Abstract: High moisture content in fruits generates post-harvest
problems such as mechanical, biochemical, microbial and physical
losses. Dehydration, which is based on the reduction of water activity
of the fruit, is a common option for overcoming such losses.
However, regular hot air drying could affect negatively the quality
properties of the fruit due to the long residence time at high
temperature. Power ultrasound (US) application during the
convective drying has been used as a novel method able to enhance
drying rate and, consequently, to decrease drying time. In the present
study, a new approach was tested to evaluate the effect of US on the
drying time, the final antioxidant activity (AA) and the total
polyphenol content (TPC) of banana slices (BS), mango slices (MS)
and guava slices (GS). There were also studied the drying kinetics
with nine different models from which water effective diffusivities
(Deff) (with or without shrinkage corrections) were calculated.
Compared with the corresponding control tests, US assisted drying
for fruit slices showed reductions in drying time between 16.23 and
30.19%, 11.34 and 32.73%, and 19.25 and 47.51% for the MS, BS
and GS respectively. Considering shrinkage effects, Deff calculated
values ranged from 1.67*10-10 to 3.18*10-10 m2/s, 3.96*10-10 and
5.57*10-10 m2/s and 4.61*10-10 to 8.16*10-10 m2/s for the BS, MS and
GS samples respectively. Reductions of TPC and AA (as DPPH)
were observed compared with the original content in fresh fruit data
in all kinds of drying assays.
Abstract: Ceramic obtained on the base of aluminum oxide has
wide application range, because it has unique properties, for example,
wear-resistance, dielectric characteristics, and exploitation ability at
high temperatures and in corrosive atmosphere. Low temperature
synthesis of α-Al2O3 is energo-economical process and it is topical
for developing technologies of corundum ceramics fabrication. In the present work possibilities of low temperature transformation
of oxyhydroxides in α-Al2O3, during the presence of small amount of
rare–earth elements compounds (also Th, Re), have been discussed.
Aluminum unstable oxyhydroxides have been obtained by hydrolysis
of aluminium isopropoxide, nitrates, sulphate, and chloride in
alkaline environment at 80-90ºC temperatures. β-Al(OH)3 has been
received from aluminum powder by ultrasonic development. Drying
of oxyhydroxide sol has been conducted with presence of various
types seeds, which amount reaches 0,1-0,2% (mas). Neodymium,
holmium, thorium, lanthanum, cerium, gadolinium, disprosium
nitrates and rhenium carbonyls have been used as seeds and they
have been added to the sol specimens in amount of 0.1-0.2% (mas)
calculated on metals. Annealing of obtained gels is carried out at 70–
1100ºC for 2 hrs. The same specimen transforms in α-Al2O3 at
1100ºC. At this temperature in case of presence of lanthanum and
gadolinium transformation takes place by 70-85%. In case of
presence of thorium stabilization of γ-and θ-phases takes place. It is
established, that thorium causes inhibition of α-phase generation at
1100ºC, and at the time when in all other doped specimens α-phase is
generated at lower temperatures (1000-1050ºC). Synthesis of various
type compounds and simultaneous consolidation has developed in the
furnace of OXY-GON. Composite materials containing oxide and
non-oxide components close to theoretical data have been obtained in
this furnace respectively. During the work the following devices have
been used: X-ray diffractometer DRON-3M (Cu-Kα, Ni filter,
2º/min), High temperature vacuum furnace OXY-GON, electronic
scanning microscopes Nikon ECLIPSE LV 150, NMM-800TRF,
planetary mill Pulverisette 7 premium line, SHIMADZU Dynamic
Ultra Micro Hardness Tester, DUH-211S, Analysette 12 Dyna sizer.
Abstract: Construction industry plays a vital role in the
economy of the world. However, due to high uncertainty and
variability in the industry, its performance is not as efficient in terms
of quality, lead times, productivity and costs as of other industries.
Moreover, there are continuous conflicts among the different actors
in the construction supply chains in terms of profit sharing. Previous
studies suggested partnership as an important approach to promote
cooperation among the different actors in the construction supply
chains and thereby it improves the overall performance. Construction
practitioners tried to focus on partnership which can enhance the
performance of construction supply chains but they are not fully
aware of different approaches and techniques for improving
partnership. In this research, a systematic review on partnership in
relation to construction supply chains is carried out to understand
different elements influencing the partnership. The research
development of this domain is analyzed by reviewing selected
articles published from 1996 to 2015. Based on the papers, three
major elements influencing partnership in construction supply chains
are identified: ‘Lean approach’, ‘Relationship building’ and ‘E-commerce
applications’. This study analyses the contributions in the
areas within each element and provides suggestions for future
developments of partnership in construction supply chains.
Abstract: Clustering is a process of grouping objects and data
into groups of clusters to ensure that data objects from the same
cluster are identical to each other. Clustering algorithms in one of the
area in data mining and it can be classified into partition, hierarchical,
density based and grid based. Therefore, in this paper we do survey
and review four major hierarchical clustering algorithms called
CURE, ROCK, CHAMELEON and BIRCH. The obtained state of
the art of these algorithms will help in eliminating the current
problems as well as deriving more robust and scalable algorithms for
clustering.
Abstract: The knitted fabric suffers a deformation in its
dimensions due to stretching and tension factors, transverse and
longitudinal respectively, during the process in rectilinear knitting
machines so it performs a dry relaxation shrinkage procedure and
thermal action of prefixed to obtain stable conditions in the knitting.
This paper presents a dry relaxation shrinkage prediction of Bordeaux
fiber using a feed forward neural network and linear regression
models. Six operational alternatives of shrinkage were predicted. A
comparison of the results was performed finding neural network
models with higher levels of explanation of the variability and
prediction. The presence of different reposes is included. The models
were obtained through a neural toolbox of Matlab and Minitab
software with real data in a knitting company of Southern
Guanajuato. The results allow predicting dry relaxation shrinkage of
each alternative operation.
Abstract: An analytical 4-DOF nonlinear model of a de Laval
rotor-stator system based on Energy Principles has been used
theoretically and experimentally to investigate fault symptoms in a
rotating system. The faults, namely rotor-stator-rub, crack and
unbalance are modeled as excitations on the rotor shaft. Mayes
steering function is used to simulate the breathing behaviour of the
crack. The fault analysis technique is based on waveform signal,
orbits and Fast Fourier Transform (FFT) derived from simulated and
real measured signals. Simulated and experimental results manifest
considerable mutual resemblance of elliptic-shaped orbits and FFT
for a same range of test data.
Abstract: Nonlinear evolution of broadband ultrasonic pulses
passed through the rock specimens is studied using the apparatus
“GEOSCAN-02M”. Ultrasonic pulses are excited by the pulses of Qswitched
Nd:YAG laser with the time duration of 10 ns and with the
energy of 260 mJ. This energy can be reduced to 20 mJ by some light
filters. The laser beam radius did not exceed 5 mm. As a result of the
absorption of the laser pulse in the special material – the optoacoustic
generator–the pulses of longitudinal ultrasonic waves are excited with
the time duration of 100 ns and with the maximum pressure
amplitude of 10 MPa. The immersion technique is used to measure
the parameters of these ultrasonic pulses passed through a specimen,
the immersion liquid is distilled water. The reference pulse passed
through the cell with water has the compression and the rarefaction
phases. The amplitude of the rarefaction phase is five times lower
than that of the compression phase. The spectral range of the
reference pulse reaches 10 MHz. The cubic-shaped specimens of the
Karelian gabbro are studied with the rib length 3 cm. The ultimate
strength of the specimens by the uniaxial compression is (300±10)
MPa. As the reference pulse passes through the area of the specimen
without cracks the compression phase decreases and the rarefaction
one increases due to diffraction and scattering of ultrasound, so the
ratio of these phases becomes 2.3:1. After preloading some horizontal
cracks appear in the specimens. Their location is found by one-sided
scanning of the specimen using the backward mode detection of the
ultrasonic pulses reflected from the structure defects. Using the
computer processing of these signals the images are obtained of the
cross-sections of the specimens with cracks. By the increase of the
reference pulse amplitude from 0.1 MPa to 5 MPa the nonlinear
transformation of the ultrasonic pulse passed through the specimen
with horizontal cracks results in the decrease by 2.5 times of the
amplitude of the rarefaction phase and in the increase of its duration
by 2.1 times. By the increase of the reference pulse amplitude from 5
MPa to 10 MPa the time splitting of the phases is observed for the
bipolar pulse passed through the specimen. The compression and
rarefaction phases propagate with different velocities. These features
of the powerful broadband ultrasonic pulses passed through the rock
specimens can be described by the hysteresis model of Preisach-
Mayergoyz and can be used for the location of cracks in the optically
opaque materials.
Abstract: Research has shown that techno-entrepreneurship is
economically significant. Therefore, it is suggested that teaching
techno-entrepreneurship may be important because such programmes
would prepare current and future generations of learners to recognise
and act on high-technology opportunities. Education in technoentrepreneurship
may increase the knowledge of how to start one’s
own enterprise and recognise the technological opportunities for
commercialisation to improve decision-making about starting a new
venture; also it influence decisions about capturing the business
opportunities and turning them into successful ventures. Universities
can play a main role in connecting and networking technoentrepreneurship
students towards a cooperative attitude with real
business practice and industry knowledge. To investigate and answer
whether education for techno-entrepreneurs really helps, this paper
choses a comparison of literature reviews as its method of research.
After reviewing literature related to the impact of technoentrepreneurship
education on self-employment 6 studies which had
similar aim and objective to this paper were. These particular papers
were selected based on a keywords search and as their aim,
objectives, and gaps were close to the current research. In addition,
they were all based on the influence of techno-entrepreneurship
education in self-employment and intention of students to start new
ventures. The findings showed that teaching techno-entrepreneurship
education may have an influence on students’ intention and their
future self-employment, but which courses should be covered and the
duration of programmes, needs further investigation.
Abstract: The need to merge software artifacts seems inherent
to modern software development. Distribution of development over
several teams and breaking tasks into smaller, more manageable
pieces are an effective means to deal with the kind of complexity. In
each case, the separately developed artifacts need to be assembled as
efficiently as possible into a consistent whole in which the parts still
function as described. In addition, earlier changes are introduced into
the life cycle and easier is their management by designers.
Interaction-based specifications such as UML sequence diagrams
have been found effective in this regard. As a result, sequence
diagrams can be used not only for capturing system behaviors but
also for merging changes in order to create a new version. The
objective of this paper is to suggest a new approach to deal with the
problem of software merging at the level of sequence diagrams by
using the concept of dependence analysis that captures, formally, all
mapping, and differences between elements of sequence diagrams
and serves as a key concept to create a new version of sequence
diagram.
Abstract: Due to the fast and flawless technological innovation
there is a tremendous amount of data dumping all over the world in
every domain such as Pattern Recognition, Machine Learning, Spatial
Data Mining, Image Analysis, Fraudulent Analysis, World Wide
Web etc., This issue turns to be more essential for developing several
tools for data mining functionalities. The major aim of this paper is to
analyze various tools which are used to build a resourceful analytical
or descriptive model for handling large amount of information more
efficiently and user friendly. In this survey the diverse tools are
illustrated with their extensive technical paradigm, outstanding
graphical interface and inbuilt multipath algorithms in which it is
very useful for handling significant amount of data more indeed.
Abstract: This paper studies a mathematical model based on the
integral equations for dynamic analyzes numerical investigations of a
non-uniform or multi-material composite beam. The beam is
subjected to a sub-tangential follower force and elastic foundation.
The boundary conditions are represented by generalized
parameterized fixations by the linear and rotary springs. A
mathematical formula based on Euler-Bernoulli beam theory is
presented for beams with variable cross-sections. The non-uniform
section introduces non-uniformity in the rigidity and inertia of beams
and consequently, more complicated equilibrium who governs the
equation. Using the boundary element method and radial basis
functions, the equation of motion is reduced to an algebro-differential
system related to internal and boundary unknowns. A generalized
formula for the deflection, the slope, the moment and the shear force
are presented. The free vibration of non-uniform loaded beams is
formulated in a compact matrix form and all needed matrices are
explicitly given. The dynamic stability analysis of slender beam is
illustrated numerically based on the coalescence criterion. A realistic
case related to an industrial chimney is investigated.
Abstract: This paper presents comparative analysis of
photovoltaic systems (PVS) and propose practical techniques to
improve operational efficiency of the PVS. The best engineering and
construction practices for PVS are identified and field oriented
recommendation are made. Comparative analysis of central and
string inverter based, as well as 600 and 1000VDC PVS are
performed. In addition, direct current (DC) and alternating current
(AC) photovoltaic (PV) module based systems are compared.
Comparison shows that 1000V DC String Inverters based PVS is the
best choice.
Abstract: New and more powerful communications technologies
continue to emerge at a rapid pace and their uses in education are
widespread and the impact remarkable in the developing societies.
This study investigates Mobile Collaboration Learning Technique
(MCLT) on learners’ outcome among students in tertiary institutions
of developing nations (a case of Nigeria students). It examines the
significance of retention achievement scores of students taught using
mobile collaboration and conventional method. The sample consisted
of 120 students using Stratified random sampling method. Five
research questions and hypotheses were formulated, and tested at
0.05 level of significance. A student achievement test (SAT) was
made of 40 items of multiple-choice objective type, developed and
validated for data collection by professionals. The SAT was
administered to students as pre-test and post-test. The data were
analyzed using t-test statistic to test the hypotheses. The result
indicated that students taught using MCLT performed significantly
better than their counterparts using the conventional method of
instruction. Also, there was no significant difference in the post-test
performance scores of male and female students taught using MCLT.
Based on the findings, the following submissions was made that:
Mobile collaboration system be encouraged in the institutions to
boost knowledge sharing among learners, workshop and training
should be organized to train teachers on the use of this technique,
schools and government should consistently align curriculum
standard to trends of technological dictates and formulate policies
and procedures towards responsible use of MCLT.
Abstract: It has been known that a characteristic
Burst-Suppression (BS) pattern appears in EEG during the early
recovery period following Cardiac Arrest (CA). Here, to explore the
relationship between cortical and subcortical neural activities
underlying BS, extracellular activity in the parietal cortex and the
centromedian nucleus of the thalamus and extradural EEG were
recorded in a rodent CA model. During the BS, the cortical firing rate
is extraordinarily high, and that bursts in EEG correlate to dense spikes
in cortical neurons. Newly observed phenomena are that 1) thalamic
activity reemerges earlier than cortical activity following CA, and 2)
the correlation coefficient of cortical and thalamic activities rises
during BS period. These results would help elucidate the underlying
mechanism of brain recovery after CA injury.
Abstract: Asphalt concrete pavements have a short life cycle,
failing mainly due to temperature changes, traffic loading and ageing.
Modified asphalt mixtures provide the technology to produce a
bituminous binder with improved viscoelastic properties, which
remain in balance over a wider temperature range and loading
conditions. In this research, 60/70 penetration grade asphalt binder
was modified by adding 2, 4, 6, 8 and 10 percent by weight of asphalt
binder following the wet process and the mineral aggregate was
modified by adding 1, 2, 3, 4 and 5 percent crumb rubber by volume
of the mineral aggregate following the dry process. The LDPE
modified asphalt binder rheological properties were evaluated. The
laboratory results showed an increase in viscosity, softening point
and stiffness of the binder. The modified asphalt was then used in
preparing asphalt mixtures by Marshall Mix design procedure. The
Marshall Stability values for mixes containing 2% crumb rubber and
4% LDPE were found to be 30% higher than the conventional asphalt
concrete mix.
Abstract: This paper describes a sliding mode controller for
autonomous underwater vehicles (AUVs). The dynamic of AUV
model is highly nonlinear because of many factors, such as
hydrodynamic drag, damping, and lift forces, Coriolis and centripetal
forces, gravity and buoyancy forces, as well as forces from thruster.
To address these difficulties, a nonlinear sliding mode controller is
designed to approximate the nonlinear dynamics of AUV and
improve trajectory tracking. Moreover, the proposed controller can
profoundly attenuate the effects of uncertainties and external
disturbances in the closed-loop system. Using the Lyapunov theory
the boundedness of AUV tracking errors and the stability of the
proposed control system are also guaranteed. Numerical simulation
studies of an AUV are included to illustrate the effectiveness of the
presented approach.
Abstract: Radiative heat transfer in participating medium was
carried out using the finite volume method. The radiative transfer
equations are formulated for absorbing and anisotropically scattering
and emitting medium. The solution strategy is discussed and the
conditions for computational stability are conferred. The equations
have been solved for transient radiative medium and transient
radiation incorporated with transient conduction. Results have been
obtained for irradiation and corresponding heat fluxes for both the
cases. The solutions can be used to conclude incident energy and
surface heat flux. Transient solutions were obtained for a slab of heat
conducting in slab and by thermal radiation. The effect of heat
conduction during the transient phase is to partially equalize the
internal temperature distribution. The solution procedure provides
accurate temperature distributions in these regions. A finite volume
procedure with variable space and time increments is used to solve
the transient radiation equation. The medium in the enclosure
absorbs, emits, and anisotropically scatters radiative energy. The
incident radiations and the radiative heat fluxes are presented in
graphical forms. The phase function anisotropy plays a significant
role in the radiation heat transfer when the boundary condition is
non-symmetric.
Abstract: Students of Higher Education Technical School of
Professional Studies in Novi Sad follow the subject ‘Maintenance of
Electric Power Equipment’ at the Electrotechnical Department. This
paper presents educational plan and program of the subject
Maintenance of Electric Power Equipment. The course deals with the
problems of preventive and investing maintenance of transformer
stations (TS), performing and maintenance of grounding of TS and
pillars, as well as tracing and detection the location of the cables
failure. There is a special elaborated subject concerning the safe work
conditions for the electrician during network maintenance, as well as
the basics of making and keeping technical documentation of the
equipment.
Abstract: Target of this study was the analysis of the impact of
crude glycerol on canine spermatozoa motility, morphology,
viability, and membrane integrity. Experiments were realized in vitro.
In the study, semen from 5 large dog breeds was used. They were
typical representatives of large breeds, coming from healthy rearing,
regularly vaccinated and integrated to the further breeding. Semen
collections were realized at the owners of animals and in the
veterinary clinic. Subsequently the experiments were realized at the
Department of Animal Physiology of the SUA in Nitra. The
spermatozoa motility was evaluated using CASA analyzer
(SpermVisionTM, Minitub, Germany) at the temperature 5 and 37°C
for 5 hours. In the study, 13 motility parameters were evaluated.
Generally, crude glycerol has generally negative effect on
spermatozoa motility. Morphological analysis was realized using
Hancock staining and the preparations were evaluated at
magnification 1000x using classification tables of morphologically
changed spermatozoa. Data clearly detected the highest number of
morphologically changed spermatozoa in the experimental groups
(know twisted tails, tail torso and tail coiling). For acrosome
alterations swelled acrosomes, removed acrosomes and acrosomes
with undulated membrane were detected. In this study also the effect
of crude glycerol on spermatozoa membrane integrity were analyzed.
The highest crude glycerol concentration significantly affects
spermatozoa integrity. Results of this study show that crude glycerol
has effect of spermatozoa motility, viability, and membrane integrity.
Detected changes are related to crude glycerol concentration,
temperature, as well as time of incubation.
Abstract: Lots of motors have been being used in industry.
Therefore many researchers have studied about the failure diagnosis of
motors. In this paper, the effect of measuring environment for
diagnosis of gear fault connected to a motor shaft is studied. The fault
diagnosis is executed through the comparison of normal gear and
abnormal gear. The measured FFT data are compared with the normal
data and analyzed for q-axis current, noise and vibration. For bad and
good environment, the diagnosis results are compared. From these, it
is shown that the bad measuring environment may not be able to detect
exactly the motor gear fault. Therefore it is emphasized that the
measuring environment should be carefully prepared.