Abstract: Numerical study of the static response of
homogeneous clay stratum considering a wide range of cohesion and
subject to foundation loads is presented. The linear elastic–perfectly
plastic constitutive relation with the von Mises yield criterion were
utilised to develop a numerically cost effective finite element model
for the soil while imposing a rigid body constrain to the foundation
footing. From the analyses carried out, estimate of the bearing
capacity factor, Nc as well as the ultimate load-carrying capacities of
these soils, effect of cohesion on foundation settlements, stress fields
and failure propagation were obtained. These are consistent with
other findings in the literature and hence can be a useful guide in
design of safe foundations in clay soils for buildings and other
structure.
Abstract: The analytical bright two soliton solution of the 3-
coupled nonlinear Schrödinger equations with variable coefficients in
birefringent optical fiber is obtained by Darboux transformation
method. To the design of ultra-speed optical devices, Soliton
interaction and control in birefringence fiber is investigated. Lax pair
is constructed for N coupled NLS system through AKNS method.
Using two-soliton solution, we demonstrate different interaction
behaviors of solitons in birefringent fiber depending on the choice of
control parameters. Our results shows that interactions of optical
solitons have some specific applications such as construction of logic
gates, optical computing, soliton switching, and soliton amplification
in wavelength division multiplexing (WDM) system.
Abstract: Broiler slaughter waste has become a major source of
pollution throughout the world. Utilization of broiler slaughter waste
by dry rendering process produced Rendered Chicken Oil (RCO), a
cheap raw material for biodiesel production and Carcass Meal a feed
ingredient for pets and fishes. Conversion of RCO into biodiesel may
open new vistas for generating wealth from waste besides controlling
the major havoc of environmental pollution. A two-step process to
convert RCO to good quality Biodiesel was invented. Acid catalysed
esterification of FFA followed by base catalysed transesterification of
triglycerides was carried out after meticulously standardizing the
methanol molar ratio, catalyst concentration, reaction temperature,
and reaction time to obtain the maximum biodiesel yield of 97.62%
and lowest glycerol yield of 6.96%. RCO biodiesel blend was tested
in a CRDI diesel engine. The results revealed that the blending of
commercial diesel with 20% RCO biodiesel (B20) lead to less engine
wear, a quieter engine and better fuel economy. The better lubricating
qualities of RCO B20 prevented over heating of engine, which
prolongs the engine life. RCO B20 can reduce the import of crude oil
and substantially reduce the engine emissions as proved by
significantly lower smoke levels, thus mitigating climatic changes.
Abstract: Lagos urban mini bus drivers play a critical role in the
transportation sector. The current major mode of transportation
within Lagos metropolis remains road transportation and this
confirms the relevance of urban mini-bus drivers in transporting the
populace to their various destinations. Other modes of transportation
such as the train and waterways are currently inadequate. Various
threats to the well-being of urban bus drivers include congested
traffic typical of modern day lifestyles, dwindling financial returns
due to long hours in traffic, fewer hours of sleep, inadequate diet,
time pressure, and assaults related to fare disputes. Several healthrelated
problems have been documented to be associated with urban
bus driving. For instance, greater rates of hypertension, obesity and
cholesterol level have been reported. Research studies are yet to
identify the influence of age and marital status on the well-being of
urban mini-bus drivers in Lagos metropolis. A study of this nature is
necessary as it is culturally perceived in Nigeria that older and
married people are especially influenced by family affiliation and
would behave in ways that would project positive outcomes. The
study sample consisted of 150 urban mini-bus drivers who were
conveniently sampled from six (6) different terminuses where their
journey begins and terminates. The well-being questionnaire was
administered to participants. The criteria for inclusion in the study
included the ability to read in English language and the confirmation
that interested participants were on duty and suited to be driving
mini-buses. Due to the nature of the job of bus driving, the researcher
administered the questionnaires on participants who were free and
willing to respond to the survey. All participants were males of
various age groups and of different marital statuses. Results of
analyses conducted revealed no significant influence of age and
marital status on the well-being of urban mini-bus drivers. This
indicates that the well-being of urban mini bus drivers is not
influenced by age or marital status. The findings of this study have
cultural implications. It negates the popularly held belief that older
and married people care more about their well-being than younger
and single people. It brings to fore the need to also identify and
consider other factors when certifying people for the job of urban bus
driving.
Abstract: Highly developed technology and highly competitive
global market highlight the important role of competitive advantages
and operation performances in sustainable company operation.
Activity-Based Costing (ABC) provides accurate operation cost and
operation performance information. Rich literatures provide relevant
research with cases study on Activity-Based Costing application, but
the research on cause relationship between key success factors and its
specific outcome, such as profitability or share market are few. These
relationships provide the ways to handle the key success factors to
achieve the specific outcomes for ensuring to promote the competitive
advantages and operation performances. The main purposes of this
research are exploring the key success paths by Key Success Paths
approach which will lead the ways to apply Activity-Base Costing.
The Key Success Paths is the innovative method which is exploring
the cause relationships and explaining what are the effects of key
success factors to specific outcomes of Activity-Based Costing
implementation. The cause relationships between key success factors
and successful specific outcomes are Key Success Paths (KSPs). KSPs
are the guidelines to lead the cost management strategies to achieve the
goals of competitive advantages and operation performances. The
research findings indicate that good management system design may
affect the well outcomes of Activity-Based Costing application and
achieve to outstanding competitive advantage, operating performance
and profitability as well by KSPs exploration.
Abstract: This study was aimed to measure effective transverse
relaxation rates (R2*) in the liver and muscle of normal New Zealand
White (NZW) rabbits. R2* relaxation rate has been widely used in
various hepatic diseases for iron overload by quantifying iron contents
in liver. R2* relaxation rate is defined as the reciprocal of T2*
relaxation time and mainly depends on the constituents of tissue.
Different tissues would have different R2* relaxation rates. The signal
intensity decay in Magnetic resonance imaging (MRI) may be
characterized by R2* relaxation rates. In this study, a 1.5T GE Signa
HDxt whole body MR scanner equipped with an 8-channel high
resolution knee coil was used to observe R2* values in NZW rabbit’s
liver and muscle. Eight healthy NZW rabbits weighted 2 ~ 2.5 kg were
recruited. After anesthesia using Zoletil 50 and Rompun 2% mixture,
the abdomen of rabbit was landmarked at the center of knee coil to
perform 3-plane localizer scan using fast spoiled gradient echo
(FSPGR) pulse sequence. Afterwards, multi-planar fast gradient echo
(MFGR) scans were performed with 8 various echo times (TEs) to
acquire images for R2* measurements. Regions of interest (ROIs) at
liver and muscle were measured using Advantage workstation.
Finally, the R2* was obtained by a linear regression of ln(sı) on TE.
The results showed that the longer the echo time, the smaller the signal
intensity. The R2* values of liver and muscle were 44.8 ± 10.9 s-1 and
37.4 ± 9.5 s-1, respectively. It implies that the iron concentration of
liver is higher than that of muscle. In conclusion, the more the iron
contents in tissue, the higher the R2*. The correlations between R2*
and iron content in NZW rabbits might be valuable for further
exploration.
Abstract: Chatter vibrations, occurring during cutting process,
cause vibration between the cutting tool and workpiece, which
deteriorates surface roughness and reduces tool life. The purpose of
this study is to investigate the influence of cutting parameters and
tool construction on surface roughness and vibration in turning of
aluminum alloy AA2024. A new design of cutting tool is proposed,
which is filled up with epoxy granite in order to improve damping
capacity of the tool. Experiments were performed at the lathe using
carbide cutting insert coated with TiC and two different cutting tools
made of AISI 5140 steel. Taguchi L9 orthogonal array was applied to
design of experiment and to optimize cutting conditions. By the help
of signal-to-noise ratio and analysis of variance the optimal cutting
condition and the effect of the cutting parameters on surface
roughness and vibration were determined. Effectiveness of Taguchi
method was verified by confirmation test. It was revealed that new
cutting tool with epoxy granite has reduced vibration and surface
roughness due to high damping properties of epoxy granite in
toolholder.
Abstract: The plastic industry plays very important role in the
economy of any country. It is generally among the leading share of
the economy of the country. Since metals and their alloys are very
rarely available on the earth. Therefore, to produce plastic products
and components, which finds application in many industrial as well
as household consumer products is beneficial. Since 50% plastic
products are manufactured by injection moulding process. For
production of better quality product, we have to control quality
characteristics and performance of the product. The process
parameters plays a significant role in production of plastic, hence the
control of process parameter is essential. In this paper the effect of
the parameters selection on injection moulding process has been
described. It is to define suitable parameters in producing plastic
product. Selecting the process parameter by trial and error is neither
desirable nor acceptable, as it is often tends to increase the cost and
time. Hence, optimization of processing parameter of injection
moulding process is essential. The experiments were designed with
Taguchi’s orthogonal array to achieve the result with least number of
experiments. Plastic material polypropylene is studied. Tensile
strength test of material is done on universal testing machine, which
is produced by injection moulding machine. By using Taguchi
technique with the help of MiniTab-14 software the best value of
injection pressure, melt temperature, packing pressure and packing
time is obtained. We found that process parameter packing pressure
contribute more in production of good tensile plastic product.
Abstract: Fading noise degrades the performance of cellular
communication, most notably in femto- and pico-cells in 3G and 4G
systems. When the wireless channel consists of a small number of
scattering paths, the statistics of fading noise is not analytically
tractable and poses a serious challenge to developing closed
canonical forms that can be analysed and used in the design of
efficient and optimal receivers. In this context, noise is multiplicative
and is referred to as stochastically local fading. In many analytical
investigation of multiplicative noise, the exponential or Gamma
statistics are invoked. More recent advances by the author of this
paper utilized a Poisson modulated-weighted generalized Laguerre
polynomials with controlling parameters and uncorrelated noise
assumptions. In this paper, we investigate the statistics of multidiversity
stochastically local area fading channel when the channel
consists of randomly distributed Rayleigh and Rician scattering
centers with a coherent Nakagami-distributed line of sight component
and an underlying doubly stochastic Poisson process driven by a
lognormal intensity. These combined statistics form a unifying triply
stochastic filtered marked Poisson point process model.
Abstract: Effective internal control system in the bursary unit of
tertiary educational institutions is geared toward achieving quality
teaching, learning and research environment and as well assist the
management of the institutions, particularly when decisions are to be
made. While internal control system exists in all institutions, the
outlined objectives above are far from being achieved. The paper
therefore assesses the effectiveness of internal control system in
tertiary educational institutions in Nasarawa State, Nigeria with
specific focus on the Nasarawa State Polytechnic, Lafia. The study is
survey, hence a simple closed ended questionnaire was developed
and administered to a sample of twenty seven (27) member staff from
the Bursary and the Internal audit unit of the Nasarawa State
Polytechnic, Lafia so as to obtain data for analysis purposes and to
test the study hypothesis. Responses from the questionnaire were
analysed using a simple percentage and chi square. Findings shows
that the right people are not assigned to the right job in the
department, budget, and management accounting were never used in
the institution’s operations and checking of subordinate by their
superior officers is not regular. This renders the current internal
control structure of the Polytechnic as ineffective and weak. The
paper therefore recommends that: transparency should be seen as
significant, as the institution work toward meeting its objectives, it
therefore means that the right staff be assigned the right job and
regular checking of the subordinates by their superiors be ensued.
Abstract: The aim of sustainable architecture is to design
buildings with the least adverse effects on the environment and
provide better conditions for people. What building forms make the
best use of land? This question was addressed in the late 1960s at the
center of Land Use and Built Form Studies in Cambridge. This led to
a number of influential papers which had a great influence on the
practice of urban design. This paper concentrates on the results of
sustainability caused by climatic conditions in Iranian traditional
architecture in hot-arid regions. As people spent a significant amount
of their time in houses, it was very important to have such houses to
fulfill their needs physically and spiritually as well as satisfying their
cultural and religious aspects of their lifestyles. In a vast country such
as Iran with different climatic zones, traditional builders have
presented series of logical solutions for human comfort. These
solutions have been able to response to the environmental problems
for a long period of time. As a result, by considering the experience
in traditional architecture of hot–arid climate in Iran, it is possible to
attain sustainable architecture.
Abstract: The paper will focus on the strategic development
deriving from the evolution of the traditional courtyard spatial
organization towards a new, contemporary sustainable way of living.
New sustainable approaches that engulf the social issues, the notion
of place, the understanding of weather architecture blended together
with the bioclimatic behavior will be seen through a series of
experimental case studies in the island of Cyprus, inspired and
originated from its traditional wisdom, ranging from small scale of
living to urban interventions. Weather and nature will be seen as co-architectural authors with
architects. Furthermore, the building will be seen not as an object but
rather as a vessel of human activities. This will further enhance the
notion of merging the material and immaterial, the built and unbuilt,
subject-human, and the object-building. This eventually will enable
to generate the discussion of the understanding of the building in
relation to the place and its inhabitants, where the human topography
is more important than the material topography. The specificities of
the divided island and the dealing with sites that are in vicinity with
the diving Green Line will further trigger explorations dealing with
the regeneration issues and the social sustainability offering
unprecedented opportunities for innovative sustainable ways of
living. Opening up a discourse with premises of weather-nature, materialimmaterial,
human-material topographies in relation to the contested
sites of the borders will lead us to develop innovative strategies for a
profound, both technical and social sustainability, which fruitfully
yields to innovative living built environments, responding to the ever
changing environmental and social needs. As a starting point, a case study in Kaimakli in Nicosia, a
refurbishment with an extension of a traditional house, already
engulfs all the traditional/ vernacular wisdom of the bioclimatic
architecture. The project focusses on the direct and quite obvious
bioclimatic features such as south orientation and cross ventilation.
Furthermore, it tries to reinvent the adaptation of these parameters in
order to turn the whole house to a contemporary living environment.
In order to succeed this, evolutions of traditional architectural
elements and spatial conditions are integrated in a way that does not
only respond to some certain weather conditions, but they integrate
and blend the weather within the built environment. A series of
innovations aiming at maximum flexibility is proposed. The house
can finally be transformed into a winter enclosure, while for the most
part of the year it turns into a ‘camping’ living environment. Parallel to experimental interventions in existing traditional units,
we will proceed examining the implementation of the same
developed methodology in designing living units and complexes.
Malleable courtyard organizations that attempt to blend the
traditional wisdom with the contemporary needs for living, the
weather and nature with the built environment will be seen tested in
both horizontal and vertical developments. Social activities are seen as directly affected and forged by the
weather conditions thus generating a new social identity of people where people are directly involved and interacting with the weather.
The human actions and interaction with the built, material
environment in order to respond to weather will be seen as the result
of balancing the social with the technological sustainability, the
immaterial, and the material aspects of the living environment.
Abstract: A solar receiver is designed for operation under
extremely uneven heat flux distribution, cyclic weather, and cloud
transient cycle conditions, which can include large thermal stress and
even receiver failure. In this study, the effect of different oil velocity
on convection coefficient factor and impact of wind velocity on local
Nusselt number by Finite Volume Method will be analyzed. This
study is organized to give an overview of the numerical modeling
using a MATLAB software, as an accurate, time efficient and
economical way of analyzing the heat transfer trends over stationary
receiver tube for different Reynolds number. The results reveal when
oil velocity is below 0.33m/s, the value of convection coefficient is
negligible at low temperature. The numerical graphs indicate that
when oil velocity increases up to 1.2 m/s, heat convection coefficient
increases significantly. In fact, a reduction in oil velocity causes a
reduction in heat conduction through the glass envelope. In addition,
the different local Nusselt number is reduced when the wind blows
toward the concave side of the collector and it has a significant effect
on heat losses reduction through the glass envelope.
Abstract: Internal circulation two-platen clamping system for
injection molding machine (IMM) has many potential advantages on
energy-saving. In order to estimate its properties, experiments were
carried out in this paper. Displacement and pressure of the components
were measured. In comparison, the model of hydraulic clamping
system was established by using AMESim. The related parameters as
well as the energy consumption could be calculated. According to the
analysis, the hydraulic system was optimized in order to reduce the
energy consumption.
Abstract: Direct Torque Control (DTC) is an AC drive control
method especially designed to provide fast and robust responses. In
this paper a progressive algorithm for direct torque control of threephase
induction drive system supplied by photovoltaic arrays using
voltage source inverter to control motor torque and flux with
maximum power point tracking at different level of insolation is
presented. Experimental results of the new DTC method obtained by
an experimental rapid prototype system for drives are presented.
Simulation and experimental results confirm that the proposed system
gives quick, robust torque and speed responses at constant switching
frequencies.
Abstract: A geoelectric survey was carried out in some parts of
Angwan Gwari, an outskirt of Lapai Local Government Area on
Niger State which belongs to the Nigerian Basement Complex, with
the aim of evaluating the soil corrosivity, aquifer transmissivity and
protective capacity of the area from which aquifer characterisation
was made. The G41 Resistivity Meter was employed to obtain fifteen
Schlumberger Vertical Electrical Sounding data along profiles in a
square grid network. The data were processed using interpex 1-D
sounding inversion software, which gives vertical electrical sounding
curves with layered model comprising of the apparent resistivities,
overburden thicknesses, and depth. This information was used to
evaluate longitudinal conductance and transmissivities of the layers.
The results show generally low resistivities across the survey area
and an average longitudinal conductance variation from
0.0237Siemens in VES 6 to 0.1261Siemens in VES 15 with almost
the entire area giving values less than 1.0 Siemens. The average
transmissivity values range from 96.45 Ω.m2 in VES 4 to 299070
Ω.m2 in VES 1. All but VES 4 and VES14 had an average
overburden greater than 400 Ω.m2, these results suggest that the
aquifers are highly permeable to fluid movement within, leading to
the possibility of enhanced migration and circulation of contaminants
in the groundwater system and that the area is generally corrosive.
Abstract: A method of effective planning and control of
industrial facility energy consumption is offered. The method allows
optimally arranging the management and full control of complex
production facilities in accordance with the criteria of minimal
technical and economic losses at the forecasting control. The method
is based on the optimal construction of the power efficiency
characteristics with the prescribed accuracy. The problem of optimal
designing of the forecasting model is solved on the basis of three
criteria: maximizing the weighted sum of the points of forecasting
with the prescribed accuracy; the solving of the problem by the
standard principles at the incomplete statistic data on the basis of
minimization of the regularized function; minimizing the technical
and economic losses due to the forecasting errors.
Abstract: Electrical Muscle Stimulation (EMS) has been
introduced and globally gained increasing attention on its usefulness.
Continuous application of EMS may lead to the increment of muscle
mass and indirectly will increase the strength. This study can be used
as an alternative to help people especially those living a sedentary
lifestyle to improve their muscle activity without having to go
through a heavy workout session. Therefore, this study intended to
investigate the effectiveness of EMS training program in 5 weeks
interventions towards male body composition. It was a quasiexperimental
design, held at the Impulse Studio Bangsar, which
examined the effects of EMS training towards skeletal muscle mass
among the subjects. Fifteen subjects (n = 15) were selected to assist
in this study. The demographic data showed that, the average age of
the subjects was 43.07 years old ± 9.90, height (173.4 cm ± 9.09) and
weight was (85.79 kg ± 18.07). Results showed that there was a
significant difference on the skeletal muscle mass (p = 0.01 < 0.05),
upper body (p = 0.01 < 0.05) and lower body (p = 0.00 < 0.05).
Therefore, the null hypothesis has been rejected in this study. As a
conclusion, the application of EMS towards body composition can
increase the muscle size and strength. This method has been proven
to be able to improve athlete strength and thus, may be implemented
in the sports science area of knowledge.
Abstract: Heat treatable aluminum alloys such as 7075 and
7055, because of high strength and low density, are used widely in
aircraft industry. For best mechanical properties, T6 heat treatment
has recommended for this regards, but this temper treatment is
sensitive to corrosion induced and Stress Corrosion Cracking (SCC)
damage. For improving this property, the over-aging treatment (T7)
applies to this alloy, but it decreases the mechanical properties up to
30 percent. Hence, to increase the mechanical properties, without any
remarkable decrease in SCC resistant, Retrogression and Re-Aging
(RRA) heat treatment is used. This treatment performs in a relatively
short time. In this paper, the RRA heat treatment was applied to 7055
aluminum alloy and then effect of RRA time on the mechanical
properties of 7055 has been investigated. The results show that the
40-minute time is suitable time for retrogression of 7055 aluminum
alloy and ultimate strength increases up to 625MPa.
Abstract: Foundation differential settlement and supported
structure tilting are an occasionally occurred engineering problem.
This may be caused by overloading, changes in ground soil properties
or unsupported nearby excavations. Engineering thinking points
directly toward the logic solution for such problem by uplifting the
settled side. This can be achieved with deep foundation elements
such as micro-piles and macro-piles™, jacked piers, and helical piers,
jet grouted mortar columns, compaction grout columns, cement
grouting or with chemical grouting, or traditional pit underpinning
with concrete and mortar. Although, some of these techniques offer
economic, fast and low noise solutions, many of them are quite the
contrary. For tilted structures, with the limited inclination, it may be much
easier to cause a balancing settlement on the less-settlement side
which shall be done carefully in a proper rate. This principal has been
applied in Leaning Tower of Pisa stabilization with soil extraction
from the ground surface. In this research, the authors attempt to
introduce a new solution with a different point of view. So, the
micro-tunneling technique is presented in here as an intended ground
deformation cause. In general, micro-tunneling is expected to induce
limited ground deformations. Thus, the researchers propose to apply
the technique to form small size ground unsupported holes to produce
the target deformations. This shall be done in four phases: 1.
Application of one or more micro-tunnels, regarding the existing
differential settlement value, under the raised side of the tilted
structure. 2. For each individual tunnel, the lining shall be pulled out
from both sides (from jacking and receiving shafts) in the slow rate.
3. If required, according to calculations and site records, an additional
surface load can be applied on the raised foundation side. 4. Finally, a
strengthening soil grouting shall be applied for stabilization after
adjustment. A finite element based numerical model is presented to simulate
the proposed construction phases for different tunneling positions and
tunnels group. For each case, the surface settlements are calculated
and induced plasticity points are checked. These results show the
impact of the suggested procedure on the tilted structure and its
feasibility. Comparing results also show the importance of the
position selection and tunnels group gradual effect. Thus, a new
engineering solution is presented to one of the structural and
geotechnical engineering challenges.