Abstract: A wireless sensor network (WSN) is a collection of
sensor nodes organized into a cooperative network. These nodes
communicate through a wireless antenna. Reduction in physical size
and multiband operation is an important requirement of WSN
antenna. Fractal antenna is used for miniaturization and multiband
operation. The self-similar or self-affine and space filling property of
fractal geometry increases the effective electrical length of the
antenna, reduces the size and make them frequency independent. This
paper elaborates on Dual band fractal antenna with Coplanar
Waveguide (CPW) feed for WSN. The proposed antenna is designed
on a FR4 substrate with the dimension of 27mm x 28.5mm x 1.6mm,
resonates at 2.4GHz and 5.2GHz with a return loss less than -10dB.
The design and simulation process is carried out using IE3D
simulation software. The simulated and measured results are found in
good agreement.
Abstract: In this paper, thick walled Cylindrical tanks or tubes
made of functionally graded material under internal pressure and
temperature gradient are studied. Material parameters have been
considered as power functions. They play important role in the
elastoplastic behavior of these materials. To clarify their role,
different materials with different parameters have been used under
temperature gradient. Finally, their effect and loading effect have
been determined in first yield point. Also, the important role of
temperature gradient was also shown. At the end the study has been
results obtained from changes in the elastic modulus and yield stress.
Also special attention is also given to the effects of this internal
pressure and temperature gradient in the creation of tensile and
compressive stresses.
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: In the present work, the effects of additives, including
contents of the added antioxidants and type of the selected metallic
stearates (either calcium stearate (CaSt) or zinc stearate (ZnSt)), on
the thermal stabilities of carbon black (CB)/high density polyethylene
(HDPE) compounds were studied. The results showed that the AO
contents played a key role in the thermal stabilities of the CB/HDPE
compounds — the higher the AO content, the higher the thermal
stabilities. Although the CaSt-containing compounds were slightly
superior to those with ZnSt in terms of the thermal stabilities, the
remaining solid residue of CaSt after heated to the temperature of 600
°C (mainly calcium carbonate (CaCO3) as characterized by the X-ray
diffraction (XRD) technique) seemed to catalyze the decomposition
of CB in the HDPE-based compounds. Hence, the quantification of
CB in the CaSt-containing compounds with a muffle furnace gave an
inaccurate CB content — much lower than actual value. However,
this phenomenon was negligible in the ZnSt-containing system.
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: This study was conducted to evaluate the manganese
removal from aqueous solution using Banana peels activated carbon
(BPAC). Batch experiments have been carried out to determine the
influence of parameters such as pH, biosorbent dose, initial metal ion
concentrations and contact times on the biosorption process. From
these investigations, a significant increase in percentage removal of
manganese 97.4% is observed at pH value 5.0, biosorbent dose 0.8 g,
initial concentration 20 ppm, temperature 25 ± 2°C, stirring rate 200
rpm and contact time 2h. The equilibrium concentration and the
adsorption capacity at equilibrium of the experimental results were
fitted to the Langmuir and Freundlich isotherm models; the Langmuir
isotherm was found to well represent the measured adsorption data
implying BPAC had heterogeneous surface. A raw groundwater
samples were collected from Baharmos groundwater treatment plant
network at Embaba and Manshiet Elkanater City/District-Giza,
Egypt, for treatment at the best conditions that reached at first phase
by BPAC. The treatment with BPAC could reduce iron and
manganese value of raw groundwater by 91.4% and 97.1%,
respectively and the effect of the treatment process on the
microbiological properties of groundwater sample showed decrease
of total bacterial count either at 22°C or at 37°C to 85.7% and 82.4%,
respectively. Also, BPAC was characterized using SEM and FTIR
spectroscopy.
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: The objective of the study was to select the survival of
probiotic strains when exposed to acidic and bile salts condition. Four
probiotic strains Lactobacillus casei subsp. rhamnosus TISTR 047,
Lactobacillus casei TISTR 1500, Lactobacillus acidophilus TISTR
1338 and Lactobacillus plantarum TISTR 1465 were cultured in
MRS broth and incubated at 35ºC for 15 hours before being inoculated
into acidic condition 5 M HCl, pH 2 for 2 hours and bile salt 0.3%,
pH 5.8 for 8 hour. The survived probiotics were counted in MRS agar.
Among four stains, Lactobacillus casei subsp. rhamnosus TISTR 047
was the highest tolerance specie. Lactobacillus casei subsp.
rhamnosus TISTR 047 reduced 6.74±0.07 log CFU/ml after growing
in acid and 5.52±0.05 log CFU/ml after growing in bile salt. Then,
double emulsion of microorganisms was chosen to encapsulate before
spray drying. Spray drying was done with the inlet temperature 170ºC
and outlet temperature 80ºC. The results showed that the survival of
encapsulated Lactobacillus casei subsp. rhamnosus TISTR 047 after
spray drying decreased from 9.63 ± 0.32 to 8.31 ± 0.11 log CFU/ml
comparing with non-encapsulated, 9.63 ± 0.32 to 4.06 ± 0.08 log
CFU/ml. Therefore, Lactobacillus casei subsp. rhamnosus TISTR 047
would be able to survive in gastrointestinal and spray drying condition.
Abstract: Advances technology in the field of photogrammetry
replaces analog cameras with reflection on aircraft GPS/IMU system
with a digital aerial camera. In this system, when determining the
position of the camera with the GPS, camera rotations are also
determined by the IMU systems. All around the world, digital aerial
cameras have been used for the photogrammetry applications in the
last ten years. In this way, in terms of the work done in
photogrammetry it is possible to use time effectively, costs to be
reduced to a minimum level, the opportunity to make fast and
accurate.
Geo-referencing techniques that are the cornerstone of the GPS /
INS systems, photogrammetric triangulation of images required for
balancing (interior and exterior orientation) brings flexibility to the
process. Also geo-referencing process; needed in the application of
photogrammetry targets to help to reduce the number of ground
control points. In this study, the use of direct and indirect georeferencing
techniques on the accuracy of the points was investigated
in the production of photogrammetric mapping.
Abstract: The organizations of European and Czech critical
infrastructure have specific position, mission, characteristics and
behaviour in European Union and Czech state/business environments,
regarding specific requirements for regional and global security
environments. They must respect policy of national security and
global rules, requirements and standards in all their inherent and
outer processes of supply - customer chains and networks. A
controlling is generalized capability to have control over situational
policy. This paper aims and purposes are to introduce the controlling
as quite new necessary process attribute providing for critical
infrastructure is environment the capability and profit to achieve its
commitment regarding to the effectiveness of the quality
management system in meeting customer/ user requirements and also
the continual improvement of critical infrastructure organization’s
processes overall performance and efficiency, as well as its societal
security via continual planning improvement via DYVELOP
modelling.
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: Due to reduced stiffness, research on second
generation titanium alloys for implant applications, like the
metastable β-titanium alloy Ti-15Mo, become more and more
important in the recent years. The machinability of these alloys is
generally poor leading to problems during implant production and
comparably large production costs. Therefore, in the present study,
Ti-15Mo was alloyed with 0.8 wt.-% of the rare earth metals
lanthanum (Ti-15Mo+0.8La) and neodymium (Ti-15Mo+0.8Nd) to
improve its machinability. Their microstructure consisted of a
titanium matrix and micrometer-size particles of the rare earth metals
and two of their oxides. The particles stabilized the microstructure as
grain growth was minimized. As especially the ductility might be
affected by the precipitates, the behavior of Ti-15Mo+0.8La and Ti-
15Mo+0.8Nd was investigated during static and dynamic
deformation at elevated temperature to develop a processing route.
The resulting mechanical properties (static strength and ductility)
were similar in all investigated alloys.
Abstract: In the present work, the effect of load and sliding
distance on the performance tribology of commercially used
aluminium-silicon engine block and piston was evaluated at ambient
conditions with humidity of 80% under dry sliding conditions using a
pin-on-disc with two different loads of 5N and 20N yielding applied
pressure of 0.30MPa and 1.4MPa, respectively, at sliding velocity of
0.29ms-1 and with varying sliding distance ranging from 260m-
4200m. Factors and conditions that had significant effect were
identified. The results showed that the load and the sliding distance
affect the wear rate of the alloys and the wear rate increased with
increasing load for both the alloys. Wear rate also increases almost
linearly at low loads and increase to a maximum then attain a plateau
with increasing sliding distance. For both applied loads the piston
alloy showed the better performance due to higher Ni and Mg
content. The worn surface and wear debris was characterized by
optical microscope, SEM and EDX analyzer. The worn surface was
characterized by surface with shallow grooves at loads while the
groove width and depth increased as the loads increases. Oxidative
wear was found to be the predominant mechanisms in the dry sliding
of Al-Si alloys at low loads.
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: Calcium phosphate coating (CaP) has been employed
for protein delivery, but the typical direct protein adsorption on the
coating led to low incorporation content and fast release of the
protein from the coating. By using bovine serum albumin (BSA) as a
model protein, rapid biomimetic co-precipitation between calcium
phosphate and BSA was employed to control the distribution of BSA
within calcium phosphate coating during biomimetic formation on
titanium surface for only 6 h at 50oC in an accelerated calcium
phosphate solution. As a result, the amount of BSA incorporation and
release duration could be increased by using a rapid biomimetic coprecipitation
technique. Up to 43 fold increases in the BSA
incorporation content and the increase from 6 h to more than 360 h in
release duration compared to typical direct adsorption technique were
observed depending on the initial BSA concentration used during coprecipitation
(1, 10 and 100 μg.ml-1). From x-ray diffraction and
Fourier transform infrared spectroscopy studies, the coating
composition was not altered with the incorporation of BSA by this
rapid biomimetic co-precipitation and mainly comprised octacalcium
phosphate and hydroxyapatite. However, the microstructure of
calcium phosphate crystals changed from straight, plate-like units to
curved, plate-like units with increasing BSA content.
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.