Abstract: This study focused on arsenate removal by nano
zero-valent iron (NZVI) in the gas-bubbled aqueous solution. It
appears that solution acidified by H2SO4 is far more favorable than by
CO2-bubbled acidification. In addition, as dissolved oxygen was
stripped out of solution by N2 gas bubbling, the arsenate removal
dropped significantly. To take advantages of common practice of
carbonation and oxic condition, pretreatment of CO2 and air bubbling
in sequence are recommended for a better removal of arsenate.
Abstract: We propose an integral tracking control method for a piezoelectric actuator system. The proposed method achieves the output tracking without requiring any hysteresis observer or schemes to compensate the hysteresis effect. With the proposed control law, the system is converted into the standard singularly perturbed model. Using Tikhonov-s theorem, we guarantee that the tracking error can be reduced to arbitrarily small bound. A numerical example is given to illustrate the effectiveness of our proposed method.
Abstract: In contrast to conventional generators, self-excited induction generators are found to be most suitable machines for wind energy conversion in remote and windy areas due to many advantages over grid connected machines. This papers presents a Self-Excited Induction Generator (SEIG) driven by wind turbine and supplying an induction motor which is coupled to a centrifugal pump. A method to describe the steady state performance based on nodal analysis is presented. Therefore the advanced knowledge of the minimum excitation capacitor value is required. The effects of variation of excitation capacitance on system and rotor speed under different loading conditions have been analyzed and considered to optimize induction motor pump performances.
Abstract: Permeability reduction induced by asphaltene
precipitation during gas injection is one of the serious problems in
the oil industry. This problem can lead to formation damage and
decrease the oil production rate. In this work, Malaysian light oil
sample has been used to investigate the effect CO2 injection and
Water Alternating Gas (WAG) injection on permeability reduction.
In this work, dynamic core flooding experiments were conducted to
study the effect of CO2 and WAG injection on the amount of
asphaltene precipitated. Core properties after displacement were
inspected for any permeability reduction to study the effect of
asphaltene precipitation on rock properties.
The results showed that WAG injection gave less asphaltene
precipitation and formation damage compared to CO2 injection. The
study suggested that WAG injection can be one of the important
factors of managing asphaltene precipitation.
Abstract: One of the robust fault detection filter (RFDF)
designing method is based on sliding-mode theory. The main purpose
of our study is to introduce an innovative simplified reference
residual model generator to formulate the RFDF as a sliding-mode
observer without any manipulation package or transformation matrix,
through which the generated residual signals can be evaluated. So the
proposed design is more explicit and requires less design parameters
in comparison with approaches requiring changing coordinates. To
the best author's knowledge, this is the first time that the sliding
mode technique is applied to detect actuator and sensor faults in a
real boiler. The designing procedure is proposed in a drum boiler in
Synvendska Kraft AB Plant in Malmo, Sweden as a multivariable
and strongly coupled system. It is demonstrated that both sensor and
actuator faults can robustly be detected. Also sensor faults can be
diagnosed and isolated through this method.
Abstract: In this paper, an analytical approach is used to study the coupled lateral-torsional vibrations of laminated composite beam. It is known that in such structures due to the fibers orientation in various layers, any lateral displacement will produce a twisting moment. This phenomenon is modeled by the bending-twisting material coupling rigidity and its main feature is the coupling of lateral and torsional vibrations. In addition to the material coupling, the effects of shear deformation and rotary inertia are taken into account in the definition of the potential and kinetic energies. Then, the governing differential equations are derived using the Hamilton-s principle and the mathematical model matches the Timoshenko beam model when neglecting the effect of bending-twisting rigidity. The equations of motion which form a system of three coupled PDEs are solved analytically to study the free vibrations of the beam in lateral and rotational modes due to the bending, as well as the torsional mode caused by twisting. The analytic solution is carried out in three steps: 1) assuming synchronous motion for the kinematic variables which are the lateral, rotational and torsional displacements, 2) solving the ensuing eigenvalue problem which contains three coupled second order ODEs and 3) imposing different boundary conditions related to combinations of simply, clamped and free end conditions. The resulting natural frequencies and mode shapes are compared with similar results in the literature and good agreement is achieved.
Abstract: Atherosclerosis was identified as a chronic inflammatory process resulting from interactions between plasma lipoproteins, cellular components (monocyte, macrophages, T lymphocytes, endothelial cells and smooth muscle cells) and the extracellular matrix of the arterial wall. Several types of genes were known to express during formation of atherosclerosis. This study is carried out to identify unknown differentially expressed gene (DEG) in atherogenesis. Rabbit’s aorta tissues were stained by H&E for histomorphology. GeneFishing™ PCR analysis was performed from total RNA extracted from the aorta tissues. The DNA fragment from DEG was cloned, sequenced and validated by Real-time PCR. Histomorphology showed intimal thickening in the aorta. DEG detected from ACP-41 was identified as cathepsin B gene and showed upregulation at week-8 and week-12 of atherogenesis. Therefore, ACP-based GeneFishing™ PCR facilitated identification of cathepsin B gene which was differentially expressed during development of atherosclerosis.
Abstract: Recently, malware attacks have become more serious
over the Internet by e-mail, denial of service (DoS) or distributed
denial of service (DDoS). The Botnets have become a significant part
of the Internet malware attacks. The traditional botnets include three
parts – botmaster, command and control (C&C) servers and bots. The
C&C servers receive commands from botmaster and control the
distributions of computers remotely. Bots use DNS to find the
positions of C&C server. In this paper, we propose an advanced hybrid
peer-to-peer (P2P) botnet 2.0 (AHP2P botnet 2.0) using web 2.0
technology to hide the instructions from botmaster into social sites,
which are regarded as C&C servers. Servent bots are regarded as
sub-C&C servers to get the instructions from social sites. The AHP2P
botnet 2.0 can evaluate the performance of servent bots, reduce DNS
traffics from bots to C&C servers, and achieve harder detection bots
actions than IRC-based botnets over the Internet.
Abstract: Yogurt is a coagulated milk product obtained from
the lactic acid fermentation by the action of Lactobacillus
bulgaricus and Streptococcus thermophilus. The additions of fruits
into milk may enhance the taste and the therapeutical values of milk
products. However fruits also may change the fermentation
behaviour. In this present study, the changes in physicochemical, the
peptide concentration, total phenolics content and the antioxidant
potential of yogurt upon the addition of Hylocereus polyrhizus and
Hylocereus undatus (white and red dragon fruit) were investigated.
Fruits enriched yogurt (10%, 20%, 30% w/w) were prepared and the
pH, TTA, syneresis measurement, peptide concentration, total
phenolics content and DPPH antioxidant inhibition percentage were
determined. Milk fermentation rate was enhanced in red dragon fruit
yogurt for all doses (-0.3606 - -0.4126 pH/h) while only white
dragon fruit yogurt with 20% and 30% (w/w) composition showed
increment in fermentation rate (-0.3471 - -0.3609 pH/h) compared to
plain yogurt (-0.3369pH/h). All dragon fruit enriched yogurts
generally showed lower pH readings (pH 3.95 - 4.03) compared to
plain yogurt (pH 4.05). Both fruit yogurts showed a higher lactic
acid percentage (1.14-1.23%) compared to plain yogurt (1.08%).
Significantly higher syneresis percentage (57.19 - 70.32%)
compared to plain yogurt (52.93%) were seen in all fruit enriched
yogurts. The antioxidant activity of plain yogurt (19.16%) was
enhanced by the presence of white and red dragon fruit (24.97-
45.74%). All fruit enriched yogurt showed an increment in total
phenolic content (36.44 - 64.43mg/ml) compared to plain yogurt
(20.25mg/ml). However, the addition of white and red dragon fruit
did not enhance the proteolysis of milk during fermentation.
Therefore, it could be concluded that the addition of white and red
dragon fruit into yogurt enhanced the milk fermentation rate, lactic
acid content, syneresis percentage, antioxidant activity, and total
phenolics content in yogurt.
Abstract: This study was aimed for investigating of
manufacturing high aluminum content Mg alloys using a horizontal
twin roll caster. Recently, weight saving has been key issues for lighter
transport equipments as well as electronic component parts. As
alternative materials to aluminum alloys, developing magnesium alloy
with higher strength has been expected. Normally high Aluminum
content Mg alloy has poor ductility and is difficult to be rolled because
of its high strength. However, twin roll casting process is suitable for
manufacturing wrought Mg alloys because materials can be cast
directly from molten metal. In this study, manufacturing of high
aluminum content magnesium alloy sheet using the roll casting
process has been carried out. Effects of manufacturing parameter, such
as roll velocity, pouring temperature and roll gap, on casting was
investigated. A microscopic observation of the crystals of cross section
of as cast strip as well as rolled strip was conducted.
Abstract: This paper presents two different sequential switching hybrid-modulation strategies and implemented for cascaded multilevel inverters. Hybrid modulation strategies represent the combinations of Fundamental-frequency pulse width modulation (FFPWM) and Multilevel sinusoidal-modulation (MSPWM) strategies, and are designed for performance of the well-known Alternative Phase opposition disposition (APOD), Phase shifted carrier (PSC). The main characteristics of these modulations are the reduction of switching losses with good harmonic performance, balanced power loss dissipation among the devices with in a cell, and among the series-connected cells. The feasibility of these modulations is verified through spectral analysis, power loss analysis and simulation.
Abstract: This paper quantifies the impact of providing a shortterm
excess active power support of a variable speed wind turbine
(VSWT) and effect of super magnetic energy storage (SMES) unit on
frequency control, particularly temporary minimum frequency (TMF)
term. To demonstrate the effect of these factors on the power system
frequency, a three-area power system is considered as a test system.
Abstract: This paper attempts to explore a new method to
improve the teaching of algorithmic for beginners. It is well known
that algorithmic is a difficult field to teach for teacher and complex to
assimilate for learner. These difficulties are due to intrinsic
characteristics of this field and to the manner that teachers (the
majority) apprehend its bases. However, in a Technology Enhanced
Learning environment (TEL), assessment, which is important and
indispensable, is the most delicate phase to implement, for all
problems that generate (noise...). Our objective registers in the
confluence of these two axes. For this purpose, EASEL focused
essentially to elaborate an assessment approach of algorithmic
competences in a TEL environment. This approach consists in
modeling an algorithmic solution according to basic and elementary
operations which let learner draw his/her own step with all autonomy
and independently to any programming language. This approach
assures a trilateral assessment: summative, formative and diagnostic
assessment.
Abstract: The cellular network is one of the emerging areas of
communication, in which the mobile nodes act as member for one
base station. The cluster based communication is now an emerging
area of wireless cellular multimedia networks. The cluster renders
fast communication and also a convenient way to work with
connectivity. In our scheme we have proposed an optimization
technique for the fuzzy cluster nodes, by categorizing the group
members into three categories like long refreshable member, medium
refreshable member and short refreshable member. By considering
long refreshable nodes as static nodes, we compute the new
membership values for the other nodes in the cluster. We compare
their previous and present membership value with the threshold value
to categorize them into three different members. By which, we
optimize the nodes in the fuzzy clusters. The simulation results show
that there is reduction in the cluster computational time and
iterational time after optimization.
Abstract: A Decision Support System/Expert System for stock
portfolio selection presented where at first step, both technical and
fundamental data used to estimate technical and fundamental return
and risk (1st phase); Then, the estimated values are aggregated with
the investor preferences (2nd phase) to produce convenient stock
portfolio.
In the 1st phase, there are two expert systems, each of which is
responsible for technical or fundamental estimation. In the technical
expert system, for each stock, twenty seven candidates are identified
and with using rough sets-based clustering method (RC) the effective
variables have been selected. Next, for each stock two fuzzy rulebases
are developed with fuzzy C-Mean method and Takai-Sugeno-
Kang (TSK) approach; one for return estimation and the other for
risk. Thereafter, the parameters of the rule-bases are tuned with backpropagation
method. In parallel, for fundamental expert systems,
fuzzy rule-bases have been identified in the form of “IF-THEN" rules
through brainstorming with the stock market experts and the input
data have been derived from financial statements; as a result two
fuzzy rule-bases have been generated for all the stocks, one for return
and the other for risk.
In the 2nd phase, user preferences represented by four criteria and
are obtained by questionnaire. Using an expert system, four estimated
values of return and risk have been aggregated with the respective
values of user preference. At last, a fuzzy rule base having four rules,
treats these values and produce a ranking score for each stock which
will lead to a satisfactory portfolio for the user.
The stocks of six manufacturing companies and the period of
2003-2006 selected for data gathering.
Abstract: Packing problems arise in a wide variety of application
areas. The basic problem is that of determining an efficient arrangement
of different objects in a region without any overlap and
with minimal wasted gap between shapes. This paper presents a
novel population based approach for optimizing arrangement of irregular
shapes. In this approach, each shape is coded as an agent and
the agents' reproductions and grouping policies results in arrangements
of the objects in positions with least wasted area between
them. The approach is implemented in an application for cutting
sheets and test results on several problems from literature are presented.
Abstract: The RANS method with Saffman-s turbulence model
was employed to solve the time-dependent turbulent Navier-Stokes
and energy equations for oscillating pipe flows. The method of
partial sums of the Fourier series is used to analyze the harmonic
velocity and temperature results. The complete structures of the
oscillating pipe flows and the averaged Nusselt numbers on the tube
wall are provided by numerical simulation over wide ranges of ReA
and ReR. Present numerical code is validated by comparing the
laminar flow results to analytic solutions and turbulence flow results
to published experimental data at lower and higher Reynolds
numbers respectively. The effects of ReA and ReR on the velocity,
temperature and Nusselt number distributions have been di scussed.
The enhancement of the heat transfer due to oscillating flows has
also been presented. By the way of analyzing the overall Nusselt
number over wide ranges of the Reynolds number Re and Keulegan-
Carpenter number KC, the optimal ratio of the tube diameter over
the oscillation amplitude is obtained based on the existence of a
nearly constant optimal KC number. The potential application of the
present results in sea water cooling has also been discussed.
Abstract: This paper shows the results obtained in the analysis
of the impact of distributed generation (DG) on distribution losses
and presents a new algorithm to the optimal allocation of distributed
generation resources in distribution networks. The optimization is
based on a Hybrid Genetic Algorithm and Particle Swarm
Optimization (HGAPSO) aiming to optimal DG allocation in
distribution network. Through this algorithm a significant
improvement in the optimization goal is achieved. With a numerical
example the superiority of the proposed algorithm is demonstrated in
comparison with the simple genetic algorithm.
Abstract: The aim of the present study was to investigate the
chemical and biological properties of local cowpea seed protein
cultivated in Gizan region. The results showed that the cowpea and
its products contain high level of protein (22.9-77.6%), high
carbohydrates (9.4-64.3%) and low fats (0.1-0.3%). The trypsin and
chymotrypsin activities were found to be 32.2 and 15.2 units,
respectively. These activities were not affected in both defatted and
protein concentrate whereas they were significantly reduced in
isolated protein and cooked samples. The phytate content of cooked
and concentrated cowpea samples varied from 0.25% -0.32%,
respectively. Tannin content was found to be 0.4% and 0.23% for
cooked and raw samples, respectively. The in vitro protein
digestibility was very high in cowpea seeds (75.04-78.76%). The
biological evaluation using rats showed that the group fed with
animal feed containing casein gain more weight than those fed with
that containing cowpea. However, the group fed with cooked cowpea
gain more weight than those fed with uncooked cowpea. On the
other hand, in vivo digestion showed high value (98.33%) among the
group consumed casein compared to other groups those consumed
cowpea contains feed. This could be attributed to low antinutritional
factors in casein contains feed compared to those of cowpea contains
feed because cooking significantly increased the digestion rate
(80.8% to 83.5%) of cowpea contains feed. Furthermore, the
biological evaluation was high (91.67%) of casein containing feed
compared to that of cowpea containing feed (80.83%-87.5%). The
net protein utilization (NPU) was higher (89.67%) in the group fed
with casein containing feed than that of cowpea containing feed
(56.33%-69.67%).
Abstract: In this work a software simulation model has been
proposed for two driven wheels mobile robot path planning; that can
navigate in dynamic environment with static distributed obstacles.
The work involves utilizing Bezier curve method in a proposed N
order matrix form; for engineering the mobile robot path. The Bezier
curve drawbacks in this field have been diagnosed. Two directions:
Up and Right function has been proposed; Probability Recursive
Function (PRF) to overcome those drawbacks.
PRF functionality has been developed through a proposed;
obstacle detection function, optimization function which has the
capability of prediction the optimum path without comparison
between all feasible paths, and N order Bezier curve function that
ensures the drawing of the obtained path.
The simulation results that have been taken showed; the mobile
robot travels successfully from starting point and reaching its goal
point. All obstacles that are located in its way have been avoided.
This navigation is being done successfully using the proposed PRF
techniques.