Abstract: This article presents a new vibration diagnostic
method designed to (PM) machines with permanent magnets. Those
devices are commonly used in small wind and water systems or
vehicles drives. The author’s method is very innovative and unique.
Specific structural properties of PM machines are used in this method
- electromotive force (EMF) generated due to vibrations. There was
analysed number of publications which describe vibration diagnostic
methods and tests of electrical PM machines and there was no
method found to determine the technical condition of such machine
basing on their own signals. In this article will be discussed: the
method genesis, the similarity of machines with permanent magnet to
vibration sensor and simulation and laboratory tests results. The
method of determination the technical condition of electrical machine
with permanent magnets basing on its own signals is the subject of
patent application and it is the main thesis of author’s doctoral
dissertation.
Abstract: Novel bio-based polymer electrolyte was synthesized
with LiClO4 as the main source of charge carrier. Initially,
polyurethane-LiClO4 polymer electrolytes were synthesized via
prepolymerization method with different NCO/OH ratios and labelled
them as PU1, PU2, PU3 and PU4. Fourier transform infrared (FTIR)
analysis indicates the co-ordination between Li+ ion and polyurethane
in PU1. Differential scanning calorimetry (DSC) analysis indicates
PU1 has the highest glass transition temperature (Tg) corresponds to
the most abundant urethane group which is the hard segment in PU1.
Scanning electron microscopy (SEM) shows the good miscibility
between lithium salt and the polymer. The study found that PU1
possessed the greatest ionic conductivity and the lowest activation
energy, Ea. All the polyurethanes exhibited linear Arrhenius
variations indicating ion transport via simple lithium ion hopping in
polyurethane. This research proves the NCO content in polyurethane
plays an important role in affecting the ionic conductivity of this
polymer electrolyte.
Abstract: The effect of trucks on the level of service is
determined by considering passenger car equivalents (PCE) of trucks.
The current version of Highway Capacity Manual (HCM) uses a
single PCE value for all tucks combined. However, the composition
of truck traffic varies from location to location; therefore, a single
PCE value for all trucks may not correctly represent the impact of
truck traffic at specific locations. Consequently, present study
developed separate PCE values for single-unit and combination
trucks to replace the single value provided in the HCM on different
freeways. Site specific PCE values, were developed using concept of
spatial lagging headways (that is the distance between rear bumpers
of two vehicles in a traffic stream) measured from field traffic data.
The study used data from four locations on a single urban freeway
and three different rural freeways in Indiana. Three-stage-leastsquares
(3SLS) regression techniques were used to generate models
that predicted lagging headways for passenger cars, single unit trucks
(SUT), and combination trucks (CT). The estimated PCE values for
single-unit and combination truck for basic urban freeways (level
terrain) were: 1.35 and 1.60, respectively. For rural freeways the
estimated PCE values for single-unit and combination truck were:
1.30 and 1.45, respectively. As expected, traffic variables such as
vehicle flow rates and speed have significant impacts on vehicle
headways. Study results revealed that the use of separate PCE values
for different truck classes can have significant influence on the LOS
estimation.
Abstract: OEE has been used in many industries as measure of
performance. However due to limitations of original OEE, it has been
modified by various researchers. OEE for mining application is
special version of classic equation, carries these limitation over. In
this paper it has been aimed to modify the OEE for mining
application by introducing the weights to the elements of it and
termed as Mine Production index (MPi). As a special application of
new index MPishovel has been developed by authors. This can be used
for evaluating the shovel effectiveness. Based on analysis, utilization
followed by performance and availability were ranked in this order.
To check the applicability of this index, a case study was done on
four electrical and one hydraulic shovel in a Swedish mine. The
results shows that MPishovel can evaluate production effectiveness of
shovels and can determine effectiveness values in optimistic view
compared to OEE. MPi with calculation not only give the
effectiveness but also can predict which elements should be focused
for improving the productivity.
Abstract: Information and Communication Technologies (ICTs)
are pervasive nowadays, including in education where they are
expected to improve the performance of learners. However, the hope
placed in ICTs to find viable solutions to the problem of poor
academic performance in schools in the developing world has not yet
yielded the expected benefits. This problem serves as a motivation to
this study whose aim is to examine the perceptions of educators on
the advantages and disadvantages of e-learning. This aim will be
subdivided into two types of research objectives. Objectives on the
identification and design of theories and models will be achieved
using content analysis and literature review. However, the objective
on the empirical testing of such theories and models will be achieved
through the survey of educators from different schools in the
Pinetown District of the South African Kwazulu-Natal province.
SPSS is used to quantitatively analyse the data collected by the
questionnaire of this survey using descriptive statistics and Pearson
correlations after assessing the validity and the reliability of the data.
The main hypothesis driving this study is that there is a relationship
between the demographics of educators’ and their adherence to
learning theories on one side, and their perceptions on the advantages
and disadvantages of e-learning on the other side, as argued by
existing research; but this research views these learning theories
under three perspectives: educators’ adherence to self-regulated
learning, to constructivism, and to progressivism. This hypothesis
was fully confirmed by the empirical study except for the
demographic factor where teachers’ level of education was found to
be the only demographic factor affecting the perceptions of educators
on the advantages and disadvantages of e-learning.
Abstract: Ongoing landscape transformation is one of the major
causes behind disappearance of traditional landscapes, and lead to
species and resource loss. Tree in paddy fields in the northeast of
Thailand is one of those traditional landscapes. Using three different
historical time layers, we acknowledged the severe deforestation and
rapid urbanization happened in the region. Despite the general
thinking of decline in tree density as consequences, the heterogeneous
trend of changes in total tree density in three studied landscapes denied
the hypothesis that number of trees in paddy field depend on the length
of land use practice. On the other hand, due to selection of planting
new trees on levees, existence of trees in paddy field now relies on
their values for human use. Besides, changes in land use and landscape
structure had a significant impact on decision of which tree density
level is considered as suitable for the landscape.
Abstract: The majority of contemporary insulation materials
commonly used in the building industry is made from non-renewable
raw materials; furthermore, their production often brings high energy
costs. A long-term trend as far as sustainable development is
concerned has been the reduction of energy and material demands of
building material production. One of the solutions is the possibility of
using easily renewable natural raw material sources which are
considerably more ecological and their production is mostly less
energy-consuming compared to the production of normal insulations
(mineral wool, polystyrene). The paper describes the results of
research focused on the development of thermal and acoustic
insulation materials based on natural fibres intended for floor
constructions. Given the characteristic open porosity of natural fibre
materials, the hygrothermal behaviour of the developed materials was
studied. Especially the influence of relative humidity and temperature
on thermal insulation properties was observed.
Abstract: As the human race will continue to explore the space
by creating new space transportation means and sending them to other
planets, the enhance of atmospheric reentry study is crucial. In this
context, an analysis of mass recession rate of ablative materials for
thermal shields of reentry spacecrafts is important to be carried out.
The paper describes a new estimation method for calculating the mass
recession of an ablator system made of carbon fiber reinforced plastic
materials. This method is based on Arrhenius equation for low
temperatures and, for high temperatures, on a theory applied for the
recession phenomenon of carbon fiber reinforced plastic materials,
theory which takes into account the presence of the resin inside the
materials. The space mission of USERS spacecraft is considered as a
case study.
Abstract: This paper focuses on the presentation of results
which were obtained as a part of the project FR-TI 3/742: “System of
Lightweight Materials for Finishing of Buildings with Waste Raw
Materials”. Attention was paid to the light weighting of polymermodified
mortars applicable as adhesives, screeds and repair mortars.
In terms of repair mortars, they were ones intended for the sanitation
of aerated concrete.
Abstract: Persea declinata (Bl.) Kosterm is a member of the
Lauraceae family, widely distributed in Southeast Asia. It is from the
same genus with avocado (Persea americana Mill), which is widely
consumed as food and for medicinal purposes. In the present study,
we examined the anticancer properties of Persea declinata (Bl.)
Kosterm bark methanolic crude extract (PDM). PDM exhibited a
potent antiproliferative effect in MCF-7 human breast cancer cells,
with an IC50 value of 16.68 .g/mL after 48h of treatment. We
observed that PDM caused cell cycle arrest and subsequent apoptosis
in MCF-7 cells, as exhibited by increased population at G0/G1 phase,
higher lactate dehydrogenase (LDH) release, and DNA
fragmentation. Mechanistic studies showed that PDM caused
significant elevation in ROS production, leading to perturbation of
mitochondrial membrane potential, cell permeability, and activation
of caspases-3/7. On the other hand, real-time PCR and Western blot
analysis showed that PDM treatment increased the expression of the
proapoptotic molecule, Bax, but decreased the expression of
prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner.
These findings imply that PDM could inhibit proliferation in MCF-7
cells via cell cycle arrest and apoptosis induction, indicating its
potential as a therapeutic agent worthy of further development.
Abstract: This paper attempts to evaluate the effect of fire
damage on concrete by using nonlinear resonance vibration method,
one of the nonlinear nondestructive method. Concrete exhibits not
only nonlinear stress-strain relation but also hysteresis and discrete
memory effect which are contained in consolidated materials.
Hysteretic materials typically show the linear resonance frequency
shift. Also, the shift of resonance frequency is changed according to
the degree of micro damage. The degree of the shift can be obtained
through nonlinear resonance vibration method. Five exposure
scenarios were considered in order to make different internal micro
damage. Also, the effect of post-fire-curing on fire-damaged concrete
was taken into account to conform the change in internal damage.
Hysteretic nonlinearity parameter was obtained by amplitudedependent
resonance frequency shift after specific curing periods. In
addition, splitting tensile strength was measured on each sample to
characterize the variation of residual strength. Then, a correlation
between the hysteretic nonlinearity parameter and residual strength
was proposed from each test result.
Abstract: Well-designed composite steel and concrete structures
highlight the good material properties and lower the deficiencies of
steel and concrete, in particular they make use of high tensile strength
of steel and high stiffness of concrete. The most common composite
steel and concrete structure is a simply supported beam, which
concrete slab transferring the slab load to a beam is connected to the
steel cross-section. The aim of this paper is to find the most adequate
numerical model of a simply supported composite beam with the
cross-sectional and material parameters based on the results of a
processed parametric study and numerical analysis. The paper also
evaluates the suitability of using compact concrete with the
lightweight aggregates for composite steel and concrete beams. The
most adequate numerical model will be used in the resent future to
compare the results of laboratory tests.
Abstract: Load Forecasting plays a key role in making today's
and future's Smart Energy Grids sustainable and reliable. Accurate
power consumption prediction allows utilities to organize in advance
their resources or to execute Demand Response strategies more
effectively, which enables several features such as higher
sustainability, better quality of service, and affordable electricity
tariffs. It is easy yet effective to apply Load Forecasting at larger
geographic scale, i.e. Smart Micro Grids, wherein the lower available
grid flexibility makes accurate prediction more critical in Demand
Response applications. This paper analyses the application of
short-term load forecasting in a concrete scenario, proposed within the
EU-funded GreenCom project, which collect load data from single
loads and households belonging to a Smart Micro Grid. Three
short-term load forecasting techniques, i.e. linear regression, artificial
neural networks, and radial basis function network, are considered,
compared, and evaluated through absolute forecast errors and training
time. The influence of weather conditions in Load Forecasting is also
evaluated. A new definition of Gain is introduced in this paper, which
innovatively serves as an indicator of short-term prediction
capabilities of time spam consistency. Two models, 24- and
1-hour-ahead forecasting, are built to comprehensively compare these
three techniques.
Abstract: Metal-enhanced Luminescence of silicon nanocrystals
(SiNCs) was determined using two different particle sizes of silver
nanoparticles (AgNPs). SiNCs have been characterized by scanning
electron microscopy (SEM), high resolution transmission electron
microscopy (HRTEM), Fourier transform infrared spectroscopy
(FTIR) and X-ray photoelectron spectroscopy (XPS). It is found that
the SiNCs are crystalline with an average diameter of 65 nm and FCC
lattice. AgNPs were synthesized using photochemical reduction of
AgNO3 with sodium dodecyl sulphate (SDS). The enhanced
luminescence of SiNCs by AgNPs was evaluated by confocal Raman
microspectroscopy. Enhancement up to x9 and x3 times were
observed for SiNCs that mixed with AgNPs which have an average
particle size of 100 nm and 30 nm, respectively. Silver NPs-enhanced
luminescence of SiNCs occurs as a result of the coupling between the
excitation laser light and the plasmon bands of AgNPs; thus this
intense field at AgNPs surface couples strongly to SiNCs.
Abstract: Diabetes is a growing health problem in worldwide.
Especially, the patients with Type 1 diabetes need strict glycemic
control because they have deficiency of insulin production. This
paper attempts to control blood glucose based on body mathematical
body model. The Bergman minimal mathematical model is used to
develop the nonlinear controller. A novel back-stepping based sliding
mode control (B-SMC) strategy is proposed as a solution that
guarantees practical tracking of a desired glucose concentration. In
order to show the performance of the proposed design, it is compared
with conventional linear and fuzzy controllers which have been done
in previous researches. The numerical simulation result shows the
advantages of sliding mode back stepping controller design to linear
and fuzzy controllers.
Abstract: Artemisia species, which are medically beneficial, are
widespread in temperate regions of both Northern and Southern
hemispheres among which Iran is located. About 35 species of
Artemisia are indigenous in Iran among them some are widespread in
all or most provinces, yet some are restricted to some specific
regions. In this review paper, initially, GC-Mass results of some
experiments done in different provinces of Iran are mentioned among
them some compounds are common among species, some others are
mostly restricted to other species; after that, medical advantages
based on some researches on species of this genus are reviewed;
different qualities such as anti-leishmania, anti-bacteria, antiviral as
well as anti-proliferative could be mentioned.
Abstract: Nonalcoholic fatty liver disease (NAFLD) has
increased in conjunction with obesity. The accuracy of risk factors
for detecting NAFLD in obese adolescents has not undergone a
formal evaluation. The aim of this study was to evaluate predictors of
NAFLD among Egyptian female obese adolescents. The study
included 162 obese female adolescents. All were subjected to
anthropometry, biochemical analysis and abdominal ultrasongraphic
assessment. Metabolic syndrome (MS) was diagnosed according to
the IDF criteria. Significant association between presence of MS and
NAFLD was observed. Obese adolescents with NAFLD had
significantly higher levels of ALT, triglycerides, fasting glucose,
insulin, blood pressure and HOMA-IR, whereas decreased HDL-C
levels as compared with obese cases without NAFLD. Receiver–
operating characteristic (ROC) curve analysis shows that ALT is a
sensitive predictor for NAFLD, confirming that ALT can be used as a
marker of NAFLD.
Abstract: Heavy metals are one of the major groups of
contaminants in the environment and many of them are toxic even at
very low concentration in plants and animals. However, some metals
play important roles in the biological function of many enzymes in
living organisms. Metals such as zinc, iron, and cooper are important
for survival and activity of enzymes in plants, however heavy metals
can inhibit enzyme which is responsible for defense system of plants.
Polyphenol oxidase (PPO) is a copper-containing metalloenzyme
which is responsible for enzymatic browning reaction of plants.
Enzymatic browning is a major problem for the handling of
vegetables and fruits in food industry. It can be increased and
effected with many different futures such as metals in the nature and
ground. In the present work, PPO was isolated and characterized
from green leaves of red poppy plant (Papaverr hoeas). Then, the
effect of some known antibrowning agents which can form
complexes with metals and metals were investigated on the red poppy
PPO activity. The results showed that glutathione was the most
potent inhibitory effect on PPO activity. Cu(II) and Fe(II) metals
increased the enzyme activities however, Sn(II) had the maximum
inhibitory effect and Zn(II) and Pb(II) had no significant effect on the
enzyme activity. In order to reduce the effect of heavy metals, the
effects of metal-antibrowning agent complexes on the PPO activity
were determined. EDTA and metal complexes had no significant
effect on the enzyme. L-ascorbic acid and metal complexes decreased
but L-ascorbic acid-Cu(II)-complex had no effect. Glutathione–metal
complexes had the best inhibitory effect on Red poppy leaf PPO
activity.
Abstract: The aim of the paper was to elaborate a novel calculator BasWilCalc, that allows to estimate the actual amount of biomass on the basket willow plantations. The proposed method is based on the results of field experiment conducted during years 2011-2013 on basket willow plantation in the south-western part of Poland. As input data the results of destructive measurements of the diameter, length and weight of willow stems and non-destructive biometric measurements of diameter in the middle of stems and their length during the growing season performed at weekly intervals were used. Performed analysis enabled to develop the algorithm which, due to the fact that energy plantations are of known and constant planting structure, allows to estimate the actual amount of willow basket biomass on the plantation with a given probability and accuracy specified by the model, based on the number of stems measured and the age of the plantation.
Abstract: The article presents the concept of an electromagnetic
circuit generator with permanent magnets mounted on the surface
rotor core designed for single phase work. Computation field-circuit
model was shown. The spectrum of time course of voltages in the
idle work was presented. The cross section with graphically
presentation of magnetic induction in particular parts of
electromagnetic circuits was presented. Distribution of magnetic
induction at the rated load point for each phase was shown. The time
course of voltages and currents for each phases for rated power were
displayed. An analysis of laboratory results and measurement of load
characteristics of the generator was discussed. The work deals with
three electromagnetic circuits of generators with permanent magnet
where output voltage characteristics versus rated power were
expressed.