Abstract: The hidden-point bar method is useful in many
surveying applications. The method involves determining the
coordinates of a hidden point as a function of horizontal and vertical
angles measured to three fixed points on the bar. Using these
measurements, the procedure involves calculating the slant angles,
the distances from the station to the fixed points, the coordinates of
the fixed points, and then the coordinates of the hidden point. The
propagation of the measurement errors in this complex process has
not been fully investigated in the literature. This paper evaluates the
effect of the bar geometry on the position accuracy of the hidden
point which depends on the measurement errors of the horizontal and
vertical angles. The results are used to establish some guidelines
regarding the inclination angle of the bar and the location of the
observed points that provide the best accuracy.
Abstract: Air conditioning systems of houses consume large
quantity of electricity. To reducing energy consumption for air
conditioning purposes it is becoming attractive the use of evaporative
cooling air conditioning which is less energy consuming compared to
air chillers. But, it is obvious that higher energy efficiency of
evaporative cooling is not enough to judge whether evaporative
cooling economically is competitive with other types of cooling
systems. To proving the higher energy efficiency and cost
effectiveness of the evaporative cooling competitive analysis of
various types of cooling system should be accomplished. For noted
purpose optimization mathematical model for each system should be
composed based on system approach analysis. In this paper different
types of evaporative cooling-heating systems are discussed and
methods for increasing their energy efficiency and as well as
determining of their design parameters are developed. The
optimization mathematical models for each of them are composed
with help of which least specific costs for each of them are reviled.
The comparison of specific costs proved that the most efficient and
cost effective is considered the “direct evaporating" system if it is
applicable for given climatic conditions. Next more universal and
applicable for many climatic conditions system providing least cost
of heating and cooling is considered the “direct evaporating" system.
Abstract: The theatre-auditorium under investigation following
the highly reflective characteristics of materials used in it (marble,
painted wood, smooth plaster, etc), architectural and structural
features of the Protocol and its intended use (very multifunctional:
Auditorium, theatre, cinema, musicals, conference room) from the
analysis of the statement of fact made by the acoustic simulation
software Ramsete and supported by data obtained through a
campaign of acoustic measurements of the state of fact made on the
spot by a Fonomet Svantek model SVAN 957, appears to be
acoustically inadequate. After the completion of the 3D model
according to the specifications necessary software used forecast in
order to be recognized by him, have made three simulations, acoustic
simulation of the state of and acoustic simulation of two design
solutions.
Improved noise characteristics found in the first design solution,
compared to the state in fact consists therefore in lowering
Reverberation Time that you turn most desirable value, while the
Indicators of Clarity, the Baricentric Time, the Lateral Efficiency,
Ratio of Low Tmedia BR and defined the Speech Intelligibility
improved significantly. Improved noise characteristics found instead
in the second design solution, as compared to first design solution, is
finally mostly in a more uniform distribution of Leq and in lowering
Reverberation Time that you turn the optimum values. Indicators of
Clarity, and the Lateral Efficiency improve further but at the expense
of a value slightly worse than the BR. Slightly vary the remaining
indices.
Abstract: These Nowadays the explosion of bombs or explosive
materials such as gas and oil near or inside the buildings cause some
losses in installations and building components. This has made the
engineers to make the buildings and their components resistance
against the effects of explosion. These activities lead to provide
regulations and different methods. The above regulations are mostly
focused on the explosion effects resulting from the vehicles around
the buildings. Therefore, the explosion resulting from the vehicles
outside the buildings will be studied in this research.
In the present study, the main goals are to investigate the
explosion load effects on the structures located on the piles with the
specific quantity of plasticity and observing the permissible response
of these structures. The concentrated mass system and the spring with
two degree of freedom will be used to study the structural system.
Abstract: Explosions may cause intensive damage to buildings
and sometimes lead to total and progressive destruction. Pressures
induced by explosions are one of the most destructive loads a
structure may experience. While designing structures for great
explosions may be expensive and impractical, engineers are looking
for methods for preventing destructions resulted from explosions. A
favorable structural system is a system which does not disrupt totally
due to local explosion, since such structures sustain less loss in
comparison with structural ones which really bear the load and
suddenly disrupt. Designing and establishing vital and necessary
installations in a way that it is resistant against direct hit of bomb and
rocket is not practical, economical, or expedient in many cases,
because the cost of construction and installation with such
specifications is several times more than the total cost of the related
equipment.
Abstract: The present study concentrates on solving the along wind oscillation problem of a tall square building from first principles and across wind oscillation problem of the same from empirical relations obtained by experiments. The criterion for human comfort at the worst condition at the top floor of the building is being considered and a limiting value of height of a building for a given cross section is predicted. Numerical integrations are carried out as and when required. The results show severeness of across wind oscillations in comparison to along wind oscillation. The comfort criterion is combined with across wind oscillation results to determine the maximum allowable height of a building for a given square cross-section.
Abstract: Buckling-Restrained Braced Frame system(BRBFs)
are a new type of steel seismic-load-resisting system that has found
use in several countries because of its efficiency and its promise of
seismic performance far superior to that of conventional braced
frames. The system is addressed in the 2005 edition of the AISC
Seismic Provisions for Structural Steel Buildings, also a set of design
provisions has been developed by NEHRP. This report illustrates the
seismic design of buckling restrained braced frames and compares
the result of design in the application of earthquake load for ordinary
bracing systems and buckling restrained bracing systems to see the
advantage and disadvantages of this new type of seismic resisting
system in comparison with the old Ordinary Concentric Braced
Frame systems (OCBFs); they are defined by the provisions
governing their design.
Abstract: Explosion occurs due to sudden release of energy.
Common examples of explosion include chemical, atomic, heat, and
pressure tank (due to ignition) explosions. Petroleum, gas, and
petrochemical industries operations are threatened by natural risks
and processes. Fires and explosions are the greatest process risks
which cause financial damages.
This study aims at designing a single-floor structure for the control
room of a petroleum refinery to be resistant against gas explosion
loads, and the information related to the structure specifications have
been provided regarding the fact that the structure is made on the
ground's surface. In this research, the lateral stiffness of single pile is
calculated by SPPLN.FOR computer program, and its value for
13624 KN/m single pile has been assessed. The analysis used due to
the loading conditions, is dynamic nonlinear analysis with direct
integration method.
Abstract: The main objective of this study was to determine if a
minimal increase in road light level (luminance) could lead to
improved driving performance among older adults. Older, middleaged
and younger adults were tested in a driving simulator following
vision and cognitive screening. Comparisons were made for the
performance of simulated night driving under two road light
conditions (0.6 and 2.5 cd/m2). At each light level, the effects of self
reported night driving avoidance were examined along with the
vision/cognitive performance. It was found that increasing road light
level from 0.6 cd/m2 to 2.5 cd/m2 resulted in improved recognition of
signage on straight highway segments. The improvement depends on
different driver-related factors such as vision and cognitive abilities,
and confidence. On curved road sections, the results showed that
driver-s performance worsened. It is concluded that while increasing
road lighting may be helpful to older adults especially for sign
recognition, it may also result in increased driving confidence and
thus reduced attention in some driving situations.
Abstract: Vernacular building is considered as sustainable in
energy consumption and environment and its thermal performance is
more and more concerned by researchers. This paper investigates the
thermal property of the vernacular building in Lhasa by theoretical
analysis on the aspects of building form, envelope and materials etc.
The values of thermal resistance and thermal capacity of the envelope
are calculated and compared with the current China building code and
modern building case. And it is concluded that Lhasa vernacular
building meets the current China building code of thermal standards
and have better performance in some aspects, which is achieved by
various passive means with close response to local climate conditions.
Abstract: This paper presents the climatic range calculations for
comfort evaporative cooling for Tehran. In this study the minimum
climatic conditions required to achieve an appropriate comfort zone
will be presented.
Physiologically uncomfortable conditions in arid climates are
mainly caused by the extreme heat and dryness. Direct evaporative
cooling adds moisture to the air stream until the air stream is close to
saturation. The dry bulb temperature is reduced, while the wet bulb
temperature stays the same. Evaporative cooling is economical,
effective, environmentally friendly, and healthy.
Comfort cooling by direct evaporative cooling (passive or fan
forced) in the 35. 41 N (such as Tehran) latitude requires design
wet-bulb temperature not over 25.4 C. Evaporative cooling outside
this limit cannot achieve the required 26.7 ET, and is recommended
for relief cooling only.
Abstract: In this study, active tendons with Proportional Integral
Derivation type controllers were applied to a SDOF and a MDOF
building model. Physical models of buildings were constituted with
virtual springs, dampers and rigid masses. After that, equations of
motion of all degrees of freedoms were obtained. Matlab Simulink
was utilized to obtain the block diagrams for these equations of
motion. Parameters for controller actions were found by using a trial
method. After earthquake acceleration data were applied to the
systems, building characteristics such as displacements, velocities,
accelerations and transfer functions were analyzed for all degrees of
freedoms. Comparisons on displacement vs. time, velocity vs. time,
acceleration vs. time and transfer function (Db) vs. frequency (Hz)
were made for uncontrolled and controlled buildings. The results
show that the method seems feasible.