Abstract: Dual phase steels (DPS)s have a microstructure
consisting of a hard second phase called Martensite in the soft Ferrite
matrix. In recent years, there has been interest in dual-phase steels,
because the application of these materials has made significant usage;
particularly in the automotive sector Composite microstructure of
(DPS)s exhibit interesting characteristic mechanical properties such
as continuous yielding, low yield stress to tensile strength
ratios(YS/UTS), and relatively high formability; which offer
advantages compared with conventional high strength low alloy
steels(HSLAS). The research dealt with the characterization of
damage in (DPS)s. In this study by review the mechanisms of failure
due to volume fraction of martensite second phase; a new method is
introduced to identifying the mechanisms of failure in the various
phases of these types of steels. In this method the acoustic emission
(AE) technique was used to detect damage progression. These failure
mechanisms consist of Ferrite-Martensite interface decohesion and/or
martensite phase fracture. For this aim, dual phase steels with
different volume fraction of martensite second phase has provided by
various heat treatment methods on a low carbon steel (0.1% C), and
then AE monitoring is used during tensile test of these DPSs. From
AE measurements and an energy ratio curve elaborated from the
value of AE energy (it was obtained as the ratio between the strain
energy to the acoustic energy), that allows detecting important
events, corresponding to the sudden drops. These AE signals events
associated with various failure mechanisms are classified for ferrite
and (DPS)s with various amount of Vm and different martensite
morphology. It is found that AE energy increase with increasing Vm.
This increasing of AE energy is because of more contribution of
martensite fracture in the failure of samples with higher Vm. Final
results show a good relationship between the AE signals and the
mechanisms of failure.
Abstract: The hot deformation behavior of high strength low
alloy (HSLA) steels with different chemical compositions under hot
working conditions in the temperature range of 900 to 1100℃ and
strain rate range from 0.1 to 10 s-1 has been studied by performing a
series of hot compression tests. The dynamic materials model has been
employed for developing the processing maps, which show variation
of the efficiency of power dissipation with temperature and strain rate.
Also the Kumar-s model has been used for developing the instability
map, which shows variation of the instability for plastic deformation
with temperature and strain rate. The efficiency of power dissipation
increased with decreasing strain rate and increasing temperature in the
steel with higher Cr and Ti content. High efficiency of power
dissipation over 20 % was obtained at a finite strain level of 0.1 under
the conditions of strain rate lower than 1 s-1 and temperature higher
than 1050 ℃ . Plastic instability was expected in the regime of
temperatures lower than 1000 ℃ and strain rate lower than 0.3 s-1. Steel
with lower Cr and Ti contents showed high efficiency of power
dissipation at higher strain rate and lower temperature conditions.
Abstract: This research investigates the suitability of fuel oil in
improving gypseous soil. A detailed laboratory tests were carried-out
on two soils (soil I with 51.6% gypsum content, and soil II with
26.55%), where the two soils were obtained from Al-Therthar site
(Al-Anbar Province-Iraq).
This study examines the improvement of soil properties using the
gypsum material which is locally available with low cost to minimize
the effect of moisture on these soils by using the fuel oil. This study
was conducted on two models of the soil gypsum, from the Tharthar
area. The first model was sandy soil with Gypsum content of (51.6%)
and the second is clayey soil and the content of Gypsum is (26.55%).
The program included tests measuring the permeability and
compressibility of the soil and their collapse properties. The shear
strength of the soil and the amounts of weight loss of fuel oil due to
drying had been found. These tests have been conducted on the
treated and untreated soils to observe the effect of soil treatment on
the engineering properties when mixed with varying degrees of fuel
oil with the equivalent of the water content.
The results showed that fuel oil is a good material to modify the
basic properties of the gypseous soil of collapsibility and
permeability, which are the main problems of this soil and retained
the soil by an appropriate amount of the cohesion suitable for
carrying the loads from the structure.
Abstract: We study the typical domain size and configuration
character of a randomly perturbed system exhibiting continuous
symmetry breaking. As a model system we use rod-like objects
within a cubic lattice interacting via a Lebwohl–Lasher-type
interaction. We describe their local direction with a headless unit
director field. An example of such systems represents nematic LC or
nanotubes. We further introduce impurities of concentration p, which
impose the random anisotropy field-type disorder to directors. We
study the domain-type pattern of molecules as a function of p,
anchoring strength w between a neighboring director and impurity,
temperature, history of samples. In simulations we quenched the
directors either from the random or homogeneous initial
configuration. Our results show that a history of system strongly
influences: i) the average domain coherence length; and ii) the range
of ordering in the system. In the random case the obtained order is
always short ranged (SR). On the contrary, in the homogeneous case,
SR is obtained only for strong enough anchoring and large enough
concentration p. In other cases, the ordering is either of quasi long
range (QLR) or of long range (LR). We further studied memory
effects for the random initial configuration. With increasing external
ordering field B either QLR or LR is realized.
Abstract: Vernonia divergens Benth., commonly known as
“Insulin Plant” (Fam: Asteraceae) is a potent sugar killer. Locally the
leaves of the plant, boiled in water are successfully administered to a
large number of diabetic patients. The present study evaluates the
putative anti-diabetic ingredients, isolated from the in vivo and in
vitro grown plantlets of V. divergens for their antimicrobial and
anticancer activities. Sterilized explants of nodal segments were
cultured on MS (Musashige and Skoog, 1962) medium in presence of
different combinations of hormones. Multiple shoots along with
bunch of roots were regenerated at 1mg l-1 BAP and 0.5 mg l-1 NAA.
Micro-plantlets were separated and sub-cultured on the double
strength (2X) of the above combination of hormones leading to
increased length of roots and shoots. These plantlets were
successfully transferred to soil and survived well in nature. The
ethanol extract of plantlets from both in vivo & in vitro sources were
prepared in soxhlet extractor and then concentrated to dryness under
reduced pressure in rotary evaporator. Thus obtainedconcentrated
extracts showed significant inhibitory activity against gram
negative bacteria like Escherichia coli and Pseudomonas
aeruginosa but no inhibition was found against gram positive
bacteria. Further, these ethanol extracts were screened for in vitro
percentage cytotoxicity at different time periods (24 h, 48 h and 72 h)
of different dilutions. The in vivo plant extract inhibited the growth of
EAC mouse cell lines in the range of 65, 66, 78, and 88% at 100, 50,
25 & 12.5μg mL-1 but at 72 h of treatment. In case of the extract of in
vitro origin, the inhibition was found against EAC cell lines even at
48h. During spectrophotometric scanning, the extracts exhibited
different maxima (ʎ) - four peaks in in vitro extracts as against single
in in vivo preparation suggesting the possible change in the nature of
ingredients during micropropagation through tissue culture
techniques.
Abstract: A numbers of important developments have led to an
increasing attractiveness for very high speed electrical machines
(either motor or generator). Specifically the increasing switching
speed of power electronics, high energy magnets, high strength
retaining materials, better high speed bearings and improvements in
design analysis are the primary drivers in a move to higher speed. The
design challenges come in the mechanical design both in terms of
strength and resonant modes and in the electromagnetic design
particularly in respect of iron losses and ac losses in the various
conducting parts including the rotor. This paper describes detailed
design work which has been done on a 50,000 rpm, 50kW permanent
magnet( PM) synchronous machine. It describes work on
electromagnetic and rotor eddy current losses using a variety of
methods including both 2D finite element analysis
Abstract: Gamboge disorder (GD) or fruit damage by the yellow sap is a major problem in mangosteen. Mangosteen plants varied in the level of GD, from very low or non GD to low, moderate and high GD. However it was difficult to differentiate between GD and non GD plants because evaluation of the disorder is strongly influenced by environment. In this study we investigated the usefulness of primer designed from bioinformatics related to cell wall strength, termed as MCWS, to predict GD. Plant materials used were 28 mangosteen plants selected based on percentage of GD categorized as high, moderate, low and very low or non GD. The result showed that the specific DNA fragments were absent in the high GD accessions. The MCWS marker suggests as a novel polymorphic marker for GD in mangosteen as well as a marker for detect variability in mangosteen as apomictic plant.
Abstract: The present paper concerns with the influence of fiber
packing on the transverse plastic properties of metal matrix
composites. A micromechanical modeling procedure is used to
predict the effective mechanical properties of composite materials at
large tensile and compressive deformations. Microstructure is
represented by a repeating unit cell (RUC). Two fiber arrays are
considered including ideal square fiber packing and random fiber
packing defined by random sequential algorithm. The
micromechanical modeling procedure is implemented for
graphite/aluminum metal matrix composite in which the
reinforcement behaves as elastic, isotropic solids and the matrix is
modeled as an isotropic elastic-plastic solid following the von Mises
criterion with isotropic hardening and the Ramberg-Osgood
relationship between equivalent true stress and logarithmic strain.
The deformation is increased to a considerable value to evaluate both
elastic and plastic behaviors of metal matrix composites. The yields
strength and true elastic-plastic stress are determined for
graphite/aluminum composites.
Abstract: Post cracking behavior and load –bearing capacity of
the steel fiber reinforced high-strength concrete (SFRHSC) are
dependent on the number of fibers are crossing the weakest crack
(bridged the crack) and their orientation to the crack surface. Filling
the mould by SFRHSC, fibers are moving and rotating with the
concrete matrix flow till the motion stops in each internal point of the
concrete body. Filling the same mould from the different ends
SFRHSC samples with the different internal structures (and different
strength) can be obtained. Numerical flow simulations (using Newton
and Bingham flow models) were realized, as well as single fiber
planar motion and rotation numerical and experimental investigation
(in viscous flow) was performed. X-ray pictures for prismatic
samples were obtained and internal fiber positions and orientations
were analyzed. Similarly fiber positions and orientations in cracked
cross-section were recognized and were compared with numerically
simulated. Structural SFRHSC fracture model was created based on
single fiber pull-out laws, which were determined experimentally.
Model predictions were validated by 15x15x60cm prisms 4 point
bending tests.
Abstract: Eight steel reinforced concrete beams (SRC), were
fabricated and tested under earthquake type cyclic loading. The
effectiveness of intermediate stiffeners, such as mid-span stiffener and
plastic hinge zone stiffeners, in enhancing composite action and
ductility of SRC beams was investigated. The effectiveness of
strengthened beam-to-column (SBC) and weakened beam-to-column
(WBC) connections in enhancing beam ductility was also studied. It
was found that: (1) All the specimens possessed fairly high flexural
ductility and were found adequate for structures in high seismic zones.
(2) WBC connections induced stress concentration which caused extra
damage to concrete near the flange tapering zone. This extra damage
inhibited the flexural strength development and the ductility of the
specimens with WBC connections to some extent. (3) Specimens with
SBC connections demonstrated higher flexural strength and ductility
compared to specimens with WBC connections. (4) The intermediate
stiffeners, especially combination of plastic hinge zone stiffener and
mid span stiffeners, have an obvious effect in enhancing the ductility
of the beams with SBC connection.
Abstract: In manufacturing industries, development of measurement leads to increase the number of monitoring variables and eventually the importance of multivariate control comes to the fore. Statistical process control (SPC) is one of the most widely used as multivariate control chart. Nevertheless, SPC is restricted to apply in processes because its assumption of data as following specific distribution. Unfortunately, process data are composed by the mixture of several processes and it is hard to estimate as one certain distribution. To alternative conventional SPC, therefore, nonparametric control chart come into the picture because of the strength of nonparametric control chart, the absence of parameter estimation. SVDD based control chart is one of the nonparametric control charts having the advantage of flexible control boundary. However,basic concept of SVDD has been an oversight to the important of data characteristic, density distribution. Therefore, we proposed DW-SVDD (Density Weighted SVDD) to cover up the weakness of conventional SVDD. DW-SVDD makes a new attempt to consider dense of data as introducing the notion of density Weight. We extend as control chart using new proposed SVDD and a simulation study of various distributional data is conducted to demonstrate the improvement of performance.
Abstract: Recordings from recent earthquakes have provided evidence that ground motions in the near field of a rupturing fault differ from ordinary ground motions, as they can contain a large energy, or “directivity" pulse. This pulse can cause considerable damage during an earthquake, especially to structures with natural periods close to those of the pulse. Failures of modern engineered structures observed within the near-fault region in recent earthquakes have revealed the vulnerability of existing RC buildings against pulse-type ground motions. This may be due to the fact that these modern structures had been designed primarily using the design spectra of available standards, which have been developed using stochastic processes with relatively long duration that characterizes more distant ground motions. Many recently designed and constructed buildings may therefore require strengthening in order to perform well when subjected to near-fault ground motions. Fiber Reinforced Polymers are considered to be a viable alternative, due to their relatively easy and quick installation, low life cycle costs and zero maintenance requirements. The objective of this paper is to investigate the adequacy of Artificial Neural Networks (ANN) to determine the three dimensional dynamic response of FRP strengthened RC buildings under the near-fault ground motions. For this purpose, one ANN model is proposed to estimate the base shear force, base bending moments and roof displacement of buildings in two directions. A training set of 168 and a validation set of 21 buildings are produced from FEA analysis results of the dynamic response of RC buildings under the near-fault earthquakes. It is demonstrated that the neural network based approach is highly successful in determining the response.
Abstract: The primary objective of this research is to improve the flexural capacity of FRP strengthened RC Beam structures with Aluminum and Titanium laminates. FRP rupture of flexural strengthened RC beams using FRP plates generally occurs at the interface between FRP plate and the beam. Therefore, in order to prevent brittle rupture and improve the ductility of the system, this research was performed by using Aluminum and Titanium materials between the two different structural systems. The research also aims to provide various strengthening/retrofitting methods for RC beam structures and to conduct a preliminary analysis of the demands on the structural systems. This was achieved by estimation using the experimental data from this research to identify a flexural capacity for the systems. Ultimately, the preliminary analysis of current study showed that the flexural capacity and system demand ductility was significantly improved by the systems inserted with Aluminum and Titanium anchor plates. Further verification of the experimental research is currently on its way to develop a new or reliable design guideline to retrofit/strengthen the concrete-FRP structural system can be evaluated.
Abstract: In this paper, the authors present architecture of a multi agent consultation system for obesity related problems, which hybrid the technology of an expert system (ES) and an intelligent agent (IA). The strength of the ES which is capable of pulling the expert knowledge is consulted and presented to the end user via the autonomous and friendly pushing environment of the intelligent agent.
Abstract: The characteristic bending strength (MOR) and mean
modulus of elasticity (MOE) of tropical hardwood red seraya (Shorea
spp.) plywood were determined using European Standard EN310 and
EN789. The thickness of the test specimen was 4.0mm, 7.0mm,
9.0mm, 12.0mm and 15.0mm. The experiment found that the MOR
of red seraya plywood in EN310 is about 12% to 20% and 7% to
24% higher than EN789 whereas MOE were about 28% to 41% and
30% to 36% lower than those obtained from EN 789 for test
specimens parallel and perpendicular to the grain direction. The
linear regression shows that MOR and MOE for EN789 is about 0.8
times less and 1.5 times more than EN310. The experiment also
found that the MOR and MOE of EN310 and EN789 also depend on
the wood species that used in the experiment.
Abstract: The present study focuses on methods allowing a convenient and quick calculation of the SIFs in order to predict the static adhesive strength of bonded joints. A new SIF calculation method is proposed, based on the stresses obtained from a FE model at a reference point located in the adhesive layer at equal distance of the free-edge and of the two interfaces. It is shown that, even limiting ourselves to the two main modes, i.e. the opening and the shearing modes, and using the values of the stresses resulting from a low detailed FE model, an efficient calculation of the peeling stress at adhesive-substrate corners can be obtained by this way. The proposed method is interesting in that it can be the basis of a prediction tool that will allow the designer to quickly evaluate the SIFs characterizing a particular application without developing a detailed analysis.
Abstract: Multimedia, as it stands now is perhaps the most
diverse and rich culture around the globe. One of the major needs of
Multimedia is to have a single system that enables people to
efficiently search through their multimedia catalogues. Many
Domain Specific Systems and architectures have been proposed but
up till now no generic and complete architecture is proposed. In this
paper, we have suggested a generic architecture for Multimedia
Database. The main strengths of our architecture besides being
generic are Semantic Libraries to reduce semantic gap, levels of
feature extraction for more specific and detailed feature extraction
according to classes defined by prior level, and merging of two types
of queries i.e. text and QBE (Query by Example) for more accurate
yet detailed results.
Abstract: A self-compacting concrete (SCC) is the one that can
be placed in the form and can go through obstructions by its own
weight and without the need of vibration. Since its first development
in Japan in 1988, SCC has gained wider acceptance in Japan, Europe
and USA due to its inherent distinct advantages. Although there are
visible signs of its gradual acceptance in the North Africa through its
limited use in construction, Libya has yet to explore the feasibility
and applicability of SCC in new construction. The contributing
factors to this reluctance appear to be lack of any supportive
evidence of its suitability with local aggregates and the harsh
environmental conditions. The primary aim of this study is to explore
the feasibility of using SCC made with local aggregates of Eastern
Province of Libya by examining its basic properties characteristics.
This research consists of: (i) Development of a suitable mix for SCC
such as the effect of water to cement ratio, limestone and silica fume
that would satisfy the requirements of the plastic state; (ii) Casting of
concrete samples and testing them for compressive strength and unit
weight. Local aggregates, cement, admixtures and industrial waste
materials were used in this research.
The significance of this research lies in its attempt to provide
some performance data of SCC made in the Eastern Province of
Libya so as to draw attention to the possible use of SCC.
Abstract: A therapeutic success is the aim of any therapeutic
intervention, but a therapeutic failure is the other side of the same
coin. The purpose of this study is to present the activity of a personal
development group, composed of 14 participants (psychologists,
doctors and a priest) registered for a 2 days course of integrative
psychotherapy. The objectives of this study are centred on: the
management of the personal development group breaking moment
realized by the therapist/trainer; the analysis of the trainer’s personal
situation and of some group participants and the brief presentation of
the main work methods applied on participants in the repairing of the
therapeutic relation and in the counter transfer management. The
therapist’s orientation is an integrative one and the demarche realized
includes T.A. techniques, role play, Gestalt and family systemic
psychotherapy. The conclusions obtained represent landmarks for the
future activity within that group and strengthen the therapeutic
relation with the group.
Abstract: These days MANET is attracting much attention as
they are expected to gratefully influence communication between
wireless nodes. Along with this great strength, there is much more
chance of leave and being attacked by a malicious node. Due to this
reason much attention is given to the security and the private issue in
MANET. A lot of research in MANET has been doing. In this paper
we present the overview of MANET, the security issues of MANET,
IP configuration in MANET, the solution to puzzle out the security
issues and the simulation of the proposal idea. We add the method to
figure out the malicious nodes so that we can prevent the attack from
them. Nodes exchange the information about nodes to prevent DAD
attack. We can get 30% better performance than the previous
MANETConf.