Abstract: The present work is a numerical simulation of
nanofluids flow in a double pipe heat exchanger provided with
porous baffles. The hot nanofluid flows in the inner cylinder, whereas
the cold nanofluid circulates in the annular gap. The Darcy-
Brinkman-Forchheimer model is adopted to describe the flow in the
porous regions, and the governing equations with the appropriate
boundary conditions are solved by the finite volume method. The
results reveal that the addition of metallic nanoparticles enhances the
rate of heat transfer in comparison to conventional fluids but this
augmentation is accompanied by an increase in pressure drop. The
highest heat exchanger performances are obtained when
nanoparticles are added only to the cold fluid.
Abstract: In the present work, the performance of the particle
swarm optimization and the genetic algorithm compared as a typical
geometry design problem. The design maximizes the heat transfer
rate from a given fin volume. The analysis presumes that a linear
temperature distribution along the fin. The fin profile generated using
the B-spline curves and controlled by the change of control point
coordinates. An inverse method applied to find the appropriate fin
geometry yield the linear temperature distribution along the fin
corresponds to optimum design. The numbers of the populations, the
count of iterations and time to convergence measure efficiency.
Results show that the particle swarm optimization is most efficient
for geometry optimization.
Abstract: Association rules are an important problem in data
mining. Massively increasing volume of data in real life databases
has motivated researchers to design novel and incremental algorithms
for association rules mining. In this paper, we propose an incremental
association rules mining algorithm that integrates shocking
interestingness criterion during the process of building the model. A
new interesting measure called shocking measure is introduced. One
of the main features of the proposed approach is to capture the user
background knowledge, which is monotonically augmented. The
incremental model that reflects the changing data and the user beliefs
is attractive in order to make the over all KDD process more
effective and efficient. We implemented the proposed approach and
experiment it with some public datasets and found the results quite
promising.
Abstract: A shaft-type activated sludge reactor has been
developed in order to study the feasibility of high-rate wastewater
treatment. The reactor having volume of about 14.5 L was operated
with the acclimated mixed activated sludge under batch and
continuous mode using a synthetic wastewater as feed. The batch
study was performed with varying chemical oxygen demand (COD)
concentrations of 1000–3500 mg·L-1 for a batch period up to 9 h. The
kinetic coefficients: Ks, k, Y and kd were obtained as 2040.2 mg·L-1
and 0.105 h-1, 0.878 and 0.0025 h-1 respectively from Monod-s
approach. The continuous study showed a stable and steady state
operation for a hydraulic retention time (HRT) of 8 h and influent
COD of about 1000 mg·L-1. A maximum COD removal efficiency of
about 80% was attained at a COD loading rate and food-tomicroorganism
(F/M) ratio (COD basis) of 3.42 kg·m-3d-1 and 1.0
kg·kg-1d-1 respectively under a HRT of 8 h. The reactor was also
found to handle COD loading rate and F/M ratio of 10.8 kg·m-3d-1
and 2.20 kg·kg-1d-1 respectively showing a COD removal efficiency
of about 46%.
Abstract: I/O workload is a critical and important factor to
analyze I/O pattern and file system performance. However tracing I/O
operations on the fly distributed parallel file system is non-trivial due
to collection overhead and a large volume of data. In this paper, we
design and implement a parallel file system logging method for high
performance computing using shared memory-based multi-layer
scheme. It minimizes the overhead with reduced logging operation
response time and provides efficient post-processing scheme through
shared memory. Separated logging server can collect sequential logs
from multiple clients in a cluster through packet communication.
Implementation and evaluation result shows low overhead and high
scalability of this architecture for high performance parallel logging
analysis.
Abstract: Currently, many types of no-reversible compressed
sound source, represented by MP3 (MPEG Audio Layer-3) are
popular in the world and they are widely used to make the music file
size smaller. The sound data created in this way has less information as
compared to pre-compressed data. The objective of this study is by
analyzing EEG to determine if people can recognize such difference as
differences in sound. A measurement system that can measure and
analyze EEG when a subject listens to music were experimentally
developed. And ten subjects were studied with this system. In this
experiment, a WAVE formatted music data and a MP3 compressed
music data that is made from the WAVE formatted data were
prepared. Each subject was made to hear these music sources at the
same volume. From the results of this experiment, clear differences
were confirmed between two wound sources.
Abstract: Simulations play a major role in education not only because they provide realistic models with which students can interact to acquire real world experiences, but also because they constitute safe environments in which students can repeat processes without any risk in order to perceive easier concepts and theories. Virtual reality is widely recognized as a significant technological advance that can facilitate learning process through the development of highly realistic 3D simulations supporting immersive and interactive features. The objective of this paper is to analyze the influence of virtual reality-s use in chemistry instruction as well as to present an integrated web-based learning environment for the simulation of chemical experiments. The proposed application constitutes a cost-effective solution for both schools and universities without appropriate infrastructure and a valuable tool for distance learning and life-long education in chemistry. Its educational objectives are the familiarization of students with the equipment of a real chemical laboratory and the execution of virtual volumetric analysis experiments with the active participation of students.
Abstract: Lean manufacturing is a production philosophy made
popular by Toyota Motor Corporation (TMC). It is globally known as
the Toyota Production System (TPS) and has the ultimate aim of
reducing cost by thoroughly eliminating wastes or muda. TPS
embraces the Just-in-time (JIT) manufacturing; achieving cost
reduction through lead time reduction. JIT manufacturing can be
achieved by implementing Pull system in the production.
Furthermore, TPS aims to improve productivity and creating
continuous flow in the production by arranging the machines and
processes in cellular configurations. This is called as Cellular
Manufacturing Systems (CMS). This paper studies on integrating the
CMS with the Pull system to establish a Big Island-Pull system
production for High Mix Low Volume (HMLV) products in an
automotive component industry. The paper will use the build-in JIT
system steps adapted from TMC to create the Pull system production
and also create a shojinka line which, according to takt time, has the
flexibility to adapt to demand changes simply by adding and taking
out manpower. This will lead to optimization in production.
Abstract: This article proposes modeling, simulation and
kinematic and workspace analysis of a spatial cable suspended robot
as incompletely Restrained Positioning Mechanism (IRPM). These
types of robots have six cables equal to the number of degrees of
freedom. After modeling, the kinds of workspace are defined then an
statically reachable combined workspace for different geometric
structures of fixed and moving platform is obtained. This workspace
is defined as the situations of reference point of the moving platform
(center of mass) which under external forces such as weight and with
ignorance of inertial effects, the moving platform should be in static
equilibrium under conditions that length of all cables must not be
exceeded from the maximum value and all of cables must be at
tension (they must have non-negative tension forces). Then the effect
of various parameters such as the size of moving platform, the size of
fixed platform, geometric configuration of robots, magnitude of
applied forces and moments to moving platform on workspace of
these robots with different geometric configuration are investigated.
Obtained results should be effective in employing these robots under
different conditions of applied wrench for increasing the workspace
volume.
Abstract: The objective of this study was to investigate hydrogen production from alcohol wastewater by anaerobic sequencing batch reactor (ASBR) under thermophillic operation. The ASBR unit used in this study had a liquid holding volume of 4 L and was operated at 6 cycles per day. The seed sludge taken from an upflow anaerobic sludge blanket unit treating the same wastewater was boiled at 95 °C for 15 min before being fed to the ASBR unit. The ASBR system was operated at different COD loading rates at a thermophillic temperature (55 °C), and controlled pH of 5.5. When the system was operated under optimum conditions (providing maximum hydrogen production performance) at a feed COD of 60 000 mg/l, and a COD loading rate of 68 kg/m3 d, the produced gas contained 43 % H2 content in the produced gas. Moreover, the hydrogen yield and the specific hydrogen production rate (SHPR) were 130 ml H2/g COD removed and 2100 ml H2/l d, respectively.
Abstract: this study was carried out to investigate the changes in
quality parameters of rye bread packaged in different polymer films
during convection air-flow thermal treatment process. Whole loafs of
bread were placed in polymer pouches, which were sealed in reduced
pressure air ambiance, bread was thermally treated in
at temperature +(130; 140; and 150) ± 5 ºC within 40min, as long as
the core temperature of the samples have reached accordingly
+80±1 ºC. For bread packaging pouches were used: anti-fog
Mylar®OL12AF and thermo resistant combined polymer material.
Main quality parameters was analysed using standard methods:
temperature in bread core, bread crumb and crust firmness value,
starch granules volume and microflora. In the current research it was
proved, that polymer films significantly influence rye bread quality
parameters changes during thermal treatment. Thermo resistant
combined polymer material film could be recommendable for
packaged rye bread pasteurization, for maximal bread quality
parameter keeping.
Abstract: Rule Discovery is an important technique for mining
knowledge from large databases. Use of objective measures for
discovering interesting rules leads to another data mining problem,
although of reduced complexity. Data mining researchers have
studied subjective measures of interestingness to reduce the volume
of discovered rules to ultimately improve the overall efficiency of
KDD process.
In this paper we study novelty of the discovered rules as a
subjective measure of interestingness. We propose a hybrid approach
based on both objective and subjective measures to quantify novelty
of the discovered rules in terms of their deviations from the known
rules (knowledge). We analyze the types of deviation that can arise
between two rules and categorize the discovered rules according to
the user specified threshold. We implement the proposed framework
and experiment with some public datasets. The experimental results
are promising.
Abstract: In this paper a novel method was presented for
evaluating the fabric pills using digital image processing techniques. This work provides a novel technique for
detecting pills and also measuring their heights, surfaces and
volumes. Surely, measuring the intensity of defects by human vision is an inaccurate method for quality control; as a result, this problem became a motivation for employing digital image processing techniques for detection of defects of fabric
surface. In the former works, the systems were just limited to measuring of the surface of defects, but in the presented
method the height and the volume of defects were also
measured, which leads to a more accurate quality control. An algorithm was developed to first, find pills and then measure their average intensity by using three criteria of height, surface
and volume. The results showed a meaningful relation
between the number of rotations and the quality of pilled fabrics.
Abstract: ECG contains very important clinical information about the cardiac activities of the heart. Often the ECG signal needs to be captured for a long period of time in order to identify abnormalities in certain situations. Such signal apart of a large volume often is characterised by low quality due to the noise and other influences. In order to extract features in the ECG signal with time-varying characteristics at first need to be preprocessed with the best parameters. Also, it is useful to identify specific parts of the long lasting signal which have certain abnormalities and to direct the practitioner to those parts of the signal. In this work we present a method based on wavelet transform, standard deviation and variable threshold which achieves 100% accuracy in identifying the ECG signal peaks and heartbeat as well as identifying the standard deviation, providing a quick reference to abnormalities.
Abstract: In the present work, study of the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is presented. Material properties are graded in the thickness direction of the shell according to volume fraction power law distribution. The objective is to study the natural frequencies, the influence of constituent volume fractions and the effects of boundary conditions on the natural frequencies of the FG cylindrical shell. The study is carried out using third order shear deformation shell theory. The analysis is carried out using Hamilton's principle. The governing equations of motion of FG cylindrical shells are derived based on shear deformation theory. Results are presented on the frequency characteristics, influence of constituent volume fractions and the effects of free-free and clamped-clamped boundary conditions.
Abstract: The one of most important objects in implementation
of damage analysis observations is manner of dam break wave
propagation. In this paper velocity and wave height due dam break in
with and without tailwater states for appointment hazardous lands
and flood radius are investigate. In order to modeling above
phenomenon finite volume method of Roe type for solving shallow
water equations is used. Results indicated that in the dry bed state
risk radius due to dam break is too high. While in the wet bed risk
radius has a less wide. Therefore in the first state constructions and
storage facilities are encountered with destruction risk. Further
velocity due to dam break in the second state is more comparing to
the first state. Hence erosion and scour the river bed in the dry bed is
too more compare to the wet bed.
Abstract: For the past one decade, biclustering has become popular data mining technique not only in the field of biological data analysis but also in other applications like text mining, market data analysis with high-dimensional two-way datasets. Biclustering clusters both rows and columns of a dataset simultaneously, as opposed to traditional clustering which clusters either rows or columns of a dataset. It retrieves subgroups of objects that are similar in one subgroup of variables and different in the remaining variables. Firefly Algorithm (FA) is a recently-proposed metaheuristic inspired by the collective behavior of fireflies. This paper provides a preliminary assessment of discrete version of FA (DFA) while coping with the task of mining coherent and large volume bicluster from web usage dataset. The experiments were conducted on two web usage datasets from public dataset repository whereby the performance of FA was compared with that exhibited by other population-based metaheuristic called binary Particle Swarm Optimization (PSO). The results achieved demonstrate the usefulness of DFA while tackling the biclustering problem.
Abstract: In this paper, the ice melting in rectangular,
cylindrical and conical forms, which are erected vertically against air
flow, are experimentally studied in the free convection regime.The
results obtained are: Nusslet Number, heat transfer coefficient
andGrashof Number, and the variations of the said numbers in
relation to the time. The variations of ice slab area and volume are
measured, too.
Abstract: Carbon Capture & Storage (CCS) is one of the various
methods that can be used to reduce the carbon footprint of the
energy sector. This paper focuses on the absorption of CO2 from
flue gas using packed columns, whose efficiency is highly dependent
on the structure of the liquid films within the column. To study the
characteristics of liquid films a CFD solver, OpenFOAM is utilised
to solve two-phase, isothermal film flow using the volume-of-fluid
(VOF) method. The model was validated using existing experimental
data and the Nusselt theory. It was found that smaller plate inclination
angles, with respect to the horizontal plane, resulted in larger wetted
areas on smooth plates. However, only a slight improvement in
the wetted area was observed. Simulations were also performed
using a ridged plate and it was observed that these surface textures
significantly increase the wetted area of the plate. This was mainly
attributed to the channelling effect of the ridges, which helped to
oppose the surface tension forces trying to minimise the surface area.
Rivulet formations on the ridged plate were also flattened out and
spread across a larger proportion of the plate width.
Abstract: The absolute Cu atoms density in Cu(2S1/22P1/2)
ground state has been measured by Resonance Optical Absorption
(ROA) technique in a DC magnetron sputtering deposition with
argon. We measured these densities under variety of operation
conditions: pressure from 0.6 μbar to 14 μbar, input power from
10W to 200W and N2 mixture from 0% to 100%. For measuring the
gas temperature, we used the simulation of N2 rotational spectra
with a special computer code. The absolute number density of Cu
atoms decreases with increasing the N2 percentage of buffer gas at
any conditions of this work. But the deposition rate, is not decreased
with the same manner. The deposition rate variation is very small
and in the limit of quartz balance measuring equipment accuracy. So
we conclude that decrease in the absolute number density of Cu
atoms in magnetron plasma has not a big effect on deposition rate,
because the diffusion of Cu atoms to the chamber volume and
deviation of Cu atoms from direct path (towards the substrate)
decreases with increasing of N2 percentage of buffer gas. This is
because of the lower mass of N2 atoms compared to the argon ones.