Abstract: Studying on the response of vegetation phenology to
climate change at different temporal and spatial scales is important for
understanding and predicting future terrestrial ecosystem dynamics
and the adaptation of ecosystems to global change. In this study, the
Moderate Resolution Imaging Spectroradiometer (MODIS)
Normalized Difference Vegetation Index (NDVI) dataset and climate
data were used to analyze the dynamics of grassland phenology as well
as their correlation with climatic factors in different eco-geographic
regions and elevation units across the Tibetan Plateau. The results
showed that during 2003–2012, the start of the grassland greening
season (SOS) appeared later while the end of the growing season
(EOS) appeared earlier following the plateau’s precipitation and heat
gradients from southeast to northwest. The multi-year mean value of
SOS showed differences between various eco-geographic regions and
was significantly impacted by average elevation and regional average
precipitation during spring. Regional mean differences for EOS were
mainly regulated by mean temperature during autumn. Changes in
trends of SOS in the central and eastern eco-geographic regions were
coupled to the mean temperature during spring, advancing by about
7d/°C. However, in the two southwestern eco-geographic regions,
SOS was delayed significantly due to the impact of spring
precipitation. The results also showed that the SOS occurred later with
increasing elevation, as expected, with a delay rate of 0.66 d/100m.
For 2003–2012, SOS showed an advancing trend in low-elevation
areas, but a delayed trend in high-elevation areas, while EOS was
delayed in low-elevation areas, but advanced in high-elevation areas.
Grassland SOS and EOS changes may be influenced by a variety of
other environmental factors in each eco-geographic region.
Abstract: Because current wireless communication requires high
reliability in a limited bandwidth environment, this paper proposes
the variable modulation scheme based on the codebook. The variable
modulation scheme adjusts transmission power using the codebook in
accordance with channel state. Also, if the codebook is composed of
many bits, the reliability is more improved by the proposed scheme.
The simulation results show that the performance of proposed scheme
has better reliability than the the performance of conventional scheme.
Abstract: This paper is concerned with the single-item
continuous review inventory system in which demand is stochastic
and discrete. The budget consumed for purchasing the ordered items
is not restricted but it incurs extra cost when exceeding specific
value. The unit purchasing price depends on the quantity ordered
under the all-units discounts cost structure. In many actual systems,
the budget as a resource which is occupied by the purchased items is
limited and the system is able to confront the resource shortage by
charging more costs. Thus, considering the resource shortage costs as
a part of system costs, especially when the amount of resource
occupied by the purchased item is influenced by quantity discounts,
is well motivated by practical concerns. In this paper, an optimization
problem is formulated for finding the optimal (r, Q) policy, when the
system is influenced by the budget limitation and a discount pricing
simultaneously. Properties of the cost function are investigated and
then an algorithm based on a one-dimensional search procedure is
proposed for finding an optimal (r, Q) policy which minimizes the
expected system costs.
Abstract: Industries produce millions of cubic meters of effluent
every year and the wastewater produced may be released into the
surrounding water bodies, treated on-site or at municipal treatment
plants. The determination of organic matter in the wastewater
generated is very important to avoid any negative effect on the
aquatic ecosystem. The scope of the present work is to assess the
physicochemical composition of the wastewater produced from one
of the brewery industry in South Africa. This is to estimate the
environmental impact of its discharge into the receiving water bodies
or the municipal treatment plant. The parameters monitored for the
quantitative analysis of brewery wastewater include biological
oxygen demand (BOD5), chemical oxygen demand (COD), total
suspended solids, volatile suspended solids, ammonia, total oxidized
nitrogen, nitrate, nitrite, phosphorus and alkalinity content. In
average, the COD concentration of the brewery effluent was 5340.97
mg/l with average pH values of 4.0 to 6.7. The BOD5 and the solids
content of the wastewater from the brewery industry were high. This
means that the effluent is very rich in organic content and its
discharge into the water bodies or the municipal treatment plant could
cause environmental pollution or damage the treatment plant. In
addition, there were variations in the wastewater composition
throughout the monitoring period. This might be as a result of
different activities that take place during the production process, as
well as the effects of peak period of beer production on the water
usage.
Abstract: The influence of physicochemical water quality
parameters on the abundance and diversity of caddisfly larvae was
studied in seven sampling stations in Mae Tao and Mae Ku
watersheds, Mae Sot District, Tak Province, northern Thailand. The
streams: MK2 and MK8 as reference site, and impacted streams
(MT1-MT5) were sampled bi-monthly during July 2011 to May
2012. A total of 4,584 individual of caddisfly larvae belonging to 10
family and 17 genera were found. The larvae of family
Hydropsychidae were the most abundance, followed by
Philopotamidae, Odontoceridae, and Leptoceridae, respectively. The
genus Cheumatopsyche, Hydropsyche, and Chimarra were the most
abundance genera in this study. Results of CCA ordination showed
the total dissolved solids, sulfate, water temperature, dissolved
oxygen and pH were the most important physicochemical factors to
affect distribution of caddisflies communities. Changes in the
caddisfly fauna may indicate changes in physicochemical factors
owing to agricultural pollution, urbanization, or other human
activities. Results revealed that the order Trichoptera, identified to
species or genus, can be potentially used to assess environmental
water quality status in freshwater ecosystems.
Abstract: Different terms of the Statistical Process Control (SPC)
has sketch in the fuzzy environment. However, Measurement System
Analysis (MSA), as a main branch of the SPC, is rarely investigated
in fuzzy area. This procedure assesses the suitability of the data to be
used in later stages or decisions of the SPC. Therefore, this research
focuses on some important measures of MSA and through a new
method introduces the measures in fuzzy environment. In this
method, which works based on Buckley approach, imprecision and
vagueness nature of the real world measurement are considered
simultaneously. To do so, fuzzy version of the gauge capability (Cg
and Cgk) are introduced. The method is also explained through
example clearly.
Abstract: Structure-borne noise is an important aspect of
offshore platform sound field. It can be generated either directly by
vibrating machineries induced mechanical force, indirectly by the
excitation of structure or excitation by incident airborne noise.
Therefore, limiting of the transmission of vibration energy
throughout the offshore platform is the key to control the structureborne
noise. This is usually done by introducing damping treatment
to the steel structures. Two types of damping treatment using onboard
are presented. By conducting a Statistical Energy Analysis
(SEA) simulation on a jack-up rig, the noise level in the source room,
the neighboring rooms, and remote living quarter cabins are
compared before and after the damping treatments been applied. The
results demonstrated that, in the source neighboring room and living
quarter area, there is a significant noise reduction with the damping
treatment applied, whereas in the source room where air-borne sound
predominates that of structure-borne sound, the impact is not
obvious. The conclusion on effective damping treatment in the
offshore platform is made which enable acoustic professionals to
implement noise control during the design stage for offshore crews’
hearing protection and habitant comfortability.
Abstract: Efficient use of energy, the increase in demand of
energy and also with the reduction of natural energy sources, has
improved its importance in recent years. Most of the losses in the
system from electricity produced until the point of consumption is
mostly composed by the energy distribution system. In this study,
analysis of the resulting loss in power distribution transformer and
distribution power cable is realized which are most of the losses in
the distribution system. Transformer losses in the real distribution
system are analyzed by CYME Power Engineering Software
program. These losses are disclosed for different voltage levels and
different loading conditions.
Abstract: The recent interest in alternative and renewable
energy systems results in increased installed capacity ratio of such
systems in total energy production of the world. Specifically, Wind
Energy Conversion Systems (WECS) draw significant attention
among possible alternative energy options, recently. On the contrary
of the positive points of penetrating WECS in all over the world in
terms of environment protection, energy independence of the
countries, etc., there are significant problems to be solved for the grid
connection of large scale WECS. The reactive power regulation,
voltage variation suppression, etc. can be presented as major issues to
be considered in this regard. Thus, this paper evaluates the
application of a Static VAr Compensator (SVC) unit for the reactive
power regulation and operation continuity of WECS during a fault
condition. The system is modeled employing the IEEE 13 node test
system. Thus, it is possible to evaluate the system performance with
an overall grid simulation model close to real grid systems. The
overall simulation model is developed in
MATLAB/Simulink/SimPowerSystems® environments and the
obtained results effectively match the target of the provided study.
Abstract: In order to help the expert to validate association rules
extracted from data, some quality measures are proposed in the
literature. We distinguish two categories: objective and subjective
measures. The first one depends on a fixed threshold and on data
quality from which the rules are extracted. The second one consists
on providing to the expert some tools in the objective to explore and
visualize rules during the evaluation step. However, the number of
extracted rules to validate remains high. Thus, the manually mining
rules task is very hard. To solve this problem, we propose, in this
paper, a semi-automatic method to assist the expert during the
association rule's validation. Our method uses rule-based
classification as follow: (i) We transform association rules into
classification rules (classifiers), (ii) We use the generated classifiers
for data classification. (iii) We visualize association rules with their
quality classification to give an idea to the expert and to assist him
during validation process.
Abstract: Coal tar is a liquid by-product of coal pyrolysis
processes. This liquid oil mixture contains various kinds of useful
compounds such as benzoic aromatic compounds and phenolic
compounds. These compounds are widely used as raw material for
insecticides, dyes, medicines, perfumes, coloring matters, and many
others. The coal tar was collected by pyrolysis process of coal
obtained from PT Kaltim Prima Coal and Arutmin-Kalimantan. The
experiments typically occurred at the atmospheric pressure in a
laboratory furnace at temperatures ranging from 300 to 550oC with a
heating rate of 10oC/min and a holding time of 1 hour at the pyrolysis
temperature. The Gas Chromatography-Mass Spectroscopy (GC-MS)
was used to analyze the coal tar components. The obtained coal tar
has the viscosity of 3.12 cp, the density of 2.78 g/cm3, the calorific
value of 11,048.44 cal/g, and the molecular weight of 222.67. The
analysis result showed that the coal tar contained more than 78
chemical compounds such as benzene, cresol, phenol, xylene,
naphtalene, etc. The total phenolic compounds contained in coal tar
are 33.25% (PT KPC) and 17.58% (Arutmin-Kalimantan). The total
naphtalene compounds contained in coal tar is 14.15% (PT KPC) and
17.13% (Arutmin-Kalimantan).
Abstract: The development of transport systems has negative
impacts on the environment although it has beneficial effects on
society. The car policy caused many problems such as: - the
spectacular growth of fuel consumption hence the very vast increase
in urban pollution, traffic congestion in certain places and at certain
times, the increase in the number of accidents. The exhaust emissions
from cars and weather conditions are the main factors that determine
the level of pollution in urban atmosphere. These conditions lead to
the phenomenon of heat transfer and radiation occurring between the
air and the soil surface of any town. These exchanges give rise, in
urban areas, to the effects of heat islands that correspond to the
appearance of excess air temperature between the city and its
surrounding space. In this object, we perform a numerical simulation
of the plume generated by the cars exhaust gases and show that these
gases form a screening effect above the urban city which cause the
heat island in the presence of wind flow. This study allows us: 1. To
understand the different mechanisms of interactions between these
phenomena.2. To consider appropriate technical solutions to mitigate
the effects of the heat island.
Abstract: The aim of our study is to project an optimized wind turbine of Darrieus type. This type of wind turbine is characterized by a low starting torque in comparison with the Savonius rotor allowing them to operate for a period greater than wind speed. This led us to reconsider the Darrieus rotor to optimize a design which will increase its starting torque. The study of a system of monitoring and control of the angle of attack of blade profile, which allows an auto start to wind speeds as low as possible is presented for the straight blade of Darrieus turbine. The study continues to extend to other configurations namely those of parabolic type.
Abstract: Synthesis of gold nanoparticles has attracted much
attention since the pioneering discovery of the high catalytic activity
of supported gold nanoparticles in the reaction of CO oxidation at
low temperature. In this research field, we used Na-montmorillonite
for gold nanoparticles stabilization; various gold loading percentage
1, 2 and 5% were used for gold nanoparticles preparation. The gold
nanoparticles were obtained using chemical reduction method using
NaBH4 as reductant agent. The obtained gold nanoparticles stabilized
in Na-montmorillonite were used as catalysts for the reduction of 4-
nitrophenol to aminophenol with sodium borohydride at room
temperature. The UV-Vis results confirmed directly the gold
nanoparticles formation. The XRD and N2 adsorption results showed
the formation of gold nanoparticles in the pores of montmorillonite
with an average size of 5 nm obtained on samples with 2% gold
loading percentage. The gold particles size increased with the
increase of gold loading percentage. The reduction reaction of 4-
nitrophenol into 4-aminophenol with NaBH4 catalyzed by Au-Namontmorillonite
catalyst exhibits remarkably a high activity; the
reaction was completed within 9 min for 1%Au-Na-montmorillonite
and within 3 min for 2%Au-Na-montmorillonite.
Abstract: Based on the hypothesis that disaster risk is
constructed socially and historically, this article shows the
importance of keeping alive the historical memory of disaster by
means of architectural and urban heritage conservation. This is
illustrated with three examples of Latin American World Heritage
cities, where disasters like floods and earthquakes have shaped urban
form. Therefore, the study of urban form or "Urban Morphology" is
proposed as a tool to understand and analyze urban transformations
with the documentation of the occurrence of disasters. Lessons
learned from such cities may be useful to reduce disasters risk in
contemporary built environments.
Abstract: Public space is essential to strengthen the social and
urban fabric and the social cohesion; there lies the importance of its
study. Hence, the aim of this paper is to analyze the quality of public
space in the XXI century in both quantitative and qualitative terms. In
this article, the concept of public space includes open spaces such as
parks, public squares and walking areas. To make this analysis, we
take Mexico City as the case study. It has a population of nearly 9
million inhabitants and is composed of sixteen boroughs. For this
analysis, we consider both existing public spaces and the government
intervention for building and improving new and existent public
spaces. Results show that on the one hand, quantitatively there is not
an equitable distribution of public spaces due to both the growth of
the city itself as well as due to the absence of political will to create
public spaces. Another factor is the evolution of this city, which has
been growing merely in a “patched pattern”, where public space has
played no role at all with a total absence of urban design. On the
other hand, qualitatively, even the boroughs with the most public
spaces have not shown interest in making these spaces qualitatively
inclusive and open to the general population aiming for integration.
Therefore, urban projects that privatize public space seem to be the
rule, rather than a rehabilitation effort of the existent public spaces.
Hence, state intervention should reinforce its role as an agent of
social change acting in benefit of the majority of the inhabitants with
the promotion of more inclusive public spaces.
Abstract: Wireless Sensor Networks (WSNs) enable new
applications and need non-conventional paradigms for the protocol
because of energy and bandwidth constraints, In WSN, sensor node’s
life is a critical parameter. Research on life extension is based on
Low-Energy Adaptive Clustering Hierarchy (LEACH) scheme,
which rotates Cluster Head (CH) among sensor nodes to distribute
energy consumption over all network nodes. CH selection in WSN
affects network energy efficiency greatly. This study proposes an
improved CH selection for efficient data aggregation in sensor
networks. This new algorithm is based on Bacterial Foraging
Optimization (BFO) incorporated in LEACH.
Abstract: The spindle system is one of the most important
components of machine tool. The dynamic properties of the spindle
affect the machining productivity and quality of the work pieces.
Thus, it is important and necessary to determine its dynamic
characteristics of spindles in the design and development in order to
avoid forced resonance. The finite element method (FEM) has been
adopted in order to obtain the dynamic behavior of spindle system.
For this reason, obtaining the Campbell diagrams and determining the
critical speeds are very useful to evaluate the spindle system
dynamics. The unbalance response of the system to the center of
mass unbalance at the cutting tool is also calculated to investigate the
dynamic behavior. In this paper, we used an ANSYS Parametric
Design Language (APDL) program which based on finite element
method has been implemented to make the full dynamic analysis and
evaluation of the results. Results show that the calculated critical
speeds are far from the operating speed range of the spindle, thus, the
spindle would not experience resonance, and the maximum
unbalance response at operating speed is still with acceptable limit.
ANSYS Parametric Design Language (APDL) can be used by spindle
designer as tools in order to increase the product quality, reducing
cost, and time consuming in the design and development stages.
Abstract: The microstrip antennas area has seen some inventive
work in recent years and is now one of the most dynamic fields of
antenna theory. A novel and simple wideband monopole antenna is
presented printed on a single dielectric substrate which is fed by a 50
ohm microstrip line having a low-profile antenna structure with two
parallel s-shaped meandered line of same size. This antenna is fed by
a coaxial feeding tube. In this research, S–form microstrip patch antenna is designed from
measuring the prototypes of the proposed antenna one available
bands with 10db return loss bandwidths of about GPS application
(GPS L2 1490 MHz) and covering the 1400 to 1580 MHz frequency
band at 1.5 GHz, the simulated results for main parameters such as
return loss, impedance bandwidth, radiation patterns, and gains are
also discussed herein. The modeling study shows that such antennas,
in simplicity design and supply, can satisfy GPS application. Two
parallel slots are incorporated to disturb the surface flow path,
introducing local inductive effect. This antenna is fed by a coaxial
feeding tube.
Abstract: In this communication, a low-cost circularly
polarized wire antenna exhibiting improved gain performance for
Dedicated Short Range Communications (DSRC), vehicle-to-vehicle
(V2V) and vehicle-to-infrastructure (V2I) communications is
presented. The proposed antenna comprises a Y-shaped quarterwavelength
monopole antenna surrounded by two iterations of eight
conductive arched walls acting as parasitic elements to enhance the
overall antenna gain and to shape the radiation pattern in the H-plane.
A hemispherical radome shell is added to protect the antenna
structure and its effect on the antenna performance is discussed. The
designed antenna demonstrates antenna gain of 8.2 dB with
omnidirectional far-field radiation pattern in the H-plane. The gain of
the proposed antenna is also compared with the characteristic of the
stand-alone Y-shaped monopole to highlight the advantages of the
proposed approach.