Abstract: Evaporator is an important and widely used heat
exchanger in air conditioning and refrigeration industries. Different
methods have been used by investigators to increase the heat transfer
rates in evaporators. One of the passive techniques to enhance heat
transfer coefficient is the application of microfin tubes. The
mechanism of heat transfer augmentation in microfin tubes is
dependent on the flow regime of two-phase flow. Therefore many
investigations of the flow patterns for in-tube evaporation have been
reported in literatures. The gravitational force, surface tension and
the vapor-liquid interfacial shear stress are known as three dominant
factors controlling the vapor and liquid distribution inside the tube. A
review of the existing literature reveals that the previous
investigations were concerned with the two-phase flow pattern for
flow boiling in horizontal tubes [12], [9]. Therefore, the objective of
the present investigation is to obtain information about the two-phase
flow patterns for evaporation of R-134a inside horizontal smooth and
microfin tubes. Also Investigation of heat transfer during flow
boiling of R-134a inside horizontal microfin and smooth tube have
been carried out experimentally The heat transfer coefficients for
annular flow in the smooth tube is shown to agree well with Gungor
and Winterton-s correlation [4]. All the flow patterns occurred in the
test can be divided into three dominant regimes, i.e., stratified-wavy
flow, wavy-annular flow and annular flow. Experimental data are
plotted in two kinds of flow maps, i.e., Weber number for the vapor
versus weber number for the liquid flow map and mass flux versus
vapor quality flow map. The transition from wavy-annular flow to
annular or stratified-wavy flow is identified in the flow maps.
Abstract: Pipeline ADCs are becoming popular at high speeds
and with high resolution. This paper discusses the options of number
of bits/stage conversion techniques in pipelined ADCs and their
effect on Area, Speed, Power Dissipation and Linearity. The basic
building blocks like op-amp, Sample and Hold Circuit, sub converter,
DAC, Residue Amplifier used in every stage is assumed to be
identical. The sub converters use flash architectures. The design is
implemented using 0.18
Abstract: Semilinear elliptic equations are ubiquitous in natural sciences. They give rise to a variety of important phenomena in quantum mechanics, nonlinear optics, astrophysics, etc because they have rich multiple solutions. But the nontrivial solutions of semilinear equations are hard to be solved for the lack of stabilities, such as Lane-Emden equation, Henon equation and Chandrasekhar equation. In this paper, bifurcation method is applied to solving semilinear elliptic equations which are with homogeneous Dirichlet boundary conditions in 2D. Using this method, nontrivial numerical solutions will be computed and visualized in many different domains (such as square, disk, annulus, dumbbell, etc).
Abstract: Successive event of explosion earthquake and harmonic tremor recorded at Semeru volcano were analyzed to investigate the dynamical system regarding to their eruptive mechanism. The eruptive activity at Semeru volcano East Java, Indonesia is intermittent emission of ash and bombs with Strombolian style which occurred at interval of 15 to 45 minutes. The explosive eruptions accompanied by explosion earthquakes and followed by volcanic tremor which generated by continuous emission of volcanic ash. The spectral and Lyapunov exponent of successive event of explosion and harmonic tremor were analyzed. Peak frequencies of explosion earthquakes range 1.2 to 1.9 Hz and those of the harmonic tremor have peak frequency range 1.5 — 2.2 Hz. The phase space is reconstructed and evaluated based on the Lyapunov exponents. Harmonic tremors have smaller Lyapunov exponent than explosion earthquakes. It can be considerably as correlated complexity of the mechanism from the variance of spectral and fractal dimension and can be concluded that the successive event of harmonic tremor and explosions are chaotic.
Abstract: Currently, one of the main directions is developing of
development based on the clustering of economic operations of
Kazakhstan, providing for the organization and concentration of
production capacity in one region or the most optimal system. In the
modern economic literature clustering is regarded as one of the most
effective tools to ensure competitive businesses, and improve their
business itself.
Abstract: Equipment miniaturisation offers several opportunities such as an increased surface-to-volume ratio and higher heat transfer coefficients. However, moving towards small-diameter channels demands extra attention to fouling, reliability and stable operation of the system. The present investigation explores possibilities to enhance the stability of the once-through micro evaporator by reducing its flow boiling induced pressure fluctuations. Experimental comparison shows that the measured reduction factor approaches a theoretically derived value. Pressure fluctuations are reduced by a factor of ten in the solid conical channel and a factor of 15 in the porous conical channel. This presumably leads to less backflow and therefore to a better flow control.
Abstract: The occurrence of missing values in database is a serious problem for Data Mining tasks, responsible for degrading data quality and accuracy of analyses. In this context, the area has shown a lack of standardization for experiments to treat missing values, introducing difficulties to the evaluation process among different researches due to the absence in the use of common parameters. This paper proposes a testbed intended to facilitate the experiments implementation and provide unbiased parameters using available datasets and suited performance metrics in order to optimize the evaluation and comparison between the state of art missing values treatments.
Abstract: In practice, wireless networks has the property that
the signal strength attenuates with respect to the distance from the
base station, it could be better if the nodes at two hop away are
considered for better quality of service. In this paper, we propose a
procedure to identify delay preserving substructures for a given
wireless ad-hoc network using a new graph operation G 2 – E (G) =
G* (Edge difference of square graph of a given graph and the
original graph). This operation helps to analyze some induced
substructures, which preserve delay in communication among them.
This operation G* on a given graph will induce a graph, in which 1-
hop neighbors of any node are at 2-hop distance in the original
network. In this paper, we also identify some delay preserving
substructures in G*, which are (i) set of all nodes, which are mutually
at 2-hop distance in G that will form a clique in G*, (ii) set of nodes
which forms an odd cycle C2k+1 in G, will form an odd cycle in G*
and the set of nodes which form a even cycle C2k in G that will form
two disjoint companion cycles ( of same parity odd/even) of length k
in G*, (iii) every path of length 2k+1 or 2k in G will induce two
disjoint paths of length k in G*, and (iv) set of nodes in G*, which
induces a maximal connected sub graph with radius 1 (which
identifies a substructure with radius equal 2 and diameter at most 4 in
G). The above delay preserving sub structures will behave as good
clusters in the original network.
Abstract: Huge losses in apple production are caused by pathogens that cannot be seen shortly after harvest. After-harvest thermotherapy treatments can considerably improve control of storage diseases on apples and become an alternative to chemical pesticides. In the years 2010-2012 carried out research in this area. Apples of 'Topaz' cultivar were harvested at optimal maturity time for long storage and subject to water bath treatment at 45, 50, 52, 55°C for 60, 120, 180 and 240 seconds. The control was untreated fruits. After 12 and 24 weeks and during so called simulated trade turnover the fruits were checked for their condition and the originators of diseases were determined by using the standard phytopathological methods. The most common originator of 'Topaz' apple infection during storage were the fungi of genus Gloeosporium. In this paper it was proven that for effective protection of 'Topaz' apples against diseases, thermotherapy by using water treatments at temperature range of 50-52°C is quite sufficient.
Abstract: The soil ecology of the organic and mineral soil layers
of laurel-leaved and Cryptomeria japonica forest in the Kasuga-yama
Hill Primeval Forest (Nara, Japan) was assessed. The number of
bacteria obtained by the dilution plate count method was less than
0.05% of those counted by the direct microscopic count. We therefore
found that forest soil contains large numbers of non-culturable
bacteria compared with agricultural soils. The numbers of bacteria and
fungi obtained by both the dilution plate count and the direct
microscopic count were larger in the deeper horizons (F and H) of the
organic layer than in the mineral soil layer. This suggests that active
microbial metabolism takes place in the organic layer. The numbers of
bacteria and the length of fungal hyphae obtained by the direct count
method were greater in the H horizon than in the F horizon. The direct
microscopic count revealed numerous non-culturable bacteria and
fungi in the soil. The ratio of fungal to bacterial biomass was lower in
the laurel-leaved forest soil. The fungal biomass was therefore
relatively low in the laurel-leaved forest soil due to differences in
forest vegetation.
Abstract: Rise/span ratio has been mentioned as one of the
reasons which contribute to the lower buckling load as compared to
the Classical theory buckling load but this ratio has not been quantified
in the equation. The purpose of this study was to determine a more
realistic buckling load by quantifying the effect of the rise/span ratio
because experiments have shown that the Classical theory
overestimates the load. The buckling load equation was derived based
on the theorem of work done and strain energy. Thereafter, finite
element modeling and simulation using ABAQUS was done to
determine the variables that determine the constant in the derived
equation. The rise/span was found to be the determining factor of the
constant in the buckling load equation. The derived buckling load
correlates closely to the load obtained from experiments.
Abstract: This paper presents a novel algorithm for path planning of mobile robots in known 3D environments using Binary Integer Programming (BIP). In this approach the problem of path planning is formulated as a BIP with variables taken from 3D Delaunay Triangulation of the Free Configuration Space and solved to obtain an optimal channel made of connected tetrahedrons. The 3D channel is then partitioned into convex fragments which are used to build safe and short paths within from Start to Goal. The algorithm is simple, complete, does not suffer from local minima, and is applicable to different workspaces with convex and concave polyhedral obstacles. The noticeable feature of this algorithm is that it is simply extendable to n-D Configuration spaces.
Abstract: Since supply chains highly impact the financial
performance of companies, it is important to optimize and analyze
their Key Performance Indicators (KPI). The synergistic combination
of Particle Swarm Optimization (PSO) and Monte Carlo simulation is
applied to determine the optimal reorder point of warehouses in
supply chains. The goal of the optimization is the minimization of the
objective function calculated as the linear combination of holding and
order costs. The required values of service levels of the warehouses
represent non-linear constraints in the PSO. The results illustrate that
the developed stochastic simulator and optimization tool is flexible
enough to handle complex situations.
Abstract: This paper presents the modeling of a MEMS based accelerometer in order to detect the presence of a wheel flat in the railway vehicle. A haversine wheel flat is assigned to one wheel of a 5 DOF pitch plane vehicle model, which is coupled to a 3 layer track model. Based on the simulated acceleration response obtained from the vehicle-track model, an accelerometer is designed that meets all the requirements to detect the presence of a wheel flat. The proposed accelerometer can survive in a dynamic shocking environment with acceleration up to ±150g. The parameters of the accelerometer are calculated in order to achieve the required specifications using lumped element approximation and the results are used for initial design layout. A finite element analysis code (COMSOL) is used to perform simulations of the accelerometer under various operating conditions and to determine the optimum configuration. The simulated results are found within about 2% of the calculated values, which indicates the validity of lumped element approach. The stability of the accelerometer is also determined in the desired range of operation including the condition under shock.
Abstract: Many works have been carried out to compare the
efficiency of several goodness of fit procedures for identifying
whether or not a particular distribution could adequately explain a
data set. In this paper a study is conducted to investigate the power
of several goodness of fit tests such as Kolmogorov Smirnov (KS),
Anderson-Darling(AD), Cramer- von- Mises (CV) and a proposed
modification of Kolmogorov-Smirnov goodness of fit test which
incorporates a variance stabilizing transformation (FKS). The
performances of these selected tests are studied under simple
random sampling (SRS) and Ranked Set Sampling (RSS). This
study shows that, in general, the Anderson-Darling (AD) test
performs better than other GOF tests. However, there are some
cases where the proposed test can perform as equally good as the
AD test.
Abstract: Preliminary results for a new flat plate test
facility are presented here in the form of Computational Fluid Dynamics (CFD), flow visualisation, pressure measurements and thermal anemometry. The results from the CFD and flow
visualisation show the effectiveness of the plate design, with the trailing edge flap anchoring the stagnation point on the working surface and reducing the extent of the leading edge separation. The flow visualization technique demonstrates the
two-dimensionality of the flow in the location where the
thermal anemometry measurements are obtained.
Measurements of the boundary layer mean velocity profiles compare favourably with the Blasius solution, thereby allowing for comparison of future measurements with the
wealth of data available on zero pressure gradient Blasius
flows. Results for the skin friction, boundary layer thickness,
frictional velocity and wall shear stress are shown to agree well with the Blasius theory, with a maximum experimental deviation from theory of 5%. Two turbulence generating grids
have been designed and characterized and it is shown that the turbulence decay downstream of both grids agrees with established correlations. It is also demonstrated that there is
little dependence of turbulence on the freestream velocity.
Abstract: Integrated Total Quality Management (TQM) with
Lean Manufacturing (LM) is a system comprises of TQM with LM
principles and is associated with financial and nonfinancial
performance measurement indicators. The ultimate goal of this
system is to focus on achieving total customer satisfaction by
removing eight wastes available in any process in an organization.
A survey questionnaire was developed and distributed to 30 highly
active automotive vendors in Malaysia and analyzed by PASW
Statistics 18. It was found out that these vendors have been
practicing and measuring the effectiveness TQM and LM
implementation. More involvement of all Malaysian automotive
vendors will represent the exact status of current Malaysian
automotive industry in implementing TQM and LM and can
determine whether the industry is ready for integrated TQM and
LM system. This is the first study that combined 4 awards
practices, ISO/TS16949, Toyota Production System and
SAEJ4000.
Abstract: Extensive information is required within a R&D environment,
and a considerable amount of time and efforts are being
spent on finding the necessary information. An adaptive information
providing system would be beneficial to the environment, and a
conceptual model of the resources, people and context is mandatory
for developing such applications. In this paper, an information model
on various contexts and resources is proposed which provides the
possibility of effective applications for use in adaptive information
systems within a R&D project and meeting environment.
Abstract: In this paper, Novel method, Particle Swarm Optimization (PSO) algorithm, based technique is proposed to estimate and analyze the steady state performance of self-excited induction generator (SEIG). In this novel method the tedious job of deriving the complex coefficients of a polynomial equation and solving it, as in previous methods, is not required. By comparing the simulation results obtained by the proposed method with those obtained by the well known mathematical methods, a good agreement between these results is obtained. The comparison validates the effectiveness of the proposed technique.
Abstract: The manufacturing transmission line tower parts has
being generated hazardous waste which is required proper disposal
of waste for protection of land pollution. Manufacturing Process in
the manufacturing of steel angle, plates, pipes, channels are passes
through conventional, semi automatic and CNC machines for
cutting, marking, punching, drilling, notching, bending operations.
All fabricated material Coated with thin layer of Zinc in Galvanizing
plant where molten zinc is used for coating. Prior to Galvanizing,
chemical like 33% concentrated HCl Acid, ammonium chloride and
d-oil being used for pretreatment of iron. The bath of water with
sodium dichromate is used for cooling and protection of the
galvanized steel. For the heating purpose the furnace oil burners are
used. These above process the Zinc dross, Zinc ash, ETP sludge and
waste pickled acid generated as hazardous waste. The RPG has
made captive secured land fill site, since 1997 since then it was
using for disposal of hazardous waste after completion of SLF
(Secured land fill) site. The RPG has raised height from ground
level then now it is being used for disposal of waste as he designed
the SLF after in creasing height of from GL it is functional without
leach ate or adverse impacts in the environment.