Abstract: Palladium-catalyzed hydrodechlorination is a
promising alternative for the treatment of environmentally relevant
water bodies, such as groundwater, contaminated with chlorinated
organic compounds (COCs). In the aqueous phase
hydrodechlorination of COCs, Pd-based catalysts were found to have
a very high catalytic activity. However, the full utilization of the
catalyst-s potential is impeded by the sensitivity of the catalyst to
poisoning and deactivation induced by reduced sulfur compounds
(e.g. sulfides). Several regenerants have been tested before to recover
the performance of sulfide-fouled Pd catalyst. But these only
delivered partial success with respect to re-establishment of the
catalyst activity. In this study, the deactivation behaviour of
Pd/Al2O3 in the presence of sulfide was investigated. Subsequent to
total deactivation the catalyst was regenerated in the aqueous phase
using potassium permanganate. Under neutral pH condition,
oxidative regeneration with permanganate delivered a slow recovery
of catalyst activity. However, changing the pH of the bulk solution to
acidic resulted in the complete recovery of catalyst activity within a
regeneration time of about half an hour. These findings suggest the
superiority of permanganate as regenerant in re-activating Pd/Al2O3
by oxidizing Pd-bound sulfide.
Abstract: In this study, an ablation, mechanical and thermal properties of a rocket motor insulation from phenolic/ fiber matrix composites forming a laminate with different fiber between fiberglass and locally available synthetic fibers. The phenolic/ fiber matrix composites was mechanics and thermal properties by means of tensile strength, ablation, TGA and DSC. The design of thermal insulation involves several factors.Determined the mechanical properties according to MIL-I-24768: Density >1.3 g/cm3, Tensile strength >103 MPa and Ablation
Abstract: In this paper, the requirement for Coke quality
prediction, its role in Blast furnaces, and the model output is
explained. By applying method of Artificial Neural Networking
(ANN) using back propagation (BP) algorithm, prediction model has
been developed to predict CSR. Important blast furnace functions
such as permeability, heat exchanging, melting, and reducing
capacity are mostly connected to coke quality. Coke quality is further
dependent upon coal characterization and coke making process
parameters. The ANN model developed is a useful tool for process
experts to adjust the control parameters in case of coke quality
deviations. The model also makes it possible to predict CSR for new
coal blends which are yet to be used in Coke Plant. Input data to the
model was structured into 3 modules, for tenure of past 2 years and
the incremental models thus developed assists in identifying the
group causing the deviation of CSR.
Abstract: Compacted clay liners (CCLs) are the main materials
used in waste disposal landfills due to their low permeability. In this
study, the effect on the shear resistant of clays with inorganic salt
solutions as permeate fluid was experimentally investigated. For this
purpose, NaCl inorganic salt solution at concentrations of 2, 5, 10%
and deionized water were used. Laboratory direct shear and Vane
shear tests were conducted on three compacted clays with low,
medium and high plasticity. Results indicated that the solutions type
and its concentration affect the shear properties of the mixture. In the
light of this study, the influence magnitude of these inorganic salts in
varies concentrations in different clays were determined and more
suitable compacted clay with the compare of plasticity were found.
Abstract: Lanthanum oxide is to be recovered from monazite,
which contains about 13.44% lanthanum oxide. The principal
objective of this study is to be able to extract lanthanum oxide from
monazite of Moemeik Myitsone Area. The treatment of monazite in
this study involves three main steps; extraction of lanthanum
hydroxide from monazite by using caustic soda, digestion with nitric
acid and precipitation with ammonium hydroxide and calcination of
lanthanum oxalate to lanthanum oxide.
Abstract: In this paper we study a system composed by carbon
nanotube (CNT) and bundle of carbon nanotube (BuCNT) interacting
with a specific fatty acid as molecular probe. Full system is
represented by open nanotube (or nanotubes) and the linoleic acid
(LA) relaxing due the interaction with CNT and BuCNT. The LA has
in his form an asymmetric shape with COOH termination provoking
a close BuCNT interaction mainly by van der Waals force field. The
simulations were performed by classical molecular dynamics with
standard parameterizations.
Our results show that these BuCNT and CNT are dynamically
stable and it shows a preferential interaction position with LA
resulting in three features: (i) when the LA is interacting with CNT
and BuCNT (including both termination, CH2 or COOH), the LA is
repelled; (ii) when the LA terminated with CH2 is closer to open
extremity of BuCNT, the LA is also repelled by the interaction
between them; and (iii) when the LA terminated with COOH is
closer to open extremity of BuCNT, the LA is encapsulated by the
BuCNT. These simulations are part of a more extensive work on
searching efficient selective molecular devices and could be useful to
reach this goal.
Abstract: Combined experimental and computational analysis of
hygrothermal performance of an interior thermal insulation system
applied on a brick wall is presented in the paper. In the experimental
part, the functionality of the insulation system is tested at simulated
difference climate conditions using a semi-scale device. The
measured temperature and relative humidity profiles are used for the
calibration of computer code HEMOT that is finally applied for a
long-term hygrothermal analysis of the investigated structure.
Abstract: Fabrication and efficiency enhancement of non-mercury, high efficiency and green field emission lamps using carbon nano-materials such as carbon nanotubes as cathode field emitters was studied. Phosphor was coated on the ITO glass or metal substrates as the anode. The luminescence efficiency enhancement was carried out by upgrading the uniform of the emitters, improving electron and thermal conductivity of the phosphor and the optimization of the design of different cathode/anode configurations. After evaluation of the aforementioned parameters, the luminescence efficiency of the field emission lamps was raised.
Abstract: Highly ordered TiO2 nanotube (TNT) arrays were
fabricated onto a pre-treated titanium foil by anodic oxidation with a
voltage of 20V in phosphoric acid/sodium fluoride electrolyte. A pretreatment
of titanium foil involved washing with acetone,
isopropanol, ethanol and deionized water. Carbon doped TiO2
nanotubes (C-TNT) was fabricated 'in-situ' with the same method in
the presence of polyvinyl alcohol and urea as carbon sources. The
affects of polyvinyl alcohol concentration and oxidation time on the
composition, morphology and structure of the C-TN were studied by
FE-SEM, EDX and XRD techniques. FESEM images of the
nanotubes showed uniform arrays of C-TNTs. The density and
microstructures of the nanotubes were greatly affected by the content
of PVA. The introduction of the polyvinyl alcohol into the electrolyte
increases the amount of C content inside TiO2 nanotube arrays
uniformly. The influence of carbon content on the photo-current of
C-TNT was investigated and the I-V profiles of the nanotubes were
established. The preliminary results indicated that the 'in-situ'
doping technique produced a superior quality nanotubes compared to
post doping techniques.
Abstract: Gasoline Octane Number is the standard measure of
the anti-knock properties of a motor in platforming processes, that is
one of the important unit operations for oil refineries and can be
determined with online measurement or use CFR (Cooperative Fuel
Research) engines. Online measurements of the Octane number can
be done using direct octane number analyzers, that it is too
expensive, so we have to find feasible analyzer, like ANFIS
estimators.
ANFIS is the systems that neural network incorporated in fuzzy
systems, using data automatically by learning algorithms of NNs.
ANFIS constructs an input-output mapping based both on human
knowledge and on generated input-output data pairs.
In this research, 31 industrial data sets are used (21 data for training
and the rest of the data used for generalization). Results show that,
according to this simulation, hybrid method training algorithm in
ANFIS has good agreements between industrial data and simulated
results.
Abstract: In this work, we experimentally study heat transfer
from exhaust particulate air of detergent spray drying tower to water
by using coiled tube heat exchanger. Water flows in the coiled
tubes, where air loaded with detergent particles of 43 micrometers
in diameter flows within the shell. Four coiled tubes with different
coil pitches are used in a counter-current flow configuration. We
investigate heat transfer coefficients of inside and outside the heat
transfer surfaces through 400 experiments. The correlations between
Nusselt number and Reynolds number, Prandtl number, mass flow
rate of particulates to mass flow rate of air ratio and coiled tube
pitch parameter are proposed. The correlations procured can be used
to predicted heat transfer between tube and shell of the heat
exchanger.
Abstract: Polymers are one of the most widely used materials in our every day life. The subject of renewable resources has attracted great attention in the last period of time. New polymeric materials derived from renewable resources, like carbohydrates draw attention to public eye especially because of their biocompatibility and biodegradability. The aim of our paper was to obtain environmentally compatible polymers from monosaccharides. Novel glycopolymers based on D-glucose have been obtained from copolymerization of a new monomer carrying carbohydrate moiety with methyl methacrylate (MMA) via free radical bulk polymerization. Differential scanning calorimetry (DSC) was performed in order to study the copolymerization process of the monomer into the chosen co-monomer; the activation energy of this process was evaluated using Ozawa method. The copolymers obtained were characterized using ATR-FTIR spectroscopy. The thermal stability of the obtained products was studied by thermogravimetry (TG).
Abstract: Exploding concentrated underwater charges to
damage underwater structures such as ship hulls is a part of naval
warfare strategies. Adding small amounts of foreign particles (like
clay or silica) of nanosize significantly improves the engineering
properties of the polymers. In the present work the clay in terms 1, 2
and 3 percent by weight was surface treated with a suitable silane
agent. The hybrid nanocomposite was prepared by the hand lay-up
technique. Mathematical regression models have been employed for
theoretical prediction. This will result in considerable savings in terms of project time, effort and cost.
Abstract: An innovative approach utilizing highly alkaline oil
shale waste ash and carbon dioxide gas (CO2), associated with power
production, as a resource for production of precipitated calcium
carbonate (PCC) is introduced in this paper. The specifics and
feasibility of the integrated ash valorization and CO2 sequestration
process by indirect aqueous carbonation of lime-consisting ash were
elaborated and the main parameters established. Detailed description
of the formed precipitates was included. Complimentary carbonation
experiments with commercial CaO fine powder were conducted for
comparative characterization of the final products obtained on the
basis of two different raw materials. Finally, the expected CO2
uptake was evaluated.
Abstract: The photoluminescence (PL) at 1.55 μm from
semiconducting β-FeSi2 has attracted a noticeable interest for
silicon-based optoelectronic applications. Moreover, its high optical
absorption coefficient (higher than 105 cm-1 above 1.0 eV) allows this
semiconducting material to be used as photovoltanics devices.
A clear PL spectrum for β-FeSi2 was observed by Cu or Au coating
on Si(001). High-crystal-quality β-FeSi2 with a low-level nonradiative
center was formed on a Cu- or Au- reated Si layer. This method of
deposition can be applied to other materials requiring high crystal
quality.
Abstract: The adsorption of simulated aqueous solution containing textile remazol reactive dye, namely Red 3BS by palm shell activated carbon (PSAC) as adsorbent was carried out using Response Surface Methodology (RSM). A Box-Behnken design in three most important operating variables; initial dye concentration, dosage of adsorbent and speed of impeller was employed for experimental design and optimization of results. The significance of independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95% confidence limits. Model indicated that with the increasing of dosage and speed give the result of removal up to 90% with the capacity uptake more than 7 mg/g. High regression coefficient between the variables and the response (R-Sq = 93.9%) showed of good evaluation of experimental data by polynomial regression model.
Abstract: Titanium oxide hollow microspheres were synthesized from organic precursor titanium tetraisopropoxide (TTIP) using continuous spray pyrolysis reactor. Effects of precursor concentration, applied voltage and annealing have been investigated. It was observed that the annealing of the as-synthesized TiO2 hollow microspheres at 2500C, which had an average external diameter of 200 nm, leads to an increase in the size and also more spherical shape. The precursor concentration was found to have a direct impact on the size of the microspheres, which is also evident in the absorption spectrum. The as-prepared TiO2 hollow microspheres exhibited good photocatalytic activity for the degradation of MO.
Abstract: In present study, two kinds of thermal power plant ashes; one the fly ash and the other waste ash are mixed with adhesive tragacanth and cement to produce new composite materials. 48 new samples are produced by varying the percentages of the fly ash, waste ash, cement and tragacanth. The new samples are subjected to some tests to find out their properties such as thermal conductivity, compressive strength, tensile strength and sucking capability of water. It is found that; the thermal conductivity decreases with increasing amount of tragacanth in the mixture. The compressive, tensile strength increases when the rate of tragacanth is up to 1%, whilst as the amount of tragacanth increases up to 1.5%, the compressive, tensile strength decreases slightly. The rate of water absorption of samples was more than 30%. From this result, it is concluded that these materials can not be used as external plaster or internal plaster material that faces to water. They can be used in internal plaster unless touching water and they can be used as cover plaster under roof and riprap material in sandwich panels. It is also found that, these materials can be cut with saw, drilled with screw and painted with any kind of paint.
Abstract: The effect of chemical treatment in CdCl2 and thermal
annealing in 400°C, on the defect structures of potentially useful
ZnS\CdS solar cell thin films deposited onto quartz substrate and
prepared by vacuum deposition method was studied using the
Thermoluminesence (TL) techniques. A series of electron and hole
traps are found in the various deposited samples studied. After
annealing, however, it was observed that the intensity and activation
energy of TL signal increases with loss of the low temperature
electron traps.
Abstract: Adsorption of Toluidine blue dye from aqueous solutions onto Neem Leaf Powder (NLP) has been investigated. The surface characterization of this natural material was examined by Particle size analysis, Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and X-Ray Diffraction (XRD). The effects of process parameters such as initial concentration, pH, temperature and contact duration on the adsorption capacities have been evaluated, in which pH has been found to be most effective parameter among all. The data were analyzed using the Langmuir and Freundlich for explaining the equilibrium characteristics of adsorption. And kinetic models like pseudo first- order, second-order model and Elovich equation were utilized to describe the kinetic data. The experimental data were well fitted with Langmuir adsorption isotherm model and pseudo second order kinetic model. The thermodynamic parameters, such as Free energy of adsorption (AG"), enthalpy change (AH') and entropy change (AS°) were also determined and evaluated.