Abstract: Modern low earth orbit (LEO) satellites that require multi-mission flexibility are highly likely to be repositioned between different operational orbits. While executing this process the satellite may experience high levels of vibration and environmental hazards, exposing the deployed solar panel to dangerous stress levels, fatigue and space debris, hence it is desirable to retract the solar array before satellite repositioning to avoid damage or failure.
A novel concept of deployable/retractable hybrid solar array systemcomposed of both rigid and flexible solar panels arranged within a petal formation, aimed to provide a greater power to volume ratio while dramatically reducing mass and cost is proposed.
Abstract: Fiber Bragg optic sensor is embedded in composite
material to detect and monitor the damage that occurs in composite
structures. In this paper, we deal with the mode-Ι delamination to
determine the material strength to crack propagation, using the
coupling mode theory and T-matrix method to simulate the FBGs
spectrum for both uniform and non-uniform strain distribution. The
double cantilever beam test is modeled in FEM to determine the
longitudinal strain. Two models are implemented, the first is the
global half model, and the second is the sub-model to represent the
FBGs with higher refined mesh. This method can simulate damage in
composite structures and converting strain to a wavelength shifting in
the FBG spectrum.
Abstract: Ocimum americanum L (Lamiaceae) is an annual herb
that is native to tropical Africa. The in vitro and in vivo antioxidant
activity of its aqueous extract was carefully investigated by assessing
the DPPH radical scavenging activity, ABTS radical scavenging
activity and hydrogen peroxide radical scavenging activity. The
reducing power, total phenol, total flavonoids and flavonols content
of the extract were also evaluated. The data obtained revealed that the
extract is rich in polyphenolic compounds and scavenged the radicals
in a concentration dependent manner. This was done in comparison
with the standard antioxidants such as BHT and Vitamin C. Also, the
induction of oxidative damage with paracetamol (2000 mg/kg)
resulted in the elevation of lipid peroxides and significant (P < 0.05)
decrease in activities of superoxide dismutase, glutathione
peroxidase, glutathione reductase and catalase in the liver and kidney
of rats. However, the pretreatment of rats with aqueous extract of O.
americanum leaves (200 and 400 mg/kg) and silymarin (100 mg/kg)
caused a significant (P < 0.05) reduction in the values of lipid
peroxides and restored the levels of antioxidant parameters in these
organs. These findings suggest that the leaves of O. americanum have
potent antioxidant properties which may be responsible for its
acclaimed folkloric uses.
Abstract: Speech enhancement is a long standing problem with
numerous applications like teleconferencing, VoIP, hearing aids and
speech recognition. The motivation behind this research work is to
obtain a clean speech signal of higher quality by applying the optimal
noise cancellation technique. Real-time adaptive filtering algorithms
seem to be the best candidate among all categories of the speech
enhancement methods. In this paper, we propose a speech
enhancement method based on Recursive Least Squares (RLS)
adaptive filter of speech signals. Experiments were performed on
noisy data which was prepared by adding AWGN, Babble and Pink
noise to clean speech samples at -5dB, 0dB, 5dB and 10dB SNR
levels. We then compare the noise cancellation performance of
proposed RLS algorithm with existing NLMS algorithm in terms of
Mean Squared Error (MSE), Signal to Noise ratio (SNR) and SNR
Loss. Based on the performance evaluation, the proposed RLS
algorithm was found to be a better optimal noise cancellation
technique for speech signals.
Abstract: Iran has several potential for using renewable
energies, so use them could significantly contribute to energy supply.
The purpose of this paper is to identify the potential of the country
and select the appropriate DG technologies with consideration the
potential and primary energy resources in the regions. In this context,
hybrid energy systems proportionate with the potential of different
regions will be determined based on technical, economic, and
environmental aspect. In the following the proposed structure will be
optimized in terms of size and cost. DG technologies used in this
project include photovoltaic system, wind turbine, diesel generator
and battery bank. The HOMER software is applied for choosing the
appropriate structure and the optimization of system sizing. The
results have been analyzed in terms of technical and economic. The
performance and the cost of each project demonstrate the appropriate
structure of hybrid energy system in that region.
Abstract: The tombolo of Giens is located in the town of Hyères
(France). We recall the history of coastal erosion, and prominent
factors affecting the evolution of the western tombolo. We then
discuss the possibility of stabilizing the western tombolo. Our
argumentation relies on a coupled model integrating swells, currents,
water levels and sediment transport. We present the conclusions of
the simulations of various scenarios, including pre-existing
propositions from coastal engineering offices. We conclude that
beach replenishment seems to be necessary but not sufficient for the
stabilization of the beach. Breakwaters reveal effective particularly in
the most exposed northern area. Some solutions fulfill conditions so
as to be elected as satisfactory. We give a comparative analysis of the
efficiency of 14 alternatives for the protection of the tombolo.
Abstract: The purpose of this study is to forecast the influences
of information and communication technology (ICT) on the structural
changes of Japanese economies. In this study, input-output (IO) and
statistical approaches are used as analysis instruments. More
specifically, this study employs Leontief IO coefficients and
constrained multivariate regression (CMR) model in order to achieve
the purpose. The periods of initial and forecast in this study are 2005
and 2015, respectively. In this study, ICT is represented by ICT capital
stocks. This study conducts two levels of analysis, namely macro and
micro. The results of macro level analysis show that the dynamics of
Japanese economies on the forecast period, relative to the initial period,
are not so high. We focus on (1) commerce, (2) business services and
office supplies, and (3) personal services sectors when conducting the
analysis of the micro level. Further, we analyze its specific IO
coefficients when doing this analysis. The results of the analysis
explain that ICT gives a strong influence on the changes of these
coefficients from initial to forecast periods.
Abstract: The aim of this paper is to give an assessment of
environmental effects of IPPC permit conditions of installations that
are in specific territory with high concentration of industrial
activities.
The IPPC permit is the permit that each operator should hold to
operate the installation as stated by the directive 2010/75/UE on
industrial emissions (integrated pollution prevention and control),
known as IED (Industrial Emissions Directive).
The IPPC permit includes all the measures necessary to achieve a
high level of protection of the environment as a whole, also defining
the monitoring requirements as measurement methodology,
frequency and evaluation procedure. The emissions monitoring of a
specific plant may also give indications of the contribution of these
emissions on the air quality of a definite area.
So, it is clear that the IPPC permits are important tools both to
improve the environmental framework and to achieve the air quality
standards, assisting to assess the possible industrial sources
contributions to air pollution.
Abstract: The present paper summarizes the analysis of the
request for consultation of information and data on industrial
emissions made publicly available on the web site of the Ministry of
Environment, Land and Sea on integrated pollution prevention and
control from large industrial installations, the so called “AIA Portal”.
As a matter of fact, a huge amount of information on national
industrial plants is already available on internet, although it is usually
proposed as textual documentation or images.
Thus, it is not possible to access all the relevant information
through interoperability systems and also to retrieval relevant
information for decision making purposes as well as rising of
awareness on environmental issue.
Moreover, since in Italy the number of institutional and private
subjects involved in the management of the public information on
industrial emissions is substantial, the access to the information is
provided on internet web sites according to different criteria; thus, at
present it is not structurally homogeneous and comparable.
To overcome the mentioned difficulties in the case of the
Coordinating Committee for the implementation of the Agreement
for the industrial area in Taranto and Statte, operating before the
IPPC permit granting procedures of the relevant installation located
in the area, a big effort was devoted to elaborate and to validate data
and information on characterization of soil, ground water aquifer and
coastal sea at disposal of different subjects to derive a global
perspective for decision making purposes. Thus, the present paper
also focuses on main outcomes matured during such experience.
Abstract: This study is concerned with the optimization of
fermentation parameters for the hyper production of mannanase from
Fusarium oxysporum SS-25 employing two step statistical strategy
and kinetic characterization of crude enzyme preparation. The
Plackett-Burman design used to screen out the important factors in
the culture medium revealed 20% (w/w) wheat bran, 2% (w/w) each
of potato peels, soyabean meal and malt extract, 1% tryptone, 0.14%
NH4SO4, 0.2% KH2PO4, 0.0002% ZnSO4, 0.0005% FeSO4, 0.01%
MnSO4, 0.012% SDS, 0.03% NH4Cl, 0.1% NaNO3 in brewer’s spent
grain based medium with 50% moisture content, inoculated with
2.8×107 spores and incubated at 30oC for 6 days to be the main
parameters influencing the enzyme production. Of these factors, four
variables including soyabean meal, FeSO4, MnSO4 and NaNO3 were
chosen to study the interactive effects and their optimum levels in
central composite design of response surface methodology with the
final mannanase yield of 193 IU/gds. The kinetic characterization
revealed the crude enzyme to be active over broader temperature and
pH range. This could result in 26.6% reduction in kappa number with
4.93% higher tear index and 1% increase in brightness when used to
treat the wheat straw based kraft pulp. The hydrolytic potential of
enzyme was also demonstrated on both locust bean gum and guar
gum.
Abstract: This study attempts to elicit the perceptions and
attitudes of EFL learners of the Preparatory Year Program at KSU
towards dialogue journal writing as an EFL learning strategy. The
descriptive research design used incorporated both qualitative and
quantitative instruments to accomplish the objectives of the study. A
learners’ attitude questionnaire and follow-up interviewswith learners
from a randomly selected representative sample of the participants
were employed. The participants were 55 female Saudi university
students in the Preparatory Year Program at King Saud University.
The analysis of the results indicated that the PYP learners had highly
positive attitudes towards dialogue journal writing in their EFL
classes and positive perceptions of the benefits of the use of dialogue
journal writing as an EFL learning strategy. The results also revealed
that dialogue journals are considered an effective EFL learning
strategy since they fulfill various needs for both learners and
instructors. Interestingly, the analysis of the results also revealed that
Saudi university level students tend to write about personal topics in
their dialogue journals more than academic ones.
Abstract: Managing and improving efficiency in the current
highly competitive global automotive industry demands that those
companies adopt leaner and more flexible systems. During the past
20 years the domestic automotive industry in North America has been
focusing on establishing new management strategies in order to meet
market demands. The lean management process also known as
Toyota Manufacturing Process (TPS) or lean manufacturing
encompasses tools and techniques that were established in order to
provide the best quality product with the fastest lead time at the
lowest cost. The following paper presents a study that focused on
improving labor efficiency at one of the Big Three (Ford, GM,
Chrysler LLC) domestic automotive facility in North America. The
objective of the study was to utilize several lean management tools in
order to optimize the efficiency and utilization levels at the “Pre-
Marriage” chassis area in a truck manufacturing and assembly
facility. Utilizing three different lean tools (i.e. Standardization of
work, 7 Wastes, and 5S) this research was able to improve efficiency
by 51%, utilization by 246%, and reduce operations by 14%. The
return on investment calculated based on the improvements made
was 284%.
Abstract: This paper presents modeling of an Alternating
Current (AC) Photovoltaic (PV) module using Matlab/Simulink. The
proposed AC-PV module model is simple, realistic, and application
oriented. The model is derived on module level as compared to cell
level directly from the information provided by the manufacturer data
sheet. DC-PV module, MPPT control, BC, VSI and LC filter, all
were treated as a single unit. The model accounts for changes in
variations of both irradiance and temperature. The AC-PV module
proposed model is simulated and the results are compared with the
datasheet projected numbers to validate model’s accuracy and
effectiveness. Implementation and results demonstrate simplicity and
accuracy, as well as reliability of the model.
Abstract: The research presented in this paper has been focused
on analysing the impact of traffic on the sustainable development of
tourism in Croatia's Dubrovacko-Neretvanska County by the year
2020, based on the figures and trends reported in 2014 and using the
relevant variables that characterise the synergy of traffic and tourism
in, speaking from the geographic viewpoint, the most problematic
county in the Republic of Croatia. The basic hypothesis has been
confirmed through scientifically obtained research results, through
the quantification of the model's variables and the direct growth rates
of the designed model. On the basis of scientific insights into the
sustainable development of traffic and tourism in Dubrovacko-
Neretvanska County, it is possible to propose a new information
model for traffic at the service of the sustainable development of
tourism in the County for the period 2014-2020.
Abstract: The paper deals with the usage of speech acts and
politeness strategies in an EFL classroom in Georgia (Rep of). It
explores the students’ and the teachers’ practice of the politeness
strategies and the speech acts of apology, thanking, request,
compliment / encouragement, command, agreeing / disagreeing,
addressing and code switching. The research method includes
observation as well as a questionnaire. The target group involves the
students from Georgian public schools and two certified, experienced
local English teachers. The analysis is based on Searle’s Speech Act
Theory and Brown and Levinson’s politeness strategies. The findings
show that the students have certain knowledge regarding politeness
yet they fail to apply them in English communication. In addition,
most of the speech acts from the classroom interaction are used by
the teachers and not the students. Thereby, it is suggested that
teachers should cultivate the students’ communicative competence
and attempt to give them opportunities to practise more English
speech acts than they do today.
Abstract: Kazakhstan is currently one of the dynamically
developing states in its region. The stable growth in all sectors of the
economy leads to a corresponding increase in energy consumption.
Thus country consumes significant amount of energy due to the high
level of industrialisation and the presence of energy-intensive
manufacturing such as mining and metallurgy which in turn leads to
low energy efficiency. With allowance for this the Government has
set several priorities to adopt a transition of Republic of Kazakhstan
to a “green economy”. This article provides an overview of
Kazakhstan’s energy efficiency situation in for the period of 1991-
2014. First, the dynamics of production and consumption of
conventional energy resources are given. Second, the potential of
renewable energy sources is summarised followed by the description
of GHG emissions trends in the country. Third, Kazakhstan’ national
initiatives, policies and locally implemented projects in the field of
energy efficiency are described.
Abstract: A parametric study on circular thin-walled pipes
subjected to pure bending is performed. Both straight and curved
pipes are considered. Ratio D/t, initial pipe curvature and internal
pressure are the parameters varying in the analyses. The study is
mainly FEA-based.
It is found that negative curvatures (opposite to bending moment)
considerably increase stiffness and buckling limit of the pipe when no
internal pressure is acting and, similarly, positive curvatures decrease
the stiffness and buckling limit. For internal pressurised pipes the
effects of initial pipe curvature are less relevant. Results show that
this phenomenon is in relationship with the cross-section deformation
due to bending moment, which undergoes relevant ovalisation for no
pressurised pipes and little ovalisation for pressurised pipes.
Abstract: The current study investigated the influence of milling
time and ball-to-powder (BPR) weight ratio on the microstructural
constituents and mechanical properties of bulk nanocrystalline Al;
Al-10%Cu; and Al-10%Cu-5%Ti alloys. Powder consolidation was
carried out using a high frequency induction heat sintering where the
processed metal powders were sintered into a dense and strong bulk
material. The powders and the bulk samples were characterized using
XRD and FEGSEM techniques. The mechanical properties were
evaluated at various temperatures of 25°C, 100°C, 200°C, 300°C and
400°C to study the thermal stability of the processed alloys. The
processed bulk nanocrystalline alloys displayed extremely high
hardness values even at elevated temperatures. The Al-10%Cu-5%Ti
alloy displayed the highest hardness values at room and elevated
temperatures which are related to the presence of Ti-containing
phases such as Al3Ti and AlCu2Ti. These phases are thermally stable
and retain the high hardness values at elevated temperatures up to
400ºC.
Abstract: There is an evident trend to elevate pressure ratio of a
single stage of a turbo compressors - axial compressors in particular.
Whilst there was an opinion recently that a pressure ratio 1,9 was a
reasonable limit, later appeared information on successful modeling
tested of stages with pressure ratio up to 2,8. The authors recon that
lack of information on high pressure stages makes actual a study of
rational choice of design parameters before high supersonic flow
problems solving. The computer program of an engineering type was
developed. Below is presented a sample of its application to study
possible parameters of the impeller of the stage with pressure ratio
3,0. Influence of two main design parameters on expected efficiency,
periphery blade speed and flow structure is demonstrated. The results
had lead to choose a variant for further analysis and improvement by
CFD methods.
Abstract: This paper introduces novel approaches to partitioning
and mapping in terms of model-based embedded multicore system
engineering and further discusses benefits, industrial relevance and
features in common with existing approaches. In order to assess
and evaluate results, both approaches have been applied to a real
industrial application as well as to various prototypical demonstrative
applications, that have been developed and implemented for
different purposes. Evaluations show, that such applications improve
significantly according to performance, energy efficiency, meeting
timing constraints and covering maintaining issues by using
the AMALTHEA platform and the implemented approaches.
Furthermore, the model-based design provides an open, expandable,
platform independent and scalable exchange format between
OEMs, suppliers and developers on different levels. Our proposed
mechanisms provide meaningful multicore system utilization since
load balancing by means of partitioning and mapping is effectively
performed with regard to the modeled systems including hardware,
software, operating system, scheduling, constraints, configuration and
more data.