Abstract: Froth flotation remains to date as one of the most used
metallurgical processes for concentrating metal-bearing minerals in
ores. Oxide ores are relatively less amenable to froth flotation and
require a judicious choice of reagents for the recovery of metals to be
optimised. Laboratory batch flotation tests were conducted to
determine the effect of two types of gasoil-rinkalore mixtures on the
flotation response of a copper cobalt oxide ore sample. The head
assay conducted on the initial ore sample showed that it contained
about 2.90% of Cu, 0.12% of Co.
Upon the flotation test work, the results obtained indicated that the
concentrate obtained with use of the mixture gazoil-rinkalore RX
yielded 8.24% Cu and 0.22% Co concentrate grades with recoveries
of 76.0% Cu and 78.0% Co respectively. But, the concentrate
obtained by use of the mixture gazoil-rinkalore RX3 yielded
relatively bad results with 5.92% Cu and 0.18% Cu concentrate
grades with recoveries of 70.3% Cu and 65.3% Co respectively.
Abstract: Software fault prediction models are created by using
the source code, processed metrics from the same or previous version
of code and related fault data. Some company do not store and keep
track of all artifacts which are required for software fault prediction.
To construct fault prediction model for such company, the training
data from the other projects can be one potential solution. Earlier we
predicted the fault the less cost it requires to correct. The training
data consists of metrics data and related fault data at function/module
level. This paper investigates fault predictions at early stage using the
cross-project data focusing on the design metrics. In this study,
empirical analysis is carried out to validate design metrics for cross
project fault prediction. The machine learning techniques used for
evaluation is Naïve Bayes. The design phase metrics of other projects
can be used as initial guideline for the projects where no previous
fault data is available. We analyze seven datasets from NASA
Metrics Data Program which offer design as well as code metrics.
Overall, the results of cross project is comparable to the within
company data learning.
Abstract: The Speexx results revealed four main factors
affecting the success of 190 Thai sophomores as follows: 1) Future
English training should be pursued in applied Speexx development.
2) Thai students didn’t see the benefit of having an Online Language
Training Program. 3) There is a great need to educate the next
generation of learners on the benefits of Speexx within the
community. 4) A great majority of Thai Sophomores didn't know
what Speexx was.
A guideline for self-reliance planning consisted of four aspects: 1)
Development planning: by arranging groups to further improve
English abilities with the Speexx Language Training program and
encourage using Speexx into every day practice. Local communities
need to develop awareness of the usefulness of Speexx and share the
value of using the program among family and friends. 2) Humanities
and Social Science staff should develop skills using this Online
Language Training Program to expand on the benefits of Speexx
within their departments. 3) Further research should be pursued on
the Thai Students progression with Speexx and how it helps them
improve their language skills with Business English. 4) University’s
and Language centers should focus on using Speexx to encourage
learning for any language, not just English.
Abstract: This paper presents the design and characterization of
analog readout interface circuits for ion sensitive field effect
transistor (ISFET) and ion selective electrode (ISE) based sensor.
These interface circuits are implemented using MIMOS’s 0.35um
CMOS technology and experimentally characterized under 24-leads
QFN package. The characterization evaluates the circuit’s
functionality, output sensitivity and output linearity. Commercial
sensors for both ISFET and ISE are employed together with glass
reference electrode during testing. The test result shows that the
designed interface circuits manage to readout signals produced by
both sensors with measured sensitivity of ISFET and ISE sensor are
54mV/pH and 62mV/decade, respectively. The characterized output
linearity for both circuits achieves above 0.999 Rsquare. The readout
also has demonstrated reliable operation by passing all qualifications
in reliability test plan.
Abstract: On the basis of the theory of nonlinear elasticity, the
effect of homogeneous stress on the propagation of Lamb waves in
an initially isotropic hyperelastic plate is analysed. The equations
governing the propagation of small amplitude waves in the prestressed
plate are derived using the theory of small deformations
superimposed on large deformations. By enforcing traction free
boundary conditions at the upper and lower surfaces of the plate,
acoustoelastic dispersion equations for Lamb wave propagation are
obtained, which are solved numerically. Results are given for an
aluminum plate subjected to a range of applied stresses.
Abstract: In educational technology, the idea of innovation is
usually tethered to contemporary technological inventions and
emerging technologies. Yet, using long-known technologies in ways
that are pedagogically or experimentially new can reposition them as
emerging educational technologies. In this study we explore how a
subtle pivot in pedagogical thinking led to an innovative education
technology. We describe the design and implementation of an online
writing tool that scaffolds students in the evaluation of their own
informational texts. We think about how pathways to innovation can
emerge from pivots, namely a leveraging of longstanding practices in
novel ways has the potential to cultivate new opportunities for
learning. We first unpack Infowriter in terms of its design, then we
describe some results of a study in which we implemented an
intervention which included our designed application.
Abstract: Removal of the widespread used drug paracetamol
from water was investigated using activated carbon originated from
dende coconut mesocarp and babassu coconut mesocarp. Kinetic and
equilibrium data were obtained at different values of pH. Both
activated carbons showed high efficiency when pH ≤ pHPZC as the
carbonil group of paracetamol molecule are adsorbed due to
positively charged carbon surface. Microporosity also played an
important role in such process. Pseudo-second order model was better
adjusted to the kinetic results. Equilibrium data may be represented
by Langmuir equation.
Abstract: Thousands of organisations store important and
confidential information related to them, their customers, and their
business partners in databases all across the world. The stored data
ranges from less sensitive (e.g. first name, last name, date of birth) to
more sensitive data (e.g. password, pin code, and credit card
information). Losing data, disclosing confidential information or
even changing the value of data are the severe damages that
Structured Query Language injection (SQLi) attack can cause on a
given database. It is a code injection technique where malicious SQL
statements are inserted into a given SQL database by simply using a
web browser. In this paper, we propose an effective pattern
recognition neural network model for detection and classification of
SQLi attacks. The proposed model is built from three main elements
of: a Uniform Resource Locator (URL) generator in order to generate
thousands of malicious and benign URLs, a URL classifier in order
to: 1) classify each generated URL to either a benign URL or a
malicious URL and 2) classify the malicious URLs into different
SQLi attack categories, and a NN model in order to: 1) detect either a
given URL is a malicious URL or a benign URL and 2) identify the
type of SQLi attack for each malicious URL. The model is first
trained and then evaluated by employing thousands of benign and
malicious URLs. The results of the experiments are presented in
order to demonstrate the effectiveness of the proposed approach.
Abstract: Sol-enhanced Zn-Ni-Al2O3 nanocomposite coatings
were electroplated on mild steel by our newly developed solenhanced
electroplating method. In this method, transparent Al2O3 sol
was added into the acidic Zn-Ni bath to produced Zn-Ni-Al2O3nanocomposite
coatings. The chemical composition, microstructure and
mechanical properties of the composite and alloy coatings deposited
at two different agitation speed were investigated. The structure of all
coatings was single γ-Ni5Zn21 phase. The composite coatings possess
refined crystals with higher microhardness compared to Zn-Ni alloy
coatings. The wear resistance of Zn-Ni coatings was improved
significantly by incorporation of alumina nano particles into the
coatings. Higher agitation speed provided more uniform coatings
with smaller grain sized and slightly higher microhardness.
Considering composite coatings, high agitation speeds may facilitate
co-deposition of alumina in the coatings.
Abstract: Transportation of long turbine blades from one place
to another is a difficult process. Hence a feasibility study of
modularization of wind turbine blade was taken from structural
standpoint through finite element analysis. Initially, a non-segmented
blade is modeled and its structural behavior is evaluated to serve as
reference. The resonant, static bending and fatigue tests are simulated
in accordance with IEC61400-23 standard for comparison purpose.
The non-segmented test blade is separated at suitable location based
on trade off studies and the segments are joined with an innovative
double strap bonded joint configuration. The adhesive joint is
modeled by adopting cohesive zone modeling approach in ANSYS.
The developed blade model is analyzed for its structural response
through simulation. Performances of both the blades are found to be
similar, which indicates that, efficient segmentation of the long blade
is possible which facilitates easy transportation of the blades and on
site reassembling. The location selected for segmentation and
adopted joint configuration has resulted in an efficient segmented
blade model which proves the methodology adopted for segmentation
was quite effective. The developed segmented blade appears to be the
viable alternative considering its structural response specifically in
fatigue within considered assumptions.
Abstract: The paper deals with the classical fiber bundle model
of equal load sharing, sometimes referred to as the Daniels’ bundle
or the democratic bundle. Daniels formulated a multidimensional
integral and also a recursive formula for evaluation of the
strength cumulative distribution function. This paper describes
three algorithms for evaluation of the recursive formula and also
their implementations with source codes in the Python high-level
programming language. A comparison of the algorithms are provided
with respect to execution time. Analysis of orders of magnitudes of
addends in the recursion is also provided.
Abstract: Aim of this work is to determine the theoretical and
experimental properties of filament wound glass fiber/epoxy resin
composite pipes with different winding design subjected under
bending. For determination of bending strength of composite samples
three point bending tests were conducted. Good correlation between
theoretical and experimental results has been obtained, where sample
No4 has shown the highest value of bending strength. All samples
have demonstrated matrix cracking and fiber failure followed by
layers delamination during testing. Also, it was found that smaller
winding angles lead to an increase in bending stress. From presented
results good merger between glass fibers and epoxy resin was
confirmed by SEM analysis.
Abstract: A new steganographic method via the use of numeric
data on public websites with a self-authentication capability is
proposed. The proposed technique transforms a secret message into
partial shares by Shamir’s (k, n)-threshold secret sharing scheme with
n = k + 1. The generated k+1 partial shares then are embedded into the
numeric items to be disguised as part of the website’s numeric content,
yielding the stego numeric content. Afterward, a receiver links to the
website and extracts every k shares among the k+1 ones from the stego
numeric content to compute k+1 copies of the secret, and the
phenomenon of value consistency of the computed k+1 copies is taken
as an evidence to determine whether the extracted message is authentic
or not, attaining the goal of self-authentication of the extracted secret
message. Experimental results and discussions are provided to show
the feasibility and effectiveness of the proposed method.
Abstract: This paper introduces symbiotic organism search (SOS)
for solving capacitated vehicle routing problem (CVRP). SOS is a new
approach in metaheuristics fields and never been used to solve discrete
problems. A sophisticated decoding method to deal with a discrete
problem setting in CVRP is applied using the basic symbiotic
organism search (SOS) framework. The performance of the algorithm
was evaluated on a set of benchmark instances and compared results
with best known solution. The computational results show that the
proposed algorithm can produce good solution as a preliminary
testing. These results indicated that the proposed SOS can be applied
as an alternative to solve the capacitated vehicle routing problem.
Abstract: Experimental studies to investigate the depth of the
scour conducted at a side-weir intersection located at the 1800 curved
flume which located Hydraulic Laboratory of Yıldız Technical
University, Istanbul, Turkey. Side weirs were located at the middle of
the straight part of the main channel. Three different lengths (25, 40
and 50 cm) and three different weir crest height (7, 10 and 12 cm) of
the side weir placed on the side weir station. There is no scour when
the material is only kaolin. Therefore, the cohesive bed was prepared
by properly mixing clay material (kaolin) with 31% sand in all
experiments. Following 24h consolidation time, in order to observe
the effect of flow intensity on the scour depth, experiments were
carried out for five different upstream Froude numbers in the range of
0.33-0.81.
As a result of this study the relation between scour depth and
upstream flow intensity as a function of time have been established.
The longitudinal velocities decreased along the side weir; towards the
downstream due to overflow over the side-weirs. At the beginning,
the scour depth increases rapidly with time and then asymptotically
approached constant values in all experiments for all side weir
dimensions as in non-cohesive sediment. Thus, the scour depth
reached equilibrium conditions. Time to equilibrium depends on the
approach flow intensity and the dimensions of side weirs. For
different heights of the weir crest, dimensionless scour depths
increased with increasing upstream Froude number. Equilibrium
scour depths which formed 7 cm side-weir crest height were obtained
higher than that of the 12 cm side-weir crest height. This means when
side-weir crest height increased equilibrium scour depths decreased.
Although the upstream side of the scour hole is almost vertical, the
downstream side of the hole is inclined.
Abstract: The concentrations of heavy metals in sediments of
Qua Iboe River Estuary (QIRE) were monitored at four different
sampling locations in wet and dry seasons. A preliminary survey to
determine the four sampling stations along the river continuum
showed that the area spanned between
Abstract: Here, we study the characteristic feature of
conventional (ON-OFF keying) and soliton based transmission
system. We consider 20Gbps transmission system implemented with
Conventional Single Mode Fiber (C-SMF) to examine the role of
Gaussian pulse which is the characteristic of conventional
propagation and Hyperbolic-secant pulse which is the characteristic
of soliton propagation in it. We note the influence of these pulses
with respect to different dispersion lengths and soliton period in
conventional and soliton system respectively and evaluate the system
performance in terms of Quality factor. From the analysis, we could
prove that the soliton pulse has the consistent performance even for
long distance without dispersion compensation than the conventional
system as it is robust to dispersion. For the length of transmission of
200Km, soliton system yielded Q of 33.958 while the conventional
system totally exhausted with Q=0.
Abstract: Waste load allocation (WLA) policies may use multiobjective
optimization methods to find the most appropriate and
sustainable solutions. These usually intend to simultaneously
minimize two criteria, total abatement costs (TC) and environmental
violations (EV). If other criteria, such as inequity, need for
minimization as well, it requires introducing more binary
optimizations through different scenarios. In order to reduce the
calculation steps, this study presents value index as an innovative
decision making approach. Since the value index contains both the
environmental violation and treatment costs, it can be maximized
simultaneously with the equity index. It implies that the definition of
different scenarios for environmental violations is no longer required.
Furthermore, the solution is not necessarily the point with minimized
total costs or environmental violations. This idea is testified for Haraz
River, in north of Iran. Here, the dissolved oxygen (DO) level of river
is simulated by Streeter-Phelps equation in MATLAB software. The
WLA is determined for fish farms using multi-objective particle
swarm optimization (MOPSO) in two scenarios. At first, the trade-off
curves of TC-EV and TC-Inequity are plotted separately as the
conventional approach. In the second, the Value-Equity curve is
derived. The comparative results show that the solutions are in a
similar range of inequity with lower total costs. This is due to the
freedom of environmental violation attained in value index. As a
result, the conventional approach can well be replaced by the value
index particularly for problems optimizing these objectives. This
reduces the process to achieve the best solutions and may find better
classification for scenario definition. It is also concluded that decision
makers are better to focus on value index and weighting its contents
to find the most sustainable alternatives based on their requirements.
Abstract: In this contribution two approaches for calculating
optimal trajectories for highly automated vehicles are presented and
compared. The first one is based on a non-linear vehicle model, used
for evaluation. The second one is based on a simplified model and
can be implemented on a current ECU. In usual driving situations
both approaches show very similar results.
Abstract: Quantitative radiobiological models can be used to
assess the optimum clinical outcome from sophisticated therapeutic
modalities by calculating tumor control probability (TCP) and normal
tissue complication probability (NTCP). In this study two 3D-CRT
and an IMRT treatment plans were developed with an initial
prescription dose of 60 Gy in 2 Gy/fraction to prostate. Sensitivity of
TCP and Complication free tumor control probability (P+) to the
different values of α/β ratio was investigated for various prescription
doses planned to be delivered in either a fixed number of fractions (I)
or in a fixed dose per fraction (II) in each of the three different
treatment plans. High dose/fraction and high α/β value result in
comparatively smaller P+ and IMRT plans resulted in the highest P+,
mainly due to the decrease in NTCP. If α/β is lower than expected,
better tumor control can be achieved by increasing dose/fraction but
decreasing the number of fractions.