Abstract: The pigments covered by film-forming polymers have
opened a prospect to improve the quality of water-based printing
inks. In this study such pigments were prepared by the initiated
polymerization of styrene and methacrylate derivative monomers in
the aqueous pigment dispersions. The formation of polymer films
covering pigment cores depends on the polymerization time and the
ratio of pigment to monomers. At the time of 4 hours and the ratio of
1/10 almost pigment particles are coated by the polymer. The formed
polymer covers of pigments have the average thickness of 5.95 nm.
The size increasing percentage of the coated particles after a week is
4.5 %, about fourteen-fold lower than of the original ones. The
obtained results indicate that the coated pigments are improved
dispersion stability in water medium along with a guarantee for the
optical colour.
Abstract: This paper made an attempt to investigate the problem associated with enhancement of emulsions of light crude oil-water recovery in an oil field of Algerian Sahara. Measurements were taken through experiments using RheoStress (RS600). Factors such as shear rate, temperature and light oil concentration on the viscosity behavior were considered. Experimental measurements were performed in terms of shear stress–shear rate, yield stress and flow index on mixture of light crude oil–water. The rheological behavior of emulsion showed Non-Newtonian shear thinning behavior (Herschel-Bulkley). The experiments done in the laboratory showed the stability of some water in light crude oil emulsions form during consolidate oil recovery process. To break the emulsion using additives may involve higher cost and could be very expensive. Therefore, further research should be directed to find solution of these problems that have been encountered.
Abstract: In this work we investigated the behavior of methane
hydrates dispersed in crude oils from different fields at temperatures
below 0°C. In case of crude oil emulsion the size of water droplets is
in the range of 50e100"m. The size of hydrate particles formed from
droplets is the same. The self-preservation is not expected in this
field. However, the self-preservation of hydrates with the size of
particles 24±18"m (electron microscopy data) in suspensions is
observed. Similar results were obtained for four different kinds of
crude oil and model system such as asphaltenes, resins and wax in ndecane.
This result can allow developing effective methods to prevent
the formation and elimination of gas-hydrate plugs in pipelines under
low temperature conditions (e. g. in Eastern Siberia). There is a
prospective to use experiment results for working out the technology
of associated petroleum gas recovery.
Abstract: In this research, natural canthaxanthin as one of the
most important carotenoids was extracted from Dietzia
natronolimnaea HS-1. The changes of canthaxanthin enriched in oilin-
water emulsions with vegetable oil (5 mg/ 100 mL), Arabic gum (5
mg/100 mL), and potassium sorbate (0.5 g/100 mL) was investigated.
The effects of different pH (3, 5 and 7), as well as, time treatment (3,
18 and 33 days) in the environmental temperature (24°C) on the
degradation were studied by response surface methodology (RSM).
The Hunter values (L*, a*, and b*) and the concentration of
canthaxanthin (C, mg/L) illustrated more degradation of this pigment
at low pHs (pH≤ 4) by passing the time (days≥10) with R² 97.00%,
91.31%, 97.60%, and 99.54% for C, L*, a*, and b* respectively. The
predicted model were found to be significant (p
Abstract: In vitro gastro-duodenal digestion model was used to investigate the changes of emulsions under digestion conditions. Oil in water emulsions stabilized by whey proteins (2%) and stabilized by whey proteins (2%) with addition of carboxymethyl cellulose (0.75%) as gelling agent of continuous phase were prepared at pH7. Both emulsions were destabilized under gastric conditions; however the protective role of carboxymethyl cellulose was indicated by recording delay of fat digestibility of this emulsion. In the presence of carboxymethyl cellulose whey proteins on the interfacial surface of droplets were more resistant to gastric degradation causing limited hydrolysis of fat due to the poor acceptability of lipids for the enzymes. Studies of emulsions using in vivo model supported results from in vitro studies. Lower content of triglycerides in blood serum and higher amount of fecal fat of rats were determined when rats were fed by diet containing emulsion made with whey proteins and carboxymethyl cellulose.
Abstract: This study was carried out to develop a flotation
procedure for an oxide copper ore from a Region in Central Africa
for producing an 18% copper concentrate for downstream processing
at maximum recovery from a 4% copper feed grade. The copper
recoveries achieved from the test work were less than 50% despite
changes in reagent conditions (multistage sulphidisation, use of RCA
emulsion and mixture, use of AM 2, etc). The poor recoveries were
attributed to the mineralogy of the ore from which copper silicates
accounted for approximately 70% (mass) of the copper minerals in
the ore. These can be complex and difficult to float using
conventional flotation methods. Best results were obtained using
basic sulphidisation procedures, a high flotation temperature and
extended flotation residence time.
Abstract: The aim of this study was to compare the
sensitometric properties of commonly used radiographic films
processed with chemical solutions in different workload hospitals.
The effect of different processing conditions on induced densities on
radiologic films was investigated. Two accessible double emulsions
Fuji and Kodak films were exposed with 11-step wedge and
processed with Champion and CPAC processing solutions. The
mentioned films provided in both workloads centers, high and low.
Our findings displays that the speed and contrast of Kodak filmscreen
in both work load (high and low) is higher than Fuji filmscreen
for both processing solutions. However there was significant
differences in films contrast for both workloads when CPAC solution
had been used (p=0.000 and 0.028). The results showed base plus
fog density for Kodak film was lower than Fuji. Generally Champion
processing solution caused more speed and contrast for investigated
films in different conditions and there was significant differences in
95% confidence level between two used processing solutions
(p=0.01). Low base plus fog density for Kodak films provide more
visibility and accuracy and higher contrast results in using lower
exposure factors to obtain better quality in resulting radiographs. In
this study we found an economic advantages since Champion
solution and Kodak film are used while it makes lower patient dose.
Thus, in a radiologic facility any change in film processor/processing
cycle or chemistry should be carefully investigated before
radiological procedures of patients are acquired.
Abstract: Most of ignition delay correlations studies have been
developed in a constant volume bombs which cannot capture the
dynamic variation in pressure and temperature during the ignition
delay as in real engines. Watson, Assanis et. al. and Hardenberg
and Hase correlations have been developed based on experimental
data of diesel engines. However, they showed limited predictive
ability of ignition delay when compared to experimental results. The
objective of the study was to investigate the dependency of ignition
delay time on engine brake power. An experimental investigation of
the effect of automotive diesel and water diesel emulsion fuels on
ignition delay under steady state conditions of a direct injection diesel
engine was conducted. A four cylinder, direct injection naturally
aspirated diesel engine was used in this experiment over a wide range
of engine speeds and two engine loads. The ignition delay
experimental data were compared with predictions of Assanis et. al.
and Watson ignition delay correlations. The results of the
experimental investigation were then used to develop a new ignition
delay correlation. The newly developed ignition delay correlation has
shown a better agreement with the experimental data than Assanis et.
al. and Watson when using automotive diesel and water diesel
emulsion fuels especially at low to medium engine speeds at both
loads. In addition, the second derivative of cylinder pressure which is
the most widely used method in determining the start of combustion
was investigated.
Abstract: Nanoemulsions are a class of emulsions with a droplet
size in the range of 50–500 nm and have attracted a great deal of
attention in recent years because it is unique characteristics. The
physicochemical properties of nanoemulsion suggests that it can be
successfully used to recover the residual oil which is trapped in the
fine pore of reservoir rock by capillary forces after primary and
secondary recovery. Oil-in-water nanoemulsion which can be formed
by high-energy emulsification techniques using specific surfactants
can reduce oil-water interfacial tension (IFT) by 3-4 orders of
magnitude. The present work is aimed on characterization of oil-inwater
nanoemulsion in terms of its phase behavior, morphological
studies; interfacial energy; ability to reduce the interfacial tension and
understanding the mechanisms of mobilization and displacement of
entrapped oil blobs by lowering interfacial tension both at the
macroscopic and microscopic level. In order to investigate the
efficiency of oil-water nanoemulsion in enhanced oil recovery
(EOR), experiments were performed to characterize the emulsion in
terms of their physicochemical properties and size distribution of the
dispersed oil droplet in water phase. Synthetic mineral oil and a series
of surfactants were used to prepare oil-in-water emulsions.
Characterization of emulsion shows that it follows pseudo-plastic
behaviour and drop size of dispersed oil phase follows lognormal
distribution. Flooding experiments were also carried out in a
sandpack system to evaluate the effectiveness of the nanoemulsion as
displacing fluid for enhanced oil recovery. Substantial additional
recoveries (more than 25% of original oil in place) over conventional
water flooding were obtained in the present investigation.
Abstract: The effect of concentration of reduction agent of
sodium borohydrate (NaBH4) on the properties of silicon
nanoparticles synthesized via microemulsion route is reported. In
this work, the concentration of the silicon tetrachloride (SiCl4) that
served as silicon source with sodium hydroxide (NaOH) and
polyethylene glycol (PEG) as stabilizer and surfactant, respectively,
are keep fixed. Four samples with varied concentration of NaBH4
from 0.05 M to 0.20 M were synthesized. It was found that the lowest
concentration of NaBH4 gave better formation of silicon
nanoparticles.
Abstract: This study was designed to formulate,
pharmaceutically evaluate a topical skin-care cream (w/o emulsion)
of Aloe Vera versus its vehicle (Base) as control and determine their
effects on Stratum Corneum (SC) water content and Transepidermal
water loss (TEWL). Base containing no extract and a Formulation
containing 3% concentrated extract of Aloe Vera was developed by
entrapping in the inner aqueous phase of w/o emulsion (cream).
Lemon oil was incorporated to improve the odor. Both the Base and
Formulation were stored at 8°C ±0.1°C (in refrigerator), 25°C±0.1°C,
40°C±0.1°C and 40°C± 0.1°C with 75% RH (in incubator) for a
period of 4 weeks to predict their stability. The evaluation parameters
consisted of color, smell, type of emulsion, phase separation,
electrical conductivity, centrifugation, liquefaction and pH. Both the
Base and Formulation were applied to the cheeks of 21 healthy
human volunteers for a period of 8 weeks Stratum corneum (SC)
water content and Transepidermal water loss (TEWL) were
monitored every week to measure any effect produced by these
topical creams. The expected organoleptic stability of creams was
achieved from 4 weeks in-vitro study period. Odor was disappeared
with the passage of time due to volatilization of lemon oil. Both the
Base and Formulation produced significant (p≤0.05) changes in
TEWL with respect to time. SC water content was significantly
(p≤0.05) increased by the Formulation while the Base has
insignificant (p 0.05) effects on SC water content. The newly
formulated cream of Aloe Vera, applied is suitable for improvement
and quantitative monitoring of skin hydration level (SC water
content/ moisturizing effects) and reducing TEWL in people with dry
skin.
Abstract: The present paper deals with problems related to the
possibilities to use fractal systems to solve some important scientific
and practical problems connected with filtering and separation of
aqueous phases from organic ones. For this purpose a special
separator have been designed. The reactor was filled with a porous
material with fractal dimension, which is an integral part of the set
for filtration and separation of emulsions. As a model emulsion
hexadecan mixture with water in equal quantities (1:1) was used. We
examined the hydrodynamics of the separation of the emulsion at
different rates of submission of the entrance of the reactor.
Abstract: Interaction effects of xanthan gum (XG), carboxymethyl
cellulose (CMC), and locust bean gum (LBG) on the flow properties
of oil-in-water emulsions were investigated by a mixture design
experiment. Blends of XG, CMC and LBG were prepared according
to an augmented simplex-centroid mixture design (10 points) and used
at 0.5% (wt/wt) in the emulsion formulations. An appropriate
mathematical model was fitted to express each response as a function
of the proportions of the blend components that are able to
empirically predict the response to any blend of combination of the
components. The synergistic interaction effect of the ternary
XG:CMC:LBG blends at approximately 33-67% XG levels was
shown to be much stronger than that of the binary XG:LBG blend at
50% XG level (p < 0.05). Nevertheless, an antagonistic interaction
effect became significant as CMC level in blends was more than 33%
(p < 0.05). Yield stress and apparent viscosity (at 10 s-1) responses
were successfully fitted with a special quartic model while flow
behaviour index and consistency coefficient were fitted with a full
quartic model (R2
adjusted ≥ 0.90). This study found that a mixture
design approach could serve as a valuable tool in better elucidating
and predicting the interaction effects beyond the conventional twocomponent
blends.
Abstract: Aim of this work was to compare the efficacy of two
loading methods of proteins onto polymeric nanocarriers: adsorption
and encapsulation methods. Preliminary studies of protein loading
were done using Bovine Serum Albumin (BSA) as model protein.
Nanocarriers were prepared starting from polylactic co-glycolic acid
(PLGA) polymer; production methods used are two different variants
of emulsion evaporation method. Nanoparticles obtained were
analyzed in terms of dimensions by Dynamic Light Scattering and
Loading Efficiency of BSA by Bradford Assay. Loaded
nanoparticles were then submitted to in-vitro protein dissolution test
in order to study the effect of the delivery system on the release rate
of the protein.
Abstract: Antimosy-doped tin oxide (ATO) particles were
prepared via chemical coprecipitation and reverse emulsion. The size
and size distribution of ATO particles were obviously decreased via
reverse microemulsion method. At the relatively high yield the ATO
particles were nearly spherical in shape, meanwhile the crystalline
structure and excellent conductivity were reserved, which could satisfy
the requirement as composite fillers, such as dielectric filler of
polyimide film.
Abstract: The spores of entomopathogenic fungi, Beauveria bassiana was evaluated for their compatibility with four surfactants; SDS (sodium dodyl sulphate) and CABS-65 (calcium alkyl benzene sulphonate), Tween 20 (polyethylene sorbitan monolaureate) and Tween 80 (polyoxyethylene sorbitan monoleate) at six different concentrations (0.1%, 0.5%, 1%, 2.5%, 5% and 10%). Incubated spores showed decrease in concentrations due to conversion of spores to hyphae. The maximum germination recorded in 72 h incubated spores varied with surfactant concentration at 49-68% (SDS), 39- 53% (CABS), 78-92% (Tween 80) and 80-92% (Tween 20), while the optimal surfactant concentration for spore germination was found to be 2.5-5%. The surfactant effect on spores was more pronounced with SDS and CABS-65, where significant deterioration and loss in viability of the incubated spores was observed. The effect of Tween 20 and Tween 80 were comparatively less inhibiting. The results of the study would help in surfactant selection for B. bassiana emulsion preparation.
Abstract: The paper presents a one-dimensional transient
mathematical model of thermal oil-water two-phase emulsion flows
in pipes. The set of the mass, momentum and enthalpy conservation
equations for the continuous fluid and droplet phases are solved. Two
friction correlations for the continuous fluid phase to wall friction are
accounted for in the model and tested. The aerodynamic drag force
between the continuous fluid phase and droplets is modeled, too. The
density and viscosity of both phases are assumed to be constant due
to adiabatic experimental conditions. The proposed mathematical
model is validated on the experimental measurements of oil-water
emulsion flows in horizontal pipe [1,2]. Numerical analysis on
single- and two-phase oil-water flows in a pipe is presented in the
paper. The continuous oil flow having water droplets is simulated.
Predictions, which are performed by using the presented model, show
excellent agreement with the experimental data if the water fraction is
equal or less than 10%. Disagreement between simulations and
measurements is increased if the water fraction is larger than 10%.
Abstract: The mechanism of microwave heating is essentially
that of dielectric heating. After exposing the emulsion to the
microwave Electromagnetic (EM) field, molecular rotation and ionic
conduction due to the penetration of (EM) into the emulsion are
responsible for the internal heating. To determine the capability of
microwave technology in demulsification of crude oil emulsions,
microwave demulsification method was applied in a 50-50 % and 20-
80 % water-in-oil emulsions with microwave exposure time varied
from 20-180 sec. Transient temperature profiles of water-in-oil
emulsions inside a cylindrical container were measured. The
temperature rise at a given location was almost horizontal (linear).
The average rates of temperature increase of 50-50 % and 20-80 %
water-in-oil emulsions are 0.351 and 0.437 oC/sec, respectively. The
rate of temperature increase of emulsions decreased at higher
temperature due to decreasing dielectric loss of water. These results
indicate that microwave demulsification of water-in-oil emulsions
does not require chemical additions. Microwave has the potential to
be used as an alternative way in the demulsification process.
Abstract: This study was conducted in order to determine the physical properties and stability of mayonnaise-like emulsions as affected by modified yam starches. Native yam starch was modified via pre-gelatinization and cross-linking phosphorylation procedures. The emulsions (50% oil dispersed phase) were prepared with 0.3% native potato, native yam, pre-gelatinized yam and cross-linking phosphorylation yam starches. The droplet size of surface weighted mean diameter was found to be significantly (p < 0.05) lower in the sample with cross-linking phosphorylation yam starch as compared to other samples. Moreover, the viscosity of the sample with pregelatinized yam starch was observed to be higher than that of other samples. The phase separation stability was low in the freshly prepared and stored (45 days, 5°C) emulsions containing native yam starch. This study thus generally suggested that modified yam starches were more suitable (i.e. better physical properties and stability) to be used as stabilizers in a similar system i.e. light mayonnaises, rather than a native yam starch.
Abstract: A new generation product made from bamboo strips,
known as laminated bamboo, has gained importance. The objective
of this research was to experiment the effect of three factors on the
mechanical property of laminated bamboo. The interested factors for
experimental design were (A) four bamboo species, namely Bambusa
blumeana Schultes (Pai See Suk), Dendrocalamus asper Backer (Pai
Tong), Dendrocalamus hamiltonii Nees (Pai Hok) and
Dendrocalamus sericeus Munro (Pai Sang Mon), (B) two types of
glue adhesive, polyvinyl acetate emulsion (PVAC) fortified with
urea-formaldehyde (UF) and urea-formaldehyde (UF) to make
parallel-oriented bamboo strips laminates and (C) glue weight per
strip area, 150 g/m2 and 190 g/m2. Experimental results showed that
Dendrocalamus asper Backer (Pai Tong) and Dendrocalamus
sericeus Munro (Pai Sang Mon) were best used for manufacturing
due to their highest MOR and MOE. The amount of glue weight 150
g/m2 yielded higher MOR and MOE than the amount of glue weight
190 g/m2. At the conclusion, the laminated bamboo manufacturers
can benefit from this research in order to select right materials
according to strength, cost and accessibility.