Gravity induced coalescence in emulsions with high volume fractions of dispersed phase in the presence of surfactants

We report studies on the effect of volume fraction and surfactant concentration on the kinetics of destabilization of emulsions under the influence of gravity. Model oil‐in‐water emulsions, designed to mimic crude oil–water emulsions, were prepared with varying volume fractions of dispersed oil but nearly identical normalized initial drop size distributions. The gravity separation process was observed by periodically withdrawing samples, and examining the droplet size distribution under the microscope. Experiments were performed for three volume fractions of dispersed phase and two surfactant concentrations (0.4 and 1.6% by weight). At higher oil fractions (20%) and a lower surfactant concentration (0.4%), it was observed that although the rate of coalescence increased, the actual oil separation was delayed. At higher surfactant concentrations (1.6%), the dominant factor in suppressing destabilization is the rate of drop to interface coalescence. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4379–4389, 2017     

Intertemporal and interspatial productivity differentials in U.S. manufacturing

This study analyzes the role productivity plays in explaining the variation in regional manufacturing growth rates. Using the neoclassical growth accounting procedure, we measure productivity from an intertemporal and interspatial perspective. Previous regional studies of U.S. manufacturing look only at the contribution of intertemporal productivity growth in explaning regional growth. These studies ignore the level of productivity and its effect on regional growth. For each year of our study, we rank regions by their interspatial productivity index. We find little difference between the productivity growth rates among the regions of the north and south. Differences among the regions emerge only when we consider interspatial productivity differentials. The North's level of factor productivity is 25 to 30% higher than the South's. The absolute productivity disadvantage of the South, however, is offset by its low input prices. Thus, it is the cost advantage of the South and not its productivity advantage that explains the region's relatively high growth rate.     

Adsorptive studies of hazardous dye Tropaeoline 000 from an aqueous phase on to coconut-husk

This contribution presents result pertaining to the adsorptive removal of water-soluble hazardous dye Tropaeoline 000, on to a low cost adsorbent-coconut-husk and its efficiency in the dye colour sorption was compared with activated carbon (AC). The results obtained from the batch experiments revealed the ability of the coconut-husk to remove the Tropaeoline 000 dye. The adsorption of dye was carried out at different pH, temperatures, amount of adsorbent, contact time, concentration of adsorbate (initial dye concentration) and particle size. The adsorption studies revealed that the ongoing adsorption validates both Langmuir and Freundlich adsorption isotherm at temperatures 30, 40 and 50 degrees C. The adsorption isotherm data was also employed to calculate thermodynamic parameters like DeltaG degrees , DeltaH degrees and DeltaS degrees . The negative values of DeltaG degrees indicate that the dye adsorption process is a spontaneous in nature. The positive value of DeltaH degrees shows the endothermic nature of AC/coconut-husk system whereas negative value of DeltaH degrees indicates that the exothermic nature of AC/coconut-husk. The adsorption was found to undergo via a pseudo-second order adsorption kinetics and the results revealed that coconut-husk, an agricultural waste, proved to be an excellent low cost adsorbent.     

Synthesis and characterization of Ni-Mo catalyst using Jatropha curcas leaves as carbon support and its catalytic activity for hydrotreating of gas oil,Jatropha oil,and their blends

A novel carbon-based Ni-Mo catalyst has been synthesized successfully from Jatropha curcas leaves using boric acid as a surface modifying agent. The Ni-Mo catalyst prepared on Jatropha curcas leaves had shown BET surface area of 316 m²/g whereas the Ni-Mo catalyst prepared without boric acid activation had shown BET surface area of only 14 m²/g. XRD and SEM data have shown that the active catalyst particles such as Ni and Mo have been found to be uniformly distributed. The inventive catalyst was studied for hydrotreating of gas oil, Jatropha curcas oil and 20% Jatropha oil in gas oil at 370°C, 90 bar H₂ pressure, liquid hour space velocity of 1 h^?1, and gas-to-oil ratio of 500 Nm³/m³ and the results obtained were found to be comparable with that of the commercial Ni-Mo catalyst supported on alumina.     

Biodosimetry using chromosome aberrations in human lymphocytes

In vitro dose-response calibration curves for (60)Co gamma rays have been established for unstable chromosome aberrations in human peripheral blood lymphocytes. The observed dose-response data were fitted to a linear quadratic model. The calibration curve parameters were used to estimate the equivalent whole-body dose and dose to the irradiated region in partial body irradiation of cancer patients. The derived partial body doses and fractions of lymphocytes irradiated were in agreement with those estimated from the radiotherapy regimes.     

Cuphea a rich source of medium chain triglycerides: Fatty acid composition and oil diversity in Cuphea procumbens

The phenological characteristics, oil content, and fatty acid composition of 34 selections of Cuphea procumbens have been studied. The mean seed yield per plant was 9.7 ± 0.43 g. Maximum seed yield (16.7 g) was noticed in NBC‐27, while the average number of fruits per plant was 124.9 ± 10.7. The oil content in the seeds ranged from 16.7—28.7%, maximum being in NBC‐34. The fatty acid composition revealed the presence of capric acid (C10:0) in all the selections of C. procumbens as the major constituent of the oil ranging from 87.7—94.6%. C. procumbens showed its novelty as an alternative source of capric acid and may be utilized as a renewable resource in the production of plasticizers and lubricants which wholly depend on petrochemical import. Researches are in progress in order to obtain tolerant cultivars against wild plant characteristics and some delayed seed shattering plants have been identified.     

Microstructure of vinylidene chloride-ethyl acrylate copolymers by one- and two-dimensional NMR spectroscopy

Vinylidene chloride/ethyl acrylate (V/E) copolymers were prepared by photopolymerization using uranyl ion as a photosensitizer at room temperature. Copolymers were characterized by chlorine estimation, gel permeation chromatography, ¹H- and ¹³C-NMR, 2D heteronuclear single quantum correlation (HSQC), and homonuclear 1H–2D double quantum filter correlation spectroscopy (DQF-COSY). Reactivity ratios for the copolymerization of V with E were calculated using the Kelen-Tudos (KT) and the nonlinear error in variables (EVM) methods. The reactivity ratios obtained from the EVM methods are r_V = 0.80 ± 0.15 and r_E = 0.87 ± 0.04. The microstructure was calculated in terms of the distribution of V- and E-centered triad sequences from ¹³C{¹H}-NMR spectra of the copolymers. 2D HSQC was used to analyze the complex ¹H-NMR spectrum and 2D COSY shows the various bond interactions, thus inferring the possible structure of the copolymers. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 417–426, 1998     

Comparison of Alkali Metal Promoted MgO Catalysts for Their Surface Acidity/Basicity and Catalytic Activity/Selectivity in the Oxidative Coupling of Methane

Alkali metal (viz. Li, Na, K, Rb and Cs) promoted MgO catalysts (with an alkali metal/Mg ratio of 0·1) calcined at 750°C have been compared for their surface properties (viz. surface area, morphology, acidity and acid strength distribution, basicity and base strength distribution, etc.) and catalytic activity/selectivity in the oxidative coupling of methane (OCM) to C₂-hydrocarbons at different temperatures (700–750°C), CH₄/O₂ ratios (4·0 and 8·0) in feed, and space velocities (10320 cm³ g⁻¹ h⁻¹). The surface and catalytic properties of alkali metal promoted MgO catalysts are found to be strongly influenced by the alkali metal promoter and the calcination temperature of the catalysts. A close relationship between the surface density of strong basic sites and the rate of C₂-hydrocarbons formation per unit surface area of the catalysts has been observed. Among the catalysts calcined at 750°C, the best performance in the OCM is shown by Li–MgO (at 750°C). © 1997 SCI.     

Dielectric spectroscopic studies on polypyrrole glucose oxidase films

An investigation was made into the dielectric spectroscopic characteristics of p-toluene sulfonate (PTS) doped polypyrrole (PPY) films in the presence and absence of immobilized glucose oxidase (GOX) in three different configurations: Al-PTS-PPY-Al-PTS-PPY/GOX-Al, and Al-PTS-PPY/GOX/β-D -glucose-Al, respectively. Measurement of dielectric loss and capacitance yielded valuable information about the dielectric properties of GOX immobilized in PTS doped PPY films. The effect of both the temperature and varying βD -glucose concentrations on the mobility of the charge carriers in these films was also systematically studied. © 1996 John Wiley & Sons, Inc.     

Ultrasensitive detection of cancer biomarkers in the clinic by use of a nanostructured microfluidic array

Multiplexed biomarker protein detection holds unrealized promise for clinical cancer diagnostics due to lack of suitable measurement devices and lack of rigorously validated protein panels. Here we report an ultrasensitive electrochemical microfluidic array optimized to measure a four-protein panel of biomarker proteins, and we validate the protein panel for accurate oral cancer diagnostics. Unprecedented ultralow detection into the 5-50 fg·mL(-1) range was achieved for simultaneous measurement of proteins interleukin 6 (IL-6), IL-8, vascular endothelial growth factor (VEGF), and VEGF-C in diluted serum. The immunoarray achieves high sensitivity in 50 min assays by using off-line protein capture by magnetic beads carrying 400,000 enzyme labels and ~100,000 antibodies. After capture of the proteins and washing to inhibit nonspecific binding, the beads are magnetically separated and injected into the array for selective capture by antibodies on eight nanostructured sensors. Good correlations with enzyme-linked immunosorbent assays (ELISA) for protein determinations in conditioned cancer cell media confirmed the accuracy of this approach. Normalized means of the four protein levels in 78 oral cancer patient serum samples and 49 controls gave clinical sensitivity of 89% and specificity of 98% for oral cancer detection, demonstrating high diagnostic utility. The low-cost, easily fabricated immunoarray provides a rapid serum test for diagnosis and personalized therapy of oral cancer. The device is readily adaptable to clinical diagnostics of other cancers.