Abstract: This paper presents the results of an experimental
study undertaken to evaluate the local bond stress-slip response of
short embedment of reinforcing bars in normal concrete (NC) and
high performance fiber reinforced cement composites (HPFRCC)
blocks. Long embedment was investigated as well to gain insights on
the distribution of strain, slip, bar stress and bond stress along the bar
especially in post-yield range. A total of 12 specimens were tested,
by means of pull-out of the reinforcing bars from concrete blocks. It
was found that the enhancement of local bond strength can be
reached up to 50% and ductility of the bond behavior was improved
significantly if HPFRCC is used. Also, under a constant strain at
loaded end, HPFRCC has delayed yielding of bars at other location
from the loaded end. Hence, the reduction of bond stress was slower
for HPFRCC in comparison with NC. Due to the same reason, the
total slips at loaded end for HPFRCC was smaller than NC as
expected. Test results indicated that HPFRCC has better bond slip
behavior which makes it a suitable material to be employed in
anchorage zone such as beam-column joints.
Abstract: Some plants of genus Schinus have been used in the
folk medicine as topical antiseptic, digestive, purgative, diuretic,
analgesic or antidepressant, and also for respiratory and urinary
infections. Chemical composition of essential oils of S. molle and S.
terebinthifolius had been evaluated and presented high variability
according with the part of the plant studied and with the geographic
and climatic regions. The pharmacological properties, namely
antimicrobial, anti-tumoural and anti-inflammatory activities are
conditioned by chemical composition of essential oils. Taking into
account the difficulty to infer the pharmacological properties of
Schinus essential oils without hard experimental approach, this work
will focus on the development of a decision support system, in terms
of its knowledge representation and reasoning procedures, under a
formal framework based on Logic Programming, complemented with
an approach to computing centered on Artificial Neural Networks
and the respective Degree-of-Confidence that one has on such an
occurrence.
Abstract: The fatigue life of tubular joints commonly found in
offshore industry is not only dependent on the value of hot-spot stress
(HSS), but is also significantly influenced by the through-thethickness
stress distribution characterized by the degree of bending
(DoB). The determination of DoB values in a tubular joint is essential
for improving the accuracy of fatigue life estimation using the stresslife
(S–N) method and particularly for predicting the fatigue crack
growth based on the fracture mechanics (FM) approach. In the
present paper, data extracted from finite element (FE) analyses of
tubular KT-joints, verified against experimental data and parametric
equations, was used to investigate the effects of geometrical
parameters on DoB values at the crown 0°, saddle, and crown 180°
positions along the weld toe of central brace in tubular KT-joints
subjected to axial loading. Parametric study was followed by a set of
nonlinear regression analyses to derive DoB parametric formulas for
the fatigue analysis of KT-joints under axial loads. The tubular KTjoint
is a quite common joint type found in steel offshore structures.
However, despite the crucial role of the DoB in evaluating the fatigue
performance of tubular joints, this paper is the first attempt to study
and formulate the DoB values in KT-joints.
Abstract: In this paper, a summary of analytical and
experimental studies into the behavior of a new hysteretic damper,
designed for seismic protection of structures is presented. The Multidirectional
Torsional Hysteretic Damper (MRSD) is a patented
invention in which a symmetrical arrangement of identical cylindrical
steel cores is so configured as to yield in torsion while the structure
experiences planar movements due to earthquake shakings. The new
device has certain desirable properties. Notably, it is characterized by
a variable and controllable-via-design post-elastic stiffness. The
mentioned property is a result of MRSD’s kinematic configuration
which produces this geometric hardening, rather than being a
secondary large-displacement effect. Additionally, the new system is
capable of reaching high force and displacement capacities, shows
high levels of damping, and very stable cyclic response. The device
has gone through many stages of design refinement, multiple
prototype verification tests and development of design guide-lines
and computer codes to facilitate its implementation in practice.
Practicality of the new device, as offspring of an academic sphere, is
assured through extensive collaboration with industry in its final
design stages, prototyping and verification test programs.
Abstract: We present a refined multiscale Shannon entropy for
analyzing electroencephalogram (EEG), which reflects the underlying
dynamics of EEG over multiple scales. The rationale behind
this method is that neurological signals such as EEG possess
distinct dynamics over different spectral modes. To deal with the
nonlinear and nonstationary nature of EEG, the recently developed
empirical mode decomposition (EMD) is incorporated, allowing a
decomposition of EEG into its inherent spectral components, referred
to as intrinsic mode functions (IMFs). By calculating the Shannon
entropy of IMFs in a time-dependent manner and summing them over
adaptive multiple scales, it results in an adaptive subscale entropy
measure of EEG. Simulation and experimental results show that
the proposed entropy properly reveals the dynamical changes over
multiple scales.
Abstract: This paper presents the design and characterization of
analog readout interface circuits for ion sensitive field effect
transistor (ISFET) and ion selective electrode (ISE) based sensor.
These interface circuits are implemented using MIMOS’s 0.35um
CMOS technology and experimentally characterized under 24-leads
QFN package. The characterization evaluates the circuit’s
functionality, output sensitivity and output linearity. Commercial
sensors for both ISFET and ISE are employed together with glass
reference electrode during testing. The test result shows that the
designed interface circuits manage to readout signals produced by
both sensors with measured sensitivity of ISFET and ISE sensor are
54mV/pH and 62mV/decade, respectively. The characterized output
linearity for both circuits achieves above 0.999 Rsquare. The readout
also has demonstrated reliable operation by passing all qualifications
in reliability test plan.
Abstract: Intermetallic materials are among advanced
technology materials that have outstanding mechanical and physical
properties for high temperature applications. Especially creep
resistance, low density and high hardness properties stand out in such
intermetallics. The microstructure, mechanical properties of %88Ni-
%10Cr and %2Mn powders were investigated using specimens
produced by tube furnace sintering at 900-1300°C temperature. A
composite consisting of ternary additions, a metallic phase, Fe, Cr
and Mn have been prepared under Ar shroud and then tube furnace
sintered. XRD, SEM (Scanning Electron Microscope), were
investigated to characterize the properties of the specimens.
Experimental results carried out for composition %88Ni-%10Cr and
%2Mn at 1300°C suggest that the best properties as 138,80HV and
6,269/cm3 density were obtained at 1300°C.
Abstract: Super steel materials play a vital role in the
construction and fabrication of structural, piping and pipeline
components. In assuring the integrity of onshore and offshore
operating systems, they enable life cycle costs to be minimized. In
this context, Duplex stainless steel (DSS) material related welding on
constructions and fabrications plays a significant role in maintaining
and assuring integrity at an optimal expenditure over the life cycle of
production and process systems as well as associated structures. In
DSS welding, factors such as gap geometry, shielding gas supply
rate, welding current, and type of the welding process are vital to the
final joint performance. Hence, an experimental investigation has
been performed using an engineering robust design approach
(ERDA) to investigate the optimal settings that generate optimal
super DSS (i.e. UNS S32750) joint performance. This manuscript
illustrates the mathematical approach and experimental design,
optimal parameter settings and results of the verification experiment.
Abstract: Aim of this work is to determine the theoretical and
experimental properties of filament wound glass fiber/epoxy resin
composite pipes with different winding design subjected under
bending. For determination of bending strength of composite samples
three point bending tests were conducted. Good correlation between
theoretical and experimental results has been obtained, where sample
No4 has shown the highest value of bending strength. All samples
have demonstrated matrix cracking and fiber failure followed by
layers delamination during testing. Also, it was found that smaller
winding angles lead to an increase in bending stress. From presented
results good merger between glass fibers and epoxy resin was
confirmed by SEM analysis.
Abstract: A new steganographic method via the use of numeric
data on public websites with a self-authentication capability is
proposed. The proposed technique transforms a secret message into
partial shares by Shamir’s (k, n)-threshold secret sharing scheme with
n = k + 1. The generated k+1 partial shares then are embedded into the
numeric items to be disguised as part of the website’s numeric content,
yielding the stego numeric content. Afterward, a receiver links to the
website and extracts every k shares among the k+1 ones from the stego
numeric content to compute k+1 copies of the secret, and the
phenomenon of value consistency of the computed k+1 copies is taken
as an evidence to determine whether the extracted message is authentic
or not, attaining the goal of self-authentication of the extracted secret
message. Experimental results and discussions are provided to show
the feasibility and effectiveness of the proposed method.
Abstract: Experimental studies to investigate the depth of the
scour conducted at a side-weir intersection located at the 1800 curved
flume which located Hydraulic Laboratory of Yıldız Technical
University, Istanbul, Turkey. Side weirs were located at the middle of
the straight part of the main channel. Three different lengths (25, 40
and 50 cm) and three different weir crest height (7, 10 and 12 cm) of
the side weir placed on the side weir station. There is no scour when
the material is only kaolin. Therefore, the cohesive bed was prepared
by properly mixing clay material (kaolin) with 31% sand in all
experiments. Following 24h consolidation time, in order to observe
the effect of flow intensity on the scour depth, experiments were
carried out for five different upstream Froude numbers in the range of
0.33-0.81.
As a result of this study the relation between scour depth and
upstream flow intensity as a function of time have been established.
The longitudinal velocities decreased along the side weir; towards the
downstream due to overflow over the side-weirs. At the beginning,
the scour depth increases rapidly with time and then asymptotically
approached constant values in all experiments for all side weir
dimensions as in non-cohesive sediment. Thus, the scour depth
reached equilibrium conditions. Time to equilibrium depends on the
approach flow intensity and the dimensions of side weirs. For
different heights of the weir crest, dimensionless scour depths
increased with increasing upstream Froude number. Equilibrium
scour depths which formed 7 cm side-weir crest height were obtained
higher than that of the 12 cm side-weir crest height. This means when
side-weir crest height increased equilibrium scour depths decreased.
Although the upstream side of the scour hole is almost vertical, the
downstream side of the hole is inclined.
Abstract: Plasmin plays an important role in the human
circulatory system owing to its catalytic ability of fibrinolysis. The
immediate injection of plasmin in patients of strokes has intrigued
many scientists to design vectors that can transport plasmin to the
desired location in human body. Here we predict the structure of
human plasmin and investigate the interaction of plasmin with the
gold-nanoparticle.
Because the crystal structure of plasminogen has been solved, we
deleted N-terminal domain (Pan-apple domain) of plasminogen and
generate a mimic of the active form of this enzyme (plasmin). We
conducted a simulated annealing process on plasmin and discovered a
very large conformation occurs. Kringle domains 1, 4 and 5 had been
observed to leave its original location relative to the main body of the
enzyme and the original doughnut shape of this enzyme has been
transformed to a V-shaped by opening its two arms. This observation
of conformational change is consistent with the experimental results of
neutron scattering and centrifugation.
We subsequently docked the plasmin on the simulated gold surface
to predict their interaction. The V-shaped plasmin could utilize its
Kringle domain and catalytic domain to contact the gold surface.
Our findings not only reveal the flexibility of plasmin structure but
also provide a guide for the design of a plasmin-gold nanoparticle.
Abstract: Al6061 alloy base matrix, reinforced with particles of
silicon carbide (10 wt %) and Graphite powder (1wt%), known as
hybrid composites have been fabricated by liquid metallurgy route
(stir casting technique) and optimized at different parameters like
applied load, sliding speed and sliding distance by taguchi method. A
plan of experiment generated through taguchi technique was used to
perform experiments based on L27 orthogonal array. The developed
ANOVA and regression equations are used to find the optimum
coefficient of friction and wear under the influence of applied load,
sliding speed and sliding distance. On the basis of “smaller the best”
the dry sliding wear resistance was analysed and finally confirmation
tests were carried out to verify the experimental results.
Abstract: Purpose: The study aimed to assess the depressant or
antidepressant effects of several Nonsteroidal Anti-Inflammatory
Drugs (NSAIDs) in mice: the selective cyclooxygenase-2 (COX-2)
inhibitor meloxicam, and the non-selective COX-1 and COX-2
inhibitors lornoxicam, sodium metamizole, and ketorolac. The
current literature data regarding such effects of these agents are
scarce.
Materials and methods: The study was carried out on NMRI mice
weighing 20-35 g, kept in a standard laboratory environment. The
study was approved by the Ethics Committee of the University of
Medicine and Pharmacy „Carol Davila”, Bucharest. The study agents
were injected intraperitoneally, 10 mL/kg body weight (bw) 1 hour
before the assessment of the locomotor activity by cage testing (n=10
mice/ group) and 2 hours before the forced swimming tests (n=15).
The study agents were dissolved in normal saline (meloxicam,
sodium metamizole), ethanol 11.8% v/v in normal saline (ketorolac),
or water (lornoxicam), respectively. Negative and positive control
agents were also given (amitryptilline in the forced swimming test).
The cage floor used in the locomotor activity assessment was divided
into 20 equal 10 cm squares. The forced swimming test involved
partial immersion of the mice in cylinders (15/9cm height/diameter)
filled with water (10 cm depth at 28C), where they were left for 6
minutes. The cage endpoint used in the locomotor activity assessment
was the number of treaded squares. Four endpoints were used in the
forced swimming test (immobility latency for the entire 6 minutes,
and immobility, swimming, and climbing scores for the final 4
minutes of the swimming session), recorded by an observer that was
„blinded” to the experimental design. The statistical analysis used the
Levene test for variance homogeneity, ANOVA and post-hoc
analysis as appropriate, Tukey or Tamhane tests.
Results: No statistically significant increase or decrease in the
number of treaded squares was seen in the locomotor activity
assessment of any mice group. In the forced swimming test,
amitryptilline showed an antidepressant effect in each experiment, at
the 10 mg/kg bw dosage. Sodium metamizole was depressant at 100
mg/kg bw (increased the immobility score, p=0.049, Tamhane test),
but not in lower dosages as well (25 and 50 mg/kg bw). Ketorolac
showed an antidepressant effect at the intermediate dosage of 5
mg/kg bw, but not so in the dosages of 2.5 and 10 mg/kg bw,
respectively (increased the swimming score, p=0.012, Tamhane test).
Meloxicam and lornoxicam did not alter the forced swimming
endpoints at any dosage level.
Discussion: 1) Certain NSAIDs caused changes in the forced
swimming patterns without interfering with locomotion. 2) Sodium
metamizole showed a depressant effect, whereas ketorolac proved
antidepressant. Conclusion: NSAID-induced mood changes are not
class effects of these agents and apparently are independent of the
type of inhibited cyclooxygenase (COX-1 or COX-2).
Disclosure: This paper was co-financed from the European Social
Fund, through the Sectorial Operational Programme Human Resources Development 2007-2013, project number POSDRU /159
/1.5 /S /138907 "Excellence in scientific interdisciplinary research,
doctoral and postdoctoral, in the economic, social and medical fields
-EXCELIS", coordinator The Bucharest University of Economic
Studies.
Abstract: In the present study, RBF neural networks were used
for predicting the performance and emission parameters of a
biodiesel engine. Engine experiments were carried out in a 4 stroke
diesel engine using blends of diesel and Honge methyl ester as the
fuel. Performance parameters like BTE, BSEC, Tex and emissions
from the engine were measured. These experimental results were
used for ANN modeling.
RBF center initialization was done by random selection and by
using Clustered techniques. Network was trained by using fixed and
varying widths for the RBF units. It was observed that RBF results
were having a good agreement with the experimental results.
Networks trained by using clustering technique gave better results
than using random selection of centers in terms of reduced MRE and
increased prediction accuracy. The average MRE for the performance
parameters was 3.25% with the prediction accuracy of 98% and for
emissions it was 10.4% with a prediction accuracy of 80%.
Abstract: The polymer foil used for manufacturing of
laminated glass members behaves in a viscoelastic manner with
temperature dependance. This contribution aims at incorporating
the time/temperature-dependent behavior of interlayer to our earlier
elastic finite element model for laminated glass beams. The model
is based on a refined beam theory: each layer behaves according
to the finite-strain shear deformable formulation by Reissner and
the adjacent layers are connected via the Lagrange multipliers
ensuring the inter-layer compatibility of a laminated unit. The
time/temperature-dependent behavior of the interlayer is accounted
for by the generalized Maxwell model and by the time-temperature
superposition principle due to the Williams, Landel, and Ferry.
The resulting system is solved by the Newton method with
consistent linearization and the viscoelastic response is determined
incrementally by the exponential algorithm. By comparing the model
predictions against available experimental data, we demonstrate that
the proposed formulation is reliable and accurately reproduces the
behavior of the laminated glass units.
Abstract: The article presents a plasma chemical technology for
processing solid fuels, using examples of bituminous and brown
coals. Thermodynamic and experimental investigation of the
technology was made. The technology allows producing synthesis
gas from the coal organic mass and valuable components (technical
silicon, ferrosilicon, aluminum, and carbon silicon, as well as
microelements of rare metals, such as uranium, molybdenum,
vanadium, etc.) from the mineral mass. The thusly produced highcalorific
synthesis gas can be used for synthesis of methanol, as a
high-calorific reducing gas instead of blast-furnace coke as well as
power gas for thermal power plants.
Abstract: As the trend in automotive technology is fast moving
towards hybridization and electrification to curb emissions as well as
to improve the fuel efficiency, air-conditioning systems in passenger
cars have not caught up with this trend and still remain as the major
energy consumers amongst others. Adsorption based air-conditioning
systems, e.g. with silica-gel water pair, which are already in use for
residential and commercial applications, are now being considered as
a technology leap once proven feasible for the passenger cars. In this
paper we discuss a methodology, challenges and feasibility of
implementing an adsorption based air-conditioning system in a
passenger car utilizing the exhaust waste heat. We also propose an
optimized control strategy with interfaces to the engine control unit
of the vehicle for operating this system with reasonable efficiency
supported by our simulation and validation results in a prototype
vehicle, additionally comparing to existing implementations,
simulation based as well as experimental. Finally we discuss the
influence of start-stop and hybrid systems on the operation strategy of
the adsorption air-conditioning system.
Abstract: In wastewater treatment processes, aeration introduces
air into a liquid. In these systems, air is introduced by different
devices submerged in the wastewater. Smaller bubbles result in more
bubble surface area per unit of volume and higher oxygen transfer
efficiency. Jet pumps are devices that use air bubbles and are widely
used in wastewater treatment processes. The principle of jet pumps is
their ability to transfer energy of one fluid, called primary or motive,
into a secondary fluid or gas. These pumps have no moving parts and
are able to work in remote areas under extreme conditions. The
objective of this work is to study experimentally the characteristics of
the jet pump and the size of air bubbles in the laboratory water tank.
The effect of flow rate ratio on pump performance is investigated in
order to have a better understanding about pump behavior under
various conditions, in order to determine the efficiency of receiving
air bubbles different sizes. The experiments show that we should take
care when increasing the flow rate ratio while seeking to decrease
bubble size in the outlet flow. This study will help improve and
extend the use of the jet pump in many practical applications.
Abstract: All current experimental methods for determination of
stress intensity factors are based on the assumption that the state of
stress near the crack tip is plane stress. Therefore, these methods rely
on strain and displacement measurements made outside the near
crack tip region affected by the three-dimensional effects or by
process zone. In this paper, we develop and validate an experimental
procedure for the evaluation of stress intensity factors from the
measurements of the out-of-plane displacements in the surface area
controlled by 3D effects. The evaluation of stress intensity factors is
possible when the process zone is sufficiently small, and the
displacement field generated by the 3D effects is fully encapsulated
by K-dominance region.