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: Honeys are produced by Apis mellifera and stingless
bees (Meliponini) in Ecuador. We studied honey produced in
beeswax combs by Apis mellifera, and honey produced in pots by
Geotrigona and Scaptotrigona bees. Chloroform extracts of honey
were obtained for fast NMR spectra. The 1D spectra were acquired at
298 K, with a 600 MHz NMR Bruker instrument, using a modified
double pulsed field gradient spin echoes (DPFGSE) sequence.
Signals of 1H NMR spectra were integrated and used as inputs for
PCA, PLS-DA analysis, and labelled sets of classes were successfully
identified, enhancing the separation between the three groups of
honey according to the entomological origin: A. mellifera,
Geotrigona and Scaptotrigona. This procedure is therefore
recommended for authenticity test of honey in Ecuador.
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: By textile science incorporating with electronic
industry, developed textile products start to take part in different
areas such as industry, military, space, medical etc. for health,
protection, defense, communication and automation. Electronic
textiles (e-textiles) are fabrics that contain electronics and
interconnections with them. In this study, two types of base yarns
(cotton and acrylic) and three types of conductive steel yarns with
different linear resistance values (14Ω/m, 30Ω/m, 70Ω/m) were used
to investigate the effect of base yarn type and linear resistance of
conductive yarns on thermal behavior of e-textile structures. Thermal
behavior of samples was examined by thermal camera.
Abstract: Control of honey frauds is needed in Ecuador to
protect bee keepers and consumers because simple syrups and new
syrups with eucalyptus are sold as genuine honeys. Authenticity of
Ecuadorian commercial honeys was tested with a vortex emulsion
consisting on one volume of honey:water (1:1) dilution, and two
volumes of diethyl ether. This method allows a separation of phases
in one minute to discriminate genuine honeys that form three phase
and fake honeys that form two phases; 34 of the 42 honeys analyzed
from five provinces of Ecuador were genuine. This was confirmed
with 1H NMR spectra of honey dilutions in deuterated water with an
enhanced amino acid region with signals for proline, phenylalanine
and tyrosine. Classic quality indicators were also tested with this
method (sugars, HMF), indicators of fermentation (ethanol, acetic
acid), and residues of citric acid used in the syrup manufacture. One
of the honeys gave a false positive for genuine, being an admixture of
genuine honey with added syrup, evident for the high sucrose.
Sensory analysis was the final confirmation to recognize the honey
groups studied here, namely honey produced in combs by Apis
mellifera, fake honey, and honey produced in cerumen pots by
Geotrigona, Melipona, and Scaptotrigona. Chloroform extractions of
honey were also done to search lipophilic additives in NMR spectra.
This is a valuable contribution to protect honey consumers, and to
develop the beekeeping industry in Ecuador.
Abstract: The intrinsic contradictions of entrepreneurship
development and self-development strategies complicate the task of
reaching compliance between the state economic policy and the
company entrepreneurship policy: on the one hand, there is a
contradiction between the social and the competitive order within
economic order policy and on the other hand, the contradiction exists
between entrepreneurship strategy and entrepreneurship culture
within entrepreneurship policy.
Abstract: In emerging economies, recycling is an opportunity
for the cities to increase the lifespan of sanitary landfills, reduce the
costs of the solid waste management, decrease the environmental
problems of the waste treatment through reincorporate waste in the
productive cycle and protect and develop people’s livelihoods of
informal waste pickers. However, few studies have analysed the
possibilities and strategies to integrate formal and informal sectors in
the solid waste management for the benefit of both. This study seek
to make a strength, weakness, opportunity, and threat (SWOT)
analysis in three recycling associations of Bogotá with the aim to
understand and determine the situation of recycling from perspective
of informal sector in its transition to enter as authorized waste
providers. Data used in the analysis are derived from multiple
strategies such as literature review, the Bogota’s recycling database,
focus group meetings, governmental reports, national laws and
regulations and specific interviews with key stakeholders. Results of
this study show as the main stakeholders of formal and informal
sector of waste management can identify the internal and internal
conditions of recycling in Bogotá. Several strategies were designed
based on the SWOTs determined, could be useful for Bogotá to
advance and promote recycling as a key strategy for integrated
sustainable waste management in the city.
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: Propylene self-metathesis to ethylene and butene was
studied over WOx/SiO2 catalysts at 450oC and atmospheric pressure.
The WOx/SiO2 catalysts were prepared by incipient wetness
impregnation of ammonium metatungstate aqueous solution. It was
found that, adding nano-sized extra supports (SiO2 and TiO2) by
physical mixing with the WOx/SiO2 enhanced propylene conversion.
The UV-Vis and FT-Raman results revealed that WOx could migrate
from the original silica support to the extra support, leading to a
better dispersion of WOx. The ICP-OES results also indicate that
WOx existed on the extra support. Coke formation was investigated
on the catalysts after 10 h time-on-stream by TPO. However, adding
nano-sized extra supports led to higher coke formation which may be
related to acidity as characterized by NH3-TPD.
Abstract: This paper presents the design and fabrication of an
optical window for an optical modulator toward image sensing
applications. An optical window consists of micrometer-order SiO2
capillaries (porous solid) that can modulate transmission light
intensity by moving the liquid in and out of porous solid. A high
optical transmittance of the optical window can be achieved due to
refractive index matching when the liquid is penetrated into the
porous solid. Otherwise, its light transmittance is lower because of
light reflection and scattering by air holes and capillary walls. Silicon
capillaries fabricated by deep reactive ion etching (DRIE) process are
completely oxidized to form the SiO2 capillaries. Therefore, high
aspect ratio SiO2 capillaries can be achieved based on silicon
capillaries formed by DRIE technique. Large compressive stress of
the oxide causes bending of the capillary structure, which is reduced
by optimizing the design of device structure. The large stress of the
optical window can be released via thin supporting beams. A 7.2 mm
x 9.6 mm optical window area toward a fully integrated with the
image sensor format is successfully fabricated and its optical
transmittance is evaluated with and without inserting liquids (ethanol
and matching oil). The achieved modulation range is approximately
20% to 35% with and without liquid penetration in visible region
(wavelength range from 450 nm to 650 nm).
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: This paper presents a model for a modified T-junction
device for microspheres generation. The numerical model is
developed using a commercial software package: COMSOL
Multiphysics. In order to test the accuracy of the numerical model,
multiple variables, such as the flow rate of cross-flow, fluid properties,
structure, and geometry of the microdevice are applied. The results
from the model are compared with the experimental results in the
diameter of the microsphere generated. The comparison shows a good
agreement. Therefore the model is useful in further optimization of the
device and feedback control of microsphere generation if any.
Abstract: The capability of exploiting the electronic charge and
spin properties simultaneously in a single material has made diluted
magnetic semiconductors (DMS) remarkable in the field of
spintronics. We report the designing of DMS based on zinc-blend
ZnO doped with Cr impurity. The full potential linearized augmented
plane wave plus local orbital FP-L(APW+lo) method in density
functional theory (DFT) has been adapted to carry out these
investigations. For treatment of exchange and correlation energy,
generalized gradient approximations have been used. Introducing Cr
atoms in the matrix of ZnO has induced strong magnetic moment
with ferromagnetic ordering at stable ground state. Cr:ZnO was found
to favor the short range magnetic interaction that
reflect tendency of Cr clustering. The electronic structure of ZnO is
strongly influenced in the presence of Cr impurity atoms where
impurity bands appear in the band gap.
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: This study investigates the suitability of using plastic,
such as polyethylene terephthalate (PET), as a partial replacement of
natural coarse and fine aggregates (for example, brick chips and
natural sand) to produce lightweight concrete for load bearing
structural members. The plastic coarse aggregate (PCA) and plastic
fine aggregate (PFA) were produced from melted polyethylene
terephthalate (PET) bottles. Tests were conducted using three
different water–cement (w/c) ratios, such as 0.42, 0.48, and 0.57,
where PCA and PFA were used as 50% replacement of coarse and
fine aggregate respectively. Fresh and hardened properties of
concrete have been compared for natural aggregate concrete (NAC),
PCA concrete (PCC) and PFA concrete (PFC). The compressive
strength of concrete at 28 days varied with the water–cement ratio for
both the PCC and PFC. Between PCC and PFC, PFA concrete
showed the highest compressive strength (23.7 MPa) at 0.42 w/c ratio
and also the lowest compressive strength (13.7 MPa) at 0.57 w/c
ratio. Significant reduction in concrete density was mostly observed
for PCC samples, ranging between 1977–1924 kg/m³. With the
increase in water–cement ratio PCC achieved higher workability
compare to both NAC and PFC. It was found that both the PCA and
PFA contained concrete achieved the required compressive strength
to be used for structural purpose as partial replacement of the natural
aggregate; but to obtain the desired lower density as lightweight
concrete the PCA is most suited.