Abstract: Cryosorption pumps are considered safe, quiet, and
ultra-high vacuum production pumps which have their application
from Semiconductor industries to ITER [International Thermonuclear
Experimental Reactor] units. The principle of physisorption of gases
over highly porous materials like activated charcoal at cryogenic
temperatures (below -1500°C) is involved in determining the
pumping speed of gases like Helium, Hydrogen, Argon, and
Nitrogen. This paper aims at providing detailed overview of
development of Cryosorption pump and characterization of different
activated charcoal materials that optimizes the performance of the
pump. Different grades of charcoal were tested in order to determine
the pumping speed of the pump and were compared with
commercially available Varian cryopanel. The results for bare panel,
bare panel with adhesive, cryopanel with pellets, and cryopanel with
granules were obtained and compared. The comparison showed that
cryopanel adhered with small granules gave better pumping speeds
than large sized pellets.
Abstract: The research explores the relationship between
management responsibility and corporate governance of listed
companies in Kazakhstan. This research employs firm level data of
selected listed non-financial firms and firm level data “operational”
financial sector, consisted from banking sector, insurance companies
and accumulated pension funds using multivariate regression analysis
under fixed effect model approach. Ownership structure includes
institutional ownership, managerial ownership and private investor’s
ownership. Management responsibility of the firm is expressed by the
decision of the firm on amount of leverage. Results of the cross
sectional panel study for non-financial firms showed that only
institutional shareholding is significantly negatively correlated with
debt to equity ratio. Findings from “operational” financial sector
show that leverage is significantly affected only by the CEO/Chair
duality and the size of financial institutions, and insignificantly
affected by ownership structure. Also, the findings show, that there is
a significant negative relationship between profitability and the debt
to equity ratio for non-financial firms, which is consistent with
pecking order theory. Generally, the found results suggest that
corporate governance and a management responsibility play
important role in corporate performance of listed firms in
Kazakhstan.
Abstract: The photovoltaic (PV) panel with no galvanic
isolation system is well known technique in the world which is
effective and delivers power with enhanced efficiency. The PV
generation presented here is for stand-alone system installed in
remote areas when as the resulting power gets connected to electronic
load installation instead of being tied to the grid. Though very small,
even then transformer-less topology is shown to be with leakage in
pico-ampere range. By using PWM technique PWM, leakage current
in different situations is shown. The results shown in this paper show
how the pico-ampere current is reduced to femto-ampere through use
of inductors and capacitors of suitable values of inductor and
capacitors with the load.
Abstract: This paper aims to determine Fundamental Natural
Frequency (FNF) of a structural composite floor system known as
Chromite. To achieve this purpose, FNFs of studied panels are
determined by development of Finite Element Models (FEMs) in
ABAQUS program. American Institute of Steel Construction (AISC)
code in Steel Design Guide Series 11 presents a fundamental formula
to calculate FNF of a steel framed floor system. This formula has
been used to verify results of the FEMs. The variability in the FNF of
the studied system under various parameters such as dimensions of
floor, boundary conditions, rigidity of main and secondary beams
around the floor, thickness of concrete slab, height of composite
joists, distance between composite joists, thickness of top and bottom
flanges of the open web steel joists, and adding tie beam
perpendicular on the composite joists, is determined. The results
show that changing in dimensions of the system, its boundary
conditions, rigidity of main beam, and also adding tie beam,
significant changes the FNF of the system up to 452.9%, 50.8%, -
52.2%, %52.6%, respectively. In addition, increasing thickness of
concrete slab increases the FNF of the system up to 10.8%.
Furthermore, the results demonstrate that variation in rigidity of
secondary beam, height of composite joist, and distance between
composite joists, and thickness of top and bottom flanges of open
web steel joists insignificant changes the FNF of the studied system
up to -0.02%, -3%, -6.1%, and 0.96%, respectively. Finally, the
results of this study help designer predict occurrence of resonance,
comfortableness, and design criteria of the studied system.
Abstract: This paper presents a grid synchronization technique based on adaptive notch filter for SPV (Solar Photovoltaic) system along with MPPT (Maximum Power Point Tracking) techniques. An efficient grid synchronization technique offers proficient detection of various components of grid signal like phase and frequency. It also acts as a barrier for harmonics and other disturbances in grid signal. A reference phase signal synchronized with the grid voltage is provided by the grid synchronization technique to standardize the system with grid codes and power quality standards. Hence, grid synchronization unit plays important role for grid connected SPV systems. As the output of the PV array is fluctuating in nature with the meteorological parameters like irradiance, temperature, wind etc. In order to maintain a constant DC voltage at VSC (Voltage Source Converter) input, MPPT control is required to track the maximum power point from PV array. In this work, a variable step size P & O (Perturb and Observe) MPPT technique with DC/DC boost converter has been used at first stage of the system. This algorithm divides the dPpv/dVpv curve of PV panel into three separate zones i.e. zone 0, zone 1 and zone 2. A fine value of tracking step size is used in zone 0 while zone 1 and zone 2 requires a large value of step size in order to obtain a high tracking speed. Further, adaptive notch filter based control technique is proposed for VSC in PV generation system. Adaptive notch filter (ANF) approach is used to synchronize the interfaced PV system with grid to maintain the amplitude, phase and frequency parameters as well as power quality improvement. This technique offers the compensation of harmonics current and reactive power with both linear and nonlinear loads. To maintain constant DC link voltage a PI controller is also implemented and presented in this paper. The complete system has been designed, developed and simulated using SimPower System and Simulink toolbox of MATLAB. The performance analysis of three phase grid connected solar photovoltaic system has been carried out on the basis of various parameters like PV output power, PV voltage, PV current, DC link voltage, PCC (Point of Common Coupling) voltage, grid voltage, grid current, voltage source converter current, power supplied by the voltage source converter etc. The results obtained from the proposed system are found satisfactory.
Abstract: Due to the interference effects, the intrinsic
aerodynamic parameters obtained from the individual component
testing are always fundamentally different than those obtained for
complete model testing. Consideration and limitation for such testing
need to be taken into account in any design work related to the
component buildup method. In this paper, the scaled model of a
straight rectangular canard of a hybrid buoyant aircraft is tested at 50
m/s in IIUM-LSWT (Low Speed Wind Tunnel). Model and its
attachment with the balance are kept rigid to have results free from
the aeroelastic distortion. Based on the velocity profile of the test
section’s floor; the height of the model is kept equal to the
corresponding boundary layer displacement. Balance measurements
provide valuable but limited information of overall aerodynamic
behavior of the model. Zero lift coefficient is obtained at -2.2o and
the corresponding drag coefficient was found to be less than that at
zero angle of attack. As a part of the validation of low fidelity tool,
plot of lift coefficient plot was verified by the experimental data and
except the value of zero lift coefficients, the overall trend has under
predicted the lift coefficient. Based on this comparative study, a
correction factor of 1.36 is proposed for lift curve slope obtained
from the panel method.
Abstract: Main purpose of this study is to identify the impact of
government expenditure on economic growth in Asian Countries.
Consequently, main objective is to analyze whether government
expenditure causes economic growth in Asian countries vice versa
and then scrutinizing long-run equilibrium relationship exists
between them. The study completely based on secondary data. The
methodology being quantitative that includes econometrical
techniques of cointegration, panel fixed effects model and granger
causality in the context of panel data of Asian countries; Singapore,
Malaysia, Thailand, South Korea, Japan, China, Sri Lanka, India and
Bhutan with 44 observations in each country, totaling to 396
observations from 1970 to 2013. The model used is the random
effects panel OLS model. As with the above methodology, the study
found the fascinating outcome. At first, empirical findings exhibit a
momentous positive impact of government expenditure on Gross
Domestic Production in Asian region. Secondly, government
expenditure and economic growth indicate a long-run relationship in
Asian countries. In conclusion, there is a unidirectional causality
from economic growth to government expenditure and government
expenditure to economic growth in Asian countries. Hence the study
is validated that it is in line with the Keynesian theory and Wagner’s
law as well. Consequently, it can be concluded that role of
government would play a vital role in economic growth of Asian
Countries. However; if government expenditure did not figure out
with the economy’s needs it might be considerably inspiration the
economy in a negative way so that society bears the costs.
Abstract: In this paper, monitoring and control of tap changer
mechanism of a transformer implementation in an Intelligent
Electronic Device (IED) is discussed. It has been a custom for
decades to provide a separate panel for on load tap changer control
for monitoring the tap position. However, this facility cannot either
record or transfer the information to remote control centers. As there
is a technology shift towards the smart grid protection and control
standards, the need for implementing remote control and monitoring
has necessitated the implementation of this feature in numerical
relays. This paper deals with the programming, settings and logic
implementation which is applicable to both IEC 61850 compatible
and non-compatible IEDs thereby eliminating the need for separate
tap changer control equipment. The monitoring mechanism has been
implemented in a 28MVA, 110 /6.9kV transformer with 16 tap
position with GE make T60 IED at Ultratech cement limited
Gulbarga, Karnataka and is in successful service.
Abstract: Consumers are demanding novel beverages that are
healthier, convenient and have appealing consumer acceptance. The
objectives of this study were to investigate the effects of adding grape
polyphenols and the influence of presenting health claims on the
sensory acceptability of wines. Fresh red sorrel calyces were
fermented into wines. The total soluble solids of the pectinase-treated
sorrel puree were from 4°Brix to 23.8°Brix. Polyphenol in the form
of grape pomace extract was added to sorrel wines (w/v) in specified
levels to give 0. 25. 50 and 75 ppm. A focus group comprising of 12
panelists was use to select the level of polyphenol to be added to
sorrel wines for sensory preference The sensory attributed of the
wines which were evaluated were colour, clarity, aroma, flavor,
mouth-feel, sweetness, astringency and overall preference. The sorrel
wine which was most preferred from focus group evaluation was
presented for hedonic rating. In the first stage of hedonic testing, the
sorrel wine was served chilled at 7°C for 24 h prior to sensory
evaluation. Each panelist was provided with a questionnaire and was
asked to rate the wines on colour, aroma, flavor, mouth-feel,
sweetness, astringency and overall acceptability using a 9-point
hedonic scale. In the second stage of hedonic testing, the panelist
were instructed to read a health abstract on the health benefits of
polyphenolic compounds and again to rate sorrel wine with added 25
ppm polyphenol. Paired t-test was used for the analysis of the
influence of presenting health information on polyphenols on hedonic
scoring of sorrel wines. Focus groups found that the addition of
polyphenol addition had no significant effect on sensory color and
aroma but affected clarity and flavor. A 25 ppm wine was liked
moderately in overall acceptability. The presentation of information
on the health benefit of polyphenols in sorrel wines to panelists had
no significant influence on the sensory acceptance of wine. More
than half of panelists would drink this wine now and then. This wine
had color L 19.86±0.68, chroma 2.10±0.12, hue° 16.90 ±3.10 and
alcohol content of 13.0%. The sorrel wine was liked moderately in
overall acceptability with the added polyphenols.
Abstract: High frequency automotive interior noise above 500
Hz considerably affects automotive passenger comfort. To reduce this
noise, sound insulation material is often laminated on body panels or
interior trim panels. For a more effective noise reduction, the sound
reduction properties of this laminated structure need to be estimated.
We have developed a new calculate tool that can roughly calculate the
sound absorption and insulation properties of laminate structure and
handy for designers. In this report, the outline of this tool and an
analysis example applied to floor mat are introduced.
Abstract: The possibility of application the dietary fibers in
production of crackers was observed in this work, as well as their
influence on rheological and textural properties on the dough for
crackers and influence on sensory properties of obtained crackers.
Three different dietary fibers, oat, potato and pea fibers, replaced
10% of wheat flour. Long fermentation process and baking test
method were used for crackers production. The changes of dough for
crackers were observed by rheological methods of determination the
viscoelastic dough properties and by textural measurements. Sensory
quality of obtained crackers was described using quantity descriptive
method (QDA) by trained members of descriptive panel. Additional
analysis of crackers surface was performed by videometer. Based on
rheological determination, viscoelastic properties of dough for
crackers were reduced by application of dietary fibers. Manipulation
of dough with 10% of potato fiber was disabled, thus the recipe
modification included increase in water content at 35%. Dough
compliance to constant stress for samples with dietary fibers
decreased, due to more rigid and stiffer dough consistency compared
to control sample. Also, hardness of dough for these samples
increased and dough extensibility decreased. Sensory properties of
final products, crackers, were reduced compared to control sample.
Application of dietary fibers affected mostly hardness, structure and
crispness of the crackers. Observed crackers were low marked for
flavor and taste, due to influence of fibers specific aroma. The sample
with 10% of potato fibers and increased water content was the most
adaptable to applied stresses and to production process. Also this
sample was close to control sample without dietary fibers by
evaluation of sensory properties and by results of videometer method.
Abstract: In addition to the advantages of light weight, resistant
corrosion and ease of processing, aluminum is also applied to the
long-span spatial structures. However, the elastic modulus of
aluminum is lower than that of the steel. This paper combines the
high performance aluminum honeycomb panel with the aluminum
latticed shell, forming a new panel-and-rod composite shell structure.
Through comparative analysis between the static and dynamic
performance, the conclusion that the structure of composite shell is
noticeably superior to the structure combined before.
Abstract: This paper examines the relationship between
corporate governance rating and stock prices of 26 Turkish firms
listed in Turkish stock exchange (Borsa Istanbul) by using panel data
analysis over five-year period. The paper also investigates the stock
performance of firms with governance rating with regards to the
market portfolio (i.e. BIST 100 Index) both prior and after
governance scoring began. The empirical results show that there is no
relation between corporate governance rating and stock prices when
using panel data for annual variation in both rating score and stock
prices. Further analysis indicates surprising results that while the
selected firms outperform the market significantly prior to rating, the
same performance does not continue afterwards.
Abstract: In recent years, honeycomb fiber reinforced plastic
(FRP) sandwich panels have been increasingly used in various
industries. Low weight, low price and high mechanical strength are
the benefits of these structures. However, their mechanical properties
and behavior have not been fully explored. The objective of this
study is to conduct a combined numerical-statistical investigation of
honeycomb FRP sandwich beams subject to torsion load. In this
paper, the effect of geometric parameters of sandwich panel on
maximum shear strain in both face and core and angle of torsion in a
honeycomb FRP sandwich structures in torsion is investigated. The
effect of Parameters including core thickness, face skin thickness,
cell shape, cell size, and cell thickness on mechanical behavior of the
structure were numerically investigated. Main effects of factors were
considered in this paper and regression equations were derived.
Taguchi method was employed as experimental design and an
optimum parameter combination for the maximum structure stiffness
has been obtained. The results showed that cell size and face skin
thickness have the most significant impacts on torsion angle,
maximum shear strain in face and core.
Abstract: Complex lifting entry was selected for precise landing
performance during the Mars Science Laboratory entry. This study
aims to develop the three-dimensional numerical method for precise
computation and the surface panel method for rapid engineering
prediction. Detailed flow field analysis for Mars exploration mission
was performed by carrying on a series of fully three-dimensional
Navier-Stokes computations. The static aerodynamic performance was
then discussed, including the surface pressure, lift and drag coefficient,
lift-to-drag ratio with the numerical and engineering method.
Computation results shown that the shock layer is thin because of
lower effective specific heat ratio, and that calculated results from both
methods agree well with each other, and is consistent with the
reference data. Aerodynamic performance analysis shows that CG
location determines trim characteristics and pitch stability, and certain
radially and axially shift of the CG location can alter the capsule lifting
entry performance, which is of vital significance for the aerodynamic
configuration design and inner instrument layout of the Mars entry
capsule.
Abstract: Toddy sediment (TS) was cultured in a PDA medium
to determine initial yeast load, and also it was undergone sun, shade,
solar, dehumidified cold air (DCA) and hot air oven (at 400, 500 and
60oC) drying with a view to preserve viability of yeast. Thereafter,
this study was conducted according to two factor factorial design in
order to determine best preservation method. Therein the dried TS
from the best drying method was taken and divided into two portions.
One portion was mixed with 3: 7 ratio of TS: rice flour and the
mixture was divided in to two again. While one portion was kept
under in house condition the other was in a refrigerator. Same
procedure was followed to the rest portion of TS too but it was at the
same ratio of corn flour. All treatments were vacuum packed in triple
laminate pouches and the best preservation method was determined
in terms of leavening index (LI). The TS obtained from the best
preservation method was used to make foods (bread and hopper) and
organoleptic properties of it were evaluated against same of ordinary
foods using sensory panel with a five point hedonic scale.
Results revealed that yeast load or fresh TS was 58×106 CFU/g.
The best drying method in preserving viability of yeast was DCA
because LI of this treatment (96%) is higher than that of other three
treatments. Organoleptic properties of foods prepared from best
preservation method are as same as ordinary foods according to Duo
trio test.
Abstract: In this study, we proposed two techniques to track the
maximum power point (MPPT) of a photovoltaic system. The first is
an intelligent control technique, and the second is robust used for
variable structure system. In fact the characteristics I-V and P–V of
the photovoltaic generator depends on the solar irradiance and
temperature. These climate changes cause the fluctuation of
maximum power point; a maximum power point tracking technique
(MPPT) is required to maximize the output power. For this we have
adopted a control by fuzzy logic (FLC) famous for its stability and
robustness. And a Siding Mode Control (SMC) widely used for
variable structure system. The system comprises a photovoltaic panel
(PV), a DC-DC converter, which is considered as an adaptation stage
between the PV and the load. The modelling and simulation of the
system is developed using MATLAB/Simulink. SMC technique
provides a good tracking speed in fast changing irradiation and when
the irradiation changes slowly or it is constant the panel power of
FLC technique presents a much smoother signal with less
fluctuations.
Abstract: This paper adopts a two-stage data envelopment
analysis to explore the impacts of financial development and bank
operating scale on bank efficiencies. The sample comprises
unbalanced panel data of 32 Taiwanese listed domestic commercial
banks over the period 1998 to 2013. Empirical results show that pure
technical efficiency is positively related to financial development,
whereas the effect of financial development on scale efficiency is
insignificant. Enlargement of bank operating scale improves bank
efficiencies, but the efficiency gains are decreased gradually when the
scale increases. Increases in capital adequacy ratio and market power
of loans lead into a growth of bank efficiencies.
Abstract: The structures obtained with the use of sandwich
technologies combine low weight with high energy absorbing
capacity and load carrying capacity. Hence, there is a growing and
markedly interest in the use of sandwiches with aluminum foam core
because of very good properties such as flexural rigidity and energy
absorption capability. In the current investigation, the static threepoint
bending tests were carried out on the sandwiches with
aluminum foam core and glass fiber reinforced polymer (GFRP)
skins at different values of support span distances aiming the analyses
of their flexural performance. The influence of the core thickness and
the GFRP skin type was reported in terms of peak load and energy
absorption capacity. For this purpose, the skins with two different
types of fabrics which have same thickness value and the aluminum
foam core with two different thicknesses were bonded with a
commercial polyurethane based flexible adhesive in order to combine
the composite sandwich panels. The main results of the bending tests
are: force-displacement curves, peak force values, absorbed energy,
collapse mechanisms and the effect of the support span length and
core thickness. The results of the experimental study showed that the
sandwich with the skins made of S-Glass Woven fabrics and with the
thicker foam core presented higher mechanical values such as load
carrying and energy absorption capacities. The increment of the
support span distance generated the decrease of the mechanical
values for each type of panels, as expected, because of the inverse
proportion between the force and span length. The most common
failure types of the sandwiches are debonding of the lower skin and
the core shear. The obtained results have particular importance for
applications that require lightweight structures with a high capacity
of energy dissipation, such as the transport industry (automotive,
aerospace, shipbuilding and marine industry), where the problems of
collision and crash have increased in the last years.
Abstract: An experimental and analytical research on shear
buckling of a comparably large polymer composite I-section is
presented. It is known that shear buckling load of a large span
composite beam is difficult to determine experimentally. In order to
sensitively detect shear buckling of the tested I-section, twenty strain
rosettes and eight displacement sensors were applied and attached on
the web and flange surfaces. The tested specimen was a pultruded
composite beam made of vinylester resin, E-glass, carbon fibers and
micro-fillers. Various coupon tests were performed before the shear
buckling test to obtain fundamental material properties of the Isection.
An asymmetric four-point bending loading scheme was
utilized for the shear test. The loading scheme resulted in a high shear
and almost zero moment condition at the center of the web panel. The
shear buckling load was successfully determined after analyzing the
obtained test data from strain rosettes and displacement sensors. An
analytical approach was also performed to verify the experimental
results and to support the discussed experimental program.