Abstract: This paper deals optimized model to investigate the
effects of peak current, pulse on time and pulse off time in EDM performance on material removal rate of titanium alloy utilizing copper tungsten as electrode and positive polarity of the electrode. The experiments are carried out on Ti6Al4V. Experiments were
conducted by varying the peak current, pulse on time and pulse off time. A mathematical model is developed to correlate the influences of these variables and material removal rate of workpiece. Design of
experiments (DOE) method and response surface methodology
(RSM) techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through
analysis of variance (ANOVA). The obtained results evidence that as
the material removal rate increases as peak current and pulse on time
increases. The effect of pulse off time on MRR changes with peak ampere. The optimum machining conditions in favor of material removal rate are verified and compared. The optimum machining
conditions in favor of material removal rate are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error (about
4%) when compared to experimental results. This result leads to desirable material removal rate and economical industrial machining to optimize the input parameters.
Abstract: Islamic banking is one the most blossoming doctrine in
economic system of the world. The Fast growing awareness about
Islamic financial system has brought strong feeling to Muslims to
confront the western interest-based economic cycle. The Islamic
economic system is emerging as a reliable alternative to the interest
based system. This study is proposed to ascertain the motivational
factors encouraging people to go for Islamic banking in Pakistan.
These pulsing factors are determined by generation of hypothesis that
there are certain factors which are urging people to opt Islamic
banking system and to see the differences in their ranking by applying
Friedman test. These factors include: Economically derived factors
such as stability of Islamic banks in crisis, profit and loss sharing
doctrine and equity sharing etc. This study also highlights the
religiously derived factors such as interest free banking, Shariah
tenets and supervisory of Islamic Shariah board and sociopsychological
factors.
Abstract: To understand complex living system an effort has
made by mechanical engineers and dentists to deliver prompt
products and services to patients concerned about their aesthetic look.
Since two decades various bracket systems have designed involving
techniques like milling, injection molding which are technically not
flexible for the customized dental product development. The aim of
this paper to design, develop a customized system which is
economical and mainly emphasizes the expertise design and
integration of engineering and dental fields. A custom made selfadjustable
lingual bracket and customized implants are designed and
developed using computer aided design (CAD) and rapid prototyping
technology (RPT) to improve the smiles and to overcome the
difficulties associated with conventional ones. Lengthy orthodontic
treatment usually not accepted by the patients because the patient
compliance is lost. Patient-s compliance can be improved by
facilitating faster tooth movements by designing a localized dental
vibrator using advanced engineering principles.
Abstract: The request for a sustainable development challenges
both managers and consumers to rethink habitual practices and
activities. While consumers are challenged to develop sustainable
consumption patterns, companies are asked to establish managerial
systems and structures considering economical, ecological, and social
issues. As this is in particular true for housing associations, this paper
aims first, at providing an understanding of sustainability strategy in
residential trade and industry (RTI) by identifying relevant facets of
this construct and second, at conceptually analyzing the impact of
sustainability strategy in RTI on operational efficiency and
performance of municipal housing companies. The author develops a
model of sustainability strategy in RTI and its effects and further,
sheds light in priorities for future research.
Abstract: This paper describes the experimental efficiency of a
compact organic Rankine cycle (ORC) system with a compact
rotary-vane-type expander. The compact ORC system can be used for
power generation from low-temperature heat sources such as waste
heat from various small-scale heat engines, fuel cells, electric devices,
and solar thermal energy. The purpose of this study is to develop an
ORC system with a low power output of less than 1 kW with a hot
temperature source ranging from 60°C to 100°C and a cold
temperature source ranging from 10°C to 30°C. The power output of
the system is rather less due to limited heat efficiency. Therefore, the
system should have an economically optimal efficiency. In order to
realize such a system, an efficient and low-cost expander is
indispensable. An experimental ORC system was developed using the
rotary-vane-type expander which is one of possible candidates of the
expander. The experimental results revealed the expander
performance for various rotation speeds, expander efficiencies, and
thermal efficiencies. Approximately 30 W of expander power output
with 48% expander efficiency and 4% thermal efficiency with a
temperature difference between the hot and cold sources of 80°C was
achieved.
Abstract: Optimizing equipment selection in heavy earthwork
operations is a critical key in the success of any construction project.
The objective of this research incentive was geared towards
developing a computer model to assist contractors and construction
managers in estimating the cost of heavy earthwork operations.
Economical operation analysis was conducted for an equipment fleet
taking into consideration the owning and operating costs involved in
earthwork operations. The model is being developed in a Microsoft
environment and is capable of being integrated with other estimating
and optimization models. In this study, Caterpillar® Performance
Handbook [5] was the main resource used to obtain specifications of
selected equipment. The implementation of the model shall give
optimum selection of equipment fleet not only based on cost
effectiveness but also in terms of versatility. To validate the model, a
case study of an actual dam construction project was selected to
quantify its degree of accuracy.
Abstract: Global competitiveness has recently become the
biggest concern of both manufacturing and service companies.
Electronic commerce, as a key technology enables the firms to reach
all the potential consumers from all over the world. In this study, we
have presented commonly used electronic payment systems, and then
we have shown the evaluation of these systems in respect to different
criteria. The payment systems which are included in this research are
the credit card, the virtual credit card, the electronic money, the
mobile payment, the credit transfer and the debit instruments. We
have realized a systematic comparison of these systems in respect to
three main criteria: Technical, economical and social. We have
conducted a fuzzy multi-criteria decision making procedure to deal
with the multi-attribute nature of the problem. The subjectiveness
and imprecision of the evaluation process are modeled using
triangular fuzzy numbers.
Abstract: Sarkhoon gas plant, located in south of Iran, has been installed to removal H2S contained in a high pressure natural gas stream. The solvent used for the H2S removal from gaseous stream is 34% by weight (wt%) Di-ethanol amine (DEA) solutions. Due to increasing concentration of heat stable salt (HSS) in solvent, corrosivity of amine solution had been increased. Reports indicated that there was corrosion on the shell of regeneration column. Because source formation of HSS was unknown, we decided to control the amount of HSS at the limit less than 3% wt amine solvent. Therefore, two small columns were filled by strong anionic base and carbon active, and then polluted amine was passed through beds. Finally a temporary amine recovery package on industrial scale was made based on laboratory’s results. From economical point of view we could save $700000 beside corrosion occurrence of the stripping column has been vigorously decreased.
Abstract: Transmission network expansion planning (TNEP) is
a basic part of power system planning that determines where, when
and how many new transmission lines should be added to the
network. Up till now, various methods have been presented to solve
the static transmission network expansion planning (STNEP)
problem. But in all of these methods, transmission expansion
planning considering network adequacy restriction has not been
investigated. Thus, in this paper, STNEP problem is being studied
considering network adequacy restriction using discrete particle
swarm optimization (DPSO) algorithm. The goal of this paper is
obtaining a configuration for network expansion with lowest
expansion cost and a specific adequacy. The proposed idea has been
tested on the Garvers network and compared with the decimal
codification genetic algorithm (DCGA). The results show that the
network will possess maximum efficiency economically. Also, it is
shown that precision and convergence speed of the proposed DPSO
based method for the solution of the STNEP problem is more than
DCGA approach.
Abstract: The purpose of determining impact significance is to
place value on impacts. Environmental impact assessment review is a
process that judges whether impact significance is acceptable or not in
accordance with the scientific facts regarding environmental,
ecological and socio-economical impacts described in environmental
impact statements (EIS) or environmental impact assessment reports
(EIAR). The first aim of this paper is to summarize the criteria of
significance evaluation from the past review results and accordingly
utilize fuzzy logic to incorporate these criteria into scientific facts. The
second aim is to employ data mining technique to construct an EIS or
EIAR prediction model for reviewing results which can assist
developers to prepare and revise better environmental management
plans in advance. The validity of the previous prediction model
proposed by authors in 2009 is 92.7%. The enhanced validity in this
study can attain 100.0%.
Abstract: This study assesses the vulnerability of Bulgarian
agriculture to drought using the WINISAREG model and seasonal
standard precipitation index SPI(2) for the period 1951-2004. This
model was previously validated for maize on soils of different water
holding capacity (TAW) in various locations. Simulations are
performed for Plovdiv, Stara Zagora and Sofia. Results relative to
Plovdiv show that in soils of large TAW (180 mm m-1) net irrigation
requirements (NIRs) range 0-40 mm in wet years and 350-380 mm in
dry years. In soils of small TAW (116 mm m-1), NIRs reach 440 mm
in the very dry year. NIRs in Sofia are about 80 mm smaller. Rainfed
maize is associated with great yield variability (29%
Abstract: This paper is concerned with the permanence and extinction problem of enterprises cluster constituted by m satellite enterprises and a dominant enterprise. We present the model involving impulsive effect based on ecology theory, which effectively describe the competition and cooperation of enterprises cluster in real economic environment. Applying comparison theorem of impulsive differential equation, we establish sufficient conditions which ultimately affect the fate of enterprises: permanence, extinction, and co-existence. Finally, we present numerical examples to explain the economical significance of mathematical results.
Abstract: Corporate social responsibility (CSR) can be defined as the management of social, environmental, economical and ethical concepts and firms sensivities to the expectations of the social stakeholders. CSR is seen as an important competitive advantage in the textile sector because this sector has an important impact on the environment and it is labor extensive. Textile sector has a strong advantage when compared with other sectors in Turkey due to its low labor costs and abundancy of raw materials. Turkey was a producer and an exporter of cotton, and an importer of fiber, clothes and dresses until 1950s. After 1950s, Turkey has begun to export fiber, ready-made clothes and become one of the most important textile producers in the world recently. CSR practices of the textile firms that are quoted in Istanbul Stock Exchange and these firms sensivities to their internal and external stakeholders and environment will be presented in this study.
Abstract: The cinema in Turkey during the 1940s was shaped
under the Second World War conditions. The amateur film makers
from different socioeconomic roots experienced movie production in
those years. Having similar socioeconomic characteristics and
autobiographies, each of them has a different understanding of
cinema. Nevertheless, they joined in making movies which address
native culture and audience. They narrated indigenous stories with
native music, amateur players and simple settings. Although the
martial law, censorship and economical deficiencies, they started to
produce films in the Second World War. The cinematographers of the
1940s usually called as thetransition period cinematographers in
Turkey, producing in the passage between the period of thetheatre
playersand the period of thenational cinema. But, 1940- 1950 period
of Turkish cinema should be defined not as a transition but a period
of forming the professional conscioussness in cinema.
Abstract: The effective machine-job assignment of injection
molding machines is very important for industry because it is not
only directly affects the quality of the product but also the
performance and lifetime of the machine as well. The phase of
machine selection was mostly done by professionals or experienced
planners, so the possibility of matching a job with an inappropriate
machine might occur when it was conducted by an inexperienced
person. It could lead to an uneconomical plan and defects. This
research aimed to develop a machine selection system for plastic
injection machines as a tool to help in decision making of the user.
This proposed system could be used both in normal times and in
times of emergency. Fuzzy logic principle is applied to deal with
uncertainty and mechanical factors in the selection of both quantity
and quality criteria. The six criteria were obtained from a plastic
manufacturer's case study to construct a system based on fuzzy logic
theory using MATLAB. The results showed that the system was able
to reduce the defects of Short Shot and Sink Mark to 24.0% and
8.0% and the total defects was reduced around 8.7% per month.
Abstract: In recent years the large scale use of the power electronic equipment has led to an increase of harmonics in the power system. The harmonics results into a poor power quality and have great adverse economical impact on the utilities and customers. Current harmonics are one of the most common power quality problems and are usually resolved by using shunt active filter (SHAF). The main objective of this work is to develop PI and Fuzzy logic controllers (FLC) to analyze the performance of Shunt Active Filter for mitigating current harmonics under balanced and unbalanced sinusoidal source voltage conditions for normal load and increased load. When the supply voltages are ideal (balanced), both PI and FLC are converging to the same compensation characteristics. However, the supply voltages are non-ideal (unbalanced), FLC offers outstanding results. Simulation results validate the superiority of FLC with triangular membership function over the PI controller.
Abstract: Nowadays, access to sustainable development in cities is assumed as one of the most important goals of urban managers. In the meanwhile, neighborhood as the smallest unit of urban spatial organization has a substantial effect on urban sustainability. Hence, attention to and focus on this subject is highly important in urban development plans. The objective of this study is evaluation of the status of Jahanshahr Neighborhood in Karaj city based on sustainable neighborhood development indicators. This research has been applied based on documentary method and field surveys. Also, evaluating of Jahanshahr Neighborhood of Karaj shows that it has a high level in sustainability in physical and economical dimension while a low level in cultural and social dimension. For this purpose, this neighborhood as a semi-sustainable neighborhood must take measures for development of collective spaces and efficiency of utilizing the public neighborhood spaces via collaboration of citizens and officials.
Abstract: Speed sensorless systems are intensively studied during recent years; this is mainly due to their economical benefit and fragility of mechanical sensors and also the difficulty of installing this type of sensor in many applications. These systems suffer from instability problems and sensitivity to parameter mismatch at low speed operation. In this paper an analysis of adaptive observer stability with stator resistance estimation is given.
Abstract: Transportation is of great importance in the current
life of human beings. The transportation system plays many roles,
from economical development to after-catastrophe aids such as
rescue operation in the first hours and days after an earthquake. In
after earthquakes response phase, transportation system acts as a
basis for ground operations including rescue and relief operation,
food providing for victims and etc. It is obvious that partial or
complete obstruction of this system results in the stop of these
operations. Bridges are one of the most important elements of
transportation network. Failure of a bridge, in the most optimistic
case, cuts the relation between two regions and in more developed
countries, cuts the relation of numerous regions. In this paper, to
evaluate the vulnerability and estimate the damage level of Tehran
bridges, HAZUS method, developed by Federal Emergency
Management Agency (FEMA) with the aid of National Institute of
Building Science (NIBS), is used for the first time in Iran. In this
method, to evaluate the collapse probability, fragility curves are
used. Iran is located on seismic belt and thus, it is vulnerable to
earthquakes. Thus, the study of the probability of bridge collapses, as
an important part of transportation system, during earthquakes is of
great importance. The purpose of this study is to provide fragility
curves for Gisha Bridge, one of the longest steel bridges in Tehran,
as an important lifeline element. Besides, the damage probability for
this bridge during a specific earthquake, introduced as scenario
earthquakes, is calculated. The fragility curves show that for the
considered scenario, the probability of occurrence of complete
collapse for the bridge is 8.6%.
Abstract: Thermo-chemical treatment (TCT) such as pyrolysis
is getting recognized as a valid route for (i) materials and valuable
products and petrochemicals recovery; (ii) waste recycling; and (iii)
elemental characterization. Pyrolysis is also receiving renewed
attention for its operational, economical and environmental
advantages. In this study, samples of polyethylene terephthalate
(PET) and polystyrene (PS) were pyrolysed in a microthermobalance
reactor (using a thermogravimetric-TGA setup). Both
polymers were prepared and conditioned prior to experimentation.
The main objective was to determine the kinetic parameters of the
depolymerization reactions that occur within the thermal degradation
process. Overall kinetic rate constants (ko) and activation energies
(Eo) were determined using the general kinetics theory (GKT)
method previously used by a number of authors. Fitted correlations
were found and validated using the GKT, errors were within ± 5%.
This study represents a fundamental step to pave the way towards the
development of scaling relationship for the investigation of larger
scale reactors relevant to industry.