Abstract: Properties of Portland cement mixtures with various
fractions of metakaolin were studied. 10% of Portland cement CEM I
42.5 R was replaced by different fractions of high reactivity
metakaolin with defined chemical and mineralogical properties.
Various fractions of metakaolin were prepared by jet mill classifying
system. There is a clear trend between fineness of metakaolin and
hydration heat development. Due to metakaolin presence in mixtures
the compressive strength development of mortars is rather slower for
coarser fractions but 28-day flexural strengths are improved for all
fractions of metakaoline used in mixtures compared to reference
sample of pure Portland cement. Yield point, plastic viscosity and
adhesion of fresh pastes are considerably influenced by fineness of
metakaolin used in cement pastes.
Abstract: The objective of countercyclical capital buffer is to
encourage banks to build up buffers in good times that can be drawn
down in bad times. The aim of the report is to assess such decisions
by banks derived from three approaches. The approaches are the
aggregate credit-to-GDP ratio, credit growth as well as banking
sector profits. The approaches are implemented for Estonia, Latvia
and Lithuania for the time period 2000-2012. The report compares
three approaches and analyses their relevance to the Baltic States by
testing the correlation between a growth in studied variables and a
growth of corresponding gaps. Methods used in the empirical part of
the report are econometric analysis as well as economic analysis,
development indicators, relative and absolute indicators and other
methods. The research outcome is a cross-Baltic comparison of two
alternative approaches to establish or release a countercyclical capital
buffer by banks and their implications for each Baltic country.
Abstract: In Jordan having deficit atmospheric precipitation, an
increase in water demand occurs during summer months. Jordan can
be regarded with a relatively high potential for wastewater recycling
and reuse. The main purpose of this paper was to investigate the
removal of total suspended solids (TSS) and chemical oxygen
demand (COD) for olive mill wastewater (OMW) by
electrocoagulation (EC) process. In the combination of
electrocoagulation by using coupled iron–aluminum electrodes, the
optimum working pH was found to be around 6. Results indicated
that the electrocoagulation process allowed removal of TSS and COD
of about 82.5% and 47.5%, respectively at 45 mA/cm2 after 70
minutes by using coupled iron–aluminum electrodes. It was
demonstrated that the maximum TSS and COD removals were
obtained at some optimum experimental parameters for current
density, pH, and reaction time.
Abstract: The effects of hypertension are often lethal thus its
early detection and prevention is very important for everybody. In
this paper, a neural network (NN) model was developed and trained
based on a dataset of hypertension causative parameters in order to
forecast the likelihood of occurrence of hypertension in patients. Our
research goal was to analyze the potential of the presented NN to
predict, for a period of time, the risk of hypertension or the risk of
developing this disease for patients that are or not currently
hypertensive. The results of the analysis for a given patient can
support doctors in taking pro-active measures for averting the
occurrence of hypertension such as recommendations regarding the
patient behavior in order to lower his hypertension risk. Moreover,
the paper envisages a set of three example scenarios in order to
determine the age when the patient becomes hypertensive, i.e.
determine the threshold for hypertensive age, to analyze what
happens if the threshold hypertensive age is set to a certain age and
the weight of the patient if being varied, and, to set the ideal weight
for the patient and analyze what happens with the threshold of
hypertensive age.
Abstract: The paper presents a thermodynamic cycle analysis
for three turboshaft engines. The first cycle is a Brayton cycle,
describing the evolution of a classical turboshaft, based on the
Klimov TV2 engine. The other four cycles aim at approaching an
Ericsson cycle, by replacing the Brayton cycle adiabatic expansion in
the turbine by quasi-isothermal expansion. The maximum quasi-
Ericsson cycles temperature is set to a lower value than the maximum
Brayton cycle temperature, equal to the Brayton cycle power turbine
inlet temperature, in order to decrease the engine NOx emissions.
Also, the power/expansion ratio distribution over the stages of the gas
generator turbine is maintained the same. In two of the considered
quasi-Ericsson cycles, the efficiencies of the gas generator turbine, as
well as the power/expansion ratio distribution over the stages of the
gas generator turbine are maintained the same as for the reference
case, while for the other two cases, the efficiencies are increased in
order to obtain the same shaft power as in the reference case. For the
two cases respecting the first condition, both the shaft power and the
thermodynamic efficiency of the engine decrease, while for the other
two, the power and efficiency are maintained, as a result of assuming
new, more efficient gas generator turbines.
Abstract: In this paper, we discuss the performance of applying
hybrid spiral dynamic bacterial chemotaxis (HSDBC) optimisation
algorithm on an intelligent controller for a differential drive robot. A
unicycle class of differential drive robot is utilised to serve as a basis
application to evaluate the performance of the HSDBC algorithm. A
hybrid fuzzy logic controller is developed and implemented for the
unicycle robot to follow a predefined trajectory. Trajectories of
various frictional profiles and levels were simulated to evaluate the
performance of the robot at different operating conditions. Controller
gains and scaling factors were optimised using HSDBC and the
performance is evaluated in comparison to previously adopted
optimisation algorithms. The HSDBC has proven its feasibility in
achieving a faster convergence toward the optimal gains and resulted
in a superior performance.
Abstract: In this paper, a new design of spherical robotic system
based on the concepts of gimbal structure and gyro dynamics is
presented. Robots equipped with multiple wheels and complex
steering mechanics may increase the weight and degrade the energy
transmission efficiency. In addition, the wheeled and legged robots are
relatively vulnerable to lateral impact and lack of lateral mobility.
Therefore, the proposed robotic design uses a spherical shell as the
main body for ground locomotion, instead of using wheel devices.
Three spherical shells are structured in a similar way to a gimbal
device and rotate like a gyro system. The design and mechanism of the
proposed robotic system is introduced. In addition, preliminary results
of the dynamic model based on the principles of planar rigid body
kinematics and Lagrangian equation are included. Simulation results
and rig construction are presented to verify the concepts.
Abstract: Interaction of Schiff base complexes of Iron and
Manganese: Iron [N, N’ Bis (5- (triphenyl phosphonium methyl)
salicylidene) -1, 2 ethanediamine) chloride, [Fe Salen]Cl; Manganese
[N, N’ Bis (5- (triphenyl phosphonium methyl) salicylidene) -1, 2
ethanediamine) acetate, were investigated by spectroscopic and
isothermal titration calorimetry techniques (ITC).
The absorbance spectra of complexes have shown hyper and
hypochromism in the presence of DNA that is indication of
interaction of complexes with DNA. The linear dichroism (LD)
measurements confirmed the bending of DNA in the presence of
complexes.
Furthermore, Isothermal titration calorimetry experiments
approved that complexes bound to DNA on the base of both
electrostatic and hydrophobic interactions. More, ITC profile exhibits
the existence of two binding phases for the complexes. Antibacterial
activity of ligand and complexes were tested in vitro to evaluate their
activity against the gram positive and negative bacteria.
Abstract: The Algeria by its location offers a rich and diverse
vegetation. A large number of aromatic and medicinal plants grow
spontaneously. The interest in these plants has continued to grow in
recent years. Their particular properties due to the essential oil
fraction can be utilized to treat microbial infections. To this end, and
in the context of the valuation of the Algerian flora, we became
interested in the species of the family Lamiaceae which is one of the
most used as a global source of spices. The plant on which we have
based our choice is a species of sage "Salvia officinalis" from the
Isser localized region within the province of Boumerdes. This work
focuses on the study of the antimicrobial activity of essential oil
extracted from the leaves of Salvia officinalis. The extraction is
carried out by essential oil hydrodistillation and reveals a yield of
1.06℅. The study of the antimicrobial activity of the essential oil by
the method of at aromatogramme shown that Gram positive bacteria
are most susceptible (Staphylococcus aureus and Bacillus subtilis)
with a strong inhibition of growth. The yeast Candida albicans
fungus Aspergillus niger and have shown moderately sensitive.
Abstract: The FOSDT (the First Order Shear Deformation
Theory) is taking into consideration to study the static behavior of a
bimorph beam, with a delamination zone between the upper and the
lower layer. The effect of limit conditions and lengths of the
delamination zone are presented in this paper, with a PVDF
piezoelectric material application. A FEM “Finite Element Method”
is used to discretize the beam. In the axial displacement, a
displacement field appears in the debonded zone with inverse effect
between the upper and the lower layer was observed.
Abstract: Electronic Word-Of-Mouth (eWOM) communities
represent today an important source of information in which more
and more customers base their purchasing decisions. They include
thousands of reviews concerning very different products and services
posted by many individuals geographically distributed all over the
world. Due to their massive audience, eWOM communities can help
users to find the product they are looking for even if they are less
popular or rare. This is known as the long tail effect, which leads to a
larger number of lower-selling niche products. This paper analyzes
the long tail effect in a well-known eWOM community and defines a
tool for finding niche products unavailable through conventional
channels.
Abstract: The heavy metal pollution degree in the soils around
the Zangezur copper and molybdenum combine in Syunik Marz,
Armenia was assessed. The results of the study showed that heavy
metal pollution degree in the soils mainly decreased with increasing
distance from the open mine and the ore enrichment combine which
indicated that the open mine and the ore enrichment combine were
the main sources of heavy metal pollution. The only exception was
observed in the northern part of the open mine where pollution
degree in the sites (along the open mine) situated 600 meters far from
the mine was higher than that in the sites located 300 meters far from
the mine. This can be explained by the characteristics of relief and air
currents as well as the weak vegetation cover of these sites and the
characteristics of soil structure. According to geo-accumulation index
(I-geo), contamination factor (Cf), contamination degree (Cd) and
pollution load index (PLI) values, the pollution degree in the soils
around the open mine and the ore enrichment combine was higher
than that in the soils around the tailing dumps which was due to the
proper and accurate operation of the Artsvanik tailing damp and the
recultivation of the Voghji tailing dump.
The high Cu and Mo pollution of the soils was conditioned by the
character of industrial activities, the moving direction of air currents
as well as the physicochemical peculiarities of the soils.
Abstract: Two finite element (FEM) models are presented in
this paper to address the random nature of the response of glued
timber structures made of wood segments with variable elastic
moduli evaluated from 3600 indentation measurements. This total
database served to create the same number of ensembles as was the
number of segments in the tested beam. Statistics of these ensembles
were then assigned to given segments of beams and the Latin
Hypercube Sampling (LHS) method was called to perform 100
simulations resulting into the ensemble of 100 deflections subjected
to statistical evaluation. Here, a detailed geometrical arrangement of
individual segments in the laminated beam was considered in the
construction of two-dimensional FEM model subjected to in fourpoint
bending to comply with the laboratory tests. Since laboratory
measurements of local elastic moduli may in general suffer from a
significant experimental error, it appears advantageous to exploit the
full scale measurements of timber beams, i.e. deflections, to improve
their prior distributions with the help of the Bayesian statistical
method. This, however, requires an efficient computational model
when simulating the laboratory tests numerically. To this end, a
simplified model based on Mindlin’s beam theory was established.
The improved posterior distributions show that the most significant
change of the Young’s modulus distribution takes place in laminae in
the most strained zones, i.e. in the top and bottom layers within the
beam center region. Posterior distributions of moduli of elasticity
were subsequently utilized in the 2D FEM model and compared with
the original simulations.
Abstract: An experimental study was performed to investigate
the behavior and strength of proposed technique to connect
reinforced concrete (RC) beam to steel or composite columns. This
approach can practically be used in several types of building
construction. In this technique, the main beam of the frame consists
of a transfer part (part of beam; Tr.P) and a common reinforcement
concrete beam. The transfer part of the beam is connected to the
column, whereas the rest of the beam is connected to the transfer part
from each side. Four full-scale beam-column connections were tested
under static loading. The test parameters were the length of the
transfer part and the column properties. The test results show that
using of the transfer part technique leads to modify the deformation
capabilities for the RC beam and hence it increases its resistance
against failure. Increase in length of the transfer part did not
necessarily indicate an enhanced behavior. The test results contribute
to the characterization of the connection behavior between RC beam -
steel column and can be used to calibrate numerical models for the
simulation of this type of connection.
Abstract: This paper introduces a proposal scheme for an
Intelligent System applied to Pedagogical Advising using Case-Based
Reasoning, to find consolidated solutions before used for the new
problems, making easier the task of advising students to the
pedagogical staff. We do intend, through this work, introduce the
motivation behind the choices for this system structure, justifying the
development of an incremental and smart web system who learns
bests solutions for new cases when it’s used, showing technics and
technology.
Abstract: In this study, the Compressive strength of concretes
made with Ground Granulated Blast furnace Slag (GGBS),
Pulverised Fuel Ash (PFA), Rice Husk Ash (RHA) and Waste Glass
Powder (WGP) after they were exposed 7800C (exposure duration of
around 60 minutes) and then allowed to cool down gradually in the
furnace for about 280 minutes at water binder ratio of 0.50 was
investigated. GGBS, PFA, RHA and WGP were used to replace up to
20% Portland cement in the control concrete. Test for the
determination of workability, compressive strength and tensile
splitting strength of the concretes were carried out and the results
were compared with control concrete. The test results showed that the
compressive strength decreased by an average of around 30% after
the concretes were exposed to the heating and cooling scenario.
Abstract: The thermal control in many systems is widely
accomplished applying mixed convection process due to its low cost,
reliability and easy maintenance. Typical applications include the
aircraft electronic equipment, rotating-disc heat exchangers, turbo
machinery, and nuclear reactors, etc. Natural convection in an inclined
square enclosure heated via wall heater has been studied numerically.
Finite volume method is used for solving momentum and energy
equations in the form of stream function–vorticity. The right and left
walls are kept at a constant temperature, while the other parts are
adiabatic. The range of the inclination angle covers a whole revolution.
The method is validated for a vertical cavity. A general power law
dependence of the Nusselt number with respect to the Rayleigh
number with the coefficient and exponent as functions of the
inclination angle is presented. For a fixed Rayleigh number, the
inclination angle increases or decreases is found.
Abstract: Ionic liquids consisting of a phosphonium cationic
moiety and a saccharinate anion are synthesized and compared with
their precursors, phosphonium chlorides, in reference to their
extraction efficiency towards L-lactic acid. On the base of
measurements of the acid and the water partitioning in the
equilibrium biphasic systems, the molar ratios between acid, water
and ionic liquid are estimated which allows to deduce the lactic acid
extractive pathway. The effect of a salting-out addition that
strengthens hydrophobicity in both phases is studied in view to reveal
the best biphasic system with respect to IL low toxicity and high
extraction efficiency.
Abstract: Catalytic combustion of methane is imperative due to
stability of methane at low temperature. Methane (CH4), therefore,
remains unconverted in vehicle exhausts thereby causing greenhouse
gas GHG emission problem. In this study, heterogeneous catalysts of
palladium with bio-char (2 wt% Pd/Bc) and Al2O3 (2wt% Pd/ Al2O3)
supports were prepared by incipient wetness impregnation and then
subsequently tested for catalytic combustion of CH4. Support-porous
heterogeneous catalytic combustion (HCC) material were selected
based on factors such as surface area, porosity, thermal stability,
thermal conductivity, reactivity with reactants or products, chemical
stability, catalytic activity, and catalyst life. Sustainable and
renewable support-material of bio-mass char derived from palm shell
waste material was compared with those from the conventional
support-porous materials. Kinetic rate of reaction was determined for
combustion of methane on Palladium (Pd) based catalyst with Al2O3
support and bio-char (Bc). Material characterization was done using
TGA, SEM, and BET surface area. The performance test was
accomplished using tubular quartz reactor with gas mixture ratio of
3% methane and 97% air. The methane porous-HCC conversion was
carried out using online gas analyzer connected to the reactor that
performed porous-HCC. BET surface area for prepared 2 wt% Pd/Bc
is smaller than prepared 2wt% Pd/ Al2O3 due to its low porosity
between particles. The order of catalyst activity based on kinetic rate
on reaction of catalysts in low temperature was 2wt%
Pd/Bc>calcined 2wt% Pd/ Al2O3> 2wt% Pd/ Al2O3>calcined 2wt%
Pd/Bc. Hence agro waste material can successfully be utilized as an
inexpensive catalyst support material for enhanced CH4 catalytic
combustion.
Abstract: Modern Portfolio Theory (MPT) according to
Markowitz states that investors form mean-variance efficient
portfolios which maximizes their utility. Markowitz proposed the
standard deviation as a simple measure for portfolio risk and the
lower semi-variance as the only risk measure of interest to rational
investors. This paper uses a third volatility estimator based on
intraday data and compares three efficient frontiers on the Croatian
Stock Market. The results show that range-based volatility estimator
outperforms both mean-variance and lower semi-variance model.