Abstract: In the present paper the design of plate heat exchangers
is formulated as an optimization problem considering two
mathematical modelling. The number of plates is the objective
function to be minimized, considering implicitly some parameters
configuration. Screening is the optimization method used to solve the
problem. Thermal and hydraulic constraints are verified, not viable
solutions are discarded and the method searches for the convergence to
the optimum, case it exists. A case study is presented to test the
applicability of the developed algorithm. Results show coherency with
the literature.
Abstract: Mobile Ad Hoc Networks (MANETs) is a collection
of mobile devices forming a communication network without
infrastructure. MANET is vulnerable to security threats due to
network’s limited security, dynamic topology, scalability and the lack
of central management. The Quality of Service (QoS) routing in such
networks is limited by network breakage caused by node mobility or
nodes energy depletions. The impact of node mobility on trust
establishment is considered and its use to propagate trust through a
network is investigated in this paper. This work proposes an
enhanced Associativity Based Routing (ABR) with Fuzzy based
Trust (Fuzzy- ABR) routing protocol for MANET to improve QoS
and to mitigate network attacks.
Abstract: In this paper numerical studies have been carried out
to examine the pre-ignition flow features of high-performance solid
propellant rocket motors with two different port geometries but with
same propellant loading density. Numerical computations have been
carried out using a validated 3D, unsteady, 2nd-order implicit, SST k-
ω turbulence model. In the numerical study, a fully implicit finite
volume scheme of the compressible, Reynolds-Averaged, Navier-
Stokes equations is employed. We have observed from the numerical
results that in solid rocket motors with highly loaded propellants
having divergent port geometry the hot igniter gases can create preignition
pressure oscillations leading to thrust oscillations due to the
flow unsteadiness and recirculation. We have also observed that the
igniter temperature fluctuations are diminished rapidly thereby
reaching the steady state value faster in the case of solid propellant
rocket motors with convergent port than the divergent port
irrespective of the igniter total pressure. We have concluded that the
prudent selection of the port geometry, without altering the propellant
loading density, for damping the total temperature fluctuations within
the motor is a meaningful objective for the suppression and control of
instability and/or thrust oscillations often observed in solid propellant
rocket motors with non-uniform port geometry.
Abstract: Concrete is strong in compression however weak in
tension. The tensile strength as well as ductile property of concrete
could be improved by addition of short dispersed fibers. Polyethylene
terephthalate (PET) fiber obtained from hand cutting or mechanical
slitting of plastic sheets generally used as discrete reinforcement in
substitution of steel fiber. PET fiber obtained from the former process
is in the form of straight slit sheet pattern that impart weaker
mechanical bonding behavior in the concrete matrix. To improve the
limitation of straight slit sheet fiber the present study considered two
additional geometry of fiber namely (a) flattened end slit sheet and
(b) deformed slit sheet. The mix for plain concrete was design for a
compressive strength of 25 MPa at 28 days curing time with a watercement
ratio of 0.5. Cylindrical and beam specimens with 0.5% fibers
volume fraction and without fibers were cast to investigate the
influence of geometry on the mechanical properties of concrete. The
performance parameters mainly studied include flexural strength,
splitting tensile strength, compressive strength and ultrasonic pulse
velocity (UPV). Test results show that geometry of fiber has a
marginal effect on the workability of concrete. However, it plays a
significant role in achieving a good compressive and tensile strength
of concrete. Further, significant improvement in term of flexural and
energy dissipation capacity were observed from other fibers as
compared to the straight slit sheet pattern. Also, the inclusion of PET
fiber improved the ability in absorbing energy in the post-cracking
state of the specimen as well as no significant porous structures.
Abstract: The right to basic sanitation, was elevated to the
category of fundamental right by the Constitution of 1988 to protect
the ecologically balanced environment, ensuring social rights to
health and adequate housing and put the dignity of the human person
as the foundation of the Brazilian Democratic State. Before their
essentiality to humans, this article seeks to understand why universal
access to basic sanitation is a goal so difficult to achieve in Brazil.
Therefore, this research uses the deductive and analytical method.
Given the nature of the research literature, research techniques were
centered in specialized books on the subject, journals, theses and
dissertations, laws, relevant law case and raising social indicators
relating to the theme. The relevance of the topic stems, among other
things, the fact that sanitation services are essential for a dignified
life, i.e., everyone is entitled to the maintenance of the necessary
existence conditions are satisfied. However, the effectiveness of this
right is undermined in society, since Brazil has huge deficit in
sanitation services, denying thus a worthy life to most of the
population. Thus, it can be seen that the provision of water and
sewage services in Brazil is still characterized by a large imbalance,
since the municipalities with lower population index have greater
disability in the sanitation service. The truth is that the precariousness
of water and sewage services in Brazil is still very concentrated in the
North and Northeast regions, limiting the effective implementation of
the Law 11.445/2007 in the country. Therefore, there is urgent need
for a positive service by the State in the provision of sanitation
services in order to prevent and control disease, improve quality of
life and productivity of individuals, besides preventing contamination
of water resources. More than just social and economic necessity,
there is a government duty to implement such services. In this sense,
given the current scenario, to achieve universal access to basic
sanitation imposes many hurdles. These are mainly in the field of
properly formulated and implemented public policies, i.e., it requires
an excellent institutional organization, management services,
strategic planning, social control, in order to provide answers to
complex challenges.
Abstract: The objective of this study was to evaluate the
effects of calving season on the production and economic efficiency
of dairy farms in Egypt. Our study was performed at dairy
production farms in the Alexandria, Behera, and Kafr El-Sheikh
provinces of Egypt from summer 2010 to winter 2013. The
randomly selected dairy farms had herds consisting of Baladi,
Holstein-Friesian, or cross-bred (Baladi × Holstein-Friesian) cows.
The data were collected from production records and responses to a
structured questionnaire. The average total return differed
significantly (P < 0.05) between the different cattle breeds and
calving seasons. The average total return was highest for the
Holstein- Friesian cows that calved in the winter (29106.42
EGP/cow/year), and it was lowest for Baladi cows that calved in the
summer (12489.79 EGP/cow/year). Differences in total returns
between the cows that calved in the winter or summer or between
the foreign and native breeds, as well as variations in calf prices,
might have contributed to the differences in milk yield. The average
net profit per cow differed significantly (P < 0.05) between the cattle
breeds and calving seasons. The average net profit values for the
Baladi cows that calved in the winter or summer were 2413 and
2994.96 EGP/cow/year, respectively, and those for the Holstein-
Friesian cows were 10744.17 and 7860.56 EGP/cow/year,
respectively, whereas those for the cross-bred cows were 10174.86
and 7571.33 EGP/cow/year, respectively. The variations in net profit
might have resulted from variation in the availability or price of feed
materials, milk prices, or sales volumes. Our results show that the
breed and calving season of dairy cows significantly affected the
economic efficiency of dairy farms in Egypt. The cows that calved
in the winter produced more milk than those that calved in the
summer, which may have been the result of seasonal influences,
such as temperature, humidity, management practices, and the type
of feed or green fodder available.
Abstract: In this work, the plastic behaviour of cold-rolled zinc
coated dual-phase steel sheets DP600 and DP800 grades is firstly
investigated with the help of uniaxial, hydraulic bulge and Forming
Limit Curve (FLC) tests. The uniaxial tensile tests were performed in
three angular orientations with respect to the rolling direction to
evaluate the strain-hardening and plastic anisotropy. True stressstrain
curves at large strains were determined from hydraulic bulge
testing and fitted to a work-hardening equation. The limit strains are
defined at both localized necking and fracture conditions according to
Nakajima’s hemispherical punch procedure. Also, an elasto-plastic
localization model is proposed in order to predict strain and stress
based forming limit curves. The investigated dual-phase sheets
showed a good formability in the biaxial stretching and drawing FLC
regions. For both DP600 and DP800 sheets, the corresponding
numerical predictions overestimated and underestimated the
experimental limit strains in the biaxial stretching and drawing FLC
regions, respectively. This can be attributed to the restricted failure
necking condition adopted in the numerical model, which is not
suitable to describe the tensile and shear fracture mechanisms in
advanced high strength steels under equibiaxial and biaxial stretching
conditions.
Abstract: The aim of study was to analyze the functioning the
new model of criminal corporate responsibility in Poland. The need
to introduce into the Polish legal system liability of corporate
(collective entities) has resulted, among others, from the Polish
Republic's international commitments, in particular related to
membership in the European Union. The study showed that responsibility of collective entities under
the Act has a criminal nature. The main question concerns the ability
of the collective entity to be brought to guilt under criminal law
sense. Polish criminal law knows only the responsibility of individual
persons. So far, guilt as a personal feature of action, based on the
ability of the offender to feel in his psyche, could be considered only
in relation to the individual person, while the said Act destroyed this
conviction. Guilt of collective entity must be proven under at least
one of the three possible forms: the guilt in the selection or
supervision and so called organizational guilt. In addition, research in
article has resolved the issue how the principle of proportionality in
relation to criminal measures in response of collective entities should
be considered. It should be remembered that the legal subjectivity of
collective entities, including their rights and freedoms, is an
emanation of the rights and freedoms of individual persons which
create collective entities and through these entities implement their
rights and freedoms. The whole study was proved that the adopted Act largely reflects
the international legal regulations but also contains the unknown and
original legislative solutions.
Abstract: These days, the industrial trend is moving away from heavy and bulky passive components to power converter systems that use more and more semiconductor elements. Also, it is difficult to connect the traditional converters to the high and medium voltage. For these reasons, a new family of multilevel inverters has appeared as a solution for working with higher voltage levels. Different modulation topologies like Sinusoidal Pulse Width Modulation (SPWM), Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) are available for multilevel inverters. In this work, different hybrid modulation techniques which are combination of fundamental frequency modulation and multilevel sinusoidal-modulation are compared. The main characteristic of these modulations are reduction of switching losses with good harmonic performance and balanced power loss dissipation among the device. The proposed hybrid modulation schemes are developed and simulated in Matlab/Simulink for cascaded H-bridge inverter. The results validate the applicability of the proposed schemes for cascaded multilevel inverter.
Abstract: Useful lifetime evaluation of chevron rubber spring
was very important in design procedure to assure the safety and
reliability. It is, therefore, necessary to establish a suitable criterion
for the replacement period of chevron rubber spring. In this study, we
performed characteristic analysis and useful lifetime prediction of
chevron rubber spring. Rubber material coefficient was obtained by
curve fittings of uniaxial tension equibiaxial tension and pure shear
test. Computer simulation was executed to predict and evaluate the
load capacity and stiffness for chevron rubber spring. In order to
useful lifetime prediction of rubber material, we carried out the
compression set with heat aging test in an oven at the temperature
ranging from 50°C to 100°C during a period 180 days. By using the
Arrhenius plot, several useful lifetime prediction equations for rubber
material was proposed.
Abstract: By enhancing the applicatıon of grounds for
establishment and due to the lack of appropriate sites, engineers
attempt to seek out a new method to reduce the weakness of soils. İn
aspect of economic situation, various ways have been used to
decrease the weak grounds. Because of the rapid development of
infrastructural facilities, spreading the construction operation is an
obligation. Furthermore, in various sites with the really bad soil
situation, engineers have considered obvious problems. One of the
most essential ways for developing the weak soils is stone column.
Obviously, the method was introduced in France in 1830 to improve
a native soil initially. Stone columns have an expanding range of
usage in different rough foundation sites all over the world to
increase the bearing capacity, to reduce the whole and differential
settlements, to enhance the rate of consolidation, to stabilize slopes
stability of embankments and to increase the liquefaction resistance
as well. A recent procedure called installing vertical nails along the
round stone columns in order to make better the performance of
considered columns is offered. Moreover, thanks to the enhancing the
nail diameter, number and embedment nail depth, the positive points
of vertical circumferential nails increases. Based on the result of this
study, load caring capacity will be develop with enhancing the length
and the power of reinforcements in vertical encasement stone column
(CESC). In this study, the main purpose is comparing two methods of
stone columns (installed a nail surrounding the stone columns and
using geogrid on clay) for enhancing the bearing capacity, decreasing
the whole and various settlements.
Abstract: Consumers are demanding novel beverages that are
healthier, convenient and have appealing consumer acceptance. The
objectives of this study were to investigate the effects of adding grape
polyphenols and the influence of presenting health claims on the
sensory acceptability of wines. Fresh red sorrel calyces were
fermented into wines. The total soluble solids of the pectinase-treated
sorrel puree were from 4°Brix to 23.8°Brix. Polyphenol in the form
of grape pomace extract was added to sorrel wines (w/v) in specified
levels to give 0. 25. 50 and 75 ppm. A focus group comprising of 12
panelists was use to select the level of polyphenol to be added to
sorrel wines for sensory preference The sensory attributed of the
wines which were evaluated were colour, clarity, aroma, flavor,
mouth-feel, sweetness, astringency and overall preference. The sorrel
wine which was most preferred from focus group evaluation was
presented for hedonic rating. In the first stage of hedonic testing, the
sorrel wine was served chilled at 7°C for 24 h prior to sensory
evaluation. Each panelist was provided with a questionnaire and was
asked to rate the wines on colour, aroma, flavor, mouth-feel,
sweetness, astringency and overall acceptability using a 9-point
hedonic scale. In the second stage of hedonic testing, the panelist
were instructed to read a health abstract on the health benefits of
polyphenolic compounds and again to rate sorrel wine with added 25
ppm polyphenol. Paired t-test was used for the analysis of the
influence of presenting health information on polyphenols on hedonic
scoring of sorrel wines. Focus groups found that the addition of
polyphenol addition had no significant effect on sensory color and
aroma but affected clarity and flavor. A 25 ppm wine was liked
moderately in overall acceptability. The presentation of information
on the health benefit of polyphenols in sorrel wines to panelists had
no significant influence on the sensory acceptance of wine. More
than half of panelists would drink this wine now and then. This wine
had color L 19.86±0.68, chroma 2.10±0.12, hue° 16.90 ±3.10 and
alcohol content of 13.0%. The sorrel wine was liked moderately in
overall acceptability with the added polyphenols.
Abstract: Batch production plants provide a wide range of
scheduling problems. In pharmaceutical industries a batch process
is usually described by a recipe, consisting of an ordering of tasks
to produce the desired product. In this research work we focused
on pharmaceutical production processes requiring the culture of
a microorganism population (i.e. bacteria, yeasts or antibiotics).
Several sources of uncertainty may influence the yield of the culture
processes, including (i) low performance and quality of the cultured
microorganism population or (ii) microbial contamination. For
these reasons, robustness is a valuable property for the considered
application context. In particular, a robust schedule will not collapse
immediately when a cell of microorganisms has to be thrown away
due to a microbial contamination. Indeed, a robust schedule should
change locally in small proportions and the overall performance
measure (i.e. makespan, lateness) should change a little if at all.
In this research work we formulated a constraint programming
optimization (COP) model for the robust planning of antibiotics
production. We developed a discrete-time model with a multi-criteria
objective, ordering the different criteria and performing a
lexicographic optimization. A feasible solution of the proposed
COP model is a schedule of a given set of tasks onto available
resources. The schedule has to satisfy tasks precedence constraints,
resource capacity constraints and time constraints. In particular
time constraints model tasks duedates and resource availability
time windows constraints. To improve the schedule robustness, we
modeled the concept of (a, b) super-solutions, where (a, b) are input
parameters of the COP model. An (a, b) super-solution is one in
which if a variables (i.e. the completion times of a culture tasks)
lose their values (i.e. cultures are contaminated), the solution can be
repaired by assigning these variables values with a new values (i.e.
the completion times of a backup culture tasks) and at most b other
variables (i.e. delaying the completion of at most b other tasks).
The efficiency and applicability of the proposed model is
demonstrated by solving instances taken from a real-life
pharmaceutical company. Computational results showed that
the determined super-solutions are near-optimal.
Abstract: An investigation has been presented to analyze the
effect of internal heat source on the onset of Hadley-Prats flow in
a horizontal fluid saturated porous medium. We examine a better
understanding of the combined influence of the heat source and mass
flow effect by using linear stability analysis. The resultant eigenvalue
problem is solved by using shooting and Runga-Kutta methods for
evaluate critical thermal Rayleigh number with respect to various
flow governing parameters. It is identified that the flow is switch from
stabilizing to destabilizing as the horizontal thermal Rayleigh number
is enhanced. The heat source and mass flow increases resulting a
stronger destabilizing effect.
Abstract: The global demand for long-tailed macaques for
medical experimentation has continued to increase. Fulfillment of
Indonesian export demands has been mostly from natural habitats,
based on a harvesting quota. This quota has been determined
according to the total catch for a given year, and not based on
consideration of any demographic parameters or physical
environmental factors with regard to the animal; hence threatening
the sustainability of the various populations. It is therefore necessary
to formulate a method for calculating a sustainable harvesting quota,
based on population parameters in natural habitats. Considering the
possibility of variations in habitat characteristics and population
parameters, a time series observation of demographic and
physical/biotic parameters, in various habitats, was performed on 13
groups of long-tailed macaques, distributed throughout the West
Java, Lampung and Yogyakarta areas of Indonesia. These provinces
were selected for comparison of the influence of human/tourism
activities. Data on population parameters that was collected included
data on life expectancy according to age class, numbers of
individuals by sex and age class, and ‘ratio of infants to reproductive
females’. The estimation of population growth was based on a
population dynamic growth model: the Leslie matrix. The harvesting
quota was calculated as being the difference between the actual
population size and the MVP (minimum viable population) for each
sex and age class. Observation indicated that there were variations within group size
(24–106 individuals), gender (sex) ratio (1:1 to 1:1.3), life expectancy
value (0.30 to 0.93), and ‘ratio of infants to reproductive females’
(0.23 to 1.56). Results of subsequent calculations showed that
sustainable harvesting quotas for each studied group of long-tailed
macaques, ranged from 29 to 110 individuals. An estimation model
of the MVP for each age class was formulated as Log Y = 0.315 +
0.884 Log Ni (number of individual on ith age class). This study also
found that life expectancy for the juvenile age class was affected by
the humidity under tree stands, and dietary plants’ density at sapling,
pole and tree stages (equation: Y=2.296 – 1.535 RH + 0.002 Kpcg –
0.002 Ktg – 0.001 Kphn, R2 = 89.6% with a significance value of
0.001). By contrast, for the sub-adult-adult age class, life expectancy
was significantly affected by slope (equation: Y=0.377 = 0.012 Kml,
R2 = 50.4%, with significance level of 0.007). The infant-toreproductive-
female ratio was affected by humidity under tree stands,
and dietary plant density at sapling and pole stages (equation: Y = -
1.432 + 2.172 RH – 0.004 Kpcg + 0.003 Ktg, R2 = 82.0% with
significance level of 0.001). This research confirmed the importance
of population parameters in determining the minimum viable
population, and that MVP varied according to habitat characteristics
(especially food availability). It would be difficult therefore, to
formulate a general mathematical equation model for determining a
harvesting quota for the species as a whole.
Abstract: One of the most critical decision points in the design of a
face recognition system is the choice of an appropriate face representation.
Effective feature descriptors are expected to convey sufficient, invariant
and non-redundant facial information. In this work we propose a set of
Hahn moments as a new approach for feature description. Hahn moments
have been widely used in image analysis due to their invariance, nonredundancy
and the ability to extract features either globally and locally.
To assess the applicability of Hahn moments to Face Recognition we
conduct two experiments on the Olivetti Research Laboratory (ORL)
database and University of Notre-Dame (UND) X1 biometric collection.
Fusion of the global features along with the features from local facial
regions are used as an input for the conventional k-NN classifier. The
method reaches an accuracy of 93% of correctly recognized subjects for
the ORL database and 94% for the UND database.
Abstract: The disposal and the treatment of sewage sludge is an
expensive and environmentally complex problem. In this work, a
lipopeptide biosurfactant extracted from corn steep liquor was used
as ecofriendly and cost-competitive alternative for the mobilization
and bioremediation of fluorene in sewage sludge. Results have
demonstrated that this biosurfactant has the capability to mobilize
fluorene to the aqueous phase, reducing the amount of fluorene in the
sewage sludge from 484.4 mg/Kg up to 413.7 mg/Kg and 196.0
mg/Kg after 1 and 27 days respectively. Furthermore, once the
fluorene was extracted the lipopeptide biosurfactant contained in the
aqueous phase allowed the biodegradation, up to 40.5% of the initial
concentration of this polycyclic aromatic hydrocarbon.
Abstract: Work presented is interested in the characterization of
the quasistatic mechanical properties and in fatigue of a composite
laminated in jute/epoxy. The natural fibers offer promising prospects
thanks to their interesting specific properties, because of their low
density, but also with their bio-deterioration. Several scientific
studies highlighted the good mechanical resistance of the vegetable
fiber composites reinforced, even after several recycling. Because of
the environmental standards that become increasingly severe, one
attends the emergence of eco-materials at the base of natural fibers
such as flax, bamboo, hemp, sisal, jute. The fatigue tests on
elementary vegetable fibers show an increase of about 60% of the
rigidity of elementary fibers of hemp subjected to cyclic loadings. In
this study, the test-tubes manufactured by the method infusion have
sequences of stacking of 0/90° and ± 45° for the shearing and tensile
tests. The quasistatic tests reveal a variability of the mechanical
properties of about 8%. The tensile fatigue tests were carried out for
levels of constraints equivalent to half of the ultimate values of the
composite. Once the fatigue tests carried out for well-defined values
of cycles, a series of static tests of traction type highlights the
influence of the number of cycles on the quasi-static mechanical
behavior of the laminate jute/epoxy.
Abstract: A large amount of software products offer a wide
range and number of features. This is called featuritis or creeping
featurism and tends to rise with each release of the product. Feautiris
often adds unnecessary complexity to software, leading to longer
learning curves and overall confusing the users and degrading their
experience. We take a look to a new design approach tendency that
has been coming up, the so-called “What You Get is What You
Need” concept that argues that products should be very focused,
simple and with minimalistic interfaces in order to help users conduct
their tasks in distraction-free ambiences. This isn’t as simple to
implement as it might sound and the developers need to cut down
features. Our contribution illustrates and evaluates this design method
through a novel distraction-free diagramming tool named Delineato
Pro for Mac OS X in which the user is confronted with an empty
canvas when launching the software and where tools only show up
when really needed.
Abstract: Steel slag is a by-product of the steel industry and can
be used potentially as aggregate in the asphalt mixture. This study
evaluates the use of Steel Slag Aggregates (SSA) as a substitute for
natural aggregates in the production of hot mix asphalt (HMA) for
road construction. Based on intensive laboratory testing program, the
characteristic properties of SSA were assessed to determine its
suitability to be used in HMA. Four different percentages (0, 50, 75,
and 100%) of SSA were used, and the proposed mix designs for
HMA were conducted in accordance with Marshall mix design. The
experiment results revealed that the addition of SSA has a significant
improvement on the properties of HMA. An increase in density and
stability and a reduction in flow and air voids values were clearly
observed in specimens prepared with 100% SSA. It is concluded that
the steel slag can be considered reasonable alternative source of
aggregate for concrete asphalt mixture production.