Abstract: The in-cylinder flow and mixture formations are
significant in view of today’s increasing concern on environmental
issues and stringent emission regulations. In this paper, the numerical
simulations of a SI engine at different engine speeds (2000-5000
rpm) at fixed intake flow pressure of 1 bar are studied using the AVL
FIRE software. The simulation results show that when the engine
speed at fixed intake flow pressure is increased, the volumetric
efficiency of the engine decreases. This is due to a richer fuel
conditions near the engine cylinder wall when engine speed is
increased. Significant effects of impingement are also noted on the
upper and side walls of the engine cylinder. These variations in
mixture formation before ignition could affect the thermodynamics
efficiency and specific fuel consumption that would lead to a reduced
engine performance.
Abstract: The present study was conducted to evaluate the
potential applicability of biological trickling filter system for the
treatment of simulated textile wastewater containing reactive azo
dyes with bacterial consortium under non-sterile conditions. The
percentage decolorization for the treatment of wastewater containing
structurally different dyes was found to be higher than 95% in all
trials. The stable bacterial count of the biofilm on stone media of the
trickling filter during the treatment confirmed the presence,
proliferation, dominance and involvement of the added microbial
consortium in the treatment of textile wastewater. Results of
physicochemical parameters revealed the reduction in chemical
oxygen demand (58.5-75.1%), sulphates (18.9-36.5%), and
phosphates (63.6-73.0%). UV-Visible and FTIR spectroscopy
confirmed decolorization of dye containing wastewater was ultimate
consequence of biodegradation. Toxicological studies revealed the
nontoxic nature of degradative metabolites.
Abstract: To evaluate the factors which predetermine the
coronary artery disease in patients having positive Exercise Tolerance
Test (ETT) that is treadmill results and coronary artery findings. This
descriptive study was conducted at Department of Cardiology,
Ibrahim Cardiac Hospital & Research Institute, Dhaka, Bangladesh
from 1st January, 2014 to 31st August, 2014. All patients who had
done ETT (treadmill) for chest pain diagnosis were studied. One
hundred and four patients underwent coronary angiogram after
positive treadmill result. Patients were divided into two groups
depending upon the angiographic findings, i.e. true positive and false
positive. Positive treadmill test patients who have coronary artery
involvement these are called true positive and who have no
involvement they are called false positive group. Both groups were
compared with each other. Out of 104 patients, 81 (77.9%) patients
had true positive ETT and 23 (22.1%) patients had false positive
ETT. The mean age of patients in positive ETT was 53.46± 8.06
years and male mean age was 53.63±8.36 years and female was
52.87±7.0 years. Sixty nine (85.19%) male patients and twelve
(14.81%) female patients had true positive ETT, whereas 15
(65.21%) males and 8 (34.79%) females had false positive ETT, this
was statistically significant (p
Abstract: Vacuum Insulation Panel (VIP) can achieve very low
thermal conductivity by evacuating its inner space. Heat transfer in the
core materials of highly-evacuated VIP occurs by conduction through
the solid structure and radiation through the pore. The effect of various
scattering modes in combined conduction-radiation in VIP is
investigated through numerical analysis. The discrete ordinates
interpolation method (DOIM) incorporated with the commercial code
FLUENT® is employed. It is found that backward scattering is more
effective in reducing the total heat transfer while isotropic scattering is
almost identical with pure absorbing/emitting case of the same optical
thickness. For a purely scattering medium, the results agrees well with
additive solution with diffusion approximation, while a modified term
is added in the effect of optical thickness to backward scattering is
employed. For other scattering phase functions, it is also confirmed
that backwardly scattering phase function gives a lower effective
thermal conductivity. Thus the materials with backward scattering
properties, with radiation shields are desirable to lower the thermal
conductivity of VIPs.
Abstract: The purpose of this study is to compare Self
Compacting Concrete (SCC) and Conventional Concrete (CC) in
terms of their capillary water absorption. During the comparison of
SCC and CC, the effects of two different factors were also
investigated: concrete strength class and curing condition. In the
study, both SCC and CC were produced in three different concrete
classes (C25, C50 and C70) and the other parameter (i.e. curing
condition) was determined as two levels: moisture and air curing. It
was observed that, for both curing environments and all strength
classes of concrete, SCCs had lower capillary water absorption values
than that of CCs. It was also detected that, for both SCC and CC,
capillary water absorption values of samples kept in moisture curing
were significantly lower than that of samples stored in air curing.
Additionally, it was determined that capillary water absorption values
for both SCC and CC decrease with increasing strength class of
concrete for both curing environments.
Abstract: In this work, a polyaniline/Iron oxide (PANI/Fe2O3)
composite was chemically prepared by oxidative polymerization of
aniline in acid medium, in presence of ammonium persulphate as an
oxidant and amount of Fe2O3. The composite was characterized by a
scanning electron microscopy (SEM). The prepared composite has
been used as adsorbent to remove Tartrazine dye form aqueous
solutions.
The effects of initial dye concentration and temperature on the
adsorption capacity of PANI/Fe2O3 for Tartrazine dye have been
studied in this paper.
The Langmuir and Freundlich adsorption models have been used
for the mathematical description of adsorption equilibrium data. The
best fit is obtained using the Freundlich isotherm with an R2 value of
0.998. The change of Gibbs energy, enthalpy, and entropy of
adsorption has been also evaluated for the adsorption of Tartrazine
onto PANI/ Fe2O3. It has been proved according the results that the
adsorption process is endothermic in nature.
Abstract: Maturity models, used descriptively to explain
changes in reality or normatively to guide managers to make
interventions to make organizations more effective and efficient, are
based on the principles of statistical quality control and PDCA
continuous improvement (Plan, Do, Check, Act). Some frameworks
developed over the concept of maturity models include COBIT,
CMM, and ITIL.
This paper presents some limitations of traditional maturity
models, most of them related to the mechanistic and reductionist
principles over which those models are built. As systems theory helps
the understanding of the dynamics of organizations and
organizational change, the development of a systemic maturity model
can help to overcome some of those limitations.
This document proposes a systemic maturity model, based on a
systemic conceptualization of organizations, focused on the study of
the functioning of the parties, the relationships among them, and their
behavior as a whole. The concept of maturity from the system theory
perspective is conceptually defined as an emergent property of the
organization, which arises as a result of the degree of alignment and
integration of their processes. This concept is operationalized through
a systemic function that measures the maturity of organizations, and
finally validated by the measuring of maturity in some organizations.
For its operationalization and validation, the model was applied to
measure the maturity of organizational Governance, Risk and
Compliance (GRC) processes.
Abstract: In sheet metal forming process, raw material
mechanical properties are important parameters. This paper is to
compare the wall’s incline angle or formability of SS 400 steel and
SUS 304 stainless steel in single point incremental forming. The two
materials are ferrous base alloyed, which have the different unit cell,
mechanical property and chemical composition. They were forming
into cone shape specimens having 100 mm diameter with different
wall’s incline angle: 90o, 75o and 60o. The investigation was
continued until the specimens formed surface facture. The
experimental result showed that the smaller the wall incline angle
higher the formability with the both materials. The formability limit
of the ferrous base alloy was approx. 60o wall’s incline angle. By
nature, SS 400 has higher formability than SUS 304. This result can
be used as the initial data in designing the single point incremental
forming parts.
Abstract: The Lean Environmental Management Integration
System (LEMIS) framework development is integration between lean
core element and ISO 14001. The curiosity on the relationship
between continuous improvement and sustainability of lean
implementation has influenced this study toward LEMIS.
Characteristic of ISO 14001 standard clauses and core elements of
lean principles are explored from past studies and literature reviews.
Survey was carried out on ISO 14001 certified companies to examine
continual improvement by implementing the ISO 14001 standard.
The study found that there is a significant and positive relationship
between Lean Principles: value, value stream, flow, pull and
perfection with the ISO 14001 requirements. LEMIS is significant to
support the continuous improvement and sustainability. The
integration system can be implemented to any manufacturing
company. It gives awareness on the importance on why organizations
need to sustain its environmental management system. In the
meantime, the lean principle can be adapted in order to streamline
daily activities of the company. Throughout the study, it had proven
that there is no sacrifice or trade-off between lean principles with ISO
14001 requirements. The framework developed in the study can be
further simplified in the future, especially the method of crossing
each sub requirements of ISO 14001 standard with the core elements
of Lean principles in this study.
Abstract: Violet Sr–Al–O:Eu2+ phosphor particles were
synthesized from a metal–ethylenediaminetetraacetic acid (EDTA)
solution of Sr, Al, Eu, and particulate alumina via spray drying and
sintering in a reducing atmosphere. The crystal structures and emission
properties at 85–300 K were investigated. The composition of the
violet Sr–Al–O:Eu2+ phosphor particles was determined from various
Sr–Al–O:Eu2+ phosphors by their emission properties’ dependence
on temperature. The highly crystalline SrAl12O19:Eu2+ emission phases
were confirmed by their crystallite sizes and the activation energies for
the 4f5d–8S7/2 transition of the Eu2+ ion. These results showed that the
material identification for the violet Sr–Al–O:Eu2+ phosphor was
accomplished by the low-temperature luminescence measurements.
Abstract: Frequency stability of microgrids under islanded
operation attracts particular attention recently. A new cooperative
frequency control strategy based on centralized multi-agent system
(CMAS) is proposed in this study. Based on this strategy, agents sent
data and furthermore each component has its own to center operating
decisions (MGCC).After deciding on the information, they are
returned. Frequency control strategies include primary and secondary
frequency control and disposal of multi-stage load in which this study
will also provide a method and algorithm for load shedding. This
could also be a big problem for the performance of micro-grid in
times of disaster. The simulation results show the promising
performance of the proposed structure of the controller based on
multi agent systems.
Abstract: In this work, a Multi-Level Artificial Bee Colony
(called MLABC) for optimizing numerical test functions is presented.
In MLABC, two species are used. The first species employs n
colonies where each of them optimizes the complete solution vector.
The cooperation between these colonies is carried out by exchanging
information through a leader colony, which contains a set of elite
bees. The second species uses a cooperative approach in which the
complete solution vector is divided to k sub-vectors, and each of
these sub-vectors is optimized by a colony. The cooperation between
these colonies is carried out by compiling sub-vectors into the
complete solution vector. Finally, the cooperation between two
species is obtained by exchanging information. The proposed
algorithm is tested on a set of well-known test functions. The results
show that MLABC algorithm provides efficiency and robustness to
solve numerical functions.
Abstract: This paper proposes the designing direct adaptive
neural controller to apply for a class of a nonlinear pendulum
dynamic system. The radial basis function (RBF) neural adaptive
controller is robust in presence of external and internal uncertainties.
Both the effectiveness of the controller and robustness against
disturbances are importance of this paper. The simulation results
show the promising performance of the proposed controller.
Abstract: Dissimilar joining of Titanium and Aluminum thin
sheets has potential applications in aerospace and automobile
industry which can reduce weight and cost and improve strength,
corrosion resistance and high temperature properties. However
successful welding of Titanium/Aluminium sheets is of challenge due
to differences in physical, chemical and metallurgical properties
between the two. This paper describes research results of Laser Beam
Welding (LBW) of Ti/Al thin sheets in which many researchers have
recently performed and critically reviewed from different
perspectives. Also some of notable works in the field of laser welding
with changes in mechanical properties, crack propagation, diffusion
behavior, chemical potential, interfacial reaction and the
microstructure are reported.
Abstract: The primary purpose of this paper is to explain the
impact of successful classroom management on the academic
achievements of students, the importance of positive relationship
between teacher and students, among students, between teacher and
parents. Effective communication plays an important role to
encourage students study hard and learn materials which are covered
by the teacher in the class. Friendly relationships among students
other than their preferred friends help them to have team working and
be socialized. In addition, a well-organized classroom arrangement
enhances students learning. As the consequence of successful
classroom management students should feel responsibility and need
to feel it. The one who is responsible to provide a comfortable
environment and help students learn is the manager of the classroom
who is named Teacher.
Abstract: We have experimentally demonstrated bright-dark
pulses in a nonlinear polarization rotation (NPR) based mode-locked
Erbium-doped fiber laser (EDFL) with a long cavity configuration.
Bright–dark pulses could be achieved when the laser works in the
passively mode-locking regime and the net group velocity dispersion
is quite anomalous. The EDFL starts to generate a bright pulse train
with degenerated dark pulse at the mode-locking threshold pump
power of 35.09 mW by manipulating the polarization states of the
laser oscillation modes using a polarization controller (PC). A split
bright–dark pulse is generated when further increasing the pump
power up to 37.95 mW. Stable bright pulses with no obvious
evidence of a dark pulse can also be generated when further adjusting
PC and increasing the pump power up to 52.19 mW. At higher pump
power of 54.96 mW, a new form of bright-dark pulse emission was
successfully identified with the repetition rate of 29 kHz. The bright
and dark pulses have a duration of 795.5 ns and 640 ns, respectively.
Abstract: The hydrogenated amorphous carbon films (α-C:H)
were deposited on p-type Si (100) substrates at different thicknesses by
radio frequency plasma enhanced chemical vapor deposition
technique (rf-PECVD). Raman spectra display asymmetric
diamond-like carbon (DLC) peaks, representative of the α-C:H films.
The decrease of intensity ID/IG ratios revealed the sp3 content arise at
different thicknesses of the α-C:H films. In terms of mechanical
properties, the high hardness and elastic modulus values showed the
elastic and plastic deformation behaviors related to sp3 content in
amorphous carbon films. Electrochemical properties showed that the
α-C:H films exhibited excellent corrosion resistance in air-saturated
3.5 wt.% NaCl solution for pH 2 at room temperature. Thickness
increasing affected the small sp2 clusters in matrix, restricting the
velocity transfer and exchange of electrons. The deposited α-C:H films
exhibited excellent mechanical properties and corrosion resistance.
Abstract: In recent decades with the development of technology
and lack of food sources, sewage sludge in production of human
foods is inevitable. Various sources of municipal and industrial
sewage sludge that is produced can provide the requirement of plant
nutrients. Soils in arid, semi-arid climate of central Iran that most
affected by water drainage, iron and zinc deficiencies, using of
sewage sludge is helpful. Therefore, the aim of this study is
investigation of sewage sludge and manure application on Ni, Pb and
Cd uptake by Savory. An experiment in a randomized complete block
design with three replications was performed. Sewage sludge
treatments consisted of four levels, control, 15, 30, 80 tons per
hectares; the manure was used in four levels of control, 20, 40 and 80
tons per hectare. Results showed that the wet and dry weights was not
affected by sewage sludge using, while, manure has significant effect
on them. The effect of sewage sludge on the cadmium and lead
concentrations were significant. Interactions of sewage sludge and
manure on dry weight values were not significant. Compare mean
analysis showed that increasing the amount of sewage sludge had no
significant effect on cadmium concentration and it reduced when
sewage sludge usage increased. This is probably due to increased
plant growth and reduced concentrations of these elements in the
plant.
Abstract: Aluminum hybrid reinforcement technology is a
response to the dynamic ever increasing service requirements of such
industries as transportation, aerospace, automobile, marine, etc. It is
unique in that it offers a platform of almost unending combinations of
materials to produce various hybrid composites. This article reviews
the studies carried out on various combinations of aluminum hybrid
composite and the effects on mechanical, physical and chemical
properties. It is observed that the extent of enhancement of these
properties of hybrid composites is strongly dependent on the nature
of the reinforcement, its hardness, particle size, volume fraction,
uniformity of dispersion within the matrix and the method of hybrid
production.
Abstract: The exposure to outdoor air pollution causes lung
cancer and increases the risk of bladder cancer. Because air pollution
in urban areas is mainly caused by transportation, it is necessary to
evaluate pollutant exhaust emissions from vehicles during their realworld
use. Nevertheless their evaluation and reduction is a key
problem, especially in the cities, that account for more than 50% of
world population.
A particular attention was given to the slope variability along the
streets during each journey performed by the instrumented vehicle.
In this paper we dealt with the problem of describing a
quantitatively approach for the reconstruction of GPS coordinates and
altitude, in the context of correlation study between driving cycles /
emission / geographical location, during an experimental campaign
realized with some instrumented cars.
Finally the slope analysis can be correlated to the emission and
consumption values in a specific road position, and it could be
evaluated its influence on their behaviour.