Abstract: Supersonic hydrogen-air cylindrical mixing layer is
numerically analyzed to investigate the effect of inlet swirl on
ignition time delay in scramjets. Combustion is treated using detail
chemical kinetics. One-equation turbulence model of Spalart and
Allmaras is chosen to study the problem and advection upstream
splitting method is used as computational scheme. The results show
that swirling both fuel and oxidizer streams may drastically decrease
the ignition distance in supersonic combustion, unlike using the swirl
just in fuel stream which has no helpful effect.
Abstract: In order to evaluation the effects of soil organic
matter and biofertilizer on chickpea quality and biological
nitrogen fixation, field experiments were carried out in 2007
and 2008 growing seasons. In this research the effects of
different strategies for soil fertilization were investigated on
grain yield and yield component, minerals, organic compounds
and cooking time of chickpea. Experimental units were
arranged in split-split plots based on randomized complete
blocks with three replications. Main plots consisted of (G1):
establishing a mixed vegetation of Vicia panunica and
Hordeum vulgare and (G2): control, as green manure levels.
Also, five strategies for obtaining the base fertilizer
requirement including (N1): 20 t.ha-1 farmyard manure; (N2):
10 t.ha-1 compost; (N3): 75 kg.ha-1 triple super phosphate;
(N4): 10 t.ha-1 farmyard manure + 5 t.ha-1 compost and (N5):
10 t.ha-1 farmyard manure + 5 t.ha-1 compost + 50 kg.ha-1
triple super phosphate were considered in sub plots.
Furthermoree four levels of biofertilizers consisted of (B1):
Bacillus lentus + Pseudomonas putida; (B2): Trichoderma
harzianum; (B3): Bacillus lentus + Pseudomonas putida +
Trichoderma harzianum; and (B4): control (without
biofertilizers) were arranged in sub-sub plots. Results showed
that integrating biofertilizers (B3) and green manure (G1)
produced the highest grain yield. The highest amounts of yield
were obtained in G1×N5 interaction. Comparison of all 2-way
and 3-way interactions showed that G1N5B3 was determined
as the superior treatment. Significant increasing of N, P2O5,
K2O, Fe and Mg content in leaves and grains emphasized on
superiority of mentioned treatment because each one of these
nutrients has an approved role in chlorophyll synthesis and
photosynthesis abilities of the crops. The combined application
of compost, farmyard manure and chemical phosphorus (N5)
in addition to having the highest yield, had the best grain
quality due to high protein, starch and total sugar contents, low
crude fiber and reduced cooking time.
Abstract: Many difficulties are faced in the process of learning
computer programming. This paper will propose a system framework
intended to reduce cognitive load in learning programming. In first
section focus is given on the process of learning and the
shortcomings of the current approaches to learning programming.
Finally the proposed prototype is suggested along with the
justification of the prototype. In the proposed prototype the concept
map is used as visualization metaphor. Concept maps are similar to
the mental schema in long term memory and hence it can reduce
cognitive load well. In addition other method such as part code
method is also proposed in this framework to can reduce cognitive
load.
Abstract: The prologue of new High Voltage (HV) transmission
mains into the community necessitates earthing design to ensure
safety compliance of the system. Conductive structures such as steel
or concrete poles are widely used in HV transmission mains. The
earth potential rise (EPR) generated by a fault on these structures
could result to an unsafe condition. This paper discusses information
on the input impedance of the over head earth wire (OHEW) system
for finite and infinite transmission mains. The definition of finite and
infinite system is discussed, maximum EPR due to pole fault. The
simplified equations for EPR assessments are introduced and
discussed for the finite and infinite conditions. A case study is also
shown.
Abstract: As new challenges emerge in power electrical
workplace safety, it is the responsibility of the systems designer to
seek out new approaches and solutions that address them. Design
decisions made today will impact cost, safety and serviceability of
the installed systems for 40 or 50 years during the useful life for the
owner. Studies have shown that this cost is an order of magnitude of
7 to 10 times the installed cost of the power distribution equipment.
This paper reviews some aspects of earthing system design in power
substation surrounded by residential houses. The electrical potential
rise and split factors are discussed and a few recommendations are
provided to achieve a safety voltage in the area beyond the boundary
of the substation.
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: The recent development of humanoid robots has led robot designers to imagine a great variety of anthropomorphic forms for human-like machine. Which form is the best ? We try to answer this question from a double meaning of the anthropomorphism : a positive anthropomorphism corresponing to the realization of an effective anthropomorphic form object and a negative one corresponding to our natural tendency in certain circumstances to give human attributes to non-human beings. We postulate that any humanoid robot is concerned by both these two anthropomorphism kinds. We propose to use gestalt theory and Heider-s balance theory in order to analyze how negative anthropomorphism can influence our perception of human-like robots. From our theoretical approach we conclude that an “even shape" as defined by gestalt theory is not a sufficient condition for a good integration of future humanoid robots into a human community. Aesthetic perception of the robot cannot be splitted from a social perception : a humanoid robot, any how the efforts made for improving its appearance, could be rejected if it is devoted to a task with too high affective implications.
Abstract: In the present work flow past circular cylinder and
cylinder with rectangular and triangular wake splitter is studied to
improve aerodynamic parameters. The Comparison of drag
coefficient is tabulated for bare cylinder, cylinder with rectangular
and triangular wake splitters. Flow past circular cylinder and cylinder
with triangular and rectangular wake splitter is performed at
Reynoldsnumber 5, 20, 40, 50,80, 100.An incompressible PISO finite
volume code employing a non-staggered grid arrangement is used, a
second order upwind scheme is used for convective terms. The time
discretization is implicit and a Second order Crank-Nicholson scheme
is employed. Length of wake splitter in both configurations is taken
to be equal to diameter of cylinder. Wake length is found to be less
with rectangular wake splitter when compared to bare cylinder and
cylinder with triangular wake splitter. Coefficient of drag is found to
be less for triangular wake splitter when compared to bare cylinder &
cylinder with rectangular wake splitter.