Abstract: This paper presents effects of the mean operating
pressure on the optimal operating frequency based on temperature
differences across stack ends in a thermoacoustic refrigerator. In
addition to the length of the resonance tube, components of the
thermoacoustic refrigerator have an influence on the operating
frequency due to their acoustic properties, i.e., absorptivity,
reflectivity and transmissivity. The interference of waves incurs and
distorts the original frequency generated by the driver so that the
optimal operating frequency differs from the designs. These acoustic
properties are not parameters in the designs and be very complicated
to infer their responses. A prototype thermoacoustic refrigerator is
constructed and used to investigate its optimal operating frequency
compared to the design at various operating pressures. Helium and air
are used as working fluids during the experiments. The results
indicate that the optimal operating frequency of the prototype
thermoacoustic refrigerator using helium is at 6 bar and 490Hz or
approximately 20% away from the design frequency. The optimal
operating frequency at other mean pressures differs from the design
in an unpredictable manner, however, the optimal operating
frequency and pressure can be identified by testing.
Abstract: A cold, thin film of liquid impinging on an isothermal
hot, horizontal surface has been investigated. An approximate
solution for the velocity and temperature distributions in the flow
along the horizontal surface is developed, which exploits the
hydrodynamic similarity solution for thin film flow. The approximate
solution may provide a valuable basis for assessing flow and heat
transfer in more complex settings.
Abstract: This paper presents dynamic models of distributed
generators (DG) and investigates dynamic behavior of the DG units
in the micro grid system. The DG units include photovoltaic and fuel
cell sources. The voltage source inverter is adopted since the
electronic interface which can be equipped with its controller to keep
stability of the micro grid during small signal dynamics. This paper
also introduces power management strategies and implements the DG
load sharing concept to keep the micro grid operation in gridconnected
and islanding modes of operation. The results demonstrate
the operation and performance of the photovoltaic and fuel cell as
distributed generators in a micro grid. The entire control system in
the micro grid is developed by combining the benefits of the power
control and the voltage control strategies. Simulation results are all
reported, confirming the validity of the proposed control technique.
Abstract: The thermal performance of a solar water heating with
1.00 m2 flat plate collectors in Cascavel - PR, is which presented in
this article, paper presents the solution to leverage the marketing of
solar heating systems through detailed constituent materials of the
solar collector studies, these abundant materials in construction, such
as expanded polyethylene, PVC, aluminum and glass tubes, mixing
them with new materials to minimize loss of efficiency while
decreasing its cost. The system was tested during months and the
collector obtained maximum recorded temperature of outlet fluid of
55°C, while the maximum temperature of the water at the bottom of
the hot water tank was 35°C. The average daily energy collected was
19.6 MJ/d; the energy supplied by the solar plate was 16.2 MJ/d; the
loss in the feed pipe was 3.2 MJ/d; the solar fraction was 32.2%, the
efficiency of the collector was 45.6% and the efficiency of the system
was 37.8%.
Abstract: The paper is focused on the identification of limiting
environmental factors of individual industrial floors on which newly
developed polymer protection and repair systems with the use of
secondary raw materials will be used. These mainly include floors
with extreme stresses and special requirements for materials used. In
relation to the environment of a particular industrial floor, it is
necessary to ensure, for example, chemical stability, resistance to
higher temperatures, resistance to higher mechanical stress, etc. for
developed materials, which is reflected in the demands for the
developed material systems. The paper describes individual
environments and, in relation to them, also requirements for
individual components of the developed materials and for the
developed materials as a whole.
Abstract: This paper presents a study the effect of nose radius
(Rz-mm) on cutting force components and temperatures during the
machining simulation in an orthogonal cutting process for titanium
alloy (Ti-6Al-4V). The cutting process was performed at various
nose radiuses (Rz-mm) while the depth of cut (d-mm), feed rate (fmm/
tooth) and cutting speed (vc-m/ min) were remained constant.
The main cutting force (Fc), feed cutting force (Ft) and temperatures
were estimated by using finite element modeling (FEM) through
ABAQUS/EXPLICIT software and the simulation was developed the
two-dimension via an orthogonal cutting process during machining
titanium alloy (Ti-6Al-4V). The results led to the conclusion that the
nose radius (Rz-mm) has affected directly on the cutting force
components. However, temperature gave no indication or has no
significant relation with nose radius during machining titanium alloy
(Ti-6Al-4V). Hence, any increase or decrease in the nose radius (Rzmm)
during machining operation led to effect on the cutting forces
and thus it will be effective on surface finish, quality, and quantity of
products.
Abstract: An innovative flooring underlayment was produced
and tested. The composite system is made of common OSB boards
and a layer of eco-friendly non-cement gypsum based material
(GeoGypTM). It was found that the shear bond between the two
materials is sufficient to secure the composite interaction between the
two. The very high compressive strength and relatively high tensile
strength of the non-cement based component together with its high
modulus of elasticity provides enough strength and stiffness for the
composite product to cover wider spacing between the joists. The
initial findings of this study indicate that with joist spacing as wide as
800 mm, the flooring system provides enough strength without
compromising the serviceability requirements of the building codes.
Abstract: Scrubbing by a liquid spraying is one of the most
effective processes used for removal of fine particles and soluble
gas pollutants (such as SO2, HCl, HF) from the flue gas. There are
many configurations of scrubbers designed to provide contact
between the liquid and gas stream for effectively capturing
particles or soluble gas pollutants, such as spray plates, packed bed
towers, jet scrubbers, cyclones, vortex and venturi scrubbers. The
primary function of venturi scrubber is the capture of fine particles
as well as HCl, HF or SO2 removal with effect of the flue gas
temperature decrease before input to the absorption column. In this
paper, sulfur dioxide (SO2) from flue gas was captured using new
design replacing venturi scrubber (1st degree of wet scrubbing).
The flue gas was prepared by the combustion of the carbon
disulfide solution in toluene (1:1 vol.) in the flame in the reactor.
Such prepared flue gas with temperature around 150°C was
processed in designed laboratory O-element scrubber. Water was
used as absorbent liquid. The efficiency of SO2 removal, pressure
drop and temperature drop were measured on our experimental
device. The dependence of these variables on liquid-gas ratio was
observed. The average temperature drop was in the range from
150°C to 40°C. The pressure drop was increased with increasing of
a liquid-gas ratio, but no too much as for the common venturi
scrubber designs. The efficiency of SO2 removal was up to 70 %.
The pressure drop of our new designed wet scrubber is similar to
commonly used venturi scrubbers; nevertheless the influence of
amount of the liquid on pressure drop is not so significant.
Abstract: Moving into a new era of healthcare, new tools and
devices are developed to extend and improve health services, such as
remote patient monitoring and risk prevention. In this concept,
Internet of Things (IoT) and Cloud Computing present great
advantages by providing remote and efficient services, as well as
cooperation between patients, clinicians, researchers and other health
professionals. This paper focuses on patients suffering from bipolar
disorder, a brain disorder that belongs to a group of conditions
called affective disorders, which is characterized by great mood
swings. We exploit the advantages of Semantic Web and Cloud
Technologies to develop a patient monitoring system to support
clinicians. Based on intelligently filtering of evidence-knowledge and
individual-specific information we aim to provide treatment
notifications and recommended function tests at appropriate times or
concluding into alerts for serious mood changes and patient’s nonresponse
to treatment. We propose an architecture as the back-end
part of a cloud platform for IoT, intertwining intelligence devices
with patients’ daily routine and clinicians’ support.
Abstract: Reliability of long-term storage products is related to
the availability of the whole system, and the evaluation of storage life
is of great necessity. These products are usually highly reliable and
little failure information can be collected. In this paper, an analytical
method based on data from accelerated storage life test is proposed to
evaluate the reliability index of the long-term storage products. Firstly,
singularities are eliminated by data normalization and residual
analysis. Secondly, with the preprocessed data, the degradation path
model is built to obtain the pseudo life values. Then by life distribution
hypothesis, we can get the estimator of parameters in high stress levels
and verify failure mechanism consistency. Finally, the life distribution
under the normal stress level is extrapolated via the acceleration model
and evaluation of the actual average life is available. An application
example with the camera stabilization device is provided to illustrate
the methodology we proposed.
Abstract: We have conducted the optimal synthesis of rootmean-
squared objective filter to estimate the state vector in the case if
within the observation channel with memory the anomalous noises
with unknown mathematical expectation are complement in the
function of the regular noises. The synthesis has been carried out for
linear stochastic systems of continuous - time.
Abstract: We investigate relaxation dynamics of a quantum
dipole emitter (QDE), e.g., a molecule or quantum dot, located near a
metal nanoparticle (MNP) exhibiting a dipolar localized surface
plasmon (LSP) resonance at the frequency of the QDE radiative
transition. It is shown that under the condition of the QDE-MNP
characteristic relaxation time being much shorter than that of the
QDE in free-space but much longer than the LSP lifetime. It is also
shown that energy dissipation in the QDE-MNP system is relatively
weak with the probability of the photon emission being about 0.75, a
number which, rather surprisingly, does not explicitly depend on the
metal absorption characteristics. The degree of entanglement
measured by the concurrency takes the maximum value, while the
distances between the QDEs and metal ball approximately are equal.
Abstract: Testability modeling is a commonly used method in
testability design and analysis of system. A dependency matrix will be
obtained from testability modeling, and we will give a quantitative
evaluation about fault detection and isolation.
Based on the dependency matrix, we can obtain the diagnosis tree.
The tree provides the procedures of the fault detection and isolation.
But the dependency matrix usually includes built-in test (BIT) and
manual test in fact. BIT runs the test automatically and is not limited
by the procedures. The method above cannot give a more efficient
diagnosis and use the advantages of the BIT.
A Comprehensive method of fault detection and isolation is
proposed. This method combines the advantages of the BIT and
Manual test by splitting the matrix. The result of the case study shows
that the method is effective.
Abstract: A cyclostationary Gaussian linearization method is
formulated for investigating the time average response of nonlinear
system under sinusoidal signal and white noise excitation. The
quantitative measure of cyclostationary mean, variance, spectrum of
mean amplitude, and mean power spectral density of noise are
analyzed. The qualitative response behavior of stochastic jump and
bifurcation are investigated. The validity of the present approach in
predicting the quantitative and qualitative statistical responses is
supported by utilizing Monte Carlo simulations. The present analysis
without imposing restrictive analytical conditions can be directly
derived by solving non-linear algebraic equations. The analytical
solution gives reliable quantitative and qualitative prediction of mean
and noise response for the Duffing system subjected to both sinusoidal
signal and white noise excitation.
Abstract: Although, lanthanum carbonate has not been approved
by the FDA for treatment of hyperphosphatemia, we prospectively
evaluated the efficacy of the combination of Calcium hydroxyapatite
(CHAp) and Lanthanum Carbonate (LaC) for the treatment of
hyperphosphatemia on mice. CHAp was prepared by co-precipitation
method using Ca(OH)2, H3PO4, NH4OH with calcination at 1200ºC.
Lanthanum carbonate was prepared by chemical method using
NaHCO3 and LaCl3 at low pH environment, below 4.0. The
structures were characterized by FTIR spectra and SEM -EDX
analysis. The study group included 16 subjects-mice divided into four
groups according to the administered substance: lanthanum carbonate
(group A), CHAp (group B), lanthanum carbonate + CHAp (group C)
and salt water (group D). The results indicate a phosphate decrease
when subjects (mice) were treated with CHAp and lanthanum
carbonate (0.5% CMC), in a single dose of 1500 mg/kg. Serum
phosphate concentration decreased [(from 4.5 ± 0.8 mg/dL) to
4.05 ± 0.2 mg/dL), P < 0.01] in group A and in group C (to 3.6
± 0.2 mg/dL) at 12 hours from the administration. The combination
of CHAp and lanthanum carbonate is a suitable regimen for
hyperphosphatemia treatment because it avoids both the
hypercalcemia of CaCO3 and the adverse effects of CHAp.
Abstract: The quality and condition of perishable products
delivered to the market and their subsequent selling prices are
directly affected by the care taken during harvesting and handling.
Mechanical injury, in fact, occurs at all stages, from pre-harvest
operations through post-harvest handling, packing and transport to
the market. The main implications of this damage are the reduction of
the product’s quality and economical losses related to the shelf life
diminution. For most perishable products, the shelf life is relatively
short and it is typically dictated by microbial growth related to the
application of dynamic and static loads during transportation. This
paper presents the correlation between vibration levels and
microbiological growth on strawberries and woodland strawberries
and detects the presence of volatile organic compounds (VOC) in
order to develop an intelligent logistic unit capable of monitoring
VOCs using a specific sensor system. Fresh fruits were exposed to
vibrations by means of a vibrating table in a temperature-controlled
environment. Microbiological analyses were conducted on samples,
taken at different positions along the column of the crates. The values
obtained were compared with control samples not exposed to
vibrations and the results show that different positions along the
column influence the development of bacteria, yeasts and filamentous
fungi.
Abstract: All the software engineering researches and best
industry practices aim at providing software products with high
degree of quality and functionality at low cost and less time. These
requirements are addressed by the Component Based Software
Engineering (CBSE) as well. CBSE, which deals with the software
construction by components’ assembly, is a revolutionary extension
of Software Engineering. CBSE must define and describe processes
to assure timely completion of high quality software systems that are
composed of a variety of pre built software components. Though
these features provide distinct and visible benefits in software design
and programming, they also raise some challenging problems. The
aim of this work is to summarize the pertinent issues and
considerations in CBSE to make an understanding in forms of
concepts and observations that may lead to development of newer
ways of dealing with the problems and challenges in CBSE.
Abstract: Alone with fast urbanization in world, traffic control
became a big issue in urban construction. Having an efficient and
reliable traffic control system is crucial to macro-traffic control.
Traffic signal is used to manage conflicting requirement by allocating
different sets of mutually compatible traffic movement during distinct
time interval. Many approaches have been made proposed to solve
this discrete stochastic problem. Recognizing the need to minimize
right-of-way impacts while efficiently handling the anticipated high
traffic volumes, the proposed alternative system gives effective
design. This model allows for increased traffic capacity and reduces
delays by eliminating a step in maneuvering through the freeway
interchange. The concept proposed in this paper involves
construction of bridges and ramps at intersection of four roads to
control the vehicular congestion and to prevent traffic breakdown.
Abstract: Subspace channel estimation methods have been
studied widely, where the subspace of the covariance matrix is
decomposed to separate the signal subspace from noise subspace. The
decomposition is normally done by using either the eigenvalue
decomposition (EVD) or the singular value decomposition (SVD) of
the auto-correlation matrix (ACM). However, the subspace
decomposition process is computationally expensive. This paper
considers the estimation of the multipath slow frequency hopping
(FH) channel using noise space based method. In particular, an
efficient method is proposed to estimate the multipath time delays by
applying multiple signal classification (MUSIC) algorithm which is
based on the null space extracted by the rank revealing LU (RRLU)
factorization. As a result, precise information is provided by the
RRLU about the numerical null space and the rank, (i.e., important
tool in linear algebra). The simulation results demonstrate the
effectiveness of the proposed novel method by approximately
decreasing the computational complexity to the half as compared
with RRQR methods keeping the same performance.
Abstract: Reliability allocation is quite important during early
design and development stages for a system to apportion its specified
reliability goal to subsystems. This paper improves the reliability
fuzzy allocation method, and gives concrete processes on determining
the factor and sub-factor sets, weight sets, judgment set, and
multi-stage fuzzy evaluation. To determine the weight of factor and
sub-factor sets, the modified trapezoidal numbers are proposed to
reduce errors caused by subjective factors. To decrease the fuzziness
in fuzzy division, an approximation method based on linear
programming is employed. To compute the explicit values of fuzzy
numbers, centroid method of defuzzification is considered. An
example is provided to illustrate the application of the proposed
reliability allocation method based on fuzzy arithmetic.