Abstract: In this paper, an improved active snubber cell is proposed on account of soft switching (SS) family of pulse width modulation (PWM) DC-DC converters. The improved snubber cell provides zero-voltage transition (ZVT) turn on and zero-current transition (ZCT) turn off for main switch. The snubber cell decreases EMI noise and operates with SS in a wide range of line and load voltages. Besides, all of the semiconductor devices in the converter operate with SS. There is no additional voltage and current stress on the main devices. Additionally, extra voltage stress does not occur on the auxiliary switch and its current stress is acceptable value. The improved converter has a low cost and simple structure. The theoretical analysis of converter is clarified and the operating states are given in detail. The experimental results of converter are obtained by prototype of 500 W and 100 kHz. It is observed that the experimental results and theoretical analysis of converter are suitable with each other perfectly.
Abstract: 10 clinically healthy hemal nodes were collected from male bulls aged 2-3 years. Light microscopy revealed a capsule of connective tissue consisted mainly of collagen fiber surrounding hemal node, numerous erythrocytes were found in wide subcapsular sinus under the capsule. The parenchyma of the hemal node was divided into cortex and medulla. Diffused lymphocytes, and lymphoid follicles, having germinal centers were the main components of the cortex, while in the medulla there was wide medullary sinus, diffused lymphocytes and few lymphoid nodules. The area occupied with lymph nodules was larger than that occupied with non-nodular structure of lymphoid cords and blood sinusoids. Electron microscopy revealed the cellular components of hemal node including elements of circulating erythrocytes intermingled with lymphocytes, plasma cells, mast cells, reticular cells, macrophages, megakaryocytes and endothelial cells lining the blood sinuses. The lymphocytes were somewhat triangular in shape with cytoplasmic processes extending between adjacent erythrocytes. Nuclei were triangular to oval in shape, lightly stained with clear nuclear membrane indentation and clear nucleoli. The reticular cells were elongated in shape with cytoplasmic processes extending between adjacent lymphocytes, rough endoplasmic reticulum, ribosomes and few lysosomes were seen in their cytoplasm. Nucleus was elongated in shape with less condensed chromatin. Plasma cells were oval to irregular in shape with numerous dilated rough endoplasmic reticulum containing electron lucent material occupying the whole cytoplasm and few mitochondria were found. Nuclei were centrally located and oval in shape with heterochromatin emarginated and often clumped near the nuclear membrane. Occasionally megakaryocytes and mast cells were seen among lymphocytes. Megakaryocytes had multilobulated nucleus and free ribosomes often appearing as small aggregates in their cytoplasm, while mast cell had their characteristic electron dense granule in the cytoplasm, few electron lucent granules were found also, we conclude that, the main function of the hemal node of cattle is proliferation of lymphocytes. No role for plasma cell in erythrophagocytosis could be suggested.
Abstract: Copreneurship is a term used to describe the business
pattern of operations run by married couples who share commitment,
goals, and responsibilities in handling a business. Research conducted
overseas showed that copreneurship business activities grew quickly
and played a role in elevating families’ and nations’ socio-economic
standards. In Malaysia, copreneurship has long been cultivated by
spouses. Thus, this study aimed to explore the factors that motivate
married partners to start a copreneurship business, and who is the
dominant partner in the management of this business. The study
participants are four entrepreneurial couples who are SME business
operators selected through purposive sampling. In-depth interviews
and direct observation were used as methods of measurement for
triangulation of qualitative data in this study. The findings of the
interviews were administered using NVivo 8.0 software. The result
shows that freedom is a key factor that drives entrepreneurs to set up
copreneurship businesses, and that the husband dominates the
management aspects of the business. The study gives an overview of
the parties involved in entrepreneurship to provide understanding of
the copreneurship concept as it is practiced. This study provides
academic value by creating understanding of the importance of a
harmonious family institution specifically for forming entrepreneurs
in the familial environment in Malaysia.
Abstract: The effect of upstream surface roughness over a
smooth forward facing step in an open channel was investigated
using a particle image velocimetry technique. Three different
upstream surface topographies consisting of hydraulically smooth
wall, sandpaper 36 grit and sand grains were examined. Besides the
wall roughness conditions, all other upstream flow characteristics
were kept constant. It was also observed that upstream roughness
decreased the approach velocity by 2% and 10% but increased the
turbulence intensity by 14% and 35% at the wall-normal distance
corresponding to the top plane of the step compared to smooth
upstream. The results showed that roughness decreased the
reattachment lengths by 14% and 30% compared to smooth upstream.
Although the magnitudes of maximum positive and negative
Reynolds shear stress in separated and reattached region were 0.02Ue
for all the cases, the physical size of both the maximum and
minimum contour levels were decreased by increasing upstream
roughness.
Abstract: Cavities are frequently found beneath conduits on pile
foundations in old embankments. Cavity reduces seepage length
significantly and consequently causes piping failure of embankments.
Case studies of embankment failures indicate that the relative
settlement between ground and pile supported-concrete conduit was
the main reason of the cavity. In this paper, an attempt to simulate the
cavity-induced piping failure mechanism was made using finite
element numerical method. Piping potential is examined by carrying
out parametric study for influencing factors such as cavity length,
water level, and flow conditions. The concentration of hydraulic
gradient adjacent to cavity was found. It is found that the hydraulic
gradient close to the cavity exceeds considerably the critical hydraulic
gradient causing piping. Piping failure potential due to the existence of
cavity is evaluated and contour map for the potential risk of an
embankment for piping failure is proposed.
Abstract: Liquid storage tanks have become widespread during the recent decades due to their extensive usage. Analysis of liquid containing tanks is known to be complex due to hydrodynamic force exerted on tank which makes the analysis a complex one. The objective of this research is to carry out analysis of liquid domain along with structural interaction for various geometries of circular tanks considering seismic effects. An attempt has been made to determine hydrodynamic pressure distribution on the tank wall considering impulsive and convective components of liquid mass. To get a better picture, a comparative study of Draft IS 1893 Part 2, ACI 350.3 and Eurocode 8 for Circular Shaped Tank has been performed. Further, the differences in the magnitude of shear and moment at base as obtained from static (IS 3370 IV) and dynamic (Draft IS 1892 Part 2) analysis of ground supported circular tank highlight the need for us to mature from the old code to a newer code, which is more accurate and reliable.
Abstract: The effectiveness of microchannels in enhancing heat
transfer has been demonstrated in the semiconductor industry. In
order to tap the microscale heat transfer effects into macro
geometries, overcoming the cost and technological constraints,
microscale passages were created in macro geometries machined
using conventional fabrication methods. A cylindrical insert was
placed within a pipe, and geometrical profiles were created on the
outer surface of the insert to enhance heat transfer under steady-state
single-phase liquid flow conditions. However, while heat transfer
coefficient values of above 10 kW/m2·K were achieved, the heat
transfer enhancement was accompanied by undesirable pressure drop
increment. Therefore, this study aims to address the high pressure
drop issue using Constructal theory, a universal design law for both
animate and inanimate systems. Two designs based on Constructal theory were developed to study
the effectiveness of Constructal features in reducing the pressure drop
increment as compared to parallel channels, which are commonly
found in microchannel fabrication. The hydrodynamic and heat
transfer performance for the Tree insert and Constructal fin (Cfin)
insert were studied using experimental methods, and the underlying
mechanisms were substantiated by numerical results. In technical
terms, the objective is to achieve at least comparable increment in
both heat transfer coefficient and pressure drop, if not higher
increment in the former parameter. Results show that the Tree insert improved the heat transfer
performance by more than 16 percent at low flow rates, as compared
to the Tree-parallel insert. However, the heat transfer enhancement
reduced to less than 5 percent at high Reynolds numbers. On the
other hand, the pressure drop increment stayed almost constant at 20
percent. This suggests that the Tree insert has better heat transfer
performance in the low Reynolds number region. More importantly,
the Cfin insert displayed improved heat transfer performance along
with favourable hydrodynamic performance, as compared to Cfinparallel
insert, at all flow rates in this study. At 2 L/min, the
enhancement of heat transfer was more than 30 percent, with 20
percent pressure drop increment, as compared to Cfin-parallel insert.
Furthermore, comparable increment in both heat transfer coefficient
and pressure drop was observed at 8 L/min. In other words, the Cfin
insert successfully achieved the objective of this study. Analysis of the results suggests that bifurcation of flows is
effective in reducing the increment in pressure drop relative to heat
transfer enhancement. Optimising the geometries of the Constructal
fins is therefore the potential future study in achieving a bigger stride
in energy efficiency at much lower costs.
Abstract: The objective of this research is to mitigate and prevent
the alkali silica reactivity (ASR) in highway construction projects.
ASR is a deleterious reaction initiated when the silica content of the
aggregate reacts with alkali hydroxides in cement in the presence of
relatively high moisture content. The ASR results in the formation of
an expansive white colored gel-like material which forms the
destructive tensile stresses inside hardened concrete. In this research, different types of local aggregates available in the
State of Arkansas were mixed and mortar bars were poured according
to the ASTM specifications. Mortar bars expansion was measured
versus time and aggregates with potential ASR problems were
detected. Different types of supplementary cementitious materials
(SCMs) were used in remixing mortar bars with highly reactive
aggregates. Length changes for remixed bars proved that different
types of SCMs can be successfully used in reducing the expansive
effect of ASR. SCMs percentage by weight is highly dependent on
the SCM type. The result of this study will help avoiding future
losses due to ASR cracking in construction project and reduce the
maintenance, repair, and replacement budgets required for highways
network.
Abstract: Digital technologies offer many opportunities in the
design and implementation of brand communication and advertising.
Augmented reality (AR) is an innovative technology in marketing
communication that focuses on the fact that virtual interaction with a
product ad offers additional value to consumers. AR enables
consumers to obtain (almost) real product experiences by the way of
virtual information even before the purchase of a certain product.
Aim of AR applications in relation with advertising is in-depth
examination of product characteristics to enhance product knowledge
as well as brand knowledge. Interactive design of advertising
provides observers with an intense examination of a specific
advertising message and therefore leads to better brand knowledge.
The elaboration likelihood model and the central route to persuasion
strongly support this argumentation. Nevertheless, AR in brand
communication is still in an initial stage and therefore scientific
findings about the impact of AR on information processing and brand
attitude are rare. The aim of this paper is to empirically investigate
the potential of AR applications in combination with traditional print
advertising. To that effect an experimental design with different
levels of interactivity is built to measure the impact of interactivity of
an ad on different variables o advertising effectiveness.
Abstract: The aim of this article is to identify the measures
companies undertake in order to adapt to the environment as well as
discussing their diversity and effectiveness. The research methods
used in the study include an in-depth analysis of the literature and a
case study, which helps to illustrate the issue in question. Referring to
the concept of agility, which is firmly embedded in the theory of
strategic management and has been developed with the aim of
adapting to the environment and its changes, the paper first examines
different types of adaptation measures for companies. Then the issue
under discussion is illustrated with the example of the company
Hortimex. This company is an eminent representative of the world’s
leading manufacturers of food additives and ingredients. The
company was established in 1988 and is a family business, which in
practice means that it conducts business in a responsible manner,
observing the law and respecting the interests of society and the
environment. The company’s mission is to develop a market in
Poland for the products and solutions offered by their partners and to
share their knowledge of additives in food production and
consumption.
Abstract: In this paper, a desiccant solar unit for air
conditioning and desalination is presented first. Secondly, a dynamic
modelling study of the desiccant wheel is developed. After that, a
simulation study and an experimental investigation of the behaviour
of desiccant wheel are developed. The experimental investigation is
done in the chamber of commerce in Freiburg-Germany. Indeed, the
variations of calculated and measured temperatures and specific
humidity of dehumidified and rejected air are presented where a good
agreement is found when comparing the model predictions with
experimental data under the considered range of operating conditions.
Finally, the study of the compartments of desalination and water
condensation shows that the unit can produce an acceptable quantity
of water at the same time of the air conditioning operation.
Abstract: The Flexible AC Transmission System (FACTS)
technology is a new advanced solution that increases the reliability
and provides more flexibility, controllability, and stability of a power
system. The Unified Power Flow Controller (UPFC), as the most
versatile FACTS device for regulating power flow, is able to control
respectively transmission line real power, reactive power, and node
voltage. The main purpose of this paper is to analyze the effect of the
UPFC on the load flow, the power losses, and the voltage stability
using NEPLAN software modules, Newton-Raphson load flow is
used for the power flow analysis and the modal analysis is used for
the study of the voltage stability. The simulation was carried out on
the IEEE 14-bus test system.
Abstract: Microstructure and fabric of soils play an important
role on structural properties e.g. stiffness and strength of compacted
earthwork. Traditional quality control monitoring based on moisturedensity
tests neither reflects the variability of soil microstructure nor
provides a direct assessment of structural property, which is the
ultimate objective of the earthwork quality control. Since stiffness
and strength are sensitive to soil microstructure and fabric, any
independent test methods that provide simple, rapid, and direct
measurement of stiffness and strength are anticipated to provide an
effective assessment of compacted earthen materials’ uniformity. In
this study, the soil stiffness gauge (SSG) and the dynamic cone
penetrometer (DCP) were respectively utilized to measure and
monitor the stiffness and strength in companion with traditional
moisture-density measurements of various earthen materials used in
Thailand road construction projects. The practical earthwork quality
control criteria are presented herein in order to assure proper
earthwork quality control and uniform structural property of
compacted earthworks.
Abstract: Solar water heating is a thermodynamic process of
heating water using sunlight with the help of solar water heater. Thus,
solar water heater is a device used to harness solar energy. In this
paper, a modified solar water heating system (MSWHS) has been
proposed over flat plate collector (FPC) and Evacuated tube collector
(ETC). The modifications include selection of materials other than
glass, and glass wool which are conventionally used for fabricating
FPC and ETC. Some modifications in design have also been
proposed. Its collector is made of double layer of semi-cylindrical
acrylic tubes and fibre reinforced plastic (FRP) insulation base. Water
tank is made of double layer of acrylic sheet except base and north
wall. FRP is used in base and north wall of the water tank. A concept
of equivalent thickness has been utilised for calculating the
dimensions of collector plate, acrylic tube and tank. A thermal model for the proposed design of MSWHS is developed
and simulation is carried out on MATLAB for the capacity of 200L
MSWHS having collector area of 1.6 m2, length of acrylic tubes of
2m at an inclination angle 25° which is taken nearly equal to the
latitude of the given location. Latitude of Allahabad is 24.45° N. The
results show that the maximum temperature of water in tank and tube
has been found to be 71.2°C and 73.3°C at 17:00hr and 16:00hr
respectively in March for the climatic data of Allahabad. Theoretical performance analysis has been carried out by varying
number of tubes of collector, the tank capacity and climatic data for
given months of winter and summer.
Abstract: HMS Industrial Networks AB has been recognized as
one of the most innovative companies in the industrial
communication industry worldwide. The creation of their Anybus
innovation during the 1990s contributed considerably to the
company’s success. From inception, HMS’ employees were
innovating for the purpose of creating new business (the creation
phase). After the Anybus innovation, they began the process of
internationalization (the commercialization phase), which in turn led
them to concentrate on cost reduction, product quality, delivery
precision, operational efficiency, and increasing growth (the growth
phase). As a result of this transformation, performing new radical
innovations have become more complicated. The purpose of our research was to explore the dynamics of
innovation at HMS from the aspect of key actors, activities, and
events, over the three phases, in order to understand what led to the
creation of their Anybus innovation, and why it has become
increasingly challenging for HMS to create new radical innovations
for the future. Our research methodology was based on a longitudinal,
retrospective study from the inception of HMS in 1988 to 2014, a
single case study inspired by the grounded theory approach. We
conducted 47 interviews and collected 1 024 historical documents for
our research. Our analysis has revealed that HMS’ success in creating the
Anybus, and developing a successful business around the innovation,
was based on three main capabilities – cultivating customer relations
on different managerial and organizational levels, inspiring business
relations, and balancing complementary human assets for the purpose
of business creation. The success of HMS has turned the management’s attention away
from past activities of key actors, of their behavior, and how they
influenced and stimulated the creation of radical innovations.
Nowadays, they are rhetorically focusing on creativity and
innovation. All the while, their real actions put emphasis on growth,
cost reduction, product quality, delivery precision, operational
efficiency, and moneymaking. In the process of becoming an
international company, HMS gradually refocused. In so doing they
became profitable and successful, but they also forgot what made
them innovative in the first place. Fortunately, HMS’ management
has come to realize that this is the case and they are now in search of
recapturing innovation once again. Our analysis indicates that HMS’ management is facing several
barriers to innovation related path dependency and other lock-in
phenomena. HMS’ management has been captured, trapped in their
mindset and actions, by the success of the past. But now their future has to be secured, and they have come to realize that moneymaking is
not everything. In recent years, HMS’ management have begun to
search for innovation once more, in order to recapture their past
capabilities for creating radical innovations. In order to unlock their
managerial perceptions of customer needs and their counter-innovation
driven activities and events, to utilize the full potential of
their employees and capture the innovation opportunity for the future.
Abstract: The exploitation of flow pulsation in micro- and
mini-channels is a potentially useful technique for enhancing cooling
of high-end photonics and electronics systems. It is thought that
pulsation alters the thickness of the hydrodynamic and thermal
boundary layers, and hence affects the overall thermal resistance
of the heat sink. Although the fluid mechanics and heat transfer
are inextricably linked, it can be useful to decouple the parameters
to better understand the mechanisms underlying any heat transfer
enhancement. Using two-dimensional, two-component particle image
velocimetry, the current work intends to characterize the heat transfer
mechanisms in pulsating flow with a mean Reynolds number of
48 by experimentally quantifying the hydrodynamics of a generic
liquid-cooled channel geometry. Flows circulated through the test
section by a gear pump are modulated using a controller to achieve
sinusoidal flow pulsations with Womersley numbers of 7.45 and
2.36 and an amplitude ratio of 0.75. It is found that the transient
characteristics of the measured velocity profiles are dependent on the
speed of oscillation, in accordance with the analytical solution for
flow in a rectangular channel. A large velocity overshoot is observed
close to the wall at high frequencies, resulting from the interaction
of near-wall viscous stresses and inertial effects of the main fluid
body. The steep velocity gradients at the wall are indicative of
augmented heat transfer, although the local flow reversal may reduce
the upstream temperature difference in heat transfer applications.
While unsteady effects remain evident at the lower frequency, the
annular effect subsides and retreats from the wall. The shear rate at
the wall is increased during the accelerating half-cycle and decreased
during deceleration compared to steady flow, suggesting that the flow
may experience both enhanced and diminished heat transfer during
a single period. Hence, the thickness of the hydrodynamic boundary
layer is reduced for positively moving flow during one half of the
pulsation cycle at the investigated frequencies. It is expected that the
size of the thermal boundary layer is similarly reduced during the
cycle, leading to intervals of heat transfer enhancement.
Abstract: Strategic investment decisions are characterized by
high innovation potential and long-term effects on the
competitiveness of enterprises. Due to the uncertainty and risks
involved in this complex decision making process, the need arises for
well-structured support activities. A method that considers cost and
the long-term added value is the cost-benefit effectiveness estimation.
One of those methods is the “profitability estimation focused on
benefits – PEFB”-method developed at the Institute of Management
Cybernetics at RWTH Aachen University. The method copes with
the challenges associated with strategic investment decisions by
integrating long-term non-monetary aspects whilst also mapping the
chronological sequence of an investment within the organization’s
target system. Thus, this method is characterized as a holistic
approach for the evaluation of costs and benefits of an investment.
This participation-oriented method was applied to business
environments in many workshops. The results of the workshops are a
library of more than 96 cost aspects, as well as 122 benefit aspects.
These aspects are preprocessed and comparatively analyzed with
regards to their alignment to a series of risk levels. For the first time,
an accumulation and a distribution of cost and benefit aspects
regarding their impact and probability of occurrence are given. The
results give evidence that the PEFB-method combines precise
measures of financial accounting with the incorporation of benefits.
Finally, the results constitute the basics for using information
technology and data science for decision support when applying
within the PEFB-method.
Abstract: Present paper enumerates highlights of seasonal
variation in floristic composition and ecological strategies for the
management of ‘Gujar Tal’ at Jaunpur in tropical semi-arid region of
eastern U.P. (India). Total composition of macrophytes recorded was
47 from 26 families with maximum 6 plant species of Cyperaceae
from April, 2012 to March, 2013 at certain periodic intervals.
Maximum number of plants (39) was present during winter followed
by (37) rainy and (27) summer seasons. The distribution pattern
depicted that maximum number of plants (27) was of marshy and
swampy habitats usually transitional between land and water.
Abstract: Recent progress in the next generation of automobile
technology is geared towards incorporating information technology
into cars. Collectively called smart cars are bringing intelligence to
cars that provides comfort, convenience and safety. A branch of smart
cars is connected-car system. The key concept in connected-cars is the
sharing of driving information among cars through decentralized
manner enabling collective intelligence. This paper proposes a
foundation of the information model that is necessary to define the
driving information for smart-cars. Road conditions are modeled
through a unique data structure that unambiguously represent the time
variant traffics in the streets. Additionally, the modeled data structure
is exemplified in a navigational scenario and usage using UML.
Optimal driving route searching is also discussed using the proposed
data structure in a dynamically changing road conditions.
Abstract: Cloud computing is a business model which provides
an easier management of computing resources. Cloud users can
request virtual machine and install additional softwares and configure
them if needed. However, user can also request virtual appliance
which provides a better solution to deploy application in much faster
time, as it is ready-built image of operating system with necessary
softwares installed and configured. Large numbers of virtual
appliances are available in different image format. User can
download available appliances from public marketplace and start
using it. However, information published about the virtual appliance
differs from each providers leading to the difficulty in choosing
required virtual appliance as it is composed of specific OS with
standard software version. However, even if user choses the
appliance from respective providers, user doesn’t have any flexibility
to choose their own set of softwares with required OS and
application. In this paper, we propose a referenced architecture for
dynamically customizing virtual appliance and provision them in an
easier manner. We also add our experience in integrating our
proposed architecture with public marketplace and Mi-Cloud, a cloud
management software.