Abstract: The objective of this study was to develop vaginal
suppository containing lactobacillus. Four kinds of vaginal
suppositories containing Lactobacillus paracasei HL32 were
formulated: 1) a conventional suppository with Witepsol H-15 as a
base, 2) a conventional suppository with mixed polyethylene glycols
(PEGs) as a base, 3) a hollow-type suppository with Witepsol H-15
as a base and 4) a hollow-type suppository with mixed PEGs as a
base. The release studies demonstrated that the hollow-type
suppository with mixed PEGs as the base gave the highest release of
L. paracasei HL32 and was microbiological stable after storage at 2-
8°C over the period of 3 months.
Abstract: Indium-tin oxide films are deposited by low plasma
temperature RF sputtering on highly flexible modification of glycol
polyethyleneterephtalate substrates. The produced layers are
characterized with transparency over 82 % and sheet resistance of
86.9 Ω/square. The film’s conductivity was further improved by
additional UV illumination from light source (365 nm), having power
of 250 W. The influence of the UV exposure dose on the structural
and electro-optical properties of ITO was investigated. It was
established that the optimum time of illumination is 10 minutes and
further UV treatment leads to polymer substrates degradation.
Structural and bonds type analysis show that at longer treatment
carbon atoms release and diffuse into ITO films, which worsen their
electrical behavior. For the optimum UV dose the minimum sheet
resistance was measured to be 19.2 Ω/square, and the maximum
transparency remained almost unchanged – above 82 %.
Abstract: A biosensor based on glucose oxidase (GOx) immobilized onto nanoparticles zirconium oxide with polyethylene nanocomposite for glucose monitoring has been designed. The CTAB/PEG/ZrO2/GOx nanocomposite was deposited onto screen printed carbon paste (SPCE) electrode via spin coating technique. The properties of CTAB/PEG/ZrO2/GOx were study using scanning electron microscopy (SEM). The SPE modified with the CTAB/PEG/ZrO2/GOx showed electrocatalytical response to the oxidation of glucose when ferrocene carboxaldehyde was used as an artificial redox mediator, which was studied by cyclic voltammetry (CV). Several parameters such as working potential, effect of pH and effect of ZrO2/PEG layers that governed the analytical performance of the biosensor, have been studied. The biosensor was applied to detect glucose with a linear range of 0.4 to 2.0 mmol L−1 with good repetability and reproducibility.
Abstract: Nonspecific protein adsorption generally occurs on
any solid surfaces and usually has adverse consequences. Adsorption
of proteins onto a solid surface is believed to be the initial and
controlling step in biofouling. Surfaces modified with end-tethered
poly(ethylene glycol) (PEG) have been shown to be protein-resistant
to some degree. In this study, the adsorption of β-casein and
lysozyme was performed on 6 different types of surfaces where PEG
was tethered onto stainless steel by polyethylene imine (PEI) through
either OH or NHS end groups. Protein adsorption was also performed
on the bare stainless steel surface as a control. The adsorption was
conducted at 23 °C and pH 7.2. In situ QCM-D was used to
determine PEG adsorption kinetics, plateau PEG chain densities,
protein adsorption kinetics and plateau protein adsorbed quantities.
PEG grafting density was the highest for a NHS coupled chain,
around 0.5 chains / nm2. Interestingly, lysozyme which has smaller
size than β-casein, appeared to adsorb much less mass than that of β-
casein. Overall, the surface with high PEG grafting density exhibited
a good protein rejection.
Abstract: The pyrolysis of hazelnut shell, polyethylene oxide and their blends were carried out catalytically at 500 and 650 ºC. Potassium dichromate was chosen according to its oxidative characteristics and decomposition temperature (500 ºC) where decomposition products are CrO3 and K2CrO4. As a main effect, a remarkable increase in gasification was observed using this catalyst for pure components and blends especially at 500 ºC rather than 650 ºC contrary to the main observation in the pyrolysis process. The increase in gas product quantity was compensated mainly with decrease in solid product and additionally in some cases liquid products.
Abstract: Liquid-liquid extraction is a process using two immiscible
liquids to extract compounds from one phase without high
temperature requirement. Mostly, the technical implementation of
this process is carried out in mixer-settlers or extraction columns. In
real chemical processes, chemicals may have high viscosity and
contain impurities. These impurities may change the settling behavior
of the process without measurably changing the physical properties
of the phases. In the current study, the settling behavior and the affected
parameters in a high-viscosity system were observed. Batchsettling
experiments were performed to experimentally quantify the
settling behavior and the mixer-settler model of Henschke [1] was
used to evaluate the behavior of the toluene + water system. The
viscosity of the system was increased by adding polyethylene glycol
4000 to the aqueous phase. NaCl and Na2SO4 were used to study the
influence of electrolytes. The results from this study show that increasing
the viscosity of water has a higher influence on the settling
behavior in comparison to the effects of the electrolytes. It can be
seen from the experiments that at high salt concentrations, there was
no effect on the settling behavior.
Abstract: Extraction of laccase produced by L. polychrous in an
aqueous two-phase system, composed of polyethylene glycol and
phosphate salt at pH 7.0 and 250C was investigated. The effect of
PEG molecular weight, PEG concentration and phosphate
concentration was determined. Laccase preferentially partitioned to
the top phase. Good extraction of laccase to the top phase was
observed with PEG 4000. The optimum system was found in the
system containing 12% w/w PEG 4000 and 16% w/w phosphate salt
with KE of 88.3, purification factor of 3.0-fold and 99.1% yield.
Some properties of the enzyme such as thermal stability, effect of
heavy metal ions and kinetic constants were also presented in this
work. The thermal stability decreased sharply with high temperature
above 60 0C. The enzyme was inhibited by Cd2+, Pb2+, Zn2+ and
Cu2+. The Vmax and Km values of the enzyme were 74.70
μmol/min/ml and 9.066 mM respectively.
Abstract: In order to study of hydropriming and halopriming on
germination and early growth stage of wheat (Triticum aestivum) an
experiment was carried out in laboratory of the Department of
Agronomy and Plant breeding, Shahrood University of Technology.
Seed treatments consisted of T1: control (untreated seeds), T2:
soaking in distilled water for 18 h (hydropriming). T3: soaking in -
1.2 MPa solution of CaSO4 for 36 h (halopriming). Germination and
early seedling growth were studied using distilled water (control) and
under osmotic potentials of -0.4, -0.8 and -1.2 MPa for NaCl and
polyethylene glycol (PEG 6000), respectively. Results showed that
Hydroprimed seeds achieved maximum germination seedling dry
weight, especially during the higher osmotic potentials. Minimum
germination was recorded at untreated seeds (control) followed by
osmopriming. Under high osmotic potentials, hydroprimed seeds had
higher GI (germination index) as compared to haloprimed or
untreated seeds. Interaction effect of seed treatment and osmotic
potential significantly affected the seedling vigour index (SVI).
Abstract: In this paper, an automated system is presented for
identification and separation of plastic resins based on near infrared
(NIR) reflectance spectroscopy. For identification and separation
among resins, a "Two-Filter" identification method is proposed that
is capable to distinguish among polyethylene terephthalate (PET),
high density polyethylene (HDPE), polyvinyl chloride (PVC),
polypropylene (PP) and polystyrene (PS). Through surveying effects
of parameters such as surface contamination, sample thickness, label
and cap existence, it was obvious that the "Two-Filter" method has a
high efficiency in identification of resins. It is shown that accurate
identification and separation of five major resins can be obtained
through calculating the relative reflectance at two wavelengths in the
NIR region.
Abstract: In the process of polyethylene extrusion polymer
material similar to powder or granule is under compression, melting
and transmission operation and on base of special form, extrudate has
been produced. Twin-screw extruders are applicable in industries
because of their high capacity. The powder mixing with chemical
additives and melting with thermal and mechanical energy in three
zones (feed, compression and metering zone) and because of gear
pump and screw's pressure, converting to final product in latest plate.
Extruders with twin-screw and short distance between screws are
better than other types because of their high capacity and good
thermal and mechanical stress.
In this paper, process of polyethylene extrusion and various tapes
of extruders are studied. It is necessary to have an exact control on
process to producing high quality products with safe operation and
optimum energy consumption.
The granule size is depending on granulator motor speed. Results
show at constant feed rate a decrease in granule size was found whit
Increase in motor speed. Relationships between HDPE feed rate and
speed of granulator motor, main motor and gear pump are calculated
following as:
x = HDPE feed flow rate, yM = Main motor speed
yM = (-3.6076e-3) x^4+ (0.24597) x^3+ (-5.49003) x^2+ (64.22092)
x+61.66786 (1)
x = HDPE feed flow rate, yG = Gear pump speed
yG = (-2.4996e-3) x^4+ (0.18018) x^3+ (-4.22794) x^2+ (48.45536)
x+18.78880 (2)
x = HDPE feed flow rate, y = Granulator motor speed
10th Degree Polynomial Fit: y = a+bx+cx^2+dx^3... (3)
a = 1.2751, b = 282.4655, c = -165.2098,
d = 48.3106, e = -8.18715, f = 0.84997
g = -0.056094, h = 0.002358, i = -6.11816e-5
j = 8.919726e-7, k = -5.59050e-9
Abstract: Utilization of waste material in asphalt pavement
would be beneficial in order to find an alternative solution to increase
service life of asphalt pavement and reduce environmental pollution
as well. One of these waste materials is Polyethylene Terephthalate
(PET) which is a type of polyester material and is produced in a large
extent. This research program is investigating the effects of adding
waste PET particles into the asphalt mixture with a maximum size of
2.36 mm. Different percentages of PET were added into the mixture
during dry process. Gap-graded mixture (SMA 14) and PG 80-100
asphalt binder have been used for this study. To evaluate PET
reinforced asphalt mixture different laboratory investigations have
been conducted on specimens. Marshall Stability test was carried
out. Besides, stiffness modulus test and indirect tensile fatigue test
were conducted on specimens at optimum asphalt content. It was
observed that in many cases PET reinforced SMA mixture had better
mechanical properties in comparison with control mixture.
Abstract: Bottle water is getting very popular all through the
world; especially in the gulf countries as the main source of drinking
water. However, concerns over leaching of toxic chemicals are
increasing. In this study, a health risk assessment was conducted in
accordance with the guidelines indicated by United States
Environmental Protection Agency (USEPA). It is conducted based on
leaching of Diethyl Phthalate (DEP) from Polyethylene terephthalate
(PET). The toxicity and exposure assessment of diethyl phthalate was
conducted to characterize its risk on human health. Risk management
is also discussed.
Abstract: This paper presents a part of research on the
rheological properties of bitumen modified by thermoplastic namely
linear low density polyethylene (LLDPE), high density polyethylene
(HDPE) and polypropylene (PP) and its interaction with 80 pen base
bitumen. As it is known that the modification of bitumen by the use
of polymers enhances its performance characteristics but at the same
time significantly alters its rheological properties. The rheological
study of polymer modified bitumen (PMB) was made through
penetration, ring & ball softening point and viscosity test. The results
were then related to the changes in the rheological properties of
polymer modified bitumen. It was observed that thermoplastic
copolymer shows profound effect on penetration rather than
softening point. The viscoelastic behavior of polymer modified
bitumen depend on the concentration of polymer, mixing
temperature, mixing technique, solvating power of base bitumen and
molecular structure of polymer used. PP offer better blend in
comparison to HDPE and LLDPE. The viscosity of base bitumen was
also enhanced with the addition of polymer. The pseudoplastic
behavior was more prominent for HDPE and LLDPE than PP. Best
results were obtained when polymer concentration was kept below
3%
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: The photocatalytic activity efficiency of TiO2 for the degradation of Toluene in photoreactor can be enhanced by nano- TiO2/LDPE composite film. Since the amount of TiO2 affected the efficiency of the photocatalytic activity, this work was mainly concentrated on the effort to embed the high amount of TiO2 in the Polyethylene matrix. The developed photocatalyst was characterized by XRD, UV-Vis spectrophotometer and SEM. The SEM images revealed the high homogeneity of the deposition of TiO2 on the polyethylene matrix. The XRD patterns interpreted that TiO2 embedded in the PE matrix exhibited mainly in anatase form. In addition, the photocatalytic results show that the toluene removal efficiencies of 30±5%, 49±4%, 68±5%, 42±6% and 33±5% were obtained when using the catalyst loading at 0%, 10%, 15%, 25% and 50% (wt. cat./wt. film), respectively.
Abstract: We succeeded to produce a high performance and flexible graphene/Manganese dioxide (G/MnO2) electrode coated on flexible polyethylene terephthalate (PET) substrate. The graphene film is initially synthesized by drop-casting the graphene oxide (GO) solution on the PET substrate, followed by simultaneous reduction and patterning of the dried film using carbon dioxide (CO2) laser beam with power of 1.8 W. Potentiostatic Anodic Deposition method was used to deposit thin film of MnO2 with different loading mass 10 – 50 and 100 μg.cm-2 on the pre-prepared graphene film. The electrodes were fully characterized in terms of structure, morphology, and electrochemical performance. A maximum specific capacitance of 973 F.g-1 was attributed when depositing 50μg.cm-2 MnO2 on the laser reduced graphene oxide rGO (or G/50MnO2) and over 92% of its initial capacitance was retained after 1000 cycles. The good electrochemical performance and long-term cycling stability make our proposed approach a promising candidate in the supercapacitor applications.
Abstract: Experiments have been carried out at the Latvia
University of Agriculture Department of Food Technology. The aim
of this work was to assess the effect of thermal treatment in flexible
retort pouch packaging on the quality of potatoes’ produce during the
storage time. Samples were evaluated immediately after retort
thermal treatment; and following 1; 2; 3 and 4 storage months at the
ambient temperature of +18±2ºC in vacuum packaging from
polyamide/polyethylene (PA/PE) and aluminum/polyethylene
(Al/PE) film pouches with barrier properties. Experimentally the
quality of the potatoes’ produce in dry butter and mushroom
dressings was characterized by measuring pH, hardness, color,
microbiological properties and sensory evaluation. The sterilization
was effective in protecting the produce from physical, chemical, and
microbial quality degradation. According to the study of obtained
data, it can be argued that the selected product processing technology
and packaging materials could be applied to provide the safety and
security during four-month storage period.
Abstract: The breakdown strength characteristic of Low Density
Polyethylene films (LDPE) under DC voltage application and the
effect of water absorption have been studied. Mainly, our experiment
was investigated under two conditions; dry and heavy water
absorption. Under DC ramp voltage, the result found that the
breakdown strength under heavy water absorption has a lower value
than dry condition. In order to clarify the effect, the temperature rise of
film was observed using non contact thermograph until the occurrence
of the electrical breakdown and the conduction current of the sample
was also measured in correlation with the thermograph measurement.
From the observations, it was shown that under the heavy water
absorption, the hot spot in the samples appeared at lower voltage. At
the same voltage the temperature of the hot spot and conduction
current was higher than that under the dry condition. The measurement
result has a good correlation between the existence of a critical field
for conduction current and thermograph observation. In case of the
heavy water absorption, the occurrence of the threshold field was
earlier than the dry condition as result lead to higher of conduction
current and the temperature rise appears after threshold field was
significantly increased in increasing of field. The higher temperature
rise was caused by the higher current conduction as the result the
insulation leads to breakdown to the lower field application.
Abstract: Renewable energy sources have gained ultimate urgency due to the need of the preservation of the environment for a sustainable development. Pyrolysis is an ultimate promising process in the recycling and acquisition of precious chemicals from wastes. Here, the co-pyrolysis of hazelnut shell with ultra-high molecular weight polyethylene was carried out catalytically and noncatalytically at 500 and 650 ºC. Potassium dichromate was added in certain amounts to act as a catalyst. The liquid, solid and gas products quantities were determined by gravimetry. As a main result, remarkable increases in gasification were observed by using this catalyst for pure components and their blends especially at 650 ºC. The increase in gas product quantity was compensated mainly with the decreases in the solid products and additionally in some cases liquid products quantities. These observations may stem from mainly the activation of carbon-carbon bonds rather than carbon-hydrogen bonds via potassium dichromate. Also, the catalytic effect of potassium dichromate on HS: PEO and HS: UHMWPE co-pyrolysis was compared.
Abstract: Plastics occupy wide place in the applications of
automotive, electronics and house goods. Especially reinforced
plastics become popular because of their high strength besides their
advantages of low weight and easy manufacturability. In this study,
mechanical and morphological properties of polypropylene (PP) and
high density polyethylene (HDPE) matrix composites reinforced with
surface modified nano titan dioxide (TiO2) particles were
investigated. Surface modification was made by coating the nano
powders with maleic anhydride grafted styrene ethylene butylene
styrene (SEBS-g-MA) and silane, respectively. After surface
modification, PP/TiO2 and HDPE/TiO2 composites were obtained by
using twin screw extruder at titan dioxide loading of 1 wt.%, 3 wt.%
and 5 wt.%. Effects of surface modification were determined by
thermal and morphological analysis. SEBS-g-MA provided bridging
effect between TiO2 particles and polymer matrix while silane was
effective as a dispersant. Depending on that, homogenous structures
without agglomeration were obtained. Mechanical tests were
performed on the injection moldings of the composites for obtaining
the impact strength, tensile strength, stress at break, elongation and
elastic modulus. Reinforced HDPE and PP moldings gave higher
tensile strength and elastic modulus due to the rigid structure of TiO2.
Slight increment was seen in stress at break. Elongation and impact
strength decreased due to the stiffness of the nano titan dioxide.