Abstract: Separation of propylene-propane mixture using
immobilized liquid membrane was investigated. The effect of transmembrane
pressure and carrier concentration on membrane
separation performance was studied. It was observed that for 30:70
(vol. %) propylene-propane mixture, at pressure of 120kPa and
carrier concentration of 20wt. %, a separation factor of 474 was
obtained.
Abstract: In order to supplement the brittle property of concrete,
fibers are added into concrete mixtures. Compared to general concrete,
various characteristics such as tensile strength, bending strength,
bending toughness, and resistance to crack are superior, and even
when cracks occur, improvements on toughness as well as resistance
to shock are excellent due to the growth of fracture energy. Increased
function of steel fiber reinforced concrete can be differentiated
depending on the fiber dispersion, and sand percentage can be an
important influence on the fiber dispersion. Therefore, in this research,
experiments were planned on sand percentage in order to apprehend
the influence of sand percentage on the bending properties and direct
tension of SFRC and basic experiments were conducted on bending
and direct tension in order to recognize the properties of bending
properties and direct tension following the size of the aggregates and
sand percentage.
Abstract: Image clustering is a process of grouping images
based on their similarity. The image clustering usually uses the color
component, texture, edge, shape, or mixture of two components, etc.
This research aims to explore image clustering using color
composition. In order to complete this image clustering, three main
components should be considered, which are color space, image
representation (feature extraction), and clustering method itself. We
aim to explore which composition of these factors will produce the
best clustering results by combining various techniques from the
three components. The color spaces use RGB, HSV, and L*a*b*
method. The image representations use Histogram and Gaussian
Mixture Model (GMM), whereas the clustering methods use KMeans
and Agglomerative Hierarchical Clustering algorithm. The
results of the experiment show that GMM representation is better
combined with RGB and L*a*b* color space, whereas Histogram is
better combined with HSV. The experiments also show that K-Means
is better than Agglomerative Hierarchical for images clustering.
Abstract: Real world Speaker Identification (SI) application
differs from ideal or laboratory conditions causing perturbations that
leads to a mismatch between the training and testing environment
and degrade the performance drastically. Many strategies have been
adopted to cope with acoustical degradation; wavelet based Bayesian
marginal model is one of them. But Bayesian marginal models
cannot model the inter-scale statistical dependencies of different
wavelet scales. Simple nonlinear estimators for wavelet based
denoising assume that the wavelet coefficients in different scales are
independent in nature. However wavelet coefficients have significant
inter-scale dependency. This paper enhances this inter-scale
dependency property by a Circularly Symmetric Probability Density
Function (CS-PDF) related to the family of Spherically Invariant
Random Processes (SIRPs) in Log Gabor Wavelet (LGW) domain
and corresponding joint shrinkage estimator is derived by Maximum
a Posteriori (MAP) estimator. A framework is proposed based on
these to denoise speech signal for automatic speaker identification
problems. The robustness of the proposed framework is tested for
Text Independent Speaker Identification application on 100 speakers
of POLYCOST and 100 speakers of YOHO speech database in three
different noise environments. Experimental results show that the
proposed estimator yields a higher improvement in identification
accuracy compared to other estimators on popular Gaussian Mixture
Model (GMM) based speaker model and Mel-Frequency Cepstral
Coefficient (MFCC) features.
Abstract: This study was carried out to develop a flotation
procedure for an oxide copper ore from a Region in Central Africa
for producing an 18% copper concentrate for downstream processing
at maximum recovery from a 4% copper feed grade. The copper
recoveries achieved from the test work were less than 50% despite
changes in reagent conditions (multistage sulphidisation, use of RCA
emulsion and mixture, use of AM 2, etc). The poor recoveries were
attributed to the mineralogy of the ore from which copper silicates
accounted for approximately 70% (mass) of the copper minerals in
the ore. These can be complex and difficult to float using
conventional flotation methods. Best results were obtained using
basic sulphidisation procedures, a high flotation temperature and
extended flotation residence time.
Abstract: As the fossil fuels kept on depleting, intense research in developing hydrogen (H2) as the alternative fuel has been done to cater our tremendous demand for fuel. The potential of H2 as the ultimate clean fuel differs with the fossil fuel that releases significant amounts of carbon dioxide (CO2) into the surrounding and leads to the global warming. The experimental work was carried out to study the production of H2 from palm kernel shell steam gasification at different variables such as heating rate, steam to biomass ratio and adsorbent to biomass ratio. Maximum H2 composition which is 61% (volume basis) was obtained at heating rate of 100oCmin-1, steam/biomass of 2:1 ratio, and adsorbent/biomass of 1:1 ratio. The commercial adsorbent had been modified by utilizing the alcoholwater mixture. Characteristics of both adsorbents were investigated and it is concluded that flowability and floodability of modified CaO is significantly improved.
Abstract: Mixed-traffic (e.g., pedestrians, bicycles, and vehicles)
data at an intersection is one of the essential factors for intersection
design and traffic control. However, some data such as pedestrian
volume cannot be directly collected by common detectors (e.g.
inductive loop, sonar and microwave sensors). In this paper, a video
based detection algorithm is proposed for mixed-traffic data collection
at intersections using surveillance cameras. The algorithm is derived
from Gaussian Mixture Model (GMM), and uses a mergence time
adjustment scheme to improve the traditional algorithm. Real-world
video data were selected to test the algorithm. The results show that
the proposed algorithm has the faster processing speed and more
accuracy than the traditional algorithm. This indicates that the
improved algorithm can be applied to detect mixed-traffic at
signalized intersection, even when conflicts occur.
Abstract: In many applications, it is a priori known that the
target function should satisfy certain constraints imposed by, for
example, economic theory or a human-decision maker. Here we
consider partially monotone problems, where the target variable
depends monotonically on some of the predictor variables but not all.
We propose an approach to build partially monotone models based
on the convolution of monotone neural networks and kernel
functions. The results from simulations and a real case study on
house pricing show that our approach has significantly better
performance than partially monotone linear models. Furthermore, the
incorporation of partial monotonicity constraints not only leads to
models that are in accordance with the decision maker's expertise,
but also reduces considerably the model variance in comparison to
standard neural networks with weight decay.
Abstract: This paper presents development of an ignition system using spark electrodes for application in a research explosion vessel.
A single spark is aimed to be discharged with quantifiable ignition energy. The spark electrode system would enable study of flame
propagation, ignitability of fuel-air mixtures and other fundamental characteristics of flames. The principle of the capacitive spark circuit
of ASTM is studied to charge an appropriate capacitance connected across the spark gap through a large resistor by a high voltage from
the source of power supply until the initiation of spark. Different spark energies could be obtained mainly by varying the value of the
capacitance and the supply current. The spark sizes produced are found to be affected by the spark gap, electrode size, input voltage
and capacitance value.
Abstract: Two commercial proteases from Bacillus
licheniformis (Alcalase 2.4 L FG and Alcalase 2.5 L, Type DX) were
screened for the production of Z-Ala-Phe-NH2 in batch reaction.
Alcalase 2.4 L FG was the most efficient enzyme for the C-terminal
amidation of Z-Ala-Phe-OMe using ammonium carbamate as
ammonium source. Immobilization of protease has been achieved by
the sol-gel method, using dimethyldimethoxysilane (DMDMOS) and
tetramethoxysilane (TMOS) as precursors (unpublished results). In
batch production, about 95% of Z-Ala-Phe-NH2 was obtained at
30°C after 24 hours of incubation. Reproducibility of different
batches of commercial Alcalase 2.4 L FG preparations was also
investigated by evaluating the amidation activity and the entrapment
yields in the case of immobilization. A packed-bed reactor (0.68 cm
ID, 15.0 cm long) was operated successfully for the continuous
synthesis of peptide amides. The immobilized enzyme retained the
initial activity over 10 cycles of repeated use in continuous reactor at
ambient temperature. At 0.75 mL/min flow rate of the substrate
mixture, the total conversion of Z-Ala-Phe-OMe was achieved after 5
hours of substrate recycling. The product contained about 90%
peptide amide and 10% hydrolysis byproduct.
Abstract: In the modern construction practices, industrial wastes
or by-products are largely used as raw materials in cement and
concrete. These impart many benefits to the environment and bringabout
an economic impact because the cost of waste disposal is
constantly increasing due to strict environmental regulations. It was
reported in literature that the leakage of oil onto concrete element in
older cement grinding unit resulted in concrete with greater resistance
to freezing and thawing. This effect was thought to be similar to
adding an air-entraining chemical admixture to concrete. This paper
presents an investigation on the load deflection behaviour and crack
patterns of reinforced concrete (RC) beams subjected to four point
loading. Ten 120x260x1900 mm beams were cast with 100%
ordinary Portland cement (OPC) concrete, 20% fly ash (FA) and 20%
rice husk ash (RHA) blended cement concrete. 0.15% dosage of
admixtures (used engine oil, new engine oil, and superplasticizer)
was used throughout the experiment. Results show that OPC and
OPC/RHA RC beams containing used engine oil and superplasticizer
exhibit higher capacity, 18-26% than their corresponding control
mix.
Abstract: To provide a better understanding of fair share policies supported by current production schedulers and their impact on scheduling performance, A relative fair share policy supported in four well-known production job schedulers is evaluated in this study. The experimental results show that fair share indeed reduces heavy-demand users from dominating the system resources. However, the detailed per-user performance analysis show that some types of users may suffer unfairness under fair share, possibly due to priority mechanisms used by the current production schedulers. These users typically are not heavy-demands users but they have mixture of jobs that do not spread out.
Abstract: Polyurethane foams (PUF) has been prepared from
vegetable; soybean based polyols. They were characterized into
flexible and semi rigid polyurethane foam. This work is directed to
production of flexible polyurethane foams by a process involving the
reaction of mixture of 2,4- and 2,6-Toluene di Isocyanate isomers,
with portion of to blends of soy polyols with petroleum polyol in the
presence of other ingredients such as blowing agents, silicone
surfactants and accelerating agents. Additon of chain extender
improves the property then further decreases the properties on further
addition of the same. The objective of this work was to study the
effect of chain extender and role of phosphoric acid catalyst to the
final properties and correlate the morphology image with mechanical
properties of these foams.
Abstract: A highly optimized implementation of binary mixture
diffusion with no initial bulk velocity on graphics processors is
presented. The lattice Boltzmann model is employed for simulating
the binary diffusion of oxygen and nitrogen into each other with
different initial concentration distributions. Simulations have been
performed using the latest proposed lattice Boltzmann model that
satisfies both the indifferentiability principle and the H-theorem for
multi-component gas mixtures. Contemporary numerical
optimization techniques such as memory alignment and increasing
the multiprocessor occupancy are exploited along with some novel
optimization strategies to enhance the computational performance on
graphics processors using the C for CUDA programming language.
Speedup of more than two orders of magnitude over single-core
processors is achieved on a variety of Graphical Processing Unit
(GPU) devices ranging from conventional graphics cards to
advanced, high-end GPUs, while the numerical results are in
excellent agreement with the available analytical and numerical data
in the literature.
Abstract: The equivalence class subset algorithm is a powerful
tool for solving a wide variety of constraint satisfaction problems and
is based on the use of a decision function which has a very high but
not perfect accuracy. Perfect accuracy is not required in the decision
function as even a suboptimal solution contains valuable information
that can be used to help find an optimal solution. In the hardest
problems, the decision function can break down leading to a
suboptimal solution where there are more equivalence classes than
are necessary and which can be viewed as a mixture of good decision
and bad decisions. By choosing a subset of the decisions made in
reaching a suboptimal solution an iterative technique can lead to an
optimal solution, using series of steadily improved suboptimal
solutions. The goal is to reach an optimal solution as quickly as
possible. Various techniques for choosing the decision subset are
evaluated.
Abstract: The effect of dry milling on the carbothermic
reduction of celestite was investigated. Mixtures of celestite
concentrate (98% SrSO4) and activated carbon (99% carbon) was
milled for 1 and 24 hours in a planetary ball mill. Un-milled and
milled mixtures and their products after carbothermic reduction were
studied by a combination of XRD and TGA/DTA experiments. The
thermogravimetric analyses and XRD results showed that by milling
celestite-carbon mixtures for one hour, the formation temperature of
strontium sulfide decreased from about 720°C (in un-milled sample)
to about 600°C, after 24 hours milling it decreased to 530°C. It was
concluded that milling induces increasingly thorough mixing of the
reactants to reduction occurring at lower temperatures
Abstract: Due to the low heavy metal concentrations, the
bottom ash from a 32 MW municipal district heating plant was
determined to be a potential forest fertilizer as such. However,
additional Ca would be needed, because its Ca concentration of 1.9-
% (d.w.) was lower than the statutory Finnish minimum limit value
of 6.0-% (d.w.) for Ca in forest fertilizer. Due to the elevated As
concentration (53.0 mg/kg; d.w.) in the fly ash from the 32 MW
municipal district heating plant, and Cr concentration (620 mg/kg;
d.w.) in the ash fraction (i.e. mixture of the bottom ash and fly ash)
from the 6 MW municipal district heating plant, which exceed the
limit values of 30 mg/kg (d.w.) and 300 mg/kg (d.w.) for As and Cr,
respectively, these residues are not suitable as forest fertilizers.
Although these ash fractions cannot be used as a forest fertilizer as
such, they can be used for the landscaping of landfills or in industrial
and other areas that are closed to the public. However, an
environmental permit is then needed.
Abstract: The studies concerned an effect of six variants of ion
exchange substrate (nutrient carriers with a different potential impact
on pH of soil solution) on vegetation of orchard grass during two
different periods (42 and 84 days). In the pot experiment plants were
grown on sand (model of degraded soil) and six mixtures of sand and
2% (v/v) additions of particular variants of ion exchange substrate
(with pH ranged from 5.5 to 8.0). The study results showed that the
addition of the substrate at pH=6.5 caused the highest increase in
plant yield after shorter vegetation period whereas the addition of the
substrate at pH=5.5 increased dry stem and root biomass of orchard
grass after longer vegetation period. Thus, the ion exchange substrate
at pH=6.5 can be recommended for restoration of exhausted soils
when shorter vegetation period is planned; the ion exchange substrate
at pH=5.5 can be used for the same purpose when longer periods of
vegetative growth are considered.
Abstract: Cements, which are intrinsically brittle materials, can
exhibit a degree of pseudo-ductility when reinforced with a sufficient
volume fraction of a fibrous phase. This class of materials, called
Engineered Cement Composites (ECC) has the potential to be used in
future tunneling applications where a level of pseudo-ductility is
required to avoid brittle failures. However uncertainties remain
regarding mechanical performance. Previous work has focused on
comparatively thin specimens; however for future civil engineering
applications, it is imperative that the behavior in tension of thicker
specimens is understood. In the present work, specimens containing
cement powder and admixtures have been manufactured following
two different processes and tested in tension. Multiple matrix
cracking has been observed during tensile testing, leading to a
“strain-hardening" behavior, confirming the possible suitability of
ECC material when used as thick sections (greater than 50mm) in
tunneling applications.
Abstract: In this investigation, the antibacterial effects of
ethanolic and 7:3 isopropyl –hexane mixture extracts of Zingiber
officinale were evaluated against three Gram positive bacteria, B.
cereus, S.epidermidis, S. aureus and three Gram negative bacteria, E.
coli, K.pneumonia and P.areuginosa. Utilizing paper disk diffusion
and well methods in-vitro, MIC and MBC were determined by
macrodilution. The results showed that ethanolic rhizome extract of
ginger had significantly active than Isopropyl –hexan extract. Further
work needs to be done in these extracts including fractionation to
isolate active constituents and subsequent pharmacological
evaluation.