Abstract: The need to save time and cost of soil testing at the
planning stage of road work has necessitated developing predictive
models. This study proposes a model for predicting the dry density of
lateritic soils stabilized with corn cob ash (CCA) and blended cement
- CCA. Lateritic soil was first stabilized with CCA at 1.5, 3.0, 4.5 and
6% of the weight of soil and then stabilized with the same
proportions as replacement for cement. Dry density, specific gravity,
maximum degree of saturation and moisture content were determined
for each stabilized soil specimen, following standard procedure.
Polynomial equations containing alpha and beta parameters for CCA
and blended CCA-cement were developed. Experimental values were
correlated with the values predicted from the Matlab curve fitting
tool, and the Solver function of Microsoft Excel 2010. The correlation
coefficient (R2) of 0.86 was obtained indicating that the model could
be accepted in predicting the maximum dry density of CCA stabilized
soils to facilitate quick decision making in roadworks.
Abstract: In the present study, analysis of heat transfer is carried
out in the slip flow region for the fluid flowing between two parallel
plates by employing the asymmetric heat fluxes at surface of the
plates. The flow is assumed to be hydrodynamically and thermally
fully developed for the analysis. The second order velocity slip and
viscous dissipation effects are considered for the analysis. Closed
form expressions are obtained for the Nusselt number as a function of
Knudsen number and modified Brinkman number. The limiting
condition of the present prediction for Kn = 0, Kn2 = 0, and Brq1 = 0
is considered and found to agree well with other analytical results.
Abstract: The advancements in technology allow the
development of a new system that can continuously measure surface
soil erosion. Continuous soil erosion measurements are required in
order to comprehend the erosional processes and propose effective
and efficient conservation measures to mitigate surface erosion.
Mitigating soil erosion, especially in Mediterranean countries such as
Greece, is essential in order to maintain environmental and
agricultural sustainability. In this paper, we present the Automated
Soil Erosion Monitoring System (ASEMS) that measures surface soil
erosion along with other factors that impact erosional process.
Specifically, this system measures ground level changes (surface soil
erosion), rainfall, air temperature, soil temperature, and soil moisture.
Another important innovation is that the data will be collected by
remote communication. In addition, stakeholder’s awareness is a key
factor to help reduce any environmental problem. The different
dissemination activities that were utilized are described. The overall
outcomes were the development of a new innovative system that can
measure erosion very accurately. These data from the system help
study the process of erosion and find the best possible methods to
reduce erosion. The dissemination activities enhance the stakeholders
and public's awareness on surface soil erosion problems and will lead
to the adoption of more effective soil erosion conservation practices
in Greece.
Abstract: It is well-known that, using principal weak flatness
property, some important monoids are characterized, such as regular
monoids, left almost regular monoids, and so on. In this article, we
define a generalization of principal weak flatness called GP-Flatness,
and will characterize monoids by this property of their right (Rees
factor) acts. Also we investigate new classes of monoids called
generally regular monoids and generally left almost regular monoids.
Abstract: Extreme formation is a theoretical concept of selfsustain
flight when a big airliner is followed by a small UAV glider
flying in the airliner wake vortex. The paper presents results of a
climb analysis with the goal to lift the gliding UAV to airliners cruise
altitude. Wake vortex models, the UAV drag polar and basic
parameters and airliner’s climb profile are introduced at first.
Afterwards, flight performance of the UAV in a wake vortex is
evaluated by analytical methods. Time history of optimal distance
between an airliner and the UAV during a climb is determined. The
results are encouraging. Therefore available UAV drag margin for
electricity generation is figured out for different vortex models.
Abstract: The development of composite materials and the
related design and manufacturing technologies is one of the most
important advances in the history of materials. Composites are
multifunctional materials having unprecedented mechanical and
physical properties that can be tailored to meet the requirements of a
particular application. Some composites also exhibit great resistance
to high-temperature corrosion, oxidation, and wear. Polymers are
widely used indoors and outdoors, therefore they are exposed to a
chemical environment which may include atmospheric oxygen, acidic
fumes, acidic rain, moisture heat and thermal shock, ultra-violet light,
high energy radiation, etc. Different polymers are affected differently
by these factors even though the amorphous polymers are more
sensitive. Ageing is also important and it is defined as the process of
deterioration of engineering materials resulting from the combined
effects of atmospheric radiation, heat, oxygen, water, microorganisms
and other atmospheric factors.
Abstract: Analytical techniques for measuring and planning
railway capacity expansion activities have been considered in this
article. A preliminary mathematical framework involving track
duplication and section sub divisions is proposed for this task. In
railways, these features have a great effect on network performance
and for this reason they have been considered. Additional motivations
have also arisen from the limitations of prior models that have not
included them.
Abstract: In this paper, we present an optimization technique or
a learning algorithm using the hybrid architecture by combining the
most popular sequence recognition models such as Recurrent Neural
Networks (RNNs) and Hidden Markov models (HMMs). In order to
improve the sequence/pattern recognition/classification performance
by applying a hybrid/neural symbolic approach, a gradient descent
learning algorithm is developed using the Real Time Recurrent
Learning of Recurrent Neural Network for processing the knowledge
represented in trained Hidden Markov Models. The developed hybrid
algorithm is implemented on automata theory as a sample test beds
and the performance of the designed algorithm is demonstrated and
evaluated on learning the deterministic finite state automata.
Abstract: This article presents the main results of a numerical
investigation on the uncertainty of dynamic response of structures
with statistically correlated random damping Gamma distributed. A
computational method based on a Linear Statistical Model (LSM) is
implemented to predict second order statistics for the response of a
typical industrial building structure. The significance of random
damping with correlated parameters and its implications on the
sensitivity of structural peak response in the neighborhood of a
resonant frequency are discussed in light of considerable ranges of
damping uncertainties and correlation coefficients. The results are
compared to those generated using Monte Carlo simulation
techniques. The numerical results obtained show the importance of
damping uncertainty and statistical correlation of damping
coefficients when obtaining accurate probabilistic estimates of
dynamic response of structures. Furthermore, the effectiveness of the
LSM model to efficiently predict uncertainty propagation for
structural dynamic problems with correlated damping parameters is
demonstrated.
Abstract: The present study focused on the investigation of the
effects of roughness elements on heat transfer during natural
convection in a rectangular cavity using numerical technique.
Roughness elements were introduced on the bottom hot wall with a
normalized amplitude (A*/H) of 0.1. Thermal and hydrodynamic
behaviors were studied using computational method based on Lattice
Boltzmann method (LBM). Numerical studies were performed for a
laminar flow in the range of Rayleigh number (Ra) from 103 to 106
for a rectangular cavity of aspect ratio (L/H) 2.0 with a fluid of
Prandtl number (Pr) 1.0. The presence of the sinusoidal roughness
elements caused a minimum to maximum decrease in the heat
transfer as 7% to 17% respectively compared to smooth enclosure.
The results are presented for mean Nusselt number (Nu), isotherms
and streamlines.
Abstract: The study conducted a simulation of the effect of sea
water to the bonding capacity of GFRP sheet on the concrete beams
using a simulation tank. Fiber reinforced polymer (FRP) has been
developed and applied in many fields civil engineering structures on
the new structures and also for strengthening of the deteriorated
structures. The FRP has advantages such as its corrosion resistance as
well as high tensile strength to weight ratio. Compared to the other
FRP materials, Glass composed FRP (GFRP) is relatively cheaper.
GFRP sheet is applied externally by bonding it on the concrete surface.
The studies regarding the application of GFRP sheet have been
conducted such as strengthening system, bonding behavior of GFRP
sheet including the application as reinforcement in new structures. For
application to the structures with direct contact to sea environment, a
study regarding the effect of sea water to the bonding capacity of
GFRP sheet is important to be clarified. To achieve the objective of the
study, a series of concrete beams strengthened with GFRP sheet on
extreme tension surface were prepared. The beams then were stored on
the sea water tank for six months. Results indicated the bonding
capacity decreased after six month exposed to the sea water.
Abstract: Modelling of building processes of a multimodal
freight transportation support information system is discussed based
on modern CASE technologies. Functional efficiencies of ports in
the eastern part of the Black Sea are analyzed taking into account
their ecological, seasonal, resource usage parameters. By resources,
we mean capacities of berths, cranes, automotive transport, as well as
work crews and neighbouring airports. For the purpose of designing
database of computer support system for Managerial (Logistics)
function, using Object-Role Modeling (ORM) tool (NORMA–Natural ORM Architecture) is proposed, after which Entity
Relationship Model (ERM) is generated in automated process.
Software is developed based on Process-Oriented and Service-Oriented architecture, in Visual Studio.NET environment.
Abstract: In the last decade the emergence of new social needs
as an effect of the economic crisis has stimulated the flourishing of
business endeavours characterised by explicit social goals. Social
start-ups, social enterprises or Corporate Social Responsibility
operations carried out by traditional companies are quintessential
examples in this regard. This paper analyses these kinds of initiatives
in order to discover the main characteristics of social business models
and to provide insights to social entrepreneurs for developing or
improving their strategies. The research is conducted through the
integration of literature review and case study analysis and, thanks to
the recognition of the importance of both profits and social impacts
as the key success factors for a social business model, proposes a
framework for identifying indicators suitable for measuring the social
impacts generated.
Abstract: The Green Urban Lab took the form of public
installations that were placed at various locations in four cities in
Cyprus. These installations - through which a series of events,
activities, workshops and research took place - were the main tools in
regenerating a series of urban public spaces in Cyprus. The purpose
of this project was to identify issues and opportunities related to
public space and to offer guidelines on how design and participatory
democracy improvements could strengthen civil society, while
raising the quality of the urban public scene. Giant inflatable
structures were injected in important urban fragments in order to
accommodate series of events. The design and playful installation
generated a wide community engagement. The fluid presence of the
installations acted as a catalyst for social interaction. They were
accessed and viewed effortlessly and surprisingly, creating
opportunities to rediscover public spaces.
Abstract: The aim of this study was to determine the factor
structure and psychometric properties (i.e., reliability and convergent
validity) of the Employee Trust Scale, a newly created instrument by
the researchers. The Employee Trust Scale initially contained 82
items to measure employees’ trust toward their supervisors. A sample
of 818 (343 females, 449 males) employees were selected randomly
from public and private organization sectors in Kota Kinabalu,
Sabah, Malaysia. Their ages ranged from 19 to 67 years old with a
mean of 34.55 years old. Their average tenure with their current
employer was 11.2 years (s.d. = 7.5 years). The respondents were
asked to complete the Employee Trust Scale, as well as a managerial
trust questionnaire from Mishra. The exploratory factor analysis on
employees’ trust toward their supervisor’s extracted three factors,
labeled ‘trustworthiness’ (32 items), ‘position status’ (11 items) and
‘relationship’ (6 items) which accounted for 62.49% of the total
variance. Trustworthiness factors were re-categorized into three sub
factors: competency (11 items), benevolence (8 items) and integrity
(13 items). All factors and sub factors of the scales demonstrated
clear reliability with internal consistency of Cronbach’s Alpha above
.85. The convergent validity of the Scale was supported by an
expected pattern of correlations (positive and significant correlation)
between the score of all factors and sub factors of the scale and the
score on the managerial trust questionnaire, which measured the same
construct. The convergent validity of Employee Trust Scale was
further supported by the significant and positive inter-correlation
between the factors and sub factors of the scale. The results suggest
that the Employee Trust Scale is a reliable and valid measure.
However, further studies need to be carried out in other groups of
sample as to further validate the Scale.
Abstract: Carbon Fiber Reinforced Plastics (CFRPs) are widely
used for advanced applications, in particular in aerospace, automotive
and wind energy industries. Once cured to near net shape, CFRP
parts need several finishing operations such as trimming, milling or
drilling in order to accommodate fastening hardware and meeting the
final dimensions. The present research aims to study the effect of the
cutting temperature in trimming on the mechanical strength of high
performance CFRP laminates used for aeronautics applications. The
cutting temperature is of great importance when dealing with
trimming of CFRP. Temperatures higher than the glass-transition
temperature (Tg) of the resin matrix are highly undesirable: they
cause degradation of the matrix in the trimmed edges area, which can
severely affect the mechanical performance of the entire component.
In this study, a 9.50mm diameter CVD diamond coated carbide tool
with six flutes was used to trim 24-plies CFRP laminates. A
300m/min cutting speed and 1140mm/min feed rate were used in the
experiments. The tool was heated prior to trimming using a
blowtorch, for temperatures ranging from 20°C to 300°C. The
temperature at the cutting edge was measured using embedded KType
thermocouples. Samples trimmed for different cutting
temperatures, below and above Tg, were mechanically tested using
three-points bending short-beam loading configurations. New cutting
tools as well as worn cutting tools were utilized for the experiments.
The experiments with the new tools could not prove any correlation
between the length of cut, the cutting temperature and the mechanical
performance. Thus mechanical strength was constant, regardless of
the cutting temperature. However, for worn tools, producing a cutting
temperature rising up to 450°C, thermal damage of the resin was
observed. The mechanical tests showed a reduced mean resistance in
short beam configuration, while the resistance in three point bending
decreases with increase of the cutting temperature.
Abstract: Rapid prototyping is a new group of manufacturing
processes, which allows fabrication of physical of any complexity
using a layer by layer deposition technique directly from a computer
system. The rapid prototyping process greatly reduces the time and
cost necessary to bring a new product to market. The prototypes
made by these systems are used in a range of industrial application
including design evaluation, verification, testing, and as patterns for
casting processes. These processes employ a variety of materials and
mechanisms to build up the layers to build the part. The present work
was to build a FDM prototyping machine that could control the X-Y
motion and material deposition, to generate two-dimensional and
three-dimensional complex shapes. This study focused on the
deposition of wax material. This work was to find out the properties
of the wax materials used in this work in order to enable better
control of the FDM process. This study will look at the integration of
a computer controlled electro-mechanical system with the traditional
FDM additive prototyping process. The characteristics of the wax
were also analysed in order to optimise the model production process.
These included wax phase change temperature, wax viscosity and
wax droplet shape during processing.
Abstract: The ferrites ZnFe2O4, CdFe2O4 and CuFe2O4 are
synthesized in laboratory conditions using ceramic technology. Their
homogeneity and structure are proven by X-Ray diffraction analysis
and Mössbauer spectroscopy. The synthesized ferrites are subjected
to strong acid and high temperature leaching with solutions of H2SO4,
HCl and HNO3. The results indicate that the highest degree of
leaching of Zn, Cd and Cu from the ferrites is achieved by use of
HCl. The charging of five zinc sulfide concentrates was optimized using
the criterion of minimal amount of zinc ferrite produced when
roasting the concentrates in a fluidized bed. The results obtained are
interpreted in terms of the hydrometallurgical zinc production and
maximum recovery of zinc, copper and cadmium from initial zinc
concentrates after their roasting.
Abstract: In recent years, the power system has been changed
and a flexible power pricing system such as demand response has been
sought in Japan. The demand response system works simply in the
household sector and the owner as the decision-maker, can benefit
from power saving. On the other hand, the execution of demand
response in the office building is more complex than in the household
because various people such as owners, building administrators and
occupants are involved in the decision-making process. While the
owners benefit from demand saving, the occupants are exposed to
restricted benefits of a demand-saved environment. One of the reasons
is that building systems are usually under centralized management and
each occupant cannot choose freely whether to participate in demand
response or not. In addition, it is unclear whether incentives give
occupants the motivation to participate. However, the recent
development of IT and building systems enables the personalized
control of the office environment where each occupant can control the
lighting level or temperature individually. Therefore, it can be possible
to have a system which each occupant can make a decision of whether
or not to participate in demand response in the office building. This study investigates personal responses to demand response
requests, under the condition where each occupant can adjust their
brightness individually in their workspace. Once workers participate
in the demand response, their desk-lights are automatically turned off.
The participation rates in the demand response events are compared
among four groups, which are divided by different motivation, the
presence, or absence of incentives and the method of participation. The
result shows that there are significant differences of participation rates
in demand response event between four groups. The method of
participation has a large effect on the participation rate. The “Opt-out”
groups where the occupants are automatically enrolled in a demand
response event if they do not express non-participation have the
highest participation rate in the four groups. Incentives also have an
effect on the participation rate. This study also reports on the impact of low illumination office
environment on the occupants, such as stress or fatigue. The
electrocardiogram and the questionnaire are used to investigate the
autonomic nervous activity and subjective fatigue symptoms of the
occupants. There is no big difference between dim workspace during
demand response event and bright workspace in autonomic nervous
activity and fatigue.
Abstract: The activation volume of 6082T6 aluminum is
investigated at different temperatures for grain size variants. The
deformation activation volume was computed on the basis of the
relationship between the Boltzmann’s constant k, the testing
temperatures, the material strain rate sensitivity and the material yield
stress grain size variants. The material strain rate sensitivity is
computed as a function of yield stress and strain rate grain size
variants. The effect of the material strain rate sensitivity and the
deformation activation volume of 6082T6 aluminum at different
temperatures of 3-D grain are discussed. It is shown that the strain rate sensitivities and activation volume
are negative for the grain size variants during the deformation of
nanostructured materials. It is also observed that the activation
volume vary in different ways with the equivalent radius, semi minor
axis radius, semi major axis radius and major axis radius. From the
obtained results it is shown that the variation of activation volume
increase and decrease with the testing temperature. It was revealed
that, increase in strain rate sensitivity led to decrease in activation
volume whereas increase in activation volume led to decrease in
strain rate sensitivity.