax and various oils, their hardness can be predicted on the basis of the solubility of wax in the oils, which in turn can be estimated from the solubility parameters of the wax and the oil, as well as from the oil molecular weights.

Murine Thyroiditis: Importance of Adjuvant and Mouse Strain for the Induction of Thyroid Lesions

Abstract For the production of experimental autoimmune thyroiditis in the mouse comparison of two preparations of complete Freund's adjuvant showed that one, using n-hexadecane and glycerol mono-oleate with freshly harvested tubercle bacilli, was more effective in eliciting both dermal hypersensitivity and thyroid lesions than a mixture of paraffin oil and mannide mono-oleate with dried tubercle bacilli. Both preparations were of comparable efficiency in eliciting thyroid-specific antibodies detected by passive hemagglutination. With either adjuvant, randomly bred CF-1 mice were consistently more susceptible to the induction of thyroid lesions than were inbred C3H mice. When the paraffin oil adjuvant was used, C3H mice developed no lesions despite high titers of circulating antibody.