Abstract: Whereas in the third generation nuclear reactors,
dimensions of core and also the kind of coolant and enrichment
percent of fuel have significantly changed than the second
generation, therefore in this article the aim is based on a
comparative investigation between two same power reactors of
second and third generations, that the neutronic parameters of both
reactors such as: K∞, Keff and its details and thermal hydraulic
parameters such as: power density, specific power, volumetric heat
rate, released power per fuel volume unit, volume and mass of clad
and fuel (consisting fissile and fertile fuels), be calculated and
compared together. By this comparing the efficiency and
modification of third generation nuclear reactors than second
generation which have same power can be distinguished.
In order to calculate the cited parameters, some information
such as: core dimensions, the pitch of lattice, the fuel matter, the
percent of enrichment and the kind of coolant are used. For
calculating the neutronic parameters, a neutronic program entitled:
SIXFAC and also related formulas have been used. Meantime for
calculating the thermal hydraulic and other parameters, analytical
method and related formulas have been applied.
Abstract: This paper reviews designs of the built environment
from a sustainability perspective, emphasizing their importance in
achieving ecological and sustainable economic objectives. The built
environment has traditionally resulted in loss of biodiversity,
extinction of some species, climate change, excessive water use, land
degradation, space depletion, waste accumulation, energy
consumption and environmental pollution. Materials used like
plastics, metals, bricks, concrete, cement, natural aggregates, glass
and plaster have wreaked havoc on the earth´s resources, since they
have high levels of embodied energy hence not sustainable.
Additional resources are consumed during use and disposal phases.
Proposed designs for sustainability solutions include: ecological
sanitation and eco-efficiency systems that ensure social, economic,
environmental and technical sustainability. Renewable materials and
energy systems, passive cooling and heating systems and material
and energy reduction, reuse and recycling can improve the sector.
These ideas are intended to inform the field of ecological design of
the built environment.
Abstract: As global industry developed rapidly, the energy
demand also rises simultaneously. In the production process, there’s a
lot of energy consumed in the process. Formally, the energy used in
generating the heat in the production process. In the total energy
consumption, 40% of the heat was used in process heat, mechanical
work, chemical energy and electricity. The remaining 50% were
released into the environment. It will cause energy waste and
environment pollution. There are many ways for recovering the waste
heat in factory. Organic Rankine Cycle (ORC) system can produce
electricity and reduce energy costs by recovering the waste of low
temperature heat in the factory. In addition, ORC is the technology
with the highest power generating efficiency in low-temperature heat
recycling. However, most of factories executives are still hesitated
because of the high implementation cost of the ORC system, even a lot
of heat are wasted. Therefore, this study constructs a nonlinear
mathematical model of waste heat recovery equipment configuration
to maximize profits. A particle swarm optimization algorithm is
developed to generate the optimal facility installation plan for the ORC
system.
Abstract: Radial flow reactor was focused for large scale
methanol synthesis and in which the heat transfer type was cross-flow.
The effects of operating conditions including the reactor inlet air
temperature, the heating pipe temperature and the air flow rate on the
cross-flow heat transfer was investigated and the results showed that
the temperature profile of the area in front of the heating pipe was
slightly affected by all the operating conditions. The main area whose
temperature profile was influenced was the area behind the heating
pipe. The heat transfer direction according to the air flow directions. In
order to provide the basis for radial flow reactor design calculation, the
dimensionless number group method was used for data fitting of the
bed effective thermal conductivity and the wall heat transfer
coefficient which was calculated by the mathematical model with the
product of Reynolds number and Prandtl number. The comparison of
experimental data and calculated value showed that the calculated
value fit the experimental data very well and the formulas could be
used for reactor designing calculation.
Abstract: The aim of current study was to investigate the
changes in the quality parameters of Holstein bull semen during the
heat stress and the effect of feeding a source of omega-3 fatty acids
in this period. Samples were obtained from 19 Holstein bulls during
the expected time of heat stress in Iran (June to September 2009).
Control group (n=10) were fed a standard concentrate feed while
treatment group (n=9) had this feed top dressed with 100 g of an
omega-3 enriched nutriceutical. Semen quality was assessed on
ejaculates collected after 1, 5, 9 and 12 weeks of supplementation.
Computer-assisted assessment of sperm motility, viability (eosinnigrosin)
and hypo-osmotic swelling test (HOST) were conducted.
Heat stress affected sperm quality parameters by week 5 and 9
(p
Abstract: This paper proposes the concept of aerocapture with
aerodynamic-environment-adaptive variable geometry flexible
aeroshell that vehicle deploys. The flexible membrane is composed
of thin-layer film or textile as its aeroshell in order to solve some
problems obstructing realization of aerocapture technique.
Multi-objective optimization study is conducted to investigate
solutions and derive design guidelines. As a result, solutions which
can avoid aerodynamic heating and enlarge the corridor width up
to 10% are obtained successfully, so that the effectiveness of this
concept can be demonstrated. The deformation-use optimum
solution changes its drag coefficient from 1.6 to 1.1, along with the
change in dynamic pressure. Moreover, optimization results show
that deformation-use solution requires the membrane for which
upper temperature limit and strain limit are more than 700 K and
120%, respectively, and elasticity (Young-s modulus) is of order of
106 Pa.
Abstract: Bangladesh is a developing country with large
population. Demand of electrical energy is increasing day by day
because of increasing population and industrialization. But due to
limited resources, people here are suffering from power crisis
problem which is considered as a major obstacle to the economic
development. In most of the cases, it is extremely difficult to extend
high tension transmission lines to some of the places that are
separated from the mainland. Renewable energy is considered to be
the right choice for providing clean energy to these remote
settlements. This paper proposes a cost effective design of off-grid
wind-diesel hybrid power system using combined heat and power
(CHP) technology in a grid isolated island, Sandwip, Bangladesh.
Design and simulation of the wind-diesel hybrid power system is
performed considering different factors for the island Sandwip.
Detailed economic analysis and comparison with solar PV system
clearly reveals that wind-diesel hybrid power system can be a cost
effective solution for the isolated island like Sandwip.
Abstract: In this paper, a one-dimensional numerical approach is
used to study the effect of applying electrohydrodynamics on the
temperature and species mass fraction profiles along the microcombustor.
Premixed mixture is H2-Air with a multi-step chemistry
(9 species and 19 reactions). In the micro-scale combustion because
of the increasing ratio of area-to-volume, thermal and radical
quenching mechanisms are important. Also, there is a significant heat
loss from the combustor walls. By inserting a number of electrodes
into micro-combustor and applying high voltage to them corona
discharge occurs. This leads in moving of induced ions toward
natural molecules and colliding with them. So this phenomenon
causes the movement of the molecules and reattaches the flow to the
walls. It increases the velocity near the walls that reduces the wall
boundary layer. Consequently, applying electrohydrodynamics
mechanism can enhance the temperature profile in the microcombustor.
Ultimately, it prevents the flame quenching in microcombustor.
Abstract: The present paper considers the steady free convection
boundary layer flow of a viscoelastic fluid on solid sphere with
Newtonian heating. The boundary layer equations are an order higher
than those for the Newtonian (viscous) fluid and the adherence
boundary conditions are insufficient to determine the solution of
these equations completely. Thus, the augmentation an extra
boundary condition is needed to perform the numerical
computational. The governing boundary layer equations are first
transformed into non-dimensional form by using special
dimensionless group and then solved by using an implicit finite
difference scheme. The results are displayed graphically to illustrate
the influence of viscoelastic K and Prandtl Number Pr parameters on
skin friction, heat transfer, velocity profiles and temperature profiles.
Present results are compared with the published papers and are found
to concur very well.
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: At the present, auto part industries have become higher challenge in strategy market. As this consequence, manufacturers need to have better response to customers in terms of quality, cost, and delivery time. Moreover, they need to have a good management in factory to comply with international standard maximum capacity and lower cost. This would lead companies to have to order standard part from aboard and become the major cost of inventory. The development of auto part research by recycling materials experiment is to compare the auto parts from recycle materials to international auto parts (CKD). Factors studied in this research were the recycle material ratios of PU-foam, felt, and fabric. Results of recycling materials were considered in terms of qualities and properties on the parameters such as weight, sound absorption, water absorption, tensile strength, elongation, and heat resistance with the CKD. The results were showed that recycling materials would be used to replace for the CKD.
Abstract: We present the development of a new underwater laser
cutting process in which a water-jet has been used along with the
laser beam to remove the molten material through kerf. The
conventional underwater laser cutting usually utilizes a high pressure
gas jet along with laser beam to create a dry condition in the cutting
zone and also to eject out the molten material. This causes a lot of gas
bubbles and turbulence in water, and produces aerosols and waste
gas. This may cause contamination in the surrounding atmosphere
while cutting radioactive components like burnt nuclear fuel. The
water-jet assisted underwater laser cutting process produces much
less turbulence and aerosols in the atmosphere. Some amount of
water vapor bubbles is formed at the laser-metal-water interface;
however, they tend to condense as they rise up through the
surrounding water. We present the design and development of a
water-jet assisted underwater laser cutting head and the parametric
study of the cutting of AISI 304 stainless steel sheets with a 2 kW
CW fiber laser. The cutting performance is similar to that of the gas
assist laser cutting; however, the process efficiency is reduced due to
heat convection by water-jet and laser beam scattering by vapor. This
process may be attractive for underwater cutting of nuclear reactor
components.
Abstract: This paper discusses the landscape design that could
increase energy efficiency in a house. By planting trees in a house
compound, the tree shades prevent direct sunlight from heating up
the building, and it enables cooling off the surrounding air. The
requirement for air-conditioning could be minimized and the air
quality could be improved. During the life time of a tree, the saving
cost from the mentioned benefits could be up to US $ 200 for each
tree. The project intends to visually describe the landscape design in
a house compound that could enhance energy efficiency and
consequently lead to energy saving. The house compound model was
developed in three dimensions by using AutoCAD 2005, the
animation was programmed by using LightWave 3D softwares i.e.
Modeler and Layout to display the tree shadings in the wall. The
visualization was executed on a VRML Pad platform and
implemented on a web environment.
Abstract: Auckland has a temperate climate with comfortable warm, dry summers and mild, wet winters. Auckland house design not only focus on winter thermal performance and indoor thermal condition, but also indoor moisture control, which is closely related to indirect health effects such as dust mites, fungi, etc. Most Auckland houses are designed to use temporary heating for winter indoor thermal comfort. Based on field study data of indoor microclimate conditions of two Auckland townhouses with a whole home mechanical ventilation system or a passive wind directional skylight vent, this study is to evaluate and compare indoor moisture conditions of two insulated townhouses only using temporary heating with different ventilation systems.
Abstract: This research aims to analyze the regenerative burner and the recuperative burner for the different reheating furnaces in the steel industry. The warm air temperatures of the burners are determined to suit with the sizes of the reheating furnaces by considering the air temperature, the fuel cost and the investment cost. The calculations of the payback period and the net present value are studied to compare the burners for the different reheating furnaces. The energy balance is utilized to calculate and compare the energy used in the different sizes of reheating furnaces for each burner. It is found that the warm air temperature is different if the sizes of reheating furnaces are varied. Based on the considerations of the net present value and the payback period, the regenerative burner is suitable for all plants at the same life of the burner. Finally, the sensitivity analysis of all factors has been discussed in this research.
Abstract: Xanthan gum is a microbial polysaccharide of great
commercial significance. The purpose of this study was to select the
optimum fermentation time for xanthan gum production by
Xanthomonas campestris (NRRL-B-1459) using 10% sugar beet
molasses as a carbon source. The pre-heating of sugar beet molasses
and the supplementation of the medium were investigated in order to
improve xanthan gum production. Maximum xanthan gum
production in fermentation media (9.02 g/l) was observed after 4 days
shaking incubation at 25°C and 240 rpm agitation speed. A solution
of 10% sucrose was used as a control medium. Results indicated that
the optimum period for xanthan gum production in this condition was
4 days.
Abstract: The aim of this research is to use artificial neural networks computing technology for estimating the net heating value (NHV) of crude oil by its Properties. The approach is based on training the neural network simulator uses back-propagation as the learning algorithm for a predefined range of analytically generated well test response. The network with 8 neurons in one hidden layer was selected and prediction of this network has been good agreement with experimental data.
Abstract: The precision of heat flux simulation influences the
temperature field and test aberration for TB test and also reflects the
test level for spacecraft development. This paper describes TB tests for
a small satellite using solar simulator, electric heaters, calrod heaters
to evaluate the difference of the three methods. Under the same
boundary condition, calrod heaters cases were about 6oC higher than
solar simulator cases and electric heaters cases for
non-external-heat-flux cases (extreme low temperature cases). While
calrod heaters cases and electric heaters cases were 5~7oC and 2~3oC
lower than solar simulator cases respectively for high temperature
cases. The results show that the solar simulator is better than calrod
heaters for its better collimation, non-homogeneity and stability.
Abstract: Many computational techniques were applied to
solution of heat conduction problem. Those techniques were the
finite difference (FD), finite element (FE) and recently meshless
methods. FE is commonly used in solution of equation of heat
conduction problem based on the summation of stiffness matrix of
elements and the solution of the final system of equations. Because
of summation process of finite element, convergence rate was
decreased. Hence in the present paper Cellular Automata (CA)
approach is presented for the solution of heat conduction problem.
Each cell considered as a fixed point in a regular grid lead to the
solution of a system of equations is substituted by discrete systems of
equations with small dimensions. Results show that CA can be used
for solution of heat conduction problem.