Abstract: We fabricated multi-walled carbon nanotube (MCNT)
emitters by an electroporetic deposition (EPD) method using a
MCNT-sodium dodecyl sulfate (SDS) suspension. MCNT films were
prepared on graphite tip using EPD. We observe field emission
properties of MCNT film after heat treatment. Consequently, The
MCNT film on graphite tip exhibit good electron emission current.
Abstract: In this study, the forty Thai medicinal plants were
used to screen the antibacterial activity against Campylobacter jejuni.
Crude 95% ethanolic extracts of each plant were prepared.
Antibacterial activity was investigated by the disc diffusion assay,
and MICs and MBCs were determined by broth microdilution. The
results of antibacterial screening showed that five plants have activity
against C.jejuni including Adenanthera pavonina L., Moringa
oleifera Lam., Annona squamosa L., Hibiscus sabdariffa L. and
Eupotorium odortum L. The extraction of A. pavonina L. and A.
squamosa L. produced an outstanding against C. jejuni, inhibiting
growth at 62.5-125 and 250-500 μg/mL, respectively. The MBCs of
two extracts were just 4-fold higher than MICs against C. jejuni,
suggesting the extracts are bactericidal against this species. These
results indicate that A. pavonina and A. squamosa could potentially
be used in modern applications aimed at treatment or prevention of
foodborne disease from C. jejuni.
Abstract: Saccharomyces cerevisiae (baker-s yeast) can exhibit
sustained oscillations during the operation in a continuous bioreactor
that adversely affects its stability and productivity. Because of
heterogeneous nature of cell populations, the cell population balance
models can be used to capture the dynamic behavior of such cultures.
In this paper an unstructured, segregated model is used which is
based on population balance equation(PBE) and then in order to
simulation, the 4th order Rung-Kutta is used for time dimension and
three methods, finite difference, orthogonal collocation on finite
elements and Galerkin finite element are used for discretization of the
cell mass domain. The results indicate that the orthogonal collocation
on finite element not only is able to predict the oscillating behavior of
the cell culture but also needs much little time for calculations.
Therefore this method is preferred in comparison with other methods.
In the next step two controllers, a globally linearizing control (GLC)
and a conventional proportional-integral (PI) controller are designed
for controlling the total cell mass per unit volume, and performances
of these controllers are compared through simulation. The results
show that although the PI controller has simpler structure, the GLC
has better performance.
Abstract: Bone growth factors, such as Bone Morphogenic
Protein-2 (BMP-2) have been approved by the FDA to replace grafting for some surgical interventions, but the high dose requirement limits its use in patients. Noggin, an extracellular protein, blocks the effect of BMP-2 by binding to BMP. Preventing
the BMP-2/noggin interaction will help increase the free
concentration of BMP-2 and therefore should enhance its efficacy to
induce bone formation. The work presented here involves
computational design of novel small molecule inhibitory agents of BMP-2/noggin interaction, based on our current understanding of
BMP-2, and its known putative ligands (receptors and antagonists). A
successful acquisition of such an inhibitory agent of BMP-2/noggin interaction would allow clinicians to reduce the dose required of
BMP-2 protein in clinical applications to promote osteogenesis. The
available crystal structures of the BMPs, its receptors, and the binding partner noggin were analyzed to identify the critical residues
involved in their interaction. In presenting this study, LUDI de novo design method was utilized to perform virtual screening of a large
number of compounds from a commercially available library against the binding sites of noggin to identify the lead chemical compounds
that could potentially block BMP-noggin interaction with a high specificity.
Abstract: A power cable is widely used for power supply in
power distributing networks and power transmission lines. Due to
limitations in the production, delivery and setting up power cables,
they are produced and delivered in several separate lengths. Cable
itself, consists of two cable terminations and arbitrary number of
cable joints, depending on the cable route length. Electrical stress
control is needed to prevent a dielectric breakdown at the end of the
insulation shield in both the air and cable insulation. Reliability of
cable joint depends on its materials, design, installation and operating
environment. The paper describes design and performance results for
new modeled cable joints. Design concepts, based on numerical
calculations, must be correct. An Equivalent Electrodes
Method/Boundary Elements Method-hybrid approach that allows
electromagnetic field calculations in multilayer dielectric media,
including inhomogeneous regions, is presented.
Abstract: One of the important factors of cracks on the asphalt
pavements is bitumen aging that associated with the loss of volatile
components and oxidation of asphalt binder. This paper is about
effect of Styrene-Butadiene-Styrene (SBS) polymer on asphalt aging
In order to decrease asphalt aging effects. For this purpose samples of
base bitumen and SBS modified bitumen aged according to the
rolling thin film oven test (RTFOT) and pressure aging vessel (PAV),
respectively. Properties of each sample were evaluated using Fourier
Transform Infrared (FTIR) spectroscopy, n-heptane precipitation,
viscosity test, softening point test and penetration test. FT-IR
Analysis, showed lower oxidation of SBS modified bitumen than
base bitumen, after aging.
Abstract: The present study has been taken to explore the
screening of in vitro antimicrobial activities of D-galactose-binding
sponge lectin (HOL-30). HOL-30 was purified from the marine
demosponge Halichondria okadai by affinity chromatography. The
molecular mass of the lectin was determined to be 30 kDa with a
single polypeptide by SDS-PAGE under non-reducing and reducing
conditions. HOL-30 agglutinated trypsinized and glutaraldehydefixed
rabbit and human erythrocytes with preference for type O
erythrocytes. The lectin was subjected to evaluation for inhibition of
microbial growth by the disc diffusion method against eleven human
pathogenic gram-positive and gram-negative bacteria. The lectin
exhibited strong antibacterial activity against gram-positive bacteria,
such as Bacillus megaterium and Bacillus subtilis. However, it did
not affect against gram-negative bacteria such as Salmonella typhi
and Escherichia coli. The largest zone of inhibition was recorded of
Bacillus megaterium (12 in diameter) and Bacillus subtilis (10 mm in
diameter) at a concentration of the lectin (250 μg/disc). On the other
hand, the antifungal activity of the lectin was investigated against six
phytopathogenic fungi based on food poisoning technique. The lectin
has shown maximum inhibition (22.83%) of mycelial growth of
Botrydiplodia theobromae at a concentration of 100 μg/mL media.
These findings indicate that the lectin may be of importance to
clinical microbiology and have therapeutic applications.
Abstract: In this paper, we provide complete end-to-end delay analyses including the relay nodes for instant messages. Message Session Relay Protocol (MSRP) is used to provide congestion control for large messages in the Instant Messaging (IM) service. Large messages are broken into several chunks. These chunks may traverse through a maximum number of two relay nodes before reaching destination according to the IETF specification of the MSRP relay extensions. We discuss the current solutions of sending large instant messages and introduce a proposal to reduce message flows in the IM service. We consider virtual traffic parameter i.e., the relay nodes are stateless non-blocking for scalability purpose. This type of relay node is also assumed to have input rate at constant bit rate. We provide a new scheduling policy that schedules chunks according to their previous node?s delivery time stamp tags. Validation and analysis is shown for such scheduling policy. The performance analysis with the model introduced in this paper is simple and straight forward, which lead to reduced message flows in the IM service.
Abstract: Attachment of the circulating monocytes to the
endothelium is the earliest detectable events during formation of
atherosclerosis. The adhesion molecules, chemokines and matrix
proteases genes were identified to be expressed in atherogenesis.
Expressions of these genes may influence structural integrity of the
luminal endothelium. The aim of this study is to relate changes in the
ultrastructural morphology of the aortic luminal surface and gene
expressions of the endothelial surface, chemokine and MMP-12 in
normal and hypercholesterolemic rabbits. Luminal endothelial
surface from rabbit aortic tissue was examined by scanning electron
microscopy (SEM) using low vacuum mode to ascertain
ultrastructural changes in development of atherosclerotic lesion. Gene
expression of adhesion molecules, MCP-1 and MMP-12 were studied
by Real-time PCR. Ultrastructural observations of the aortic luminal
surface exhibited changes from normal regular smooth intact
endothelium to irregular luminal surface including marked globular
appearance and ruptures of the membrane layer. Real-time PCR
demonstrated differentially expressed of studied genes in
atherosclerotic tissues. The appearance of ultrastructural changes in
aortic tissue of hypercholesterolemic rabbits is suggested to have
relation with underlying changes of endothelial surface molecules,
chemokine and MMP-12 gene expressions.
Abstract: In-vitro mouse co-culture of E14 embryonic stem cells
(ESCs) and OP9 stromal cells can recapitulate the earliest stages of
haematopoietic development, not accessible in human embryos,
supporting both haemogenic precursors and their primitive
haematopoietic progeny. 1α, 25-Dihydroxy-vitamin D3 (VD3) has
been demonstrated to be a powerful differentiation inducer for a wide
variety of neoplastic cells, and could enhance early differentiation of
ESCs into blood cells in E14/OP9 co-culture. This study aims to
ascertain whether VD3 is key in promoting differentiation and
suppressing proliferation, by separately investigating the effects of
VD3 on the proliferation phase of the E14 cell line and on stromal
OP9 cells.The results showed that VD3 inhibited the proliferation of
the cells in a dose-dependent manner, quantitatively by decreased cell
number, and qualitatively by alkaline-phosphatase staining that
revealed significant differences between VD3-treated and untreated
cells, characterised by decreased enzyme expression (colourless
cells). Propidium-iodide cell-cycle analyses showed no significant
percentage change in VD3-treated E14 and OP9 cells within their G
and S-phases, compared to the untreated controls, despite the
increased percentage of G-phase compared to the S-phase in a dosedependent
manner. These results with E14 and OP9 cells indicate that
adequate VD3 concentration enhances cellular differentiation and
inhibits proliferation. The results also suggest that if E14 and OP9
cells were co-cultured andVD3-treated, there would be furtherenhanced
differentiation of ESCs into blood cells.
Abstract: Space exploration is a highly visible endeavour of
humankind to seek profound answers to questions about the origins
of our solar system, whether life exists beyond Earth, and how we
could live on other worlds. Different platforms have been utilized in
planetary exploration missions, such as orbiters, landers, rovers, and
penetrators.
Having low mass, good mechanical contact with the surface,
ability to acquire high quality scientific subsurface data, and ability to
be deployed in areas that may not be conducive to landers or rovers,
Penetrators provide an alternative and complimentary solution that
makes possible scientific exploration of hardly accessible sites (icy
areas, gully sites, highlands etc.).
The Canadian Space Agency (CSA) has put space exploration as
one of the pillars of its space program, and established ExCo program
to prepare Canada for future international planetary exploration.
ExCo sets surface mobility as its focus and priority, and invests
mainly in the development of rovers because of Canada's niche space
robotics technology. Meanwhile, CSA is also investigating how
micro-penetrators can help Canada to fulfill its scientific objectives
for planetary exploration.
This paper presents a review of the micro-penetrator technologies,
past missions, and lessons learned. It gives a detailed analysis of the
technical challenges of micro-penetrators, such as high impact
survivability, high precision guidance navigation and control, thermal
protection, communications, and etc. Then, a Canadian perspective of
a possible micro-penetrator mission is given, including Canadian
scientific objectives and priorities, potential instruments, and flight
opportunities.
Abstract: A generalized Digital Modulation Identification algorithm for adaptive demodulator has been developed and presented in this paper. The algorithm developed is verified using wavelet Transform and histogram computation to identify QPSK and QAM with GMSK and M–ary FSK modulations. It has been found that the histogram peaks simplifies the procedure for identification. The simulated results show that the correct modulation identification is possible to a lower bound of 5 dB and 12 dB for GMSK and QPSK respectively. When SNR is above 5 dB the throughput of the proposed algorithm is more than 97.8%. The receiver operating characteristics (ROC) has been computed to measure the performance of the proposed algorithm and the analysis shows that the probability of detection (Pd) drops rapidly when SNR is 5 dB and probability of false alarm (Pf) is smaller than 0.3. The performance of the proposed algorithm has been compared with existing methods and found it will identify all digital modulation schemes with low SNR.
Abstract: This article describes design of the 8-bit asynchronous
microcontroller simulation model in VHDL. The model is created in
ISE Foundation design tool and simulated in Modelsim tool. This
model is a simple application example of asynchronous systems
designed in synchronous design tools. The design process of creating
asynchronous system with 4-phase bundled-data protocol and with
matching delays is described in the article. The model is described in
gate-level abstraction.
The simulation waveform of the functional construction is the
result of this article. Described construction covers only the
simulation model. The next step would be creating synthesizable
model to FPGA.
Abstract: The production of activated carbon from low or zero cost of agricultural by-products or wastes has received great attention from academics and practitioners due to its economic and environmental benefits. In the production of bamboo furniture, a significant amount of bamboo waste is inevitably generated. Therefore, this research aimed to prepare activated carbons from bamboo furniture waste by chemical (KOH) activation and determine their properties and adsorption capacities for water treatment. The influence of carbonization time on the properties and adsorption capacities of activated carbons was also investigated. The finding showed that the bamboo-derived activated carbons had microporous characteristics. They exhibited high tendency for the reduction of impurities present in effluent water. Their adsorption capacities were comparable to the adsorption capacity of a commercial activated carbon regarding to the reduction in COD, TDS and turbidity of the effluent water.
Abstract: This paper presented a proposed design for
transcutaneous inductive powering links. The design used to transfer
power and data to the implanted devices such as implanted
Microsystems to stimulate and monitoring the nerves and muscles.
The system operated with low band frequency 13.56 MHZ according
to industrial- scientific – medical (ISM) band to avoid the tissue
heating. For external part, the modulation index is 13 % and the
modulation rate 7.3% with data rate 1 Mbit/s assuming Tbit=1us. The
system has been designed using 0.35-μm fabricated CMOS
technology. The mathematical model is given and the design is
simulated using OrCAD P Spice 16.2 software tool and for real-time
simulation the electronic workbench MULISIM 11 has been used.
The novel circular plane (pancake) coils was simulated using
ANSOFT- HFss software.
Abstract: This paper describes a UDP over IP based, server-oriented redundant host configuration protocol (RHCP) that can be used by collaborating embedded systems in an ad-hoc network to acquire a dynamic IP address. The service is provided by a single network device at a time and will be dynamically reassigned to one of the other network clients if the primary provider fails. The protocol also allows all participating clients to monitor the dynamic makeup of the network over time. So far the algorithm has been implemented and tested on an 8-bit embedded system architecture with a 10Mbit Ethernet interface.
Abstract: In this paper we present a technique to speed up
ICA based on the idea of reducing the dimensionality of the data
set preserving the quality of the results. In particular we refer to
FastICA algorithm which uses the Kurtosis as statistical property
to be maximized. By performing a particular Johnson-Lindenstrauss
like projection of the data set, we find the minimum dimensionality
reduction rate ¤ü, defined as the ratio between the size k of the reduced
space and the original one d, which guarantees a narrow confidence
interval of such estimator with high confidence level. The derived
dimensionality reduction rate depends on a system control parameter
β easily computed a priori on the basis of the observations only.
Extensive simulations have been done on different sets of real world
signals. They show that actually the dimensionality reduction is very
high, it preserves the quality of the decomposition and impressively
speeds up FastICA. On the other hand, a set of signals, on which the
estimated reduction rate is greater than 1, exhibits bad decomposition
results if reduced, thus validating the reliability of the parameter β.
We are confident that our method will lead to a better approach to
real time applications.
Abstract: One of the disadvantages of using OFDM is the larger
peak to averaged power ratio (PAPR) in its time domain signal. The
larger PAPR signal would course the fatal degradation of bit error
rate performance (BER) due to the inter-modulation noise in the nonlinear
channel. This paper proposes an improved DSI (Dummy
Sequence Insertion) method, which can achieve the better PAPR and
BER performances. The feature of proposed method is to optimize
the phase of each dummy sub-carrier so as to reduce the PAPR
performance by changing all predetermined phase coefficients in the
time domain signal, which is calculated for data sub-carriers and
dummy sub-carriers separately. To achieve the better PAPR
performance, this paper also proposes to employ the time-frequency
domain swapping algorithm for fine adjustment of phase coefficient
of the dummy subcarriers, which can achieve the less complexity of
processing and achieves the better PAPR and BER performances
than those for the conventional DSI method. This paper presents
various computer simulation results to verify the effectiveness of
proposed method as comparing with the conventional methods in the
non-linear channel.
Abstract: In this paper a tuning fork type structure of Ultra
Wideband (UWB) antenna is proposed. The antenna offers excellent
performance for UWB system, ranging from 3.7 GHz to 13.8 GHz.
The antenna exhibits a 10 dB return loss bandwidth over the entire
frequency band. The rectangular patch antenna is designed on FR4
substrate and fed with 50 ohms microstrip line by optimizing the
width of partial ground, the width and position of the feedline to
operate in UWB. The rectangular patch is then modified to tuning
fork structure by maintaining UWB frequency range.
Abstract: This article presents the results using a parametric approach and a Wavelet Transform in analysing signals emitting from the sperm whale. The extraction of intrinsic characteristics of these unique signals emitted by marine mammals is still at present a difficult exercise for various reasons: firstly, it concerns non-stationary signals, and secondly, these signals are obstructed by interfering background noise. In this article, we compare the advantages and disadvantages of both methods: Auto Regressive models and Wavelet Transform. These approaches serve as an alternative to the commonly used estimators which are based on the Fourier Transform for which the hypotheses necessary for its application are in certain cases, not sufficiently proven. These modern approaches provide effective results particularly for the periodic tracking of the signal's characteristics and notably when the signal-to-noise ratio negatively effects signal tracking. Our objectives are twofold. Our first goal is to identify the animal through its acoustic signature. This includes recognition of the marine mammal species and ultimately of the individual animal (within the species). The second is much more ambitious and directly involves the intervention of cetologists to study the sounds emitted by marine mammals in an effort to characterize their behaviour. We are working on an approach based on the recordings of marine mammal signals and the findings from this data result from the Wavelet Transform. This article will explore the reasons for using this approach. In addition, thanks to the use of new processors, these algorithms once heavy in calculation time can be integrated in a real-time system.