Abstract: This paper presents a study on the thermodynamics
and transport properties of hot potassium carbonate aqueous system
(HPC) using electrolyte non-random two liquid, (ELECNRTL)
model. The operation conditions are varied to determine the system
liquid phase stability range at the standard and critical conditions. A
case study involving 30 wt% K2CO3, H2O standard system at
pressure of 1 bar and temperature range from 280.15 to 366.15 K has
been studied. The estimated solubility index, viscosity, water
activity, and density which obtained from the simulation showed a
good agreement with the experimental work. Furthermore, the
saturation temperature of the solution has been estimated.
Abstract: In the present study, the incorporation of graphene
into blends of acrylonitrile-butadiene-styrene terpolymer with
polypropylene (ABS/PP) was investigated focusing on the
improvement of their thermomechanical characteristics and the effect
on their rheological behavior. The blends were prepared by melt
mixing in a twin-screw extruder and were characterized by measuring
the MFI as well as by performing DSC, TGA and mechanical tests.
The addition of graphene to ABS/PP blends tends to increase their
melt viscosity, due to the confinement of polymer chains motion.
Also, graphene causes an increment of the crystallization temperature
(Tc), especially in blends with higher PP content, because of the
reduction of surface energy of PP nucleation, which is a consequence
of the attachment of PP chains to the surface of graphene through the
intermolecular CH-π interaction. Moreover, the above nanofiller
improves the thermal stability of PP and increases the residue of
thermal degradation at all the investigated compositions of blends,
due to the thermal isolation effect and the mass transport barrier
effect. Regarding the mechanical properties, the addition of graphene
improves the elastic modulus, because of its intrinsic mechanical
characteristics and its rigidity, and this effect is particularly strong in
the case of pure PP.
Abstract: Reinforced concrete crash barriers used in road traffic
must meet a number of criteria. Crash barriers are laid lengthwise,
one behind another, and joined using specially designed steel locks.
While developing BSV reinforced concrete crash barriers (type
ŽPSV), experiments and calculations aimed to optimize the shape of
a newly designed lock and the reinforcement quantity and
distribution in a crash barrier were carried out. The tension carrying
capacity of two parallelly joined locks was solved experimentally.
Based on the performed experiments, adjustments of nonlinear
properties of steel were performed in the calculations. The obtained
results served as a basis to optimize the lock design using a
computational model that takes into account the plastic behaviour of
steel and the influence of the surrounding concrete [6]. The response
to the vehicle impact has been analyzed using a specially elaborated
complex computational model, comprising both the nonlinear model
of the damping wall or crash barrier and the detailed model of the
vehicle [7].
Abstract: The objective of this paper is twofold: (1) discuss and
analyze the successful case studies worldwide, and (2) identify the
similarities and differences of case studies worldwide. Design
methodology/approach: The nature of this research is mainly method
qualitative (multi-case studies, literature review). This investigation
uses ten case studies, and the data was mainly collected and
organizational documents from the international countries. Finding:
The finding of this research can help incubator manager, policy
maker and government parties for successful implementation.
Originality/value: This paper contributes to the current literate review
on the best practices worldwide. Additionally, it presents future
perspective for academicians and practitioners.
Abstract: This paper deals with the problem of thermal and
mechanical shocks, which rising during operation, mostly at
interrupted cut. Here will be solved their impact on the cutting edge
tool life, the impact of coating technology on resistance to shocks
and experimental determination of tool life in heating flame.
Resistance of removable cutting edges against thermal and
mechanical shock is an important indicator of quality as well as its
abrasion resistance. Breach of the edge or its crumble may occur due
to cyclic loading. We can observe it not only during the interrupted
cutting (milling, turning areas abandoned hole or slot), but also in
continuous cutting. This is due to the volatility of cutting force on
cutting. Frequency of the volatility in this case depends on the type
of rising chips (chip size element). For difficult-to-machine materials
such as austenitic steel particularly happened at higher cutting speeds
for the localization of plastic deformation in the shear plane and for
the inception of separate elements substantially continuous chips.
This leads to variations of cutting forces substantially greater than for
other types of steel.
Abstract: Two-phase frictional pressure drop data were
obtained for condensation of carbon dioxide in single horizontal
micro tube of inner diameter ranged from 0.6 mm up to 1.6 mm over
mass flow rates from 2.5*10-5 to 17*10-5 kg/s and vapor qualities
from 0.0 to 1.0. The inlet condensing pressure is changed from 33.5
to 45 bars. The saturation temperature ranged from -1.5 oC up to 10
oC. These data have then been compared against three (two-phase)
frictional pressure drop prediction methods. The first method is by
Muller-Steinhagen and Heck (Muller-Steinhagen H, Heck K. A
simple friction pressure drop correlation for two-phase flow in pipes.
Chem. Eng. Process 1986;20:297–308) and that by Gronnerud R.
Investigation of liquid hold-up, flow-resistance and heat transfer in
circulation type evaporators, part IV: two-phase flow resistance in
boiling refrigerants, Annexe 1972. Then the method used by
FriedelL. Improved friction pressures drop in horizontal and vertical
two-phase pipe flow. European Two-Phase Flow Group Meeting,
Paper E2; 1979 June, Ispra, Italy. The methods are used by M.B Ould
Didi et al (2001) “Prediction of two-phase pressure gradients of
refrigerant in horizontal tubes". Int.J.of Refrigeration 25(2002) 935-
947. The best available method for annular flow was that of Muller-
Steinhagen and Heck. It was observed that the peak in the two-phase
frictional pressure gradient is at high vapor qualities.
Abstract: The shortest path routing problem is a multiobjective nonlinear optimization problem with constraints. This problem has been addressed by considering Quality of service parameters, delay and cost objectives separately or as a weighted sum of both objectives. Multiobjective evolutionary algorithms can find multiple pareto-optimal solutions in one single run and this ability makes them attractive for solving problems with multiple and conflicting objectives. This paper uses an elitist multiobjective evolutionary algorithm based on the Non-dominated Sorting Genetic Algorithm (NSGA), for solving the dynamic shortest path routing problem in computer networks. A priority-based encoding scheme is proposed for population initialization. Elitism ensures that the best solution does not deteriorate in the next generations. Results for a sample test network have been presented to demonstrate the capabilities of the proposed approach to generate well-distributed pareto-optimal solutions of dynamic routing problem in one single run. The results obtained by NSGA are compared with single objective weighting factor method for which Genetic Algorithm (GA) was applied.
Abstract: The influence of flakes from biologically activated
hull-less barley grain and malt extract on chemical composition of
yoghurt was studied.
Pasteurized milk, freeze-dried yoghurt culture YF-L811 (Chr.
Hansen, Denmark), flakes from biologically activated hull-less
barley grain (Latvia) and malt extract (Ilgezeem, Latvia) were used
for experiments. Yoghurt samples with and without flakes from
biologically activated hull-less barley grain and malt extract were
analyzed for content of total solids, total proteins, fats, amino acids
and riboflavin.
The addition of flakes from biologically activated hull-less barley
grain and malt extract allowed increase of nutritional value of
yoghurt samples. There was obtained the increase of total proteins
(p>0.05) and the decrease of fat (p>0.05). The presence of flakes
from biologically activated hull-less barley grain and malt extract in
yoghurt samples provided significant increase of amino acids amount
(p
Abstract: Ethanol has become more attractive in fuel industry
either as fuel itself or an additive that helps enhancing the octane
number and combustibility of gasoline. This research studied a
pressure swing adsorption using cassava-based adsorbent prepared
from mixture of cassava starch and cassava pulp for dehydration of
ethanol vapor. The apparatus used in the experiments consisted of
double adsorption columns, an evaporator, and a vacuum pump. The
feed solution contained 90-92 %wt of ethanol. Three process
variables: adsorption temperatures (110, 120 and 130°C), adsorption
pressures (1 and 2 bar gauge) and feed vapor flow rate (25, 50 and 75
% valve opening of the evaporator) were investigated. According to
the experimental results, the optimal operating condition for this
system was found to be at 2 bar gauge for adsorption pressure, 120°C
for adsorption temperature and 25% valve opening of the evaporator.
Production of 1.48 grams of ethanol with concentration higher than
99.5 wt% per gram of adsorbent was obtained. PSA with cassavabased
adsorbent reported in this study could be an alternative method
for production of nearly anhydrous ethanol. Dehydration of ethanol
vapor achieved in this study is due to an interaction between free
hydroxyl group on the glucose units of the starch and the water
molecules.
Abstract: In this work we introduce an efficient method to limit
the impact of the hiding process on the quality of the cover speech.
Vector quantization of the speech spectral information reduces drastically
the number of the secret speech parameters to be embedded
in the cover signal. Compared to scalar hiding, vector quantization
hiding technique provides a stego signal that is indistinguishable from
the cover speech. The objective and subjective performance measures
reveal that the current hiding technique attracts no suspicion about the
presence of the secret message in the stego speech, while being able
to recover an intelligible copy of the secret message at the receiver
side.
Abstract: This research focuses on micro-enterprise of
Malaysian Malays that are involved in very small-scaled business
activities. Among them include food stall and burger stall operators,
night market hawkers, grocery store operators as well as construction
and small service activities works. The study seeks to explore why
some micro-entrepreneurs still lag in entrepreneurship and what
needs to be rectified. This quantitative study is conducted on 173
Malay micro-enterprise owners (MEOs) and 58 Malay failed microenterprise
owners (FMEOs) involved in all range of businesses
throughout the state of Perak, Malaysia. The main aims are to
identify the gaps between the failed micro-enterprise owners
(FMEOs) and existing micro-enterprise owners (MEOs) and the
problems faced among FMEOs. The results reveal that the MEOs had
strong motivations and better marketing approaches as compared to
FMEOs. Furthermore, the FMEOs failed in the business ventures
mainly due to lack of management, sales and marketing skills and
poor competitive abilities to keep up with rivals.
Abstract: In the article the experience of principle new
technology development of ethnopsychological experiment on the
basis of using other virtual independent experimental variables is
presented. It is shown that ethnic prejudices are the result of forming
and development of specific semantic barriers, arising up in the
conditions of interethnic co-operation and people-s communication.
Their overcoming is more successful in the conditions of the special
organized process of teaching in a polyethnic environment,
characteristic for the modern institute
Abstract: An ordered porous antimony-doped tin oxide (ATO) film was successfully prepared using a simple coating process with colloidal templates. The facile production was effective when a combination of 16-nm ATO (as a model of an inorganic nanoparticle) and polystyrene (PS) spheres (as a model of the template) weresimply coated to produce a composite ATO/PS film. Heat treatment was then used to remove the PS and produce the porous film. The porous film with a spherical pore shape and a highly ordered porous structure could be obtained. A potential way for the control of pore size could be also achieved by changing initial template size. The theoretical explanation and mechanism of porous formation were also added, which would be important for the scaling-up prediction and estimation.
Abstract: In this paper, four carbazole-based D-D-π-A organic
dyes code as CCT2A, CCT3A, CCT1PA and CCT2PA were reported.
A series of these organic dyes containing identical donor and
acceptor group but different π-system. The effect of replacing of
thiophene by phenyl thiophene as π-system on the physical
properties has been focused. The structural, energetic properties and
absorption spectra were theoretically investigated by means of
Density Functional Theory (DFT) and Time-Dependent Density
Functional Theory (TD-DFT). The results show that nonplanar
conformation due to steric hindrance in donor part (cabazolecarbazole
unit) of dye molecule can prevent unfavorable dye
aggregation. By means of the TD-DFT method, the absorption
spectra were calculated by B3LYP and BHandHLYP to study the
affect of hybrid functional on the excitation energy (Eg). The results
revealed the increasing of thiophene units not only resulted in
decreasing of Eg, but also found the shifting of absorption spectra to
higher wavelength. TD-DFT/BHandHLYP calculated results are
more strongly agreed with the experimental data than B3LYP
functions. Furthermore, the adsorptions of CCT2A and CCT3A on the
TiO2 anatase (101) surface were carried out by mean of the chemical
periodic calculation. The result exhibit the strong adsorption energy.
The calculated results provide our new organic dyes can be
effectively used as dye for Dye Sensitized Solar Cell (DSC).
Abstract: In this paper, we intend to study the synthesis of the
multibeam arrays. The synthesis implementation-s method for this
type of arrays permits to approach the appropriated radiance-s
diagram. The used approach is based on neural network that are
capable to model the multibeam arrays, consider predetermined
general criteria-s, and finally it permits to predict the appropriated
diagram from the neural model. Our main contribution in this paper is
the extension of a synthesis model of these multibeam arrays.
Abstract: This paper describes the design process and the realtime validation of an innovative autonomous mid-air flight and landing system developed by the Italian Aerospace Research Center in the framework of the Italian national funded project TECVOL (Technologies for the Autonomous Flight). In the paper it is provided an insight of the whole development process of the system under study. In particular, the project framework is illustrated at first, then the functional context and the adopted design and testing approach are described, and finally the on-ground validation test rig on purpose designed is addressed in details. Furthermore, the hardwarein- the-loop validation of the autonomous mid-air flight and landing system by means of the real-time test rig is described and discussed.
Abstract: Augmented Reality (AR) shows great promises for
its usage as a tool for simulation and verification of design proposal
of new technological systems. Main advantage of augmented reality
application usage is possibility of creation and simulation of new
technological unit before its realization. This may contribute to
increasing of safety and ergonomics and decreasing of economical
aspects of new proposed unit. Virtual model of proposed workcell
could reveal hidden errors which elimination in later stage of new
workcell creation should cause great difficulties. Paper describes
process of such virtual model creation and possibilities of its
simulation and verification by augmented reality tools.
Abstract: Aircraft propulsion systems often use Y-shaped
subsonic diffusing ducts as twin air-intakes to supply the ambient air
into the engine compressor for thrust generation. Due to space
constraint, the diffusers need to be curved, which causes severe flow
non-uniformity at the engine face. The present study attempt to
control flow in a mild-curved Y-duct diffuser using trapezoidalshaped
vortex generators (VG) attached on either both the sidewalls
or top and bottom walls of the diffuser at the inflexion plane. A
commercial computational fluid dynamics (CFD) code is modified
and is used to simulate the effects of SVG in flow of a Y-duct
diffuser. A few experiments are conducted for CFD code validation,
while the rest are done computationally. The best combination of Yduct
diffuser is found with VG-2 arranged in co-rotating sequence
and attached to both the sidewalls, which ensures highest static
pressure recovery, lowest total pressure loss, minimum flow
distortion and less flow separation in Y-duct diffuser. The decrease in
VG height while attached to top and bottom walls further improves
axial flow uniformity at the diffuser outlet by a great margin as
compared to the bare duct.
Abstract: This paper presents a new and efficient approach for capacitor placement in radial distribution systems that determine the optimal locations and size of capacitor with an objective of improving the voltage profile and reduction of power loss. The solution methodology has two parts: in part one the loss sensitivity factors are used to select the candidate locations for the capacitor placement and in part two a new algorithm that employs Plant growth Simulation Algorithm (PGSA) is used to estimate the optimal size of capacitors at the optimal buses determined in part one. The main advantage of the proposed method is that it does not require any external control parameters. The other advantage is that it handles the objective function and the constraints separately, avoiding the trouble to determine the barrier factors. The proposed method is applied to 9, 34, and 85-bus radial distribution systems. The solutions obtained by the proposed method are compared with other methods. The proposed method has outperformed the other methods in terms of the quality of solution.
Abstract: In this paper the features of multiple material gate
silicon-on-insulator MOSFETs are presented and compared with
single material gate silicon-on-insulator MOSFET structures. The
results indicate that the multiple material gate structures reduce short
channel effects such as drain induce barrier lowering, hot electron
effect and better current characteristics in comparison with single
material structures