Abstract: The connection between past travel experience and
tourists’ revisit behavioral intentions has not been widely explored
but the existing studies suggest a close relationship between them.
Destination image can equally be construed as having effects on the
attitudes of the tourists at the end of their actual visitation and the
satisfaction of a tourist with his or her travel experiences contributes
to a revisit intention towards a particular destination. With strong
marketing efforts, UAE is not only considered to be successful in
attracting foreign investors, but is becoming the most popular tourism
destination in the Arab region. UAE is seriously developing its
tourism image and taking serious initiatives to attract new or repeat
visitations from the international tourists. This study empirically
investigates the causal relationships between tourism destination
image, tourist satisfaction and revisit intention using UAE as a
contextual study setting. A very clear picture emerged which
provides a host country with potential implications for its tourism
industry practitioners, Department of Tourism and Commerce
Marketing and the travel agencies who act as the intermediaries
between the potential tourists and the hotel operators.
Abstract: In this study, we aim to demonstrate a microgrid
system experimental simulation for an easy understanding of a
large-scale microgrid system. This model is required for industrial
training and learning environments. However, in order to create an
exact representation of a microgrid system, the laboratory-scale
system must fulfill the requirements of a grid-connected inverter, in
which power values are assigned to the system to cope with the
intermittent output from renewable energy sources. Aside from that,
during fluctuations in load capacity, the grid-connected system must
be able to supply power from the utility grid side and microgrid side in
a balanced manner. Therefore, droop control is installed in the
inverter’s control board to maintain a balanced power sharing in both
sides. This power control in a stand-alone condition and droop control
in a grid-connected condition must be implemented in order to
maintain a stabilized system. Based on the experimental results, power
control and droop control can both be applied in the system by
comparing the experimental and reference values.
Abstract: This work presents a Computational Fluid Dynamics
(CFD) simulation of a butterfly valve used to control the flow of
combustible gas mixture in an industrial process setting.The work
uses CFD simulation to analyze the flow characteristics in the
vicinity of the valve, including the pressure distributions and
Frequency spectrum of the pressure pulsations downstream the valves
and the vortex shedding allow predicting the torque fluctuations
acting on the valve shaft and the possibility of generating mechanical
vibration and resonance.These fluctuations are due to aerodynamic
torque resulting from fluid turbulence and vortex shedding in the
valve vicinity.
The valve analyzed is located in a pipeline between two opposing
90o elbows, which exposes the valve and the surrounding structure to
the turbulence generated upstream and downstream the elbows at
either end of the pipe.CFD simulations show that the best location for
the valve from a vibration point of view is in the middle of the pipe
joining the elbows.
Abstract: With advances in solid-state power electronic devices
and microprocessors, various pulse-width-modulation (PWM)
techniques have been developed for industrial applications. This
paper presents the comparison of two different PWM techniques, the
sinusoidal PWM (SPWM) technique and the space-vector PWM
(SVPWM) technique applied to two level VSI for micro grid
applications. These two methods are compared by discussing their
ease of implementation and by analyzing the output harmonic spectra
of various output voltages (line-to-neutral voltages, and line-to-line
voltages) and their total harmonic distortion (THD). The SVPWM
technique in the under-modulation region can increase the
fundamental output voltage by 15.5% over the SPWM technique.
Abstract: Off-site construction methods have played an
important role in the construction sector in the past few decades. It is
increasingly becoming a major alternative technique and strategic
direction compared to traditional in-situ method. It produces a
significant amount of value for the construction industry and the
economy more generally. To date, an impressive number of studies
have been lunched on the perceived perception of off-site
construction. However, it seems that a quantifying benefit on the
offsite construction area is lacking. Therefore, this paper examines
the recent research literature on the benefits of off- site construction
and provides future direction. In the beginning, this paper provides a
brief history and current value of the off-site construction followed
by a detailed discussion on the benefit of off-site construction. These
benefits include but not limited to time saving, quality improvement,
relieving skills shortages, cost reduction and productivity
improvement. Toward this end, off-site construction should learn
from other productive industry similar to services or manufacturing
industry by applying operational management tools and techniques
with extensive focus on employee empowerment will shed the light
on future uptake of Off-site construction. This study is of value in
providing scholars have a clear picture of perceived benefit of off-site
construction research and give an opportunities for future uptake of
off-site method.
Abstract: The paper deals with communication standards for
control and production system. The authors formulate the
requirements for communication security protection. The paper is
focused on application protocols of the industrial networks and their
basic classification. The typical attacks are analysed and the safety
protection, based on requirements for specific industrial network is
suggested and defined in this paper.
Abstract: Natural gas, as one of the most important sources of
energy for many of the industrial and domestic users all over the
world, has a complex, huge supply chain which is in need of heavy
investments in all the phases of exploration, extraction, production,
transportation, storage and distribution. The main purpose of supply
chain is to meet customers’ need efficiently and with minimum cost.
In this study, with the aim of minimizing economic costs, different
levels of natural gas supply chain in the form of a multi-echelon,
multi-period fuzzy linear programming have been modeled. In this
model, different constraints including constraints on demand
satisfaction, capacity, input/output balance and presence/absence of a
path have been defined. The obtained results suggest efficiency of the
recommended model in optimal allocation and reduction of supply
chain costs.
Abstract: The purpose of this project is to carry out an analysis
and determine the profile of actual lean manufacturing processes in
the Metropolitan Area of Bucaramanga. Through the analysis of
qualitative and quantitative variables it was possible to establish how
these manufacturers develop production practices that ensure their
competitiveness and productivity in the market.
In this study, a random sample of metallurgic and wrought iron
companies was applied, following which a quantitative focus and
analysis was used to formulate a qualitative methodology for
measuring the level of lean manufacturing procedures in the industry.
A qualitative evaluation was also carried out through a multivariate
analysis using the Numerical Taxonomy System (NTSYS) program
which should allow for the determination of Lean Manufacturing
profiles.
Through the results it was possible to observe how the companies
in the sector are doing with respect to Lean Manufacturing Practices,
as well as identify the level of management that these companies
practice with respect to this topic. In addition, it was possible to
ascertain that there is no one dominant profile in the sector when it
comes to Lean Manufacturing.
It was established that the companies in the metallurgic and
wrought iron industry show low levels of Lean Manufacturing
implementation. Each one carries out diverse actions that are
insufficient to consolidate a sectoral strategy for developing a
competitive advantage which enables them to tie together a
production strategy.
Abstract: In this paper, snow samples containing dust particles
from several sampling points around the city of Ostrava were
analyzed. The pH values of sampled snow were measured and solid
particles analyzed. Particle size, zeta potential and content of selected
heavy metals were determined in solid particles. The pH values of
most samples lay in the slightly acid region. Mean values of particle
size ranged from 290.5 to 620.5 nm. Zeta potential values varied
between -5 and -26.5 mV. The following heavy metal concentration
ranges were found: copper 0.08-0.75 mg/g, lead 0.05-0.9 mg/g,
manganese 0.45-5.9 mg/g and iron 25.7-280.46 mg/g. The highest
values of copper and lead were found in the vicinity of busy
crossroads, and on the contrary, the highest levels of manganese and
iron were detected close to a large steelworks. The proportion
between pH values, zeta potentials, particle sizes and heavy metal
contents was established. Zeta potential decreased with rising pH
values and, simultaneously, heavy metal content in solid particles
increased. At the same time, higher metal content corresponded to
lower particle size.
Abstract: The purpose of the present work is to review some
data for the management challenges that the aquaculture industry in
Greece is currently facing. The results indicate that Greek
aquaculture fish farms apply Human Resources Management (HRM)
practices which can increase motivation, commitment and job
satisfaction of their personnel. In turn, these practices can increase
the productivity of the business. The Greek fish farms appear to
invest in research and technological innovation with a good record in
research activities and the generation of patents. Interestingly, the
results of the present work were carried out during the period of the
recent economic crisis in Greece. Several sectors of the Greek
economy were severely affected by the financial problems of the
Greek government and the Greek banks. Under the adverse
economical conditions created by the Greek economic crisis, even the
Greek aquaculture industry, which historically is considered as a
thriving national exporting business sector, experienced harsh
economic and market conditions. As a result of the global, European
and national economic crisis, consumption of fish dropped while
companies had to hold most of their stocked fish in order to regulated
the flow to the market and the price. This occurred at a time where
Banks in Greece had their own financial crisis – banking crisis -
which resulted in limited access to lending for the all business sectors
of the national economy including the Greek aquaculture industry. In
spite of these economic conditions, the Greek aquaculture industry,
after a series of mergers and acquisitions, has now stabilized
production and exhibits very good prospects for future growth.
Evidently, the firms had to cut salaries and on some occasions even
pay their staff in arrears. Nevertheless, the results presented in this
paper indicate that during the economic crisis, the surveyed fish
farms maintained their HRM practices, investing in their human
capital and technological input. In fact, human capital and
technological input are the ticket for future success of companies in
any business sector.
Abstract: A novel simulation method to determine the
displacements of machine tools due to thermal factors is presented.
The specific characteristic of this method is the employment of
original CAD data from the design process chain, which is
interpreted by an algorithm in terms of geometry-based allocation of
convection and radiation parameters. Furthermore analogous models
relating to the thermal behaviour of machine elements are
automatically implemented, which were gained by extensive
experimental testing with thermography imaging. With this a
transient simulation of the thermal field and in series of the
displacement of the machine tool is possible simultaneously during
the design phase. This method was implemented and is already used
industrially in the design of machining centres in order to improve
the quality of herewith manufactured workpieces.
Abstract: Identification and selection of appropriate product and
manufacturing technologies are key factors for competitiveness and
market success of technology-based companies. Therefore, many
companies perform technology intelligence (TI) activities to ensure
the identification of evolving technologies at the right time.
Technology monitoring is one of the three base activities of TI,
besides scanning and scouting.
As the technological progress is accelerating, more and more
technologies are being developed. Against the background of limited
resources it is therefore necessary to focus TI activities. In this paper
we propose a concept for defining appropriate search fields for
technology monitoring. This limitation of search space leads to more
concentrated monitoring activities. The concept will be introduced
and demonstrated through an anonymized case study conducted
within an industry project at the Fraunhofer Institute for Production
Technology IPT.
The described concept provides a customized monitoring
approach, which is suitable for use in technology-oriented companies.
It is shown in this paper that the definition of search fields and search
tasks are suitable methods to define topics of interest and thus to
align monitoring activities. Current as well as planned product,
production and material technologies and existing skills, capabilities
and resources form the basis for derivation of relevant search areas.
To further improve the concept of technology monitoring the
proposed concept should be extended during future research e.g. by
the definition of relevant monitoring parameters.
Abstract: Different strategies and tools are available at the oil
and gas industry for detecting and analyzing tension and possible
fractures in borehole walls. Most of these techniques are based on
manual observation of the captured borehole images. While this
strategy may be possible and convenient with small images and few
data, it may become difficult and suitable to errors when big
databases of images must be treated. While the patterns may differ
among the image area, depending on many characteristics (drilling
strategy, rock components, rock strength, etc.). In this work we
propose the inclusion of data-mining classification strategies in order
to create a knowledge database of the segmented curves. These
classifiers allow that, after some time using and manually pointing
parts of borehole images that correspond to tension regions and
breakout areas, the system will indicate and suggest automatically
new candidate regions, with higher accuracy. We suggest the use of
different classifiers methods, in order to achieve different knowledge
dataset configurations.
Abstract: This research focuses on the optimization of glazed
surfaces and the assessment of possible solar gains in industrial
buildings. Existing window rating methods for single windows were
evaluated and a new method for a simple analysis of energy gains and
losses by single windows was introduced. Furthermore extensive
transient building simulations were carried out to appraise the
performance of low cost polycarbonate multi-cell sheets in
interaction with typical buildings for industrial applications. Mainly
energy saving potential was determined by optimizing the orientation
and area of such glazing systems in dependency on their thermal
qualities. Moreover the impact on critical aspects such as summer
overheating and daylight illumination was considered to ensure the
user comfort and avoid additional energy demand for lighting or
cooling. Hereby the simulated heating demand could be reduced by
up to 1/3 compared to traditional architecture of industrial halls using
mainly skylights.
Abstract: OEE has been used in many industries as measure of
performance. However due to limitations of original OEE, it has been
modified by various researchers. OEE for mining application is
special version of classic equation, carries these limitation over. In
this paper it has been aimed to modify the OEE for mining
application by introducing the weights to the elements of it and
termed as Mine Production index (MPi). As a special application of
new index MPishovel has been developed by authors. This can be used
for evaluating the shovel effectiveness. Based on analysis, utilization
followed by performance and availability were ranked in this order.
To check the applicability of this index, a case study was done on
four electrical and one hydraulic shovel in a Swedish mine. The
results shows that MPishovel can evaluate production effectiveness of
shovels and can determine effectiveness values in optimistic view
compared to OEE. MPi with calculation not only give the
effectiveness but also can predict which elements should be focused
for improving the productivity.
Abstract: The majority of contemporary insulation materials
commonly used in the building industry is made from non-renewable
raw materials; furthermore, their production often brings high energy
costs. A long-term trend as far as sustainable development is
concerned has been the reduction of energy and material demands of
building material production. One of the solutions is the possibility of
using easily renewable natural raw material sources which are
considerably more ecological and their production is mostly less
energy-consuming compared to the production of normal insulations
(mineral wool, polystyrene). The paper describes the results of
research focused on the development of thermal and acoustic
insulation materials based on natural fibres intended for floor
constructions. Given the characteristic open porosity of natural fibre
materials, the hygrothermal behaviour of the developed materials was
studied. Especially the influence of relative humidity and temperature
on thermal insulation properties was observed.
Abstract: Heavy metals are one of the major groups of
contaminants in the environment and many of them are toxic even at
very low concentration in plants and animals. However, some metals
play important roles in the biological function of many enzymes in
living organisms. Metals such as zinc, iron, and cooper are important
for survival and activity of enzymes in plants, however heavy metals
can inhibit enzyme which is responsible for defense system of plants.
Polyphenol oxidase (PPO) is a copper-containing metalloenzyme
which is responsible for enzymatic browning reaction of plants.
Enzymatic browning is a major problem for the handling of
vegetables and fruits in food industry. It can be increased and
effected with many different futures such as metals in the nature and
ground. In the present work, PPO was isolated and characterized
from green leaves of red poppy plant (Papaverr hoeas). Then, the
effect of some known antibrowning agents which can form
complexes with metals and metals were investigated on the red poppy
PPO activity. The results showed that glutathione was the most
potent inhibitory effect on PPO activity. Cu(II) and Fe(II) metals
increased the enzyme activities however, Sn(II) had the maximum
inhibitory effect and Zn(II) and Pb(II) had no significant effect on the
enzyme activity. In order to reduce the effect of heavy metals, the
effects of metal-antibrowning agent complexes on the PPO activity
were determined. EDTA and metal complexes had no significant
effect on the enzyme. L-ascorbic acid and metal complexes decreased
but L-ascorbic acid-Cu(II)-complex had no effect. Glutathione–metal
complexes had the best inhibitory effect on Red poppy leaf PPO
activity.
Abstract: In Capitalism all economic activity rests upon a set of
core institutional foundations, main from which are privately owned
capital assets and profit. How these core institutional foundations are
working in former soviet countries, in particular in Travel and
Tourism Industry of Georgia?
The role of Travel and Tourism as a key pillar of economic growth
is being increasingly recognized by governments in all regions of the
world. For the last few years Georgia succeeded in the World Bank
and IFC “Doing Business” rankings. Despite of that, during decades
totally different statistical data of the tourism sector were provided by
the different State bodies; economic parameters were published few,
or not published at all.
The frequency and extent of property rights violation in Georgia
has repeatedly been the subject of concern for the last decade. Total
value of abrogated by the former Georgian Government private
property is estimated approximately in US$4-5 billion.
Thus, if economic profitability is unknown and property rights are
not protected – that means that the main institutional foundations of
capitalism in Georgia, are not working properly yet, that cause
management problems at all levels of the national Travel and
Tourism industry of Georgia.
Abstract: Mass flow measurement is the basis of most technoeconomic
formulations in the chemical industry. This calls for
reliable and accurate detection of mass flow. Flow measurement
laboratory experiments were conducted using various instruments.
These consisted of orifice plates, various sized rotameters, wet gas
meter and soap bubble meter. This work was aimed at evaluating
appropriate operating conditions and accuracy of the aforementioned
devices. The experimental data collected were compared to
theoretical predictions from Bernoulli’s equation and calibration
curves supplied by the instrument’s manufacturers. The results
obtained showed that rotameters were more reliable for measuring
high and low flow rates; while soap-bubble meters and wet-gas
meters were found to be suitable for measuring low flow rates. The
laboratory procedures and findings of the actual work can assist
engineering students and professionals in conducting their flow
measurement laboratory test work.
Abstract: This paper presents an anthropometric study
conducted to 300 employees in a maquiladora industry that belongs
to the cluster of medical products as part of a research project to
pretend simulate workplace conditions under which operators
conduct their activities. This project is relevant because traditionally
performed a study to design ergonomic workspaces according to
anthropometric profile of users, however, this paper demonstrates the
importance of making decisions when the infrastructure cannot be
adapted for economic whichever put emphasis on user activity.