Abstract: We propose a low-cost uniform analysis framework
allowing comparison of the strengths and weaknesses of the
bicycling experience within and between cities. A primary
component is an expedient, one-page mobility survey from which
mode share is calculated. The bicycle mode share of many cities
remains unknown, creating a serious barrier for both scientists and
policy makers aiming to understand and increase rates of bicycling.
Because of its low cost and expedience, this framework could be
replicated widely, uniformly filling the data gap. The framework has
been applied to 13 Central European cities with success. Data is
collected on multiple modes with specific questions regarding both
behavior and quality of travel experience. Individual preferences are
also collected, examining the conditions under which respondents
would change behavior to adopt more sustainable modes (bicycling
or public transportation). A broad analysis opportunity results,
intended to inform policy choices.
Abstract: Materials added to the matrix help improving operating properties of a composite. This experimental study has targeted to investigate this aim where Silicon Oxide particles were added to glass fibre and epoxy resin at an amount of 15% to the main material to obtain a sort of new composite material. Erosive wear behavior of epoxy-resin dipped composite materials reinforced with glass fibre and Silicon Oxide under three different impingement angles (30°, 60° and 90°), three different impact velocities (23, 34 and 53 m/s), two different angular Aluminum abrasive particle sizes (approximately 200 and 400 μm) and the fibre orientation of 45° (45/-45) were investigated. In the test results, erosion rates were obtained as functions of impingement angles, impact velocities, particle sizes and fibre orientation. Moreover, materials with addition of Silicon Oxide filler material exhibited lower wear as compared to neat materials with no added filler material. In addition, SEM views showing worn out surfaces of the test specimens were scrutinized.
Abstract: Even though so many efforts have been taken to
renovate and renew the architecture of Miyaneh villages in cold and
dry regions of Iran-s northwest, these efforts failed due to lack of
significant study and ignoring the past and sustainable history of
those villages. Considering the overpopulation of Iran-s villages as
well as the importance in preventing their immigration to cities,
recognizing village architecture and its construction technology is of
great significance to attain sustainable residence in villages. As the
only vertical surface in the space, wall possesses its unique special
characteristics, and it is also a very important architectural element
able to provide the immunity and comfort space for the residents.
This article analyzes the characteristics of this vertical element, main
types of adobe and stone walls, locally constructed technologies,
implementation, the elements forming the walls in the frame of
village house typology of Miyaneh, which has the most villages in
East Azerbaijan, based on sustainable architectural construction
materials of walls.
Abstract: Climate change could lead to changes in cultural
environments and landscapes as we know them.Climate change
presents an immediate and significant threat to our natural and built
environments and to the ways of life which co-exist with these
environments. In most traditional buildings, the harmony of texture
with nature and environment has been ever considered; so houses and
cities have been mixed with their natural environment so
astonishingly and the selection and usage of materials have been in
such a way that they have provided the utmost conformity with the
environment, as the result the created areas have a unique beauty and
attraction.The extent to which climate change contributes to
destruction procedure on Iran-s historic buildings.is a subject of
current discussion. Cities, towns and built-up areas also have their
own characteristics that might make them particularly vulnerable to
climate change.
Abstract: Iran has diverse climates and each have established distinct properties in their area. The extent and intensity of climatic factors effects on the lives of people living in various regions of Iran is so great that it cannot be simply ignored. In a large part of Iran known as the Central Plateau there is no precipitation for more than half of the year and dry weather and scarcity of fresh water pose an ever present problem for the people of these regions while in north of Iran upon the southern shores of the Caspian Sea the people face 80% humidity caused by the sea and 2 meters of annual precipitation. This article tries to review the past experiences of local architecture of Iran-s various regions so that they can be used to reshape and redirect the urban areas and structure of Iran-s current cities to provide environmental comfort by minimum use of fossil fuels.
Abstract: The problems associated with wind predictions of
WAsP model in complex terrain are already the target of several
studies in the last decade. In this paper, the influence of surrounding
orography on accuracy of wind data analysis of a train is
investigated. For the case study, a site with complex surrounding
orography is considered. This site is located in Manjil, one of the
windiest cities of Iran. For having precise evaluation of wind regime
in the site, one-year wind data measurements from two metrological
masts are used. To validate the obtained results from WAsP, the
cross prediction between each mast is performed. The analysis
reveals that WAsP model can estimate the wind speed behavior
accurately. In addition, results show that this software can be used
for predicting the wind regime in flat sites with complex surrounding
orography.
Abstract: Medical applications are among the most impactful
areas of microrobotics. The ultimate goal of medical microrobots is
to reach currently inaccessible areas of the human body and carry out
a host of complex operations such as minimally invasive surgery
(MIS), highly localized drug delivery, and screening for diseases at
their very early stages. Miniature, safe and efficient propulsion
systems hold the key to maturing this technology but they pose
significant challenges. A new type of propulsion developed recently,
uses multi-flagella architecture inspired by the motility mechanism of
prokaryotic microorganisms. There is a lack of efficient methods for
designing this type of propulsion system. The goal of this paper is to
overcome the lack and this way, a numerical strategy is proposed to
design multi-flagella propulsion systems. The strategy is based on the
implementation of the regularized stokeslet and rotlet theory, RFT
theory and new approach of “local corrected velocity". The effects of
shape parameters and angular velocities of each flagellum on overall
flow field and on the robot net forces and moments are considered.
Then a multi-layer perceptron artificial neural network is designed
and employed to adjust the angular velocities of the motors for
propulsion control. The proposed method applied successfully on a
sample configuration and useful demonstrative results is obtained.
Abstract: In this paper, we study the knapsack sharing problem, a variant of the well-known NP-Hard single knapsack problem. We investigate the use of a tree search for optimally solving the problem. The used method combines two complementary phases: a reduction interval search phase and a branch and bound procedure one. First, the reduction phase applies a polynomial reduction strategy; that is used for decomposing the problem into a series of knapsack problems. Second, the tree search procedure is applied in order to attain a set of optimal capacities characterizing the knapsack problems. Finally, the performance of the proposed optimal algorithm is evaluated on a set of instances of the literature and its runtime is compared to the best exact algorithm of the literature.
Abstract: Addis Ababa is a seat of African Union (AU), United
Nations Economic Commission for Africa (UN-ECA) and hundreds of
embassies and consular representatives. Addis Ababa is one of the
highest capitals in the world with an average 2400 meters above sea
level. It is dichotomous city with a blend of modern high-rise and
deteriorating slum quarters. Water supply and sanitation, waste
management and housing are continuing to be serious problems.
Forest wood based domestic energy use as well as uncontrolled
emissions from mobile and fixed sources has endangered the state of
the urban environment. Analysis based on satellite imagery has
revealed the deteriorating urban environment within the last three
decades. The recently restructured city administration has brought
improvements in the condition of the urban environment. However,
the overwhelming size of the challenges faced by the city dwarfed
their fairly good results.
Abstract: In this article, a simulation method called the Homotopy Perturbation Method (HPM) is employed in the steady flow of a Walter's B' fluid in a vertical channel with porous wall. We employed Homotopy Perturbation Method to derive solution of a nonlinear form of equation obtained from exerting similarity transforming to the ordinary differential equation gained from continuity and momentum equations of this kind of flow. The results obtained from the Homotopy Perturbation Method are then compared with those from the Runge–Kutta method in order to verify the accuracy of the proposed method. The results show that the Homotopy Perturbation Method can achieve good results in predicting the solution of such problems. Ultimately we use this solution to obtain the other terms of velocities and physical discussion about it.
Abstract: The network of delivering commodities has been an important design problem in our daily lives and many transportation applications. The delivery performance is evaluated based on the system reliability of delivering commodities from a source node to a sink node in the network. The system reliability is thus maximized to find the optimal routing. However, the design problem is not simple because (1) each path segment has randomly distributed attributes; (2) there are multiple commodities that consume various path capacities; (3) the optimal routing must successfully complete the delivery process within the allowable time constraints. In this paper, we want to focus on the design optimization of the Multi-State Flow Network (MSFN) for multiple commodities. We propose an efficient approach to evaluate the system reliability in the MSFN with respect to randomly distributed path attributes and find the optimal routing subject to the allowable time constraints. The delivery rates, also known as delivery currents, of the path segments are evaluated and the minimal-current arcs are eliminated to reduce the complexity of the MSFN. Accordingly, the correct optimal routing is found and the worst-case reliability is evaluated. It has been shown that the reliability of the optimal routing is at least higher than worst-case measure. Two benchmark examples are utilized to demonstrate the proposed method. The comparisons between the original and the reduced networks show that the proposed method is very efficient.
Abstract: The present report describes the characteristics of
damages and behavior of reinforced concrete buildings during the
tsunami action. The discussion is based on the field damage survey in
selected cities located on the coast of the zone affected by the Great
East Japan Earthquake on March 11, 2011. This earthquake is the most
powerful know earthquake that has hit Japan with a magnitude 9.0 and
with epicenter located at 129 km of Sendai city (off the coast). The
earthquake triggered a destructive tsunami with run up height of up to
40 meters that mainly affect cities located on the Pacific Ocean coast of
the Tohoku region (north-east region of Japan). Reinforced concrete
buildings in general resist the tsunami without collapse however the
non-structural elements like panels and ceilings were severely
damaged. The analysis of damages has permitted to understand the
behavior of RC buildings under tsunami attack, and has also permitted
to establish recommendations for their use to take refuge from tsunami
in places where natural topography makes impossible to reach hilltops
or other safer places.
Abstract: It-s difficult for China-s current land transfer
institutions limited to county-wide to solve the contradiction between
urban-rural development and construction land shortage. On the basis of analyzing China-s construction land transfer system, and evaluation
toward Transfer of development rights (TDR) practices in Anhui and
Chongqing, the passage proposes: (1) we should establish a multi-level
land indicators trade market under the guidance of regional spatial
objectives, and allow land transfer paid across cities and counties
within a specific area following the regulation of both government and
market; (2) it would be better to combine organically the policy ntentions of land plan, regional plan, urban plan and economic plan, and link them with land indicators transfer to promote a wider range of
urban-rural balance and regional coordination.
Abstract: Threedimensional numerical simulations are conducted on a full scale CANDU Moderator and Transient variations of the temperature and velocity distributions inside the tank are determined. The results show that the flow and temperature distributions inside the moderator tank are three dimensional and no symmetry plane can be identified.Competition between the upward moving buoyancy driven flows and the downward moving momentum driven flows, results in the formation of circulation zones. The moderator tank operates in the buoyancy driven mode and any small disturbances in the flow or temperature makes the system unstable and asymmetric. Different types of temperature fluctuations are noted inside the tank: (i) large amplitude are at the boundaries between the hot and cold (ii) low amplitude are in the core of the tank (iii) high frequency fluctuations are in the regions with high velocities and (iv) low frequency fluctuations are in the regions with lower velocities.
Abstract: For a long time as a result of accommodating car
traffic, planning ideologies in the past put a low priority on public
space, pedestrianism and the role of city space as a meeting place for
urban dwellers. In addition, according to authors such as Jan Gehl,
market forces and changing architectural perceptions began to shift
the focus of planning practice from the integration of public space in
various pockets around the contemporary city to individual buildings.
Eventually, these buildings have become increasingly more isolated
and introverted and have turned their backs to the realm of the public
space adjoining them. As a result of this practice, the traditional
function of public space as a social forum for city dwellers has in
many cases been reduced or even phased out. Author Jane Jacobs
published her seminal book “The Death and Life of Great American
Cities" more than fifty years ago, but her observations and
predictions at the time still ring true today, where she pointed out
how the dramatic increase in car traffic and its accommodation by the
urban planning ideology that was brought about by the Modern
movement has prompted a separation of the uses of the city. At the
same time it emphasizes free standing buildings that threaten urban
space and city life and result in underutilized and lifeless urban cores.
In this discussion context, the aim of this paper is to showcase a
reversal of just such a situation in the case of the Dasoupolis
neighborhood in Strovolos, Cyprus, where enlightened urban design
practice has see the reclamation of pedestrian space in a car
dominated area.
Abstract: Nowadays, a passenger car suspension must has high
performance criteria with light weight, low cost, and low energy
consumption. Pilot controlled proportional valve is designed and
analyzed to get small pressure change rate after blow-off, and to get a
fast response of the damper, a reverse damping mechanism is adapted.
The reverse continuous variable damper is designed as a HS-SH
damper which offers good body control with reduced transferred input
force from the tire, compared with any other type of suspension
system. The damper structure is designed, so that rebound and
compression damping forces can be tuned independently, of which the
variable valve is placed externally. The rate of pressure change with
respect to the flow rate after blow-off becomes smooth when the fixed
orifice size increases, which means that the blow-off slope is
controllable using the fixed orifice size. Damping forces are measured
with the change of the solenoid current at the different piston
velocities to confirm the maximum hysteresis of 20 N, linearity, and
variance of damping force. The damping force variance is wide and
continuous, and is controlled by the spool opening, of which scheme is
usually adapted in proportional valves. The reverse continuous
variable damper developed in this study is expected to be utilized in
the semi-active suspension systems in passenger cars after its
performance and simplicity of the design is confirmed through a real
car test.
Abstract: It is the living conditions in the cities that determine the future of our livelihood. “To change life, we must first change space"- Henri Lefebvre. Sustainable development is a utopian aspiration for South African cities (especially the case study of the Gauteng City Region), which are currently characterized by unplanned growth and increasing urban sprawl. While the reasons for poor environmental quality and living conditions are undoubtedly diverse and complex, having political, economical and social dimensions, it is argued that the prevailing approach to layout planning in South Africa is part of the problem. This article seeks a solution to the problem of sustainability, from a spatial planning perspective. The spatial planning tool, the urban development boundary, is introduced as the concept that will ensure empty talk being translated into a sustainable vision. The urban development boundary is a spatial planning tool that can be used and implemented to direct urban growth towards a more sustainable form. The urban development boundary aims to ensure planned urban areas, in contrast to the current unplanned areas characterized by urban sprawl and insufficient infrastructure. However, the success of the urban development boundary concept is subject to effective implementation measures, as well as adequate and efficient management. The concept of sustainable development can function as a driving force underlying societal change and transformation, but the interface between spatial planning and environmental management needs to be established (as this is the core aspects underlying sustainable development), and authorities needs to understand and implement this interface consecutively. This interface can, however, realize in terms of the objectives of the planning tool – the urban development boundary. The case study, the Gauteng City Region, is depicted as a site of economic growth and innovation, but there is a lack of good urban and regional governance, impacting on the design (layout) and function of urban areas and land use, as current authorities make uninformed decisions in terms of development applications, leading to unsustainable urban forms and unsustainable nodes. Place and space concepts are thus critical matters applicable to planning of the Gauteng City Region. The urban development boundary are thus explored as a planning tool to guide decision-making, and create a sustainable urban form, leading to better environmental and living conditions, and continuous sustainability.
Abstract: The State of Rio de Janeiro, Brazil, will hold two important events in the nearby future. In 2014 it will have the final game of the Football World Cup, and in 2016 it will be holding the Olympic Games. Therefore, the public transportation system (mainly buses) is of a major concern to the Rio de Janeiro State authorities-. The main objective of this work is to compare the quality of service of the bus companies operating in the cities of ItaperunaandCampos, both cities situated in the state of Rio de Janeiro, Brazil. The outcome of thiscomparison, based on the opinion of the bus users, has shownthemdispleased with the quality of the service provided by the bus companies operating in both cities. It is urgent the need to find possible practical alternatives to minimize the consequences of the main problems detected in this work. With these practical alternatives available, we will be able to offer to the Rio de Janeiro State authorities- suggestions about possible solutions to the main problems identified in this survey, as well as the time of implantation and costs of these solutions.
Abstract: Understanding how airborne pathogens are
transported through hospital wards is essential for determining the
infection risk to patients and healthcare workers. This study utilizes
Computational Fluid Dynamics (CFD) simulations to explore
possible pathogen transport within a six-bed partitioned Nightingalestyle
hospital ward.
Grid independence of a ward model was addressed using the Grid
Convergence Index (GCI) from solutions obtained using three fullystructured
grids. Pathogens were simulated using source terms in
conjunction with a scalar transport equation and a RANS turbulence
model. Errors were found to be less than 4% in the calculation of air
velocities but an average of 13% was seen in the scalar field.
A parametric study of variations in the pathogen release point
illustrated that its distribution is strongly influenced by the local
velocity field and the degree of air mixing present.
Abstract: We attempted investigate a boat model, based on the
conversion of energy of surface wave into a sequence of
unidirectional pulses of jet spurts, in other words - model of the boat,
which is thrusting by the waves field on water surface. These pulses
are forming some average reactive stream from the output nozzle on
the stern of boat. The suggested model provides the conversion of its
oscillatory motions (both pitching and rolling) into a jet flow. This
becomes possible due to special construction of the boat and due to
several details, sensitive to the local wave field. The boat model
presents the uniflow jet engine without slow conversions of
mechanical energy into intermediate forms and without any external
sources of energy (besides surface waves). Motion of boat is
characterized by fast jerks and average onward velocity, which
exceeds the velocities of liquid particles in the wave.