Abstract: Due to growing environmental concerns of the cement
industry, alternative cement technologies have become an area of
increasing interest. It is now believed that new binders are
indispensable for enhanced environmental and durability
performance. Self-compacting Geopolymer concrete is an innovative
method and improved way of concreting operation that does not
require vibration for placing it and is produced by complete
elimination of ordinary Portland cement.
This paper documents the assessment of the compressive strength
and workability characteristics of low-calcium fly ash based selfcompacting
geopolymer concrete. The essential workability
properties of the freshly prepared Self-compacting Geopolymer
concrete such as filling ability, passing ability and segregation
resistance were evaluated by using Slump flow, V-funnel, L-box and
J-ring test methods. The fundamental requirements of high
flowability and segregation resistance as specified by guidelines on
Self Compacting Concrete by EFNARC were satisfied. In addition,
compressive strength was determined and the test results are included
here. This paper also reports the effect of extra water, curing time and
curing temperature on the compressive strength of self-compacting
geopolymer concrete. The test results show that extra water in the
concrete mix plays a significant role. Also, longer curing time and
curing the concrete specimens at higher temperatures will result in
higher compressive strength.
Abstract: The mechanical properties of granular solids are
dependent on the flow of stresses from one particle to another
through inter-particle contact. Although some experimental methods
have been used to study the inter-particle contacts in the past,
preliminary work with these techniques indicated that they do not
have the necessary resolution to distinguish between those contacts
that transmit the load and those that do not, especially for systems
with a wide distribution of particle sizes. In this research, computer
simulations are used to study the nature and distribution of contacts
in a compact with wide particle size distribution, representative of
aggregate size distribution used in asphalt pavement construction.
The packing fraction, the mean number of contacts and the
distribution of contacts were studied for different scenarios. A
methodology to distinguish and compute the fraction of load-bearing
particles and the fraction of space-filling particles (particles that do
not transmit any force) is needed for further investigation.
Abstract: The reduction of hexavalent chromium by scrap iron
was investigated in continuous system, using long-term column
experiments, for aqueous Cr(VI) solutions having low buffering
capacities, over the Cr(VI) concentration range of 5 – 40 mg/L. The
results showed that the initial Cr(VI) concentration significantly
affects the reduction capacity of scrap iron. Maximum reduction
capacity of scrap iron was observed at the beginning of the column
experiments; the lower the Cr(VI) concentration, the greater the
experiment duration with maximum scrap iron reduction capacity.
However, due to passivation of active surface, scrap iron reduction
capacity continuously decreased in time, especially after Cr(VI)
breakthrough. The experimental results showed that highest
reduction capacity recorded until Cr(VI) breakthrough was 22.8 mg
Cr(VI)/g scrap iron, at CI = 5 mg/L, and decreased with increasing
Cr(VI) concentration. In order to assure total reduction of greater
Cr(VI) concentrations for a longer period of time, either the mass of
scrap iron filling, or the hydraulic retention time should be increased.
Abstract: Amount of dissolve oxygen in a river has a great direct affect on aquatic macroinvertebrates and this would influence on the region ecosystem indirectly. In this paper it is tried to predict dissolved oxygen in rivers by employing an easy Fuzzy Logic Modeling, Wang Mendel method. This model just uses previous records to estimate upcoming values. For this purpose daily and hourly records of eight stations in Au Sable watershed in Michigan, United States are employed for 12 years and 50 days period respectively. Calculations indicate that for long period prediction it is better to increase input intervals. But for filling missed data it is advisable to decrease the interval. Increasing partitioning of input and output features influence a little on accuracy but make the model too time consuming. Increment in number of input data also act like number of partitioning. Large amount of train data does not modify accuracy essentially, so, an optimum training length should be selected.
Abstract: Palestinian cities face the challenges of land scarcity,
high population growth rates, rapid urbanization, uneven
development and territorial fragmentation. Due to geopolitical
constrains and the absence of an effective Palestinian planning
institution, urban development in Palestinian cities has not followed
any discernable planning scheme. This has led to a number of
internal contradictions in the structure of cities, and adversely
affected land use, the provision of urban services, and the quality of
the living environment.
This paper explores these challenges, and the potential that exists
for introducing a more sustainable urban development pattern in
Palestinian cities. It assesses alternative development approaches
with a particular focus on sustainable development, promoting ecodevelopment
imperatives, limiting random urbanization, and meeting
present and future challenges, including fulfilling the needs of the
people and conserving the scarce land and limited natural resources.
This paper concludes by offering conceptual proposals and guidelines
for promoting sustainable physical development in Palestinian cities.
Abstract: The solvated electron is self-trapped (polaron) owing
to strong interaction with the quantum polarization field. If the
electron and quantum field are strongly coupled then the collective
localized state of the field and quasi-particle is formed. In such a
formation the electron motion is rather intricate. On the one hand the
electron oscillated within a rather deep polarization potential well
and undergoes the optical transitions, and on the other, it moves
together with the center of inertia of the system and participates in
the thermal random walk. The problem is to separate these motions
correctly, rigorously taking into account the conservation laws. This
can be conveniently done using Bogolyubov-Tyablikov method of
canonical transformation to the collective coordinates. This
transformation removes the translational degeneracy and allows one
to develop the successive approximation algorithm for the energy and
wave function while simultaneously fulfilling the law of conservation
of total momentum of the system. The resulting equations determine
the electron transitions and depend explicitly on the translational
velocity of the quasi-particle as whole. The frequency of optical
transition is calculated for the solvated electron in ammonia, and an
estimate is made for the thermal-induced spectral bandwidth.
Abstract: Circle grid space filling plate is a flow conditioner with a fractal pattern and used to eliminate turbulence originating from pipe fittings in experimental fluid flow applications. In this paper, steady state, incompressible, swirling turbulent flow through circle grid space filling plate has been studied. The solution and the analysis were carried out using finite volume CFD solver FLUENT 6.2. Three turbulence models were used in the numerical investigation and their results were compared with the pressure drop correlation of BS EN ISO 5167-2:2003. The turbulence models investigated here are the standard k-ε, realizable k-ε, and the Reynolds Stress Model (RSM). The results showed that the RSM model gave the best agreement with the ISO pressure drop correlation. The effects of circle grids space filling plate thickness and Reynolds number on the flow characteristics have been investigated as well.
Abstract: This paper presents a numerical analysis of the
seismic behaviour of earth dams. Analysis is conducted for the solid
phase. It may correspond to the response of the dam before water
filling. Analysis is conducted for a simple case which concerns the
elastic response of the dam. Numerical analyses are conducted using
the FLAC3D program. The behaviour of the Shell and core of the
dam and the foundation behaviour is assumed to be elastic. Result
shows the influence of the variation of the shear modulus of the core
and shell on the seismic amplification of the dam. It can be observed
that the variation of the shearing modulus of the core leads to a
moderate increase in the dynamic amplification and the increase in
the shell shearing modulus leads to a significant increase in the
dynamic amplification.
Abstract: Supply chain consists of all stages involved, directly
or indirectly, includes all functions involved in fulfilling a customer
demand. In two stage transportation supply chain problem,
transportation costs are of a significant proportion of final product
costs. It is often crucial for successful decisions making approaches
in two stage supply chain to explicit account for non-linear
transportation costs. In this paper, deterministic demand and finite
supply of products was considered. The optimized distribution level
and the routing structure from the manufacturing plants to the
distribution centres and to the end customers is determined using
developed mathematical model and solved by proposed particle
swarm optimization based genetic algorithm. Numerical analysis of
the case study is carried out to validate the model.
Abstract: This paper discuss the separation of the miscible
liquids by means of fractional distillation. For complete separation of
liquids, the process of heating, condensation, separation and storage
is done automatically to achieve the objective. PIC micro-controller
has been used to control each and every process of the work. The
controller also controls the storage process by activating and deactivating
the conveyors. The liquids are heated which on reaching
their respective boiling points evaporate and enter the condensation
chamber where they convert into liquid. The liquids are then directed
to their respective tanks by means of stepper motor which moves in
three directions, each movement into different tank. The tank on
filling sends the signal to controller which then opens the solenoid
valves. The tank is emptied into the beakers below the nozzle. As the
beaker filled, the nozzle closes and the conveyors come into
operation. The filled beaker is replaced by an empty beaker from
behind. The work can be used in oil industries, chemical industries
and paint industries.
Abstract: When the foundations of structures under cyclic
loading with amplitudes less than their permissible load, the concern exists often for the amount of uniform and non-uniform settlement of
such structures. Storage tank foundations with numerous filling and discharging and railways ballast course under repeating
transportation loads are examples of such conditions. This paper
deals with the effects of using the new generation of reinforcements,
Grid-Anchor, for the purpose of reducing the permanent settlement
of these foundations under the influence of different proportions of
the ultimate load. Other items such as the type and the number of
reinforcements as well as the number of loading cycles are studied numerically. Numerical models were made using the Plaxis3D
Tunnel finite element code. The results show that by using gridanchor
and increasing the number of their layers in the same
proportion as that of the cyclic load being applied, the amount of
permanent settlement decreases up to 42% relative to unreinforced
condition depends on the number of reinforcement layers and percent
of applied load and the number of loading cycles to reach a constant
value of dimensionless settlement decreases up to 20% relative to
unreinforced condition.
Abstract: Modelling techniques for a fluid coupling taken from
published literature have been extended to include the effects of the
filling and emptying of the coupling with oil and the variation in
losses when the coupling is partially full. In the model, the fluid flow
inside the coupling is considered to have two principal velocity
components; one circumferentially about the coupling axis
(centrifugal head) and the other representing the secondary vortex
within the coupling itself (vortex head). The calculation of liquid
mass flow rate circulating between the two halves of the coupling is
based on: the assumption of a linear velocity variation in the
circulating vortex flow; the head differential in the fluid due to the
speed difference between the two shafts; and the losses in the
circulating vortex flow as a result of the impingement of the flow
with the blades in the coupling and friction within the passages
between the blades.
Abstract: This paper begins with formal defining of human rights and freedoms, and the basic document regarding the said subject is undoubtedly French Declaration of the Rights of Man and of the Citizen from 789. This paper furthermore parses legal sources relevant for the workers' rights in legal system of the Republic of Croatia, international contracts and the Labour Act, which is also a master bill regarding workers' rights The authors are also dealing with issues of Constitutional Court of the Republic of Croatia and its' position in judicial system of the Republic of Croatia, as well as with the specifics of Constitutional Complaint, and the crucial part of the paper is based on the research conducted with an aim to determine implementation of rights and liberties guaranteed by the articles 54. and 55. of the Constitution of the Republic of Croatia by means of Constitutional Complaint.
Abstract: The objectives of this research were 1) to study the
opinions of newspaper journalists about their trustworthiness in the
National Press Council of Thailand (NPCT) and the NPCT-s success
in regulating the professional ethics; and 2) to study the differences
among mean vectors of the variables of trustworthiness in the NPCT
and opinions on the NPCT-s success in regulating professional ethics
among samples working at different work positions and from
different affiliation of newspaper organizations. The results showed
that 1) Interaction effects between the variables of work positions and
affiliation were not statistically significant at the confidence level of
0.05. 2) There was a statistically significant difference (p
Abstract: This paper proposes the numerical simulation of the
investment casting of gold jewelry. It aims to study the behavior of
fluid flow during mould filling and solidification and to optimize the
process parameters, which lead to predict and control casting defects
such as gas porosity and shrinkage porosity. A finite difference
method, computer simulation software FLOW-3D was used to
simulate the jewelry casting process. The simplified model was
designed for both numerical simulation and real casting production.
A set of sensor acquisitions were allocated on the different positions
of the wax tree of the model to detect filling times, while a set of
thermocouples were allocated to detect the temperature during
casting and cooling. Those detected data were applied to validate the
results of the numerical simulation to the results of the real casting.
The resulting comparisons signify that the numerical simulation can
be used as an effective tool in investment-casting-process
optimization and casting-defect prediction.
Abstract: This paper introduced the status quo of laws and
regulations of sustainable construction in China and investigated the
existing problems of current laws and regulations through
person-interviews in Beijing, Shanghai, Chongqing and Shenzhen in
China. The problems include incomplete legal system, lack of
guidance of higher-level laws, backward in some laws and regulations,
unclear legal liability and poor law enforcement. Aimed at these
problems, this paper also put forward some improvement approaches,
such as filling the legal gap, revising laws and regulations, establishing
incentive system and keeping pace with level of development.