Abstract: This study aims to evaluate the effective size, section
and structural characteristics of circular hollow steel (CHS) damper.
CHS damper is among steel dampers which are used widely for
seismic energy dissipation because they are easy to install, maintain
and are inexpensive. CHS damper dissipates seismic energy through
metallic deformation due to the geometrical elasticity of circular shape
and fatigue resistance around connection part. After calculating the
effective size, which is found to be height to diameter ratio of √3,
nonlinear FE analyses were carried out to evaluate the structural
characteristics and effective section (diameter-to-ratio).
Abstract: In this paper, improved performance scheme for
joint transmission (JT) is proposed in downlink (DL) coordinated
multi-point (CoMP) in case of the constraint transmission power.
This scheme is that a serving transmission point (TP) requests the
JT to an inter-TP and it selects a precoding technique according
to the channel state information (CSI) from user equipment (UE).
The simulation results show that the bit error rate (BER) and the
throughput performances of the proposed scheme provide the high
spectral efficiency and the reliable data at the cell edge.
Abstract: The reduction of phosphorus and sulfur in engine oil
are the main topics of this paper. Very reproducible boundary
lubrication tests were conducted as part of Design of Experiment
software (DOE) to study the behavior of fluorinated catalyst iron
fluoride (FeF3), and polutetrafluoroethylene or Teflon (PTFE) in
developing environmentally friendly (reduced P and S) anti-wear
additives for future engine oil formulations. Multi-component
Chevron fully formulated oil (GF3) and Chevron plain oil were used
with the addition of PTFE and catalyst to characterize and analyze
their performance. Lower phosphorus blends were the goal of the
model solution. Experiments indicated that new sub-micron FeF3
catalyst played an important role in preventing breakdown of the
tribofilm.
Abstract: It is a major challenge to build a bridge superstructure
that has long-term durability and low maintenance requirements. A
solution to this challenge may be to use new materials or to
implement new structural systems. Fiber Reinforced Polymer (FRP)
composites have continued to play an important role in solving some
of persistent problems in infrastructure applications because of its
high specific strength, light weight, and durability. In this study, the
concept of the hybrid FRP-concrete structural systems is applied to a
bridge superstructure. The hybrid FRP-concrete bridge superstructure
is intended to have durable, structurally sound, and cost effective
hybrid system that will take full advantage of the inherent properties
of both FRP materials and concrete. In this study, two hybrid FRP-concrete
bridge systems were investigated. The first system consists
of trapezoidal cell units forming a bridge superstructure. The second
one is formed by arch cells. The two systems rely on using cellular
components to form the core of the bridge superstructure, and an
outer shell to warp around those cells to form the integral unit of the
bridge. Both systems were investigated analytically by using finite
element (FE) analysis. From the rigorous FE studies, it was
concluded that first system is more efficient than the second.
Abstract: The main objective of this study was to determine the
effects of Nitrogen fixing bacteria and manure application on the seed
yield and yield components in black cumin (Nigella sativa L.). The
experiment was carried out at the RAN Research Station in
Firouzkouh in 2012. A 4×4 factorial experiment, arranged in a
randomized complete blocks designed with three replications.
Nitrogen fixing bacteria at 4 levels (control, Azotobacter,
Azospirillum and Azotobacter + Azospirillum) and manure
application at 4 levels (0, 2.5, 5 and 7.5 ton ha-1) were used at this
investigation. The present results have shown that the highest height,
1000 seeds weight, seed number per follicle, follicle yield, seed yield
and harvest index were obtained after using Azotobacter and
Azospirillum, simultaneously. Manure application only effects on
follicle yield and by 5ton manure ha-1 the highest follicle yield
obtained. Results of this investigation showed that the maximum seed
yield obtained when Aotobacter+Azospirillum inoculated with black
cumin seeds and 5 ton manure ha-1 applied. According to the results
of this investigation the integrated management of Azotobacter and
Azospirillum with manure application is the best treatment for
achieving the maximum quantitative charactersitics of Black cumin.
Abstract: Effect of sprue/metal head height on mould filling,
microstructure and mechanical properties of TWDI casting is studied.
Results show that metal/sprue height of 50 mm is not sufficient to
push the melt through the gating channel, but as it is increased from
100-350 mm, proper mould filling is achieved. However at higher
heights between 200 mm and 350 mm, defects associated with
incomplete solidification, carbide precipitation and turbulent flow are
evident. This research shows that superior UTS, hardness, nodularity
and nodule count are obtained at 100 mm sprue height.
Abstract: Sampled-data controller is presented for solid oxide
fuel cell systems which is expressed by a sector bounded nonlinear
model. The proposed control law is obtained by solving a convex
problem satisfying several linear matrix inequalities. Simulation
results are given to show the effectiveness of the proposed design
method.
Abstract: Based on Business and Consumer Survey (BCS) data,
the European Commission (EC) regularly publishes the monthly
Economic Sentiment Indicator (ESI) for each EU member state. ESI
is conceptualized as a leading indicator, aimed ad tracking the overall
economic activity. In calculating ESI, the EC employs arbitrarily
chosen weights on 15 BCS response balances. This paper raises the
predictive quality of ESI by applying nonlinear programming to find
such weights that maximize the correlation coefficient of ESI and
year-on-year GDP growth. The obtained results show that the highest
weights are assigned to the response balances of industrial sector
questions, followed by questions from the retail trade sector. This
comes as no surprise since the existing literature shows that the
industrial production is a plausible proxy for the overall Croatian
economic activity and since Croatian GDP is largely influenced by
the aggregate personal consumption.
Abstract: Waste Load Allocation (WLA) strategies usually
intend to find economic policies for water resource management.
Water quality trading (WQT) is an approach that uses discharge
permit market to reduce total environmental protection costs. This
primarily requires assigning discharge limits known as total
maximum daily loads (TMDLs). These are determined by monitoring
organizations with respect to the receiving water quality and
remediation capabilities. The purpose of this study is to compare two
approaches of TMDL assignment for WQT policy in small catchment
area of Haraz River, in north of Iran. At first, TMDLs are assigned
uniformly for the whole point sources to keep the concentrations of
BOD and dissolved oxygen (DO) at the standard level at checkpoint
(terminus point). This was simply simulated and controlled by
Qual2kw software. In the second scenario, TMDLs are assigned
using multi objective particle swarm optimization (MOPSO) method
in which the environmental violation at river basin and total treatment
costs are minimized simultaneously. In both scenarios, the equity
index and the WLA based on trading discharge permits (TDP) are
calculated. The comparative results showed that using economically
optimized TMDLs (2nd scenario) has slightly more cost savings rather
than uniform TMDL approach (1st scenario). The former annually
costs about 1 M$ while the latter is 1.15 M$. WQT can decrease
these annual costs to 0.9 and 1.1 M$, respectively. In other word,
these approaches may save 35 and 45% economically in comparison
with command and control policy. It means that using multi objective
decision support systems (DSS) may find more economical WLA,
however its outcome is not necessarily significant in comparison with
uniform TMDLs. This may be due to the similar impact factors of
dischargers in small catchments. Conversely, using uniform TMDLs
for WQT brings more equity that makes stakeholders not feel that
much envious of difference between TMDL and WQT allocation. In
addition, for this case, determination of TMDLs uniformly would be
much easier for monitoring. Consequently, uniform TMDL for TDP
market is recommended as a sustainable approach. However,
economical TMDLs can be used for larger watersheds.
Abstract: This work consists of a numerical simulation of
convective heat transfer in a vertical plane channel filled with a heat
generating porous medium, in the absence of local thermal
equilibrium. The walls are maintained to a constant temperature and
the inlet velocity is uniform. The dynamic range is described by the
Darcy-Brinkman model and the thermal field by two energy
equations model. A dimensionless formulation is developed for
performing a parametric study based on certain dimensionless groups
such as, the Biot interstitial number, the thermal conductivity ratio
and the volumetric heat generation, q '''. The governing equations are
solved using the finite volume method, gave rise to a multitude of
results concerning in particular the thermal field in the porous
channel and the existence or not of the local thermal equilibrium.
Abstract: The elastic properties and fracture of two-dimensional
graphene were calculated purely from the atomic bonding (stretching
and bending) based on molecular mechanics method. Considering the
representative unit cell of graphene under various loading conditions,
the deformations of carbon bonds and the variations of the interlayer
distance could be realized numerically under the geometry constraints
and minimum energy assumption. In elastic region, it was found that
graphene was in-plane isotropic. Meanwhile, the in-plane deformation
of the representative unit cell is not uniform along armchair direction
due to the discrete and non-uniform distributions of the atoms. The
fracture of graphene could be predicted using fracture criteria based on
the critical bond length, over which the bond would break. It was
noticed that the fracture behavior were directional dependent, which
was consistent with molecular dynamics simulation results.
Abstract: Several parameters are established in order to measure
biodiesel quality. One of them is the iodine value, which is an
important parameter that measures the total unsaturation within a
mixture of fatty acids. Limitation of unsaturated fatty acids is
necessary since warming of higher quantity of these ones ends in
either formation of deposits inside the motor or damage of lubricant.
Determination of iodine value by official procedure tends to be very
laborious, with high costs and toxicity of the reagents, this study uses
artificial neural network (ANN) in order to predict the iodine value
property as an alternative to these problems. The methodology of
development of networks used 13 esters of fatty acids in the input
with convergence algorithms of back propagation of back
propagation type were optimized in order to get an architecture of
prediction of iodine value. This study allowed us to demonstrate the
neural networks’ ability to learn the correlation between biodiesel
quality properties, in this caseiodine value, and the molecular
structures that make it up. The model developed in the study reached
a correlation coefficient (R) of 0.99 for both network validation and
network simulation, with Levenberg-Maquardt algorithm.
Abstract: Currently, continuous two-phase decanter process
used for olive oil production is the more internationally widespread.
The wastewaters generated from this industry (OMW) are a real
environmental problem because of its high organic load. Among
proposed treatments for these wastewaters, advanced oxidation
technologies (Fenton, ozone, photoFenton, etc.) are the most
favourable. The direct application of these processes is somewhat
expensive. Therefore, the application of a previous stage based on a
flocculation-sedimentation operation is of high importance. In this
research five commercial flocculants (three cationic, and two anionic)
have been used to achieve the separation of phases (liquid clarifiedsludge).
For each flocculant, different concentrations (0-1000 mg/L)
have been studied. In these experiments, sludge volume formed and
the final water quality were determined. The final removal
percentages of total phenols (11.3-25.1%), COD (5.6-20.4%), total
carbon (2.3-26.5%), total organic carbon (1.50-23.8%), total nitrogen
(1.45-24.8%), and turbidity (27.9-61.4%) were determined. The
variation on electric conductivity reduction percentage (1-8%) was
also determined. Finally, the best flocculants with highest removal
percentages have been determined (QG2001 and Flocudex CS49).
Abstract: Amoxicillin is an antibiotic which is widely used to
treat various infections in both human beings and animals. However,
when amoxicillin is released into the environment, it is a major
problem. Amoxicillin causes bacterial resistance to these drugs and
failure of treatment with antibiotics. Liquid membrane is of great
interest as a promising method for the separation and recovery of the
target ions from aqueous solutions due to the use of carriers for the
transport mechanism, resulting in highly selectivity and rapid
transportation of the desired metal ions. The simultaneous processes
of extraction and stripping in a single unit operation of liquid
membrane system are very interesting. Therefore, it is practical to
apply liquid membrane, particularly the HFSLM for industrial
applications as HFSLM is proved to be a separation process with
lower capital and operating costs, low energy and extractant with
long life time, high selectivity and high fluxes compared with solid
membranes. It is a simple design amenable to scaling up for industrial
applications. The extraction and recovery for (Amoxicillin) through
the hollow fiber supported liquid membrane (HFSLM) using
aliquat336 as a carrier were explored with the experimental data. The
important variables affecting on transport of amoxicillin viz.
extractant concentration and operating time were investigated. The
highest AMOX- extraction percentages of 85.35 and Amoxicillin
stripping of 80.04 were achieved with the best condition at 6 mmol/L
[aliquat336] and operating time 100 min. The extraction reaction
order (n) and the extraction reaction rate constant (kf) were found to
be 1.00 and 0.0344 min-1, respectively.
Abstract: In this paper, the energy saving and human thermal
comfort in a typical office room are investigated. The impact of a
combined system of exhaust inlet air with light slots located at the
ceiling level in a room served by displacement ventilation system is
numerically modelled. Previous experimental data are used to
validate the Computational Fluid Dynamic (CFD) model. A case
study of simulated office room includes two seating occupants, two
computers, two data loggers and four lamps. The combined system is
located at the ceiling level above the heat sources. A new method of
calculation for the cooling coil load in Stratified Air Distribution
(STRAD) system is used in this study. The results show that 47.4%
energy saving of space cooling load can be achieved by combing the
exhaust inlet air with light slots at the ceiling level above the heat
sources.
Abstract: In this paper, the cable model of dendrites have been
considered. The dendrites are cylindrical cables of various segments
having variable length and reducing radius from start point at synapse
and end points. For a particular event signal being received by a
neuron in response only some dendrite are active at a particular
instance. Initial current signals with different current flows in
dendrite are assumed. Due to overlapping and coupling of active
dendrite, they induce currents in the dendrite segments of each other
at a particular instance. But how these currents are induced in the
various segments of active dendrites due to coupling between these
dendrites, It is not presented in the literature. Here the paper presents
a model for induced currents in active dendrite segments due to
mutual coupling at the starting instance of an activity in dendrite. The
model is as discussed further.
Abstract: This paper presents a rheological model for producing
shape-memory thermoplastic polymers. Shape-memory occurs as a
result of internal rearrangement of the structural elements of a
polymer. A non-linear viscoelastic model was developed that allows
qualitative and quantitative prediction of the stress-strain behavior of
shape-memory polymers during heating. This research was done to
develop a technique to determine the maximum possible change in
size of shape-memory products during heating. The rheological
model used in this work was particularly suitable for defining process
parameters and constructive parameters of the processing equipment.
Abstract: This study aims at developing a novel cold asphalt
concrete binder course mixture by using Ordinary Portland Cement
(OPC) as a replacement for conventional mineral filler (0%-100%)
with new by-product material (LJMU-A2) used as a supplementary
cementitious material. With this purpose, cold asphalt concrete binder
course mixtures with cationic emulsions were studied by means of
stiffness modulus whereas water sensitivity was assessed by
measuring the stiffness modulus ratio before and after sample
conditioning.
The results indicate that a substantial enhancement in the stiffness
modulus and a considerable improvement of water sensitivity
resistance is achieved by adding LJMU-A2 to the cold asphalt
mixtures as a supplementary cementitious material. Moreover, the
addition of LJMU-A2 to those mixtures leads to a stiffness modulus
after 2-day curing compared to that obtained with Portland cement,
which occurs after 7-day curing.
Abstract: This paper presents Carrier Sense Multiple Access
(CSMA) communication models based on SoC design methodology.
Such a model can be used to support the modeling of the complex
wireless communication systems. Therefore, the use of such
communication model is an important technique in the construction
of high-performance communication. SystemC has been chosen
because it provides a homogeneous design flow for complex designs
(i.e. SoC and IP-based design). We use a swarm system to validate
CSMA designed model and to show how advantages of incorporating
communication early in the design process. The wireless
communication created through the modeling of CSMA protocol that
can be used to achieve communication between all the agents and to
coordinate access to the shared medium (channel).
Abstract: Interstitial free steels possess better formability and
have many applications in automotive industries. Forming limit
diagrams (FLDs) indicate the formability of materials which can be
determined by experimental and finite element (FE) simulations.
FLDs were determined experimentally by LDH test, utilizing optical
strain measurement system for measuring the strains in different
width specimens and by FE simulations in Interstitial Free (IF) and
Interstitial Free High Strength (IFHS) steels. In this study, the
experimental and FE simulated FLDs are compared and also the
stress based FLDs were investigated.