Abstract: The social logic of 'Sequina' slum area in Alexandria details the integral measure of space syntax at the room-level of twenty-building samples. The essence of spatial structure integrates the central 'visitor' domain with the 'living' frontage of the 'children' zone against the segregated privacy of the opposite 'parent' depth. Meanwhile, the multifunctioning of shallow rooms optimizes the integral 'visitor' structure through graph and visibility dimensions in contrast to the 'inhabitant' structure of graph-tails out of sight. Common theme of the layout integrity increases in compensation to the decrease of room visibility. Despite the 'pheno-type' of collective integration, the individual layouts observe 'geno-type' structure of spatial diversity per room adjoins. In this regard, the layout integrity alternates the cross-correlation of the 'kitchen & living' rooms with the 'inhabitant & visitor' domains of 'motherhood' dynamic structure. Moreover, the added 'grandparent' restructures the integral measure to become the deepest space, but opens to the 'living' of 'household' integrity. Some isomorphic layouts change the integral structure just through the 'balcony' extension of access, visual or ignored 'ringiness' of space syntax. However, the most integrated or segregated layouts invert the 'geno-type' into a shallow 'inhabitant' centrality versus the remote 'visitor' structure. Overview of the multivariate social logic of spatial integrity could never clarify without the micro-data analysis.
Abstract: Lightweight and efficient structures have the aim to
enhance the efficiency of the components in various industries.
Toward this end, composites are one of the most widely used
materials because of durability, high strength and modulus, and low
weight. One type of the advanced composites is grid-stiffened
composite (GSC) structures, which have been extensively considered
in aerospace, automotive, and aircraft industries. They are one of the
top candidates for replacing some of the traditional components,
which are used here. Although there are a good number of published
surveys on the design aspects and fabrication of GSC structures, little
systematic work has been reported on their material modification to
improve their properties, to our knowledge. Matrix modification
using nanoparticles is an effective method to enhance the flexural
properties of the fibrous composites. In the present study, a silanecoupling
agent (3-glycidoxypropyltrimethoxysilane/3-GPTS) was
introduced onto the silica (SiO2) nanoparticle surface and its effects
on the three-point flexural response of isogrid E-glass/epoxy
composites were assessed. Based on the Fourier Transform Infrared
Spectrometer (FTIR) spectra, it was inferred that the 3-GPTS
coupling agent was successfully grafted onto the surface of SiO2
nanoparticles after modification. Flexural test revealed an
improvement of 16%, 14%, and 36% in stiffness, maximum load and
energy absorption of the isogrid specimen filled with 3 wt.% 3-
GPTS/SiO2 compared to the neat one. It would be worth mentioning
that in these structures, considerable energy absorption was observed
after the primary failure related to the load peak. In addition, 3-
GPTMS functionalization had a positive effect on the flexural
behavior of the multiscale isogrid composites. In conclusion, this
study suggests that the addition of modified silica nanoparticles is a
promising method to improve the flexural properties of the gridstiffened
fibrous composite structures.
Abstract: Polymeric composites are being increasingly used as
repair material for repairing critical infrastructures such as building,
bridge, pressure vessel, piping and pipeline. Technique in repairing
damaged pipes is one of the major concerns of pipeline owners.
Considerable researches have been carried out on the repair of
corroded pipes using composite materials. This article attempts a
short review of the subject matter to provide insight into various
techniques used in repairing corroded pipes, focusing on a wide range
of composite repair systems. These systems including pre-cured
layered, flexible wet lay-up, pre-impregnated, split composite sleeve
and flexible tape systems. Both advantages and limitations of these
repair systems were highlighted. Critical technical aspects have been
discussed through the current standards and practices. Research gaps
and future study scopes in achieving more effective design
philosophy are also presented.
Abstract: Over the last two decades, externally bonded fiber
reinforced polymer (FRP) composites bonded to concrete substrates
has become a popular method for strengthening reinforced concrete
(RC) highway and railway bridges. Such structures are exposed to
severe cyclic loading throughout their lifetime often resulting in
fatigue damage to structural components and a reduction in the
service life of the structure. Since experimental and numerical results
on the fatigue performance of FRP-to-concrete joints are still limited,
the current research focuses on assessing the fatigue performance of
externally bonded FRP-to-concrete joints using a direct shear test.
Some early results indicate that the stress ratio and the applied cyclic
stress level have a direct influence on the fatigue life of the externally
bonded FRP. In addition, a calibrated finite element model is
developed to provide further insight into the influence of certain
parameters such as: concrete strength, FRP thickness, number of
cycles, frequency, and stiffness on the fatigue life of the FRP-toconcrete
joints.
Abstract: Both steady and unsteady turbulent mixed convection
heat transfer in a 3D lid-driven enclosure, which has constant heat
flux on the middle of bottom wall and with isothermal moving
sidewalls, is reported in this paper for working fluid with Prandtl
number Pr = 0.71. The other walls are adiabatic and stationary. The
dimensionless parameters used in this research are Reynolds number,
Re = 5000, 10000 and 15000, and Richardson number, Ri = 1 and 10.
The simulations have been done by using different turbulent methods
such as RANS, URANS, and LES. The effects of using different k-ε
models such as standard, RNG and Realizable k-ε model are
investigated. Interesting behaviours of the thermal and flow fields
with changing the Re or Ri numbers are observed. Isotherm and
turbulent kinetic energy distributions and variation of local Nusselt
number at the hot bottom wall are studied as well. The local Nusselt
number is found increasing with increasing either Re or Ri number.
In addition, the turbulent kinetic energy is discernibly affected by
increasing Re number. Moreover, the LES results have shown good
ability of this method in predicting more detailed flow structures in
the cavity.
Abstract: In this study, the time-dependent behavior of damaged
reinforced concrete shear wall structures strengthened with composite
plates having variable fibers spacing was investigated to analyze their
seismic response. In the analytical formulation, the adherent and the
adhesive layers are all modeled as shear walls, using the mixed Finite
Element Method (FEM). The anisotropic damage model is adopted to
describe the damage extent of the Reinforced Concrete shear walls.
The phenomenon of creep and shrinkage of concrete has been
determined by Eurocode 2. Large earthquakes recorded in Algeria
(El-Asnam and Boumerdes) have been tested to demonstrate the
accuracy of the proposed method. Numerical results are obtained for non-uniform distributions of
carbon fibers in epoxy matrices. The effects of damage extent and the
delay mechanism creep and shrinkage of concrete are highlighted.
Prospects are being studied.
Abstract: Steel extended end plate bolted connections are
recommended to be widely utilized in special moment-resisting frame
subjected to monotonic loading. Improper design of steel beam to
column connection can lead to the collapse and fatality of structures.
Therefore comprehensive research studies of beam to column
connection design should be carried out. Also the performance and
effect of corrugated on the strength of beam column end plate
connection up to failure under monotonic loading in horizontal
direction is presented in this paper. The non-linear elastic–plastic
behavior has been considered through a finite element analysis using
the multi-purpose software package LUSAS. The effect of vertically
and horizontally types of corrugated web was also investigated.
Abstract: Foundation differential settlement and supported
structure tilting are an occasionally occurred engineering problem.
This may be caused by overloading, changes in ground soil properties
or unsupported nearby excavations. Engineering thinking points
directly toward the logic solution for such problem by uplifting the
settled side. This can be achieved with deep foundation elements
such as micro-piles and macro-piles™, jacked piers, and helical piers,
jet grouted mortar columns, compaction grout columns, cement
grouting or with chemical grouting, or traditional pit underpinning
with concrete and mortar. Although, some of these techniques offer
economic, fast and low noise solutions, many of them are quite the
contrary. For tilted structures, with the limited inclination, it may be much
easier to cause a balancing settlement on the less-settlement side
which shall be done carefully in a proper rate. This principal has been
applied in Leaning Tower of Pisa stabilization with soil extraction
from the ground surface. In this research, the authors attempt to
introduce a new solution with a different point of view. So, the
micro-tunneling technique is presented in here as an intended ground
deformation cause. In general, micro-tunneling is expected to induce
limited ground deformations. Thus, the researchers propose to apply
the technique to form small size ground unsupported holes to produce
the target deformations. This shall be done in four phases: 1.
Application of one or more micro-tunnels, regarding the existing
differential settlement value, under the raised side of the tilted
structure. 2. For each individual tunnel, the lining shall be pulled out
from both sides (from jacking and receiving shafts) in the slow rate.
3. If required, according to calculations and site records, an additional
surface load can be applied on the raised foundation side. 4. Finally, a
strengthening soil grouting shall be applied for stabilization after
adjustment. A finite element based numerical model is presented to simulate
the proposed construction phases for different tunneling positions and
tunnels group. For each case, the surface settlements are calculated
and induced plasticity points are checked. These results show the
impact of the suggested procedure on the tilted structure and its
feasibility. Comparing results also show the importance of the
position selection and tunnels group gradual effect. Thus, a new
engineering solution is presented to one of the structural and
geotechnical engineering challenges.
Abstract: In this study, static and dynamic responses of a typical
reinforced concrete solid slab, designed to British Standard (BS 8110:
1997) and under self and live loadings for dance halls are reported.
Linear perturbation analysis using finite element method was
employed for modal, impulse loading and frequency response
analyses of the slab under the aforementioned loading condition.
Results from the static and dynamic analyses, comprising of the slab
fundamental frequencies and mode shapes, dynamic amplification
factor, maximum deflection, stress distributions among other
valuable outcomes are presented and discussed. These were gauged
with the limiting provisions in the design code with a view of
justifying valid optimization objective function for the structure that
can ensure both adequate strength and economical section for large
clear span slabs. This is necessary owing to the continued increase in
cost of erecting building structures and the squeeze on public finance
globally.
Abstract: Radio Frequency Identification (RFID) has become a
key technology in the emerging concept of Internet of Things (IoT).
Naturally, business applications would require the deployment of
various RFID systems developed by different vendors that use
different data formats and structures. This heterogeneity poses a
challenge in developing real-life IoT systems with RFID, as
integration is becoming very complex and challenging. Semantic
integration is a key approach to deal with this challenge. To do so,
ontology for RFID systems need to be developed in order to
annotated semantically RFID systems, and hence, facilitate their
integration. Accordingly, in this paper, we propose ontology for
RFID systems. The proposed ontology can be used to semantically
enrich RFID systems, and hence, improve their usage and reasoning.
Abstract: The purpose of this paper is to contribute to the
enhancement of a hydroelectric plant protection by coordinating
protection measures / existing security and introducing new measures
under a risk management process. In addition, plan identifies key
critical elements of a hydroelectric plant, from its level vulnerabilities
and threats it is subjected to in order to achieve the necessary
protection measures to reduce the level of risk.
Abstract: Large-scale machine tools for the manufacturing of
large work pieces, e.g. blades, casings or gears for wind turbines,
feature pose-dependent dynamic behavior. Small structural damping
coefficients lead to long decay times for structural vibrations that
have negative impacts on the production process. Typically, these
vibrations are handled by increasing the stiffness of the structure by
adding mass. This is counterproductive to the needs of sustainable
manufacturing as it leads to higher resource consumption both in
material and in energy. Recent research activities have led to higher
resource efficiency by radical mass reduction that is based on controlintegrated
active vibration avoidance and damping methods. These
control methods depend on information describing the dynamic
behavior of the controlled machine tools in order to tune the
avoidance or reduction method parameters according to the current
state of the machine. This paper presents the appearance, consequences and challenges
of the pose-dependent dynamic behavior of lightweight large-scale
machine tool structures in production. It starts with the theoretical
introduction of the challenges of lightweight machine tool structures
resulting from reduced stiffness. The statement of the pose-dependent
dynamic behavior is corroborated by the results of the experimental
modal analysis of a lightweight test structure. Afterwards, the
consequences of the pose-dependent dynamic behavior of lightweight
machine tool structures for the use of active control and vibration
reduction methods are explained. Based on the state of the art of
pose-dependent dynamic machine tool models and the modal
investigation of an FE-model of the lightweight test structure, the
criteria for a pose-dependent model for use in vibration reduction are
derived. The description of the approach for a general posedependent
model of the dynamic behavior of large lightweight
machine tools that provides the necessary input to the aforementioned
vibration avoidance and reduction methods to properly tackle
machine vibrations is the outlook of the paper.
Abstract: Novel wind-lens turbine designs can augment power
output. Vacuum-Assisted Resin Transfer Molding (VARTM) is used
to form large and complex structures from a Carbon Fiber Reinforced
Polymer (CFRP) composite. Typically, wind-lens turbine structures
are fabricated in segments, and then bonded to form the final structure.
This paper introduces five new adhesive joints, divided into two
groups: one is constructed between dry carbon and CFRP fabrics, and
the other is constructed with two dry carbon fibers. All joints and
CFRP fabrics were made in our laboratory using VARTM
manufacturing techniques. Specimens were prepared for tensile testing
to measure joint performance. The results showed that the second
group of joints achieved a higher tensile strength than the first group.
On the other hand, the tensile fracture behavior of the two groups
showed the same pattern of crack originating near the joint ends
followed by crack propagation until fracture.
Abstract: Non-linear dynamic time history analysis is
considered as the most advanced and comprehensive analytical
method for evaluating the seismic response and performance of
multi-degree-of-freedom building structures under the influence of
earthquake ground motions. However, effective and accurate
application of the method requires the implementation of advanced
hysteretic constitutive models of the various structural components
including masonry infill panels. Sophisticated computational research
tools that incorporate realistic hysteresis models for non-linear
dynamic time-history analysis are not popular among the professional
engineers as they are not only difficult to access but also complex and
time-consuming to use. In addition, commercial computer programs
for structural analysis and design that are acceptable to practicing
engineers do not generally integrate advanced hysteretic models
which can accurately simulate the hysteresis behavior of structural
elements with a realistic representation of strength degradation,
stiffness deterioration, energy dissipation and ‘pinching’ under cyclic
load reversals in the inelastic range of behavior. In this scenario,
push-over or non-linear static analysis methods have gained
significant popularity, as they can be employed to assess the seismic
performance of building structures while avoiding the complexities
and difficulties associated with non-linear dynamic time-history
analysis. “Push-over” or non-linear static analysis offers a practical
and efficient alternative to non-linear dynamic time-history analysis
for rationally evaluating the seismic demands. The present paper is
based on the analytical investigation of the effect of distribution of
masonry infill panels over the elevation of planar masonry infilled
reinforced concrete [R/C] frames on the seismic demands using the
capacity spectrum procedures implementing nonlinear static analysis
[pushover analysis] in conjunction with the response spectrum
concept. An important objective of the present study is to numerically
evaluate the adequacy of the capacity spectrum method using
pushover analysis for performance based design of masonry infilled
R/C frames for near-field earthquake ground motions.
Abstract: The objective of the paper is a numerical study of heat
transfer between perforated metal plates and the surrounding air
flows. Different perforation structures can nowadays be found in
various industrial products. Besides improving the mechanical
properties, the perforations can intensify the heat transfer as well. The
heat transfer coefficient depends on a wide range of parameters such
as type of perforation, size, shape, flow properties of the surrounding
air etc. The paper was focused on three different perforation
structures which have been investigated from the point of the view of
the production in the previous studies. To determine the heat
coefficients and the Nusselt numbers, the numerical simulation
approach was adopted. The calculations were performed using the
OpenFOAM software. The three-dimensional, unstable, turbulent and
incompressible air flow around the perforated surface metal plate was
considered.
Abstract: In present study, a large deposit of oolitic iron ore of
Late Carboniferous-Permotriassic-Lower Jurassic age was discovered
in Wadi Halfa and Argein areas, North Sudan. It seems that the iron
ore mineralization exists in the west and east bank of the River Nile
of the study area that are found on the Egyptian-Sudanese border.
The Carboniferous-Lower Jurassic age strata were covered by 67
sections and each section has been examined and carefully described.
The iron-ore in Wadi Halfa occurs as oolitic ironstone and contained
two horizons: (A) horizon and (B) horizon. Only horizon (A) was
observed in southern Argein area. The texture of the ore is variable
depending on the volume of the component. In thin sections, the
average of the ooids was ranged between 90%-80%. The matrix
varies between 10%-20% by volume and detritus quartz in other
component my reach up to 30% by volume in sandy massive ore.
Ooids size ranges from 0.2mm-1.00 mm on average in very coarse
ooids may attend up to 1 mm in size. The matrix around the ooids is
dominated by iron hydroxide, carbonate, fine, and amorphous silica.
The probable ore reserve estimate of 1.234 billion at a head grade of
41.29% Fe for the Wadi Halfa Oolitic Ironstone Formation. The iron
ore shows higher content of phosphorus ranges from 6.15% to 0.16%,
with mean 1.45%. The new technology Hatch–Ironstone Chloride
Segregation (HICS) can be used to produce commercial-quality of
iron and reduce phosphorus and silica to acceptable levels for steel
industry. The presence of infrastructures in addition to the presence
of massive quantities of iron ore would make exploitation
economically.
Abstract: The objective of this study was to synthesize and
characterize the poly(alkenoic acid)s with different molecular
structures, use these polymers to formulate a dental cement
restorative, and study the effect of molecular structures on reaction
kinetics, viscosity, and mechanical strengths of the formed polymers
and cement restoratives. In this study, poly(alkenoic acid)s with
different molecular structures were synthesized. The purified
polymers were formulated with commercial Fuji II LC glass fillers to
form the experimental cement restoratives. The reaction kinetics was
studied via 1HNMR spectroscopy. The formed restoratives were
evaluated using compressive strength, diametral tensile strength,
flexural strength, hardness and wear-resistance tests. Specimens were
conditioned in distilled water at 37oC for 24 h prior to testing. Fuji II
LC restorative was used as control. The results show that the higher
the arm number and initiator concentration, the faster the reaction
was. It was also found that the higher the arm number and branching
that the polymer had, the lower the viscosity of the polymer in water
and the lower the mechanical strengths of the formed restorative. The
experimental restoratives were 31-53% in compressive strength, 37-
55% in compressive modulus, 80-126% in diametral tensile strength,
76-94% in flexural strength, 4-21% in fracture toughness and 53-96%
in hardness higher than Fuji II LC. For wear test, the experimental
restoratives were only 5.4-13% of abrasive and 6.4-12% of attritional
wear depths of Fuji II LC in each wear cycle. The aging study also
showed that all the experimental restoratives increased their strength
continuously during 30 days, unlike Fuji II LC. It is concluded that
polymer molecular structures have significant and positive impact on
mechanical properties of dental cement restoratives.
Abstract: A growing demand is felt today for realistic 3D
models enabling the cognition and popularization of historical-artistic
heritage. Evaluation and preservation of Cultural Heritage is
inextricably connected with the innovative processes of gaining,
managing, and using knowledge. The development and perfecting of
techniques for acquiring and elaborating photorealistic 3D models,
made them pivotal elements for popularizing information of objects
on the scale of architectonic structures.
Abstract: Obturator Foramen is a specific structure in Pelvic
bone images and recognition of it is a new concept in medical image
processing. Moreover, segmentation of bone structures such as
Obturator Foramen plays an essential role for clinical research in
orthopedics. In this paper, we present a novel method to analyze the
similarity between the substructures of the imaged region and a hand
drawn template as a preprocessing step for computation of Pelvic
bone rotation on hip radiographs. This method consists of integrated
usage of Marker-controlled Watershed segmentation and Zernike
moment feature descriptor and it is used to detect Obturator Foramen
accurately. Marker-controlled Watershed segmentation is applied to
separate Obturator Foramen from the background effectively. Then,
Zernike moment feature descriptor is used to provide matching
between binary template image and the segmented binary image for
final extraction of Obturator Foramens. Finally, Pelvic bone rotation
rate calculation for each hip radiograph is performed automatically to
select and eliminate hip radiographs for further studies which depend
on Pelvic bone angle measurements. The proposed method is tested
on randomly selected 100 hip radiographs. The experimental results
demonstrated that the proposed method is able to segment Obturator
Foramen with 96% accuracy.
Abstract: Graphene, a single-atom sheet, has been considered as
the most promising material for making future nanoelectromechanical
systems as well as purely electrical switching with graphene
transistors. Graphene-based devices have advantages in scaled-up
device fabrication due to the recent progress in large area graphene
growth and lithographic patterning of graphene nanostructures. Here
we investigated its mechanical responses of circular graphene
nanoflake under the nanoindentation using classical molecular
dynamics simulations. A correlation between the load and the
indentation depth was constructed. The nanoindented force in this
work was applied to the center point of the circular graphene nanoflake
and then, the resonance frequency could be tuned by a nanoindented
depth. We found the hardening or the softening of the graphene
nanoflake during its nanoindented-deflections, and such properties
were recognized by the shift of the resonance frequency. The
calculated mechanical parameters in the force-vs-deflection plot were
in good agreement with previous experimental and theoretical works.
This proposed schematics can detect the pressure via the deflection
change or/and the resonance frequency shift, and also have great
potential for versatile applications in nanoelectromechanical systems.