Abstract: Many footbridges have natural frequencies that
coincide with the dominant frequencies of the pedestrian-induced
load and therefore they have a potential to suffer excessive vibrations
under dynamic loads induced by pedestrians. Some of the design
standards introduce load models for pedestrian loads applicable for
simple structures. Load modeling for more complex structures, on the
other hand, is most often left to the designer. The main focus of this
paper is on the human induced forces transmitted to a footbridge and
on the ways these loads can be modeled to be used in the dynamic
design of footbridges. Also design criteria and load models proposed
by widely used standards were introduced and a comparison was
made. The dynamic analysis of the suspension bridge in Kolin in the
Czech Republic was performed on detailed FEM model using the
ANSYS program system. An attempt to model the load imposed by a
single person and a crowd of pedestrians resulted in displacements
and accelerations that are compared with serviceability criteria.
Abstract: The microbiological and physicochemical
characteristics of wetland soils in Eket Local Government Area were
studied between May 2001 and June 2003. Total heterotrophic
bacterial counts (THBC), total fungal counts (TFC), and total
actinomycetes counts (TAC) were determined from soil samples
taken from four locations at two depths in the wet and dry seasons.
Microbial isolates were characterized and identified. Particle size and
chemical parameters were also determined using standard methods.
THBC ranged from 5.2 (+0.17) x106 to 1.7 (+0.18) x107 cfu/g and
from 2.4 (+0.02) x106 to 1.4 (+0.04) x107cfu/g in the wet and dry
seasons, respectively. TFC ranged from 1.8 (+0.03) x106 to 6.6 (+
0.18) x106 cfu/g and from 1.0 (+0.04) x106 to 4.2 (+ 0.01) x106 cfu/g
in the wet and dry seasons, respectively .TAC ranged from 1.2
(+0.53) x106 to 6.0 (+0.05) x106 cfu/g and from 0.6 (+0.01) x106 to
3.2 (+ 0.12) x106 cfu/g in the wet and dry season, respectively.
Acinetobacter, Alcaligenes, Arthrobacter, Bacillus, Beijerinckja,
Enterobacter, Micrococcus, Flavobacterium, Serratia, Enterococcus,
and Pseudomonas species were predominant bacteria while
Aspergillus, Fusarium, Mucor, Penicillium, and Rhizopus were the
dominant fungal genera isolated. Streptomyces and Norcadia were
the actinomycetes genera isolated. The particle size analysis showed
high sand fraction but low silt and clay. The pH and % organic
matter were generally acidic and low, respectively at all locations.
Calcium dominated the exchangeable bases with low electrical
conductivity and micronutrients. These results provide the baseline
data of Eket wetland soils for its management for sustainable
agriculture.
Abstract: Recently, as information industry and mobile
communication technology are developing, this study is conducted on
the new concept of intelligent structures and maintenance techniques
that applied wireless sensor network, USN (Ubiquitous Sensor
Network), to social infrastructures such as civil and architectural
structures on the basis of the concept of Ubiquitous Computing that
invisibly provides human life with computing, along with mutually
cooperating, compromising and connecting networks each other by
having computers within all objects around us.
Therefore, the purpose of this study is to investigate the capability
of wireless communication of sensor node embedded in reinforced
concrete structure with a basic experiment on an electric wave
permeability of sensor node by fabricating molding with variables of
concrete thickness and steel bars that are mostly used in constructing
structures to determine the feasibility of application to constructing
structures with USN.
At this time, with putting the pitches of steel bars, the thickness of
concrete placed, and the intensity of RF signal of a
transmitter-receiver as variables and when wireless communication
module was installed inside, the possible communication distance of
plain concrete and the possible communication distance by the pitches
of steel bars was measured in the horizontal and vertical direction
respectively. Besides, for the precise measurement of diminution of an
electric wave, the magnitude of an electric wave in the range of used
frequencies was measured by using Spectrum Analyzer. The
phenomenon of diminution of an electric wave was numerically
analyzed and the effect of the length of wavelength of frequencies was
analyzed by the properties of a frequency band area.
As a result of studying the feasibility of an application to
constructing structures with wireless sensor, in case of plain concrete,
it shows 45cm for the depth of permeability and in case of reinforced
concrete with the pitches of 5cm, it shows 37cm and 45cm for the
pitches of 15cm.
Abstract: In this paper is study the possibility of successfully
implementing of hollow roller concept in order to minimize inertial
mass of the large bearings, with major results in diminution of the
material consumption, increasing of power efficiency (in wind power
station area), increasing of the durability and life duration of the large
bearings systems, noise reduction in working, resistance to
vibrations, an important diminution of losses by abrasion and
reduction of the working temperature. In this purpose was developed
an original solution through which are reduced mass, inertial forces
and moments of large bearings by using of hollow rollers. The
research was made by using the method of finite element analysis
applied on software type Solidworks - Nastran. Also, is study the
possibility of rapidly changing the manufacturing system of solid and
hollow cylindrical rollers.
Abstract: In this work, the plate bending formulation of the boundary element method - BEM, based on the Reissner?s hypothesis, is extended to the analysis of plates reinforced by beams taking into account the membrane effects. The formulation is derived by assuming a zoned body where each sub-region defines a beam or a slab and all of them are represented by a chosen reference surface. Equilibrium and compatibility conditions are automatically imposed by the integral equations, which treat this composed structure as a single body. In order to reduce the number of degrees of freedom, the problem values defined on the interfaces are written in terms of their values on the beam axis. Initially are derived separated equations for the bending and stretching problems, but in the final system of equations the two problems are coupled and can not be treated separately. Finally are presented some numerical examples whose analytical results are known to show the accuracy of the proposed model.
Abstract: When a high DC voltage is applied to a capacitor with
strongly asymmetrical electrodes, it generates a mechanical force that
affects the whole capacitor. This is caused by the motion of ions generated around the smaller of the two electrodes and their subsequent interaction with the surrounding medium. If one of the electrodes is heated, it changes the conditions around the capacitor
and influences the process of ionisation, thus changing the value of the generated force. This paper describes these changes and gives
reasons behind them. Further the experimental results are given as proof of the ionic mechanism of the phenomenon.
Abstract: Gated community has gained its dominant in residential areas development that it has become the standard development pattern of the newly built residential areas in contemporary China. The form of gated community has its own advantages and rationality that meet the needs of quite a lot of residents, but it-s also believed by researchers that the form has great damage to the urban morphology and development, and has a negative impact on residents- living style. However, there is still a considerable controversy of the origins and outcomes. Though recognized as a global phenomenon, gated community developed in China is greatly to do with the specific local forces, respect to the unique historical, political and socio-cultural momentums. A historical review of the traditional settlements in China and the trends that how Gated community has gained its contemporary form, is indispensable for comprehending the local forces, and provide a new perspective to solve the controversy.
Abstract: The liberalization and privatization processes have
forced public utility companies to face new competitive challenges,
implementing strategies to gain market share and, at the same time,
keep the old customers. To this end, many companies have carried
out mergers, acquisitions and conglomerations in order to diversify
their business. This paper focuses on companies operating in the free
energy market in Italy. In the last decade, this sector has undergone
profound changes that have radically changed the competitive
scenario and have led companies to implement diversification
strategies of the business. Our work aims to evaluate the economic
and financial performances obtained by energy companies, following
the beginning of the liberalization process, verifying the possible
relationship with the implemented diversification strategies.
Abstract: Sensorized instruments that accurately measure the interaction forces (between biological tissue and instrument endeffector) during surgical procedures offer surgeons a greater sense of immersion during minimally invasive robotic surgery. Although there is ongoing research into force measurement involving surgical graspers little corresponding effort has been carried out on the measurement of forces between scissor blades and tissue. This paper presents the design and development of a force measurement test apparatus, which will serve as a sensor characterization and evaluation platform. The primary aim of the experiments is to ascertain whether the system can differentiate between tissue samples with differing mechanical properties in a reliable, repeatable manner. Force-angular displacement curves highlight trends in the cutting process as well the forces generated along the blade during a cutting procedure. Future applications of the test equipment will involve the assessment of new direct force sensing technologies for telerobotic surgery.
Abstract: Application of nanoparticles as additives in membrane
synthesis for improving the resistance of membranes against fouling
has triggered recent interest in new membrane types. However, most
nanoparticle-enhanced membranes suffer from the tradeoff between
permeability and selectivity. In this study, nano-WS2 was explored as
the additive in membrane synthesis by non-solvent induced phase
separation. Blended PES-WS2 flat-sheet membranes with the
incorporation of ultra-low concentrations of nanoparticles (from 0.025
to 0.25%, WS2/PES ratio) were manufactured and investigated in
terms of permeability, fouling resistance and solute rejection.
Remarkably, a significant enhancement in the permeability was
observed as a result of the incorporation of ultra-low fractions of
nano-WS2 to the membrane structure. Optimal permeability values
were obtained for modified membranes with 0.10%
nanoparticle/polymer concentration ratios. Furthermore, fouling
resistance and solute rejection were significantly improved by the
incorporation of nanoparticles into the membrane matrix. Specifically,
fouling resistance of modified membrane can increase by around 50%.
Abstract: Four design alternatives for lateral force-resisting
systems of tall buildings in Dubai, UAE are presented. Quantitative
comparisons between the different designs are also made. This paper
is intended to provide different feasible lateral systems to be used in
Dubai in light of the available seismic hazard studies of the UAE.
The different lateral systems are chosen in conformance with the
International Building Code (IBC). Moreover, the expected behavior
of each system is highlighted and light is shed on some of the cost
implications associated with lateral system selection.
Abstract: With the increase of economic behavior and the upgrade
of living standar, the ratio for people in Taiwan who own automobiles
and motorcycles have recently increased with multiples. Therefore,
parking issues will be a big challenge to facilitate traffic network and
ensure urban life quality. The Parking Guidance and Information
System is one of important systems for Advanced Traveler Information
Services (ATIS). This research proposes a parking guidance and
information system which integrates GPS and 3G network for a map on
the Geographic Information System to solution inadequate of roadside
information kanban. The system proposed in this study mainly includes
Parking Host, Parking Guidance and Information Server, Geographic
Map and Information System as well as Parking Guidance and
Information Browser. The study results show this system can increase
driver-s efficiency to find parking space and efficiently enhance
parking convenience in comparison with roadside kanban system.
Abstract: Since prestressed concrete members rely on the tensile
strength of the prestressing strands to resist loads, loss of even few
them could result catastrophic. Therefore, it is important to measure
present residual prestress force. Although there are some techniques
for obtaining present prestress force, some problems still remain. One
method is to install load cell in front of anchor head but this may
increase cost. Load cell is a transducer using the elastic material
property. Anchor head is also an elastic material and this might result
in monitoring monitor present prestress force. Features of fiber optic
sensor such as small size, great sensitivity, high durability can assign
sensing function to anchor head. This paper presents the concept of
smart anchor head which acts as load cell and experiment for the
applicability of it. Test results showed the smart anchor head worked
good and strong linear relationship between load and response.
Abstract: A research program is conducted to evaluate the
mechanical properties of Ultra High Performance Concrete, target
compressive strength at the age of 28 days being more than 150 MPa.
The methodology to develop such mix has been explained. The
material properties, mix design and curing regime are determined.
The material attributes are understood by studying the stress strain
behaviour of UHPC cylinders under uniaxial compressive loading.
The load –crack mouth opening displacement (cmod) of UHPC
beams, flexural strength and fracture energy was evaluated using
third point loading test. Compressive strength and Split tensile
strength results are determined to find out the compressive and tensile
behaviour. Residual strength parameters are presented vividly
explaining the flexural performance, toughness of concrete.Durability
studies were also done to compare the effect of fibre to that of a
control mix For all the studies the Mechanical properties were
evaluated by varying the percentage and aspect ratio of steel fibres
The results reflected that higher aspect ratio and fibre volume
produced drastic changes in the cube strength, cylinder strength, post
peak response, load-cmod, fracture energy flexural strength, split
tensile strength, residual strength and durability. In regards to null
application of UHPC in India, an initiative is undertaken to
comprehend the mechanical behaviour of UHPC, which will be vital
for longer run in commercialization for structural applications.
Abstract: Fracture process in mechanically loaded steel fiber
reinforced high-strength (SFRHSC) concrete is characterized by
fibers bridging the crack providing resistance to its opening.
Structural SFRHSC fracture model was created; material fracture
process was modeled, based on single fiber pull-out laws, which were
determined experimentally (for straight fibers, fibers with end hooks
(Dramix), and corrugated fibers (Tabix)) as well as obtained
numerically ( using FEM simulations). For this purpose experimental
program was realized and pull-out force versus pull-out fiber length
was obtained (for fibers embedded into concrete at different depth
and under different angle). Model predictions were validated by
15x15x60cm prisms 4 point bending tests. Fracture surfaces analysis
was realized for broken prisms with the goal to improve elaborated
model assumptions. Optimal SFRHSC structures were recognized.
Abstract: In the national and professional music of oral tradition
of many people in the East there is the metric formula called “ussuli",
that is to say rhythmic constructions of different character and a
composition. Ussuli in translation from Arabic means the law. The
cultural contacts of the ancient and medieval inhabitants of the
Central Asia, India, China, East Turkestan, Iraq, Afghanistan,
Turkey, and Iran have played a certain role in formation of both
musical and dancing heritage of each of these people. During
theatrical shows many dances were performed under the
accompaniment of percussion instruments as nagra, dayulpaz, doll.
The abovementioned tools are used as the obligatory accompanying
tool in an orchestra and at support of dancing acts as the solo tool.
Dynamics of development of a dancing composition, at times
execution of technique of movement depends on various
combinations of ussuli and their receptions of execution.
Abstract: Continuation of an active call is one of the most important quality measurements in the cellular systems. Handoff process enables a cellular system to provide such a facility by transferring an active call from one cell to another. Different approaches are proposed and applied in order to achieve better handoff service. The principal parameters used to evaluate handoff techniques are: forced termination probability and call blocking probability. The mechanisms such as guard channels and queuing handoff calls decrease the forced termination probability while increasing the call blocking probability. In this paper we present an overview about the issues related to handoff initiation and decision and discuss about different types of handoff techniques available in the literature.
Abstract: One of the essential requirements in order to have a
realistic surgical simulator is real-time interaction by means of a
haptic interface is. In fact, reproducing haptic sensations increases
the realism of the simulation. However, the interaction need to be
performed in real-time, since a delay between the user action and the
system reaction reduces the user immersion. In this paper, we present
a prototype of the coronary stent implant simulator developed in the
HERMES Project; this system allows real-time interactions with a
artery by means of a specific haptic device; thus the user can
interactively navigate in a reconstructed artery and force feedback is
produced when contact occurs between the artery walls and the
medical instruments
Abstract: The Integrated Performance Modelling Environment
(IPME) is a powerful simulation engine for task simulation and
performance analysis. However, it has no high level cognition such
as memory and reasoning for complex simulation. This article
introduces a knowledge representation and reasoning scheme that can
accommodate uncertainty in simulations of military personnel with
IPME. This approach demonstrates how advanced reasoning models
that support similarity-based associative process, rule-based abstract
process, multiple reasoning methods and real-time interaction can be
integrated with conventional task network modelling to provide
greater functionality and flexibility when modelling operator
performance.
Abstract: In today-s global and competitive market,
manufacturing companies are working hard towards improving their
production system performance. Most companies develop production
systems that can help in cost reduction. Manufacturing systems
consist of different elements including production methods,
machines, processes, control and information systems. Human issues
are an important part of manufacturing systems, yet most companies
do not pay sufficient attention to them. In this paper, a workforce
planning (WP) model is presented. A non-linear programming model
is developed in order to minimize the hiring, firing, training and
overtime costs. The purpose is to determine the number of workers
for each worker type, the number of workers trained, and the number
of overtime hours. Moreover, a decision support system (DSS) based
on the proposed model is introduced using the Excel-Lingo software
interfacing feature. This model will help to improve the interaction
between the workers, managers and the technical systems in
manufacturing.